MiR-181a inhibits vascular inflammation induced by ox-LDL via targeting TLR4 in human macrophages

MicroRNA-181 in cardiovascular disease: Emerging biomarkers and therapeutic targets

Cardiovascular disease (CVD) is the leading cause of death worldwide. MicroRNAs (MiRNAs) have attracted considerable attention for their roles in several cardiovascular disease states, including both the physiological and pathological processes. In this review, we will briefly describe microRNA-181 (miR-181) transcription and regulation and summarize recent findings on the roles of miR-181 family members as biomarkers or therapeutic targets in different cardiovascular-related conditions, including atherosclerosis, myocardial infarction, hypertension, and heart failure. Lessons learned from these studies may provide new theoretical foundations for CVD.

Is the suppression of CD36 a promising way for atherosclerosis therapy?

Atherosclerosis is the main underlying pathology of many cardiovascular diseases and is marked by plaque formation in the artery wall. It has posed a serious threat to the health of people all over the world. CD36 acts as a significant regulator of lipid homeostasis, which is closely associated with the onset and progression of atherosclerosis and may be a new therapeutic target. The abnormal overexpression of CD36 facilitates lipid accumulation, foam cell formation, inflammation, endothelial apoptosis, and thrombosis. Numerous natural products and lipid-lowering agents are found to target the suppression of CD36 or inhibit the upregulation of CD36 to prevent and treat atherosclerosis. Here, the structure, expression regulation and function of CD36 in atherosclerosis and its related pharmacological therapies are reviewed. This review highlights the importance of drugs targeting CD36 suppression in the treatment and prevention of atherosclerosis, in order to develop new therapeutic strategies and potential anti-atherosclerotic drugs both preclinically and clinically.

The emerging crosstalk between atherosclerosis-related microRNAs and Bermuda triangle of foam cells: Cholesterol influx, trafficking, and efflux

In atherosclerosis, the gradual buildup of lipid particles into the sub-endothelium of damaged arteries leads to numerous lipid alterations. The absorption of these modified lipids by monocyte-derived macrophages in the arterial wall leads to cholesterol accumulation and increases the likelihood of foam cell formation and fatty streak, which is an early characteristic of atherosclerosis. Foam cell formation is related to an imbalance in cholesterol influx, trafficking, and efflux. The formation of foam cells is heavily regulated by various mechanisms, among them, the role of epigenetic factors like microRNA alteration in the formation of foam cells has been well studied. Recent studies have focused on the potential interplay between microRNAs and foam cell formation in the pathogenesis of atherosclerosis; nevertheless, there is significant space to progress in this attractive field. This review has focused to examine the underlying processes of foam cell formation and microRNA crosstalk to provide a deep insight into therapeutic implications in atherosclerosis.

CD36, a signaling receptor and fatty acid transporter that regulates immune cell metabolism and fate

CD36 is a type 2 cell surface scavenger receptor widely expressed in many immune and non-immune cells. It functions as both a signaling receptor responding to DAMPs and PAMPs, as well as a long chain free fatty acid transporter. Recent studies have indicated that CD36 can integrate cell signaling and metabolic pathways through its dual functions and thereby influence immune cell differentiation and activation, and ultimately help determine cell fate. Its expression along with its dual functions in both innate and adaptive immune cells contribute to pathogenesis of common diseases, including atherosclerosis and tumor progression, which makes CD36 and its downstream effectors potential therapeutic targets. This review comprehensively examines the dual functions of CD36 in a variety of immune cells, especially macrophages and T cells. We also briefly discuss CD36 function in non-immune cells, such as adipocytes and platelets, which impact the immune system via intercellular communication. Finally, outstanding questions in this field are provided for potential directions of future studies.

