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Kiyomoto K, Matsuo I, Suita K, Ohnuki Y, Ishikawa M, Ito A, Mototani Y, Tsunoda M, Morii A, Nariyama M, Hayakawa Y, Amitani Y, Gomi K, Okumura S. Oral angiotensin-converting enzyme inhibitor captopril protects the heart from Porphyromonas gingivalis LPS-induced cardiac dysfunction in mice. PLoS One 2023; 18:e0292624. [PMID: 37983238 PMCID: PMC10659197 DOI: 10.1371/journal.pone.0292624] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 09/25/2023] [Indexed: 11/22/2023] Open
Abstract
Although angiotensin converting enzyme (ACE) inhibitors are considered useful for the treatment of human heart failure, some experimental failing-heart models have shown little beneficial effect of ACE inhibitors in animals with poor oral health, particularly periodontitis. In this study, we examined the effects of the ACE inhibitor captopril (Cap; 0.1 mg/mL in drinking water) on cardiac dysfunction in mice treated with Porphyromonas gingivalis lipopolysaccharide (PG-LPS) at a dose (0.8 mg/kg/day) equivalent to the circulating level in patients with periodontal disease. Mice were divided into four groups: 1) Control, 2) PG-LPS, 3) Cap, and 4) PG-LPS + Cap. After1 week, we evaluated cardiac function by echocardiography. The left ventricular ejection fraction was significantly decreased in PG-LPS-treated mice compared to the control (from 66 ± 1.8 to 59 ± 2.5%), while Cap ameliorated the dysfunction (63 ± 1.1%). The area of cardiac fibrosis was significantly increased (approximately 2.9-fold) and the number of apoptotic myocytes was significantly increased (approximately 5.6-fold) in the heart of PG-LPS-treated group versus the control, and these changes were suppressed by Cap. The impairment of cardiac function in PG-LPS-treated mice was associated with protein kinase C δ phosphorylation (Tyr-311), leading to upregulation of NADPH oxidase 4 and xanthine oxidase, and calmodulin kinase II phosphorylation (Thr-286) with increased phospholamban phosphorylation (Thr-17). These changes were also suppressed by Cap. Our results suggest that the renin-angiotensin system might play an important role in the development of cardiac diseases induced by PG-LPS.
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Affiliation(s)
- Kenichi Kiyomoto
- Department of Physiology, Tsurumi University School of Dental Medicine, Yokohama, Japan
- Department of Periodontology, Tsurumi University School of Dental Medicine, Yokohama, Japan
| | - Ichiro Matsuo
- Department of Periodontology, Tsurumi University School of Dental Medicine, Yokohama, Japan
| | - Kenji Suita
- Department of Physiology, Tsurumi University School of Dental Medicine, Yokohama, Japan
| | - Yoshiki Ohnuki
- Department of Physiology, Tsurumi University School of Dental Medicine, Yokohama, Japan
| | - Misao Ishikawa
- Department of Oral Anatomy, Tsurumi University School of Dental Medicine, Yokohama, Japan
| | - Aiko Ito
- Department of Orthodontology, Tsurumi University School of Dental Medicine, Yokohama, Japan
| | - Yasumasa Mototani
- Department of Physiology, Tsurumi University School of Dental Medicine, Yokohama, Japan
| | - Michinori Tsunoda
- Department of Physiology, Tsurumi University School of Dental Medicine, Yokohama, Japan
- Department of Periodontology, Tsurumi University School of Dental Medicine, Yokohama, Japan
| | - Akinaka Morii
- Department of Physiology, Tsurumi University School of Dental Medicine, Yokohama, Japan
- Department of Periodontology, Tsurumi University School of Dental Medicine, Yokohama, Japan
| | - Megumi Nariyama
- Department of Pediatric Dentistry, Tsurumi University School of Dental Medicine, Yokohama, Japan
| | - Yoshio Hayakawa
- Department of Dental Anesthesiology, Tsurumi University School of Dental Medicine, Yokohama, Japan
| | - Yasuharu Amitani
- Department of Mathematics, Tsurumi University School of Dental Medicine, Yokohama, Japan
| | - Kazuhiro Gomi
- Department of Periodontology, Tsurumi University School of Dental Medicine, Yokohama, Japan
| | - Satoshi Okumura
- Department of Physiology, Tsurumi University School of Dental Medicine, Yokohama, Japan
