Knockdown of lncRNA MALAT1 attenuates acute myocardial infarction through miR-320-Pten axis

Metastasis-associated lung adenocarcinoma transcript 1 overexpression in testis contributes to idiopathic non-obstructive azoospermia via repressing ETS variant transcription factor 5

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), is a long non-coding RNA localized in the cell nucleus, known for its multifunctional roles, including potential involvement in spermatogenesis. This study investigates the mechanism by which MALAT1 dysregulation contributes to the pathogenesis of idiopathic non-obstructive azoospermia (iNOA). We analyzed MALAT1 levels in two gene expression profiling datasets comprising patients with obstructive azoospermia (OA) who have normal spermatogenesis and 13 patients with iNOA. The dysregulation of MALAT1 along with the expression levels of its negatively correlated genes were confirmed in a larger cohort of 24 OA patients and 38 iNOA patients. We examined the effects of MALAT1 overexpression in primary human spermatogonial stem cells (SSCs) and Sertoli cells. Additionally, we assessed DNA methylation, as well as levels of H3K27me3 and H3K27Ac level near the etv5 promoter region using ChIP-qPCR. We observed that MALAT1 was overexpressed in testes of iNOA patients with its levels negatively correlating with six spermatogenesis related genes and positively correlated with three others. Overexpression of MALAT1 in SSCs repressed proliferation and induced apoptosis while also suppressing ETS variant transcription factor 5 (ETV5) expression by promoting H3K27 tri-methylation of the ETV5 promoter. Overexpression of MALAT1 in Sertoli cells did not induce apoptosis but impaired their cell supporting function. In conclusion, MALAT1 overexpression in SSCs contributes to the pathogenesis of iNOA via downregulating ETV5 expression and promoting cell apoptosis.

Pivotal Role of miRNA-lncRNA Interactions in Human Diseases

New technologies have shown that most of the genome comprises transcripts that cannot code for proteins and are referred to as non-coding RNAs (ncRNAs). Some ncRNAs, like long non-coding RNAs (lncRNAs) and microRNAs (miRNAs), are of substantial interest because of their critical function in controlling genes and numerous biological activities. The expression levels and function of miRNAs and lncRNAs are rigorously monitored throughout developmental processes and the maintenance of physiological homeostasis. Due to their critical roles, any dysregulation or changes in their expression can significantly influence the pathogenesis of various human diseases. The interactions between miRNAs and lncRNAs have been found to influence gene expression in various ways. These interactions significantly influence the understanding of disease etiology, cellular processes, and potential therapeutic targets. Different experimental and in silico methods can be used to investigate miRNA-lncRNA interactions. By aiding the elucidation of miRNA-lncRNA interactions and deepening the understanding of post-transcriptional gene regulation, researchers can open a new window for designing hypotheses, conducting experiments, and discovering methods for diagnosing and treating complex human diseases. This review briefly summarizes miRNA and lncRNA functions, discusses their interaction mechanisms, and examines the experimental and computational methods used to study these interactions. Additionally, we highlight significant studies on lncRNA and miRNA interactions in various diseases from 2000 to 2024, using the academic research databases such as PubMed, Google Scholar, ScienceDirect, and Scopus.

Fat mass and obesity-associated protein alleviates cerebral ischemia/reperfusion injury by inhibiting ferroptosis via miR-320-3p/SLC7A11 axis

Fat mass and obesity-associated protein (FTO) is a demethylase and has recently been found to have a protective effect in acute ischemic stroke (AIS), but the underlying mechanism is unclear to a large extent. New studies have found that the expression of certain miRNAs may be affected by N6-methyladenosine (m6A) levels. Here, using high-throughput sequencing and quantitative polymerase chain reaction, we found miR-320-3p was significantly up-regulated in AIS patients. miR-320-3p aggravated the neurobehavioral manifestation, infarct volume and histopathology of middle cerebral artery occlusion/reperfusion model mice. Mechanically, miR-320-3p binds to the 3' untranslated region of solute carrier family 7 member 11 (SLC7A11) mRNA, promoting oxidative stress and ferroptosis induced by oxygen-glucose deprivation/reoxygenation in neurons. FTO inhibited the m6A methylation of the primary transcript pri-miR-320 and the maturation of miR-320-3p, thus having a protective effect on cerebral ischemia/reperfusion injury after AIS. Clinically, we also confirmed the down-regulation of FTO and SLC7A11 mRNA in the peripheral blood of AIS patients and their correlation with the expression of miR-320-3p. Our study found that FTO inhibits ferroptosis through miR-320-3p/SLC7A11 axis in an m6A-dependent manner, and thus has a protective effect on cerebral ischemic reperfusion injury. Our results provided a promising therapeutic target of cerebral ischemia/reperfusion injury after AIS.

LncRNA NEAT1 Inhibits Neuronal Apoptosis and Induces Neuronal Viability of Depressed Rats Via microRNA-320-3p/CRHR1 Axis

Long noncoding RNA nuclear enriched abundant transcript 1 (NEAT1) has been reported to be involved in depression. This study aims to investigate the mechanism of NEAT1/microRNA (miR)-320-3p/Corticotropin-releasing hormone receptor 1 (CRHR1) axis in depressed rats. Rats with depression-like behaviors were prepared by exposing the rats to chronic unpredictable mild stress. Behavioral functions, pathological damage, neuronal apoptosis and monoamine neurotransmitter were examined in depressed rats . Primary hippocampal neurons were injured through simulation with corticosterone(CORT). Cell viability and apoptosis were measured in CORT-Induced hippocampal neurons. The binding relationship between NEAT1 and miR-320-3p and the targeting relationship between miR-320-3p and CRHR1 were detected. Elevated NEAT1, CRHR1 and reduced miR-320-3p exhibited in depressed rats and CORT-treated hippocampal neurons, NEAT1 bound to miR-320-3p to target CRHR1. Silencing NEAT1 or elevating miR-320-3p improved behavioral functions, attenuated pathological damage and apoptosis in the hippocampus, and increased monoamine neurotransmitter in depressed rats. Repression of NEAT1 or promotion of miR-320-3p enhanced viability and suppressed apoptosis of CORT-treated hippocampal neurons. The study highlights that NEAT1 competitively binds to miR-320-3p to up-regulate CRHR1 expression, thereby promoting hippocampal damage of depressed rats.

Unveiling the role of long non-coding RNA MALAT1: a comprehensive review on myocardial infarction

Myocardial infarction (MI) stands at top global causes of death in developed countries, owing mostly to atherosclerotic plaque growth and endothelial injury-induced reduction in coronary blood flow. While early reperfusion techniques have improved outcomes, long-term treatment continues to be difficult. The function of lncRNAs extends to regulating gene expression in various conditions, both physiological and pathological, such as cardiovascular diseases. The objective of this research is to extensively evaluate the significance of the lncRNA called Metastasis associated lung adenocarcinoma transcript 1 (MALAT1) in the development and management of MI. According to research, MALAT1 is implicated in processes such as autophagy, apoptosis, cell proliferation, and inflammation in the cardiovascular system. This investigation examines recent research examining the effects of MALAT1 on heart function and its potential as a mean of diagnosis and treatment for post- MI complications and ischemic reperfusion injury.

The SNHG10-miR-495-3p-PTEN axis is involved in sevoflurane-mediated protective effects in cardiomyocytes against hypoxia/reoxygenation injury

Myocardial infarction (MI) has been considered a leading cause of death worldwide. Relieving ischemia-reperfusion myocardial damage is one of the major roles in treating MI. Sevoflurane postconditioning provides myocardial protection, and this study probes the mechanism of sevoflurane-mediated protective effects. A hypoxia/reoxygenation (H/R) model was constructed in cardiomyocytes, which were pretreated with 2.4% sevoflurane. Alterations in SNHG10, miR-495-3p, and PTEN levels were determined, and gain- or loss-of functional assays were conducted to confirm the role of the SNHG10/miR-495-3p axis, which is potentially regulated by sevoflurane. Cell viability, oxidative stress, and inflammatory reactions were all evaluated. The results indicated that sevoflurane post-conditioning attenuated H/R-induced cardiomyocyte damage and reduced the SHNH10 level. SNHG10 overexpression reversed sevoflurane-mediated protective effects on cardiomyocytes. Moreover, SNHG10 targeted miR-495-3p and restrained its expression, while miR-495-3p targeted PTEN, suppressed PTEN levels, and promoted HIF-1α expression. miR-495-3p overexpression decreased SNHG10-mediated myocardial injury and enhanced HIF-1α levels. However, no additional protection was found when sevoflurane was administered to H/R-exposed cardiomyocytes following treatment with the HIF-1α inhibitor LW6. Overall, sevoflurane protects cardiomyocytes from H/R by modulating the SNHG10-miR-495-3p-PTEN-HIF-1α axis.