Beneficial Effects of Bovine Milk Exosomes in Metabolic Interorgan Cross-Talk

Extracellular vesicles are membrane-enclosed secreted vesicles involved in cell-to-cell communication processes, identified in virtually all body fluids. Among extracellular vesicles, exosomes have gained increasing attention in recent years as they have unique biological origins and deliver different cargos, such as nucleic acids, proteins, and lipids, which might mediate various health processes. In particular, milk-derived exosomes are proposed as bioactive compounds of breast milk, which have been reported to resist gastric digestion and reach systemic circulation, thus being bioavailable after oral intake. In the present manuscript, we critically discuss the available evidence on the health benefits attributed to milk exosomes, and we provide an outlook for the potential future uses of these compounds. The use of milk exosomes as bioactive ingredients represents a novel avenue to explore in the context of human nutrition, and they might exert important beneficial effects at multiple levels, including but not limited to intestinal health, bone and muscle metabolism, immunity, modulation of the microbiota, growth, and development.

Global identification of circular RNAs in imatinib (IM) resistance of chronic myeloid leukemia (CML) by modulating signaling pathways of circ_0080145/miR-203/ABL1 and circ 0051886/miR-637/ABL1

Imatinib (IM), targeting of BCR-ABL1 tyrosine kinase, is currently one of the first-line choices in the treatment of chronic myeloid leukemia (CML). This study aims to explore the molecular mechanisms underlying IM resistance in CML treatment. 108 CML patients were recruited and grouped according to their sensitivity to IM as the responder group (N = 66) and the non-responder group (N = 42). Real-time quantitative PCR (RT-qPCR) was performed to evaluate the expression of candidate circular RNAs (circRNAs), microRNA (miRNAs) and messenger RNA (mRNAs). No significant difference was noted regarding demographic and clinicopathological characteristics between the responder group and the non-responder group. The expression of circ_0080145, circ_0051886 and ABL1 mRNA was significantly increased, while the expression of miR-203 and miR-637 was decreased in the non-responder group as compared with the responders. By using in-silicon analysis, it was predicted that circ_0080145 and circ_0051886 targeted miR-203 and miR-637 respectively, and ABL1 was found to be shared direct target gene of miR-203 and miR-637. Ectopic over-expression of circ_0080145 and circ_0051886 respectively reduced the expression of miR-203 and miR-637. The expression of ABL1 mRNA/protein was most upregulated in culture cells co-transfected with circ_0080145 and circ_0051886 as compared with those cells individually transfected. This study established the signaling pathways of circ_0080145/miR-203/ABL1 and circ 0051886/miR-637/ABL1. The deregulation of circ_0080145 and circ_0051886 is, at least partially, responsible for the development of IM chemoresistance in CML by regulating expression of ABL1 via modulating expression of miR-203 and miR-637.

Deficiency of MicroRNA-181a Results in Transcriptome-Wide Cell-Specific Changes in the Kidney and Increases Blood Pressure

[Figure: see text].

Fatty acids and evolving roles of their proteins in neurological, cardiovascular disorders and cancers

The dysregulation of fat metabolism is involved in various disorders, including neurodegenerative, cardiovascular, and cancers. The uptake of long-chain fatty acids (LCFAs) with 14 or more carbons plays a pivotal role in cellular metabolic homeostasis. Therefore, the uptake and metabolism of LCFAs must constantly be in tune with the cellular, metabolic, and structural requirements of cells. Many metabolic diseases are thought to be driven by the abnormal flow of fatty acids either from the dietary origin and/or released from adipose stores. Cellular uptake and intracellular trafficking of fatty acids are facilitated ubiquitously with unique combinations of fatty acid transport proteins and cytoplasmic fatty acid-binding proteins in every tissue. Extensive data are emerging on the defective transporters and metabolism of LCFAs and their clinical implications. Uptake and metabolism of LCFAs are crucial for the brain's functional development and cardiovascular health and maintenance. In addition, data suggest fatty acid metabolic transporter can normalize activated inflammatory response by reprogramming lipid metabolism in cancers. Here we review the current understanding of how LCFAs and their proteins contribute to the pathophysiology of three crucial diseases and the mechanisms involved in the processes.

