scholarly journals Samm50 Promotes Hypertrophy by Regulating Pink1-Dependent Mitophagy Signaling in Neonatal Cardiomyocytes

2021 ◽  
Vol 8 ◽  
Author(s):  
Ran Xu ◽  
Le Kang ◽  
Siang Wei ◽  
Chunjie Yang ◽  
Yuanfeng Fu ◽  
...  
Keyword(s):  
Cardiac Hypertrophy ◽  
Molecular Mechanisms ◽  
Pressure Overload ◽  
Protective Role ◽  
Cardiomyocyte Hypertrophy ◽  
Marker Genes ◽  
Autophagic Flux ◽  
Ang Ii ◽  
Neonatal Cardiomyocytes ◽  
Primary Mouse

Pathological cardiac hypertrophy, the adaptive response of the myocardium to various pathological stimuli, is one of the primary predictors and predisposing factors of heart failure. However, its molecular mechanisms underlying pathogenesis remain poorly understood. Here, we studied the function of Samm50 in mitophagy during Ang II-induced cardiomyocyte hypertrophy via lentiviruses mediated knockdown and overexpression of Samm50 protein. We first found that Samm50 is a key positive regulator of cardiac hypertrophy, for western blot and real-time quantitative PCR detection revealed Samm50 was downregulated both in pressure-overload-induced hypertrophic hearts and Ang II-induced cardiomyocyte hypertrophy. Then, Samm50 overexpression exhibits enhanced induction of cardiac hypertrophy marker genes and cell enlargement in primary mouse cardiomyocytes by qPCR and immunofluorescence analysis, respectively. Meanwhile, Samm50 remarkably reduced Ang II-induced autophagy as indicated by decreased mitophagy protein levels and autophagic flux, whereas the opposite phenotype was observed in Samm50 knockdown cardiomyocytes. However, the protective role of Samm50 deficiency against cardiac hypertrophy was abolished by inhibiting mitophagy through Vps34 inhibitor or Pink1 knockdown. Moreover, we further demonstrated that Samm50 interacted with Pink1 and stimulated the accumulation of Parkin on mitochondria to initiate mitophagy by co-immunoprecipitation analysis and immunofluorescence. Thus, these results suggest that Samm50 regulates Pink1-Parkin-mediated mitophagy to promote cardiac hypertrophy, and targeting mitophagy may provide new insights into the treatment of cardiac hypertrophy.

Abstract 51: Thymosin β4 Targets Wisp1 to Protect Cardiomyocytes in AngII- induced Cardiac Hypertrophy

2015 ◽  
Vol 117 (suppl_1) ◽  
Author(s):  
Sudhiranjan Gupta ◽  
Li Li ◽  
Rakesh Guleria ◽  
Kenneth M Baker
Keyword(s):  
Cardiac Hypertrophy ◽  
Fluorescent Microscopy ◽  
Marker Genes ◽  
Protective Mechanism ◽  
Ang Ii ◽  
Hypertrophic Response ◽  
Antiapoptotic Proteins ◽  
Neonatal Cardiomyocytes ◽  
Cell Proliferation And Differentiation ◽  
Pre Treatment

