scholarly journals Long noncoding RNA MALAT1 promotes cardiomyocyte apoptosis after myocardial infarction via targeting miR-144-3p

2019 ◽  
Vol 39 (8) ◽  
Author(s):  
Xiaohong Gong ◽  
Yun Zhu ◽  
Haixia Chang ◽  
Yongqin Li ◽  
Feng Ma

AbstractOur study aims to excavate the role of metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) in myocardial infarction (MI), especially in an ischemia/reperfusion injury model and the underlying mechanism involving the MALAT1-miR144 axis. Our results demonstrated that the expression of MALAT1 has a higher level, while miR-144 expression significantly reduced in myocardial tissue after MI and also in left anterior descending (LAD)-ligation mice. This result was confirmed in vitro studies in HL-1 cardiomyocytes followed with hypoxia/reoxygenation. In addition, overexpression of MALAT1 by MALAT1-pcDNA injection into the mice with LAD increased myocardial apoptosis in vivo, while this effect was attenuated by miR-144 mimic. Bioinformatics analysis exhibits that 3′-UTR of MALAT1 is targeted to the miR-144-3p. Up-regulation miR-144 blunted the hypoxia- or MALAT1-induced cell apoptosis. In conclusion, the expression of MALAT1 was increased, whereas miR-144 expression was down-regulated in the myocardium after AMI. MALAT1 up-regulation plays a critical role in promoting cardiomyocytes apoptosis via targeting miR-144.

2020 ◽  
Vol 129 (6) ◽  
pp. 1460-1467
Author(s):  
Tianhao Li ◽  
Yuru Luo ◽  
Peng Zhang ◽  
Shewei Guo ◽  
Hongwei Sun ◽  
...  

To study the role of long noncoding RNA (lncRNA) maternally expressed gene 3 (MEG3) in cerebral ischemia-reperfusion (I/R) injury, we clarified the mechanism by which lncRNA MEG3 regulates the secretion of inflammatory cytokines in microglia through in vitro and in vivo experiments. We discovered that inhibition of MEG3 could alleviate cerebral I/R injury via inhibiting M1 polarization and promoting M2 polarization through Krüppel-like factor 4 (KLF4), indicating an effective theoretical basis for potential therapeutic targets of cerebral I/R injury.


2020 ◽  
Vol 318 (2) ◽  
pp. H332-H344 ◽  
Author(s):  
Qiang Su ◽  
Yang Liu ◽  
Xiang-Wei Lv ◽  
Ri-Xin Dai ◽  
Xi-Heng Yang ◽  
...  

Increased production of reactive oxygen species (ROS) significantly contributed to the pathogenesis of acute myocardial infarction (AMI). Recent studies suggest that hypoxia upregulated the long noncoding RNA taurine upregulated gene 1 (TUG1). In this study, we explored the functional significance and molecular mechanisms of TUG1/miR-132-3p axis in ischemia-challenged cardiomyocytes. In primary cardiomyocytes challenged with H2O2, expressions of miR-132-3p, TUG1, and other target proteins were measured by RT quantitative PCR or Western blot analysis; cell viability by 3-(4,5-dimethylthiazolyl-2)-2,5-diphenyltetrazolium bromide assay; apoptosis by annexin V and propidium iodide staining; the abundance of acetylated H3K9 or histone deacetylase 3 (HDAC3) within the promoter of target genes by chromatin immunoprecipitation; the direct interaction between miR-132-3p and HDAC3 or TUG1 by luciferase reporter assay. The biological significance of miR-132-3p, TUG1, and HDAC3 was assessed using miR-132-3p mimic, siRNA-targeting TUG1 and HDAC3 inhibitor RGF966, respectively, in H2O2-challenged cells in vitro or ischemia-reperfusion (I/R)-induced AMI in vivo. miR-132-3p was downregulated, whereas TUG1 upregulated in H2O2-challenged cardiomyocytes. Overexpressing miR-132-3p or knocking down TUG1 significantly improved viability, inhibited apoptosis, and reduced ROS production in H2O2-stressed cardiomyocytes in vitro and alleviated I/R-induced AMI in vivo. Mechanistically, TUG1 sponged miR-132-3p and upregulated HDAC3, which reduced the acetylation of H3K9 and epigenetically inhibited expressions of antioxidative genes, including Bcl-xL, Prdx2, and Hsp70. The TUG1/miR-132-3p/HDAC3 axis critically regulates ROS production and the pathogenic development of AMI. Targeting TUG1, upregulating miR-132-3p, or inhibiting HDAC3 may benefit AMI treatment. NEW & NOTEWORTHY Increased production of reactive oxygen species (ROS) significantly contributed to the pathogenesis of acute myocardial infarction (AMI). Recent studies suggest that hypoxia upregulated the long noncoding RNA taurine upregulated gene 1 (TUG1). However, the underlying mechanisms remain elusive. In the present study, we reported for the first time that H2O2 or ischemia-reperfusion-induced TUG1, by sponging microRNA 132-3p, activated histone deacetylase 3, which in turn targeted multiple protective genes, stimulated intracellular ROS accumulation, and aggravated the injury of AMI. Our findings might provide some insight to seek new targets for AMI treatment.


