IDDF2024-ABS-0076 Targeting the USP9X/IGF2BP2 axis contributes to the therapeutic effects of chicoric acid in DSS-induced ulcerative colitis

<h3>Background</h3> Chicoric acid (CA), a hydroxycinnamic acid, has been reported to possess anti-inflammation activities. However, the specific mechanisms by which CA influences dextran sulfate sodium (DSS)-induced colitis remain unclear. This study aimed to elucidate the molecular mechanisms underlying the protective effect of CA in DSS-induced colitis. <h3>Methods</h3> Different concentrations of CA were given to mice with DSS-induced colitis for a week. The symptoms of colitis, colonic pathology, inflammation-related indicators, and intestinal mucosal barrier function were evaluated. RNA sequencing was performed on colon tissues to obtain differentially expressed genes. The deubiquitinating enzyme USP9X was selected, and the inhibitory and targeting effects of CA on USP9X were subsequently determined. The USP9X inhibitors WP1130 and EOAI3402143 were used to treat the DSS-induced colitis. Ubiquitination label-free quantitative proteomic analysis was performed to identify protein peptides that may potentially undergo deubiquitination by USP9X. It was also validated in vivo and in vitro by co-immunoprecipitation (Co-IP), immunohistochemistry, and Western blotting. <h3>Results</h3> CA significantly alleviated clinical activity and histological changes (IDDF2024-ABS-0076 Figure 1. CA treatment ameliorated DSS-induced colitis in mice), inhibited pro-inflammatory cytokine production (IDDF2024-ABS-0076 Figure 2. CA inhibited the expressions of proinflammatory cytokines in DSS-induced colitis mice), and improved the integrity of the intestinal barrier (IDDF2024-ABS-0076 Figure 3. CA protected the colonic mucosa and epithelial barrier function in mice with DSS-induced colitis) in UC mice. Moreover, CA suppressed USP9X expression in the colon tissues of mice with DSS-induced UC (IDDF2024-ABS-0076 Figure 4. CA reduced USP9X expression in the colon tissues of mice with DSS-induced UC). Furthermore, USP9X played a role in promoting the onset of UC and that insulin-like growth factor 2 mRNA-binding protein 2 (IGF2BP2) was deubiquitinated by USP9X (IDDF2024-ABS-0076 Figure 5. USP9X interacted with and deubiquitinated IGF2BP2, IDDF2024-ABS-0076 Figure 6. CA suppressed the USP9X/IGF2BP2 axis in vivo and in vitro). <h3>Conclusions</h3> CA ameliorated DSS-induced colitis by targeting the USP9X/IGF2BP2 axis, indicating that targeting the USP9X/IGF2BP2 axis presents a promising and innovative therapeutic approach for the treatment of UC.