Foam Cells as Therapeutic Targets in Atherosclerosis with a Focus on the Regulatory Roles of Non-Coding RNAs

Atherosclerosis is a major cause of human cardiovascular disease, which is the leading cause of mortality around the world. Various physiological and pathological processes are involved, including chronic inflammation, dysregulation of lipid metabolism, development of an environment characterized by oxidative stress and improper immune responses. Accordingly, the expansion of novel targets for the treatment of atherosclerosis is necessary. In this study, we focus on the role of foam cells in the development of atherosclerosis. The specific therapeutic goals associated with each stage in the formation of foam cells and the development of atherosclerosis will be considered. Processing and metabolism of cholesterol in the macrophage is one of the main steps in foam cell formation. Cholesterol processing involves lipid uptake, cholesterol esterification and cholesterol efflux, which ultimately leads to cholesterol equilibrium in the macrophage. Recently, many preclinical studies have appeared concerning the role of non-encoding RNAs in the formation of atherosclerotic lesions. Non-encoding RNAs, especially microRNAs, are considered regulators of lipid metabolism by affecting the expression of genes involved in the uptake (e.g., CD36 and LOX1) esterification (ACAT1) and efflux (ABCA1, ABCG1) of cholesterol. They are also able to regulate inflammatory pathways, produce cytokines and mediate foam cell apoptosis. We have reviewed important preclinical evidence of their therapeutic targeting in atherosclerosis, with a special focus on foam cell formation.

CircTM7SF3 contributes to oxidized low-density lipoprotein-induced apoptosis, inflammation and oxidative stress through targeting miR-206/ASPH axis in atherosclerosis cell model in vitro

BACKGROUND

Atherosclerosis (AS) is a chronic inflammatory disorder. The aim of our study was to explore the role of circular RNA (circRNA) transmembrane 7 superfamily member 3 (circTM7SF3) in AS progression.

METHODS

Experiments were conducted using oxidized low-density lipoprotein (ox-LDL)-induced THP-1-derived macrophages and differentiated human monocyte-derived macrophages (hMDMs). Quantitative real-time polymerase chain reaction (qRT-PCR) was used to detect the expression of circTM7SF3, its linear form TM7SF3, microRNA-206 (miR-206) and aspartyl (asparaginyl) β-hydroxylase (ASPH) messenger RNA (mRNA). Cell viability and apoptosis were examined by 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry. Cell inflammation was analyzed by measuring the production of tumor necrosis factor α (TNF-α) and interleukin 6 (IL-6) using enzyme-linked immunosorbent assay (ELISA) kits. Cell oxidative stress was assessed through analyzing the levels of oxidative stress markers using their corresponding commercial kits. Dual-luciferase reporter assay and RNA-pull down assay were used to confirm the interaction between miR-206 and circTM7SF3 or ASPH. The protein level of ASPH was examined by Western blot assay.

RESULTS

CircTM7SF3 level was markedly increased in the serum samples of AS patients and ox-LDL-induced THP-1-derived macrophages compared with their matching counterparts. ox-LDL induced-damage in THP-1 cells was partly attenuated by the interference of circTM7SF3. MiR-206 was a downstream molecular target of circTM7SF3. Si-circTM7SF3-mediated effects in ox-LDL-induced THP-1-derived macrophages were partly ameliorated by the addition of anti-miR-206. MiR-206 directly interacted with ASPH mRNA. CircTM7SF3 silencing reduced the expression of ASPH partly through up-regulating miR-206 in THP-1-derived macrophages. ASPH overexpression partly counteracted the effects induced by miR-206 overexpression in ox-LDL-induced THP-1-derived macrophages.

CONCLUSION

CircTM7SF3 contributed to ox-LDL-induced injury in AS cell model through up-regulating the expression of ASPH via targeting miR-206.

Knockdown of circular RNA circZNF652 remits LPS-induced inflammatory damage by regulating miR-181a

BACKGROUND

Infantile pneumonia (IP) is a usual disease in infants and young children. The function and underlying mechanism of circZNF652 on lipopolysaccharide (LPS)-triggered inflammatory damage in WI-38 cells were detected in this article.

METHODS

WI-38 cells were induced by dosages of LPS to construct inflammatory injury model. WI-38 cell viability and apoptosis were detected by CCK-8 assay and flow cytometry, respectively. CircZNF652 and miR-181a levels were changed and detected by cell transfection and qRT-PCR. The levels of apoptosis and JNK/p38 and NF-κB pathways-related proteins, as well as the level of Cox-2 were detected by western blot. Finally, the concentrations of inflammatory factors were detected by ELISA.

