Overexpression of microRNA-145 in atherosclerotic plaques from hypertensive patients

micro-RNA screening and prediction model construction for diagnosis of salt-sensitive essential hypertension

Commonly used tests for diagnosis of salt-sensitive hypertension (SSH) are complex and time-consuming, so new methods are required. Many studies have demonstrated roles for miRNAs in hypertension; however, the diagnostic value of miRNAs has yet to be determined for human SSH. In this study, we examined miRNA expression profiles by initial high-throughput miRNA sequencing of samples from patients with salt-sensitive and salt-resistant hypertension (SSH and SRH, respectively; n = 6, both groups), followed by validation by quantitative real-time polymerase chain reaction (qRT-PCR) in a larger cohort (n = 91). We also evaluated differences in baseline characteristics (e.g., age, sex, body mass index, consumption of specific foods) between the SSH and SRH groups. Of 36 miRNAs identified as differentially expressed between SSH and SRH groups by RNA-Seq, 8 were analyzed by qRT-PCR. There were significant differences in the expression levels of hsa-miR-361-5p and hsa-miR-362-5p between the 2 groups (P = .023 and.049, respectively). In addition, there were significant differences in sauce and poultry consumption between the 2 groups (P = .004 and.001, respectively). The areas under the curve (AUC) determined by receptor operating characteristic (ROC) analysis for hsa-miR-361-5p and all 8 miRNAs were 0.793 (95% CI, 0.698-0.888; sensitivity = 73.9%, specificity = 74.4%; P < .001) and 0.836 (95% CI, 0.749-0.922; sensitivity = 80.4%, specificity = 81.4%; P < .001), respectively, when sauce and poultry consumption were included in the models. Assay feasibility and economic considerations make hsa-miR-361-5p combined with the dietary factors the preferred markers for diagnosis of SSH.

microRNA profiling in atherosclerosis, diabetes, and migraine

microRNAs (miRNAs) are a broad group of endogenous small non-coding molecules that reduce the transcription of mRNA and play a key role in post-transcriptional gene processes. miRNAs are involved in onset and progression of several human disorders such as infectious and immune non-infectious diseases, cancers, metabolic and cardiovascular disorders. They regulate the expression of gene targets (e.g. oncogenes and tumor suppressor genes) and act as gene repressors with mRNA binding and cleavage. The increasing evidence that miRNAs play a key role in the pathogenesis of cardiovascular conditions could radically change the future management approach to these disorders. This review focuses on current knowledge about the influence of miRNAs on cardiovascular disease, with particular regard to common conditions such as atherosclerosis, diabetes and migraine. Key messages miRNAs are a group of endogenous small non-coding RNA segments measuring 19-25 nucleotides that are involved in physiologic processes and onset and progression of disorders such as infectious and immune non-infectious diseases, cancers, metabolic and cardiovascular disorders. miRNAs expression guarantees vascular integrity, by regulating apoptosis, VEGF pathway and VCAM 1 expression (-126), and is involved in atherosclerotic plaque formation process and progression. Hyperglycemia, overt diabetes, and their complications are associated with overexpression of several miRNAs. An altered expression of miRNAs has also been postulated in migraine patients, although only a few preliminary studies have so far been performed with this respect.

miRNA-145 inhibits VSMC proliferation by targeting CD40

Recent studies have demonstrated functions of miR-145 in vascular smooth muscle cells (VSMCs) phenotypes and vascular diseases. In this study, we aim to determine whether CD40 is involved in miR-145 mediated switch of VSMC phenotypes. In cultured VSMCs, the effects of miR-145 and CD40 on TNF-α, TGF-β, and Homocysteine (Hcy) induced cell proliferation were evaluated by over-expression of miR-145 or by siRNA-mediated knockdown of CD40. We also used ultrasound imaging to explore the effect of miR-145 on carotid artery intima-media thickness (CIMT) in atherosclerotic cerebral infarction (ACI) patients. The results showed 50 ng/mL TNF-α, 5 ng/mL TGF-β, and 500 μmol/L Hcy significantly increased the expression of CD40, both at mRNA and protein levels, and also induced the proliferation of VSMCs. We found that over-expression of miR-145 significantly inhibited the expression of CD40 and the differentiation of VSMCs, and over-expression of miR-145 decreased IL-6 levels in VSMC supernatants. In ACI patients, the lower expression of miR-145 was associated with thicker CIMT and higher levels of plasma IL-6. Our results suggest that the miR-145/CD40 pathway is involved in regulating VSMC phenotypes in TNF-α, TGF-β, and Hcy induced VSMCs proliferation model. Targeting miR-145/CD40 might be a useful strategy for treating atherosclerosis.

