James Parkinson

200 years later, the search for a cure for Parkinson’s continues

/ Kevin McCormack / Leave a comment

On the surface, actor Michael J. Fox, singer Neil Diamond, civil rights activist Jesse Jackson and Scottish comedian Billy Connolly would appear to have little in common. Except for one thing. They all have Parkinson’s Disease (PD).

Their celebrity status has helped raise public awareness about the condition, but studies show that awareness doesn’t amount to an understanding of PD or the extent to which it impacts someone’s life. In fact a study in the UK found that many people still don’t think PD is a serious condition.

To try and help change that people around the world will be holding events today, April 11th, World Parkinson’s Day.

The disease was first described by James Parkinson in 1817 in “An Essay on the Shaking Palsy”. In the essay Parkinson described a pattern of trembling in the hands and fingers, slower movement and loss of balance. Our knowledge about the disease has advanced in the last 200 years and now there are treatments that can help slow down the progression of the disease. But those treatments only last for a while, and so there is a real need for new treatments.  

That’s what Jun Takahashi’s team at Kyoto University in Japan hope to provide. In a first-of-its-kind procedure they took skin cells from a healthy donor and reprogrammed them to become induced pluripotent stem cells (iPSCs), or stem cells that become any type of cell. These iPSCs were then turned into the precursors of dopamine-producing neurons, the cells destroyed by PD, and implanted into 12 brain regions known to be hotspots for dopamine production.

The procedure was carried out in October and the patient, a male in his 50s, is still healthy. If his symptoms continue to improve and he doesn’t experience any bad side effects, he will receive a second dose of dopamine-producing stem cells. Six other patients are scheduled to receive this same treatment.

Earlier tests in monkeys showed that the implanted stem cells improved Parkinson’s symptoms without causing any serious side effects.

Dompaminergic neurons derived from stem cells

Scientists at UC San Francisco are trying a different approach, using gene therapy to tackle one of the most widely recognized symptoms of PD, muscle movement.

In the study, published in the journal Annals of Neurology, the team used an inactive virus to deliver a gene to boost production of dopamine in the brain. In a Phase 1 clinical trial 15 patients, whose medication was no longer able to fully control their movement disorder, were treated with this approach. Not only were they able to reduce their medication – up to 42 percent in some cases – the medication they did take lasted longer before causing dyskinesia, an involuntary muscle movement that is a common side effect of the PD medication.

In a news article Dr. Chad Christine, the first author of the study, says this approach may also help reduce other symptoms.

“Since many patients were able to substantially reduce the amount of Parkinson’s medications, this gene therapy treatment may also help patients by reducing dose-dependent side effects, such as sleepiness and nausea.” 

At CIRM we have a long history of funding research into PD. Over the years we have invested more than $55 million to try and develop new treatments for the disease.

In June 2018, the CIRM Board awarded $5.8 million to UC San Francisco’s Krystof Bankiewicz and Cedars-Sinai’s Clive Svendsen. They are using neural progenitor cells, which have the ability to multiply and turn into other kinds of brain cells, and engineering them to express the growth factor GDNF which is known to protect the cells damaged in PD. The hope is that when transplanted into the brain of someone with PD, it will help slow down, or even halt the progression of the disease. 

The CIRM funding will hopefully help the team do the pre-clinical research needed to get the FDA’s go-ahead to test this approach in a clinical trial. 

David Higgins, CIRM Board member and Patient Advocate for Parkinson’s Disease

At the time of the award David Higgins, PhD, the CIRM Board Patient Advocate for Parkinson’s Disease, said: “One of the big frustrations for people with Parkinson’s, and their families and loved ones, is that existing therapies only address the symptoms and do little to slow down or even reverse the progress of the disease. That’s why it’s important to support any project that has the potential to address Parkinson’s at a much deeper, longer-lasting level.”

But we don’t just fund the research, we try to bring the scientific community together to help identify obstacles and overcome them. In March of 2013, in collaboration with the Center for Regenerative Medicine (CRM) of the National Institutes of Health (NIH), we held a two-day workshop on cell therapies for Parkinson’s Disease. The experts outlined the steps needed to help bring the most promising research to patients.

Around one million Americans are currently living with Parkinson’s Disease. Worldwide the number is more than ten million. Those numbers are only expected to increase as the population ages. There is clearly a huge need to develop new treatments and, hopefully one day, a cure.

Till then days like April 11th will be an opportunity to remind ourselves why this work is so important.

How Parkinson’s disease became personal for one stem cell researcher

/ Kevin McCormack / Leave a comment

April is Parkinson’s disease Awareness Month. This year the date is particularly significant because 2017 is the 200th anniversary of the publication of British apothecary James Parkinson’s “An Essay on the Shaking Palsy”, which is now recognized as a seminal work in describing the disease.

Schuele_headshotTo mark the occasion we talked with Dr. Birgitt Schuele, Director Gene Discovery and Stem Cell Modeling at the Parkinson’s Institute and Clinical Center in Sunnyvale, California. Dr. Schuele recently received funding from CIRM for a project using new gene-editing technology to try and halt the progression of Parkinson’s.

 

 

What got you interested in Parkinson’s research?

People ask if I have family members with Parkinson’s because a lot of people get into this research because of a family connection, but I don’t.  I was always excited by neuroscience and how the brain works, and I did my medical residency in neurology and had a great mentor who specialized in the neurogenetics of Parkinson’s. That helped fuel my interest in this area.

I have been in this field for 15 years, and over time I have gotten to know a lot of people with Parkinson’s and they have become my friends, so now I’m trying to find answers and also a cure for Parkinson’s. For me this has become personal.

