Lrrking in low orbit

Last Monday, a SpaceX rocket lifted off from the Florida peninsular on route to the International Space Station.

On board that craft was an experiment that could have big implications for Parkinson’s disease. It involves a Parkinson’s-associated protein called Leucine-rich repeat kinase 2 (or LRRK2).

In today’s post, we will discuss why we needed to send this protein into orbit.

The International Space Station. Source: NASA

When you look up at the sky tonight – if you look for long enough – you may well see a bright little object hurtling across the sky (Click here to learn more about how to track the International Space Station). Know that inside that bright little object passing over you there is currently some Parkinson’s disease-related research being conducted.

What is the International Space Station?

The International Space Station (or the ISS) is the largest human-made object that we have ever put into space. It is so big in fact that you can see it with the naked eye from Earth.

(How’s that for exciting viewing?)

The current space station is 73.3 metres (240 feet) long and 44.5 metres (146 feet) wide, weighing approximately 420 tonnes (924,740 lb), and it has been continuously occupied for 16 years and 289 days, making it the longest continuous human presence in low Earth orbit. The ISS travels at a speed of 7.67 km/second, maintains an altitude of between 330 and 435 km (205 and 270 mi), and completes 15.54 orbits per day (it has made over 102,000 orbits!).

The size of the the ISS compared to a Boeing Jumbo jet. Source: Reddit

First approved by President Ronald Reagan in 1984, it was not until November 1998 that the first components of the International space station were first launched into orbit. 36 shuttle flights were made to help build the station. The first crew members took up residence on the 2nd November 2000, and the station was completed in 2011. There is always 6 crew members on board – the current team are Expedition 52 – and it has been visited by 220 astronauts, cosmonauts and space tourists from 17 different nations since the project began.

Oh yeah, and if you want to see what it looks like on board the ISS, in 2015 the European Space Agency provided an interactive tour and earlier this year Google Maps added an interactive tour of the ISS.

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Dementia with Lewy Bodies: New recommendations

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Last year – two years after actor Robin Williams died – his wife Susan Schneider Williams wrote an essay entitled The terrorist inside my husband’s head, published in the journal Neurology.

It is a heartfelt/heartbreaking insight into the actor’s final years. It also highlights the plight of many who are diagnosed with Parkinson’s disease, but experience an array of additional symptoms that leave them feeling that something else is actually wrong.

Today’s post is all about Dementia with Lewy bodies (or DLB). In particular, we will review the latest refinements and recommendations of the Dementia with Lewy Bodies Consortium, regarding the clinical and pathologic diagnosis of DLB.

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Robin Williams. Source: Quotesgram

On the 28th May of 2014, the actor Robin Williams was diagnosed with Parkinson’s disease.

At the time, he had a slight tremor in his left hand, a slow shuffling gait and mask-like face – some of the classical features of Parkinson’s disease.

According to his wife, the diagnosis gave the symptoms Robin had been experiencing a name. And this brought her a sense of relief and comfort. Now they could do something about the problem. Better to know what you are dealing with rather than be left unsure and asking questions.

But Mr Williams sensed that something else was wrong, and he was left unsure and asking questions. While filming the movie Night at the Museum 3, Williams experienced panic attacks and regularly forgot his lines. He kept asking the doctors “Do I have Alzheimer’s? Dementia? Am I schizophrenic?”

Williams took his own life on the 11th August 2014, and the world mourned the tragic loss of a uniquely talented performer.

Source: WSJ

When the autopsy report came back from the coroner, however, it indicated that the actor had been misdiagnosed.

He didn’t have Parkinson’s disease.

What he actually had was Dementia with Lewy bodies (or DLB).

What is Dementia with Lewy bodies?

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DPP-4: Not a Star Wars character

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Dipeptidyl peptidase-4 (or DPP-4) is an enzyme that breaks down the protein (GLP-1) that stimulates insulin release in your body. 

Inhibitors of DPP-4 are used in the treatment of Type 2 diabetes, because they help increase insulin levels in the body.

Recently some Swedish researchers noticed something curious about DPP-4 inhibitors: They appear to reduce the risk of developing Parkinson’s disease.

In today’s post, we will review what DPP-4 inhibitors do and look at how this could be reducing the risk of Parkinson’s disease.