RESULTS

LPS induced inflammatory injury showing as notably decreased the viability, while increased the numbers of apoptotic cells, as well as the levels of apoptosis and inflammatory factors in a dose dependent way. Besides, LPS inducement remarkably enhanced the expression of circZNF652. However, knockdown of circZNF652 remitted LPS-triggered inflammatory damage and restrained NF-κB and JNK/p38 pathways. Moreover, circZNF652 knockdown promoted miR-181a expression. Whereas, miR-181a inhibition markedly relieved circZNF652 knockdown-induced impacts.

CONCLUSION

Knockdown of circZNF652 remitted LPS-triggered WI-38 cells inflammatory damage through deactivation of NF-κB and JNK/p38pathways by up-regulating miR-181a.

CD36 in Atherosclerosis: Pathophysiological Mechanisms and Therapeutic Implications

PURPOSE OF REVIEW

Atherosclerosis is a chronic disease characterized by lipid retention and inflammation in the artery wall. The retention and oxidation of low-density lipoprotein (LDL) in sub-endothelial space play a critical role in atherosclerotic plaque formation and destabilization. Oxidized LDL (ox-LDL) and other modified LDL particles are avidly taken up by endothelial cells, smooth muscle cells, and macrophages mainly through several scavenger receptors, including CD36 which is a class B scavenger receptor and membrane glycoprotein.

RECENT FINDINGS

Animal studies performed on CD36-deficient mice suggest that deficiency of CD36 prevents the development of atherosclerosis, though with some debate. CD36 serves as a signaling hub protein at the crossroad of inflammation, lipid metabolism, and fatty acid metabolism. In addition, the level of soluble CD36 (unattached to cells) in the circulating blood was elevated in patients with atherosclerosis and other metabolic disorders. We performed a state-of-the-art review on the structure, ligands, functions, and regulation of CD36 in the context of atherosclerosis by focusing on the pathological role of CD36 in the dysfunction of endothelial cells, smooth muscle cells, monocytes/macrophages, and platelets. Finally, we highlight therapeutic possibilities to target CD36 expression/activity in atherosclerosis.

MicroRNA sequences modulating inflammation and lipid accumulation in macrophage “foam” cells: Implications for atherosclerosis

Accumulation of macrophage “foam” cells, laden with cholesterol and cholesteryl ester, within the intima of large arteries, is a hallmark of early “fatty streak” lesions which can progress to complex, multicellular atheromatous plaques, involving lipoproteins from the bloodstream and cells of the innate and adaptive immune response. Sterol accumulation triggers induction of genes encoding proteins mediating the atheroprotective cholesterol efflux pathway. Within the arterial intima, however, this mechanism is overwhelmed, leading to distinct changes in macrophage phenotype and inflammatory status. Over the last decade marked gains have been made in understanding of the epigenetic landscape which influence macrophage function, and in particular the importance of small non-coding micro-RNA (miRNA) sequences in this context. This review identifies some of the miRNA sequences which play a key role in regulating “foam” cell formation and atherogenesis, highlighting sequences involved in cholesterol accumulation, those influencing inflammation in sterol-loaded cells, and novel sequences and pathways which may offer new strategies to influence macrophage function within atherosclerotic lesions.

Dysregulations of MicroRNA and Gene Expression in Chronic Venous Disease

Chronic venous disease (CVD) is a vascular disease of lower limbs with high prevalence worldwide. Pathologic features include varicose veins, venous valves dysfunction and skin ulceration resulting from dysfunction of cell proliferation, apoptosis and angiogenesis. These processes are partly regulated by microRNA (miRNA)-dependent modulation of gene expression, pointing to miRNA as a potentially important target in diagnosis and therapy of CVD progression. The aim of the study was to analyze alterations of miRNA and gene expression in CVD, as well as to identify miRNA-mediated changes in gene expression and their potential link to CVD development. Using next generation sequencing, miRNA and gene expression profiles in peripheral blood mononuclear cells of subjects with CVD in relation to healthy controls were studied. Thirty-one miRNAs and 62 genes were recognized as potential biomarkers of CVD using DESeq2, Uninformative Variable Elimination by Partial Least Squares (UVE-PLS) and ROC (Receiver Operating Characteristics) methods. Regulatory interactions between potential biomarker miRNAs and genes were projected. Functional analysis of microRNA-regulated genes revealed terms closely related to cardiovascular diseases and risk factors. The study shed new light on miRNA-dependent regulatory mechanisms involved in the pathology of CVD. MicroRNAs and genes proposed as CVD biomarkers may be used to develop new diagnostic and therapeutic methods.

