Role of Gpr124 in the Migration and Proliferation of Retinal Microvascular Endothelial Cells and Microangiopathies in Diabetic Retinopathy.

Retinal microangiopathies, such as neovascularization and preretinal and vitreous hemorrhages, are the primary pathological features of diabetic retinopathy (DR). These conditions can worsen visual impairment and may result in blindness. Furthermore, multiple metabolic pathways are associated with microangiopathy in DR. However, the specific underlying pathological mechanisms remain unclear. Several studies have demonstrated the important role of G protein-coupled receptor 124 (Gpr124) in cerebral vascular endothelial cells, but its effect on the retinal endothelium has not been elucidated. In this study, we found that Gpr124 is expressed in both pathological retinal fibrous vascular membranes of DR patients and retinal blood vessels of mice, with elevated protein expression specifically observed in the retinas of DR model mice. Furthermore, Gpr124 expression was elevated after high-glucose treatment of human retinal microvascular endothelial cells (HRMECs). Inhibition of Gpr124 expression affected the high glucose-induced proliferation, migration, and tube-forming ability of HRMECs. We concluded that Gpr124 expression was upregulated in DR and promoted HRMECs angiogenesis in a high-glucose environment. This finding may help to elucidate the pathogenesis of DR and provide a critical research basis for identifying effective treatments.