An rs4705342 T>C polymorphism in the promoter of miR-143/145 is associated with a decreased risk of ischemic stroke

The expression of miR-143/miR-145 was up-regulated in ischemic stroke (IS), which may be used as biomarkers and/or therapeutic targets for IS. We aimed to investigate the association of rs4705342 and rs4705343 polymorphisms in the promoter of miR-143/145 with risk of IS. The study population comprised 445 patients with IS and 518 controls. The rs4705342 genotype was analyzed by using a TaqMan Assay and the rs4705343 genotype was determined by using a polymerase chain reaction-restriction fragment length polymorphism assay. Relative expression of miR-143/miR-145 was measured by quantitative real-time PCR. We found that the rs4705342 was associated with a decreased risk of IS (TC vs. TT: adjusted OR = 0.74, 95% CI, 0.57-0.97; CC vs. TT: adjusted OR = 0.53, 95% CI, 0.34-0.83). Haplotype analysis showed that the TC haplotype was associated with an increased risk of IS risk (OR = 1.33, 95% CI, 1.01-1.75), whereas the CT haplotype was associated with a decreased risk of IS risk (OR = 0.68, 95% CI, 0.50-0.92). Importantly, patients carrying the rs4705342TC/CC genotypes had a lower level of miR-145 (P = 0.03). We found for the first time that the rs4705342 CC was a protective factor for IS, probably by reducing the level of miR-145.

Differential Expression of MicroRNAs in Endarterectomy Specimens Taken from Patients with Asymptomatic and Symptomatic Carotid Plaques

Objective

Stroke and transient ischemic attacks are considered as clinical manifestations of atherosclerotic disease due to on-going vascular inflammation and finally atherothrombosis of the carotid arteries. MicroRNAs (miRNA/miR) are known to be involved in vascular inflammation and plaque destabilization. The aim of this study was to analyze the expression profile of selected miRNAs in endarterectomy specimen from carotid arteries that were taken from patients with asymptomatic and symptomatic atherosclerotic plaques.

Methods and Results

11 miRNAs were selected and their expression was analyzed using real-time RT-PCR. Therefore, samples were divided into three different groups. On the one hand we investigated the expression patterns from patients in asymptomatic (n = 14) and symptomatic (n = 10) plaques; on the other hand we took samples from normal configurated internal mammary arteries (n = 15). Out of these 11 targets we identified some miRNAs, which were up- or down-regulated in either one of the two groups. Interestingly, the expression of two miRNAs was significantly different between asymptomatic and symptomatic samples, namely miR-21 (P<0.01) and miR-143 (P<0.05).

Conclusion

In the present study, we identified miRNA subtypes which showed different expression in endarterectomy specimen from patients with asymptomatic and symptomatic plaques, suggesting that these miRNAs correlated with advanced vascular inflammation and plaque stability. They may represent new therapeutic targets for vascular proliferative diseases such as atherosclerosis.

Phenotypic switching of vascular smooth muscle cells in the 'normal region' of aorta from atherosclerosis patients is regulated by miR-145

Switching of vascular smooth muscle cells (VSMCs) from a contractile phenotype to an adverse proliferative phenotype is a hallmark of atherosclerosis or vascular restenosis. However, the genetic modulators responsible for this switch have not been fully elucidated in humans nor have they been correlated with clinical abnormalities. This study investigated genetic mechanisms involved in phenotypic switching of VSMCs at non-defect areas of the aorta in patients with atherosclerosis. Aortic wall samples were obtained from patients with (N = 53) and without (N = 27) atherosclerosis undergoing cardiovascular surgery. Vascular smooth muscle cell cultures were generated, and expression of microRNA-145 (miR-145), its target gene Kruppel-Like Factor 5 (KLF5) and Myocardin (MYOCD, a smooth muscle-specific transcriptional coactivator) were analysed using RT-qPCR, along with expression of relevant proteins. Vascular smooth muscle cells were transduced with miR-145 inhibitor and mimic to determine the effect of miR-145 expression on VSMC proliferation. miR-145 expression decreased while KLF5 expression increased in atherosclerotic aortas. Atherosclerotic samples and VSMCs had decreased expression of contractile markers calponin and alpha smooth muscle actin (α-SMA) and MYOCD. miR-145 inhibitor-transduced VSMCs from non-atherosclerotic patients showed decreased expression of calponin and α-SMA and increased proliferation compared with non-transduced controls, and these levels were close to those of atherosclerotic patients. miR-145 mimic-transduced VSMCs from atherosclerotic patients showed increased expression of calponin and α-SMA and decreased proliferation compared with non-transduced controls, and these levels were close to those found in non-atherosclerotic patients. These data demonstrate that miR-145 modulates the phenotypic switch of VSMCs from a contractile to a proliferative state via KLF5 and MYOCD in atherosclerosis.

