The Long Noncoding RNA Hotair Regulates Oxidative Stress and Cardiac Myocyte Apoptosis during Ischemia-Reperfusion Injury.
Meng Kai,Jiao Jiao,Zhu Rui-Rui,Wang Bo-Yuan,Mao Xiao-Bo,Zhong Yu-Cheng,Zhu Zheng-Feng,Yu Kun-Wu,Ding Yan,Xu Wen-Bin,Yu Jian,Zeng Qiu-Tang,Peng Yu-Dong
Oxidative medicine and cellular longevity
Oxidative stress and subsequent cardiac myocyte apoptosis play central roles in the initiation and progression of myocardial ischemia-reperfusion (I/R) injury. Homeobox transcript antisense intergenic RNA () was previously implicated in various heart diseases, yet its role in myocardial I/R injury has not been clearly demonstrated. Mice with cardiac-restricted knockdown or overexpression of were exposed to I/R surgery. H9c2 cells were cultured and subjected to hypoxia/reoxygenation (H/R) stimulation to further verify the role and underlying mechanisms of in vitro. Histological examination, molecular detection, and functional parameters were determined in vivo and in vitro. In response to I/R or H/R treatment, expression was increased in a bromodomain-containing protein 4-dependent manner. Cardiac-restricted knockdown of exacerbated, whereas overexpression prevented I/R-induced oxidative stress, cardiac myocyte apoptosis, and cardiac dysfunction. Mechanistically, we observed that exerted its beneficial effects via activating AMP-activated protein kinase alpha (AMPK). Further detection revealed that activated AMPK through regulating the enhancer of zeste homolog 2/microRNA-451/calcium-binding protein 39 (EZH2//Cab39) axis. We provide the evidence that endogenous lncRNA is an essential negative regulator for oxidative stress and cardiac myocyte apoptosis in myocardial I/R injury, which is dependent on AMPK activation via the EZH2//Cab39 axis.
Non-coding RNAs as therapeutic targets for preventing myocardial ischemia-reperfusion injury.
Ong Sang-Bing,Katwadi Khairunnisa,Kwek Xiu-Yi,Ismail Nur Izzah,Chinda Kroekkiat,Ong Sang-Ging,Hausenloy Derek J
Expert opinion on therapeutic targets
INTRODUCTION:New treatments are required to improve clinical outcomes in patients with acute myocardial infarction (AMI), for reduction of myocardial infarct (MI) size and preventing heart failure. Following AMI, acute ischemia/reperfusion injury (IRI) ensues, resulting in cardiomyocyte death and impaired cardiac function. Emerging studies have implicated a fundamental role for non-coding RNAs (microRNAs [miRNA], and more recently long non-coding RNAs [lncRNA]) in the setting of acute myocardial IRI. Areas covered: In this article, we discuss the roles of miRNAs and lncRNAs as potential biomarkers and therapeutic targets for the detection and treatment of AMI, review their roles as mediators and effectors of cardioprotection, particularly in the settings of interventions such as ischemic pre- and post-conditioning (IPC & IPost) as well as remote ischemic conditioning (RIC), and highlight future strategies for targeting ncRNAs to reduce MI size and prevent heart failure following AMI. Expert opinion: Investigating the roles of miRNAs and lncRNAs in the setting of AMI has provided new insights into the pathophysiology underlying acute myocardial IRI, and has identified novel biomarkers and therapeutic targets for detecting and treating AMI. Pharmacological and genetic manipulation of these ncRNAs has the therapeutic potential to improve clinical outcomes in AMI patients.
Expression profiling and ontology analysis of long noncoding RNAs in post-ischemic heart and their implied roles in ischemia/reperfusion injury.
Liu Youbin,Li Guangnan,Lu Huimin,Li Wei,Li Xianglu,Liu Huimin,Li Xingda,Li Tianyu,Yu Bo
Long noncoding RNAs (lncRNAs) play important regulatory roles in cellular physiology. The contributions of lncRNAs to ischemic heart disease remain largely unknown. The aim of this study was to investigate the profile of myocardial lncRNAs and their potential roles at early stage of reperfusion. lncRNAs and mRNAs were profiled by microarray and the expression of some highly-dysregulated lncRNAs was further validated using polymerase chain reaction. Our results revealed that 64 lncRNAs were up-regulated and 87 down-regulated, while 50 mRNAs were up-regulated and 60 down-regulated in infarct region at all reperfusion sampled. Gene ontology analysis indicated that dysregulated transcripts were associated with immune response, spermine catabolic process, taxis, chemotaxis, polyamine catabolic process, spermine metabolic process, chemokine activity and chemokine receptor binding. Target gene-related pathway analysis showed significant changes in cytokine-cytokine receptor interaction, the chemokine signaling pathway and nucleotide oligomerization domain (NOD)-like receptor signaling pathway which have a close relationship with myocardial ischemia/reperfusion injury (MI/RI). Besides, a gene co-expression network was constructed to identify correlated targets of 10 highly-dysregulated lncRNAs. These lncRNAs may play their roles by this network in post-ischemic heart. Such results provide a foundation for understanding the roles and mechanisms of myocardial lncRNAs at early stage of reperfusion.
Long Noncoding RNA AK12348 is Involved in the Regulation of Myocardial Ischaemia-Reperfusion Injury by Targeting PARP and Caspase-3.
Zheng Chengfei,Wu Ziheng,Tian Lu,Li Donglin,Wang Xiaohui,He Yunjun,He Yangyan,Jin Wei,Li Ming,Zhu Qianqian,Shang Tao,Zhang Hongkun
Heart, lung & circulation
BACKGROUD:Recently long non-coding RNAs (lncRNAs) have attracted attention in several biomedical fields. The purpose of this study is to investigate the profile of myocardial lncRNAs and their potential roles in myocardial ischaemia-reperfusion injury (IRI). METHODS:EdgeR bioconductor package was used to screen differentially expressed lncRNAs in myocardial IRI, and lncRNA AK12348 was selected. The mRNA levels of lncRNA AK12348 in normal and anoxia/reoxygenation (A/R) cardiomyocytes were determined by qRT-PCR. After transfection with siRNA-lncRNA, AK12348, LDH release and cell apoptotic rates in normal and A/R cardiomyocytes were determined. The protein expression values of PARP and Caspase-3 were also determined by western blotting. RESULTS:The relative level of lncRNA AK12348, LDH release and cell apoptotic rate in A/R cardiomyocytes was significantly higher than that in normal cardiomyocytes. After transfection with siRNA-lncRNA AK12348, LDH release and cell apoptotic rates in A/R cardiomyocytes were reduced, while the values in normal cardiomyocytes had almost no change. The protein expression values of PARP and Caspase-3 in A/R cardiomyocytes were much higher than the Control. After knockdown of lncRNA AK12348, the values decreased. CONCLUSION:Long non-coding RNAs AK12348 could be potential therapeutic targets for the treatment of myocardial IRI.
RNA sequencing revealing the role of AMP-activated protein kinase signaling in mice myocardial ischemia reperfusion injury.
Sun Huankun,Wang Jiaoni,Que Jiaqun,Peng Yangpei,Yu Yongwei,Wang Lei,Ye Haihao,Huang Kaiyu,Xue Yangjing,Zhou Yingying,Ji Kangting
Long non-coding RNAs (lncRNA) and circular RNAs (circRNA) that sponge miRNAs could indirectly regulate gene expression, contributing to certain biological processes. This study aimed to investigate the role of non-coding RNAs in the pathogenesis of myocardial ischemia reperfusion-injury (MIRI). MIRI in male C57B/6J mice was induced by left anterior descending coronary artery ligation occlusion for 30 min, and 4 h of reperfusion. RNA sequencing was performed to obtain the mRNA and non-coding RNA expression profiles of the MIRI and sham groups. Bioinformatic methods were used to analyze the co-expression RNAs, miRNA binding sites and competitive endogenous RNA (ceRNA) pairs. Differentially expressed RNAs were identified with a cutoff fold change > 2 and p < 0.05. A total of 64 mRNAs were upregulated and 98 mRNAs were downregulated, and 10 lncRNAs were upregulated and 10 lncRNAs were downregulated. All altered (p < 0.05) mRNAs were selected for gene ontology and pathway analysis. The AMP-activated protein kinase (AMPK) signaling pathway was enriched in the downregulated genes, and the activation of AMPK was confirmed by western blotting. The lncRNA co-expression network and ceRNA network base on genes in AMPK signaling pathway were then constructed, revealing that ENSMUST00000147762.7 and TUCP_000184 might be key regulators in MIRI induced AMPK activation. The expression levels of AMPK signaling-related RNAs and those involved in the ceRNA network were validated using qRT-PCR. Overall, this study identified potential new targets on AMPK signaling in MIRI.
Long noncoding RNA NEAT1 sponges miR-495-3p to enhance myocardial ischemia-reperfusion injury via MAPK6 activation.
Luo Man,Sun Qingsong,Zhao Hongmei,Tao Jiali,Yan Dongsheng
Journal of cellular physiology
The biological function of long noncoding RNA NEAT1 has been revealed in a lot of diseases. Nevertheless, it is still not yet clear whether NEAT1 can modulate the process of myocardial ischemia-reperfusion injury (M-I/R). Here, we reported that NEAT1 was able to sponge miR-495-3p to contribute to M-I/R injury through activating mitogen-activated protein kinase 6 (MAPK6). First, elevated expression of NEAT1 was revealed in M-I/R injury mice, meanwhile, lactate dehydrogenase (LDH) and creatine kinase-muscle/brain (CK-MB) were also upregulated in the serum. Meanwhile, as previously reported, miR-495 serves as a tumor suppressor or an oncogenic miRNA in different types of cancer. Currently, we found miR-495-3p was remarkably reduced in M-I/R mice. Additionally, NEAT1 was significantly induced whereas miR-495-3p was greatly reduced by H O treatment in H9C2 cells. Moreover, loss of NEAT1 in H9C2 cells could repress the viability and proliferation of cells. For another, overexpression of NEAT1 exhibited an opposite phenomenon. Furthermore, LDH release and caspase-3 activity were obviously triggered by upregulation of NEAT1 while suppressed by NEAT1 knockdown. miR-495-3p was indicated and validated as a target of NEAT1 using the analysis of bioinformatics. Interestingly, we observed that miR-495-3p mimics repressed tumor necrosis factor-α (TNF-α), interleukin-1β (IL-1β), and IL-18 protein expression while their levels were enhanced by the inhibition of miR-495-3p in H9c2 cells. Subsequently, it was manifested that MAPK6 was a target of miR-495-3p, which could exert a lot in the NEAT1/miR-495-3p-mediated M-I/R injury. Overall, our results implied that NEAT1 contributed to M-I/R injury via the modulation of miR-495-3p and MAPK6.
Down-regulation of lncRNA KCNQ1OT1 protects against myocardial ischemia/reperfusion injury following acute myocardial infarction.
