scholarly journals The Novel Non-coding Transcriptional Regulator Gm18840 Drives Cardiomyocyte Apoptosis in Myocardial Infarction Post Ischemia/Reperfusion

Author(s):  
Changjun Luo ◽  
Si Xiong ◽  
Yiteng Huang ◽  
Ming Deng ◽  
Jing Zhang ◽  
...  

BackgroundIschemia/reperfusion-mediated myocardial infarction (MIRI) is a major pathological factor implicated in the progression of ischemic heart disease, but the key factors dysregulated during MIRI have not been fully elucidated, especially those essential non-coding factors required for cardiovascular development.MethodsA murine MIRI model and RNA sequencing (RNA-seq) were used to identify key lncRNAs after myocardial infarction. qRT-PCR was used to validate expression in cardiac muscle tissues and myocardial cells. The role of Gm18840 in HL-1 cell growth was determined by flow cytometry experiments in vitro. Full-length Gm18840 was identified by using a rapid amplification of cDNA ends (RACE) assay. The subcellular distribution of Gm18840 was examined by nuclear/cytoplasmic RNA fractionation and qRT-PCR. RNA pulldown and RNA immunoprecipitation (RIP)-qPCR assays were performed to identify Gm18840-interacting proteins. Chromatin isolation by RNA purification (ChIRP)-seq (chromatin isolation by RNA purification) was used to identify the genome-wide binding of Gm18840 to chromatin. The regulatory activity of Gm18840 in transcriptional regulation was examined by a luciferase reporter assay and qRT-PCR.ResultsGm18840 was upregulated after myocardial infarction in both in vivo and in vitro MIRI models. Gm18840 was 1,471 nt in length and localized in both the cytoplasm and the nucleus of HL-1 cells. Functional studies showed that the knockdown of Gm18840 promoted the apoptosis of HL-1 cells. Gm18840 directly interacts with histones, including H2B, highlighting a potential function in transcriptional regulation. Further ChIRP-seq and RNA-seq analyses showed that Gm18840 is directly bound to the cis-regulatory regions of genes involved in developmental processes, such as Junb, Rras2, and Bcl3.ConclusionGm18840, a novel transcriptional regulator, promoted the apoptosis of myocardial cells via direct transcriptional regulation of essential genes and might serve as a novel therapeutic target for MIRI.

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Yeqian Zhu ◽  
Pengcheng Zhao ◽  
Ling Sun ◽  
Yao Lu ◽  
Wenwu Zhu ◽  
...  

AbstractIschemic cardiomyopathy seriously endangers human health leading to a poor prognosis. Acute myocardial infarction (AMI) is the primary etiology, and the pathophysiological process concludes with the death of cardiomyocytes caused by acute and persistent ischemia and hypoxia in the coronary arteries. We identified a circRNA (circSNRK) which was downregulated in rats with myocardial infarction (MI), however, the role it plays in the MI environment is still unclear. This study contained experiments to investigate the role of circSNRK in the regulation of cardiac survival and explore the mechanisms underlying circSNRK functions. Quantitative real-time PCR (qRT-PCR) was performed to determine the circSNRK expression patterns in hearts. Gain-of-function assays were also conducted in vitro and in vivo to determine the role of circSNRK in cardiac repair. qRT-PCR, western blot, and luciferase reporter assays were used to study circRNA interactions with micro RNAs (miRNAs). Overexpression of circSNRK in cardiomyocytes reduced apoptosis and increased proliferation. Adeno associated virus 9 (AAV9) mediated myocardium overexpression of circSNRK in post MI hearts reduced cardiomyocyte apoptosis, promoted cardiomyocyte proliferation, enhanced angiogenesis, and improved cardiac functions. Overall, upregulation of circSNRK promotes cardiac survival and functional recovery after MI. Mechanistically, circSNRK regulates cardiomyocyte apoptosis and proliferation by acting as a miR-103-3p sponge and inducing increased expression of SNRK which can bind GSK3β to regulate its phosphorylated activity. And thus circSNRK may be a promising therapeutic target for improving clinical prognosis after MI.


2021 ◽  
Vol 2021 ◽  
pp. 1-23
Author(s):  
Xiao Ke ◽  
Rongfeng Yang ◽  
Fang Wu ◽  
Xing Wang ◽  
Jiawen Liang ◽  
...  