Malat1 promotes macrophage-associated inflammation by increasing PPAR-γ methylation through binding to EZH2 in acute myocardial infarction

The inflammatory microenvironment of macrophage plays an important role in acute myocardial infarction (AMI), but the regulatory mechanism is unknown. Here, we aimed to investigate the role of Malat1 on inflammation microenvironment of macrophage in AMI. Our study found that Malat1 expression was increased in AMI, which mainly expressed in macrophages. Malat1 inhibition improved collagen deposition and inflammation in infarcted heart. In vitro, Malat1 inhibition evidently reduced macrophage-associated inflammation. The results from ribonucleic acid pull-down (RNA pull-down) and RNA Immunoprecipitation (RIP) assay demonstrated that Malat1 directly binds to EZH2. Malat1 and EZH2 complex could increase histone H3K27me3 expression and further inhibit the production of PPAR-γ. In vivo, inhibition of Malat1 also leaded to the down-regulation of both EZH2 and H3K27me3, as well as up-regulation of PPAR-γ in infarcted heart. Therefore, these findings demonstrate a novel mechanism of Malat1 on inflammation microenvironment of macrophage in AMI, which provide a new target for its treatment.

miR-27a-5p alleviates periodontal inflammation by targeting phosphatase and tensin homolog deleted on chromosome ten

INTRODUCTION

MicroRNAs (miRNAs), a type of non-coding RNA, have been demonstrated to be essential posttranscriptional modulators in oral diseases and inflammatory responses. However, the specific role of miR-27a-5p in periodontitis requires further investigation. In this study, we used both cellular and animal models to determine how miR-27a-5p affects the pathogenesis of periodontitis and its associated biological functions.

METHODS

Quantitative real-time polymerase chain reaction and western blotting were used to analyze the expression of cytokines, phosphatase and tensin homolog deleted on chromosome ten (PTEN), and miR-27a-5p transcription. Investigation of alveolar bone resorption and inflammation of the periodontium in ligature-induced periodontitis in mice was performed using micro-computed tomography (micro-CT), hematoxylin-eosin (HE) staining, and tartrate-resistant acid phosphatase (TRAP) staining. The binding of miR-27a-5p and PTEN was predicted using the TargetScan database and experimentally confirmed using dual luciferase reporter gene assays.

RESULTS

The inflamed gingiva showed lower levels of miR-27a-5p. Macrophages from miR-27a-5p^-/- mice produced much higher quantities of pro-inflammatory cytokines owing to the stimulation of Porphyromonas gingivalis lipopolysaccharide, and miR-27a-5p^-/- mice with ligature-induced periodontitis also exhibited more severe alveolar bone resorption and damage to the periodontium. Target validation assays identified PTEN as a direct target of bona. Blocking PTEN expression partially reduced inflammation, both in vitro and in vivo.

CONCLUSIONS

miR-27a-5p alleviated the inflammatory response in periodontitis by targeting PTEN.

LncRNA AC005332.7 Inhibited Ferroptosis to Alleviate Acute Myocardial Infarction Through Regulating miR-331-3p/CCND2 Axis

BACKGROUND AND OBJECTIVES

Acute myocardial infarction (AMI) often occurs suddenly and leads to fatal consequences. Ferroptosis is closely related to the progression of AMI. However, the specific mechanism of ferroptosis in AMI remains unclear.

METHODS

We constructed a cell model of AMI using AC16 cells under oxygen and glucose deprivation (OGD) conditions and a mice model of AMI using the left anterior descending (LAD) ligation. The 3-(4, 5-dimethylthiazol-2-yl)-2, 5 diphenyltetrazolium bromide was employed to determine cell viability. The levels of lactate dehydrogenase, creatine kinase, reactive oxygen species (ROS), glutathione (GSH), malondialdehyde (MDA), and iron were measured using corresponding kits. Dual luciferase reporter gene assay, RNA-binding protein immunoprecipitation, and RNA pull-down were performed to validate the correlations among AC005332.7, miR-331-3p, and cyclin D2 (CCND2). Hematoxylin and eosin staining was employed to evaluate myocardial damage.

RESULTS

AC005332.7 and CCND2 were lowly expressed, while miR-331-3p was highly expressed in vivo and in vitro models of AMI. AC005332.7 sufficiency reduced ROS, MDA, iron, and ACSL4 while boosting the GSH and GPX4, indicating that AC005332.7 sufficiency impeded ferroptosis to improve cardiomyocyte injury in AMI. Mechanistically, AC005332.7 interacted with miR-331-3p, and miR-331-3p targeted CCND2. Additionally, miR-331-3p overexpression or CCND2 depletion abolished the suppressive impact of AC005332.7 on ferroptosis in OGD-induced AC16 cells. Moreover, AC005332.7 overexpression suppressed ferroptosis in mice models of AMI.

CONCLUSIONS

AC005332.7 suppressed ferroptosis in OGD-induced AC16 cells and LAD ligation-operated mice through modulating miR-331-3p/CCND2 axis, thereby mitigating the cardiomyocyte injury in AMI, which proposed novel targets for AMI treatment.

Anti-angiogenic effect of exo-LncRNA TUG1 in myocardial infarction and modulation by remote ischemic conditioning

The successful use of exosomes in therapy after myocardial infarction depends on an improved understanding of their role in cardiac signaling and regulation. Here, we report that exosomes circulating after myocardial infarction (MI) carry LncRNA TUG1 which downregulates angiogenesis by disablement of the HIF-1α/VEGF-α axis and that this effect can be counterbalanced by remote ischemic conditioning (RIC). Rats with MI induced through left coronary artery ligation without (MI model) and with reperfusion (ischemia/reperfusion I/R model) were randomized to RIC, or MI (I/R) or sham-operated (SO) control. Data from one cohort study and one randomized-controlled trial of humans with MI were also utilized, the former involving patients who had not received percutaneous coronary intervention (PCI) and the latter patients with PCI. Exosome concentrations did not differ between intervention groups (RIC vs. control) in rats (MI and I/R model) as well as humans (with and without PCI). However, MI and I/R exosomes attenuated HIF-1α, VEGF-α, and endothelial function. LncRNA TUG1 was increased in MI and I/R exosomes, but decreased in SO and RIC exosomes. HIF-1α expression was downregulated with MI and I/R exosomes but increased with RIC exosomes. Exosome inhibition suppressed HIF-1α upregulation through RIC exosomes. VEGF-α was identified as HIF-1α-regulated target gene. Knockdown of HIF-1α decreased VEGF-α, endothelial cell capability, and tube formation. Overexpression of HIF-1α exerted opposite effects. Transfection and co-transfection of 293 T cells with exosome-inhibitor GW4869 and HIF-1α inhibitor si-HIF-1α confirmed the exosomal-LncRNA TUG1/HIF-1α/VEGF-α pathway. LncRNA TUG1 is a potential therapeutic target after MI with or without reperfusion through PCI.

lncRNA NEAT1 Downregulation Ameliorates the Myocardial Infarction of Mice by Regulating the miR-582-5p/F2RL2 Axis

BACKGROUND

This study is aimed at effectively investigating the role of coagulation factor II thrombin receptor like 2 (F2RL2) in myocardial infarction (MI) as well as the upstream regulatory miRNA and lncRNA.

METHODS

Regulatory genes of F2RL2 were analyzed using StarBase and verified by dual-luciferase reporter assay. The MI mouse model was established. The left ventricular ejection fraction (EF) and fractional shortening (FS) were examined by echocardiography. The infarct area, pathological changes, and cell apoptosis in mouse myocardial tissue were evaluated using triphenyltetrazolium chloride and Evans blue, hematoxylin-eosin, and TUNEL staining assays. Oxygen-glucose deprivation- (OGD-) induced human cardiac myocytes (HCMs) were cultured and transfected. The cell viability, proliferation, and apoptosis were determined by CCK-8, EdU staining, and flow cytometry assays. The expressions of F2RL2, miR-582-5p, and nuclear paraspeckle assembly transcript 1 (NEAT1) in myocardial tissues and HCMs were quantified by qRT-PCR or Western blot.

RESULTS

NEAT1 sponged miR-582-5p which targeted F2RL2. NEAT1 and F2RL2 were highly expressed while miR-582-5p was lowly expressed in MI mice. F2RL2 downregulation prevented the reduction in EF and SF and the elevation in infarct area and cell apoptosis of MI mice. Both F2RL2 and NEAT1 downregulations reversely modulated the decreased viability and proliferation and the increased apoptosis of OGD-induced HCMs, while miR-582-5p inhibitor did oppositely. NEAT1 silencing upregulated miR-582-5p level but downregulated F2RL2 level. miR-582-5p inhibitor upregulated the F2RL2 level. The role of NEAT1 silencing in OGD-induced HCMs was reversed by miR-582-5p inhibitor whose effect was further offset by F2RL2 downregulation.

CONCLUSION

NEAT1 downregulation ameliorates MI by regulating the miR-582-5p/F2RL2 axis, providing novel biomarkers for MI treatment.

A novel circulating biomarker lnc-MALAT1 for acute myocardial infarction: Its relationship with disease risk, features, cytokines, and major adverse cardiovascular events

OBJECTIVE

Long noncoding RNA MALAT1 (lnc-MALAT1) modulates atherosclerotic progression, myocardial ischemia injury, and systematic inflammation, which may be closely involved in acute myocardial infarction (AMI) pathogenesis. Thus, the current study intended to explore the relationship of lnc-MALAT1 to disease risk, features, cytokines, and prognostication in AMI patients.

