Tagged: researchers

The autoimmunity of Parkinson’s disease?

Auto

In this post we discuss several recently published research reports suggesting that Parkinson’s disease may be an autoimmune condition. “Autoimmunity” occurs when the defence system of the body starts attacks the body itself.

This new research does not explain what causes of Parkinson’s disease, but it could explain why certain brain cells are being lost in some people with Parkinson’s disease. And such information could point us towards novel therapeutic strategies.


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The first issue of Nature. Source: SimpleWikipedia

The journal Nature was first published on 4th November 1869, by Alexander MacMillan. It hoped to “provide cultivated readers with an accessible forum for reading about advances in scientific knowledge.” It has subsequently become one of the most prestigious scientific journals in the world, with an online readership of approximately 3 million unique readers per month (almost as much as we have here at the SoPD).

Each Wednesday afternoon, researchers around the world await the weekly outpouring of new research from Nature. And this week a research report was published in Nature that could be big for the world of Parkinson’s disease. Really big!

On the 21st June, this report was published:

Nature
Title: T cells from patients with Parkinson’s disease recognize α-synuclein peptides
Authors: Sulzer D, Alcalay RN, Garretti F, Cote L, Kanter E, Agin-Liebes J, Liong C, McMurtrey C, Hildebrand WH, Mao X, Dawson VL, Dawson TM, Oseroff C, Pham J, Sidney J, Dillon MB, Carpenter C, Weiskopf D, Phillips E, Mallal S, Peters B, Frazier A, Lindestam Arlehamn CS, Sette A
Journal: Nature. 2017 Jun 21. doi: 10.1038/nature22815.
PMID: 28636593

In their study, the investigators collected blood samples from 67 people with Parkinson’s disease and from 36 healthy patients (which were used as control samples). They then exposed the blood samples to fragments of proteins found in brain cells, including fragments of alpha synuclein – this is the protein that is so closely associated with Parkinson’s disease (it makes regular appearances on this blog).

What happened next was rather startling: the blood from the Parkinson’s patients had a strong reaction to two specific fragments of alpha synuclein, while the blood from the control subjects hardly reacted at all to these fragments.

In the image below, you will see the fragments listed along the bottom of the graph (protein fragments are labelled with combinations of alphabetical letters). The grey band on the plot indicates the two fragments that elicited a strong reaction from the blood cells – note the number of black dots (indicating PD samples) within the band, compared to the number of white dots (control samples). The numbers on the left side of the graph indicate the number of reacting cells per 100,000 blood cells.

Table1

Source: Nature

The investigators concluded from this experiment that these alpha synuclein fragments may be acting as antigenic epitopes, which would drive immune responses in people with Parkinson’s disease and they decided to investigate this further.

What does antigenic epitopes mean?

It is probably best if we start with a bit of basic immunology.

Approximately 1/5 of all the cells in your body are involved in the immune system, which is responsible for defending you against substances that can make you sick. And usually those cells are really good – read: utterly ruthless and relentless – at protecting us against molecules that can cause infection and disease. They are particularly good at determining what is ‘self’ and what is not ‘self’ – that is to say, they can tell which substances are part of you (as an organism) and which are not. Not ‘self’ could simply be considered as anything that does not have an origin inside your body.

If the immune system is working correctly, when a pathogen (an agent that causes disease or damage) is detected in your body,  it will quickly be determined to be not ‘self’. This judgement will be made by the identification of antigens on the surface of the pathogen. An antigen is defined as any substance or molecule that is capable of causing an immune response in an organism.

A good example of a pathogen is the common cold virus. Once inside the body, the presence of the virus will be detected by cells in the immune system and given that the virus will be presenting antigens on its surface that are clearly not self, an immune response will be initiated. The cells that carry out the immune response are white blood cells known as lymphocytes.

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That big cell in the middle is a lymphocyte. Source: ASH

There are basically two types of immune response:

  1. An antibody response
  2. A cell-mediated immune response

These processes are carried out by two different types of lymphocytes (B cells and T cells). In the antibody response, B cells are activated and they begin to secrete Y-shaped proteins called antibodies. These are used by the immune system to label and neutralise foreign or dangerous substances.

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Antibodies binding to a virus. Source: Biology-questions-and-answers

Antibodies bind to parts of the antigen called epitopes. Also known as antigenic determinants, an epitope is the part of an antigen that is recognised by an antibody. Antibodies by themselves can do a pretty good job of stopping pathogens, by blocking them from attaching to cells or by sticking together and clustering the antigens to prevent them from doing anything bad.

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Antibody binding to antigens. Source: Venngage

Cell-mediated immunity, on the other hand, is an immune response that does not involve antibodies. This approach relies on antigen-presenting cells, cytotoxic T-cells, and the release of various cytokines in response to an antigen.

Que?

In cell-mediated immune response, when a foreign object (like a bacteria) enters the body it will be detected by what we call ‘antigen-presenting cells’ (such as macrophage cells). Upon detection, these brave, selfless little cells will engulf the bacteria and digest them into hundreds or thousands of antigen fragments. The macrophage cell will bundle these fragments together in what we call a major histocompatibility complex (MHC). The macrophage cell next displays this MHC on its own cell surface for other cells discover.

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Source: Boundless

The ‘other’ cells are another type of lymphocyte called a T cell. T cells derive their name from the fact that they mature in the thymus. Once mature, they are released to do very specific tasks. Until they encounter an ‘antigen-presenting cells’, however, T-cells are as useless and witless as teenagers. They need to be stimulated by the ‘antigen-presenting cells’ before they know what they are going to do with their lives.

Once stimulated, there are basically two main types of T cells:

  • helper T cells
  • cytotoxic T cells

Helper T cells are nice and useful because they like to tell other immune cells about particular pathogens. Cytotoxic T cells, on the other hand, simply get on with the dirty job of killing off antigen presenting cells/bacteria/viruses/etc. And these brutal, heartless thugs do not discriminate – all they care about is whether a particular antigen is present or not.

As we suggested above, in order to do its job a mature T cell must encounter an antigen-presenting cell which will offer the T cell a particular MHC complex to inspect. This interaction will activate the T cell, and it also provides the T-cell a specific set of antigens to go looking for.

Once activated by an antigen-presenting cell, a cytotoxic T cells will begin creating many versions of itself (or clones) through a process of cell division (called mitosis). These clones will have one specific set of cell-surface receptors which will bind to the antigens in the MHC complex that was offered by the antigen-presenting cell. These “brutal, heartless thugs” will next go searching the body for anything that has the antigens it can bind to.

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Source: Immuneresponse

Once these cloned cytotoxic T cells have identified something (cell, bacteria, virus, etc) that exhibits the antigens they are looking for they will begin the process of killing that thing. They do their killing by releasing signalling molecules (called cytokines) which encourage an antigen presenting bacteria or cell to undergo apoptosis (or programmed cell death). Some of the cytokines will also recruit other members of the immune system to come and help with the killing, and subsequent cleaning up of the mess.

Ok, so if a cell is presenting an antigen on its surface that a cytotoxic T cell is looking for then that cell could be in big trouble?

Exactly. Anything that is acting as an antigenic epitope for the cytotoxic T cell to bind to will increase the risk of driving an immune response.

So do the brain cells that are lost in Parkinson’s disease presenting these MHC complexes on their cell surface?

Excellent question.

There are actually different types of MHC complexes. The most common are MHC class I and MHC class II. MHC class I complexes are found on all cells except red blood cells, while MHC class II complexes are only found on the antigen-presenting cells. In the brain, MHC class I complexes are present during development, but their levels drop off as we age.

A few years ago, however, the researchers who conducted the study we are reviewing today, published data suggesting that the cells most affected in Parkinson’s disease may have higher levels of MHC class I complexes, which may be making them vulnerable:

Nature

Title: MHC-I expression renders catecholaminergic neurons susceptible to T-cell-mediated degeneration.
Authors: Cebrián C, Zucca FA, Mauri P, Steinbeck JA, Studer L, Scherzer CR, Kanter E, Budhu S, Mandelbaum J, Vonsattel JP, Zecca L, Loike JD, Sulzer D
Journal: Nat Commun. 2014 Apr 16;5:3633.
PMID: 24736453           (This article is OPEN ACCESS if you would like to read it)

The investigators analysed human postmortem brain samples from people with and without Parkinson’s disease and they found that MHC class I complexes were present on many of the populations of neurons in the brain that are vulnerable to Parkinson’s disease (particularly the dopamine neurons in the substantia nigra and the norepinephrine producing neurons in an area called the locus coeruleus.

The investigators next conducted experiments in cell cultures using dopamine neurons that were made from human embryonic stem cells and they found that these cells were more susceptible to presenting MHC class I complexes when encouraged to than other types of neurons. The encouragement was caused by the activation of the helper cells in the brain called microglia. And the microglia were activated by exposure to alpha synuclein protein.

Thus, the researchers became interested in the idea that alpha synuclein from one dying cell could be activating microglia cells, which in turn makes other dopamine neurons present MHC class I complexes, making them vulnerable to inducing an immune response (Click here to read an OPEN ACCESS review of this topic by the investigators themselves).

And this was just a cute idea until the researchers published their results this week.

Which brings us back to the report again – there is a really interesting twist in it:

Nature

Title: T cells from patients with Parkinson’s disease recognize α-synuclein peptides
Authors: Sulzer D, Alcalay RN, Garretti F, Cote L, Kanter E, Agin-Liebes J, Liong C, McMurtrey C, Hildebrand WH, Mao X, Dawson VL, Dawson TM, Oseroff C, Pham J, Sidney J, Dillon MB, Carpenter C, Weiskopf D, Phillips E, Mallal S, Peters B, Frazier A, Lindestam Arlehamn CS, Sette A.
Journal: Nature. 2017 Jun 21. doi: 10.1038/nature22815.
PMID: 28636593

So the researchers observed T cells in the blood from people with Parkinson’s disease having a strong reaction to two specific fragments from alpha synuclein. These two fragments are from a region of the alpha synuclein protein called Y39. Interestingly, this Y39 region is very close to many of the genetic mutations in alpha synuclein that are associated with Parkinson’s disease (specifically A30P, E46K, A53T – in red on the left in the figure below).

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Structure of alpha synuclein, showing mutation sites. Source: Frontiers

The researchers next looked at which MHC-associated proteins were responsible for putting the Y39 fragments into the MHC complexes for cell membrane presentation. The organising and presenting of these MHC complexes on the surface of a cell requires a lot of proteins all working together in perfect synchrony. The researchers found that the fragments were specifically displayed by two MHC class II proteins called HLA/DRB5*01:01 and HLA/DRB1*15:01,…

(and here comes the BIG twist)

…which if mutated are both associated with increased risk of developing Parkinson’s disease.

HLA
Title: Association of Parkinson disease with structural and regulatory variants in the HLA region.
Authors: Wissemann WT, Hill-Burns EM, Zabetian CP, Factor SA, Patsopoulos N, Hoglund B, Holcomb C, Donahue RJ, Thomson G, Erlich H, Payami H.
Journal: Am J Hum Genet. 2013 Nov 7;93(5):984-93.
PMID: 24183452                (This report is OPEN ACCESS if you would like to read it)

In this study, the investigators analysed the DNA from 2000 people with Parkinson’s disease and 1986 control subjects and they found that the risk of developing Parkinson’s disease was positively associated with variations in both HLA/DRB5*01:01 and HLA/DRB1*15:01 (in addition to other regions). Whereas approximately 15% of healthy control subjects carry variations in one of these genes, 1/3 of people with Parkinson’s disease have one of them.

So collectively these findings suggest that certain genetic variants in MHC-associated genes may cause particular fragments of alpha synuclein to be exposed in MHC complexes, causing T cells to mistakenly identify the alpha synuclein as a pathogen and thus trigger an autoimmune response that destroys any cell presenting alpha synuclein in MHC complexes. Likewise, the mutations in alpha synuclein which are located near the Y39 region and associated with Parkinson’s disease, could be causing this fragment to accidentally be exposed in MHC complexes (this needs to be further investigated though).

 

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Source: Seekingalpha

The investigators are now seeking to discover whether the immune response provoked by alpha synuclein is a primary cause of Parkinson’s disease or whether it merely contributes to the brain cell death associated with the condition after the disease is triggered by something else. It is already apparent from the results of the study, however, that this ‘antigen presenting process’ is not going to explain every case of Parkinson’s disease, and the investigators acknowledge this. Hence the reason why the media headlines are reporting that autoimmunity may partly explain Parkinson’s disease.

In fact, only 40% of the blood from people with Parkinson’s disease in the study exhibited immune responses to the alpha synuclein fragments, and this may reflect differences between the participants in the study, particularly with regards to genetic variations. For example, last year a research report was published in the journal Cell that identified Parkinson’s associated proteins PINK1 and Parkin as suppressors of an immune response eliciting pathway (Click here to read more about that study).

That study found that in the absence of PINK1 or Parkin fragments of mitochondria (the power stations of cells) could be presented in MCH class I complexes, which would result in an immune response. PINK1 and Parkin are both involved in the normal removal of unhealthy mitochondria (Click here and here to read more about this). Without PINK1 or Parkin, old and dysfunctioning mitochondria start piling, making the cell sick. Thus, it may that people with PINK1 or Parkin genetic mutations may have an autoimmune component to their disease (perhaps falling into ‘the 40%’), while other people with Parkinson’s disease who don’t have these sorts of genetic variants will have alternative explanations to explain their condition.

The research groups that conducted the study we are reviewing today are now recruiting and analysing additional participants (with and without Parkinson’s disease), and are working to identify the molecular steps that lead to the autoimmune response in animal and cellular models.

What exactly is an autoimmune response?

An autoimmune response is an immune response within an organism against its own healthy cells and tissues. Any disease that results from such an immune response is called an autoimmune disease.

AutoImmune-1024x768

Different types of autoimmune diseases. Source: DrJockers

So is Parkinson’s disease an autoimmune disease?

For a condition to be considered an autoimmune disease it needs to conform to what is called Witebsky’s postulates (first formulated by Ernest Witebsky and associates in 1957; though they were modified in 1994). An autoimmune disease must show:

  • Direct evidence from transfer of disease-causing antibody or disease-causing T lymphocyte white blood cells
  • Indirect evidence based on reproduction of the autoimmune disease in experimental animals
  • Circumstantial evidence from clinical clues
  • Genetic evidence suggesting “clustering” with other autoimmune diseases

The research report we have reviewed in this post provides us with evidence of the first requirement. We also have evidence of the second requirement – Click here to read more about this. For the final two requirements, there has been an ever increasing number of reports regarding associations between Parkinson’s disease and other autoimmune diseases.

In fact, just this month alone we have had two separate studies published: one suggesting that naturally occurring “autoantibodies” (which play an important role in clearing and blocking circulating ‘self’ proteins) are lower in people with Parkinson’s disease than healthy control subjects. The second study presents strong evidence that Parkinson’s disease shares a number of genetic associations with autoimmune diseases.

Here is the first study:

Autoanti
Title: Autoimmune antibody decline in Parkinson’s disease and Multiple System Atrophy; a step towards immunotherapeutic strategies.
Authors: Brudek T, Winge K, Folke J, Christensen S, Fog K, Pakkenberg B, Pedersen LØ.
Journal: Mol Neurodegener. 2017 Jun 7;12(1):44.
PMID: 28592329           (This article is OPEN ACCESS if you would like to read it)

In this study, the researchers collected blood samples from samples from 46 people with Parkinson’s disease, 18 people with Multiple System Atrophy (a condition very similar to Parkinson’s disease), and 41 healthy control subjects. When they analysed the blood for autoantibodies targeting the alpha synuclein protein, they found reduced levels in people with Parkinson’s disease when compared to healthy controls, and even more reduced in people with Multiple System Atrophy. The researchers concluded that reduced levels of these antibodies for alpha synuclein results in more alpha synuclein floating around and causing an inflammatory environment. They also propose that the results provide a good rationale for testing immune-based therapeutic strategies directed against pathological alpha synuclein (such as the Affiris and Prothena clinical trials we have previously discussed – click here to read more about this).

The second report is a much larger study:

Autoimmune
Title: Genome-wide Pleiotropy Between Parkinson Disease and Autoimmune Diseases
Authors: Witoelar A, Jansen IE, Wang Y, Desikan RS, Gibbs JR, Blauwendraat C, Thompson WK, Hernandez DG, Djurovic S, Schork AJ, Bettella F, Ellinghaus D, Franke A, Lie BA, McEvoy LK, Karlsen TH, Lesage S, Morris HR, Brice A, Wood NW, Heutink P, Hardy J, Singleton AB, Dale AM, Gasser T, Andreassen OA, Sharma M; International Parkinson’s Disease Genomics Consortium (IPDGC), North American Brain Expression Consortium (NABEC), and United Kingdom Brain Expression Consortium (UKBEC) Investigators.
Journal: JAMA Neurol. 2017 Jun 5. doi: 10.1001/jamaneurol.2017.0469.
PMID: 28586827

In this study, the researchers analysed DNA collected from 138 511 individuals of European ancestry and they identified 17 novel genetic loci shared between Parkinson disease and a series of autoimmune conditions (including type 1 diabetes, Crohn disease, ulcerative colitis, rheumatoid arthritis, celiac disease, psoriasis, and multiple sclerosis). According to this study, apparently healthy individuals with a lot of these shared genetic variants which predisposes them to inflammation conditions, could also be at increased risk for developing Parkinson’s disease.

