MicroRNA-24 inhibits high glucose-induced vascular smooth muscle cell proliferation and migration by targeting HMGB1

MicroRNA-24 therapeutic potentials in infarction, stroke, and diabetic complications

The prevalence of cardiovascular events, stroke, and diabetes worldwide underscores the urgent need for effective and minimally invasive treatments. With nearly 20 million annual casualties attributed to cardiovascular diseases and an estimated 463 million people living with diabetes in 2022. Identifying promising therapeutic candidates is paramount. MicroRNAs, short nucleic acids involved in regulating gene expression, emerge as potential game-changers. Among these, microRNA-24 (miR-24), a hypoxia-sensitive player in endothelial vessels, has protective roles against diverse vascular complications. Following heart infarction and stroke, elevating miR-24 expression proves beneficial by mitigating oxidative stress, inflammation, and apoptosis while enhancing cell survival. It reduces cardiac fibrosis in heart disease, regulates aberrant angiogenesis in cerebral hemorrhagic strokes, and enhances the functionality of cardiomyocytes and brain neurons. In diabetic conditions, augmenting miR-24 expression mitigates complications. Further, being miR-24 also expressed by the skeletal muscle (i.e., myo-miR) in response to exercise, this miRNA may participate in the complex molecular network that systemically spreads the beneficial effects of physical exercise. This review provides a comprehensive vision of the molecular mechanisms underpinning the miR-24 protective effects, offering new insights into its therapeutic potential and proposing a novel avenue for medical intervention.

New insights on genetic background of major diabetic vascular complications

BACKGROUND

By 2045, it is expected that 693 million individuals worldwide will have diabetes and with greater risk of morbidity, mortality, loss of vision, renal failure, and a decreased quality of life due to the devastating effects of macro- and microvascular complications. As such, clinical variables and glycemic control alone cannot predict the onset of vascular problems. An increasing body of research points to the importance of genetic predisposition in the onset of both diabetes and diabetic vascular complications.

OBJECTIVES

Purpose of this article is to review these approaches and narrow down genetic findings for Diabetic Mellitus and its consequences, highlighting the gaps in the literature necessary to further genomic discovery.

MATERIAL AND METHODS

In the past, studies looking for genetic risk factors for diabetes complications relied on methods such as candidate gene studies, which were rife with false positives, and underpowered genome-wide association studies, which were constrained by small sample sizes.

RESULTS

The number of genetic findings for diabetes and diabetic complications has over doubled due to the discovery of novel genomics data, including bioinformatics and the aggregation of global cohort studies. Using genetic analysis to determine whether diabetes individuals are at the most risk for developing diabetic vascular complications (DVC) might lead to the development of more accurate early diagnostic biomarkers and the customization of care plans.

CONCLUSIONS

A newer method that uses extensive evaluation of single nucleotide polymorphisms (SNP) in big datasets is Genome-Wide Association Studies (GWAS).

The Role of Alarmins in the Pathogenesis of Atherosclerosis and Myocardial Infarction

Atherosclerosis is a condition that is associated with lipid accumulation in the arterial intima. Consequently, the enlarging lesion, which is also known as an atherosclerotic plaque, may close the blood vessel lumen, thus leading to organ ischaemia. Furthermore, the plaque may rupture and initiate the formation of a thrombus, which can cause acute ischaemia. Atherosclerosis is a background pathological condition that can eventually lead to major cardiovascular diseases such as acute coronary syndrome or ischaemic stroke. The disorder is associated with an altered profile of alarmins, stress response molecules that are secreted due to cell injury or death and that induce inflammatory responses. High-mobility group box 1 (HMGB1), S100 proteins, interleukin-33, and heat shock proteins (HSPs) also affect the behaviour of endothelial cells and vascular smooth muscle cells (VSMCs). Thus, alarmins control the inflammatory responses of endothelial cells and proliferation of VSMCs, two important processes implicated in the pathogenesis of atherosclerosis. In this review, we will discuss the role of alarmins in the pathophysiology of atherosclerosis and myocardial infarction.

The ability of microRNAs to regulate the immune response in ischemia/reperfusion inflammatory pathways

MicroRNAs play a crucial role in regulating the immune responses induced by ischemia/reperfusion injury. Through their ability to modulate gene expression, microRNAs adjust immune responses by targeting specific genes and signaling pathways. This review focuses on the impact of microRNAs on the inflammatory pathways triggered during ischemia/reperfusion injury and highlights their ability to modulate inflammation, playing a critical role in the pathophysiology of ischemia/reperfusion injury. Dysregulated expression of microRNAs contributes to the pathogenesis of ischemia/reperfusion injury, therefore targeting specific microRNAs offers an opportunity to restore immune homeostasis and improve patient outcomes. Understanding the complex network of immunoregulatory microRNAs could provide novel therapeutic interventions aimed at attenuating excessive inflammation and preserving tissue integrity.

Procyanidins: A promising anti-diabetic agent with potential benefits on glucose metabolism and diabetes complications

Diabetes mellitus (DM) is a complex disease with alarming worldwide health implications and high mortality rates, largely due to its complications such as cardiovascular disease, nephropathy, neuropathy, and retinopathy. Recent research has shown that procyanidins (PC), a type of flavonoid, have strong antioxidant and free radical elimination effects, and may be useful in improving glucose metabolism, enhancing pancreatic islet cell activity, and decreasing the prevalence of DM complications. This review article presents a systematic search for peer-reviewed articles on the use of PC in the treatment of DM, without any language restrictions. The article also discusses the potential for PC to sensitise DM medications and improve their efficacy. Recent in vivo and in vitro studies have demonstrated promising results in improving the biological activity and bioavailability of PC for the treatment of DM. The article concludes by highlighting the potential for novel materials and targeted drug delivery methods to enhance the pharmacokinetics and bioactivity of PC, leading to the creation of safer and more effective anti-DM medications in the future.

Regulatory effects of trimetazidine in cardiac ischemia/reperfusion injury

Ischemia/reperfusion (I/R) injury is a tissue damage during reperfusion after an ischemic condition. I/R injury is induced by pathological cases including stroke, myocardial infarction, circulatory arrest, sickle cell disease, acute kidney injury, trauma, and sleep apnea. It can lead to increased morbidity and mortality in the context of these processes. Mitochondrial dysfunction is one of the hallmarks of I/R insult, which is induced via reactive oxygen species (ROS) production, apoptosis, and autophagy. MicroRNAs (miRNAs, miRs) are non-coding RNAs that play a main regulatory role in gene expression. Recently, there are evidence, which miRNAs are the major modulators of cardiovascular diseases, especially myocardial I/R injury. Cardiovascular miRNAs, specifically miR-21, and probably miR-24 and miR-126 have protective effects on myocardial I/R injury. Trimetazidine (TMZ) is a new class of metabolic agents with an anti-ischemic activity. It has beneficial effects on chronic stable angina by suppressing mitochondrial permeability transition pore (mPTP) opening. The present review study addressed the different mechanistic effects of TMZ on cardiac I/R injury. Online databases including Scopus, PubMed, Web of Science, and Cochrane library were assessed for published studies between 1986 and 2021. TMZ, an antioxidant and metabolic agent, prevents the cardiac reperfusion injury by regulating AMP-activated protein kinase (AMPK), cystathionine-γ-lyase enzyme (CSE)/hydrogen sulfide (H2S), and miR-21. Therefore, TMZ protects the heart against I/R injury by inducing key regulators such as AMPK, CSE/H2S, and miR-21.

