Abstract 206: A New MicroRNA Family Regulating Cardiac Autophagy and Hypertrophy

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Thomas Thum ◽  
Shashi K Gupta ◽  
Ahmet Ucar ◽  
Jan Fiedler ◽  
Leon DeWindt ◽  
...  

Pathologic growth of cardiomyocytes and derailed autophagy are major determinants for the development of heart failure, one of the leading medical causes of mortality worldwide. Here, we show the microRNA (miRNA)-212/132 family to regulate hypertrophy and autophagy in cardiomyocytes. Hypertrophic stimuli lead to the upregulation of miR-212 and miR-132 expression in cardiomyocytes, which are both necessary and sufficient to drive the hypertrophic growth of cardiomyocytes. MiR-212/132 null mice are protected from pressure-overload induced heart failure, whereas cardiomyocyte-specific overexpression of the miR-212/132 family leads to pathological cardiac hypertrophy, heart failure and lethality in mice. Mechanistically, both miR-212 and miR-132 directly target the anti-hypertrophic and pro-autophagic FoxO3 transcription factor and overexpression of these miRNAs leads to hyperactivation of pro-hypertrophic calcineurin/NFAT signalling and impaired autophagic response upon starvation. Pharmacologic miRNA inhibition by antagomir injection rescues cardiac hypertrophy and heart failure in mice, offering a possible therapeutic approach for cardiac failure.

2018 ◽  
Vol 115 (1) ◽  
pp. 71-82 ◽  
Author(s):  
Andrea Grund ◽  
Malgorzata Szaroszyk ◽  
Janina K Döppner ◽  
Mona Malek Mohammadi ◽  
Badder Kattih ◽  
...  

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.


2010 ◽  
Vol 298 (6) ◽  
pp. H2082-H2092 ◽  
Author(s):  
Yonggang Liu ◽  
Man Yu ◽  
Ling Wu ◽  
Michael T. Chin

Cardiac hypertrophy is a common response to hemodynamic stress in the heart and can progress to heart failure. To investigate whether the transcription factor cardiovascular basic helix-loop-helix factor 1/hairy/enhancer of split related with YRPW motif 2 (CHF1/Hey2) influences the development of cardiac hypertrophy and progression to heart failure under conditions of pressure overload, we performed aortic constriction on 12-wk-old male wild-type (WT) and heterozygous (HET) mice globally underexpressing CHF1/Hey2. After aortic banding, WT and HET mice showed increased cardiac hypertrophy as measured by gravimetric analysis, as expected. CHF1/Hey2 HET mice, however, demonstrated a greater increase in the ventricular weight-to-body weight ratio compared with WT mice ( P < 0.05). Echocardiographic measurements showed a significantly decreased ejection fraction compared with WT mice ( P < 0.05). Histological examination of Masson trichrome-stained heart tissue demonstrated extensive fibrosis in HET mice compared with WT mice. TUNEL staining demonstrated increased apoptosis in HET hearts ( P < 0.05). Exposure of cultured neonatal myocytes from WT and HET mice to H2O2 and tunicamycin, known inducers of apoptosis that work through different mechanisms, demonstrated significantly increased apoptosis in HET cells compared with WT cells ( P < 0.05). Expression of Bid, a downstream activator of the mitochondrial death pathway, was expressed in HET hearts at increased levels after aortic banding. Expression of GATA4, a transcriptional activator of cardiac hypertrophy, was also increased in HET hearts, as was phosphorylation of GATA4 at Ser105. Our findings demonstrate that CHF1/Hey2 expression levels influence hypertrophy and the progression to heart failure in response to pressure overload through modulation of apoptosis and GATA4 activity.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ning Zhou ◽  
Xin Chen ◽  
Jing Xi ◽  
Ben Ma ◽  
Christiana Leimena ◽  
...  

