Tagged: aggregation

We’re re-branding: It’s now called PARPinson’s

 

A new research report has been published this week which may point not only towards a new understanding of the biology of Parkinson’s, but also to potentially novel therapies which are clinically available.

These exciting new findings involve a DNA repair mechanism called ‘poly ADP ribose polymerase’ (or simply PARP) and a process of cell death called Parthanatos.

Biotech companies have developed PARP inhibitors which have been reported to rescue models of Parkinson’s. With a bit of tweaking, this class of drugs could potentially be re-purposed for Parkinson’s.

In today’s post, we will look at what PARP is, explain how PARP inhibitors work, review what previous PD research has been conducted on this topic, evaluate the new report, and consider what it means for the Parkinson’s community (Spoiler alert: this will be a long post!).

 



Source: Quotefancy

Ah, the good old days!

Remember them. Way back before Netflix. When life was sooo much easier.

You know what I’m talking about.

Back when biology was simple. Remember when DNA gave rise to RNA and RNA gave rise to protein, and that was it. Simpler times they were. Now, everything is so much more complicated. We have all manner of ‘regulatory RNA’, epigentics, splice variants, and let’s not get started on the labyrinthian world of protein folding.

Oh, how I long for the good old days.

Back when a cell could only die one of two ways: apoptosis (a carefully controlled programmed manner of death) and necrosis (cell death by injury):

Source: Researchgate

Now life is too complicated and complex beyond reason or imagination.

Let’s just take the example of cell death that I mentioned above: over the past decade, the Nomenclature Committee on Cell Death (or NCCD – I kid you not there is actually a committee for this) has written up guidelines for the definition/interpretation of ‘cell death’. And as part of that effort they have decided that there are now at least 12 (yes, 12) different ways a cell can die:

Source: Nature

For those of who are interested in reading more about all of these different kinds of cell death, click here to read NCCD committee’s most recent recommendations which were updated this year (2018). Some riveting betime reading.

Which form of cell death applies to Parkinson’s?

Now that’s a really good question!

One that has been studied and the source of debate for a very long time.

To be fair, we don’t really know. But fascinating new research published this week suggests that the Parthanatos pathway could be involved in the cell death associated with Parkinson’s.

What is Parthanatos?

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A Lewy body condition?

 

Lewy bodies are densely packed, circular clusters of protein that have traditionally been considered a characteristic feature of the Parkinsonian brain. Recently, however, evidence has been accumulating which calls into question this ‘defining feature’ of the condition.

The presence Lewy bodies in some cases of other neurological conditions (such as Alzheimer’s), and their complete absence in some cases of Parkinson’s, are leading many researchers to question their pivotal role in PD.

In today’s post, we will look at a new research report of Parkinson’s post mortem cases studies which present no Lewy bodies, and we will disucss what this might mean for our understanding of Parkinson’s and the future treatment of the condition.

 


Neuropathologists conducting a gross examination of a brain. Source: NBC

At present, a definitive diagnosis of Parkinson’s can only be made at the postmortem stage with an examination of the brain. Until that moment, all cases of Parkinson’s are ‘suspected’. When a neuropathologist makes an examination of the brain of a person who passed away with the clinical features of Parkinson’s, there are two characteristic hallmarks that they will be looking for in order to provide a final diagnosis of the condition:

1.  The loss of specific populations of cells in the brain, such as the dopamine producing neurons in a region called the substantia nigra, which lies in an area called the midbrain (at the base of the brain/top of the brain stem). As the name suggests, the substantia nigra region is visible due to the production of a ‘substance dark’ molecule called neuromelanin in the dopamine neurons. And as you can see in the image below, the Parkinsonian brain has less dark pigmented cells in the substantia nigra region of the midbrain.

The dark pigmented dopamine neurons in the substantia nigra are reduced in the Parkinsonian brain (right). Source:Memorangapp

2.  Dense, circular clusters (or aggregates) of protein within cells, which are called Lewy bodies.

shutterstock_227273575A cartoon of a neuron, with the Lewy body indicated within the cell body. Source: Alzheimer’s news

A Lewy body is referred to as a cellular inclusion, as they are almost always found inside the cell body. They generally measure between 5–25 microns in diameter (5 microns is 0.005 mm) and thus they are tiny. But when compared to the neuron within which they reside they are rather large (neurons usually measures 40-100 microns in diameter).

A photo of a Lewy body inside of a neuron. Source: Neuropathology-web

Do all Parkinson’s brains have Lewy bodies?

This is a really interesting question. Welcome to the topic of this post.

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When you stop going native

 

Alpha synuclein is a protein that is closely associated with Parkinson’s. But exactly if and how it is connected to the neurodegenerative process underlying the condition, remains unclear. 

