Abstract 49: Prolyl Isomerase Pin1 Regulates Cardiac Hypertrophy via Controlling Phosphorylation of Akt and MEK

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Haruhiro Toko ◽  
Mathias Konstandin ◽  
Natalie Gude ◽  
Mark Sussman
Keyword(s):  
Cardiac Hypertrophy ◽  
Protein Expression ◽  
High Serum ◽  
Neonatal Rat ◽  
Border Zone ◽  
Prolyl Isomerase ◽  
Rat Cardiomyocytes ◽  
Growth And Survival ◽  
Pin1 Protein

Rationale: Kinases and phosphatases regulate crucial aspects of growth and survival through phosphorylation and dephosphorylation of target substrates. Processes of cardiac hypertrophy, myocardial infarction, and heart failure are dictated in part by which kinases or phosphatases are involved and also by the intensity and duration of specific enzymatic activities. While research has identified numerous critical regulatory kinases and phosphatases in the myocardium, the intracellular mechanism for temporal regulation of signaling duration and intensity remains obscure. In the non-myocyte context, control of folding, activity, stability, and subcellular localization of proteins responsible for growth and survival is mediated by the prolyl isomerase Pin1. Objective: To establish the role of Pin1 in the heart. Method and Results: Initial characterization of myocardial Pin1 involved assessment of expression and localization during postnatal development or pathological challenge. Pin1 protein level was decreased and the location of Pin1 was changed from nucleus to cytoplasm with increasing age. Next, Pin1 protein expression and localization were assessed in the pathological challenged heart. Pin1 protein expression increases with pressure overload and ischemia, particularly in perivascular areas and in border zone myocytes, respectively. To determine the role of Pin1 on cardiac hypertrophy, siRNA to Pin1 (siPin1) was applied to neonatal rat cardiomyocytes. Western blot analysis showed that siPin1 decreased phosphorylation of Akt, and immunohistochemical analysis showed that siPin1 reduced cardiomyocyte size in response to high serum. siPin1 also decreased phosphorylation of MEK and reduced cardiomyocyte size in response to phenylephrine treatment. Furthermore, cardiac hypertrophy induced by transaortic constriction was ameliorated in Pin1 knockout mice, compared with littermate wild type mice. Conclusion: Expression and location of Pin1 during development and in response to pathologic challenge point to an important role for Pin1 in adaptation to myocardial growth or stress. Collective evidence indicates that Pin1 controls cardiac hypertrophy at least in part via regulating phosphorylation of Akt and MEK.

Role of myofibrillogenesis regulator-1 in myocardial hypertrophy

2006 ◽  
Vol 290 (1) ◽  
pp. H279-H285 ◽  
Author(s):  
Xiuhua Liu ◽  
Tianbo Li ◽  
Sheng Sun ◽  
Feifei Xu ◽  
Yiguang Wang
Keyword(s):  
Rna Interference ◽  
Cardiac Hypertrophy ◽  
Protein Expression ◽  
Western Blotting ◽  
Left Ventricular ◽  
Neonatal Rat ◽  
Heart Weight ◽  
Homologous Gene ◽  
Ang Ii ◽  
Rat Cardiomyocytes

Myofibrillogenesis regulator-1 (MR-1) is a novel homologous gene, identified from a human skeletal muscle cDNA library, that interacts with contractile proteins and exists in human myocardial myofibrils. The present study investigated MR-1 protein expression in hypertrophied myocardium and MR-1 involvement in cardiac hypertrophy. Cardiac hypertrophy was induced by abdominal aortic stenosis (AAS) in Sprague-Dawley rats. Left ventricular (LV) hypertrophy was assessed by the ratio of LV wet weight to whole heart weight (LV/HW) or LV weight to body weight (LV/BW). Rat MR-1 (rMR-1) expression in the myocardium was detected by immunohistochemical and Western blotting analysis. Hypertrophy was induced by ANG II incubation in cultured neonatal rat cardiomyocytes. The effect of rMR-1 RNA interference on ANG II-induced hypertrophy was studied by transfection of cardiomyocytes with an RNA interference plasmid, pSi-1, which targets rMR-1. Hypertrophy in cardiomyocytes was assessed by [3H]Leu incorporation and myocyte size. rMR-1 protein expression in cardiomyocytes was detected by Western blotting. We found that AAS resulted in a significant increase in LV/HW and LV/BW: 89% and 86%, respectively ( P < 0.01). Immunohistochemistry and Western blot analysis demonstrated upregulated rMR-1 protein expression in hypertrophic myocardium. ANG II induced a 24% increase in [3H]Leu incorporation and a 65.8% increase in cell size compared with control cardiomyocytes ( P < 0.01), which was prevented by treatment with losartan, an angiotensin (AT1) receptor inhibitor, or transfection with pSi-1. rMR-1 expression increased in ANG II-induced hypertrophied cardiomyocytes, and pSi-1 transfection abolished the upregulation. These findings suggest that MR-1 is associated with cardiac hypertrophy in rats in vivo and in vitro.

