MicroRNA-346 mediates tumor necrosis factor α-induced downregulation of gut epithelial vitamin D receptor in inflammatory bowel diseases.

Background We recently reported that the gut epithelial vitamin D receptor (VDR) signaling inhibits colitis through inhibition of intestinal epithelial cell apoptosis, and the level of colonic epithelial VDR is markedly reduced in patients with inflammatory bowel diseases (IBD). VDR down-regulation promotes colitis, but the mechanism underlying VDR down-regulation in IBD is unknown.