scholarly journals Oxytocin Protects Against Isoproterenol-Induced Cardiac Hypertrophy by Inhibiting PI3K/AKT Pathway via a lncRNA GAS5/miR-375-3p/KLF4-Dependent Mechanism

2021 ◽  
Vol 12 ◽  
Author(s):  
Yuqiao Yang ◽  
Zhuoran Wang ◽  
Mengran Yao ◽  
Wei Xiong ◽  
Jun Wang ◽  
...  

Cardiac hypertrophy is caused by cardiac volume or pressure overload conditions and ultimately leads to contractile dysfunction and heart failure. Oxytocin (OT), an endocrine nonapeptide, has been identified as a cardiovascular homeostatic hormone with anti-hypertrophic effects. However, the underlying mechanism remains elusive. In this study, we aimed to investigate the role and mechanism of OT in cardiac hypertrophy. The rats with cardiac hypertrophy induced by isoproterenol (ISO) were treated with or without oxytocin. Cardiac functional parameters were analyzed by echocardiography. The changes in cell surface area were observed using wheat germ agglutinin (WGA) or immunofluorescence staining. The expressions of cardiac hypertrophy markers (B-Natriuretic Peptide, BNP and β-myosin heavy chain, β-MHC), long non-coding RNA Growth (LcRNA) Arrest-Specific transcript 5 (lncRNA GAS5), miR-375-3p, and Kruppel-like factor 4 (Klf4) were detected by qRT-PCR. KLF4 protein and PI3K/AKT pathway related proteins were detected by Western blot. The interactions among lncRNA GAS5, miR-375-3p, and Klf4 were verified by dual-luciferase reporter assays. The findings showed that OT significantly attenuated cardiac hypertrophy, increased expressions of lncRNA GAS5 and KLF4, and decreased miR-375-3p expression. In vitro studies demonstrated that either knock-down of lncRNA GAS5 or Klf4, or over-expression of miR-375-3p blunted the anti-hypertrophic effects of OT. Moreover, down-regulation of lncRNA GAS5 promoted the expression of miR-375-3p and inhibited KLF4 expression. Similarly, over-expression of miR-375-3p decreased the expression of KLF4. Dual-luciferase reporter assays validated that lncRNA GAS5 could sponge miR-375-3p and Klf4 was a direct target gene of miR-375-3p. In addition, OT could inactivate PI3K/AKT pathway. The functional rescue experiments further identified OT regulated PI3K/AKT pathway through lncRNA GAS5/miR-375-3p/KLF4 axis. In summary, our study demonstrates that OT ameliorates cardiac hypertrophy by inhibiting PI3K/AKT pathway via lncRNA GAS5/miR-375-3p/KLF4 axis.

Author(s):  
Wei Wang ◽  
Nian Liu ◽  
Li Xin ◽  
Yanfei Ruan ◽  
Xin Du ◽  
...  

AbstractHeart often undergoes mal-remodeling and hypertrophic growth in response to pathological stress. MiRNAs can regulate the cardiac function and participate in the regulation of cardiac hypertrophy. The present study aims at identifying the role of miR-296-5p in cardiac hypertrophy and further the underlying mechanism in hypertrophic cascades. Mice with cardiac hypertrophy were established by transverse aortic constriction (TAC). Cardiac hypertrophy in cardiomyocytes was induced by angiotensin II. Expression of miR-296-5p and its target gene CACNG6 was examined in cardiomyocytes transfected by miRNA. The expression of miR-296-5p was upregulated in mice with TAC surgery. The inhibition of miR-296-5p attenuated cardiac hypertrophy both in vitro and in vivo. And dual-luciferase reporter assays showed CACNG6 was the direct target of miR-296-5p, which modulated the expression of calcium signaling. MiR-296-5p was found to aggravate cardiac hypertrophy by targeting CACNG6, which suggests inhibition of miR-296-5p might have clinical potential to suppress cardiac hypertrophy and heart failure.


Author(s):  
Fu-han Gong ◽  
Xi-Lu Chen ◽  
Quan Zhang ◽  
Xiao-qiang Xiao ◽  
Yong-sheng Yang ◽  
...  