METHODS

This multicenter study consecutively enrolled 160 newly diagnosed AMI patients and 50 controls (angina pectoris patients). Their peripheral blood mononuclear cells were obtained to measure lnc-MALAT1 by RT-qPCR. Serum cytokines in AMI patients were detected by ELISA. In addition, AMI patients were followed up for major adverse cardiovascular event (MACE) risk evaluation.

RESULTS

Lnc-MALAT1 was higher in AMI patients than in controls (median: 2.245 vs. 0.996, p = 0.004), and it also presented a good capacity for differentiating AMI patients from controls with an area under the curve of 0.823. Lnc-MALAT1 was positively related to C-reactive protein (p = 0.005), low-density lipoprotein cholesterol (p = 0.022), cardiac troponin I (p = 0.021), and infarct size (p = 0.007), but not other biochemical indexes in AMI patients. Meanwhile, lnc-MALAT1 was positively associated with tumor necrosis factor-alpha (p = 0.001), interleukin (IL)-6 (p = 0.031), IL-17A (p = 0.042), vascular cell adhesion molecule-1 (p = 0.004), and intercellular adhesion molecule-1 (p = 0.021) among AMI patients. Importantly, after categorization, lnc-MALAT1 high (vs. low) was related to an elevated MACE accumulation rate (p = 0.035); furthermore, a higher lnc-MALAT1 quartile showed a trend to be linked with an increased MACE accumulation rate (p = 0.092).

CONCLUSION

Lnc-MALAT1 may serve as a biomarker for AMI risk, infarct size, inflammation and prognosis, but further validation by large-scale studies is needed.

Long noncoding RNA CASC2 protect ROS-induced oxidative stress in myocardial infarction by miR-18a/SIRT2

We aimed to investigate the function and its possible mechanisms of long noncoding RNA (lncRNA) in acute myocardial infarction (AMI) model. Patients with AMI and normal volunteers were selected from our hospital. Sprague-Dawley rats were induced into in vivo model of AMI. H9c2 cells were treated with H₂ O₂ to generate injury model. A significantly lower serum gene expression of lncRNA CASC2 was detected. In rat models of AMI, lncRNA CASC2 gene expressions in heart tissue of mice with AMI were decreased. In in vitro model, downregulation of lncRNA CASC2 increased reactive oxygen species (ROS)-induced oxidative stress; lncRNA CASC2 induced NADPH oxidase (NOX-2) expression and suppressed miR-18a expression; MiR-18a promoted ROS-induced oxidative stress; downregulation of miR-18a decreased ROS-induced oxidative stress. The inhibition of miR-18a reversed the effects of CASC2 downregulation on ROS-induced oxidative stress in in vitro model of AMI. The activation of miR-18a reversed the effects of CASC2 on ROS-induced oxidative stress in in vitro model of AMI. These data for the first time suggest that lncRNA CASC2 have better protective effects on AMI, which could reduce oxidative stress through their carried miR-18a and subsequently downregulating the SIRT2/ROS pathway.

LncRNA KCNQ1OT1 contributes to hydrogen peroxide-induced apoptosis, inflammation, and oxidative stress of cardiomyocytes via miR-130a-3p/ZNF791 axis

It has been reported that long noncoding RNA (lncRNA) KCNQ1 opposite strand/antisense transcript 1 (KCNQ1OT1) played an important role in myocardial infarction (MI). However, the regulatory network behind KCNQ1OT1 in MI is largely unknown. Quantitative real time polymerase chain reaction (qRT-PCR) was applied to detect the enrichment of KCNQ1OT1, microRNA-130a-3p (miR-130a-3p) and zinc finger 791 (ZNF791). The viability and apoptosis of AC16 cells were measured by (4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and flow cytometry. Enzyme-linked immunosorbent assay (ELISA) was conducted to assess the inflammation and oxidative stress status of AC16 cells. The targeted relationship between miR-130a-3p and KCNQ1OT1 or ZNF791 was predicted by StarBase bioinformatic database, and dual-luciferase reporter assay and RNA immunoprecipitation (RIP) assay were carried out to verify these predictions. Hydrogen peroxide (H₂ O₂ ) stimulation caused a significant upregulation in the expression of KCNQ1OT1, while the level of miR-130a-3p showed an opposite phenomenon. KCNQ1OT1 was a crucial downstream component in H₂ O₂ -mediated toxic effects, and KCNQ1OT1 accelerated H₂ O₂ -induced toxic effects in AC16 cells. KCNQ1OT1 could sponge miR-130a-3p and down-regulate its expression. MiR-130a-3p exerted opposite effects to KCNQ1OT1, and the depletion of miR-130a-3p attenuated the protective effects of KCNQ1OT1 intervention on AC16 cells exposed to H₂ O₂ . MiR-130a-3p could bind to ZNF791, and ZNF791 served as the target of miR-130a-3p to promote H₂ O₂ -induced injury of AC16 cells. ZNF791 was modulated by KCNQ1OT1/miR-130a-3p signaling in H₂ O₂ -treated AC16 cells. In all, lncRNA KCNQ1OT1 deteriorated H₂ O₂ -mediated injury in cardiomyocytes through upregulating ZNF791 via serving as a molecular sponge for miR-130a-3p.

MiR-19b-3p regulated by BC002059/ABHD10 axis promotes cell apoptosis in myocardial infarction

BACKGROUND

Recently, microRNAs (miRNAs), have been extensively investigated in diseases. The upregulated expression of miR-19b-3p has been validated in patients with hypertrophic cardiomyopathy. Nonetheless, it regulatory mechanism in myocardial infarction (MI) is still unclear.

PURPOSE

This research aimed to investigate the role and molecular regulation mechanism of miR-19b-3p in MI.

METHODS

QRT-PCR and western blot assays measured RNA and protein expression. Cell apoptosis were tested by flow cytometry and TUNEL assays. Cell viability was measured by trypan blue staining method. RIP and luciferase report assays examined gene interaction. The assays were performed under hypoxia condition.

RESULTS

MiR-19b-3p was highly expressed in myocardial cell line H9C2, primary cardiomyocytes, and tissues from MI mouse model. MiR-19b-3p inhibition suppressed the apoptosis of cardiomyocytes. BC002059 could up-regulate ABHD10 through sequestering miR-19b-3p. BC002059 upregulation was observed to repress cell apoptosis. Rescue experiments demonstrated that miR-19b-3p overexpression abrogated the suppressive impact of BC002059 on the apoptosis of MI cells, and infarct size, area at risk as well as CK-MB and LDH release of MI mouse model tissues, which was further abolished via ABHD10 increment.

CONCLUSION

MiR-19b-3p regulated by BC002059/ABHD10 axis promotes cell apoptosis in MI, which might provide a novel perspective for MI alleviation research.

LncRNA MALAT1 Regulates USP22 Expression Through EZH2-Mediated H3K27me3 Modification to Accentuate Sepsis-Induced Myocardial Dysfunction

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1), a long non-coding RNA (lncRNA), has been confirmed to recruit enhancer of zeste 2 polycomb repressive complex 2 subunit (EZH2) to regulate cardiomyocyte apoptosis in diabetic cardiomyopathy. However, whether the similar regulatory axis exists in sepsis-induced myocardial dysfunction (SIMD) has not been clearly established. The current study sought to define the mechanism governing MALAT1-mediated EZH2 in SIMD. MALAT1 was significantly upregulated in lipopolysaccharide-induced cardiomyocytes. Depletion of MALAT1 by caudal vein injection of small interfering RNA targeting MALAT1 alleviated myocardial injury in SIMD rats, restored cardiac function, reduced oxidative stress production and fibrosis, and inhibited inflammatory factors and apoptosis in myocardial tissues. Moreover, MALAT1 bound to EZH2 and promoted EZH2 activity in the nucleus of cardiomyocytes. EZH2 repressed ubiquitin-specific peptidase 22 (USP22) expression through H3K27me3 modification. EZH2 elevation aggravated the cardiac injury in SIMD rats, while USP22 upregulation inhibited the effect of EZH2, which reduced the cardiac injury in SIMD rats. Taken together, MALAT1 decreased USP22 expression by interacting with EZH2, thereby worsening SIMD, highlighting an attractive therapeutic strategy for SIMD.

Tanshinone IIA improves cardiac function via regulating miR-499-5p dependent angiogenesis in myocardial ischemic mice

BACKGROUND/AIMS

Myocardial ischemia-reperfusion injury leads to aggravated cardiac remodeling and heart failure. After myocardial infarction (MI), angiogenesis plays a vital role in the repair and regeneration of tissue. The purpose of the current study was to determine the effect of Tanshinone IIA (Tan IIA) on angiogenesis and elucidate its related mechanism.

