LA JOLLA, CA - Like most neurodegenerative diseases, Alzheimer's disease usually appears late in life, raising the question of whether it is a disastrous consequence of aging or if the toxic protein aggregates that cause the disease simply take a long time to form.
Now, a collaboration between researchers at the Salk Institute for Biological Studies and the Scripps Research Institute shows that aging is what's critical. Harmful beta amyloid aggregates accumulate when aging impedes two molecular clean-up crews from getting rid of these toxic species.
This finding opens the door for development of drugs preventing build-up of toxic protein aggregates in the brain. The study appears in the Aug. 10 issue of Science Express, the advanced online edition of the journal Science.
Biogerontologist Aubrey de Grey has repeatedly made the argument that biomedical science could do more to reduce death from assorted diseases of old age by reversing aging than by researching treatments for each disease. This paper provides evidence for his assertion. If brain cells could be rejuvenated they'd once more break down toxic proteins as well as they did when they were younger. Then the incidence of Alzheimer's diease would plummet.
The clearing out of beta amyloid protein fragments becomes less efficient as we age.
Throughout life, brain cells produce aggregation-prone beta-amyloid fragments that must be cleared. "This process is very efficient when we are young but as we get older it gets progressively less efficient," says Cohen. As the affected individual reaches the seventh decade of life the clearance machineries fail to degrade the continually forming toxic aggregates and the disease emerges. In individuals who carry early onset Alzheimer's-linked mutation, an increased "aggregation challenge" leads to clearance failure and the emergence of Alzheimer's much earlier – usually during their fifth decade.
Drugs that block steps in the formation of beta amyloid protein fragments might help. But we'd be better if we could get brain cells to once again effectively taking out the trash. We need Strategies for Engineered Negligible Senescence.
|Share |||Randall Parker, 2006 August 15 11:29 PM Brain Alzheimers Disease|