Abstract BACKGROUND MicroRNAs serve as important regulators of the pathogenesis of cardiac hypertrophy. Among them, miR-183 is well documented as a novel tumor suppressor in previous studies, whereas it exhibits a downregulated expression in cardiac hypertrophy recently. The present study was aimed to examine the effect of miR-183 on cardiomyocytes hypertrophy. METHODS Angiotensin II (Ang II) was used for establishment of cardiac hypertrophy model in vitro. Neonatal rat ventricular cardiomyocytes transfected with miR-183 mimic or negative control were further utilized for the phenotype analysis. Moreover, the bioinformatics analysis and luciferase reporter assays were used for exploring the potential target of miR-183 in cardiomyocytes. RESULTS We observed a significant decreased expression of miR-183 in hypertrophic cardiomyocytes. Overexpression of miR-183 significantly attenuated the cardiomyocytes size morphologically and prohypertrophic genes expression. Moreover, we demonstrated that TIAM1 was a direct target gene of miR-183 verified by bioinformatics analysis and luciferase reporter assays, which showed a decreased mRNA and protein expression in the cardiomyocytes transfected with miR-183 upon Ang II stimulation. Additionally, the downregulated TIAM1 expression was required for the attenuated effect of miR-183 on cardiomyocytes hypertrophy. CONCLUSIONS Taken together, these evidences indicated that miR-183 acted as a cardioprotective regulator for the development of cardiomyocytes hypertrophy via directly regulation of TIAM1.


2020 ◽  
Author(s):  
Huiping Zhang ◽  
Kun Xiao ◽  
Shengchao Ma ◽  
Long Xu ◽  
Ning Ding ◽  
...  

Abstract Background: Increasing evidences supported that elevated homocysteine (Hcy) levels contribute to cell apoptosis is implicated in the pathogenesis of liver injury, it correlates with liver disease severity. However, the underlying mechanism of apoptosis in Hcy-mediated liver injury remains obscure. Results: In this study, we found that homocysteine increases ER stress-mediated apoptosis and aggravates liver injury through up-regulation of PSMD10 expression in cbs+/- mice mice fed with high methionine diet and hepatocytes treated with homocysteine in vitro. Knockdown of PSMD10 expression remarkably reduced ER stress or apoptosis-associated protein in hepatocytes exposed to homocysteine. Moreover, bioinformatics analysis revealed that PSMD10 is a potential target gene of miR-212-5p, and luciferase reporter assay also confirmed that miR-212-5p negatively regulated PSMD10 expression by direct binding to its 3’-UTR regions. Subsequently, over-expression of miR-212-5p inhibited ER stress-mediated hepatocytes apoptosis though targeting PSMD10, all of which were abrogated by knockdown of miR-212-5p expression. Further study showed that the interaction between PSMD10 and GRP78 accelerated ER stress-mediated hepatic apoptosis induced by homocysteine. Conclusion: Taken together, these results demonstrated that down-regulation of miR-212-5p facilitates homocysteine-induced hepatocytes apoptosis via targeting PSMD10, which provides novel insight into the mechanism of homocysteine induced apoptosis in liver injury.


2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Guijun He ◽  
Wenfeng Yao ◽  
Liang Li ◽  
Yang Wu ◽  
Guojian Feng ◽  
...  

Abstract Background LOXL1-AS1 is a long non-coding RNA (lncRNA) that plays crucial roles in various cancers. However, the functional role of LOXL1-AS1 in laryngocarcinoma remains unclear. Thus we planned to probe into the function and underlying mechanism of LOXL1-AS1 in laryngocarcinoma. Methods Gene expression was evaluated in laryngocarcinoma cells using RT-qPCR. The ability of cell proliferation and migration was assessed by CCK8, colony formation, wound healing and transwell assays. The interaction among LOXL1-AS1, miR-589-5p and TRAF6 was detected by Ago2-RIP, RNA pull down and luciferase reporter assays. Results LOXL1-AS1 was overexpressed in laryngocarcinoma cells. Silencing of LOXL1-AS1 suppressed cell proliferation, migration and EMT in laryngocarcinoma. Moreover, miR-589-5p, the downstream of LOXL1-AS1, directly targeted TRAF6 in laryngocarcinoma. Importantly, LOXL1-AS1 augmented TRAF6 expression in laryngocarcinoma cells by sequestering miR-589-5p. Besides, miR-589-5p worked as a tumor-inhibitor while TRAF6 functioned as a tumor-facilitator in laryngocarcinoma. Of note, rescue experiments both in vitro and in vivo validated that LOXL1-AS1 aggravated the malignancy in laryngocarcinoma by targeting miR-589-5p/TRAF6 pathway. Conclusions LOXL1-AS1 promotes the proliferation and migration of laryngocarcinoma cells through absorbing miR-589-5p to upregulate TRAF6 expression.