miRNAs and High-Density Lipoprotein metabolism

Altered lipoprotein metabolism plays a key role during atherogenesis. For over 50years, epidemiological data have fueled the proposal that HDL-cholesterol (HDL-c) in circulation is inversely correlated to cardiovascular risk. However, the atheroprotective role of HDL is currently the focus of much debate and remains an active field of research. The emerging picture from research in the past decade suggests that HDL function, rather than HDL-c content, is important in disease. Recent developments demonstrate that miRNAs play an important role in fine-tuning the expression of key genes involved in HDL biogenesis, lipidation, and clearance, as well as in determining the amounts of HDL-c in circulation. Thus, it has been proposed that miRNAs that affect HDL metabolism might be exploited therapeutically in patients. Whether HDL-based therapies, alone or in combination with LDL-based treatments (e.g. statins), provide superior outcomes in patients has been recently questioned by human genetics studies and clinical trials. The switch in focus from "HDL-cholesterol" to "HDL function" opens a new paradigm to understand the physiology and therapeutic potential of HDL, and to find novel modulators of cardiovascular risk. In this review we summarize the current knowledge on the regulation of HDL metabolism and function by miRNAs. 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.

Small but smart: MicroRNAs orchestrate atherosclerosis development and progression

MicroRNAs (miRNAs) are short non-coding RNA able to bind specific sequences on target messenger RNAs (mRNAs) and thereby to post-transcriptionally modulate gene expression. Being expressed in all vertebrate cell types, miRNAs have emerged as key players in a wide array of biological processes, including cell proliferation, differentiation and apoptosis. Over the past decade, knowledge concerning the contribution of miRNAs to human pathology has grown with an astonishing pace. In particular, a major involvement of miRNAs in atherosclerosis as a leading cause of global mortality has been supported by ample evidence from in vitro, in vivo and clinical studies. This review aims to summarize and highlight current concepts of miRNA function in the continuum of atherogenesis ranging from risk factors (i.e. dyslipidemia, diabetes, hypertension), to endothelial dysfunction up to the events leading to plaque rupture. Areas in need for further research and potential perspectives for translational applications will be scrutinized. 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.

MicroRNA-143/-145 in Cardiovascular Diseases

MicroRNAs (miRNAs) play an essential role in the onset and development of many cardiovascular diseases. Increasing evidence shows that miRNAs can be used as potential diagnostic biomarkers for cardiovascular diseases, and miRNA-based therapy may be a promising therapy for the treatment of cardiovascular diseases. The microRNA-143/-145 (miR-143/-145) cluster is essential for differentiation of vascular smooth muscle cells (VSMCs) and determines VSMC phenotypic switching. In this review, we summarize the recent progress in knowledge concerning the function of miR-143/-145 in the cardiovascular system and their role in cardiovascular diseases. We discuss the potential role of miR-143/-145 as valuable biomarkers for cardiovascular diseases and explore the potential strategy of targeting miR-143 and miR-145.

Identification of microRNAs 758 and 33b as potential modulators of ABCA1 expression in human atherosclerotic plaques

BACKGROUND AND AIM

Adenosine triphosphate (ATP)-binding cassette (ABC) transporters A1 and G1 are the main transporters involved in macrophage cholesterol efflux. The understanding of the molecular mechanism(s) of their regulation in atherosclerosis is crucial for potential therapeutic approaches. Preclinical studies support a role for microRNAs in the posttranscriptional regulation of these transporters; however, no evidence is still available on human atherosclerosis. Thus, the aim of this study was to investigate the modulation of the ABCA1 and ABCG1 pathway in human atherosclerotic plaques and microRNA involvement in its modulation.

