Integrated Stress Response and Necroptosis Drive Epithelial Dysfunction in Crohn's Disease: Repurposing Cancer drugs for Permeability Barrier Healing.

Epithelial permeability barrier dysfunction is a central pathogenic driver of Crohn's disease (CD), fueling microbial translocation, chronic inflammation, and progressive tissue injury. While current therapies suppress inflammation, none directly restore epithelial barrier function. Importantly, in CD patients, permeability barrier healing (BH) rather than mucosal healing is associated with long-term remission and a reduced risk of disease complications. Yet BH remains an unaddressed therapeutic target in CD. Here we investigated whether pharmacologic inhibition of the integrated stress response (ISR) and RIPK3-mediated necroptosis, two convergent pathways of epithelial injury, can promote epithelial viability, regeneration, and barrier integrity in CD. We employed villin-1/gelsolin double knockout (DKO) mice with epithelial-intrinsic ISR activation TNFΔARE/+ mice with chronic inflammation, and CD patient-derived enteroids (PDEs). Animals and PDE were treated with ISR inhibitor ISRIB, RIPK3 inhibitor Necrostatin-1 (Nec-1), or FDA-approved cancer drugs pazopanib and ponatinib, repurposed as potent RIPK3 inhibitors. Epithelial survival, regenerative growth (enteroid formation, budding), and barrier function (transepithelial electrical resistance, TEER) were assessed. Chronic ISR activation and necroptosis were prominent in both murine models and CD PDEs, causing epithelial cell death, Paneth cell expansion, impaired enteroid survival, and regenerative failure. Pharmacologic inhibition with ISRIB, Nec-1, pazopanib, or ponatinib restored villus architecture, reduced inflammation, enhanced epithelial survival and regeneration, and significantly improved TEER. ISR activation and RIPK3-mediated necroptosis converge to drive epithelial injury and barrier dysfunction in CD. Repurposing pazopanib and ponatinib restore epithelial regeneration and BH, offering an immediately translatable therapeutic strategy for sustained remission in CD.