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.
Recently a Parkinson’s-associated research report was published that was the first of many to come.
It involves the use of a genetic screening experiment that incorporates new technology called ‘CRISPR’.
There is an absolute tidal wave of CRISPR-related Parkinson’s disease research coming down the pipe towards us, and it is important that the Parkinson’s community understands how this powerful technology works.
In today’s post we will look at what the CRISPR technology is, how it works, what the new research report actually reported, and discuss how this technology can be used to tackle a condition like Parkinson’s.
Me and my mother (and yes, the image is to scale). Source: Openclipart
My mother: Simon, what is all this new ‘crispy’ research for Parkinson’s I heard about on the news?
Me: Huh? (I was not really paying attention to the question. Terrible to ignore one’s mother I know, but what can I say – I am the black sheep of the family)
My mother: Yes, something about ‘crispy’ and Parkinson’s.
Me: Oh! You mean CRISPR. Yeah, it’s really cool stuff.
My mother: Ok, well, can you explain it all to me please, this ‘Crisper’ stuff?
CRISPR.101 (or CRISPR for beginners)
In almost every cell of your body, there is a nucleus.
It is the command centre for the cell – issuing orders and receiving information concerning everything going on inside and around the cell. The nucleus is also a storage bank for the genetic blueprint that provides most of the instructions for making a physical copy of you. Those grand plans are kept bundled up in 23 pairs of chromosomes, which are densely coiled strings of a molecule called Deoxyribonucleic acid (or DNA).
DNA’s place inside the cell. Source: Kids.Britannica
Recently I discussed my ‘Plan B’ idea, which involves providing a cheap alternative to expensive drugs for folks living in the developing world with Parkinson’s (Click here for that post).
While doing some research for that particular post, I came across another really interesting bit of science that is being funded by Parkinson’s UK.
It involves Beetroot.
In today’s post we will look at how scientists are attempting turn this red root vegetable into a white root vegetable in an effort to solve Parkinson’s in the developing world.
Pompeii and Mount Vesuvius. Source: NationalGeo
During visits to the ancient Roman city of Pompeii (in Italy), tourists are often drawn by their innocent curiosity to the ‘red light’ district of the city. And while they are there, they are usually amused by the ‘descriptive’ murals that still line the walls of the buildings in that quarter.
So amused in fact that they often miss the beetroots.
I’m not suggesting that anyone spends a great deal of time making a close inspection of the walls, but if you look very carefully, you will often see renditions of beetroots.
They are everywhere. For example:
Two beetroots hanging from the ceiling.
The Romans considered beetroot to be quite the aphrodisiac, believing that the juice ‘promoted amorous feelings’. They also ate the red roots for medicinal purposes, consuming it as a laxative or to cure fever.
And this medicinal angle lets me segway nicely into the actual topic of today’s post. You see, in the modern era researcher are hoping to use beetroot for medicinal purposes again. But this time, the beetroot will be used to solve an issue close to my heart: treating people with Parkinson’s in the developing world.
Using beetroot to treat Parkinson’s?
In American slang, to ‘nix‘ something is to ‘put an end to it’.
Curiously, a protein called NIX may be about to help us put an end to Parkinson’s disease, at least in people with specific genetic mutations.
In today’s post we will look at what NIX is, outline a new discovery about it, and discuss what this new information will mean for people living with Parkinson’s disease.
Sydney harbour. Source: uk.Sydney
Before we start, I would like the reader to appreciate that I am putting trans-Tasman rivalry side here to acknowledge some really interesting research that is being conducted in Australia at the moment.
And this is really interesting.
I have previously spoken a lot about mitochondria and Parkinson’s on this website. For the uninitiated, mitochondria are the power house of each cell. They help to keep the lights on. Without them, the party is over and the cell dies.
Mitochondria and their location in the cell. Source: NCBI
You may remember from high school biology class that mitochondria are tiny bean-shaped objects within the cell. They convert nutrients from food into Adenosine Triphosphate (or ATP). ATP is the fuel which cells run on. Given their critical role in energy supply, mitochondria are plentiful (some cells have thousands) and highly organised within the cell, being moved around to wherever they are needed.
Like you and I and all other things in life, however, mitochondria have a use-by date.
As mitochondria get old and worn out (or damaged) with time, the cell will recycle them via a process called mitophagy (a blending of the words mitochondria and autophagy – the waste disposal system of each cell).
What does this have to do with Parkinson’s disease?
