At the end of each year, it is a useful practise to review the triumphs (and failures) of the past 12 months. It is an exercise of putting everything into perspective.
2017 has been an incredible year for Parkinson’s research.
And while I appreciate that statements like that will not bring much comfort to those living with the condition, it is still important to consider and appreciate what has been achieved over the last 12 months.
In this post, we will try to provide a summary of the Parkinson’s-related research that has taken place in 2017 (Be warned: this is a VERY long post!)
The number of research reports and clinical trial studies per year since 1817
As everyone in the Parkinson’s community is aware, in 2017 we were observing the 200th anniversary of the first description of the condition by James Parkinson (1817). But what a lot of people fail to appreciate is how little research was actually done on the condition during the first 180 years of that period.
The graphs above highlight the number of Parkinson’s-related research reports published (top graph) and the number of clinical study reports published (bottom graph) during each of the last 200 years (according to the online research search engine Pubmed – as determined by searching for the term “Parkinson’s“).
PLEASE NOTE, however, that of the approximately 97,000 “Parkinson’s“-related research reports published during the last 200 years, just under 74,000 of them have been published in the last 20 years.
That means that 3/4 of all the published research on Parkinson’s has been conducted in just the last 2 decades.
And a huge chunk of that (almost 10% – 7321 publications) has been done in 2017 only.
So what happened in 2017? Continue reading
This week Denali Therapeutics released the results of a phase I clinical trial of their primary product, called DNL-201.
DNL-201 is a LRRK2 inhibitor that the company is attempting to take to the clinic for Parkinson’s disease.
In today’s post we will look at what LRRK2 is, how an inhibitor might help in Parkinson’s, and what the results of the trial actually mean.
Denali. Source: Wikipedia
Denali (Koyukon for “the high one”; also known as Mount McKinley) in Alaska is the highest mountain peak in North America, with a summit elevation of 20,310 feet (6,190 m) above sea level. The first verified ascent to Denali’s summit occurred on June 7, 1913, by four climbers Hudson Stuck, Harry Karstens, Walter Harper, and Robert Tatum.
Tatum (left), Karstens (middle), and Harper (right). Source: Gutenberg
Robert Tatum later commented, “The view from the top of Mount McKinley is like looking out the windows of Heaven!”
More recently another adventurous group associated with ‘Denali’ have been trying to scale lofty heights, but of a completely different sort from the mountaineering kind.
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.
Genetic mutations (or ‘variants’) in the Leucine-rich repeat kinase 2 (or LRRK2; also known as Dardarin) gene are associated with increased risk of Parkinson’s. As a result this gene has become the focus of a lot of genetic research.
But what about LRRK2’s less well-known, rather neglected sibling LRRK1?
In today’s post, we will look at new research that suggests the LRRK siblings could both be involved with Parkinson’s disease.
I recommend to the reader that today’s post should be read with the following music playing in the background:
Inspired by a poem of the same title, English composer Ralph Vaughan Williams wrote ‘The Lark Ascending’ in 1914. It is still to this day, a tune that remains a firm favourite with BBC listeners here in the UK (Source).
On to business:
While the music and the poem are about a songbird, today’s SoPD post deals with a different kind of Lark.
Or should I say LRRK.
This is Sergey Brin.
He was one of the founders of a small company you may have heard of – it’s called “Google”.
Having changed the way the world searches the internet, he is now turning his attention to other projects.
One of those other projects is close to our hearts: Parkinson’s disease.
Nuclear receptor related 1 protein (or NURR1) is a protein that is critical to the development and survival of dopamine neurons – the cells in the brain that are affected in Parkinson’s disease.
Given the importance of this protein for the survival of these cells, a lot of research has been conducted on finding activators of NURR1.
In today’s post we will look at this research, discuss the results, and consider issues with regards to using these activators in Parkinson’s disease.
Comet Hale–Bopp. Source: Physics.smu.edu
Back in 1997, 10 days after Comet Hale–Bopp passed perihelion (April 1, 1997 – no joke; perihelion being the the point in the orbit of a comet when it is nearest to the sun) and just two days before golfer Tiger Woods won his first Masters Tournament, some researchers in Stockholm (Sweden) published the results of a study that would have a major impact on our understanding of how to keep dopamine neurons alive.
Dopamine neurons are one group of cells in the brain that are severely affected by Parkinson’s disease. By the time a person begins to exhibit the movement symptoms of the condition, they will have lost 40-60% of the dopamine neurons in a region called the substantia nigra. In the image below, there are two sections of brain – cut on a horizontal plane through the midbrain at the level of the substantia nigra – one displaying a normal compliment of dopamine neurons and the other from a person who passed away with Parkinson’s demonstrating a reduction in this cell population.
