Glutathione Transferase Omega-1 Regulates NLRP3 Inflammasome Activation through NEK7 Deglutathionylation

Summary: The NLRP3 inflammasome is a cytosolic complex sensing phagocytosed material and various damage-associated molecular patterns, triggering production of the pro-inflammatory cytokines interleukin-1 beta (IL)-1β and IL-18 and promoting pyroptosis. Here, we characterize glutathione transferase omega 1-1 (GSTO1-1), a constitutive deglutathionylating enzyme, as a regulator of the NLRP3 inflammasome. Using a small molecule inhibitor of GSTO1-1 termed C1-27, endogenous GSTO1-1 knockdown, and GSTO1-1−/− mice, we report that GSTO1-1 is involved in NLRP3 inflammasome activation. Mechanistically, GSTO1-1 deglutathionylates cysteine 253 in NIMA related kinase 7 (NEK7) to promote NLRP3 activation. We therefore identify GSTO1-1 as an NLRP3 inflammasome regulator, which has potential as a drug target to limit NLRP3-mediated inflammation. : NLRP3 inflammasome activation contributes to chronic inflammation associated with autoinflammatory disease, yet understanding of NLRP3 inflammasome regulation is incomplete. Hughes et al. show that the deglutathionylating enzyme GSTO1-1 promotes NLRP3 inflammasome activation through deglutathionylation of NEK7. Furthermore, the GSTO1-1 inhibitor C1-27 reduces NLRP3 inflammasome activation in vitro and in vivo. Keywords: NLRP3 inflammasome, GSTO1-1, glutathione, NEK7, IL-1β, deglutathionylation, pyroptosis