Additive contribution of microRNA-34a/b/c to human arterial ageing and atherosclerosis

Polycyclic aromatic hydrocarbons exposure and arterial stiffness-related plasma miRNAs: A panel study

The underlying mechanisms between polycyclic aromatic hydrocarbons (PAHs) exposure and arterial stiffness are poorly understood. We carried out a panel study involving three repeated surveys to examine the associations of individual and mixture of PAHs exposure with arterial stiffness-related miRNAs among 123 community adults. In linear mixed-effect (LME) models, we found that urinary 9-hydroxyfluorene (9-OHFlu), 2-hydroxyphenanthrene (2-OHPh), 9-hydroxyphenanthrene (9-OHPh) at lag 0 day were positively linked to miR-146a and/or miR-222. The Bayesian kernel machine regression (BKMR) analyses revealed positive overall associations of PAHs mixture at lag 0 day with miR-146a and miR-222, and urinary 9-OHFlu contributed the most. In addition, an inter-quartile range (IQR) increase in urinary 9-OHFlu at lag 0 day was associated with elevated miR-146a and miR-222 by 0.16 (95% CI: 0.02, 0.30) to 0.34 (95% CI: 0.13, 0.54). Accordingly, exposure to PAHs, especially 9-OHFlu at lag 0 day, was related to elevated arterial stiffness-related plasma miRNAs.

MicroRNA-34a-Dependent Attenuation of Angiogenesis in Right Ventricular Failure

BACKGROUND

The right ventricle (RV) is at risk in patients with complex congenital heart disease involving right-sided obstructive lesions. We have shown that capillary rarefaction occurs early in the pressure-loaded RV. Here we test the hypothesis that microRNA (miR)-34a, which is induced in RV hypertrophy and RV failure (RVF), blocks the hypoxia-inducible factor-1α-vascular endothelial growth factor (VEGF) axis, leading to the attenuated angiogenic response and increased susceptibility to RV failure.

METHODS AND RESULTS

Mice underwent pulmonary artery banding to induce RV hypertrophy and RVF. Capillary rarefaction occurred immediately. Although hypoxia-inducible factor-1α expression increased (0.12±0.01 versus 0.22±0.03, P=0.05), VEGF expression decreased (0.61±0.03 versus 0.22±0.05, P=0.01). miR-34a expression was most upregulated in fibroblasts (4-fold), but also in cardiomyocytes and endothelial cells (2-fold). Overexpression of miR-34a in endothelial cells increased cell senescence (10±3% versus 22±2%, P<0.05) by suppressing sirtulin 1 expression, and decreased tube formation by 50% via suppression of hypoxia-inducible factor-1α, VEGF A, VEGF B, and VEGF receptor 2. miR-34a was induced by stretch, transforming growth factor-β1, adrenergic stimulation, and hypoxia in cardiac fibroblasts and cardiomyocytes. In mice with RVF, locked nucleic acid-antimiR-34a improved RV shortening fraction and survival half-time and restored capillarity and VEGF expression. In children with congenital heart disease-related RVF, RV capillarity was decreased and miR-34a increased 5-fold.

CONCLUSIONS

In summary, miR-34a from fibroblasts, cardiomyocytes, and endothelial cells mediates capillary rarefaction by suppressing the hypoxia-inducible factor-1α-VEGF axis in RV hypertrophy/RVF, raising the potential for anti-miR-34a therapeutics in patients with at-risk RVs.

Unlocking the miRNA-34a-5p/TGF-β and HMGB1/PI3K/Akt/mTOR crosstalk participate in the enhanced cardiac protection of liraglutide against isoproterenol-induced acute myocardial injury rat model