Accumulating evidence has shown that endothelial progenitor cell-derived exosomes (EPC-Exos) can ameliorate myocardial fibrosis. The purpose of the present study was to investigate the effects of EPC-Exos-derived microRNAs (miRNAs) on myocardial infarction (MI). A miRNA-Seq dataset of miRNAs differentially expressed between EPCs and exosomes was collected. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to validate the miRNA expression indicated by miRNA-Seq. Immunofluorescence, cell proliferation, and angiogenesis assays were employed to investigate the effects of miRNAs on cardiac fibroblasts (CFs) in vitro. Interactions between miRNAs and their respective targets were examined via immunoblotting, qRT-PCR, and luciferase reporter assays. An MI rat model was constructed, and various staining and immunohistochemical assays were performed to explore the mechanisms underlying the miRNA-mediated effects on MI. miR-363-3p and miR-218-5p were enriched in EPC-Exos, and miR-218-5p and miR-363-3p mimic or inhibitor enhanced or suppressed CF proliferation and angiogenesis, respectively. miR-218-5p and miR-363-3p regulated p53 and junction-mediating and regulatory protein (JMY) by binding to the promoter region of p53 and the 3 ′ untranslated region of JMY. Additionally, treatment of CFs with Exo-miR-218-5p or Exo-miR-363-3p upregulated p53 and downregulated JMY expression, promoted mesenchymal-endothelial transition, and inhibited myocardial fibrosis. Administration of exosomes containing miR-218-5p mimic or miR-363-3p mimic ameliorated left coronary artery ligation-induced MI and restored myocardial tissue integrity in the MI model rats. In summary, these results show that the protective ability of EPC-Exos against MI was mediated by the shuttled miR-218-5p or miR-363-3p via targeting of the p53/JMY signaling pathway.


Author(s):  
Lanfang Zhang ◽  
Xinwei Jia

Abstract Background Ischemia/hypoxia-induced cardiomyocyte apoptosis has been considered as a main cause of myocardial infarction. Here, we aimed to investigate the functional role of miR-30b-5p in hypoxic cardiomyocytes. Methods AC16 human cardiomyocytes were cultured under hypoxia to simulate myocardial infarction. A qRT-PCR assay was performed to determine miR-30b-5p expression in hypoxic cardiomyocytes. Cell survival, injury and apoptosis were assessed by MTT, lactate dehydrogenase (LDH) release, and flow cytometry assays, respectively. The target gene of miR-30b-5p in hypoxic cardiomyocytes was validated by luciferase reporter assay and Western blotting. Results MiR-30b-5p expression was found to be significantly upregulated in hypoxic AC16 cells. The in vitro experiments showed that downregulation of miR-30b-5p effectively alleviated hypoxia-induced cardiomyocyte injury. Furthermore, Aven is a potential target gene of miR-30b-5p and its downregulation could partially reverse the influence of miR-30b-5p knockdown on AC16 cells under hypoxia. Conclusions Inhibition of miR-30b-5p could protect cardiomyocytes against hypoxia-induced injury by targeting Aven.


2021 ◽  
Author(s):  
Xiao Ke ◽  
Rongfeng Yang ◽  
Fang Wu ◽  
Xing Wang ◽  
Jiawen Liang ◽  
...  

Abstract BackgroundAccumulating evidence has shown that endothelial progenitor cell-derived exosomes (EPC-Exos) can ameliorate myocardial fibrosis. The purpose of the present study was to investigate the effects of EPC-Exos-derived microRNAs (miRNAs) on myocardial infarction (MI). MethodsA miRNA-Seq dataset of miRNAs differentially expressed between EPCs and exosomes was collected. Quantitative real-time polymerase chain reaction (qRT-PCR) was used to validate the miRNA expression indicated by miRNA-Seq. Immunofluorescence, cell proliferation and angiogenesis assays were employed to investigate the effects of miRNAs on cardiac fibroblasts (CFs) in vitro. Interactions between miRNAs and their respective targets were examined via immunoblotting, qRT-PCR and luciferase reporter assays. An MI rat model was constructed, and various staining and immunohistochemical assays were performed to explore the mechanisms underlying the miRNA-mediated effects on MI. ResultsmiR-363-3p and miR-218-5p were enriched in EPC-Exos, and miR-218-5p and miR-363-3p mimic or inhibitor enhanced or suppressed CF proliferation and angiogenesis, respectively. miR-218-5p and miR-363-3p regulated P53 and junction-mediating and regulatory protein (JMY) by binding to the promoter region of P53 and the 3’ untranslated region of JMY. Additionally, treatment of CFs with exo-miR-218-5p or miR-363-3p mimic upregulated P53 and down-regulated JMY expression, promoted mesenchymal-endothelial transition and inhibited myocardial fibrosis. Administration of exosomes containing miR-218-5p mimic or miR-363-3p mimic ameliorated left coronary artery ligation-induced MI and restored myocardial tissue integrity in the MI model rats. ConclusionsIn summary, these results show that the protective ability of EPC-Exos against MI was mediated by the shuttled miR-218-5p or miR-363-3p via targeting of the P53/JMY signaling pathway.


