Tag: lysosome

The modification of acidification

~ Simon ~ 4 Comments

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In Parkinson’s research, a great deal of the attention is focused on a handful of proteins that are associated with Parkinson’s. The majority of this knowledge has come from the discovery of genetic variations being apparent in some member of the PD community.

The proteins (and biological pathways) underlying these genetic variations include alpha synuclein, LRRK2, PARKIN and GBA – all of which have been discussed on this website. But scientists have identified over 80 different regions of DNA that are associated with Parkinson’s and only recently have some of the proteins associated with these other regions of DNA been investigated.

One of these proteins is particularly interesting. It’s called TMEM175. And recently published research has provided new insights into this protein.

In today’s post, we will look at what is known about TMEM175 and discuss how biotech companies are therapeutically modulating it as a potential novel treatment for Parkinson’s.

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Source: Sciencetrends

Lysosomes are a key component of the waste disposal/recycling system of our cells.

They are small bags that are full of digestive enzymes that help to break down material inside of cells. Sometimes that material is newly imported from outside of the cell, while other times it may be old proteins that need to be disposed of.

Lysosomes provide the digestive enzymes for the job of breaking down the material.
Lysosomes

How lysosomes work. Source: Prezi

We haver discussed lysosomes in previous posts in more depth (Click here to read that SoPD post) – but understand that they are an absolutely critical component of normal biological function inside of cells.

Got it. What do they have to do with Parkinson’s?

Continue reading “The modification of acidification” →

Making a (G)case for quetiapine

~ Simon ~ 8 Comments

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Drug repurposing (repositioning, reprofiling or re-tasking) is a strategy of identifying novel uses for clinically approved (or experimental) drugs that fall outside the scope of the original medical indication.

Many drug repurposing efforts have started with screening experiments, looking for drugs with certain properties.

Recently, researchers conducted a drug repurposing screening experiment for molecules that enhance a Parkinson’s protein (called GCase) and they found an interesting result: the antipsychotic medication quetiapine.

In today’s post, we will explain what GCase does, review what the new study found, and consider what could happen next.

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At the recent “Rallying to the Challenge” meeting (which was conducting in parallel with the Van Andel Institute‘s “Grand Challenges in Parkinson’s Disease“), I was asked by Cure Parkinson’s to present on why the biology surrounding genetic risk factors – like variation in the GBA and LRRK2 genes – are important targets for potential therapeutic intervention in Parkinson’s (my presentation starts at 2 hours & 10 minutes into the video above).

Specifically, I was asked to discuss why they are important targets not just for individuals carrying the genetic variations in these genes, but for the wider Parkinson’s community in general. And it is a good question.

How could inhibitors of LRRK2 or enhancers of GCase activity possibly be useful to individuals with idiopathic (spontaneous or not associated with a genetic risk factor) Parkinson’s?

My answer was rather simple.

What was it?

Continue reading “Making a (G)case for quetiapine” →

Forget Special K, maybe focus on LysoK

~ Simon ~ 1 Comment

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Over the last 20 years, researchers have identified a number of genetic variations that can confer an increased risk of developing Parkinson’s. Tiny alterations in regions of DNA (called genes) – which provide the instructions for making a protein – can increase one’s chances of Parkinson’s.

A better understanding of the biological pathways associated with these genetic risk factors is opening up vast new areas of research.

Recently researchers have been exploring the biology behind one particular genetic risk factor – involving a gene called TMEM175 – and they have discovered something quite unexpected: While one genetic variation in the TMEM175 gene increases the risk of Parkinson’s, another variation reduces it.

In today’s post, we will explore the biology of TMEM175, review what the results of the new research indicate, and consider why these findings might be interesting in terms of potential future therapeutic targets.

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Wadlow (back left). Source: Telegraph

Robert Pershing Wadlow was always in the back of school photos.

Born February 22nd 1918, Wadlow’s birth certificate indicated that he was “normal height and weight“, but from that point onwards, there was nothing normal about his rate of growth.

By the time, Robert was 8 years old, he was taller than his father (he was 6 foot/183cm). And eight years later when he turned 16, Robert was 8 foot 1 (2.47 m)… and he was still growing.

Here is a picture of him with his family at 19 years of age:

Source: Businessinsider

Robert was the tallest person in recorded history, and at the time of his death – at the tragically young age of 22 – Robert was almost 9 feet tall (8 ft 11; 2.72 m)… and still growing.

His incredible growth was caused by a condition called hyperplasia of his pituitary gland. This condition that results in an overactive pituitary gland which causes an abnormally high level of the human growth hormone to be produced.

Source: Britannica

Human growth hormone (or somatotropin) is a peptide hormone that belongs to a much larger group of molecules that are referred to as growth factors.

In general terms, growth factors are small molecule that plays an important and fundamental role in biology. They stimulate cell proliferation, wound healing, and occasionally cellular differentiation.