METHODS

The C57BL/6 mice MI model was established to evaluate the therapeutic effect of Tan IIA in vivo. MicroRNA (miRNA) microarray and bioinformatics analysis were performed to determine the differential expressions of miRNAs after Tan IIA administration. Cell proliferation, migration, and angiogenesis capacity were detected by EdU, Transwell, and Tube formation assay in vitro, respectively. The relationship between miR-499-5p (miR-499) and paired phosphate and tension homolog deleted on chromosome ten (PTEN) was confirmed by using a Dual-luciferase reporter assay.

RESULTS

Our results showed that Tan IIA administration improved cardiac function after MI by activating angiogenesis. Further miRNA microarray and bioinformatics analysis revealed that miR-499 was significantly down-regulated, while PTEN was remarkably upregulated after Tan IIA administration post-MI. In addition, we found that miR-499 knock-down effectively promotes cell proliferation, migration, and tube formation ability of HUVECs. Dual-luciferase reporter assay demonstrated that PTEN contains a direct binding site for miR-499-5p.

CONCLUSION

Tan IIA improves cardiac function post-MI by inducing angiogenesis. In terms of the mechanism, Tan IIA promotes therapeutic angiogenesis by regulating miR-499-5p/PTEN signaling pathway.

MIR22HG Aggravates Oxygen-Glucose Deprivation and Reoxygenation-Induced Cardiomyocyte Injury through the miR-9-3p/SH2B3 Axis

Reperfusion therapy, the standard treatment for acute myocardial infarction (MI), can trigger necrotic death of cardiomyocytes and provoke ischemia/reperfusion (I/R) injury. However, molecular mechanisms that regulate cardiomyocyte death remain largely unknown. The abnormal expression of lncRNA MIR22HG has been found in types of diseases. The current study was aimed at exploring the function and mechanism of MIR22HG in I/R injury. In this study, mouse myocardial cells (HL-1) treated with oxygen-glucose deprivation and reoxygenation (OGD/R) were used as the in vitro models, and myocardial ischemia reperfusion injury (MIRI) animal models in vivo were established in male C57BL/6 mice. Experiments including CCK-8, flow cytometry, TUNEL, HE staining, RT-qPCR, western blotting, and luciferase reporter assays were performed to explore the function and potential mechanism of MIR22HG in MIRI in vitro and in vivo. Bioinformatics analysis was performed to predict the binding site between miR-9-3p and MIR22HG (or SH2B3). Our results indicated that the MIR22HG level was upregulated in cardiomyocytes after OGD/R treatment. The knockdown of MIR22HG promoted cell viability and inhibited apoptosis and extracellular matrix (ECM) production in OGD/R-treated HL-1 cells. In mechanism, MIR22HG binds to miR-9-3p, and miR-9-3p targets the SH2B3 3 ${}^{\prime }$ untranslated region (UTR). Moreover, SH2B3 expression was positively regulated by MIR22HG but negatively modulated by miR-9-3p. Rescue assays suggested that the suppressive effect of MIR22HG knockdown on cell viability, apoptosis, and ECM accumulation was reversed by the overexpression of SH2B3. The in vivo experiments demonstrated that MIR22HG knockdown alleviated cardiomyocyte apoptosis and reduced myocardial infarct size in MIRI mice. In summary, MIR22HG knockdown alleviates myocardial injury through the miR-9-3p/SH2B3 axis.

Suppression of lncRNA Gm47283 attenuates myocardial infarction via miR-706/ Ptgs2/ferroptosis axis

Myocardial infarction (MI) is the leading cause of sudden death. Long non-doing RNAs (lncRNAs) were demonstrated to play crucial roles in multiple diseases, including cancer and cardiovascular diseases. Nevertheless, the molecular mechanism of lncNRAs in MI is unclear. In this study, we integrated bioinformatics and molecular biological experiments to identify the novel lncRNA transcripts and elucidated its regulatory mechanism in MI. First, we identified 10 dysregualted lncRNAs and found that lncRNA Gm47283 was the top risk factor in MI. Bioinformatics analysis predicted that lncRNA Gm47283 exerted function via targeting miR-706 and Ptgs2. Ptgs2 was also the known regulator of ferroptosis. Inhibition or overexpression of lncRNA Gm47283 could regulate Ptgs2 expression and downstream ferroptosis activity. Overexpression of miR-706 could inhibit the expression of Ptgs2 and the activity of ferroptosis, thereby attenuated cellular injury. Mechanically, co-transfection experiments showed that overexpression of miR-706 could reverse the damage effect that was caused by lncRNA Gm47283 overexpression, via inhibiting Ptgs2 and ferroptosis. Additionally, inhibition of lncRNA Gm47283 by stem cell membrane coated siRNA could attenuate MI in vivo. Our study elucidated a novel mechanism containing lncRNA Gm47283/miR-706/Ptgs2/ferroptosis in MI, which provided a potential therapeutic for MI.

Graphical Abstract. Stem cell membrane coated siRNA of lncRNA Gm47283 inhibits cardiomyocyte ferroptosis in myocardial infarction rat. Stem cell membrane-coated siRNA of lncRNA Gm47283 increases miR-706, and then miR-706 suppresses the expression of Ptgs2 to reduce lipid peroxidation toxicity, and then inhibits cardiomyocyte ferroptosis. PUFA: polyunsaturated fatty acid.

Long noncoding RNA MALAT1 polymorphism predicts MACCEs in patients with myocardial infarction

Background

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) participates in the occurrence and development of cardiovascular and cerebrovascular diseases such as stroke and coronary heart disease by regulating inflammatory reactions, programmed cell death, and other pathological processes. Previous studies revealed that the MALAT1 gene polymorphism was associated with cardiac and cerebrovascular diseases. However, the prognostic role of the MALAT1 polymorphism in major adverse cardiac and cerebrovascular events (MACCEs) remains unknown. Therefore, this study intends to explore the association between the MALAT1 rs3200401 polymorphism and MACCEs.

Method

We enrolled 617 myocardial infarction (MI) patients and 1125 control participants who attended the First Affiliated Hospital of Xinjiang Medical University from January 2010 to 2018. SNPscan™ typing assays were used to detect the MALAT1 rs3200401 genotype. During the follow-up, MACCEs were recorded. Kaplan–Meier curves and univariate and multivariate Cox survival analyses were used to explore the correlation between MALAT1 gene polymorphisms and the occurrence of MACCEs.

Results

Among the total participants and MI patients, the frequencies of the T allele (total Participants 19.5% vs. 15.3%, P = 0.047, MI patients 20.7% vs. 14.1%, P = 0.014) and CT + TT genotypes (total Participants 37.4% vs. 28.1%, P = 0.013, MI patients 39.5% vs. 25.8%, P = 0.003) were significantly higher in subjects with MACCEs than in subjects without MACCEs. However, in control participants, the frequencies of the T allele (16.6% vs. 16.0%, P = 0.860) and CT + TT genotypes (31.4% vs. 29.3%, P = 0.760) were not higher in subjects with MACCEs than in subjects without MACCEs. In addition, among the total participants and MI patients, the Kaplan–Meier curve analysis indicated that the subjects with rs3200401 CT + TT genotypes had a higher incidence of MACCEs than CC genotype carriers (P = 0.015, P = 0.001). Nevertheless, similar results were not observed in the control participants (P = 0.790). Multivariate Cox regression indicated that compared with patients with the CC genotype, patients with CT + TT genotypes had a 1.554-fold increase in MACCE risk (hazard ratio: 1.554, 95% confidence interval: 1.060–2.277, P = 0.024).

Conclusions

The MALAT1 rs3200401 CT + TT genotypes could be a risk factor for MACCEs in MI patients, suggesting that the MALAT1 gene may become a biomarker for poor prognosis in MI patients.

LncRNA NORAD promotes the progression of myocardial infarction by targeting the miR-22-3p/PTEN axis

NORAD is a newly identified long non-coding RNA (lncRNA) that plays an important role in cancers. NORAD has been found to be highly expressed in the mouse model of acute myocardial infarction (AMI). However, the role of NORAD in the regulation of AMI remains unknown. In the present study, we aimed to investigate the function of NORAD in AMI and explore the potential regulatory mechanisms. A mouse model of AMI was established and NORAD was knocked-down. The infarcted size of heart tissues and the cardiac function were evaluated. In addition, two cardiomyocyte cell lines were treated with hypoxia/re-oxygenation (H/R) to mimic AMI . Luciferase reporter assay, RNA pull-down assay, fluorescence hybridization, qRT-PCR, and western blot analysis were performed. Apoptotic cells and the levels of L-lactate dehydrogenase (LDH) and malondialdehyde (MDA) were detected. Our results show that downregulation of NORAD efficiently attenuates heart damage in the AMI mouse model. NORAD interacts with miR-22-3p. Knock-down of NORAD inhibits H/R-induced cell apoptosis and reduces LDH and MDA levels, while its effects are abolished by miR-22-3p inhibitor. MiR-22-3p interacts with PTEN and inhibits its expression. Overexpression of miR-22-3p inhibits H/R-induced cell apoptosis and reduces LDH and MDA levels, while its effects are abolished by overexpression of PTEN. Finally, overexpression of NORAD inhibits the AKT/mTOR signaling pathway, and its effects are attenuated by overexpression of miR-22-3p. Taken together, our study reveals that NORAD promotes the progression of AMI by regulating the miR-22-3p/PTEN axis, and the AKT/mTOR signaling may also be involved in the regulatory processes.