Abstract Pressure overload-induced cardiac hypertrophy, such as that caused by hypertension, is a key risk factor for heart failure. However, the underlying molecular mechanisms remain largely unknown. We previously reported that the valosin-containing protein (VCP), an ATPase-associated protein newly identified in the heart, acts as a significant mediator of cardiac protection against pressure overload-induced pathological cardiac hypertrophy. Still, the underlying molecular basis for the protection is unclear. This study used a cardiac-specific VCP transgenic mouse model to understand the transcriptomic alterations induced by VCP under the cardiac stress caused by pressure overload. Using RNA sequencing and comprehensive bioinformatic analysis, we found that overexpression of the VCP in the heart was able to normalize the pressure overload-stimulated hypertrophic signals by activating G protein-coupled receptors, particularly, the olfactory receptor family, and inhibiting the transcription factor controlling cell proliferation and differentiation. Moreover, VCP overexpression restored pro-survival signaling through regulating alternative splicing alterations of mitochondrial genes. Together, our study revealed a novel molecular regulation mediated by VCP under pressure overload that may bring new insight into the mechanisms involved in protecting against hypertensive heart failure.


Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Kisuk Min ◽  
Yan Huang ◽  
Frank J Giordano ◽  
Sudip Bajpeyi ◽  
Anton M Bennett

Introduction: Cardiac remodeling occurs in response to pathological stimuli including chronic pressure overload, subsequently leading to heart failure. Despite considerable research efforts, the molecular mechanisms responsible for heart failure have yet to be fully elucidated. One of the prominent signaling pathways involved in the development of pathological cardiac hypertrophy is the mitogen-activated protein kinases (MAPKs) pathways. The MAPKs are inactivated by the MAPK phosphatases (MKPs) through direct dephosphorylation. Growing evidence suggests the importance of MKP-5 signaling mechanisms in physiological and pathological processes. However, the role of MKP-5 has not been explored in cardiac muscle. The objective of this study is to investigate how MKP-5-mediated MAPK activity contributes to mechanisms responsible for pressure overload-induced cardiac hypertrophy. Hypothesis: We tested the hypothesis that MKP-5 serves as a central regulator of MAPKs in pressure overload-induced cardiac hypertrophy. Methods: To investigate the role of MKP-5 in cardiac muscle, we caused pressure overload-induced cardiac hypertrophy in wild type (mkp-5 +/+ ) mice and MKP-5 deficient mice (mkp-5 -/- ) through transverse aortic constriction (TAC). Cardiac function was evaluated by echocardiographic analysis at 4 weeks after TAC. Cardiac hypertrophy was measured by heart-to-body weight ratio. Interstitial myocardial fibrosis was evaluated by Sirius red stains and expression of fibrogenic genes was determined by quantitative PCR. Results: Echocardiographic analysis showed that the ejection fraction and fractional shortening of mkp-5 +/+ mice significantly decreased by at 4 weeks after TAC. Heart-to-body weight ratio increased in mkp-5 +/+ mice. However, MKP-5-deficient heart was protected from cardiac dysfunction and cardiac hypertrophy induced by TAC. Importantly, the fibrogenic genes were markedly reduced in mkp-5 -/- mice as compared with mkp-5 +/+ mice at 4 weeks after TAC. Conclusions: Collectively, our study demonstrates that MKP-5 deficiency prevents the heart from pressure overload-induced cardiac hypertrophy and suggests that MKP-5 may serve as a novel therapeutic target for treatment of heart disease.


2020 ◽  
Vol 7 (1) ◽  
pp. 9 ◽  
Author(s):  
Michael J. Zeitz ◽  
James W. Smyth

Cardiac hypertrophy in response to chronic pathological stress is a common feature occurring with many forms of heart disease. This pathological hypertrophic growth increases the risk for arrhythmias and subsequent heart failure. While several factors promoting cardiac hypertrophy are known, the molecular mechanisms governing the progression to heart failure are incompletely understood. Recent studies on altered translational regulation during pathological cardiac hypertrophy are contributing to our understanding of disease progression. In this brief review, we describe how the translational machinery is modulated for enhanced global and transcript selective protein synthesis, and how alternative modes of translation contribute to the disease state. Attempts at controlling translational output through targeting of mTOR and its regulatory components are detailed, as well as recently emerging targets for pre-clinical investigation.


2020 ◽  
Vol 2020 ◽  
pp. 1-15
Author(s):  
Shi Peng ◽  
Xiao-feng Lu ◽  
Yi-ding Qi ◽  
Jing Li ◽  
Juan Xu ◽  
...  