I have patients that I talk to every couple of months and I can see how their disease is progressing, and especially for people with early or young onset Parkinson’s. It’s devastating. It has a huge effect on the person and their family, and on relationships, even how they have to talk to their kids about their risk of getting the disease themselves. It’s hard to see that and the impact it has on people’s lives. And because Parkinson’s is progressive, I get to see, over the years, how it affects people, it’s very hard.

Talk about the project you are doing that CIRM is funding

It’s very exciting. The question for Parkinson’s is how do you stop disease progression, how do you stop the neurons from dying in areas affected by the disease. One protein, identified in 1997 as a genetic form of Parkinson’s, is alpha-synuclein. We know from studying families that have Parkinson’s that if you have too much alpha-synuclein you get early onset, a really aggressive form of Parkinson’s.

I followed a family that carries four copies of this alpha-synuclein gene (two copies is the normal figure) and the age of onset in this family was in their mid 30’s. Last year I went to a funeral for one of these family members who died from Parkinson’s at age 50.

We know that this protein is bad for you, if you have too much it kills brains cells. So we have an idea that if you lower levels of this protein it might be an approach to stop or shield those cells from cell death.

We are using CRISPR gene editing technology to approach this. In the Parkinson’s field this idea of down-regulation of alpha-synuclein protein isn’t new, but previous approaches worked at the protein level, trying to get rid of it by using, for example, immunotherapy. But instead of attacking the protein after it has been produced we are starting at the genomic level. We want to use CRISPR as a way to down-regulate the expression of the protein, in the same way we use a light dimmer to lower the level of light in a room.

But this is a balancing act. Too much of the protein is bad, but so is too little. We know if you get rid of the protein altogether you get negative effects, you cause complications. So we want to find the right level and that’s complex because the right level might vary from person to person.

We are starting with the most extreme levels, with people who have twice as much of this protein as is normal. Once we understand that better, then we can look at people who have levels that are still higher than normal but not at the upper levels we see in early-onset Parkinson’s. They have more subtle changes in their production or expression of this protein. It’s a little bit of a juggling act and it might be different for different patients. We start with the most severe ones and work our way to the most common ones.

One of the frustrations I often hear from patients is that this is all taking so long. Why is that?

Parkinson’s has been overall frustrating for researchers as well. Around 100 years ago, Dr. Lewy first described the protein deposits and the main neuropathology in Parkinson’s. About 20 years ago, mutations in the alpha-synuclein gene were discovered, and now we know approximately 30 genes that are associated with, or can cause Parkinson’s. But it was all very descriptive. It told us what is going on but not why.

Maybe we thought it was straight forward and maybe researchers only focused on what we knew at that point. In 1957, the neurotransmitter dopamine was identified and since the 1960s people have focused on Parkinson’s as a dopamine-deficient problem because we saw the amazing effects L-Dopa had on patients and how it could help ease their symptoms.

But I would say in the last 15 years we have looked at it more closely and realized it’s more complicated than that. There’s also a loss of sense of smell, there’s insomnia, episodes of depression, and other things that are not physical symptoms. In the last 10 years or so we have really put the pieces together and now see Parkinson’s as a multi-system disease with neuronal cell death and specific protein deposits called Lewy Bodies. These Lewy Bodies contain alpha-synuclein and you find them in the brain, the gut and the heart and these are organs people hadn’t looked at because no one made the connection that constipation or depression could be linked to the disease. It turns out that Parkinson’s is much more complicated than just a problem in one particular region of the brain.

The other reason for slow progress is that we don’t have really good models for the disease that are predictive for clinical outcomes. This is why probably many clinical trials in the neurodegenerative field have failed to date. Now we have human induced pluripotent stem cells (iPSCs) from people with Parkinson’s, and iPSC-derived neurons allow us to better model the disease in the lab, and understand its underlying mechanisms  more deeply. The technology has now advanced so that the ability to differentiate these cells into nerve cells is better, so that you now have iPSC-derived neurons in a dish that are functionally active, and that act and behave like dopamine-producing neurons in the brain. This is an important advance.

Will this lead to a clinical trial?

That’s the idea, that’s our hope.

We are working with professor Dr. Deniz Kirik at the University of Lund in Sweden. He’s an expert in the field of viral vectors that can be used in humans – it’s a joint grant between us – and so what we learn from the human iPS cultures, he’ll transfer to an animal model and use his gene vector technology to see if we can see the same effects in vivo, in mice.

We are using a very special Parkinson’s mouse model – developed at UC San Francisco – that has the complete human genomic structure of the alpha-synuclein gene. If all goes well, we hope that ultimately we could be ready in a couple of years to think about preclinical testing and then clinical trials.

What are your hopes for the future?

My hope is that I can contribute to stopping disease progression in Parkinson’s. If we can develop a drug that can get rid of accumulated protein in someone’s brain that should stop the cells from dying. If someone has early onset PD and a slight tremor and minor walking problems, stopping the disease and having a low dose of dopamine therapy to control symptoms is almost a cure.

The next step is to develop better biomarkers to identify people at risk of developing Parkinson’s, so if you know someone is a few years away from developing symptoms, and you have the tools in place, you can start treatment early and stop the disease from kicking in, even before you clinically have symptoms.

Thinking about people who have been diagnosed with a disease, who are ten years into the disease, who already have side effects from the disease, it’s a little harder to think of regenerative medicine, using embryonic or iPSCs for this. I think that it will take longer to see results with this approach, but that’s the long-term hope for the future. There are many  groups working in this space, which is critical to advance the field.

Why is Parkinson’s Awareness Month important?

It’s important because, while a lot of people know about the disease, there are also a lot of misconceptions about Parkinson’s.

Parkinson’s is confused with Alzheimer’s or dementia and cognitive problems, especially the fact that it’s more than just a gait and movement problem, that it affects many other parts of the body too.