Epac-2 ameliorates spontaneous colitis in Il-10-/- mice by protecting the intestinal barrier and suppressing NF-κB/MAPK signalling.

Intestinal barrier dysfunction and intestinal inflammation interact in the progression of Crohn's disease (CD). A recent study indicated that Epac-2 protected the intestinal barrier and had anti-inflammatory effects. The present study examined the function of Epac-2 in CD-like colitis. Interleukin-10 gene knockout (Il-10-/- ) mice exhibit significant spontaneous enteritis and were used as the CD model. These mice were treated with Epac-2 agonists (Me-cAMP) or Epac-2 antagonists (HJC-0350) or were fed normally (control), and colitis and intestinal barrier structure and function were compared. A Caco-2 and RAW 264.7 cell co-culture system were used to analyse the effects of Epac-2 on the cross-talk between intestinal epithelial cells and inflammatory cells. Epac-2 activation significantly ameliorated colitis in mice, which was indicated by reductions in the colitis inflammation score, the expression of inflammatory factors and intestinal permeability. Epac-2 activation also decreased Caco-2 cell permeability in an LPS-induced cell co-culture system. Epac-2 activation significantly suppressed nuclear factor (NF)-κB/mitogen-activated protein kinase (MAPK) signalling in vivo and in vitro. Epac-2 may be a therapeutic target for CD based on its anti-inflammatory functions and protective effects on the intestinal barrier.