Non-canonical features of microRNAs: paradigms emerging from cardiovascular disease

Research showing that microRNAs (miRNAs) are versatile regulators of gene expression has instigated tremendous interest in cardiovascular research. The overwhelming majority of studies are predicated on the dogmatic notion that miRNAs regulate the expression of specific target mRNAs by inhibiting mRNA translation or promoting mRNA decay in the RNA-induced silencing complex (RISC). These efforts mostly identified and dissected contributions of multiple regulatory networks of miRNA-target mRNAs to cardiovascular pathogenesis. However, evidence from studies in the past decade indicates that miRNAs also operate beyond this canonical paradigm, featuring non-conventional regulatory functions and cellular localizations that have a pathophysiological role in cardiovascular disease. In this Review, we highlight the functional relevance of atypical miRNA biogenesis and localization as well as RISC heterogeneity. Moreover, we delineate remarkable non-canonical examples of miRNA functionality, including direct interactions with proteins beyond the Argonaute family and their role in transcriptional regulation in the nucleus and in mitochondria. We scrutinize the relevance of non-conventional biogenesis and non-canonical functions of miRNAs in cardiovascular homeostasis and pathology, and contextualize how uncovering these non-conventional properties can expand the scope of translational research in the cardiovascular field and beyond.

Amniotic Fluid microRNA in Severe Twin-Twin Transfusion Syndrome Cardiomyopathy-Identification of Differences and Predicting Demise

Twin-twin transfusion syndrome (TTTS) is a rare but serious cause of fetal cardiomyopathy with poorly understood pathophysiology and challenging prognostication. This study sought a nonbiased, comprehensive assessment of amniotic fluid (AF) microRNAs from TTTS pregnancies and associations of these miRNAs with clinical characteristics. For the discovery cohort, AF from ten fetuses with severe TTTS cardiomyopathy were selected and compared to ten normal singleton AF. Array panels assessing 384 microRNAs were performed on the discovery cohort and controls. Using a stringent q < 0.0025, arrays identified 32 miRNAs with differential expression. Top three microRNAs were miR-99b, miR-370 and miR-375. Forty distinct TTTS subjects were selected for a validation cohort. RT-PCR targeted six differentially-expressed microRNAs in the discovery and validation cohorts. Expression differences by array were confirmed by RT-PCR with high fidelity. The ability of these miRNAs to predict clinical differences, such as cardiac findings and later demise, was evaluated on TTTS subjects. Down-regulation of miRNA-127-3p, miRNA-375-3p and miRNA-886 were associated with demise. Our results indicate AF microRNAs have potential as a diagnostic and prognostic biomarker in TTTS. The top microRNAs have previously demonstrated roles in angiogenesis, cardiomyocyte stress response and hypertrophy. Further studies of the mechanism of actions and potential targets is warranted.

The Regulation Mechanisms and Clinical Application of MicroRNAs in Myocardial Infarction: A Review of the Recent 5 Years

Myocardial infarction (MI) is the most frequent end-point of cardiovascular pathology, leading to higher mortality worldwide. Due to the particularity of the heart tissue, patients who experience ischemic infarction of the heart, still suffered irreversible damage to the heart even if the vascular reflow by treatment, and severe ones can lead to heart failure or even death. In recent years, several studies have shown that microRNAs (miRNAs), playing a regulatory role in damaged hearts, bring light for patients to alleviate MI. In this review, we summarized the effect of miRNAs on MI with some mechanisms, such as apoptosis, autophagy, proliferation, inflammatory; the regulation of miRNAs on cardiac structural changes after MI, including angiogenesis, myocardial remodeling, fibrosis; the application of miRNAs in stem cell therapy and clinical diagnosis; other non-coding RNAs related to miRNAs in MI during the past 5 years.

lncRNA MALAT1/miR-143 axis is a potential biomarker for in-stent restenosis and is involved in the multiplication of vascular smooth muscle cells

The purpose of this study is to observe the potential value and underlying mechanism of the metastasis-associated lung adenocarcinoma transcript 1 (MALAT1)/miR-143 axis in ISR. A total of 150 participants were enrolled, including 100 patients (observation group) with coronary heart disease who underwent stent implantation in the Department of Cardiology of our hospital between January 2018 and January 2020, and 50 healthy people (control group) concurrently underwent a physical examination. Serum MALAT1 and miR-143 levels were detected by quantitative reverse transcription-polymerase chain reaction (qRT-PCR). Tumor necrosis factor-α (TNF-α; 10 ng/mL) induced human vascular smooth muscle cells (HVSMCs). MALAT1 increased while miR-143 decreased in the observation group versus the control group (P < 0.001). The non-restenosis group had significantly elevated MALAT1 expression while decreased miR-143 expression than the restenosis group (P < 0.001). The areas under the curves of the expression of MALAT1 and miR-143 in predicting restenosis were 0.917 and 0.881, respectively. Following si-MALAT1 transfection, HVSMC multiplication and invasiveness decreased significantly (P < 0.05). miR-143-inhibitor was observed to upregulate the luciferase activity of MALAT1-WT (P < 0.05). MALAT1 is highly expressed in patients with ISR while miR-143 is decreased, and the MALAT1/miR-143 axis is a potential pathway to modulate the multiplication and invasiveness of HVSMCs.

Value of PTEN and Echocardiography in Predicting the Efficacy of Trimetazidine Combined with Metoprolol in the Treatment of Heart Failure

Objective

To investigate the predictive value of PTEN and echocardiography in the treatment of heart failure with trimetazidine combined with metoprolol.

Methods

A total of 100 patients with coronary heart disease and HF who admitted to our hospital from August 2018 to August 2020 were enrolled into research. All patients received routine treatment according to the guidelines and were treated with trimetazidine and metoprolol for a total course of 6 months. Echocardiographic parameters and PTEN levels were measured at baseline and after treatment. The patients were divided into groups according to the quartile of basic PTEN level, and the total effective rates were compared. The echocardiographic parameters of patients with different prognosis were analyzed. Bivariate correlation analysis was used to evaluate the correlation between PTEN, echocardiography and treatment effect.

Results

Compared with that before treatment, the level of PTEN increased significantly after treatment (P < 0.01). According to the quartile of basic PTEN level, the total effective rate of patients with different levels of basic PTEN was was statistically different (P < 0.01). There was a linear correlation between the level of basic PTEN and the treatment effect, and the total effective rate of patients with high level of basic PTEN was higher than that of patients with low level of PTEN. Compared with before treatment, LVEF, SV, E/A and lvfs increased significantly after treatment (P < 0.01). There was a correlation between the basic echocardiographic parameters and the treatment effect of patients. The basic echocardiographic parameters of patients with poor prognosis were worse than those with good prognosis. PTEN expression in patients’ serum was only positively correlated with E/A, but not with LVFE, SV and LVFS (P < 0.01).

Conclusion

PTEN and echocardiographic parameters serve as a good method to evaluate the short-term therapeutic effect of trimetazidine combined with metoprolol in patients with heart failure.

Mitophagy Regulation Following Myocardial Infarction

Mitophagy, which mediates the selective elimination of dysfunctional mitochondria, is essential for cardiac homeostasis. Mitophagy is regulated mainly by PTEN-induced putative kinase protein-1 (PINK1)/parkin pathway but also by FUN14 domain-containing 1 (FUNDC1) or Bcl2 interacting protein 3 (BNIP3) and BNIP3-like (BNIP3L/NIX) pathways. Several studies have shown that dysregulated mitophagy is involved in cardiac dysfunction induced by aging, aortic stenosis, myocardial infarction or diabetes. The cardioprotective role of mitophagy is well described, whereas excessive mitophagy could contribute to cell death and cardiac dysfunction. In this review, we summarize the mechanisms involved in the regulation of cardiac mitophagy and its role in physiological condition. We focused on cardiac mitophagy during and following myocardial infarction by highlighting the role and the regulation of PI NK1/parkin-; FUNDC1-; BNIP3- and BNIP3L/NIX-induced mitophagy during ischemia and reperfusion.

ZNF561-AS1 Regulates Cell Proliferation and Apoptosis in Myocardial Infarction Through miR-223-3p/NLRP3 Axis

Long non-coding RNAs (lncRNAs) have been widely recognized as important regulators in myocardial infarction (MI) and other heart diseases. Our study aimed to investigate the mechanism and biological function of an unknown lncRNA zinc finger protein 561 antisense RNA 1 (ZNF561-AS1) in MI. After confirming the MI model was successful, we applied reverse transcription quantitative polymerase chain reaction and Western blot (WB) and found that the expression of NLR family pyrin domain containing 3 (NLRP3), interleukin (IL)-1β, and IL-18 was substantially increased in infarct and border zones of MI mice heart at 24 h and 72 h compared with that in sham-operated models. Moreover, we found that NLRP3 expression was promoted in hypoxia human cardiomyocytes (HCMs). Through cell function assays including CCK-8, 5-Ethynyl-2’-deoxyuridine (EdU), flow cytometry, and TdT-mediated dUTP Nick-End Labeling (TUNEL), supported by WB analysis, we verified that silencing of NLRP3 facilitated proliferation but impeded apoptosis of hypoxia-induced myocardial cell. Moreover, Ago2-RIP and RNA pull-down assays displayed that NLRP3 could combine with miR-223-3p. Luciferase reporter assays further confirmed that NLRP3 was directly targeted by miR-223-3p. Simultaneously, we found that miR-223-3p was the downstream gene of ZNF561-AS1. In addition, we conducted a series of rescue experiments to affirm that ZNF561-AS1 regulated cell proliferation and apoptosis in MI through miR-223-3p/NLRP3 axis.

