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Bell D, Zhao YY, Devine AB, McDermott BJ. Influence of atenolol and nifedipine on nitric-oxide deficient cardiomyocyte hypertrophy and expression of the cardio-endocrine peptide intermedin and its receptor components. Cell Physiol Biochem 2008; 21:203-14. [PMID: 18209487 DOI: 10.1159/000113870] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/09/2007] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS Chronic inhibition of nitric oxide (NO) synthesis is associated with hypertension, myocardial ischemia, oxidative stress and hypertrophy; expression of adrenomedullin (AM) and intermedin (IMD) and their receptor activity modifying proteins (RAMPs 1-3) is augmented in cardiomyocytes, indicating that the myocardial AM/ IMD system may be activated in response to pressure loading and ischemic insult. The aim was to examine effects on (i) parameters of cardiomyocyte hypertrophy and on (ii) expression of AM and IMD and their receptor components in NO-deficient cardiomyocytes of an intervention chosen specifically for ability to alleviate pressure loading and ischemic injury concurrently. METHODS The NO synthesis inhibitor, N(G)-nitro-L-arginine methyl ester (L-NAME, 35 mg.kg(-1).day(-1)) was given to rats for 8 weeks, with/ without concurrent administration of beta-adrenoceptor antagonist, atenolol (25 mg.kg(-1).day(-1)) / calcium channel blocker, nifedipine (20mg.kg(-1).day(-1)). RESULTS In L-NAME treated rats, atenolol / nifedipine abolished increases in systolic blood pressure and plasma AM and IMD levels and in left ventricular cardiomyocytes: (i) normalized increased cell width and mRNA expression of hypertrophic (sk-alpha-actin) and cardio-endocrine (ANP, BNP, ET) genes; (ii) normalized augmented membrane protein oxidation; (iii) normalized mRNA expression of AM, IMD, RAMP1, RAMP2 and RAMP3. CONCLUSIONS normalization of blood pressure and membrane oxidant status together with prevention of hypertrophy and normalization of the augmented expression of AM, IMD and their receptor components in NO-deficient cardiomyocytes by atenolol / nifedipine supports involvement of both pressure loading and ischemic insult in stimulating cardiomyocyte hypertrophy and induction of these counter-regulatory peptides and their receptor components. Attenuation of augmented expression of IMD in this model cannot however be explained simply by prevention of cardiomyocyte hypertrophy.
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Affiliation(s)
- David Bell
- Cardiovascular Research Group, Division of Medicine and Therapeutics, School of Medicine and Dentistry, The Queen's University of Belfast, Belfast, Northern Ireland, UK.
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102
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Murtaza I, Wang HX, Feng X, Alenina N, Bader M, Prabhakar BS, Li PF. Down-regulation of catalase and oxidative modification of protein kinase CK2 lead to the failure of apoptosis repressor with caspase recruitment domain to inhibit cardiomyocyte hypertrophy. J Biol Chem 2008; 283:5996-6004. [PMID: 18171680 DOI: 10.1074/jbc.m706466200] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Cardiac hypertrophy is regulated by a complex interplay of pro- and anti-hypertrophic factors. Here, we report a novel anti-hypertrophic pathway composed of catalase, protein kinase CK2 (CK2), and apoptosis repressor with caspase recruitment domain (ARC). Our results showed that ARC phosphorylation levels, CK2 activity, and catalase expression levels were decreased in the hearts of the angiotensinogen transgenic mice and in cardiomyocytes treated with the hypertrophic stimuli, including phenylephrine, tumor necrosis factor-alpha, and angiotensin II. To understand the role of ARC in hypertrophy, we observed that enforced expression of ARC could inhibit hypertrophy. Knockdown of endogenous ARC or inhibition of its phosphorylation could sensitize cardiomyocytes to undergoing hypertrophy. The phosphorylatable, but not the nonphosphorylatable, ARC could inhibit hypertrophy. Thus, ARC is able to inhibit hypertrophy in a phosphorylation-dependent manner. In exploring the molecular mechanism by which CK2 activity is reduced, we found that CK2 was carbonylated in angiotensinogen transgenic mice and in cardiomyocytes treated with the hypertrophic stimuli. The decrease in catalase expression led to an elevated level of reactive oxygen species. The latter oxidatively modified CK2, resulting in its carbonylation. CK2 lost its catalytic activity upon carbonylation. ARC is phosphorylated by CK2, and ARC phosphorylation levels were reduced as a consequence of the decrease of CK2 activity. To understand the molecular mechanism by which ARC inhibits hypertrophy, we observed that ARC could inhibit the activation of mitochondrial permeability transition. These results suggest that catalase, CK2, and ARC constitute an anti-hypertrophic pathway in the heart.
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Affiliation(s)
- Iram Murtaza
- Division of Cardiovascular Research, National Key Laboratory of Biomembrane and Membrane Biotechnology, Institute of Zoology, Chinese Academy of Sciences, Beijing, China
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Bell D, Zhao Y, McCoy FP, Devine A, McDermott BJ. Expression of the Counter-Regulatory Peptide Intermedin is Augmented in the Presence of Oxidative Stress in Hypertrophied Cardiomyocytes. Cell Physiol Biochem 2008; 21:409-20. [DOI: 10.1159/000129633] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/26/2008] [Indexed: 12/19/2022] Open
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Song HJ, Kim JS, Lee MJ, Nam YS, Sohn UD. Reactive oxygen species mediate ET-1-induced activation of ERK1/2 signaling in cultured feline esophageal smooth muscle cells. Arch Pharm Res 2007; 30:1080-7. [PMID: 17958324 DOI: 10.1007/bf02980241] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Reactive oxygen species (ROS) have been shown to play a critical role in propagating the signals of several growth factors, peptide hormones, and cytokines, such as epidermal growth factor, insulin, and interleukin-1. We investigated a possible role for ROS generation in mediating the action of ET-1 on activation of ERK1/2 in cultured feline esophageal smooth muscle cells (ESMC). Confluent layers of ESMC were stimulated by 10nM ET-1; activation of ERK was examined by western blot analysis with phospho-specific antibodies of ERKs. ET-1 induced ERK1/2 phosphorylation in a dose- and time- dependent manner. ERK1/2 activation by ET-1 reached the maximal levels at 5min showing slight activation up to 20min, and then slowly declined. It was confirmed that the activation of ERK1/2 was reduced by MEK inhibitor PD98059. We observed the dose-dependent inhibitory effect of diphenyleneiodonium (DPI), an inhibitor of reduced nicotinamide adenine dinucleotide phosphate (NADPH) oxidase on the ET-1-enhanced ERK1/2 phosphorylation in ESMC. Pretreatment of ESMC with N-acetylcysteine, a ROS scavenger, also attenuated the ET-1-induced ERK1/2 activation. In addition, DPI significantly inhibited the ET-1- induced ROS production when ROS was measured as a function of DCF fluorescence. The results suggest that ROS might be critical mediators of the ET-1-induced ERK1/2 signaling events in ESMC.
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Affiliation(s)
- Hyun Ju Song
- Department of Pharmacology, College of Pharmacy, Chung Ang University, Seoul 156-756, Korea
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105
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Asano S, Rice KM, Kakarla S, Katta A, Desai DH, Walker EM, Wehner P, Blough ER. Aging influences multiple indices of oxidative stress in the heart of the Fischer 344/NNia x Brown Norway/BiNia rat. Redox Rep 2007; 12:167-80. [PMID: 17705987 DOI: 10.1179/135100007x200254] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
We report the influence of aging on multiple markers of oxidative-nitrosative stress in the heart of adult (6-month), aged (30-month) and very aged (36-month) Fischer 344/NNiaHSd x Brown Norway/BiNia (F344/NXBN) rats. Compared to adult (6-month) hearts, indices of oxidative (superoxide anion [O2*-], 4-hydroxy-2-nonenal [4-HNE]) and nitrosative (protein nitrotyrosylation) stress were 34.1 +/- 28.1%, 186 +/- 28.1% and 94 +/- 5.8% higher, respectively, in 36-month hearts and these findings were highly correlated with increases in left ventricular wall thickness (r > 0.669; r > 0.710 and P < 0.01, respectively). Regression analysis showed that increases in cardiac oxidative-nitrosative stress with aging were significantly correlated with changes in the expression and/or regulation of proteins involved in transcriptional (NF-kappaB) activities, signaling (mitogen-activated protein kinases along with Src), apoptotic (Bcl-2, Traf-2), and cellular stress (HSPs). These results suggest that the aging F344/NXBN heart may be highly suited for unraveling the molecular events that lead to age-associated alterations in cardiac oxidative stress.
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Affiliation(s)
- Shinichi Asano
- Department of Biological Sciences, Marshall University, Huntington, West Virginia 25755-1090, USA
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106
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Ohnishi S, Sumiyoshi H, Kitamura S, Nagaya N. Mesenchymal stem cells attenuate cardiac fibroblast proliferation and collagen synthesis through paracrine actions. FEBS Lett 2007; 581:3961-6. [PMID: 17662720 DOI: 10.1016/j.febslet.2007.07.028] [Citation(s) in RCA: 155] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2007] [Accepted: 07/12/2007] [Indexed: 01/11/2023]
Abstract
Mesenchymal stem cells (MSC) transplantation has been shown to decrease fibrosis in the heart; however, whether MSC directly influence the function of cardiac fibroblasts (CFB) remains unknown. MSC-conditioned medium significantly attenuated proliferation of CFB compared with CFB-conditioned medium. MSC-conditioned medium upregulated antiproliferation-related genes such as elastin, myocardin and DNA-damage inducible transcript 3, whereas CFB-conditioned medium upregulated proliferation-related genes such as alpha-2-macroglobulin and v-kit Hardy-Zuckerman 4 feline sarcoma viral oncogene homolog. MSC-conditioned medium significantly downregulated type I and III collagen expression, and significantly suppressed type III collagen promoter activity. MSC may exert paracrine anti-fibrotic effects at least in part through regulation of CFB proliferation and collagen synthesis.
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Affiliation(s)
- Shunsuke Ohnishi
- Department of Regenerative Medicine and Tissue Engineering, National Cardiovascular Center Research Institute, 5-7-1 Fujishirodai, Osaka 565-8565, Japan.
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107
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Chopra M, Sharma AC. Distinct cardiodynamic and molecular characteristics during early and late stages of sepsis-induced myocardial dysfunction. Life Sci 2007; 81:306-16. [PMID: 17612571 PMCID: PMC1986677 DOI: 10.1016/j.lfs.2007.05.021] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2007] [Revised: 05/14/2007] [Accepted: 05/18/2007] [Indexed: 01/12/2023]
Abstract
We hypothesized that progressive decline in myocardial performance would correlate with upregulation of markers for apoptotic mechanisms following increased duration of polymicrobial sepsis in the rat. Male Sprague-Dawley rats (350-400 g) were randomized into sham, 1-, 3- and 7-day sepsis groups. Each septic rat received 200 mg/kg cecal inoculum intraperitoneally (i.p). The post-mortem analysis showed a severely inflamed peritoneum with the presence of pus in all septic animals that was directly proportional to the duration of sepsis. We observed 10, 33 and 42% mortality in the 1-, 3- and 7-day sepsis groups, respectively. Septic animals at 3 and 7 days exhibited an increased wet lung/total body weight and heart weight/total body weight. A significant increase in total cardiac troponin I (cTnI) and C Reactive Protein (CRP) and endothelin-1 (ET-1) was also observed with an increased duration of sepsis. Myocardial ET-1 concentration in the 7-day post-sepsis group was significantly elevated compared to the sham and 1-day post-sepsis groups. Sepsis also produced a significant decrease in the mean arterial pressure in the 7-day post-sepsis group and tachycardia in the 1-, 3-, and 7-day post-sepsis groups compared to the sham group. A significant prolongation of the left ventricular isovolumic relaxation rate constant, tau, and left ventricular end-diastolic pressure in the 1-, 3- and 7-day post-sepsis groups compared to the sham group was observed. In addition, a significant decrease in the rates of left ventricular relaxation (-dP/dt) and contraction (+dP/dt) in the 3- and 7-day post-sepsis groups compared to the sham and 1-day post-sepsis group was observed. Sepsis produced a significant upregulation in the expression of myocardial TRADD, cytosolic active caspase-3, the Bax/Bcl(2) ratio, and the mitochondrial release of cytochrome C in the 3- and 7-day post-sepsis groups. We observed a progressive increase in the number of TUNEL positive nuclei, cytosolic caspase-3 activation and co-localization of PARP in the nuclei at 1, 3 and 7 days post-sepsis. These data suggest that the progression of sepsis from 1 day to 3-7 days produce distinct cardiodynamic characteristics with a more profound effect during later stages. The sepsis-induced decline in myocardial performance correlates with the induction of myocardial apoptosis.