Well, about 10% of Parkinson’s cases are associated with particular genetic variations that render people vulnerable to developing the condition. Some of these mutations are in sections of DNA (called genes) that provide the instructions for proteins that are involved in the process of mitophagy. Two genes, in particular, are the focus of a lot of Parkinson’s-related research – they are called PARKIN and PINK1.
What do PARKIN and PINK1 do?
In a recent post, I discussed research looking at foods that can influence the progression of Parkinson’s (see that post here). I am regularly asked about the topic of food and will endeavour to highlight more research along this line in future post.
In accordance with that statement, today we are going to discuss Cruciferous vegetables, and why we need a clinical trial of broccoli.
I’m not kidding.
There is growing research that a key component of broccoli and other cruciferous vegetables – called Glucoraphanin – could have beneficial effects on Parkinson’s disease. In today’s post, we will discuss what Glucoraphanin is, look at the research that has been conducted and consider why a clinical trial of broccoli would be a good thing for Parkinson’s disease.
Cruciferous vegetables. Source: Diagnosisdiet
Like most kids, when I was young I hated broccoli.
Man, I hated it. With such a passion!
Usually they were boiled or steamed to the point at which they have little or no nutritional value, and they largely became mush upon contact with my fork.
The stuff of my childhood nightmares. Source: Modernpaleo
As I have matured (my wife might debate that statement), my opinion has changed and I have come to appreciate broccoli. Our relationship has definitely improved.
In fact, I have developed a deep appreciation for all cruciferous vegetables.
And yeah, I know what you are going to ask:
What are cruciferous vegetables?
Cruciferous vegetables are vegetables of the Brassicaceae family (also called Cruciferae). They are a family of flowering plants commonly known as the mustards, the crucifers, or simply the cabbage family. They include cauliflower, cabbage, garden cress, bok choy, broccoli, brussels sprouts and similar green leaf vegetables.
Cruciferous vegetables. Source: Thetherapyshare
So what have Cruciferous vegetables got to do with Parkinson’s?
Well, it’s not the vegetables as such that are important. Rather, it is a particular chemical that this family of plants share – called Glucoraphanin – that is key.
What is Glucoraphanin?
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?
The title of this post probably reads like the mad, drug-fuelled scream of a drunk Saturday night party animal, but the elements of it may be VERY important for a particular kind of Parkinson’s disease.
Mutations in a gene called DJ-1 can cause an early onset form of Parkinson’s disease. The protein of DJ-1 plays an important role in how cells handle oxidative stress – or the increase in damaging free radicals (explained below).
This week researchers announced that they have found an interesting new therapeutic target for people with DJ-1 associated Parkinson’s disease: A chemical called Isocitrate.
In this post, we will discuss what DJ-1 is involved with Parkinson’s disease, how isocitrate helps the situation, and what the results of new research mean for future therapeutic strategies.
In 2017, we are not only observing the 200 year anniversary of the first description of Parkinson’s disease (by one Mr James Parkinson), but also the 20th anniversary of the discovery of the first genetic variation associated with the condition (Click here to read more about that). Our understanding of the genetics of Parkinson’s disease since 1997, has revolutionised the way we look at Parkinson’s disease and opened new doors that have aided us in our understanding.
During the last 20 years, we have identified numerous sections of DNA (these regions are called genes) where small errors in the genetic coding (mutations or variants) can result in an increased risk of developing Parkinson’s disease. As the graph below indicates, mutations in some of these genes are very rare, but infer a very high risk, while others are quite common but have a low risk of Parkinson’s disease.
The genetics of PD. Source: Journal of Parkinson’s disease
Some of the genetic mutation need to be provided by both the parents for Parkinson’s to develop (an ‘autosomal recessive‘ mutation – the yellow circles in the graph above); while in other cases the genetic variant needs only to be provided by one of the parents (an ‘autosomal dominant’ mutation – the blue circles). Many of the genetic mutations are very common and simply considered a region of increased risk (green circles).
Importantly, all of these genes provide the instructions for making a protein – which are the functional parts in a cell. And each of these proteins have specific roles in biological processes. These functions tell us a little bit about how Parkinson’s disease may be working. Each of them is a piece of the jigsaw puzzle that we are trying to finish. As you can see in the image below, many of the genes mentioned in the graph above give rise to proteins that are involved in different parts of the process of autophagy – or the waste disposal system of the cell. You may notice that some proteins, like SCNA (otherwise known as alpha synuclein), are involved in multiple steps in this process.
The process of autophagy. Source: Nature
In today’s post we are going to look at new research regarding just one of these genes/proteins. It is called DJ-1, also known as Parkinson disease protein 7 (or PARK7).
