Ursodeoxycholic acid protects against intestinal barrier breakdown by promoting enterocyte migration via EGFR- and COX-2-dependent mechanisms.

The intestinal barrier is often disrupted in disease states, and intestinal barrier failure leads to sepsis. Ursodeoxycholic acid (UDCA) is a bile acid that may protect the intestinal barrier. We hypothesized that UDCA would protect the intestinal epithelium in injury models. To test this hypothesis, we utilized an in vitro wound-healing assay and a mouse model of intestinal barrier injury. We found that UDCA stimulates intestinal epithelial cell migration in vitro, and this migration was blocked by inhibition of cyclooxygenase 2 (COX-2), epidermal growth factor receptor (EGFR), or ERK. Furthermore, UDCA stimulated both COX-2 induction and EGFR phosphorylation. In vivo UDCA protected the intestinal barrier from LPS-induced injury as measured by FITC dextran leakage into the serum. Using 5-bromo-2'-deoxyuridine and 5-ethynyl-2'-deoxyuridine injections, we found that UDCA stimulated intestinal epithelial cell migration in these animals. These effects were blocked with either administration of Rofecoxib, a COX-2 inhibitor, or in EGFR-dominant negative Velvet mice, wherein UDCA had no effect on LPS-induced injury. Finally, we found increased COX-2 and phosphorylated ERK levels in LPS animals also treated with UDCA. Taken together, these data suggest that UDCA can stimulate intestinal epithelial cell migration and protect against acute intestinal injury via an EGFR- and COX-2-dependent mechanism. UDCA may be an effective treatment to prevent the early onset of gut-origin sepsis. NEW & NOTEWORTHY In this study, we show that the secondary bile acid ursodeoxycholic acid stimulates intestinal epithelial cell migration after cellular injury and also protects the intestinal barrier in an acute rodent injury model, neither of which has been previously reported. These effects are dependent on epidermal growth factor receptor activation and downstream cyclooxygenase 2 upregulation in the small intestine. This provides a potential treatment for acute, gut-origin sepsis as seen in diseases such as necrotizing enterocolitis.