SASP (Senescence-Associated Secretory Phenotype)

The senescence-associated secretory phenotype (SASP) is the broad set of pro-inflammatory cytokines, chemokines, growth factors, and proteases secreted by senescent cells — cells that have undergone permanent cell-cycle arrest but remain metabolically active and resistant to apoptosis. As a non-cell-autonomous program, the SASP propagates inflammation to neighboring tissue and contributes to tissue dysfunction and organ degeneration during aging. A major driver of the SASP is activation of the cGAS-STING pathway, triggered by endogenous DNA sources that accumulate in senescent cells, such as cytosolic chromatin fragments and leaked mitochondrial DNA.