Circulating miR-214 is associated with the severity of coronary artery disease

OBJECTIVE To study whether miR-214 is regulated in coronary artery disease (CAD) patients and whether placental growth factor (PLGF) is a possible target for miR-214 in atherosclerosis. METHODS Circulating miR-214 was measured by quantitative PCR using RNA isolated from 40 patients with CAD, including 12 with stable angina pectoris, 16 with unstable angina pectoris and 12 with acute myocardial infarction, and 15 controls without CAD. Plasma level of PLGF was measured by ELISA. RESULTS The miR-214 level was significantly lower in CAD patients compared with that in controls (P < 0.01). Compared to controls, patients with unstable angina pectoris (UAP, 38.6±9.1 pg/mL) and acute myocardial infarction (AMI, 46.3±13.4 pg/mL) had significantly higher level of plasma PLGF, but not those with stable angina pectoris (SAP; P = 0.012, UAP vs. Control; P = 0.005, AMI vs. Control). In patients with AMI, the plasma level of miR-214 was positively correlated to that of PLGF. CONCLUSIONS The results suggest that miR-214 is a beneficial microRNA for CAD patients. Loss of its protection may lead to increased PLGF levels and worsening atherosclerosis. Circulating miR-214 is a promising biomarker for alerting severe CAD.