Liraglutide (LIRA), a drug used to treat type 2 diabetes mellitus that belongs to the glucagon-like peptide-1 class, has recently drawn attention for its potential cardioprotective properties because of its anti-oxidative and anti-inflammatory properties. This current investigation was designed to assess the impact of LIRA on myocardial injury induced by isoproterenol (ISO). The experiment included 24 male Wistar rats in total, and they were divided into four groups: Control, LIRA (200 µg/kg/12 hrs., S.C.), ISO (85 mg/kg, S.C.), and ISO + LIRA. To assess the results, various biochemical and histopathological analyses were carried out. The findings showed elevated serum enzyme levels, a sign of cardiac injury. ISO-treated rats showed an upregulation of oxidative stress and inflammatory biomarkers like MDA, MPO, nitrites, NADPH oxidase, TNF-α, IL-1β, IL-6, 8-Hydroxyguanosine (8-OHdG), and TGF-β, as well as altered gene expressions like TLR-1 and miRNA-34a-5p. According to western blotting analysis, protein levels of AKT, PI3K, and mTOR were obviously enhanced. Additionally, ISO-treated samples showed altered tissue morphology, elevated caspase 3, and decreased Bcl2 concentrations. The levels of these dysregulated parameters were significantly normalized by LIRA therapy, demonstrating its cardioprotective function against ISO-induced myocardial injury in rats. This protective mechanism was linked to anti-inflammatory properties, redox balance restoration, and modulation of the miRNA-34a-5p/TGF-β pathway.

Traditional Therapeutics and Potential Epidrugs for CVD: Why Not Both?

Cardiovascular disease (CVD) is the leading cause of death worldwide. In addition to the high mortality rate, people suffering from CVD often endure difficulties with physical activities and productivity that significantly affect their quality of life. The high prevalence of debilitating risk factors such as obesity, type 2 diabetes mellitus, smoking, hypertension, and hyperlipidemia only predicts a bleak future. Current traditional CVD interventions offer temporary respite; however, they compound the severe economic strain of health-related expenditures. Furthermore, these therapeutics can be prescribed indefinitely. Recent advances in the field of epigenetics have generated new treatment options by confronting CVD at an epigenetic level. This involves modulating gene expression by altering the organization of our genome rather than altering the DNA sequence itself. Epigenetic changes are heritable, reversible, and influenced by environmental factors such as medications. As CVD is physiologically and pathologically diverse in nature, epigenetic interventions can offer a ray of hope to replace or be combined with traditional therapeutics to provide the prospect of addressing more than just the symptoms of CVD. This review discusses various risk factors contributing to CVD, perspectives of current traditional medications in practice, and a focus on potential epigenetic therapeutics to be used as alternatives.

Effect of diet and genotype on the miRNome of mice with altered lipoprotein metabolism

The molecular mechanism by which lipid/lipoprotein biosynthesis is regulated in mammals involves a very large number of genes that are subject to multiple levels of regulation. miRNAs are recognized contributors to lipid homeostasis at the post-transcriptional level, although the elucidation of their role is made difficult by the multiplicity of their targets and the ability of more miRNAs to affect the same mRNAs. In this study, an evaluation of how miRNA expression varies in organs playing a key role in lipid/lipoprotein metabolism was conducted in control mice and in two mouse models carrying genetic ablations which differently affect low-density lipoprotein metabolism. Mice were fed a lipid-poor standard diet and a diet enriched in cholesterol and saturated fat. The results obtained showed that there are no miRNAs whose expression constantly vary with dietary or genetic changes. Furthermore, it appears that diet, more than genotype, impacts on organ-specific miRNA expression profiles.

MicroRNAs Regulate Function in Atherosclerosis and Clinical Implications

Background

Atherosclerosis is considered the most common cause of morbidity and mortality worldwide. Athermanous plaque formation is pathognomonic of atherosclerosis. The main feature of atherosclerosis is the formation of plaque, which is inseparable from endothelial cells, vascular smooth muscle cells, and macrophages. MicroRNAs, a small highly conserved noncoding ribonucleic acid (RNA) molecule, have multiple biological functions, such as regulating gene transcription, silencing target gene expression, and affecting protein translation. MicroRNAs also have various pharmacological activities, such as regulating cell proliferation, apoptosis, and metabolic processes. It is noteworthy that many studies in recent years have also proved that microRNAs play a role in atherosclerosis.