Role of Non-Coding RNA of Human Platelet in Cardiovascular Disease

Cardiovascular diseases (CVD) are the major cause of death in the world. Numerous genetic studies involving transcriptomic approaches aimed at the detailed understanding of the disease and the development of new therapeutic strategies have been conducted over recent years. There has been an increase in research on platelets, which are implicated in CVD due to their capacity to release regulatory molecules that affect various pathways. Platelets secrete over 500 various kinds of molecules to plasma including large amounts of non-coding (nc) RNA (miRNA, lncRNA or circRNA). These ncRNA correspond to 98% of transcripts that are not translated into proteins as they are important regulators in physiology and disease. Thus, miRNAs can direct protein complexes to mRNAs through base-pairing interactions, thus causing translation blockage or/and transcript degradation. The lncRNAs act via different mechanisms by binding to transcription factors. Finally, circRNAs act as regulators of miRNAs, interfering with their action. Alteration in the repertoire and/or the amount of the platelet-secreted ncRNA can trigger CVD as well as other diseases. NcRNAs can serve as effective biomarkers for the disease or as therapeutic targets due to their disease involvement. In this review, we will focus on the most important ncRNAs that are secreted by platelets (9 miRNA, 9 lncRNA and 5 circRNA), their association with CVD, and the contribution of these ncRNA to CVD risk to better understand the relation between ncRNA of human platelet and CVD.

Long non-coding RNA MALAT1 modulates myocardial ischemia-reperfusion injury though the PI3K/Akt/eNOS pathway by sponging miRNA-133a-3p to target IGF1R expression

The mechanism of myocardial ischemia-reperfusion injury (MIRI) is a complex pathophysiological process that can lead to poor patient outcomes. Although LncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is reported to be highly expressed in myocardial ischemia reperfusion (IR) injury, the specific mechanism remains largely unknown. This study aimed to elucidate the roles and possible mechanism of MALAT1 in myocardial IR injury. IR model was established in rats by ligation of the anterior descending artery in vivo, and H9c2 and HL-1 cells were treated by hypoxia/reoxygenation (HR) to construct the model in vitro. The small interfering RNA (siRNA) for MALAT1 and miR-133a-3p mimics, inhibitor was used to transfect the cells. The expression of MALAT1, miR-133a-3p in MIRI were evaluated using real-time quantitative polymerase chain reaction (qRT-PCR)，immunohistochemistry (IHC) and western blot (WB). Relationships between MALAT1, insulin-like growth factor 1 receptor (IGF1R) with miR-133a-3p were confirmed by luciferase reporter assay. Annexin V-FITC/PI double-labeled flow cytometry, terminal dexynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL), Cell Counting Kit-8 (CCK-8), serum creatine kinase MB (CK-MB), and lactate dehydrogenase (LDH) were evaluated to examine the impact of MALAT1 on MIRI. Our results revealed that MALAT1 was highly expressed, while miR-133a-3p and IGF1R were repressed in IR and HR groups. Knockdown of MALAT1 alleviate the pro-apoptotic effect and myocardial injury in vitro and in vivo. Systematically, MALAT1 may serve as a sponge for miR-133a-3p to suppress IGF1R, which a direct target of miR-133a-3p, then inhibit the PI3K/Akt/eNOS survival pathway. Mechanistically, our study demonstrated that MALAT1 regulates PI3K/Akt/eNOS signaling via miR-133a-3p. In summary, these results suggest that MALAT1 and miR-133a-3p play important roles in MIRI. MALAT1 regulates miR-133a-3p /IGF1R axis. These results show light on the underlying mechanisms of MIRI and provide potential therapeutic targets for MIRI.

lncRNA NRON knockdown alleviates hypoxia/reoxygenation (H/R)-induced cardiomyocyte apoptosis by upregulating HIF-1α expression

ABSTRACT

Acute myocardial infarction (AMI) has become the most common cause of death in the developed countries. However, its pathogenesis is poorly understood. Increasing studies have revealed that lncRNAs are important modulators of AMI development. This study aimed to explore the function of lncRNA noncoding repressor of nuclear factor of activated T cells (NRON) in hypoxia/reoxygenation (HR)-stimulated H9c2 cells. NRON expression in peripheral blood of AMI patients and H/R-stimulated H9c2 cells was measured by qRT-PCR. H9c2 cells were transfected with si-NRON or co-transfected with si-NRON and si-hypoxia-inducible factor-1 alpha (HIF-1α). The viability and apoptosis of these cells were evaluated by MTT assay and flow cytometer, respectively. In addition, HIF-1α, AKT/mTOR signal pathways, and ERK1/2 were detected by Western blot. NRON knockdown in the MI mouse model was conducted through adeno-associated virus (AAV) injection, and cardiac function was evaluated by motion-mode echocardiography. The results showed that NRON was highly expressed in peripheral blood of AMI patients and H/R-stimulated H9c2 cells. NRON knockdown promoted cell viability and inhibited cell apoptosis of H/R-stimulated H9c2 cells. Meanwhile, NRON knockdown also significantly attenuated heart damage and improved cardiac function in an AMI mouse model. Further, compared with si-normal control (NC), NRON knockdown increased the levels of HIF-1α, p-AKT, p-mTOR, and p-ERK1/2. HIF-1α knockdown reversed the effects of NRON knockdown in H/R-stimulated-H9c2 cells damage. Overall, our study revealed that NRON knockdown alleviated H/R-induced cardiomyocyte apoptosis by upregulating HIF-1α expression, suggesting that NRON might be a novel therapeutic target for AMI.

Deep Sequencing of the Rat MCAO Cortexes Reveals Crucial circRNAs Involved in Early Stroke Events and Their Regulatory Networks

Circular RNAs (circRNAs) are highly enriched in the central nervous system and significantly involved in a range of brain-related physiological and pathological processes. Ischemic stroke is a complex disorder caused by multiple factors; however, whether brain-derived circRNAs participate in the complex regulatory networks involved in stroke pathogenesis remains unknown. Here, we successfully constructed a cerebral ischemia-injury model of middle cerebral artery occlusion (MCAO) in male Sprague-Dawley rats. Preliminary qualitative and quantitative analyses of poststroke cortical circRNAs were performed through deep sequencing, and RT-PCR and qRT-PCR were used for validation. Of the 24,858 circRNAs expressed in the rat cerebral cortex, 294 circRNAs were differentially expressed in the ipsilateral cerebral cortex between the MCAO and sham rat groups. Cluster, GO, and KEGG analyses showed enrichments of these circRNAs and their host genes in numerous biological processes and pathways closely related to stroke. We selected 106 of the 294 circRNAs and constructed a circRNA-miRNA-mRNA interaction network comprising 577 sponge miRNAs and 696 target mRNAs. In total, 15 key potential circRNAs were predicted to be involved in the posttranscriptional regulation of a series of downstream target genes, which are widely implicated in poststroke processes, such as oxidative stress, apoptosis, inflammatory response, and nerve regeneration, through the competing endogenous RNA mechanism. Thus, circRNAs appear to be involved in multilevel actions that regulate the vast network of multiple mechanisms and events that occur after a stroke. These results provide novel insights into the complex pathophysiological mechanisms of stroke.

Long Non-coding RNA N1LR Protects Against Myocardial Ischemic/Reperfusion Injury Through Regulating the TGF-β Signaling Pathway

Long non-coding RNAs (lncRNAs) have been shown to play critical roles in various cell biological processes. However, the mechanism of lncRNAs in acute myocardial infarction (AMI) is not fully understood. Previous studies showed that lncRNA N1LR was down-regulated in ischemic cerebral stroke and its up-regulation was protective. The current study was designed to assess the protective effect of N1LR and further to explore potential mechanisms of N1LR in ischemic/reperfusion (I/R) injury after AMI. Male C57BL/6J mice and H9c2 cardiomyocytes were selected to construct in vivo and in vitro pathological models. In H9c2 cell line, N1LR expression was markedly decreased after H₂O₂ and CoCl₂ treatments and N1LR overexpression alleviated apoptosis, inflammation reaction, and LDH release in cardiomyocytes treated with H₂O₂ and CoCl₂. Mouse in vivo study showed that overexpression of N1LR enhanced cardiac function and suppressed inflammatory response and fibrosis. Mechanistically, we found that the expression of transforming growth factor (TGF)-β1 and smads were significantly decreased in the N1LR overexpression group exposed to H₂O₂. In a summary, our study indicated that N1LR can act as a protective factor against cardiac ischemic-reperfusion injury through regulating the TGF-β/Smads signaling pathway.