Nucleolin Regulates Pulmonary Artery Smooth Muscle Cell Proliferation under Hypoxia by Modulating miRNA Expression

Hypoxia induces the abnormal proliferation of vascular smooth muscle cells (VSMCs), resulting in the pathogenesis of various vascular diseases. RNA-binding proteins (RBPs) are involved in a wide range of biological processes, including cell proliferation and responses to hypoxia. In this study, we observed that the RBP nucleolin (NCL) was downregulated by histone deacetylation in response to hypoxia. We evaluated its regulatory effects on miRNA expression under hypoxic conditions in pulmonary artery smooth muscle cells (PASMCs). miRNAs associated with NCL were assessed using RNA immunoprecipitation in PASMCs and small RNA sequencing. The expression of a set of miRNAs was increased by NCL but reduced by hypoxia-induced downregulation of NCL. The downregulation of miR-24-3p and miR-409-3p promoted PASMC proliferation under hypoxic conditions. These results clearly demonstrate the significance of NCL-miRNA interactions in the regulation of hypoxia-induced PASMC proliferation and provide insight into the therapeutic value of RBPs for vascular diseases.

miR-582-5p targets Skp1 and regulates NF-κB signaling-mediated inflammation

A well-tuned inflammatory response is crucial for an effective immune process. Nuclear factor-kappa B (NF-κB) is a key mediator of inflammatory and innate immunity responses, and its dysregulation is closely associated with immune-related diseases. MicroRNAs (miRNAs) are important inflammation modulators. However, miRNA-regulated mechanisms that implicate NF-κB activity are not fully understood. This study aimed to identify a potential miRNA that could modulate the dysregulated NF-κB signaling during inflammation. We identified miR-582-5p that was significantly downregulated in inflamed murine adipose tissues and RAW264.7 cells. S-phase kinase-associated protein 1 (SKP1), a core component of an E3 ubiquitin ligase that regulates the NF-κB pathway, was proposed as a biological target of miR-582-5p by using TargetScan. The binding of miR-582-5p to a 3'-untranslated region site on Skp1 was confirmed using a dual-luciferase reporter assay; in addition, transfection with a miR-582-5p mimic suppressed SKP1 expression in RAW264.7 cells. Importantly, exogenous miR-582-5p attenuated the production of pro-inflammatory cytokines such as tumor necrosis factor-alpha, interleukin-1 beta, and interleukin-6 through suppressing the degradation of the NF-κB inhibitor alpha, followed by the nuclear translocation of NF-κB. Therefore, exogenously applied miR-582-5p can attenuate the NF-κB signaling pathway via targeting Skp1; this provides a prospective therapeutic strategy for treating inflammatory and immune diseases.

MicroRNAs as Biomarkers for Coronary Artery Disease Related to Type 2 Diabetes Mellitus-From Pathogenesis to Potential Clinical Application

Type 2 diabetes mellitus (T2DM) is a chronic metabolic disease with still growing incidence among adults and young people worldwide. Patients with T2DM are more susceptible to developing coronary artery disease (CAD) than non-diabetic individuals. The currently used diagnostic methods do not ensure the detection of CAD at an early stage. Thus, extensive research on non-invasive, blood-based biomarkers is necessary to avoid life-threatening events. MicroRNAs (miRNAs) are small, endogenous, non-coding RNAs that are stable in human body fluids and easily detectable. A number of reports have highlighted that the aberrant expression of miRNAs may impair the diversity of signaling pathways underlying the pathophysiology of atherosclerosis, which is a key player linking T2DM with CAD. The preclinical evidence suggests the atheroprotective and atherogenic influence of miRNAs on every step of T2DM-induced atherogenesis, including endothelial dysfunction, endothelial to mesenchymal transition, macrophage activation, vascular smooth muscle cells proliferation/migration, platelet hyperactivity, and calcification. Among the 122 analyzed miRNAs, 14 top miRNAs appear to be the most consistently dysregulated in T2DM and CAD, whereas 10 miRNAs are altered in T2DM, CAD, and T2DM-CAD patients. This up-to-date overview aims to discuss the role of miRNAs in the development of diabetic CAD, emphasizing their potential clinical usefulness as novel, non-invasive biomarkers and therapeutic targets for T2DM individuals with a predisposition to undergo CAD.

MicroRNA-25-5p negatively regulates TXNIP expression and relieves inflammatory responses of brain induced by lipopolysaccharide

Sepsis is one of the most common causes of death in patients suffering from severe infection or injury. Currently, a specific effective therapy remains to be established. In the present study, miR-25-5p, miR-105, miR-106b-5p, miR-154-3p, miR-20b-5p, miR-295-3p, miR-291-3p, miR-301b, miR-352, and miR-93-5p were predicted to target TXNIP mRNA from the databases of miRDB, Targetscan, and microT-CDS. The luciferase reporter assay confirmed that miR-25-5p negatively regulates TXNIP expression. The ELISA analyses and western blotting demonstrated that miR-25-5p downregulated the production of IL-1β, IL-6, IL-8, and TNF-α in lipopolysaccharide (LPS)-stimulated cells or rats, as well as the protein levels of TXNIP, NLRP3, and cleaved caspase-1. In addition, miR-25-5p increased the cell viability and decreased the apoptosis in LPS-stimulated CTX TNA2 cells and reduced the abnormal morphology of the brain in LPS-stimulated rats. Besides, miR-25-5p decreased the relative mean fluorescence intensity of DCF in LPS-stimulated CTX TNA2 cell, apoptosis, and protein levels of MnSOD and catalase in LPS-stimulated brains. These findings indicate that miR-25-5p downregulated LPS-induced inflammatory responses, reactive oxygen species production, and brain damage, suggesting that miR-25-5p is a candidate treatment for septic encephalopathy.

Discovering the Secret of Diseases by Incorporated Tear Exosomes Analysis via Rapid-Isolation System: iTEARS

Nanoscale small extracellular vesicles (sEVs, exosomes) in tears allow us to investigate the multisignatures of diseases. However, the translations of tear sEVs for biomarker discovery and clinical diagnostics are practically limited by low recovery, long processing time, and small sample volume. Here, we report an incorporated tear-exosomes analysis via rapid-isolation system (iTEARS) via nanotechnology to discover the secrets of ocular disorders and systemic diseases. We isolate exosomes rapidly with high yield and purity from a few teardrops (∼10 μL) within 5 min via nanoporous membrane-based resonators for the quantitative detection and biomarker discovery through proteomic and transcriptomic analysis. We have identified 904 proteins, among which 228 proteins are discovered, 426 proteins are detected from exosomes of dry eye disease, and demonstrate CALML5, KRT6A, and S100P for the classification of dry eye disease. We have also investigated 484 miRNAs in tear exosomes and show miR-145-5p, miR-214-3p, miR-218-5p, and miR-9-5p are dysregulated during diabetic retinopathy development. We believe iTEARS can be used for improving molecular diagnostics via tears to identify ocular disorders, systemic diseases, and numerous other neurodegenerative diseases and cancer.

Tracking an Elusive Killer: State of the Art of Molecular-Genetic Knowledge and Laboratory Role in Diagnosis and Risk Stratification of Thoracic Aortic Aneurysm and Dissection

The main challenge in diagnosing and managing thoracic aortic aneurysm and dissection (TAA/D) is represented by the early detection of a disease that is both deadly and “elusive”, as it generally grows asymptomatically prior to rupture, leading to death in the majority of cases. Gender differences exist in aortic dissection in terms of incidence and treatment options. Efforts have been made to identify biomarkers that may help in early diagnosis and in detecting those patients at a higher risk of developing life-threatening complications. As soon as the hereditability of the TAA/D was demonstrated, several genetic factors were found to be associated with both the syndromic and non-syndromic forms of the disease, and they currently play a role in patient diagnosis/prognosis and management-guidance purposes. Likewise, circulating biomarker could represent a valuable resource in assisting the diagnosis, and several studies have attempted to identify specific molecules that may help with risk stratification outside the emergency department. Even if promising, those data lack specificity/sensitivity, and, in most cases, they need more testing before entering the “clinical arena”. This review summarizes the state of the art of the laboratory in TAA/D diagnostics, with particular reference to the current and future role of molecular-genetic testing.

Pathogenic role of microRNAs in atherosclerotic ischemic stroke: Implications for diagnosis and therapy

Ischemic stroke resulting from atherosclerosis (particularly in the carotid artery) is one of the major subtypes of stroke and has a high incidence of death. Disordered lipid homeostasis, lipid deposition, local macrophage infiltration, smooth muscle cell proliferation, and plaque rupture are the main pathological processes of atherosclerotic ischemic stroke. Hepatocytes, macrophages, endothelial cells and vascular smooth muscle cells are the main cell types participating in these processes. By inhibiting the expression of the target genes in these cells, microRNAs play a key role in regulating lipid disorders and atherosclerotic ischemic stroke. In this article, we listed the microRNAs implicated in the pathology of atherosclerotic ischemic stroke and aimed to explain their pro- or antiatherosclerotic roles. Our article provides an update on the potential diagnostic use of miRNAs for detecting growing plaques and impending clinical events. Finally, we provide a perspective on the therapeutic use of local microRNA delivery and discuss the challenges for this potential therapy.

