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Hayashi T. [Proteinase-activated Receptor 1 and 2 under Hypoxic Stress]. YAKUGAKU ZASSHI 2021; 141:1195-1204. [PMID: 34602516 DOI: 10.1248/yakushi.21-00140] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Patients with sleep-disordered breathing exhibit intermittent hypoxia that causes increased oxidative stress, accelerates atherosclerosis, and pulmonary hypertension, resulting in life-threatening arrhythmias and congestive heart failure. Hypoxic stress caused by intermittent hypoxia might be involved in the pathophysiology of many cardiovascular diseases, especially those involving atrial fibrillation, for which anti-coagulant therapy may be recommended. In this study, the inhibition of proteinase-activated receptor (PAR) 1/2 significantly reduced oxidative stress and fibrosis while suppressing the activation of MAPK or Smad pathways and the gene expression of molecules responsible for the pathways in the myocardium, consequently attenuating hypoxia-mediated cardiomyocyte hypertrophy. These findings suggest that the inhibition of PAR 1/2 could be a novel potential treatment option to prevent cardiac remodeling in patients with sleep apnea syndrome and atrial fibrillation or chronic thromboembolic pulmonary hypertension.
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Affiliation(s)
- Tetsuya Hayashi
- Department of Cardiovascular Pharmacotherapy and Toxicology, Osaka University of Pharmaceutical Sciences, Educational Foundation of Osaka Medical and Pharmaceutical University
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2
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Rangrez AY, Eden M, Poyanmehr R, Kuhn C, Stiebeling K, Dierck F, Bernt A, Lüllmann-Rauch R, Weiler H, Kirchof P, Frank D, Frey N. Myozap Deficiency Promotes Adverse Cardiac Remodeling via Differential Regulation of Mitogen-activated Protein Kinase/Serum-response Factor and β-Catenin/GSK-3β Protein Signaling. J Biol Chem 2015; 291:4128-43. [PMID: 26719331 DOI: 10.1074/jbc.m115.689620] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2015] [Indexed: 01/22/2023] Open
Abstract
The intercalated disc (ID) is a "hot spot" for heart disease, as several ID proteins have been found mutated in cardiomyopathy. Myozap is a recent addition to the list of ID proteins and has been implicated in serum-response factor signaling. To elucidate the cardiac consequences of targeted deletion of myozap in vivo, we generated myozap-null mutant (Mzp(-/-)) mice. Although Mzp(-/-) mice did not exhibit a baseline phenotype, increased biomechanical stress due to pressure overload led to accelerated cardiac hypertrophy, accompanied by "super"-induction of fetal genes, including natriuretic peptides A and B (Nppa/Nppb). Moreover, Mzp(-/-) mice manifested a severe reduction of contractile function, signs of heart failure, and increased mortality. Expression of other ID proteins like N-cadherin, desmoplakin, connexin-43, and ZO-1 was significantly perturbed upon pressure overload, underscored by disorganization of the IDs in Mzp(-/-) mice. Exploration of the molecular causes of enhanced cardiac hypertrophy revealed significant activation of β-catenin/GSK-3β signaling, whereas MAPK and MKL1/serum-response factor pathways were inhibited. In summary, myozap is required for proper adaptation to increased biomechanical stress. In broader terms, our data imply an essential function of the ID in cardiac remodeling beyond a mere structural role and emphasize the need for a better understanding of this molecular structure in the context of heart disease.
