Immunoregulatory actions of epithelial cell PPAR g at the colonic mucosa

BACKGROUND: Peroxisome proliferator-activated receptor g (PPAR g) is a nuclear receptor whose activation has been shown to modulate macrophage and epithelial cell-mediated inflammation. The objective of this study was to use a systems approach for investigating the mechanism by which the deletion of PPAR g in epithelial cells modulates the severity of dextran-sodium sulfate (DSS)-induced colitis, immune cell distribution and global gene expression. RESULTS: The deficiency of PPAR g in epithelial cells does not significantly affect disease activity or body weight but worsens colon histopathlogy. WT mice have greater CD4+IL10+ T cells and fewer MHC II+ macrophages in mesenteric lymph nodes. Global gene expression analysis reveals greater changes after 7 days of DSS challenge (compared to 2 days). Colonic mucosa from VC- (WT) and VC+ (PPARg knock-out in epithelial cells) mice were sampled at 0 (no DSS), 2, and 7 days of DSS-induced experimental colitis