My piece was called the Dilemma of Success, and it explored a hypothetical situation that we may very well face in the not-so-distant future.
Optimistic as I am about the future of Parkinson’s research, I think this is a very serious issue – one which the Parkinson’s community needs to discuss and start planning for. I am re-posting it here today as I am keen for some thoughts/discussion on this matter.
Lord Robert Baden-Powell. Source: Utahscouts
My scout master looked around the horse shoe, making eye contact with each of us, before asking a simple question:
“When did Noah build the ark?”
My fellow scouts and I looked at each other. Some of us were wondering if the guy had completely lost the plot and somehow thought that it was Sunday morning and he was doing the sermon. Others seriously looked like they were trying to calculate an exact date.
He waited a moment for one of us to offer up some idiotic attempt at an answer, before he solemnly said:
“Before the rain”
It’s one of those childhood moments that didn’t make sense at the time, but comes back to haunt you whenever you can foresee certain troubles coming over the hill towards you.
The dilemma of success
It will be nice to have this problem, but it will still be a problem.
And we need to plan for it
“Repurposing” in medicine refers to taking drugs that are already approved for the treatment of one condition and testing them to see if they are safe and effective in treating other diseases. Given that these clinically available drugs have already been shown to be safe in humans, repurposing represents a method of rapidly acquiring new potential therapeutics for a particular condition.
The antidepressant, Trazodone, has recently been proposed for repurposing to neurodegenerative conditions, such as Parkinson’s.
In today’s post we will look at what Trazodone is, why it is being considered for repurposing, and we will review the results of a new primate study that suggests it may not be ideal for the task.
Opinions. Everyone has them. Source: Creativereview
I am regularly asked by readers to give an opinion on specific drugs and supplements.
And I usually cut and paste in my standard response: I can not answer these sorts of questions as I am just a research scientist not a clinician; and even if I was a clinician, it would be unethical for me to comment as I have no idea of your medical history.
In many of these cases, there simply isn’t much proof that the drug/supplement has any effect in Parkinson’s, so it is hard to provide any kind of “opinion”. But even if there was proof, I don’t like to give opinions.
Eleven out of every ten opinions are usually wrong (except in the head of the beholder) so why would my opinion be any better? And each individual is so different, why would one particular drug/supplement work the same for everyone?
In offering an answer to “my opinion” questions, I prefer to stick to the “Just the facts, ma’am” approach and I focus solely on the research evidence that we have available (Useless pub quiz fact: this catchphrase “Just the facts, ma’am” is often credited to Detective Joe Friday from the TV series Dragnet, and yet he never actually said it during any episode! – Source).
Detective Joe Friday. Source: Wikipedia
Now, having said all of that, there is one drug in particularly that is a regular topic of inquiry (literally, not a week goes by without someone asking about): an antidepressant called Trazodone.
What is Trazodone?
In 2017, Parkinson’s UK – the largest charitable funder of Parkinson’s disease research in Europe – took a bold step forward in their efforts to find novel therapies.
In addition to funding a wide range of small and large academic research projects and supporting clinical trials, they have also decided to set up ‘virtual biotech’ companies – providing focused efforts to develop new drugs for Parkinson’s, targeting very specific therapeutic areas.
In today’s post we will look at the science behind their first virtual biotech company: Keapstone.
A virtual world of bioscience. Source: Cast-Pharma
I have previously discussed the fantastic Parkinson’s-related research being conducted at Sheffield University (Click here to read that post). Particularly at the Sheffield Institute for Translational Neuroscience (SITraN) which was opened in 2010 by Her Majesty The Queen. It is the first European Institute purpose-built and dedicated to basic and clinical research into Motor Neuron Disease as well as other neurodegenerative disorders such as Parkinson’s and Alzheimer’s disease.
The research being conducted at the SITraN has given rise to multiple lines of research following up interesting drug candidates which are gradually being taken to the clinic for various conditions, including Parkinson’s.
It’s all very impressive.
And apparently I’m not the only one who thought it was impressive.
Mitochondrial division inhibitor-1 (mdivi-1) is a small molecule drug that is demonstrating very impressive effects in preclinical models of Parkinson’s disease. With further research it could represent a potential future therapy for people with Parkinson’s disease, particularly those with genetic mutations affecting the mitochondria in their cells.