Mangiferin Relieves Lipopolysaccharide-Induced Injury by Up-Regulating miR-181a via Targeting PTEN in ATDC5 Cells

Background

Mangiferin (MF) was reported to possess anti-inflammatory activity. This investigation tried to probe into the underlying mechanism of MF in osteoarthritis.

Methods

ATDC5 cells were pretreated with series concentrations of MF (0.1, 1, 5, 10, 15, 20 μM) for 2 h and then were exposed to lipopolysaccharide (LPS) (5 μg/ml) for 12 h to construct the inflammatory injury model. The cell viability, productions of pro-inflammatory cytokines and enzymes were respectively measured by employing CCK-8 assay, western blot, ELISA, and quantitative reverse-transcription (qRT)-PCR. miR-181a expression was altered by employing cell transfection. Dichloro-dihydro-fluorescein diacetate (DCFH-DA) method was employed for detection of reactive oxygen species (ROS) generation. Dual luciferase activity assay was conducted for analyzing the relationship between miR-181a and PTEN. The underlying mechanism was determined by employing western blot.

Results

High doses of MF treatment (15 and 20 μM) noticeably induced inflammatory injury exhibiting as increased the productions of pro-inflammatory cytokines, enzymes and ROS, activated NF-κB pathway and deactivated PTEN/PI3K/AKT pathway in ATDC5 cells. Besides, MF treatment notably remitted LPS-induced inflammatory injury through deactivation of NF-κB pathway and activation of PTEN/PI3K/AKT pathway. PTEN was a target of miR-181a. Inhibition of miR-181a remarkably reversed MF-triggered impacts on ATDC5 cells.

Conclusion

MF attenuated LPS-induced inflammatory damage through miR-181a/PTEN axis and thereby inhibiting NF-κB pathway and activating PI3K/AKT pathway.

Effect of Mn3O4 Nanoparticles on Lipopolysaccharide-Induced Inflammatory Factors in the Human Tendon Cells and Its Mechanism

Objective. To investigate the effect of Mn3O4 nanoparticles (Mn3O4NPs) on inflammatory factors induced by lipopolysaccharide (LPS) in human tendon cells and its mechanism. Methods. The Mn3O4NPs were synthesized by a hydrothermal method. RT-qPCR was used to detect the expression levels of miRNAs related to inflammation in human tendon cells. The expression level of NLRP1 (NOD-like receptor containing pyrin domain 1) was measured by Western blotting. ELISA assay was used to measure the level of TNF-α, IL-1β, IL-4, and IL-10. The relationship between miR-181a-5p and NLRP1 was verified by dual-luciferase reporter assay. Results. Mn3O4NPs produced in this study were brown spherical particles with an average size of 7-10 nm. Mn3O4NP treatment significantly reduced the levels of TNF-α and IL-1β but increased the levels of IL-4 and IL-10 in the human tendon cells induced by LPS. In addition, Mn3O4NP treatment remarkably increased the expression level of miR-181a-5p. NLRP1 is one of the targets of miR-181a-5p, and miR-181a-5p downregulated its expression. Further study showed that Mn3O4NPs could alleviate the inflammatory response of human tendon cells induced by LPS by upregulating miR-181a-5p and thus downregulating the expression of NLRP1. Conclusion. Mn3O4NPs affect the expression of inflammatory cytokines in the human tendon cells induced by LPS by modulating the molecular axis of miR-181a-5p/NLRP1.

MiR-342-3p inhibition promotes cell proliferation and invasion by directly targeting ID4 in pre-eclampsia

AIM

This study aimed to explore the miR-342-3p expression in pre-eclampsia (PE) placentas and confirm whether miR-342-3p exerts effects on proliferation and migration of HTR-8/SVneo trophoblastic cells.