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Affiliation(s)
- Ashraf Yusuf Rangrez
- From the Department of Internal Medicine III, Molecular Cardiology and Angiology, and
| | - Matthias Eden
- From the Department of Internal Medicine III, Molecular Cardiology and Angiology, and
| | - Reza Poyanmehr
- From the Department of Internal Medicine III, Molecular Cardiology and Angiology, and
| | - Christian Kuhn
- From the Department of Internal Medicine III, Molecular Cardiology and Angiology, and
| | - Katharina Stiebeling
- From the Department of Internal Medicine III, Molecular Cardiology and Angiology, and
| | - Franziska Dierck
- From the Department of Internal Medicine III, Molecular Cardiology and Angiology, and
| | - Alexander Bernt
- From the Department of Internal Medicine III, Molecular Cardiology and Angiology, and
| | - Renate Lüllmann-Rauch
- German Centre for Cardiovascular Research (DZHK, partner site Hamburg/Kiel/Lübeck), University Medical Center Schleswig-Holstein, Kiel D-24105, Germany
| | - Hartmut Weiler
- the Anatomical Institute, Christian Albrechts University of Kiel, Kiel D-24098, Germany
| | - Paulus Kirchof
- the Blood Research Institute, Blood Center of Wisconsin, Milwaukee, Wisconsin 53233, and
| | - Derk Frank
- From the Department of Internal Medicine III, Molecular Cardiology and Angiology, and
| | - Norbert Frey
- From the Department of Internal Medicine III, Molecular Cardiology and Angiology, and
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3
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Arunachalam S, Kim SY, Lee SH, Lee YH, Kim MS, Yun BS, Yi HK, Hwang PH. Davallialactone protects against adriamycin-induced cardiotoxicity in vitro and in vivo. J Nat Med 2011; 66:149-57. [DOI: 10.1007/s11418-011-0567-1] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2011] [Accepted: 07/07/2011] [Indexed: 11/29/2022]
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4
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Essick EE, Ouchi N, Wilson RM, Ohashi K, Ghobrial J, Shibata R, Pimentel DR, Sam F. Adiponectin mediates cardioprotection in oxidative stress-induced cardiac myocyte remodeling. Am J Physiol Heart Circ Physiol 2011; 301:H984-93. [PMID: 21666115 DOI: 10.1152/ajpheart.00428.2011] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Reactive oxygen species (ROS) induce matrix metalloproteinase (MMP) activity that mediates hypertrophy and cardiac remodeling. Adiponectin (APN), an adipokine, modulates cardiac hypertrophy, but it is unknown if APN inhibits ROS-induced cardiomyocyte remodeling. We tested the hypothesis that APN ameliorates ROS-induced cardiomyocyte remodeling and investigated the mechanisms involved. Cultured adult rat ventricular myocytes (ARVM) were pretreated with recombinant APN (30 μg/ml, 18 h) followed by exposure to physiologic concentrations of H(2)O(2) (1-200 μM). ARVM hypertrophy was measured by [(3)H]leucine incorporation and atrial natriuretic factor (ANF) and brain natriuretic peptide (BNP) gene expression by RT-PCR. MMP activity was assessed by in-gel zymography. ROS was induced with angiotensin (ANG)-II (3.2 mg·kg(-1)·day(-1) for 14 days) in wild-type (WT) and APN-deficient (APN-KO) mice. Myocardial MMPs, tissue inhibitors of MMPs (TIMPs), p-AMPK, and p-ERK protein expression were determined. APN significantly decreased H(2)O(2)-induced cardiomyocyte hypertrophy by decreasing total protein, protein synthesis, ANF, and BNP expression. H(2)O(2)-induced MMP-9 and MMP-2 activities were also significantly diminished by APN. APN significantly increased p-AMPK in both nonstimulated and H(2)O(2)-treated ARVM. H(2)O(2)-induced p-ERK activity and NF-κB activity were both abrogated by APN pretreatment. ANG II significantly decreased myocardial p-AMPK and increased p-ERK expression in vivo in APN-KO vs. WT mice. ANG II infusion enhanced cardiac fibrosis and MMP-2-to-TIMP-2 and MMP-9-to-TIMP-1 ratios in APN-KO vs. WT mice. Thus APN inhibits ROS-induced cardiomyocyte remodeling by activating AMPK and inhibiting ERK signaling and NF-κB activity. Its effects on ROS and ultimately on MMP expression define the protective role of APN against ROS-induced cardiac remodeling.