The miR-23-27-24 cluster: an emerging target in NAFLD pathogenesis

The incidence of non-alcoholic fatty liver disease (NAFLD) is increasing globally, being the most widespread form of chronic liver disease in the west. NAFLD includes a variety of disease states, the mildest being non-alcoholic fatty liver that gradually progresses to non-alcoholic steatohepatitis, fibrosis, cirrhosis, and eventually hepatocellular carcinoma. Small non-coding single-stranded microRNAs (miRNAs) regulate gene expression at the miRNA or translational level. Numerous miRNAs have been shown to promote NAFLD pathogenesis and progression through increasing lipid accumulation, oxidative stress, mitochondrial damage, and inflammation. The miR-23-27-24 clusters, composed of miR-23a-27a-24-2 and miR-23b-27b-24-1, have been implicated in various biological processes as well as many diseases. Herein, we review the current knowledge on miR-27, miR-24, and miR-23 in NAFLD pathogenesis and discuss their potential significance in NAFLD diagnosis and therapy.

Expression of miR-24-1-5p in Tumor Tissue Influences Prostate Cancer Recurrence: The PROCA-life Study

The role of miR-24-1-5p and its prognostic implications associated with prostate cancer are mainly unknown. In a population-based cohort, the Prostate Cancer Study throughout life (PROCA-life), all men had a general health examination at study entry and were followed between 1994 and 2016. Patients with available tissue samples after a prostatectomy with curative intent were identified (n = 189). The tissue expression of miR-24-1-5p in prostate cancer was examined by in situ hybridization (ISH) in tissue microarray (TMA) blocks by semi-quantitative scoring by two independent investigators. Multivariable Cox regression models were used to study the associations between miR-24-1-5p expression and prostate cancer recurrence. The prostate cancer patients had a median age of 65.0 years (range 47−75 years). The Cancer of the Prostate Risk Assessment Postsurgical Score, International Society of Urological Pathology grade group, and European Association of Urology Risk group were all significant prognostic factors for five-year recurrence-free survival (p < 0.001). Prostate cancer patients with a high miR-24-1-5p expression (≥1.57) in the tissue had a doubled risk of recurrence compared to patients with low expression (HR 1.99, 95% CI 1.13−3.51). Our study suggests that a high expression of miR-24-1-5p is associated with an increased risk of recurrence of prostate cancer after radical prostatectomy, which points to the potential diagnostic and therapeutic value of detecting miR-24-1-5p in prostate cancer cases.

Heart failure in diabetes

Heart failure and cardiovascular disorders represent the leading cause of death in diabetic patients. Here we present a systematic review of the main mechanisms underlying the development of diabetic cardiomyopathy. We also provide an excursus on the relative contribution of cardiomyocytes, fibroblasts, endothelial and smooth muscle cells to the pathophysiology of heart failure in diabetes. After having described the preclinical tools currently available to dissect the mechanisms of this complex disease, we conclude with a section on the most recent updates of the literature on clinical management.

miR-141-5p suppresses vascular smooth muscle cell inflammation, proliferation, and migration via inhibiting the HMGB1/NF-κB pathway

MicroRNAs (miRNAs) have been identified as significant modulators in the pathogenesis of atherosclerosis (AS). Additionally, the dysregulation of vascular smooth muscle cells (VSMCs) is a crucial biological event during AS. Our study aimed to explore the functional roles and molecular mechanisms of miR-141-5p in VSMCs dysfunction. C57BL/6 mice were used to establish AS animal model. Human VSMCs were treated by oxidized low-density lipoprotein (ox-LDL) to establish AS cell model. Quantitative real-time polymerase chain reaction (qRT-PCR) was employed to probe miR-141-5p and high-mobility group box 1 (HMGB1) mRNA expressions in VSMCs or plasma samples of the mice. Inflammatory cytokines were detected by enzyme-linked immunosorbent assay kits. Cell counting kit-8 and bromodeoxyuridine assays were performed to evaluate cell proliferation. Cell migration and apoptosis were detected with Transwell assay and flow cytometry analysis, respectively. The target gene of miR-141-5p was predicted with the TargetScan database, and the interaction between miR-141-5p and HMGB1/nuclear factor-κB (NF-κB) was further validated by dual-luciferase reporter assay, qRT-PCR, and Western blot analysis. miR-141-5p was found to be decreased in the plasma of patients and mice model with AS. Its expression was also downregulated in VSMCs treated by ox-LDL. miR-141-5p overexpression inhibited the inflammation, proliferation, migration of VSMCs, and promoted the apoptosis of VSMCs. HMGB1 was identified as a direct target of miR-141-5p, and miR-141-5p could repress the activity of HMGB1/NF-κB signaling. HMGB1 restoration reversed the effects of miR-141-5p, and NF-κB inhibitor JSH-23 showed similar effects with miR-141-5p mimics. miR-141-5p inhibits VSMCs' dysfunction by targeting the HMGB1/NF-κB pathway, which probably functions as a protective factor during the development of AS.

High-mobility group box-1 promotes vascular calcification in diabetic mice via endoplasmic reticulum stress

Several studies reported the role of endoplasmic reticulum stress (ERS) in vascular calcification. High-mobility group box-1 (HMGB-1) plays a substantial role in diabetes and its complications. However, relatively little information is available regarding the association between HMGB-1 and calcification, and the underlying mechanism has still remained elusive. Therefore, in the present study, we attempted to indicate whether HMGB-1 could promote vascular calcification via ERS in diabetes. After induction of diabetes by Streptozotocin (STZ), mice were treated with glycyrrhizin (Gly) or 4-phenylbutyrate (4-PBA). Mineral deposition was confirmed by reverse transcription-polymerase chain reaction (RT-PCR) and calcium assay. In cell experiments, calcification of vascular smooth muscle cells (VSMCs) was performed with Alizarin Red staining, alkaline phosphatase (ALP) activity and RT-PCR. Expression and location of HMGB-1 in aortic tissue were detected by Western blotting, immunocytochemistry (ICC) and immunohistochemistry (IHC). Diabetic mice demonstrated increased HMGB-1 expression, ERS and vascular calcification. However, inhibition of HMGB-1 with Gly or inhibition of ERS with 4-PBA ameliorated the enhanced vascular calcification and ERS in diabetic mice. In vitro experiments unveiled that inhibition of HMGB-1 attenuated advanced glycation end products (AGEs)-induced ERS in VSMCs. In addition, AGEs promoted translocation and secretion of HMGB-1 in VSMCs, which was reversed by 4-PBA. Moreover, VSMCs exhibited increased mineralization and osteogenic gene expressions in response to HMGB-1 and AGEs. However, inhibition of ERS with 4-PBA partially, although noticeably, attenuated VSMC calcification induced by HMGB-1. Thus, diabetes induced translocation and secretion of HMGB-1 via ERS, which resulted in calcification in diabetic mice and in AGEs-treated VSMCs.

Trimetazidine Increases Plasma MicroRNA-24 and MicroRNA-126 Levels and Improves Dyslipidemia, Inflammation and Hypotension in Diabetic Rats

Trimetazidine (TMZ) improves endothelial dysfunction. However, its beneficial effect on endothelial miRNAs is unexplored in diabetes. The aim of the present study was to evaluate the effects of TMZ on plasma miRNA-24 and miRNA-126, dyslipidemia, inflammation, and blood pressure in the diabetic rats. Adult male Sprague-Dawley rats were randomly assigned into four groups (250 ± 20 g, n = 8): a control (C), an untreated diabetic (D), a diabetic group administrated with TMZ at 10 mg/kg (T10), and a diabetic group administrated with TMZ at 30 mg/kg (T30) for eight weeks. Diabetes was induced by injection of alloxan (120 mg/kg). The plasma levels of miR-24, miR-126, lipid profile, malondialdehyde (MDA), tumor necrosis factor-alpha (TNF-α) and interleukin-6 (IL-6), blood glucose, body weight and systolic blood pressure were measured. The diabetic rats showed decreased plasma miR-24, HDL-c (P < 0.05), miR-126 (P < 0.01), body weight changes percent, body weight, and systolic blood pressure (P < 0.001) and increased triglycerides (TG), VLDL-c (P < 0.05), TNF-α, total cholesterol (TC) (P < 0.01) glucose, MDA and IL-6 (P < 0.001). Interestingly, all these changes were significantly improved by TMZ treatment. Our findings propose that TMZ has protective effects on decreased plasma miR-24 and miR-126 levels, inflammation, dyslipidemia and hypotension, and it may participate in endothelial dysfunction and atherosclerosis.

