Pregnancy-associated plasma protein-A (PAPP-A) and cardiovascular disease

There is strong evidence that PAPP-A, a local regulator of insulin-like growth factor signaling through proteolytic cleavage of inhibitory binding proteins, is involved in multiple physiological processes associated with cardiovascular disease. This review will describe the various roles of PAPP-A with a focus on atherosclerosis, neointimal hyperplasia, and acute coronary syndrome in animal models and in humans.

Role of Flow-Sensitive Endothelial Genes in Atherosclerosis and Antiatherogenic Therapeutics Development

Atherosclerosis is a chronic inflammatory disease that is the underlying cause of cardiovascular disease which initiates from endothelial dysfunction from genetic and environmental risk factors, including biomechanical forces: blood flow. Endothelial cells (ECs) lining the inner arterial wall regions exposed to disturbed flow are prone to atherosclerosis development, whereas the straight regions exposed to stable flow are spared from the disease. These flow patterns induce genome- and epigenome-wide changes in gene expression in ECs. Through the sweeping changes in gene expression, disturbed flow reprograms ECs from athero-protected cell types under the stable flow condition to pro-atherogenic cell conditions. The pro-atherogenic changes induced by disturbed flow, in combination with additional risk factors such as hypercholesterolemia, lead to the progression of atherosclerosis. The flow-sensitive genes and proteins are critical in understanding the mechanisms and serve as novel targets for antiatherogenic therapeutics.

CVD phenotyping in oncologic disorders: cardio-miRNAs as a potential target to improve individual outcomes in revers cardio-oncology

With the increase of aging population and prevalence of obesity, the incidence of cardiovascular disease (CVD) and cancer has also presented an increasing tendency. These two different diseases, which share some common risk factors. Relevant studies in the field of reversing Cardio-Oncology have shown that the phenotype of CVD has a significant adverse effect on tumor prognosis, which is mainly manifested by a positive correlation between CVD and malignant progression of concomitant tumors. This distal crosstalk and the link between different diseases makes us aware of the importance of diagnosis, prediction, management and personalized treatment of systemic diseases. The circulatory system bridges the interaction between CVD and cancer, which suggests that we need to fully consider the systemic and holistic characteristics of these two diseases in the process of clinical treatment. The circulating exosome-miRNAs has been intrinsically associated with CVD -related regulation, which has become one of the focuses on clinical and basic research (as biomarker). The changes in the expression profiles of cardiovascular disease-associated miRNAs (Cardio-miRNAs) may adversely affect concomitant tumors. In this article, we sorted and screened CVD and tumor-related miRNA data based on literature, then summarized their commonalities and characteristics (several important pathways), and further discussed the conclusions of Cardio-Oncology related experimental studies. We take a holistic approach to considering CVD as a risk factor for tumor malignancy, which provides an in-depth analysis of the various regulatory mechanisms or pathways involved in the dual attribute miRNAs (Cardio-/Onco-miRNAs). These mechanisms will be key to revealing the systemic effects of CVD on tumors and highlight the holistic nature of different diseases. Therefore, the Cardio-miRNAs should be given great attention from researchers in the field of CVD and tumors, which might become new targets for tumor treatment. Meanwhile, based on the principles of precision medicine (such as the predictive preventive personalized medicine, 3PM) and reverse Cardio-oncology to better improve individual outcomes, we should consider developing personalized medicine and systemic therapy for cancer from the perspective of protecting cardiovascular function.

MiR-20b-5p involves in vascular aging induced by hyperhomocysteinemia

Hyperhomocysteinemia (HHcy) is an independent risk factor of atherosclerosis (AS). Some reports have shown that homocysteine (Hcy) could accelerate the development of AS by promoting endothelial cell senescence. miRNAs were widely involved in the pathophysiology of HHcy. However, few studies have focused on the changes of miRNA-mRNA networks in the artery of HHcy patients. For this reason, RNA-sequencing was adopted to investigate the expression of miRNA and mRNA in HHcy model mouse arteries. We found that the expression of 216 mRNAs and 48 miRNAs were significantly changed. Using TargetScan and miRDB web tools, 29 miRNA-mRNA pairs were predicted. Notably, miR-20b-5p and FJX1 shared the highest predicted score in TargetScan, and further study indicated that the miR-20b-5p inhibitor significantly upregulated the FJX1 expression in HHcy human umbilical vein endothelial cells (HUVECs) model. PPI analysis revealed an important sub-network which was centered on CDK1. Gene ontology (GO) enrichment analysis showed that HHcy had a significant effect on cell cycle. Further experiments found that Hcy management increased reactive oxygen species (ROS) generation, the activity of senescence associated β-galactosidase (SA-β-gal) and the protein expression of p16 and p21 in HUVECs, which were rescued by miR-20b-5p inhibitor. In general, our research indicated the important role of miR-20b-5p in HHcy-related endothelial cell senescence.

miR-221-3p targets Ang-2 to inhibit the transformation of HCMECs to tip cells

Postembryonic angiogenesis is mainly induced by various proangiogenic factors derived from the original vascular network. Previous studies have shown that the role of Ang-2 in angiogenesis is controversial. Tip cells play a vanguard role in angiogenesis and exhibit a transdifferentiated phenotype under the action of angiogenic factors. However, whether Ang-2 promotes the transformation of endothelial cells to tip cells remains unknown. Our study found that miR-221-3p was highly expressed in HCMECs cultured for 4 h under hypoxic conditions (1% O2 ). Moreover, miR-221-3p overexpression inhibited HCMECs proliferation and tube formation, which may play an important role in hypoxia-induced angiogenesis. By target gene prediction, we further demonstrated that Ang-2 was a downstream target of miR-221-3p and miR-221-3p overexpression inhibited Ang-2 expression in HCMECs under hypoxic conditions. Subsequently, qRT-PCR and western blotting methods were performed to analyse the role of miR-221-3p and Ang-2 on the regulation of tip cell marker genes. MiR-221-3p overexpression inhibited CD34, IGF1R, IGF-2 and VEGFR2 proteins expression while Ang-2 overexpression induced CD34, IGF1R, IGF-2 and VEGFR2 expression in HCMECs under hypoxic conditions. In addition, we further confirmed that Ang-2 played a dominant role in miR-221-3p inhibitors promoting the transformation of HCMECs to tip cells by using Ang-2 shRNA to interfere with miR-221-3p inhibitor-treated HCMECs under hypoxic conditions. Finally, we found that miR-221-3p expression was significantly elevated in both serum and myocardial tissue of AMI rats. Hence, our data showed that miR-221-3p may inhibit angiogenesis after acute myocardial infarction by targeting Ang-2 to inhibit the transformation of HCMECs to tip cells.

Investigation of miR-26a-5p and miR-19a-3p expression levels in angiographically confirmed coronary artery disease

BACKGROUND

MicroRNAs have been found to have an essential role in cardiovascular diseases. In previous experiments, the changed expressions of miR-26a-5p and miR-19a-3p were confirmed in patients with severe coronary atherosclerosis by miRNA microarrays. However, the role of two miRNAs in coronary artery diseases (CAD) still needs to be investigated further. Our current study aimed to analyse two miRNAs in angiographically confirmed CAD and non-CAD with insignificant coronary stenosis. This study aimed to identify the potential diagnostic value of circulating miRNA with CAD.

METHODS

The CAD patients (n = 50) and non-CAD controls (n = 43) were studied. miRNAs (miR-26a-5p and miR-19a-3p) were quantified by TaqMan miRNA assays using real-time PCR. We subsequently assessed the diagnostic value of the miRNAs and correlations of miRNA with clinical parameters. Target prediction tools were utilised to identify miRNA target genes.

RESULTS

The expression of miR-26a-5p was significantly increased in CAD compared to non-CAD controls (p < 0.05). Tertile groups were formed according to the expression levels of miRNAs, and high expression tertile (T3) was compared with low expression tertile (T1). It was found that CAD presence was more prevalent in T3 of miR-26a-5p, and the frequency of diabetes was higher in T3 of miR-19a-3p. There were significant correlations between miRNAs and diabetes risk factors such as HbA1c, glucose levels, and BMI (p < 0.05).

