The peroxisome-proliferator-activated gamma receptor and chronic inflammatory bowel disease (PPARgamma and IBD)

PPARgamma has been recently described as being a gene of susceptibility for Intestinal Bowel Diseases (IBD) as NOD2/CARD15 gene. IBD are pathologies due to an abnormal immune response, in genetically predisposed patients, to the bacteria of the intestinal flora. PPARgamma, known for its significant role in adipogenesis, is strongly expressed by the epithelial cells of the colon mucosa. PPARgamma is implicated in the regulation of inflammation. Indeed, agonists of this nuclear receptor decrease strongly the intensity of inflammation during experimental colitis induced by chemical agents. A deficit of PPARgamma in patients with ulcerative colitis has been highlighted, that could in part explain the acute inflammation. In addition, bacteria, including those of the commensal flora, are able to regulate PPARgamma. Toll Like Receptor-4 (TLR-4), responsible for the recognition of bacterial motif as lipopolysaccharide (LPS), is implicated in PPARgamma regulation and its anti-inflammatory properties. All these arguments make of PPARgamma a very interesting therapeutic target for the treatment of IBD.