scholarly journals miR-139-5p inhibits isoproterenol-induced cardiac hypertrophy by targetting c-Jun

2018 ◽  
Vol 38 (2) ◽  
Author(s):  
Su Ming ◽  
Wang Shui-yun ◽  
Qiu Wei ◽  
Li Jian-hui ◽  
Hui Ru-tai ◽  
...  
Keyword(s):  
Cardiac Hypertrophy ◽  
Left Ventricular ◽  
Neonatal Rat ◽  
Monogenic Disease ◽  
Transverse Aortic Constriction ◽  
Aortic Constriction ◽  
Rat Cardiomyocytes ◽  
Neonatal Rat Cardiomyocytes ◽  
Regulatory Effects

Hypertrophic cardiomyopathy (HCM) is a serious monogenic disease characterized by cardiac hypertrophy, fibrosis, sudden cardiac death, and heart failure. Previously, we identified that miR-139-5p was down-regulated in HCM patients. However, the regulatory effects of miR-139-5p remain unclear. Thus, we investigated the role of miR-139-5p in the regulation of cardiac hypertrophy. The expression of miR-139-5p in left ventricular tissues in HCM patients and mice subjected to transverse aortic constriction (TAC) was significantly down-regulated. Knockdown of miR-139-5p expression in neonatal rat cardiomyocytes (NRCMs) induced cardiomyocyte enlargement and increased atrial natriuretic polypeptide (ANP) expression. Overexpression of miR-139-5p antagonized isoproterenol (ISO)-induced cardiomyocyte enlargement and ANP/brain natriuretic peptide (BNP) up-regulation. More importantly, we found that c-Jun expression was inhibited by miR-139-5p in NRCMs. Knockdown of c-Jun expression significantly attenuated cardiac hypertrophy induced by miR-139-5p deprivation. Our data indicated that miR-139-5p was down-regulated in the hearts of HCM patients and that it inhibited cardiac hypertrophy by targetting c-Jun expression.

Abstract 320: Roles of Estrogen, AMPK and Micro RNAs in the Progression of Cardiac Hypertrophy

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Yulia Lipovka ◽  
John P Konhilas
Keyword(s):  
Heart Failure ◽  
Cardiac Hypertrophy ◽  
Neonatal Rat ◽  
Cardiomyocyte Hypertrophy ◽  
Estradiol Treatment ◽  
Rat Cardiomyocytes ◽  
Altered Expression ◽  
Ampk Pathway ◽  
Micro Rnas