What are mitochondria?
In this post, we will explain what mitochondria are, how they may be involved in Parkinson’s disease, and we will discuss what the results of new research mean for future therapeutic strategies.
Mitochondria are fascinating.
Utterly. Utterly. Fascinating.
On the most basic level, Mitochondria (mitochondrion, singular; from the Greek words mitos (thread) and chondros (granule)) are just tiny little bean-shaped structures within the cells in our body, and their primary function is to act as the power stations. They supply the bulk of energy that cells require to keep the lights on. This chemical form of energy produced by the mitochondria is called adenosine triphosphate (or ATP). Lots of mitochondria are required in each cell to help keep the cell alive (as is shown in the image below, which is showing just the mitochondria (red) and the nucleus (blue) of several cells).
Lots of mitochondria (red) inside cells (nucleus in blue). Source: Clonetech
That’s the basic stuff – the general definition you will find in most text books on biology.
But let me ask you this:
How on earth did mitochondria come to be inside each cell and playing such a fundamental role?
I don’t know. Are you going to tell me?
Because we simply don’t know.
But understand this: Mitochondria are intruders.
In my previous post, we briefly reviewed the results of the phase II double-blind, randomised clinical trial of Exenatide in Parkinson’s disease. The study indicates a statistically significant effect on motor symptom scores after being treated with the drug.
Over the last few days, there have been many discussions about the results, what they mean for the Parkinson’s community, and where things go from here, which have led to further questions.
In this post I would like to address several matters that have arisen which I did not discuss in the previous post, but that I believe are important.
I found out about the Exenatide announcement – via whispers online – on the afternoon of the release. And it was in a mad rush when I got home that night that I wrote up the post explaining what Exenatide is. I published the post the following evening however because I could not access the research report from home (seriously guys, biggest finding in a long time and it’s not OPEN ACCESS?!?!?) and I had to wait until I got to work the next day to actually view the publication.
I was not really happy with the rushed effort though and decided to follow up that post. In addition, there has been A LOT of discussion about the results over the weekend and I thought it might be good to bring aspects of those different discussion together here. The individual topics are listed below, in no particular order of importance:
1. Size of the effect
There are two considerations here.
Firstly, there have been many comments about the actual size of the effect in the results of the study itself. When people have taken a deeper look at the findings, they have come back with questions regarding those findings.
And second, there have also been some comments about the size of the effect that this result has already had on the Parkinson’s community, which has been considerable (and possibly disproportionate to the actual result).
The size of the effect in the results
The results of the study suggested that Exenatide had a positive effect on the motor-related symptoms of Parkinson’s over the course of the 60 week trial. This is what the published report says, it is also what all of the media headlines have said, and it sounds really great right?
The main point folks keep raising, however, is that the actual size of the positive effect is limited to just the motor features of Parkinson’s disease. If one ignores the Unified Parkinson’s Disease Rating Scale (UPDRS) motor scores and focuses on the secondary measures, there isn’t much to talk about. In fact, there were no statistically significant differences in any of the secondary outcome measures. These included:
In October 2015, researchers from Georgetown University announced the results of a small clinical trial that got the Parkinson’s community very excited. The study involved a cancer drug called Nilotinib, and the results were rather spectacular.
What happened next, however, was a bizarre sequence of disagreements over exactly what should happen next and who should be taking the drug forward. This caused delays to subsequent clinical trials and confusion for the entire Parkinson’s community who were so keenly awaiting fresh news about the drug.
Earlier this year, Georgetown University announced their own follow up phase II clinical trial and this week a second phase II clinical trial funded by a group led by the Michael J Fox foundation was initiated.
In todays post we will look at what Nilotinib is, how it apparently works for Parkinson’s disease, what is planned with the new trial, and how it differs from the ongoing Georgetown Phase II trial.
The FDA. Source: Vaporb2b
This week the U.S. Food and Drug Administration (FDA) has given approval for a multi-centre, double-blind, randomised, placebo-controlled Phase IIa clinical trial to be conducted, testing the safety and tolerability of Nilotinib (Tasigna) in Parkinson’s disease.