2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Yue-Ming Zhang ◽  
Xiao-Yu Qu ◽  
Jing-Hui Zhai ◽  
Li-Na Tao ◽  
Huan Gao ◽  
...  

Xingnaojing (XNJ) injection, derived from traditional Chinese medicine formulation, has a protective effect against stroke, but the underlying mechanism is unclear, which severely limited its clinical application. This research aims to elucidate the role and mechanism of XNJ in reducing cerebral ischemic reperfusion (I/R) injury. Rats received 2 h cerebral ischemia followed by reperfusion of 24 h and were intraperitoneally given 5, 10, or 15 ml/kg XNJ 24 h before ischemia and at the onset of reperfusion, respectively. TTC staining, HE staining, and neurological score were implied to evaluate the effectiveness of XNJ. The protein expressions of PI3K/Akt and eNOS signaling were measured. Experiments were further performed in human brain microvascular endothelial cells (HBMECs) to investigate the protective mechanisms of XNJ. HBMECs were subjected to 3 h oxygen and glucose deprivation following 24 h of reoxygenation (OGD) to mimic cerebral I/R in vitro. PI3K inhibitor LY294002 was added with or without the preconditioning of XNJ. Multiple methods including western blot, immunofluorescence, DAPI staining, JC-1, and flow cytometry were carried out to evaluate the effect of XNJ on HBMECs. XNJ could improve rat cerebral ischemic injury and OGD induced HBMECs apoptosis. In vivo and in vitro researches indicated that the mechanism might be relevant to the activation of PI3K/Akt/eNOS signaling.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Juho Heliste ◽  
Anne Jokilammi ◽  
Katri Vaparanta ◽  
Ilkka Paatero ◽  
Klaus Elenius

AbstractThe return of blood flow to ischemic heart after myocardial infarction causes ischemia–reperfusion injury. There is a clinical need for novel therapeutic targets to treat myocardial ischemia–reperfusion injury. Here we screened for targets for the treatment of ischemia–reperfusion injury using a combination of shRNA and drug library analyses in HL-1 mouse cardiomyocytes subjected to hypoxia and reoxygenation. The shRNA library included lentiviral constructs targeting 4625 genes and the drug library 689 chemical compounds approved by the Food and Drug Administration (FDA). Data were analyzed using protein–protein interaction and pathway analyses. EGFR inhibition was identified as a cardioprotective mechanism in both approaches. Inhibition of EGFR kinase activity with gefitinib improved cardiomyocyte viability in vitro. In addition, gefitinib preserved cardiac contractility in zebrafish embryos exposed to hypoxia-reoxygenation in vivo. These findings indicate that the EGFR inhibitor gefitinib is a potential candidate for further studies of repurposing the drug for the treatment of myocardial infarction.


2021 ◽  
Author(s):  
Zhi Dong ◽  
Ling Deng ◽  
Yi Guo ◽  
Jingdong Liu ◽  
Sha Chen ◽  
...  