miR-22 Host Gene Enhances Nuclear Factor-kappa B Activation to Aggravate Hypoxia-induced Injury in AC16 Cardiomyocytes

Myocardial infarction (MI) is a severe life-threatening disease caused by acute and persistent ischemia and hypoxia and eventually leads to heart failure and sudden death. Long noncoding RNAs (lncRNAs) play significant roles in the pathology, diagnosis, and development of various cardiovascular diseases, including MI. This study aimed to explore the effect and molecular mechanism of lncRNA miR-22 host gene (MIR22HG) on hypoxia-induced injury in AC16 cardiomyocytes. The expression of MIR22HG and miR-24 in hypoxia-treated AC16 cardiomyocytes was detected by quantitative real-time polymerase chain reaction. Cell viability, lactate dehydrogenase release, levels of aspartate aminotransferase (AST) and creatine kinase-MB (CK-MB), and apoptosis were detected by Cell Counting Kit-8, lactate dehydrogenase (LDH) release assay, commercial enzyme-linked immune sorbent assay kits, and flow cytometry analysis, respectively. The protein levels of nuclear factor-kappa B (NF-κB) p65 and cytoplasmic inhibitor of kappa B alpha (IκBα) and phosphorylated IκBα were detected by western blot. Results showed that hypoxia treatment decreased viability and increased MIR22HG expression in AC16 cardiomyocytes. MIR22HG overexpression aggravated hypoxia-induced viability reduction, leakage of myocardial injury markers LDH, AST, and CK-MB, and apoptosis in AC16 cardiomyocytes, while MIR22HG knockdown elicited the reverse effects. MIR22HG overexpression enhanced NF-κB activation in hypoxia-treated AC16 cardiomyocytes. Inhibition of NF-κB pathway impaired the effects of MIR22HG overexpression on hypoxia-induced injury in AC16 cardiomyocytes. Moreover, MIR22HG knockdown inhibited the NF-κB pathway by upregulating miR-24 in AC16 cardiomyocytes. Inhibition of miR-24 resisted the effects of MIR22HG silencing on hypoxia-induced injury in AC16 cardiomyocytes. In conclusion, MIR22HG overexpression aggravated hypoxia-induced injury in AC16 cardiomyocytes via enhancing NF-κB activation by targeting miR-24.

miR-381-3p inhibits high glucose-induced vascular smooth muscle cell proliferation and migration by targeting HMGB1

BACKGROUND

Hyperglycemia increases the risk of many cardiovascular diseases (CVD), and the dysregulation of proliferation and migration in vascular smooth muscle cells (VSMCs) also participates in the pathogenesis of CVD. miR-381-3p is known to suppress the proliferation and migration of multiple human cell types. Nevertheless, the function of miR-381-3p in VSMCs remains largely indistinct.

METHODS

A quantitative real-time polymerase chain reaction (qRT-PCR) was employed to investigate miR-381-3p expression in high-glucose-induced VSMCs. Inflammatory cytokines tumor necrosis factor-α, interleukin-1β and interleukin-6, as well as oxidative stress markers SOD and MDA, were determined by an enzyme-linked immunosorbent assay. Reactive oxygen species generation was examined using a 2,7'-dichlorofluorescein kit. The proliferation, migration and apoptosis of VSMCs were monitored by 3-(4,5-dimethylthiazl2-yl)-2,5-diphenyltetazolium bromide (MTT), transwell and terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling (TUNEL) assays. The TargetScan database (http://www.targetscan.org) was employed to seek the potential target gene of miR-381-3p. Interaction between miR-381-3p and HMGB1 was determined by a qRT-PCR, western blotting and a luciferase reporter assay.

RESULTS

miR-381-3p expression was significantly reduced in a VSMCs dysfunction model induced by high-glucose in a dose- and time-dependent manner. Transfection of miR-381-3p mimics suppressed the inflammation, oxidative stress, proliferation and migration of VSMCs, whereas apoptosis of VSMCs was promoted, and the transfection of miR-381-3p inhibitors had the opposite effect. Mechanistically, HMGB1, an important factor in inflammation response, was confirmed as a target gene of miR-381-3p.

CONCLUSIONS

miR-381-3p targets HMGB1 to suppress the inflammation, oxidative stress, proliferation and migration of high-glucose-induced VSMCs by targeting HMGB1.

MiR-24 Protects Cardiomyocytes Against Hypoxia/Reoxygenation-Induced Injury Through Regulating Mitogen-Activated Protein Kinase 14

This study aimed to explore the function of miR-24 in hypoxia/reoxygenation (H/R) -induced cardiomyocyte injury.We constructed a cardiomyocyte model of H/R using the primary cardiomyocytes isolated from Sprague-Dawley rats. To explore the role of miR-24, cells were transfected with a miR-24 mimic or miR-24 inhibitor. The RNA expression levels of miR-24 and Mapk14 were determined using qRT-PCR. The proliferation and apoptosis of cells were determined using a CCK8 assay and a flow cytometer. The TargetScan website was used to predict the targets of miR-24. A dual-luciferase reporter gene assay was conducted to verify whether Mapk14 is indeed a target of miR-24. A Western blot was applied for protein detection.H/R exposure decreased the expression of miR-24 in rat cardiomyocytes. Transfection of the miR-24 mimic into cardiomyocytes reduced H/R-induced injury as evidenced by an increase in proliferation and a decrease in the apoptotic rate. By contrast, transfection of the miR-24 inhibitor aggravated H/R-induced injury. The expression of Bcl-2 was increased while the levels of Bax and Active-caspase 3 were reduced in the H/R+miR-24 mimic group compared to those in the H/R group. H/R+miR-24 inhibitor group showed the opposite results. Mapk14 was identified as a target of miR-24. The mRNA level of Mapk14 and its protein (p38 MAPK) level were negatively affected by miR-24. Furthermore, we discovered that depletion of Mapk14 reduced the promoting effect of the miR-24 inhibitor on cell apoptosis.Overall, our results illustrated that miR-24 could attenuate H/R-induced injury partly by regulating Mapk14.

Knock-Down of Long Non-Coding RNA ANRIL Suppresses Mouse Mesangial Cell Proliferation, Fibrosis, Inflammation via Regulating Wnt/β-Catenin and MEK/ERK Pathways in Diabetic Nephropathy

Aims Our study aimed to investigate the role of long non-coding RNA ANRIL (lnc-ANRIL) knock-down in regulating cell activities, inflammation and downstream signaling pathways in mouse mesangial cellular diabetic nephropathy (DN) model.

Methods The mouse mesangial cells (SV40-MES13 cells) were treated with high-glucose (HG) to construct cellular DN model. Lnc-ANRIL knock-down plasmid and control knock-down plasmid were transfected into HG-treated SV40-MES13 cells as Sh-ANRIL group and Sh-NC group respectively.

Results Lnc-ANRIL expression was significantly higher in HG-treated SV40-MES13 cells compared with normal glucose-treated SV40-MES13 cells and osmotic control-treated SV40-MES13 cells. Lnc-ANRIL knock-down suppressed cell proliferation and promoted cell apoptosis in HG-treated SV40-MES13 cells. As for fibrosis, lnc-ANRIL knock-down reduced fibronectin and collagen I expressions in HG-treated SV40-MES13 cells. Besides, the expressions of supernatant tumor necrosis factor-alpha (TNF-α), monocyte chemoattractant protein-1 (MCP-1), interleukin (IL)-1β, IL-6, IL-8 and IL-18 were reduced in Sh-ANRIL group compared with Sh-NC group. Furthermore, Wnt3, β-catenin, p-MEK1 and p-ERK1 expressions were suppressed in Sh-ANRIL group compared with Sh-NC group, which suggested that lnc-ANRIL knock-down inhibited Wnt/β-catenin and MEK/ERK pathways in HG-treated SV40-MES13 cells.

Conclusions Lnc-ANRIL knock-down suppresses mouse mesangial cell proliferation, fibrosis, inflammation, Wnt/β-catenin and MEK/ERK pathways in DN.