Constitutive activation of the NEAT1/miR-22-3p/Ltb4r1 signaling pathway in mice with myocardial injury following acute myocardial infarction

Coronary heart disease (CHD) with myocardial infarction (MI) being the manifestation of its advanced manifestation, remains the primary cause of mortality and disability worldwide. Aberrant expression of long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) can affect the occurrence of MI in CHD. The present study aimed to explore whether NEAT1 sponging with miR-22-3p affected MI in CHD and its related mechanism. We established that the NEAT1 and Ltb4r1 expressions were increased, while miR-22-3p expression was down-regulated in MI mice following CHD. NEAT1 could competitively bind to miR-22-3p and positively regulate Ltb4r1 expression. Ltb4r1 was the downstream target of miR-22-3p. Moreover, silencing NEAT1 or downregulating Ltb4rl expression resulted in improved cardiac function, reduced infarct size, and declined levels of IL-1β, IL-6, and IL-18. Furthermore, silencing of NEAT1 also inhibited apoptosis by decreasing levels of Cleaved caspase-3 and Bax, and increasing Bcl-2 level through sponging miR-22-3p, resulting in reduced myocardial injury in CHD. Altogether, the activation of the NEAT1/miR-22-3p/Ltb4r1 signaling pathway appears to aggravate myocardial injury following a MI, which suggested that this signaling may be a useful target for improved and more individualized treatments for MI.

Long non-coding RNA SENCR alleviates hypoxia/reoxygenation-induced cardiomyocyte apoptosis and inflammatory response by sponging miR-1

Background

Myocardial cell apoptosis is one of the main reasons for the occurrence of acute myocardial infarction (AMI). The role of smooth muscle and endothelial cell enriched migration/differentiation-associated lncRNA (SENCR) in the cardiomyocyte apoptosis induced by hypoxia/reoxygenation (H/R) injury and its potential mechanism were investigated in this study to provide a novel biomarker for the development of AMI.

Methods

The expression levels of SENCR in the serum of AMI patients and non-AMI patients with chest pain (control) were detected by qRT-PCR. The function of SENCR in the cardiomyocyte apoptosis and inflammatory response induced by H/R injury was evaluated by MTT, cell apoptosis, and ELISA assay, respectively. The mechanism underlying the function of SENCR was investigated with the luciferase reporter assay.

Results

SENCR was significantly downregulated in AMI compared with the control volunteers, which showed negative correlations with the cardiac troponin I (cTnI) and creatine kinase-MB (CK-MB) level of patients. The H/R injury-induced cell apoptosis and inflammatory response in cardiomyocytes, which were attenuated by the overexpression of SENCR. The expression of miR-1 was suppressed by the overexpression of SENCR, while the overexpression of miR-1 could alleviate the cell apoptosis, enhance cell viability, and attenuate inflammatory response in cardiomyocyte. SENCR reversed H/R-induced myocardial cell injury by regulating the expression of miR-1.

Conclusions

SENCR was correlated with the clinicopathological features of patients and was revealed to alleviate the cardiomyocyte apoptosis and inflammatory response induced by H/R injury via sponging miR-1.

Modulation of miR-382-5p reduces apoptosis of myocardial cells after acute myocardial infarction

BACKGROUND

Acute myocardial infarction (AMI) is a severe cardiovascular condition. Blocking the apoptosis of myocardial cells may mitigate AMI. Excessive expression of Stanniocalcin-1 (STC1) plays a protective role in the heart by inhibiting myocardial cell apoptosis. Here, we looked at the mechanism by which miR-382-5p regulates STC1 and affects myocardial cell apoptosis after AMI.

METHODS

An AMI mouse model with a descending anterior ligament coronary artery and an HL-1 cell model with reproducible hypoxia/reoxygenation (H/R) were established. For pathological changes in myocardial tissues, terminal deoxynucleotidyl transferase dUTP nick end labelling staining and haematoxylin and eosin staining were performed. STC1 mRNA and miR-382-5p levels were measured using quantitative real-time PCR. Protein levels of STC1 and apoptosis-related proteins were measured by western blotting. The 3-(4,5)-dimethylthiahiazo (-z-y1)-3,5-di- phenytetrazoliumromide assay was used to detect cell viability, and a dual-luciferase reporter assay was carried out to verify potential targets of miR-382-5p.

RESULTS

The level of miR-382-5p was raised in myocardial tissues of AMI mice and H/R-induced HL-1 cells. Compared with the control group, the myocardial tissue cells in the AMI group were disordered, with evident necrosis of myocardial cells, apoptosis and inflammatory infiltration. Interference with miR-382-5p inhibited myocardial cell apoptosis after H/R, as well as inferior lactate dehydrogenase. Also, miR-382-5p adversely regulated STC1 and the expression of STC1 was increased after transfection with miR-382-5p antagomir. Furthermore, interference with miR-382-5p reduced myocardial cell apoptosis after H/R by increasing the expression level of STC1.

CONCLUSION

To summarise, our study showed an increase in miR-382-5p in myocardial tissues in the AMI mouse model. Interference with miR-382-5p reduced apoptosis of myocardial cells after AMI and the effect was achieved by increasing STC1 expression.

Decoding LncRNAs

Non-coding RNAs (ncRNAs) have been considered as unimportant additions to the transcriptome. Yet, in light of numerous studies, it has become clear that ncRNAs play important roles in development, health and disease. Long-ignored, long non-coding RNAs (lncRNAs), ncRNAs made of more than 200 nucleotides have gained attention due to their involvement as drivers or suppressors of a myriad of tumours. The detailed understanding of some of their functions, structures and interactomes has been the result of interdisciplinary efforts, as in many cases, new methods need to be created or adapted to characterise these molecules. Unlike most reviews on lncRNAs, we summarize the achievements on lncRNA studies by taking into consideration the approaches for identification of lncRNA functions, interactomes, and structural arrangements. We also provide information about the recent data on the involvement of lncRNAs in diseases and present applications of these molecules, especially in medicine.

EZH2 as an epigenetic regulator of cardiovascular development and diseases

ABSTRACT

Enhancer of zeste homolog 2(EZH2) is an enzymatic subunit of polycomb repressive complex 2 (PRC2) and is responsible for catalyzing mono-, di-, and trimethylation of histone H3 at lysine-27(H3K27me1/2/3). Many noncoding RNAs or signaling pathways are involved in EZH2 functional alterations. This new epigenetic regulation of target genes is able to silence downstream gene expression and modify physiological and pathological processes in heart development, cardiomyocyte regeneration and cardiovascular diseases such as hypertrophy, ischemic heart diseases, atherosclerosis and cardiac fibrosis. Targeting the function of EZH2 could be a potential therapeutic approach for cardiovascular diseases.

Past, Present, and Future of Blood Biomarkers for the Diagnosis of Acute Myocardial Infarction-Promises and Challenges

Despite important advancements in acute myocardial infarction (AMI) management, it continues to represent a leading cause of mortality worldwide. Fast and reliable AMI diagnosis can significantly reduce mortality in this high-risk population. Diagnosis of AMI has relied on biomarker evaluation for more than 50 years. The upturn of high-sensitivity cardiac troponin testing provided extremely sensitive means to detect cardiac myocyte necrosis, but this increased sensitivity came at the cost of a decrease in diagnostic specificity. In addition, although cardiac troponins increase relatively early after the onset of AMI, they still leave a time gap between the onset of myocardial ischemia and our ability to detect it, thus precluding very early management of AMI. Newer biomarkers detected in processes such as inflammation, neurohormonal activation, or myocardial stress occur much earlier than myocyte necrosis and the diagnostic rise of cardiac troponins, allowing us to expand biomarker research in these areas. Increased understanding of the complex AMI pathophysiology has spurred the search of new biomarkers that could overcome these shortcomings, whereas multi-omic and multi-biomarker approaches promise to be game changers in AMI biomarker assessment. In this review, we discuss the evolution, current application, and emerging blood biomarkers for the diagnosis of AMI; we address their advantages and promises to improve patient care, as well as their challenges, limitations, and technical and diagnostic pitfalls. Questions that remain to be answered and hotspots for future research are also emphasized.

Role of N6-Methyladenosine RNA Modification in Cardiovascular Disease

Despite treatments being improved and many risk factors being identified, cardiovascular disease (CVD) is still a leading cause of mortality and disability worldwide. N⁶-methyladenosine (m⁶A) is the most common, abundant, and conserved internal modification in RNAs and plays an important role in the development of CVD. Many studies have shown that aabnormal m⁶A modifications of coding RNAs are involved in the development of CVD. In addition, non-coding RNAs (ncRNAs) exert post-transcriptional regulation in many diseases including CVD. Although ncRNAs have also been found to be modified by m⁶A, the studies on m⁶A modifications of ncRNAs in CVD are currently lacking. In this review, we summarized the recent progress in understanding m⁶A modifications in the context of coding RNAs and ncRNAs, as well as their regulatory roles in CVD.