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Affiliation(s)
- Mani Chopra
- Cardionome Laboratory Department of Biomedical Sciences Baylor College of Dentistry, Texas A&M Health Science Center, 3302 Gaston Avenue, Dallas, TX 75246, USA
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108
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Abstract
Cell-based therapy is emerging as an innovative approach for the treatment of degenerative diseases, and stem cells appear to be an ideal source of cells for this. In cardiology, in particular, human embryonic stem cell (hESC)-derived cardiomyocytes theoretically fulfill most, if not all, of the properties of an ideal donor cell, but several critical obstacles need to be overcome. Many research projects are focusing on set-up strategies for directing hESC differentiation toward the cardiac lineage. It is one of the main difficulties in the search to provide a valuable source of cells to effect regeneration of myocardial tissue in patients with severe heart failure. To date, there are no easy and efficient protocols for the induction of hESC differentiation toward the cardiac lineage. Discovering new molecules or tools capable of doing this is imperative.
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109
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Differential role of reactive oxygen species in the activation of mitogen-activated protein kinases and Akt by key receptors on B-lymphocytes: CD40, the B cell antigen receptor, and CXCR4. J Cell Commun Signal 2007; 1:33-43. [PMID: 18481208 DOI: 10.1007/s12079-007-0006-y] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2007] [Revised: 03/27/2007] [Accepted: 04/04/2007] [Indexed: 12/18/2022] Open
Abstract
BACKGROUND Antibodies produced by B-lymphocytes play a key role in the host defense against infection. The development, survival, and activation of B cell is regulated by multiple receptors including the B cell antigen receptor (BCR), which detects the presence of pathogens, CD40, which binds co-stimulatory molecules on activated T cells, and chemokines such as SDF-1 (CXCL12) that play key roles in B cell development and trafficking. Signaling by many receptors results in the generation of reactive oxygen species (ROS) that function as second messengers by regulating the activity of redox-sensitive kinases and phosphatases. We investigated the role of ROS in signaling by the BCR, CD40, and CXCR4, the receptor for SDF-1. We focused on activation of ERK, JNK, p38, and Akt, kinases that regulate multiple processes including cell survival, proliferation, and migration. RESULTS Using the anti-oxidants N-acetyl L-cysteine (NAC) and ebselen to deplete intracellular ROS, we identified a differential requirement for ROS in the activation of ERK, JNK, p38, and Akt by these receptors. We found that CD40 activated JNK, p38, and Akt via redox-dependent pathways that were sensitive to ROS depletion by NAC and ebselen. In contrast, BCR-induced activation of ERK, JNK, p38, and Akt was not affected by ROS depletion. We also found that CXCR4-induced Akt activation was ROS-dependent even though activation of the ERK, JNK, and p38 MAP kinases by CXCR4 occurred via ROS-independent pathways. CONCLUSION The differential requirement for ROS in the activation of ERK, JNK, p38, and Akt by the BCR, CD40, and CXCR4 likely reflects the multiplicity of upstream activators for each of these kinases, only some of which may be regulated in a redox-dependent manner. These findings support the idea that ROS are important second messengers in B cells and suggest that oxidants or anti-oxidants could be used to modulate B cell activation.
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110
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Clerk A, Kemp TJ, Zoumpoulidou G, Sugden PH. Cardiac myocyte gene expression profiling during H2O2-induced apoptosis. Physiol Genomics 2007; 29:118-27. [PMID: 17148688 DOI: 10.1152/physiolgenomics.00168.2006] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
High levels of oxidative stress promote cardiac myocyte death, though lower levels are potentially cytoprotective/anabolic. We examined the changes in gene expression in rat neonatal cardiac myocytes exposed to apoptotic (0.2 mM) or nontoxic (0.04 mM) concentrations of H2O2(2, 4, or 24 h) using Affymetrix microarrays. Using U34B arrays, we identified a ubiquitously expressed, novel H2O2-responsive gene [putative peroxide-inducible transcript 1 (Perit1)], which generates two alternatively spliced transcripts. Using 230 2.0 arrays, H2O2(0.04 mM) promoted significant changes in expression of only 32 genes, all of which were seen with 0.2 mM H2O2. We failed to detect any increase in the rate of protein synthesis in cardiac myocytes exposed to <0.1 mM H2O2, further suggesting that global, low concentrations of H2O2are not anabolic in this system. H2O2(0.2 mM) promoted significant ( P < 0.05, >1.75-fold) changes in expression of 649 mRNAs and 187 RNAs corresponding to no established gene. Of the mRNAs, 114 encoded transcriptional regulators including Krüppel-like factors (Klfs). Quantitative PCR independently verified the changes in Klf expression. Thus, H2O2-induced cardiac myocyte apoptosis is associated with dynamic changes in gene expression. The expression of these genes and their protein products potentially influences the progression of the apoptotic response.
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Affiliation(s)
- Angela Clerk
- National Heart and Lung Institute Division, Faculty of Medicine, Imperial College London, London, United Kingdom.
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111
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Affiliation(s)
- Eiki Takimoto
- Division of Cardiology, Department of Medicine, Johns Hopkins Medical Institutions, Baltimore, MD 21205, USA
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112
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Ohnishi S, Yanagawa B, Tanaka K, Miyahara Y, Obata H, Kataoka M, Kodama M, Ishibashi-Ueda H, Kangawa K, Kitamura S, Nagaya N. Transplantation of mesenchymal stem cells attenuates myocardial injury and dysfunction in a rat model of acute myocarditis. J Mol Cell Cardiol 2006; 42:88-97. [PMID: 17101147 DOI: 10.1016/j.yjmcc.2006.10.003] [Citation(s) in RCA: 149] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/11/2006] [Revised: 08/29/2006] [Accepted: 10/02/2006] [Indexed: 12/25/2022]
Abstract
Acute myocarditis is a non-ischemic inflammatory disease of the myocardium for which there is currently no specific treatment. We have previously shown that mesenchymal stem cells (MSC) can ameliorate heart injury during acute ischemia and in dilated cardiomyopathy; however, the therapeutic potential in acute myocarditis is unclear. In this study, we investigated the ability of MSC to attenuate myocardial injury and dysfunction during the acute phase of experimental myocarditis. Ten-week-old male Lewis rats were injected with porcine myosin to induce myocarditis. Cultured MSC (3x10(6) cells/rat) were injected intravenously 7 days after myosin injection. At 3 weeks, myosin injection resulted in severe inflammation and significant deterioration of cardiac function. MSC transplantation attenuated increases in CD68-positive inflammatory cells and monocyte chemoattractant protein-1 (MCP-1) expression in myocardium, and improved cardiac function in this model. Furthermore, myocardial capillary density was higher in myocarditis tissue, and was further increased by MSC transplantation. In vitro, cultured adult rat cardiomyocytes were injured in response to MCP-1, whereas this effect was attenuated by MSC-derived conditioned medium, suggesting cardioprotective effects of MSC acting in a paracrine manner. MSC transplantation attenuated myocardial injury and dysfunction in a rat model of acute myocarditis, at least in part through paracrine effects of MSC.
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Affiliation(s)
- Shunsuke Ohnishi
- Department of Regenerative Medicine and Tissue Engineering, National Cardiovascular Center Research Institute, Fujishirodai 5-7-1, Osaka 565-8565, Japan
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113
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Kuster GM, Siwik DA, Pimentel DR, Colucci WS. Role of reversible, thioredoxin-sensitive oxidative protein modifications in cardiac myocytes. Antioxid Redox Signal 2006; 8:2153-9. [PMID: 17034357 DOI: 10.1089/ars.2006.8.2153] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Reactive oxygen species (ROS) are important mediators of myocardial remodeling. However, the precise molecular mechanisms by which ROS exert their effects are incompletely understood. ROS induce oxidative posttranslational protein modifications that can regulate the function of structural, functional, and signaling proteins. For example, oxidative modification of free reactive thiols (S-thiolation) on the small G protein Ras increases Ras activity and thereby promotes ROS-dependent hypertrophic signaling in cardiac myocytes. By reducing thiols and restoring reversible thiol modifications, thioredoxin and glutaredoxin can act as regulators of ROS-mediated protein function. Understanding the regulation and functional relevance of oxidative protein modifications in myocardial remodeling may lead to new therapeutic strategies.
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Affiliation(s)
- Gabriela M Kuster
- Cardiovascular Medicine Section and the Myocardial Biology Unit, Boston University Medical Center, Boston, Massachusetts 02118, USA
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114
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Sugden PH, Clerk A. Oxidative stress and growth-regulating intracellular signaling pathways in cardiac myocytes. Antioxid Redox Signal 2006; 8:2111-24. [PMID: 17034354 DOI: 10.1089/ars.2006.8.2111] [Citation(s) in RCA: 93] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
The toxic effects of oxidative stress on cells (including cardiac myocytes, the contractile cells of the heart) are well known. However, an increasing body of evidence has suggested that increased production of reactive oxygen species (ROS) promotes cardiac myocyte growth. Thus, ROS may be 'second messenger' molecules in their own right, and growth-promoting neurohumoral agonists might exert their effects by stimulating production of ROS. The authors review the principal growth-promoting intracellular signaling pathways that are activated by ROS in cardiac myocytes, namely the mitogen-activated protein kinase cascades (extracellular signal-regulated kinases 1/2, c-Jun N-terminal kinases, and p38-mitogen-activated protein kinases) and the phosphoinositide 3-kinase/protein kinase B (Akt) pathway. Possible mechanisms are discussed by which these pathways are activated by ROS, including the oxidation of active site cysteinyl residues of protein and lipid phosphatases with their consequent inactivation, the potential involvement of protein kinase C or the apoptosis signal-regulating kinase 1, and the current models for the activation of the guanine nucleotide binding protein Ras.
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Affiliation(s)
- Peter H Sugden
- National Heart and Lung Institute Division, Faculty of Medicine, Imperial College London, London, United Kingdom.
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115
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Abstract
Apoptosis signal-regulating kinase 1 (ASK1), a serine/threonine protein kinase, is a reactive oxygen species-sensitive mitogen-activated protein kinase kinase kinase and activates both p38 and c-Jun N-terminal kinase pathways. Two isoforms of thioredoxin (Trx), cytosolic and mitochondrial Trx (Trx1 and Trx2, respectively), have been identified in mammalian cells. Trx1 was initially identified as an ASK1-binding protein. Trx1 and Trx2 bind directly to the N-terminal regulatory domain of ASK1 and inhibit ASK1-dependent apoptosis. Numerous other proteins interact with ASK1 and regulate its activity. In cardiomyocytes, ASK1 is involved not only in cardiac apoptosis, leading to cardiac remodeling, but also in cardiac hypertrophy as well as nonapoptotic cardiomyocyte death.