MicroRNA‑125a‑mediated regulation of the mevalonate signaling pathway contributes to high glucose‑induced proliferation and migration of vascular smooth muscle cells

Hyperglycemia contributes to the excessive proliferation and migration of vascular smooth muscle cells (VSMC), which are closely associated with atherosclerosis. MicroRNAs (miRNAs/miRs) constitute a novel class of gene regulators, which have important roles in various pathological conditions. The aim of the present study was to identify miRNAs involved in the high glucose (HG)‑induced VSMC phenotype switch, and to investigate the underlying mechanism. miRNA sequencing and reverse transcription‑quantitative PCR results indicated that inhibition of miR‑125a expression increased the migration and proliferation of VSMCs following HG exposure, whereas the overexpression of miR‑125a abrogated this effect. Furthermore, dual‑luciferase reporter assay results identified that 3‑hydroxy‑3-methyglutaryl‑coA reductase (HMGCR), one of the key enzymes in the mevalonate signaling pathway, is a target of miR‑125a. Moreover, HMGCR knockdown, similarly to miR‑125a overexpression, suppressed HG‑induced VSMC proliferation and migration. These results were consistent with those from the miRNA target prediction programs. Using a rat model of streptozotocin‑induced diabetes mellitus, it was demonstrated that miR‑125a expression was gradually downregulated, and that the expressions of key enzymes in the mevalonate signaling pathway in the aortic media were dysregulated after several weeks. In addition, it was found that HG‑induced excessive activation of the mevalonate signaling pathway in VSMCs was suppressed following transfection with a miR‑125a mimic. Therefore, the present results suggest that decreased miR‑125a expression contributed to HG‑induced VSMC proliferation and migration via the upregulation of HMGCR expression. Thus, miR‑125a‑mediated regulation of the mevalonate signaling pathway may be associated with atherosclerosis.

MicroRNA‑24 attenuates diabetic vascular remodeling by suppressing the NLRP3/caspase‑1/IL‑1β signaling pathway

Vascular remodeling plays an important role in the pathogenesis of diabetic cardiovascular complications. Previous published research has indicated that microRNA-24 (miR-24) is involved in diabetic vascular remodeling, but the underlying molecular mechanisms have yet to be fully elucidated. The aim of the present study was to investigate whether adenovirus-mediated miR-24 overexpression can suppress the NOD-like receptor family pyrin domain-containing 3 (NLRP3)-related inflammatory signaling pathway and attenuate diabetic vascular remodeling. The carotid arteries of diabetic rats were harvested and prepared for analysis. Reverse transcription-quantitative PCR and western blotting assays were used to detect the expressions of related mRNAs and proteins. Morphological examinations, including hematoxylin and eosin, immunohistochemical and Masson’s trichrome staining, were also performed. The results of the present study demonstrated that miR-24 upregulation suppressed neointimal hyperplasia and accelerated reendothelialization in the injured arteries, lowered the expression of NLRP3, apoptosis-associated speck-like protein, caspase-1, proliferating cell nuclear antigen, CD45, interleukin (IL)-1β, IL-18 and tumor necrosis factor-α, and increased the expression of CD31, smooth muscle (SM) α-actin and SM-myosin heavy chain. These data indicated that miR-24 overexpression can attenuate vascular remodeling in a diabetic rat model through suppressing the NLRP3/caspase-1/IL-1β signaling pathway.

Metformin inhibits high glucose-induced smooth muscle cell proliferation and migration

We investigated the protective effects and mechanism of action of metformin on high glucose-induced smooth muscle cell proliferation and migration. Vascular smooth muscle cells (VSMCs) were subjected to a series of concentrations (0-10 mM) of metformin. CCK-8, wound healing, and transwell assays were performed. Correlations between metformin concentration and high-mobility group box 1 (HMGB1) and miR-142-3p levels were assessed. In addition, miR-142-3p mimic and siRNA were used to investigate VSMC migration in the presence or absence of metformin. In the high-glucose condition, metformin decreased cell growth and inhibited cell migration. HMGB1 gene expression correlated negatively with metformin concentration, whereas miR-142-3p expression correlated positively with metformin concentration. In addition, mimic-induced miR-142-3p elevation resulted in decreased HMGB1 and LC3II levels and elevated p62 levels in the high-glucose condition, whereas miR-142-3p knockdown had the reverse effects, and metformin abolished those effects. Metformin inhibits high glucose–induced VSMC hyperproliferation and increased migration by inducing miR-142-3p-mediated inhibition of HMGB1 expression via the HMGB1-autophagy related pathway.

Screening and functional prediction of differentially expressed circRNAs in proliferative human aortic smooth muscle cells

Vascular smooth muscle cell (VSMC) proliferation is the pathological base of vascular remodelling diseases. Circular RNAs (circRNAs) are important regulators involved in various biological processes. However, the function of circRNAs in VSMC proliferation regulation remains largely unknown. This study was conducted to identify the key differentially expressed circRNAs (DEcircRNAs) and predict their functions in human aortic smooth muscle cell (HASMC) proliferation. To achieve this, DEcircRNAs between proliferative and quiescent HASMCs were detected using a microarray, followed by quantitative real-time RT-PCR validation. A DEcircRNA-miRNA-DEmRNA network was constructed, and functional annotation was performed using Gene Ontology (GO) and KEGG pathway analysis. The function of hsa_circ_0002579 in HASMC proliferation was analysed by Western blot. The functional annotation of the DEcircRNA-miRNA-DEmRNA network indicated that the four DEcircRNAs might play roles in the TGF-β receptor signalling pathway, Ras signalling pathway, AMPK signalling pathway and Wnt signalling pathway. Twenty-seven DEcircRNAs with coding potential were screened. Hsa_circ_0002579 might be a pro-proliferation factor of HASMC. Overall, our study identified the key DEcircRNAs between proliferative and quiescent HASMCs, which might provide new important clues for exploring the functions of circRNAs in vascular remodelling diseases.

Agonism of GPR120 prevents ox-LDL-induced attachment of monocytes to endothelial cells

Oxidized low-density lipoprotein (ox-LDL)-induced endothelial inflammation plays an important role in the development of cardiovascular diseases. G protein-coupled receptors (GPCR) are gaining traction as potential treatment targets due to their roles in mediating a wide range of physiological processes. GPR120 is a recently identified omega-3 fatty acid receptor. We hypothesized that agonism of GPR120 might attenuate ox-LDL-induced endothelial dysfunction. In the present study, we tested the effects of two GPR120 agonists-GW9508 and TUG-891-in mitigating endothelial insult induced by ox-LDL in human aortic endothelial cells (HAECs). Real-time PCR, western blot, and ELISA analyses were used in our experiments. Our findings demonstrate that GPR120 is downregulated by exposure to ox-LDL, suggesting a role for GPR120 in mediating ox-LDL insult. Furthermore, we found that agonism of GPR120 could suppress oxidative stress and inflammation by inhibiting the production of reactive oxygen species and the expression of proinflammatory cytokines. Importantly, we show that agonism of GPR120 prevents the attachment of monocytes to endothelial cells by suppressing the expression of VCAM-1 and E-selectin. Finally, we show that agonism of GPR120 exerts a remarkable atheroprotective effect by elevating the expression level of Krüppel-like factor 2 (KLF2). Together, our results demonstrate a potential role for specific agonism of GPR120 in the prevention of endothelial damages induced by ox-LDL.

Noncoding RNAs in inflammation and colorectal cancer

Despite advanced clinical treatments, mortality in patients with metastatic colorectal cancer (CRC) remains high. Three critical determinants in CRC progression include the epithelial proliferation checkpoints, epithelial-to-mesenchymal transition (EMT) and inflammatory cytokines in the tumour microenvironment. Genes involved in these three processes are regulated at the transcriptional and post-transcriptional level. Recent studies revealed previously unappreciated roles of non-coding ribonucleic acids (ncRNAs) in modulating the proliferation checkpoints, EMT, and inflammatory gene expression in CRC. In this review, we will discuss the mechanisms underlying the roles of ncRNAs in CRC as well as examine future perspectives in this field. Better understanding of ncRNA biology will provide novel targets for future therapeutic development.

MicroRNA-24 inhibits the oxidative stress induced by vascular injury by activating the Nrf2/Ho-1 signaling pathway

BACKGROUND AND AIMS

The process of endothelial repair in diabetic patients after stent implantation was significantly delayed compared with that in non-diabetic patients, and oxidative stress is increasingly considered to be relevant to the pathogenesis of diabetic endothelial repair. However, the mechanisms linking diabetes and reendothelialization after vascular injury have not been fully elucidated. The aim of this study was to evaluate the effect of microRNA-24 (miR-24) up-regulation in delayed endothelial repair caused by oxidative stress after balloon injury in diabetic rats.

