A clinical and in-silico study of microRNA-21 and growth differentiation factor-15 expression in pre-diabetes, type 2 diabetes and diabetic nephropathy.

Background: Diabetic nephropathy (DN), a microvascular complication associated with long-standing diabetes, is a major cause of the end-stage renal disease (ESRD). Our in-silico analysis indicates several enrichment analyses involved in glucose metabolism to be affected by GDF15 transcription factors.

Methods: In-silico analysis was used to identify GDF15 and Insulin related protein-protein interaction (PPI) network and a common set of GDF15 regulating transcription factors by various databases. Common targeting miRNA of GDF15 regulating transcription factors were investigated in miRNet and TargetScan. Further, healthy controls (N.=30) and patients with pre-type-2 diabetes mellitus (pre-diabetes) (N.=30), T2DM (N.=30) and DN (N.=30) were included for analysis of routine biochemical tests, serum GDF15 levels by ELISA and to evaluate the Fold change expression (FCE) of circulating hsa-miR-21 by RT-PCR.

Results: MicroRNA-21 was found to directly target GDF15 downregulating transcription factors KLF4, TP53, and CEBPB. A significant difference in the levels of serum GDF15 was observed in Pre-diabetes (708.56±76.37), T2DM (1528.87±140.75) and DN patients (10-fold higher; 5507.90±503.88) when compared to healthy controls (567.36±69.99). The FCE of circulating hsa-miR-21 was 6.19 (pre-diabetes), 8.22 (T2DM), 9.19 (DN), folds higher in cases as compared to controls, reflecting an increasing trend and several folds higher levels of hsa-miR-21 in patients.

Conclusions: We suggest the potential of serum GDF15 and circulating-hsa-miR-21 to serve as clinically important biomarkers and therapeutic targets for controlling advancement of diabetes to DN.