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Affiliation(s)
- Kazuhiko Nishida
- Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Osaka, Japan
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116
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Eduardo Carreño J, Apablaza F, Paz Ocaranza M, E. Jalil J. Hipertrofia cardiaca: eventos moleculares y celulares. Rev Esp Cardiol 2006. [DOI: 10.1157/13087900] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
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117
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Carreño JE, Apablaza F, Ocaranza MP, Jalil JE. Cardiac Hypertrophy: Molecular and Cellular Events. ACTA ACUST UNITED AC 2006. [DOI: 10.1016/s1885-5857(06)60796-2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/23/2022]
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118
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Engelbrecht AM, Esterhuyse J, du Toit EF, Lochner A, van Rooyen J. p38-MAPK and PKB/Akt, possible role players in red palm oil-induced protection of the isolated perfused rat heart? J Nutr Biochem 2006; 17:265-71. [PMID: 16229999 DOI: 10.1016/j.jnutbio.2005.05.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2005] [Revised: 04/29/2005] [Accepted: 05/02/2005] [Indexed: 11/21/2022]
Abstract
It has been shown that dietary red palm oil (RPO) supplementation improves reperfusion function. However, no exact protective cellular mechanisms have been established. To determine a potential mechanism for functional improvement, we examined the regulation of both mitogen-activated protein kinases (MAPKs) and PKB/Akt in the presence and absence of dietary RPO supplementation in ischemia/reperfusion-induced injury. Wistar rats were fed a control diet or control diet plus 7 g RPO/kg diet for 6 weeks. Hearts were excised and mounted on an isolated working heart perfusion apparatus. Cardiac function was measured before and after hearts were subjected to 25 min of total global ischemia. Hearts subjected to the same conditions were freeze clamped and used to characterize the degree of phosphorylation of extracellular signal-regulated kinase, p38, c-Jun NH(2)-terminal protein kinase (JNK) and PKB/Akt. Dietary RPO supplementation significantly improved aortic output recovery (72.1 +/- 3.2% vs. 54.0 +/- 3.2%, P < .05). This improved aortic output recovery was associated with significant increases in p38 and PKB/Akt phosphorylation during reperfusion when compared with control hearts. Furthermore, a significant decrease in JNK phosphorylation and attenuation of poly(ADP-ribose) polymerase cleavage occurred in the RPO-supplemented group during reperfusion. Our results suggest that dietary RPO supplementation caused differential phosphorylation of the MAPKs and PKB/Akt during ischemia/reperfusion-induced injury. These changes in phosphorylation were associated with improved functional recovery and reduced cleavage of an apoptotic marker, arguing that dietary RPO supplementation may confer protection via the MAPK and PKB/Akt signaling pathways during ischemia/reperfusion-induced injury.
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119
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Javadov S, Baetz D, Rajapurohitam V, Zeidan A, Kirshenbaum LA, Karmazyn M. Antihypertrophic effect of Na+/H+ exchanger isoform 1 inhibition is mediated by reduced mitogen-activated protein kinase activation secondary to improved mitochondrial integrity and decreased generation of mitochondrial-derived reactive oxygen species. J Pharmacol Exp Ther 2006; 317:1036-43. [PMID: 16513848 DOI: 10.1124/jpet.105.100107] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Although inhibition of Na+/H+ exchanger isoform 1 (NHE-1) reduces cardiomyocyte hypertrophy, the mechanisms underlying this effect are not known. Recent evidence suggests that this may be associated with improved mitochondrial function. To understand the mechanistic bases for mitochondrial involvement in the antihypertrophic effect of NHE-1 inhibition, we examined the effect of the NHE-1-specific inhibitor N-[2-methyl-4,5-bis(methylsulphonyl)-benzoyl]-guanidine, hydrochloride (EMD, EMD87580; 5 microM) on the hypertrophic phenotype, mitogen-activated protein kinase (MAPK) activity, mitochondrial membrane potential (Deltapsim), permeability transition (MPT) pore opening, and superoxide generation in phenylephrine (PE)-treated neonatal rat cardiomyocytes. EMD significantly suppressed markers of cell hypertrophy, including cell surface area and gene expression of atrial natriuretic peptide and alpha-skeletal actin. EMD inhibited the PE-induced MPT pore opening, prevented the loss in Deltapsim, and attenuated superoxide generation induced by PE. Moreover, the activation of p38 MAPK (p38) and extracellular signal-regulated kinase (ERK) 1/2 MAPKs induced by PE was significantly attenuated in the presence of EMD as well as the antioxidant catalase. To examine the role of MPT and mitochondrial Ca2+ uniport in parallel with EMD, the effects of cyclosporin A (0.2 microM) and ruthenium red (10 microM) were evaluated. Both agents significantly attenuated PE-induced hypertrophy and inhibited both mitochondrial dysfunction and p38 and ERK1/2 MAPK activation. Our results suggest a novel mechanism for attenuation of the hypertrophic phenotype by NHE-1 inhibition that is mediated by a reduction in PE-induced MAPK activation and superoxide production secondary to improved mitochondrial integrity.
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Affiliation(s)
- Sabzali Javadov
- Department of Physiology and Pharmacology, University of Western Ontario, London, ON, N6A 5C1, Canada
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120
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Oxidative stress and DNA damage–DNA repair system in vascular smooth muscle cells in artery and vein grafts. ACTA ACUST UNITED AC 2006. [DOI: 10.1016/j.jccr.2005.11.003] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
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121
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Cheng-Hsien C, Yung-Ho H, Yuh-Mou S, Chun-Cheng H, Horng-Mo L, Huei-Mei H, Tso-Hsiao C. Src homology 2-containing phosphotyrosine phosphatase regulates endothelin-1-induced epidermal growth factor receptor transactivation in rat renal tubular cell NRK-52E. Pflugers Arch 2005; 452:16-24. [PMID: 16261333 DOI: 10.1007/s00424-005-0006-9] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2005] [Revised: 09/05/2005] [Accepted: 10/03/2005] [Indexed: 12/31/2022]
Abstract
Epidermal growth factor (EGF) and endothelin-1 (ET-1) have been shown to be involved in proliferation and autoregeneration of renal tubular cells. This study aims to investigate the regulatory mechanism of ET-1-mediated EGF receptor (EGFR) transactivation in rat renal tubular cells (NRK-52E). Exposure of NRK-52E cells to ET-1 was found to stimulate the phosphorylation of EGFR and induce reactive oxygen species (ROS) generation. Both NAD(P)H oxidase inhibitor, diphenyliodonium (DPI) and ROS scavenger N-acetylcysteine (NAC), inhibited EGFR transactivation and extracellular signal-regulated kinase (ERK) phosphorylation caused by ET-1. In contrast, blockade of EGFR by AG1478 inhibited the phosphorylation of ERK but not ROS generation following ET-1 exposure. We found that the catalytic cysteine of Src homology 2-containing phosphotyrosine phosphatase (SHP-2) was transiently oxidized by ET-1 treatment in a modified malachite green phosphatase assay. In EGFR co-immunoprecipitation, SHP-2 was also found to interact with EGFR following ET-1 treatment. In SHP-2 knockdown NRK-52E cells, ET-1-induced EGFR transactivation was dramatically elevated and not influenced by NAC. However, GM6001 (an MMP inhibitor) and heparin binding (HB)-EGF neutralizing antibody suppressed this elevation. Our data suggest that ROS-mediated oxidation of SHP-2 is essential for HB-EGF-mediated EGFR transactivation in ET-1 signaling pathway in NRK-52E cells.
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Affiliation(s)
- Chen Cheng-Hsien
- Department of Internal Medicine, Taipei Medical University-Wan Fang Hospital, No 111, Sing-Lung Road, Sec. 3, Wen-Shan District, Taipei City, 117, Taiwan
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122
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Cheng TH, Shih NL, Chen CH, Lin H, Liu JC, Chao HH, Liou JY, Chen YL, Tsai HW, Chen YS, Cheng CF, Chen JJ. Role of mitogen-activated protein kinase pathway in reactive oxygen species-mediated endothelin-1-induced beta-myosin heavy chain gene expression and cardiomyocyte hypertrophy. J Biomed Sci 2005; 12:123-33. [PMID: 15864745 DOI: 10.1007/s11373-004-8168-6] [Citation(s) in RCA: 47] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2004] [Accepted: 08/11/2004] [Indexed: 10/25/2022] Open
Abstract
Endothelin-1 (ET-1) has been found to increase cardiac beta-myosin heavy chain (beta-MyHC) gene expression and induce hypertrophy in cardiomyocytes. ET-1 has been demonstrated to increase intracellular reactive oxygen species (ROS) in cardiomyocytes. The exact molecular mechanism by which ROS regulate ET-1-induced beta-MyHC gene expression and hypertrophy in cardiomyocytes, however, has not yet been fully described. We aim to elucidate the molecular regulatory mechanism of ROS on ET-1-induced beta-MyHC gene expression and hypertrophic signaling in neonatal rat cardiomyocytes. Following stimulation with ET-1, cultured neonatal rat cardiomyocytes were examined for 3H-leucine incorporation and beta-MyHC promoter activities. The effects of antioxidant pretreatment on ET-1-induced cardiac hypertrophy and mitogen-activated protein kinase (MAPKs) phosphorylation were studied to elucidate the redox-sensitive pathway in cardiomyocyte hypertrophy and beta-MyHC gene expression. ET-1 increased 3H-leucine incorporation and beta-MyHC promoter activities, which were blocked by the specific ET(A) receptor antagonist BQ-485. Antioxidants significantly reduced ET-1-induced 3H-leucine incorporation, beta-MyHC gene promoter activities and MAPK (extracellular signal-regulated kinase, p38, and c-Jun NH2 -terminal kinase) phosphorylation. Both PD98059 and SB203580 inhibited ET-1-increased 3H-leucine incorporation and beta-MyHC promoter activities. Co-transfection of the dominant negative mutant of Ras, Raf, and MEK1 decreased the ET-1-induced beta-MyHC promoter activities, suggesting that the Ras-Raf-MAPK pathway is required for ET-1 action. Truncation analysis of the beta-MyHC gene promoter showed that the activator protein-2 (AP-2)/specificity protein-1 (SP-1) binding site(s) were(was) important cis-element(s) in ET-1-induced beta-MyHC gene expression. Moreover, ET-1-induced AP-2 and SP-1 binding activities were also inhibited by antioxidant. These data demonstrate the involvement of ROS in ET-1-induced hypertrophic responses and beta-MyHC expression. ROS mediate ET-1-induced activation of MAPK pathways, which culminates in hypertrophic responses and beta-MyHC expression.
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Affiliation(s)
- Tzu-Hurng Cheng
- Department of Medicine, Taipei Medical University-Wan Fang Hospital, Taiwan
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123
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Wenzel S, Müller C, Piper HM, Schlüter KD. p38 MAP-kinase in cultured adult rat ventricular cardiomyocytes: expression and involvement in hypertrophic signalling. Eur J Heart Fail 2005; 7:453-60. [PMID: 15921779 DOI: 10.1016/j.ejheart.2004.07.001] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/01/2004] [Revised: 05/07/2004] [Accepted: 07/05/2004] [Indexed: 11/25/2022] Open
Abstract
Both alpha-adrenoceptor- and beta-adrenoceptor-stimulation lead to hypertrophic growth of the myocardium. But only beta-adrenoceptor-stimulation requires the pre-cultivation of cells with active TGF-beta. In order to define signalling molecules that are specifically involved in beta-adrenoceptor-dependent hypertrophy, changes in expression and hypertrophic responsiveness during pre-cultivation with TGF-beta were investigated. Isolated adult ventricular cardiomyocytes from rats were either cultured in 20% (v/v) foetal calf serum (FCS) to activate autocrine released TGF-beta or used without pre-treatment. Protein synthesis was analysed by (14)C-phenylalanine incorporation. Expression of signalling molecules was determined by immunoblotting. During cultivation of cardiomyocytes with active TGF-beta only the expression of p38 MAP-kinase increased. Subsequent stimulation of beta-adrenoceptors induced protein synthesis in a p38 MAP-kinase-dependent way. However, stimulation of beta-adrenoceptors activated p38 MAP-kinase irrespective of pre-treatment with TGF-beta. In the absence of this cytokine, hyperosmolarity or reconstitution of mechanical activity increased protein synthesis via p38 MAP-kinase activation in freshly isolated cells. In conclusion, activation of p38 MAP-kinase is a newly identified necessary signalling step required for beta-adrenoceptor induced hypertrophic growth. Like activation of adenyl cyclase, activation of p38 MAP-kinase is up-stream of the TGF-beta-induced coupling to the regulation of protein synthesis. Reconstitution of mechanical activity mimics the co-activation required and induced by TGF-beta.
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Affiliation(s)
- Sibylle Wenzel
- Physiologisches Institut, Justus-Liebig-Universität, Aulweg 129, D-35392 Giessen, Germany.