Li Xin,Dai Yingnan,Yan Shujun,Shi Yanli,Han Baihe,Li Jingxiu,Cha Li,Mu Jianjun
Biochemical and biophysical research communications
This study aimed to investigate the protective effects of long non-coding RNA KCNQ1OT1 against myocardial ischemia/reperfusion (I/R) injury following acute myocardial infarction, as well as its regulatory mechanism. We used the cardiac muscle H9c2 cells under condition of oxygen glucose deprivation followed by reperfusion (OGD/R) to induce myocardial I/R injury. Then H9C2 cells were transfected with si-NC, si-KCNQ1OT1, pc-NC, pc-KCNQ1OT1, si-AdipoR1 and si-AdipoR2, respectively. The myocardial cell viability and apoptosis were respectively detected. In addition, the expression levels of inflammatory factors, apoptosis-related proteins and p38 MAPK/NF-κB pathway-related proteins were detected. Besides, an inhibitor of p38 MAPK/NF-κB pathway SB203580 was used to treat cells to verify the relationship between KCNQ1OT1 and p38 MAPK/NF-κB pathway. The expression of KCNQ1OT1 was significantly up-regulated in OGD/R-induced myocardial H9C2 cells. The OGD/R-induced decreased cell viability and AdipoR1 expression could be reversed after suppression of KCNQ1OT1. In addition, suppression of KCNQ1OT1 reduced OGD/R-induced increased expressions of TNF-α, IL-6 and IL-1β and OGD/R-induced increased cell apoptosis, which were reversed after knockdown of AdipoR1. Besides, suppression of KCNQ1OT1 significantly down-regulated the OGD/R-induced increased expression of p-p38 and p-NF-κB, which were also reversed after knockdown of AdipoR1. Moreover, SB203580, an inhibitor of p38 MAPK/NF-κB signal pathway, could further enhance the inhibitory effects of KCNQ1OT1 suppression on the expression of p-p38, TNF-α, IL-6, IL-1β and p-NF-κB in OGD/R-induced myocardial H9C2 cells. Suppression of KCNQ1OT1 may prevent myocardial I/R injury following acute myocardial infarction via regulating AdipoR1 and involving in p38 MAPK/NF-κB signal pathway.
Long non-coding RNA-ROR aggravates myocardial ischemia/reperfusion injury.
Zhang Weiwei,Li Ying,Wang Peng
Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas
Long non-coding RNAs (lncRNAs) play an important role in the pathogenesis of cardiovascular diseases, especially in myocardial infarction and ischemia/reperfusion (I/R). However, the underlying molecular mechanism remains unclear. In this study, we determined the role and the possible underlying molecular mechanism of lncRNA-ROR in myocardial I/R injury. H9c2 cells and human cardiomyocytes (HCM) were subjected to either hypoxia/reoxygenation (H/R), I/R or normal conditions (normoxia). The expression levels of lncRNA-ROR were detected in serum of myocardial I/R injury patients, H9c2 cells, and HCM by qRT-PCR. Then, levels of lactate dehydrogenase (LDH), malondialdehyde (MDA), superoxide dismutase (SOD), and glutathione peroxidase (GSH-PX) were measured by kits. Cell viability, apoptosis, apoptosis-associated factors, and p38/MAPK pathway were examined by MTT, flow cytometry, and western blot assays. Furthermore, reactive oxygen species (ROS) production was determined by H2DCF-DA and MitoSOX Red probes with flow cytometry. NADPH oxidase activity and NOX2 protein levels were measured by lucigenin chemiluminescence and western blot. Results showed that lncRNA-ROR expression was increased in I/R patients and in H/R treatment of H9c2 cells and HCM. Moreover, lncRNA-ROR significantly promoted H/R-induced myocardial injury via stimulating release of LDH, MDA, SOD, and GSH-PX. Furthermore, lncRNA-ROR decreased cell viability, increased apoptosis, and regulated expression of apoptosis-associated factors. Additionally, lncRNA-ROR increased phosphorylation of p38 and ERK1/2 expression and inhibition of p38/MAPK, and rescued lncRNA-ROR-induced cell injury in H9c2 cells and HCM. ROS production, NADPH oxidase activity, and NOX2 protein levels were promoted by lncRNA-ROR. These data suggested that lncRNA-ROR acted as a therapeutic agent for the treatment of myocardial I/R injury.
Down-regulation of myocardial infarction associated transcript 1 improves myocardial ischemia-reperfusion injury in aged diabetic rats by inhibition of activation of NF-κB signaling pathway.
Liu Yaoxia,Wang Tao,Zhang Min,Chen Ping,Yu Yerong
OBJECTIVE:This study is performed to investigate the effect of long chain noncoding RNA myocardial infarction associated transcript 1 (MIRT1) on myocardial ischemia reperfusion (I/R) injury in aged diabetic rats. METHODS:The aged diabetic rat model and myocardial I/R injury model were established. Through injecting MIRT1 siRNA into caudal vein of rats, the cardiac function, myocardial pathological injury, myocardial fibrosis, cardiomyocytes apoptosis, oxidative stress and inflammatory injury of myocardial tissue of rats were measured. RESULTS:For diabetic I/R rats, the expression of MIRT1 in myocardial tissue was increased, the activation of nuclear factor kappa B (NF-κB) signaling pathway was increased, the degree of damage to cardiac function was aggravated, the area of myocardial pathological injury and myocardial fibrosis was enlarged, the degree of cardiomyocytes apoptosis was increased, the degree of oxidative stress and inflammatory injury was increased. After inhibiting the expression of MIRT1, the activation of NF-κB signaling pathway was inhibited, the damage of cardiac function and cardiomyopathy was alleviated, the area of myocardial fibrosis was decreased, the degree of myocardial apoptosis was decreased, the degree of oxidative stress and inflammatory injury was obviously improved. CONCLUSION:Our study highlights that down-regulation of MIRT1 improves myocardial I/R injury in aged diabetic rats by inhibition of activation of NF-κB signaling pathway.
Insight into long noncoding RNA-miRNA-mRNA axes in myocardial ischemia-reperfusion injury: the implications for mechanism and therapy.
Xiong Wei,Qu Yan,Chen Hongmei,Qian Jinqiao
Emerging evidence has demonstrated that regulatory noncoding RNAs (ncRNAs), such as long noncoding RNAs (lncRNAs) and miRNAs, play crucial roles in the initiation and progress of myocardial ischemia-reperfusion injury (MIRI), which is associated with autophagy, apoptosis and necrosis of cardiomyocytes, as well as oxidative stress, inflammation and mitochondrial dysfunction. LncRNAs serve as a precursor or host of miRNAs and directly/indirectly affecting miRNAs via competitive binding or sponge effects. Simultaneously, miRNAs post-transcriptionally regulate the expression of genes by targeting various mRNA sequences due to their imperfect pairing with mRNAs. This review summarizes the potential regulatory role of lncRNA-miRNA-mRNA axes in MIRI and related molecular mechanisms of cardiac disorders, also provides insight into the potential therapies for MIRI-induced diseases.
Noncoding transcribed ultraconserved region (T-UCR) UC.48+ is a novel regulator of high-fat diet induced myocardial ischemia/reperfusion injury.
Ding Lu,Gong Chengxin,Zhao Jiani,Liu Xingzi,Li Tao,Rao Shenqiang,Wang Shuo,Liu Yuanyuan,Peng Shanping,Xiao Wen,Xiong Chaopeng,Wang Rumeng,Liang Shangdong,Xu Hong
Journal of cellular physiology
Increasing evidence has suggested high-fat diet (HFD) is an independent risk factor for myocardial ischemia/reperfusion (MI/R) injury. Long noncoding RNAs (lncRNAs) recently attracted much attraction in the study of MI/R injury. However, the functional questions of specific lncRNAs in HFD-induced MI/R injury have not been well elucidated. Uc.48+ is a lncRNA from a transcribed ultraconserved region (T-UCR) of human, mouse, and rat genomes. Here, we explored the aggravating role of uc.48+and identified purinergic P2X7 receptor (P2X7R) as a downstream regulator of uc.48+ in HFD-induced MI/R vulnerability. We demonstrated uc.48+ expression was upregulated, accompanied by the corresponding upregulation of P2X7R in HFD I/R myocardium and HFD-induced MI/R vulnerability. Overexpression of uc.48+enhanced, whereas silencing of uc.48 + decreased the expression of P2X7R, cardiomyocyte apoptosis, and MI/R injury. The functional relevance of uc.48+ regulated P2X7R expression and the subsequent NF-κB signaling to promote cardiomyocyte apoptosis was supported by inhibition of P2X7R with its specific antagonist (A438079) as well as the inhibitor of NF-κB signaling (pyrrolidine dithiocarbamate, PDTC) in H9c2 hypoxia/reoxygenation (H/R) cells transfected with pcDNA3.0-uc.48 + plasmid, and RNA immunoprecipitation (RIP) suggested uc.48+ could interact with transcription factor Sp1. Importantly, Sp1 inhibitor (mithramycin, MIT) was found to suppress uc.48+ -induced P2X7R expression and the NF-κB signaling and cardiomyocyte apoptosis. Our findings provide a potential novel mechanism through which uc.48+ boosts cardiomyocyte apoptosis and MI/R vulnerability to HFD. Thus, uc.48+ is a novel regulator of HFD-induced MI/R injury; targeting uc.48+ may be a novel therapeutic approach of MI/R vulnerability to HFD.
LncRNA TUG1 protects against cardiomyocyte ischaemia reperfusion injury by inhibiting HMGB1.
Shi Hanyu,Dong Zhenhua,Gao Haiqing
Artificial cells, nanomedicine, and biotechnology
The aim of this study was to investigate whether lncRNA TUG1 could mediate the progression of ischemia-reperfusion injury following acute myocardial infraction. Mouse cardiomyocytes HL-1 cells were subjected to oxygen glucose deprivation followed by reperfusion (OGD/R) to induce myocardial I/R injury. The expression of TUG1 was detected by real-time PCR. Overexpression or down expression of TUG1 was performed in mouse HL-1 cardiomyocytes. The myocardial cell viability and apoptosis were respectively detected. In addition, the expression levels of inflammatory factors, apoptosis-related proteins and HMGB1 proteins were detected. Besides, an inhibitor of HMGB1 was used to treat cells to verify the relationship between TUG1 and HMGB1 protein. The expression of TUG1 was significantly up-regulated in OGD/R-induced myocardial HL-1 cells. The overexpression of TUG1-induced inflammation and apoptosis in OGD-R-induced myocardial HL-1 cells. Knock down of TUG1 protected OGD/R-induced myocardial I/R injury by inhibiting HMGB1 expression. Suppression of lncRNA TUG1 may prevent myocardial I/R injury following acute myocardial infarction via inhibiting HMGB1 expression.
Long noncoding RNA-MEG3 contributes to myocardial ischemia-reperfusion injury through suppression of miR-7-5p expression.