This is exciting and welcomed news.
What is Nilotinib?
Nilotinib (pronounced ‘nil-ot-in-ib’ and also known by its brand name Tasigna) is a small-molecule tyrosine kinase inhibitor, that has been approved for the treatment of imatinib-resistant chronic myelogenous leukemia (CML).
What does any that mean?
Basically, it is the drug that is used to treat a type of blood cancer (leukemia) when the other drugs have failed. It was approved for treating this cancer by the FDA in 2007.
The contents of today’s post may not be appropriate for all readers. An illegal and potentially damaging drug is discussed. Please proceed with caution.
3,4-Methylenedioxymethamphetamine (or MDMA) is more commonly known as Ecstasy, ‘Molly’ or simply ‘E’. It is a controlled Class A, synthetic, psychoactive drug that was very popular with the New York and London club scene of the 1980-90s.
It is chemically similar to both stimulants and hallucinogens, producing a feeling of increased energy, pleasure, emotional warmth, but also distorted sensory perception.
Another curious effect of the drug: it has the ability to reduce dyskinesias – the involuntary movements associated with long-term Levodopa treatment.
In today’s post, we will (try not to get ourselves into trouble by) discussing the biology of MDMA, the research that has been done on it with regards to Parkinson’s disease, and what that may tell us about dyskinesias.
Good times. Source: Carwash
You may have heard this story before.
It is about a stuntman.
His name is Tim Lawrence, and in 1994 – at 34 years of age – he was diagnosed with Parkinson’s disease.
Tim Lawrence. Source: BBC
Following the diagnosis, Tim was placed on the standard treatment for Parkinson’s disease: Levodopa. But after just a few years of taking this treatment, he began to develop dyskinesias.
Dyskinesias are involuntary movements that can develop after regular long-term use of Levodopa. There are currently few clinically approved medications for treating this debilitating side effect of Levodopa treatment. I have previously discussed dyskinesias (Click here and here for more of an explanation about them).
As his dyskinesias progressively got worse, Tim was offered and turned down deep brain stimulation as a treatment option. But by 1997, Tim says that he spent most of his waking hours with “twitching, spasmodic, involuntary, sometimes violent movements of the body’s muscles, over which the brain has absolutely no control“.
And the dyskinesias continued to get worse…
…until one night while he was out at a night club, something amazing happened:
“Standing in the club with thumping music claiming the air, I was suddenly aware that I was totally still. I felt and looked completely normal. No big deal for you, perhaps, but, for me, it was a revelation” he said.
His dyskinesias had stopped.
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.
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.
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.
The Federal Drug Administration (FDA) in the USA has approved the first drug in 22 years for treating the neurodegenerative condition of Amyotrophic lateral sclerosis (ALS).
The drug is called Edaravone, and it is only the second drug approved for ALS.
In today’s post we’ll discuss what this announcement could mean for Parkinson’s disease.
Lou Gehrig. Source: NBC
In 1969, Henry Louis “Lou” Gehrig was voted the greatest first baseman of all time by the Baseball Writers’ Association. He played 17 seasons with the New York Yankees, having signed with his hometown team in 1923.
For 56 years, he held the record for the most consecutive games played (2,130), and he was only prevented from continuing that streak when he voluntarily took himself out of the team lineup on the 2nd May, 1939, after his ability to play became hampered by the disease that now often bears his name. A little more than a month later he retired, and a little less than two years later he passed away.
Amyotrophic lateral sclerosis (or 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.
ALS in a nutshell. Source: Walkforals
In addition to Lou Gehrig, you may have heard of ALS via the ‘Ice bucket challenge‘ (see image in the banner of this post). In August 2014, an online video challenge went viral.
By July 2015, the ice bucket campaign had raised an amazing $115 million for the ALS Association.
Another reason you may have heard of ALS is that theoretical physicist, Prof Stephen Hawking also has the condition:
He was diagnosed with in a very rare early-onset, slow-progressing form of ALS in 1963 (at age 21) that has gradually left him wheel chair bound.
This is very interesting, but what does it have to do with Parkinson’s disease?
