Association of blood miR-15a, miR-146a and miR-200b levels with stages of diabetic retinopathy.

Diabetic retinopathy (DR) is a serious complication of diabetes mellitus (DM). MicroRNAs (miRNAs) play crucial roles in DR pathogenesis, but their expression patterns across different DR stages remain unclear. To investigate the expression levels of hsa-miR-200b-5p, hsa-miR-146a-5p, and hsa-miR-15a-5p in the blood of patients in different stages of diabetic retinopathy. The research involved a sample size of 92 patients who had been diagnosed with type 2 diabetes. These patients were classified into three distinct groups: 50 patients with proliferative diabetic retinopathy (PDR), 30 patients with non-proliferative diabetic retinopathy (NPDR), and 12 patients with type 2 diabetes mellitus without retinopathy (DM) as a control group. The extraction of total RNA from whole blood samples was followed by RT-qPCR analysis to assess miRNA expression levels. miR-15a showed significantly higher expression in PDR compared to NPDR (P < 0.05), but no significant differences between NPDR vs. DM or PDR vs. DM. miR-146a expression was significantly increased in PDR compared to both NPDR and DM, with no significant difference between NPDR and DM. miR-200b expression was significantly higher in PDR compared to DM but showed no significant differences between NPDR vs. DM or PDR vs. NPDR. Our findings suggest that miR-15a and miR-146a are promising minimally invasive biomarkers for tracking the progression from NPDR to PDR, and distinguishing between these two stages. While elevated levels of miR-200b in PDR indicate potential utility in identifying at-risk patients. These insights may guide early therapeutic interventions and better diabetic retinopathy management.