2020 ◽  
Vol 17 (3) ◽  
pp. 259-266 ◽  
Author(s):  
Xuan Chen ◽  
Sumei Zhang ◽  
Peipei Shi ◽  
Yangli Su ◽  
Dong Zhang ◽  
...  

Objective: Ischemia-reperfusion (I/R) injury is a pathological feature of ischemic stroke. This study investigated the regulatory role of miR-485-5p in I/R injury. Methods: SH-SY5Y cells were induced with oxygen and glucose deprivation/reoxygenation (OGD/R) to mimic I/R injury in vitro. Cells were transfected with designated constructs (miR-485- 5p mimics, miR-485-5p inhibitor, lentiviral vectors overexpressing Rac1 or their corresponding controls). Cell viability was evaluated using the MTT assay. The concentrations of lactate dehydrogenase, malondialdehyde, and reactive oxygen species were detected to indicate the degree of oxidative stress. Flow cytometry and caspase-3 activity assay were used for apoptosis assessment. Dual-luciferase reporter assay was performed to confirm that Rac family small GTPase 1 (Rac1) was a downstream gene of miR-485-5p. Results: OGD/R resulted in decreased cell viability, elevated oxidative stress, increased apoptosis, and downregulated miR-485-5p expression in SH-SY5Y cells. MiR-485-5p upregulation alleviated I/R injury, evidenced by improved cell viability, decreased oxidative markers, and reduced apoptotic rate. OGD/R increased the levels of Rac1 and neurogenic locus notch homolog protein 2 (Notch2) signaling-related proteins in cells with normal miR-485-5p expression, whereas miR- 485-5p overexpression successfully suppressed OGD/R-induced upregulation of these proteins. Furthermore, the delivery of vectors overexpressing Rac1 in miR-485-5p mimics-transfected cells reversed the protective effect of miR-485-5p in cells with OGD/R-induced injury. Conclusion: This study showed that miR-485-5p protected cells following I/R injury via targeting Rac1/Notch2 signaling suggest that targeted upregulation of miR-485-5p might be a promising therapeutic option for the protection against I/R injury.


2021 ◽  
Vol 12 (6) ◽  
Author(s):  
Xiaoping Zhang ◽  
Dan Li ◽  
Chengyou Jia ◽  
Haidong Cai ◽  
Zhongwei Lv ◽  
...  

Abstract Background Papillary thyroid cancer (PTC) is the most common type of cancer of the endocrine system. Long noncoding RNAs (lncRNAs) are emerging as a novel class of gene expression regulators associated with tumorigenesis. Through preexisting databases available for differentially expressed lncRNAs in PTC, we uncovered that lncRNA OIP5-AS1 was significantly upregulated in PTC tissues. However, the function and the underlying mechanism of OIP5-AS1 in PTC are poorly understood. Methods Expression of lncRNA OIP5-AS1 and miR-98 in PTC tissue and cells were measured by quantitative real-time PCR (qRT-PCR). And expression of METTL14 and ADAMTS8 in PTC tissue and cells were measured by qRT-PCR and western blot. The biological functions of METTL14, OIP5-AS1, and ADAMTS8 were examined using MTT, colony formation, transwell, and wound healing assays in PTC cells. The relationship between METTL14 and OIP5-AS1 were evaluated using RNA immunoprecipitation (RIP) and RNA pull down assay. And the relationship between miR-98 and ADAMTS8 were examined by luciferase reporter assay. For in vivo experiments, a xenograft model was used to investigate the effects of OIP5-AS1 and ADAMTS8 in PTC. Results Functional validation revealed that OIP5-AS1 overexpression promotes PTC cell proliferation, migration/invasion in vitro and in vivo, while OIP5-AS1 knockdown shows an opposite effect. Mechanistically, OIP5-AS1 acts as a target of miR-98, which activates ADAMTS8. OIP5-AS1 promotes PTC cell progression through miR-98/ADAMTS8 and EGFR, MEK/ERK pathways. Furthermore, RIP and RNA pull down assays identified OIP5-AS1 as the downstream target of METTL14. Overexpression of METTL14 suppresses PTC cell proliferation and migration/invasion through inhibiting OIP5-AS1 expression and regulating EGFR, MEK/ERK pathways. Conclusions Collectively, our findings demonstrate that OIP5-AS1 is a METTL14-regulated lncRNA that plays an important role in PTC progression and offers new insights into the regulatory mechanisms underlying PTC development.


