Regulation of TFPIa expression by miR-27a/b-3p in human endothelial cells under normal conditions and in response to androgens

Abstract

The increased risk of cardiovascular events in older men is multifactorial, but the significant reduction of testosterone levels has been involved. As this hormone regulates the expression of TFPI by unknown mechanisms, we aimed to evaluate the role of miRNAs in the regulation of TFPI? expression under normal conditions and in response to androgens. In silico studies allowed the selection of 4 miRNAs as potential TFPI? regulators. Only miR-27a/b-3p significantly reduced TFPI? expression in two endothelial cell lines. Luciferase assays demonstrated a direct interaction between miR-27a/b-3p and TFPI 3'UTR. Ex vivo analysis of TFPI and miRNA levels in 74 HUVEC samples from healthy subjects, showed a significant and inverse correlation between TFPI and miR-27a-3p. Moreover, anticoagulant activity of TFPI? from cells supernatants decreased ~30% with miR-27a/b-3p and increased ~50% with anti-miR-27a/b-3p. Interestingly, treatment of EA.hy926 with a physiological dose of dihydrotestosterone (30 nM) significantly increased (~40%) TFPI? expression with a parallel decreased (~50%) of miR-27a/b-3p expression. In concordance, increased levels of miR-27a/b-3p normalized the up-regulation induced by testosterone. Our results suggest that testosterone is a hinge in miR-27/TFPI? regulation axis. Future studies are needed to investigate whether testosterone variations are involved in a miR-27/TFPI? dysregulation that could increase the cardiovascular risk.