Objectives: This study aimed to investigate the association between microRNA-155 (miR-155) and the severity and extent of coronary stenotic lesions.
Patients and methods: We measured the miR-155 expression by real-time PCR in 110 consecutive patients undergoing coronary angiography for suspected coronary artery disease. The severity and extent of coronary stenotic lesions were evaluated on the basis of coronary angiography findings by the Gensini score.
Results: The miR-155 expression was significantly lower in 56 patients with coronary heart disease than those in 54 controls (P<0.01). The level of miR-155 in peripheral blood mononuclear cells or plasma was lower in patients with unstable angina pectoris and acute myocardial infarction than in patients with chest pain syndrome, whereas no statistically significant differences were observed between patients with stable angina pectoris and chest pain syndrome. Spearman's correlation analysis showed that the expression of miR-155 in plasma correlated positively with the expression in peripheral blood mononuclear cells. The levels of miR-155 in the patients with diseased vessels of two and three or more were significantly lower than in those with diseased vessel of zero and one. The levels of miR-155 were not significantly different among groups with diseased vessels of zero and one. miR-155 were associated negatively with Gensini scores (r = -0.663, P<0.001). The miR-155 expression was correlated significantly to age (r = -0.227), hypertension (r = -0.440), total cholesterol (r = 0.239), high-density lipoprotein cholesterol (r = 0.280), low-density lipoprotein cholesterol (r = -0.315), tobacco use (r = -0.363), angiotensin-converting enzyme inhibitor (r = -0.250), statins (r = -0.368), and high-sensitivity C-reactive protein (r = -0.515).
Conclusion: miR-155 expression is associated inversely with complicated proatherogenic metabolic risk factors, and the severity of coronary stenotic lesions calculated by Gensini scores.