Farnesoid X receptor agonists attenuate colonic epithelial secretory function and prevent experimental diarrhoea in vivo

作者：Mroz Magdalena S; Keating Niamh; Ward Joseph B; Sarker Rafiquel; Amu Silvie; Aviello Gabriella; Donowitz Mark; Fallon Padraic G; Keely Stephen J^*

来源：Gut, 2014, 63(5): 808-817.

DOI：10.1136/gutjnl-2013-305088

Objective Bile acids are important regulators of intestinal physiology, and the nuclear bile acid receptor, farnesoid X receptor (FXR), is emerging as a promising therapeutic target for several intestinal disorders. Here, we investigated a role for FXR in regulating intestinal fluid and electrolyte transport and the potential for FXR agonists in treating diarrhoeal diseases. %26lt;br%26gt;Design Electrogenic ion transport was measured as changes in short-circuit current across voltage-clamped T-84 cell monolayers or mouse tissues in Ussing chambers. NHE3 activity was measured as BCECF fluorescence in Caco-2 cells. Protein expression was measured by immunoblotting and cell surface biotinylation. Antidiarrhoeal efficacy of GW4064 was assessed using two in vivo mouse models: the ovalbumin-induced diarrhoea model and cholera toxin (CTX)-induced intestinal fluid accumulation. %26lt;br%26gt;Results GW4064 (5 mu mol/L; 24 h), a specific FXR agonist, induced nuclear translocation of the receptor in T-84 cells and attenuated Cl- secretory responses to both Ca2+ and cAMP-dependent agonists. GW4064 also prevented agonist-induced inhibition of NHE3 in Caco-2 cells. In mice, intraperitoneal administration of GW4064 (50 mg/mL) also inhibited Ca2+ and cAMP-dependent secretory responses across ex vivo colonic tissues and prevented ovalbumin-induced diarrhoea and CTX-induced intestinal fluid accumulation in vivo. At the molecular level, FXR activation attenuated apical Cl- currents by inhibiting expression of cystic fibrosis transmembrane conductance regulator channels and inhibited basolateral Na+/K+-ATPase activity without altering expression of the protein. %26lt;br%26gt;Conclusions These data reveal a novel antisecretory role for the FXR in colonic epithelial cells and suggest that FXR agonists have excellent potential for development as a new class of antidiarrheal drugs.

• 出版日期2014-5