"We've been bumping around looking at a few genes," said Lawrence Steinman, MD, professor of neurology and neurological sciences. "Now there are hundreds if not thousands of other genes that may be critical." This work will be published in the May issue of Nature Medicine.
MS occurs when cells of the immune system target their attack on cells that insulate neurons in the brain. The disease generally progresses in stages with an acute attack followed by a recovery - or chronic phase - in which the insulating cells degenerate and scar tissue builds up. Eventually, the disease can lead to paralysis and sensory disturbances such as blindness or deafness.
Steinman looked at which genes were being expressed in both acute and chronic attacks and compared them with the genes active in normal brain tissue.
To do this, Steinman's team isolated messenger RNA from acute, chronic and normal brain samples (mRNA is produced by active genes and can be used to identify which genes are being expressed in a given sample). They then exposed the mRNA samples to a gene chip - a glass slide dotted with human genes. If a sample contained mRNA corresponding to a gene on the chip, it would bind to the spot and produce a visible signal. The bigger the signal, the more mRNA, and therefore the more actively the gene is expressed in the sample.
With this technique, Steinman picked out thousands of genes that were expressed at either higher or lower levels in MS compared to the normal brain sample. Some of these genes were exactly wh
Contact: Amy Adams
Stanford University Medical Center