Zou Liyuan,Ma Xiaokun,Lin Shuo,Wu Bingyuan,Chen Yang,Peng Chaoquan
Long noncoding RNA (lncRNA) maternally expressed gene 3 (MEG3) plays an important role in protection of ischemia-reperfusion (I/R) injury in brain and liver. However, role of MEG3 in myocardial I/R injury remains unclear. Here, the role of MEG3 in protection of myocardial I/R injury and its association with microRNA-7-5p (miR-7-5p) was investigated using rat cardiac I/R model and myocardial I/R cell model. Our results showed that MEG3 was significantly up-regulated and miR-7-5p was significantly down-regulated after I/R. Following I/R, the levels of intact PARP and intact caspase-3 were reduced, while the cleaved fragments of PARP and caspase-3 were increased. TUNEL assay showed an increase in cardiomyocyte apoptosis after I/R. The levels of I/R-induced creatine kinase (CK) and lactate dehydrogenase (LDH) were inhibited by knockdown of MEG3 (siMEG3). SiMEG3 increased cell proliferation and inhibited cell apoptosis after I/R. In contrast, overexpression of MEG3 increased the I/R-induced CK and LDH activities and cell apoptosis and decreased cell proliferation. The dual-luciferase reporter system showed a direct binding of MEG3 to miR-7-5p. The level of miR-7-5p was negatively associated with the change in levels of MEG3 in H9c2 cells. The levels of intact RARP1 and caspase-3 were significantly increased by knockdown of MEG3. Co-transfection of miR-7-5p inhibitor with siMEG3 activates CK and LDH, significantly decreased cell proliferation, increased cell apoptosis, and decreased intact poly(ADP-ribose) polymerase 1 (PARP1) and caspase-3. In summary, down-regulation of MEG3 protects myocardial cells against I/R-induced apoptosis through miR-7-5p/PARP1 pathway, which might provide a new therapeutic target for treatment of myocardial I/R injury.
Knockdown of lncRNA AK139328 alleviates myocardial ischaemia/reperfusion injury in diabetic mice via modulating miR-204-3p and inhibiting autophagy.
Yu Si-Yang,Dong Bo,Fang Zhen-Fei,Hu Xin-Qun,Tang Liang,Zhou Sheng-Hua
Journal of cellular and molecular medicine
This study was aimed at investigating the effects of lncRNA AK139328 on myocardial ischaemia/reperfusion injury (MIRI) in diabetic mice. Ischaemia/reperfusion (I/R) model was constructed in normal mice (NM) and diabetic mice (DM). Microarray analysis was utilized to identify lncRNA AK139328 overexpressed in DM after myocardial ischaemia/reperfusion (MI/R). RT-qPCR assay was utilized to investigate the expressions of lncRNA AK139328 and miR-204-3p in cardiomyocyte and tissues. Left ventricular end diastolic diameter (LVEDD), left ventricular end systolic diameter (LVESD), left ventricular ejection fraction (LVEF) and fractioning shortening (FS) were obtained by transthoracic echocardiography. Haematoxylin-eosin (HE) staining and Masson staining were utilized to detect the damage of myocardial tissues degradation of myocardial fibres and integrity of myocardial collagen fibres. Evans Blue/TTC staining was used to determine the myocardial infarct size. TUNEL staining was utilized to investigate cardiomyocyte apoptosis. The targeted relationship between lncRNA AK139328 and miR-204-3p was confirmed by dual-luciferase reporter gene assay. MTT assay was used for analysis of cardiomyocyte proliferation. Western blot was utilized to investigate the expression of alpha smooth muscle actin (α-SMA), Atg7, Atg5, LC3-II/LC3-I and p62 marking autophagy. Knockdown of lncRNA AK139328 relieved myocardial ischaemia/reperfusion injury in DM and inhibited cardiomyocyte autophagy as well as apoptosis of DM. LncRNA AK139328 modulated miR-204-3p directly. MiR-204-3p and knockdown of lncRNA AK139328 relieved hypoxia/reoxygenation injury via inhibiting cardiomyocyte autophagy. Silencing lncRNA AK139328 significantly increased miR-204-3p expression and inhibited cardiomyocyte autophagy, thereby attenuating MIRI in DM.
Long non-coding RNA nuclear-enriched abundant transcript 1 inhibition blunts myocardial ischemia reperfusion injury via autophagic flux arrest and apoptosis in streptozotocin-induced diabetic rats.
Ma Min,Hui Jie,Zhang Qi-Yin,Zhu Ye,He Yong,Liu Xiao-Jing
BACKGROUND AND AIMS:This study aimed to investigate the effects of long non-coding RNA (lncRNA)-nuclear-enriched abundant transcript (Neat1) on myocardial ischemia reperfusion injury in diabetic rats ex vivo and in vivo. METHODS:Screening for LncRNA Neat1 expression was performed in rat myocardial tissues using microarray analysis and verified by qRT-PCR. Cell viability of rat cardiomyocytes was analyzed by MTT assay. Levels of autophagy-related proteins Atg7, Atg5, LC3-II/LC3-I and p62 were determined by Western blot assay. Left ventricular end diastolic diameter (LVEDD), left ventricular end systolic diameter (LVESD), left ventricular ejection fraction (LVEF) and fractioning shortening were obtained by transthoracic echocardiography. Left ventricular end systolic pressure (LVESP), left ventricular end diastolic pressure (LVEDP), maximum rate of increase or decrease of left ventricular pressure (±dp/dtmax) and heart rate were obtained by computer algorithms and an interactive videographics programme. Myocardial infarct size was determined by Evans blue and triphenyltetrazolium chloride (TTC) staining. Myocardial apoptotic index was analyzed by TUNEL assay and immunohistochemical staining. Autophagic flux was examined by evaluating fluorescent LC3 puncta. RESULTS:Neat1 was highly expressed in ischemia reperfusion-treated diabetic rat myocardial tissues. Overexpression of Neat1 promoted the production of lactate dehydrogenase, inhibited superoxide dismutase content and cardiomyocyte viability. Neat1 overexpression also promoted the production of serum myocardial enzymes, including creatine kinase and creatine kinase-MB, and increased infarct size. By promoting myocardial apoptosis and autophagy, Neat1 aggravated myocardial ischemia reperfusion (I/R) injury in diabetic rats. Neat1 promoted cardiomyocyte autophagy by up-regulating Foxo1 expression to increase hypoxia-reoxygenation injury. CONCLUSIONS:I/R treatment caused more injuries in diabetic rats compared with normal rats. Elevated Neat1 expression aggravates myocardial ischemia reperfusion injury via activation of apoptosis and autophagy in diabetic rats. Foxo1 is one of the molecular mechanisms underlying Neat1-induced autophagy.
Long noncoding RNA RMRP upregulation aggravates myocardial ischemia-reperfusion injury by sponging miR-206 to target ATG3 expression.
Kong Fei,Jin Juan,Lv Xiaolin,Han Yubo,Liang Xue,Gao Yanyu,Duan Xinglin
Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie
OBJECTIVE:Coronary heart disease is a common cause of death and disability worldwide and mainly results from myocardial ischemia-reperfusion (I/R) injury. This study aimed to elucidate the roles and possible mechanism of long noncoding RNA Component Of Mitochondrial RNA Processing Endoribonuclease (RMRP) in protecting against ischemic myocardial injury. MATERIAL AND METHODS:The H9c2 cardiomyocytes were cultured under hypoxia condition to induce myocardial injury. The RMRP expression under hypoxia condition was determined, followed by investigation of the effects of RMRP dysregulation on hypoxia-induced injury in H9c2 cells. In addition, the regulatory relationship between RMRP and miR-206 was detected, and the potential target of miR-206 was identified. Besides, the association of RMRP and activation of PI3K/AKT/mTOR signaling pathway was explored. Furthermore, an in vivo rat model of myocardial I/R injury was established by subjection to 60 min ischemia and subsequently 24 h reperfusion for validation of the role of RMRP in regulating myocardial I/R injury in vivo. RESULTS:The results showed that overexpression of RMRP aggravated hypoxia-induced injury in H9c2 cells. Moreover, miR-206 was negatively regulated by RMRP and overexpression of RMRP aggravated hypoxia injury by downregulation of miR-206. Furthermore, ATG3 was a target of miR-206, and he effects of miR-206 on hypoxia injury were through targeting ATG3. Besides, overexpression of RMRP activated PI3K/AKT/mTOR pathway in hypoxia-treated H9c2 cells, which were reversed by miR-206 overexpression at the same time. Furthermore, in an in vivo rat model of myocardial I/R injury, suppression of RMPR improved cardiac function and inhibited apoptosis after myocardial I/R injury. CONCLUSIONS:Our findings reveal that upregulation of RMRP may aggravate myocardial I/R injury possible by downregulation of miR-206 and subsequently upregulation of ATG3. Activation of PI3K/Akt/mTOR pathway may be a key downstream mechanism mediating the cardioprotection of RMPR/miR-206/ATG3 axis against myocardial I/R injury.
Suppression of long noncoding RNA NEAT1 attenuates hypoxia-induced cardiomyocytes injury by targeting miR-378a-3p.
Zhao Jiali,Chen Fudi,Ma Wei,Zhang Peng
BACKGROUND/AIMS:lncRNA NEAT1 is involved in the development of many diseases. However, the function of lncRNA NEAT1 in myocardial infarction is unclear. Therefore, this experimental design based on lncRNA NEAT1 to explore the pathogenesis of myocardial infarction. METHODS:RT-qPCR was used to detect the expression of lncRNA NEAT1 and miR-378a-3p in peripheral blood and mouse cardiomyocytes of patients with myocardial infarction. MTT assay, flow cytometry, Caspase-3 kit and transwell assay were used to detect the effects of lncRNA NEAT1 and miR-378a-3p on cardiomyocyte proliferation, apoptosis and migration. Target gene prediction and screening, luciferase reporter assays were used to verify downstream target genes for lncRNA NEAT1 and miR-378a-3p. Western blotting was used to detect the protein expression of Atg12 and related autophagy genes. RESULTS:lncRNA NEAT1 was highly expressed in peripheral blood and mouse cardiomyocytes of patients with myocardial infarction. Moreover, lncRNA NEAT1 significantly promoted cell proliferation and migration of cardiomyocytes. In addition, lncRNA NEAT1 inhibited miR-378a-3p expression, and miR-378a-3p inhibited Atg12 expression, while lncRNA NEAT1 regulated expression of Atg12 and related autophagic factors via miR-378a-3p. Knockout of microRNA-378-3p reversed the effects of NEAT1 silencing on cell damage. CONCLUSION:lncRNA NEAT1 can regulate the proliferation of cardiomyocytes by regulating miR-378-3p/Atg12 axis, thus accelerating the occurrence and development of cardiomyocytes.
Long Noncoding RNAs: New Players in Ischaemia-Reperfusion Injury.