METHODS

The PE placentas (n = 8) were taken from gravidas complicated by PE and delivered after 34 weeks. The chorionic plates and the basal plates were separately taken from the placenta disc near the position of umbilical cord insertion. RT-qPCR was used to measure the expression of miR-342-3p in the chorionic plates and the basal plates. Cell invasion assay and MMT assay were used to assess the effects of miR-342-3p on proliferation and migration of HTR-8/SVneo trophoblastic cells. Luciferase reporter assay and Western blotting were used to analyze the target of miR-342-3p and investigate the detailed mechanisms.

RESULTS

The expression of miR-342-3p was upregulated in both basal plates and chorionic plates in patients with PE compared with healthy pregnant individuals. MiR-342-3p inhibitor suppressed the cell viability and invasion, and induced apoptosis in trophoblast cells. Furthermore, inhibitor of DNA binding (ID)-4 (ID4) was a direct target of miR-342-3p, and knockdown of ID4 abrogated the regulation effect of miR-342-3p on cell viability, apoptosis and invasion.

CONCLUSION

Inhibition of miR-342-3p expression may suppress the occurrence of PE by targeting ID4 in vitro.

Research Progress of Mechanisms and Drug Therapy For Atherosclerosis on Toll-Like Receptor Pathway

Recent reports have established atherosclerosis (AS) as a major factor in the pathogenetic process of cardiovascular diseases such as ischemic stroke and coronary heart disease. Although the possible pathogenesis of AS remains to be elucidated, a large number of investigations strongly suggest that the inhibition of toll-like receptors (TLRs) alleviates the severity of AS to some extent by suppressing vascular inflammation and the formation of atherosclerotic plaques. As pattern recognition receptors, TLRs occupy a vital position in innate immunity, mediating various signaling pathways in infective and sterile inflammation. This review summarizes the available data on the research progress of AS and the latest antiatherosclerotic drugs associated with TLR pathway.

Role of circular RNA in hematological malignancies

Compared with linear RNA, circular RNAs (circRNAs) form a covalently closed circular continuous loop and are highly conserved, stable and tissue-specific. In recent years, circRNAs received considerable attention in the diagnosis, classification, treatment and prognosis of hematological tumors. circRNAs function as microRNA sponges and competitive endogenous RNAs that play an essential role in the translation, regulation and interaction of proteins. The present review discussed the fundamental properties and functions of circRNAs and the latest advancements in the context of circRNAs in the clinical research of hematological malignancies, namely acute and chronic myeloid leukemia, and chronic lymphocytic leukemia. circRNAs show potential in the diagnosis and prognosis of various diseases and can be used as therapeutic targets and biomarkers for disease.

MicroRNA‑217 is involved in the progression of atherosclerosis through regulating inflammatory responses by targeting sirtuin 1

Atherosclerosis is a chronic inflammatory disease, and it is a global clinical problem. The development of new and effective therapeutic targets for atherosclerosis is necessary. A number of microRNAs (miRNAs) have been demonstrated to serve a crucial role in atherosclerosis. However, the role of miRNA (miR)-217 in atherosclerosis remains unclear. Therefore, the aim of the present study was to investigate the role and mechanism of miR-217 in atherosclerosis. The level of miR-217 was detected in the blood of patients with atherosclerosis using reverse transcription-quantitative PCR. THP-1 acute monocytic leukemia cells were treated with oxidized low-density lipoprotein (ox-LDL) to develop an atherosclerotic cell model of macrophages. The relationship between miR-217 and sirtuin 1 (SIRT1) was determined by TargetScan and dual luciferase reporter assay. Cell apoptosis was measured by flow cytometry. Production of pro-inflammatory factors and triglyceride (TG) and total cholesterol (TC) levels were also determined. The results demonstrated that miR-217 was significantly upregulated in atherosclerosis. SIRT1 was demonstrated to be a direct target of miR-217 and was downregulated in atherosclerosis. Downregulation of miR-217 significantly inhibited ox-LDL-induced TG and TC level increase, cell apoptosis and the upregulation of the pro-inflammatory factors tumor necrosis factor α, interleukin (IL)-6 and IL-1β. Additionally, the SIRT1/AMP-activated protein kinase α/NF-κB pathway was at least partially involved in modulating the effects of miR-217 inhibition on THP-1 cells treated with ox-LDL. In addition, the effects of miR-217 downregulation on ox-LDL-treated THP-1 cells were eliminated by SIRT1 silencing. In conclusion, the results of the present study indicated that miR-217 downregulation may relieve atherosclerosis through the inhibition of macrophage apoptosis and inflammatory response by targeting SIRT1.

