Purchase this article with an account.
AH Kakazu, G Chandrasekher, HE P Bazan; Hepatocyte Growth Factor (HGF) Promotes Cell Survival in Corneal Epithelial Cells . Invest. Ophthalmol. Vis. Sci. 2002;43(13):1633.
Download citation file:
© ARVO (1962-2015); The Authors (2016-present)
Purpose: HGF has been known to induce corneal epithelial cell proliferation. Studies from our laboratory showed that HGF stimulates phosphatidylinositol-3 kinase (PI-3K) and p70S6 kinase and inhibitors of these two kinases effectively block HGF-promoted corneal epithelial wound repair (Exp Eye Res 2001, 73, 191). We have also reported that HGF can stimulate PKB/Akt (ARVO Abs No 4786, 2001), which is known to play a role in protecting cells from apoptosis. The aim of the current study was to determine if there is a correlation between HGF-dependent cell survival and PKB/Akt activation. Methods: Apoptosis was induced in rabbit corneal epithelial cells by incubating for 24 h with a nutrient-deprived exhausted medium obtained from confluent corneal epithelial cell cultures incubated for 7 days with the same medium (DMEM/F12 with 10% FCS) (Kim et al, Aus Nz J Ophthalmol, 1999, 27, 214). HGF (50 ng/ml) was added 12 h before the addition of exhausted medium. Presence of apoptotic cells in the cultures was identified by staining with Hoechst 33342 Reagent (2 µM). Percentage of apoptotic cells was quantified by IMAGE-Proplus graphics software. Akt activity was assayed in immunoprecipitates using the specific substrate peptide RPRAATF and [γ32P]ATP. Results: Incubation with exhausted medium induced significant increase in Hoechst 33342 staining characteristic of DNA fragmentation within 24 h. Percentages of apoptotic cells in the cultures ranged from 35-60% in different areas of the culture dish. Akt activity in the cells treated with exhausted medium was decreased by more than 40% compared to untreated controls. HGF treatment significantly inhibited the apototic cell death induced by the exhausted medium and the percentage of apoptotic cells was decreased to 12-20% while Akt activity was increased 3-4 fold. PI-3K inhibitors wortmannin (125 nM) and LY294002 (10 µM) inhibited Akt phosphorylation stimulated by HGF. Conclusion: These studies suggest that in corneal epithelial cells, HGF in addition to being mitogenic, functions as an anti-apoptotic factor. The latter property may be directed by the PI-3K- Akt signaling pathway.
This PDF is available to Subscribers Only