CONCLUSIONS

Our findings show that miR-26a-5p expression is altered in CAD presence while miR-19a-3p expression is different in diabetes. Both miRNAs are closely related to risk factors of CAD, therefore, could be therapeutic targets for CAD treatment.

Lipid-laden foam cells in the pathology of atherosclerosis: shedding light on new therapeutic targets

INTRODUCTION

Lipid-laden foam cells within atherosclerotic plaques are key players in all phases of lesion development including its progression, necrotic core formation, fibrous cap thinning, and eventually plaque rupture. Manipulating foam cell biology is thus an attractive therapeutic strategy at early, middle, and even late stages of atherosclerosis. Traditional therapies have focused on prevention, especially lowering plasma lipid levels. Despite these interventions, atherosclerosis remains a major cause of cardiovascular disease, responsible for the largest numbers of death worldwide.

AREAS COVERED

Foam cells within atherosclerotic plaques are comprised of macrophages, vascular smooth muscle cells, and other cell types which are exposed to high concentrations of lipoproteins accumulating within the subendothelial intimal layer. Macrophage-derived foam cells are particularly well studied and have provided important insights into lipid metabolism and atherogenesis. The contributions of foam cell-based processes are discussed with an emphasis on areas of therapeutic potential and directions for drug development.

EXERT OPINION

As key players in atherosclerosis, foam cells are attractive targets for developing more specific, targeted therapies aimed at resolving atherosclerotic plaques. Recent advances in our understanding of lipid handling within these cells provide insights into how they might be manipulated and clinically translated to better treat atherosclerosis.

NLRP3 inflammasome pathway in atherosclerosis: Focusing on the therapeutic potential of non-coding RNAs

NLRP3 (NOD-, LRR-, and pyrin domain-containing protein 3) inflammasome pathway has a critical role in the pathogenesis of atherosclerosis. Activation of this pathway is implicated in the subendothelial inflammation and atherosclerosis progression. The NLRP3 inflammasome are cytoplasmic sensors with the distinct capacity to identify a wide range of inflammation-related signals, which enhance NLRP3 inflammasome assembly and allow it to trigger inflammation. This pathway is triggered by a variety of intrinsic signals which exist in atherosclerotic plaques, like cholesterol crystals and oxidized LDL. Further pharmacological findings indicated that NLRP3 inflammasome enhanced caspase-1-mediated secretion of pro-inflammatory mediators like interleukin (IL)- 1β/18. Newly published cutting-edge studies suggested that non-coding RNAs (ncRNAs) including microRNAs (miRNAs, miRs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs) are major modulators of NLRP3 inflammasome in atherosclerosis. Therefore, in this review, we aimed to discuss the NLRP3 inflammasome pathway, biogenesis of ncRNAs as well as the modulatory role of ncRNAs in regulating the various mediators of NLRP3 inflammasome pathway including TLR4, NF-kB, NLRP3, and caspase 1. We also discussed the importance of NLRP3 inflammasome pathway-related ncRNAs as a diagnostic biomarker in atherosclerosis and current therapeutics in the modulation of NLRP3 inflammasome in atherosclerosis. Finally, we speak about the limitations and future prospects of ncRNAs in regulating inflammatory atherosclerosis via the NLRP3 inflammasome pathway.

MicroRNA-202-5p-dependent inhibition of Bcl-2 contributes to macrophage apoptosis and atherosclerotic plaque formation

BACKGROUND

The identification of microRNA (miRNA)-related molecular mechanisms has advanced the development of new therapeutics for atherosclerosis (AS). The roles of miR-202-5p- in the pathogenic mechanisms of AS have not been explored.

METHODS

Macrophages were transfected with a series of miR-202-5p mimic/inhibitor, and then assessed for changes in viability, apoptosis, and secretion of inflammatory cytokines. The regulatory mechanism of miR-202-5p was explored through dual-luciferase reporter gene assay. A mouse model of AS was developed in ApoE^-/- mice fed with high-fat diet to examine the in vivo effects of miR-202-5p on atherosclerotic plaque formation, collagen synthesis, and fiber cap thickness.

RESULTS

Elevated miR-202-5p was found in atherosclerotic plaque tissues of the mice. miR-202-5p was able to induce macrophage apoptosis and release of pro-inflammatory factors. Besides, miR-202-5p limited Bcl-2 expression and elevated the levels of Bax, cleaved caspase-3, and cleaved caspase-9. Bcl-2 was concluded as a target gene of miR-202-5p. The pro-apoptotic effect of miR-202-5p on macrophages was achieved via limiting Bcl-2. In the mouse AS model, restoration of miR-202-5p stimulated atherosclerotic plaque formation, but reduced collagen synthesis and fiber cap thickness.

CONCLUSION

These data collectively suggest a pro-apoptotic action of miR-202-5p in macrophages that contributes to atherosclerotic plaque formation.

Studying Epigenetics of Cardiovascular Diseases on Chip Guide

Epigenetics is defined as the study of inheritable changes in the gene expressions and phenotypes that occurs without altering the normal DNA sequence. These changes are mainly due to an alteration in chromatin or its packaging, which changes the DNA accessibility. DNA methylation, histone modification, and noncoding or microRNAs can best explain the mechanism of epigenetics. There are various DNA methylated enzymes, histone-modifying enzymes, and microRNAs involved in the cause of various CVDs (cardiovascular diseases) such as cardiac hypertrophy, heart failure, and hypertension. Moreover, various CVD risk factors such as diabetes mellitus, hypoxia, aging, dyslipidemia, and their epigenetics are also discussed together with CVDs such as CHD (coronary heart disease) and PAH (pulmonary arterial hypertension). Furthermore, different techniques involved in epigenetic chromatin mapping are explained. Among these techniques, the ChIP-on-chip guide is explained with regard to its role in cardiac hypertrophy, a final form of heart failure. This review focuses on different epigenetic factors that are involved in causing cardiovascular diseases.

The Profile of Circulating Blood microRNAs in Outpatients with Vulnerable and Stable Atherosclerotic Plaques: Associations with Cardiovascular Risks

Non-coding RNAs reflect many biological processes in the human body, including athero-sclerosis. In a cardiology outpatient department cohort (N = 83), we aimed to compare the levels of circulating microRNAs in groups with vulnerable plaques (N = 22), stable plaques (N = 23) and plaque-free (N = 17) depending on coronary computed tomography angiography and to evaluate associations of microRNA levels with calculated cardiovascular risks (CVR), based on the SCORE2 (+OP), ACC/AHA, ATP-III and MESA scales. Coronary computed tomography was performed on a 640-slice computed tomography scanner. Relative plasma levels of microRNA were assessed via a real-time polymerase chain reaction. We found significant differences in miR-143-3p levels (p = 0.0046 in plaque-free vs. vulnerable plaque groups) and miR-181b-5p (p = 0.0179 in stable vs. vulnerable plaques groups). Analysis of microRNA associations with CVR did not show significant differences for SCORE2 (+OP) and ATPIII scales. MiR-126-5p and miR-150-5p levels were significantly higher (p < 0.05) in patients with ACC/AHA risk >10% and miR-145-5p had linear relationships with ACC/AHA score (adjusted p = 0.0164). The relative plasma level of miR-195 was higher (p < 0.05) in patients with MESA risk > 7.5% and higher (p < 0.05) in patients with zero coronary calcium index (p = 0.036). A linear relationship with coronary calcium was observed for miR-126-3p (adjusted p = 0.0484). A positive correlation with high coronary calcium levels (> 100 Agatson units) was found for miR-181-5p (p = 0.036). Analyzing the biological pathways of these microRNAs, we suggest that miR-143-3p and miR-181-5p can be potential markers of the atherosclerosis process. Other miRNAs (miR-126-3p, 126-5p, 145-5p, 150-5p, 195-5p) can be considered as potential cardiovascular risk modifiers, but it is necessary to validate our results in a large prospective trial.

The role of ferroptosis in endothelial cell dysfunction

Ferroptosis is a form of iron-dependent cell death caused by an excessive accumulation of reactive oxygen species and lipid peroxidation. The importance of ferroptosis in the occurrence and progression of various diseases is gradually being recognized; however, the exact biological effects and potential mechanisms of endothelial cell ferroptosis remain unclear. The endothelium forms the innermost layer of the blood vessels and lymphatic vessels. It acts as an important functional interface, responds to various pathological stimuli and causes endothelial dysfunction. Here, we review recent findings to elucidate the role of ferroptosis in endothelial cells under different pathophysiologic settings.

