Platelet-Derived Growth Factor Subunit A Strengthens the Neurovascular Unit and Inhibits Retinal Vascular Regression Under Hyperoxic Conditions.

Retinopathy of prematurity (ROP) is primarily caused by the exposure of preterm infants with underdeveloped blood vessels to high oxygen concentrations. This damages the astrocytes that promote normal vascular development, leading to avascularity, pathological neovascularization, and retinal detachment, and even blindness as the disease progresses. In this study, the aim was to investigate the differences in the characteristics of astrocytes and blood vessels between wild-type (WT) and genetically modified mice overexpressing platelet-derived growth factor subunit A (PDGF-A) in the retina immediately after high oxygen exposure, a protocol in the oxygen-induced retinopathy (OIR) model of ROP. Our results showed that PDGF-A mice exhibited an increased population of astrocytes and higher vascular density than WT mice and that PDGF-A strengthened the resistance to hyperoxic conditions. In the OIR model, PDGF-A mice had reduced avascular zone areas following hyperoxia exposure. Furthermore, immunostaining for NG2 and CD31 showed that pericytes tended to regress earlier than endothelial cells, particularly at the vessel edges in both WT and transgenic mice, indicating relatively higher susceptibility to hyperoxia-induced damage. These findings suggest that PDGF-A plays a crucial role in stabilizing retinal vessels and may serve as a novel therapeutic target for ROP, highlighting the potential significance of PDGF-A in the pathological mechanisms of retinal diseases.