Last week researchers reported that removing a particular form of alpha synuclein in mice results in a very early onset appearance of characteristics that closely resemble the features of Parkinson’s that we observe in humans. This finding has caused some excitement in the research community, as not only does this tell us more about the alpha synuclein protein, but it may also provide us with a useful, more disease-relevant mouse model for testing therapies.

In today’s post, we will discuss what alpha synuclein is, explain which form of the protein was disrupted in this mouse model, review the results of the new study, and look at how tetramer stablising drugs could be a new area of PD therapeutics.

 


The 337 metre (1,106 ft) long USS Gerald R. Ford. Source: Wikipedia

Imagine you and I are standing in front of the world’s largest aircraft carrier, the USS Gerald R. Ford.

It is a VAST warship – measuring in at 337 metres (1,106 ft) in length, 76 metres (250 feet) in height – and it is a wonder of engineering composed of over a billion individual components.

And as we are standing there, gazing up at this amazing machine, I turn to you and put a nut & bolt into the palm of your hand.

A nut and bolt. Source: Atechleader

You look down at it for a moment, then turn to me, puzzled.

And that is when I say: “I would like you to find (without aid/instructions) where on this ship versions of this particular type of nut and bolt live, and try to determine exactly what functions they have“.

Where would you even start?

What tools would you use for the job? Considering the size and complexity of the vessel, would you simply give up before even starting?

It sounds like a ridiculously daunting task, but this is in effect what neurobiologists are trying to do with their study of the  brain. They start with a protein – one of the functional pieces of machinery inside each cell of our body – and then try to determine where in the brain it lives (the easy part) and what it does exactly (the REALLY hard part – most proteins have multiple functions and different configurations).

A good example of this is the Parkinson’s-associated protein alpha synuclein:

 

Alpha synuclein. Source: Wikipedia

Alpha synuclein is one of the most abundant proteins in our brains – making up about 1% of all the proteins floating around in each neuron in your head – and it is a very well studied protein (with over 9700 research reports listed on the Pubmed search engine with the key words ‘alpha synuclein’).

But here’s the thing: we are not entirely clear on what alpha synuclein actually does inside the cell. 

Que? 

In fact, biologists are not even sure about what the ‘native’ form of alpha synuclein is!

What do you mean?

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EGCG: Anyone fancy a cuppa?

 

The clustering (or aggregation) of the protein, alpha synuclein, is a cardinal feature of the Parkinsonian brain, and it is believed to be associated with the neurodegeneration that characterises the condition.

As a result, many pharmaceutical and biotech companies are focused a great deal of attention on identifying novel compounds that can enter the brain and inhibit alpha synuclein from aggregating. Recently, a collaboration of companies published the results of an amazingly large study highlighting novel inhibitors.

But an interesting aspect of the results was the ‘positive control’ compound they used: Epigallocatechin Gallate (or simply EGCG)

In today’s post, we will review the results of the study, discuss what EGCG is, and look at what is known about this compound in the context of Parkinson’s.

 


Source: Cargocollective

Every now and then, the research report of a huge study comes along.

And by that, I don’t mean that the results have a major impact. Rather, I am referring to the scope and scale of the work effort required to conduct the study. For example, the GIANT study which is looking for genetic variations associated with height (Click here to read a previous SoPD post that briefly touches on that study).

Recently, the report of one huge study was published:

Title: Potent α-Synuclein Aggregation Inhibitors, Identified by High-Throughput Screening, Mainly Target the Monomeric State
Authors: Kurnik M, Sahin C, Andersen CB, Lorenzen N, Giehm L, Mohammad-Beigi H, Jessen CM, Pedersen JS, Christiansen G, Petersen SV, Staal R, Krishnamurthy G, Pitts K, Reinhart PH, Mulder FAA, Mente S, Hirst WD, Otzen DE.
Journal: Cell Chem Biol. 2018 Aug 29. pii: S2451-9456(18)30271-X.
PMID: 30197194

In this study, researchers from Arrhus University, Biogen, Amgen, Genentech, Forma Therapeutics, & Alentis Pharma screened almost 750,000 different compounds for their ability to interact with the Parkinsons-associated protein alpha synuclein.

And before we go any further, just take a moment to fully appreciate the size of that number again:

Source: peopleforbikes

That is eye watering stuff! That is a “I need to sit down for a moment and let this sink in” kind of number. That is a “Are there that many compounds in all of the known universe?” number.

After reading the number, I was left wondering what each of the scientists involved in this study must have been thinking when the boss first said “Hey guys, let’s screen half a million compounds…. no, wait, better yet, why stop there. Let’s make it 3/4 of a million compounds

How enthusiastic was the “Yes boss” response, I wonder?

All kidding aside, this is an amazing study (and the actual number of compounds screened was only 746,000).