Methods

To summarize the functions of microRNAs in atherosclerosis, we reviewed all relevant articles published in the PubMed database before June 2022, with keywords "atherosclerosis," "microRNA," "endothelial cells," "vascular smooth muscle cells," "macrophages," and "cholesterol homeostasis," briefly summarized a series of research progress on the function of microRNAs in endothelial cells, vascular smooth muscle cells, and macrophages and atherosclerosis. Results and Conclusion. In general, the expression levels of some microRNAs changed significantly in different stages of atherosclerosis pathogenesis; therefore, MicroRNAs may become new diagnostic biomarkers for atherosclerosis. In addition, microRNAs are also involved in the regulation of core processes such as endothelial dysfunction, plaque formation and stabilization, and cholesterol metabolism, which also suggests the great potential of microRNAs as a therapeutic target.

miR34a-5p impedes CLOCK expression in chronodisruptive C57BL/6J mice and potentiates pro-atherogenic manifestations

INTRODUCTION

Altered circadian rhythms underlie manifestation of several cardiovascular disorders, however a little is known about the mediating biomolecules. Multiple transcriptional-translational feedback loops control circadian-clockwork wherein; micro RNAs (miRNAs) are known to manifest post transcriptional regulation. This study assesses miR34a-5p as a mediating biomolecule.

METHOD

8-10-week-old male C57BL/6J mice (n = 6/group) were subjected to photoperiodic manipulation induced chronodisruption and thoracic aortae were examined for miRNA, gene (qPCR) and protein (Immunoblot) expression studies. Histomorphological changes were assessed for pro-atherogenic manifestations (fibrillar arrangement, collagen/elastin ratio, intima-media thickening). Computational studies for miRNA-mRNA target prediction were done using TargetScan and miRDB. Correlative in vitro studies were done in serum synchronized HUVEC cells. Time point based studies were done at five time points (ZT 0, 6, 12, 18, 24) in 24h.

RESULTS

Chronodisruption induced hypomethylation in the promoter region of miR34a-5p, in the thoracic aortae, culminating in elevated miRNA titers. In a software-based detection of circadian-clock-associated targets of miR34a-5p, Clock and Sirt1 genes were identified. Moreover, miR34a-5p exhibited antagonist circadian oscillations to that of its target genes CLOCK and SIRT1 in endothelial cells. Luciferase reporter gene assay further showed that miR34a-5p interacts with the 3'UTR of the Clock gene to lower its expression, disturbing the operation of positive arm of circadian clock system. Elevated miR34a-5p and impeded SIRT1 expression in a chronodisruptive aortae exhibited pro-atherogenic changes observed in form of gene expression, increased collagen/elastin ratio, fibrillar derangement and intimal-media thickening.

CONCLUSION

The study reports for the first time chronodisruption mediated miR34a-5p elevation, its circadian expression and interaction with the 3'UTR of Clock gene to impede its expression. Moreover, elevated miR34a-5p and lowered SIRT1 expression in the chronodisruptive aortae lead off cause-consequence relationship of chronodisruption mediated proatherogenic changes.

MIR34A modulates lens epithelial cell apoptosis and cataract development via the HK1/caspase 3 signaling pathway

Cataracts are the leading cause of blindness in the world. Age is a major risk factor for cataracts, and with increasing aging, the burden of cataracts will grow, but the exact details of cataractogenesis remain unclear. A recent study showed that microRNA-34a (MIR34A) is involved in the development of cataracts, but the underlying pathogenesis remains obscure. Here, our results of microRNA target prediction showed that hexokinase 1 (HK1) is one of the genes targeted by MIR34A. Based on this finding, we focused on the function of MIR34A and HK1 in the progress of cataracts, whereby the human lens epithelial cell line SRA01/04 and mouse lens were treated with MIR34A mimics and HK1 siRNA. We found that HK1 mRNA is a direct target of MIR34A, whereby the high expression of MIR34A in the cataract lens suppresses the expression of HK1. In vitro, the upregulation of MIR34A together with the downregulation of HK1 inhibits the proliferation, induces the apoptosis of SRA01/04 cells, and accelerates the opacification of mouse lenses via the HK1/caspase 3 signaling pathway. In summary, our study demonstrates that MIR34A modulates lens epithelial cell (LEC) apoptosis and cataract development through the HK1/caspase 3 signaling pathway.

