BACKGROUND/AIMS: Expression of the hepatocyte growth factor (HGF) and cyclooxygenase-2 (COX-2) is upregulated at the margins of healing gastric ulcers. We investigated in vitro the interference of HGF, the selective COX-2 inhibitor NS-398 and the nonselective COX inhibitor indomethacin with gastric epithelial wound healing and actin microfilament (actin-MF) formation. METHODS: Standardized gastric epithelial wounds, created in confluent RGM1 rat cell monolayers were treated with: HGF (10 ng/ml), NS-398 (1-100 microM) or indomethacin (0.01- 0.5 mM). The areas of re-epithelialization and cell proliferation were measured 24 h after wounding. Actin-MFs were labeled with fluorescein-conjugated phalloidin and their distribution was examined using a Nikon epifluorescence microscope. RESULTS: HGF caused a significant increase in gastric monolayer wound re-epithelialization and this was not affected by mitomycin C. Both indomethacin and NS-398 inhibited HGF-stimulated re-epithelialization, but the basal wound re-epithelialization rate and cell proliferation was only significantly inhibited by indomethacin. HGF triggered actin stress fiber formation which was inhibited by both indomethacin and NS-398, but only indomethacin interfered with actin-MF formation at the baseline condition. CONCLUSIONS: HGF significantly increased gastric wound re-epithelialization by activating cell migration which may be mediated by the COX-2 pathway. Copyright 2003 S. Karger AG, Basel
BACKGROUND/AIMS: Expression of the hepatocyte growth factor (HGF) and cyclooxygenase-2 (COX-2) is upregulated at the margins of healing gastric ulcers. We investigated in vitro the interference of HGF, the selective COX-2 inhibitor NS-398 and the nonselective COX inhibitor indomethacin with gastric epithelial wound healing and actin microfilament (actin-MF) formation. METHODS: Standardized gastric epithelial wounds, created in confluent RGM1 rat cell monolayers were treated with: HGF (10 ng/ml), NS-398 (1-100 microM) or indomethacin (0.01- 0.5 mM). The areas of re-epithelialization and cell proliferation were measured 24 h after wounding. Actin-MFs were labeled with fluorescein-conjugated phalloidin and their distribution was examined using a Nikon epifluorescence microscope. RESULTS:HGF caused a significant increase in gastric monolayer wound re-epithelialization and this was not affected by mitomycin C. Both indomethacin and NS-398 inhibited HGF-stimulated re-epithelialization, but the basal wound re-epithelialization rate and cell proliferation was only significantly inhibited by indomethacin. HGF triggered actin stress fiber formation which was inhibited by both indomethacin and NS-398, but only indomethacin interfered with actin-MF formation at the baseline condition. CONCLUSIONS:HGF significantly increased gastric wound re-epithelialization by activating cell migration which may be mediated by the COX-2 pathway. Copyright 2003 S. Karger AG, Basel