N-CAM Exhibits a Regulatory Function in Pathological Angiogenesis in Oxygen Induced Retinopathy

Background: Diabetic retinopathy and retinopathy of prematurity are diseases caused by pathological angiogenesis in the retina as a consequence of local hypoxia. The underlying mechanism for epiretinal neovascularization (tuft formation), which contributes to blindness, has yet to be identified. Neural cell adhesion molecule (N-CAM) is expressed by Muller cells and astrocytes, which are in close contact with the retinal vasculature, during normal developmental angiogenesis. Methodology/Principal Findings: Notably, during oxygen induced retinopathy (OIR) N-CAM accumulated on astrocytes surrounding the epiretinal tufts. Here, we show that N-CAM ablation results in reduced vascular tuft formation due to reduced endothelial cell proliferation despite an elevation in VEGFA mRNA expression, whereas retinal developmental angiogenesis was unaffected. Conclusion/Significance: We conclude that N-CAM exhibits a regulatory function in pathological angiogenesis in OIR. This is a novel finding that can be of clinical relevance in diseases associated with proliferative vasculopathy.