Individuals affected by ALS are generally treated with a drug called Riluzole (brand names Rilutek or Teglutik). Approved in December of 1995 by the FDA, this drug increases survival by approximately two to three months.
Until this last week, Riluzole was the only drug approved for the treatment of ALS.
So what happened this week?
On the 5th May, the FDA announced that they had approved a second drug for the treatment of ALS (Click here for the press release).
It is called Edaravone.
What is Edaravone?
Edaravone is a free radical scavenger – a potent antioxidant – that is marketed as a neurovascular protective agent in Japan by Mitsubishi Tanabe Pharma Corporation.
An antioxidant is simply a molecule that prevents the oxidation of other molecules.
Molecules in your body often go through a process called oxidation – losing an electron 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?
A free radical is simply an unstable molecule – unstable because they are missing electrons. They react quickly with other molecules, trying to capture the needed electron to re-gain stability. Free radicals will literally attack the nearest stable molecule, stealing an electron. This leads to the “attacked” molecule becoming a free radical itself, and thus a chain reaction is started. Inside a living cell this can cause terrible damage, ultimately killing the cell.
Antioxidants are thus the good guys in this situation. They are molecules that neutralize free radicals by donating one of their own electrons. The antioxidant don’t become free radicals by donating an electron because by their very nature they are stable with or without that extra electron.
Thus when we say ‘Edaravone is a free radical scavenger’, we mean it’s really good at scavenging all those unstable molecules and stabilising them.
It is an intravenous drug (injected into the body via a vein) and administrated for 14 days followed by 14 days drug holiday.
So, again what has this got to do with Parkinson’s disease?
Well, it is easier to start a clinical trial of a drug if it is already approved for another disease.
And the good news is: Edaravone has been shown to be neuroprotective in several models of Parkinson’s disease.
In this post, we’ll lay out some of the previous research and try to make an argument justifying the clinical testing of Edaravone in Parkinson’s disease
Ok, so what research has been done so far in models of Parkinson’s disease?
The first study to show neuroprotection in a model of Parkinson’s disease was published in 2008:
Title: Role of reactive nitrogen and reactive oxygen species against MPTP neurotoxicity in mice.
Authors: Yokoyama H, Takagi S, Watanabe Y, Kato H, Araki T.
Journal: J Neural Transm (Vienna). 2008 Jun;115(6):831-42.
In this first study, the investigators assessed the neuroprotective properties of several drugs in a mouse model of Parkinson’s disease. The drugs included Edaravone (described above), minocycline (antibiotic discussed in a previous post), 7-nitroindazole (neuronal nitric oxide synthase inhibitor), fluvastatin and pitavastatin (both members of the statin drug class).
With regards to Edaravone, the news was not great: the investigators found that Edaravone (up to 30mg/kg) treatment 30 minutes before administering a neurotoxin (MPTP) and then again 90 minutes afterwards had no effect on the survival of the dopamine neurons (compared to a control treatment).
Not a good start for making a case for clinical trials!
This research report, however, was quickly followed by another from an independent group in Japan:
Title: Neuroprotective effects of edaravone-administration on 6-OHDA-treated dopaminergic neurons.
Authors: Yuan WJ, Yasuhara T, Shingo T, Muraoka K, Agari T, Kameda M, Uozumi T, Tajiri N, Morimoto T, Jing M, Baba T, Wang F, Leung H, Matsui T, Miyoshi Y, Date I.
Journal: BMC Neurosci. 2008 Aug 1;9:75.
PMID: 18671880 (This article is OPEN ACCESS if you would like to read it)
These researchers did find a neuroprotective effect using Edaravone (both in cell culture and in a rodent model of Parkinson’s disease), but they used a much higher dose than the previous study (up to 250 mg/kg in this study). This increase in dose resulted in a graded increase in neuroprotection – interestingly, these researchers also found that 30mg/kg of Edaravone had limited neuroprotective effects, while 250mg/kg exhibited robust dopamine cell survival and rescued the behavioural/motor features of the model even when given 24 hours after the neurotoxin.