Background: Thymosin beta-4 (Tβ4) is a ubiquitous protein with many properties relating to cell proliferation and differentiation that promotes wound healing and modulates inflammatory mediators. However, the role of Tβ4 in cardiomyocytes hypertrophy is currently unknown. The purpose of this study is to dissect the cardio-protective mechanism of Tβ4 in Ang II induced cardiac hypertrophy. Methods: Rat neonatal cardiomyocytes with or without Tβ4 pretreatment were stimulated with Ang II and expression of cell sizes, hypertrophy marker genes and Wnt signaling components was evaluated by quantitative real-time PCR, western blotting and fluorescent microscopy. Selected target gene Wisp-1 was either overexpressed or silenced by siRNA transfections in neonatal cardiomyocytes and effect of Tβ4 in Ang II-induced cardiac hypertrophy was evaluated. Results: Pre-treatment of Tβ4 resulted in reduction of cell sizes, hypertrophy marker genes and WNT-associated gene expression and levels induced by Ang II in cardiomyocytes. Tβ4 pretreatment also resulted in an increase in the expression of antiapoptotic proteins and reduction of Bax/BCl 2 ratio in the cardiomyocytes. Wisp-1 overexpression promotes cardiac hypertrophy and was reversed by pretreatment with Tβ4. Knocking down of Wisp1 partly rescue the cells from hypertrophic response after Tβ4 treatment. Conclusion: This is the first report that demonstrates the effect of Tβ4 on cardiomyocytes hypertrophy and its capability to selectively target Wisp-1 in neonatal cardiomyocytes thus preventing cell death, thereby, protecting the myocardium. Wisp-1 promotes the cardiac hypertrophy which was prevented by Tβ4 treatment.

Gene profiling during regression of pressure overload-induced cardiac hypertrophy

2007 ◽  
Vol 30 (1) ◽  
pp. 1-7 ◽  
Author(s):  
Dong Kwon Yang ◽  
Bo Youn Choi ◽  
Young-Hoon Lee ◽  
Young-Gyu Kim ◽  
Myeong-Chan Cho ◽  
...  
Keyword(s):  
Cardiac Hypertrophy ◽  
Gene Array ◽  
Pressure Overload ◽  
Gene Profiling ◽  
Cardiomyocyte Hypertrophy ◽  
Eyes Absent ◽  
Neonatal Cardiomyocytes ◽  
Mechanical Unloading ◽  
Regression Of Cardiac Hypertrophy ◽  
Profiling Analysis

Regression of cardiac hypertrophy and improvement of the functional capacity of failing hearts have reportedly been achieved by mechanical unloading in cardiac work. In this study, cardiac hypertrophy was first induced in rats by transverse aortic constriction and then mechanically unloaded by relieving the constriction after significant cardiac hypertrophy had developed. Hypertrophy was significantly regressed at the cellular and molecular levels at day 1, 3, and 7 after constriction relief. Gene profiling analysis revealed that 52 genes out of 9,911 genes probed on a gene array were specifically upregulated during the early regression period. Among these regression-induced genes, Eyes absent 2 ( eya2) was of particular interest because it is a transcriptional cofactor involved in mammalian organogenesis as well as Drosophila eye development. Adenovirus-mediated overexpression of eya2 in rat neonatal cardiomyocytes completely abrogated phenylephrine-induced development of cardiomyocyte hypertrophy as determined by cell size, sarcomere rearrangement and fetal gene re-expression. Our data strongly suggest that transcriptional programs distinct from those mediating cardiac hypertrophy may be operating during the regression of hypertrophy, and eya2 may be a key regulator of one of these programs.

scholarly journals Knockdown of TUG1 rescues cardiomyocyte hypertrophy through targeting the miR-497/MEF2C axis

2021 ◽  
Vol 16 (1) ◽  
pp. 242-251
Author(s):  
Guorong Zhang ◽  
Xinghua Ni
Keyword(s):  
Cardiac Hypertrophy ◽  
Noncoding Rna ◽  
Protective Role ◽  
Luciferase Reporter ◽  
Cardiomyocyte Hypertrophy ◽  
Ang Ii ◽  
Western Blot Assay ◽  
Rna Immunoprecipitation

