Expression and significance of miR-126 and VEGF in proliferative diabetic retinopathy

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 im-munosorbent 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 (HbA1c) 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 HbA1c (P<0.05), but negatively correlated with the expressions of miR-126 (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. Key words: Diabetic retinopathy/BL; MicroRNAs/BL; Vascular endothelial growth factors/BL