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Affiliation(s)
- Eric E Essick
- Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, Massachusetts 02118, USA
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5
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Ameliorative role of rosiglitazone in hyperhomocysteinemia-induced experimental cardiac hypertrophy. J Cardiovasc Pharmacol 2010; 56:53-9. [PMID: 20351560 DOI: 10.1097/fjc.0b013e3181de308b] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
The present study has been designed to explore the beneficial effect of rosiglitazone, a peroxisome proliferator activated receptor-gamma agonist, in hyperhomocysteinemia-induced cardiac hypertrophy in rats. The hyperhomocysteinemia was induced in rats by feeding L-methionine (1.7 g/kg per day orally) for 8 weeks. The development of cardiac hypertrophy was assessed by measuring ratio of left ventricular weight to body weight, left ventricular wall thickness, cardiomyocyte diameter, and mean arterial blood pressure. The extent of fibrosis was checked by biochemical and histological assessment of collagen deposition. Moreover, the oxidative stress in heart was measured in terms of an increase in thiobarbituric acid reactive substances, superoxide anion generation, and decrease in reduced glutathione levels. The treatment with rosiglitazone (5 and 10 mg/kg per day orally) started from the first day of administration of L-methionine significantly abolished hyperhomocysteinemia-induced increase in left ventricular weight to body weight ratio, left ventricular wall thickness, cardiomyocyte diameter, collagen deposition, and oxidative stress without affecting serum homocysteine levels in rats. At high dose, rosiglitazone markedly reduced mean arterial blood pressure but at low dose, a significant reduction in mean arterial blood pressure was not observed in hyperhomocysteinemic rats. Hence, our results suggest that rosiglitazone provides benefit in hyperhomocysteinemia-induced cardiac hypertrophy and fibrosis in a dose-dependent manner and its protective action is independent of change in mean arterial blood pressure and serum homocysteine levels in rats.
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6
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Kim M, Oh JK, Sakata S, Liang I, Park W, Hajjar RJ, Lebeche D. Role of resistin in cardiac contractility and hypertrophy. J Mol Cell Cardiol 2008; 45:270-80. [PMID: 18597775 DOI: 10.1016/j.yjmcc.2008.05.006] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2008] [Revised: 04/26/2008] [Accepted: 05/11/2008] [Indexed: 12/15/2022]
Abstract
Cardiovascular sequelae including diabetic cardiomyopathy constitute the major cause of death in diabetic patients. Although several factors may contribute to the development of this cardiomyopathy, the underlying molecular/cellular mechanisms leading to cardiac dysfunction are still partially understood. Recently, a novel paradigm for the role of the adipocytokine resistin in diabetes has emerged. Resistin has been proposed to be a link between obesity, insulin resistance and diabetes. Using microarray analysis, we have recently found that cardiomyocytes isolated from type 2 diabetic hearts express high levels of resistin. However, the function of resistin with respect to cardiac function is unknown. In this study we show that resistin is not only expressed in the heart, but also promotes cardiac hypertrophy. Adenovirus-mediated overexpression of resistin in cultured neonatal rat ventricular myocytes (NRVM) significantly increased sarcomere organization and cell size, increased protein synthesis and increased the expression of atrial natriuretic factor and beta-myosin heavy chain. Overexpression of resistin in NRVM was also associated with activation of the mitogen-activated protein (MAP) kinases, ERK1/2 and p38, as well as increased Ser-636 phosphorylation of insulin receptor substrate-1 (IRS-1), indicating that IRS-1/MAPK pathway may be involved in the observed hypertrophic response. Overexpression of resistin in adult cultured cardiomyocytes significantly altered myocyte mechanics by depressing cell contractility as well as contraction and relaxation velocities. Intracellular Ca(2+) measurements showed slower Ca(2+) transients decay in resistin-transduced myocytes compared to controls, suggesting impaired cytoplasmic Ca(2+) clearing or alterations in myofilament activation. We conclude that resistin overexpression alters cardiac contractility, confers to primary cardiomyocytes all the features of the hypertrophic phenotype and promotes cardiac hypertrophy possibly via the IRS-1/MAPK pathway.
