Effect of Long-term Anti-VEGF Treatment on Viability and Function of RPE Cells

Purpose/Aim of the study: Vascular endothelial growth factor (VEGF)-antagonists are given over long time periods in the clinic, but the long-term effects on retinal pigment epithelium (RPE) cells are not fully investigated. This study aims to investigate these effects with two clinical relevant VEGF antagonists, bevacizumab and aflibercept, on the function of primary RPE cells. Materials and Methods: All tests were conducted with primary porcine RPE. Cells were stimulated with bevacizumab or aflibercept (both 250 mu g/ml) for 1 day, 7 days or 4 weeks. Cell viability was tested in MTT Assay. Secretion of TGF-ss was tested in ELISA, phagocytosis in a microscopic assay, migration in a scratch assay, and expression of RPE65 in Western blot. Barrier function was tested for bevacizumab in transwell-cultured cells by measuring transepithelial electrical resistance for up to 3 days. Results: Viability was reduced by both antagonists at all time points tested. TGF-ss secretion was not altered by any treatment. Phagocytosis was not significantly reduced by any treatment. Wound healing ability was not significantly altered by any treatment. The expression of RPE65 was reduced by bevacizumab but not aflibercept after 4 weeks. Transepithelial electrical resistance was not altered. Conclusions: Long-term treatment with anti VEGF may affect viability of RPE cells, and treatment with bevacizumab may have effects on RPE function in long-term treatment.