Targeting NLRP3 palmitoylation: Celastrol alleviates inflammasome activation induced by immunometabolism...

Protein palmitoylation, the only reversible lipid-linked post-translational modification, acts as a critical regulatory mechanism for modulating protein function and subcellular localization. However, its specific roles and underlying mechanisms in the inflammatory response of liver macrophages (Kupffer cells) remain largely undefined. This study aimed to elucidate the precise mechanism by which palmitoylation regulates inflammation in Kupffer cells and to explore potential therapeutic interventions targeting this modification. Through metabolomic and membrane proteomic analyses, we demonstrated that LPS induces metabolic reprogramming, disrupts lipid homeostasis, and elicits palmitic acid accumulation in Kupffer cells. This lipid overload promotes NLRP3 palmitoylation at conserved cysteines Cys126 and Cys898, which in turn facilitates its translocation to the trans-Golgi network membrane and subsequent inflammasome activation. Targeting this palmitoylation switch thus represents a promising therapeutic strategy for inflammatory liver diseases. We further identified the natural compound celastrol as an effective inhibitor of NLRP3 palmitoylation. Mechanistically, this effect may be cooperatively mediated by the regulation of intracellular lipid metabolism and the covalent binding of celastrol to NLRP3. Our results uncover a novel mechanistic link between metabolic dysregulation and inflammasome activation in Kupffer cells mediated by palmitoylation. Importantly, we highlight celastrol as a promising therapeutic agent that targets immunometabolic crosstalk in the pathogenesis of inflammatory liver diseases.