Cleaning up the house

Boosting the activity of a cellular quality-control mechanism may prevent the functional decay associated with ageing, according to a study published online this week in Nature Medicine.

Chaperone-mediated autophagy (CMA) is a mechanism for protein degradation in lysosomes ? units within the cell that contain digestive enzymes. CMA contributes to the removal of damaged proteins as part of a cell’s quality-control system and declines as an organism ages. This failure in cellular clearance has been proposed to contribute to the ageing process.

Cong Zhang and Ana Maria Cuervo corrected the CMA defect in the liver of old mice, improving its function. They genetically modified mice in order to regulate the amount of a lysosomal molecule crucial for CMA. By maintaining CMA activity until advanced ages, they observed reduced intracellular accumulation of damaged proteins and improved liver function.

The relevance of this mechanism to ageing in other organs remains to be tested, but these results indicate that modulation of CMA might be effective in countering aspects of the functional decline observed in old age.