CD 36: Focus on Epigenetic and Post-Transcriptional Regulation

CD36 is a transmembrane protein involved in fatty acid translocation, scavenging for oxidized fatty acids acting as a receptor for adhesion molecules. It is expressed on macrophages, as well as other types of cells, such as endothelial and adipose cells. CD36 participates in muscle lipid uptake, adipose energy storage, and gut fat absorption. Recently, several preclinical and clinical studies demonstrated that upregulation of CD36 is a prerequisite for tumor metastasis. Cancer metastasis-related research emerged much later and has been less investigated, though it is equally or even more important. CD36 protein expression can be modified by epigenetic changes and post-transcriptional interference from non-coding RNAs. Some data indicate modulation of CD36 expression in specific cell types by epigenetic changes via DNA methylation patterns or histone tails, or through miRNA interference, but this is largely unexplored. The few papers addressing this topic refer mostly to lipid metabolism-related pathologies, whereas in cancer research, data are even more scarce. The aim of this review was to summarize major epigenetic and post-transcriptional mechanisms that impact CD36 expression in relation to various pathologies while highlighting the areas in need of further exploration.

Effects of miR-181a-5p abnormal expression on zebrafish (Danio rerio) vascular development following triclosan exposure

Triclosan (TCS), one of the important bactericides, is widely used in personal care products, and its chronic exposure leads to severe toxic effects on the growth and development of blood vessels in zebrafish (Danio rerio). Herein, we screened out three differentially expressed miRNAs (miR-181a-5p, miR-132-3p and miR-128-3p) by sequencing and qRT-PCR analyses of 4-96-hpf TCS-exposed zebrafish, among which miR-181a-5p was found to regulate many signaling pathways involved in fatty acid biosynthesis and phosphatidylimositol signaling systems. By O-dianisidine staining, TCS-exposure resulted in decreased distribution of red blood cells and induced blood hypercoagulable state and thrombotic effects. Defective subintestinal veins (SIVs), and decreased branching and curvature of blood vessels were observed with increasing TCS-exposure concentrations. After microinjection of miR-181a-5p mimic and inhibitor, zebrafish malformation type and percentage were prominently increased such as distorted SIV vessels along with reduced venation and abnormal branches by ALP staining. Overexpressed miR-181a-5p had a greater effect on development and branching patterns of arteries and veins than its knockdown. By laser confocal microscopy observation, the 72-hpf Tg (flk1: mCherry) zebrafish obviously displayed vascular proliferation and ablation in the miR-181a-5p mimic group. Microinjection of miR-181a-5p mimics and inhibitors led to abnormal expressions (20-50%) of two key target genes (pax2a and vash2) by WISH, and increased malformation percentages (18-45%) by IOD analysis. Overexpression of vash2 led to the inhibitory or promoting effects on the expression of PI3K signaling pathway-related genes, proving that the effect of vash2 on development of blood vessels could be realized by inhibiting PI3K signaling pathway. These observations lay theoretical foundation for deep insight into the molecular mechanisms on TCS-induced cardiovascular diseases.

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.

MiR-590 Inhibits Endothelial Cell Apoptosis by Inactivating the TLR4/NF-κB Pathway in Atherosclerosis

PURPOSE

Previous study has well documented the anti-apoptotic effects of miR-590 on oxidized low-density lipoprotein (ox-LDL)-treated endothelial cells (ECs). However, the mechanism underlying the anti-apoptotic effects of miR-590 in ox-LDL-treated ECs remains to be further addressed.