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124
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Lund AK, Peterson SL, Timmins GS, Walker MK. Endothelin-1-mediated increase in reactive oxygen species and NADPH Oxidase activity in hearts of aryl hydrocarbon receptor (AhR) null mice. Toxicol Sci 2005; 88:265-73. [PMID: 16107552 DOI: 10.1093/toxsci/kfi284] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
The aryl hydrocarbon receptor (AhR) is a ligand-activated transcription factor characterized to play a role in detection and adaptation to environmental stimuli. Genetic deletion of the AhR results in cardiac hypertrophy that is mediated primarily by endothelin-1 (ET-1); ET-1 has been implicated in the elevation of reactive oxygen species (ROS) in the heart, which are thought to contribute to several cardiovascular disorders, including cardiac hypertrophy. Thus, we tested the novel hypothesis that ET-1 induces ROS in AhR null mice via ET(A) receptor activation. We first confirmed the presence of ROS in the hearts of AhR null mice by measuring superoxide (O2*-)-dependent oxidation of dihydroethidium. Ethidium fluorescence was increased 10-fold in the hearts of AhR null mice, compared to the wild type. Then, to elucidate whether ET-1 mediated the increase in ROS, mice were chronically treated with 100 ng/kg/day of the ET(A) receptor antagonist BQ-123. In AhR null mice, BQ-123 significantly reduced elevated plasma 8-isoprostane, a systemic end product of phospholipid oxidation by ROS, and cardiac thiobarbituric acid reactive substances (TBARS), a nonspecific assessment of ROS production. Furthermore, BQ-123 reduced both cardiac lucigenin chemiluminescence and cardiac mRNA expression of NAD(P)H oxidase subunits gp91phox, p47phox, and p67phox in AhR null mice below the levels observed in wild-type mice. These findings demonstrate that ET-1 activation of ET(A) receptors mediates an increase in ROS that is associated with cardiac hypertrophy in AhR null mice. In addition, the ET-1-mediated increase in ROS appears to be initiated via increased NAD(P)H oxidase activity.
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Affiliation(s)
- Amie K Lund
- College of Pharmacy, School of Medicine, University of New Mexico, Albuquerque, New Mexico 87131, USA
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125
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Bi WF, Yang HY, Liu JC, Cheng TH, Chen CH, Shih CM, Lin H, Wang TC, Lian WS, Chen JJ, Chiu HC, Chang NC. INHIBITION OF CYCLIC STRAIN-INDUCED ENDOTHELIN-1 SECRETION BY TETRAMETHYLPYRAZINE. Clin Exp Pharmacol Physiol 2005; 32:536-40. [PMID: 16026512 DOI: 10.1111/j.1440-1681.2005.04227.x] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
1. Chuanxiong is a Chinese herb that has been used widely in China to treat vascular disorders. 2,3,5,6-Tetramethylpyrazine (TMP) is one of the major components purified from chuanxiong. Many studies have demonstrated that TMP is effective in the treatment of cardiovascular diseases. However, the mechanism of action by which TMP exerts relaxation in vascular vessels remains unclear. 2. Endothelin (ET)-1 is a potent vasopressor synthesised by endothelial cells both in culture and in vivo. The aims of the present study were to test the hypothesis that TMP may alter strain-induced ET-1 secretion and to identify the putative underlying signalling pathways in endothelial cells. 3. We showed that TMP inhibits strain-induced ET-1 secretion. 2,3,5,6-Tetramethylpyrazine also inhibits the strain-induced formation of reactive oxygen species (ROS) and phosphorylation of extracellular signal-regulated kinases (ERK) 1/2. Furthermore, pretreating cells with TMP or the anti-oxidant N-acetyl-cysteine decreased strain-induced increases in ET-1 secretion and ERK1/2 phosphorylation. Using a reporter gene assay, TMP and N-acetyl-cysteine were demonstrated to also attenuate the strain-induced activity of the activator protein-1 reporter. 4. In summary, we have demonstrated, for the first time, that TMP inhibits strain-induced ET-1 gene expression, in part by interfering with the ERK1/2 pathway via attenuation of ROS formation. Thus, the present study provides important new insights into the molecular pathways that may contribute to the proposed beneficial effects of TMP in the vascular system.
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Affiliation(s)
- Wei-Fung Bi
- Department of Medicine, Taipei Medical University Hospital, Taipei, Taiwan ROC
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126
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Schiffrin EL. Vascular endothelin in hypertension. Vascul Pharmacol 2005; 43:19-29. [PMID: 15955745 DOI: 10.1016/j.vph.2005.03.004] [Citation(s) in RCA: 184] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2004] [Revised: 01/17/2005] [Accepted: 03/01/2005] [Indexed: 12/31/2022]
Abstract
Endothelins are powerful vasoconstrictor peptides that also play numerous other functions in many different organs. Endothelin-1 (ET-1) is the most abundant and important of this family of peptides in blood vessels. Production of ET-1 is increased in the endothelium and the kidney in salt-dependent models of hypertension (e.g.: DOCA-salt rats and Dahl salt-sensitive rats, in salt-loaded SHR-SP, in angiotensin II-infused and in diabetic rats). ET-1 elicits an inflammatory response by increasing oxidant stress in the vascular wall, which induces vascular remodeling and endothelial dysfunction found in the hypertensive models that exhibit an endothelin-mediated component. Endothelin receptor antagonism reduces blood pressure and vascular hypertrophic remodeling present in these hypertensive models. Patients with stage 2 hypertension have enhanced vascular expression of ET-1. Endothelin receptor antagonists lower blood pressure in hypertensive patients. They could become therapeutic agents for prevention of target organ damage in hypertension and in type 2 diabetes, chronic renal failure and congestive heart failure. Side effects of endothelin receptor blockers have prevented up to the present their development for these indications. New endothelin antagonists devoid of these side effects, or alternatively inhibitors of the endothelin converting enzymes that generate ET-1 may in the future become available to block the endothelin system. However, to date endothelin antagonists have been approved only for the treatment of primary pulmonary hypertension, a rapidly fatal condition in which the endothelin system plays an important role and endothelin antagonists exert favorable effects.
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Affiliation(s)
- Ernesto L Schiffrin
- CIHR Multidisciplinary Research Group on Hypertension, Clinical Research Institute of Montreal, 110 Pine Avenue West, Montreal, Quebec H2W 1R7, Canada.
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127
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Chao HH, Chen JJ, Chen CH, Lin H, Cheng CF, Lian WS, Chen YL, Juan SH, Liu JC, Liou JY, Chan P, Cheng TH. Inhibition of angiotensin II induced endothelin-1 gene expression by 17-beta-oestradiol in rat cardiac fibroblasts. Heart 2005; 91:664-9. [PMID: 15831659 PMCID: PMC1768884 DOI: 10.1136/hrt.2003.031898] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
OBJECTIVE To examine whether 17-beta-oestradiol (E(2)) may alter angiotensin II (Ang II) induced cell proliferation and to identify the putative underlying signalling pathways in rat cardiac fibroblasts. DESIGN Cultured rat cardiac fibroblasts were preincubated with E(2) then stimulated with Ang II. [(3)H]Thymidine incorporation and endothelin-1 (ET-1) gene expression were examined. The effect of E(2) on Ang II induced NADPH oxidase activity, reactive oxygen species (ROS) formation, and extracellular signal regulated kinase (ERK) phosphorylation were tested to elucidate the intracellular mechanism of E(2) in proliferation and ET-1 gene expression. RESULTS Ang II increased DNA synthesis, which was inhibited with E(2) (1-100 nmol/l). E(2), but not 17-alpha-oestradiol, inhibited Ang II induced ET-1 gene expression as shown by northern blotting and promoter activity assay. This effect was prevented by co-incubation with the oestrogen receptor antagonist ICI 182,780 (1 micromol/l). E(2) also inhibited Ang II increased NADPH oxidase activity, ROS formation, ERK phosphorylation, and activator protein-1 mediated reporter activity. CONCLUSIONS The results suggest that E(2) inhibits Ang II induced cell proliferation and ET-1 gene expression, partially by interfering with the ERK pathway through attenuation of ROS generation. Thus, this study provides important new insight regarding the molecular pathways that may contribute to the proposed beneficial effects of oestrogen on the cardiovascular system.
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Affiliation(s)
- H-H Chao
- Graduate Institute of Medical Science, Taipei Medical University, Taipei, Taiwan
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128
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Snabaitis AK, Muntendorf A, Wieland T, Avkiran M. Regulation of the extracellular signal-regulated kinase pathway in adult myocardium: differential roles of G(q/11), Gi and G(12/13) proteins in signalling by alpha1-adrenergic, endothelin-1 and thrombin-sensitive protease-activated receptors. Cell Signal 2005; 17:655-64. [PMID: 15683740 DOI: 10.1016/j.cellsig.2004.10.008] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2004] [Revised: 10/13/2004] [Accepted: 10/13/2004] [Indexed: 11/21/2022]
Abstract
Using adenoviruses encoding RGS2, RGS4 and Lsc (regulator of G protein signalling (RGS) domain of p115 RhoGEF), we investigated the contributions of G(q/11), Gi and G(12/13) proteins to G protein-coupled receptor (GPCR)-mediated activation of the extracellular signal-regulated kinase (ERK) pathway in adult rat ventricular myocytes (ARVM). Exposure to phenylephrine, endothelin-1 (ET-1) or thrombin induced significant activation of ERK1/2 and their downstream target 90 kDa ribosomal S6 kinase (p90RSK), which was abolished by overexpression of RGS4 (inhibits signalling via G(q/11) and Gi) or RGS2 (inhibits signalling via G(q/11)). Pertussis toxin (inhibits signalling via Gi) only partially attenuated the activation of ERK1/2 and p90(RSK) by phenylephrine and ET-1, but abolished such activation by thrombin. Overexpression of Lsc (inhibits signalling via G(12/13)) did not affect the responses to phenylephrine and ET-1, but suppressed the activation of ERK1/2 and p90RSK by thrombin. We conclude that full activation of the ERK pathway in ARVM by alpha1-adrenergic, ET-1 and thrombin receptors requires the activation of distinct families of heterotrimeric G proteins.
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MESH Headings
- Adenoviridae/genetics
- Adrenergic alpha-1 Receptor Agonists
- Adrenergic alpha-Agonists/pharmacology
- Animals
- GTP-Binding Protein alpha Subunits/physiology
- GTP-Binding Protein alpha Subunits, G12-G13/physiology
- GTP-Binding Protein alpha Subunits, Gi-Go/physiology
- GTP-Binding Protein alpha Subunits, Gq-G11/physiology
- Genetic Vectors
- Guanine Nucleotide Exchange Factors/chemistry
- MAP Kinase Signaling System
- Male
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/enzymology
- Myocytes, Cardiac/metabolism
- Pertussis Toxin/pharmacology
- Phenylephrine/pharmacology
- Protein Structure, Tertiary
- RGS Proteins/genetics
- RGS Proteins/metabolism
- Rats
- Rats, Wistar
- Receptor, Endothelin A/metabolism
- Receptors, Adrenergic, alpha-1/metabolism
- Receptors, G-Protein-Coupled/metabolism
- Receptors, Thrombin/metabolism
- Rho Guanine Nucleotide Exchange Factors
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Affiliation(s)
- Andrew K Snabaitis
- Cardiovascular Division, King's College London, The Rayne Institute, St Thomas' Hospital, London, SE1 7EH, United Kingdom
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129
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Chao HH, Juan SH, Liu JC, Yang HY, Yang E, Cheng TH, Shyu KG. Resveratrol inhibits angiotensin II-induced endothelin-1 gene expression and subsequent proliferation in rat aortic smooth muscle cells. Eur J Pharmacol 2005; 515:1-9. [PMID: 15878161 DOI: 10.1016/j.ejphar.2005.03.035] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2005] [Accepted: 03/31/2005] [Indexed: 02/07/2023]
Abstract
Resveratrol is a phytoestrogen naturally found in grapes and is the major constituent of wine thought to have a cardioprotective effect. The aims of this study were to examine whether resveratrol alters angiotenisn II-induced cell proliferation and endothelin-1 gene expression and to identify the putative underlying signaling pathways in rat aortic smooth muscle cells. Cultured rat aortic smooth muscle cells were preincubated with resveratrol then stimulated with angiotensin II, after which [3H]thymidine incorporation and endothelin-1 gene expression were examined. The intracellular mechanism of resveratrol in cellular proliferation and endothelin-1 gene expression was elucidated by examining the phosphorylation level of angiotensin II-induced extracellular signal-regulated kinase (ERK). The inhibitory effects of resveratrol (1-100 microM) on angiotensin II-induced DNA synthesis and endothelin-1 gene expression were demonstrated with Northern blot and promoter activity assays. Measurements of 2'7'-dichlorofluorescin diacetate, a redox-senstive fluorescent dye, showed a resveratrol-mediated inhibition of intracellular reactive oxygen species generated by the effects of angiotensin II. The inductive properties of angiotensin II and H2O2 on ERK phosphorylation and activator protein-1-mediated reporter activity were found reversed with resveratrol and antioxidants such as N-acetyl-cysteine. In summary, we speculate that resveratrol inhibits angiotensin II-induced cell proliferation and endothelin-1 gene expression, and does so in a manner which involves the disruption of the ERK pathway via attenuation of reactive oxygen species generation. Thus, this study provides important insight into the molecular pathways that may contribute to the proposed beneficial effects of resveratrol on the cardiovascular system.