Yu Si-Yang,Tang Liang,Zhou Sheng-Hua
Heart, lung & circulation
Long noncoding RNAs (lncRNAs) constitute a new class of noncoding RNAs that interfere with gene expression. It has been shown that lncRNAs exert comprehensive effects on biological processes and are associated with numerous diseases such as cancer. However, the possible role of lncRNAs in ischaemia/reperfusion (I/R) injury have received relatively little attention. Accumulating evidence indicates that lncRNAs are also involved in the progression of I/R injury such as myocardial, cerebral, hepatic, renal and mesenteric I/R injury. In this review, we summarise the current knowledge of lncRNAs in I/R injury, attempting to better explain the molecular mechanism of I/R injury and provide new directions for its therapy.
LncRNA HIF1A-AS1 contributes to ventricular remodeling after myocardial ischemia/reperfusion injury by adsorption of microRNA-204 to regulating SOCS2 expression.
Xue Xiang,Luo Libo
Cell cycle (Georgetown, Tex.)
: Long non-coding RNAs (lncRNAs) serve pivotal roles in heart disease, while the role of lncRNA hypoxia-inducible factor 1α-antisense RNA 1 (HIF1A-AS1) is rarely mentioned. Therefore, the objective of this study was to investigate the mechanism of lncRNA HIF1A-AS1 regulating suppressor of cytokine signaling 2 (SOCS2) expression by adsorption of microRNA-204 (miR-204) on ventricular remodeling after myocardial ischemia-reperfusion (I/R) injury in mice. : The mouse model of I/R was established by left coronary artery occlusion. The expression of HIF1A-AS1, miR-204 and SOCS2 was determined. The mice were injected with HIF1A-AS1-siRNA, miR-204 mimics or their controls to investigate their effects on cardiac function and ventricular remodeling of mice after I/R injury. The binding relationship between HIF1A-AS1 and miR-204 as well as between miR-204 and SOCS2 were verified. : HIF1A-AS1 and SOCS2 were upregulated and miR-204 was downregulated in myocardial tissues in mice after I/R injury. LVEDD, LVEDS, LVEDP, LVMI and RVMI expression reduced while LVEF, LVFS, +dp/dt max and - dp/dt max increased through knockdown HIF1A-AS1 and upregulated miR-204. The expression of BNP, cTnI, LDH, CK, TNF-α, IL-1β, IL-6 and β-MHC reduced, and the expression of α-MHC increased when HIF1A-AS1 was poorly expressed and miR-204 was highly expressed. Silencing HIF1A-AS1 and upregulating miR-204 inhibited apoptosis of cells. LncRNA HIF1A-AS1 could act as ceRNA to adsorb miR-204 to suppress miR-204 expression and elevate SOCS2 expression. : Our study provides evidence that downregulation of HIF1A-AS1 and upregulation of miR-204 could alleviate ventricular remodeling and improve cardiac function in mice after myocardial I/R injury via regulating SOCS2.
Inhibition of the LncRNA Gpr19 attenuates ischemia-reperfusion injury after acute myocardial infarction by inhibiting apoptosis and oxidative stress via the miR-324-5p/Mtfr1 axis.
Huang Liu,Guo Bingyan,Liu Suyun,Miao Chenglong,Li Yongjun
Reperfusion therapy after acute myocardial infarction (AMI) can effectively restore the blood supply and nutritional support of ischemic myocardium and save the dying myocardium. However, myocardial ischaemia-reperfusion (I/R) injury has become a new threat to reperfusion therapy for AMI. Many long-chain noncoding RNAs (lncRNAs) are dysregulated by I/R damage. Of these dysregulated lncRNAs, Gpr19 was selected as a potential gene of interest based on its high expression change. We aimed to explore the functional role and molecular mechanism of Gpr19 in I/R injury of AMI. C57BL/6 mice underwent I/R injury as in vivo models. Neonatal rat ventricular cardiomyocytes (NRCMs) exposed to an oxygen glucose deprivation/recovery (OGD/R) system were used as an in vitro model. A TUNEL assay, western blot, and oxidative stress analysis were conducted in this study to determine apoptosis and oxidative stress levels. Our results indicated that inhibition of Gpr19 improves cardiac function and reduces apoptosis and myocardial fibrosis scar formation in vivo. Suppression of Gpr19 attenuates oxidative stress and apoptosis in NRCMs exposed to OGD/R. We further demonstrated that inhibition of Gpr19 decreases oxidative stress and apoptosis in OGD/R-induced NRCMs by regulating miR-324-5p and mitochondrial fission regulator 1 (Mtfr1). We elucidated the functional role and potential molecular mechanism of Gpr19 in I/R injury of AMI, provided a theoretical basis for the importance of Gpr9 in I/R injury, and provided a new perspective for the clinical treatment of I/R injury of AMI.
LncRNA PEAMIR inhibits apoptosis and inflammatory response in PM2.5 exposure aggravated myocardial ischemia/reperfusion injury as a competing endogenous RNA of miR-29b-3p.
Pei Ying-Hao,Chen Jie,Wu Xiang,He Yun,Qin Wei,He Shu-Yin,Chang Ning,Jiang Hua,Zhou Jiang,Yu Peng,Shi Hai-Bo,Chen Xiao-Hu
The sensitivity of myocardium is enhanced to ischemia/reperfusion (I/R) injury under PM2.5 exposure. It is still under prelude for lncRNA-miRNA pair in the study of aggravated myocardial I/R injury under PM2.5 exposure. In this study, we first built a rat model of 30 min ischemia and 24 h reperfusion followed PM2.5 (6.0 mg/kg) exposure. We found PM2.5 exposure could obviously aggravate I/R injury in the fields of myocardium damage, apoptosis levels and cardiac function which were evaluated by TTC staining, TUNEL and echocardiography, respectively. Then, based on results of sequencing and RT-qPCR, we selected NONRATT003473.2 in the follow-up experiments and named this lncRNA as PM2.5 exposure aggravated myocardial I/R injury lncRNA (PEAMIR). Consistent with the results rat model, we confirmed PEAMIR to be a protective lncRNA against PM + HR triggered damages in H9c2 cells. Next, according to the bioinformatics analysis from miRanda database and a series of gain- and loss-of-function experiments, we proved PEAMIR to be a ceRNA for miR-29b-3p to inhibit cardiac inflammation and apoptosis. Finally, using Target-Scan database, the conserved binding sites for miR-29b-3p was identified in the 3'UTR of PI3K (p85a), a key protein of apoptosis. Our subsequent experiments validated the regulatory relationship between PEAMIR-miR-29b-3p ceRNA pair and PI3K (p85a)/Akt/GSK3b/p53 cascade pathway. In conclusion, our study demonstrated the role and mechanism of PEAMIR in the augment of I/R injury under PM2.5 exposure, suggesting a promising strategy for the prevention and treatment of I/R injury under PM2.5 exposure.
The long noncoding RNA NRF regulates programmed necrosis and myocardial injury during ischemia and reperfusion by targeting miR-873.
Wang K,Liu F,Liu C-Y,An T,Zhang J,Zhou L-Y,Wang M,Dong Y-H,Li N,Gao J-N,Zhao Y-F,Li P-F
Cell death and differentiation
Emerging evidences suggest that necrosis is programmed and is one of the main forms of cell death in the pathological process in cardiac diseases. Long noncoding RNAs (lncRNAs) are emerging as new players in gene regulation. However, it is not yet clear whether lncRNAs can regulate necrosis in cardiomyocytes. Here, we report that a long noncoding RNA, named necrosis-related factor (NRF), regulates cardiomyocytes necrosis by targeting miR-873 and RIPK1 (receptor-interacting serine/threonine-protein kinase 1)/RIPK3 (receptor-interacting serine/threonine-protein kinase 3). Our results show that RIPK1 and RIPK3 participate in H2O2-induced cardiomyocytes necrosis. miR-873 suppresses the translation of RIPK1/RIPK3 and inhibits RIPK1/RIPK3-mediated necrotic cell death in cardiomyocytes. miR-873 reduces myocardial infarct size upon ischemia/reperfusion (I/R) injury in the animal model. In exploring the molecular mechanism by which miR-873 expression is regulated, we identify NRF as an endogenous sponge RNA and repress miR-873 expression. NRF directly binds to miR-873 and regulates RIPK1/RIPK3 expression and necrosis. Knockdown of NRF antagonizes necrosis in cardiomyocytes and reduces necrosis and myocardial infarction upon I/R injury. Further, we identify that p53 transcriptionally activates NRF expression. P53 regulates cardiomyocytes necrosis and myocardial I/R injury through NRF and miR-873.Our results identify a novel mechanism involving NRF and miR-873 in regulating programmed necrosis in the heart and suggest a potential therapeutic avenue for cardiovascular diseases.
MicroRNA-103/107 Regulate Programmed Necrosis and Myocardial Ischemia/Reperfusion Injury Through Targeting FADD.
Wang Jian-Xun,Zhang Xiao-Jie,Li Qian,Wang Kun,Wang Yin,Jiao Jian-Qin,Feng Chang,Teng Sun,Zhou Lu-Yu,Gong Ying,Zhou Zhi-Xia,Liu Jia,Wang Jian-Ling,Li Pei-feng
RATIONALE:Necrosis is one of the main forms of cardiomyocyte death in heart disease. Recent studies have demonstrated that certain types of necrosis are regulated and programmed dependent on the activation of receptor-interacting serine/threonine-protein kinase (RIPK) 1 and 3 which may be negatively regulated by Fas-associated protein with death domain (FADD). In addition, microRNAs and long noncoding RNAs have been shown to play important roles in various biological processes recently. OBJECTIVE:The purpose of this study was to test the hypothesis that microRNA-103/107 and H19 can participate in the regulation of RIPK1- and RIPK3-dependent necrosis in fetal cardiomyocyte-derived H9c2 cells and myocardial infarction through targeting FADD. METHODS AND RESULTS:Our results show that FADD participates in H2O2-induced necrosis by influencing the formation of RIPK1 and RIPK3 complexes in H9c2 cells. We further demonstrate that miR-103/107 target FADD directly. Knockdown of miR-103/107 antagonizes necrosis in the cellular model and also myocardial infarction in a mouse ischemia/reperfusion model. The miR-103/107-FADD pathway does not participate in tumor necrosis factor-α-induced necrosis. In exploring the molecular mechanism by which miR-103/107 are regulated, we show that long noncoding RNA H19 directly binds to miR-103/107 and regulates FADD expression and necrosis. CONCLUSIONS:Our results reveal a novel myocardial necrosis regulation model, which is composed of H19, miR-103/107, and FADD. Modulation of their levels may provide a new approach for preventing myocardial necrosis.
The lncRNA ROR/miR-124-3p/TRAF6 axis regulated the ischaemia reperfusion injury-induced inflammatory response in human cardiac myocytes.
