Adapted from New York University School of Medicine
For unknown reasons a protein called amyloid beta aggregates into toxic plaques in the brain, killing neurons. These plaques are one of the hallmarks of Alzheimer’s disease. Now two new animal studies show for the first time that the deadly transformation of amyloid beta into plaques can be prevented through an interaction between amyloid beta and another protein called cystatin C.
Although much work needs to be done, these new findings may open the door to new treatments for Alzheimer’s disease that mimic the effects of cystatin C, says Efrat Levy, Ph.D., Associate Professor in the Departments of Psychiatry and Pharmacology at New York University School of Medicine, and the lead author of the study. “We are really excited by these findings because recent studies show that cystatin C is protective against a variety of insults that cause cell death in the brain. Our potential therapeutic approach focuses on keeping amyloid beta in a water soluble form, preventing its accumulation in the brain, and thus slowing, halting, or reversing disease progression,” says Dr. Levy.
The research shows that cystatin C binds soluble amyloid beta also in the human brain, and suggests that this binding inhibits its aggregation into insoluble plaques in humans, says Dr. Levy. Cystatin C production and body fluid levels vary among healthy individuals and can be influenced by certain hormones, aging, and certain pathological conditions, she says. Furthermore, it was recently demonstrated that a genetic variation in the cystatin C gene in human populations is linked to a greater risk of developing Alzheimer’s disease during aging.
These findings suggest, says Dr .Levy, that even subtle modifications of cystatin C protein levels could affect amyloid beta accumulation and deposition in the brain, thereby modifying disease progression.
The two studies appear in the on-line November 18, 2007, edition of the journal Nature Genetics.