New research from multiple independent research groups proposes that one Parkinson’s associated protein (LRRK2) may be affecting the activity of another Parkinson’s associated protein (GCase).
Specifically, when LRRK2 becomes hyperactive (as is the situation in some cases of Parkinson’s), it causes is associated with a reduction in the amount of GCase activity.
In today’s post, we will discuss what LRRK2 and GCase both do, what the new research suggests, and how this news could influence efforts to treat Parkinson’s in the future.
Connections. Source: Philiphemme
For a long time, the Parkinson’s research community had a set of disconnected genetic risk factors – tiny errors in particular regions of DNA that were associated with an increased risk of developing Parkinson’s – but there seemed to be little in the way of common connections between them.
Known genetic associations with PD. Source: PMC
The researchers studied the biological pathways associated with these risk factors, trying to identify potential therapeutic angles as well as looking for connections between them.
The therapies are currently being clinically tested (Click here to read more about these), but the connections have taken a lot longer to find.
Recently one important connection has been identified by several research groups and it could have important implications for how Parkinson’s will be treated in the future.
What’s the connection?
There is a great deal of interest in genetic risk factors in Parkinson’s at the moment. A number of companies are providing direct-to-consumer services which provide individuals with some information about their family history and whether they have any of the more common genetic variations that are associated with medical conditions, like Parkinson’s.
Recently a new genetic data company has started – called Nebula Genomics – and they are offering a slightly different kind of service.
While many of the direct-to-consumer genetic companies have a business model that involves selling on genetic information to third parties, Nebula is offering a more patient-empowering option.
In today’s post, we will discuss the genetics of Parkinson’s, what Nebula Genomics is offering, and how this new service could be useful for the Parkinson’s community.
Prof George Church. Source: Biospace
Professor George Church is a person most readers will have never heard of.
He is the Robert Winthrop Professor of Genetics at Harvard Medical School and Professor of Health Sciences and Technology at Harvard and MIT, and was a founding member of the Wyss Institute for Biologically Inspired Engineering at Harvard.
He has co-author of over 500 academic papers, 143 patents and co-founded 22 biotech companies. In addition, he has participated in technology development, advising most of the major Genetic Sequencing companies, and he has been at the forefront of genetic research since the 1980s when he was involved with setting up the Human Genome Project.
His impact in the world of genetics has been tremendous.
But Prof Church is also something of a maverick. A left-field thinker. A disrupter.
He is a great supporter of open access genome sequencing and shareable human medical data. He is also keen to bring back extinct species, such as the Woolly Mammoth (Click here for more on this idea).
The return of the woolly mammoth. Source: Phys
Most recently, however, his name has been associated with a new company called Nebula Genomics.
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???