Background: Diabetic retinopathy (DR) is the common complication of diabetes, accounting for most blindness cases worldwide. MicroRNAs (miRs) are small non-coding RNAs and participate in the pathogenesis and develop-ment of various diseases, including DR. The present study aimed to investigate miR-335-3p and vascular endothelial growth factor (EGFR) roles in DR diagnosis and development.
Methods: A total of 104 healthy volunteers, 96 type 2 diabetes mellitus (T2DM) patients, and 102 DR cases were enrolled in this study. The clinicopathological information of all subjects were collected and analyzed using chisquared test. After collecting plasma from each participant, a ROC assay was conducted to determine the dis-criminative value of miR-335-3p and EGFR in DR diagnosis. The targeted relationship between miR-335-3p and EGFR was examined by dual-luciferase reporter assay and correlation analysis. After exposing APRE-19 cells to different concentrations of high glucose (HG), the DR in vitro cell model was constructed. The expression levels of miR-335-3p and EGFR were detected using RT-qPCR. The effects of miR-335-3p and EGFR on HG-treated APRE-19 cell viability were determined by CCK-8 assay.
Results: Clinicopathological information presented that BMI index, fasting blood glucose (FBP), 2h-BG, HbA1c, miR-335-3p, and EGFR levels were strongly associated with DR pathogenesis. MiR-335-3p was significantly decreased while EGFR was increased in DR patients and HG-treated APRE-19 cells. MiR-335-3p and EGFR presented high accuracy, sensitivity, and specificity in differentiating DR from healthy cases and T2DM patients; moreover, miR-335-3p and EGFR could also discriminate proliferative DR (PDR) cases from healthy controls. After confirming that miR-335-3p was negatively correlated with its target EGFR, we found miR-335-3p could increase the viability in HG-treated APRE-19 cells while silencing of EGFR could also reverse the inhibitory effects of HG conditions on APRE-19 cell viability.
Conclusions: We concluded that plasma miR-335-3p and EGFR may be utilized as non-invasive biomarkers for screening DR cases, contributing to DR diagnosis and treatment.