Expression levels of miR-22, miR-30c, miR-145, and miR-519d and their possible associations with inflammatory markers among patients with coronary artery disease

Abstract

Background: Coronary artery disease (CAD) is a leading cause of death around the world. Micro-ribonucleic acid (miRNA) can be involved in forming of atherosclerotic plaques, inflammation, cholesterol metabolism, and other mechanisms involved in CAD development. This study aimed to evaluate the expression level of miR-22, miR-30c, miR-145, and miR-519d and their possible association with inflammatory markers among patients with CAD.

Methods: The expression level of miR-22, miR-30c, miR-145, miR-519d, interleukin 6 (IL-6), and transforming growth factor beta (TGF-β) was determined in peripheral blood mononuclear cells (PBMCs) from 46 patients with CAD and 39 healthy controls using real-time quantitative polymerase chain reaction (qPCR) assay.

Results: 53.8% (n = 21) and 52.2% (n = 24) of controls and cases were men, respectively; the mean age was 59.8 ± 7.4 and 57.0 ± 9.8 years, respectively. The miRNA expression pattern of each group showed significantly different expression profiles. In the CAD patients group, miR-22, miR-30c, and miR-145 were down-regulated compared to the control group. On the opposite, miR-519d was up-regulated in patients with CAD compared to the control group. Our results also showed that the expression levels of IL-6 and TGF-β were up-regulated among patients with CAD compared to the control group. In addition, the expression of miR-145 and miR-519d had a significantly negative and positive correlation with TGF-β and IL-6, respectively.

Conclusion: The change in expression levels of miR-22, miR-30c, miR-145, and miR-519d in PBMCs of patients with CAD could be considered as a potential biomarker for CAD.

Keywords: Coronary Artery Diseases; MiRNAs; Peripheral Blood Mononuclear Cell.

Figure 1

Comparison of micro-ribonucleic acids (miRNAs) (miR-22, miR-30c, miR-145, and miR-519d) expression level between patients with coronary artery disease (CAD) (n = 46) and healthy controls (n = 39); in patients with CAD compared to healthy control, the mean expression level of miR-22 (-4.49-fold), miR-30c (-4.68-fold), and miR-145 (-6-fold) were downregulated, and also the mean expression level of miR-519d (3.92-fold) was upregulated. The expression level of selected cellular miRNAs in peripheral blood mononuclear cells (PBMCs) was measured by quantitative polymerase chain reaction (qPCR). The Mann-Whitney U test and unpaired t-test were used to compare the expression level of cellular miRNAs between the case and control groups (****P ≤ 0.0001).

Figure 2

Comparison of the expression levels of inflammation-associated cytokines [interleukin 6 (IL-6) and transforming growth factor beta (TGF-β)] in the patients with coronary artery disease (CAD) (n = 46) and healthy control (n = 39) samples; the mean expression levels of IL-6 (4.08-fold), and TGF-β (3.8-fold) were upregulated in patients with CAD compared to healthy controls. Quantitative polymerase chain reaction (qPCR) was used to determine the expression levels of IL-6 and TGF-β. The unpaired t-test was used to compare the expression levels of cytokines between the CAD and healthy control groups (****P ≤ 0.0001).

Figure 3

Receiver operating characteristic (ROC) curve analysis using peripheral blood mononuclear cells (PBMCs) miR-22, miR-30c, miR-145, and miR-519d for discriminating between patients with coronary artery disease (CAD) (n = 46) and healthy controls (n = 39); PBMC miR-145 [area under the curve (AUC) = 0.98] probably can be a good biomarker for discriminating between patients with CAD and healthy controls.