Long Noncoding RNAs in Myocardial Ischemia-Reperfusion Injury

Following an acute myocardial infarction, reperfusion therapy is currently the most effective way to save the ischemic myocardium; however, restoring blood flow may lead to a myocardial ischemia-reperfusion injury (MIRI). Recent studies have confirmed that long-chain noncoding RNAs (LncRNAs) play important roles in the pathophysiology of MIRIs. These LncRNA-mediated roles include cardiomyocyte apoptosis, autophagy, necrosis, oxidative stress, inflammation, mitochondrial dysfunction, and calcium overload, which are regulated through the expression of target genes. Thus, LncRNAs may be used as clinical diagnostic markers and therapeutic targets to treat or prevent MIRI. This review evaluates the research on LncRNAs involved in MIRIs and provides new ideas for preventing and treating this type of injury.

MALAT1 gene rs600231 polymorphism positively associated with acute coronary syndrome in Chinese population: a case-control study

Background

Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) has been recognized as a major player in the pathogenesis of coronary artery disease (CAD). The aim of the study was to determine the association between polymorphisms of the MALAT1 gene and acute coronary syndrome (ACS) in a Chinese population in Xinjiang.

Methods

In the case-control study, we genotyped three nucleotide polymorphisms (rs3200401, rs4102217, rs600231) of the MALAT1 gene using SNPscan^TM typing assays (1,053 controls and 929 ACS patients). Furthermore, we explored a predictive model using MALAT1 rs600231 and clinical variables to predict the risk of ACS. Finally, the relative expression of long noncoding RNA (lncRNA) MALAT1 was also measured in 92 ACS patients and 92 controls using quantitative real-time polymerase chain reaction (qRT-PCR).

Results

The prevalence of the GG genotype of rs600231 in ACS group was higher than that in control group (15.7% vs. 14.7%, P=0.048). The dominant model differed (AG + GG vs. AA) and the G allele of rs600231 in ACS group was higher than that in control group (for dominant model: 66.2% vs. 60.9%, P=0.014; for allele: 41.0% vs. 37.8%, P=0.042). Multivariate logistic regression analysis and the predictive nomogram model showed that the dominant model of rs600231 remained an independent risk factor for ACS [odds ratio (OR) =1.32, 95% confidence interval (CI): 1.07-1.63, P=0.009]. The area under the receiver operating characteristic (ROC) curve (AUC) for the nomogram model for the prediction of ACS was 0.738 (95% CI: 0.716-0.761). In addition, in the AG and GG phenotypes, the relative expression of lncRNA MALAT1 was significantly higher in ACS patients than in controls with the same phenotypes (P<0.05). Among ACS group, compared to other genotype carriers, the relative expression level of MALAT1 in GG genotype carriers was higher (P<0.05).

Conclusions

The present study suggested that the AG and GG genotype of rs600231 in MALAT1 gene was independently associated with ACS, and could be a risk genetic marker of ACS in a Chinese population in Xinjiang.

Aerobic exercise improves cardiac function in rats with chronic heart failure through inhibition of the long non-coding RNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1)

Background

To explore the beneficial effects and underlying mechanisms of aerobic exercise on chronic heart failure (CHF).

Methods

A CHF rat model was induced via left anterior descending coronary artery ligation. Four weeks post-surgery, CHF rats received aerobic exercise training over an 8-week period and cardiac function indexes including xxx were analyzed. To investigate the mechanisms involved in the aerobic exercise-induced benefits on CHF, overexpression of the long non-coding RNA MALAT1 was examined both in vivo and in vitro. Furthermore, the interaction between MALAT1 and the microRNA miR-150-5p and the downstream PI3K/Akt signaling pathway was investigated.

Results

Compared to the control group, the CHF rats showed evidence of left ventricular dysfunction including aggravated cardiac function indexes and lung to body weight ratio. The Masson staining demonstrated a significant degree of blue-stained fibrotic myocardial tissue in CHF rats compared to control rats. Furthermore, the levels of collagen I and collagen II were also markedly increased in CHF rats. Aerobic exercise improved cardiac function and left ventricular remodeling in rats with CHF. There was a significant reduction in the levels of the reactive oxygen species (ROS), inflammatory cytokines including TNF-α, IL-6, and IL-1β, and inflammatory mediums containing the matrix metalloproteinases (MMPs) MMP-2 and MMP-9. Moreover, CHF rats receiving aerobic exercise showed decreased myocardial apoptosis and increased expression of autophagy-related proteins including beclin-1 and LC3B-II. Overexpression of the lncRNA MALAT1 eliminated all the beneficial effects related to aerobic exercise in CHF rats. Subsequent investigations demonstrated that miR-150-5p expression was up-regulated in CHF-Tr rats and down-regulated in CHF-Tr-MALAT1 rats. Furthermore, the downstream PI3K/Akt signaling pathway was re-activated in CHF-Tr-MALAT1 rats. In vitro experiments revealed that overexpression of MALAT1 reduced the miR-150-5p levels, resulting in increased cellular apoptosis and less autophagy. In addition, overexpression of MALAT1 suppressed the downstream PI3K/Akt signaling pathway. Restoring miR-150-5p level with a miR-150-5p mimic decreased the cellular apoptosis and increased autophagy, and the downstream PI3K/Akt signaling pathway was re-activated.

Conclusions

Aerobic exercise improved cardiac function through inhibition of the lncRNA MALAT1 in CHF, and the potential mechanisms may be mediated via the miR-150-5p/PI3K/Akt signaling pathway.

LINC00528 regulates myocardial infarction by targeting the miR-143-3p/COX-2 axis

This study is aimed to explore the roles of LINC00528 in myocardial infarction (MI) progression. Quantitative real-time PCR showed that the expression of LINC00528 and COX-2 was upregulated while miR-143-3p expression was down-regulated in post-MI cells. In function assays, LINC00528 suppression promoted post-MI cells proliferation and reduced cell apoptosis in vitro. In mechanism, LINC00528 interacted with miR-143-3p in post-MI cells. COX-2 served as a target of miR-143-3p in post-MI cells. Besides, LINC00528 inhibition on COX-2 expression and post-MI cells progression could be partially abolished by miR-143-3p inhibitors. Therefore, our findings suggested that LINC00528 exerted its regulatory roles in MI via the miR-143-3p/COX-2 axis, which provided a potential therapeutic target for MI patients treatment.

Long non-coding RNA DANCR alleviates hypoxia-caused H9c2 cells damage through up regulation of HIF-1α

Hypoxia is an important cause of myocardial cell loss, further inducing various heart illnesses, including acute myocardial infraction (AMI). Long non-coding RNA (LncRNA) discrimination antagonising non-protein coding RNA (DANCR) was firstly identified as epidermal cell differentiation suppressor. Here, we aimed to explore the effects and mechanism of DNACR in hypoxia-induced H9c2 cells. Hypoxic cells were made through 94% N₂, 5% CO₂, and 1% O₂ environment for 24 h. Cell viability and apoptosis were detected via methyl thiazolyl tetrazolium (MTT) method and flow cytometry analysis, respectively. The expression of DANCR and HIF-1α was examined via qRT-PCR. The expression of proteins related to cell apoptosis and PI3K/AKT/mTOR and ERK1/2 signal pathways was examined through western blot analysis. We found that hypoxia induced obvious cell activity inhibition and apoptosis increasing in H9c2 cells. DANCR was negatively regulated under hypoxia condition. Overexpression of DANCR rescued activity and attenuated apoptosis. Moreover, the overexpression of DANCR elevated the activation of PI3K/AKT/mTOR and ERK1/2 pathways. Further study indicated that DANCR could up-regulate the expression of HIF-1α. Si-HIF-1α transfection could remove the beneficial effects of DANCR overexpression in hypoxia-caused H9c2 cells damage. In conclusion, DANCR alleviated hypoxia-caused H9c2 cells damage through positive regulation of HIF-1α.

PTEN inhibitor improves vascular remodeling and cardiac function after myocardial infarction through PI3k/Akt/VEGF signaling pathway

Background

Myocardial infarction (MI) is the leading cause of death from cardiovascular disease (CVD). Currently, the efficacy for MI treatment remains unsatisfactory. Therefore, it is urgent to develop a novel therapeutic strategy.

Methods

Left anterior descending arteries (LAD) of mice were ligated to induce MI. Another set of mice were intravenously injected with PTEN inhibitor BPV (1 mg/kg) 1 h after LAD ligation and continued to receive BPV injection daily for the following 6 days. Mice were performed echocardiography 14 days after surgery.

Results

Mice in MI group displayed an increased expression of PTEN with impaired cardiac function, enhanced cardiomyocyte apoptosis and decreased angiogenesis. BPV treatment significantly improved cardiac function, with reduced cardiomyocyte apoptosis, promoted angiogenesis, and activated PI3K/Akt/vascular endothelial growth factor (VEGF) signaling pathway.

Conclusion

PTEN inhibitor BPV could effectively prevent myocardial infarction in mice, highlighting its potential as a candidate therapeutic drug.