Liang Ying-Ping,Liu Qin,Xu Guo-Hai,Zhang Jing,Chen Yong,Hua Fu-Zhou,Deng Chang-Qing,Hu Yan-Hui
Journal of bioenergetics and biomembranes
Myocardial ischaemia reperfusion injury (MIRI) is considered the primary cause of death in patients with cardiovascular diseases. Recently, long non-coding RNAs (lncRNAs) and microRNAs (miRNAs) have been found to be involved in the pathogenesis of MIRI. However, whether lncRNA ROR and miR-124-3p play roles in MIRI and the underlying mechanism remain undetermined. HCMs were exposed to hypoxic conditions for 2 h followed by re-oxygenation (H/R) treatment. Expression of miR-124-3p and lncRNA ROR in HCMs was measured by qRT-PCR. TRAF6 expression was evaluated by qRT-PCR and western blotting. ELISA and qRT-PCR were conducted to assess the production of TNF-α, IL-6, and IL-1β. The interaction between miR-124-3p and TRAF6, as well as between miR-124-3p and lncRNA ROR, was verified by dual-luciferase reporter assay. Cell apoptosis was detected by flow cytometry analysis. Our data revealed that miR-124-3p was significantly downregulated, while TRAF6 and lncRNA ROR were upregulated in both MIRI rat model and H/R treated HCMs. Overexpression of miR-124-3p reversed the H/R-induced cell apoptosis and upregulation of TNF-α, IL-6, and IL-1β. Mechanistically, miR-124-3p bound and negatively regulated TRAF6 expression in HCMs. Moreover, TRAF6 overexpression significantly blocked the effects of miR-124-3p mimics on cell apoptosis and inflammatory response of HCMs, which involved the NF-κB pathway. Further analysis showed that lncRNA ROR sponged and negatively regulated miR-124-3p in HCMs. Overexpression of IL-1β was demonstrated to promote H/R induced cell apoptosis in HCMs. In addition, overexpression of ROR further enhanced the H/R-induced inflammation and cell apoptosis through its action on miR-124-3p. The lncRNA ROR/miR-124-3p/TRAF6 axis regulated the H/R-induced cell apoptosis and inflammatory response of HCMs.
LncRNA CAIF inhibits autophagy and attenuates myocardial infarction by blocking p53-mediated myocardin transcription.
Liu Cui-Yun,Zhang Yu-Hui,Li Rui-Bei,Zhou Lu-Yu,An Tao,Zhang Rong-Cheng,Zhai Mei,Huang Yan,Yan Kao-Wen,Dong Yan-Han,Ponnusamy Murugavel,Shan Chan,Xu Sheng,Wang Qi,Zhang Yan-Hui,Zhang Jian,Wang Kun
Increasing evidence suggests that long noncoding RNAs (lncRNAs) play crucial roles in various biological processes. However, little is known about the effects of lncRNAs on autophagy. Here we report that a lncRNA, termed cardiac autophagy inhibitory factor (CAIF), suppresses cardiac autophagy and attenuates myocardial infarction by targeting p53-mediated myocardin transcription. Myocardin expression is upregulated upon HO and ischemia/reperfusion, and knockdown of myocardin inhibits autophagy and attenuates myocardial infarction. p53 regulates cardiomyocytes autophagy and myocardial ischemia/reperfusion injury by regulating myocardin expression. CAIF directly binds to p53 protein and blocks p53-mediated myocardin transcription, which results in the decrease of myocardin expression. Collectively, our data reveal a novel CAIF-p53-myocardin axis as a critical regulator in cardiomyocyte autophagy, which will be potential therapeutic targets in treatment of defective autophagy-associated cardiovascular diseases.
Inhibition of lncRNA TUG1 upregulates miR-142-3p to ameliorate myocardial injury during ischemia and reperfusion via targeting HMGB1- and Rac1-induced autophagy.
Su Qiang,Liu Yang,Lv Xiang-Wei,Ye Zi-Liang,Sun Yu-Han,Kong Bing-Hui,Qin Zhen-Bai
Journal of molecular and cellular cardiology
BACKGROUND:Long non-coding RNAs (lncRNAs) play a central role in regulating heart diseases. In the present study, we examined the effects of lncRNA taurine up-regulated gene 1 (TUG1) in ischemia/reperfusion (I/R)- or hydrogen peroxide-challenged cardiomyocytes, with specific focus on autophagy-induced cell apoptosis. METHODS:The expressions of miR-142-3p and TUG1 in HO-challenged cardiomyocytes and I/R-injured heart tissue were measured by RT-qPCR. Cell death was measured by trypan blue staining assay. Cell apoptosis was determined by Annexin V/PI staining and TUNEL assay. Autophagy was examined by quantifying cells or tissues containing LC3 autophagic vacuoles by immunofluorescence, or by measuring the expressions of autophagy-related biomarkers by Western blot. The direct interaction between miR-142-3p and TUG1, high mobility group box 1 protein (HMGB1), or Ras-related C3 botulinum toxin substrate 1 (Rac1) was examined using luciferase reporter assay. The significance of miR-142-3p and TUG1 on cell apoptosis or autophagy was examined using both gain-of-function and loss-of-function approaches. The importance of HMGB1 or Rac1 was assessed using siRNA-mediated gene silencing. RESULTS:miR-142-3p was down-regulated, while TUG1 up-regulated in HO-challenged cardiomyocytes in vitro and I/R-injured heart tissues in vivo. Functionally, inhibition of TUG1 and overexpression of miR-142-3p inhibited cell apoptosis and autophagy in cardiomyocytes. The function of TUG1 were achieved by sponging miR-142-3p and releasing the suppression of the putative targets of miR-142-3p, HMGB1 and Rac1. Both HMGB1 and Rac1 essentially mediated cell apoptosis and autophagy induced by TUG1. CONCLUSIONS:TUG1, by targeting miR-142-3p and up-regulating HMGB1 and Rac1, plays a central role in stimulating autophagic cell apoptosis in ischemia/hypoxia-challenged cardiomyocytes. Down-regulating TUG1 or up-regulating miR-142-3p may ameliorate myocardial injury and protect against acute myocardial infarction.
LncRNA SNHG1 alleviates hypoxia-reoxygenation-induced vascular endothelial cell injury as a competing endogenous RNA through the HIF-1α/VEGF signal pathway.
Liang Shuangchao,Ren Kai,Li Buying,Li Fangkuan,Liang Zhuowen,Hu Jiqiong,Xu Bei,Zhang Andong
Molecular and cellular biochemistry
Long noncoding ribonucleic acids (lncRNAs) are critical regulators in various biological processes. In the present study, we aimed to explore whether miR140-3p was involved in the underlying molecular mechanisms of small nucleolar RNA host gene 1 (SNHG1) in myocardial ischemia/reperfusion (I/R) injury. A mouse model of I/R injury and hypoxia-reoxygenation (H/R)-stimulated human umbilical vein endothelial cells (HUVECs) was used in this study. Cell proliferation was detected by MTT. The mRNA and protein levels of vascular endothelial growth factor (VEGF), VE-cadherin, and MMP2 were detected by RT-PCR and western blot, respectively. The angiogenesis was assessed by tube formation assay. Cell migration was assessed using wound-healing assay. Results showed that SNHG1 expression was increased in the cardiac microvasculature of a mouse model of I/R injury and in H/R-stimulated HUVECs. H/R stimulation significantly reduced cell proliferation, tube formation, and cell migration, but increased expression of VEGF, VE-cadherin, and MMP2. SNHG1 upregulation under H/R increased HUVECs proliferation, tube formation, and cell migration, and upregulated expression of VEGF, VE-cadherin, and MMP2, compared with the H/R group. SNHG1 knockdown exhibited the opposite effect. SNHG1 functioned as a competing endogenous RNA (ceRNA) of miR-140-3p. HIF-1α was identified as a target of miR-140-3p. SNHG1 upregulation enhanced cell proliferation, tube formation, and expression of VEGF, VE-cadherin, and MMP2 through HIF-1α/VEGF signaling. This process could be offset by miR-140-3p mimic or VEGF inhibitor. Our results reveal a novel protective function of SNHG1 that furthers understanding of cardiac I/R injury and provides experimental evidence for future therapy.
Long non-coding RNA MALAT1 regulates cardiomyocytes apoptosis after hypoxia/reperfusion injury via modulating miR-200a-3p/PDCD4 axis.
Sun Rongguo,Zhang Liang
Biomedicine & pharmacotherapy = Biomedecine & pharmacotherapie
Long non-coding RNAs (lncRNAs) have been reported to be crucial modulators in various heart diseases, including myocardial infarction (MI). LncRNA metastasis associated lung adenocarcinoma transcript 1 (MALAT1) has been reported to be highly expressed in MI samples. However, the mechanism and biological function of MALAT1 in myocardial infarction are still marked. Similarly, programmed cell death 4 (PDCD4) was also upregulated in MI samples. Therefore, MALAT1 and PDCD4 were chosen to do further study. At first, qRT-PCR was applied to examine the expression patterns of MALAT1 and PDCD4. The results showed that both MALAT1 and PDCD4 were upregulated in MI mice model and the hypoxia-induced myocardial cell. Subsequently, loss-of function assays were conducted to examine the impacts of MALAT1 or PDCD4 on cellular processes. Results of MTT assay and flow cytometry analyses manifested that knockdown of MALAT1 or PDCD4 enhanced cell viability, promoted cell cycle progress and suppressed cell apoptosis. Transferase-mediated dUTP nick end labeling (TUNEL) assay revealed that MALAT1 knockdown or PDCD4 knockdown decreased cell apoptosis in MI mice model. Subsequently, mechanism experiments revealed that microRNA-200a-3p (miR-200a-3p) could bind to either MALATA1 or PDCD4. Combining with the cytoplasmic location of MALAT1, we confirmed that MALAT1 acted as a competing endogenous RNA (ceRNA) to upregulate PDCD4 by sponging miR-200a-3p. Finally, rescue assay suggested that MALAT1-miR-200a-3p-PDCD4 axis regulated the proliferation, cell cycle progression and apoptosis of hypoxia-induced myocardial cells.
Long noncoding RNA FTX regulates cardiomyocyte apoptosis by targeting miR-29b-1-5p and Bcl2l2.
Long Bo,Li Na,Xu Xi-Xia,Li Xiao-Xin,Xu Xin-Jie,Guo Dan,Zhang Dong,Wu Zhi-Hong,Zhang Shu-Yang
Biochemical and biophysical research communications
Cardiomyocyte apoptosis correlates with the pathogenesis of heart disease. Long noncoding RNA (LncRNA) emerges as a class of noncoding RNAs that regulate gene expression and participate in various cellular processes. However, the role of lncRNAs in cardiomyocyte apoptosis remains to be elucidated. In our study, we found that lncRNA FTX is significantly down-regulated upon ischemia/reperfusion injury and hydrogen peroxide treatment. Enhanced expression of FTX inhibits cardiomyocyte apoptosis induced by hydrogen peroxide. miR-29b-1-5p was found to interact with FTX and regulate the expression of Bcl2l2. Inhibition of miR-29b-1-5p attenuated cardiomyocyte apoptosis upon hydrogen peroxide treatment. We then found that FTX functions as endogenous sponge for miR-29b-1-5p and regulates the activity of miR-29b-1-5p. The results demonstrate that FTX regulates cardiomyocyte apoptosis through modulating the expression of Bcl2l2 which is mediated by miR-29b-1-5p. Our findings reveal a novel regulatory model which is composed of FTX, miR-29b-1-5p and Bcl2l2. Manipulating of their levels may become a new approach to tackling cardiomyocyte apoptosis related heart diseases.