Man, this all sounds really bad. What can we do about it?

Well firstly, we can start by not considering these results as bad news.

In fact, these studies could represent a major step forward in the right direction for a lot of people with Parkinson’s disease. These research findings are extremely useful for us.

As one of the investigators in the blood study, Dr. Alessandro Sette, (from the Centre for Infectious Disease in La Jolla, Calif.) has suggested the findings “raise the possibility that an immunotherapy approach could be used to increase the immune system’s tolerance for alpha synuclein, which could help to ameliorate or prevent worsening symptoms in Parkinson’s disease patients,”.

Dr. Sette also adds that “These findings could provide a much-needed diagnostic test for Parkinson’s disease, and could help us to identify individuals at risk or in the early stages of the disease.”

And the authors of the study also point towards drugs that could be applied to individuals that fit a potential autoimmune criteria for Parkinson’s disease. For example, they mentioned in the research article that candesartan cilexetil – a drug used for hypertension – was recently shown to reduce the activation microglia (the helper cells in the brain) which is caused by a build up of the Parkinson’s associated protein alpha synuclein:

Synuclein

Title: Activation of MyD88-dependent TLR1/2 signaling by misfolded α-synuclein, a protein linked to neurodegenerative disorders.
Authors: Daniele SG, Béraud D, Davenport C, Cheng K, Yin H, Maguire-Zeiss KA.
Journal: Sci Signal. 2015 May 12;8(376):ra45.
PMID: 25969543              (This article is OPEN ACCESS if you would like to read it)

This study found that candesartan cilexetil reversed the activation of microglia exposed to alpha synuclein, supporting the possibility of repurposing this drug for conditions like Parkinson’s disease. And other research groups have also reported neuroprotective effects of candesartan cilexetil in models of Parkinson’s disease (Click here to read more on this). Candesartan (also known by trade names such as Blopress, Atacand, Amias, and Ratacand) is an angiotensin II receptor antagonist used mainly for the treatment of hypertension.

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Candesartan. Source: Wikipedia

In addition to pointing us towards novel therapy options, the new results suggesting an autoimmune component to some people with Parkinson’s disease would also represent a tremendous boost of support for therapies that are currently being clinically tested. Specifically those trials that are focused on suppressing the immune system, such as the immunomodulation study being conducted in Nebraska – a clinical trial of the drug Sargramostim in Parkinson’s disease.

IMG_0689-Nebraska-sign

Nebraska. Source: The Toast

Sargramostim stimulates regulatory T (Treg) cells. Treg cells are an important part of the immune system that we haven’t discussed in this particular post. They basically maintain law and order in the immune system. They do this by enforcing a dominant negative regulation on other immune cells, particularly other T-cells. Think of T-cells as the inquisitive neighbours curious about and snooping around a local crime scene, and then imagine that Treg cells are the police telling them “nothing to see here, move along”.

Regulatory_T_Cell-smaller

Tregs maintaining order. Source: Keywordsuggestions

Treg cells are particularly important for calming down Helper T cells and Cytotoxic T cells (often referred to in combination as T-effectors). The normal situation in your body is to have a balance between Helper T cells/Cytotoxic T cells and Treg cells. If there are too many excited Helper T cells and Cytotoxic T cells, there is increased chances of things going wrong and autoimmunity occurring.

Microsoft Word - Tregs Review Final

A delicate balance between healthy and autoimmune disease. Source: Researchgate

Thus, treatments that suppress the T-effectors may be very useful in slowing down a condition like Parkinson’s disease (particularly if autoimmunity is a component of this condition). One caveat here, however, is that too many Treg cells is not a good situation either, as they can leave the immune system too suppressed and individuals vulnerable to other diseases. A delicate balancing act will be required for such a treatment approach. To read more about the Sargramostim clinical trial in Nebraska, please click here to see our post about it.

So what does it all mean?

Phew! Long post.

It is basically the combination of three posts, each dealing with separate autoimmunity research reports associated with Parkinson’s disease,… plus a lesson in elements of basic immunology (which dragged on a bit). But I felt the research results are really important and the topic deserved to be done as one big post. Understand this: collectively, the research may represent a major turning point for the Parkinson’s disease community.

The research suggests that Parkinson’s disease may – at least partly – be an autoimmune condition. If further investigations (including replication of these original results by independent research groups) supports the idea that some people with Parkinson’s disease have an autoimmune component to their condition, this knowledge will provide us with a starting point to begin dividing the affected individuals into groups which could be better treated by the use of therapies oriented towards autoimmunity.

Ultimately any cure of this condition will probably utilise multiple treatments (eg. something to slow the progress of the disease, something protect cells from dying, something to distract the immune system, and something to begin replacing the cells that have been lost). Key to that future is a better understanding of the various components underlying the disease. The potential discovery of an autoimmune component to Parkinson’s disease in some people may help in the personalisation of therapy.

We are really excited by this.


EDITORIAL NOTE: The information provided by the SoPD website is for information and educational purposes only. Under no circumstances should it ever be considered medical or actionable advice. It is provided by research scientists, not medical practitioners. While many of the drugs/treatments discussed on the website are clinically available, they can have significant side effects and may affect the efficacy of other treatments. Any actions taken – based on what has been read on the website – are the sole responsibility of the reader. Any actions being contemplated by readers should firstly be discussed with a qualified healthcare professional who is aware of your medical history. While some of the information discussed in this post may cause concern, please speak with your medical physician before attempting any change in an existing treatment regime.


The banner for today’s post was sourced from Niaid

On the hunt: Parkure

Lysimachos-zografos-naturejobs-blog

This is Lysimachos.

Pronounced: “Leasing ma horse (without the R)” – his words not mine.

He is one of the founders of an Edinburgh-based biotech company called “Parkure“.

In today’s post, we’ll have a look at what the company is doing and what it could mean for Parkinson’s disease.


parkure7

Source: Parkure

The first thing I asked Dr Lysimachos Zografos when we met was: “Are you crazy?”

Understand that I did not mean the question in a negative or offensive manner. I asked it in the same way people ask if Elon Musk is crazy for starting a company with the goal of ‘colonising Mars’.

In 2014, Lysimachos left a nice job in academic research to start a small biotech firm that would use flies to screen for drugs that could be used to treat Parkinson’s disease. An interesting idea, right? But a rather incredible undertaking when you consider the enormous resources of the competition: big pharmaceutical companies. No matter which way you look at this, it has the makings of a real David versus Goliath story.

But also understand this: when I asked him that question, there was a strong element of jealousy in my voice.

Logo_without_strapline_WP

Incorporated in October 2014, this University of Edinburgh spin-out company has already had an interesting story. Here at the SoPD, we have been following their activities with interest for some time, and decided to write this post to make readers aware of them.

After struggling to raise much initial start-up capital, the company took the innovative approach of ‘crowd funding’ their first steps, and they managed to attract over £75,000 in investment through the Edinburgh-based technology-focussed crowd funding enterprise ShareIn. Here is the original video of that fund raising effort:

The company was also awarded a SMART Scotland grant from the Scottish Government in December 2014 which matched the investment raised by the crowd funding effort. This was a huge moment for the young company and Lysimachos described it as the most pivotal piece of support he has ever received in his research career.

Dr Zografos was also awarded a one-year RSE Enterprise Fellowship, which started in April of 2015. This award provided not only financial support, but also invaluable sources of advice and help for the young CEO learn the ropes of the business world.

And with this small pot of funding, they were off on their quest to find a cure for Parkinson’s disease.

What did they plan to do?

Before starting Parkure, Lysimachos was working for another University of Edinburgh spin-out company called Brainwave discovery Ltd where he had been working on genetically engineered flies. Specifically, the company uses flies to screen drugs to identify potential treatments and therapies for human conditions.

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Drosophila (flies). Source: The Converstation

Why do they use flies to do this?

Several reasons:

  1. Our understanding of the genetics of Drosophila is very good
  2. We can manipulate Drosophila DNA very easily – human genes can be inserted, etc
  3. As you can see from the image below the Drosophila life cycle is very short, meaning that experiments can be conducted very quickly

slide_1

Source: Slideplayer

Drosophila are also very small and easy to house, which helps a company to reduce the costs associated with research.

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Housing Drosophila in jars. Source: Crowdfundinsider

While working at Brainwave (and later with Parkure), Lysimachos and his colleagues generated a lot of different types of flies with human genes inserted into their DNA. That work resulted in this publication:

Parkure1

Title: Functional characterisation of human synaptic genes expressed in the Drosophila brain.
Authors: Zografos L, Tang J, Hesse F, Wanker EE, Li KW, Smit AB, Davies RW, Armstrong JD.
Journal: Biol Open. 2016 May 15;5(5):662-7. doi: 10.1242/bio.016261.
PMID: 27069252                  (This article is OPEN ACCESS if you would like to read it)

In this study, the researchers began by engineered 30 different strains of flies with human genes inserted into their DNA. These genes are specifically associated with having activity at a region of each neuron called the synapse. The synapse is where one neuron communicates with another by releasing a neurotransmitter, like the chemical dopamine. Most neurons have thousands of synapses and the proteins involved with activity in the synapse are critical for normal neurological functioning.

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Neurotransmitters being released across a synapse from one neuron (on the right) to another. Source: Truelibido

The researchers selected three of the 30 strains to focus on for further investigation: one containing the human tyrosine protein kinase Fyn, another containing the human small GTPase Rap1a, and the third had the human gene Arc inserted into its DNA. The first strain of fly (human Fyn) demonstrated a ‘gain-of-function’ effect in learning, while the second strain (human Rap1a) exhibited a ‘gain-of-function’ effect in motor ability. Curiously, the third strain (human Arc) did not show any effect at all, but this may be due to the fact that Drosophila do not have an equivalent gene (also called an ortholog).

While generating these and other flies with human genes, Lysimachos and his colleagues noticed that genes associated with Parkinson’s disease in particular could be easily inserted into flies and those genes would result in the flies developing Parkinson’s disease like features (for example, the loss of dopamine neurons and locomotion motor issues).

These flies not only gave the researchers an interesting new fly model of a specific disease, but also a quantifiable method of screening drugs that could protect the flies from developing Parkinson’s disease. They could treat the flies with different drugs and then watch to see which flies didn’t develop locomotion motor issues. In the image below you can see a wild-type (WT) normal fly walking around in a petri dish in panel A&B, while the fly in panel C has had a gene removed (or knocked out – KO) which has resulted in movement issues:

Fig-4-Experimental-study-of-Drosophila-locomotor-behaviour-a-An-adult-wild-type

An example of motor issues in a fly. Source: PMC

And this using flies to screen drug for Parkinson’s disease is not such a crazy idea – remember we have previously written a post about the amazing efforts of another biotech company called Yumanity Therapeutics which is using yeast to screen drugs for Parkinson’s disease (Click here to read more about that).

The problem for Yumanity: yeast cells don’t develop Parkinson’s-like motor issues.

Lysimachos and his research colleagues tested the feasibility of this idea and found that it worked. If fact it worked really well.

It resulted not only in the founding of Parkure, but also in the company’s second research report:

Parkure2

Title: Validating the Predicted Effect of Astemizole and Ketoconazole Using a Drosophila Model of Parkinson’s Disease.
Authors: Styczyńska-Soczka K, Zechini L, Zografos L.
Journal; Assay Drug Dev Technol. 2017 Apr;15(3):106-112.
PMID: 28418693

In this study, the researchers at Parkure wanted to validate two compounds derived from their screening process:

  1. Astemizole (an antihistamine drug)
  2. Ketoconazole (an anti-fungal drug)

They used flies that were genetically engineered to produce high levels of human alpha synuclein in the brain. Alpha synuclein is a protein that is closely associated with Parkinson’s disease. It is believed to be responsible for the loss of cells in the brain. As these genetically engineered flies aged, they developed motor problems and started to lose dopamine neurons in the brain – nicely modelling the human condition.

The investigators took two groups of these flies and treated them with the two drugs (one group received Astemizole, while the other group was treated with ketoconazole). The results of the study show that both drugs increased the survival rates of the flies and could also rescue the motor problems that developed in these flies with age. Only ketoconazole treatment, however, actually reversed the loss of dopaminergic neurons. The effect of ketoconazole treatment was also apparent earlier in the life-cycle of the flies.

Ketoconazole is an interesting drug with a wide range of targets particularly within pathways of androgen and estrogen metabolism, including the androgen receptor itself. The androgen receptor has been associated with some neuroprotective properties, particularly in newly born neurons (Click here for more on this).

4ab17031-4603-4be2-9d45-2abf27074d53-01

Ketoconazole. Source: Drugs

Astemizole on the other hand is known to bind to the human histamine H1 receptor, and it is important to note here that there is no strong fly equivalent for this receptor which may explain the lack of neuroprotection in this study.

Astemizole

Astemizole. Source: Wikipedia

One interesting aspect of the Parkure study, however, is that another (independent) group in China also noted beneficial effects of Astemizole, but in a different kind of screening study:

NRF2.jpg

Title: Identification of Non-Electrophilic Nrf2 Activators from Approved Drugs
Authors: Zhang QY, Chu XY, Jiang LH, Liu MY, Mei ZL, Zhang HY.
Journal: Molecules. 2017 May 26;22(6).
PMID: 28587109              (This article is OPEN ACCESS if you would like to read it)

In this study, the investigators conducted a screen for drugs that activated the Nuclear Factor Erythroid 2-Related Factor 2 (Nrf2) pathway (We have previously discussed Nrf2 – click here to see that post). The researchers found that astemizole increased the activity of antioxidant genes NQO1, HO-1, and GCLM (which are all part of the Nrf2 pathway).

Interesting. So where is the company now?

The company recently announced that they have two lead compounds that it is now trying to take to the clinic (Click here to read more about this). The two drugs in question are repurposed (so we know that they are safe in humans), but Parkure has been able to isolate the active part of the drug that is causing the beneficial effects and make a whole new drug out of it. And they have now tested those novel chemical derivatives in preclinical studies.

The company currently seeking to take one of these preclinically validated seed molecules to the investigational new drug application (or IND) stage. Over the last year, Parkure has secured an Innovation Voucher from Interface, as well as some seed funding from Deepbride Capital LLP. In addition, the company also has contracts for the testing of a number of compounds for third party pharmaceutical companies using the Parkure’s unique approach and platform.

What does it all mean?

The better question is: do I still think Lysimachos is crazy? And the answer is no. The company has a very clear mission and they are taking very prudent steps towards achieving their goals. More importantly, he and his team are off on a fantastic adventure that may have tremendous benefits for the whole Parkinson’s community.

Yes, I’m still jealous.

It will be very interesting to watch the progress of this company over the next few years, and if you would like to contact Lysimachos to ask any questions or offer any help, he is happy to hear from you – his email address is lzografos@parkure.co.uk).


Editorial Note:  This post highlights the activities of a privately owned biotech company. The folks at SoPD have no equity in the company, nor were we asked or paid by the company to write this post. We simply believe that what they are doing is really interesting (the science, the business model, the ultimate goal), and we thought we would make readers aware of them and their mission. SoPD initiated the production of this post, and we were very grateful to Lysimachos for providing us with his time to answer some questions when we reached out to him.


The banner for todays post was sourced from Nature

Cholesterol, statins, and Parkinson’s disease

Eraser deleting the word Cholesterol

A new research report looking at the use of cholesterol-reducing drugs and the risk of developing Parkinson’s disease has just been published in the scientific journal Movement disorders.

The results of that study have led to some pretty startling headlines in the media, which have subsequently led to some pretty startled people who are currently taking the medication called statins.

In todays post, we will look at what statins are, what the study found, and discuss what it means for our understanding of Parkinson’s disease.


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Cholesterol forming plaques (yellow) in the lining of arteries. Source: Healthguru

Cholesterol gets a lot of bad press.

Whether it’s high and low, the perfect balance of cholesterol in our blood seems to be critical to our overall health and sense of wellbeing. At least that is what we are constantly being told this by media and medical professionals alike.

But ask yourself this: Why? What exactly is cholesterol?

Good question. What is cholesterol?

Cholesterol (from the Greek ‘chole‘- bile and ‘stereos‘ – solid) is a waxy substance that is circulating our bodies. It is generated by the liver, but it is also found in many foods that we eat (for example, meats and egg yolks).

cholesterol-svg

The chemical structure of Cholesterol. Source: Wikipedia

Cholesterol falls into one of three major classes of lipids – those three classes of lipids being TriglyceridesPhospholipids and Steroids (cholesterol is a steroid). Lipids are major components of the cell membranes and thus very important. Given that the name ‘lipids’ comes from the Greek lipos meaning fat, people often think of lipids simply as fats, but fats more accurately fall into just one class of lipids (Triglycerides).

