MicroRNA-145 and microRNA-486 are potential serum biomarkers for vascular calcification

INTRODUCTION

MicroRNAs (miRs) regulate vascular calcification (VC), their quantification may contribute to suspect the presence of VC.

MATERIAL AND METHODS

The study was performed in 4 phases. 1) miRs sequencing of rat calcified and non-calcified aortas. 2) miRs with the highest rate of change, plus miR-145 (the most abundant miR in vascular smooth muscle cells (VSMCs), were validated in aortas and serum from rats with and without VC. 3) The selected miRs were analyzed in epigastric arteries from kidney donors and recipients, and serum samples from general population. 4) VSMCs were exposed to different phosphorus concentrations and miR-145 and miR-486 were overexpressed to investigate their role in VC.

RESULTS

miR-145, miR-122-5p, miR-486 and miR-598-3p decreased in the rat calcified aortas, but only miR-145 and miR-486, were detected in serum. In human epigastric arteries, miR-145 and miR-486 were lower in kidney transplant recipients compared to donors. Both miRs inversely correlated with arterial calcium content and with VC (Kauppila index). In the general population, the severe VC was associated with the lowest serum levels of both miRs. The ROC curve showed that serum miR-145 was a good biomarker of VC. In VSMCs exposed to high phosphorus, calcium content, osteogenic markers (Runx2 and Osterix) increased, and the contractile marker (α-actin), miR-145 and miR-486 decreased. Overexpression of miR-145, and in lesser extent miR-486, prevented the increase in calcium content induced by high phosphorus, the osteogenic differentiation, and the loss of the contractile phenotype.

CONCLUSION

miR-145 and miR-486 regulate the osteogenic differentiation of VSMCs, their quantification in serum could serve as markers of VC.