And Robert’s story is an example of how powerful the effect these tiny molecules can have.

Growth factors are secreted from one cell and they float around in the extracellular world until they interact with another cell and initiate survival- and growth-related processes.

Source: Wikimedia

We have often discussed growth factors on this website in the past, with posts of growth factors like GDNF (Click here to read a SoPD about this) and CDNF (Click here to read a SoPD post on this). These discussions have largely focused on how growth factors could have neuroprotective and regenerative potential for Parkinson’s, stimulating survival and growth of cells.

Recently, however, new research has been published that demonstrates how some of these growth factors could be influencing an entirely different aspect of cellular biology that is connected to Parkinson’s: lysosomal function.

What is lysosomal function?

Continue reading “Forget Special K, maybe focus on LysoK” →

Trying to LIMP-2 the lysosome

~ Simon ~ 7 Comments

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Lysosomes are small bags of enzymes that are used to break down material inside of cells – digesting newly absorbed food or recycling old/used proteins and rubbish. Recently researchers have been discovering increasing evidence that points towards dysfunction in lysosomes as a key influential player in neurodegenerative conditions, like Parkinson’s.

There are several Parkinson’s genetic risk factors associated with lysosomal function (GBA being the obvious one), that can increase one’s risk of developing Parkinson’s.

But there is also data indicating that individuals without any of these risk factors may also have reduced lysosomal activity. And recently researchers have identified one possible explanation.

In today’s post, we will explore what lysosomes are, investigate how they maybe involved with Parkinson’s, review what the new data reports, and discuss how this information might be useful.

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Type of endocytosis. Source: Slidemodel

On a continual basis, cells inside your body are absorbing material from the world around them with the aim of collecting all that they need to survive. They do this predominantly via a process called endocytosis, in which a small part of the cell membrane envelopes around an object (or objects) and it is brought inside the cell.

As the section of cell membrane enters the interior of the cell, it detaches from the membranes and forms what is called an endosomes (sometimes it is also called a vacuole). Once inside, the endosome transported deeper into the interior of the cells where it will bind to another small bag that is full of digestive enzymes that help to break down the contents of the endosome.

This second bag is called a lysosome.

Lysosomes

How lysosomes work. Source: Prezi

Once bound, the lysosome and the endosome/vacuole will fuse together and the enzymes from the lysosome will be unleashed on the material contained in the vacuole. The digestion that follows will break down the material into more manageable components that the cell needs to function and survive.

This enzymatic process works in a very similar fashion to the commercial products that you use for washing your clothes.

Enzymatic degradation. Source: Samvirke

The reagents that you put into the washing machine with your clothes contain a multitude of enzymes, each of which help to break down the dirty, bacteria, flakes of skin, etc that cling to your clothes. Each enzyme breaks down a particular protein, fat or such like. And this situation is very similar to the collection of enzymes in the lysosome. Each enzyme has a particular task and all of them are needed to break down the contents of the endosome.

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

Continue reading “Trying to LIMP-2 the lysosome” →

Prevail lands on a Lilly pad

~ Simon ~ 5 Comments

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2020 has been a dreadful year for most of the world – burdened by the outbreak and consequences of COVID-19. Despite this, there has been a steady stream of biotech acquisitions related to Parkinson’s which have helped to keep morale high in the PD research community.

In October alone, we saw the Portuguese pharmaceutical company Bial purchase GBA-associated Parkinson’s biotech firm Lysosomal Therapeutics (Click here to read more about this) and the acquisition of the inflammasome-focused biotech firm Inflazome was being bought by Roche (Click here to read more about this).

Today brought news of yet another pharmaceutical company – this time Eli Lilly – purchasing a Parkinson’s-focused biotech company (Prevail Therapeutics).

In today’s post, we will explore what Prevail Therapeutics does, why Eli Lilly might be so interested in this company, and why it could be an encouraging move for individuals with a sub-type of Parkinson’s.

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Colonel Eli Lilly. Source: SS

The civil war veteran, Colonel Eli Lilly started his pharmaceutical career in a drug store in Greencastle (Indiana) in 1869.

Several years later (in 1873) he shifted into the manufacturing of pharmaceuticals (in association with John F Johnston). Two years after that, Lily disolved their partnership, sold his assets, and used the proceeds to set up “Eli Lilly and Co” in Indianapolis.

Source: Wikimedia

He started the company in a rented building on the 10th May, 1876. He was 38 years old, with working capital of $1400 and just three employees. The first medicine that he produced was quinine – a drug used to treat malaria.

Since that humble start, the company (now more commonly known as just “Lilly”) has grown to become one of the 20 largest pharmaceutical companies in the world (Source), with offices in 18 countries and products sold in 125 countries (Source).

