Repairing Age-Related Damage in the Liver
ScienceDaily reports on a promising demonstration: "The cells of all organisms have several surveillance systems designed to find, digest and recycle damaged proteins. ... One of these surveillance systems - responsible for handling 30 percent or more of damaged cellular protein - uses molecules known as chaperones to seek out damaged proteins. After finding such a protein, the chaperone ferries it towards one of the cell's many lysosomes ... Dr. Cuervo found that the chaperone surveillance system, in particular, becomes less efficient as cells become older, resulting in a buildup of undigested proteins within the cells. She also detected the primary cause for this age-related decline: a fall-off in the number of lysosomal receptors capable of binding chaperones and their damaged proteins. Could replenishing lost receptors in older animals maintain the efficiency of this protein-removal system throughout an animal's lifespan and, perhaps, maintain the function of the animal's cells and organs as well?" As it turned out, this strategy does indeed work to maintain liver function at young levels in older animals.
Link: http://www.sciencedaily.com/releases/2008/08/080810213958.htm
Another article on the same theme -- clearing out garbage proteins -- is http://www.sciencedaily.com/releases/2011/03/110304123640.htm
It's a very plausible theme, and interestingly it suggests a possible rationale for the effectiveness of calorie restriction: if you've restricted the amount of nutrition drifting around at the cellular level, it both leaves less work for scavengers to do and makes scavengers all the hungrier to find nasties to nosh on. :-)