Abstract The aim of this study was to investigate the detailed role and molecular mechanism of long noncoding RNA (lncRNA) taurine upregulated gene 1 (TUG1) in cardiac hypertrophy. Cardiac hypertrophy was established by transverse abdominal aortic constriction (TAC) in vivo or angiotensin II (Ang II) treatment in vitro. Levels of lncRNA TUG1, miR-497 and myocyte enhancer factor 2C (MEF2C) mRNA were assessed by quantitative reverse transcriptase PCR (qRT-PCR). Western blot assay was performed to determine the expression of MEF2C protein. The endogenous interactions among TUG1, miR-497 and MEF2C were confirmed by dual-luciferase reporter and RNA immunoprecipitation assays. Our data indicated that TUG1 was upregulated and miR-497 was downregulated in the TAC rat model and Ang II-induced cardiomyocytes. TUG1 knockdown or miR-497 overexpression alleviated the hypertrophy induced by Ang II in cardiomyocytes. Moreover, TUG1 acted as a sponge of miR-497, and MEF2C was directly targeted and repressed by miR-497. miR-497 overexpression mediated the protective role of TUG1 knockdown in Ang II-induced cardiomyocyte hypertrophy. MEF2C was a functional target of miR-497 in regulating Ang II-induced cardiomyocyte hypertrophy. In addition, TUG1 regulated MEF2C expression through sponging miR-497. Knockdown of TUG1 rescued Ang II-induced hypertrophy in cardiomyocytes at least partly through targeting the miR-497/MEF2C axis, highlighting a novel promising therapeutic target for cardiac hypertrophy treatment.

FNDC5/Irisin inhibits pathological cardiac hypertrophy

2019 ◽  
Vol 133 (5) ◽  
pp. 611-627 ◽  
Author(s):  
Qing Yu ◽  
Wenxin Kou ◽  
Xu Xu ◽  
Shunping Zhou ◽  
Peipei Luan ◽  
...  
Keyword(s):  
Cardiac Hypertrophy ◽  
Cardiac Function ◽  
Pressure Overload ◽  
Protective Role ◽  
Cardiomyocyte Hypertrophy ◽  
Dependent Manner ◽  
Pathological Cardiac Hypertrophy ◽  
Adam Family ◽  
A Disintegrin And Metalloproteinase

Abstract Cardiac hypertrophy is a common pathophysiological process in various cardiovascular diseases, which still has no effective therapies. Irisin is a novel myokine mainly secreted by skeletal muscle and is believed to be involved in the regulation of energy metabolism. In the present study, we found that irisin expression was elevated in hypertrophic murine hearts and serum. Moreover, angiotension II-induced cardiomyocyte hypertrophy was attenuated after irisin administration and aggravated after irisin knockdown in vitro. Next, we generated transverse aortic constriction (TAC)-induced cardiac hypertrophy murine model and found that cardiac hypertrophy and fibrosis were significantly attenuated with improved cardiac function assessed by echocardiography after irisin treatment. Mechanistically, we demonstrated that FNDC5 was cleaved into irisin, at least partially, in a disintegrin and metalloproteinase (ADAM) family-dependent manner. ADAM10 was the candidate enzyme responsible for the cleavage. Further, we found irisin treatment activated AMPK and subsequently inhibited activation of mTOR. AMPK inhibition ablated the protective role of irisin administration. In conclusion, we find irisin is secreted in an ADAM family-dependent manner, and irisin treatment improves cardiac function and attenuates pressure overload-induced cardiac hypertrophy and fibrosis mainly through regulating AMPK-mTOR signaling.

scholarly journals Rap1GAP Mediates Angiotensin II-Induced Cardiomyocyte Hypertrophy by Inhibiting Autophagy and Increasing Oxidative Stress

2021 ◽  
Vol 2021 ◽  
pp. 1-20
Author(s):  
Yan Gao ◽  
Di Zhao ◽  
Wen-zhi Xie ◽  
Tingting Meng ◽  
Chunxiao Xu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Heart Failure ◽  
Angiotensin Ii ◽  
Cardiac Hypertrophy ◽  
Cardiomyocyte Hypertrophy ◽  
Ros Generation ◽  
Ang Ii ◽  
Sprague Dawley ◽  
Neonatal Cardiomyocytes ◽  
And Oxidative Stress