The investigators concluded that “Edaravone might be a hopeful therapeutic option for PD, although several critical issues remain to be solved, including high therapeutic dosage of Edaravone for the safe clinical application in the future”
This results was followed by several additional studies investigating edaravone in models of Parkinson’s disease (Click here, here and here to read more on this). Of particular interest in all of those follow up studies was a report in which Edaravone treatment resulted in neuroprotective in genetic model of Parkinson’s disease:
Title: Edaravone prevents neurotoxicity of mutant L166P DJ-1 in Parkinson’s disease.
Authors: Li B, Yu D, Xu Z.
Journal: J Mol Neurosci. 2013 Oct;51(2):539-49.
DJ-1 is a gene that has been associated Parkinson’s disease since 2003. The gene is sometimes referred to as PARK7 (there are now more than 20 Parkinson’s associated genomic regions, which each have a number and are referred to as the PARK genes). Genetic mutations in the DJ-1 gene can result in an autosomal recessive (meaning two copies of the mutated gene are required), early-onset form of Parkinson disease. For a very good review of DJ-1 in the context of Parkinson’s disease, please click here.
The exact function of DJ-1 is not well understood, though it does appear to play a role in helping cells deal with ‘oxidative stress’ – the over-production of those free radicals we were talking about above. Now given that edaravone is a potent antioxidant (reversing the effects of oxidative stress), the researchers conducting this study decided to test Edaravone in cells with genetic mutations in the DJ-1 gene.
Their results indicated that Edaravone was able to significantly reduce oxidative stress in the cells and improve the functioning of the mitochondria – the power stations in each cell, where cells derive their energy. Furthermore, Edaravone was found to reduce the amount of cell death in the DJ-1 mutant cells.
More recently, researchers have begun digging deeper into the mechanisms involved in the neuroprotective effects of Edaravone:
Title: Edaravone leads to proteome changes indicative of neuronal cell protection in response to oxidative stress.
Authors: Jami MS, Salehi-Najafabadi Z, Ahmadinejad F, Hoedt E, Chaleshtori MH, Ghatrehsamani M, Neubert TA, Larsen JP, Møller SG.
Journal: Neurochem Int. 2015 Nov;90:134-41.
PMID: 26232623 (This article is OPEN ACCESS if you would like to read it)
The investigators who conducted this report began by performing a comparative two-dimensional gel electrophoresis analyses of cells exposed to oxidative stress with and without treatment of Edaravone.
Um, what is “comparative two-dimensional gel electrophoresis analyses”?
Two-dimensional gel electrophoresis analyses allows researchers to determine particular proteins within a given solution. Mixtures of proteins are injected into a slab of gel and they are then separated according to two properties (mass and acidity) across two dimensions (left-right side of the gel and top-bottom of the gel).
A two-dimensional gel electrophoresis result may look something like this:
Two-dimensional gel electrophoresis. Source: Nature
As you can see, individual proteins have been pointed out on the image of this slab of gel.
In comparative two-dimensional gel electrophoresis, two samples of solution are analysed by comparing two slabs of gel that have been injected with protein mix solution from two groups of cells treated exactly the same except for one variable. Each solution gets its own slab of gel, and the differences between the gel product will highlight which proteins are present in one condition versus the other (based on the variable being tested).
In this experiment, the variable was Edaravone.
And when the researchers compared the proteins of Edaravone treated cells with those of cells not treated with Edaravone, they found that the neuroprotective effect of Edaravone was being caused by an increase in a protein called Peroxiredoxin-2.
Now this was a really interesting finding.
You see, Peroxiredoxin proteins are a family (there are 6 members) of antioxidant enzymes. And of particular interest with regards to Parkinson’s disease is the close relationship between DJ-1 (the Parkinson’s associated protein discussed above) and peroxiredoxin proteins (Click here, here, here and here to read more about this).
In addition, there are also 169 research reports dealing with the peroxiredoxin proteins and Parkinson’s disease (Click here to see a list of those reports).
So, what do you think about a clinical trial for Edaravone in Parkinson’s disease?
Are you convinced?
Regardless, it an interesting drug huh?
Are there any downsides to the drug?
One slight issue with the drug is that it is injected via a vein. Alternative systems of delivery, however, are being explored.A biotech company in the Netherlands, called Treeway is developing an oral formulation of edaravone (called TW001) and is currently in clinical development.