METHODS

In vitro, vascular smooth muscle cells (VSMCs) isolated from the thoracic aorta were stimulated with high glucose (HG) after miR-24 recombinant adenovirus (Ad-miR-24-GFP) transfection for 3 days. In vivo, diabetic rats induced using high-fat diet (HFD) and low-dose streptozotocin (30 mg/kg) underwent carotid artery balloon injury followed by Ad-miR-24-GFP transfection for 20 min.

RESULTS

The expression of miR-24 was decreased in HG-stimulated VSMCs and balloon-injured carotid arteries of diabetic rats, which was accompanied by increased expression of Ogt and Keap1 and decreased expression of Nrf2 and Ho-1. Up-regulation of miR-24 suppressed VSMC oxidative stress induced by HG in vitro, and miR-24 up-regulation promoted reendothelialization in balloon-injured diabetic rats. The underlying mechanism was related to the activation of the Nrf2/Ho-1 signaling pathway, which subsequently suppressed intracellular reactive oxidative species (ROS) production and malondialdehyde (MDA) and NADPH oxidase (Nox) activity, and to the restoration of Sod and Gsh-px activation.

CONCLUSIONS

The up-regulation of miR-24 significantly promoted endothelial repair after balloon injury through inhibition of oxidative stress by activating the Nrf2/Ho-1 signaling pathway.

Bta-miR-24-3p Controls the Myogenic Differentiation and Proliferation of Fetal, Bovine, Skeletal Muscle-Derived Progenitor Cells by Targeting ACVR1B

Simple Summary

MicroRNAs play pivotal roles in skeletal muscle development, but the molecular basis of their functions in fetal bovine skeletal muscle development is largely unknown. Here, we report a mechanistic study of bta-miR-24-3p, a key miRNA regulator of the myogenic differentiation of fetal bovine platelet-derived growth factor receptor alpha negative (PDGFRα^-) progenitor cells. We isolated progenitor cells from the bovine fetal longissimus dorsi muscle and purified them with PDGFRα antibodies to remove fibro-adipogenic progenitors. We observed elevated bta-miR-24-3p expression during differentiation, and bta-miR-24-3p overexpression led to promoted myogenic differentiation but suppressed proliferation. Moreover, activin receptor type 1B (ACVR1B) was identified as a direct target of bta-miR-24-3p, and ACVR1B-silencing cells exhibited similar phenotypes to bta-miR-24-3p-overexpressing bovine PDGFRα^- progenitor cells. These results extended our understanding on the roles of miRNA in fetal muscle development. The method of removing fibro-adipogenic progenitors in our study will also provide useful information for other investigators.

Abstract

MicroRNAs modulate a variety of cellular events, including skeletal muscle development, but the molecular basis of their functions in fetal bovine skeletal muscle development is poorly understood. In this study, we report that bta-miR-24-3p promotes the myogenic differentiation of fetal bovine PDGFRα^- progenitor cells. The expression of bta-miR-24-3p increased during myogenic differentiation. Overexpression of bta-miR-24-3p significantly promoted myogenic differentiation, but inhibited proliferation. A dual-luciferase assay identified ACVR1B as a direct target of bta-miR-24-3p. Similarly, knocking down ACVR1B by RNA interference also significantly inhibited proliferation and promoted the differentiation of bovine PDGFRα^- progenitor cells. Thus, our study provides a mechanism in which bta-miR-24-3p regulates myogenesis by inhibiting ACVR1B expression.

miR‑132 inhibits high glucose‑induced vascular smooth muscle cell proliferation and migration by targeting E2F5

The dysregulated behavior of vascular smooth muscle cells (VSMCs) serves an important role in the pathogenesis of cardiovascular diseases in diabetes. The present study aimed to investigate the effects of microRNA (miR)‑132 on the proliferation and migration of VSMCs under high glucose conditions to mimic diabetes. We observed that the expression of miR‑132 was significantly decreased and that of E2F transcription factor 5 (E2F5) was upregulated in high glucose (HG)‑treated VSMCs or those obtained from diabetic rats. A dual luciferase reporter gene assay revealed that miR‑132 could specifically bind to the 3'‑untranslated region of E2F5 and significantly suppress the luciferase activity. The proliferation and migration of diabetic rat or HG‑treated VSMCs were increased compared with non‑diabetic rat VSMCs and those under normal glucose conditions. Upregulation of miR‑132 significantly inhibited the proliferation and migration of diabetic rat VSMCs; similar effects were observed following E2F5 downregulation. The inhibitory effects of miR‑132 on the proliferation and migration of HG‑treated VSMCs could be reversed by E2F5 overexpression. In conclusion, miR‑132 was proposed to inhibit the proliferation and migration of diabetic rat or high‑glucose‑treated VSMCs by targeting E2F5. The findings of the present study suggested that increasing the expression of miR‑132 may serve as a novel therapeutic approach to inhibit the progression of cardiovascular disease in diabetes.

MicroRNA-24 attenuates vascular remodeling in diabetic rats through PI3K/Akt signaling pathway

BACKGROUND AND AIMS

The vascular remodeling plays a crucial role in pathogenesis of diabetic cardiovascular complications. In this study, we intended to explore the effects and potential mechanisms of microRNA-24 (miR-24) on vascular remodeling under diabetic conditions.

METHODS AND RESULTS

MiR-24 recombinant adenovirus (Ad-miR-24-GFP) was used to induce miR-24 overexpression either in carotid arteries or high glucose (HG)-induced vascular smooth muscle cells (VSMCs). Cell proliferation was analyzed using CCK-8 method. Cell migration was examined using wound-healing and transwell assay. mRNA and protein expressions of critical factors were, respectively, measured by real-time PCR and western blot as follows: qRT-PCR for the levels of miR-24, PIK3R1; western blot for the protein levels of PI3K (p85α), Akt, p-Akt, mTOR, p-mTOR, 4E-BP1, p-4E-BP1, p70s6k, p-p70s6k, MMP 2, MMP 9, collagen Ⅰ, as well as collagen Ⅲ. Carotid arteries in diabetic rats suffered balloon injury were harvested and examined by HE, immunohistochemical and Masson trichrome staining. The expression of miR-24 was decreased in HG-stimulated VSMCs and balloon-injured carotid arteries of diabetic rats, accompanied by increased mRNA expression of PIK3R1. The up-regulation of miR-24 suppressed VSMCs proliferation, migration, collagen deposition not only induced by HG in vitro, but also in balloon-injured diabetic rats, which were related to inactivation of PI3K/Akt signaling pathway.

CONCLUSION

The up-regulation of miR-24 significantly attenuated vascular remodeling both in balloon-injured diabetic rats and HG-stimulated VSMCs via suppression of proliferation, migration and collagen deposition by acting on PIK3R1 gene that modulated the PI3K/Akt/mTOR axes.

High Glucose Enhances the Odonto/Osteogenic Differentiation of Stem Cells from Apical Papilla via NF-KappaB Signaling Pathway

Objective

The transport and metabolism of glucose are important during mammalian development. High glucose can mediate the biological characteristics of mesenchymal stem cells (MSCs). However, the role of high glucose in the odonto/osteogenic differentiation of stem cells from apical papilla (SCAPs) is unclear.

Materials and Methods

SCAPs were isolated and identified in vitro. Then, SCAPs were cultured in normal α-MEM and high glucose α-MEM separately. MTT assay was applied to observe the proliferation of SCAPs. ALP activity, alizarin red staining, real-time RT-PCR, and western blot were used to detect the odonto/osteogenic capacity of SCAPs as well as the participation of NF-κB pathway.

Results

SCAPs in 25mmol/L glucose group expressed the maximum proteins of RUNX2 and ALP as compared with those in 5, 10, and 15 mmol/L groups. MTT assay showed that 25 mmol/L glucose suppressed the proliferation of SCAPs. ALP assay, alizarin red staining, real-time RT-PCR, and western blot showed 25 mmol/L high glucose can obviously enhance the odonto/osteogenic capacity of SCAPs. Moreover, the NF-κB pathway was activated in 25mmol/L glucose-treated SCAPs and the odonto/osteogenic differentiation was inhibited following the inhibition of NF-κB signaling pathway.