LncRNA MALAT1 knockdown alleviates oxygen-glucose deprivation and reperfusion induced cardiomyocyte apoptotic death by regulating miR-122.
Gong Licheng,Chang Hong,Xu Haiming
Experimental and molecular pathology
BACKGROUND:Metastasis associated lung adenocarcinoma transcript 1 (MALAT1) has been reported to be critical in the onset and progression of acute myocardial ischemia (AMI). This study attempted to reveal the biological function of MALAT1 in AMI. METHODS:Expression of MALAT1 in H9c2 cells was silenced by shRNA-mediated transfection, following which cells were suffered from oxygen-glucose deprivation and reperfusion (OGD/R). CCK-8, flow cytometry and western blot were carried out to evaluate the effects of MALAT1 against OGD/R injury. Further, the correlation between MALAT1, miR-122 and AKT/GSK-3β/β-catenin signaling was studied to decode the underlying mechanisms. RESULTS:MALAT1 expression was highly expressed following OGD/R. Suppression of MALAT1 attenuated OGD/R-induced cardiomyocyte apoptosis, as evidenced by the increase of cell viability and the decrease of apoptosis rate. Besides that, miR-122 was found to be positive regulated by MALAT1. The protective effects of MALAT1 knockdown were flattened by miR-122 overexpression. Furthermore, AKT/GSK-3β/β-catenin signaling was activated by MALAT1 knockdown. The effects of MALAT1 knockdown on the signaling were flattened when miR-122 was overexpressed. CONCLUSION:Our finding revealed protective effects of MALAT1 knockdown on OGD/R induced cardiomyocyte apoptosis. MALAT1 exerted its function possibly through regulating AKT/GSK-3β/β-catenin signaling through up-regulating miR-122.
Long noncoding RNA AK088388 regulates autophagy through miR-30a to affect cardiomyocyte injury.
Wang Jing-Jing,Bie Zi-Dong,Sun Chao-Feng
Journal of cellular biochemistry
Finding ways to reduce myocardial ischemia/reperfusion injury in the process of myocardial infarction has been an area of intense study in the field of heart disease. Recent studies have shown that long noncoding RNA (lncRNA) and autophagy play important roles in cardiovascular diseases. In our study, software analysis and dual-luciferase reporter assays have shown that miR-30a has binding sites on both AK088388 and Beclin-1. Continuing experiments found that miR-30a expression is downregulated, while the expressions of AK088388, Beclin-1, and LC3-II are upregulated in hypoxia/reoxygenation (H/R) cardiomyocytes; miR-30a inhibits the expression of AK088388, Beclin-1, and LC3-II in H/R cardiomyocytes, while AK088388 promotes the expression of Beclin-1 and LC3-II and inhibits miR-30a expression. AK088388 small interfering RNA and miR-30a mimics can promote the viability of H/R cardiomyocytes, reduce lactate dehydrogenase release, and reduce apoptosis. Mutations of the miR-30a binding site in AK088388 could not block the effects of miR-30a mentioned above. Therefore, AK088388 can competitively bind to miR-30a, promoting the expression of Beclin-1 and LC3-II, autophagy, and eventually cell damage. This finding provides new evidence for understanding the role of lncRNA in myocardial ischemia/reperfusion injury.
The lncRNA H19/miR-675 axis regulates myocardial ischemic and reperfusion injury by targeting PPARα.
Luo Hong,Wang Jing,Liu Donghai,Zang Suhua,Ma Ning,Zhao Lixuan,Zhang Liang,Zhang Xin,Qiao Chenhui
Increasing evidence has indicated that lncRNAs and miRNAs play important roles in the pathogenesis of myocardial ischemic and reperfusion (I/R) injury. This study investigated the potential roles and underlying molecular mechanisms of lncRNA H19 and H19-derived miR-675 in regulating myocardial I/R injury in vitro and in vivo. The results showed that expression of H19 and H19-derived miR-675 was upregulated in cardiomyocytes exposed to oxygen-glucose deprivation and reperfusion. Knockdown of H19 increased cell viability, reduced cell apoptosis, decreased inflammatory cytokines (IL-1β, TNF-α and IL-6), inhibited oxidative stress, downregulated p-IκB-α and p-p65, and upregulated expression of Nrf2 and HO-1. All of these effects were partly reversed by overexpression of miR-675. Furthermore, we found that PPARα was a target gene of miR-675 and that H19 negatively regulated PPARα expression via miR-675. By inhibiting PPARα, the biological effects of miR-675 or H19 inhibition on cellular functions (apoptosis, inflammation and oxidative stress) were at least partially reversed. Moreover, knockdown of H19 significantly reduced infarct size, increased left ventricular systolic pressure, and decreased left ventricular end-diastolic pressure in a mouse model of myocardial I/R. Taken together, these data indicate that H19 inhibition protects the heart against myocardial I/R injury, which may be partly attributed to regulation of the miR-675/PPARα axis.
lncRNA expression character associated with ischemic reperfusion injury.
Wu Xiaowei,Zhu Hongyi,Zhu Suhua,Hao Maojuan,Li Qingping
Molecular medicine reports
Ischemic reperfusion injury (IRI) contributes to morbidity and mortality worldwide and results in a poor outcome for patients suffering from myocardial infarction. Ischemic post‑conditioning (IPostC), consisting of one or several brief periods of ischemia and reperfusion, generates powerful protection against IRI. The mechanism of IPostC initiation and development has previously been investigated, however still remains to be fully elucidated. Notably, long non‑coding (lnc) RNAs have previously been demonstrated to be important in cardiovascular diseases. However, there is little information about the systematic analysis of IRI‑associated lncRNA expression signature. The present study used microarrays to analyze the lncRNA expression characters of ischemic IPostc (corresponding to IRI), and demonstrated that 2,292 lncRNAs were observed to be upregulated and 1,848 lncRNAs downregulated. Gene ontology (GO) and Pathway analysis subsequently demonstrated that dysregulated lncRNAs participated in various biological processes, which are upregulated or downregulated in IPostC tissues. Finally, the present study verified that AK144818, ENSMUST00000156637, ENSMUST00000118342, ENSMUST00000118149, uc008ane.1, ENSMUST00000164933, ENSMUST00000162347, ENSMUST00000135945, and ENSMUST00000176338, ENSMUST00000120587, ENDMUST00000155271, ENSMUST00000125121 and Uc008thl.1 were associated with the initiation and development of IPostC. The present study may aid in the understanding of the initiation and development mechanisms of IPostC and provide novel and potential biomarkers that may be used in the diagnosis or as therapeutic targets in the treatment of IRI.
Inhibition of LncRNA-HRIM Increases Cell Viability by Regulating Autophagy Levels During Hypoxia/Reoxygenation in Myocytes.
Huang Zhouqing,Ye Bozhi,Wang Zhengxian,Han Jibo,Lin Lu,Shan Peiren,Cai Xueli,Huang Weijian
Cellular physiology and biochemistry : international journal of experimental cellular physiology, biochemistry, and pharmacology
Backgrund/Aims: Ischemia reperfusion (I/R) promotes the severity of cardiomyocyte injury. Long noncoding RNAs (LncRNAs) are key regulators in cardiovascular diseases. However, the association between LncRNAs and myocardial I/R injury has not been thoroughly characterized to date. We attempted to clarify the potential biological role of a LncRNA (E230034O05Rik), which we named hypoxia/reoxygenation (H/R) injury-related factor in myocytes (HRIM), by investigating the differential expression of LncRNAs between groups of myocytes exposed to either a normal level of oxygen or to H/R. METHODS:Microarray analysis was used to determine analyze the global differential expression of LncRNAs in H9c2 myocytes exposed either to a normal level of oxygen or to H/R. Target LncRNA levels were further verified in vitro and ex vivo by real-time polymerase chain reaction (qPCR). Cell viability was analyzed using the Cell Counting Kit-8 assay. Autophagy levels were confirmed by Western blotting, transmission electron microscopy, and autophagic double-labeled (mRFP-GFP-LC3) adenovirus analyses. RESULTS:Gene expression profiling revealed that 797 LncRNAs and 1898 mRNAs were differentially expressed in the H/R group compared with the normal oxygen group. Among these LncRNAs and mRNAs, 6 upregulated LncRNAs and 2 downregulated LncRNAs in the H/R group were selected and further validated by qPCR in vitro and ex vivo. Additionally, LncRNA-HRIM was inhibited by specific siRNAs in H9c2 myocytes exposed to H/R. The inhibition of LncRNA-HRIM by siRNA prevented cell death by suppressing excessive autophagic activity in myocytes, This finding suggests a detrimental role of LncRNA-HRIM in the regulation of I/R injury. CONCLUSIONS:LncRNAs are involved in H/R injury of H9c2 myocytes. Inhibition of LncRNA-HRIM increased cell viability by reducing autophagy in myocytes during H/R.
LINC-PINT Activates the Mitogen-Activated Protein Kinase Pathway to Promote Acute Myocardial Infarction by Regulating miR-208a-3p.
Zhu Jianzhong,Gu Huimin,Lv Xiaolei,Yuan Chunying,Ni Ping,Liu Feng
Circulation journal : official journal of the Japanese Circulation Society
BACKGROUND:This study is performed to explore the differential expression of long intergenic non-coding-p53 induced non-coding transcript, miR-208a-3p and JUN in acute myocardial infarction (AMI) and their potential mechanisms. Methods and Results: Gene Expression Omnibus, R software, Kyoto Encyclopedia of Genes and Genomes (KEGG) and gene ontology (GO) analysis were used for analyzing the differentially expressed genes (DEGs) and pathways. The differential expressions of LINC-PINT and miR-208a-3p were examined by qRT-PCR. The expressions of JUN and the mitogen-activated protein kinase (MAPK) pathway-related proteins were analyzed by Western blot. The triphenyltetrazolium chloride (TTC) staining and terminal deoxynucleotidyl transferase-mediated dUTP-biotin nick end labeling assay (TUNEL) staining methods were used to measure the myocardial infarction size and tissue apoptosis respectively. The targeted relationships between miR-208a-3p and LINC-PINT or JUN were confirmed using a dual luciferase reporter assay. DEGs were significantly enriched in the MAPK signaling pathway. LINC-PINT could sponge miR-208a-3p, which targeted and regulated JUN. LINC-PINT and JUN were confirmed to be overexpressed in AMI tissues. Silencing LINC-PINT and JUN could exert a protective influence against AMI. The expression of miR-208a-3p was significantly decreased in AMI tissues, and miR-208a-3p reduced myocardial ischemia-reperfusion injury and apoptosis. Downregulation of LINC-PINT facilitated miR-208a-3p expression and suppressed the protein level of JUN, contributing to the inactivation of the MAPK pathway in the AMI tissues and thus generating protective effects. CONCLUSIONS:Knockdown of LINC-PINT inactivated the MAPK pathway by releasing miR-208a-3p and suppressing the JUN, protecting the injury during the process of AMI.