Like many fats though, cholesterol dose not dissolve in water. As a result, it is transported within the blood system encased in a protein structure called a lipoprotein.

Chylomicron.svg

The structure of a lipoprotein; the purple C inside represents cholesterol. Source: Wikipedia

Lipoproteins have a very simple classification system based on their density:

  • very low density lipoprotein (VLDL)
  • low density lipoprotein (LDL)
  • intermediate density lipoprotein (IDL)
  • high density lipoprotein (HDL).

Now understand that all of these different types of lipoproteins contain cholesterol, but they are carrying it to different locations and this is why some of these are referred to as good and bad.

The first three types of lipoproteins carry newly synthesised cholesterol from the liver to various parts of the body, and thus too much of this activity would be bad as it results in an over supply of cholesterol clogging up different areas, such as the arteries.

LDLs, in particular, carry a lot of cholesterol (with approximately 50% of their contents being cholesterol, compared to only 20-30% in the other lipoproteins), and this is why LDLs are often referred to as ‘bad cholesterol’. High levels of LDLs can result in atherosclerosis (or the build-up of fatty material inside your arteries).

Progressive and painless, atherosclerosis develops as cholesterol silently and slowly accumulates in the wall of the artery, in clumps that are called plaques. White blood cells stream in to digest the LDL cholesterol, but over many years the toxic mess of cholesterol and cells becomes an ever enlarging plaque. If the plaque ever ruptures, it could cause clotting which would lead to a heart attack or stroke.

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Source: MichelsonMedical

So yeah, some lipoproteins can be considered bad.

HDLs, on the other hand, collects cholesterol and other lipids from cells around the body and take them back to the liver. And this is why HDLs are sometimes referred to as “good cholesterol” because higher concentrations of HDLs are associated with lower rates of atherosclerosis progression (and hopefully regression).

But why is cholesterol important?

While cholesterol is usually associated with what is floating around in your bloodstream, it is also present (and very necessary) in every cell in your body. It helps to produce cell membranes, hormones, vitamin D, and the bile acids that help you digest fat.

It is particularly important for your brain, which contains approximately 25 percent of the cholesterol in your body. Numerous neurodegenerative conditions are associated with cholesterol disfunction (such as Alzheimer’s disease and Huntington’s disease – Click here for more on this). In addition, low levels of cholesterol is associated with violent behaviour (Click here to read more about this).

Are there any associations between cholesterol and Parkinson’s disease?

The associations between cholesterol and Parkinson’s disease is a topic of much debate. While there have been numerous studies investigating cholesterol levels in blood in people with Parkinson’s disease, the results have not been consistent (Click here for a good review on this topic).

Rather than looking at cholesterol directly, a lot of researchers have chosen to focus on the medication that is used to treat high levels of cholesterol – a class of drugs called statins.

Gao

Title: Prospective study of statin use and risk of Parkinson disease.
Authors: Gao X, Simon KC, Schwarzschild MA, Ascherio A.
Journal: Arch Neurol. 2012 Mar;69(3):380-4.
PMID: 22410446              (This article is OPEN ACCESS if you would like to read it)

In this study the researchers conduced a prospective study involving the medical details of 38 192 men and 90 874 women from two huge US databases: the Nurses’ Health Study (NHS) and the Health Professionals Follow-Up Study (HPFS).

NHS study was started in 1976 when 121,700 female registered nurses (aged 30 to 55 years) completed a mailed questionnaire. They provided an overview of their medical histories and health-related behaviours. The HPFS study was established in 1986, when 51,529 male health professionals (40 to 75 years) responded to a similar questionnaire. Both the NHS and the HPFS send out follow-up questionnaires every 2 years.

By analysing all of that data, the investigators found 644 cases of Parkinson’s disease (338 women and 306 men). They noticed that the risk of Parkinson’s disease was approximately 25% lower among people currently taking statins when compared to people not using statins. And this association was significant in statin users younger than 60 years of age (P = 0.02).

What are statins?

Also known as HMG-CoA reductase inhibitors, statins are a class of drug that inhibits/blocks an enzyme called 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase.

HMG-CoA reductase is the key enzyme regulating the production of cholesterol from mevalonic acid in the liver. By blocking this process statins help lower the total amount of cholesterol available in your bloodstream.

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Source: Myelomacrowd

Statins are used to treat hypercholesterolemia (also called dyslipidemia) which is high levels of cholesterol in the blood. And they are one of the most widely prescribed classes of drugs currently available, with approximately 23 percent of adults in the US report using statin medications (Source).

Now, while the study above found an interesting association between statin use and a lower risk of Parkinson’s disease, the other research published on this topic has not been very consistent. In fact, a review in 2009 found a significant associations between statin use and lower risk of Parkinson’s disease was observed in only two out of five prospective studies (Click here to see that review).

New research published this week has attempted to clear up some of that inconsistency, by starting with a huge dataset and digging deep into the numbers.

So what new research has been published?

Statins

Title: Statins may facilitate Parkinson’s disease: Insight gained from a large, national claims database
Authors: Liu GD, Sterling NW, Kong L, Lewis MM, Mailman RB, Chen H, Leslie D, Huang X
Journal: Movement Disorder, 2017 Jun;32(6):913-917.
PMID: 28370314

Using the MarketScan Commercial Claims and Encounters database which catalogues the healthcare use and medical expenditures of more than 50 million employees and their family members each year, the researcher behind that study identified 30,343,035 individuals that fit their initial criteria (that being “all individuals in the database who had 1 year or more of continuous enrolment during January 1, 2008, to December 31, 2012, and were 40 years of age or older at any time during their enrolment”). From this group, the researcher found a total of 21,599 individuals who had been diagnosed with Parkinson’s disease.

In their initial analysis, the researchers found that Parkinson’s disease was positively associated with age, male gender, hypertension, coronary artery disease, and usage of cholesterol-lowering drugs (both statins and non-statins). The condition was negatively associated with hyperlipidemia (or high levels of cholesterol). This result suggests not only that people with higher levels of cholesterol have a reduced chance of developing Parkinson’s disease, but taking medication to lower cholesterol levels may actually increase ones risk of developing the condition.

One interesting finding in the data was the effect that different types of statins had on the association.

Statins can be classified into two basic groups: water soluble (or hydrophilic) and lipid soluble (or lipophilic) statins. Hydrophilic molecule have more favourable interactions with water than with oil, and vice versa for lipophilic molecules.

wataer_oil

Hydrophilic vs lipophilic molecules. Source: Riken

Water soluble (Hydrophilic) statins include statins such as pravastatin and rosuvastatin; while all other available statins (eg. atorvastatin, cerivastatin, fluvastatin, lovastatin and simvastatin) are lipophilic.

In this new study, the researchers found that the association between statin use and increased risk of developing Parkinson’s disease was more pronounced for lipophilic statins (a statistically significant 58% increase – P < 0.0001), compared to hydrophilic statins (a non-significant 19% increase – P = 0.25). One possible explanation for this difference is that lipophilic statins (like simvastatin and atorvastatin) cross the blood-brain barrier more easily and may have more effect on the brain than hydrophilic ones.

The investigators also found that this association was most robust during the initial phase of statin treatment. That is to say, the researchers observed a 82% in risk of PD within 1 year of having started statin treatment, and only a 37% increase five years after starting statin treatment.; P < 0.0001). Given this finding, the investigators questioned whether statins may be playing a facilitatory role in the development of Parkinson’s disease – for example, statins may be “unmasking” the condition during its earliest stages.

So statins are bad then?

Can I answer this question with a diplomatic “I don’t know”?

It is difficult to really answer that question based on the results of just this one study. This is mostly because this new finding is in complete contrast to a lot of experimental research over the last few years which has shown statins to be neuroprotective in many models of Parkinson’s disease. Studies such as this one:

statins
Title: Simvastatin inhibits the activation of p21ras and prevents the loss of dopaminergic neurons in a mouse model of Parkinson’s disease.
Authors: Ghosh A, Roy A, Matras J, Brahmachari S, Gendelman HE, Pahan K.
Journal: J Neurosci. 2009 Oct 28;29(43):13543-56.
PMID: 19864567              (This study is OPEN ACCESS if you would like to read it)

In this study, the researchers found that two statins (pravastatin and simvastatin – one hydrophilic and one lipophilic, respectively) both exhibited the ability to suppress the response of helper cells in the brain (called microglial) in a neurotoxin model of Parkinson’s disease. This microglial suppression resulted in a significant neuroprotective effect on the dopamine neurons in these animals.

Another study found more Parkinson’s disease relevant effects from statin treatment:

Synau

TItle: Lovastatin ameliorates alpha-synuclein accumulation and oxidation in transgenic mouse models of alpha-synucleinopathies.
Authors: Koob AO, Ubhi K, Paulsson JF, Kelly J, Rockenstein E, Mante M, Adame A, Masliah E.
Journal: Exp Neurol. 2010 Feb;221(2):267-74.
PMID: 19944097            (This study is OPEN ACCESS if you would like to read it)

In this study, the researchers treated two different types of genetically engineered mice (both sets of mice produce very high levels of alpha synuclein – the protein closely associated with Parkinson’s disease) with a statin called lovastatin. In both groups of alpha synuclein producing mice, lovastatin treatment resulted in significant reductions in the levels of cholesterol in their blood when compared to the saline-treated control mice. The treated mice also demonstrated a significant reduction in levels of alpha synuclein clustering (or aggregation) in the brain than untreated mice, and this reduction in alpha synuclein accumulation was associated with a lessening of pathological damage in the brain.

So statins may not be all bad?

One thing many of these studies fail to do is differentiate between whether statins are causing the trouble (or benefit) directly or whether simply lowering cholesterol levels is having a negative impact. That is to say, do statins actually do something else? Other than lowering cholesterol levels, are statins having additional activities that could cause good or bad things to happen?

 

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Source: Liverissues

The recently published study we are reviewing in this post suggested that non-statin cholesterol medication is also positively associated with developing Parkinson’s disease. Thus it may be that statins are not bad, but rather the lowering of cholesterol levels that is. This raises the question of whether high levels of cholesterol are delaying the onset of Parkinson’s disease, and one can only wonder what a cholesterol-based process might be able to tell us about the development of Parkinson’s disease.

If the findings of this latest study are convincingly replicated by other groups, however, we may need to reconsider the use of statins not in our day-to-day clinical practice. At the very least, we will need to predetermine which individuals may be more susceptible to developing Parkinson’s disease following the initiation of statin treatment. It would actually be very interesting to go back to the original data set of this new study and investigate what addition medical features were shared between the people that developed Parkinson’s disease after starting statin treatment. For example, were they all glucose intolerant? One would hope that the investigators are currently doing this.

Are Statins currently being tested in the clinic for Parkinson’s disease?

(Oh boy! Tough question) Yes, they are.

There is currently a nation wide study being conducted in the UK called PD STAT.

PDSTATLogo_Large

The study is being co-ordinated by the Plymouth Hospitals NHS Trust (Devon). For more information, please see their website or click here for the NHS Clinical trials gateway website.

Is this dangerous given the results of the new research study?

(Oh boy! Even tougher question!)

Again, we are asking this question based on the results of one recent study. Replication with independent databases is required before definitive conclusions can be made.

There have, however, been previous clinical studies of statins in neurodegenerative conditions and these drugs have not exhibited any negative effects (that I am aware of). In fact, a clinical trial for multiple sclerosis published in 2014 indicated some positive results for sufferers taking simvastatin:

MS-STAT
Title: Effect of high-dose simvastatin on brain atrophy and disability in secondary progressive multiple sclerosis (MS-STAT): a randomised, placebo-controlled, phase 2 trial.
Authors: Chataway J, Schuerer N, Alsanousi A, Chan D, MacManus D, Hunter K, Anderson V, Bangham CR, Clegg S, Nielsen C, Fox NC, Wilkie D, Nicholas JM, Calder VL, Greenwood J, Frost C, Nicholas R.
Journal: Lancet. 2014 Jun 28;383(9936):2213-21.
PMID: 24655729             (This article is OPEN ACCESS if you would like to read it)

In this double-blind clinical study (meaning that both the investigators and the subjects in the study were unaware of which treatment was being administered), 140 people with multiple sclerosis were randomly assigned to receive either the statin drug simvastatin (70 people; 40 mg per day for the first month and then 80 mg per day for the remainder of 18 months) or a placebo treatment (70 people).

Patients were seen at 1, 6, 12, and 24 months into the study, with telephone follow-up at months 3 and 18. MRI brain scans were also made at the start of the trial, and then again at 12 months and 25 months for comparative sake.

The results of the study indicate that high-dose simvastatin was well tolerated and reduced the rate of whole-brain shrinkage compared with the placebo treatment. The mean annualised shrinkage rate was significantly lower in patients in the simvastatin group. The researchers were very pleased with this result and are looking to conduct a larger phase III clinical trial.

Other studies have not demonstrated beneficial results from statin treatment, but they have also not observed a worsening of the disease conditions:

Alzh
Title: A randomized, double-blind, placebo-controlled trial of simvastatin to treat Alzheimer disease.
Authors:Sano M, Bell KL, Galasko D, Galvin JE, Thomas RG, van Dyck CH, Aisen PS.
Journal: Neurology. 2011 Aug 9;77(6):556-63.
PMID: 21795660            (This article is OPEN ACCESS if you would like to read it)

In this study, the investigators recruited a total of 406 individuals were mild to moderate Alzheimer’s disease, and they were randomly assigned to two groups: 204 to simvastatin (20 mg/day, for 6 weeks then 40 mg per day for the remainder of 18 months) and 202 to placebo control treatment. While Simvastatin displayed no beneficial effects on the progression of symptoms in treated individuals with mild to moderate Alzheimer’s disease (other than significantly lowering of cholesterol levels), the treatment also exhibited no effect on worsening the disease.

 

So what does it all mean?

Research investigating cholesterol and its association with Parkinson’s disease has been going on for a long time. This week a research report involving a huge database was published which indicated that using cholesterol reducing medication could significantly increase one’s risk of developing Parkinson’s disease.

These results do not mean that someone being administered statins is automatically going to develop Parkinson’s disease, but – if the results are replicated – it may need to be something that physicians should consider before prescribing this class of drug.

Whether ongoing clinical trials of statins and Parkinson’s disease should be reconsidered is a subject for debate well above my pay grade (and only if the current results are replicated independently). It could be that statin treatment (or lowering of cholesterol) may have an ‘unmasking’ effect in some individuals, but does this mean that any beneficial effects in other individuals should be discounted? If preclinical data is correct, for example, statins may reduce alpha synuclein clustering in some people which could be beneficial in Parkinson’s.

As we have said above, further research is required in this area before definitive conclusions can be made. This is particularly important given the inconsistencies of the previous research results in the statin and Parkinson’s disease field of investigation.


EDITORIAL NOTE: The information provided by the SoPD website is for information and educational purposes only. Under no circumstances should it ever be considered medical or actionable advice. It is provided by research scientists, not medical practitioners. Any actions taken – based on what has been read on the website – are the sole responsibility of the reader. Any actions being contemplated by readers should firstly be discussed with a qualified healthcare professional who is aware of your medical history. While some of the information discussed in this post may cause concern, please speak with your medical physician before attempting any change in an existing treatment regime.


The banner for today’s post was sourced from HarvardHealth

Are Dyskinesias days NAM-bered?

header

Addex Therapeutics and the Michael J Fox Foundation are preparing to initiate a new clinical trial testing a new drug called Dipraglurant on levodopa-induced dyskinesia (Source).

Dipraglurant is a mGluR5 negative allosteric modulator (don’t panic, it’s not as complicated as it sounds).

In today’s post, we’ll explain what all of that means and look at the science behind this new treatment.


Dysco

An example of a person with dyskinesia. Source: JAMA Neurology

For anyone familiar with Parkinson’s disease, they will know that long term use of the treatment L-dopa can lead to two possible outcomes:

  1. The treatment loses it’s impact, requiring ever higher doses to be administered
  2. The appearance of dykinesias

Now, not everyone taking L-dopa will be affected by both of these outcomes, but people with young, onset Parkinson’s disease do seem to be at risk of developing L-dopa induced dykinesias.

What are Dyskinesias?

Dyskinesias (from Greek: dys – abnormal; and kinēsis – motion, movement) are simply a category of movement disorders that are characterised by involuntary muscle movements. And they are certainly not specific to Parkinson’s disease.

As we have suggested above, they are associated in Parkinson’s disease with long-term use of L-dopa.

Below is a video of two legends: the late Tom Isaacs (who co-founded the Cure Parkinson’s Trust) and David Sangster (he founded www.1in20Parkinsons.org.uk). They were both diagnosed with Parkinson’s disease in their late 20’s. Tom, having lived with Parkinson’s for 20 years at the time of this video provides a good example of what dyskinesias look like:

As you can see, dyskinesias are a debilitating issue for anyone who suffers them.