And the researchers who conducted the study should be congratulated on their achievement, as the results of their study may have a profound impact in the longer-term for the Parkinson’s community – you see, the researchers found 58 compounds that markedly inhibited the aggregation of alpha synuclein, as well as another 100 compounds that actually increased its aggregation. A great deal of research will result from this single, remarkable piece of work.

But of particular interest to us here at the SoPD, was the activity of one of the positive control compounds that the researchers used in some of the tests.

What was the control compound?

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Wanted: EEF2K inhibitors

Nuclear factor erythroid 2–related factor 2 (or NRF2) is a protein in each of your cells that plays a major role in regulating resistance to stress. As a result of this function, NRF2 is also the target of a lot of research focused on neuroprotection.

A group of researchers from the University of British Columbia have recently published interesting findings that point towards to a biological pathway that could help us to better harness the beneficial effects of NRF2 in Parkinson’s.

In today’s post, we will discuss what NRF2 is, what the new research suggests, and how we could potentially make use of this new information.


GettyImages-548553969-56a134395f9b58b7d0bd00df

Rusting iron. Source: Thoughtco

In his book ‘A Red Herring Without Mustard‘, author Alan Bradley wrote:

Oxidation nibbles more slowly – more delicately, like a tortoise – at the world around us, without a flame, we call it rust and we sometimes scarcely notice as it goes about its business consuming everything from hairpins to whole civilizations

And he was right on the money.

Oxidation is the loss of electrons from a molecule, which in turn destabilises that particular molecule. It is a process that is going on all around us – even within us.

Iron rusting is the example that is usually used to explain oxidation. Rust is the oxidation of iron – in the presence of oxygen and water, iron molecules will lose electrons over time. And given enough time, this results in the complete break down of objects made of iron.

The combustion process of fire is another example, albeit a very rapid form of oxidation.

Oxidation is one half of a process called Redox – the other half being reduction (which involves the gaining of electrons).

The redox process. Source: Academic

Here is a video that explains the redox process:

Now it is important to understand, that oxidation also occurs in biology.

Molecules in your body go through the same process of losing electrons and becoming unstable. This chemical reaction leads to the production of what we call free radicals, which can then go on to damage cells.

What is a free radical?

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Prothena: Phase I results published

This week, biotech firm Prothena published the results of their Phase I safety and tolerance clinical trial of their immunotherapy treatment called PRX002 (also known as RG7935).

Immunotherapy is a method of artificially boosting the body’s immune system to better fight a particular disease. 

PRX002 is a treatment that targets a toxic form of a protein called alpha synuclein – which is believed by many to be one of the main villains in Parkinson’s. 

In today’s post, we will discuss what immunotherapy is, review the results of the clinical trial, and consider what immunotherapy could mean for the Parkinson’s community.


Source: uib

I have previously mentioned on this website that any ‘cure for Parkinson’s’ is going to require three components:

  1. A disease halting mechanism
  2. A neuroprotective agent
  3. Some form of cell replacement therapy

This week we got some interesting clinical news regarding the one of these components: A disease halting mechanism.

The Phase I results of a clinical trial being conducted by a company called Prothena suggest that a new immunotherapy approach in people with Parkinson’s is both safe and well tolerated over long periods of time.

The good folks at Prothena Therapeutics. Source: Prothena

What is immunotherapy?

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The Mannitol results

Last week the first results of an ambitious project are being shared with the Parkinson’s community.

Clinicrowd is a “crowd sourcing platform exploring disease treatments that Pharma companies have no interest to investigate or promote”. Their initial focus was Parkinson’s (though they now have additional projects for other medical conditions), and their first experimental treatment for Parkinson’s was the sweetener ‘mannitol’.

The results provide some interesting insights into the properties of mannitol and into crowd sourced projects.

In today’s post, we will discuss what mannitol is, why it is interesting, outline the Clinicrowd project, and review the results of the mannitol study.


152386jpg

Mannitol. Source: Qualifirst

Without a shadow of doubt, one of the most popular topics searched for on this website is ‘mannitol’.

In 2017, the second most visited page on the site (behind only the main/home page) was a post called “Update – Mannitol and Parkinson’s“. And as if to put an exclamation point on the matter, the fourth most visited page was “Manna from heaven? Mannitol and Parkinson’s

Understand though, that both of these posts were actually written in 2016!

Throughout 2017-18, not a week has gone by without someone contacting me to ask about mannitol and the ‘CliniCrowd‘ project.

Thus, it brings me great pleasure to sit down tonight and write this post.

What is mannitol?

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A vaccine for Parkinson’s – the AFFiRiS update

This week Austrian biotech firm, AFFiRiS AG, made an announcement regarding their experimental immunotherapy/’vaccine’ approach for Parkinson’s.

In their press release, the company provided the results of a long-term Phase I clinical trial testing the tolerability and safety of their treatment AFFITOPE® PD01A.

