Insights for miR-9, miR-21, and miR-34a Expression Levels and Their Cross-Talk with TNF-α, IL-1β, and Nrf2 Levels in Diabetic Nephropathy Patients

Oxidative stress and inflammatory mediators are considered the main culprits responsible for orchestrating diabetic complications and triggering the onset of diabetes mellitus. Members of the noncoding ribonucleic acid (ncRNAs) play critical roles in regulating various diabetic complications. However, the role of the micro-ncRNAs (miR-9, miR-21, and miR-34a) in diabetic nephropathy remains elusive. Hence, we determined the prospective value of serum miR-9, miR-21, and miR-34a as biological indicators for diabetic nephropathy and examined their correlations with TNF-α, IL-1β, and Nrf2 signaling in patients with DN. This study involved healthy individuals represented by the control group and individuals with DM classified into non-nephropathy group and diabetic nephropathy group. Those with DM exhibited noticeable increases in parameters related to diabetes as fasting blood sugar, and HbA1c. Furthermore, the diabetic groups had substantially significant elevated levels of TNF-α compared to the control healthy group. Interestingly, the molecular biomarkers miR-9, miR-21, and miR-34a expressions were significantly higher in diabetic patients who showed interrupted glomerular filtration rate (eGFR) function. On the other hand, the expression of circulating Nfr2 in blood exhibited a sustained low level of expression in DM groups exhibiting a negative correlation with miR-9, miR-21, miR-34a, TNF-α and IL1β levels. This study highlights the potential of non-coding RNA expression as a prospective biomarker for diabetes mellitus. These biomarkers could potentially assist in predicting the progression of associated complications.