How do dyskinesias develop in Parkinson’s disease?

Before being diagnosed and beginning a course of L-dopa, the locomotion parts of the brain in a person with Parkinson’s disease gradually becomes more and more inhibited. This increasing inhibition results in the slowness and difficulty in initiating movement that characterises this condition. A person with Parkinson’s may want to move, but they can’t.

They are akinetic (from Greek: a-, not, without; and kinēsis – motion).

972px-Paralysis_agitans_(1907,_after_St._Leger)

Drawing of an akinetic individual with Parkinson’s disease, by Sir William Richard Gowers
Source: Wikipedia

L-dopa tablets provide the brain with the precursor to the chemical dopamine. Dopamine producing cells are lost in Parkinson’s disease, so replacing the missing dopamine is one way to treat the motor features of the condition. Simply giving people pills of dopamine is a non-starter: dopamine is unstable, breaks down too quickly, and (strangely) has a very hard time getting into the brain. L-dopa, on the other hand, is very robust and has no problem getting into the brain.

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Sinemet is L-dopa. Source: Drugs

Once inside the brain, L-dopa is quickly converted into dopamine. It is changed into dopamine by an enzyme called DOPA decarboxylase, and this change rapidly increases the levels of dopamine in the brain, allowing the locomotion parts of the brain to function more normally.

4INJ4aV

The chemical conversion of L-dopa to dopamine. Source: Nootrobox

In understanding this process, it is important to appreciate that when an L-dopa tablet is consumed and L-dopa enters the brain, there is a rapid increase in the levels of dopamine. A ‘spike’ in the supply of dopamine, if you will, and this will last for the next few hours, before the dopamine is used up.

As the effects of the L-dopa tablet wear off, another tablet will be required. This use of multiple L-dopa pills across the day gives rise to a wave-like shape to the dopamine levels in the brain over the course of the day (see the figure below). The first pill in the morning will quickly lift the levels of dopamine enough that the individual will no longer feel akinetic. This will allow them to be able to function with normal controlled movement for several hours before the L-dopa begins to wear off. As the L-dopa wears off, the dopamine levels in the brain drop back towards levels that will leave the person feeling akinetic and at this point another L-dopa tablet is required.

Dysk1

After several years of L-dopa use, many people with Parkinson’s disease will experience a weaker response to each tablet. They will also find that they have more time during which they will be unable to move (exhibiting akinesia). This is simply the result of the progression of Parkinson’s disease – L-dopa treats the motor features of the disease but only hides/masks the fact that the disease is still progressing.

To combat this shorter response time, the dose of L-dopa is increased. This will result in increasing levels of dopamine in the brain (as illustrated by the higher wave form over time in the image below). It will take more L-dopa medication induced dopamine to lift the individual out of the akinetic state.

Dyskinesias3

This increasing of L-dopa dosage, however, is often associated with the gradual development of abnormal involuntary movements that appear when the levels of L-dopa induced dopamine are the highest.

These are the dyskinesias.

Are there different types of dyskinesias?

Yes there are.

Dyskinesias have been broken down into many different subtypes, but the two main types of dyskinesia are:

Chorea – these are involuntary, irregular, purposeless, and unsustained movements. To an observer, Chorea will look like a very disorganised/uncoordinated attempt at dancing (hence the name, from the Greek word ‘χορεία’ which means ‘dance’). While the overall activity of the body can appear continuous, the individual movements are brief, infrequent and isolated. Chorea can cause problems with maintaining a sustained muscle contraction,  which may result in affected people dropping things or even falling over.

Dystonia – these are sustained muscle contractions. They often occur at rest and can be either focal or generalized. Focal dystonias are involuntary contractions in a single body part, for example the upper facial area. Generalized dystonia, as the name suggests, are contraction affecting multiple body regions at the same time, typically the trunk, one or both legs, and another body part. The intensity of muscular movements in sufferers can fluctuate, and symptoms usually worsen during periods of fatigue or stress.

We have previously discussed the current treatment options for dyskinesias (click here to see that post).

Ok, so what clinical trials are Addex Therapeutics and the Michael J Fox Foundation preparing and why?

They are preparing to take a drug called Dipraglurant through phase III testing for L-dopa inducing dyskinesias in Parkinson’s disease. Dipraglurant is a mGluR5 negative allosteric modulator.

And yes, I know what you are going to ask next: what does any of that mean?

Ok, so mGluR5 (or Metabotropic glutamate receptor 5) is a G protein-coupled receptor. This is a structure that sits in the skin of a cell (the cell membrane), with one part exposed to the outside world – waiting for a chemical to bind to it – while another part is inside the cell, ready to act when the outside part is activated. The outside part of the structure is called the receptor.

Metabotropic receptors are a type of receptor that is indirectly linked with channels in cell membrane. These channels open and close, allowing specific elements to enter the cell. When a chemical (or agonist) binds to the receptor and it becomes activated, the part of the structure inside the cell will send a signal to the channel via a messenger (called a G-protein).

The chemical that binds to mGluR5 is the neurotransmitter glutamate.

U4.cp2.1_nature01307-f1.2

Metabotropic glutamate receptor 5 activation. Source: Nature

But what about the “negative allosteric modulator” part of ‘mGluR5 negative allosteric modulator’

Good question.

This is the key part of this new approach. Allosteric modulators are a new class of orally available small molecule therapeutic agents. Traditionally, most marketed drugs bind directly to the same part of receptors that the body’s own natural occurring proteins attach to. But this means that those drugs are competing with those endogenous proteins, and this can limit the potential effect of the drug.

Allosteric modulators get around this problem by binding to a different parts of the receptor. And instead of simply turning on or off the receptor, allosteric modulators can either turn up the volume of the signal being sent by the receptor or decrease the signals. This means that when the body’s naturally occurring protein binds in the receptor, allosteric modulators can either amplify the effect or reduce it depending on which type of allosteric modulators is being administered.

allosteric_modulation_mechanism

How Allosteric modulators work. Source: Addrex Thereapeutics

There are two different types of allosteric modulators: positive and negative. And as the label suggests, positive allosteric modulators (or PAMs) increase the signal from the receptor while negative allosteric modulators (or NAMs) reduce the signal.

So Dipraglurant turns down the volume of the signal from the mGluR5 receptor?

Exactly.

By turning down the volume of the glutamate receptor mGluR5, researchers believe that we can reduce the severity of dyskinesias.

But hang on a second. Why are we looking at glutamate in dyskinesias? Isn’t dopamine the chemical of interest in Parkinson’s disease?

So almost 10 years ago, some researchers noticed something interesting in the brains of Parkinsonian monkeys that had developed dyskinesias:

Monkey2
Title: mGluR5 metabotropic glutamate receptors and dyskinesias in MPTP monkeys.
Authors: Samadi P, Grégoire L, Morissette M, Calon F, Hadj Tahar A, Dridi M, Belanger N, Meltzer LT, Bédard PJ, Di Paolo T.
Journal: Neurobiol Aging. 2008 Jul;29(7):1040-51.
PMID: 17353071

The researchers conducting this study induced Parkinson’s disease in monkeys using a neurotoxin called MPTP, and they then treated the monkeys with L-dopa until they began to develop dyskinesias. At this point when they looked in the brains of these monkeys, the researchers noticed a significant increase in the levels of mGluR5, which was associated with the dyskinesias. This finding led the researchers to speculate that reducing mGluR5 levels might reduce dyskinesias.

And it did!

Subsequent preclinical research indicated that targeting mGluR5 might be useful in treating dyskinesias, especially with negative allosteric modulators:

Monkey
Title: The mGluR5 negative allosteric modulator dipraglurant reduces dyskinesia in the MPTP macaque model
Authors: Bezard E, Pioli EY, Li Q, Girard F, Mutel V, Keywood C, Tison F, Rascol O, Poli SM.
Journal: Mov Disord. 2014 Jul;29(8):1074-9.
PMID: 24865335

In this study, the researchers tested the efficacy of dipraglurant in Parkinsonian primates  that had developed L-dopa induced dyskinesias. They tested three different doses of the drug (3, 10, and 30 mg/kg).

Dipraglurant significantly reduced dyskinesias in the monkeys, with best effect being reached using the 30 mg/kg dose. Importantly, the dipraglurant treatment had no impact on the efficacy of L-dopa which was still being used to treat the monkeys Parkinson’s features.

This research lead to a clinical trials in man, and last year Addex Therapeutics published the results of their phase IIa clinical trial of Dipraglurant (also called ADX-48621):

NAM

Title: A Phase 2A Trial of the Novel mGluR5-Negative Allosteric Modulator Dipraglurant for Levodopa-Induced Dyskinesia in Parkinson’s Disease.
Authors: Tison F, Keywood C, Wakefield M, Durif F, Corvol JC, Eggert K, Lew M, Isaacson S, Bezard E, Poli SM, Goetz CG, Trenkwalder C, Rascol O.
Journal: Mov Disord. 2016 Sep;31(9):1373-80.
PMID: 27214664

The Phase IIa double-blind, placebo-controlled, randomised trial was a dose escalation study, conducted in 76 patients with Parkinson’s disease L-dopa-induced dyskinesia – 52 subjects were given dipraglurant and 24 received a placebo treatment. The dose escalation assessment of dipraglurant started at 50 mg once daily to 100 mg 3 times daily. The study was conducted over 4 weeks.

The investigators found that dipraglurant significantly reduced the dyskinesias on both day 1 of the study and on day 14, and this treatment did not result in any worsening of the Parkinsonian features. And remember that this was a double blind study, so both the investigators and the participants had no idea which treatment was being given to each subject. Thus little bias can influence the outcome, indicating that dipraglurant really is having a beneficial effect on dyskinesias.

The company suggested that dipraglurant’s efficacy in reducing L-dopa-induced dyskinesia warrants further investigations in a larger number of patients. And this is what the company is now doing with the help of the Michael J. Fox Foundation (MJFF). In addition, dipraglurant’s potential benefits on dystonia are also going to be investigated with support from the Dystonia Medical Research Foundation (DMRF).

And the really encouraging aspect of this research is that Addex Therapeutics are not the only research group achieving significant beneficial results for dykinesias using this treatment approach (click here to read about other NAM-based clinical studies for dyskinesias).

Fingers crossed for more positive results here.

What happens next?

L-dopa induced dyskinesias can be one of the most debilitating aspects of living with Parkinson’s disease, particularly for the early-onset forms of the condition. A great deal of research is being conducted in order to alleviate these complications, and we are now starting to see positive clinical results starting to flow from that research.

These results are using new type of therapeutic drug that are designed to increase or decrease the level of a signal occurring in a cell without interfering with the normal functioning of the chemicals controlling the activation of that signal.

This is really impressive biology.


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A connection between ALS & Parkinson’s disease? Oh’ll, SOD it!

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Please excuse our use of UK slang in the title of this post, but a group of Australian researchers have recently discovered something really interesting about Parkinson’s disease.

And being a patriotic kiwi, it takes something REALLY interesting for me to even acknowledge that other South Pacific nation. This new finding, however, could be big.

In today’s post, we will review new research dealing with a protein called SOD1, and discuss what it could mean for the Parkinson’s community.


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The number of dark pigmented dopamine cells in the substantia nigra are reduced in the Parkinson’s disease brain (right). Source: Adaptd from Memorangapp

Every Parkinson’s-associated website and every Parkinson’s disease researchers will tell you exactly the same thing when describing the two cardinal features in the brain of a person who died with Parkinson’s disease:

  1. The loss of certain types of cells (such as the dopamine producing cells of the substantia nigra region of the brain – see the image above)
  2. The clustering (or aggregation) of a protein called Alpha synuclein in tightly packed, circular deposits, called Lewy bodies (see image below).

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A Lewy body inside a cell. Source: Adapted from Neuropathology-web

The clustered alpha synuclein protein, however, is not limited to just the Lewy bodies. In the affected areas of the brain, aggregated alpha synuclein can be seen in the branches of cells – see the image below where alpha synuclein has been stained brown on a section of brain from a person with Parkinson’s disease.

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Examples of Lewy neurites (indicated by arrows). Source: Wikimedia

Now, one of the problems with our understanding of Parkinson’s disease is disparity between the widespread presence of clustered alpha synuclein and very selective pattern of cell loss. Alpha synuclein aggregation can be seen distributed widely around the affected areas of the brain, but the cell loss will be limited to specific populations of cells.

If the disease is killing a particular population of cells, why is alpha synuclein clustering so wide spread?

So why is there a difference?

We don’t know.

It could be that the cells that die have a lower threshold for alpha synuclein toxicity (we discussed this is a previous post – click here?).

But this question regarding the difference between these two features has left many researchers wondering if there may be some other protein or agent that is actually killing off the cells and then disappearing quickly, leaving poor old alpha synuclein looking rather guilty.

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Poor little Mr “A Synuclein” got the blame, but his older brother actually did it! Source: Youtube

And this is a very serious discussion point.

This year of 2017 represents the 200th anniversary of James Parkinson’s first description of Parkinson’s disease, but it also represents the 20th anniversary since the association between alpha synuclein and PD was first established. We have produced almost 7,000 research reports on the topic of alpha synuclein and PD during that time, and we currently have ongoing clinical trials targetting alpha synuclein.

But what if our basic premise – that alpha synuclein is the bad guy – is actually wrong?

Is there any evidence to suggest this?

We are just speculating here, but yes there is.

For example, in a study of 904 brains, alpha synuclein deposits were observed in 11.3% of the brains (or 106 cases), but of those cases only 32 had been diagnosed with a neurodegenerative disorder (Click here to read more on this). The remaining 74 cases had demonstrated none of the clinical features of Parkinson’s disease.

So what else could be causing the cell death?

Well, this week some scientists from sunny Sydney (Australia) reported a protein that could fit the bill.

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Sydney. Source: Vagabond

The interesting part of their finding is that the protein is also associated with another neurodegenerative condition: Amyotrophic lateral sclerosis.

Remind me again, what is Amyotrophic lateral sclerosis?

Parkinson’s disease and Amyotrophic lateral sclerosis (ALS) are the second and third most common adult-onset neurodegenerative conditions (respectively) after Alzheimer’s disease. We recently discussed ALS in a previous post (Click here to read that post).

ALS, also known as Lou Gehrig’s disease and motor neuron disease, is a neurodegenerative condition in which the neurons that control voluntary muscle movement die. The condition affects 2 people in every 100,000 each year, and those individuals have an average survival time of two to four years.

You may have heard of ALS due to it’s association with the internet ‘Ice bucket challenge‘ craze that went viral in 2014-15.

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The Ice bucket challenge. Source: Forbes

What is the protein associated with ALS?

In 1993, scientists discovered that mutations in the gene called SOD1 were associated with familial forms of ALS (Click here to read more about this). We now know that mutations in the SOD1 gene are associated with around 20% of familial cases of ALS and 5% of sporadic ALS.

The SOD1 gene produces an enzyme called Cu-Zn superoxide dismutase.

This enzyme is a very powerful antioxidant that protects the body from damage caused by toxic free radical generated in the mitochondria.

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SOD1 protein structure. Source: Wikipedia

One important note here regarding ALS: the genetic mutations in the SOD1 gene do not cause ALS by affecting SOD1’s antioxidant properties (Click here to read more about this). Rather, researchers believe that the cell death seen in SOD1-associated forms of ALS is the consequences of some kind of toxic effect caused by the mutant protein.

So what did the Aussie researchers find about SOD1 in Parkinson’s disease?

This week, the Aussie researchers published this research report:

SOD
Title: Amyotrophic lateral sclerosis-like superoxide dismutase 1 proteinopathy is associated withneuronal loss in Parkinson’s disease brain.
Authors: Trist BG, Davies KM, Cottam V, Genoud S, Ortega R, Roudeau S, Carmona A, De Silva K, Wasinger V, Lewis SJG, Sachdev P, Smith B, Troakes C, Vance C, Shaw C, Al-Sarraj S, Ball HJ, Halliday GM, Hare DJ, Double KL.
Journal: Acta Neuropathol. 2017 May 19. doi: 10.1007/s00401-017-1726-6.
PMID: 28527045

Given that oxidative stress is a major feature of Parkinson’s disease, the Aussie researchers wanted to investigate the role of the anti-oxidant enzyme, SOD1 in this condition. And what they found surprised them.

Heck, it surprised us!

Two areas affected by Parkinson’s disease – the substantia nigra (where the dopamine neurons reside; SNc in the image below) and the locus coeruleus (an area in the brain stem that is involved with physiological responses to stress; LC in the image below) – exhibited little or no SOD1 protein in the control brains.

But in the Parkinsonian brains, there was a great deal of SOD1 protein (see image below).

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SO1 staining in PD brain and Control brains. Source: Springer

In the image above, you can see yellowish-brown stained patches in both the PD and control images. This a chemical called neuromelanin and it can be used to identify the dopamine-producing cells in the SNc and LC. The grey staining in the PD images (top) are cells that contain SOD1. Note the lack of SOD1 (grey staining) in the control images (bottom).