Edaravone was first approved for clinical use in Japan on May 23, 2001. With almost 17 years of Edaravone clinical use, a few adverse events including acute renal failure have been noted, thus precautions should be taken with individuals who have a history of renal problems. The most common side effects associated with the drug, however, are: fatigue, nausea, and some mild anxiety.
Click here for a good overview of the clinical history of Edaravone.
So what does it all mean?
The announcement from the FDA this week regarding the approval of Edaravone as a new treatment for ALS represents a small victory for the ALS community, but it may also have a significant impact on other neurodegenerative conditions, such as Parkinson’s disease.
Edaravone is a potent antioxidant agent, which has been shown to have neuroprotective effects in various models of Parkinson’s disease and other neurodegenerative conditions. It could be interesting to now test the drug clinically for Parkinson’s disease. Many of the preclinical research reports indicate that the earlier Edaravone treatment starts, the better the outcomes, so any initial clinical trials should focus on recently diagnosed subjects (perhaps even those with DJ-1 mutations).
The take home message of this post is: given that Edaravone has now been approved for clinical use by the FDA, it may be advantageous for the Parkinson’s community to have a good look at whether this drug could be repurposed for Parkinson’s disease.
It’s just a thought.
The banner for today’s post was sourced from Forbes
We all suffer it. Whether it is work related, relationship related, or simply self-induced, we humans foolishly put a great deal of pressure on our bodies.
Many pieces of research suggest that this pressure takes a toll on our health, which could lead to long-term conditions like Parkinson’s disease.
Recently some Korean researchers have identified a stress-related hormone that could have beneficial effects for Parkinson’s disease.
In today’s post, we will review their recently published research and look at what it means for people with Parkinson’s disease.
Shortly before leaving the role of President of the United States of America, ex-President Barrack Obama was asked about the stress that comes with the job, and his answer was interesting. He suggested that it is important to take a ‘long view’ of events and not to get bogged down by the weight of everything going on around you:
Despite these sage words, it is difficult not to notice the impact that his previous job has had on the man:
What a stress can do to a person. Source: Reddit
Stress seems to be a major part of modern life for many people – some people even indicate that they need it and that they thrive on it. But this pressure that we put on our bodies tends to have a damaging effect on our general health. And there is evidence that that stress may even lead to long term consequences such as cancer and neurodegenerative conditions such as Parkinson’s disease.
Causality, however, is very difficult to determine in science.
The best we can do is suggest that a particular variable (such as stress) may increase one’s risk of developing a particular condition (such as Parkinson’s disease).
So what do we know about stress and Parkinson’s disease?
This is Professor Bas Bloem.
Prof Bloem – no stress here. Source: NRC
Professor Bloem is a consultant neurologist at the Department of Neurology, Radboud University Nijmegen Medical Centre (the Netherlands). He is also one of the researchers behind ParkinsonNet – an innovative healthcare concept that now consists of 64 professional networks for people with Parkinson’s disease covering all of the Netherlands.
In 2010, his research group noticed something interesting:
Title: Artistic occupations are associated with a reduced risk of Parkinson’s disease.
Authors: Haaxma CA, Borm GF, van der Linden D, Kappelle AC, Bloem BR.
Journal: J Neurol. 2015 Sep;262(9):2171-6.
PMID: 26138540 (This article is OPEN ACCESS if you would like to read it)
In their study, Prof Bloem and his colleagues conducted a case–controlled analysis of 750 men with Parkinson’s disease (onset ≥40 years) and 1300 healthy men, which involved the participants completing a questionnaire about their occupational history. As expected (based on previous reports), they found that farming was associated with an increased risk of developing Parkinson’s disease (click here for more on this).
Interestingly, artistic occupations late in life were associated with a reduced risk of subsequent Parkinson’s disease. Another interesting observation from the study was that no initial occupation (early in life) predicted Parkinson’s disease, which the researchers proposed indicated that the premotor phase of the disease starts later in life.
One interpretation of this finding is that creative people are less likely to develop Parkinson’s disease. An alternative theory, however, may be that artist jobs are associated with a less stressful, more relaxed lifestyle.