Abnormal autophagy and oxidative stress contribute to angiotensin II- (Ang II-) induced cardiac hypertrophy and heart failure. We previously showed that Ang II increased Rap1GAP gene expression in cardiomyocytes associated with hypertrophy and autophagy disorders. Using real-time PCR and Western blot, we found that Rap1GAP expression was increased in the heart of Sprague Dawley (SD) rats infused by Ang II compared with saline infusion and in Ang II vs. vehicle-treated rat neonatal cardiomyocytes. Overexpression of Rap1GAP in cultured cardiomyocytes exacerbated Ang II-induced cardiomyocyte hypertrophy, reactive oxygen species (ROS) generation, and cell apoptosis and inhibited autophagy. The increased oxidative stress caused by Rap1GAP overexpression was inhibited by the treatment of autophagy agonists. Knockdown of Rap1GAP by siRNA markedly attenuated Ang II-induced cardiomyocyte hypertrophy and oxidative stress and enhanced autophagy. The AMPK/AKT/mTOR signaling pathway was inhibited by overexpression of Rap1GAP and activated by the knockdown of Rap1GAP. These results show that Rap1GAP-mediated pathway might be a new mechanism of Ang II-induced cardiomyocyte hypertrophy, which could be a potential target for the future treatment of cardiac hypertrophy and heart failure.

scholarly journals Role of PI3-Kinase in Angiotensin II-Induced Cardiac Hypertrophy: Class I Versus Class III

2021 ◽  
Vol 12 ◽  
Author(s):  
Tiecheng Zhong ◽  
Zonggui Wang ◽  
Sayeman Islam Niloy ◽  
Yue Shen ◽  
Stephen T. O’Rourke ◽  
...  
Keyword(s):  
Cardiac Hypertrophy ◽  
Molecular Mechanisms ◽  
Class I ◽  
Cardiomyocyte Hypertrophy ◽  
Ros Production ◽  
Ang Ii ◽  
Class Iii ◽  
Mitochondrial Ros ◽  
Autophagy Activity

Cardiac hypertrophy is an adaptive response to cardiac overload initially but turns into a decompensated condition chronically, leading to heart failure and sudden cardiac death. The molecular mechanisms involved in cardiac hypertrophy and the signaling pathways that contribute to the switch from compensation to decompensation are not fully clear. The aim of the current study was to examine the role of PI3-kinases Class I (PI3KC1) and Class III (PI3KC3) in angiotensin (Ang) II-induced cardiac hypertrophy. The results demonstrate that treatment of cardiomyocytes with Ang II caused dose-dependent increases in autophagy, with an increasing phase followed by a decreasing phase. Ang II-induced autophagic increases were potentiated by inhibition of PI3KC1 with LY294002, but were impaired by inhibition of PI3KC3 with 3-methyladenine (3-MA). In addition, blockade of PI3KC1 significantly attenuated Ang II-induced ROS production and cardiomyocyte hypertrophy. In contrast, blockade of PI3KC3 potentiated Ang II-induced ROS production and cardiac hypertrophy. Moreover, blockade of PI3KC1 by overexpression of dominant negative p85 subunit of PI3KC1 significantly attenuated Ang II-induced cardiac hypertrophy in normotensive rats. Taken together, these results demonstrate that both PI3KC1 and PI3KC3 are involved in Ang II-induced cardiac hypertrophy by different mechanisms. Activation of PI3KC1 impairs autophagy activity, leading to accumulation of mitochondrial ROS, and, hence, cardiac hypertrophy. In contrast, activation of PI3KC3 improves autophagy activity, thereby reducing mitochondrial ROS and leads to a protective effect on Ang II-induced cardiac hypertrophy.

scholarly journals The immunoproteasome catalytic β5i subunit regulates cardiac hypertrophy by targeting the autophagy protein ATG5 for degradation

2019 ◽  
Vol 5 (5) ◽  
pp. eaau0495 ◽  
Author(s):  
Xin Xie ◽  
Hai-Lian Bi ◽  
Song Lai ◽  
Yun-Long Zhang ◽  
Nan Li ◽  
...  
Keyword(s):  
Cardiac Hypertrophy ◽  
Inflammatory Diseases ◽  
Pressure Overload ◽  
Cardiomyocyte Hypertrophy ◽  
Ang Ii ◽  
Adequate Treatment ◽  
Hypertrophic Response ◽  
Pathological Cardiac Hypertrophy ◽  
Mediated Reduction ◽  
Expression And Activity

