ABSTRACT
Objective To investigate the expression and clinical significance of miR-126 and vascular endothelial growth factor (VEGF) in proliferative diabetic retinopathy (PDR).Methods 226 cases of diabetic retinopathy (DR) patients admitted in our hospital were studied,including 110 cases of PDR (group PDR),116 non proliferative diabetic retinopathy (NPDR) (group NPDR).80 patients with diabetes mellitus without retinopathy (NDR) were enrolled in DR group at the same period,another 80 healthy subjects (control group) were selected as control group.The plasma miR-126 level of all subjects was detected by real-time fluorescence quantitative polymerase chain reaction (qRT-PCR).The enzyme linked immunosorbent assay (ELISA) method was used to detect plasma VEGF level.The clinical diagnostic value of miR-126 and VEGF in PDR patients was further analyzed.Results Plasma levels of miR-126 in PDR group,NPDR group and NDR group were lower than those in control group (P ＜ 0.05),PDR group was lower than NPDR group and NDR group (P ＜ 0.05);plasma levels of VEGF in PDR group,NPDR group and NDR group were higher than those in control group (P ＜ 0.05),PDR group was higher than NPDR group and NDR group (P ＜ 0.05).Total cholesterol (TC),triglyceride (TG) and glycated hemoglobin (HbAlc) in PDR group were higher than those in NPDR group and NDR group (P ＜0.05),low density lipoprotein cholesterol (LDL-C) in PDR group,NPDR group and NDR group were higher than those in control group (P ＜ 0.05),and LDL-C in PDR group was higher than that in NPDR group and NDR group (P ＜0.05).High density lipoprotein cholesterol (HDL-C) in PDR group and NDR group was lower than that in control group (P ＜ 0.05),C-reactive protein (CRP) in PDR group,NPDR group and NDR group was higher than that in control group (P ＜ 0.05);plasma miR-126 levels in PDR group were negatively correlated with TC,LDL-C,CRP and HbA1c (P ＜ 0.05),but positively correlated with HDL-C (P ＜ 0.05),and no correlation with TG;the plasma levels of VEGF in PDR patients were positively correlated with TC,TG,LDL-C,CRP and HbAlc (P ＜0.05),but negatively correlated with the expressions of miR126 (r =-0.573,P =0.000);the AUC of miR-126 was 0.861,and when the cut-off value was ＜0.64,the diagnostic sensitivity and specificity were 82.50％,83.64％;the area under curve (AUC) of VEGF was 0.889,and when the cut-off value was ＜ 7.000,the sensitivity and specificity of diagnosis were 82.73％,86.25％;0.847 for the AUC of HbA1c,and the sensitivity and specificity 81.82％,87.50％ respectively.Conclusions Plasma miR-126 is low-expressed and VEGF is high-expressed in PDR patients,there is a negative correlation between the two indexes.They may be involved in the course of PDR through abnormal lipid metabolism and inflammatory reaction and may be a potential biomarker for early diagnosis of PDR.
ABSTRACT
Objective To investigate the effects of transcription factor 2(TCF2) overexpression on insulin resistance in HepG2 cells. Methods HepG2 cells were treated with high concentration of insulin(1×10-8mol/L) for 24 hours to induce insulin resistance (IR). Cells were divided into four groups:control group,IR group,IR+vector group and IR+TCF2 overexpression group. RT-qPCR and Western blot were performed to detect the expres-sion of TCF2. Glucose consumption and glycogen synthesis were assayed by glucose oxidase method and anthrone method respectively. Cell viability was evaluated by MTT assay. The activities of hexokinase and pyruvate kinase were detected by colorimetry. The protein level of IRS-1 and GLUT4 was detected by Western blot.Results Com-pared with control group,the decreased glucose consumption was observed in IR group(P＜0.05),indicating that insulin-resistance model was established successfully. The mRNA and protein expression of TCF2 was remarkably down-regulated in IR group as compared with control group. Compared with IR group,overexpression of TCF2 sig-nificantly improved glucose consumption, liver glycogen content, and the activities of hexokinase and pyruvate kinase (P＜0.05). Moreover,TCF2 overexpression up-regulated the protein expression of IRS-1 and GLUT4 (P＜0.05).Conclusions TCF2 overexpression ameliorates insulin resistance of HepG2 cells.