Lubiprostone, but Not Linaclotide, Protects T84 Cells Against Damage to Barrier Function by Interferon-γ

Abstract

Purpose: Lubiprostone, a prostone derivative, activates ClC-2 chloride channels and is used for the treatment of chronic idiopathic constipation in adults and irritable bowel syndrome with constipation in adult women. Linaclotide is also being developed for these indications. It is a peptide whose structure is closely related to the bacterial heat-stable endotoxin, STa. Lubiprostone has been shown to promote repair of intestinal barrier properties whereas nothing is known of the effect of linaclotide. The aim of the present study was to compare the effect of lubiprostone and linaclotide on loss of barrier function induced by interferon-γ (IFN-γ), a proinflammatory cytokine which reduces transepithelial resistance (TER) in part through reduction of occludin levels. IFN-γ is thought to be involved in the pathology of celiac sprue enteropathy, inflammatory bowel disease, ulcerative colitis and Crohn's disease. Intestinal barrier breakdown can lead to visceral pain. Methods: T84 cells grown on permeable supports were treated with and without 100 ng/mL IFN-γ and with 100 nM lubiprostone, 200 nM of the 13 amino acid active metabolite of linaclotide (CCEYCCNPACTGC) or 0.1% DMSO (vehicle control) daily for 3 days. TER, flux of FITC-labeled E. coli lipopolysaccharide (LPS, bacterial endotoxin preparation) and occludin levels were measured. Results: Incubation with lubiprostone alone did not affect TER, LPS flux or occludin levels. In contrast, linaclotide alone partially reduced TER, increased LPS flux and decreased occludin levels. IFN-γ reduced TER, increased LPS flux and decreased occludin levels. Lubiprostone, but not linaclotide countered the effects of IFN-γ. Conclusion: In this in vitro study, lubiprostone (but not linaclotide) protected against IFN-γ-induced loss of intestinal barrier function and this may involve preservation of occludin levels. Linaclotide alone caused partial barrier breakdown. These findings suggest that treatment with lubiprostone, but not linaclotide, may lead to reduced visceral damage and reduced pain in inflammatory events in the intestine. Supported by Sucampo Pharmaceuticals, Inc. Disclosure: John Cuppoletti is consultant to, has stock options from and is PI on grant from Sucampo Pharmaceuticals, Inc. All other authors are supported by funds from the research grant. Supported by a grant from Sucampo Pharmaceuticals, Inc.