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MESH Headings
- Angiotensin II/pharmacology
- Animals
- Aorta/cytology
- Binding Sites/genetics
- Blotting, Northern
- Blotting, Western
- Cell Proliferation/drug effects
- Cells, Cultured
- Dose-Response Relationship, Drug
- Endothelin-1/genetics
- Extracellular Signal-Regulated MAP Kinases/metabolism
- Gene Expression/drug effects
- Hydrogen Peroxide/pharmacology
- Luciferases/genetics
- Luciferases/metabolism
- Male
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Phosphorylation/drug effects
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- Rats
- Rats, Sprague-Dawley
- Reactive Oxygen Species/metabolism
- Resveratrol
- Stilbenes/pharmacology
- Transcription Factor AP-1/metabolism
- Transfection
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Affiliation(s)
- Hung-Hsing Chao
- Graduate Institute of Medical Sciences, Taipei Medical University, Taipei, Taiwan, ROC; Shin Kong Wu Ho-Su Memorial Hospital, Taipei, Taiwan, ROC
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130
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Tsujimoto I, Hikoso S, Yamaguchi O, Kashiwase K, Nakai A, Takeda T, Watanabe T, Taniike M, Matsumura Y, Nishida K, Hori M, Kogo M, Otsu K. The antioxidant edaravone attenuates pressure overload-induced left ventricular hypertrophy. Hypertension 2005; 45:921-6. [PMID: 15824197 DOI: 10.1161/01.hyp.0000163461.71943.e9] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The free radical scavenger 3-methyl-1-phenyl-2-pyrazolin-5-one (edaravone) is used to treat patients with ischemic brain damage. We and others reported previously that in vitro and in vivo reactive oxygen species (ROS) act as second messengers to develop cardiac hypertrophy. In this study, we used an in vivo murine model of pressure overload-induced cardiac hypertrophy to examine the effects of edaravone on left ventricular hypertrophy. The animals were subjected to the transverse thoracic aorta constriction, and edaravone (10 mg/kg) was infused intraperitoneally twice daily. Seven days after the operation, we observed a significant increase in ROS production in hearts, which was eliminated by the treatment with edaravone. Pressure-overloaded hearts showed a significant increase in left ventricular weight/body weight ratio and the expression level of atrial natriuretic factor mRNA, which were attenuated by edaravone. It also reduced perivascular and intermuscular fibrosis and inhibited pressure overload-induced activation of apoptosis signal-regulating kinase 1 (ASK1) and its downstream kinases of c-Jun N-terminal protein kinase and p38 mitogen-activated protein kinase. Edaravone attenuated the hypertrophic response even when the treatment was started after the onset of cardiac hypertrophic response. These findings indicate that edaravone significantly attenuates pressure overload-induced cardiac hypertrophy mediated through its antioxidative function and subsequent inhibition of ASK1 signaling pathway.
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Affiliation(s)
- Ikuko Tsujimoto
- Department of Internal Medicine and Therapeutics, Osaka University Graduate School of Medicine, Suita, Osaka, Japan
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131
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Kuster GM, Pimentel DR, Adachi T, Ido Y, Brenner DA, Cohen RA, Liao R, Siwik DA, Colucci WS. Alpha-adrenergic receptor-stimulated hypertrophy in adult rat ventricular myocytes is mediated via thioredoxin-1-sensitive oxidative modification of thiols on Ras. Circulation 2005; 111:1192-8. [PMID: 15723974 DOI: 10.1161/01.cir.0000157148.59308.f5] [Citation(s) in RCA: 103] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Alpha-adrenergic receptor (alphaAR)-stimulated hypertrophy in adult rat ventricular myocytes is mediated by reactive oxygen species-dependent activation of the Ras-Raf-MEK1/2-ERK1/2 signaling pathway. Because Ras is known to have redox-sensitive cysteine residues, we tested the hypothesis that alphaAR-stimulated hypertrophic signaling is mediated via oxidative modification of Ras thiols. METHODS AND RESULTS The effect of alphaAR stimulation on the number of free thiols on Ras was measured with biotinylated iodoacetamide labeling. alphaAR stimulation caused a 48% decrease in biotinylated iodoacetamide-labeled Ras that was reversed by dithiothreitol (10 mmol/L), indicating a decrease in the availability of free thiols on Ras as a result of an oxidative posttranslational modification. This effect was abolished by adenoviral overexpression of thioredoxin-1 (TRX1) and potentiated by the TRX reductase inhibitor azelaic acid. Likewise, alphaAR-stimulated Ras activation was abolished by TRX1 overexpression and potentiated by azelaic acid. TRX1 overexpression inhibited the alphaAR-stimulated phosphorylation of MEK1/2, ERK1/2, and p90RSK and prevented cellular hypertrophy, sarcomere reorganization, and protein synthesis (versus beta-galactosidase). Azelaic acid potentiated alphaAR-stimulated protein synthesis. Although TRX1 can directly reduce thiols, it also can scavenge ROS by increasing peroxidase activity. To examine this possibility, peroxidase activity was increased by transfection with catalase, and intracellular reactive oxygen species were measured with dichlorofluorescein diacetate fluorescence. Although catalase increased peroxidase activity approximately 20-fold, TRX1 had no effect. Likewise, the alphaAR-stimulated increase in dichlorofluorescein diacetate fluorescence was abolished with catalase but retained with TRX1. CONCLUSIONS AlphaAR-stimulated hypertrophic signaling in adult rat ventricular myocytes is mediated via a TRX1-sensitive posttranslational oxidative modification of thiols on Ras.
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Affiliation(s)
- Gabriela M Kuster
- Cardiovascular Medicine Section, Department of Medicine, and the Myocardial and Vascular Biology Units, Boston University Medical Center, Boston, Mass 02118, USA
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132
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Blendea MC, Jacobs D, Stump CS, McFarlane SI, Ogrin C, Bahtyiar G, Stas S, Kumar P, Sha Q, Ferrario CM, Sowers JR. Abrogation of oxidative stress improves insulin sensitivity in the Ren-2 rat model of tissue angiotensin II overexpression. Am J Physiol Endocrinol Metab 2005; 288:E353-9. [PMID: 15494608 DOI: 10.1152/ajpendo.00402.2004] [Citation(s) in RCA: 132] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
To evaluate the role of renin-angiotensin system (RAS)-mediated oxidative stress in insulin resistance (IR), we compared the effects of the angiotensin II (ANG II) receptor blocker (ARB) valsartan and a superoxide dismutase (SOD) mimetic, tempol, on whole body glucose tolerance and soleus muscle insulin-stimulated glucose uptake in transgenic hypertensive TG(mREN-2)27 (Ren-2) rats. Ren-2 rats and Sprague-Dawley (SD) controls were given valsartan (30 mg/kg) or tempol (1 mmol/l) in their drinking water for 21 days. IR was measured by glucose tolerance testing (1 g/kg glucose ip). IR index (AUC(glucose) x AUC(insulin)) was significantly higher in the Ren-2 animals compared with SD controls (30.5 +/- 7.0 x 10(6) arbitrary units in Ren-2 vs. 10.2 +/- 2.4 x 10(6) in SD, P < 0.01). Both valsartan and tempol treatment normalized Ren-2 IR index. Compared with SD controls (100%), there was a significant increase in superoxide anion production (measured by lucigenin-enhanced chemiluminescence) in soleus muscles of Ren-2 rats (133 +/- 15%). However, superoxide production was reduced in both valsartan- and tempol-treated (85 +/- 22% and 59 +/- 12%, respectively) Ren-2 rats. Insulin (INS)-mediated 2-deoxyglucose (2-DG) uptake (%SD basal levels) was substantially lower in Ren-2 rat soleus muscle compared with SD (Ren-2 + INS = 110 +/- 3% vs. SD + INS = 206 +/- 12%, P < 0.05). However, Ren-2 rats treated with valsartan or tempol exhibited a significant increase in insulin-mediated 2-DG uptake compared with untreated transgenic animals. Improvements in skeletal muscle insulin-dependent glucose uptake and whole body IR in rats overexpressing ANG II by ARB or SOD mimetic indicate that oxidative stress plays an important role in ANG II-mediated insulin resistance.
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Affiliation(s)
- Mihaela C Blendea
- Department of Internal Medicine, University of Missouri, Columbia, MO 65201, USA
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133
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Hong HJ, Liu JC, Chan P, Juan SH, Loh SH, Lin JG, Cheng TH. 17beta-estradiol downregulates angiotensin-II-induced endothelin-1 gene expression in rat aortic smooth muscle cells. J Biomed Sci 2004; 11:27-36. [PMID: 14730207 DOI: 10.1007/bf02256546] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2003] [Accepted: 08/25/2003] [Indexed: 02/07/2023] Open
Abstract
It is well documented that 17beta-estradiol (E(2)) exerts a cardiovascular protective effect. A possible role of E(2) in the regulation of endothelin-1 (ET-1) production has been reported. However, the complex mechanisms by which E(2) inhibits ET-1 expression are not completely understood. The aims of this study were to examine whether E(2) may alter angiotensin II (Ang II)-induced cell proliferation and ET-1 gene expression and to identify the putative underlying signaling pathways in rat aortic smooth muscle cells. Cultured rat aortic smooth muscle cells were preincubated with E(2), then stimulated with Ang II, and [(3)H]thymidine incorporation and ET-1 gene expression were examined. The effect of E(2) on Ang-II-induced extracellular signal-regulated kinase (ERK) phosphorylation was tested to elucidate the intracellular mechanism of E(2) in proliferation and ET-1 gene expression. Ang II increased DNA synthesis which was inhibited with E(2) (1- 100 nM). E(2), but not 17alpha-estradiol, inhibited the Ang-II-induced ET-1 gene expression as revealed by Northern blotting and promoter activity assay. This effect was prevented by coincubation with the estrogen receptor antagonist ICI 182,780 (1 microM). E(2) also inhibited Ang-II-increased intracellular reactive oxygen species (ROS) as measured by a redox-sensitive fluorescent dye, 2',7'-dichlorofluorescin diacetate, and ERK phosphorylation. Furthermore, E(2) and antioxidants, such as N-acetyl cysteine and diphenylene iodonium, decreased Ang-II-induced cell proliferation, ET-1 promoter activity, ET-1 mRNA, ERK phosphorylation, and activator protein-1-mediated reporter activity. In summary, our results suggest that E(2) inhibits Ang-II-induced cell proliferation and ET-1 gene expression, partially by interfering with the ERK pathway via attenuation of ROS generation. Thus, this study provides important new insight regarding the molecular pathways that may contribute to the proposed beneficial effects of estrogen on the cardiovascular system.
