Decoding of miR-7-5p in Colony Forming Unit–Hill Colonies as a Biomarker of Subclinical Cardiovascular Disease—A MERIT Study †

Colony forming unit–Hill (CFU–Hill) colonies were established to serve as a sensitive biomarker for vascular health. In animals, the overexpression of miR-7-5p was shown to be pro-atherogenic and associated with increased cardiovascular disease (CVD) risk. In a MERIT study, we aimed to explore the role of miR-7-5p expression in CFU–Hill colonies in type 1 diabetes mellitus (T1DM) and the effect of metformin in subclinical CVD. The expression of miR-7-5p in CFU–Hill colonies in 29 T1DM subjects without CVD and 20 healthy controls (HC) was measured. Metformin was administered to T1DM subjects for eight weeks. MiR-7-5p was upregulated in T1DM whereas metformin reduced it to HC levels. MiR-7-5p was positively correlated with c-reactive protein, and C-X-C motif chemokine ligand 10. The receiver operating characteristic curve revealed miR-7-5p as a biomarker of CVD, and upregulated miR-7-5p, defining subclinical CVD at a HbA1c level of 44.3 mmol/mol. Ingenuity pathway analysis predicted miR-7-5p to inhibit the mRNA expression of Krüppel-like factor 4, epidermal growth factor receptor, insulin-like growth factor 1 receptor, v-raf-1 murine leukemia viral oncogene homolog 1 and insulin receptor substrate ½, and insulin receptor, while metformin activated these miRNAs via transforming growth factor-β1 and Smad2/3. We proved the pro-atherogenic effect of miR-7-5p that maybe used as a prognostic biomarker.