Aims. We aimed to investigate whether LCZ696 protects against pathological cardiac hypertrophy by regulating the Sirt3/MnSOD pathway. Methods. In vivo, we established a transverse aortic constriction animal model to establish pressure overload-induced heart failure. Subsequently, the mice were given LCZ696 by oral gavage for 4 weeks. After that, the mice underwent transthoracic echocardiography before they were sacrificed. In vitro, we introduced phenylephrine to prime neonatal rat cardiomyocytes and small-interfering RNA to knock down Sirt3 expression. Results. Pathological hypertrophic stimuli caused cardiac hypertrophy and fibrosis and reduced the expression levels of Sirt3 and MnSOD. LCZ696 alleviated the accumulation of oxidative reactive oxygen species (ROS) and cardiomyocyte apoptosis. Furthermore, Sirt3 deficiency abolished the protective effect of LCZ696 on cardiomyocyte hypertrophy, indicating that LCZ696 induced the upregulation of MnSOD and phosphorylation of AMPK through a Sirt3-dependent pathway. Conclusions. LCZ696 may mitigate myocardium oxidative stress and apoptosis in pressure overload-induced heart failure by regulating the Sirt3/MnSOD pathway.


2017 ◽  
Vol 121 (suppl_1) ◽  
Author(s):  
Diem H Tran ◽  
Jianping Li ◽  
Xiaoding Wang ◽  
Herman I May ◽  
Gabriele G Schiattarella ◽  
...  

Background & significance: Heart failure affects approximately 6 million Americans, with 5-year survival of 50%, which is responsible for a huge burden on the US economy and healthcare system. The relevance and significance of the metabolic alteration to the pathogenesis of pressure overload-induced cardiac hypertrophy and heart failure are largely unknown. The hexosamine biosynthetic pathway (HBP) that is linked to metabolism of glucose, fatty acids and amino acids, has been implicated in the pathophysiology of heart diseases. Methods & results: Thoracic aortic constriction (TAC) was performed to induce heart failure by pressure overload in mice. At the in vitro levels, treatment of phenylephrine (PE, 50 μM) was used to induce cellular hypertrophy in neonatal rat ventricular myocytes (NRVM). Our data revealed that all the enzymes of the HBP were upregulated while induction of hypertrophy at both in vivo and in vitro levels. Consistently, the intermediate product of the HBP was elevated in heart by afterload stress, as measured by metabolomics analyses. In the transgenic mice model for Gfat1, the rate-limiting enzyme of the HBP, we found more profound cardiac hypertrophy and cardiac remodeling in response to pressure overload. The increase of O-GlcNAc was also observed. In addition, the regulation of O-GlcNAcylation by specific targeting of two enzymes of the HBP (1 mM Alloxan, an inhibitor of OGT and 10 μM PUGNAc, an inhibitor of OGA) in NRVM suggested an involvement of the mTOR signaling in the activation of O-GlcNAc levels and the hypertrophy response. Targeting of the HBP by either specific siRNA or Gfat1 inhibitor (Azaserine, 5 μM) led to decrease in cellular hypertrophic response. Conclusions: Together, our data strongly suggest that the HBP participates in cardiac hypertrophic growth and pharmacologic targeting of the HBP may represent a novel approach to ameliorate pathological remodeling.


Circulation ◽  
2020 ◽  
Vol 141 (21) ◽  
pp. 1704-1719 ◽  
Author(s):  
Zongna Ren ◽  
Peng Yu ◽  
Dandan Li ◽  
Zheng Li ◽  
Yingnan Liao ◽  
...  