Could it be that the lower levels of stress associated with artistic occupations may be having an impact on the risk of developing Parkinson’s disease?
This idea is not as crazy as it sounds.
Consider different kinds of stress. Research suggests that people who undergo tremendous emotional stress have a higher risk of developing Parkinson’s disease. For example, there is the case of ex-prisoners of war:
Title:Neurological disease in ex-Far-East prisoners of war
Authors: Gibberd FB, Simmonds JP.
Journal: Lancet. 1980 Jul 19;2(8186):135-7.
At the end of World war II, a neurological unit was set up at Queen Mary’s Hospital (Roehampton) to treat Ex-Far East prisoners of war. 4684 individuals were referred to the unit, of these 679 were found to have neurological disease (most of these – 593 cases – were loss of sight and peripheral nerve damage).
In follow up work in the 1970s, however, it was found that many of these individuals had gone on to develop other neurological conditions (dementia, multiple sclerosis, etc). Of interest to us, though was the finding that across the entire group of ex-prisoners investigated (4684 individuals), Parkinson’s disease was apparent in 24 of them – this is a frequency 5x that of the general population!
Even in animal models of Parkinson’s disease, emotional stress seems to exaccerbate the neurodegeneration that is being modelled:
Title: Stress accelerates neural degeneration and exaggerates motor symptoms in a rat model ofParkinson’s disease.
Authors: Smith LK, Jadavji NM, Colwell KL, Katrina Perehudoff S, Metz GA.
Journal: Eur J Neurosci. 2008 Apr;27(8):2133-46.
PMID: 18412632 (This article is OPEN ACCESS if you would like to read it)
The investigators in this study demonstrated that chronic stress exaggerates the motor/behavioural deficits in a rat model of Parkinson’s disease. In addition, the stress resulted in a greater loss of dopamine neurons in the brains of these rats.
For an interesting review of the effect of stress in Parkinson’s disease – Click here.
Interesting. So what did the Korean researchers – you mentioned above – find this week?
This is Dr Yoon-Il Lee.
He’s a dude.
He is a senior research scientists at the Daegu Gyeongbuk Institute of Science and Technology (DGIST) in Daegu Metropolitan City, South Korea.
Recently, his group has collaborated with Professor Yunjong Lee’s research team published this research report:
Title: Hydrocortisone-induced parkin prevents dopaminergic cell death via CREB pathway inParkinson’s disease model
Authors: Ham S, Lee YI, Jo M, Kim H, Kang H, Jo A, Lee GH, Mo YJ, Park SC, Lee YS, Shin JH, Lee Y.
Journal: Sci Rep. 2017 Apr 3;7(1):525. doi: 10.1038/s41598-017-00614-w.
PMID: 28366931 (This article is OPEN ACCESS if you would like to read it)
Dr Lee and his colleagues began this study with cells were engineered to produce a bioluminescent signal when a gene called Parkin was activated. Parkin is a Parkinson’s associated gene as genetic mutations in this gene can result in carriers developing a juvenile-onset/early-onset form of Parkinson’s disease.
The researchers then conducted an enormous screening experiment to find agents that turn on the Parkin gene. They applied a library of 1172 FDA-approved drugs (from Selleck Chemicals) to these cells – one drug per cell culture – and looked at which cell cultures began to produce a bioluminescent signal. They found 5 drugs that not only made the cells bioluminescent, but also resulted in Parkin protein being produced at levels 2-3 times higher than normal. Those drugs were:
- Deferasirox – an iron chelator (interesting considering our previous post)
- Vorinostat – a cancer drug (for treating lymphoma)
- Metformin – a diabetes medication
- Clindamycin – an antibiotic
Hydrocortisone produced the highest levels of Parkin (Interestingly, hydrocortisone also did not increase the activity of PERK, an indicator of endoplasmic reticulum stress, while the other drugs did).
What is Hydrocortisone?
Hydrocortisone is the name for the hormone ‘cortisol’ when supplied as a medication.
Ok, so what is cortisol?
Cortisol is a glucocorticoid (a type of hormone) produced from cholesterol by enzymes in the cortex of the adrenal gland, which sits on top of the kidneys. It is produced in response to stress (physical or emotional)
The location of the adrenal glands. Source: Cancer
Cortisol helps us to deal with physical or emotional stress by reducing the activity of certain bodily functions – such as the immune system – so that the body can focus all of it’s energies toward dealing with the stress at hand.
