Elaidic acid induced NLRP3 inflammasome activation via ERS-MAPK signaling pathways in Kupffer cells

Abstract

Trans fatty acids (TFA) in food can cause liver inflammation. Activation of NOD-like receptor protein-3 (NLRP3) inflammasome is a key factor in the regulation of inflammation. Accumulating evidence suggests that ERS-induced NLRP3 inflammasome activation underlies the pathological basis of various inflammatory diseases, but the precise mechanism has not been fully elucidated. Therefore, this paper focused on TFA, represented by elaidic acid (EA), to investigate the mechanism of liver inflammation. Levels of mRNA and protein were detected by RT-qPCR and Western blotting, the release of proinflammatory cytokines was measured by ELISA, and intracellular Ca2+ levels were determined by flow cytometer using Fluo 4-AM fluorescent probes. Our research indicated that EA induced the endoplasmic reticulum stress (ERS) response in Kupffer cells (KCs), accompanied by the activation of the mitogen-activated protein kinase (MAPK) signaling pathway, which resulted in NLRP3 inflammasome formation, and eventually increased the release of inflammatory factors. NLRP3 inflammasome activation was inhibited when KCs were pretreated with ERS inhibitors (4-PBA) and MAPK selective inhibitors. Furthermore, when ERS was blocked, the MAPK pathway was inhibited.