Approximately 90% of Lewy bodies in the Parkinson’s affected brains contained SOD1 protein. The investigators did report that the levels of SOD1 protein varied between Lewy bodies. But the clustered (or ‘aggregated’) SOD1 protein was not just present with alpha synuclein, often it was found by itself in the degenerating regions.

The researchers occasional saw SOD1 aggregation in regions of age-matched control brains, and they concluded that a very low level of SOD1 must be inherent to the normal ageing process.

But the density of SOD1 clustering was (on average) 8x higher in the SNc and 4x higher in the LC in the Parkinsonian brain compared to age-matched controls. In addition, the SOD1 clustering was significantly greater in these regions than all of the non-degenerating regions of the same Parkinson’s disease brains.

The investigators concluded that these data suggest an association between SOD1 aggregation and neuronal loss in Parkinson’s disease. Importantly, the presence of SOD1 aggregations “closely reflected the regional pattern of neuronal loss”.

They also demonstrated that the SOD1 protein in the Parkinsonian brain was not folded correctly, a similar characteristic to alpha synuclein. A protein must fold properly to be able to do it’s assigned jobs. By not folding into the correct configuration, the SOD1 protein could not do it’s various functions – and the investigators observed a 66% reduction in SOD1 specific activity in the SNc of the Parkinson’s disease brains.

Interestingly, when the researchers looked at the SNc and LC of brains from people with ALS, they identified SOD1 aggregates matching the SOD1 clusters they had seen in these regions of the Parkinson’s disease brain.

Is this the first time SOD1 has been associated with Parkinson’s disease?

No, but it is the first major analysis of postmortem Parkinsonian brains. SOD1 protein in Lewy bodies has been reported before:

1995

Title: Cu/Zn superoxide dismutase-like immunoreactivity is present in Lewy bodies from Parkinson disease: a light and electron microscopic immunocytochemical study
Authors: Nishiyama K, Murayama S, Shimizu J, Ohya Y, Kwak S, Asayama K, Kanazawa I.
Journal: Acta Neuropathol. 1995;89(6):471-4.
PMID: 7676802

The investigators behind this study reported SOD1 protein was present in Lewy bodies, in the substantia nigra and locus coeruleus of brains from five people with Parkinson’s disease. Interestingly, they showed that SOD1 is present in the periphery of the Lewy body, similar to alpha synuclein. Both of these protein are present on the outside of the Lewy body, as opposed to another Parkinson’s associated protein, Ubiquitin, which is mainly present in the centre (or the core) of Lewy bodies (see image below).

Lewy-bodies

A more recent study also demonstrated SOD1 protein in the Parkinsonian brain, including direct interaction between SOD1 and alpha synuclein:

Alspha

Title: α-synuclein interacts with SOD1 and promotes its oligomerization
Authors: Helferich AM, Ruf WP, Grozdanov V, Freischmidt A, Feiler MS, Zondler L, Ludolph AC, McLean PJ, Weishaupt JH, Danzer KM.
Journal: Mol Neurodegener. 2015 Dec 8;10:66.
PMID: 26643113              (This article is OPEN ACCESS if you would like to read it)

These researchers found that alpha synuclein and SOD1 interact directly, and they noted that Parkinson’s disease related mutations in alpha synuclein (A30P, A53T) and ALS associated mutation in SOD1 (G85R, G93A) modify the binding of the two proteins to each other. They also reported that alpha synuclein accelerates SOD1 aggregation in cell culture. This same group of researchers published another research report last year in which they noted that aggregated alpha synuclein increases SOD1 clustering in a mouse model of ALS (Click here for more on this).

We should add that alpha synuclein aggregations in ALS are actually quite common (click here and here to read more on this).

Are there any genetic mutations in the SOD1 gene that are associated with Parkinson’s disease?

Two studies have addressed this question:

genes

Title: Sequence of the superoxide dismutase 1 (SOD 1) gene in familial Parkinson’s disease.
Authors: Bandmann O, Davis MB, Marsden CD, Harding AE.
Journal: J Neurol Neurosurg Psychiatry. 1995 Jul;59(1):90-1.
PMID: 7608718                   (This article is OPEN ACCESS if you would like to read it)

And then in 2001, a second analysis:

Genes2

Title: Genetic polymorphisms of superoxide dismutase in Parkinson’s disease.
Authors: Farin FM, Hitosis Y, Hallagan SE, Kushleika J, Woods JS, Janssen PS, Smith-Weller T, Franklin GM, Swanson PD, Checkoway H.
Journal: Mov Disord. 2001 Jul;16(4):705-7.
PMID: 11481695

Both studies found no genetic variations in the SOD1 gene that were more frequent in the Parkinson’s affected community than the general population. So, no, there are no SOD1 genetic mutations that are associated with Parkinson’s disease.

Are there any treatments targeting SOD1 that could be tested in Parkinson’s disease?

Great question. Yes there are. And they have already been tested in models of PD:

als

Title: The hypoxia imaging agent CuII(atsm) is neuroprotective and improves motor and cognitive functions in multiple animal models of Parkinson’s disease.
Authors: Hung LW, Villemagne VL, Cheng L, Sherratt NA, Ayton S, White AR, Crouch PJ, Lim S, Leong SL, Wilkins S, George J, Roberts BR, Pham CL, Liu X, Chiu FC, Shackleford DM, Powell AK, Masters CL, Bush AI, O’Keefe G, Culvenor JG, Cappai R, Cherny RA, Donnelly PS, Hill AF, Finkelstein DI, Barnham KJ.
Title: J Exp Med. 2012 Apr 9;209(4):837-54.
PMID: 22473957               (This article is OPEN ACCESS if you would like to read it)

CuII(atsm) is a drug that is currently under clinical investigation as a brain imaging agent for detecting hypoxia (damage caused by lack of oxygen – Click here to read more about this).

The researchers conducting this study, however, were interested in this compound for other reasons: CuII(atsm) is also a highly effective scavenger of a chemical called ONOO, which can be very toxic. CuII(atsm) not only inhibits this toxicity, but it also blocks the clustering of alpha synuclein. And given that CuII(atsm) is capable of crossing the blood–brain barrier, these investigators wanted to assess the drug for its ability to rescue model of Parkinson’s disease.

And guess what? It did!

And not just in one model of Parkinson’s disease, but FOUR!

The investigators even waited three days after giving the neurotoxins to the mice before giving the CuII(atsm) drug, and it still demonstrated neuroprotection. It also improved the behavioural features of these models of Parkinson’s disease.

Is CuII(atsm) being tested for anything else in Clinical trials?

Yes, there is a clinical trial ongoing for ALS in Australia.

The Phase I study, being run by Collaborative Medicinal Development Pty Limited, is a dose escalating study of Cu(II)ATSM to determine if this drug is safe for use in ALS (Click here for more on this study).

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Cu(II)ATSM is an orally administered drug that inhibits the activity of misfolded SOD1 protein. It has been shown to paradoxically increase mutant SOD1 protein in a mouse model of ALS, but it also provides neuroprotection and improves the outcome for these mice (Click here to read more on this).

If this trial is successful, it would be interesting to test this drug on a cohort of people with Parkinson’s disease. Determining which subgroup of the Parkinson’s affected community would most benefit from this treatment is still to be determined. There is some evidence published last year that suggests people with genetic mutations in the Parkinson’s associated gene PARK2 could benefit from the approach (Click here to read more on this). More research, however, is needed in this area.

So what does it all mean?

Right, so summing up, a group of Australian researchers have reported that the ALS associated protein SOD1 is closely associated with the cell death that we observe in the brains of people with Parkinson’s disease.

They suggest that this could highlight a common mechanisms of toxic SOD1 aggregation in both Parkinson’s disease and ALS. Individuals within the Parkinson’s affected community do not appear to have any genetic mutations in the SOD1 gene, which makes this finding is very interesting.

What remains to be determined is whether SOD1 aggregation is a “primary pathological event”, or if it is secondary to some other disease causing agent. We are also waiting to see if a clinical trial targeting SOD1 in ALS is successful. If it is, there may be good reasons for targeting SOD1 as a novel treatment for Parkinson’s disease.


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The Antibiotic and Parkinson’s: Oppsy, they got doxy!

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The general population are wrong to look up to scientists as the holders of the keys to some kind of secret knowledge that allows them to render magic on a semi-irregular basis.

All too often, the great discoveries are made by accident.

A while back, some researchers from Germany and Brazil made an interesting discovery that could have important implications for Parkinson’s disease. But they only made this discovery because their mice were feed the wrong food.

Today we’ll review their research and discuss what it could mean for Parkinson’s disease.


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Sir Alexander Fleming. Source: Biography

Sir Alexander Fleming is credited with discovering the antibiotic properties of penicillin.

But, as it is often pointed out, that the discovery was a purely chance event – an accident, if you like.

After returning from a two week holiday, Sir Fleming noticed that many of his culture dishes were contaminated with fungus, because he had not stored them properly before leaving. One mould in particular caught his attention, however, as it was growing on a culture plate with the bacteria staphylococcus. Upon closer examination, Fleming noticed that the contaminating fungus prevented the growth of staphylococci.

In an article that Fleming subsequently published in the British Journal of Experimental Pathology in 1929, he wrote, “The staphylococcus colonies became transparent and were obviously undergoing lysis … the broth in which the mould had been grown at room temperature for one to two weeks had acquired marked inhibitory, bactericidal and bacteriolytic properties to many of the more common pathogenic bacteria.”

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Penicillin in a culture dish of staphylococci. Source: NCBI

Fleming isolated the organism responsible for prohibiting the growth of the staphylococcus, and identified it as being from the penicillium genus.

He named it penicillin and the rest is history.

Fleming himself appreciated the serendipity of the finding:

“When I woke up just after dawn on Sept. 28, 1928, I certainly didn’t plan to revolutionise all medicine by discovering the world’s first antibiotic, or bacteria killer. But I guess that was exactly what I did.” (Source)

And this gave rise to his famous quote:

“One sometimes finds what one is not looking for” (Source)

While Fleming’s discovery of the antibiotic properties of penicillin was made as he was working on a completely different research problem, the important thing to note is that the discovery was made because the evidence came to prepared mind.

Louis-Pasteur-Quotes-1

Pasteur knew the importance of a prepared mind. Source: Thequotes

And this is the purpose of all the training in scientific research – not acquiring ‘the keys to some secret knowledge’, but preparing the investigator to notice the curious deviation.

That’s all really interesting. But what does any of this have to do with Parkinson’s disease?

Three things:

  1. Serendipity
  2. Prepared minds
  3. Antibiotics.

Huh?

Five years ago, a group of Brazilian and German Parkinson’s disease researchers made a serendipitous discovery:

While modelling Parkinson’s disease in some mice, they noticed that only two of the 40 mice that were given a neurotoxic chemical (6-OHDA) developed the motor features of Parkinson’s disease, while the rest remained healthy. This result left them scratching their heads and trying to determine what had gone wrong.

Then it clicked:

“A lab technician realised the mice had mistakenly been fed chow containing doxycycline, so we decided to investigate the hypothesis that it might have protected the neurons.” (from the press release).

The researchers had noted the ‘curious deviation’ and decided to investigate it further.

They repeated the experiment, but this time they added another group of animals which were given doxycycline in low doses (via injection) and fed on normal food (not containing the doxycycline).

And guess what: both group demonstrated neuroprotection!

Hang on a second. Two questions: 1. What exactly is 6-OHDA?
6-hydroxydopamine (or 6-OHDA) is one of several chemicals that researchers use to cause dopamine cells to die in an effort to model the cell death seen in Parkinson’s disease. It shares many structural similarities with the chemical dopamine (which is so severely affected in the Parkinson’s disease brain), and as such it is readily absorbed by dopamine cells who unwittingly assume that they are re-absorbing excess dopamine.

Once inside the cell, 6-OHDA rapidly transforms (via oxidisation) into hydrogen peroxide (H2O2 – the stuff folk bleach their hair with) and para-quinone (AKA 1,4-Benzoquinone). Neither of which the dopamine neurons like very much. Hydrogen peroxide in particular quickly causes massive levels of ‘oxidative stress’, resulting in the cell dying.
6OHDA

Transformation of the neurotoxin 6-OHDA. Source: NCBI

Think of 6-OHDA as a trojan horse, being absorbed by the cell because it looks like dopamine, only for the cell to work out (too late) that it’s not.

Ok, and question 2. What is doxycycline?

Doxycycline is an antibiotic that is used in the treatment of a number of types of infections caused by bacteria.

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Remind me again, what is an antibiotic?

Antibiotics are a class of drugs that either kill or inhibit the growth of bacteria. They function in one of several ways, either blocking the production of bacterial proteins, inhibiting the replication of bacterial DNA (nuclei acid in the image below), or by rupturing/inhibiting the repair of the bacteria’s outer membrane/wall.

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The ways antibiotics function. Source: FastBleep

So the researchers accidentally discovered that the a bacteria-killing drug called doxycycline prevented a trojan horse called 6-OHDA from killing dopamine cells?

Basically, yeah.

And then these prepared minds followed up this serendipitous discovery with a series of experiments to investigate the phenomenon further, and they published the results recently in the journal ‘Glial’:

Glial

Title: Doxycycline restrains glia and confers neuroprotection in a 6-OHDA Parkinson model.
Authors: Lazzarini M, Martin S, Mitkovski M, Vozari RR, Stühmer W, Bel ED.
Journal: Glia. 2013 Jul;61(7):1084-100. doi: 10.1002/glia.22496. Epub 2013 Apr 17.
PMID: 23595698

In the report of their research, the investigators noted that doxycycline significantly protected the dopamine neurons and their nerve branches (called axons) in the striatum – an area of the brain where dopamine is released – when 6-OHDA was given to mice. Both oral administration and peripheral injections of doxycycline were able to have this effect.

They also reported that doxycycline inhibited the activation of astrocytes and microglial cells in the brains of the 6-OHDA treated mice. Astrocytes and microglial cells are usually the helper cells in the brain, but in the context of disease or injury these cells can quickly take on the role of judge and executioner – no longer supporting the neurons, but encouraging them to die. The researchers found that doxycycline reduced the activity of the astrocytes and microglial cells in this alternative role, allowing the dopamine cells to recuperate and survive.

The researchers concluded that the “neuroprotective effect of doxycycline may be useful in preventing or slowing the progression of Parkinson’s disease”.

Wow, was this the first time this neuroprotective effect of doxycycline has been observed?

Curiously, No.

We have known of doxycycline’s neuroprotective effects in different models of brain injury since the 1990s (Click here, here and here for more on this). In fact, in their research report, the German and Brazilian researchers kindly presented a table of all the previous neuroprotective research involving doxycycline:

table1

And there was so much of it that the table carried on to a second page:

Table2

Source: Glia

And as you can see from the table, the majority of these reports found that doxycycline treatment had positive neuroprotective effects.

Is doxycycline the only antibiotic that exhibits neuroprotective properties?

No.

Doxycycline belongs to a family of antibiotics called ‘tetracyclines‘ (named for their four (“tetra-“) hydrocarbon rings (“-cycl-“) derivation (“-ine”)), and other members of this family have also been shown to display neuroprotection in models of Parkinson’s disease:

MPTP

Title: Minocycline prevents nigrostriatal dopaminergic neurodegeneration in the MPTP model ofParkinson’s disease.
Authors: Du Y, Ma Z, Lin S, Dodel RC, Gao F, Bales KR, Triarhou LC, Chernet E, Perry KW, Nelson DL, Luecke S, Phebus LA, Bymaster FP, Paul SM.
Journal: Proc Natl Acad Sci U S A. 2001 Dec 4;98(25):14669-74.
PMID: 11724929                    (This article is OPEN ACCESS if you would like to read it)

In this study, the researchers treated mice with an antibiotic called minocycline and it protected dopamine cells from the damaging effects of a toxic chemical called MPTP (or 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine). MPTP is also used in models of Parkinson’s disease, as it specifically affects the dopamine cells, while leaving other cells unaffected.

The researchers found that the neuroprotective effect of minocycline is associated a reduction in the activity of proteins that initiate cell death (for example, Caspace 1). This left the investigators concluding that ‘tetracyclines may be effective in preventing or slowing the progression of Parkinson’s disease’.

Importantly, this result was quickly followed by two other research papers with very similar results (Click here and here to read more about this). Thus, it would appear that some members of the tetracycline class of antibiotics share some neuroprotective properties.

So what did the Brazilian and German researchers do next with doxycycline?