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Affiliation(s)
- Maengjo Kim
- Cardiovascular Research Center, Mount Sinai School of Medicine, USA
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7
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Vahebi S, Ota A, Li M, Warren CM, de Tombe PP, Wang Y, Solaro RJ. p38-MAPK induced dephosphorylation of alpha-tropomyosin is associated with depression of myocardial sarcomeric tension and ATPase activity. Circ Res 2007; 100:408-15. [PMID: 17234967 DOI: 10.1161/01.res.0000258116.60404.ad] [Citation(s) in RCA: 80] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Our objective in work presented here was to understand the mechanisms by which activated p38alpha MAPK depresses myocardial contractility. To test the hypothesis that activation of p38 MAPK directly influences sarcomeric function, we used transgenic mouse models with hearts in which p38 MAPK was constitutively turned on by an upstream activator (MKK6bE). These hearts demonstrated a significant depression in ejection fraction after induction of the transgene. We also studied hearts of mice expressing a dominant negative p38alpha MAPK. Simultaneous determination of tension and ATPase activity of detergent-skinned fiber bundles from left ventricular papillary muscle demonstrated a significant inhibition of both maximum tension and ATPase activity in the transgenic-MKK6bE hearts. Fibers from hearts expressing dominant negative p38alpha MAPK demonstrated no significant change in tension or ATPase activity. There were no significant changes in phosphorylation level of troponin-T3 and troponin-T4, or myosin light chain 2. However, compared with controls, there was a significant depression in levels of phosphorylation of alpha-tropomyosin and troponin I in fiber bundles from transgenic-MKK6bE hearts, but not from dominant negative p38alpha MAPK hearts. Our experiments also showed that p38alpha MAPK colocalizes with alpha-actinin at the Z-disc and complexes with protein phosphatases (PP2alpha, PP2beta). These data are the first to indicate that chronic activation of p38alpha MAPK directly depresses sarcomeric function in association with decreased phosphorylation of alpha-tropomyosin.
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Affiliation(s)
- Susan Vahebi
- Department of Physiology and Biophysics, Center for Cardiovascular Research, College of Medicine, University of Illinois at Chicago, 835 S. Wolcott Ave., Chicago, IL 60612-7342, USA
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8
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Tenhunen O, Rysä J, Ilves M, Soini Y, Ruskoaho H, Leskinen H. Identification of cell cycle regulatory and inflammatory genes as predominant targets of p38 mitogen-activated protein kinase in the heart. Circ Res 2006; 99:485-93. [PMID: 16873723 DOI: 10.1161/01.res.0000238387.85144.92] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Mitogen-activated protein kinases (MAPKs) regulate cardiomyocyte growth and apoptosis in response to extracellular stimulation, but the downstream effectors that mediate their pathophysiological effects remain poorly understood. We determined the targets and role of p38 MAPK in the heart in vivo by using local adenovirus-mediated gene transfer of constitutively active upstream kinase mitogen-activated protein kinase kinase 3b (MKK3bE) and wild-type p38alpha in rats. DNA microarray analysis of animals with cardiac-specific overexpression of p38 MAPK revealed that 264 genes were upregulated more than 2-fold including multiple genes controlling cell division, cell signaling, inflammation, adhesion, and transcription. A large number of previously unknown p38 target genes were found. Using gel mobility-shift assays we identified several cardiac transcription factors that were directly activated by p38 MAPK. Finally, we determined the functional significance of the altered cardiac gene-expression profile by histological analysis and echocardiographic measurements, which indicated that p38 MAPK overexpression-induced gene expression results in myocardial cell proliferation, inflammation, and fibrosis. In conclusion, we defined the novel target genes and transcription factors as well as the functional effects of p38 MAPK in the heart. Expression profiling of p38 MAPK overexpression identified cell cycle regulatory and inflammatory genes critical for pathological processes in the adult heart.
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Affiliation(s)
- Olli Tenhunen
- Department of Pharmacology and Toxicology, Biocenter Oulu, Finland
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9
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Shemarova IV, Nesterov VP. Role of Ca2+ and transmitters of the sympathetic nervous system in transduction of stress signal in cardiomyocytes. J EVOL BIOCHEM PHYS+ 2006. [DOI: 10.1134/s0022093006020013] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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10
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Abstract
The purine nucleoside adenosine acts via four distinct adenosine receptor subtypes: the adenosine A(1), A(2A), A(2B), and A(3) receptor. They are all G protein-coupled receptors (GPCR) coupling to classical second messenger pathways such as modulation of cAMP production or the phospholipase C (PLC) pathway. In addition, they couple to mitogen-activated protein kinases (MAPK), which could give them a role in cell growth, survival, death and differentiation. Although each of the adenosine receptors can activate one or more of the MAPKs, the mechanisms appear to differ substantially, both between receptor subtypes in the same cell type and between the same receptor in different cell types.
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Affiliation(s)
- Gunnar Schulte
- Department of Physiology and Pharmacology, Karolinska Institutet, S-171 77, Stockholm, Sweden.
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11
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Affiliation(s)
- Eric N Olson
- Department of Molecular Biology, University of Texas Southwestern Medical Center, Dallas, Texas 75390-9148, USA.