Circulation ◽  
2007 ◽  
Vol 116 (suppl_16) ◽  
Author(s):  
Tetsuro Ago ◽  
Tong Liu ◽  
Hong Li ◽  
Jeffery Molkentin ◽  
Junichi Sadoshima

Thioredoxin1 (Trx1) reduces redox-sensitive proteins and regulates cell growth and death. We previously reported that cardiac hypertrophy induced by pressure-overload is suppressed in mice with cardiac specific overexpression of Trx1 (Tg-Trx1). To elucidate the mechanisms by which Trx1 suppresses cardiac hypertrophy, we performed DNA microarray analysis using Tg-Trx1 mouse hearts. We identified DnaJb5, a heat shock protein 40, as a gene significantly upregulated by Trx1. Immunostaining and immunoblot analyses indicated that Trx1 and DnaJb5 are co-localized in the nucleus of myocytes. Pull-down and immunoprecipitation assays showed that DnaJb5 interacts with TBP-2, a Trx1-binding protein. DnaJb5 did not disturb the interaction between Trx1 and TBP-2, and enhanced the Trx1 reducing activity. Both Trx1 and DnaJb5 attenuated phenylephrine (PE)-induced activation of NFAT and myocyte hypertrophy in vitro . Using transgenic mice harboring an NFAT luciferase reporter, we confirmed that Trx1 suppresses both NFAT activation and cardiac hypertrophy induced by PE in vivo . We also found that DnaJb5 binds directly to histone deacetylase 4 (HDAC4), a class II HDAC. An HDAC4 mutant lacking the minimal region responsible for the interaction with DnaJb5 (residues 628 – 881) was localized in the cytosol, in contrast to the nuclear localization of the wild-type HDAC4, suggesting the importance of the interaction for the nuclear localization of HDAC4. Overexpression of Trx1 suppressed PE-induced nuclear export of HDAC4 in myocytes. Using mass spectroscopy, we found that HDAC4 forms a disulfide bond between Cys-667 and -669, which was reduced by Trx1. The HDAC4 Cys667/669Ser mutant was localized in the cytosol, and its nuclear export was suppressed by leptomycin B, an inhibitor of exportin, suggesting that the redox modification induces nuclear export regardless of phosphorylation. Consistently, the Cys667/669Ser substitution abolished the suppressive effect of HDAC4 on NFAT activity and cardiac hypertrophy. Collectively, these results show that Trx1 upregulates DnaJb5, which recruits HDAC4 into the complex formed by Trx1-TBP-2-DnaJb5, thereby reducing HDAC4, retaining its nuclear localization, and suppressing NFAT activity and cardiac hypertrophy.


2020 ◽  
Author(s):  
Jinyang Liu ◽  
Yaqin Zhu ◽  
Chunlin Ge

Abstract Background: The mortality and morbidity rates of pancreatic adenocarcinoma have been increasing over the past two decades, and an understanding of the mechanisms underlying pancreatic adenocarcinoma progression is urgently needed. The long non-coding RNA ZFAS1 has been demonstrated to be an oncogene in some cancers, but its function and mechanism in pancreatic adenocarcinoma remain unclear.Methods: The ZFAS1 expression level in pancreatic adenocarcinoma was predicted by bioinformatic analysis, and the expression level of ZFAS1 in pancreatic adenocarcinoma tissue samples and cell lines was further investigated by quantitative real-time PCR and in situ hybridization. The functions of ZFAS1 in pancreatic adenocarcinoma in vitro and in vivo were investigated by further bioinformatic analysis. Dual-luciferase reporter assays were used to investigate the binding of ZFAS1/miR-3924 and miR-3924/ROCK2, and rescue assays were performed to further investigate the underlying mechanism.Results: ZFAS1 overexpression in pancreatic adenocarcinoma was predicted and experimentally verified. ZFAS1 silencing inhibited pancreatic adenocarcinoma metastasis in vitro and in vivo. The competing endogenous RNA mechanism of ZFAS1 was also identified.Conclusions: Our results demonstrated the promotive effect of ZFAS1 on pancreatic adenocarcinoma metastasis and suggested its potential role as a novel regulator of ROCK2.