Epigenetic Regulation in Pathology of Atherosclerosis: A Novel Perspective

Atherosclerosis, characterized by atherosclerotic plaques, is a complex pathological process that involves different cell types and can be seen as a chronic inflammatory disease. In the advanced stage, the ruptured atherosclerotic plaque can induce deadly accidents including ischemic stroke and myocardial infarction. Epigenetics regulation, including DNA methylation, histone modification, and non-coding RNA modification. maintains cellular identity via affecting the cellular transcriptome. The epigenetic modification process, mediating by epigenetic enzymes, is dynamic under various stimuli, which can be reversely altered. Recently, numerous studies have evidenced the close relationship between atherosclerosis and epigenetic regulations in atherosclerosis, providing us with a novel perspective in researching mechanisms and finding novel therapeutic targets of this serious disease. Here, we critically review the recent discoveries between epigenetic regulation mechanisms in atherosclerosis.

Regulatory Non-coding RNAs in Atherosclerosis

Regulatory RNAs like microRNAs (miRNAs) and long non-coding RNAs (lncRNAs) control vascular and immune cells' phenotype and thus play a crucial role in atherosclerosis. Moreover, the mutual interactions between miRNAs and lncRNAs link both types of regulatory RNAs in a functional network that affects lesion formation. In this review, we deduce novel concepts of atherosclerosis from the analysis of the current data on regulatory RNAs' role in endothelial cells (ECs) and macrophages. In contrast to arterial ECs, which adopt a stable phenotype by adaptation to high shear stress, macrophages are highly plastic and quickly change their activation status. At predilection sites of atherosclerosis, such as arterial bifurcations, ECs are exposed to disturbed laminar flow, which generates a dysadaptive stress response mediated by miRNAs. Whereas the highly abundant miR-126-5p promotes regenerative proliferation of dysadapted ECs, miR-103-3p stimulates inflammatory activation and impairs endothelial regeneration by aberrant proliferation and micronuclei formation. In macrophages, miRNAs are essential in regulating energy and lipid metabolism, which affects inflammatory activation and foam cell formation.Moreover, lipopolysaccharide-induced miR-155 and miR-146 shape inflammatory macrophage activation through their oppositional effects on NF-kB. Most lncRNAs are not conserved between species, except a small group of very long lncRNAs, such as MALAT1, which blocks numerous miRNAs by providing non-functional binding sites. In summary, regulatory RNAs' roles are highly context-dependent, and therapeutic approaches that target specific functional interactions of miRNAs appear promising against cardiovascular diseases.

MicroRNA-146a-5p alleviates lipopolysaccharide-induced NLRP3 inflammasome injury and pro-inflammatory cytokine production via the regulation of TRAF6 and IRAK1 in human umbilical vein endothelial cells (HUVECs)

Background

Microribonucleic acids (miRNAs) have an evident role in regulating endothelial inflammation and dysfunction, which characterizes the early stages of atherosclerosis. The NOD-like receptor family pyrin domain-containing protein 3 (NLRP3) inflammasome has been reported to contribute to the endothelial inflammatory response that promotes atherosclerosis development and progression. This study sought to investigate the effects of miR-146a-5p on lipopolysaccharide (LPS)-induced NLRP3 inflammasome injury and pro-inflammatory cytokine production in human umbilical vein endothelial cells (HUVECs).

Methods

HUVECs were transfected with a miR-146a-5p mimic, small-interfering RNA (siRNA) (si-TRAF6, and si-IRAK1), and were then stimulated with LPS for 24 h. The messenger (mRNA) and the protein levels of p-NF-κB/NF-κB, NLRP3, Caspase-1, pro-inflammatory cytokine [interleukin (IL)-6, IL-1β and tumor necrosis factor alpha (TNF-α)] in the HUVECs were analyzed by quantitative real-time polymerase chain reactions (PCRs) and western blot assays, respectively. The secretion of IL-6 from the cells was detected by enzyme-linked immunoassay (ELISA). Bioinformatic and dual-luciferase reporter assays were performed to identify the targets of miR-146a-5p.

Results

LPS promoted pro-inflammatory cytokine expression in a dose-dependent manner and significantly increased the expression levels of p-NF-κB/NF-κB p65, NLRP3, and Caspase-1. After transfection with a miR-146a-5p mimic, or si-TRAF6 or si-IRAK1, we observed that the mRNA and protein levels of NF-κB/p-NF-κB, NLRP3, Caspase-1, and pro-inflammatory cytokine in the HUVECs were all down-regulated, and the secretion of IL-6 from cells declined significantly. After transfection with a miR-146-5p mimic, the expression of TRAF6 and IRAK1 in HUVECs were both down-regulated. Dual-luciferase reporter assays confirmed that miR-146-5p directly targets the 3'-untranslated region (3'-UTR) of TRAF6 and IRAK1 to regulate their expression.

Conclusions

As a modulator of TRAF6 and IRAK1, miR-146a-5p negatively regulated LPS-induced NF-κB activation and the NLRP3 inflammasome signaling pathway in HUVECs. Thus, miRNA-146a-5p may serve as a potential therapeutic target for atherosclerosis.

Multifactorial Basis and Therapeutic Strategies in Metabolism-Related Diseases

Throughout the 20th and 21st centuries, the incidence of non-communicable diseases (NCDs), also known as chronic diseases, has been increasing worldwide. Changes in dietary and physical activity patterns, along with genetic conditions, are the main factors that modulate the metabolism of individuals, leading to the development of NCDs. Obesity, diabetes, metabolic associated fatty liver disease (MAFLD), and cardiovascular diseases (CVDs) are classified in this group of chronic diseases. Therefore, understanding the underlying molecular mechanisms of these diseases leads us to develop more accurate and effective treatments to reduce or mitigate their prevalence in the population. Given the global relevance of NCDs and ongoing research progress, this article reviews the current understanding about NCDs and their related risk factors, with a focus on obesity, diabetes, MAFLD, and CVDs, summarizing the knowledge about their pathophysiology and highlighting the currently available and emerging therapeutic strategies, especially pharmacological interventions. All of these diseases play an important role in the contamination by the SARS-CoV-2 virus, as well as in the progression and severity of the symptoms of the coronavirus disease 2019 (COVID-19). Therefore, we briefly explore the relationship between NCDs and COVID-19.

circ_0003204 Regulates Cell Growth, Oxidative Stress, and Inflammation in ox-LDL-Induced Vascular Endothelial Cells via Regulating miR-942-5p/HDAC9 Axis

Background: Atherosclerosis (AS) is a typical inflammatory vascular disease. Many reports corroborated that circular RNAs (circRNAs) is involved in AS progression. However, the potential function and possible mechanism of circ_0003204 in AS progression remain indistinct.

Methods: Expression level analysis was performed using qRT-PCR and western blot. Cell viability and apoptosis were determined using Cell Counting Kit-8 (CCK-8), flow cytometry, and western blot assays. The status of oxidative stress and inflammation was determined via commercial detection kits and ELISA assay, respectively. The binding relationship was verified via dual-luciferase reporter and RNA immunoprecipitation assays.

Results: ox-LDL increased circ_0003204 and HDAC9 levels and decreased miR-942-5p level. Silencing of circ_0003204 enhanced cell viability and inhibited cell apoptosis, oxidative stress and inflammation in ox-LDL-disposed HUVECs. In addition, circ_0003204 targeted miR-942-5p to regulate ox-LDL-resulted HUVECs injury. Also, miR-942-5p affected ox-LDL-triggered HUVECs injury by targeting HDAC9. Furthermore, circ_0003204 elevated HDAC9 expression via decoying miR-942-5p.

Conclusion: circ_0003204 aggravated ox-LDL-induced HUVECs damage via modulating miR-942-5p/HDAC9 pathway.