Cellular and molecular biology of sirtuins in cardiovascular disease

Sirtuins (SIRTs) are a nicotinic adenine dinucleotide (+) -dependent histone deacetylase that regulates critical signaling pathways in prokaryotes and eukaryotes. Studies have identified seven mammalian homologs of the yeast SIRT silencing message regulator 2, namely, SIRT1-SIRT7. Recent in vivo and in vitro studies have successfully demonstrated the involvement of SIRTs in key pathways for cell biological function in physiological and pathological processes of the cardiovascular system, including processes including cellular senescence, oxidative stress, apoptosis, DNA damage, and cellular metabolism. Emerging evidence has stimulated a significant evolution in preventing and treating cardiovascular disease (CVD). Here, we review the important roles of SIRTs for the regulatory pathways involved in the pathogenesis of cardiovascular diseases and their molecular targets, including novel protein post-translational modifications of succinylation. In addition, we summarize the agonists and inhibitors currently identified to target novel specific small molecules of SIRTs. A better understanding of the role of SIRTs in the biology of CVD opens new avenues for therapeutic intervention with great potential for preventing and treating CVD.

p53/MicroRNA-34 axis in cancer and beyond

Cancer is serious endangers human life. After a long period of research and accumulation, people's understanding of cancer and the corresponding treatment methods are constantly developing. p53 is an important tumor suppressor gene. With the more in-depth understanding of the structure and function of p53, the more importance of this tumor suppressor gene is realized in the process of inhibiting tumor formation. MicroRNAs (miRNAs) are important regulatory molecules with a length of about 22nucleotides (nt), which belong to non-coding RNA and play an important role in the occurrence and development of tumors. miR-34 is currently considered to be a master regulator of tumor suppression. The positive feedback regulatory network formed by p53 and miR-34 can inhibit the growth and metastasis of tumor cells and inhibit tumor stem cells. This review focuses on the latest progress of p53/miR-34 regulatory network, and discusses its application in tumor diagnosis and treatment.

MicroRNA in the Diagnosis and Treatment of Doxorubicin-Induced Cardiotoxicity

Doxorubicin (DOX), a broad-spectrum chemotherapy drug, is widely applied to the treatment of cancer; however, DOX-induced cardiotoxicity (DIC) limits its clinical therapeutic utility. However, it is difficult to monitor and detect DIC at an early stage using conventional detection methods. Thus, sensitive, accurate, and specific methods of diagnosis and treatment are important in clinical practice. MicroRNAs (miRNAs) belong to non-coding RNAs (ncRNAs) and are stable and easy to detect. Moreover, miRNAs are expected to become biomarkers and therapeutic targets for DIC; thus, there are currently many studies focusing on the role of miRNAs in DIC. In this review, we list the prominent studies on the diagnosis and treatment of miRNAs in DIC, explore the feasibility and difficulties of using miRNAs as diagnostic biomarkers and therapeutic targets, and provide recommendations for future research.

IDH2 Deficiency Promotes Endothelial Senescence by Eliciting miR-34b/c-Mediated Suppression of Mitophagy and Increased ROS Production

Endothelial senescence impairs vascular function and thus is a primary event of age-related vasculature diseases. Isocitrate dehydrogenase 2 (IDH2) plays an important role in inducing alpha-ketoglutarate (α-KG) production and preserving mitochondrial function. However, the mechanism and regulation of IDH2 in endothelial senescence have not been elucidated. We demonstrated that downregulation of IDH2 induced accumulation of miR-34b/c, which impaired mitophagy and elevated mitochondrial reactive oxygen species (ROS) levels by inhibiting mitophagy-related markers (PTEN-induced putative kinase 1 (PINK1), Parkin, LC-II/LC3-I, and p62) and attenuating Sirtuin deacetylation 3 (Sirt3) expression. The mitochondrial dysfunction induced by IDH2 deficiency disrupted cell homeostasis and the cell cycle and led to endothelial senescence. However, miR-34b/c inhibition or α-KG supplementation restored Sirt3, PINK1, Parkin, LC-II/LC3-I, p62, and mitochondrial ROS levels, subsequently alleviating endothelial senescence. We showed that IDH2 played a crucial role in regulating endothelial senescence via induction of miR-34b/c in endothelial cells.

