Hepatocyte growth factor stimulates proliferation and migration during wound healing of retinal pigment epithelial cells in vitro

Purpose: A defect in retinal pigment epithelial (RPE) cells may cause dysfunction of the neural retina, so rapid recovery of differentiated RPE cells is required after RPE injury. We investigated the effect of hepatocyte growth factor (HGF) on wound healing in RPE cells. Methods: Confluent monolayers of bovine RPE cells were denuded, and the cells were allowed to recover in the presence or absence of HGF. The effect of HGF on RPE cell proliferation was evaluated by a 3-(4;5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2- (4-sulphophenyl)-2H-tetraz olium assay. In a migration assay, mitomycin C was used to inhibit proliferation, and the number of migrated cells was counted. The signaling pathways involved were examined using inhibitors of mitogen-activated protein kinase (MAPK), phosphatidylinositol-3 (PI3) kinase and protein kinase C pathways. Results: At 80 ng/mL, HGF stimulated the wound closure of RPE monolayers and rendered the restituted cells more epithelioid in shape. HGF at 10 ng/mL stimulated RPE cell migration the most, whereas 80 ng/mL of HGF inhibited migration, but stimulated proliferation the most. In particular, PI3 kinase and MAPK inhibitor inhibited PRE cell migration and proliferation, respectively. Conclusions: HGF stimulated wound closure in cultured RPE cells, and rendered restituted cells epithelioid in shape. HGF may become a therapeutic candidate for RPE wound healing.