Lilly was the first company to mass-produce the polio vaccine and it was also one of the first pharmaceutical companies to produce human insulin using recombinant DNA. Lilly is currently the largest manufacturer of psychiatric medications, including Prozac (Source).

Today, the company employs approximately 38,000 people worldwide, and operates through two key business divisions:

  • Human Pharmaceutical Products, which involves the production and sale of prescription medications in the fields of endocrinology, oncology, cardiovascular health, and neuroscience
  • Animal Health Products, comprising the development and sale of treatments for domestic and farm animals

This is all very interesting, but what does any of it have to do with Parkinson’s?

This week the biotech world was alerted to the news that Eli Lilly was purchasing a biotech company that is focused on developing a novel treatment for a subtype of Parkinson’s.

That company is called Prevail Therapeutics.

What does Prevail Therapeutics do?

Continue reading “Prevail lands on a Lilly pad” →

Too much LRRK2 begets too little GCase?

~ Simon ~ 1 Comment

 

New research from multiple independent research groups proposes that one Parkinson’s associated protein (LRRK2) may be affecting the activity of another Parkinson’s associated protein (GCase).

Specifically, when LRRK2 becomes hyperactive (as is the situation in some cases of Parkinson’s), it causes is associated with a reduction in the amount of GCase activity.

In today’s post, we will discuss what LRRK2 and GCase both do, what the new research suggests, and how this news could influence efforts to treat Parkinson’s in the future.

         

Connections. Source: Philiphemme

For a long time, the Parkinson’s research community had a set of disconnected genetic risk factors – tiny errors in particular regions of DNA that were associated with an increased risk of developing Parkinson’s – but there seemed to be little in the way of common connections between them.

Known genetic associations with PD. Source: PMC

The researchers studied the biological pathways associated with these risk factors, trying to identify potential therapeutic angles as well as looking for connections between them.

The therapies are currently being clinically tested (Click here to read more about these), but the connections have taken a lot longer to find.

Recently one important connection has been identified by several research groups and it could have important implications for how Parkinson’s will be treated in the future.

What’s the connection?

Continue reading “Too much LRRK2 begets too little GCase?” →

The Ambroxol Results

~ Simon ~ 52 Comments

 

The new year has started with some pleasing clinical trial news for the Parkinson’s community: The results of the “Ambroxol in Disease Modification in Parkinson Disease” (AiM-PD study) have been published.

This is a clinically available drug that is used for the treatment of respiratory issues, which researchers are re-purposing for Parkinson’s based on some interesting properties the drug has.

The results of the clinical trial suggest that ambroxol was safe and well tolerated in people with Parkinson’s for the length of the 6 month study. It accessed the brain and increased levels of target proteins while there.

In today’s post, we will discuss what ambroxol is, what research has been conducted on it, and what the results of this study suggest.

 

The author of this blog is the deputy director of research at The Cure Parkinson’s Trust, and as such he feels that it is necessary to start this post with a very clear declaration –  FULL DISCLOSURE: The Cure Parkinson’s Trust (in partnership with the Van Andel Institute) was a funder of the ambroxol clinical trial which is going to be discussed in this post.

Right. That said, let’s try and do a completely unbiased review of the ambroxol trial results 🙂

In one particular SoPD post last year we discussed the Linked Clinical Trials initiative, which is an international program that was set up 8 years ago with the goal of rapidly repurposing clinically available drugs exhibiting disease modifying potential in models of Parkinson’s (Click here to read the previous SoPD post on this topic).

What is meant by repurposing?

Drug repurposing (repositioning, reprofiling or re-tasking) is a strategy of identifying novel uses for clinically approved drugs that fall outside the scope of the original medical indication.

An example of this is “Viagra”.

It was originally developed as an anti-hypertensive medication, but was hugely more successful in the treatment of erectile dysfunction.

The strategy has been adopted and applied by many organisations because it allows for the by-passing of large parts of the drug discovery process, saving time and resources in getting new treatments to the clinic.

Source: Austinpublishinggroup

By repurposing a clinically approved drug – for which we may know a great deal about already in terms of safety, tolerability and dose range – we can skip large parts of the clinical trial process and jump straight to testing the drug in our population of interest (in this case people with Parkinson’s).

And this is what the Linked Clinical Trials (or LCT) program was set up to do in Parkinson’s.

The first drug that was prioritised by the LCT committee for repurposing was a diabetes drug called exenatide (also known as Bydureon).

It is fair to say this LCT-initiated clinical trial program has provided interesting results thus far (Click here and here to read a SoPD post on this) and the exenatide program is now entering Phase III testing in Parkinson’s (Click here to read more about the Phase III trial).

In late 2014, the LCT committee prioritised another clinically available drug for repurposing to Parkinson’s.

That drug is called ambroxol.

What is ambroxol?