The treatment was found to be safe and well-tolerated in people with Parkinson’s. But there was one sentence which was particularly intriguing in the press release regarding clinical symptoms.

In today’s post, we will discuss what is meant by ‘immunotherapy’, outline what this particular clinical trial involved, review the results, and explore what this could mean for the Parkinson’s community.


Source: uib

I have previously mentioned on this website that any ‘cure for Parkinson’s’ is going to require three components:

  1. A disease halting mechanism
  2. A neuroprotective agent
  3. Some form of cell replacement therapy

This week we got some interesting clinical news regarding the one of these components: A disease halting mechanism

Clinical trial results from Austria suggest that a new immunotherapy approach in people with Parkinson’s is both safe and well tolerated over long periods of time.

What is immunotherapy?

Continue reading

I’ll have the fish please

We have previously discussed the importance of the right foods for people with Parkinson’s on this blog – Click here for a good example.

Recently, new data from researchers in Sweden points towards the benefits of a specific component of fish in particular.

It is a protein called β-parvalbumin, which has some very interesting properties.

In today’s post, we discuss what beta-parvalbumin is, review the new research findings, and consider how this new information could be applied to Parkinson’s.


A very old jaw bone. Source: Phys

In 2003, researchers found 34 bone fragments belonging to a single individual in a cave near Tianyuan, close to Beijing (China).

But it was not the beginning of a potential murder investigation.

No, no.

This was the start of something far more interesting.

Naming the individual “Tianyuan man”, the researchers have subsequently found that “many present-day Asians and Native Americans” are genetically related to this individual. His bones represented one of the oldest set of modern human remains ever found in the eastern Eurasia region.

Tianyuan caves. Source: Sciencemag

But beyond the enormous family tree, when researchers further explored specific details about his jaw bone (or lower mandible as it is called) they found something else that was very interesting about Tianyuan man:


Title: Stable isotope dietary analysis of the Tianyuan 1 early modern human.
Authors: Hu Y, Shang H, Tong H, Nehlich O, Liu W, Zhao C, Yu J, Wang C, Trinkaus E, Richards MP.
Journal: Proc Natl Acad Sci U S A. 2009 Jul 7;106(27):10971-4.
PMID: 19581579                     (This research article is OPEN ACCESS if you would like to read it)

In this study, the investigators analysed the carbon and nitrogen isotopes found within bone collagen samples taken from the jaw bone of Tianyuan man. In humans, the carbon and nitrogen isotope values indicate the sources of dietary protein over many years of life.

The researchers found that a substantial portion of Tianyuan man’s diet 40,000 years ago came from freshwater fish.

Interesting preamble, but what does this have to do with Parkinson’s?

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On the importance of Calcium

Recently researcher from the University of Cambridge reported that an imbalance in calcium and the Parkinson’s-associated protein alpha synuclein can cause the clustering of synaptic vesicles.

What does this mean? And should we reduce our calcium intake as a result?

In today’s post, we will review the research report, consider the biology behind the findings and how it could relate to Parkinson’s, and discuss what can or should be done.


Me and Brie. Source: Wikipedia

When I turned 25, I realised that my body no longer accepted cheese.

This was a very serious problem.

You see, I still really liked cheese.

A bottle of red wine, a baguette and a chunk of brie – is there any better combination in life?

So obviously my body and I had a falling out. And yes, it got ugly. I wanted things to keep going the way they had always been, so I tried to make things interesting with new and exotic kinds of cheeses, which my body didn’t want to know about it. It rejected all of my efforts. And after a while, I gradually started resenting my body for not letting me be who I was.

We sought help. We tried interventions. But sadly, nothing worked.

And then things got really bad: My body decided that it didn’t have room in its life for yogurt, milk or even ice cream anymore (not even ice cream!!!). Basically no dairy what so ever.

There’s something’s missing in my life. Source: Morellisices

OMG. How did you survive without ice cream?

Well, I’ll tell ye – it’s been rough.

All silliness aside though, here is what I know: It is actually very common to develop a lactase deficiency as we get older – lactase being the enzyme responsible for the digestion of whole milk. In fact, about 65% of the global population has a reduced ability to digest lactose after infancy (Source: NIH). I am not lactose intolerant (one of the few tests that I actually aced in my life), but I do have trouble digesting a particular component of dairy products – which can result in discomfort and socially embarrassing situations (one day over a drink I’ll tell you the ‘cheese fondue story’). Curiously, that mystery ingredient is also present in products that have no dairy (such as mayonnaise – it absolutely kills me).

But spare me your tears, if one is forced to drop a particular food group, dairy is not too bad (if I am ever forced to give up wine, I swear I’ll go postal).

My biggest concern when I dropped dairy, however, was “where was I going to get my daily requirements of calcium?“.

Understand that calcium is really rather important.

Why is calcium important?

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