LncRNA MALAT1 prevents the protective effects of miR-125b-5p against acute myocardial infarction through positive regulation of NLRC5.
Liu Zhiyong,Liu Jing,Wei Ying,Xu Jing,Wang Zhaoning,Wang Peng,Sun Hao,Song Zhijing,Liu Qian
Experimental and therapeutic medicine
Acute myocardial infarction (AMI), as the first manifestation of ischemic heart disease, is the most common cause of death in developed countries. A recent study showed that metastasis associated lung adenocarcinoma transcript 1 (MALAT1), a prognostic marker for lung cancer metastasis, could promote myocardial ischemia-reperfusion injury by regulating the levels of microRNA (miR)-145. In order to elucidate the biological function of MALAT1 in the pathogenesis of AMI and to explore the mechanisms underlying its action, an AMI rat model was established by ligation of the left anterior descending coronary artery. Downregulation of MALAT1 by siRNA transfection attenuated heart damage in an AMI model rat. The mouse cardiomyocyte cell line HL-1 was used to show that downregulation of nucleotide binding and oligomerization domain-like receptor C5 (NLRC5) and upregulation of miR-125b-5p were the results of MALAT1 silencing. TargetScan and a dual-luciferase reporter assay indicated that NLRC5 is a direct target of miR-125b-5p. Overexpression of miR-125b-5p significantly reduced hypoxia/reperfusion-induced apoptosis of HL-1 cells, an effect that could be blocked by NLCR5 overexpression. Taken together, these results suggest that MALAT1 reduced the protective effect of miR-125b-5p on injured cells through upregulation of NLCR5. This study highlights the role of MALAT1 in the pathogenesis of AMI and may guide future genetic therapeutic strategies for AMI treatment.
LncRNA MALAT1 Promotes Oxygen-Glucose Deprivation and Reoxygenation Induced Cardiomyocytes Injury Through Sponging miR-20b to Enhance beclin1-Mediated Autophagy.
Wang Shuang,Yao Tao,Deng Fan,Yu Wenqian,Song Yiting,Chen Jingyi,Ruan Zhihua
Cardiovascular drugs and therapy
BACKGROUND/AIMS:LncRNA metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is reported to be highly expressed in myocardial I/R injury and closely related to autophagy. However, the exact biological role of MALAT1 and its underlying mechanism in myocardial I/R injury remain to be elucidated. METHODS:We established incultured H9C2 cardiomyocytes an oxygen-glucose deprivation and reoxygenation (OGD/R) model for 6 h and then reoxygen-glucose for 4 h. We measured cell damage and autophagy levels after OGD/R by real-time quantitative PCR and Western blot. The relationships between miR-20b and MALAT1, beclin1 were confirmed by luciferase reporter assay. RESULTS:We found that the expression of MALAT1 and beclin1, cell damage levels (lactate dehydrogenase (LDH) release, 222.4 ± 29.4 vs. 577.5 ± 27.4 U/L; creatine kinase MB isoenzyme (CK-MB), 1.0 ± 0.2 vs. 4.3 ± 0.4; cardiac troponin I (cTn-I), 1.0 ± 0.3 vs. 3.0 ± 0.3; p < 0.05), and autophagy levels were significantly increased after OGD/R model, while cell viability (100.0 vs. 54.2 ± 2.2%, p < 0.05) and the expression of miR-20b and P62 were reduced; the trend of all the above data was significantly reversed by MALAT1 siRNA. In addition, the luciferase reporter assay results confirmed that MALAT1 directly binds to miR-20b-5p and functions as a ceRNA for miR-20b-5p to regulate beclin1. As a result, MALAT1 overexpression antagonized while MALAT1 knockdown enhanced the inhibitory effects of miR-20b-5p on beclin1-related cardiomyocytes autophagy in OGD/R injury. CONCLUSION:LncRNA MALAT1 promotes OGD/R-induced cardiomyocytes injury through sponging miR-20b to enhance beclin1-mediated autophagy.
Overexpression of lncRNA Gm2691 attenuates apoptosis and inflammatory response after myocardial infarction through PI3K/Akt signaling pathway.
Li Tingting,Tian Hongbo,Li Jun,Zuo Anju,Chen Jiying,Xu Dan,Guo Yuan,Gao Haiqing
Acute myocardial infarction is one of the most threatening disease in the world. In previous studies, numerous dysregulated lncRNAs exposed to ischemic reperfusion injury have been identified. In this differential lncRNAs, Gm2691 attracted our attention due to its high fold change. The aim of the study was to investigate the function and mechanism of lncRNA Gm2691 in ischemic reperfusion injury. AnaeroPack anaerobic system treated neonatal rat ventricular cardiomyocytes were used to analyze the function of lncRNA Gm2691 in vitro. Tunel, Caspase3, and inflammation markers were detected to evaluate apoptosis and inflammatory response. Rat acute myocardial infarction was performed to elucidate the function of lncRNA Gm2691 in vivo. The results showed that LncRNA Gm2691 improved the cardiac function and attenuated the inflammatory response in vivo. We also found that lncRNA Gm2691 reduced the apoptosis and improved cell survival rates in anaeroPack anaerobic system treated neonatal rat ventricular cardiomyocytes. Western blot analysis revealed that lncRNA Gm2691 decreased Akt and ERK1/2 activities, suggesting that lncRNA Gm2691 may functioned through Akt signaling pathway. We verified the function and mechanism of lncRNA Gm2691 and provide evidence that lncRNA Gm2691 may play important role in ischemic reperfusion injury, and understanding the precise role of Gm2691 will undoubtedly shed new light on the clinical treatment.
The roles of long noncoding RNAs in myocardial pathophysiology.
Chen Cheng,Tang Yuting,Sun Hui,Lin Xiaofang,Jiang Bimei
Long noncoding RNAs (lncRNAs), more than 200 nt in length, are functional molecules found in various species. These lncRNAs play a vital role in cell proliferation, differentiation, and degeneration and are also involved in pathophysiological processes of cancer and neurodegenerative, autoimmune, and cardiovascular diseases (CVDs). In recent years, emerging challenges for intervention studies on ischemic heart diseases have received much attention. LncRNAs have a key function in the alleviation of myocardial infarction (MI) injury and myocardial ischemia-reperfusion injury. During cardiac hypertrophy (CH) and fibrosis, cardiac cells undergo structural changes and become dysfunctional due to the effects of neurohormonal factors. LncRNAs may serve as important therapeutic targets that promote cardiac remodeling and then retard the development of heart failure (HF). In addition, studies on the roles and mechanisms of action of lncRNAs participating in cardiac pathophysiology via other factors have become the focus of research worldwide. Here, we review the current knowledge on various lncRNAs and their functions in cardiac biology, particularly concentrating on ischemic heart disease, CH, and cardiac fibrosis. We next discuss the predictive value of lncRNAs as diagnostic biomarkers of CVDs.
lncRNA H19 Alleviated Myocardial I/RI via Suppressing miR-877-3p/Bcl-2-Mediated Mitochondrial Apoptosis.
Li Xin,Luo Shenjian,Zhang Jifan,Yuan Yin,Jiang Wenmei,Zhu Haixia,Ding Xin,Zhan Linfeng,Wu Hao,Xie Yilin,Song Rui,Pan Zhenwei,Lu Yanjie
Molecular therapy. Nucleic acids
Ischemic cardiac disease is the leading cause of morbidity and mortality in the world. Despite the great efforts and progress in cardiac research, the current treatment of cardiac ischemia reperfusion injury (I/RI) is still far from being satisfactory. This study was performed to investigate the role of long non-coding RNA (lncRNA) H19 in regulating myocardial I/RI. We found that H19 expression was downregulated in the I/R hearts of mice and cardiomyocytes treated with HO. Overexpression of H19 alleviated myocardial I/RI of mice and cardiomyocyte injury induced by HO. We found that H19 functioned as a competing endogenous RNA of miR-877-3p, which decreased the expression of miR-877-3p through the base-pairing mechanism. In parallel, miR-877-3p was upregulated in HO-treated cardiomyocytes and mouse ischemia reperfusion (I/R) hearts. miR-877-3p exacerbated myocardial I/RI and cardiomyocyte apoptosis. We further established Bcl-2 as a downstream target of miR-877-3p. miR-877-3p inhibited the mRNA and protein expression of Bcl-2. Furthermore, H19 decreased the Bcl-2/Bax ratio at mRNA and protein levels, cytochrome c release, and activation of caspase-9 and caspase-3 in myocardial I/RI mice, which were canceled by miR-877-3p. In summary, the H19/miR-877-3p/Bcl-2 pathway is involved in regulation of mitochondrial apoptosis during myocardial I/RI, which provided new insight into molecular mechanisms underlying regulation of myocardial I/RI.
LncRNA H19 is involved in myocardial ischemic preconditioning via increasing the stability of nucleolin protein.
Chen Cheng,Liu Meidong,Tang Yuting,Sun Hui,Lin Xiaofang,Liang Pengfei,Jiang Bimei
Journal of cellular physiology
Myocardial ischemic preconditioning (IP) is defined as a brief period of myocardial ischemia/reperfusion (I/R) that significantly reduces injury during the subsequent exposure to long-term I/R. However, the underlying mechanisms of myocardial IP are yet to be elucidated. This study investigated the expression and roles of long noncoding RNA (lncRNA) H19 in myocardial IP in vitro and in vivo. LncRNA H19 expression levels were analyzed by quantitative reverse-transcription polymerase chain reaction, cell viability was determined by the Cell Counting Kit-8 assay, apoptosis was evaluated based on the caspase 3 activity, and RNA immunoprecipitation was performed to examine the interaction between lncRNA H19 and nucleolin. The results of this study showed that lncRNA H19 expression was significantly upregulated in mouse hearts subjected to myocardial IP, in rat H9C2 cells exposed to H O preconditioning (H O -PC), and in neonatal rat cardiomyocytes subjected to hypoxia preconditioning. H19 knockdown abrogated the H O -PC-mediated protection in cardiomyocytes evidenced by the decreased cell viability and increased caspase-3 activity. Conversely, H19 overexpression enhanced the protective role of H O -PC in cardiomyocytes. In addition, H19 overexpression increased the expression of nucleolin, whereas H19 ablation abrogated H O -PC-induced upregulation of nucleolin in cardiomyocytes. Furthermore, H19 overexpression increased the stabilization of nucleolin; an interaction between H19 and nucleolin was identified using the RNA-protein interaction studies. Furthermore, nucleolin small interfering RNA relieved the protective role of lncRNA H19. These findings demonstrated that the lncRNA H19 is involved in myocardial IP via increasing the stability of nucleolin protein and lncRNA H19 may represent a potential therapeutic target for the treatment of the myocardial injury.