In industrialized countries, the prevalence of congestive heart failure (CHF) is increasing steadily and has become one of the leading causes of hospitalization. In addition, the risk of cardiovascular disease increases in post-menopausal women. Yet, the association between estrogen and the risk of CHF has not been adequately studied. Recently, MicroRNAs (miR) and AMP-kinase (AMPK) have emerged as prominent players in the development of cardiac hypertrophy and heart failure. Our on-going studies indicate differential AMPK regulation through two miR species (miR195 and miR451) in a mouse model harboring a missense mutation (R403Q) in alpha-myosin heavy chain (αMHC) causing hypertrophic cardiomyopathy (HCM). Using bioinformatic algorithms (TargetScanMouse, 5.2), we were able to predict miR candidates that potentially target the AMPK axis. In addition, Altered expression of miRs that target AMPK axis was found in phenylephrine induced hypertrophic neonatal rat cardiomyocytes (NRCM). However, Estradiol treatment of NRCM blocked the hypertrophic changes induced by phenylephrine treatment. It was known that the activation of AMPK pathway inhibits cardiomyocyte hypertrophy. Our data showed that AMPK pathway was activated by Estradiol treatment, which can be blocked by estrogen receptor (ER) β antagonist. Therefore, estradiol increase AMPK pathway activation which in turn attenuate phenylephrine induced increase in cardiomyocyte cell size. Further studies are need to further explore the role of estrogen in the regulation of miR expression in hypertrophic cardiomyocytes, and the role of the expression changes of miRs regulated by estrogen in the development of hypertrophic phenotype.

Abstract P236: Tripartite Motif 8 Contributes to Pathological Cardiac Hypertrophy Through Enhancing TAK1-dependent Signaling Pathways

Hypertension ◽  
2016 ◽  
Vol 68 (suppl_1) ◽  
Author(s):  
Hongliang Li ◽  
Yan-Xiao Ji ◽  
Peng Zhang
Keyword(s):  
Cardiac Hypertrophy ◽  
Signaling Pathways ◽  
Specific Inhibitor ◽  
Pressure Overload ◽  
Neonatal Rat ◽  
Physical Interaction ◽  
Rat Cardiomyocytes ◽  
Pathological Cardiac Hypertrophy ◽  
Tripartite Motif

Tripartite motif (TRIM) 8 functions as an E3 ligase, interacting with and ubiquitinating diverse substrates, and is implicated in various pathological processes. However, the biological function of TRIM8 in the heart remains largely uncharacterized. This study aims to explore the role of TRIM8 in the development of cardiac hypertrophy and heart failure (HF). Mice and isolated neonatal rat cardiomyocytes (NRCMs) overexpressing or lacking TRIM8 were examined in several experiment. The effect of aortic banding (AB)-induced cardiac hypertrophy were analyzed by echocardiographic, pathological and molecular analyses. Our results indicated that the TRIM8 overexpression in hearts exacerbated the pathological cardiac hypertrophy triggered by AB, promoting cardiomyocytes enlargement and fibrosis formation by about 41% and 52%. In contrast, the development of pathological cardiac hypertrophy was profoundly blocked in TRIM8-deficient hearts. Mechanistically, the present study suggests that TRIM8 may elicit cardio-detrimental effects by promoting the activation of TAK1-p38/JNK signaling pathways. Similar results were observed in cultured NRCMs treated with angiotensin II. In addition, the rescue experiments using the TAK1-specific inhibitor 5z-7-ox confirmed the requirement of TAK1 activation in pressure overload-mediated pathological cardiac hypertrophy in TRIM8-overexpressing hearts. Furthermore, a physical interaction between TRIM8 and TAK1 was identified by co-immunoprecipitation experiments. Our study demonstrated that TRIM8 plays a deleterious role in pressure overload-induced cardiac hypertrophy by accelerating the activation of TAK1-dependent signaling pathways.

Abstract P279: YAP, a Transcriptional Cofactor of the Hippo Pathway, Regulates Cardiomyocyte Growth, Survival, and Proliferation

2011 ◽  
Vol 109 (suppl_1) ◽  
Author(s):  
Yanfei Yang ◽  
Noritsugu Nakano ◽  
Junichi Sadoshima
Keyword(s):  
Cardiac Hypertrophy ◽  
Hippo Pathway ◽  
Neonatal Rat ◽  
Border Zone ◽  
Luciferase Reporter ◽  
Tunel Staining ◽  
H2o2 Treatment ◽  
Rat Hearts ◽  
The Hippo Pathway

