Science

Restoration of autophagy improves liver function in aged rodents

Last Updated: 2008-08-11 9:47:10 -0400 (Reuters Health)

NEW YORK (Reuters Health) - Restoring the autophagy mechanism that removes altered proteins from cells may help older organs function as if they were new, the results of an animal study suggest.

By clearing damaged proteins, chaperone-mediated autophagy (CMA) plays a key role in cellular quality-control systems, Drs. Ana Maria Cuervo and Cong Zhang, from Albert Einstein College of Medicine in New York, explain. With age, however, the CMA activity declines, which ultimately leads to a drop in organ function.

The goal of the present study was to determine if restoring CMA activity could enhance organ function -- in this case the liver -- in aged mice.

Prior research has shown that the drop in CMA activity with age is due, at least in part, to a reduction in its lysosomal receptor. In the present study, reported in the August 10th online issue of Nature Medicine, the authors created a murine model in which levels of this receptor could be changed.

By increasing receptor abundance, and indirectly CMA activity, the researchers found that they could, in fact, reduce the intracellular accumulation of damaged proteins in aged mice and improve organ function.

"Our study showed that (liver) functions can be maintained in older animals so long as damaged proteins continue to be efficiently removed -- strongly supporting the idea that protein buildup in cells plays an important role in aging itself," Dr. Cuervo said in a statement.

"Even more important, these results show that it's possible to correct this protein 'logjam' that occurs in our cells as we get older, thereby perhaps helping us to enjoy healthier lives well into old age."

Nat Med 2008.