MicroRNA-301a-3p increases oxidative stress, inflammation and apoptosis in ox-LDL-induced HUVECs by targeting KLF7

Arteriosclerotic cardiovascular disease is an inflammatory disease of ischemia or endothelial dysfunction caused by atherosclerosis, thereby causing high mortality. The viability and apoptosis of human umbilical vein endothelial cells (HUVECs) following oxidized low-density lipoprotein (ox-LDL) induction or transfection was detected by Cell Counting Kit-8 (CCK-8) assay and flow cytometry analysis. MicroRNA (miR)-301a-3p and Krueppel-like factor 7 (KLF7) mRNA expression was determined by reverse transcription-quantitative PCR (RT-qPCR). The levels of monocyte chemoattractant protein-1 (MCP-1) and IL-6, activities of reactive oxygen species and superoxide dismutase and lactate dehydrogenase leakage were analyzed by respective commercial assay kits. The protein expression of IL-6, MCP-1, Bcl2, Bax, poly (ADP-ribose) polymerase (PARP), cleaved PARP, pro-caspase3 and cleaved caspase-3 was detected by western blotting. miR-301a-3p expression is highly expressed in ox-LDL-induced HUVECs. miR-301a-3p is also a target of KLF7. Inhibition of miR-301a-3p suppressed oxidative stress, inflammation and apoptosis in ox-LDL-induced HUVECs, which was reversed by KLF7 inhibition. In conclusion, miR-301a-3p promotes oxidative stress, inflammation and apoptosis in ox-LDL-induced HUVECs via decreasing KLF7 expression.

CTRP12 ameliorates atherosclerosis by promoting cholesterol efflux and inhibiting inflammatory response via the miR-155-5p/LXRα pathway

C1q tumor necrosis factor-related protein 12 (CTRP12), a conserved paralog of adiponectin, is closely associated with cardiovascular disease. However, little is known about its role in atherogenesis. The aim of this study was to examine the influence of CTRP12 on atherosclerosis and explore the underlying mechanisms. Our results showed that lentivirus-mediated CTRP12 overexpression inhibited lipid accumulation and inflammatory response in lipid-laden macrophages. Mechanistically, CTRP12 decreased miR-155-5p levels and then increased its target gene liver X receptor α (LXRα) expression, which increased ATP binding cassette transporter A1 (ABCA1)- and ABCG1-dependent cholesterol efflux and promoted macrophage polarization to the M2 phenotype. Injection of lentiviral vector expressing CTRP12 decreased atherosclerotic lesion area, elevated plasma high-density lipoprotein cholesterol levels, promoted reverse cholesterol transport (RCT), and alleviated inflammatory response in apolipoprotein E-deficient (apoE-/-) mice fed a Western diet. Similar to the findings of in vitro experiments, CTRP12 overexpression diminished miR-155-5p levels but increased LXRα, ABCA1, and ABCG1 expression in the aortas of apoE-/- mice. Taken together, these results suggest that CTRP12 protects against atherosclerosis by enhancing RCT efficiency and mitigating vascular inflammation via the miR-155-5p/LXRα pathway. Stimulating CTRP12 production could be a novel approach for reducing atherosclerosis.

Epigenetic mechanisms underlying the benefits of flavonoids in cardiovascular health and diseases: are long non-coding RNAs rising stars?

Cardiovascular diseases (CVDs) rank as the first leading cause of death globally. High dietary polyphenol (especially flavonoids) intake has strongly been associated with low incidence of the primary outcome, overall mortality, blood pressure, inflammatory biomarkers, onset of new-onset type 2 diabetes mellitus (T2DM), and obesity. Phytogenic flavonoids affect the physiological and pathological processes of CVDs by modulating various biochemical signaling pathways. Non-coding RNAs (ncRNAs) have attracted increasing attention as fundamental regulator of gene expression involved in CVDs. Among the different ncRNA subgroups, long ncRNAs (lncRNAs) have recently emerged as regulatory eukaryotic transcripts and therapeutic targets with important and diverse functions in health and diseases. lncRNAs may be associated with the initiation, development and progression of CVDs by modulating acute and chronic inflammation, adipogenesis and lipid metabolism, and cellular physiology. This review summarizes this research on the modulatory effects of lncRNAs and their roles in mediating cellular processes. The mechanisms of action of flavonoids underlying their therapeutic effects on CVDs are also discussed. Based on our review, flavonoids might facilitate a significant epigenetic modification as part (if not full) of their tissue-/cell-related biological effects. This finding may be attributed to their interaction with cellular signaling pathways involved in chronic diseases. Certain lncRNAs might be the target of specific flavonoids, and some critical signaling processes involved in the intervention of CVDs might mediate the therapeutic roles of flavonoids.

Intestinal miRNAs regulated in response to dietary lipids

The role of miRNAs in intestinal lipid metabolism is poorly described. The small intestine is constantly exposed to high amounts of dietary lipids, and it is under conditions of stress that the functions of miRNAs become especially pronounced. Approaches consisting in either a chronic exposure to cholesterol and triglyceride rich diets (for several days or weeks) or an acute lipid challenge were employed in the search for intestinal miRNAs with a potential role in lipid metabolism regulation. According to our results, changes in miRNA expression in response to fat ingestion are dependent on factors such as time upon exposure, gender and small intestine section. Classic and recent intestinal in vitro models (i.e. differentiated Caco-2 cells and murine organoids) partially mirror miRNA modulation in response to lipid challenges in vivo. Moreover, intestinal miRNAs might play a role in triglyceride absorption and produce changes in lipid accumulation in intestinal tissues as seen in a generated intestinal Dicer1-deletion murine model. Overall, despite some variability between the different experimental cohorts and in vitro models, results show that some miRNAs analysed here are modulated in response to dietary lipids, hence likely to participate in the regulation of lipid metabolism, and call for further research.

Upregulation of miR-200c-3p induced by NaF promotes endothelial apoptosis by activating Fas pathway

Fluoride has been considered as a risk factor of cardiovascular disease due to its endothelial toxicology. However, the mechanism underlying the endothelial toxicity of fluoride has not been clearly illustrated. MiR-200c-3p was strongly linked with endothelial function and its level is increased in serum of fluorosis patients, but it is unclear the role of miR-200c-3p in the fluoride induced endothelial dysfunction. In this study, we confirmed that fluoride exposure induced the apoptosis of endothelial cells both in established rats model and cultured human umbilical vein endothelial cells (HUVECs). And miR-200c-3p was found to be upregulated in NaF treated HUVECs. Fluoride stimulation increased caspase-dependent apoptosis through miR-200c-3p upregulation, with repressing expression of its target gene Fas-associated phosphatase 1 (Fap-1), which functioned as Fas inhibitor. This resulted in activation of Fas-associated extrinsic apoptosis via interaction with increased Fas, Fadd, Cleaved Caspase-8 and Cleaved Caspase-3. The activation of Fas-associated extrinsic apoptosis was abrogated by miR-200c-3p inhibitor. Furthermore, the antiapoptotic effect of downregulated miR-200c-3p was restored by Fap-1 siRNA. These results suggested a determinant role of the miR-200c-3p/Fap-1 axis in fluoride induced endothelial apoptosis.

Knockdown of circular RNA circMAT2B reduces oxygen-glucose deprivation-induced inflammatory injury in H9c2 cells through up-regulating miR-133

Myocardial infarction (MI) is the main cause of morbidity and mortality. Reperfusion ways can cause damage to cardiomyocytes. CircMAT2B, a novel circRNA, takes positive roles in regulating glucose metabolism under hypoxia. Therefore, we aimed to explore the effects of circMAT2B on MI. Oxygen-glucose deprivation (OGD)-induced H9c2 cell model was employed to stimulate MI. Ex-circMAT2B, si-circMAT2B, miR-133 inhibitor and relative control were transfected into H9c2 cells. qRT-PCR was employed to examine levels of circMAT2B and miR-133. Cell activity, apoptosis, ROS generation and release of inflammatory factors were assessed by CCK-8, flow cytometry, ROS species assay kit and ELISA, respectively. Moreover, the expression of apoptosis-related and pathway-related factors was detected through western blot analysis. The results showed that circMAT2B expression was notably up-regulated by OGD treatment. Moreover, circMAT2B knockdown could effectively decrease OGD-induced the increasing of apoptosis, ROS generation and the expression of IL-1β, IL-6 and TNF-α. Besides, miR-133 was positively regulated by si-circMAT2B. CircMAT2B knockdown attenuated OGD-induced H9c2 cell damage and alleviated OGD-induced the inhibition of PI3K/AKT and Raf/MEK/ERK pathways through up-regulating miR-133. In brief, circMAT2B knockdown works as an inflammatory inhibitor in OGD-induced H9c2 cells inflammatory injury through up-regulating miR-133.