Background: Pressure overload–induced pathological cardiac hypertrophy is a common predecessor of heart failure, the latter of which remains a major cardiovascular disease with increasing incidence and mortality worldwide. Current therapeutics typically involve partially relieving the heart’s workload after the onset of heart failure. Thus, more pathogenesis-, stage-, and cell type–specific treatment strategies require refined dissection of the entire progression at the cellular and molecular levels. Methods: By analyzing the transcriptomes of 11,492 single cells and identifying major cell types, including both cardiomyocytes and noncardiomyocytes, on the basis of their molecular signatures, at different stages during the progression of pressure overload–induced cardiac hypertrophy in a mouse model, we characterized the spatiotemporal interplay among cell types, and tested potential pharmacological treatment strategies to retard its progression in vivo. Results: We illustrated the dynamics of all major cardiac cell types, including cardiomyocytes, endothelial cells, fibroblasts, and macrophages, as well as those of their respective subtypes, during the progression of disease. Cellular crosstalk analysis revealed stagewise utilization of specific noncardiomyocytes during the deterioration of heart function. Specifically, macrophage activation and subtype switching, a key event at middle-stage of cardiac hypertrophy, was successfully targeted by Dapagliflozin, a sodium glucose cotransporter 2 inhibitor, in clinical trials for patients with heart failure, as well as TD139 and Arglabin, two anti-inflammatory agents new to cardiac diseases, to preserve cardiac function and attenuate fibrosis. Similar molecular patterns of hypertrophy were also observed in human patient samples of hypertrophic cardiomyopathy and heart failure. Conclusions: Together, our study not only illustrated dynamically changing cell type crosstalk during pathological cardiac hypertrophy but also shed light on strategies for cell type- and stage-specific intervention in cardiac diseases.


Author(s):  
Janika Viereck ◽  
Anne Bührke ◽  
Ariana Foinquinos ◽  
Shambhabi Chatterjee ◽  
Jan A Kleeberger ◽  
...  

Abstract Aims Pathological cardiac remodelling and subsequent heart failure represents an unmet clinical need. Long non-coding RNAs (lncRNAs) are emerging as crucial molecular orchestrators of disease processes, including that of heart diseases. Here, we report on the powerful therapeutic potential of the conserved lncRNA H19 in the treatment of pathological cardiac hypertrophy. Method and results Pressure overload-induced left ventricular cardiac remodelling revealed an up-regulation of H19 in the early phase but strong sustained repression upon reaching the decompensated phase of heart failure. The translational potential of H19 is highlighted by its repression in a large animal (pig) model of left ventricular hypertrophy, in diseased human heart samples, in human stem cell-derived cardiomyocytes and in human engineered heart tissue in response to afterload enhancement. Pressure overload-induced cardiac hypertrophy in H19 knock-out mice was aggravated compared to wild-type mice. In contrast, vector-based, cardiomyocyte-directed gene therapy using murine and human H19 strongly attenuated heart failure even when cardiac hypertrophy was already established. Mechanistically, using microarray, gene set enrichment analyses and Chromatin ImmunoPrecipitation DNA-Sequencing, we identified a link between H19 and pro-hypertrophic nuclear factor of activated T cells (NFAT) signalling. H19 physically interacts with the polycomb repressive complex 2 to suppress H3K27 tri-methylation of the anti-hypertrophic Tescalcin locus which in turn leads to reduced NFAT expression and activity. Conclusion H19 is highly conserved and down-regulated in failing hearts from mice, pigs and humans. H19 gene therapy prevents and reverses experimental pressure-overload-induced heart failure. H19 acts as an anti-hypertrophic lncRNA and represents a promising therapeutic target to combat pathological cardiac remodelling.


2005 ◽  
Vol 23 (1) ◽  
pp. 18-27 ◽  
Author(s):  
Beverly A. Rothermel ◽  
Kambeez Berenji ◽  
Paul Tannous ◽  
William Kutschke ◽  
Asim Dey ◽  
...  

Hypertrophic growth of the myocardium occurs in most forms of heart failure and may contribute to the pathogenesis of the failure state. Little is known about the regulatory mechanisms governing the often-coexisting phenotypes of hypertrophy, systolic failure, and diastolic stiffness that characterize clinical disease. We hypothesized that intracellular signaling pathways are differentially activated by graded degrees of hemodynamic stress. To test this, we developed models of graded pressure stress in mice and used them to directly compare compensated hypertrophy and pressure-overload heart failure. Surgical interventions were designed to be similar, on either side of a threshold separating compensated from decompensated responses. Our findings revealed two dramatically different hypertrophic phenotypes with only modest differences in the activation of relevant intracellular signaling pathways. Furthermore, we uncovered a functional requirement of calcineurin signaling in each model such that calcineurin suppression blunted hypertrophic growth. Remarkably, in each case, suppression of calcineurin signaling was not associated with clinical deterioration or increased mortality. Profiles of stress-response signaling and Ca2+ handling differ between the steady-state, maintenance phases of load-induced cardiac hypertrophy and failure. This information may be useful in identifying novel targets of therapy in chronic disease.


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