Author(s):  
Linling Lin ◽  
Jian Xiao ◽  
Liang Shi ◽  
Wangwang Chen ◽  
Yugang Ge ◽  
...  

Abstract Background Increasing evidence shows that stimulated by retinoic acid 6 (STRA6) participates in regulating multiple cancers. However, the biological roles of STRA6 in gastric cancer (GC) remain unknown. This study aimed to investigate the biological function of STRA6 and reveal the underlying mechanism of its dysregulation in GC. Methods The expression level of STRA6 was detected through quantitative real-time PCR and Western blot analysis. The effects of STRA6 on the proliferation of GC cells were studied through CCK-8 proliferation, colony formation and 5-ethynyl-2′-deoxyuridine (EdU) assays. The effects of STRA6 on migration and invasion were detected via wound healing and Transwell assays. Upstream miRNAs, which might regulate STRA6 expression, was predicted through bioinformatics analysis. Their interaction was further confirmed through dual-luciferase reporter assays and rescue experiments. Results STRA6 was up-regulated in GC and enhanced the proliferation and metastasis of GC cells in vitro and in vivo. STRA6 knockdown could inhibit the Wnt/β-catenin signalling pathway. STRA6 was confirmed as an miR-873 target, which acted as a tumour suppressor in GC. Rescue assays showed that the repressing effect of miR-873 could be partially reversed by overexpressing STRA6. Conclusions STRA6 is down-regulated by miR-873 and plays an oncogenic role by activating Wnt/β-catenin signalling in GC.


2019 ◽  
Vol 116 (7) ◽  
pp. 1323-1334 ◽  
Author(s):  
Hui Li ◽  
Jin-Dong Xu ◽  
Xian-Hong Fang ◽  
Jie-Ning Zhu ◽  
Jing Yang ◽  
...  

Abstract Aims Circular RNAs (circRNAs) are involved in gene regulation in a variety of physiological and pathological processes. The present study aimed to investigate the effect of circRNA_000203 on cardiac hypertrophy and the potential mechanisms involved. Methods and results CircRNA_000203 was found to be up-regulated in the myocardium of Ang-II-infused mice and in the cytoplasma of Ang-II-treated neonatal mouse ventricular cardiomyocytes (NMVCs). Enforced expression of circRNA_000203 enhances cell size and expression of atrial natriuretic peptide and β-myosin heavy chain in NMVCs. In vivo, heart function was impaired and cardiac hypertrophy was aggravated in Ang-II-infused myocardium-specific circRNA_000203 transgenic mice (Tg-circ203). Mechanistically, we found that circRNA_000203 could specifically sponge miR-26b-5p, -140-3p in NMVCs. Further, dual-luciferase reporter assay showed that miR-26b-5p, -140-3p could interact with 3′-UTRs of Gata4 gene, and circRNA_000203 could block the above interactions. In addition, Gata4 expression is transcriptionally inhibited by miR-26b-5p, -140-3p mimic in NMVCs but enhanced by over-expression of circRNA_000203 in vitro and in vivo. Functionally, miR-26b-5p, -140-3p, and Gata4 siRNA, could reverse the hypertrophic growth in Ang-II-induced NMVCs, as well as eliminate the pro-hypertrophic effect of circRNA_000203 in NMVCs. Furthermore, we demonstrated that NF-κB signalling mediates the up-regulation of circRNA_000203 in NMVCs exposed to Ang-II treatment. Conclusions Our data demonstrated that circRNA_000203 exacerbates cardiac hypertrophy via suppressing miR-26b-5p and miR-140-3p leading to enhanced Gata4 levels.