RNA modifications in cardiovascular health and disease

RNA is not always a faithful copy of DNA. Advances in tools enabling the interrogation of the exact RNA sequence have permitted revision of how genetic information is transferred. We now know that RNA is a dynamic molecule, amenable to chemical modifications of its four canonical nucleotides by dedicated RNA-binding enzymes. The ever-expanding catalogue of identified RNA modifications in mammals has led to a burst of studies in the past 5 years that have explored the biological relevance of the RNA modifications, also known as epitranscriptome. These studies concluded that chemical modification of RNA nucleotides alters several properties of RNA molecules including sequence, secondary structure, RNA-protein interaction, localization and processing. Importantly, a plethora of cellular functions during development, homeostasis and disease are controlled by RNA modification enzymes. Understanding the regulatory interface between a single-nucleotide modification and cellular function will pave the way towards the development of novel diagnostic, prognostic and therapeutic tools for the management of diseases, including cardiovascular disease. In this Review, we use two well-studied and abundant RNA modifications - adenosine-to-inosine RNA editing and N⁶-methyladenosine RNA methylation - as examples on which to base the discussion about the current knowledge on installation or removal of RNA modifications, their effect on biological processes related to cardiovascular health and disease, and the potential for development and application of epitranscriptome-based prognostic, diagnostic and therapeutic tools for cardiovascular disease.

Inflammatory and Prothrombotic Biomarkers, DNA Polymorphisms, MicroRNAs and Personalized Medicine for Patients with Peripheral Arterial Disease

Classical risk factors play a major role in the initiation and development of atherosclerosis. However, the estimation of risk for cardiovascular events based only on risk factors is often insufficient. Efforts have been made to identify biomarkers that indicate ongoing atherosclerosis. Among important circulating biomarkers associated with peripheral arterial disease (PAD) are inflammatory markers which are determined by the expression of different genes and epigenetic processes. Among these proinflammatory molecules, interleukin-6, C-reactive protein, several adhesion molecules, CD40 ligand, osteoprotegerin and others are associated with the presence and progression of PAD. Additionally, several circulating prothrombotic markers have a predictive value in PAD. Genetic polymorphisms significantly, albeit moderately, affect risk factors for PAD via altered lipoprotein metabolism, diabetes, arterial hypertension, smoking, inflammation and thrombosis. However, most of the risk variants for PAD are located in noncoding regions of the genome and their influence on gene expression remains to be explored. MicroRNAs (miRNAs) are single-stranded, noncoding RNAs that modulate gene expression at the post-transcriptional level. Patterns of miRNA expression, to some extent, vary in different atherosclerotic cardiovascular diseases. miRNAs appear to be useful in the detection of PAD and the prediction of progression and revascularization outcomes. In conclusion, taking into account one’s predisposition to PAD, i.e., DNA polymorphisms and miRNAs, together with circulating inflammatory and coagulation markers, holds promise for more accurate prediction models and personalized therapeutic options.

Beta-secretase-1 antisense RNA is associated with vascular ageing and atherosclerotic cardiovascular disease

Background  The noncoding antisense transcript for β-secretase-1 ( BACE1-AS ) is a long noncoding RNA with a pivotal role in the regulation of amyloid-β (Aβ). We aimed to explore the clinical value of BACE1-AS expression in atherosclerotic cardiovascular disease (ASCVD).

Methods  Expression of BACE1-AS and its target, β-secretase 1 ( BACE1 ) mRNA, was measured in peripheral blood mononuclear cells derived from 434 individuals (259 without established ASCVD [non-CVD], 90 with stable coronary artery disease [CAD], and 85 with acute coronary syndrome). Intima-media thickness and atheromatous plaques evaluated by ultrasonography, as well as arterial wave reflections and pulse wave velocity, were measured as markers of subclinical ASCVD. Patients were followed for a median of 52 months for major adverse cardiovascular events (MACE).

Results  In the cross-sectional arm, BACE1-AS expression correlated with BACE1 expression ( r  = 0.396, p  < 0.001) and marginally with Aβ1–40 levels in plasma ( r  = 0.141, p  = 0.008). Higher BACE1-AS was associated with higher estimated CVD risk assessed by HeartScore for non-CVD subjects and by European Society of Cardiology clinical criteria for the total population ( p  < 0.05 for both). BACE1-AS was associated with higher prevalence of CAD (odds ratio [OR] = 1.85, 95% confidence interval [CI]: 1.37–2.5), multivessel CAD (OR = 1.36, 95% CI: 1.06–1.75), and with higher number of diseased vascular beds (OR = 1.31, 95% CI: 1.07–1.61, for multiple diseased vascular beds) after multivariable adjustment for traditional cardiovascular risk factors. In the prospective arm, BACE1-AS was an independent predictor of MACE in high cardiovascular risk patients (adjusted hazard ratio = 1.86 per ascending tertile, 95% CI: 1.011–3.43, p  = 0.046).

Conclusion   BACE1-AS is associated with the incidence and severity of ASCVD.