Knockdown of LINC00657 inhibits ox-LDL-induced endothelial cell injury by regulating miR-30c-5p/Wnt7b/β-catenin

Long noncoding RNAs (lncRNAs) play pivotal roles in the pathogenesis, development, and treatment of atherosclerosis (AS). The endothelial cell injury is a feature of AS. However, the role and mechanism of lncRNA LINC00657 in oxidized low-density lipoprotein (ox-LDL)-induced endothelial cell injury remain unclear. The serum samples were collected from 32 AS patients and normal volunteers. Ox-LDL-treated human umbilical vein endothelial cells (HUVEC) were used for the experiments in vitro. The levels of LINC00657, microRNA (miR)-30c-5p and Wnt family member 7B (Wnt7b) were measured by quantitative real-time polymerase chain reaction or western blot. The expression levels of proteins in Wnt7b/β-catenin pathway or endothelial-mesenchymal transition (EndMT) were detected by western blot. The secretion of inflammatory cytokine was examined by enzyme linked immunosorbent assay (ELISA). Cell viability and apoptosis were determined by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-tetrazolium bromide, flow cytometry, and western blot. The target association of miR-30c-5p and LINC00657/Wnt7b was analyzed via dual-luciferase reporter assay and RNA pull-down assay. LINC00657 expression was increased in AS serum and ox-LDL-treated HUVEC cells. LINC00657 knockdown suppressed ox-LDL-induced Wnt7b/β-catenin activation, EndMT, inflammatory response, and apoptosis in HUVEC cells. MiR-30c-5p was bound to LINC00657 and it knockdown reversed the role of LINC00657 inhibition in ox-LDL-induced HUVEC cell injury. MiR-30c-5p targeted Wnt7b to inhibit ox-LDL-induced Wnt7b/β-catenin activation, EndMT, inflammatory response, and apoptosis in HUVEC cells. Silence of LINC00657 repressed ox-LDL-induced injury via inhibiting EndMT, inflammatory response, and apoptosis in HUVEC cells by regulating miR-30c-5p/Wnt7b/β-catenin, indicating a potential target for treatment of AS.

miR-130b-3p regulates M1 macrophage polarization via targeting IRF1

Polarized macrophages can be broadly classified into classically activated macrophages (M1) and alternatively activated macrophages (M2) in response to the microenvironment signals. Interferon regulatory factor 1 (IRF1) has been demonstrated to play a critical role in macrophage polarization. However, the mechanisms underlying the regulation of IRF1 expression in macrophage polarization still remain unclear. In this study, IRF1 expression was significantly increased in interferon-γ (IFN-γ) and lipopolysaccharide (LPS)-treated RAW264.7 cells. Moreover, miR-130b-3p was decreased and negatively associated with Irf1 in M1 macrophages. miR-130b-3p repressed M1 polarization by inhibiting IRF1 and subsequently reducing the levels of the targets of IRF1, C-C motif chemokine ligand 5 (CCL5), C-X-C motif chemokine ligand 10 (CXCL10), inducible NO synthase (iNOS), and tumor necrosis factor (TNF). Consistent with these data, overexpressed miR-130b-3p in LPS-treated mice suppressed M1 macrophage polarization in lung macrophages and peritoneal macrophages by inhibiting Irf1 expression and alleviated the inflammation in mouse lung tissues. Furthermore, the predicted binding site between the Irf1 messenger RNA 3'-untranslated region (3'-UTR) and miR-130b-3p was confirmed by the dual-luciferase reporter assay. In conclusion, our research gave the first evidence that miR-130b-3p affected the polarization of M1 macrophages by directly inhibiting Irf1. The miR-130b-3p/IRF1 pathway may be a potential target for regulating macrophage polarization.

Korean Red ginseng prevents endothelial senescence by downregulating the HO-1/NF-κB/miRNA-155-5p/eNOS pathway

Background

Korean Red ginseng extract (KRGE) has beneficial effects on the cardiovascular system by improving endothelial cell function. However, its pharmacological effect on endothelial cell senescence has not been clearly elucidated. Therefore, we examined the effect and molecular mechanism of KRGE on the senescence of human umbilical vein endothelial cells (HUVECs).

Methods

HUVECs were grown in normal or KRGE-supplemented medium. Furthermore, they were transfected with heme oxygenase-1 (HO-1) gene or treated with its inhibitor, a NF-κB inhibitor, and a miR-155-5p mimic or inhibitor. Senescence-associated characteristics of endothelial cells were determined by biochemical and immunohistochemical analyses.

Results

Treatment of HUVECs with KRGE resulted in delayed onset and progression of senescence-associated characteristics, such as increased lysosomal acidic β-galactosidase and decreased telomerase activity, angiogenic dysfunction, and abnormal cell morphology. KRGE preserved the levels of anti-senescent factors, such as eNOS-derived NO, MnSOD, and cyclins D and A: however, it decreased the levels of senescence-promoting factors, such as ROS, activated NF-κB, endothelial cell inflammation, and p21 expression. The beneficial effects of KRGE were due to the induction of HO-1 and the inhibition of NF-κB-dependent biogenesis of miR-155-5p that led to the downregulation of eNOS. Moreover, treatment with inhibitors of HO-1, NF-κB, and miR-155-5p abolished the anti-senescence effects of KRGE.

Conclusion

KRGE delayed or prevented HUVEC senescence through a signaling cascade involving the induction of HO-1, the inhibition of NF-κB-dependent miR-155-5p biogenesis, and the maintenance of the eNOS/NO axis activity, suggesting that it may protect against vascular diseases associated with endothelial senescence.

MicroRNA-761 modulates foam cell formation and inflammation through autophagy in the progression of atherosclerosis

Macrophage-derived foam cells formation is the initial stage of atherosclerosis, and lipid-laden macrophage accumulation is also considered as the symbol of unstable plaque. Autophagy is a subcellular process responsible for the degradation of damaged organelles and aggregated proteins in cells (Grootaert in Oxid Med Cell Longev: 7687083, 2018). Macrophage autophagy plays an important role in atherosclerosis under various stress conditions, and microRNAs are involved in this complicated process. The present study was programmed to explore the effects of microRNA-761 on macrophage-derived foam cell formation, focusing on the role of autophagy in this pathological process. The differentiated human THP-1 macrophages were used in the study. THP-1-derived macrophages were treated with miR-761 mimics or inhibitors and cultured with oxidized low-density lipoprotein to mimic the lipid-rich environment in blood vessel. The expression of miR-761 and mRNA levels of IL-1β and IL-18 were analyzed by quantitative real-time PCR. The effect of miR-761 on autophagy was evaluated by the protein levels of Beclin1, p62/SQSTM1, microtubule-associated protein light chain 3, mammalian target of rapamycin (mTOR), and unc-51-like autophagy activating kinase 1 (ULK1), determined by immunoblot and autophagic flux detected by fluorescent staining. The secretion of IL-1β and IL-18 was tested by enzyme-linked immunosorbent reaction kit. Lipid accumulation in foam cells was detected by oil red "O" staining. We demonstrated that miR-761 was able to repress foam cell formation and reduce the production of atherogenic inflammatory cytokines IL-1β and IL-18 in an autophagy-dependent manner in atherosclerosis, possibly via mTOR-ULK1 signaling pathway. In summary, we described an athero-protective function of miR-761 in macrophages incubated with excess ox-LDL and identified an important novel modulator of mTOR signaling and autophagy in macrophage-derived foam cells. This finding may provide a potential target for the prevention and early treatment in high-risk group of atherosclerosis.

