MicroRNAs in vascular biology--metabolism and atherosclerosis

MircoRNA-126-5p inhibits apoptosis of endothelial cell in vascular arterial walls via NF-κB/PI3K/AKT/mTOR signaling pathway in atherosclerosis

Atherosclerosis is considered as a chronic inflammatory disease. MircoRNA-126-5p (miR-126-5p) may be pathophysiological relevant with the apoptotic processes in the endothelial cells in the arterial wall. Here, this study determined the role of circulating atherosclerosis-regulatory miR-126-5p in atherosclerotic mice and explored the possible mechanism in human aortic endothelial cells (HAECs). Atherosclerotic mice model was established, oxidative stress-induced apoptosis of HAECs was analyzed, and nuclear factor kappa B (NF-κB)/PI3K/AKT/mTOR signaling pathway was investigated both in vitro and in vivo. This study showed that miR-126-5p mice had less coronary atherosclerotic plaque and lower blood lipid than control mice after being induced by high cholesterol diet. Apoptosis of endothelial cells was inhibited and NF-κB/PI3K/AKT/mTOR signal pathway was downregulated in miR-126-5p mice compared to control. MiR-126-5p increased proliferation and inhibited apoptosis of HAECs induced by oxidative stress. In vitro assay showed that miR-126-5p regulated apoptosis of HAECs via downregulation of NF-κB-mediated PI3K/AKT/mTOR signaling pathway. In conclusion, these data indicated that transfection of miR-126-5p rescued apoptosis of HAECs and limited atherosclerosis, introducing a potential therapeutic approach for atherosclerosis.

Plasma miR-208b and miR-499: Potential Biomarkers for Severity of Coronary Artery Disease

Aims

MicroRNAs (miRNAs) are associated with the pathogenesis of coronary artery disease (CAD). The objective of this study is to explore plasma levels of miR-208b and miR-499 in CAD and analyze its association with the severity of CAD.

Materials and Methods

195 consecutive CAD patients who underwent coronary angiography were enrolled in this study. Severity of coronary lesions was evaluated by the synergy between percutaneous coronary intervention with taxus and cardiac surgery score (SYNTAX) score (SS). Plasma levels of miR-208b and miR-499 were assessed by quantitative real-time polymerase chain reaction (qRT-PCR). The relationship between miR-208b and miR-499 and SS was analyzed.

Results

The qRT-PCR results showed that plasma levels of miR-208b and miR-499 in SS > 32 (high SS) group was higher than those in low (SS ≤ 22) and intermediate (22 < SS ≤ 32) groups. Meanwhile, plasma miR-208b and miR-499 levels were significantly positive correlated with the SS (Spearman's r = 0.535 and r = 0.407, respectively; both p < 0.001). Multivariate logistic analysis results showed that miR-208b (odds ratio [OR]: 2.069; 95% confidence interval [CI]: 1.351-3.167; p = 0.001) and miR-499 (OR: 1.652; 95% CI: 1.222-2.233; p = 0.001) were independent predictors of high SS. In receiver operating characteristic curve, the area under the curve of miR-208b and miR-499 in prediction of high SS was 0.775 and 0.713, respectively.

Conclusions

Higher plasma levels of miR-208b and miR-499 were positively associated with the severity of CAD, and plasma miR-208b and miR-499 can act as potential biomarkers for estimating the severity of CAD.

Circulating MicroRNA-145 is Associated with Acute Myocardial Infarction and Heart Failure

Background:

Recent studies show that microRNA-145 (miRNA-145) might be an attractive tumor biomarker of considerable prognostic value, but little is known about their relationship with acute myocardial infarction (AMI). This study investigated the correlation between the level of miR-145 and AMI.

Methods:

One-hundred patients were divided into three groups: no coronary artery disease (CAD) group, non-ST segment elevation myocardial infarction group, and ST segment elevation myocardial infarction group. The plasma levels of miR-145 were quantified using real-time quantitative polymerase chain reaction. Logarithmic transformation of miRNA-145 levels (Ln_miRNA-145) was used for statistical analysis due to the skewed data distribution.

Results:

Plasma levels of miR-145 were significantly lower in patients with AMI compared to patients in the non-CAD group (−6.38 ± 0.11 vs. −4.47 ± 0.17, P < 0.0001). Compared to those without heart failure, the levels of miR-145 were significantly lower in patients with heart failure (−6.91 ± 0.20 vs. −5.35 ± 0.13, P < 0.0001). We also found that the lower plasma levels of miRNA-145 significantly correlated with increased serum levels of B-type natriuretic peptide (Spearman ρ= −0.60, P < 0.0001), troponin T (Spearman ρ= −0.62, P < 0.0001), and decreased ejection fraction (Spearman ρ= 0.65, P < 0.0001). In a multivariable linear regression analysis, AMI and heart failure were independently associated with lower Ln_miRNA-145 (estimate −0.99, standard error [SE] 0.28; P = 0.001 and estimate −0.62, SE 0.21; P = 0.004).

Conclusions:

Our results suggest that decreased plasma levels of miR-145 are associated with AMI. Circulating miR-145 may be useful in prognosticating cardiac function and the risk of developing heart failure.

