Elsevier

Cardiovascular Pathology

Volume 23, Issue 4, July–August 2014, Pages 217-223
Cardiovascular Pathology

Original Article
The up-regulation of endothelin-1 and down-regulation of miRNA-125a-5p, -155, and -199a/b-3p in human atherosclerotic coronary artery

https://doi.org/10.1016/j.carpath.2014.03.009Get rights and content

Abstract

Background

Previous studies have reported important roles of endothelin-1 (ET-1) and angiotensin II (Ang II) in the pathogenesis of atherosclerosis. However, the expression of these two proteins and the underlying mechanisms in human atherosclerotic coronary arteries are largely unknown.

Methods

We examined the expression of ET-1 and Ang II in pericardial fluid and coronary arteries from 25 individuals (n=25) using enzyme-linked immuno sorbent assay (ELISA) and immunohistochemistry. Twelve patients died from acute coronary syndrome were classified as atherosclerotic plaque group (AP group) (n=12), while 13 patients died from other causes were classified as non-AP group (n=13). Meanwhile, we performed reverse transcription-polymerase chain reaction (RT-PCR) to measure the expression of six microRNAs targeting ET-1 in formalin-fixed, paraffin-embedded coronary arteries.

Results

Our data showed that ET-1 was significantly higher in both pericardial fluid and coronary arteries from AP group. However, Ang II showed no significant difference in pericardial fluid between the two groups, while it was even significantly lower in coronary arteries from AP group. Besides, miR-125a-5p, miR-155, and miR-199a/b-3p, which suppressed the expression of ET-1, were down-regulated in the coronary arteries from AP group.

Conclusion

The up-regulation of ET-1, regulated by miR-125a-5p, miR-155, and miR-199a/b-3p, indicated that ET-1 played an important role in human coronary atherosclerosis.

Summary

We focused on the human coronary arteries with atherosclerotic plaques. The expression of ET-1, as well as its upstream miRNAs, was determined. Unlike any of previous study regarding miRNAs expression, we could exclude the discrepancy of artery-bed-specific miRNA expression. Besides, our data indicated, to some degree, that ET-1 might play a more vital role than Ang II in coronary atherosclerosis.

Introduction

Atherosclerotic plaque (AP) rupture is considered the most important mechanism that underlies the onset of acute ischemic syndromes, including stroke, unstable angina, acute myocardial infarction, and sudden death [1], [2]. Imaging modalities which involve noninvasive and invasive methods are developed and validated to accurately characterize APs, but they may destabilize plaques and cause subsequent clinical events. Furthermore, circulating biomarkers are being investigated as a measure of plaque vulnerability [2]. Although many molecular approaches have been performed, the pathophysiology of plaque progress and rupture is not completely understood.

Previous studies indicated that endothelin-1 (ET-1) played a vital role in the pathophysiology of plaque progress and rupture. ET-1 is synthesized and released mostly from endothelial cells [3]. Besides this predominant source, experiments in vivo showed that ET-1 was also synthesized in the macrophages, fibroblasts, cardiomyocytes, and other cells [4]. It was reported that ET-1 had mitogenic effects on smooth muscle cells and fibroblasts and it stimulated synthesis of inflammatory mediators in macrophages and fibronectin in smooth muscle cells [5], [6]. Moreover, ET-1 was proved to activate nuclear factor-ΚB, a key transcription factor of inflammation-cascade, in human monocytes [7]. The constrictor and chemoattractant properties of ET-1 also supported its role in the pathogenesis of atherosclerosis [8].

One of the possible explanations for the up-regulation of ET-1 might be the down-regulation of its upstream microRNAs. MicroRNAs are short non-coding RNAs that regular protein expression at the transcriptional level by inhibiting mRNA translation or inducing its degradation [9]. Meanwhile, they are considered to be novel biomarkers for diagnosing and preventing the coronary artery disease, since they act as important regulators in inflammation and angiogenesis, both of which are core characteristics of plaque vulnerability [10], [11]. In recent studies, several expression profiles of miRNAs in APs were reported. They indicated that the expression of specific miRNA signatures might contribute to the plaque evolution toward an unstable phenotype [11], [12], [13].

In the present study, we determined the expression of ET-1 and angiotensin II (Ang II) in pericardial fluid from coronary atherosclerotic patients. Then, we conducted immunohistochemical staining (IHC) and semiquantified the proteins in the diseased vessel wall. Furthermore, we determined the expression of miRNAs targeting ET-1 in the atherosclerotic coronary arteries.

