Abstract
Purpose :
We have shown previously that non-enzymatic nitration (NEN) of extracellular matrix, which serves as a model Bruch’s membrane (BM) aging, has a profound effect on the behavior of retinal pigment epithelium (RPE), including altered phagocytic ability, reduced cell adhesion, and inhibition of proliferation. We know that transplanted RPE will encountered a hostile subretinal environment, including BM alterations that may compromise cell function and survival. Here we use our previous model of BM aging (NEN) to determine the effects of NEN on growth factor release and complement activation in RPE.
Methods :
Human induced pluripotent stem cells (iPSC) were differentiated into RPE, and analyzed by immunohistochemistry, confocal microscopy, and polymerase chain reaction (PCR). IPSC-derived RPE were plated onto RPE-derived extracellular matrix (ECM) conditions (untreated or nitrite-modified). Cells were cultured for 7 days and barrier function measured by transepithelial resistance (TER) and vascular endothelial growth factor (VEGF), pigment epithelium-derived factor (PEDF), and C3a were measured using enzyme linked immunosorbent assay (ELISA).
Results :
Nitrite-modified ECM increased VEGF release both apically and basally by 0.14 ng/mL (p <0.001) and 0.27 ng/mL (p <0.001), respectively, in iPSC-derived RPE. Nitrite-modified ECM increased PEDF release in iPSC-derived RPE apically by 0.26 ng/mL (p <0.001). Nitrite-modified ECM increased production of C3a both apically and basally in iPSC-derived RPE by 0.19 ng/mL (p <0.001) and 0.15 ng/mL (p <0.001), respectively.
Conclusions :
Nitrite-modified ECM increase VEGF, PEDF release, and C3a production in human iPSC-derived RPE. This model demonstrates changes seen in the pathophysiology of age-related macular degeneration.
This is an abstract that was submitted for the 2017 ARVO Annual Meeting, held in Baltimore, MD, May 7-11, 2017.