Continue reading “The Ambroxol Results” →

Making a strong case for GCase

~ Simon ~ 6 Comments

Novel therapies are increasing being developed to focus on specific subtypes of Parkinson’s. The hope is that if they work on one type of Parkinson’s, then maybe they will also work on others.

Many of these new experimental treatments are focused on specific genetic subtypes of the condition, which involve having a specific genetic variation that increases one’s risk of developing Parkinson’s.

Increasing amounts of data, however, are accumulating that some of the biological pathways affected by these genetic variations, are also dysfunctional in people with sporadic (or idiopathic) Parkinson’s – where a genetic variation can not explain the abnormality.

In today’s post, we will review some new research that reports reductions in a specific Parkinson’s-associated biological pathway, and discuss what it could mean for future treatment of the Parkinson’s.

Source: Medium

I was recently at a conference on Parkinson’s research where a prominent scientist reminded the audience that just because a person with Parkinson’s carries certain genetic risk factor (an error in a region of their DNA that increases their risk of developing Parkinson’s), does not mean that their Parkinson’s is attributable that genetic variation. Indeed, lots of people in the general population carry Parkinson’s associated genetic risk factors, but never go on to develop the condition.

And this is a really important idea for the Parkinson’s community to understand: Most of the genetics of Parkinson’s deals with ‘association’, not with ‘causation’.

But that begs the question ‘if we do not know that these errors in our DNA are causing Parkinson’s, then why should we be trying to develop therapies based on their biology?’

It is a fair question (it is also a very deep and probing question to start a post off with!).

The genetics of Parkinson’s has been extremely instructive in providing us with insights into the potential underlying biology of the condition. We have learnt a great deal about what many of the biological processess thatare associated with these genetic risk factors, and (yes) various experimental therapies have been developed to target them.

These novel treatments are clinically tested in the hope that they will have beneficial effects not just on individuals carrying certain genetic risk factors, but also on the wider Parkinson’s community.

And recently, there has been increasing evidence supporting this possibility. Some of the biological pathways associated with these genetic mutations appear to also be abnormal in people with Parkinson’s who do not carry the genetic variation.

What do you mean?

Continue reading “Making a strong case for GCase” →

Say it with me: Farn-e-syl-trans-fer-ase

~ Simon ~ 5 Comments

 

Not a week goes by without some new peice of research suggesting yet another biological mechanism that could be useful in slowing or stopping Parkinson’s. This week researchers in Chicago reported that pharmacologically inhibiting a specific enzyme – farnesyltransferase – may represent a novel means of boosting waste disposal and helping stressed cells to survive.

A number of farnesyltransferase inhibitors are being developed for cancer, and there is the possibility of repurposing some of them for Parkinson’s.

In today’s post, we will discuss what farnesyltransferase is and does, what the new research report found, and we will consider whether inhibition of this biological pathway is do-able for Parkinson’s.

 

Source: Knowledgepathinc

I am in the midst of preparing the “end of year review” and “road ahead” posts for 2019/2020 (they take a while to pull together). But it is already extremely apparent that we have an incredible amount of preclinical data piling up,…. and a serious bottleneck at the transition to clinical testing.

It is actually rather disturbing.

Previously this was a concern, but going forward – as more and more novel preclinical work continues to pile up – one can foresee that it is going to be a serious problem.

But there is just SOOOO much preclinical data on Parkinson’s coming out at the moment. Every single week, there is a new method/molecular pathway proposed for attacking the condition.

A good example of this frenetic pace of preclinical research is a recent report from researchers in Chicago, who discovered that a farnesyltransferase inhibitor could be beneficial in Parkinson’s.

Farne…syl… what?

Continue reading “Say it with me: Farn-e-syl-trans-fer-ase” →

A fine time for Felodipine?

~ Simon ~ 11 Comments

 

Researchers at the University of Cambridge have published an interesting research report last week regarding a clinically available drug that they suggest boosts autophagy in the brain.

Autophagy is one of several processes that cells use to dispose of waste and old proteins.

The drug is called Felodipine, and it is a calcium channel blocker that is used to treat high blood pressure.

In today’s post, we will look at what autophagy is, how boosting it could help with neurodegenerative conditions, and whether Felodipine should be clinically tested for re-purposing to Parkinson’s.

 

Source: Novusbio

This is Prof David Rubinsztein (blue shirt) and the members of his research lab at the Cambridge Institute for Medical Research (CIMR) in Cambridge (UK).

Prof Rubinsztein is the Deputy Director of the CIMR, the Academic Lead of the UK Alzheimer’s Research UK Cambridge Drug Discovery Institute, and he is a group leader at the UK Dementia Research Institute at the University of Cambridge.

He is also one of the world’s leading experts in the field of autophagy in neurodegenerative conditions.

What is autophagy?

Continue reading “A fine time for Felodipine?” →