Section snippets

Autopsy cases

The study included medicolegal autopsy cases (n=25) in Sun Yat-Sen University Zhongshan School of Medicine. All the autopsies were conducted within 72 h after death. The cases were subdivided into two groups: AP group (n=12) and non-AP group (n=13) (details shown in Table 1). The ethnicity of all the selected cases was the Chinese Han. The individuals in AP group suffered atypical chest pains and sudden deaths resulting from acute myocardial infarction, while the patients in non-AP group

The expression of ET-1 and Ang II in the pericardial fluid

A four-parameter logistic curve-fit was generated using computer software to transfer optical density (OD) values to protein concentrations. Compared with those in non-AP group (mean±S.D., 0.32±0.29) (pg/ml), pericardial fluid samples in AP group showed a significantly high ET-1 level (mean±S.D., 0.82±0.51, P<.01) (pg/ml) (Fig. 1a). In contrast, there was no significantly statistical difference in the levels of Ang II between AP group (mean±S.D., 44.33±17.08) (pg/ml) and non-AP group

Discussion

Largely owing to the vast literature on the role of Ang II in the inflammation response of vessel walls, it has become common to believe that Ang II, the final effector of the renin-angiotensin system (RAS), should be involved in the initiation and development of atherosclerosis [15]. However, our data obtained in human pericardial fluid and human coronary artery tissues showed that Ang II had no significant difference in pericardial fluid between the two groups. Even, it showed a significantly

Acknowledgments

The authors are deeply grateful to coworkers in the Sun Yat-Sen University Zhongshan School of Medicine. This study was supported by the Provincial Natural Science Fund Project of Guangdong (Grant No.: S2013010016749), National Natural Science Foundation of China (Grant No.: 81300106).

References (36)

  • FD Russell et al.

    Secretory pathways in endothelin synthesis

    Br J Pharmacol

    (1999)
  • RM Kedzierski et al.

    Endothelin system: the double-edged sword in health and disease

    Annu Rev Pharmacol Toxicol

    (2001)
  • Y Fujitani et al.

    Suppression of endothelin-1-induced mitogenic responses of human aortic smooth muscle cells by interleukin-1 beta

    J Clin Invest

    (1995)
  • H Ruetten et al.

    Endothelin-1 stimulates the biosynthesis of tumour necrosis factor in macrophages: ET-receptors, signal transduction and inhibition by dexamethasone

    J Physiol Pharmacol

    (1997)
  • J Xiao et al.

    MicroRNAs: novel regulators of the heart

    J Thorac Dis

    (2010)
  • S Dimmeler et al.

    Circulating microRNAs: novel biomarkers for cardiovascular diseases?

    Eur Heart J

    (2010)
  • K Bidzhekov et al.

    microRNA expression signatures and parallels between monocyte subsets and atherosclerotic plaque in humans

    Thromb Haemost

    (2012)
  • F Cipollone et al.

    A unique microRNA signature associated with plaque instability in humans

    Stroke

    (2011)
  • Cited by (48)

    • Physical exercise and the functions of microRNAs

      2022, Life Sciences
      Citation Excerpt :

      On the other hand, ultramarathon runners showed 28 times greater expression of miRNA-125a-5p compared to control subjects, while miRNA-let-7e and -126 did not differ statistically between ultramarathon runners and controls [150]. miRNA-125a can be downregulated in patients with atherosclerosis, and both miRNA-125a-5p and -126 have been shown to diminish ox-LDL uptake in endothelial cells and monocytes, and thus may protect against the development of atherosclerosis [151]. In terms of cardioprotection and insulin response, physical exercise can reduce miRNA-135b, -144, -206, -34a, -122, -135b, -144, -486, and -206, stimulating genes that are important for glucose metabolism, such as IRS1, FOXO1, and GSK3β, which are related to the regulation of the acute insulin response to glucose and insulin secretion, as well as glycogen formation [152,153].

    • Molecular mechanisms involved in pre-eclampsia through expressional regulation of endothelin-1

      2022, Placenta
      Citation Excerpt :

      Enquobahrie et al. reported down-regulation of miR-1 levels in placental samples of pre-eclamptic pregnants, similar to our findings [22]. Another study showed that ET-1 levels were found significantly higher in coronary arteries from atherosclerotic plaque group with decreased levels of miR-125b [21]. Li et al. showed that inhibition of ET-1 expression in vascular endothelial cells by miR-125a/b-5p [9].

    • The role of endothelial miRNAs in myocardial biology and disease

      2020, Journal of Molecular and Cellular Cardiology
      Citation Excerpt :

      In vitro approaches, including luciferase reporter assays, overexpression cell models, and western blotting, indicate a direct interaction between miR-125a/b and the 3′ untranslated region of prepro-endothelin-1 mRNA. In accordance with this, upregulation of endothelin-1 was detected in aortic tissue upon administration of miR-125a/b inhibitors to stroke-prone spontaneously hypertensive rats and in pericardial fluid of patients with acute coronary syndrome [115,116]. Another important paracrine factor for vascular pathology, which is partly regulated in a miRNA-dependent manner, is neuregulin-1.

    View all citing articles on Scopus

     Conflicts of interest. The authors declare that there are no conflicts of interest.

    Name of grants: Provincial Natural Science Fund Project of Guangdong (Grant No.: S2013010016749); National Natural Science Foundation of China (Grant No.: 81300106).

    View full text