METHODS AND RESULTS

Thirty-one human atherosclerotic plaques were obtained from patients undergoing carotid endarterectomy for high-grade (>70%) vessel stenosis, and divided into normocholesterolemic (n = 15) and hypercholesterolemic groups (n = 16) according to the presence/absence of hypercholesterolemia. Both ABCA1 and ABCG1 messenger RNAs (mRNAs) were significantly upregulated in carotid plaques from hypercholesterolemic patients as assessed by real-time polymerase chain reaction (RT-PCR). Despite this result, no difference was found at the protein levels analyzed by Western blot, thus suggesting a strong posttranscriptional modulation. MicroRNA microarray and subsequent validation by RT-PCR showed a significant upregulation of ABCA1-linked miR-758 and miR-33b in plaques from hypercholesterolemic patients.

CONCLUSION

We provide evidence of a strong posttranscriptional regulation of ABCA1 and ABCG1 expression in human atherosclerotic plaques from hypercholesterolemic patients. This effect is potentially due to the concomitant increase of miR-33b and miR-758, two well-established regulators of ABCA1 and ABCG1 expression. The identification of miR-33b and miR-758 as putative key regulators of ABCA1 protein expression within human atherosclerotic plaques provides further data for the realization of new anti-atherosclerotic drugs with specific targets based on anti-miRNA technologies.

Hypertensive epigenetics: from DNA methylation to microRNAs

The major epigenetic features of mammalian cells include DNA methylation, posttranslational histone modifications and RNA-based mechanisms including those controlled by small non-coding RNAs (microRNAs (miRNAs)). An important aspect of epigenetic mechanisms is that they are potentially reversible and may be influenced by nutritional-environmental factors and through gene-environment interactions. Studies on epigenetic modulations could help us understand the mechanisms involved in essential hypertension and further prevent it's progress. This review is focused on new knowledge on the role of epigenetics, from DNA methylation to miRNAs, in essential hypertension.

MicroRNA profiling in migraine without aura: pilot study

BACKGROUND AND PURPOSE

MicroRNAs (miRNAs) are short, non-coding RNAs whose deregulation has been shown in several human diseases, including pain states and diseases associated with increased cardiovascular (CV) risk. This study aimed at identifying differentially expressed circulating miRNAs in patients with 'migraine without aura' (MO), a pain condition whose link with CV risk remains debated.

METHODS

Fifteen female MO patients and 13 matching healthy controls underwent a circulating microRNA expression profiling. MiR-22, miR-26a, miR-26b, miR-27b, miR-29b, let-7b, miR-181a, miR-221, miR-30b, and miR-30e were selected for validation by quantitative real-time polymerase chain reaction.

RESULTS

In migraineurs versus controls, four miRNAs were differentially expressed: miR-27b was significantly up-regulated (q < 0.004), while miR-181a, let-7b, and miR-22 were significantly down-regulated (q ≤ 0.01). MiR-22 and let-7b down-regulation was also confirmed in circulating blood monocytes. A logistic regression model based on microRNA expression profile showed a high accuracy for identifying migraine (AUC of ROC curve: 0.956; P < 0.001).

CONCLUSION

A specific circulating miRNAs profile is associated with migraine without aura. Remarkably, the same miRNAs are known to be modulated in the setting of atherosclerosis and stroke in humans. This study represents a first step towards further characterization of MO diagnosis/pathophysiology, also in relation to its link with cardiovascular risk.

Non-coding RNAs and hypertension-unveiling unexpected mechanisms of hypertension by the dark matter of the genome

Hypertension is a major risk factor of cardiovascular diseases and a most important health problem in developed countries. Investigations on pathophysiology of hypertension have been based on gene products from coding region that occupies only about 1% of total genome region. On the other hand, non-coding region that occupies almost 99% of human genome has been regarded as "junk" for a long time and went unnoticed until these days. But recently, it turned out that noncoding region is extensively transcribed to non-coding RNAs and has various functions. This review highlights recent updates on the significance of non-coding RNAs such as micro RNAs and long non-coding RNAs (lncRNAs) on the pathogenesis of hypertension, also providing an introduction to basic biology of noncoding RNAs. For example, microRNAs are associated with hypertension via neuro-fumoral factor, sympathetic nerve activity, ion transporters in kidneys, endothelial function, vascular smooth muscle phenotype transformation, or communication between cells. Although reports of lncRNAs on pathogenesis of hypertension are scarce at the moment, new lncRNAs in relation to hypertension are being discovered at a rapid pace owing to novel techniques such as microarray or next-generation sequencing. In the clinical settings, clinical use of non-coding RNAs in identifying cardiovascular risks or developing novel tools for treating hypertension such as molecular decoy or mimicks is promising, although improvement in chemical modification or drug delivery system is necessary.

