Uhrf1-Mediated PKM2 Degradation via Ubiquitination Alleviates Inflammation and Pyroptosis in Inflammatory Bowel...

Inflammatory bowel disease (IBD) is characterized by chronic relapsing intestinal inflammation and closely associated with persistent inflammatory responses and impairment of the mucosal barrier integrity. In this work, we demonstrated that Th17/Treg immune imbalance drove inflammation and pyroptosis in IBD, as revealed by single-cell RNA sequencing, and pyruvate kinase M2 (PKM2) and ubiquitin-like with PHD and RING finger domains 1‌ (Uhrf1) displayed a negative correlation in IBD clinic samples. Target fishing analysis revealed that eupatolide (EPT) covalently bound to C165 of PKM2 with a dissociation constant (K_d) of 106 nM, corroborated by follow-up chemical biology assays. We gained a deeper understanding of the mechanistic by which EPT interfered PKM2 function, specifically by promoting its interaction with Uhrf1, enhancing the K48-linked ubiquitylation and degradation of PKM2 to block its nuclear translocation. Critically, PKM2 silencing mitigated dextran sodium sulfate (DSS)-driven inflammation and pyroptosis across in vitro and in vivo models, with EPT showing no further efficacy upon PKM2 knockdown in IBD mice. This work uncovered Uhrf1-dependent PKM2 ubiquitination/degradation as a previously unrecognized therapeutic axis for IBD, while positioning EPT as a molecular glue capable of targeting the Uhrf1-PKM2 complex.