Decline of chaperone-mediated autophagy in aging impairs macrophage clearance of senescent cells.

Abstract

Autophagy dysfunction and senescence are established drivers of aging, but their potential interaction remains poorly understood. Here we show that age-related decline of chaperone-mediated autophagy (CMA), a pathway for selective lysosomal protein degradation, changes senescent cell properties and impairs their immune clearance. CMA-deficient cells undergo senescence but acquire proteomic, metabolic and secretory features resembling those in aged senescent cells. Their senescence-associated secretory phenotype exhibits enhanced pro-senescence effects on neighboring cells and inhibits macrophage CMA, which impairs their ability to engulf senescent cells. Accordingly, blockage of CMA specifically in macrophages increases senescent cell accumulation in mice and delays senescence resolution during wound healing. Conversely, pharmacological CMA activation reduces senescent cell burden in aged mice and disease severity in a pulmonary fibrosis mouse model. Our findings identify CMA decline as a driver of senescent cell persistence and highlight CMA upregulation as a promising strategy to promote senescence resolution in aged organisms.