Repeated enemas with hepatocyte growth factor selectively stimulate epithelial cell proliferation of injured mucosa in rats with experimental colitis

AimsHepatocyte growth factor (HGF) modulates intestinal epithelial cell proliferation and migration. We previously reported that systemic administration of recombinant human HGF (rh-HGF) ameliorated experimental colitis. However, an increase in serum HGF concentrations may induce undesired systemic effects, limiting the use of rh-HGF. To avoid possible side effects, we investigated the safety and efficacy of rectally administered rh-HGF as a treatment for experimental colitis.Main methodsWe measured serum human HGF concentration following a single rectal enema of rh-HGF. Rats with 2,4,6-trinitrobenzene sulfonic acid (TNBS)- or dextran sulfate sodium (DSS)-induced colitis were treated with rectal enemas of rh-HGF once a day for seven days. The degree of mucosal injuries and the proliferative activity of the colon epithelium were examined.Key findingsRats administered a rectal enema of rh-HGF at a dose of 0.1 mg/ml or less had no detectable rh-HGF in the serum. Repeated enemas of rh-HGF at this dose significantly reduced mucosal injuries, both with respect to lesion size and inflammatory cell infiltration. This regimen also stimulated proliferation of epithelial cells surrounding injured mucosa; however, the cell proliferation of uninjured mucosa was not affected by this local treatment.SignificanceRectally administered rh-HGF selectively accelerates the repair of injured mucosa in rat experimental colitis without systemic exposure to HGF. Rectal enemas of HGF are thus a potential novel and safe therapy for IBD.