Open AccessIL‐1α cleavage by inflammatory caspases of the noncanonical inflammasome controls the senescence‐associated secretory phenotype
Author(s) -
Wiggins Kimberley A.,
Parry Aled J.,
Cassidy Liam D.,
Humphry Melanie,
Webster Steve J.,
Goodall Jane C.,
Narita Masashi,
Clarke Murray C. H.
Publication year - 2019
Publication title -
aging cell
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 3.103
H-Index - 140
eISSN - 1474-9726
pISSN - 1474-9718
DOI - 10.1111/acel.12946
Subject(s) - inflammasome , caspase , microbiology and biotechnology , biology , caspase 1 , senescence , secretion , calpain , inflammation , cytokine , aim2 , phenotype , apoptosis , programmed cell death , immunology , biochemistry , enzyme , gene
Interleukin‐1 alpha (IL‐1α) is a powerful cytokine that modulates immunity, and requires canonical cleavage by calpain for full activity. Mature IL‐1α is produced after inflammasome activation and during cell senescence, but the protease cleaving IL‐1α in these contexts is unknown. We show IL‐1α is activated by caspase‐5 or caspase‐11 cleavage at a conserved site. Caspase‐5 drives cleaved IL‐1α release after human macrophage inflammasome activation, while IL‐1α secretion from murine macrophages only requires caspase‐11, with IL‐1β release needing caspase‐11 and caspase‐1. Importantly, senescent human cells require caspase‐5 for the IL‐1α‐dependent senescence‐associated secretory phenotype (SASP) in vitro, while senescent mouse hepatocytes need caspase‐11 for the SASP‐driven immune surveillance of senescent cells in vivo. Together, we identify IL‐1α as a novel substrate of noncanonical inflammatory caspases and finally provide a mechanism for how IL‐1α is activated during senescence. Thus, targeting caspase‐5 may reduce inflammation and limit the deleterious effects of accumulated senescent cells during disease and Aging.