Conclusions

High glucose can enhance the odonto/osteogenic capacity of SCAPs via NF-κB pathway.

Involvement of the MiR-181b-5p/HMGB1 Pathway in Ang II-induced Phenotypic Transformation of Smooth Muscle Cells in Hypertension

Phenotypic transformation of vascular smooth muscle cells (VSMCs) contributes to vascular remodeling in hypertension. High mobility group box-1 (HMGB1) has been reported to be involved in several pathogenic processes including VSMC proliferation and migration. The present study was designed to determine the role of HMGB1 in VSMC phenotypic transformation in hypertension. First, we demonstrated that HMGB1 was elevated in a model of Ang II-induced VSMC phenotypic transformation, which showed down-regulation of contractile proteins and up-regulation of synthetic proteins. Knockdown of HMGB1 and losartan could block the phenotypic transformation. Next, we identified three potential miRNAs for upstream regulation of HMGB1 by bioinformatic analysis; only miR-181b-5p was significantly down-regulated in Ang II-treated cells. Co-treating the cells with miR-181b-5p mimics suppressed HMGB1 expression as well as the phenotypic transformation, migration, and proliferation. Furthermore, the luciferase reporter gene assay confirmed the direct interaction between miR-181b-5p and HMGB1. Finally, to extend these cell-based studies to clinical patients, we demonstrated that plasma miR-181b-5p levels were decreased, while Ang II and HMGB1 levels, as well as the intima-media thickness (IMT) were increased in hypertensive patients; these effects were reversed following the administration of angiotensin receptor blockers. Based on these observations, we conclude that the down-regulation of miR-181b-5p leads to the elevation of HMGB1 levels in hypertensive patients, which accounts, at least partially, for VSMCs phenotypic transformation and vascular remodeling. Our findings also highlight that the plasma levels of miR-181b-5p and HMGB1 may serve as novel biomarkers for vascular remodeling in the hypertensive patients.

MicroRNA-328 ameliorates oxidized low-density lipoprotein-induced endothelial cells injury through targeting HMGB1 in atherosclerosis

Atherosclerosis has been recognized as a chronic inflammatory disease, which can harden the vessel wall and narrow the arteries. MicroRNAs exhibit crucial roles in various diseases including atherosclerosis. However, so far, the role of miR-328 in atherosclerosis remains barely explored. Therefore, our study concentrated on the potential role of miR-328 in vascular endothelial cell injury during atherosclerosis. In our current study, we observed that oxidized low-density lipoprotein (ox-LDL)-induced human umbilical vein endothelial cells (HUVECs) apoptosis and inhibited cell viability dose-dependently and time-dependently. In addition, indicated dosage of ox-LDL obviously triggered HUVECs inflammation and oxidative stress process. Then, it was found that miR-328 in HUVECs was reduced by ox-LDL. HUVECs apoptosis was greatly repressed and cell survival was significantly upregulated by overexpression of miR-328. Furthermore, mimics of miR-328 rescued cell inflammation and oxidative stress process induced by ox-LDL. Oppositely, inhibitors of miR-328 strongly promoted ox-LDL-induced endothelial cells injury in HUVECs. By using bioinformatics analysis, high-mobility group box-1 (HMGB1) was predicted as a downstream target of miR-328. HMGB1 has been reported to be involved in atherosclerosis development. The correlation between miR-328 and HMGB1 was validated in our current study. Taken these together, it was implied that miR-328 ameliorated ox-LDL-induced endothelial cells injury through targeting HMGB1 in atherosclerosis.

The microRNAs Regulating Vascular Smooth Muscle Cell Proliferation: A Minireview

Vascular smooth muscle cell (VSMC) proliferation plays a critical role in atherosclerosis. At the beginning of the pathologic process of atherosclerosis, irregular VSMC proliferation promotes plaque formation, but in advanced plaques VSMCs are beneficial, promoting the stability and preventing rupture of the fibrous cap. Recent studies have demonstrated that microRNAs (miRNAs) expressed in the vascular system are involved in the control of VSMC proliferation. This review summarizes recent findings on the miRNAs in the regulation of VSMC proliferation, including miRNAs that exhibit the inhibition or promotion of VSMC proliferation, and their targets mediating the regulation of VSMC proliferation. Up to now, most of the studies were performed only in cultured VSMC. While the modulation of miRNAs is emerging as a promising strategy for the regulation of VSMC proliferation, most of the effects of miRNAs and their targets in vivo require further investigation.

GALLIC ACID IMPROVES OXIDATIVE STRESS AND INFLAMMATION THROUGH REGULATING MICRORNAS EXPRESSIONS IN THE BLOOD OF DIABETIC RATS

Context

Endothelial dysfunction and diabetic cardiomyopathy are critical complications of diabetes. Gallic acid (GA) plays a significant role in cardiovascular disorders resulted from diabetes. In addition, increased plasma miR-24, miR-126 associated with endothelial dysfunction.

Aim

The current study was designed to assess the effects of GA on plasma miR-24, miR-126 levels in the diabetic rats.

Animals and Methods

Adult male Sprague-Dawley rats were divided into three groups (n=8): control (C), diabetic (D) and diabetic group treated with GA (D+G, 25 mg/kg, by gavage) for eight weeks. The blood glucose level, body weight, lipid profile, blood pressure, plasma miR-24 and miR-126 levels, antioxidant and inflammatory biomarkers were measured.

Results

The plasma levels of miR-24, miR-126, body weight, high-density lipoprotein cholesterol (HDL-c), total anti-oxidant capacity (TAC) and the systolic blood pressure significantly reduced and blood glucose, total cholesterol (TC), triglycerides (TG), very low-density lipoprotein cholesterol (VLDL-c), malondialdehyde (MDA), interleukin-6 (IL-6), tumor necrosis factor-alpha (TNF-α) and low-density lipoprotein cholesterol (LDL-c) significantly elevated among the diabetic rats compared with the control group. However, GA restored body weight, blood pressure, TC, TG, VLDL-c, TNF-α, miR-126, blood glucose, HDL-c, MDA, TAC, miR-24 and IL-6 among the GA treated rats compared with the diabetic group.

Conclusion

GA improves inflammation, oxidative stress and hypotension result from diabetes. These protective effects are probably mediated via increasing plasma miR-24 and miR-126 levels.

Anti-Inflammatory MicroRNAs and Their Potential for Inflammatory Diseases Treatment

Inflammation is a complicated biological and pathophysiological cascade of responses to infections and injuries, and inflammatory mechanisms are closely related to many diseases. The magnitude, the complicated network of pro- and anti-inflammatory factors, and the direction of the inflammatory response can impact on the development and progression of various disorders. The currently available treatment strategies often target the symptoms and not the causes of inflammatory disease and may often be ineffective. Since the onset and termination of inflammation are crucial to prevent tissue damage, a range of mechanisms has evolved in nature to regulate the process including negative and positive feedback loops. In this regard, microRNAs (miRNAs) have emerged as key gene regulators to control inflammation, and it is speculated that they are fine-tune signaling regulators to allow for proper resolution and prevent uncontrolled progress of inflammatory reactions. In this review, we discuss recent findings related to significant roles of miRNAs in immune regulation, especially the potential utility of these molecules as novel anti-inflammatory agents to treat inflammatory diseases. Furthermore, we discuss the possibilities of using miRNAs as drugs in the form of miRNA mimics or miRNA antagonists.

RP105 protects PC12 cells from oxygen‑glucose deprivation/reoxygenation injury via activation of the PI3K/AKT signaling pathway

Radioprotective 105 kDa protein (RP105) has been reported to produce favorable outcomes in various cardiovascular disorders via a toll‑like receptor 4‑dependent or ‑independent manner. However, whether RP105 exerts neuroprotective effects against oxygen‑glucose deprivation (OGD)/reoxygenation (OGD/R) injury remains to be elucidated. In the present study, the PC12 neuronal cell line was exposed to 4 h of OGD followed by 24 h of reoxygenation. Adenoviral vectors encoding RP105 were utilized to upregulate the level of RP105 in PC12 cells prior to OGD/R induction. The results demonstrated that OGD/R reduced the expression of RP105 at the mRNA and protein levels. The overexpression of RP105 significantly reversed OGD/R‑induced neuronal injuries, as demonstrated by the reduced release of lactate dehydrogenate and enhanced cellular viability, in addition to decreased inflammation, apoptosis and reactive oxygen species. The mechanistic evaluations indicated that the neuroprotective functions of RP105 were, in part, a result of activation of the phosphatidylinositol 3‑kinase (PI3K)/protein kinase B (AKT) pathway. In addition, elimination of the PI3K/AKT axis via the use of a pharmacological inhibitor inhibited the OGD/R‑inhibitory effects induced by the overexpression of RP105. Taken together, RP105 protected PC12 cells from OGD/R injury through promotion of the PI3K/AKT pathway; therefore, the RP105‑PI3K‑AKT axis may provide a novel therapeutic target for the prevention of cerebral ischemia/reperfusion injury.