They continued to investigate the neuroprotective effect of doxycycline in different models of Parkinson’s disease. They also got some Argentinians and Frenchies involved in the studies. And these lines of research led to their recent research report in the journal Scientific Reports:

Doxy1
Title: Repurposing doxycycline for synucleinopathies: remodelling of α-synuclein oligomers towards non-toxic parallel beta-sheet structured species.
Authors: González-Lizárraga F, Socías SB, Ávila CL, Torres-Bugeau CM, Barbosa LR, Binolfi A, Sepúlveda-Díaz JE, Del-Bel E, Fernandez CO, Papy-Garcia D, Itri R, Raisman-Vozari R, Chehín RN.
Journal: Sci Rep. 2017 Feb 3;7:41755.
PMID: 28155912                (This article is OPEN ACCESS if you would like to read it)

In this study, the researchers wanted to test doxycycline in a more disease-relevant model of Parkinson’s disease. 6-OHDA is great for screening and testing neuroprotective drugs. But given that 6-OHDA is not involved with the underlying pathology of Parkinson’s disease, it does not provide a great measure of how well a drug will do against the disease itself. So, the researchers turned their attention to our old friend, alpha synuclein – the protein which forms the clusters of protein (called Lewy bodies) in the Parkinsonian brain.

What the researchers found was fascinating: Doxycycline was able to inhibit the disease related clustering of alpha synuclein. In fact, by reshaping alpha synuclein into a less toxic version of the protein, doxycycline was able to enhance cell survival. The investigators also conducted a ‘dosing’ experiment to determine the most effect dose and they found that taking doxycycline in sub-antibiotic doses (20–40 mg/day) would be enough to exert neuroprotection. They concluded their study by suggesting that these novel effects of doxycycline could be exploited in Parkinson’s disease by “repurposing an old safe drug”.

Wow, has doxycycline ever been used in clinical trials for brain-related conditions before?

Yes.

From 2005-12,there was a clinical study to determine the safety and efficacy of doxycycline (in combination with Interferon-B-1a) in treating Multiple Sclerosis (Click here for more on this trial). The results of that study were positive and can be found here.

More importantly, the other antibiotic to demonstrate neuroprotection in models of Parkinson’s disease, minocycline (which we mentioned above), has been clinically tested in Parkinson’s disease:

title1

Title: A pilot clinical trial of creatine and minocycline in early Parkinson disease: 18-month results.
Authors: NINDS NET-PD Investigators..
Journal: Clin Neuropharmacol. 2008 May-Jun;31(3):141-50.
PMID: 18520981                (This article is OPEN ACCESS if you would like to read it)

This research report was the follow up of a 12 month clinical study that can be found by clicking here. The researchers had taken two hundred subjects with Parkinson’s disease and randomly sorted them into the three groups: creatine (an over-the-counter nutritional supplement), minocycline, and placebo (control). All of the participants were diagnosed less than 5 years before the start of the study. At 12 months, both creatine and minocycline were noted as not interfering with the beneficial effects of symptomatic therapy (such as L-dopa), but a worrying trend began with subjects dropping out of the minocycline arm of the study.

At the 18 month time point, approximately 61% creatine-treated subjects had begun to take additional treatments (such as L-dopa) for their symptoms, compared with 62% of the minocycline-treated subjects and 60% placebo-treated subjects. This result suggested that there was no beneficial effect from using either creatine or minocycline in the treatment of Parkinson’s disease, as neither exhibited any greater effect than the placebo. In addition, the investigators suggested that the decreased tolerability of minocycline was a concern.

Ok, so where do I sign up for the next doxy clinical trial?

Well, the researchers behind the Scientific reports research (discussed above) are hoping to begin planning clinical trials soon.

But theoretically speaking, there shouldn’t be a trial.

Huh?!?

There’s a good reason why not.

In fact, if you look at the comments section under the research article, a cautionary message has been left by Prof Paul M. Tulkens of the Louvain Drug Research Institute in Belgium. He points out that:

“…using antibiotics at sub-therapeutic doses is the best way to trigger the emergence of resistance (supported by many in vitro and in vivo studies). Using an antibiotic for other indications than an infection caused by a susceptible bacteria is something that should be discouraged”

And he is correct.

We recklessly over use antibiotics all over the world at the moment and they are one of the few lines of defence that we have against the bacterial world. Long term use (which Parkinson’s disease would probably require) of an antibiotic at sub-therapeutic levels will only encourage the rise of antibiotic resistant bacteria (possibly within individuals).

The resistance of bacteria to antibiotics can occur spontaneously via several means (for example, through random genetic mutations during cell division). With the right mutation (inferring antibiotic resistance), an individual bacteria would then have a natural advantage over their friends and it would survive our attempts to kill it with antibiotics. Being resistant to antibiotic would leave that bacteria to wreak havoc upon us.

Its the purest form of natural selection.

natural-selection_140211

How bacteria become resistant to antibiotics. Source: Reactgroup

And antibiotic resistant bacteria are fast becoming a major health issue for us, with the number of species of bacteria developing resistance increasing every year (Click here for a good review on factors contributing to the emergence of resistance, and click here for a review of the antibiotic resistant bacteria ‘crisis’).

But don’t be upset on the Parkinson’s disease side of things. Prof Tulken adds that:

“If doxycycline really acts as the authors propose, the molecular targets are probably very different from those causing antibacterial activity. it should therefore be possible to dissociate these effect from the antibacterial effects and to get active compounds devoid of antibacterial activity This is where research must go to rather than in trying to use doxycycline itself.”

And he is correct again.

Rather than tempting disaster, we need to take the more prudent approach.

Independent researchers must now attempt to replicate the neuroprotective results in carefully controlled conditions. At the same time, chemists should conduct an analysis of the structure of doxycycline to determine which parts of it are having this neuroprotective effect.

Doxycycline_structure.svg

The structure of doxycycline. Source: Wikipedia

If researchers can isolate those neuroprotective elements and those same parts are separate from the antibiotic properties, then we may well have another experimental drug for treating Parkinson’s disease.

And the good news is that researchers are already reasonably sure that the mechanisms of the neuroprotective effect of doxycycline are distinct from its antimicrobial action.

So what does it all mean?

Researchers have once again identified an old drug that can perform a new trick.

The bacteria killing antibiotic, doxycycline, has a long history of providing neuroprotection in models of brain disease, but recently researchers have demonstrated that doxycycline may have beneficial effects on particular aspects of Parkinson’s disease.

Given that doxycycline is an antibiotic, we must be cautious in our use of it. It will be interesting to determine which components of doxycycline are neuroprotective, and whether other antibiotics share these components. Given the number of researchers now working in this area, it should not take too long.

We’ll let you know when we hear something.


EDITOR’S NOTE: Under absolutely no circumstances should anyone reading this material consider it medical advice. The material provided here is for educational purposes only. Before considering or attempting any change in your treatment regime, PLEASE consult with your doctor or neurologist. While some of the drugs discussed on this website are clinically available, they may have serious side effects. We therefore urge caution and professional consultation before any attempt to alter a treatment regime. SoPD can not be held responsible for any actions taken based on the information provided here. 


The banner for today’s post was sourced from Youtube

On astrocytes and neurons – reprogramming for Parkinson’s

NG2+-flare

Last week scientists in Sweden published research demonstrating a method by which the supportive cells of the brain (called astrocytes) can be re-programmed into dopamine neurons… in the brain of a live animal!

It was a really impressive trick and it could have major implications for Parkinson’s disease.

In today’s post is a long read, but in it we will review the research leading up to the study, explain the science behind the impressive feat, and discuss where things go from here.


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Different types of cells in the body. Source: Dreamstime

In your body at this present moment in time, there is approximately 40 trillion cells (Source).

The vast majority of those cells have developed into mature types of cell and they are undertaking very specific functions. Muscle cells, heart cells, brain cells – all working together in order to keep you vertical and ticking.

Now, once upon a time we believed that the maturation (or the more technical term: differentiation) of a cell was a one-way street. That is to say, once a cell became what it was destined to become, there was no going back. This was biological dogma.

Then a guy in Japan did something rather amazing.

Who is he and what did he do?

This is Prof Shinya Yamanaka:

yamanaka-s

Prof Shinya Yamanaka. Source: Glastone Institute

He’s a rockstar in the scientific research community.

Prof Yamanaka is the director of Center for induced Pluripotent Stem Cell Research and Application (CiRA); and a professor at the Institute for Frontier Medical Sciences at Kyoto University.

But more importantly, in 2006 he published a research report demonstrating how someone could take a skin cell and re-program it so that was now a stem cell – capable of becoming any kind of cell in the body.

Here’s the study:

IPS2

Title: Induction of pluripotent stem cells from mouse embryonic and adult fibroblast cultures by defined factors.
Authors: Takahashi K, Yamanaka S.
Journal: Cell. 2006 Aug 25;126(4):663-76.
PMID: 16904174                (This article is OPEN ACCESS if you would like to read it)

Shinya Yamanaka‘s team started with the hypothesis that genes which are important to the maintenance of embryonic stem cells (the cells that give rise to all cells in the body) might also be able to cause an embryonic state in mature adult cells. They selected twenty-four genes that had been previously identified as important in embryonic stem cells to test this idea. They used re-engineered retroviruses to deliver these genes to mouse skin cells. The retroviruses were emptied of all their disease causing properties, and could thus function as very efficient biological delivery systems.

The skin cells were engineered so that only cells in which reactivation of the embryonic stem cells-associated gene, Fbx15, would survive the testing process. If Fbx15 was not turned on in the cells, they would die. When the researchers infected the cells with all twenty-four embryonic stem cells genes, remarkably some of the cells survived and began to divide like stem cells.

In order to identify the genes necessary for the reprogramming, the researchers began removing one gene at a time from the pool of twenty-four. Through this process, they were able to narrow down the most effective genes to just four: Oct4, Sox2, cMyc, and Klf4, which became known as the Yamanaka factors.

This new type of cell is called an induced pluripotent stem (IPS) cell – ‘pluripotent’ meaning capable of any fate.

The discovery of IPS cells turned biological dogma on it’s head.

And in acknowledgement of this amazing bit of research, in 2012 Prof Yamanaka and Prof John Gurdon (University of Cambridge) were awarded the Nobel prize for Physiology and Medicine for the discovery that mature cells can be converted back to stem cells.

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Prof Yamanaka and Prof Gurdon. Source: UCSF

Prof Gurdon achieved the feat in 1962 when he removed the nucleus of a fertilised frog egg cell and replaced it with the nucleus of a cell taken from a tadpole’s intestine. The modified egg cell then grew into an adult frog! This fascinating research proved that the mature cell still contained the genetic information needed to form all types of cells.

EDITOR’S NOTE: We do not want to be accused of taking anything away from Prof Gurdon’s contribution to this field (which was great!) by not mentioning his efforts here. For the sake of saving time and space, we are focusing on Prof Yamanaka’s research as it is more directly related to today’s post.

 

ips-cells

Making IPS cells. Source: learn.genetics

This amazing discovery has opened new doors for biological research and provided us with incredible opportunities for therapeutic treatments. For example, we can now take skins cells from a person with Parkinson’s disease and turn those cells into dopamine neurons which can then be tested with various drugs to see which treatment is most effective for that particular person (personalised medicine in it’s purest form).

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Some of the option available to Parkinson’s disease. Source: Nature

Imagination is literally the only limiting factor with regards to the possible uses of IPS cell technology.

Shortly after Yamanaka’s research was published in 2006, however, the question was asked ‘rather than going back to a primitive state, can we simply change the fate of a mature cell directly?’ For example, turn a skin cell into a neuron.

This question was raised mainly to address the issue of ‘age’ in the modelling disease using IPS cells. Researchers questioned whether an aged mature cell reprogrammed into an immature IPS cell still carried the characteristics of an aged cell (and can be used to model diseases of the aged), or would we have to wait for the new cell to age before we can run experiments on it. Skin biopsies taken from aged people with neurodegenerative conditions may lose the ‘age’ element of the cell and thus an important part of the personalised medicine concept would be lost.

So researchers began trying to ‘re-program’ mature cells. Taking a skin cell and turning it directly into a heart cell or a brain cell.

And this is probably the craziest part of this whole post because they actually did it! 

figure 1

Different methods of inducing skin cells to become something else. Source: Neuron

In 2010, scientists from Stanford University published this report:

Nature2

Title: Direct conversion of fibroblasts to functional neurons by defined factors
Authors: Vierbuchen T, Ostermeier A, Pang ZP, Kokubu Y, Südhof TC, Wernig M.
Journal: Nature. 2010 Feb 25;463(7284):1035-41.
PMID: 20107439

In this study, the researchers demonstrated that the activation of three genes (Ascl1, Brn2 and Myt1l) was sufficient to rapidly and efficiently convert skin cells into functional neurons in cell culture. They called them ‘iN’ cells’ or induced neuron cells. The ‘re-programmed’ skin cells made neurons that produced many neuron-specific proteins, generated action potentials (the electrical signal that transmits a signal across a neuron), and formed functional connection (or synapses) with neighbouring cells. It was a pretty impressive achievement, which they beat one year later by converting mature liver cells into neurons – Click here to read more on this – Wow!

The next step – with regards to our Parkinson’s-related interests – was to convert skin cells directly into dopamine neurons (the cells most severely affected in the condition).

And guess what:

PSNA

Title: Direct conversion of human fibroblasts to dopaminergic neurons.
Authors: Pfisterer U, Kirkeby A, Torper O, Wood J, Nelander J, Dufour A, Björklund A, Lindvall O, Jakobsson J, Parmar M
Journal:  Proc Natl Acad Sci U S A (2011) 108:10343-10348.
PMID: 21646515          (This article is OPEN ACCESS if you would like to read it)

In this study, Swedish researchers confirmed that activation of Ascl1, Brn2, and Myt1l re-programmed human skin cells directly into functional neurons. But then if they added the activation of two additional genes, Lmx1a andFoxA2 (which are both involved in dopamine neuron generation), they could convert skin cells directly into dopamine neurons. And those dopamine neurons displayed all of the correct features of normal dopamine neurons.

With the publication of this research, it suddenly seemed like anything was possible and people began make all kinds of cell types out of skin cells. For a good review on making neurons out of skin cells – Click here.

Given that all of this was possible in a cell culture dish, some researchers started wondering if direct reprogramming was possible in the body. So they tried.

And again, guess what:

Nature1

Title: In vivo reprogramming of adult pancreatic exocrine cells to beta-cells.
Authors: Zhou Q, Brown J, Kanarek A, Rajagopal J, Melton DA.
Journal: Nature. 2008 Oct 2;455(7213):627-32.
PMID: 18754011

Using the activation of three genes (Ngn3, Pdx1 and Mafa), the investigators behind this study re-programmed differentiated pancreatic exocrine cells in adult mice into cells that closely resemble b-cells. And all of this occurred inside the animals, while the animals were wandering around & doing their thing!

Now naturally, researchers in the Parkinson’s disease community began wondering if this could also be achieved in the brain, with dopamine neurons being produced from re-programmed cells.

And (yet again) guess what:

in-vivo

Title: Generation of induced neurons via direct conversion in vivo
Authors: Torper O, Pfisterer U, Wolf DA, Pereira M, Lau S, Jakobsson J, Björklund A, Grealish S, Parmar M.
Journal: Proc Natl Acad Sci U S A. 2013 Apr 23;110(17):7038-43.
PMID: 23530235         (This article is OPEN ACCESS if you would like to read it)

In this study, the Swedish scientists (behind the previous direct re-programming of skin cells into dopamine neurons) wanted to determine if they could re-program cells inside the brain. Firstly, they engineered skin cells with the three genes (Ascl1, Brn2a, & Myt1l) under the control of a special chemical – only in the presence of the chemical, the genes would be activated. They next transplanted these skin cells into the brains of mice and began adding the chemical to the drinking water of the mice. At 1 & 3 months after transplantation, the investigators found re-programmed cells inside the brains of the mice.

Next, the researchers improved on their recipe for producing dopamine neurons by adding the activation of two further genes: Otx2 and Lmx1b (also important in the development of dopamine neurons). So they were now activating a lot of genes: Ascl1, Brn2a, Myt1l, Lmx1a, FoxA2, Otx2 and Lmx1b. Unfortunately, when these reprogrammed cells were transplanted into the brain, few of them survived to become mature dopamine neurons.

The investigators then ask themselves ‘do we really need to transplant cells? Can’t we just reprogram cells inside the brain?’ And this is exactly what they did! They injected the viruses that allow for reprogramming directly into the brains of mice. The experiment was designed so that the cargo of the viruses would only become active in the astrocyte cells, not neurons. And when the researchers looked in the brains of these mice 6 weeks later, they found numerous re-programmed neurons, indicating that direct reprogramming is possible in the intact brain.

So what was so special about the research published last week about? Why the media hype?

The research published last week, by another Swedish group, took this whole process one step further: Not only did they re-program astrocytes in the brain to become dopamine neurons, but they also did this on a large enough scale to correct the motor issues in a mouse model of Parkinson’s disease.