MATERIALS AND METHODS

ApoE^-/- mice fed with a high-fat diet (HFD) and human aortic endothelial cells (HAECs) treated with ox-LDL were used as in vivo and in vitro models of atherosclerosis. The expressions of miR-590 and toll-like receptor 4 (TLR4) were detected by quantitative real-time PCR and Western blot, respectively. Atherosclerotic lesion analysis was performed using Evans blue and hematoxylin-eosin staining. Cell proliferation was assessed by MTT assay. Apoptosis was examined using flow cytometry analysis and Western blot analysis of Cleaved poly (ADP-ribose) polymerase (PARP) and Cleaved Caspase-3 levels. The effect of miR-590 on TLR4/nuclear factor kappa B (NF-κB) pathway was evaluated by Western blot. Binding between miR-590 and TLR4 was confirmed by luciferase reporter assay and Western blot.

RESULTS

miR-590 was downregulated in the aorta tissues from HFD-fed apoE^-/- mice and ox-LDL-treated HAECs. miR-590 overexpression inhibited atherosclerotic lesion in HFD-induced apoE^-/- mice and promoted proliferation and inhibited apoptosis of ox-LDL-treated HAECs. Additionally, TLR4 was identified as a direct target of miR-590 in ox-LDL-treated HAECs. Moreover, anti-miR-590 reversed TLR4 knockdown-mediated promotion of cell proliferation and suppression of apoptosis in ox-LDL-treated HAECs. miR-590 overexpression suppressed the TLR4/NF-κB pathway, and inhibition of the TLR4/NF-κB pathway promoted cell proliferation and impeded apoptosis in ox-LDL-treated HAECs.

CONCLUSION

miR-590 promoted proliferation and blocked ox-LDL-induced apoptosis in HAECs through inhibition of the TLR4/NF-κB pathway.

Global identification of circular RNAs in chronic myeloid leukemia reveals hsa_circ_0080145 regulates cell proliferation by sponging miR-29b

Circular RNAs (circRNAs) are a class of non-coding RNAs that participate in various biological processes and disease pathogenesis. However, the role of circRNAs in chronic myeloid leukemia (CML) remains largely unknown. In this study, high-throughput sequencing was performed to explore the expression profile of circRNAs in CML patients for the first time, and a large number of differentially expressed circRNAs were identified. In addition, we constructed potential circRNA-miRNA interaction networks in CML, including a detailed hsa_circ_0080145-mediated competing endogenous RNA (ceRNA) regulatory network. Furthermore, functional experiments demonstrated that hsa_circ_0080145 knockdown significantly suppressed CML cell proliferation and hsa_circ_0080145 regulated CML cell proliferation by acting as an miR-29b sponge.

MiR-188-3p upregulation results in the inhibition of macrophage proinflammatory activities and atherosclerosis in ApoE-deficient mice

BACKGROUND

Atherosclerosis occurs as a result of a chronic inflammatory response in the arterial wall associated with an increased uptake of low-density lipoprotein by macrophages and the subsequent transformation of this lipoprotein into foam cells. It has been found that miR-188-3p can suppress autophagy and myocardial infarction. Therefore, we conducted the present study with determining the suppressive role played by miR-188-3p in atherosclerosis.

METHODS

The atherosclerosis model was established using ApoE knockout mice. The healthy C57BL/6J wide-type mice were used as control, while miR-188-3p mimics or inhibitors were applied for the elevation or the depletion of the miR-188-3p expression in mice. The macrophage content was observed in atherosclerotic plaque. Once the miR-188-3p expression was determined, the effects of the over-expression of miR-188-3p on the lipid accumulation and macrophage inflammatory response were accessed. The plasma levels of pro-inflammatory factors and serum RANTES level, as well as OLR1, iNOS, ABCA1 and KLF2 expression were determined in order to evaluate the potential anti-inflammatory and antioxidative activities of miR-188-3p.

RESULTS

ApoE knockout mice with atherosclerosis presented with increased lipid accumulation and macrophage content. MiR-188-3p was found to reduce intravascular lipid accumulation in atherosclerotic mice. In addition to the alleviation of macrophage inflammatory response, the upregulation of miR-188-3p also leads to the suppression of oxidation with reduced macrophage accumulation, plasma expression of pro-inflammatory factors and serum RANTES level, OLR1 and iNOS, while it increases ABCA1 and KLF2.

CONCLUSIONS

In conclusion, the findings from our study found a new potential therapy for atherosclerosis by investigating the inhibitory effects of miR-188-3p on macrophage inflammatory response and oxidation.