In collaboration with international researchers, UW-Madison scientists are developing promising new treatments for Parkinson's disease.
The work centers on a protein called \glial cell line derived neurotrophic factor"" and its effects in the brain. A recent study published in Nature Medicine demonstrates GDNF's ability to ease the effects of Parkinson's disease.
""This was a new approach that had never been tried before,"" said Clive Svendsen, UW-Madison professor of anatomy and neurology and co-author of the study. Five patients fitted with specialized pumps received a constant supply of GDNF directly into their brains, markedly decreasing Parkinson symptoms, according to Svendsen.
Parkinson's disease is a degenerative brain disease affecting the cells that control function and movement, according to Gloria Bock, of the Wisconsin Parkinson Association. ""The physiological reasons are clear: We know dopamine is in short supply.""
Though GDNF had been pumped into the brain before, it was not received in the area affected by Parkinson's disease, Svendsen said. When he and his and colleagues channeled a constant supply of GDNF directly to the dying cells, the brain responded.
""Brain imaging showed about a 30 percent increase in the amount of dopamine in the brain,"" Svendsen said. ""And patients began to feel better.""
""I'm a neuroscientist first, and I use stem cells as a tool,"" Svendsen said. ""We would like to make stem cells that make GDNF, and our long-term preference would be to transplant those cells into the brain.""
The cells must first be engineered so they not only produce GDNF, but that its production may also be controlled, Svendsen said.
To do this, scientists are using neural progenitor cells combined with GDNF. ""The progenitor cells have the ability to form the different cells in the brain because they are not yet fully determined.
""They are still flexible,"" said Soshana Behrstock, a post-doctoral fellow at the Waisman center. ""And this is the first time these human cells have been used with GDNF.""
Creating regulated GDNF-secreting cells may allow physicians to safely control the amount of growth factor that enters the brain, Behrstock said. ""This has great therapeutic potential.""
Parkinson's disease is progressive, and the current treatments just replace the dopamine levels in the brain. The transplanted cells, however, ""will hopefully delay the death of the neurons and protect the dopamine,"" Behrstock said.
Scientists can watch the levels of dopamine change in the brain by PET scanning, said Andrew Roberts, assistant professor of Medical Physics. ""We can look at the chemical changes in the brain without being invasive,"" he said.
Researchers are set to begin trials with GDNF-secreting cells transplanted into rats and will later do the same with primates. Behrstock estimates it will be a few years until the procedure will be used clinically.
""We are very hopeful about his research,"" Bock said. ""This is where we will be enlightened-and see where the research can be expanded.\