Here is the study:
Arenas

Title: Induction of functional dopamine neurons from human astrocytes in vitro and mouse astrocytes in a Parkinson’s disease model
Authors: di Val Cervo PR, Romanov RA, Spigolon G, Masini D, Martín-Montañez E, Toledo EM, La Manno G, Feyder M, Pifl C, Ng YH, Sánchez SP, Linnarsson S, Wernig M, Harkany T, Fisone G, Arenas E.
Journal: Nature Biotechnology (2017) doi:10.1038/nbt.3835
PMID: 28398344

These researchers began this project 6 years ago with a new cocktail of genes for reprogramming cells to become dopamine neurons. They used the activation of NEUROD1, ASCL1 and LMX1A, and a microRNA miR218 (microRNAs are genes that produce RNA, but not protein – click here for more on this). These genes improved the reprogramming efficiency of human astrocytes to 16% (that is the percentage of astrocytes that were infected with the viruses and went on to became dopamine neurons). The researchers then added some chemicals to the reprogramming process that helps dopamine neurons to develop in normal conditions, and they observed an increase in the level of reprogramming to approx. 30%. And these reprogrammed cells display many of the correct properties of dopamine neurons.

Next the investigators decided to try this conversion inside the brains of mice that had Parkinson’s disease modelled in them (using a neurotoxin). The delivery of the viruses into the brains of these mice resulted in reprogrammed dopamine neurons beginning to appear, and 13 weeks after the viruses were delivered, the researchers observed improvements in the Parkinson’s disease related motor symptoms of the mice. The scientists concluded that with further optimisation, this reprogramming approach may enable clinical therapies for Parkinson’s disease, by the delivery of genes rather than transplanted cells.

How does this reprogramming work?

As we have indicated above, the re-programming utilises re-engineered viruses. They have been emptied of their disease causing elements, allowing us to use them as very efficient biological delivery systems. Importantly, retroviruses infect dividing cells and integrate their ‘cargo’ into the host cell’s DNA.

RetroviralIntegration

Retroviral infection and intergration into DNA. Source: Evolution-Biology

The ‘cargo’ in the case of IPS cells, is a copy of the genes that allow reprogramming (such as the Yamanaka genes), which the cell will then start to activate, resulting in the production of protein for those genes. These proteins subsequently go on to activate a variety of genes required for the maintenance of embryonic stem cells (and re-programming of mature cells).

And viruses were also used for the re-programming work in the brain as well.

There is the possibility that one day we will be able to do this without viruses – in 2013, researchers made IPS cells using a specific combination of chemicals (Click here to read more about this) – but at the moment, viruses are the most efficient biological targeting tool we have.

So what does it all mean?

Last week researchers is Sweden published research explaining how they reprogrammed some of the helper cells in the brains of Parkinsonian mice so that they turned into dopamine neurons and helped to alleviate the symptoms the mice were feeling.

This result and the trail of additional results outlined above may one day be looked back upon as the starting point for a whole new way of treating disease and injury to particular organs in the body. Suddenly we have the possibility of re-programming cells in our body to under take a new functions to help combat many of the conditions we suffer.

It is important to appreciate, however, that the application of this technology is still a long way from entering the clinic (a great deal of optimisation is required). But the fact that it is possible and that we can do it, raises hope of more powerful medical therapies for future generations.

As the researchers themselves admit, this technology is still a long way from the clinic. Improving the efficiency of the technique (both the infection of the cells and the reprogramming) will be required as we move down this new road. In addition, we will need to evaluate the long-term consequences of removing support cells (astrocytes) from the carefully balanced system that is the brain. Future innovations, however, may allow us to re-program stronger, more disease-resistant dopamine neurons which could correct the motor symptoms of Parkinson’s disease without being affected by the disease itself (as may be the case in transplanted cells – click here to read more about this).

Watch for a lot more research coming from this topic.


The banner for today’s post was sourced from Greg Dunn (we love his work!)

An Ambroxol update – active in the brain

Ambroxol-800x400

This week pre-clinical data was published demonstrating that the Ambroxol is active in the brain.

This is important data given that there is currently a clinical trial being conducted for Ambroxol in Parkinson’s disease.

Today’s post will review the new data and discuss what is happening regarding the clinical trial.


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Ambroxol. Source: Skinflint

We have previously discussed the potential use of Ambroxol in the treatment of Parkinson’s disease (Click here to read that post). Today we follow up that post with new data that provides further support for an on-going clinical trial.

Firstly, what is Ambroxol?

Ambroxol is a commonly used treatment for respiratory diseases (the respiratory system being the lungs and related components required for breathing). Ambroxol promotes the clearance of mucus and eases coughing. It also has anti-inflammatory properties, reducing redness in a sore throat. It is the active ingredient of products like Mucosolvan, Mucobrox, and Mucol.

 

What is the connection between Ambroxol and Parkinson’s disease?

So this is where a gene called GBA comes into the picture.

Genetic mutations in the GBA (full name: Glucosylceramidase Beta) gene are the most common genetic anomaly associated with Parkinson’s disease. People with a mutation in their GBA gene have a higher risk of developing Parkinson’s disease than the general population. And interestingly, people with Parkinson’s disease are approximately five times more likely to carry a GBA mutation than healthy control subjects.

What does GBA do?

The GBA gene provides the instructions for making an enzyme (called glucocerebrosidase) that helps with the digestion and recycling of waste inside cells. The enzyme is located and active inside ‘lysosomes‘.

What are Lysosomes?

Lysosomes are small bags of digestive enzymes that can be found inside cells. They help to break down proteins that have either been brought into the cell or that have served their function and need to be digested and disposed of (or recycled).

Lysosomes

How lysosomes work. Source: Prezi

Inside the lysosomes are enzymes like glucocerebrosidase which help to break material down into useful parts. The lysosome will fuse with other small bags (called vacuole) that act as storage vessels of material inside a cell. The enzymes from the lysosome will mix with the material in the vacuole and digest it (or it break down into more manageable components).

Now people with a genetic mutation in their GBA gene will often have an abnormally short, non-functioning version of the glucocerebrosidase enzyme. In those cases the breaking down of waste inside the lysosome becomes inhibited. And if waste can’t be disposed of or recycled properly, things start to go wrong in the cell.

How does Ambroxol correct this?

It was recently shown that Ambroxol triggers exocytosis of lysosomes (Source). Exocytosis is the process by which waste is exported out of the cell.

exocytosis

Exocytosis. Source: Socratic

Thus by encouraging lysosomes to undergo exocytosis and spit their contents out of the cell – digested or not – Ambroxol allows the cell to remove waste effectively and therefore function in a more normal fashion. This mechanism of treatment seemingly bi-passes the faulty glucocerebrosidase digestion enzyme entirely.

Until recently, two important questions, however, have remained unanswered:

  1. Does Ambroxol enter the brain and have this function there?
  2. What are the consequences of long term Ambroxol use?

We now have an answer for question no. 1:

Amb2

Title: Ambroxol effects in glucocerebrosidase and α-synuclein transgenic mice.
Authors: Migdalska-Richards A, Daly L, Bezard E, Schapira AH.
Journal: Ann Neurol. 2016 Nov;80(5):766-775.
PMID: 27859541            (This article is OPEN ACCESS if you would like to read it)

In this study, the researchers treated mice with Ambroxol for 12 days and then measured the level of glucocerebrosidase activity in the brain. They gave Ambroxol to three different groups of mice:

  • a group of normal mice,
  • a group of mice which had been genetically engineered with a specific mutation in their GBA gene (the heterozygous L444P mutation)
  • a group of mice that produced human alpha synuclein (the protein closely associated with Parkinson’s disease).

When they looked at the level of glucocerebrosidase enzyme activity in normal mice, they found an increase of approximately 20% (in mice treated with 4mM Ambroxol). One curious finding was that this dose was the only dose that increase glucocerebrosidase activity (1, 3, and 5mM of Ambroxol had no effect). The investigators noted, however, a reduction in water drinking of mice receiving 5mM in their drinking water (maybe they didn’t like the taste of it!), suggesting that they were not getting as much Ambroxol as the 4mM group.

The 4mM level of of Ambroxol also increased glucocerebrosidase activity in the L444P mutation mice and the alpha-synuclein mice (which interestingly also has reduced levels of glucocerebrosidase activity). One important observation in the alpha synuclein mice was the finding that Ambroxol was able to reduce the levels of alpha synuclein in the cells, indicating better clearance of un-wanted excess of proteins.

These combined results suggested to the investigators that Ambroxol is entering the brain of mice (passing through the protective blood brain barrier) and able to be effective there. In addition, they did not witness any serious adverse effects of ambroxol administration in the mice – an observation made in other studies of Ambroxol in normal mice (Click here to read more about this).

These studies have been followed up by a dosing study in primates which was just published:

Ambrox

Title: Oral ambroxol increases brain glucocerebrosidase activity in a nonhuman primate.
Authors: Migdalska-Richards A, Ko WK, Li Q, Bezard E, Schapira AH.
Journal: Synapse. 2017 Mar 12. doi: 10.1002/syn.21967.
PMID: 28295625            (This article is OPEN ACCESS if you would like to read it)

In this study, the investigators analysed the effect of Ambroxol treatment on glucocerebrosidase activity in three healthy non-human primates. One subject was given an ineffective control solution vehicle, another subject received 22.5 mg/day of Ambroxol and the third subject received 100 mg/day of Ambroxol. They showed that daily administration 100 mg/day of Ambroxol results in increased levels of glucocerebrosidase activity in the brain (approximately 20% increase on average across different areas of the brain). Importantly, the 22.5 mg treatment did not result in any increase.

The investigators wanted to determine if the effect of Ambroxol was specific to glucocerebrosidase, and so they analysed the activity of another lysosome enzyme called beta-hexosaminidase (HEXB). They found that 100 mg/day of Ambroxol also increased HEXB activity (again by approximately 20%), suggesting that Ambroxol may be having an effect on other lysosome enzymes and not just glucocerebrosidase.

The researches concluded that these results provide the first data of the effect of Ambroxol treatment on glucocerebrosidase activity in the brain of non-human primates. In addition, the results indicate that Ambroxol is active and as the researchers wrote “should be further investigated in the context of clinical trials as a potential treatment for Parkinson’s disease”.

And there is a clinical trial currently underway?

Yes indeed.

Funded by the Cure Parkinson’s Trust and the Van Andel Research Institute (USA), there is currently a phase I clinical trial with 20 people with Parkinson’s disease receiving Ambroxol over 24 months. Importantly, the participants being enrolled in the study have both Parkinson’s disease and a mutation in their GBA gene. The study is being led by Professor Anthony Schapira at the Royal Free Hospital (London).

EDITORS NOTE HERE: Readers may be interested to know that Prof Schapira is also involved with another clinical trial for GBA-associated Parkinson’s disease. The work is being conducted in collaboration with the biotech company Sanofi Genzyme, and involves a phase II trial, called MOVE-PD, which is testing the efficacy, and safety of a drug called GZ/SAR402671 (Click here to read more about this clinical trial). GZ/SAR402671 is a glucosylceramide synthase inhibitor, which will hopefully reduce the production and consequent accumulation of glycosphingolipids in people with a mutation in the GBA gene. This approach is trying to reduce the amount of protein that can not be broken down by the faulty glucocerebrosidase enzyme. The MOVE-PD study will enroll more than 200 patients worldwide (Click here and here to read more on this).

The current Phase 1 trial at the Royal Free Hospital will be primarily testing the safety of Ambroxol in GBA-associated Parkinson’s disease. The researchers will, however, be looking to see if Ambroxol can increase levels of glucocerebrosidase and also assess whether this has any beneficial effects on the Parkinson’s features.

So what does it all mean?

There is a major effort from many of the Parkinson’s disease related charitable groups to clinically test available medications for their ability to slow this condition. Big drug companies are not interested in this ‘re-purposing effort’ as many of these drugs are no longer patent protected and thus providing limited profit opportunities for them. This is one of the unfortunate realities of the pharmaceutical industry business model.

One of the most interesting drugs being tested in this re-purposing effort is the respiratory disease-associated treatment, Ambroxol. Recently new research has been published that indicates Ambroxol is able to enter the brain and have an impact by increasing the level of protein disposal activity.

A clinical trial testing Ambroxol in Parkinson’s disease is underway and we will be watching for the results when they are released (most likely late 2019/early 2020, though preliminary results may be released earlier).

This trial is worth watching.

Stay tuned.


EDITOR’S NOTE: Under absolutely no circumstances should anyone reading this material consider it medical advice. The material provided here is for educational purposes only. Before considering or attempting any change in your treatment regime, PLEASE consult with your doctor or neurologist. Amboxol is a commercially available medication, but it is not without side effects (for more on this, see this website). We urge caution and professional consultation before altering a treatment regime. SoPD can not be held responsible for any actions taken based on the information provided here. 


The banner for today’s post was sourced from Pharmacybook

Stimulating research in London (Canada)

Spinal-Cord-final

Recently the SoPD has been contacted by readers asking about this video:

http://london.ctvnews.ca/video?clipId=1080895

The video presents a news article from Canada describing a clinical study of spinal cord stimulation for Parkinson’s disease.

In today’s post we review what spinal cord stimulation is and what research has been done in Parkinson’s disease.


 

should-say-50th-birthday-speech_67e6879f1e6fbd7

50 years celebration. Source: Reference

As many readers will be aware from 2017 represents the 200 year anniversary of the first description of Parkinson’s disease by one Mr James Parkinson.

Many readers will not be aware, however, that 2017 is also represents the 50th anniversary of the first use of a technique called spinal cord stimulation:

What is spinal cord stimulation?

Anterior_thoracic_SCS

An x-ray of the spine with a stimulator implanted (towards the top of the image, and cords leading off to the bottom left). Source: Wikipedia

A spinal cord stimulator involves a small device being used to apply pulsed electrical signals to the spinal cord. It is generally used for pain relief, but it has recently been tested in a variety of other medical conditions.

The device is a column of stimulating electrodes that is surgically implanted in the epidural space of the spine. And before you ask: the epidural space is the area between the outer protective skin of the spinal cord (called the dura mater) and the surrounding vertebrae. So the device lies against the spinal cord, and is protected by the bones that make up the spine (as shown in the image below).

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The stimulating electrodes within the epidural space. Source: SpineOne

An electrical pulse generator is implanted in the lower abdomen and conducting wires are connected between the electrodes to the generator. Much like deep brain stimulation, the system is entirely enclosed in the body and operated with a remote control.

How does spinal cord stimulation work?

The stimulation basically interrupts the feeling of pain – blocking it from reaching the brain – substituting it with a more pleasing sensation called paresthesia (a kind of tingling or numbness).

PE-SCS Fig1

Source: MayoClinic

The stimulation does not eliminate the source of pain, it simply masks it by interfering with the signal going to the brain.  As a result the amount of relief from pain varies from person to person. In general, spinal cord stimulation resulting in a 50-70% reduction in pain.

But Parkinson’s results from inability to move, how would spinal cord stimulation work in Parkinson’s disease?

Yeah, this is a good question and the answer is not entirely clear, but the researchers (behind the research we discuss below) suggest that beneficial effects from spinal cord stimulation in Parkinson’s disease could be coming from direct activation of ascending pathways reaching thalamic nuclei and the cerebral cortex. That is to say (in plain English): activation of the spinal cord results in a signal going up into the brain where it alters the interaction between two of the regions involved in the initiation of movement (the thalamus and the cortex). And as we shall discuss below, there is evidence backing this idea.

Ok, so how much research has been done on spinal cord stimulation for Parkinson’s disease?

Actually quite a bit (in fact, for a good early review on the topic – click here).

The first real attempt at spinal cord stimulation for Parkinson’s disease was this report here:

Spinal1

Title: Spinal Cord Stimulation Restores Locomotion in Animal Models of Parkinson’s Disease
Authors: Fuentes, R., Petersson, P., Siesser, W. B., Caron, M. G., & Nicolelis, M. A. L.
Journal: Science (2009) 323(5921), 1578-1582.
PMID: 19299613                   (This article is OPEN ACCESS if you would like to read it)

It was conducted by Prof Miguel Nicolelis and his colleagues at Duke University. Duke were kind enough to make this short video about the research:

In their research report, the scientists injected mice with a drug that reduced the level of dopamine in the brain (the tyrosine hydroxylase inhibitor alpha-methyl-para-tyrosine  or AMPT). Similar to Parkinson’s disease, this resulted in a significant reduction in the movements of those mice. It also resulted in changes in the neuronal activity patterns of cells in an area of the brain called the motor cortex (we have talked about the motor cortex in a previous post). When the researchers then conducted spinal cord stimulation on these mice, they found that stimulation corrected both the loss of movement and the altered activity in the motor cortex.

The researchers then tested spinal cord stimulation in rats which had their dopamine system severely depleted (using the neurotoxin 6-OHDA), and they again found that the treatment could rescue the loss of locomotor ability. Curiously, spinal cord stimulation in the rats also caused an increase in locomotion activity after the stimulation period had stopped. On top of this, the researchers found that spinal cord stimulation aided the effect of L-dopa, allowing lower doses of L-dopa to achieve the same behavioural results as higher doses in animals not receiving spinal cord stimulation.