microRNAs in Cerebrovascular Disease

Cardiovascular diseases are major causes of morbidity and mortality in developed countries. Cerebrovascular diseases, especially stroke, represent major burden of disability and economy impact. Major advances in primary and secondary prevention and therapy are needed in order to tackle this public health problem. Our better understanding of pathophysiology is essential in order to develop novel diagnostic and therapeutic tools and strategies. microRNAs are a family of important post-transcriptional regulators of gene expression and their involvement in the pathophysiology of cerebrovascular diseases has already been reported. Moreover, microRNAs may represent above-mentioned potential diagnostic and therapeutic tools in clinical practice. Within this chapter, we briefly describe basic epidemiology, aetiology and clinical manifestation of following cerebrovascular diseases: extracranial carotid atherosclerosis, acute stroke, intracranial aneurysms and cerebral arterio-venous malformations. Further, in each chapter, the current knowledge about the involvement of specific microRNAs and their potential use in clinical practice will be summarized. More specifically, within the subchapter "miRNAs in carotid atherosclerosis", general information about miRNA involvement in atherosclerosis will be described (miR-126, miR-17-92, miR-155 and others) with special emphasis put on miRNAs affecting carotid plaque progression and stability (e.g. miR-145, miR-146 or miR-217). In the subchapter "miRNAs in acute stroke", we will provide insight into recent knowledge from animal and human studies concerning miRNA profiling in acute stroke and their expression dynamics in brain tissue and extracellular fluids (roles of, e.g. let-7 family, miR-21, miR-29 family, miR-124, miR-145, miR-181 family, miR-210 and miR-223). Subchapters dealing with "miRNAs and AV malformations" and "miRNAs and intracranial aneurysms" will focus on miR-21, miR-26, miR-29 family and miR-143/145.

Circulating microRNAs as Biomarkers in Cardiovascular Diseases

MicroRNAs, key regulators of biological processes, are involved in the pathophysiological mechanisms underlying human diseases, including cardiovascular diseases. Their recent discovery revealed a previously unknown layer of pathophysiologic regulators, which also play a key role in the regulation of several aspects of cardiovascular diseases. More recently, it was demonstrated that circulating microRNAs can be measured in the blood. Hence, the potential use of microRNAs as disease biomarkers attracted many research groups. Indeed, their unusual stability in the bloodstream and during prolonged storage make circulating miRs very interesting as potential biomarkers. Circulating microRNAs are emerging as the next generation "smart" biomarkers and could be helpful in further improving the diagnostic and therapeutic processes of cardiovascular diseases. The present chapter summarizes the most relevant experimental evidence on circulating microRNAs in cardiovascular diseases, including arterial remodeling, restenosis, coronary artery disease, acute coronary syndromes, hypertension, heart failure, and ischemic stroke, highlighting potential pathophysiological correlations to the mechanisms underlying cardiovascular diseases.

microRNAs in Essential Hypertension and Blood Pressure Regulation

Unravelling the complete genetic predisposition to high blood pressure (BP) has proven to be challenging. This puzzle and the fact that coding regions of the genome account for less than 2 % of the entire human DNA support the hypothesis that mechanisms besides coding genes are likely to contribute to BP regulation. Non-coding RNAs, especially microRNAs, are emerging as key players of transcription regulation in both health and disease states. They control basic functions in virtually all cell types relevant to the cardiovascular system and, thus, a direct involvement with BP regulation is highly probable. Here we review the literature about microRNAs associated with regulation of BP and hypertension, highlighting investigations, methodology and difficulties arising in the field. These molecules are being studied for exploitation in diagnostics, prognostics and therapeutics in many diseases. There have been some studies that examined biological fluid microRNAs as biomarkers for hypertension, but most remain inconclusive due to the small sample sizes and differences in methodological standardisation. Fewer studies have analysed tissue microRNA levels in vascular smooth muscle cells and the kidney. Others focused on the interaction between single nucleotide polymorphisms and microRNA binding sites. Studies in animals have shown that angiotensin II, high-salt diet and exercise change microRNA levels in hypertension. Treatment of spontaneously hypertensive rats with a miR-22 inhibitor and treatment of hypertensive Schlager BPH/2J mice with a miR-181a mimic decreased their BP. This supports the use of microRNAs as therapeutic targets in hypertension, and future studies should test the use of other microRNAs found in human association studies. In conclusion, there is a clear need of increased pace of human, animal and functional studies to help us understand the multifaceted roles of microRNAs as critical regulators of the development and physiology of BP.

