• Question: Does anyone have an opinion on using stem cells to treat Parkinson's disease?

    Asked by tobysmith to Anne, Carolyn, Joe, Mariana, Nick on 15 Mar 2010 in Categories: .
    • Photo: Joseph Devlin

      Joseph Devlin answered on 15 Mar 2010:

      I have an opinion but it’s nothing more than that.

      In Parkinson’s disease, we know that a large part of the problem is that a special set of cells are dying off so in theory, it should be easy to replace them. These are a particular type of brain cell that release dopamine — a chemical signal in the brain — that are found in a brain structure called the substantia nigra. So pump in some new dopamine cells and all should be ok, right? That’s the idea behind stem cell work in this case.

      The problem with implanting stem cells into the brain is the same problem as why brain cells don’t regrow after injury. Specifically, it is because what makes a brain cell work is the way it is wired up to other cells. A really course wiring pattern is setup before a baby is born and then it is refined a lot in the first two years of life. After that, the specialized equipment you need to get the connections to go to the right place (that is, for a cell to connect to the correct set of other cells) no longer exist, so new brain cells face the nearly impossible task of somehow connecting up correctly without any guidance. Since there are about 100 billions cells to chose from, find the right 1000 is pretty tough. Compare this to what happens when skin cells regrow after say, a cut. The damaged cells can die off and new cells will divide and start to fill the gap. The cells don’t need anything special other than to knit with their neighbors to form a continuous piece of skin so it’s no problem.

      So when stem cells are introduced into the brain, they don’t form the right connections and as result, they tend to die off pretty quickly. Most of the research in this area is trying to come up with clever ways to keep them alive and get them to form the right connections but it’s a really hard problem.

      So my opinion is that stem cells probably are not a likely solution to Parkinson’s disease. Sadly.

    • Photo: Mariana Vargas

      Mariana Vargas answered on 15 Mar 2010:

      Hi there, I don’t do research on stem cells. But from what I see on the news… I think that If a therapy was discovered to treat Parkinsons disease (where the brain cells that produce dopamine in the brain just die) I think it should be used (of course closely regulated by law and ethics when it comes to the use of human stem cells), as the effects of this disease can be devastating. However, the use of stem cells as a therapy is still a long way off as it is necessary to prove first that it will be a safe therapy for humans. There are still many problems associated with it, mainly that the newly implanted cells don’t form all the correct connections, and also a danger that they will grow into tumours. There are other therapies being researched too (such as deep brain stimulation).

    • Photo: Nick Bradshaw

      Nick Bradshaw answered on 16 Mar 2010:

      A lot of stem cell questions today. This is the answer I gave regarding stem cells in MS treatment, I think it also equally true for Parkinsons:

      From what I understand, its a very promising field of research and one that is likely to be of great benefit to MS sufferers in the long run.

      As for the use of stem cells generally, that is a complex area. Speaking scientifically the embryos used to generate them are two early to have the ability to “think” or be a person, and most of them are unused IVF embryos that were to be destroyed anyway. However it is still for me a grey area (I doubt that an embryo at this stage is really “human”, but I’m not 100% sure).

      There are a lot of people working on ways of generating more “ethical” stem cells, but whether these will ever be as useful as embryonic ones remains to be seen.

    • Photo: Carolyn McGettigan

      Carolyn McGettigan answered on 16 Mar 2010:

      It’s a tough topic. This is what I wrote in response to a very similar question earlier:

      Well, because I don’t work with stem cells I have to admit I really know only a little about the topic. I think this question is a good model for many issues in the development of science. There are pros and cons, and it will be crucial for scientists and the rest of the public to work together in forming policies that will ensure that all of the ethical issues are fairly addressed.

      The potential therapeutic benefits of stem cell research are considerable, but then there is still a lot of uncertainty about the long-term consequences of therapy for the recipients. And then of course there is the very sensitive topic of whether it is right to use embryos to generate these cells. From my reading around today, it does seem that there are several types of stem cells that can be derived from adult tissue and could be used therapeutically, although these may not be *as* useful as embryonic cells for several reasons. Maybe investing more time in the development of the adult stem cell types will help to re-focus the debate on the pros and cons of the clinical applications, and less on the moral issues surrounding ‘the use of a life’ for research.

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