Abstract Increasing evidence suggests that long noncoding RNAs can exert neuroprotective effects in cerebral ischemia-reperfusion injury. Levels of the long noncoding RNA ANRIL (ANRIL) are reportedly altered in ischemic stroke (IS) patients, but its role in IS requires further clarification. This study was designed to explore the mechanistic function of ANRIL in IS. In vitro, HT22 cells was treated with an oxygen-glucose deprivation/reperfusion (OGD/R). In vivo, brain ischemia/reperfusion was induced by 60-minute transient middle cerebral artery occlusion/ reperfusion (MCAO/R) IS model in C57/BL6 mice. Additionally, cells were transfected with si-ANRIL, pcDNA3.1-ANRIL, pcDNA3.1-NF-κB, or appropriate negative controls, and si-ANRIL and pcDNA3.1-NF-κB were administered into the lateral ventricles in MCAO/R model mice. Cell viability and apoptosis were detected via MTT and flow cytometry assays. mRNA and protein expression of NF-κB were detected via qRT-PCR and Western blotting. IL-1β, IL-6, TNF-a, and iNOS levels were detected via ELISA. In addition, infarcted area and neuronal injury were evaluated via TTC, Nissl, and immunofluorescent staining. We found that ANRIL knockdown increased cell viability and reduced apoptosis in vitro. Additionally, we found that ANRIL knockdown decreased p-P65, P65, IL-1β, IL-6, TNF-a, and iNOS levels, whereas these effects were reversed by NF-κB overexpression both in vitro and in vivo. Our results suggest that ANRIL knockdown attenuates neuroinflammation by suppressing the expression of NF-κB both in vitro and vivo model of IS, sugguesting that ANRIL might be a potentially viable therapeutictarget to diminish neuroinflammation in IS patients.


Planta Medica ◽  
2013 ◽  
Vol 79 (14) ◽  
pp. 1289-1297 ◽  
Author(s):  
Rui Zhang ◽  
Weirong Fang ◽  
Dan Han ◽  
Lan Sha ◽  
Jie Wei ◽  
...  

Oncogene ◽  
2021 ◽  
Author(s):  
Pengpeng Zhu ◽  
Fang He ◽  
Yixuan Hou ◽  
Gang Tu ◽  
Qiao Li ◽  
...  

AbstractThe hostile hypoxic microenvironment takes primary responsibility for the rapid expansion of breast cancer tumors. However, the underlying mechanism is not fully understood. Here, using RNA sequencing (RNA-seq) analysis, we identified a hypoxia-induced long noncoding RNA (lncRNA) KB-1980E6.3, which is aberrantly upregulated in clinical breast cancer tissues and closely correlated with poor prognosis of breast cancer patients. The enhanced lncRNA KB-1980E6.3 facilitates breast cancer stem cells (BCSCs) self-renewal and tumorigenesis under hypoxic microenvironment both in vitro and in vivo. Mechanistically, lncRNA KB-1980E6.3 recruited insulin-like growth factor 2 mRNA-binding protein 1 (IGF2BP1) to form a lncRNA KB-1980E6.3/IGF2BP1/c-Myc signaling axis that retained the stability of c-Myc mRNA through increasing binding of IGF2BP1 with m6A-modified c-Myc coding region instability determinant (CRD) mRNA. In conclusion, we confirm that lncRNA KB-1980E6.3 maintains the stemness of BCSCs through lncRNA KB-1980E6.3/IGF2BP1/c-Myc axis and suggest that disrupting this axis might provide a new therapeutic target for refractory hypoxic tumors.


2021 ◽  
Vol 12 (5) ◽  
Author(s):  
Ying Dong Du ◽  
Wen Yuan Guo ◽  
Cong Hui Han ◽  
Ying Wang ◽  
Xiao Song Chen ◽  
...  

AbstractDespite N6-methyladenosine (m6A) is functionally important in various biological processes, its role and the underlying regulatory mechanism in the liver remain largely unexplored. In the present study, we showed that fat mass and obesity-associated protein (FTO, an m6A demethylase) was involved in mitochondrial function during hepatic ischemia–reperfusion injury (HIRI). We found that the expression of m6A demethylase FTO was decreased during HIRI. In contrast, the level of m6A methylated RNA was enhanced. Adeno-associated virus-mediated liver-specific overexpression of FTO (AAV8-TBG-FTO) ameliorated the HIRI, repressed the elevated level of m6A methylated RNA, and alleviated liver oxidative stress and mitochondrial fragmentation in vivo and in vitro. Moreover, dynamin-related protein 1 (Drp1) was a downstream target of FTO in the progression of HIRI. FTO contributed to the hepatic protective effect via demethylating the mRNA of Drp1 and impairing the Drp1-mediated mitochondrial fragmentation. Collectively, our findings demonstrated the functional importance of FTO-dependent hepatic m6A methylation during HIRI and provided valuable insights into the therapeutic mechanisms of FTO.


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