Deficiency of osteopontin in gut epithelial cells enhances intestinal integrity by promoting gut renewal through the JAK3/STAT4 pathway in acetaminophen (APAP)-induced acute liver injury

Gut barrier dysfunction is a key feature of acute liver injury (ALI) and leads to systemic immune responses (SIRS). Our previous studies have demonstrated that knockout of osteopontin (OPN) modulates antimicrobial peptide expression and reduces intestinal flora, thereby ameliorating sepsis. In this study, we employed an acetaminophen (APAP)-induced hepatotoxicity model, the leading cause of acute liver failure (ALF) worldwide, to investigate the role of intestinal epithelial-derived OPN in gut barrier integrity during ALF. We found that intestinal epithelial-specific OPN knockout mice (Opn^△^IEC) exhibited significant protection against APAP-induced liver injury and reduced gut barrier leakage. Fecal transplantation experiments revealed that mice receiving feces from Opn^△^IEC mice showed increased resistance to APAP-induced liver injury and enhanced immune defense. Mechanistically, transcriptome analysis of the gut barrier indicated that OPN exacerbated gut barrier damage by inhibiting gut self-renewal via the JAK3/STAT4 signaling pathway. Epithelial-derived OPN may play a critical role in compromising gut barrier integrity and may be a target for suppressing inflammation and ameliorating ALI.