MiR-132-3p regulates proliferation of endothelial progenitor cells mediated by FOXO1

Abstract

Objective To investigate the effect of miR-132-3p on the proliferation of endothelial progenitor cells and its regulatory mechanism in order to provide a new theoretical basis for the treatment of deep venous thrombosis. Methods Real-time quantitative PCR (qPCR) was used to detect the expression of miR-132-3p in the plasma and endothelial progenitor cells of 27 healthy volunteers and 22 thrombus patients, and in endothelial progenitor cells under normoxic and hypoxic conditions. The miR-132-3p analogue and the specific siRNA were transferred into endothelial progenitor cells by the electroporation method. The effect of miR-132-3p on the proliferation of endothelial progenitor cells was detected using MMT and Cell Counting Kit-8 (CCK-8) methods. The effects of miR-132-3p on the expression of FOXO1 in endothelial cells were analyzed using the luciferase assay and western blots. Results The expression of miR-132-3p in clinical patients with thrombosis was significantly decreased to 0.45 ± 0.05 times of that of the healthy volunteers (P<0.05). The expression of miR-132-3p in endothelial progenitor cells under hypoxia was down-regulated to (0.23 ± 0.13) times of that of under normoxia (P<0.05). The expression of miR-132-3p of experiment group under hypoxia was up-regulated to (15.72 ± 2.06) times of that of control group (P<0.05). MMT assay showed that the proliferation of cells in the experimental group under hypoxic condition was up-regulated to (7.79 ±1.37) times of that in the control group (P<0.01). CCK-8 assay showed that cell proliferation in experimental group was up-regulated to (6.46 ± 0.38) times of that in the control group (P<0.01). Software analysis showed that FOXO1 was a direct target of miR-132-3p. Luciferase activity of miR-132-3p mimics transfected endothelial progenitor cells under hypoxic conditions were 0.47 times of that in siRNA treatment group. Western blot showed that the expression of FOXO1 protein in endothelial progenitor cells transfected with miR-132-3p mimics in hypoxia was 0.18 times of that in siRNA treatment group. Conclusions Compared with healthy volunteers, miR-132-3p expression in the blood of patients with thrombosis was significantly reduced that can promote transcription of the FOXO1 gene (and protein expression) and inhibit the proliferation of endothelial progenitor cells. It could be closely related to the formation of venous thrombosis. Key words: Endothelial progenitor cells; miRNA; miRNA-132-3p; Mimic; Hypoxia; Cell proliferation; FOXO1; Thrombosis