June 29, 2012
Skin Cells Create Stem Cells In Huntington Disease Study
Connie K. Ho for redOrbit.com — Your Universe Online
In 1993, the autosomal dominant gene mutation responsible for Huntington´s Disease (HD) was discovered. However, no treatments are known to slow its progression. New research may pave the way to better understanding of the disease. Researchers at Johns Hopkins recently announced that they were able to produce stem cells from skin cells from a person who had severe, early-onset form of HD; the cells were then changed into neurons that degenerated like the cells affected by HD.
The research was recently published in the journal Cell Stem Cell. The investigators worked with an international consortium in creating “HD in a dish.” The group was made up of scientists from Johns Hopkins University School of Medicine, Cedars-Sinai Medical Center, the University of California at Irvine, as well as six other groups. The team looked at many other HD cell lines and control cell lines to verify that the results were consistent and reproducible in other labs. The investigators believe that the findings allow them to better understand and eliminate cells in people in with HD. They hope to study the effects of possible drug treatments on cells that would be otherwise found deep in the brain.
"Having these cells will allow us to screen for therapeutics in a way we haven't been able to before in Huntington's disease," remarked lead researcher Dr. Christopher A. Ross, a professor of psychiatry and behavioral sciences, neurology, pharmacology and neuroscience at the Johns Hopkins University School of Medicine, in a prepared statement. "For the first time, we will be able to study how drugs work on human HD neurons and hopefully take those findings directly to the clinic."
The team of researchers is studying small molecules for the ability to block HD iPSC degeneration to see if they can be developed into new drugs for HD. As well, the ability to produce from stem cells the same neurons found in HD may have effects for similar research in other neurodegenerative diseases like Alzheimer´s and Parkinson´s. In the experiment, Ross took a skin biopsy from a patient with very early onset HD. The patient was seven years old at the time, with a severe form of disease and a mutation that caused it. By using cells from a patient who had quickly progressing HD, Ross´ team were able to mimic HD in a way that could be used by patients who had different forms of HD.
The skin cells were grown in culture and reprogrammed to induce stem cells that were pluripotent. Then, another cell line was created in the same way from someone who didn´t have HD. The other HD and control iPS cells were produced as part of the NINDS funded HD iPS cell consortium. Investigators from Johns Hopkins and the other consortium labs changed the cells into typical neurons and then into medium spiny neurons. The process took a total of three months and the scientists found the medium spiny neurons from the HD cells acted how the medium spiny neurons form an HD patient would. The cells demonstrated quick degeneration when cultured in the lab with a basic culture medium that didn´t include extensive supporting nutrients. On the other hand, control cell lines didn´t demonstrate neuronal degeneration.
"These HD cells acted just as we were hoping," says Ross, director of the Baltimore Huntington's Disease Center. "A lot of people said, 'You'll never be able to get a model in a dish of a human neurodegenerative disease like this.' Now, we have them where we can really study and manipulate them, and try to cure them of this horrible disease. The fact that we are able to do this at all still amazes us."