SASP (Senescence-associated secretory phenotype)

The senescence-associated secretory phenotype, or SASP, is the complex mixture of cytokines, chemokines, growth factors, proteases and extracellular vesicles released by senescent cells. It is regulated by multiple pathways, prominently including NF-kB, with mTOR, cGAS-STING, p38 MAPK and C/EBPbeta also influencing SASP output in certain contexts. Depending on context, the SASP can recruit immune cells to clear damaged tissue or, when persistent, fuel chronic low-grade inflammation, fibrosis and paracrine senescence in neighbouring cells, making it a key mechanistic link between cellular senescence and age-related disease.