2021 ◽  
Vol 11 ◽  
Author(s):  
Yalin Lu ◽  
Gaochao Guo ◽  
Rujun Hong ◽  
Xingjie Chen ◽  
Yan Sun ◽  
...  

GBM (Glioblastoma multiform) is the most malignant tumor type of the central nervous system and has poor diagnostic and clinical outcomes. LncRNAs (Long non-coding RNAs) have been reported to participate in multiple biological and pathological processes, but their underlying mechanism remains poorly understood. Here, we aimed to explore the role of the lncRNA HAS2-AS1 (HAS2 antisense RNA 1) in GBM. GSE103227 was analyzed, and qRT-PCR was performed to measure the expression of HAS2-AS1 in GBM. FISH (Fluorescence in situ hybridization) was performed to verify the localization of HAS2-AS1. The interaction between HAS2-AS1 and miR-137 (microRNA-137) was predicted by LncBook and miRcode followed by dual‐luciferase reporter assays, and the relationships among HAS2-AS1, miR-137 and LSD1 (lysine-specific demethylase 1) were assessed by WB (western blot) and qRT-PCR. Colony formation and CCK-8 (cell counting kit-8) assays were performed as functional tests. In vivo, nude mice were used to confirm the function of HAS2-AS1. HAS2-AS1 expression was upregulated in GBM cell lines, and HAS2-AS1 was localized mainly in the cytoplasm. In vitro, high HAS2-AS1 expression promoted proliferation, and knockdown of HAS2-AS1 significantly inhibited proliferation. Furthermore, HAS2-AS1 functioned as a ceRNA (competing endogenous RNA) of miR-137, leading to the disinhibition of its downstream target LSD1. The miR-137 level was downregulated by HAS2-AS1 overexpression and upregulated by HAS2-AS1 knockdown. In a subsequent study, LSD1 expression was negatively regulated by miR-137, while miR-137 reversed the LSD1 expression levels caused by HAS2-AS1. These results were further supported by the nude mouse tumorigenesis experiment; compared with xenografts with high HAS2-AS1 expression, the group with low levels of HAS2-AS1 exhibited suppressed proliferation and better survival. We conclude that lncRNA HAS2-AS1 promotes proliferation by functioning as a miR‐137 decoy to increase LSD1 levels and thus might be a possible biomarker for GBM.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Lei Wang ◽  
Yehui Zhou ◽  
Liang Jiang ◽  
Linlin Lu ◽  
Tiantian Dai ◽  
...  

Abstract Background Chemotherapeutic resistance is the main cause of clinical treatment failure and poor prognosis in triple-negative breast cancer (TNBC). There is no research on chemotherapeutic resistance in TNBC from the perspective of circular RNAs (circRNAs). Methods TNBC-related circRNAs were identified based on the GSE101124 dataset. Quantitative reverse transcription PCR was used to detect the expression level of circWAC in TNBC cells and tissues. Then, in vitro and in vivo functional experiments were performed to evaluate the effects of circWAC in TNBC. Results CircWAC was highly expressed in TNBC and was associated with worse TNBC patient prognosis. Subsequently, it was verified that downregulation of circWAC can increase the sensitivity of TNBC cells to paclitaxel (PTX) in vitro and in vivo. The expression of miR-142 was negatively correlated with circWAC in TNBC. The interaction between circWAC and miR-142 in TNBC cells was confirmed by RNA immunoprecipitation assays, luciferase reporter assays, pulldown assays, and fluorescence in situ hybridization. Mechanistically, circWAC acted as a miR-142 sponge to relieve the repressive effect of miR-142 on its target WWP1. In addition, the overall survival of TNBC patients with high expression of miR-142 was significantly better than that of patients with low expression of miR-142, and these results were verified in public databases. MiR-142 regulated the expression of WWP1 and the activity of the PI3K/AKT pathway. It was confirmed that WWP1 is highly expressed in TNBC and that the prognosis of patients with high WWP1 expression is poor. Conclusions CircWAC/miR-142/WWP1 form a competing endogenous RNA (ceRNA) network to regulate PI3K/AKT signaling activity in TNBC cells and affect the chemosensitivity of cells.


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