MicroRNA Inhibiting Atheroprotective Proteins in Patients with Unstable Angina Comparing to Chronic Coronary Syndrome

Abstract

Patients with unstable angina present clinical characteristics of atherosclerotic plaque vulnerability, contrary to chronic coronary syndrome patients. The process of athersclerotic plaque destabilization is also regulated by microRNA particles. In this study, the investigation on expression levels of microRNAs inhibiting the expression of proteins that protect from atherosclerotic plaque progression (miR-92a inhibiting KLF2, miR-10b inhibiting KLF4, miR-126 inhibiting MerTK, miR-98 inhibiting IL-10, miR-29b inhibiting TGFβ1) was undertaken. A number of 62 individuals were enrolled-unstable angina (UA, n = 14), chronic coronary syndrome (CCS, n = 38), and healthy volunteers (HV, n = 10). Plasma samples were taken, and microRNAs expression levels were assessed by qRT-PCR. As a result, the UA patients presented significantly increased miR-10b levels compared to CCS patients (0.097 vs. 0.058, p = 0.033). Moreover, in additional analysis when UA patients were grouped together with stable patients with significant plaque in left main or proximal left anterior descending ("UA and LM/proxLAD" group, n = 29 patients) and compared to CCS patients with atherosclerotic lesions in other regions of coronary circulation ("CCS other" group, n = 25 patients) the expression levels of both miR-10b (0.104 vs. 0.046; p = 0.0032) and miR-92a (92.64 vs. 54.74; p = 0.0129) were significantly elevated. In conclusion, the study revealed significantly increased expression levels of miR-10b and miR-92a, a regulator of endothelial protective KLF factors (KLF4 and KLF2, respectively) in patients with more vulnerable plaque phenotypes.

Keywords: atheroprotective factors; atherosclerosis; chronic coronary syndrome; microRNA; stable plaque; unstable angina; vulnerable plaque.

Figure 1

The relative expression levels of study microRNAs ((A)—hsa-miR-92a-3p; (B)—hsa-miR-10b-5p, (C)—hsa-miR-126-3p, (D)—hsa-miR-98-5p, (E)—hsa-miR-29b-3p) to reference microRNAs (mean of miR-93 and miR-191 expression levels) in unstable angina (UA) patients comparing to CCS (chronic coronary syndrome—stable angina) patients and healthy volunteers (HV). *—Normality rejected, ANOVA Kruskall-Wallis test applied, **—value for ANOVA Kruskall-Wallis test, pair comparison, U-Mann Whitney tests were applied, and results were presented in Figure 2, ***—normality non-rejected, equal variances in Levene test, F-ANOVA test applied. p < 0.05 is considered statistically significant.

Figure 2

The relative expression levels of hsa-miR-10b-5p to reference microRNAs (mean of miR-93 and miR-191 expression levels) in unstable angina (UA) patients compared to CCS (chronic coronary syndrome—stable angina) patients and healthy volunteers (HV). *—Normality rejected, U-Mann Whitney tests were applied, p < 0.05 considered as statistically significant **—effect size calculated by Cohen’s d.

Figure 3

The relative expression levels of study microRNAs ((A)—miR-92a; (B)—miR-10b, (C)—miR-126, (D)—miR-98, (E)—miR-29b) to reference miRNAs (the mean of miR-93 and miR-191 expression levels) in unstable angina (UA) comparing to CCS (chronic coronary syndrome—stable angina) male patients. *—Normality rejected, U-Mann Whitney Test was applied, **—effect size, assessed by Cohen’s d; ***—normal distribution, non-equal variances in Levene test, Cochrane-Cox test applied. p < 0.05 is considered statistically significant.

Figure 4

Study flow chart. CCS—chronic coronary syndrome, UA—unstable angina.

Figure 5

The relative expression levels of study microRNAs ((A)—hsa-miR-92a-3p; (B)—hsa-miR-10b-5p, (C)—hsa-miR-126-3p, (D)—hsa-miR-98-5p, (E)—hsa-miR-29b-3p) to reference microRNAs (mean of miR-93 and miR-191 expression levels) in unstable angina patients and patients with left main or proximal left anterior descending (“UA and LM/proxLAD”) group, CCS patients with atherosclerotic lesions in other places in coronary artery bed (“CCS other” group) and healthy volunteers (HV). *—Normality rejected, ANOVA Kruskall-Wallis test was applied, p < 0.05 is considered statistically significant.

Figure 6

The relative expression levels of hsa-miR-92a-3p to reference microRNAs (the mean of miR-93 and miR-191 expression levels) in unstable angina patients and patients with left main or proximal left anterior descending (“UA and LM/proxLAD”) group, CCS patients with atherosclerotic lesions in other places in coronary artery bed (“CCS other” group) and healthy volunteers (HV). *—Normality rejected, U-Mann Whitney tests were applied, p < 0.05 considered as statistically significant, **—effect size assessed by Cohen’s d.

Figure 7

The expression levels of hsa-miR-10b-5p to reference microRNAs (mean of miR-93 and miR-191 expression levels) in unstable angina patients and patients with left main or proximal left anterior descending (“UA and LM/proxLAD”) group, CCS patients with atherosclerotic lesions in other places in coronary artery bed (“CCS other” group) and healthy volunteers (HV). *—Normality rejected, ANOVA Kruskall-Wallis test was applied, p < 0.05 is considered statistically significant, **—effect size assessed by Cohen’s d.