These initial results were then replicated in primates:

Monkey

Title: Spinal cord stimulation alleviates motor deficits in a primate model of Parkinson disease.
Authors: Santana MB, Halje P, Simplício H, Richter U, Freire MA, Petersson P, Fuentes R, Nicolelis MA.
Journal: Neuron. 2014 Nov 19;84(4):716-22.
PMID: 25447740              (This article is OPEN ACCESS if you would like to read it)

In this study, the researchers modelled Parkinson’s disease in five adult marmosets using the neurotoxin 6-OHDA, which resulted in a reduction in spontaneous behaviour and a significant loss of dopamine neurons in the brain. They then implanted a spinal cord stimulator in each of the animals, which once activated resulted in a 200% improvement in some aspects of behavioural activity. Improvements observed in Parkinson’s-like features included freezing (31%), hypokinesia (23%), posture (23%), and bradykinesia (21%) as calculated by investigators blind to the treatment conditions of each subject.

In the brain, the researchers found that spinal cord stimulation resulted in similar improvements in neural activity as that seen with L-dopa treatment. Given all of these results, the investigators concluded that spinal cord stimulation “should be further tested in clinical studies aimed at measuring its long-term efficacy as a less invasive, long-term therapy for” people with Parkinson’s disease.

And it was not just Prof Nicolelis’ group that has achieved these results. Japanese researchers have also reported spinal cord stimulation having beneficial effects in models of Parkinson’s disease:

NeuoroProtect

Title: Spinal cord stimulation exerts neuroprotective effects against experimental Parkinson’s disease.
Authors: Shinko A, Agari T, Kameda M, Yasuhara T, Kondo A, Tayra JT, Sato K, Sasaki T, Sasada S, Takeuchi H, Wakamori T, Borlongan CV, Date I.
Journal: PLoS One. 2014 Jul 10;9(7):e101468.
PMID: 25009993           (This article is OPEN ACCESS if you would like to read it)

In this report, the researchers actually found that spinal cord stimulation resulted in neuroprotection in a classical model of Parkinson’s disease (rodent 6-OHDA striatal delivery). Across three different levels of stimulation, the researchers reported better rescue of motor deficits and protection of dopamine neurons (particularly for 50Hz stimulation). The researchers also provided evidence suggesting that the neuroprotective effect might have something to do with a protein called Vascular endothelial growth factor (or VEGF). Interestingly, they found that the neuroprotective protein GDNF (that we have discussed before – click here for that post) was not involved.

So has this spinal stimulation procedure ever been conducted in humans with Parkinson’s disease before?

Yes, it has. But the results were a bit disappointing.

Stim1

Title: Spinal cord stimulation failed to relieve akinesia or restore locomotion in Parkinson disease.
Authors: Thevathasan W, Mazzone P, Jha A, Djamshidian A, Dileone M, Di Lazzaro V, Brown P.
Journal: Neurology. 2010 Apr 20;74(16):1325-7.
PMID: 20404313          (This article is OPEN ACCESS if you would like to read it)

In this very small clinical study, just two people (both 75+ years of age) with Parkinson’s disease were fitted with spinal cord stimulators. Ten days after the surgery, the subjects participated in a blind analysis of the motor effects of spinal stimulation (blind analysis meaning that the assessors were not aware of their surgical treatment). The assessors, however, found no improvements as a result of the stimulation treatment.

This report lead to a letter to the journal from Prof Nicolelis and his colleagues:

Neurol

In their letter, Prof Nicolelis and co point out several issues with the clinical study that may impact the final results (such as the tiny size of the study (only two participants) and the fact that the electrodes were located at a high cervical level, while in the rodent study they were located at a high thoracic level). In addition, the commercially available electrodes used in the human clinical study did not match the relative size or orientation of the electrodes used in the rodent study.

The researchers of the clinical study suggested that the beneficial motor effect described in the rodent study may be due to an increase in arousal (as a result of higher stimulation). But Prof Nicolelis and colleagues pointed out in their letter that their rodent study included three control experiments (including air puffs, trigeminal stimulation at the highest intensity tolerated by the animals, and direct measurements of changes in heart rate following spinal stimulation) which did not find a strong connection between arousal response and recovery seen in the level of locomotion.

The letter concluded that the results of the small clinical trial were inconclusive, and that further research in nonhuman primate models of Parkinson’s are required to determine the effects of electrode design and stimulation parameters. The doctors behind the clinical study agreed that more research is required.

And what do we know about this new clinical study?

Unfortunately, not very much.

The study is being conducted by Prof. Mandar Jog of Western University. Recently the Parkinson’s Society Southwestern Ontario provided some funding towards the study (Click here for more on this), but that is about as much as we could find on the work.

So what does it all mean?

Summing up: Spinal cord stimulation is a technique that is used to alleviate severe back pain. It has recently been proposed for Parkinson’s disease, resulting in several clinical trials. Here at the SoPD we are not sure what our opinion on spinal cord stimulation is at present, except that more research is obviously required.

If the results from the new clinical study (being conducted in Canada) indicate that spinal cord stimulation has beneficial effects for people with Parkinson’s disease, it would certainly represent a significant step forward for the community which relies heavily on symptom masking drugs at present. Before proceeding to wider clinical availability, however, larger clinical studies will be required to truly demonstrate safety and efficacy.

We’ll let you know if we hear anything else about this developing area of research.


The banner for today’s post was sourced from Greg Dunn

James: The man behind the disease (Part 1)

jamesp-signature

As part of Parkinson’s awareness month, and in observation of the 200 year anniversary of the first description of Parkinson’s disease, today we begin a four part set of posts looking at the man who made that first observation: James Parkinson.

Each week we will present various aspects about the man and his life.

Much of the material presented here has been replicated from our sister site Searching 4 James – a (much neglected) website celebrating the man and documenting the search for his likeness. To date, no portrait or image of the man has ever been found.

L0068467 The Villager's Friend and Physician

Source: Wellcome Images.

In her excellent book “James Parkinson, 1755-1824: From Apothecary to General Practitioner“, Shirley Roberts wrote that other sources have proposed that the man standing in the middle of the image above, talking to the villagers, is James Parkinson. The image appeared in James’ book ‘The Villager’s friend and physician’ (published in 1800), but (and I think you’ll agree) it does not give us much to work with.

Unfortunately Shirley Roberts made no reference to the sources of the proposal, but it is as close as we get to a likeness of the man, as he died before the first photographs were taken and there is no recorded painting of him.


Most people think of James Parkinson as a medical practitioner given his association with the disease that bears his name. But this singular association doesn’t really do the man credit. His contributions to medicine went well beyond the first description of ‘Parkinson’s disease’ – for example, James also gave the western world our first description of gout – a form of inflammatory arthritis that he and his father both suffered.

In addition, James was a ‘rockstar’ to the geological community, producing one of the most well regarded series of textbooks on the subject at the time. He was a political radical who wrote many pamphlets under the pseudonym “Old Hubert” and his associations with other radicals almost got him ‘transported’ (shipped out to the colonies). He was also a social reformist, calling for parliamentary reforms and universal suffrage. And his religious devotion made him a prominent figure within his church.

In short, he was a very interesting chap, who lived in (and had an impact on) interesting times.

THE WORLD OF JAMES

Before discussing the man himself, we must consider the world that James Parkinson was born into and the era he lived through. It provides us with the context within which we can fully appreciate the contributions that he made (including those beyond medicine).

James Parkinson was born on the 11th April 1755.

In the grand scale of things, the mid 1700’s was the peak of the little ice age, the middle of the age of enlightenment, and (critically) the start of the industrial revolution. The world was:

  • Pre USA (1776)
  • Pre French Revolution (1789)
  • Pre public electricity supply (1881)
  • Pre Napoleon (1769)
  • Pre Darwin (1809)

In London, King George II was on the English throne (soon to be replaced by George III), and Westminster bridge had just been finished (1750). The population of the city was approx. 700,000, but most of them lived in terrible conditions.

seutter_1750_london_view

A view of London (1750). Source: Historic Cities

James was born into a world where 74% of children born in London failed to reach the age of five. The medical world still practised humoral medicine (black bile, yellow bile, phlegm, and blood). Diseases were believed to be caused by an accumulation of “poisons” in the body, cured by bleeding, enemas, and sweating or blistering. The medical profession was:

  • Pre Ed Jenner’s vaccine for smallpox (1796)
  • Pre Rene Laennec’s stethoscope (1816)
  • Pre nitrous oxide (1800) or ether anaesthesia (1846)
  • Pre germ theory (Ignaz Semmelweis, 1847)
  • Pre Joseph Lister’s anti-septic surgery (1863).

Amputations were by far the most frequent surgeries, but the survival rate of the procedure was only 40% (and remember, there was no anaesthesia).

James Parkinson was born at no. 1 Hoxton Square in the liberty of Hoxton in Shoreditch, Middlesex. He would live all but the last 2 years of his life at that address.

In 1755, Hoxton was simply a scattering of houses, orchards and market gardens that lay approximately half a mile from one of the north-east gates of the walls of London. During the 17-1800s, Hoxton Square was considered a very fashionable area and young James would have grown up surrounded by open, reasonably well to do areas.

The maps below were made shortly before James was born, and it suggests open spaces, gardens, orchards and fields surrounding Hoxton.

London-1746

London in 1746 (Shoreditch is indicated by the black square)
Source: John Roque’s Map

Shoreditch

A map of Hoxton in 1746 – no 1. Hoxton Square (red arrow)
and St Leonard Church (blue arrow) are indicated.

James was born at the onset of the industrial revolution and with London prospering there was an enormous increase in the number of inhabitants. As more and more of London’s real estate became dedicated to business purposes, the inhabitants began spilling out into the surrounding areas. With transportation still limited to foot and horse, the people who worked in London needed to stay close to their place of employment, thus areas like Hoxton began to fill up rapidly. In 1788, there were 34,700 people living in Hoxton (in 5730 houses), which grew to 109,200 people in 1851 (in 15,433 houses).

Thus, during James’ life, Hoxton went through a radical transition. The large homes, orchards and gardens of his youth gave way to factories and over-crowding. And as a result, the ‘Parkinson and Son’ practise that he ran with his father (and later his own son) changed from serving a middle class clientele to dealing predominantly with the working class. With the prosperity of the time, there came a new trend of philanthropy, giving rise to the building of hospitals and mental asylums (‘madhouses’). James was the medical attendant for one of these madhouses, Holly House (Hoxton road, Hoxton).

The maps below were made in 1830 (shortly after James died – 1824) and indicate tremendous growth and expansion in London and the Hoxton area with the loss of much of the open spaces.

Greenwood

GREENWOOD MAP OF LONDON 1830 – Hoxton is indicated by the black square;
Tower of London (black arrow) and Westminster Abbey (red arrow) are also labelled – source: here

JP-Hoxton

 A map of Hoxton in 1830 – no 1. Hoxton Square (red arrow), St Leonard Church (blue arrow) and Holly House (Magenta arrow) are indicated.


THE FORMATIVE YEARS

James was baptised on the 29th of April 1755 in St Leonard’s church (Shoreditch) – the same church where he attended weekly services, got married, baptised his own children (and married some of them), and where he was eventually buried. The details of the baptism are recorded in the parish register, and read simply: James son of John and Mary Parkinson. Hoxton Square, Born 11th. Baptised 29th inst.

St Leonards

St Leonard’s church (1827) – Source

St Leonard’s church formed one of the key pillars of James’ life, and he could readily view the spire of the church one just block away from no.1 Hoxton Square.

The Parkinson family never owned the house at no. 1 Hoxton Square, which was owned by one Joshua Jenning. The building they lived in is gone now, but it was still standing in 1910 when Prof Leonard George Rowntree, a lecturer at Johns Hopkins Medical School (Baltimore), visited it and described it as:

“The house is a plain old three story building facing the east, on the northwest corner of Hoxton Square. Behind the main building and connected with it is a smaller two-story one with a central door opening into the little side street. This apparently was Parkinson’s office. Behind this again is another smaller building which may have served as a laboratory, as a library, or perhaps as a museum. Leading up to the deeply set, black, massive looking front door are a stone walk and deeply worn stone steps. The house is only a few feet back from the street and before it stands an old iron fence.

Uninteresting though the exterior is, upon entering this building one is impressed at the large size of the rooms and with the evidences of the prosperity of other days. We see in almost every room great carved open fire-places of elaborate design, and between some rooms large connecting arches. The deep panelling of walls and ceiling which was formerly so much in vogue is well preserved in some of the rooms on the second floor. One is surprised to find such an interesting interior behind such an uninviting exterior”  

(Rowntree, 1912)

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An image of no.1 Hoxton Square – Source

James was the eldest surviving child of John (an apothecary and surgeon) and Mary Parkinson. James had two sisters who survived to adulthood, Margaret Townley Parkinson (born 3rd August,1759) and Mary Sedgewood (born 11th January, 1763).

Little is known about the formative years of James Parkinsons. From his own writings, we know that he had a solid education in Latin and Greek as well as chemistry, biology and mathematics. James was fortunate to grow up in a ‘comfortable, cultured home’ with ‘a medical atmosphere’. But a thriving literary, scientific, and religious atmosphere also existed in Hoxton square. No fewer than fifteen residents of the Square are biographized in the Dictionary of National Biography – a distinction not shared by any other London Square from that time. Nothing is known about where James received his education. His name does not appear on the registry of scholars of the well known public schools of London, such as St Paul’s, the charterhouse, Christ’s Hospital, Merchants Taylors – all of which were within walking distance of Hoxton Square. Private home schooling was very popular during this time. James certainly did not attend Cambridge or Oxford University.

At age 16, James began his training to be an apothecary. In accordance with an antiquated Elizabethan Act of Parliament, in order to become a surgeon a young man had to serve an apprenticeship of seven years. James was apprenticed to his father, but 20 years later he wrote that “no apprenticeship should be advisable except to a hospital”. James was extremely critical of the traditional methods used in the teaching of medicine at the time:

“The first four or five years are almost entirely appropriated to the compounding of medicines; the art of which,with every habit of necessary exactness, might just as well be obtained in as many months. The remaining years of his apprenticeship bring with them the acquisition of the art of bleeding, of dressing a blister, and, for the completion of the climax – of exhibiting an enema”  Parkinson, J. p32 (1800)

To further his training, James became one of the first medical students of the London Hospital Medical College (Whitechapel Road), founded by William Blizzard – surgeon of the Hospital. The college register records that he entered for training on Feb 20th 1776 when he was in his twentieth year. He was a ‘hospital pupil’ (or dresser) under Richard Grindall, FRS, at that time assistant surgeon. James remained for 6 months, but after this training he still felt ‘miserably ignorant’.

NPG D12199; Richard Grindall by William Daniell, after  George Dance

Richard Grindall (1716-1795) – by William Daniell, (21 Aug 1793)  – Source

On 1st April 1784, James was examined and granted the grand diploma of the Company of Surgeons. He then joined his father in a practice, called “Parkinson and Son” (that practice was to last through 4 generations – approx. 80 years). Unfortunately, John Parkinson died only 6 years later, and James was left to manage the practice single-handedly. James was fortunate to take over his father’s prosperous practise as he noted that ‘a physician seldom obtains bread by his profession until he has no teeth left to eat it’. The clientele requiring the services of Parkinson and son, however, would change dramatically during James’s life. Parkinson’s and son’s evolved from a upper-middle class practise to an almost entirely working class practise by the time James passed on.

It says a great deal about the man that he did not move away from the community as it evolved (as many early inhabitants of Hoxton Square did).

On 21st May 1783, James married Mary Dale in St Leonard’s Church, by special license which was the custom of the upper and middle classes of that period. He was 25 and she was 23 years old. James’s friend Wakelin Welch Jr of Lympstone (Devon) acted as his best man (many years later, James’ book ‘Organic Remains of a Former World’ was dedicated to Welch).

According to the Family Pursuits website, Mary Dale (daughter of John Dale and Mary Hardy) was born 2nd September, 1757 in Shoreditch, Middlesex. Her family lived lived in Charles Square, Hoxton. Mary’s grandfather, Francis Dale (1650-1716), was an apothecary in Hoxton Old Town. He had three sons: Francis (also an apothecary), Thomas (1699-1750), and John (a silk merchant and Mary’s father). Her family not only had a medical history, but also geological. Mary’s grand uncle, Samuel Dale (1659-1739) was a keen botanist and one of the first to describe the fossils in the cliffs of Harwich (Essex).

 

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Samuel Dale (1659-1739) – Source: The Essex Field Club

Thus the marriage was most likely a good fit for James. Mary Parkinson would live a long life, dying on 28 March 1838 of typhus fever (Gardner-Thorpe, 2013). Together with James, she had six children, key amongst them was John William Keys Parkinson (born 11th July, 1785) who apprenticed to his father and would later become the ‘Son’ in ‘Parkinson and Son’ (and ultimately John’s son James Keys Parkinson would follow in this process).


In the next post of this series, we will look at James’ early years as a physician and his foray into political radicalism.