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Affiliation(s)
- Hong-Jye Hong
- School of Chinese Medicine, China Medical University, Taichung, Taiwan, ROC
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134
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Liu JC, Chan P, Chen JJ, Lee HM, Lee WS, Shih NL, Chen YL, Hong HJ, Cheng TH. The inhibitory effect of trilinolein on norepinephrine-induced beta-myosin heavy chain promoter activity, reactive oxygen species generation, and extracellular signal-regulated kinase phosphorylation in neonatal rat cardiomyocytes. J Biomed Sci 2004; 11:11-8. [PMID: 14730205 DOI: 10.1007/bf02256544] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2003] [Accepted: 09/25/2003] [Indexed: 10/25/2022] Open
Abstract
The myocardial protective effects of trilinolein, isolated from the traditional Chinese herb Sanchi (Panax notoginseng), are thought to be related to its antioxidant activity. However, the intracellular mechanism underlying the protective effect of trilinolein in the heart remains unclear. In the present study, we investigated the effect of trilinolein on norepinephrine (NE)-induced protein synthesis in cardiomyocytes. Cultured neonatal rat cardiomyocytes were stimulated with NE, then protein content, [(3)H]-leucine incorporation, and beta-myosin heavy chain (beta-MyHC) promoter activity were examined. The effect of trilinolein on NE-induced intracellular reactive oxygen species (ROS) generation was measured with a redox- sensitive fluorescent dye (2',7'-dichlorofluorescin diacetate) and extracellular signal-regulated kinase (ERK) phosphorylation by Western blotting. Trilinolein inhibited NE-increased protein synthesis, beta-MyHC promoter activity, and intracellular ROS. Both trilinolein and the antioxidant, N-acetyl-cysteine, decreased NE- and H(2)O(2)-induced protein synthesis, beta-MyHC promoter activity, and ERK phosphorylation. These data indicate that trilinolein inhibits NE-induced protein synthesis via attenuation of ROS generation in cardiomyocytes.
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Affiliation(s)
- Ju-Chi Liu
- Graduate Institute of Medical Sciences, Taipei Medical University, Wan Fang Hospital, No. 111 Hsing-Lung Road, Sec. 3, Wen Shan District, Taipei 117, Taiwan, ROC
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135
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Juan SH, Chen JJ, Chen CH, Lin H, Cheng CF, Liu JC, Hsieh MH, Chen YL, Chao HH, Chen TH, Chan P, Cheng TH. 17β-Estradiol inhibits cyclic strain-induced endothelin-1 gene expression within vascular endothelial cells. Am J Physiol Heart Circ Physiol 2004; 287:H1254-61. [PMID: 15130882 DOI: 10.1152/ajpheart.00723.2003] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
It has been well documented previously that 17β-estradiol (E2) exerts a protective effect on cardiovascular tissue. The possible role of E2in the regulation of endothelin (ET)-1 production has been previously reported, although the complex mechanisms by which E2inhibits ET-1 expression are not completely understood. The aims of this study were to examine whether E2was able to alter strain-induced ET-1 gene expression and also to identify the putative underlying signaling pathways that exist within endothelial cells. For cultured endothelial cells, E2(1–100 nM), but not 17α-estradiol, inhibited the level of strain-induced ET-1 gene expression and also peptide secretion. This inhibitory effect elicited by E2was able to be prevented by the coincubation of endothelial cells with the estrogen receptor antagonist ICI-182,780 (1 μM). E2also inhibited strain-enhanced NADPH oxidase activity and intracellular reactive oxygen species (ROS) generation as measured by the redox-sensitive fluorescent dye 2′,7′-dichlorofluorescin diacetate and the level of extracellular signal-regulated kinase (ERK) phosphorylation. Furthermore, the presence of E2and antioxidants such as N-acetylcysteine and diphenylene iodonium were able to elicit a decrease in the level of strain-induced ET-1 secretion, ET-1 promoter activity, ET-1 mRNA, ERK phosphorylation, and activator protein-1 binding activity. In summary, we demonstrated, for the first time, that E2inhibits strain-induced ET-1 gene expression, partially by interfering with the ERK pathway via the attenuation of strain-induced ROS generation. Thus this study delivers important new insight regarding the molecular pathways that may contribute to the proposed beneficial effects of estrogen on the cardiovascular system.
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Affiliation(s)
- Shu-Hui Juan
- Graduate Institute of Medical Sciences and Department of Physiology, School of Medicine, Taipei Medical University, Republic of China
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136
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de Boer RA, Pokharel S, Flesch M, van Kampen DA, Suurmeijer AJH, Boomsma F, van Gilst WH, van Veldhuisen DJ, Pinto YM. Extracellular signal regulated kinase and SMAD signaling both mediate the angiotensin II driven progression towards overt heart failure in homozygous TGR(mRen2)27. J Mol Med (Berl) 2004; 82:678-87. [PMID: 15322702 DOI: 10.1007/s00109-004-0579-3] [Citation(s) in RCA: 49] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2004] [Accepted: 06/15/2004] [Indexed: 11/24/2022]
Abstract
Angiotensin (Ang) II is a key player in left ventricular (LV) remodeling and cardiac fibrosis. Its effects are thought to be transferred at least in part by mitogen-activated protein kinases (MAPK), transforming growth factor (TGF) beta1, and the Smad pathway. In this study we sought to elucidate whether Ang II related effects on LV dysfunction and fibrosis in vivo are mediated via MAPK or rather via Smad stimulation. We treated homozygous REN2 rats (7-11 weeks) with placebo, Ang II type 1 (AT1) receptor blocker or tyrphostin A46 (TYR), an inhibitor of epidermal growth factor receptor tyrosine kinase that blocks extracellular signal-regulated kinase (ERK) activity. REN2 rats had LV hypertrophy (LVH) and LV dysfunction that progressed to heart failure between 10 and 13 weeks. Blood pressure normalized over time. Renin, N-terminal atrial natriuretic peptide (N-ANP), and ERK were activated while p38 MAPK was not. Treatment with AT1 receptor blockade prevented LVH and right ventricular hypertrophy, normalized systolic and diastolic d P/d t, N-ANP levels, and reduced collagen apposition. Similarly, TYR reduced LVH, N-ANP levels, and collagen apposition. Myocardial ERK activation did not depend on AT1 receptor signaling as it was not affected by AT1 receptor blockade. TYR abolished myocardial ERK activity. Smad2 activation was inhibited by AT1 receptor blockade but was unaltered by TYR. Ang II induced LV remodeling and fibrosis are dependent on both ERK and Smad2 activation. This process is prevented by both AT1 receptor blockade and TYR, and therefore inhibition of either pathway is equally efficacious in restoring LV function and architecture.
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Affiliation(s)
- Rudolf A de Boer
- Thoraxcenter, Department of Cardiology, University Hospital Groningen, PO Box 30001, 9700 RB, Groningen, The Netherlands.
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137
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Ceolotto G, Bevilacqua M, Papparella I, Baritono E, Franco L, Corvaja C, Mazzoni M, Semplicini A, Avogaro A. Insulin generates free radicals by an NAD(P)H, phosphatidylinositol 3'-kinase-dependent mechanism in human skin fibroblasts ex vivo. Diabetes 2004; 53:1344-51. [PMID: 15111505 DOI: 10.2337/diabetes.53.5.1344] [Citation(s) in RCA: 64] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Oxidative stress may be involved in the development of vascular complications associated with diabetes; however, the molecular mechanism responsible for increased production of free radicals in diabetes remains uncertain. Therefore, we examined whether acute hyperinsulinemia increases the production of free radicals and whether this condition affects proliferative extracellular signal-regulated kinase (ERK-1 and -2) signaling in human fibroblasts in vitro. Insulin treatment significantly increased intracellular superoxide anion (O(2)(-)) production, an effect completely abolished by Tiron, a cell-permeable superoxide dismutase (SOD) mimetic and by polyethylene glycol (PEG)-SOD, but not by PEG catalase. Furthermore, insulin-induced O(2)(-) production was attenuated by the NAD(P)H inhibitor apocynin, but not by rotenone or oxypurinol. Inhibition of the phosphatidylinositol 3'-kinase (PI 3'-kinase) pathway with LY294002 blocked insulin-stimulated O(2)(-) production, suggesting a direct involvement of PI 3'-kinase in the activation of NAD(P)H oxidase. The insulin-induced free radical production led to membranous translocation of p47phox and markedly enhanced ERK-1 and -2 activation in human fibroblasts. In conclusion, these findings provided direct evidence that elevated insulin levels generate O(2)(-) by an NAD(P)H-dependent mechanism that involves the activation of PI 3'-kinase and stimulates ERK-1- and ERK-2-dependent pathways. This effect of insulin may contribute to the pathogenesis and progression of cardiovascular disease in the insulin resistance syndrome.
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Affiliation(s)
- Giulio Ceolotto
- Department of Clinical and Experimental Medicine, University of Padua Medical School, Via Giustiniani 2, 35128 Padua, Italy
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138
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Tanaka K, Honda M, Takabatake T. ANTI-APOPTOTIC EFFECT OF ATORVASTATIN, A 3-HYDROXY-3-METHYLGLUTARYL COENZYME A REDUCTASE INHIBITOR, ON CARDIAC MYOCYTES THROUGH PROTEIN KINASE C ACTIVATION. Clin Exp Pharmacol Physiol 2004; 31:360-4. [PMID: 15191412 DOI: 10.1111/j.1440-1681.2004.04010.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Pleiotropic effects of statins, which are independent of lipid lowering, have been reported. In the present study, we examined the effect of a statin on apoptosis of adult rat cultured cardiac myocytes. We used the protein kinase C (PKC) inhibitors staurosporine (1 micro mol/L), chelerythrine (10 micro mol/L) and rottlerin (5 micro mol/L) to induce myocyte apoptosis. The effect of atorvastatin (10(-7) g/mL), a statin, on myocyte apoptosis induced by these PKC inhibitors was examined. All these PKC inhibitors markedly increased the percentage of terminal deoxyribonucleotidyl transferase-mediated dUTP-digoxigenin nick end-labeling (TUNEL)-positive myocytes. This increase was significantly suppressed by atorvastatin treatment. Both chelerythrine and rottlerin induced subcellular translocation of PKCdelta and elevated caspase-3 activity in myocytes. The changes in the subcellular distribution of PKCdelta and caspase-3 activity induced by these PKC inhibitors were suppressed by atorvastatin treatment. The results of the present study suggest that the inhibitory effect of atorvastatin on apoptosis of adult rat cardiac myocytes induced by the PKC inhibitors is through activation of PKCdelta pathway.
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Affiliation(s)
- Koichi Tanaka
- The 4th Department of Internal Medicine, Shimane Medical University, Shimane, Japan
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139
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Zhang X, Li SY, Brown RA, Ren J. Ethanol and acetaldehyde in alcoholic cardiomyopathy: from bad to ugly en route to oxidative stress. Alcohol 2004; 32:175-86. [PMID: 15282111 DOI: 10.1016/j.alcohol.2004.01.005] [Citation(s) in RCA: 86] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2003] [Revised: 01/21/2004] [Accepted: 01/23/2004] [Indexed: 10/26/2022]
Abstract
Alcoholic cardiomyopathy is characterized by cardiomegaly, disruptions of myofibrillary architecture, reduced myocardial contractility, decreased ejection fraction, and enhanced risk of stroke and hypertension. Although several mechanisms have been postulated for alcoholic cardiomyopathy, including oxidative damage, accumulation of triglycerides, altered fatty acid extraction, decreased myofilament Ca(2+) sensitivity, and impaired protein synthesis, neither the mechanism nor the ultimate toxin has been unveiled. Primary candidates acting as specific toxins of myocardial tissue are ethanol; its first and major metabolic product, acetaldehyde; and fatty acid ethyl esters. Acetaldehyde has been demonstrated to impair directly cardiac contractile function, disrupt cardiac excitation-contractile coupling, and contribute to oxidative damage and lipid peroxidation. Acetaldehyde-elicited cardiac dysfunction may be mediated through cytochrome P450 oxidase, xanthine oxidase, and the stress-signaling cascade. Unfortunately, the most direct approach that can be used to examine toxicity is hampered by the fact that direct intake of acetaldehyde is highly toxic and unsuitable for long-term study. To overcome this obstacle, transgenic mice have been used to alter artificially ethanol/acetaldehyde metabolism, resulting in elevated acetaldehyde concentrations after ethanol ingestion. In this review, we summarize results obtained with the use of transgenic animal models to elucidate the role of acetaldehyde in the mechanism of action in alcoholic cardiomyopathy.