Insights Into Platelet-Derived MicroRNAs in Cardiovascular and Oncologic Diseases: Potential Predictor and Therapeutic Target

Non-communicable diseases (NCDs), represented by cardiovascular diseases and cancer, have been the leading cause of death globally. Improvements in mortality from cardiovascular (CV) diseases (decrease of 14%/100,000, United States) or cancers (increase 7.5%/100,000, United States) seem unsatisfactory during the past two decades, and so the search for innovative and accurate biomarkers of early diagnosis and prevention, and novel treatment strategies is a valuable clinical and economic endeavor. Both tumors and cardiovascular system are rich in angiological systems that maintain material exchange, signal transduction and distant regulation. This pattern determines that they are strongly influenced by circulating substances, such as glycolipid metabolism, inflammatory homeostasis and cyclic non-coding RNA and so forth. Platelets, a group of small anucleated cells, inherit many mature proteins, mRNAs, and non-coding RNAs from their parent megakaryocytes during gradual formation and manifest important roles in inflammation, angiogenesis, atherosclerosis, stroke, myocardial infarction, diabetes, cancer, and many other diseases apart from its classical function in hemostasis. MicroRNAs (miRNAs) are a class of non-coding RNAs containing ∼22 nucleotides that participate in many key cellular processes by pairing with mRNAs at partially complementary binding sites for post-transcriptional regulation of gene expression. Platelets contain fully functional miRNA processors in their microvesicles and are able to transport their miRNAs to neighboring cells and regulate their gene expression. Therefore, the importance of platelet-derived miRNAs for the human health is of increasing interest. Here, we will elaborate systematically the roles of platelet-derived miRNAs in cardiovascular disease and cancer in the hope of providing clinicians with new ideas for early diagnosis and therapeutic strategies.

The association of plasma levels of miR-146a, miR-27a, miR-34a, and miR-149 with coronary artery disease

BACKGROUND

Coronary artery disease (CAD) is considered to be one of the most pivotal causes of death in the world. Over the past two decades, significant changes occurred in the diagnosis, prognosis, and treatment of CAD, which has helped reduce mortality rates. microRNAs (miRs) are a class of more than 5000 non-encoding RNA molecules (21-25 nucleotides across the length) that regulate complex biological processes. Today, miRNAs are used to study cardiovascular diseases. In the present study, the expression of miR-146a،miR-27, miR-149, and miR-34a in plasma suffering from CAD and the control group were investigated.

METHODS AND RESULTS

The present research was performed on 30 men with CAD and 30 healthy men as controls. The expression levels of miR-146a, miR-27a, miR-149, and miR-34a in the plasma of patients with CAD and the control group were measured using real-time PCR. Also, the correlation between the expression of circulating miRs levels and biochemical LDL-C, HDL-C, BMI, and total cholesterol was evaluated. The expression of miR-27a in the plasma of the CAD group was higher than in the control group (p = 0.020). The expression of miR-146a was downregulated in CAD patients compared to normal subjects (p = 0. 026). However, the expression of miR-34a, miR-149 in the plasma of CAD patients was not significantly different with the control group. In addition to, a direct correlation was found between the expression of miR-146a and HDL-c, the expression of miR-27a and LDL-C and the expression of miR-34a and total cholesterol. Also, the negative correlation between expressions of miR-149 with BMI was reported.

CONCLUSION

The obtained results demonstrated that miRs were closely related to biochemical factors and it points out the fact that miRNAs can be applied as a potential strategy for diagnosis and treatment of CAD.

Targeting the microRNA-34a as a Novel Therapeutic Strategy for Cardiovascular Diseases

Cardiovascular diseases (CVDs) are still the main cause of morbidity and mortality worldwide and include a group of disorders varying from vasculature, myocardium, arrhythmias and cardiac development. MicroRNAs (miRs) are endogenous non-coding RNAs with 18–23 nucleotides that regulate gene expression. The miR-34 family, including miR-34a/b/c, plays a vital role in the regulation of myocardial physiology and pathophysiological processes. Recently, miR-34a has been implicated in cardiovascular fibrosis, dysfunction and related cardiovascular disorders as an essential regulator. Interestingly, there is a pivotal link among miR-34a, cardiovascular fibrosis, and Smad4/TGF-β1 signaling. Notably, both loss-of-function and gain-of-function approaches identified the critical roles of miR-34a in cardiovascular apoptosis, autophagy, inflammation, senescence and remodeling by modulating multifunctional signaling pathways. In this article, we focus on the current understanding of miR-34a in biogenesis, its biological effects and its implications for cardiac pathologies including myocardial infarction, heart failure, ischaemia reperfusion injury, cardiomyopathy, atherosclerosis, hypertension and atrial fibrillation. Thus, further understanding of the effects of miR-34a on cardiovascular diseases will aid the development of effective interventions. Targeting for miR-34a has emerged as a potential therapeutic target for cardiovascular dysfunction and related diseases.

