Circulating Levels of miR-155 and CTBP1-AS2 as a Promising Biomarker for Early Detection of Diabetic Nephropathy

Diabetic nephropathy (DN) is one of the most frequent complications of diabetes mellitus. Since the early diagnosis of DN is crucial to prevent the progression of the disease towards renal failure, many efforts have been made in recent years to introduce new diagnostic biomarkers. Recent studies suggest that non-coding RNAs could act as a novel diagnostic biomarker for the early detection and prediction of DN progress. Accordingly, in the current study we investigated the expression levels of miR-155 and CTBP1-AS2 in type 2 diabetes (T2D), DN patients and control subjects, and evaluated their diagnostic potential for DN. A total of 189 age and sex-matched subjects including 65 T2D patients with normo-albuminuria, 61 DN patients who had a history of albuminuria, and 63 control subjects were included in this case-control study. The expression levels of miR-155 and CTBP1-AS2 were determined using QRT-PCR. The results revealed that the expression level of miR-155 was significantly reduced in T2D patients. In addition, miR-155 level was significantly higher in DN patients with macroalbuminuria compared to DN patients with microalbuminuria and T2D patients with normo-albuminuria. The expression level of CTBP1-AS2 in T2D without proteinuria was higher than DN subjects with macroalbuminuria. The results also showed that there was a significant positive correlation between the miR-155 level with DBP, TG, TC, SCr and, BUN levels and a negative correlation with HDL-C and eGFR values. Deregulation levels of miR-155 and CTBP1-AS2 may represent useful novel diagnostic biomarkers for DN.