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Affiliation(s)
- Xiaochun Zhang
- Division of Pharmaceutical Sciences, Graduate Neuroscience Program, Center for Cardiovascular Research and Alternative Medicine, University of Wyoming College of Health Sciences, Laramie, WY 82071-3375, USA
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140
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Maytin M, Siwik DA, Ito M, Xiao L, Sawyer DB, Liao R, Colucci WS. Pressure Overload–Induced Myocardial Hypertrophy in Mice Does Not Require gp91
phox. Circulation 2004; 109:1168-71. [PMID: 14981002 DOI: 10.1161/01.cir.0000117229.60628.2f] [Citation(s) in RCA: 74] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Background—
Reactive oxygen species (ROS) may mediate pressure overload–induced myocardial hypertrophy. NADPH oxidase may be involved in this process, because its expression and activity are upregulated by pressure overload and because myocardial hypertrophy caused by a subpressor infusion of angiotensin is attenuated in mice deficient in the gp91
phox
catalytic subunit of NADPH oxidase.
Methods and Results—
To test the role of NADPH oxidase–dependent ROS in mediating pressure overload–induced myocardial hypertrophy, we subjected transgenic mice lacking gp91
phox
to chronic pressure overload caused by constriction of the ascending aorta. Contrary to our hypothesis, neither myocardial hypertrophy nor NADPH-dependent superoxide generation was decreased in gp91
phox
-deficient mice after aortic constriction. Aortic constriction caused an exaggerated increase in p22
phox
and p47
phox
mRNA in gp91
phox
-deficient mice.
Conclusions—
These results indicate that gp91
phox
is not necessary for pressure overload–induced hypertrophy in the mouse and suggest the involvement of another source of ROS, possibly an NADPH oxidase that does not require the gp91
phox
subunit.
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Affiliation(s)
- Melanie Maytin
- Department of Medicine, Cardiovascular Section, Boston University Medical Center, and Whitaker Cardiovascular Institute, Boston University School of Medicine, Boston, Mass 02118, USA
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141
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Marczin N, El-Habashi N, Hoare GS, Bundy RE, Yacoub M. Antioxidants in myocardial ischemia-reperfusion injury: therapeutic potential and basic mechanisms. Arch Biochem Biophys 2004; 420:222-36. [PMID: 14654061 DOI: 10.1016/j.abb.2003.08.037] [Citation(s) in RCA: 112] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Oxidative stress is a constant threat to all living organisms and an immense repertoire of cellular defense systems is being employed by most pro- and eukaryotic systems to eliminate or to attenuate oxidative stress. Ischemia and reperfusion is characterized by both a significant oxidative stress and characteristic changes in the antioxidant defense. By focusing on this antioxidant response of the cardiovascular system in the setting of ischemia-reperfusion injury, the aim of this review was threefold. First, based on recent animal experiments and clinical studies we shall discuss how endogenous antioxidants respond to oxidative stress during ischemia-reperfusion injury and highlight the results of recent trials on the ability of antioxidants to modulate ischemia-reperfusion injury. In this aspect, we will particularly focus on the emerging concept that various lines of antioxidant defenses do not act individually but are linked to each other in a systematic relationship as part of an antioxidant network. It is well known that enzymatic mechanisms are important components of the endogenous antioxidant repertoire; however, the relative importance of the different enzyme systems and isoforms has been much debated. The second part will focus on recent suggestions attributing a potentially key role of mitochondrial MnSOD in cardiac ischemia-reperfusion injury. Finally, the third part of the review will critically examine how endogenous antioxidants might regulate the complex signal transduction pathways of cellular activation with particular attention to the NF-kappaB and MAPK systems that appears to determine outcome of injury, survival, and adaptation.
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Affiliation(s)
- Nándor Marczin
- Department of Cardiothoracic Surgery, Imperial College London, Faculty of Medicine, National Heart and Lung Institute at the Heart Science Centre, Harefield Hospital, Harefield, Middlesex UB9 6JH, UK.
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142
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Liu JC, Cheng TH, Lee HM, Lee WS, Shih NL, Chen YL, Chen JJ, Chan P. Inhibitory effect of trilinolein on angiotensin II-induced cardiomyocyte hypertrophy. Eur J Pharmacol 2004; 484:1-8. [PMID: 14729376 DOI: 10.1016/j.ejphar.2003.10.043] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The myocardial protective effects of trilinolein, isolated from the Chinese herb Sanchi (Panax notoginseng), may be related to its antioxidant effects. In the present study, we investigated the effects of trilinolein on angiotensin II-induced cardiomyocyte hypertrophy. Cultured neonatal rat cardiomyocytes were stimulated with angiotensin II, [3H]leucine incorporation and the beta-myosin heavy chain promoter activity were examined. We also examined the effects of trilinolein on angiotensin II-induced intracellular reactive oxygen species generation. Trilinolein significantly inhibited angiotensin II-increased protein synthesis, beta-myosin heavy chain promoter activity, and intracellular reactive oxygen species generation. Antioxidant N-acetylcysteine also decreased angiotensin II-increased protein synthesis and beta-myosin heavy chain promoter activity. Furthermore, trilinolein and N-acetylcysteine decreased angiotensin II- or hydrogen peroxide (H2O2)-activated mitogen-activated protein kinases (MAPKs) phosphorylation, and activator protein-1 (AP-1)- [or nuclear factor-kappaB (NF-kappaB)]-reporter activities. These data indicate that trilinolein inhibits angiotensin II-induced cardiomyocyte hypertrophy and beta-myosin heavy chain promoter activity via attenuation of reactive oxygen species generation.
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Affiliation(s)
- Ju Chi Liu
- Graduate Institute of Medical Sciences, Taipei Medical University, Taipei, Taiwan
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143
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Cheng TH, Liu JC, Lin H, Shih NL, Chen YL, Huang MT, Chan P, Cheng CF, Chen JJ. Inhibitory effect of resveratrol on angiotensin II-induced cardiomyocyte hypertrophy. Naunyn Schmiedebergs Arch Pharmacol 2003; 369:239-44. [PMID: 14663554 DOI: 10.1007/s00210-003-0849-6] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2003] [Accepted: 10/27/2003] [Indexed: 10/26/2022]
Abstract
Resveratrol is proposed to account in part for the protective effect of red wine on the cardiovascular system. Angiotensin II (Ang II) is a potent hypertrophic stimulus in cardiomyocytes. In this study, we determined the effect of resveratrol on Ang II-induced cardiomyocyte hypertrophy. Cultured neonatal rat cardiomyocytes were stimulated with Ang II, and [3H]leucine incorporation and beta-myosin heavy chain (beta-MyHC) promoter activity were examined. Intracellular reactive oxygen species (ROS) were measured by a redox-sensitive fluorescent dye, 2' 7'-dichlorofluorescin diacetate, and the extracellular signal-regulated kinase (ERK) phosphorylation was examined by Western blotting. Resveratrol inhibited Ang II-increased intracellular ROS levels. Furthermore, resveratrol, as well as the antioxidant N-acetyl-cysteine, decreased Ang II- or H2O2-increased protein synthesis, beta-MyHC promoter activity, and ERK phosphorylation. In summary, we demonstrate for the first time that resveratrol inhibits Ang II-induced cardiomyocyte hypertrophy via attenuation of ROS generation.
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MESH Headings
- Acetylcysteine/pharmacology
- Angiotensin II/metabolism
- Angiotensin II/pharmacology
- Animals
- Animals, Newborn
- Antioxidants/pharmacology
- Cells, Cultured
- Hypertrophy/prevention & control
- Leucine/metabolism
- Mitogen-Activated Protein Kinases/metabolism
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Muscle, Smooth, Vascular/pathology
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/metabolism
- Myocytes, Cardiac/pathology
- Myosin Heavy Chains/genetics
- Phosphorylation
- Promoter Regions, Genetic
- Rats
- Rats, Sprague-Dawley
- Reactive Oxygen Species/metabolism
- Resveratrol
- Stilbenes/pharmacology
- Transfection
- Ventricular Myosins/genetics
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Affiliation(s)
- Tzu-Hurng Cheng
- Department of Medicine, Taipei Medical University-Wan Fang Hospital, Taipei, Taiwan, Republic of China
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144
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Liu JC, Chen JJ, Chan P, Cheng CF, Cheng TH. Inhibition of Cyclic Strain-Induced Endothelin-1 Gene Expression by Resveratrol. Hypertension 2003; 42:1198-205. [PMID: 14623829 DOI: 10.1161/01.hyp.0000103162.76220.51] [Citation(s) in RCA: 73] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Resveratrol is a phytoestrogen naturally found in grapes and is among the major constituents of wine thought to have a cardioprotective effect. Endothelin-1 (ET-1) is a potent vasopressor synthesized by endothelial cells both in culture and in vivo. The aims of this study were to test the hypothesis that resveratrol may alter strain-induced ET-1 gene expression and to identify the putative underlying signaling pathways in endothelial cells. We show that resveratrol indeed potently inhibits strain-induced ET-1 secretion, ET-1 mRNA level, and ET-1 promoter activity. Resveratrol also inhibits strain-increased NADPH oxidase activity, reactive oxygen species formation, and extracellular signal–regulated kinases1/2 (ERK1/2) phosphorylation. Furthermore, pretreating cells with resveratrol or antioxidant
N
-acetyl-cysteine decreases strain-increased or hydrogen peroxide–increased ET-1 secretion, ET-1 promoter activity, and ET-1 mRNA and ERK1/2 phosphorylation. Using both the electrophoretic mobility shift assay and a reporter gene assay, resveratrol and
N
-acetyl-cysteine also attenuated the strain-stimulated activator protein-1 binding activity and activator protein-1 reporter activity. In summary, we demonstrate for the first time that resveratrol inhibits strain-induced ET-1 gene expression, partially by interfering with the ERK1/2 pathway through attenuation of reactive oxygen species formation. Thus, this study provides important new insights in the molecular pathways that may contribute to the proposed beneficial effects of resveratrol in the cardiovascular system.
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Affiliation(s)
- Ju-Chi Liu
- Department of Medicine, Taipei Medical University, Wan Fang Hospital, Wen-Shan District, Taipei, Taiwan
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145
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Sabri A, Hughie HH, Lucchesi PA. Regulation of hypertrophic and apoptotic signaling pathways by reactive oxygen species in cardiac myocytes. Antioxid Redox Signal 2003; 5:731-40. [PMID: 14588146 DOI: 10.1089/152308603770380034] [Citation(s) in RCA: 160] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Increasing evidence suggests that oxidative and nitrosative stress play an important role in regulation of cardiac myocyte growth and survival. The cardiovascular system is continuously exposed to both reactive oxygen species (ROS) and nitrogen species (RNS), collectively termed reactive inflammatory species (RIS), and imbalances between the enzymes that regulate their bioavailability are associated with cardiac hypertrophy and the pathogenesis of cardiomyopathies, myocardial infarction and heart failure. It is now clear that RIS act as critical regulators of cardiac myocyte hypertrophy and apoptosis through control of redox-sensitive signaling cascades, such as tyrosine kinases and phosphatases, protein kinase C, and mitogen-activated protein kinases. This review will focus on the mechanisms by which ROS/RNS modulate cardiac myocyte growth and apoptosis induced by neurohormones and cytokines, and will discuss evidence for a role in the pathophysiology of heart failure.
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Affiliation(s)
- Abdelkarim Sabri
- Department of Physiology and Biophysics, University of Alabama Birmingham, Birmingham, AL 35294, USA
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146
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Takeuchi M, Takahashi T, Taga N, Iwasaki T, Ohe K, Shimizu H, Suzuki T, Nakatsuka H, Yokoyama M, Sano S, Akagi R, Morita K. Right Ventricle of Patients Undergoing Congenital Cardiac Surgery Differentially Expresses Haem Oxygenase-1 and Heat Shock Protein 70 Genes. J Int Med Res 2003; 31:413-7. [PMID: 14587309 DOI: 10.1177/147323000303100509] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Reactive oxygen species are implicated in the pathogenesis of cardiac hypertrophy. Haem oxygenase-1 (HO-1), the rate-limiting enzyme in haem catabolism, is induced by oxidative stress and confers protection against oxidative tissue injuries. We used Northern blotting to examine expression of HO-1 and heat shock protein 70 (HSP70) in the hypertrophic cardiac muscle of eight patients (one infant and seven children) who underwent surgery for congenital heart disease. Levels of HO-1 and HSP70 mRNA were significantly increased in all specimens, but the orders of magnitude of the increases were different, suggesting that the genes expressing HO-1 and HSP70 are regulated separately.