Pathophysiology of Circulating Biomarkers and Relationship With Vascular Aging: A Review of the Literature From VascAgeNet Group on Circulating Biomarkers, European Cooperation in Science and Technology Action 18216

Impairment of the arteries is a product of sustained exposure to various deleterious factors and progresses with time; a phenomenon inherent to vascular aging. Oxidative stress, inflammation, the accumulation of harmful agents in high cardiovascular risk conditions, changes to the extracellular matrix, and/or alterations of the epigenetic modification of molecules, are all vital pathophysiological processes proven to contribute to vascular aging, and also lead to changes in levels of associated circulating molecules. Many of these molecules are consequently recognized as markers of vascular impairment and accelerated vascular aging in clinical and research settings, however, for these molecules to be classified as biomarkers of vascular aging, further criteria must be met. In this paper, we conducted a scoping literature review identifying thirty of the most important, and eight less important, biomarkers of vascular aging. Herein, we overview a selection of the most important molecules connected with the above-mentioned pathological conditions and study their usefulness as circulating biomarkers of vascular aging.

MicroRNA-34a in coronary heart disease: Correlation with disease risk, blood lipid, stenosis degree, inflammatory cytokines, and cell adhesion molecules

Background

MicroRNA‐34a (miR‐34a) plays an essential role in regulating blood lipid, inflammation, cell adhesion molecules, and atherosclerosis, the latter factors are closely involved in the etiology of coronary heart disease (CHD). However, the clinical value of miR‐34a in CHD patients' management is rarely reported. Hence, this study aimed to assess the correlation of miR‐34a with disease risk, blood lipid, coronary artery stenosis, inflammatory cytokines, and cell adhesion molecules of CHD.

Methods

A total of 203 CHD patients and 100 controls were recruited in this study, then their plasma samples were collected to detect the miR‐34a by reverse transcription quantitative polymerase chain reaction. Furthermore, serum samples from CHD patients were obtained for inflammatory cytokines and cell adhesion molecule measurement by enzyme‐linked immunosorbent assay.

Results

MiR‐34a was elevated in CHD patients compared to controls (p < 0.001) and it disclosed a good diagnostic value of CHD (area under curve: 0.899, 95% confidence interval: 0.865–0.934). Besides, miR‐34a positively correlated with triglyceride (p < 0.001), total cholesterol (p = 0.022) and low‐density lipoprotein cholesterol (p = 0.004), but not with high‐density lipoprotein cholesterol (p = 0.110) in CHD patients. Moreover, miR‐34a associated with Gensini score in CHD patients (p < 0.001). As to inflammation‐related indexes and cell adhesion molecules, MiR‐34a expression was positively linked with C‐reactive protein (p < 0.001), tumor necrosis factor alpha (p = 0.005), interleukin (IL)‐1β (p = 0.020), IL‐17A (p < 0.001), vascular cell adhesion molecule‐1 (p < 0.001), and intercellular adhesion molecule‐1 (p = 0.010) in CHD patients, but not with IL‐6 (p = 0.118) and IL‐10 (p = 0.054).

Conclusion

MiR‐34a might serve as a biomarker in assistance of diagnosis and management of CHD.

Cerebrovascular microRNA Expression Profile During Early Development of Alzheimer's Disease in a Mouse Model

BACKGROUND

Emerging evidence demonstrates association of Alzheimer's disease (AD) with impaired delivery of blood oxygen and nutrients to and throughout the brain. The cerebral circulation plays multiple roles underscoring optimal brain perfusion and cognition entailing moment-to-moment blood flow control, vascular permeability, and angiogenesis. With currently no effective treatment to prevent or delay the progression of AD, cerebrovascular microRNA (miRNA) markers corresponding to post-transcriptional regulation may distinguish phases of AD.