2020 ◽  
Vol 11 (10) ◽  
Author(s):  
Chenguang Ding ◽  
Xiaoming Ding ◽  
Jin Zheng ◽  
Bo Wang ◽  
Yang Li ◽  
...  

Abstract Renal tubular cell death is the key factor of the pathogenesis of ischemia/reperfusion (I/R) kidney injury. Ferroptosis is a type of regulated cell death (RCD) found in various diseases. However, the underlying molecular mechanisms related to ferroptosis in renal I/R injury remain unclear. In the present study, we investigated the regulatory role of microRNAs on ferroptosis in I/R-induced renal injury. We established the I/R-induced renal injury model in rats, and H/R induced HK-2 cells injury in vitro. CCK-8 was used to measure cell viability. Fe2+ and ROS levels were assayed to evaluate the activation of ferroptosis. We performed RNA sequencing to profile the miRNAs expression in H/R-induced injury and ferroptosis. Western blot analysis was used to detect the protein expression. qRT-PCR was used to detect the mRNA and miRNA levels in cells and tissues. We further used luciferase reporter assay to verify the direct targeting effect of miRNA. We found that ischemia/reperfusion-induced ferroptosis in rat’s kidney. We identified that miR-182-5p and miR-378a-3p were upregulated in the ferroptosis and H/R-induced injury, and correlates reversely with glutathione peroxidases 4 (GPX4) and solute carrier family 7 member 11 (SLC7A11) expression in renal I/R injury tissues, respectively. In vitro studies showed that miR-182-5p and miR-378a-3p induced ferroptosis in cells. We further found that miR-182-5p and miR-378a-3p regulated the expression of GPX4 and SLC7A11 negatively by directly binding to the 3′UTR of GPX4 and SLC7A11 mRNA. In vivo study showed that silencing miR-182-5p and miR-378a-3p alleviated the I/R-induced renal injury in rats. In conclusion, we demonstrated that I/R induced upregulation of miR-182-5p and miR-378a-3p, leading to activation of ferroptosis in renal injury through downregulation of GPX4 and SLC7A11.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Sashwati Roy ◽  
Savita Khanna ◽  
Chandan K Sen

Background . Transforming growth factor beta-1 (TGFbeta-1) is a key cytokine implicated in the development of cardiac fibrosis following ischemia-reperfusion (IR) injury. The profibrotic effects of TGFbeta-1 are primarily attributable to the differentiation of cardiac fibroblasts (CF) to myofibroblasts. Previously, we have reported perceived hyperoxia (Circ Res 92:264 –71), sub-lethal reoxygenation shock during IR, induces differentiation of CF to myofibroblasts at the infarct site. The mechanisms underlying oxygen-sensitive induction of TGFbeta-1 mRNA remain to be characterized. Hypothesis . Fra2 mediates oxygen-induced TGFbeta-1 mRNA expression in adult cardiac fibroblasts. Methods. TGFbeta-1 mRNA expression in infarct tissue was investigated in an IR injury model. The left anterior descending coronary artery of mice was transiently occluded for 60 minutes followed by reperfusion to induce IR injury. Spatially resolved infarct and non-infarct tissues were collected at 0, 1, 3, 5, and 7 days post-IR using laser capture microdissection. TGFbeta-1 mRNA levels were measured using real-time PCR. To investigate the role of oxygen in the regulation of TGFbeta-1, we used our previously reported model of perceived hyperoxia where CF (from 5wks old mice) after isolation were cultured at 5%O 2 (physiological pO 2 ) followed by transferring them to 20%O 2 to induce hyperoxic insult. Results & Conclusions. In vivo, a significant increase (p<0.01; n=5) in TGFbeta-1 mRNA was observed at the infarct site already at day 1 post-IR. The levels continued to increase until day 7 post-IR. In vitro, exposure of CF to 20%O 2 hyperoxic insult induced TGFbeta-1 mRNA (p<0.001; n=4) and protein (p<0.01; n=4) expression. Using a TGFbeta-1 promoter-luciferase reporter and DNA binding assays, we collected first evidence that AP-1 and its component Fra2 as major mediators of oxygen-induced TGFbeta-1 expression. Exposure to 20%O 2 resulted in increased localization of Fra2 in nucleus. siRNA-dependent Fra-2 knock-down completely abrogated oxygen-induced TGFbeta1 expression. In conclusion, this study presents first evidence that Fra-2 is involved in inducible TGFbeta1 expression in CF. Fra2 was noted as being central in regulating oxygen-induced TGFbeta-1 expression.s


2021 ◽  
Vol 20 (9) ◽  
pp. 1845-1853
Author(s):  
Qinfeng Han ◽  
Zhong Xu ◽  
Xiaolei Zhang ◽  
Kun Yang ◽  
Zhifei Sun ◽  
...  