Non-coding RNAs in Physiological Cardiac Hypertrophy

Non-coding RNA (ncRNA) is a class of RNAs that are not act as translational protein templates. They are involved in the regulation of gene transcription, RNA maturation and protein translation, participating in a variety of physiological and physiological processes. NcRNAs have important functions, and are recently one of the hotspots in biomedical research. Cardiac hypertrophy is classified into physiological cardiac hypertrophy and pathological cardiac hypertrophy. Different from pathological cardiac hypertrophy, physiological cardiac hypertrophy usually developed during exercise, pregnancy, normal postnatal growth, accompanied with preservation or improvement of systolic function, while no cardiac fibrosis. In this chapter, we will briefly introduce the definition, characteristics, and functions of ncRNAs, including miRNAs, lncRNAs, and circRNAs, as well as a summary of the existing bioinformatics online databases which commonly used in the study of ncRNAs. Specially, this chapter will be focused on the characteristics and the underlying mechanisms about physiological cardiac hypertrophy. Furthermore, the regulatory mechanism of ncRNAs in physiological hypertrophy and the latest research progress will be summarized. Taken together, exploring physiologic cardiac hypertrophy-specific ncRNAs might be a unique research perspective that provides new point of view for interventions in heart failure and other cardiovascular diseases.

How do Uremic Toxins Affect the Endothelium?

Uremic toxins can induce endothelial dysfunction in patients with chronic kidney disease (CKD). Indeed, the structure of the endothelial monolayer is damaged in CKD, and studies have shown that the uremic toxins contribute to the loss of cell–cell junctions, increasing permeability. Membrane proteins, such as transporters and receptors, can mediate the interaction between uremic toxins and endothelial cells. In these cells, uremic toxins induce oxidative stress and activation of signaling pathways, including the aryl hydrocarbon receptor (AhR), nuclear factor kappa B (NF-κB), and mitogen-activated protein kinase (MAPK) pathways. The activation of these pathways leads to overexpression of proinflammatory (e.g., monocyte chemoattractant protein-1, E-selectin) and prothrombotic (e.g., tissue factor) proteins. Uremic toxins also induce the formation of endothelial microparticles (EMPs), which can lead to the activation and dysfunction of other cells, and modulate the expression of microRNAs that have an important role in the regulation of cellular processes. The resulting endothelial dysfunction contributes to the pathogenesis of cardiovascular diseases, such as atherosclerosis and thrombotic events. Therefore, uremic toxins as well as the pathways they modulated may be potential targets for therapies in order to improve treatment for patients with CKD.

Circular RNA circ_0124644 exacerbates the ox-LDL-induced endothelial injury in human vascular endothelial cells through regulating PAPP-A by acting as a sponge of miR-149-5p

The modulatory roles of numerous circular RNAs (circRNAs) have been exposited in atherosclerosis (AS). Our study paid attention to the function of circRNA_ 0124644 (circ_0124644) in AS development, as well as its functional mechanism. The AS cell model was established by the treatment of oxidized low-density lipoprotein (ox-LDL) to human vascular endothelial cells (HUVECs). Cell proliferation and cycle were severally measured by Cell Counting Kit-8 (CCK-8) and cell cycle detection kit. The examination of apoptosis rate was executed through flow cytometry. Western blot was exploited for detecting the associated proteins. The expression levels of circ_0124644 and microRNA-149-5p (miR-149-5p) and pregnancy-associated plasma protein-A (PAPP-A) were assayed using quantitative real-time polymerase chain reaction. The combination of targets was validated via the dual-luciferase reporter assay, RNA immunoprecipitation (RIP), and RNA pull-down assay. Clonal capacity was analyzed using colony formation assay. Ox-LDL restrained HUVECs proliferation and cycle, but facilitated apoptosis. Circ_0124644 expression was increased, while miR-149-5p was downregulated in ox-LDL-treated HUVECs. Besides, circ_0124644 served as a molecular sponge of miR-149-5p and intensified the ox-LDL-induced HUVECs injury by sponging miR-149-5p. PAPP-A was a target of miR-149-5p and miR-149-5p could mitigate the HUVECs injury caused by ox-LDL through inhibiting PAPP-A. Moreover, PAPP-A was positively regulated by circ_0124644 via the miR-149-5p. In this report, we concluded the promoted role of circ_0124644 in the ox-LDL-induced endothelial injury of HUVECs via the miR-149-5p/PAPP-A axis with an emphasis on its diagnostic and therapeutic values in AS.

Long non-coding RNA MIAT/miR-148b/PAPPA axis modifies cell proliferation and migration in ox-LDL-induced human aorta vascular smooth muscle cells

AIMS

Atherosclerosis (AS) performs the important pathogenesis which refers to coronaryheart and vascular diseases. Long non-coding RNAs (lncRNAs) was reported to be related to the AS progression. We aimed to probe the role and potential mechanism of Myocardial Infarction Associated Transcript (MIAT) in AS.

MATERIALS AND METHODS

Levels of MIAT, microRNA-148b (miR-148b) and pregnancy-associated plasma protein A (PAPPA) were detected by quantitative Real-time polymerase chain reaction (qRT-PCR) in oxidized low-density lipoprotein (ox-LDL)-induced human aorta vascular smooth muscle cells (HA-VSMCs). Proliferation and migration were examined by Cell counting kit-8 (CCK-8) and wound-healing assays, respectively. Protein levels of Ki-67, proliferating cell nuclear antigen (PCNA), matrix metalloproteinase (MMP)-2, MMP-9 and PAPPA were examined by western blot assay. Ki-67 and PCNA level was detected by flow cytometry. The interaction among MIAT, miR-148b and PAPPA was confirmed via dual-luciferase reporter and RNA immunoprecipitation (RIP). The biology role of MIAT was detected by an AS model in vivo.

KEY FINDINGS

The levels of MIAT and PAPPA were augmented, whereas mature miR-148b level was repressed in ox-LDL-induced AS model. The inhibitory effects of knockdown of MIAT on proliferation and migration were relieved by miR-148b inhibitor. Additionally, miR-148b regulated proliferation and migration by targeting PAPPA. Mechanically, MIAT functioned as sponge of miR-148b to impact PAPPA expression. MIAT knockdown protected AS mice against lipid metabolic disorders in vivo.

SIGNIFICANCE

Proliferation and migration were modified by MIAT/miR-148b/PAPPA axis in ox-LDL induced AS cell model, supplying a novel insight into the underlying application of MIAT in the clinical treatment of AS.

The impact of epigenetics on cardiovascular disease

Mortality and morbidity from cardiovascular diseases (CVDs) represents a huge burden to society. It is recognized that environmental factors and individual lifestyles play important roles in disease susceptibility, but the link between these external risk factors and our genetics has been unclear. However, the discovery of sequence-independent heritable DNA changes (epigenetics) have helped us to explain the link between genes and the environment. Multiple diverse epigenetic processes, including DNA methylation, histone modification, and the expression of non-coding RNA molecules affect the expression of genes that produce important changes in cellular differentiation and function, influencing the health and adaptability of the organism. CVDs such as congenital heart disease, cardiomyopathy, heart failure, cardiac fibrosis, hypertension, and atherosclerosis are now being viewed as much more complex and dynamic disorders. The role of epigenetics in these and other CVDs is currently under intense scrutiny, and we can expect important insights to emerge, including novel biomarkers and new approaches to enable precision medicine. This review summarizes the recent advances in our understanding of the role of epigenetics in CVD.

Epigenetic Mechanisms in Monocytes/Macrophages Regulate Inflammation in Cardiometabolic and Vascular Disease

Cardiometabolic and vascular disease, with their associated secondary complications, are the leading cause of morbidity and mortality in Western society. Chronic inflammation is a common theme that underlies initiation and progression of cardiovascular disease. In this regard, monocytes/macrophages are key players in the development of a chronic inflammatory state. Over the past decade, epigenetic modifications, such as DNA methylation and posttranslational histone processing, have emerged as important regulators of immune cell phenotypes. Accumulating studies reveal the importance of epigenetic enzymes in the dynamic regulation of key signaling pathways that alter monocyte/macrophage phenotypes in response to environmental stimuli. In this review, we highlight the current paradigms of monocyte/macrophage polarization and the emerging role of epigenetic modification in the regulation of monocyte/macrophage phenotype in obesity, diabetes mellitus, atherosclerosis, and abdominal aortic aneurysms.