MicroRNAs as regulators of endothelial cell functions in cardiometabolic diseases

Endothelial cells (ECs) provide nutrients and oxygen essential for tissue homeostasis. Metabolic imbalances and other environmental stimuli, like cytokines or low shear stress, trigger endothelial inflammation, increase permeability, compromise vascular tone, promote cell proliferation, and ultimately cause cell death. These factors contribute to EC dysfunction, which is crucial in the development of cardiometabolic diseases. microRNAs (miRNAs) are small non-coding RNAs that have important functions in the regulation of ECs. In the present review, we discuss the role of miRNAs in various aspects of EC pathology in cardiometabolic diseases like atherosclerosis, type 2 diabetes, obesity, and the metabolic syndrome, and in complication of those pathologies, like ischemia. We also discuss the potential therapeutic applications of miRNAs in promoting angiogenesis and neovascularization in tissues where the endothelium is damaged in different cardiometabolic diseases. This article is part of a Special Issue entitled: MicroRNAs and lipid/energy metabolism and related diseases edited by Carlos Fernández-Hernando and Yajaira Suárez.

Interaction between microRNA expression and classical risk factors in the risk of coronary heart disease

The aim of this study was to identify the synergistic effect of microRNA expression with classical risk factors of coronary heart disease (CHD) and to explore their diagnostic value for coronary stenotic lesions in subjects with CHD. Plasma samples were obtained from 66 subjects with CHD and from 58 control individuals. A quantitative reverse-transcription PCR (RT-qPCR) assay was conducted to confirm the relative expressions of the known CHD-related miRNAs. The severity of coronary atherosclerosis was based on the Gensini scoring system. The expression of miR-125b in plasma of the CHD group was lower than that of the non-CHD group (0.14 ± 0.09 vs. 0.18 ± 0.10, p = 0.055), and the miR-125b levels significantly decreased following an increasing Gensini score (P = 0.037). Spearman correlation analyses indicated the Gensini score was negatively associated with miR-125b (r = −0.215, p = 0.017). Of all the miRNAs, miR-125b showed the lowest AUC (0.405; 95% CI: 0.305 ~ 0.506, p = 0.070). We found several synergistic effects between miR-125b and classical risk factors, such as age, sex, CR, FBG and HDL-C; the proportion of CHD attributable to the interaction of miR-125b and age was as high as 80%. Therefore, miR-125b was shown to play an important role in individual’s susceptibility to developing CHD.

Plasma Levels of microRNA-145 Are Associated with Severity of Coronary Artery Disease

Background and Objective

MicroRNAs (miRNAs) have been shown to be associated with various physiological and pathological conditions, including inflammation and cardiovascular disease, but little is known about their relationship with the presence of coronary artery disease (CAD) and disease severity.

Methods

A total of 195 consecutive subjects who underwent coronary angiography for chest pain evaluation were enrolled in this study. In CAD patients severity of coronary lesions was assessed by the number of diseased vessels and the Synergy between PCI with Taxus and Cardiac surgery score (SYNTAX score). Plasma levels of miRNA-145 were quantified by real-time quantitative polymerase chain reaction test, and logarithmic transformation of miRNA-145 levels (Ln_miRNA-145) was used for analyses due to its skewed distribution.

Results

Of the 195 total subjects 167 patients were diagnosed as having CAD. Ln_miRNA-145 was significantly lower in CAD patients compared with the non-CAD group (-6.11±0.92 vs. -5.06±1.25; p <0.001). In multivariable linear regression analyses CAD was significantly associated with lower Ln_miRNA-145 (Estimate, -0.50; standard error (SE), 0.11; p <0.0001). Furthermore, among CAD patients, three-vessel disease, higher SYNTAX scores and STEMI were significantly associated with lower Ln_miRNA-145 ([Estimate, -0.40; SE, 0.07; p <0.0001]; [Estimate, -0.02, SE, 0.10; p = 0.005] and [Estimate, -0.35, SE, 0.10; p <0.001] respectively).

Conclusions

Lower plasma levels of miRNA-145 were significantly associated with the presence as well as severity of CAD. As a potential biomarker for CAD, plasma miRNA-145 may be useful in predicting CAD and its severity in patients presenting with chest pain.

MicroRNAs as pharmacological targets in endothelial cell function and dysfunction

Endothelial cell dysfunction is a term which implies the dysregulation of normal endothelial cell functions, including impairment of the barrier functions, control of vascular tone, disturbance of proliferative, migratory and morphogenic capacities of endothelial cells, as well as control of leukocyte trafficking. MicroRNAs are short non-coding RNAs that have emerged as critical regulators of gene expression acting predominantly at the post-transcriptional level. This review summarizes the latest insights in the identification of endothelial-specific microRNAs and their targets, as well as their roles in controlling endothelial cell functions in both autocrine and paracrine manner. In addition, we discuss the therapeutic potential for the treatment of endothelial cell dysfunction and associated vascular pathophysiological conditions.

Induction of thoracic aortic remodeling by endothelial-specific deletion of microRNA-21 in mice

MicroRNAs (miRs) are known to have an important role in modulating vascular biology. MiR21 was found to be involved in the pathogenesis of proliferative vascular disease. The role of miR21 in endothelial cells (ECs) has well studied in vitro, but the study in vivo remains to be elucidated. In this study, miR21 endothelial-specific knockout mice were generated by Cre/LoxP system. Compared with wild-type mice, the miR21 deletion in ECs resulted in structural and functional remodeling of aorta significantly, such as diastolic pressure dropping, maximal tension depression, endothelium-dependent relaxation impairment, an increase of opening angles and wall-thickness/inner diameter ratio, and compliance decrease, in the miR21 endothelial-specific knockout mice. Furthermore, the miR21 deletion in ECs induced down-regulation of collagen I, collagen III and elastin mRNA and proteins, as well as up-regulation of Smad7 and down-regulation of Smad2/5 in the aorta of miR21 endothelial-specific knockout mice. CTGF and downstream MMP/TIMP changes were also identified to mediate vascular remodeling. The results showed that miR21 is identified as a critical molecule to modulate vascular remodeling, which will help to understand the role of miR21 in vascular biology and the pathogenesis of vascular diseases.