Enzyme may protect nerve cells from brain disorders

Telomerase, an enzyme believed to have a role in determining the life span of cells, also may protect nerve cells against decreased function and premature death caused by Alzheimer's disease and other age-related neurological disorders, according to Mark Mattson, Ph.D., chief of the Laboratory of Neurosciences at the National Institute on Aging (NIA).

In experiments designed to mimic conditions in neurologically impaired brains, Mattson and his colleagues at the NIA and the Sanders-Brown Research Center on Aging at the University of Kentucky Medical Center in Lexington found that nerve cells with low levels of telomerase were particularly vulnerable to being killed by amyloid peptide, a toxic protein that accumulates in the brains of people with Alzheimer's disease. In contrast, nerve cells with high levels of telomerase displayed a remarkable resistance to being damaged or killed in experimental models of Alzheimer's disease or stroke. The researchers have found that telomerase blocks a biochemical cascade of reactions called apoptosis, which causes nerve cells to self-destruct. Accumulating evidence implicates the process of apoptosis in the death of nerve cells that occurs in Alzheimer's disease, Parkinson's disease and stroke.

If scientists can develop methods to stimulate the production of telomerase in nerve cells, Dr. Mattson said, it might help fend off age-related neurological disorders.

This research will be published in the June 2, 2000 issue of the Journal of Molecular Neuroscience. Further details on Dr. Mattson's telomerase research will be published in the July issue of the Journal of Neurochemistry, which will be available after June 15.