Oxidized Low Density Lipoprotein-Induced Atherogenic Response of Human Umbilical Vascular Endothelial Cells (HUVECs) was Protected by Atorvastatin by Regulating miR-26a-5p/Phosphatase and Tensin Homolog (PTEN)

Background

Atherosclerosis is a chronic and multifactorial disease, and it is the main reason of coronary heart disease, cerebral infarction, and peripheral vascular disease, which leads to the formation of lesions in arterial blood vessels. Our study aimed to explore the protective effect and its underlying mechanism of atorvastatin (ATV) on oxidized low-density lipoprotein (ox-LDL)-induced atherosclerosis.

Material/Methods

Human umbilical vascular endothelial cells (HUVECs) were cultured and pretreated with ox-LDL to establish an in vitro atherosclerotic cell model. Cell Counting Kit-8 (CCK-8) assay, TUNEL staining, and Transwell assay were used to detect the cell activity, apoptosis, and migration in HUVECs. Quantitative real-time polymerase chain reaction (qRT-PCR) and western blot were applied to measure the mRNA and protein expressions of adhesion-related genes in HUVECs.

Results

Pretreated with 100 mg/L ox-LDL resulted in a 57.23% decrease of cell viability and 81.09% increase of apoptotic injury in HUVECs compare to the control. Meanwhile, ox-LDL pretreatment increased the cell migration and the expression of miR-26a-5p in HUVECs. ATV treatment could effectively reverse the cellular damage induced by ox-LDL, decrease the release of adhesion-related molecules, and downregulate the expression of miR-26a-5p by 44.79% in HUVECs. Moreover, phosphatase and tensin homolog (PTEN) was demonstrated to be the target gene of miR-26a-5p.

Conclusions

Our results highlight that ATV protects against ox-LDL-induced downregulation of cell viability, upregulation of cell apoptosis, migration, as well as the release of adhesion-related molecules in HUVECs through the miR-26a-5p/PTEN axis. This study provides new insights into the underlying mechanism of ATV therapeutic potential in atherosclerosis, and also provides a new strategy for the treatment of atherosclerosis.

Influence of miRNA Gene Polymorphism on Recurrence and Age at Onset of Ischemic Stroke in a Chinese Han Population

Polymorphisms in microRNAs (miRNAs) are associated with ischemic stroke occurrence and traditional risk factors for ischemic stroke such as atherosclerosis, hypertension, hyperlipidemia, and diabetes. However, few studies have examined recurrent ischemic stroke as an outcome. Thus, the aim of our study was to examine association of miRNA gene polymorphisms (namely, miR-126 rs4636297, miR-149 rs2292832, miR-124 rs531564, miR-499 rs3746444, miR-143 rs12655723, and miR-122 rs17669) with recurrence of ischemic stroke. miRNA gene polymorphisms were genotyped using the polymerase chain reaction-ligation detection reaction (PCR-LDR) method in 657 patients with ischemic stroke. Association of miRNA polymorphisms with prognosis outcomes was examined by the Kaplan-Meier method, log-rank test, and Cox proportional hazards models. miR-122 rs17669 was significantly associated with recurrence risk of ischemic stroke under the recessive model. Cox regression analysis showed that the CC genotype of rs17669 was associated with an increased risk of 1.9-fold for stroke recurrence (hazard ratio = 1.879; 95% confidence interval = 1.182-2.985; P = 0.008). Further, this effect was more evident among the non-drinker and male subgroups. We found no difference in risk of recurrent ischemic stroke among the other five miRNA polymorphisms. Furthermore, we identified a significant association between the miR-149 rs2292832 polymorphism and age at onset of first-ever stroke. Altogether, miR-122 rs17669 is a significant predictor for the risk of recurrent stroke, independent of traditional risk factors.

Exosome-Transmitted miR-25 Induced by H. pylori Promotes Vascular Endothelial Cell Injury by Targeting KLF2

Background: Increasing evidence has shown that Helicobacter pylori is associated with coronary heart disease (CHD); however, the underlying mechanism remains unclear. Methods: The expression of miR-25 and mRNAs was measured using qRT-PCR. Protein levels were detected using western blotting and exosomes were assessed with an electron microscope. The target gene of miR-25 was identified using the luciferase report system. Results: H. pylori infection increased the expression of miR-25 in gastric epithelial cells and was associated with increased levels of exosome-transmitted miR-25 in human peripheral blood. Mechanistic investigation showed the Kruppel-like factor 2 (KLF2) was a direct target of exosome-transmitted miR-25 in vascular endothelial cells. In addition, the miR-25/KLF2 axis regulated the NF-κB signaling pathway, resulting in increased expression of interleukin 6 (IL6), monocyte chemoattractant protein-1 (MCP-1), vascular cell adhesion molecule-1 (VCAM-1), and intercellular adhesion molecule-1 (ICAM-1). Conclusion: Our findings suggest that the miR-25/KLF2 axis may be a potential therapeutic target for H. pylori-associated CHD. Furthermore, high levels of exosome-transmitted miR-25 in peripheral blood may pose a potential risk for CHD.

Dicer in Macrophages Prevents Atherosclerosis by Promoting Mitochondrial Oxidative Metabolism

BACKGROUND

Alternative macrophage activation, which relies on mitochondrial oxidative metabolism, plays a central role in the resolution of inflammation and prevents atherosclerosis. Moreover, macrophages handle large amounts of cholesterol and triglycerides derived from the engulfed modified lipoproteins during atherosclerosis. Although several microRNAs regulate macrophage polarization, the role of the microRNA-generating enzyme Dicer in macrophage activation during atherosclerosis is unknown.

METHODS

To evaluate the role of Dicer in atherosclerosis, Apoe^-/- mice with or without macrophage-specific Dicer deletion were fed a high-fat diet for 12 weeks. Anti-argonaute 2 RNA immunoprecipitation chip and RNA deep sequencing combined with microRNA functional screening were performed in the Dicer wild-type and knockout bone marrow-derived macrophages to identify the individual microRNAs and the mRNA targets mediating the phenotypic effects of Dicer. The role of the identified individual microRNA and its target in atherosclerosis was determined by tail vein injection of the target site blockers in atherosclerotic Apoe^-/- mice.

RESULTS

We show that Dicer deletion in macrophages accelerated atherosclerosis in mice, along with enhanced inflammatory response and increased lipid accumulation in lesional macrophages. In vitro, alternative activation was limited whereas lipid-filled foam cell formation was exacerbated in Dicer-deficient macrophages as a result of impaired mitochondrial fatty acid oxidative metabolism. Rescue of microRNA (miR)-10a, let-7b, and miR-195a expression restored the oxidative metabolism in alternatively activated Dicer-deficient macrophages. Suppression of ligand-dependent nuclear receptor corepressor by miR-10a promoted fatty acid oxidation, which mediated the lipolytic and anti-inflammatory effect of Dicer. miR-10a expression was negatively correlated to the progression of atherosclerosis in humans. Blocking the interaction between ligand-dependent nuclear receptor corepressor and miR-10a by target site blockers aggravated atherosclerosis development in mice.

CONCLUSIONS

Dicer plays an atheroprotective role by coordinately regulating the inflammatory response and lipid metabolism in macrophages through enhancing fatty acid-fueled mitochondrial respiration, suggesting that promoting Dicer/miR-10a-dependent metabolic reprogramming in macrophages has potential therapeutic implications to prevent atherosclerosis.

High Levels of Circulating MicroRNA-3667-3p Are Associated with Coronary Plaque Erosion in Patients with ST-Segment Elevation Myocardial Infarction

Plaque erosion (PE) is a significant substrate of acute coronary thrombosis. An improved ability to distinguish plaque phenotype in vivo among patients with ST-segment elevation myocardial infarction (STEMI) is of considerable interest because of the potential to formulate tailored treatment. This study assessed the plaque features and screened the circulating microRNAs (miRNAs) characteristically expressed in patients with PE compared with those with plaque rupture (PR). An miRNA microarray profile was generated in an initial cohort of eight STEMI patients with PE and eight clinically matched subjects with PR to select the circulating miRNAs with significant differences. miRNAs of interest were validated in a prospective cohort, and the plaque characteristics of enrolled patients were assessed by optical coherence tomography (OCT). Thirty culprit lesions were classified as PE (32.6%) and 46 as PR (50%). The main component of PE was fibrotic tissue, whereas the chief component of PR was lipids (P < 0.001). Thirty-four miRNAs were differentially expressed between the two groups; we validated five candidates and found that only the level of circulating miR-3667-3p exhibited significant discriminatory power in predicting the presence of PE (AUC = 0.767; P < 0.001). Our results show that high levels of circulating miR-3667-3p are closely related to PE in STEMI patients, which provides further evidence for PE pathophysiology and potential tailor treatment strategies.

