Final Progress Report

Proposal No. IBD-0118
Principal Investigator:  George H. Greeley, Jr., Ph.D.
Applicant Organization:  The University of Texas Medical Branch (Galveston, U.S.A.)
Project Title:  Protective and repair action of apelin, a new enteric protein, on the intestinal mucosa in experimental colitis
Period of Award:  June 1, 2004 - September 30, 2006

Lay summary:

Inflammatory Bowel Disease (IBD) (Crohn’s disease, ulcerative colitis) are long term inflammatory diseases of the gastrointestinal (GI) tract in humans. They are characterized in part by dying cells that line the intestine and ulceration. Repair and renewal of the intestinal lining is essential for the regeneration of intestinal tissue damaged by the inflammation. Apelin is a recently discovered peptide that works in the body by activation of the APJ receptor. Apelin and APJ are produced in the normal GI tract. Our research shows that production of apelin in the intestine is increased in patients with UC. We also show that apelin production is increased in rodents that have experimentally-induced colitis. Additional experiments show that apelin administration to mice with experimental colitis increases proliferation of intestinal epithelial cells, the cells that will line the intestine and facilitate repair of intestinal ulcers. Together our findings suggest that the increased apelin production during UC in humans is an adaptive mechanism of the intestine that attempts to repair itself.