MIT physicists played a role in a Brigham and Women's Hospital (BWH) study showing that brain damage related to Alzheimer's disease may start far earlier than previously thought and may be caused by newly implicated protein molecules.
Physics research associate Aleksey Lomakin and George Benedek, the Alfred H Caspary Professor of Physics, collaborated with senior author David Teplow of BWH on the study, which appeared Jan. 7 in the Proceedings of the National Academy of Sciences.
Previous work has shown that the build-up in the brain of toxic proteins called amyloids leads to the emergence of Alzheimer's disease symptoms. Eliminating or lowering the levels of these proteins in the brain is the goal of potential treatments for the disease.
Now BWH and MIT researchers believe that the memory loss associated with the disease begins long before protein deposits collect in the brain.
"Until now, we knew these proteins were toxic, but we had little understanding of how they formed toxic structures," Teplow said. "Our new studies show that in the most damaging form of Alzheimer's disease, amyloid protein sticks together in a very distinct way, producing structures that enhance toxicity."
In their work, which did not involve human subjects, Teplow, BWH researcher Gal Bitan and the MIT physicists determined that the amyloid protein associated with Alzheimer's binds to itself to form larger, more damaging structures known as oligomers. These oligomers then form structures resembling beads on a string, a destructive molecular chain believed to cause nerve cell damage and death.
Approximately four million Americans suffer from Alzheimer's. The disease is the most common form of dementia in the elderly and gradually erodes intellectual functions and memory.
Teplow said that this new research adds credibility to an increasing body of evidence that suggests fibrils, twisted ropes of amyloid protein that clog cells, may not be as damaging as the oligomer strings of the most toxic proteins.