Purpose: To investigate the effect of miR-486 on rats with acute myocardial infarction (AMI), and its mechanism of action.Methods: A rat model of AMI was established. They were randomly divided into 4 groups, namely, sham, model, agomiR-486 and antagomiR-486 groups, respectively. Rats in these different groups were treated with agomiR-21 (5 μL, 40 nmol/mL), antagomiR-21 (5 μL, 40 nmol/mL) or agomiR-NC (5 μL, 40 nmol/mL), respectively. Then, key miRNAs were sorted out using gene-chip assay and verified by quantitative reverse transcription polymerase chain reaction (qRT-PCR) assay. Luciferase reporter gene assay was conducted to determine the interaction between miR-486 and gene of PTEN. After intraperitoneal injection of agomiR-486 and antagomiR-486, hemodynamics was measured to determine the effect of miR-486 on myocardial function of the rats. The effect of miR-486 expression level on the expression of myocardial enzymes in serum, the morphology of myocardial tissues, and the apoptosis of myocardial tissues in rats, were investigated. Additionally, the effect of miR-486 expression level on PTEN/AKT signaling pathway in the rats was determined by Western blotting.Results: The results of gene-chip and qRT-PCR assays revealed that there were 8 differentially expressed genes in rat myocardial tissues in the model group when compared with the sham group. MiR-486 improved the cardiac function of rats and the morphology of myocardial tissues, but reduced AMI-induced apoptosis of myocardial cells and the expression of myocardial enzymes (markers of myocardial injury) in a dose-dependent manner (p < 0.05). The results of luciferase reporter gene assay showed that PTEN was a direct target of miR-486. In rat models of AMI, a raised expression of miR-486 remarkably suppressed the protein expression level of PTEN and up-regulated that of p-AKT/AKT (p < 0.05).Conclusion: MiR-486 protects against AMI in rats probably by targeting PTEN and activating the AKT signaling pathway. The results of the current study may provide new insights for the treatment of AMI.


2020 ◽  
Author(s):  
Yijing Chu ◽  
Yan Zhang ◽  
Guoqiang Gao ◽  
Jun Zhou ◽  
Yang Lv ◽  
...  

Abstract Background: Human chorionic villous mesenchymal stem cells (CV-MSCs) are found to be a promising and effective treatment for tissue injury. Trophoblast dysfunction during pregnancies is significantly involved in the pathogenesis of preeclampsia (PE). This work was to understand how CV-MSCs regulated trophoblast function. Methods: In this study, we treated trophoblasts with CV-MSC-derived exosomes and RNA-seq analysis was used to understand the changes in trophoblasts. We examined the levels of TXNIP and β-catenin in trophoblasts by immunohistochemistry, western blot and qRT-PCR assays. Luciferase reporter assays and qRT-PCR assays were used to understand the role of miR135b-5p in the effects of CV-MSC-derived exosomes. The growth and invasion of trophoblasts was evaluated with the CCK-8 and transwell assays. Results: The treatment markedly enhanced the trophoblast proliferation and invasion. Furthermore, a significant decrease of TXNIP expression and inactivation of the β-catenin pathway in CV-MSCs exosomes-treated trophoblasts was observed. Consistent with these findings, TXNIP inhibition exhibited the same effect of promoting trophoblast proliferation and invasion as induced by CV-MSC-derived exosomes, also with the accompaniment of inactivation of β-catenin pathway. In addition, overexpression of TXNIP activated the β-catenin pathway in trophoblasts, and reduced the proliferation and invasion of trophoblasts. Importantly, miR135b-5p was found to be highly expressed in CV-MSC exosomes and interact with TXNIP. The miR-135b-5p overexpression significantly elevated the proliferation and invasion of trophoblasts, which could be attenuated by TXNIP overexpression. Conclusion: Our results suggest that TXNIP-dependent β-catenin pathway inactivation mediated by miR135b-5p which is delivered by CV-MSC-derived exosomes could promote the proliferation and invasion of trophoblasts.


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