Protective Effect of HGF Against Hydrogen Peroxide Induced Damage in Human RPE Cells in vitro

Abstract

Purpose: : To test the protective effects of hepatocyte growth factor (HGF) against hydrogen peroxide (H₂O₂) induced damage in human RPE cells in vitro.

Methods: : Confluent cultured human retinal pigment epithelial (RPE) cells were subjected to oxidative stress induced by H₂O₂ ( 0.4 mM ). Quantity of viable cells was measured using the MTT assay. To determine the protective antioxidant effect of HGF, some wells of RPE cells were pretreated with 10-100 ng/ml HGF. Cells cultured without HGF or H₂O₂ were used as controls. All tests were performed intriplicate.

Results: : . HGF at concentrations of 10-100 ng/ml did not influence the amount of viable cells in confluent cultures of human RPE. H₂O₂ at 0.4 mM decreased viable cells to 22% of the negative control. Viable cells cultured with 10, 30 and 100 ng/ml HGF and H₂O₂ were 108%, 126% and 169% of cells cultured with H₂O₂ but without HGF. The difference between cells cultured with and without HGF was statistically significant at 30-100 ng/ml (0.05>P>0.01 at 30 ng/ml and P < 0.01 at 100 ng/ml). As compared to the controls (without H₂O₂), viable cells cultured with 10, 30 and 100 ng/ml HGF and H₂O₂ were 23.8%, 27.7% and 37.2% of the controls. All of these differences were statistically significant.

Conclusions: : HGF at concentrations of 30-100 ng/ml has a partial protective effect against oxidative damage of human RPE cells induced by H₂O₂. Human RPE are constantly exposed to oxidative stress, such as sunlight, smoking and phagocytosis that results in the formation of reactive oxygen species which may damage these cells. HGF is a growth factor normally present in the eye (0.5-2.5 ng/ml in the aqueous humor and vitreous). High levels of exogenous HGF (30-100 ng/ml) have a protective effect on the RPE against oxidative stress.

Keywords: retinal pigment epithelium • oxidation/oxidative or free radical damage • growth factors/growth factor receptors