Cytokine regulation of intestinal epithelial cell proliferation

Inflammation in the gut is associated with changes in the epithelial layer. Barrier function is diminished, epithelial cell death may occur and the epithelial cells themselves secrete proinflammatory cytokines. One of the most obvious changes, however, is in the rate of epithelial renewal, which most often manifests as increased epithelial proliferation, with an increase in mucosal thickness in the colon and the length of the crypts of Lieberkuhn in the small bowel. The factors that control the basal rate of renewal and the epithelial stem cell niche have been well studied and it is clear that Wnt signaling is critically important. Inflammatory cytokines, therefore, may alter epithelial renewal in the gut by modifying or antagonizing Wnt signaling pathways.