GCG and colitis: Because the in vivo results demonstrate that regulation of Ace2 mRNA expression in response to BAR501 in the TNBS model of colitis involves a GLP-1-dependent mechanism, we then investigated whether liraglutide, a GLP-1 receptor agonist, reverses the inhibitory effects exerted by the GPBAR1 agonist on ACE2 expression in vitro.