The use of hyperoxia to induce chronic mild oxidative stress inRPE cells in vitro

[摘要] Purpose: To establish a model of mild and chronic oxidative stressusing hyperoxia for retinal pigment epithelial (RPE) cells in vitro.Methods: RPE340 cells and WI38 lung fibroblasts were grown in normaloxygen (20% O2) and hyperoxia (40% O2 or 60% O2).After cell viability was examined, the levels of reactive oxygenintermediates (ROI) by flow cytometry and heme oxygenase-1 (HO-1) mRNA bynorthern analysis were measured as markers of oxidative stress in bothcell types. Proliferative ability and gene expression pattern of growthfactors were studied to demonstrate the phenotypic changes induced bymild oxidative stress upon these cells.Results: While decreased by 60% O2, 40% O2 did notaffect viability in both cell types, ROI production and HO-1 mRNAexpression were elevated in hyperoxia compared to controls, but wereinhibited with the antioxidant dehydro-ascorbic acid (DHA). Theproliferation of cells by hyperoxia was inhibited in both cell types.The expression of growth factors induced by hyperoxia was cell typedependent. Fibroblast growth factor-2 mRNA was unchanged in RPE cells,but was increased in fibroblasts. Transforming growth factor-b2 wasdecreased in RPE cells, but unchanged in fibroblasts. Vascularendothelial growth factor was downregulated in RPE cells, whileupregulated in fibroblasts. Connective tissue growth factor wasdecreased in RPE cells, but was unchanged in fibroblasts.Conclusions: The results demonstrate that hyperoxia induces mildoxidative stress which alters the phenotype of cells in a cell typespecific manner.

[学科分类] 生物化学/生物物理