OBJECTIVE

We tested the hypothesis that cerebrovascular miRNA expression profiles indicate developmental stages of AD pathology.

METHODS

Total RNA was isolated from total brain vessel segments of male and female 3xTg-AD mice [young, 1-2 mo; cognitive impairment (CI), 4-5 mo; extracellular amyloid-β plaques (Aβ), 6-8 mo; plaques+neurofibrillary tangles (AβT), 12-15 mo]. NanoString technology nCounter miRNA Expression panel for mouse was used to screen for 599 miRNAs.

RESULTS

Significant (p < 0.05) downregulation of various miRNAs indicated transitions from young to CI (e.g., let-7g & miR-1944, males; miR-133a & miR-2140, females) and CI to Aβ (e.g., miR-99a, males) but not from Aβ to AβT. In addition, altered expression of select miRNAs from overall Pre-AD (young + CI) versus AD (Aβ+ AβT) were detected in both males (let-7d, let-7i, miR-23a, miR-34b-3p, miR-99a, miR-126-3p, miR-132, miR-150, miR-151-5p, miR-181a) and females (miR-150, miR-539). Altogether, at least 20 cerebrovascular miRNAs effectively delineate AD versus Pre-AD pathology.

CONCLUSION

Using the 3xTg-AD mouse model, these data demonstrate that cerebrovascular miRNAs pertaining to endothelial function, vascular permeability, angiogenesis, inflammation, and Aβ/tau metabolism can track early development of AD.

Deciphering the Role of microRNAs in Large-Artery Stiffness Associated With Aging: Focus on miR-181b

Large artery stiffness (LAS) is a major, independent risk factor underlying cardiovascular disease that increases with aging. The emergence of microRNA signaling as a key regulator of vascular structure and function has stimulated interest in assessing its role in the pathophysiology of LAS. Identification of several microRNAs that display age-associated changes in expression in aorta has focused attention on defining their molecular targets and deciphering their role in age-associated arterial stiffening. Inactivation of the microRNA-degrading enzyme, translin/trax, which reverses the age-dependent decline in miR-181b, confers protection from aging-associated arterial stiffening, suggesting that inhibitors targeting this enzyme may have translational potential. As LAS poses a major public health challenge, we anticipate that future studies based on these advances will yield innovative strategies to combat aging-associated arterial stiffening.

MicroRNA-34a: the bad guy in age-related vascular diseases

The age-related vasculature alteration is the prominent risk factor for vascular diseases (VD), namely, atherosclerosis, abdominal aortic aneurysm, vascular calcification (VC) and pulmonary arterial hypertension (PAH). The chronic sterile low-grade inflammation state, alias inflammaging, characterizes elderly people and participates in VD development. MicroRNA34-a (miR-34a) is emerging as an important mediator of inflammaging and VD. miR-34a increases with aging in vessels and induces senescence and the acquisition of the senescence-associated secretory phenotype (SASP) in vascular smooth muscle (VSMCs) and endothelial (ECs) cells. Similarly, other VD risk factors, including dyslipidemia, hyperglycemia and hypertension, modify miR-34a expression to promote vascular senescence and inflammation. miR-34a upregulation causes endothelial dysfunction by affecting ECs nitric oxide bioavailability, adhesion molecules expression and inflammatory cells recruitment. miR-34a-induced senescence facilitates VSMCs osteoblastic switch and VC development in hyperphosphatemia conditions. Conversely, atherogenic and hypoxic stimuli downregulate miR-34a levels and promote VSMCs proliferation and migration during atherosclerosis and PAH. MiR34a genetic ablation or miR-34a inhibition by anti-miR-34a molecules in different experimental models of VD reduce vascular inflammation, senescence and apoptosis through sirtuin 1 Notch1, and B-cell lymphoma 2 modulation. Notably, pleiotropic drugs, like statins, liraglutide and metformin, affect miR-34a expression. Finally, human studies report that miR-34a levels associate to atherosclerosis and diabetes and correlate with inflammatory factors during aging. Herein, we comprehensively review the current knowledge about miR-34a-dependent molecular and cellular mechanisms activated by VD risk factors and highlight the diagnostic and therapeutic potential of modulating its expression in order to reduce inflammaging and VD burn and extend healthy lifespan.