Investigating microRNAs in diabetic cardiomyopathy as tools for early detection and therapeutics

To profile microRNAs population of glucose-induced cardiomyoblast cell line and identify the differentially expressed microRNAs and their role under pre-diabetes and diabetes condition in vitro. Rat fetal ventricular cardiomyoblast cell line H9c2 was treated with D-glucose to mimic pre-diabetic, diabetic, and high-glucose conditions. Alteration in cellular, nuclear morphology, and change in ROS generation was analyzed through fluorescent staining. Small RNA sequencing was performed using Illumina NextSeq 550 sequencer and was validated using stem-loop qRT-PCR. A large number (~ 100) differential miRNAs were detected in each treated samples as compared to control; however, a similar expression pattern was observed between pre-diabetes and diabetes conditions with the exception for miR-429, miR-101b-5p, miR-503-3p, miR-384-5p, miR-412-5p, miR-672-5p, and miR-532-3p. Functional annotation of differential expressed target genes revealed their involvement in significantly enriched key pathways associated with diabetic cardiomyopathy. For the first time, we report the differential expression of miRNAs (miR-1249, miR-3596d, miR- 3586-3p, miR-7b-3p, miR-191, miR-330-3p, miR-328a, let7i-5p, miR-146-3p, miR-26a-3p) in diabetes-induced cardiac cells. Hyperglycemia threatens the cell homeostasis by dysregulation of miRNAs that begins at a glucose level 10 mM and remains undetected. Analysis of differential expressed miRNAs in pre-diabetes and diabetes conditions and their role in regulatory mechanisms of diabetic cardiomyopathy holds high potential in the direction of using miRNAs as minimally invasive diagnostic and therapeutic tools.