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12
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Petrich BG, Gong X, Lerner DL, Wang X, Brown JH, Saffitz JE, Wang Y. c-Jun N-terminal kinase activation mediates downregulation of connexin43 in cardiomyocytes. Circ Res 2002; 91:640-7. [PMID: 12364393 DOI: 10.1161/01.res.0000035854.11082.01] [Citation(s) in RCA: 109] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Loss of gap junctions and impaired intercellular communication are characteristic features of pathological remodeling in heart failure as a result of stress or injury, yet the underlying regulatory mechanism has not been identified. Here, we report that in cultured myocytes, rapid loss of the gap junction protein connexin43 (Cx43) occurs in conjunction with the activation of c-Jun N-terminal kinase (JNK), a stress-activated protein kinase, on stress stimulation. To investigate the specific role of JNK activation in the regulation of connexin in cardiomyocytes, an activated mutant of mitogen-activated protein kinase kinase 7 (mutant D), a JNK-specific upstream activator, was expressed in myocytes by adenovirus-mediated gene transfer. JNK activation in infected cardiomyocytes resulted in significant reduction of Cx43 expression at both mRNA and protein levels and impaired cell-cell communication. To evaluate the role of JNK in the regulation of Cx43 expression and gap junction structure in vivo, a Cre-LoxP-mediated gene-switch system was used to establish a transgenic animal model with targeted activation of JNK in ventricular myocardium. The transgenic hearts exhibited significant downregulation of Cx43 expression and loss of gap junctions in myocardium that may contribute to the cardiac dysfunction and premature death phenotype. Our report represents the first evidence, both in vitro and in vivo, implicating JNK as an important mediator of stress-induced Cx43 downregulation and impaired intercellular communication in the failing heart.
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Affiliation(s)
- Brian G Petrich
- Department of Cell Biology, The Scripps Research Institute, La Jolla, Calif, USA
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13
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Nicol RL, Frey N, Olson EN. From the sarcomere to the nucleus: role of genetics and signaling in structural heart disease. Annu Rev Genomics Hum Genet 2002; 1:179-223. [PMID: 11701629 DOI: 10.1146/annurev.genom.1.1.179] [Citation(s) in RCA: 59] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The identification of genetic mutations underlying familial structural heart disease has provided exciting new insights into how alterations in structural components of the cardiomyocyte lead to different forms of cardiomyopathy. Specifically, mutations in components of the sarcomere are frequently associated with hypertrophic cardiomyopathy, whereas mutations in cytoskeletal proteins lead to dilated cardiomyopathy. In addition, extrinsic stresses such as hypertension and valvular disease can produce myocardial remodeling that is very similar to that observed in genetic cardiomyopathy. For myocardial remodeling to occur, changes in gene expression must occur; therefore, changes in contractile function or wall stress must be communicated to the nucleus via signal transduction pathways. The identity of these signaling pathways has become a key question in molecular biology. Numerous signaling molecules have been implicated in the development of hypertrophy and failure, including the beta-adrenergic receptor, G alpha(q) and downstream effectors, mitogen-activated protein kinase pathways, and the Ca(2+)-regulated phosphatase, calcineurin. In the past it has been difficult to discern which signaling molecules actually contributed to disease progression in vivo; however, the development of numerous transgenic and knockout mouse models of cardiomyopathy is now allowing the direct testing of stimulatory and inhibitory molecules in the mouse heart. From this work it has been possible to identify signaling molecules and pathways that are required for different aspects of disease progression in vivo. In particular, a number of signaling pathways have now been identified that may be key regulators of changes in myocardial structure and function in response to mutations in structural components of the cardiomyocyte. Myocardial structure and signal transduction are now merging into a common field of research that will lead to a more complete understanding of the molecular mechanisms that underly heart disease.