Efferocytosis and Atherosclerosis: Regulation of Phagocyte Function by MicroRNAs

There is evidence of the critical role of efferocytosis, the clearance of apoptotic cells (ACs) by phagocytes, in vascular cell homeostasis and protection against atherosclerosis. Specific microRNAs (miRs) can regulate atherogenesis by controlling the accumulation of professional phagocytes (e.g., macrophages) and nonprofessional phagocytes (i.e., neighboring tissue cells with the ability to acquire a macrophage-like phenotype) within the arterial wall, the differentiation of phagocytes into foam cells, the efferocytosis of apoptotic foam cells by phagocytes, and the phagocyte-mediated inflammatory response. A better understanding of the mechanisms involved in miR-regulated phagocyte function might lead to novel therapeutic antiatherosclerotic strategies. In this review, we try to shed light on the relationship between miRs and cellular players in the process of efferocytosis in the context of atherosclerotic plaque and their potential as molecular targets for novel antiatherosclerotic therapies.

Resveratrol attenuates endothelial oxidative injury by inducing autophagy via the activation of transcription factor EB

Background

Endothelial oxidative injury is a key event in the pathogenesis of atherosclerosis (AS). Resveratrol (RSV) attenuates the oxidative injury in human umbilical vein endothelial cells (HUVECs). Autophagy is critical for the RSV-induced protective effects. However, the exact underlying mechanisms haven’t been completely elucidated. Thus, we aimed to explore the role of autophagy of the anti-oxidation of RSV and the underlying mechanism in palmitic acid (PA)-stimulated HUVECs.

Methods

HUVECs were pretreated with 10 μM of RSV for 2 h and treated with 200 μM of PA for an additional 24 h. Cell viability, intracellular reactive oxygen species (ROS) and malondialdehyde (MDA) levels were estimated with a microplate reader and confocal microscope. Autophagosomes were analyzed by transmission electron microscopy, while lysosomes by confocal microscopy. The expression of transcription factor EB (TFEB) and related genes were quantified by qRT-PCR assay. Furthermore, TFEB levels, autophagy, and lysosomes were examined by western blot assay.

Results

RSV pretreatment suppressed the PA-induced decline in cell viability and elevation in ROS and MDA levels in HUVECs. RSV pretreatment also increased LC3 production and P62 degradation while promoted the autophagosomes formation. However, 3-methyladenine (3-MA) treatment attenuated RSV-induced autophagy. RSV pretreatment upregulated the TFEB and TFEB-modulated downstream genes expression in a concentration-dependent manner. Additionally, in cells transfected with TFEB small interfering RNA, RSV-induced TFEB expression and subsequent autophagy were abolished. Meanwhile, the TFEB-modulated genes expression, the lysosomes formation and the RSV-induced anti-oxidation were suppressed.

Conclusions

In HUVECs, RSV attenuates endothelial oxidative injury by inducing autophagy in a TFEB-dependent manner.

MicroRNA-122 promotes endothelial cell apoptosis by targeting XIAP: Therapeutic implication for atherosclerosis

Endothelial cell (EC) apoptosis is fundamental for the pathophysiology of atherosclerosis, in which microRNAs (miRNAs) emerge as critical regulators. miR-122 has been shown to regulate the apoptosis of various cell types, however, whether miR-122 is associated with atherosclerosis and EC apoptosis remains unknown. In this study, we found that miR-122 expression was increased in the aortic ECs of ApoE^-/- mice fed with a high-fat diet (HFD), as compared to normal-diet (ND), implying a potential association between miR-122 elevation and atherogenesis. In addition, in vitro, miR-122 expression was also induced in human aortic ECs (HAECs) by the treatment of oxidized low-density lipoprotein (ox-LDL), a common atherogenic factor. Functionally, miR-122 knockdown suppressed ox-LDL-induced apoptosis of HAECs, suggesting a pro-apoptotic role of miR-122 in HAECs under this pro-atherogenic condition. Further evidence revealed that the X-linked inhibitor-of-apoptosis protein (XIAP) was directly targeted and suppressed by miR-122 in HAECs, and more importantly, XIAP knockdown diminished miR-122 effect on apoptosis, thus establishing XIAP as a prominent target that mediates miR-122 regulation of the apoptosis of HAECs. Together, these results may identify miR-122 as a novel regulator in EC apoptosis, which offers it as a possible target for therapeutic interventions of atherosclerosis.

Aloe-emodin attenuates myocardial infarction and apoptosis via up-regulating miR-133 expression

Aloe-emodin (AE) is an anthraquinone derived from rhubarb and has a variety of pharmacological actions. However, the role of AE in regulating ischemic heart diseases is still unclear. The present study investigated the effect of AE on cardiac injuries induced by myocardial infarction (MI) in vivo and oxidative insults in vitro and explored the mechanisms involved. TUNEL and Flow cytometry were performed to measure cell apoptosis. Western blot analysis was employed to detect expression of Bcl-2, Bax and Caspase-3 proteins. Real-time PCR was used to quantify the microRNAs levels. Our data showed that AE protected neonatal rat ventricular myocytes (NRVMs) from hydrogen peroxide (H₂O₂) induced apoptosis and significantly inhibited H₂O₂-induced reactive oxygen species (ROS) elevation. Furthermore, AE treatment significantly reversed H₂O₂-induced upregulation of Bax/Bcl-2 and the loss of mitochondrial membrane potential. In vivo, AE treatment significantly reduced infarct size, ameliorated impaired cardiac function and obviously decreased cardiac apoptosis and oxidative stress in MI mice heart. Meanwhile, AE restored H₂O₂-induced downregulation of miR-133, and transfection with miR-133 inhibitor abolished the anti-apoptotic and anti-oxidative effects of AE. Moreover, AE prevented H₂O₂-induced increase in caspase-3 activity, which was diminished by application of miR-133 inhibitor. Our results indicate that AE protectes against myocardial infarction via the upregulation of miR-133, inhibition of ROS production and suppression of caspase-3 apoptotic signaling pathway.

Targeting epigenetics and non-coding RNAs in atherosclerosis: from mechanisms to therapeutics

Atherosclerosis, the principal cause of cardiovascular death worldwide, is a pathological disease characterized by fibro-proliferation, chronic inflammation, lipid accumulation, and immune disorder in the vessel wall. As the atheromatous plaques develop into advanced stage, the vulnerable plaques are prone to rupture, which causes acute cardiovascular events, including ischemic stroke and myocardial infarction. Emerging evidence has suggested that atherosclerosis is also an epigenetic disease with the interplay of multiple epigenetic mechanisms. The epigenetic basis of atherosclerosis has transformed our knowledge of epigenetics from an important biological phenomenon to a burgeoning field in cardiovascular research. Here, we provide a systematic and up-to-date overview of the current knowledge of three distinct but interrelated epigenetic processes (including DNA methylation, histone methylation/acetylation, and non-coding RNAs), in atherosclerotic plaque development and instability. Mechanistic and conceptual advances in understanding the biological roles of various epigenetic modifiers in regulating gene expression and functions of endothelial cells (vascular homeostasis, leukocyte adhesion, endothelial-mesenchymal transition, angiogenesis, and mechanotransduction), smooth muscle cells (proliferation, migration, inflammation, hypertrophy, and phenotypic switch), and macrophages (differentiation, inflammation, foam cell formation, and polarization) are discussed. The inherently dynamic nature and reversibility of epigenetic regulation, enables the possibility of epigenetic therapy by targeting epigenetic "writers", "readers", and "erasers". Several Food Drug Administration-approved small-molecule epigenetic drugs show promise in pre-clinical studies for the treatment of atherosclerosis. Finally, we discuss potential therapeutic implications and challenges for future research involving cardiovascular epigenetics, with an aim to provide a translational perspective for identifying novel biomarkers of atherosclerosis, and transforming precision cardiovascular research and disease therapy in modern era of epigenetics.