Mst1 and Lats2, components of the mammalian Hippo pathway, stimulate apoptosis and inhibit hypertrophy of cardiomyocytes (CMs), thereby mediating reperfusion injury and heart failure. YAP, a transcription factor co-factor, is negatively regulated by the Hippo pathway, and controls cell survival, proliferation and tissue regeneration. The role of YAP in regulating growth and death of CMs is poorly understood. YAP overexpression in CMs induced cardiac hypertrophy, as indicated by increases in cell size (+1.2 fold, p<0.01), protein content (+1.1 fold, p<0.01) and ANF (luciferase reporter activity +1.7 fold, mRNA +2.2 fold, and staining +2.7 fold, p<0.01). Lats2 phosphorylates YAP at Serine 127, which induces cytoplasmic translocation of YAP, whereas YAP(S127A) is localized constitutively in the nucleus. Expression of YAP(S127A) enhanced hypertrophy in cultured CMs compared to that of wild type YAP (+1.87 fold ANF staining, p<0.05), suggesting that the Mst1/Hippo pathway negatively regulates cardiac hypertrophy through YAP. YAP inhibited cell death induced by H2O2 treatment, as evaluated with TUNEL staining (-65%, p<0.05) and CellTiter Blue assays (+34.9%, p<0.01), indicating that YAP plays an essential role in mediating CM survival. Interestingly, YAP also significantly increased Ki67 positive cells in cultured CMs compared to LacZ (+2.65 fold, p<0.05). We used a mouse model of chronic myocardial infarction (MI) to evaluate the function of YAP in the heart in vivo. Although YAP is diffusely localized both in the nucleus and cytosol in CMs in control hearts, CMs in the border zone of MI exhibited nuclear localization of YAP whereas YAP was excluded from the nucleus in CMs in the remodeling area four days after MI (+6.52 fold and +1.28 fold). Some of the YAP positive CMs in the border zone exhibited positive co-staining with Ki67, suggesting that YAP potentially induces CM proliferation. A significant increase in nuclear YAP and Ki67 positive CMs (+2.95 fold, p<0.01 and +2.18 fold, p<0.05) was also observed in neonatal rat hearts whose apex was surgically resected three days before euthanasia. These results suggest that YAP plays an important role in mediating not only hypertrophy and survival, but also proliferation of CMs in response to myocardial injury.

Abstract P320: The Gut Microbial Metabolite Butyrate Suppresses Cardiac Hypertrophy Via An Epigenetic Mechanism

2021 ◽  
Vol 129 (Suppl_1) ◽  
Author(s):  
Masahiko Umei ◽  
Hiroshi Akazawa ◽  
Akiko Saga-Kamo ◽  
Hiroki Yagi ◽  
Qing Liu ◽  
...  
Keyword(s):  
Heart Failure ◽  
Fatty Acid ◽  
Cardiac Hypertrophy ◽  
Short Chain Fatty Acid ◽  
Chain Fatty Acid ◽  
Epigenetic Mechanism ◽  
Neonatal Rat ◽  
Short Chain ◽  
Rat Cardiomyocytes ◽  
Hypertrophic Growth

Introduction: Short-chain fatty acids (SCFA) are one of the gut microbial metabolites that can influence host health and disease. We previously reported that gut dysbiosis is associated with heart failure, and that the proportion of butyrate-producing bacteria is decreased in the gut of patients with heart failure. Purpose: We investigated the molecular mechanism of butyrate in the development of cardiac hypertrophy. Methods and Results: Single-cell transcriptome analysis and co-expression network analysis revealed that G protein-coupled receptors for short-chain fatty acid receptors were not expressed in cardiomyocytes and that Olfr78 was expressed in vascular smooth muscle cells in the heart. On the other hand, treatment with butyrate inhibited ET1-induced and isoproterenol (ISO)-induced hypertrophic growth in cultured neonatal rat cardiomyocytes. Moreover, butyrate increased the acetylation levels of histone H3, suggesting the inhibitory effect of butyrate on HDAC. In addition, butyrate caused the degradation of HDAC2 and up-regulation of Inpp5f, encoding inositol polyphosphate-5-phosphatase f, leading to a significant decrease in the phosphorylation levels of Akt and glycogen synthase kinase 3β (GSK3β). Finally, intraperitoneal injection of butyrate inhibited ISO-induced cardiac hypertrophy in mice. These results suggest that butyrate protects against hypertrophic responses via suppression of the Akt-GSK3β pathway through HDAC inhibition. Conclusion: In the heart, there were no known short-chain fatty acid receptors in cardiomyocytes. However, butyrate was shown to have an epigenetic mechanism in suppressing effect on cardiomyocyte hypertrophy via suppression of HDAC2-Akt-GSK3β axis. Our results uncover a potential link between dysbiosis of intestinal microbiota and the development of cardiac hypertrophy.

