Effects of ascorbic acid on retinal pigment epithelial cells

Abstract

Purpose. Evaluation of effects of ascorbic acid on cell characteristics of dedifferentiated porcine retinal pigment epithelial (pRPE) cells. Methods. pRPE cells were incubated in vitro with increasing concentrations of ascorbic acid (0.25–1.5 mMol). Cell proliferation was assayed by measuring the incorporation of 5-bromo-2'-deoxy-uridine (BrdU) into cellular DNA. Migration and contraction properties were studied on a cell permissive porous membrane and collagen gels, respectively. Phenotypic changes in response to ascorbic acid and its derivative ascorbic acid 2-phophate were evaluated by microscopy and indirect immunofluorescence. Results. Ascorbic acid significantly inhibits cell proliferation, migration, and contraction in concentrations of 1 mMol or more. Under the influence of at least 1 mMol ascorbic acid dedifferentiated pRPE cells exhibited a pigmented status within 24 hours. Addition of 500 U/ml catalase prevented the antiproliferative effect of ascorbic acid and the formation of pigment. Concentrations of 0.5 mMol ascorbic acid as well as 1 mMol ascorbic acid 2-phosphate promoted differentiation of cell phenotype. Furthermore, ascorbic acid 2-phosphate supported the formation of in vivo -like epithelial structures. Conclusions. Ascorbic acid has an influence on vital cell characteristics such as proliferation, migration, contraction and differentiation of pRPE cells. As dedifferentiation of these cells is an integral part in the development of proliferative vitreoretinopathy (PVR), ascorbic acid should be taken into consideration as a supplement in the clinical management of this disease.