Now generally, the functions of cortisol are supposed to be short-lived – long enough for the body to deal with the offending stressor and then levels go back to normal. But the normal levels of cortisol also fluctuate across the span of the day, with levels peaking around 8-9am:
A graph of cortisol levels over the day. Source: HealthTap
Ok, so what did the Korean researchers do next?
Dr Lee and his colleagues gave the hydrocortisone drug to cell cultures which they then stressed (causing cell death). Hydrocortisone protected the cells from dying, and (importantly) it achieved this feat in a manner that was dependent on parkin activation. In cells that do not naturally have parkin, hydrocortisone was found to have no effect on cell survival.
Next the researchers treated mice with hydrocortisone before they then modelled Parkinson’s disease using the neurotoxin 6-OHDA. Hydrocortisone treatment resulted in approximate a two-fold increase in levels of parkin within particular areas of the brain. Without hydrocortisone treatment, the mice suffered the loss of approximately 45% of their dopamine neurons. Mice pre-treated with hydrocortisone, however, demonstrated enhanced dopamine neuron survival.
The researchers concluded that a sufficient physiological supply of hydrocortisone was required for protection of the brain, and that hydrocortisone treatment could be further tested as a means of maintaining high levels of parkin in the brain.
So what do we know about cortisol in Parkinson’s disease?
So this is where the story gets interesting;
Title: Cortisol is higher in parkinsonism and associated with gait deficit.
Authors: Charlett A, Dobbs RJ, Purkiss AG, Wright DJ, Peterson DW, Weller C, Dobbs SM.
Journal: Acta Neurol Scand. 1998 Feb;97(2):77-85.
The researchers who conducted this study were interested in the role of cortisol in Parkinson’s disease. They measured cortisol levels in the blood of 96 subjects with Parkinson’s disease and 170 control subjects. They found that cortisol levels were 20% higher in the subjects with Parkinson’s disease, and that MAO-B inhibitor treatment for Parkinson’s (Selegiline) reduced cortisol levels.
And MAO-B inhibitors are not the only Parkinson’s medication associated with reduced levels of cortisol:
Title: Acute levodopa administration reduces cortisol release in patients with Parkinson’s disease.
Authors: Müller T, Welnic J, Muhlack S.
Journal: J Neural Transm (Vienna). 2007 Mar;114(3):347-50.
In this study the researchers found that cortisol levels started to decrease significantly just 30 minutes after L-dopa was taken.
Whether this lowering of cortisol levels may have any kind of detrimental effect on Parkinson’s disease is yet to be determined and required further investigation.
Is hydrocortisone or cortisol used in the clinic?
Yes it is.
Hydrocortisone is used to treat rheumatism, skin diseases, and allergies.
Hydrocortisone tablets. Source: Wisegeeks
Thus, there is the potential for another example of drug repurposing here. But the drug is not without side effects, which include:
- Sleep problems (insomnia)
- Mood changes
- Acne, dry skin, thinning skin, bruising or discoloration;
- Slow wound healing
- Increased sweating
- Headache, dizziness, spinning sensation;
- nausea, stomach pain
For the full list of potential side effects – click here.
So what does it all mean?
Researchers in Korea have recently found that hydrocortisone (cortisol) can increase levels of Parkinson’s associated protein Parkin in cells, which in turn has a positive, neuroprotective effect on models of Parkinson’s disease.
We will now wait to see if the results can be independently replicated before attempting to take this drug to clinical trials for Parkinson’s disease. Any replication of the study should involve a range of treatment regimes so that we can determine if delayed administration can also be beneficial (this would involve delaying hydrocortisone treatment until after the neurotoxin has been given). Those studies could also look at the inflammatory effect in the brains as hydrocortisone has previously been demonstrated to have anti-inflammatory effects.
Interesting times. 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. While some of the drugs discussed on this website are clinically available, they may have serious side effects. We urge caution and professional consultation before altering any treatment regime. SoPD can not be held responsible for any actions taken based on the information provided here.
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