The Role of Mitochondria-Associated Reactive Oxygen Species in the Amyloid beta Induced Production of Angiogenic Factors by ARPE-19 Cells

Objective: This study aimed to investigate the mechanisms whereby Amyloidbeta (A beta) induces the production of angiogenic factors by a human retinal pigment epithelial cell line (ARPE-19) cells.

Methods: ARPE-19 cells obtained from the American Type Culture Collection (ATCC) were utilized in this study. The expression level of vascular endothelial growth factor (VEGF), Interleukin-8 (IL-8), monocyte chemoattractant protein-1 (MCP-1) and complement activation fragments C3a and C5a were measured by Real-time quantitative PCR (RT-PCR) and Enzyme-linked immunosorbent assay (ELISA). The production of mitochondria-associated reactive oxygen species (ROS) was measured by flow cytometry.

Results: The expression of VEGF, IL-8, MCP-1, C3a and C5a was significantly increased in A beta-treated ARPE-19 cells. Mitochondria-associated ROS production was also significantly increased when exposed to A beta. Inhibition of mitochondrial ROS with Diphenyleneiodonium chloride (DPI) markedly decreased the A beta induced production of VEGF, IL-8, MCP-1, C3a and C5a by ARPE-19 cells. Anti-C3a or anti-C5a neutralizing antibodies did not have a detectable influence on the secretion of VEGF, IL-8 and MCP-1 by ARPE-19 cells upon stimulation with A beta.

Conclusion: Our results support the hypothesis that A beta is involved in the pathogenesis of choroidal neovascularization (CNV) formation by promoting the production of the angiogenic cytokines VEGF, IL-8 and MCP-1 by RPE cells. Mitochondrial ROS was shown to play a role in the regulation of A beta induced expression of these cytokines.