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ABSTRACT
Objective To investigate the effect of circular RNA bromodomain PHD finger transcription factor (circBPTF) targeting microRNA (miR)-224-3p on the damage of human retinal vascular endothelial cells (HRECs) induced by high glucose.
Methods HRECs were divided into control group and high glucose group, which were cultured with medium containing 5.5 mmol/L glucose and 30 mmol/L glucose for 48 hours, respectively.HRECs were transfected with siRNA negative control (si-NC), siRNA of circBPTF (si-circBPTF), miRNA mimic control (miR-NC), and miR-224-3p by Lipofectamine 2000, followed by cultured in 30 mmol/L glucose medium for 48 hours and were recorded as si-NC group, si-circBPTF group, miR-NC group and miR-224-3p group, respectively.HRECs were transfected with si-circBPTF and anti-miR-NC or si-circBPTF and anti-miR-224-3p by double transfection method, and then treated with 30 mmol/L glucose medium for 48 hours and were recorded as anti-miR-NC group and anti-miR-224-3p group, respectively.The expression of circBPTF and miR-224-3p was detected by real-time fluorescence quantitative PCR.Cell apoptosis was detected by flow cytometry.Reactive oxygen species (ROS) level was determined by 2′, 7′-dichlorodihydrofluorescein diacetate probe.Superoxide dismutase (SOD) activity and malondialdehyde (MDA) content were detected by colorimetric method.Expression of cleaved-caspase-3/caspase-3 and cleaved-caspase-9/caspase-9 proteins was detected by Western blot.The interaction between circBPTF and miR-224-3p was identified by the dual luciferase reporter method.
Results Compared with the control group, the apoptosis rate, cleaved-caspase-3/caspase-3 protein expression, cleaved-caspase-9/caspase-9 protein expression, ROS level, MDA content, and circBPTF relative expression were significantly increased and SOD activity and miR-224-3p expression were decreased in the high glucose group (all P<0.05).Compared with the si-NC group, circBPTF relative expression, ROS level, MDA content, cleaved-caspase-3/caspase-3 protein expression, cleaved-caspase-9/caspase-9 protein expression, and cell apoptosis rate were significantly reduced and SOD activity was significantly increased in the si-circBPTF group (all P<0.05).Compared with the miR-NC group, miR-224-3p relative expression and SOD activity were significantly enhanced and ROS level, MDA content, cleaved-caspase-3/caspase-3 protein expression, cleaved-caspase-9/caspase-9 protein expression and cell apoptosis rate were significantly reduced in the miR-224-3p group (all P<0.05).The relative luciferase activity of HRECs after co-transfection of wild type circBPTF and miR-224-3p mimic was 0.43±0.04, which was significantly decreased compared with 0.99±0.06 after co-transfection of wild type circBPTF and miR-NC ( t=23.297, P<0.05).Compared with anti-miR-NC group, the relative expression of miR-224-3p and SOD activity were significantly decreased and ROS level, MDA content, cell apoptosis rate, cleaved-caspase-3/caspase-3 protein expression, and cleaved-caspase-9/caspase-9 protein expression were significantly increased in the anti-miR-224-3p group (all P<0.05).
Conclusions Interfering with circBPTF can inhibit high glucose induced HRECs apoptosis and oxidative stress damage by targeting miR-224-3p.