scholarly journals Bakuchiol protects against pathological cardiac hypertrophy by blocking NF-κB signaling pathway

2018 ◽  
Vol 38 (5) ◽  
Author(s):  
Zheng Wang ◽  
Lu Gao ◽  
Lili Xiao ◽  
Lingyao Kong ◽  
Huiting Shi ◽  
...  
Keyword(s):  
Cardiac Hypertrophy ◽  
Signaling Pathway ◽  
Pressure Overload ◽  
Neonatal Rat ◽  
Oral Gavage ◽  
Aortic Banding ◽  
Rat Cardiomyocytes ◽  
Pathological Cardiac Hypertrophy ◽  
First Time

Bakuchiol (Bak), a monoterpene phenol isolated from the seeds of Psoralea corylifolia, has been widely used to treat a large variety of diseases in both Indian and Chinese folkloric medicine. However, the effects of Bak on cardiac hypertrophy remain unclear. Therefore, the present study was designed to determine whether Bak could alleviate cardiac hypertrophy. Mice were subjected to aortic banding (AB) to induce cardiac hypertrophy model. Bak of 1 ml/100 g body weight was given by oral gavage once a day from 1 to 8 weeks after surgery. Our data demonstrated for the first time that Bak could attenuate pressure overload-induced cardiac hypertrophy and could attenuate fibrosis and the inflammatory response induced by AB. The results further revealed that the effect of Bak on cardiac hypertrophy was mediated by blocking the activation of the NF-κB signaling pathway. In vitro studies performed in neonatal rat cardiomyocytes further proved that the protective effect of Bak on cardiac hypertrophy is largely dependent on the NF-κB pathway. Based on our results, Bak shows profound potential for its application in the treatment of pathological cardiac hypertrophy, and we believe that Bak may be a promising therapeutic candidate to treat cardiac hypertrophy and heart failure.

A gene therapeutic approach to inhibit calcium and integrin binding protein 1 ameliorates maladaptive remodelling in pressure overload

2018 ◽  
Vol 115 (1) ◽  
pp. 71-82 ◽  
Author(s):  
Andrea Grund ◽  
Malgorzata Szaroszyk ◽  
Janina K Döppner ◽  
Mona Malek Mohammadi ◽  
Badder Kattih ◽  
...  
Keyword(s):  
Heart Failure ◽  
Cardiac Hypertrophy ◽  
Cardiac Function ◽  
Binding Protein ◽  
Treatment Strategies ◽  
Pressure Overload ◽  
Cellular Growth ◽  
Neonatal Rat ◽  
Rat Cardiomyocytes ◽  
Pathological Cardiac Hypertrophy

Abstract Aims Chronic heart failure is becoming increasingly prevalent and is still associated with a high mortality rate. Myocardial hypertrophy and fibrosis drive cardiac remodelling and heart failure, but they are not sufficiently inhibited by current treatment strategies. Furthermore, despite increasing knowledge on cardiomyocyte intracellular signalling proteins inducing pathological hypertrophy, therapeutic approaches to target these molecules are currently unavailable. In this study, we aimed to establish and test a therapeutic tool to counteract the 22 kDa calcium and integrin binding protein (CIB) 1, which we have previously identified as nodal regulator of pathological cardiac hypertrophy and as activator of the maladaptive calcineurin/NFAT axis. Methods and results Among three different sequences, we selected a shRNA construct (shCIB1) to specifically down-regulate CIB1 by 50% upon adenoviral overexpression in neonatal rat cardiomyocytes (NRCM), and upon overexpression by an adeno-associated-virus (AAV) 9 vector in mouse hearts. Overexpression of shCIB1 in NRCM markedly reduced cellular growth, improved contractility of bioartificial cardiac tissue and reduced calcineurin/NFAT activation in response to hypertrophic stimulation. In mice, administration of AAV-shCIB1 strongly ameliorated eccentric cardiac hypertrophy and cardiac dysfunction during 2 weeks of pressure overload by transverse aortic constriction (TAC). Ultrastructural and molecular analyses revealed markedly reduced myocardial fibrosis, inhibition of hypertrophy associated gene expression and calcineurin/NFAT as well as ERK MAP kinase activation after TAC in AAV-shCIB1 vs. AAV-shControl treated mice. During long-term exposure to pressure overload for 10 weeks, AAV-shCIB1 treatment maintained its anti-hypertrophic and anti-fibrotic effects, but cardiac function was no longer improved vs. AAV-shControl treatment, most likely resulting from a reduction in myocardial angiogenesis upon downregulation of CIB1. Conclusions Inhibition of CIB1 by a shRNA-mediated gene therapy potently inhibits pathological cardiac hypertrophy and fibrosis during pressure overload. While cardiac function is initially improved by shCIB1, this cannot be kept up during persisting overload.