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Affiliation(s)
- M Takeuchi
- Department of Anaesthesiology and Resuscitology, Okayama University Medical School, Japan
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147
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Crawford RM, Jovanović S, Budas GR, Davies AM, Lad H, Wenger RH, Robertson KA, Roy DJ, Ranki HJ, Jovanović A. Chronic mild hypoxia protects heart-derived H9c2 cells against acute hypoxia/reoxygenation by regulating expression of the SUR2A subunit of the ATP-sensitive K+ channel. J Biol Chem 2003; 278:31444-55. [PMID: 12791696 PMCID: PMC2134977 DOI: 10.1074/jbc.m303051200] [Citation(s) in RCA: 76] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Chronic exposure to lower oxygen tension may increase cellular resistance to different types of acute metabolic stress. Here, we show that 24-h-long exposure to slightly decreased oxygen tension (partial pressure of oxygen (PO2) of 100 mm Hg instead of normal 144 mm Hg) confers resistance against acute hypoxia/reoxygenation-induced Ca2+ loading in heart-derived H9c2 cells. The number of ATP-sensitive K+ (K(ATP)) channels were increased in cells exposed to PO2 = 100 mm Hg relative to cells exposed to PO2 = 144 mm Hg. This was due to an increase in transcription of SUR2A, a K(ATP) channel regulatory subunit, but not Kir6.2, a K(ATP) channel pore-forming subunit. PO2 = 100 mm Hg also increased the SUR2 gene promoter activity. Experiments with cells overexpressing wild type of hypoxia-inducible factor (HIF)-1alpha and dominant negative HIF-1beta suggested that the HIF-1-signaling pathway did not participate in observed PO2-mediated regulation of SUR2A expression. On the other hand, NADH inhibited the effect of PO2 = 100 mm Hg but not the effect of PO2 = 20 mm Hg. LY 294002 and PD 184 352 prevented PO2-mediated regulation of K(ATP) channels, whereas rapamycin was without any effect. HMR 1098 inhibited the cytoprotective effect of PO2 = 100 mm Hg, and a decrease of PO2 from 144 to 100 mm Hg did not change the expression of any other gene, including those involved in stress and hypoxic response, as revealed by Affymetrix high density oligonucleotide arrays. We conclude that slight hypoxia activates HIF-1alpha-independent signaling cascade leading to an increase in SUR2A protein, a higher density of K(ATP) channels, and a cellular phenotype more resistant to acute metabolic stress.
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Affiliation(s)
- Russell M. Crawford
- Maternal and Child Health Sciences, Tayside Institute of Child Health, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, United Kingdom
| | - Sofija Jovanović
- Maternal and Child Health Sciences, Tayside Institute of Child Health, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, United Kingdom
| | - Grant R. Budas
- Maternal and Child Health Sciences, Tayside Institute of Child Health, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, United Kingdom
| | - Anthony M. Davies
- Maternal and Child Health Sciences, Tayside Institute of Child Health, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, United Kingdom
| | - Harish Lad
- Maternal and Child Health Sciences, Tayside Institute of Child Health, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, United Kingdom
| | - Roland H. Wenger
- Carl-Ludwig-Institute of Physiology, University of Leipzig, D-04103 Leipzig, Germany
| | - Kevin A. Robertson
- Scottish Centre for Genomic Technology and Informatics, The University of Edinburgh, Summerhall EH9 1QH, United Kingdom
| | - Douglas J. Roy
- Scottish Centre for Genomic Technology and Informatics, The University of Edinburgh, Summerhall EH9 1QH, United Kingdom
| | - Harri J. Ranki
- Maternal and Child Health Sciences, Tayside Institute of Child Health, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, United Kingdom
| | - Aleksandar Jovanović
- Maternal and Child Health Sciences, Tayside Institute of Child Health, Ninewells Hospital and Medical School, University of Dundee, Dundee DD1 9SY, United Kingdom
- To whom correspondence should be addressed: Tayside Inst. of Child Health, Ninewells Hospital and Medical School, University of Dundee, Dundee, DD1 9SY, UK. Tel.: 44-0-1382-496-269; Fax: 44-0-1382-632-597; E-mail:
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148
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Cheng CM, Hong HJ, Liu JC, Shih NL, Juan SH, Loh SH, Chan P, Chen JJ, Cheng TH. Crucial role of extracellular signal-regulated kinase pathway in reactive oxygen species-mediated endothelin-1 gene expression induced by endothelin-1 in rat cardiac fibroblasts. Mol Pharmacol 2003; 63:1002-11. [PMID: 12695528 DOI: 10.1124/mol.63.5.1002] [Citation(s) in RCA: 58] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Endothelin-1 (ET-1) has been implicated in fibroblast proliferation. However, the mechanism involving ET-1 is not clear. The present study was performed to examine the role of endogenous ET-1 in ET-1-stimulated fibroblast proliferation and to investigate the regulatory mechanism of ET-1-induced ET-1 gene expression in cardiac fibroblasts. Both ET(A) receptor antagonist [(hexahydro-1H-azepinyl)carbonyl-Leu-D-Trp-D-OH (BQ485)] and endothelin-converting enzyme inhibitor (phosphoramidon) inhibited the increased DNA synthesis caused by ET-1. ET-1 gene was induced by ET-1, as revealed with Northern blotting and ET-1 promoter activity assay. ET-1 increased intracellular reactive oxygen species (ROS), which were significantly inhibited by BQ485 and antioxidants. Antioxidants suppressed ET-1 gene expression and DNA synthesis stimulated by ET-1. ET-1 activated mitogen-activated protein kinases (MAPK), including extracellular signal-regulated kinase (ERK), p38 MAPK, and c-Jun N-terminal kinase, which were significantly inhibited by antioxidants. Only ERK inhibitor U0126 could inhibit ET-1-induced transcription of the ET-1 gene. Cotransfection of dominant-negative mutant of Ras, Raf, and MEK1 decreased the ET-1-induced increase in ET-1 transcription, suggesting that the Ras-Raf-ERK pathway is required for ET-1 action. Truncation and mutational analysis of the ET-1 gene promoter showed that the activator protein-1 (AP-1) binding site was an important cis-element in ET-1-induced ET-1 gene expression. Antioxidants attenuated the ET-1-stimulated AP-1 binding activity. Our data suggest that ROS were involved in ET-1-induced fibroblast proliferation and mediated ET-1-induced activation of ERK pathways, which culminated in ET-1 gene expression.
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Affiliation(s)
- Cheng-Ming Cheng
- Department of Obstetrics and Gynecology, Changhua Christian Hospital, Changhua, Taiwan, ROC
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149
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Shah BH, Catt KJ. A central role of EGF receptor transactivation in angiotensin II -induced cardiac hypertrophy. Trends Pharmacol Sci 2003; 24:239-44. [PMID: 12767723 DOI: 10.1016/s0165-6147(03)00079-8] [Citation(s) in RCA: 87] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
In addition to their physiological roles in the cardiovascular system (CVS), G-protein-coupled receptor (GPCR) agonists such as noradrenaline, endothelin-1 and angiotensin II (Ang II) are known to be involved in the development of cardiac hypertrophy. Recent studies using targeted overexpression of the angiotensin AT(1) receptor in cardiomyocytes suggest that Ang II can directly promote the growth of cardiomyocytes via transactivation of the epidermal growth factor (EGF) receptor and subsequent activation of mitogen-activated protein kinases (MAPKs). This process is mediated by the production of heparin-binding EGF (HB-EGF) by metalloproteases. Blockade of the generation of HB-EGF by metalloprotease inhibitors, or abrogation of EGF receptor kinase activity by selective pharmacological inhibitors or antisense oligonucleotides, protects against Ang II-mediated cardiac hypertrophy. These approaches offer a potential therapeutic strategy to prevent cardiac remodeling and hypertrophy, and possibly prevent progression to heart failure.
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Affiliation(s)
- Bukhtiar H Shah
- Endocrinology and Reproduction Research Branch, National Institute of Child Health and Human Development, National Institutes of Health, Bethesda, MD 20892-4510, USA.
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150
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Laplante MA, Wu R, El Midaoui A, de Champlain J. NAD(P)H oxidase activation by angiotensin II is dependent on p42/44 ERK-MAPK pathway activation in rat's vascular smooth muscle cells. J Hypertens 2003; 21:927-36. [PMID: 12714867 DOI: 10.1097/00004872-200305000-00017] [Citation(s) in RCA: 54] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
OBJECTIVE To determine whether the activation of nicotinamide adenine dinucleotide phosphate (NAD(P)H) oxidase and the increase of superoxide anion production by angiotensin II is dependent upon the activation of the ERK-MAPK pathway. METHODS Hypertension was induced in Sprague-Dawley rats by infusing angiotensin II (200 ng/kg per min) through osmotic pumps for 12 days. The effects of treatments including an angiotensin II type 1 (AT(1)) blocker losartan (20 mg/kg per day), a tyrosine kinase inhibitor genistein (1.6 microg/kg per min), a specific ERK-MAPK inhibitor, PD98059 (2 mg/kg per day) and an antioxidant alpha-lipoic acid (500 mg/kg of chow) were evaluated during angiotensin infusion. The aortic superoxide anion production, the ERK-MAPK pathway activity and the systolic blood pressure (SBP), were measured following those treatments. RESULTS Increases in the concentration of the superoxide anion (1622 to 3719 cpm), in NAD(P)H activity (107%) and in the ERK-MAPK activity (3.6-fold) in the aorta as well as a rise in the arterial pressure (136 to 184 mmHg) were observed 12 days after initiating the treatments (P < 0.05). When the angiotensin-treated rats were treated either with losartan, genistein, PD98059 or alpha-lipoic acid, increases in superoxide anion production, in NAD(P)H oxidase activity, in ERK-MAPK activity and in blood pressure were attenuated. A correlation between the superoxide anion production and the ERK-MAPK activity was also observed. CONCLUSIONS The present study suggests that the NAD(P)H-dependent increase of the superoxide anion production in the vascular tissue following a treatment with angiotensin II is dependent on the activation of the ERK-MAPK pathway.
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MESH Headings
- Angiotensin II/pharmacology
- Animals
- Antihypertensive Agents/pharmacology
- Antioxidants/pharmacology
- Aorta/cytology
- Aorta/drug effects
- Aorta/metabolism
- Blood Pressure/drug effects
- Disease Models, Animal
- Endothelium, Vascular/cytology
- Endothelium, Vascular/drug effects
- Endothelium, Vascular/metabolism
- Enzyme Activation/drug effects
- Enzyme Activation/physiology
- Enzyme Inhibitors/pharmacology
- Flavonoids/antagonists & inhibitors
- Genistein/antagonists & inhibitors
- Hypertension/metabolism
- Losartan/pharmacology
- Male
- Mitogen-Activated Protein Kinase 1/drug effects
- Mitogen-Activated Protein Kinase 1/metabolism
- Mitogen-Activated Protein Kinase 3
- Mitogen-Activated Protein Kinases/drug effects
- Mitogen-Activated Protein Kinases/metabolism
- Models, Cardiovascular
- Muscle, Smooth, Vascular/cytology
- Muscle, Smooth, Vascular/drug effects
- Muscle, Smooth, Vascular/metabolism
- Myocytes, Smooth Muscle/drug effects
- Myocytes, Smooth Muscle/enzymology
- NADPH Oxidases/drug effects
- NADPH Oxidases/metabolism
- Rats
- Rats, Sprague-Dawley
- Superoxides/metabolism
- Thioctic Acid/pharmacology
- Vasoconstrictor Agents/pharmacology
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Affiliation(s)
- Marc-André Laplante
- Department of Physiology, Faculty of Medicine, University of Montreal, Montreal, Quebec, Canada
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