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Sitagliptin. Source: Diabetesmedicine

Last year an interesting research report about a class of medications that could possibly reduce the risk of developing Parkinson’s disease was published in the journal Movement disorders:

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Title: Reduced incidence of Parkinson’s disease after dipeptidyl peptidase-4 inhibitors-A nationwide case-control study.
Authors: Svenningsson P, Wirdefeldt K, Yin L, Fang F, Markaki I, Efendic S, Ludvigsson JF.
Journal: Movement Disorders 2016 Jul 19.
PMID: 27431803

In this study, the investigators used the Swedish Patient Register, to find the medical records of 980 people who were diagnosed with Parkinson’s disease but also had type 2 diabetes. Importantly, all of the subjects had been treated with Type 2 diabetes medication for at least 6 months prior to the date of Parkinson’s being diagnosed.

For comparative sake, they selected 5 controls (non-Parkinsonian) with Type 2 diabetes (n = 4,900) for each of their Parkinsonian+diabetes subjects. They next looked at whether GLP-1R agonists (such as Exenatide), Dipeptidyl peptidase-4 (or DPP-4) inhibitors, or any other oral Type 2 diabetic medication can influence the incidence of Parkinson’s disease.

Now, if all things are considered equal, then when looking at each diabetes medication there should be 1 person in the Parkinson’s disease + Type 2 diabetes for every 5 people in the Type 2 diabetes control group taking each medication right? That is because there are almost 1000 people in the first group and 5000 in the second group.

But this is not what the researchers found.

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Exenatide: An editorial

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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.

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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:

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Exenatide: One step closer to joblessness!

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The title of today’s post is written in jest – my job as a researcher scientist is to find a cure for Parkinson’s disease…which will ultimately make my job redundant! But all joking aside, today was a REALLY good day for the Parkinson’s community.

Last night (3rd August) at 23:30, a research report outlining the results of the Exenatide Phase II clinical trial for Parkinson’s disease was published on the Lancet website.

And the results of the study are good:while the motor symptoms of Parkinson’s disease subject taking the placebo drug proceeded to get worse over the study, the Exenatide treated individuals did not.

The study represents an important step forward for Parkinson’s disease research. In today’s post we will discuss what Exenatide is, what the results of the trial actually say, and where things go from here.

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Last night, the results of the Phase II clinical trial of Exenatide in Parkinson’s disease were published on the Lancet website. In the study, 62 people with Parkinson’s disease (average time since diagnosis was approximately 6 years) were randomly assigned to one of two groups, Exenatide or placebo (32 and 30 people, respectively). The participants were given their treatment once per week for 48 weeks (in addition to their usual medication) and then followed for another 12-weeks without Exenatide (or placebo) in what is called a ‘washout period’. Neither the participants nor the researchers knew who was receiving which treatment.

At the trial was completed (60 weeks post baseline), the off-medication motor scores (as measured by MDS-UPDRS) had improved by 1·0 points in the Exenatide group and worsened by 2·1 points in the placebo group, providing a statistically significant result (p=0·0318). As you can see in the graph below, placebo group increased their UPDRS motor score over time (indicating a worsening of motor symptoms), while Exenatide group (the blue bar) demonstrated improvements (or a lowering of motor score).

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Reduction in motor scores in Exenatide group. Source: Lancet

This is a tremendous result for Prof Thomas Foltynie and his team at University College London Institute of Neurology, and for the Michael J Fox Foundation for Parkinson’s Research who funded the trial. Not only do the results lay down the foundations for a novel range of future treatments for Parkinson’s disease, but they also validate the repurposing of clinically available drug for this condition.

In this post we will review what we know thus far. And to do that, let’s start at the very beginning with the obvious question:

So what is Exenatide?

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The next killer APP: LRRK2 inhibitors?

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In Silicon valley (California), everyone is always looking for the “next killer app” – the piece of software (or application) that is going to change the world. The revolutionary next step that will solve all of our problems.

The title of today’s post is a play on the words ‘killer app’, but the ‘app’ part doesn’t refer to the word application. Rather it relates to the Alzheimer’s disease-related protein Amyloid Precursor Protein (or APP). Recently new research has been published suggesting that APP is interacting with a Parkinson’s disease-related protein called Leucine-rich repeat kinase 2 (or LRRK2).

The outcome of that interaction can have negative consequences though.

In today’s post we will discuss what is known about both proteins, what the new research suggests and what it could mean for Parkinson’s disease.

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Seattle. Source: Thousandwonders

In the mid 1980’s James Leverenz and Mark Sumi of the University of Washington School of Medicine (Seattle) made a curious observation.

After noting the high number of people with Alzheimer’s disease that often displayed some of the clinical features of Parkinson’s disease, they decided to examined the postmortem brains of 40 people who had passed away with pathologically confirmed Alzheimer’s disease – that is, an analysis of their brains confirmed that they had Alzheimer’s.