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Affiliation(s)
- R L Nicol
- Department of Molecular Biology, University of Texas Southwestern Medical Center at Dallas, 6000 Harry Hines Blvd., Dallas, Texas 75390-9148, USA
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14
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Zou Y, Nagai R, Yamazaki T. Urotensin II induces hypertrophic responses in cultured cardiomyocytes from neonatal rats. FEBS Lett 2001; 508:57-60. [PMID: 11707268 DOI: 10.1016/s0014-5793(01)03015-0] [Citation(s) in RCA: 63] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Urotensin II (UII), a cyclic neuropeptide, functions not only in the central nervous system but also in non-neural systems including cardiovascular systems. In the present study we examined whether UII regulates hypertrophy in cardiomyocytes. The exposure of cultured cardiomyocytes from neonatal rats to UII dose-dependently activated extracellular signal-regulated kinases (ERKs), important molecules in the development of cardiac hypertrophy. ERK activation by UII at 100 nM peaked at 8 min after stimulation. UII markedly induced expression of specific genes encoding atrial natriuretic peptide and brain natriuretic peptide, and significantly increased amino acid incorporation into proteins. Incubation of cardiomyocytes with UII increased cell size and myofibril organisation. UII, then, might participate in cardiomyocyte hypertrophy.
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Affiliation(s)
- Y Zou
- Department of Cardiovascular Medicine, University of Tokyo Graduate School of Medicine, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8655, Japan
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15
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Aggeli IK, Gaitanaki C, Lazou A, Beis I. Stimulation of multiple MAPK pathways by mechanical overload in the perfused amphibian heart. Am J Physiol Regul Integr Comp Physiol 2001; 281:R1689-98. [PMID: 11641142 DOI: 10.1152/ajpregu.2001.281.5.r1689] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The mitogen-activated protein kinase (MAPK) signal transduction pathway activated by mechanical stress was investigated in the isolated perfused amphibian (Rana ridibunda) heart. High perfusion pressure induced the rapid (30 s) and prolonged (30 min) phosphorylation of a p43-extracellular regulated kinase, a response almost completely inhibited by 25 microM PD-98059. c-Jun NH2-terminal kinase (JNK) was also phosphorylated with maximal values attained at 15 min and remained elevated over 30 min. In-gel kinase assays verified that phosphorylated JNKs are active, phosphorylating the transcription factor c-Jun. Furthermore, pressure overload rapidly stimulated the p38-MAPK phosphorylation (30 s), a transient process (5 min) abolished by 1 microM SB-203580. In-gel kinase assays revealed that with phosphorylation, active p38-MAPKs phosphorylate their substrate MAP kinase-activated protein kinase 2. Biochemical analysis along with immunohistochemical studies showed that with activation, the three MAPK subfamily members examined are localized not only in the cytoplasm but in the nucleus as well. Present results therefore demonstrate for the first time in an amphibian species the involvement of multiple MAPK pathways in the mechanical overload-induced adaptive responses of the heart as well as their possible physiological roles.
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Affiliation(s)
- I K Aggeli
- Department of Animal and Human Physiology, School of Biology, Faculty of Sciences, University of Athens, Panepistimioupolis, Athens 157 84, Greece
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16
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Rogalski SL, Chavkin C. Eicosanoids inhibit the G-protein-gated inwardly rectifying potassium channel (Kir3) at the Na+/PIP2 gating site. J Biol Chem 2001; 276:14855-60. [PMID: 11278615 PMCID: PMC1262640 DOI: 10.1074/jbc.m010097200] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We previously showed that activation of the human endothelin A receptor (HETAR) by endothelin-1 (Et-1) selectively inhibits the response to mu opioid receptor (MOR) activation of the G-protein-gated inwardly rectifying potassium channel (Kir3). The Et-1 effect resulted from PLA2 production of an eicosanoid that inhibited Kir3. In this study, we show that Kir3 inhibition by eicosanoids is channel subunit-specific, and we identify the site within the channel required for arachidonic acid sensitivity. Activation of the G-protein-coupled MOR by the selective opioid agonist D-Ala(2)Glyol, enkephalin, released Gbetagamma that activated Kir3. The response to MOR activation was significantly inhibited by Et-1 activation of HETAR in homomeric channels composed of either Kir3.2 or Kir3.4. In contrast, homomeric channels of Kir3.1 were substantially less sensitive. Domain deletion and channel chimera studies suggested that the sites within the channel required for Et-1-induced inhibition were within the region responsible for channel gating. Mutation of a single amino acid in the homomeric Kir3.1 to produce Kir3.1(F137S)(N217D) dramatically increased the channel sensitivity to arachidonic acid and Et-1 treatment. Complementary mutation of the equivalent amino acid in Kir3.4 to produce Kir3.4(S143T)(D223N) significantly reduced the sensitivity of the channel to arachidonic acid- and Et-1-induced inhibition. The critical aspartate residue required for eicosanoid sensitivity is the same residue required for Na(+) regulation of PIP(2) gating. The results suggest a model of Kir3 gating that incorporates a series of regulatory steps, including Gbetagamma, PIP(2), Na(+), and arachidonic acid binding to the channel gating domain.