The dark pigmented dopamine neurons in the substantia nigra are reduced in the Parkinson’s disease brain (right). Source:Memorangapp
The researchers in Sweden had made an amazing discovery – they had identified a single gene that was critical to the survival of dopamine neurons. When they artificially mutated the section of DNA where this gene lives – an action which resulted in no protein for this gene being produced – they generated genetically engineered mice with no dopamine neurons:
Title: Dopamine neuron agenesis in Nurr1-deficient mice
Authors: Zetterström RH, Solomin L, Jansson L, Hoffer BJ, Olson L, Perlmann T.
Journal: Science. 1997 Apr 11;276(5310):248-50.
The researchers who conducted this study found that the mice with no NURR1 protein exhibited very little movement and did not survive long after birth. And this result was very quickly replicated by other research groups (Click here and here to see examples)
So what was this amazing gene called?
We have previously discussed the powerful antioxidant Resveratrol, and reviewed the research suggesting that it could be beneficial in the context of Parkinson’s disease (Click here to read that post).
I have subsequently been asked by several readers to provide a critique of the Parkinson’s-associated research focused on Resveratrol’s twin sister, Pterostilbene (pronounced ‘Terra-still-bean’).
But quite frankly, I can’t.
Why? Because there is NO peer-reviewed scientific research on Pterostilbene in models of Parkinson’s disease.
In today’s post we will look at what Pterostilbene is, what is known about it, and why we should seriously consider doing some research on this compound (and its cousin Piceatannol) in the context of Parkinson’s disease.
Blue berries are the best natural source of Pterostilbene. Source: Pennington
So this is likely to be the shortest post in SoPD history.
Because there is nothing to talk about.
There is simply no Parkinson’s-related research on the topic of today’s post: Pterostilbene. And that is actually a crying shame, because it is a very interesting compound.
What is Pterostilbene?
Like Resveratrol, Pterostilbene is a stilbenoid.
Stilbenoids are a large class of compounds that share the basic chemical structure of C6-C2-C6:
Resveratrol is a good example of a stilbenoid. Source: Wikipedia
Stilbenoids are phytoalexins (think: plant antibiotics) produced naturally by numerous plants. They are small compounds that become active when the plant is under attack by pathogens, such as bacteria or fungi. Thus, their function is generally considered to part of an anti-microbial/anti-bacterial plant defence system for plants.
The most well-known stilbenoid is resveratrol which grabbed the attention of the research community in a 1997 study when it was found to inhibit tumour growth in particular animal models of cancer:
This week a group of scientists have published an article which indicates differences between mice and human beings, calling into question the use of these mice in Parkinson’s disease research.
The results could explain way mice do not get Parkinson’s disease, and they may also partly explain why humans do.
In today’s post we will outline the new research, discuss the results, and look at whether Levodopa treatment may (or may not) be a problem.
The humble lab mouse. Source: PBS
Much of our understanding of modern biology is derived from the “lower organisms”.
From yeast to snails (there is a post coming shortly on a snail model of Parkinson’s disease – I kid you not) and from flies to mice, a great deal of what we know about basic biology comes from experimentation on these creatures. So much in fact that many of our current ideas about neurodegenerative diseases result from modelling those conditions in these creatures.
Now say what you like about the ethics and morality of this approach, these organisms have been useful until now. And I say ‘until now’ because an interesting research report was released this week which may call into question much of the knowledge we have from the modelling of Parkinson’s disease is these creatures.
You see, here’s the thing: Flies don’t naturally develop Parkinson’s disease.
Nor do mice. Or snails.
Or yeast for that matter.
So we are forcing a very un-natural state upon the biology of these creatures and then studying the response/effect. Which could be giving us strange results that don’t necessarily apply to human beings. And this may explain our long history of failed clinical trials.
We work with the best tools we have, but it those tools are flawed…
What did the new research report find?
This is the study:
Title: Dopamine oxidation mediates mitochondrial and lysosomal dysfunction in Parkinson’s disease
Authors: Burbulla LF, Song P, Mazzulli JR, Zampese E, Wong YC, Jeon S, Santos DP, Blanz J, Obermaier CD, Strojny C, Savas JN, Kiskinis E, Zhuang X, Krüger R, Surmeier DJ, Krainc D
Journal: Science, 07 Sept 2017 – Early online publication
The researchers who conducted this study began by growing dopamine neurons – a type of cell badly affected by Parkinson’s disease – from induced pluripotent stem (IPS) cells.
What are induced pluripotent stem cells?
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.
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.
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.
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:
Title: Parkinson’s disease in patients with Alzheimer’s disease.
Authors: Leverenz J, Sumi SM.
Journal: Arch Neurol. 1986 Jul;43(7):662-4.
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).
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???