ACSS2-Mediated Histone H4 Lysine 12 Crotonylation (H4K12cr) Alleviates Colitis via Enhancing Transcription of CLDN7.

Histone lysine crotonylation (Kcr), a highly conserved posttranslational modification, plays critical roles in various biological processes. Nevertheless, the dynamic alterations and functions of histone Kcr in inflammatory bowel disease (IBD) remain poorly explored. Herein, a notable decrease of both Pan-Kcr and ACSS2 (acyl-CoA synthetase short-chain family member 2), the key enzyme for crotonyl-CoA generation, is revealed in inflamed intestinal epithelial cells. Genetic or pharmacological inhibition of ACSS2 dramatically impairs mouse intestinal barrier integrity and exacerbates colitis. Mechanistically, ACSS2-mediated histone H4 lysine 12 crotonylation (H4K12cr) upregulates CLDN7 expression to fortify intestinal epithelial barrier, which can be augmented by crotonate supplementation. Furthermore, tumor necrosis factor-α (TNF-α) is revealed to enhance the m6A modification of ACSS2 mRNA, consequently destabilizing and downregulating ACSS2. Combinational therapy involving anti-TNF-α and crotonate can significantly ameliorate colitis. Overall, ACSS2-mediated H4K12cr emerges as a pivotal modulator governing intestinal barrier function during IBD progression.