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Affiliation(s)
| | - Charles Chavkin
- ‡ To whom correspondence should be addressed: Dept. of Pharmacology, Box 357280, University of Washington, Seattle, WA 98195-7280. Tel.: 206-543-4266; Fax: 206-685-3822; E-mail:
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17
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Aggeli IK, Gaitanaki C, Lazou A, Beis I. Activation of multiple MAPK pathways (ERKs, JNKs, p38-MAPK) by diverse stimuli in the amphibian heart. Mol Cell Biochem 2001; 221:63-9. [PMID: 11506188 DOI: 10.1023/a:1010933013533] [Citation(s) in RCA: 20] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
We investigated the expression and activation of three MAPK subfamilies in the isolated perfused amphibian heart. ERK was detected as a 43 kDa band; p38-MAPK was detected as a band corresponding to 38 kDa and JNKs were detected as two bands corresponding to 46 and 52 kDa, respectively. PMA induced the activation of the ERK pathway as assessed by determining the phosphorylation state of ERK and the upstream component MEK1/2. PD98059 abolished this activation. p38-MAPK was phosphorylated by sorbitol (almost 12-fold, maximal within 10-15 min) and JNKs were phosphorylated and activated by sorbitol or anoxia/reoxygenation (approximately 4- and 2.5-fold, respectively). SB203580 completely blocked the activation of p38-MAPK by sorbitol. These results indicate that the MAPK pathways activated by phorbol esters, hyperosmotic stress or anoxia/ reoxygenation in the amphibian heart may have an important role in this experimental system.
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Affiliation(s)
- I K Aggeli
- Department of Animal and Human Physiology, School of Biology, Faculty of Sciences, University of Athens, Greece
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18
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Morisco C, Zebrowski D, Condorelli G, Tsichlis P, Vatner SF, Sadoshima J. The Akt-glycogen synthase kinase 3beta pathway regulates transcription of atrial natriuretic factor induced by beta-adrenergic receptor stimulation in cardiac myocytes. J Biol Chem 2000; 275:14466-75. [PMID: 10799529 DOI: 10.1074/jbc.275.19.14466] [Citation(s) in RCA: 213] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
We examined the mechanism of atrial natriuretic factor (ANF) transcription by isoproterenol (ISO), an agonist for the beta-adrenergic receptor (betaAR), in cardiac myocytes. ISO only modestly activated members of the mitogen-activated protein kinase family. ISO-induced ANF transcription was not affected by inhibition of mitogen-activated protein kinases, whereas it was significantly inhibited by KN93, an inhibitor of Ca(2+)/calmodulin-dependent kinase (CaM kinase II). Production of 3'-phosphorylated phosphatidylinositides (3 phosphoinositides) was also required for ISO-induced ANF transcription. ISO caused phosphorylation (Ser-473) and activation of Akt through CaM kinase II- and 3 phosphoinositides-dependent mechanisms. Constitutively active Akt increased myocyte surface area, total protein content, and ANF expression, whereas dominant negative Akt blocked ISO-stimulated ANF transcription. ISO caused Ser-9 phosphorylation and decreased activities of GSK3beta. Overexpression of GSK3beta inhibited ANF transcription, which was reversed by ISO. ISO failed to reverse the inhibitory effect of GSK3beta(S9A), an Akt-insensitive mutant. Kinase-inactive GSK3beta increased ANF transcription. Cyclosporin A partially inhibited ISO-stimulated ANF transcription, indicating that calcineurin only partially mediates ANF transcription. These results suggest that both CaM kinase II and 3 phosphoinositides mediate betaAR-induced Akt activation and ANF transcription in cardiac myocytes. Furthermore, betaAR-stimulated ANF transcription is predominantly mediated by activation of Akt and subsequent phosphorylation/inhibition of GSK3beta.
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Affiliation(s)
- C Morisco
- Weis Center for Research, Department of Molecular Cellular Physiology, Pennsylvania State University College of Medicine, Danville, Pennsylvania 17822, USA
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