MicroRNA-376b-3p Suppresses Choroidal Neovascularization by Regulating Glutaminolysis in Endothelial Cells.

Purpose: Choroidal neovascularization (CNV) is a common pathological change of various ocular diseases that causes serious damage to central vision. Accumulated evidence shows that microRNAs (miRNAs) are closely related with the regulation of endothelial metabolism, which plays crucial roles in angiogenesis. Here, we investigate the molecular mechanism underlying the regulation of endothelial glutamine metabolism by miR-376b-3p in the progression of CNV. Methods: Human retinal microvascular endothelial cells (HRMECs) were transfected with control or miR-376b-3p mimics, and the expression of glutaminase 1 (GLS1), a rate-limiting enzyme in glutaminolysis, was detected by real-time PCR or Western blotting. The biological function and glutamine metabolism of transfected HRMECs were measured by related kits. Luciferase reporter assays were used to validate the CCAAT/enhancer-binding protein beta (CEBPB) was a target of miR-376b-3p. Chromatin immunoprecipitation and RNA immunoprecipitation assays were performed to verify the binding of CEBPB on the promoter region of GLS1. Fundus fluorescein angiography and immunofluorescence detected the effect of miR-376b-3p agomir on rat laser-induced CNV. Results: The expression of miR-376b-3p was decreased, whereas GLS1 expression was increased in the retinal pigment epithelial-choroidal complexes of rats with CNV. HRMECs transfected with miR-376b-3p mimic showed inhibition of CEBPB, resulting in the inactivation of GLS1 transcription and glutaminolysis. Moreover, the miR-376b-3p mimic inhibited proliferation, migration and tube formation but promoted apoptosis in HRMECs, whereas these effects counteracted by α-ketoglutarate supplementation or transfection with CEBPB overexpression plasmid. Finally, the intravitreal administration of the miR-376b-3p agomir restrained CNV formation. Conclusions: Collectively, miR-376b-3p is a suppressor of glutamine metabolism in endothelial cells that could be expected to become a therapeutic target for the treatment of CNV-related diseases.

Effect of Fufang Xueshuantong Capsule on a rat model of retinal vein occlusion.

OBJECTIVE: To establish a retinal vein occlusion (RVO) animal model and observe the therapeutic effect of a Chinese herbal composition (Fufang Xueshuantong Capsule, , FXC)inischemicinischemic) in ischemic retinal disease. METHODS: Fifteen adult male Sprague-Dawley rats underwent laser photothrombosis to induce RVO on their right eyes and were subsequently randomized to receive FXC (the intervention group, n=7) or placebo treatment (the control group, n=8). Fundus fluorescein angiography was performed after 2, 4 and 8 weeks of treatment. Real-time reverse transcription-PCR was used to quantify the mRNA expression of vascular endothelial growth factor (VEGF) and stromal cell-derived factor-1 (SDF-1). The main outcomes were the mRNA copies of VEGF and SDF-1 and the counts of RVO signs. RESULTS: Laser photothrombosis procedure induced typical lesions of RVO, including hemorrhage, leakage, retinal detachment, capillary non-perfusion, filling defect of retinal vessels, and lateral circulation/dilation of small vessels. The retinal lesions were associated with an increased expression of VEGF (P<0.05). No significant change of SDF-1 expression was noticed. Compared with the control group, the intervention group had numerically fewer RVO lesions at week 2 (1.71±0.76 vs. 3.50±1.51, t=-2.82, P<0.05). The benefit of intervention remained at weeks 4 and 8. CONCLUSIONS: A rat model of laser photothrombosis-induced RVO was established and an increase in the VEGF expression was observed in the retinal lesion. The FXC had therapeutic benefit in improving retinal lesions in the rat model of RVO.