Pathological cardiac hypertrophy eventually leads to heart failure without adequate treatment. The immunoproteasome is an inducible form of the proteasome that is intimately involved in inflammatory diseases. Here, we found that the expression and activity of immunoproteasome catalytic subunit β5i were significantly up-regulated in angiotensin II (Ang II)–treated cardiomyocytes and in the hypertrophic hearts. Knockout of β5i in cardiomyocytes and mice markedly attenuated the hypertrophic response, and this effect was aggravated by β5i overexpression in cardiomyocytes and transgenic mice. Mechanistically, β5i interacted with and promoted ATG5 degradation thereby leading to inhibition of autophagy and cardiac hypertrophy. Further, knockdown of ATG5 or inhibition of autophagy reversed the β5i knockout-mediated reduction of cardiomyocyte hypertrophy induced by Ang II or pressure overload. Together, this study identifies a novel role for β5i in the regulation of cardiac hypertrophy. The inhibition of β5i activity may provide a new therapeutic approach for hypertrophic diseases.

scholarly journals Novel Therapeutic Effects of Pterosin B on Ang II-Induced Cardiomyocyte Hypertrophy

Molecules ◽  
2020 ◽  
Vol 25 (22) ◽  
pp. 5279
Author(s):  
Chang Youn Lee ◽  
Han Ki Park ◽  
Bok-Sim Lee ◽  
Seongtae Jeong ◽  
Sung-Ae Hyun ◽  
...  
Keyword(s):  
Cardiac Hypertrophy ◽  
Protective Role ◽  
Cardiomyocyte Hypertrophy ◽  
Therapeutic Effects ◽  
Ang Ii ◽  
Pathological Cardiac Hypertrophy ◽  
Glycation End Products ◽  
Abnormal Increase

Pathological cardiac hypertrophy is characterized by an abnormal increase in cardiac muscle mass in the left ventricle, resulting in cardiac dysfunction. Although various therapeutic approaches are being continuously developed for heart failure, several studies have suggested natural compounds as novel potential strategies. Considering relevant compounds, we investigated a new role for Pterosin B for which the potential life-affecting biological and therapeutic effects on cardiomyocyte hypertrophy are not fully known. Thus, we investigated whether Pterosin B can regulate cardiomyocyte hypertrophy induced by angiotensin II (Ang II) using H9c2 cells. The antihypertrophic effect of Pterosin B was evaluated, and the results showed that it reduced hypertrophy-related gene expression, cell size, and protein synthesis. In addition, upon Ang II stimulation, Pterosin B attenuated the activation and expression of major receptors, Ang II type 1 receptor and a receptor for advanced glycation end products, by inhibiting the phosphorylation of PKC-ERK-NF-κB pathway signaling molecules. In addition, Pterosin B showed the ability to reduce excessive intracellular reactive oxygen species, critical mediators for cardiac hypertrophy upon Ang II exposure, by regulating the expression levels of NAD(P)H oxidase 2/4. Our results demonstrate the protective role of Pterosin B in cardiomyocyte hypertrophy, suggesting it is a potential therapeutic candidate.

scholarly journals Caspase-1 regulates Ang II-induced cardiomyocyte hypertrophy via up-regulation of IL-1β

2018 ◽  
Vol 38 (2) ◽  
Author(s):  
Yunlong Bai ◽  
Xi Sun ◽  
Qun Chu ◽  
Anqi Li ◽  
Ying Qin ◽  
...  
Keyword(s):  
Cardiac Hypertrophy ◽  
Molecular Mechanisms ◽  
Therapeutic Potential ◽  
Cardiomyocyte Hypertrophy ◽  
Ang Ii ◽  
Compensatory Response ◽  
Caspase 1

