Overexpression of Gremlin1 in Crohn's Disease-Associated Bowel Strictures.

OBJECTIVE: One of the most serious complications of Crohn's disease is intestinal strictures that may lead to bowel obstruction. Understanding the underlying mechanisms of stricture formation is essential in order to develop more effective nonsurgical prevention and treatment modalities. The aim of this pilot study was to determine whether Gremlin1, a protein implicated in fibrogenesis and smooth muscle proliferation, is overexpressed in Crohn's-associated bowel strictures. METHODS: Paired sections from three strictured and non-strictured surgically resected bowel from patients with Crohn's disease were evaluated for Gremlin1 expression by immunohistochemistry. RESULTS: Strictured areas from all three specimens showed strong Gremlin1 staining in the hypertrophic muscularis mucosae area compared to no staining in the mucosa or muscularis propria in the same sections and in contrast to sections from non-strictured areas which were negative. CONCLUSIONS: This short report is the first to describe the overexpression of Gremlin1 in the hypertrophied muscularis mucosae of strictured small intestine from patients with Crohn's disease. Additional studies are needed to elucidate the potential role of Gremlin1 in the etiopathogenesis of Crohn's disease strictures, and to investigate whether targeting Gremlin1 may be an option for preventing or treating strictures in patients with Crohn's disease.