What the two researchers found shocked them:

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Title: Parkinson’s disease in patients with Alzheimer’s disease.
Authors: Leverenz J, Sumi SM.
Journal: Arch Neurol. 1986 Jul;43(7):662-4.
PMID: 3729742

Of the 40 Alzheimer’s disease brains that they looked at nearly half of them (18 cases) had either dopamine cell loss or Lewy bodies – the characteristic features of Parkinsonian brain – in a region called the substantia nigra (where the dopamine neurons are located). They next went back and reviewed the clinical records of these cases and found that rigidity, with or without tremor, had been reported in 13 of those patients. According to their analysis 11 of those patients had the pathologic changes that warranted a diagnosis of Parkinson’s disease.

And the most surprising aspect of this research report: Almost all of the follow up studies, conducted by independent investigators found exactly the same thing!

It is now generally agreed by neuropathologists (the folks who analyse sections of brain for a living) that 20% to 50% of cases of Alzheimer’s disease have the characteristic round, cellular inclusions that we call Lewy bodies which are typically associated with Parkinson disease. In fact, in one analysis of 145 Alzheimer’s brains, 88 (that is 60%!) had chemically verified Lewy bodies (Click here to read more about that study).

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A lewy body (brown with a black arrow) inside a cell. Source: Cure Dementia

Oh, and if you are wondering whether this is just a one way street, the answer is “No sir, this phenomenon works both ways”: the features of the Alzheimer’s brain (such as the clustering of a protein called beta-amyloid) are also found in many cases of pathologically confirmed Parkinson’s disease (Click here and here to read more about this).

So what are you saying? Alzheimer’s and Parkinson’s disease are the same thing???

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Nilotinib: the other phase II trial

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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.

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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.

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The myth of Spring babies

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In large datasets, strange anomalies can appear that may tell us something new about a condition, such as the curious association between melanoma and Parkinson’s disease.

These anomalies can also appear in small datasets, such as the idea that spring babies are more at risk of developing Parkinson’s disease. But the smaller dataset results may be a bit misleading.

In today’s post, we will look at what evidence there is supporting the idea that people born in the spring are more vulnerable to Parkinson’s disease.

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Spring lambs. Source: Wenatcheemumblog

When is your birthday?

More specifically, which month were you born in? Please feel free to leave your answer in the comments section below this post.

Why do I ask?

In 1987, an interesting research report was published in a scientific research book:

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Title: Season of birth in parkinsonism.
Authors: Miura, T., Shimura, M., and Kimura, T.
Book: Miura T. (ed) Seasonality of birth:Progress in biometeorology, 1987.p157-162. Hague, Netherlands.
PMID: N/A

In the report, the researchers outlined a study that they had conducted on the inhabitants of an asylum for the aged in Tokyo (Japan). They had found not only a very high rate of Parkinsonism (6.5% of the inhabitants), but also that the majority of those individuals affected by the Parkinsonism were born in the first half of the year (regardless of which year they were actually born).

Sounds crazy right? (excuse the pun)

And that was probably what everyone who read the report thought….

…except that one year later this independent group in the UK published a very similar result:

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The Agony and the Ecstasy

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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.

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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.

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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.

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Higher socioeconomic status jobs

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People with high socioeconomic status jobs are believed to be better off in life.

New research published last week by the Centre for Disease Control, however, suggests that this may not be the case with regards to one’s risk of developing Parkinson’s disease.

In today’s post we will review the research and discuss what it means for our understanding of Parkinson’s disease.

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The impact of socioeconomic status. Source: Medicalxpress

In 2013, a group of researchers at Carnegie Mellon University found a rather astonishing but very interesting association:

Children from lower socioeconomic status have shorter telomeres as adults.

Strange, right?

Yeah, wow, strange… sorry, but what are telomeres?

Do you remember how all of your DNA is wound up tightly into 23 pairs of chromosomes? Well, telomeres are at the very ends of each of those chromosomes. They are literally the cap on each end. The name is derived from the Greek words ‘telos‘ meaning “end”, and ‘merοs‘ meaning “part”.

Telomeres are regions of repetitive nucleotide sequences (think the As, Gs, Ts, & Cs that make up your DNA) at each end of a chromosome. Their purpose seems to involve protecting the end of each chromosome from deteriorating or fusing with neighbouring chromosomes. Researchers also use their length is a marker of ageing because every time a cell divides, the telomeres on each chromosome gradually get shorter.

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