Cardiac hypertrophy is a compensatory response to stress or stimuli, which results in arrhythmia and heart failure. Although multiple molecular mechanisms have been identified, cardiac hypertrophy is still difficult to treat. Pyroptosis is a caspase-1-dependent pro-inflammatory programmed cell death. Caspase-1 is involved in various types of diseases, including hepatic injury, cancers, and diabetes-related complications. However, the exact role of caspase-1 in cardiac hypertrophy is yet to be discovered. The present study aimed to explore the possible role of caspase-1 in pathogenesis of cardiac hypertrophy. We established cardiac hypertrophy models both in vivo and in vitro to detect the expression of caspase-1 and interleukin-1β (IL-1β). The results showed that caspase-1 and IL-1β expression levels were significantly up-regulated during cardiac hypertrophy. Subsequently, caspase-1 inhibitor was co-administered with angiotensin II (Ang II) in cardiomyocytes to observe whether it could attenuate cardiac hypertrophy. Results showed that caspase-1 attenuated the pro-hypertrophic effect of Ang II, which was related to the down-regulation of caspase-1 and IL-1β. In conclusion, our results provide a novel evidence that caspase-1 mediated pyroptosis is involved in cardiac hypertrophy, and the inhibition of caspase-1 will offer a therapeutic potential against cardiac hypertrophy.

Abstract 241: Cardiac-Specific Overexpression of Runx2 Mediates Cardiac Hypertrophy and Dysfunction in Mice

2012 ◽  
Vol 111 (suppl_1) ◽  
Author(s):  
Hiroyuki Nakayama ◽  
Tatsuto Hamatani ◽  
Shohei Kumagai ◽  
Kota Tonegawa ◽  
Tomomi Yamashita ◽  
...  
Keyword(s):  
Cardiac Hypertrophy ◽  
Weight Ratio ◽  
Pressure Overload ◽  
Premature Death ◽  
Heart Weight ◽  
Pcr Analysis ◽  
Marker Genes ◽  
Hypertrophic Response ◽  
Neonatal Cardiomyocytes

Backgrounds: Recent studies demonstrated that the osteopontin (OPN), an acid phosphoprotein plays pivotal roles in cardiac hypertrophy and failure. An osteogenic transcription factor Runx2 regulates the expression of OPN in osteoblasts. In the present study, we examined the pathological role of Runx2 in cardiac hypertrophy and failure. Methods and Results: Runx2 expression was detected in neonatal cardiomyocytes and upregulated in heart 14 days after myocardial infarction (MI) as well as 7days after transverse aortic constriction (TAC) procedures. To determine the functional role of Runx2 in heart, we generated transgenic mice (TG) with inducible cardiac-specific overexpression of Runx2. Two TG lines (low and high) were obtained and high-expressing TG (HE-TG) showed premature death within 8 weeks of age specifically in male mice. At two months of age, the survived male and female HE-TG displayed significant increases in heart weight/body weight ratio (mg/g) compared to controls (control; 4.95±0.26, n=6 vs HE-TG; 6.63±0.12, n=5, p<.05). Consistent with those results, the expression of hypertrophic marker genes such as atrial natriuretic factor (ANF) and αskeletal actin significantly increased in HE-TG heart assessed by real-time RT-PCR analysis. In addition, HE-TG mice demonstrated decreased fractional shortening assessed by echocardiography (control; 44.1±1.89%, n=9 vs HE-TG; 23.9±3.48%, n=7, p<.05). HE-TG mice demonstrated significantly lower heart rate (control; 630±18 bpm, vs HE-TG; 350±74 bpm, n=3 each, p<.05) and complete atrioventricular block by telemetry analysis. In response to pressure overload, low expressing TG (LE-TG) demonstrated higher mortality and enhanced cardiac hypertrophic response after TAC (control; 6.20±0.23, n=6 vs LE-TG; 6.90±0.26, n=4, p<.05). Conclusions: Targeted expression of Runx2 in heart mediates cardiac dysfunction and hypertrophy in mice. Thus, Runx2 could be a novel therapeutic target for heart failure.

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