LncRNA-HOTAIR inhibition aggravates oxidative stress-induced H9c2 cells injury through suppression of MMP2 by miR-125.
Li Linlin,Zhang Mengna,Chen Weizhen,Wang Ruirui,Ye Zi,Wang Yanyan,Li Xiao,Cai Cheguo
Acta biochimica et biophysica Sinica
Acute myocardial infarction (AMI) is one of the major causes of morbidity and mortality in the world. Ischemia/reperfusion (I/R) injury-induced cardiomyocytes death is the main obstacle that limits the heart function recovery of the AMI patients. Reactive oxygen species (ROS) generated by mitochondria is the main pathological stimulus of cardiomyocytes death during heart I/R injury process. Hence, to understand the underlying mechanism of cardioymocytes proliferation and apoptosis under oxidative stress is crucial for effective AMI therapy. In this study, we found that the expression of long non-coding RNA HOTAIR was significantly downregulated in H9c2 cells in response to oxidative stimuli. HOTAIR knockdown further attenuated H9c2 cells proliferation and accelerated H9c2 cells apoptosis in oxidative stress, while HOTAIR overexpression can protect H9c2 cells from oxidative stress-induced injury. Additionally, HOTAIR acted as a sponge for miR-125. MiR-125 inhibitors restored the H9c2 cells proliferation and migration potential after HOTAIR knockdown in oxidative stress. Meanwhile, MMP2 was identified as a target of miR-125. MMP2 knockdown blocked miR-125 inhibitors' protect effect on H9c2 cells in oxidative stress. Further study demonstrated that HOTAIR inhibition can aggravate oxidative stress-induced H9c2 cells injury through HOTAIR/miR-125/MMP2 axis. Our finding revealed a novel regulatory mechanism for cardiomyocytes proliferation and apoptosis under oxidative stress conditions, which provided a therapeutic approach for myocardium repair after AMI injury.
Long Noncoding RNAs: From Clinical Genetics to Therapeutic Targets?
Boon Reinier A,Jaé Nicolas,Holdt Lesca,Dimmeler Stefanie
Journal of the American College of Cardiology
Recent studies suggest that the majority of the human genome is transcribed, but only about 2% accounts for protein-coding exons. Long noncoding RNAs (lncRNAs) constitute a heterogenic class of RNAs that includes, for example, intergenic lncRNAs, antisense transcripts, and enhancer RNAs. Moreover, alternative splicing can lead to the formation of circular RNAs. In support of putative functions, GWAS for cardiovascular diseases have shown predictive single-nucleotide polymorphisms in lncRNAs, such as the 9p21 susceptibility locus that encodes the lncRNA antisense noncoding RNA in the INK4 locus (ANRIL). Many lncRNAs are regulated during disease. For example, metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) and myocardial infarction-associated transcript (MIAT) were shown to affect endothelial cell functions and diabetic retinopathy, whereas lincRNA-p21 controls neointima formation. In the heart, several lncRNAs were shown to act as microRNA sponges and to control ischemia-reperfusion injury or act as epigenetic regulators. In this review, the authors summarize the current understanding of lncRNA functions and their role as biomarkers in cardiovascular diseases.
The long noncoding RNA NKILA protects against myocardial ischaemic injury by enhancing myocardin expression via suppressing the NF-κB signalling pathway.
Liu Qing,Liu Zheng,Zhou Li-Jun,Cui Yu-Long,Xu Jun-Mei
Experimental cell research
BACKGROUND:The lncRNA NKILA has been reported to interact with NF-κB and has an important role in various human diseases. However, the role of NKILA in myocardial ischaemic injury is still unknown. METHODS:We established cell and animal models of myocardial ischaemic injury. We confirmed our findings by overexpressing NKILA, silencing myocardin and using an NF-κB pathway inhibitor in a hypoxia/reoxygenation (H/R) model of H9c2 cells. An animal model of ischaemia-reperfusion (I/R) injury was established by LAD ligation. Overexpression of NKILA was achieved by adeno-associated virus (AAV) injection through the tail vein. Annexin-V/PI staining and flow cytometric analysis were performed to test cell apoptosis. ELISAs were used to determine the secretion of inflammatory factors. TTC, HE and TUNEL staining were performed to study myocardial pathological injury. qRT-PCR or Western blotting were used to test the expression levels of NKILA, myocardin, the NF-κB pathway and apoptosis-related proteins. RESULTS:H/R and I/R treatment significantly suppressed the expression of NKILA and activated the NF-κB pathway, resulting in the loss of myocardin. Overexpressing NKILA led to the suppression of the NF-κB pathway and successfully prevented the cell apoptosis and inflammatory responses caused by H/R stimulation in H9c2 cells. Silencing myocardin reversed the protective effect of NKILA and led to severe injury in the H9c2 cells that underwent H/R. Furthermore, the NF-κB pathway inhibitor BAY11-7028 reduced the H/R injury in H9c2 cells with little effect on NKILA expression. Similar results were confirmed in an animal model of myocardial I/R injury and showed that overexpression of NKILA inhibited I/R-triggered myocardial injury in vivo. CONCLUSION:NKILA enhanced the expression of myocardin via inhibiting the NF-κB signalling pathway and preventing cell apoptosis and the inflammatory response of cardiomyocytes, thus ameliorating myocardial I/R injury.
LncRNA-mRNA competing endogenous RNA network depicts transcriptional regulation in ischaemia reperfusion injury.
Liu Hongying,Xu Danping,Zhong Xin,Xu Dongsheng,Chen Geng,Ge Junbo,Li Hua
Journal of cellular and molecular medicine
The study aimed to investigate time-course transcriptomes in myocardial ischaemia reperfusion injury (IRI) via RNA-Seq. Transcriptomes of 10 samples derived from patients with acute ST-segment elevation myocardial infarction (ASTEMI) who were assigned to percutaneous coronary intervention (PCI), were sequenced at the time of 0 (before PCI), 2, 12, 24 and 72 hours after PCI, respectively. Using the genefilter package in r, wgcna and stem, different expression lncRNA (DEL) and mRNA (DEM) were analysed. Out of 756 mRNAs and 206 lncRNAs shared by enrolled patients, 135 RNAs were screened to be significantly associated with the IRI. Furthermore, combined with lncRNA-mRNA, lncRNA-miRNA and miRNA-mRNA network, 51 RNAs and 131 relationship pairs were ascertained in the competing endogenous RNAs (ceRNA) network. Among these nodes, SH2D3C and GTF2H4 were significantly enriched in cellular response to stress and their interaction module were isolated from functional ceRNA network. Subsequently, their critical role was confirmed via down-regulation of SH2D3C and GTF2H4 expression in vitro model. These results identified that lncRNA-mRNA ceRNA network, associated significantly with IRI, functioned as critical regulative pivotal roles after PCI-AMI, and SH2D3C and GTF2H4 may be the most responsive transcriptional regulator in the early-phase of IRI.
Long non-coding RNA NEAT1 modulates hypoxia/reoxygenation-induced cardiomyocyte injury via targeting microRNA-520a.
Wu Hua-Jun,Tang Guan-Min,Shao Ping-Yang,Zou Hong-Xing,Shen Wei-Feng,Huang Ming-De,Pan Hang-Hai,Zhai Chang-Lin,Qian Gang
Experimental and therapeutic medicine
In the present study, a hypoxia/reoxygenation (H/R) model of cardiomyocytes was established to investigate the effects of long non-coding RNA (LncRNA) Nuclear Enriched Abundant Transcript 1 (NEAT1) and microRNA (miR)-520a on H/R-induced cardiomyocyte apoptosis. Flow cytometry and terminal deoxynucleotidyl transferase dUTP nick end labeling staining were used to evaluate cell apoptosis. Luciferase activity assay was used to investigate whether miR-520a targets NEAT1. Results revealed that NEAT1 was significantly upregulated and miR-520a was downregulated in the ischemia/reperfusion myocardium and the cardiomyocytes that received H/R treatment. Further study demonstrated that knockdown of NEAT1 and overexpression of miR-520a serves a protective role against H/R-induced cardiomyocyte apoptosis. miR-520a directly targets NEAT1 and its expression level is negatively correlated with that of NEAT1. The findings suggested that NEAT1 and miR-520a may protect cardiomyocytes from apoptosis through regulating apoptotic proteins B-cell lymphoma 2 (Bcl-2) and Bcl-2-associated X protein, and altering cleaved caspase3 expression levels.
Long non-coding RNA ROR sponges miR-138 to aggravate hypoxia/reoxygenation-induced cardiomyocyte apoptosis via upregulating Mst1.
Hu Yan-Hui,Sun Jing,Zhang Jing,Hua Fu-Zhou,Liu Qin,Liang Ying-Ping
Experimental and molecular pathology
BACKGROUND:Hypoxia/reoxygenation (H/R) injury of cardiomyocytes causes an irreversible damage to heart and largely results in acute myocardial infarction. Study has indicated lncRNA ROR aggravates myocardial ischemia/reperfusion (I/R) injury. Also, lncRNA ROR sponges miR-138 to promote osteogenesis. MiR-138 involves in hypoxic pulmonary vascular remodelling by targeting Mst1. However, the interaction between lncRNA ROR, miR-138 and Mst1 involved in myocardial H/R injury is still unknown. METHODS:H9C2 cells were used to establish H/R injury model. The expression levels of lncRNA ROR and miR-138 were modified by transfection with the miR-138 mimics or lncRNA ROR overexpression plasmid. MTT and flow cytometry analysis were performed to detect cell proliferation and apoptosis. Dual luciferase reporter assay was used to determine interaction between lncRNA ROR and miR-138 or miR-138 and Mst1. Expression levels of lncRNA ROR, miR-138, Mst1 and apoptosis-related markers were determined by qRT-PCR or western blotting. RESULTS:LncRNA ROR was significantly up-regulated, while miR-138 was obviously down-regulated in H/R-induced injury of H9C2 cells. Furthermore, miR-138 overexpression alleviated cardiac cell apoptosis induced by H/R injury. Mst1 was revealed to be a target of miR-138 and negatively regulated by miR-138. Mst1 overexpression reversed the protective effects of miR-138 on H/R injury of H9C2 cells. LncRNA ROR was identified as a sponge for miR-138. MiR-138 could protect H9C2 cells form H/R injury induced by lncRNA ROR overexpression. CONCLUSION:Our study provides that lncRNA ROR sponges miR-138 to aggravate H/R-induced myocardial cell injury by upregulating the expression of Mst1.