Celastrol ameliorates ulcerative colitis by inhibiting HSP90-mediated necroptosis of intestinal epithelial cells

Abstract

Introduction Ulcerative colitis (UC) is a chronic inflammatory bowel disease characterized by intestinal barrier dysfunction and epithelial cell death. Necroptosis of intestinal epithelial cells (IECs) mediated by the RIPK1/RIPK3/MLKL pathway has emerged as a key driver of UC progression. Celastrol, a bioactive compound from Celastrus wilfordii, has shown anti-inflammatory potential, but its effect on necroptosis in UC remains unclear. Methods A dextran sulfate sodium (DSS)-induced UC mouse model and a TSZ-induced HT-29 cell necroptosis model were established. Disease activity, colon length, histology, mucus barrier integrity, and tight junction protein expression were evaluated. Western blotting, immunofluorescence, qRT-PCR, and a cellular thermal shift assay (CESTA) were used to assess necroptosis and potential targeting of HSP90. Results Celastrol significantly improved body weight, disease activity index, and colon length, while restoring mucus secretion and tight junction proteins (ZO-1, Occludin, Muc-2). It reduced phosphorylation of RIPK1, RIPK3, and MLKL both in vivo and in vitro, decreased pro-inflammatory cytokines (TNF-α, IL-1β, IL-6), and attenuated TUNEL-positive IEC death. CESTA indicated that celastrol increased HSP90 thermal stability, suggesting HSP90 engagement. Discussion Celastrol ameliorates DSS-induced colitis by inhibiting HSP90-mediated necroptosis of intestinal epithelial cells, supporting its potential as a candidate for UC therapy.