Our Spring Brunch held on Sunday, April 21 at the Embassy Banquets in Addison was a wonderful place to talk, share and listen to two wonderful doctors and their hope for the HD community in the near future.
There were 154 tickets sold to this year's brunch ... three times as many as last year. The following is a summary of the talk given by Dr. Kathleen Shannon and Dr. Jeffrey Kordower entitled "Neurosurgical Horizons in the Treatment of HD: From the Laboratory to the Clinic."
Great progress has been made in our understanding of the genetic basis of Huntington's disease. The discovery in 1993 of the genetic mutation which underlies all cases of Huntington's disease has led to an explosion in work about the nature of the genetic defect and its connection with brain degeneration. The details remain a little sketchy, but we now know that an abnormal protein is manufactured under the direction of this abnormal gene and that the abnormal protein is somehow responsible for brain cell degeneration, probably by weakening the cell's resistance to excitatory chemical messengers in the brain. There is great hope that some treatment will be developed which prevents cell degeneration in HD. However, even if the magic pill which stops brain degeneration were found today, every HD patient would have to live with the results of the degeneration that has already occurred in the brain. This is because the brain is not capable of cell regeneration. Thus, there is a compelling need to develop strategies for brain repair. Two main approaches to brain repair are being studied at centers all over the world. The first is transplantation, the second, trophic factor research.
Huntington's disease is a very good candidate for brain cell transplantation. Despite the overwhelming symptoms of the disease, the brain cell degeneration is confined to a relatively small region in the brain, the striatum. This localized brain cell degeneration can be reproduced fairly well in animals using several different strategies so that transplant effectiveness can readily be tested.
In order for brain cell transplants to be effective, they have to (1) survive in the brain (2) establish connections with the existing or 'host' cells and (3) function in a manner similar to the cells they are replacing. Studies in rodents and monkeys have clearly demonstrated that transplants of cells from animal as well as human fetal brains survive, and make cellular connections which are functional and that abnormal behaviors in these animals are improved by this technique. Thus, transplants of fetal cells look promising based on animal research. Only a few such transplants have been performed in humans with HD, and it is too early to tell how successful these are. One problem with human fetal transplants is that the tissue is obtained from voluntary abortions. This area of the brain is frequently damaged by the abortion technique, so many fetuses have to be obtained for each patient in order to ensure adequate tissue harvest. Researchers are looking to other sources for brain cell transplants. One very promising area is pig cells. Pig cells have been studied in animal models of HD, and appear to survive and function well. Early reports on the success of pig cell transplants in humans with Parkinson's Disease are very encouraging.
Trophic factors are chemicals which are naturally produced by the brain and have the potential to protect vulnerable cells and may play a role in brain repair. Many trophic factors have been isolated in the laboratory and are being studied for a number of degenerative diseases. Nerve growth factor (NGF) is one such trophin. Brain implantation of cells which have been genetically modified to secrete NGF appears to protect cells from degeneration. Other growth factors including one called CNTF may prevent cell degeneration when injected directly into the brain. Human trials of these agents have not yet begun in HD, but rapid progress is being made and such trials are just on the horizon.
Send comments to Renette Davis by clicking here.
Last updated: Dec. 5, 2010