Epigenetics in Ascending Thoracic Aortic Aneurysm and Dissection

Thoracic aortic aneurysm (TAA) is an asymptomatic and progressive dilatation of the thoracic aorta. Ascending aortic dissection (AAD) is an acute intraparietal tear, occurring or not on a pre-existing dilatation. AAD is a condition associated with a poor prognosis and a high mortality rate. TAA and AAD share common etiology as monogenic diseases linked to transforming growth factor β signaling pathway, extracellular matrix defect, or smooth muscle cell protein mutations. They feature a complex pathogenesis including loss of smooth muscle cells, altered phenotype, and extracellular matrix degradation in aortic media layer. A better knowledge of the mechanisms responsible for TAA progression and AAD occurrence is needed to improve healthcare, nowadays mainly consisting of aortic open surgery or endovascular replacement. Recent breakthrough discoveries allowed a deeper characterization of the mechanisms of gene regulation. Since alteration in gene expression has been linked to TAA and AAD, it is conceivable that a better knowledge of the causes of this alteration may lead to novel theranostic approaches. In this review article, the authors will focus on epigenetic regulation of gene expression, including the role of histone methylation and acetylation, deoxyribonucleic acid methylation, and noncoding ribonucleic acids in the pathogenesis of TAA and AAD. They will provide a translational perspective, presenting recent data that motivate the evaluation of the potential of epigenetics to diagnose TAA and prevent AAD.

MCPIP1-induced autophagy mediates ischemia/reperfusion injury in endothelial cells via HMGB1 and CaSR

Monocyte chemotactic protein-1-induced protein 1 (MCPIP1) plays a important role in ischemia/reperfusion (I/R) injury. Autophagy is involved in activating endothelial cells in response to I/R. However, researchers have not clearly determined whether MCPIP1 mediates I/R injury in endothelial cells via autophagy, and its downstream mechanism remains unclear. Western blotting analyses and immunocytochemistry were applied to detect protein levels were detected in HUVECs. An in vitro scratch assay was used to detect cell migration. Cells were transfected with siRNAs to knockdown MCPIP1 and high mobility group box 1 (HMGB1) expression. The pharmacological activator of autophagy rapamycin and the specific calcium-sensing receptor (CaSR) inhibitor NPS-2143 were used to confirm the roles of autophagy and CaSR in I/R injury. I/R induced HMGB1 and CaSR expression, which subsequently upreguated the migration and apoptosis of HUVECs and coincided with the increase of autophagy. HMGB1 was involved in cell migration, whereas CaSR specifically participated in I/R-induced HUVEC apoptosis. Based on these findings, I/R-induced MCPIP1 expression regulates the migration and apoptosis of HUVECs via HMGB1 and CaSR, respectively, suggesting a new therapeutic targetof I/R injury.

miR-24-p53 pathway evoked by oxidative stress promotes lens epithelial cell apoptosis in age-related cataracts

MicroRNA-24 (miR-24) serves an important role in cell proliferation, migration and inflammation in various types of disease. In the present study, the biological function and molecular mechanism of miR-24 was investigated in association with the progression of age-associated cataracts. To the best of our knowledge the present study is the first to report that the expression of miR-24 was significantly increased in human anterior lens capsules affected by age-associated cataracts as well as lens epithelial cells (LECs) exposed to oxidative stress. Overexpression of miR-24 induced p53 expression and p53 was verified as a direct target of miR-24. Overexpression of miR-24 enhanced LEC death by directly targeting p53. The present study revealed that oxidative stress induced the upregulation of miR-24 and enhanced LEC death by directly targeting p53. These results suggest that the miR-24-p53 signaling pathway is involved in a novel mechanism of age-associated cataractogenesis and miR-24 may be a useful therapeutic target for age-associated cataracts.

Type 2 Diabetes Mellitus and Cardiovascular Disease: Genetic and Epigenetic Links

Type 2 diabetes mellitus (DM) is a common metabolic disorder predisposing to diabetic cardiomyopathy and atherosclerotic cardiovascular disease (CVD), which could lead to heart failure through a variety of mechanisms, including myocardial infarction and chronic pressure overload. Pathogenetic mechanisms, mainly linked to hyperglycemia and chronic sustained hyperinsulinemia, include changes in metabolic profiles, intracellular signaling pathways, energy production, redox status, increased susceptibility to ischemia, and extracellular matrix remodeling. The close relationship between type 2 DM and CVD has led to the common soil hypothesis, postulating that both conditions share common genetic and environmental factors influencing this association. However, although the common risk factors of both CVD and type 2 DM, such as obesity, insulin resistance, dyslipidemia, inflammation, and thrombophilia, can be identified in the majority of affected patients, less is known about how these factors influence both conditions, so that efforts are still needed for a more comprehensive understanding of this relationship. The genetic, epigenetic, and environmental backgrounds of both type 2 DM and CVD have been more recently studied and updated. However, the underlying pathogenetic mechanisms have seldom been investigated within the broader shared background, but rather studied in the specific context of type 2 DM or CVD, separately. As the precise pathophysiological links between type 2 DM and CVD are not entirely understood and many aspects still require elucidation, an integrated description of the genetic, epigenetic, and environmental influences involved in the concomitant development of both diseases is of paramount importance to shed new light on the interlinks between type 2 DM and CVD. This review addresses the current knowledge of overlapping genetic and epigenetic aspects in type 2 DM and CVD, including microRNAs and long non-coding RNAs, whose abnormal regulation has been implicated in both disease conditions, either etiologically or as cause for their progression. Understanding the links between these disorders may help to drive future research toward an integrated pathophysiological approach and to provide future directions in the field.

Chicoric acid prevents PDGF-BB-induced VSMC dedifferentiation, proliferation and migration by suppressing ROS/NFκB/mTOR/P70S6K signaling cascade

Phenotypic switch of vascular smooth muscle cells (VSMCs) is characterized by increased expressions of VSMC synthetic markers and decreased levels of VSMC contractile markers, which is an important step for VSMC proliferation and migration during the development and progression of cardiovascular diseases including atherosclerosis. Chicoric acid (CA) is identified to exert powerful cardiovascular protective effects. However, little is known about the effects of CA on VSMC biology. Herein, in cultured VSMCs, we showed that pretreatment with CA dose-dependently suppressed platelet-derived growth factor type BB (PDGF-BB)-induced VSMC phenotypic alteration, proliferation and migration. Mechanistically, PDGF-BB-treated VSMCs exhibited higher mammalian target of rapamycin (mTOR) and P70S6K phosphorylation, which was attenuated by CA pretreatment, diphenyleneiodonium chloride (DPI), reactive oxygen species (ROS) scavenger N-acetyl-l-cysteine (NAC) and nuclear factor-κB (NFκB) inhibitor Bay117082. PDGF-BB-triggered ROS production and p65-NFκB activation were inhibited by CA. In addition, both NAC and DPI abolished PDGF-BB-evoked p65-NFκB nuclear translocation, phosphorylation and degradation of Inhibitor κBα (IκBα). Of note, blockade of ROS/NFκB/mTOR/P70S6K signaling cascade prevented PDGF-BB-evoked VSMC phenotypic transformation, proliferation and migration. CA treatment prevented intimal hyperplasia and vascular remodeling in rat models of carotid artery ligation in vivo. These results suggest that CA impedes PDGF-BB-induced VSMC phenotypic switching, proliferation, migration and neointima formation via inhibition of ROS/NFκB/mTOR/P70S6K signaling cascade.

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Chicoric acid attenuated PDGF-BB-evoked VSMC phenotypic transformation, proliferation and migration.

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Chicoric acid antagonized the activated ROS/NFκB/mTOR/P70S6K signaling pathway in VSMCs.

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Chicoric acid treatment prevented intimal hyperplasia in rat models of carotid artery ligation.