Inflammasome-independent role of NLRP12 in suppressing colonic inflammation regulated by Blimp-1.

NLRP12 is a member of the Nod-like receptor (NLR). Previous studies have reported enhanced colitis-associated inflammatory responses in NLRP12-deficient mice. In this study, we sought to investigate the role of NLRP12 in DSS-stimulated proinflammatory response in dendritic cells and mice colitis, and the molecular mechanisms involved in the development of the inflammation. Our results showed that down-regulation of NLRP12 is required for DSS-induced release of proinflammatory cytokines IL-1β and TNF-α; that PR domain zinc finger protein 1 (also known as Blimp-1) induces NLRP12 down-regulation during DSS-induced proinflammatory response and colitis; and that TLR4 is implicated in the up-regulation of Blimp-1 that led to the down-regulation of NLRP12 expression in DSS-induced colitis. Taken together, the results suggest that the TLR4-Blimp-1 axis promotes DSS induced experimental colitis through the down-regulation of NLRP12.