A Cure for Parkinson's Disease

In many biology courses I learn about various neurological diseases such as Alzheimer’s, Parkinson’s, ALS, etc. For some reason these diseases are quite scary to me. Perhaps this is because there are not really any cure for these diseases. Researchers are certainly looking for cures and treatments though. Hopefully they can find some soon as many of these diseases have devastating effects to not only the person afflicted, but also to their friends and family.

Symptoms of Parkinson’s disease include tremors, balance problems, rigidity of muscles coordination problems, and more. Parkinson’s disease kills neurons that produce dopamine, a neurotransmitter. Severe problems with movement and balance are symptoms of this disease. Stem cell research is when stem cells are transplanted into the body in order to differentiate into something that the body needs.

Dopamine cells are made in human fetal midbrain tissues and so Goldman et al took these tissues and extracted glial cells from them. Glial cells support and maintain the growth of neurons. From here the researchers now had an environment where stem cells could grow. The stem cells were transplanted into the brains of rats that showed symptoms of Parkinson’s disease. The symptoms almost completely disappeared!

This seems like the perfect solution to curing the disease but there are two main problems. The first is that there are several types of dopamine neurons and not all of them fix the problems caused by Parkinson’s disease. This makes it hard to produce the right cell. The right kind of dopamine that would fix the problem is known, the trouble is how to be able to isolate the right kind. We know that the right type are in the part of the brain called the substantia niava. These cells send signals to cells involved in generating movement. The second problem is that some stem cells fail to become neurons. They remain undifferentiated and continue to divide. This can result in tumors. The rats in this study were killed before the tumors actually developed so this aspect has not actually been studied. It seem obvious thought that these cells will likely have detrimental effects. This side effect is common in embryonic stem cell treatments. I did not know this! The way to fix this would be to sort the differentiated cells from the undifferentiated cells. The article did not really go into how this would happen and left me wondering if it was an easy process; also if this would be don before or after the cells were transplanted into the brain.

Though these results look promising, it will likely be many more years before clinical trials even take place. Current treatments involved giving a person dopamine with drugs. Researchers feel that treatment using stem cells to make replacement dopamine neurons will work both better and longer. They know this because of the results they have seen in experiments using stem cell treatment, and other types of treatment. Other treatments being researched include stimulating neurons that are already in the brain to produce more dopamine. There have been successful preliminary trials of this in an American biotechnology company called Neuroglix. Gene therapy however also comes with its fair share of problems which make it hard to use as treatment. Also, in the previously mentioned “successful” studies there was only 25% improvement shown. This is much less than with stem cell treatments.

Posted by KMellman