To study whether miR-23 is regulated in coronary artery disease (CAD) patients and what is the possible mechanism of miR-23 in regulating CAD progression. Method Three different cohorts (including 13 AMI patients, 176 angina pectoris patients and 127 control subjects) were enrolled to investigate the expression levels of circulating miR-23 in patients with myocardial ischemia and also the relationship between plasma miR-23 and severity of coronary stenosis. Plasma miR-23 levels of participants were examined by real-time quantitative PCR. We further detected the correlation of miR-23 and VEGF by molecular and animal assays. Result miR-23 was enriched in not only diseased endothelial progenitor cells (EPCs) but also the plasma of CAD patients. Besides, we found out miR-23 was able to suppress VEGF expression and EPC activities. Reporter assays confirmed the direct binding and repression of miR-23 to the 3'-UTR of VEGF mRNA. Knock down of miR-23 not only restored VEGF levels and angiogenic activities of diseased EPCs in vitro, but further promoted blood flow recovery in ischemic limbs of mice. Conclusion Circulating miR-23 may be a new biomarker for CAD and as a potential diagnostic tool. And increased miR-23 level may be used to predict the presence and severity of coronary lesions in CAD patients.
Keywords: VEGF; coronary artery disease (CAD); disease marker; endothelial progenitor cells (EPCs); miR-23.