Abstract 182: CTRP9 - A Novel Cardiac Derived Secreted Factor With Anti-hypertrophic Properties

2013 ◽  
Vol 113 (suppl_1) ◽  
Author(s):  
Astrid H Breitbart ◽  
Florian Brandes ◽  
Oliver Müller ◽  
Natali Froese ◽  
Mortimer Korf-Klingebiel ◽  
...  
Keyword(s):  
Cardiac Hypertrophy ◽  
Real Time ◽  
Real Time Pcr ◽  
Weight Ratio ◽  
Neonatal Rat ◽  
Heart Weight ◽  
Cardiomyocyte Hypertrophy ◽  
Quantitative Real Time Pcr ◽  
Rat Cardiomyocytes ◽  
Knock Out

Background: CTRP9 (also called C1qtnf9) is a newly discovered secreted protein and a paralog of adiponectin. The biological functions of CTRP9, however, are still largely unknown. Results: Although previous data from a semi-quantitative real-time PCR had suggested that CTRP9 is mainly secreted by adipose tissue, we found its mRNA to be predominantly expressed in the heart by quantitative real-time PCR. Interestingly, we identified CTRP9 mRNA as significantly upregulated in hypertrophied mouse hearts (after 2 weeks of aortic constriction, TAC) as well as in hypertrophied human hearts (24±4-fold versus healthy human myocardium; p<0.01). LacZ staining in myocardial sections of C1qtnf9 tm1(KOMP)Vlcg mice (knock-out for CTRP9, containing a lacZ cassette to replace exon 1-3 of the gene) revealed exclusive expression of CTRP9 in capillary and venous endothelial cells. Adenoviral overexpression of CTRP9 or recombinant CTRP9 strongly inhibited cardiomyocyte hypertrophy (assessed as cell size, protein/DNA-ratio, expression of skeletal α-actin) after stimulation with phenylephrine (PE). Accordingly, myocardial overexpression of CTRP9 via a cardioselective adeno-associated virus (AAV9-CTRP9) in mice dramatically reduced cardiac hypertrophy after two weeks of pressure overload (heart weight/body weight ratio, HW/BW in mg/g: AAV9-control 6.5±0.2 versus AAV9-CTRP9 5.6±0.2; p<0.01). In turn, downregulation of CTRP9 by a specific siRNA aggravated cardiomyocyte growth in response to PE in vitro and CTRP9 knock-out (KO) mice exerted an enhanced hypertrophic response after two weeks of TAC in vivo (% increase in HW/BW versus sham: wild-type 77±13, KO 106±9; p<0.05). Mechanistically, we found that CTRP9 binds to the adiponectin receptor 1 (AdipoR1) and inhibits prohypertrophic mTOR signalling in cardiac myocytes. SiRNA mediated downregulation of AdipoR1 or mTOR in neonatal rat cardiomyocytes abolished the anti-hypertrophic effect of CTRP9. Conclusion: Endothelial cell derived CTRP9 inhibits cardiac hypertrophy through binding to AdipoR1 and inhibition of the mTOR pathway in cardiomyocytes. Therefore, myocardial application of CTRP9 could be a novel strategy to combat pathological cardiac hypertrophy.

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