What is DJ-1?
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???
Two months ago a research report was published in the scientific journal ‘Nature’ and it caused a bit of a fuss in the embryonic stem cell world.
Embryonic stem (ES) cells are currently being pushed towards the clinic as a possible source of cells for regenerative medicine. But this new report suggested that quite a few of the embryonic stem cells being tested may be carrying genetic variations that could be bad. Bad as in cancer bad.
In this post, I will review the study and discuss what it means for cell transplantation therapy for Parkinson’s disease.
For folks in the stem cell field, the absolute go-to source for all things stem cell related is Prof Paul Knoepfler‘s blog “The Niche“. From the latest scientific research to exciting new stem cell biotech ventures (and even all of the regulatory changes being proposed in congress), Paul’s blog is a daily must read for anyone serious about stem cell research. He has his finger on the pulse and takes the whole field very, very seriously.
For a long time now, Paul has been on a personal crusade. Like many others in the field (including yours truly), he has been expressing concern about the unsavoury practices of the growing direct-to-consumer, stem cell clinic industry. You may have seen him mentioned in the media regarding this topic (such as this article).
The real concern is that while much of the field is still experimental, many stem cell clinics are making grossly unsubstantiated claims to draw in customers. From exaggerated levels of successful outcomes (100% satisfaction rate?) all the way through to talking about clinical trials that simply do not exist. The industry is badly (read: barely) regulated which is ultimately putting patients at risk (one example: three patients were left blind after undergoing an unproven stem cell treatment – click here to read more on this).
While the stem cell research field fully understands and appreciates the desperate desire of the communities affected by various degenerative conditions, there has to be regulations and strict control standards that all practitioners must abide by. And first amongst any proposed standards should be that the therapy has been proven to be effective for a particular condition in independently audited double blind, placebo controlled trials. Until such proof is provided, the sellers of such products are simply preying on the desperation of the people seeking these types of procedures.
In this post we discuss several recently published research reports suggesting that Parkinson’s disease may be an autoimmune condition. “Autoimmunity” occurs when the defence system of the body starts attacks the body itself.
This new research does not explain what causes of Parkinson’s disease, but it could explain why certain brain cells are being lost in some people with Parkinson’s disease. And such information could point us towards novel therapeutic strategies.
The first issue of Nature. Source: SimpleWikipedia
The journal Nature was first published on 4th November 1869, by Alexander MacMillan. It hoped to “provide cultivated readers with an accessible forum for reading about advances in scientific knowledge.” It has subsequently become one of the most prestigious scientific journals in the world, with an online readership of approximately 3 million unique readers per month (almost as much as we have here at the SoPD).
Each Wednesday afternoon, researchers around the world await the weekly outpouring of new research from Nature. And this week a research report was published in Nature that could be big for the world of Parkinson’s disease. Really big!
On the 21st June, this report was published:
Title: T cells from patients with Parkinson’s disease recognize α-synuclein peptides
Authors: Sulzer D, Alcalay RN, Garretti F, Cote L, Kanter E, Agin-Liebes J, Liong C, McMurtrey C, Hildebrand WH, Mao X, Dawson VL, Dawson TM, Oseroff C, Pham J, Sidney J, Dillon MB, Carpenter C, Weiskopf D, Phillips E, Mallal S, Peters B, Frazier A, Lindestam Arlehamn CS, Sette A
Journal: Nature. 2017 Jun 21. doi: 10.1038/nature22815.
In their study, the investigators collected blood samples from 67 people with Parkinson’s disease and from 36 healthy patients (which were used as control samples). They then exposed the blood samples to fragments of proteins found in brain cells, including fragments of alpha synuclein – this is the protein that is so closely associated with Parkinson’s disease (it makes regular appearances on this blog).
What happened next was rather startling: the blood from the Parkinson’s patients had a strong reaction to two specific fragments of alpha synuclein, while the blood from the control subjects hardly reacted at all to these fragments.
In the image below, you will see the fragments listed along the bottom of the graph (protein fragments are labelled with combinations of alphabetical letters). The grey band on the plot indicates the two fragments that elicited a strong reaction from the blood cells – note the number of black dots (indicating PD samples) within the band, compared to the number of white dots (control samples). The numbers on the left side of the graph indicate the number of reacting cells per 100,000 blood cells.
The investigators concluded from this experiment that these alpha synuclein fragments may be acting as antigenic epitopes, which would drive immune responses in people with Parkinson’s disease and they decided to investigate this further.