MicroRNAs in atherosclerosis

Micro-ribonucleic acids (miRNAs) are a class of endogenous non-coding ribonucleic acids that regulate gene expression. MiRNAs have been shown to act as key regulators in the vascular system, with wide-ranging physio-pathological effects. Atherosclerotic disease is a leading cause of morbidity and mortality worldwide. This review presents current knowledge on miRNAs implicated in atherosclerosis susceptibility, development and progression. They are involved in cell phenotype switching, response to shear stress, cell senescence, adhesion molecule expression, macrophage response to oxidised low-density lipoprotein, Toll-like receptor 4 expression, neointimal lesion formation, plaque angiogenesis and cellular cholesterol homeostasis. Clinically, early work has demonstrated the utility of miRNAs for differentiating patients with arterial disease from controls and predicting future cardiac events; this highlights potential diagnostic and prognostic roles. MiRNA involvement in the crucial stages of atherosclerosis promises new hope in treating arterial disease. However, issues regarding multiple miRNA targets, stability and delivery continue to present challenges.

Identifying microRNAs involved in aging of the lateral wall of the cochlear duct

Age-related hearing loss is a progressive sensorineural hearing loss that occurs during aging. Degeneration of the organ of Corti and atrophy of the lateral wall of the cochlear duct (or scala media) in the inner ear are the two primary causes. MicroRNAs (miRNAs), a class of short non-coding RNAs that regulate the expression of mRNA/protein targets, are important regulators of cellular senescence and aging. We examined miRNA gene expression profiles in the lateral wall of two mouse strains, along with exploration of the potential targets of those miRNAs that showed dynamic expression during aging. We show that 95 and 60 miRNAs exhibited differential expression in C57 and CBA mice during aging, respectively. A majority of downregulated miRNAs are known to regulate pathways of cell proliferation and differentiation, while all upregulated miRNAs are known regulators in the pro-apoptotic pathways. By using apoptosis-related gene array and bioinformatic approaches to predict miRNA targets, we identify candidate miRNA-regulated genes that regulate apoptosis pathways in the lateral wall of C57 and CBA mice during aging.

The emerging role of non-coding RNA in essential hypertension and blood pressure regulation

Unravelling the complete genetic predisposition to high blood pressure (BP) has proven to be challenging. This puzzle and the fact that coding regions of the genome account for less than 2% of the entire human DNA support the hypothesis that genetic mechanism besides coding genes are likely to contribute to BP regulation. Non-coding RNAs (ncRNAs) are emerging as key players of transcription regulation in both health and disease states. They control basic functions in virtually all cell types relevant to the cardiovascular system and, thus, a direct involvement with BP regulation is highly probable. Here, we review the literature about ncRNAs associated with human BP and essential hypertension, highlighting investigations, methodology and difficulties arising in the field. The most investigated ncRNAs so far are microRNAs (miRNAs), small ncRNAs that modulate gene expression by posttranscriptional mechanisms. We discuss studies that have examined miRNAs associated with BP in biological fluids, such as blood and urine, and tissues, such as vascular smooth muscle cells and the kidney. Furthermore, we review the interaction between miRNA binding sites and single nucleotide polymorphisms in genes associated with BP. In conclusion, there is a clear need for more human and functional studies to help elucidate the multifaceted roles of ncRNAs, in particular mid- and long ncRNAs in BP regulation.

