miR-146a suppresses the expression of vascular endothelial growth factor and inflammatory responses in diabetic retinopathy.

This study was designed to explore the role of miR-146a in diabetic retinopathy (DR). 30 healthy control (HC), 50 patients with type 2 diabetes mellitus, and 48 DR patients were enrolled. Blood was collected and levels of miR-146a expression, vascular endothelial growth factor (VEGF), and three inflammatory cytokines (NF-κB, IL-1ß, and TNF-α) were detected. Moreover, ARPE-19 cells were treated with miR-146a mimic or inhibitor in the presence of high glucose to evaluate its effect in vitro. DR patients had the lowest level of miR-146a and the highest level of VEGF as well as the most severe inflammation among the three groups. In addition, the miR-146a level was negatively correlated with the expression of VEGF and three inflammatory cytokines, respectively in DR patients. Moreover, VEGF expression was positively correlated with these three inflammatory cytokines in DR patients. In summary, miR-146a could inhibit VEGF expression and inflammation in DR.