Elevated expression levels of miR-143/5 in saphenous vein smooth muscle cells from patients with Type 2 diabetes drive persistent changes in phenotype and function

Type 2 diabetes (T2DM) promotes premature atherosclerosis and inferior prognosis after arterial reconstruction. Vascular smooth muscle cells (SMC) respond to patho/physiological stimuli, switching between quiescent contractile and activated synthetic phenotypes under the control of microRNAs (miRs) that regulate multiple genes critical to SMC plasticity. The importance of miRs to SMC function specifically in T2DM is unknown. This study was performed to evaluate phenotype and function in SMC cultured from non-diabetic and T2DM patients, to explore any aberrancies and investigate underlying mechanisms. Saphenous vein SMC cultured from T2DM patients (T2DM-SMC) exhibited increased spread cell area, disorganised cytoskeleton and impaired proliferation relative to cells from non-diabetic patients (ND-SMC), accompanied by a persistent, selective up-regulation of miR-143 and miR-145. Transfection of premiR-143/145 into ND-SMC induced morphological and functional characteristics similar to native T2DM-SMC; modulating miR-143/145 targets Kruppel-like factor 4, alpha smooth muscle actin and myosin VI. Conversely, transfection of antimiR-143/145 into T2DM-SMC conferred characteristics of the ND phenotype. Exposure of ND-SMC to transforming growth factor beta (TGFβ) induced a diabetes-like phenotype; elevated miR-143/145, increased cell area and reduced proliferation. Furthermore, these effects were dependent on miR-143/145. In conclusion, aberrant expression of miR-143/145 induces a distinct saphenous vein SMC phenotype that may contribute to vascular complications in patients with T2DM, and is potentially amenable to therapeutic manipulation.

MicroRNA-155 inhibits angiotensin II-induced vascular smooth muscle cell proliferation

BACKGROUND

MicroRNA-155 (miR-155) is a multifunctional signal microRNA that participates in a variety of cardiovascular diseases and is involved in physiological and pathological processes in different cell types.

OBJECTIVE

The objective of this article is to examine the effect of miR-155 on angiotensin II (Ang II)-induced primary mice vascular smooth muscle cell (VSMC) proliferation.

METHODS

Primary cultured VSMCs from the aorta of C57/BL6 mice were incubated with Ang II and miR-155. Cells were counted using CCK-8 and EdU, and flow cytometric analysis of cell cycle progression was performed. Angiotensin II 1 type receptor (AT1R) gene and protein expression were measured by real-time polymerase chain reaction and Western blotting.

RESULTS

1) Ang II increased the viability of VSMCs in a dose- and time-dependent manner. 2) miR-155 opposed the Ang II-induced increase in VSMC viability. 3) miR-155 inhibited Ang II-induced proliferation of VSMCs. 4) miR-155 increased the number of VSMCs in the G1 phase compared to G2 and M cell cycle phases. 5) miR-155 decreased ATR1 gene and protein expression.

CONCLUSION

miR-155 downregulation of Ang II-induced VSMC viability identifies it as an important regulator of cell proliferation.

Diagnosis, prognosis and therapeutic role of circulating miRNAs in cardiovascular diseases

Cardiovascular diseases (CVD) are the leading cause of morbidity and mortality in the world. Although much progress has been made for cardiovascular diseases in diagnosis, treatment and prognosis during the past two decades, the clinical need for a novel diagnostic biomarker and new therapeutic interventions to decrease the cardiovascular disease incidence is ongoing. MicroRNAs (miRNAs) are endogenous, small (∼22 nucleotides), single-stranded, non-coding RNAs that regulate gene expression and are detectable in whole blood, serum, plasma, urine and other body fluids in a highly stable form. Accumulating evidence suggests that miRNAs are potential novel biomarkers with high sensitivity for early diagnosis and modern treatment for cardiovascular diseases. Altered circulating miRNAs expressions have been reported in acute myocardial infarction (AMI), acute coronary syndrome (ACS), stable coronary artery disease, heart failure, atherosclerosis, essential hypertension and stroke. In the present review, we examine more recent data regarding circulating miRNAs and their potential roles in diagnosis, prognosis and therapeutic strategies for cardiovascular diseases. In addition, we briefly present our own recent experience in detecting circulating miRNAs, and the significance of these miRNAs in AMI prognosis.

All's well that transcribes well: non-coding RNAs and post-stroke brain damage

The mammalian genome is replete with various classes of non-coding (nc) RNA genes. Many of them actively transcribe, and their relevance to CNS diseases is just beginning to be understood. CNS is one of the organs in the body that shows very high ncRNAs activity. Recent studies demonstrated that cerebral ischemia rapidly changes the expression profiles of different classes of ncRNAs: including microRNA, long noncoding RNA and piwi-interacting RNA. Several studies further showed that post-ischemic neuronal death and/or plasticity/regeneration can be altered by modulating specific microRNAs. These studies are of interest for therapeutic development as they may contribute to identifying new ncRNA targets that can be modulated to prevent secondary brain damage after stroke.