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Titus AS, V H, Kailasam S. Coordinated regulation of cell survival and cell cycle pathways by DDR2-dependent SRF transcription factor in cardiac fibroblasts. Am J Physiol Heart Circ Physiol 2020; 318:H1538-H1558. [PMID: 32412792 DOI: 10.1152/ajpheart.00740.2019] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Relative resistance to apoptosis and the ability to proliferate and produce a collagen-rich scar determine the critical role of cardiac fibroblasts in wound healing and tissue remodeling following myocardial injury. Identification of cardiac fibroblast-specific factors and mechanisms underlying these aspects of cardiac fibroblast function is therefore of considerable scientific and clinical interest. In the present study, gene knockdown and overexpression approaches and promoter binding assays showed that discoidin domain receptor 2 (DDR2), a mesenchymal cell-specific collagen receptor tyrosine kinase localized predominantly in fibroblasts in the heart, acts via ERK1/2 MAPK-activated serum response factor (SRF) transcription factor to enhance the expression of antiapoptotic cIAP2 in cardiac fibroblasts, conferring resistance against oxidative injury. Furthermore, DDR2 was found to act via ERK1/2 MAPK-activated SRF to transcriptionally upregulate Skp2 that in turn facilitated post-translational degradation of p27, the cyclin-dependent kinase inhibitor that causes cell cycle arrest, to promote G1-S transition, as evidenced by Rb phosphorylation, increased proliferating cell nuclear antigen (PCNA) levels, and flow cytometry. DDR2-dependent ERK1/2 MAPK activation also suppressed forkhead box O 3a (FoxO3a)-mediated transcriptional induction of p27. Inhibition of the binding of collagen type I to DDR2 using WRG-28 indicated the obligate role of collagen type I in the activation of DDR2 and its regulatory role in cell survival and cell cycle protein expression. Notably, DDR2 levels positively correlated with SRF, cIAP2, and PCNA levels in cardiac fibroblasts from spontaneously hypertensive rats. To conclude, DDR2-mediated ERK1/2 MAPK activation facilitates coordinated regulation of cell survival and cell cycle progression in cardiac fibroblasts via SRF.NEW & NOTEWORTHY Relative resistance to apoptosis and the ability to proliferate and produce a collagen-rich scar enable cardiac fibroblasts to play a central role in myocardial response to injury. This study reports novel findings that mitogen-stimulated cardiac fibroblasts exploit a common regulatory mechanism involving collagen receptor (DDR2)-dependent activation of ERK1/2 MAPK and serum response factor to achieve coordinated regulation of apoptosis resistance and cell cycle progression, which could facilitate their survival and function in the injured myocardium.
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Affiliation(s)
- Allen Sam Titus
- Division of Cellular and Molecular Cardiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India
| | - Harikrishnan V
- Division of Cellular and Molecular Cardiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India
| | - Shivakumar Kailasam
- Division of Cellular and Molecular Cardiology, Sree Chitra Tirunal Institute for Medical Sciences and Technology, Trivandrum, India
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Coppini R, Santini L, Palandri C, Sartiani L, Cerbai E, Raimondi L. Pharmacological Inhibition of Serine Proteases to Reduce Cardiac Inflammation and Fibrosis in Atrial Fibrillation. Front Pharmacol 2019; 10:1420. [PMID: 31956307 PMCID: PMC6951407 DOI: 10.3389/fphar.2019.01420] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2019] [Accepted: 11/07/2019] [Indexed: 12/18/2022] Open
Abstract
Systemic inflammation correlates with an increased risk of atrial fibrillation (AF) and thrombogenesis. Systemic inflammation alters vessel permeability, allowing inflammatory and immune cell migration toward target organs, including the heart. Among inflammatory cells infiltrating the atria, macrophages and mast cell have recently attracted the interest of basic researchers due to the pathogenic mechanisms triggered by their activation. This chemotactic invasion is likely implicated in short- and long-term changes in cardiac cell-to-cell communication and in triggering fibrous tissue accumulation in the atrial myocardium and electrophysiological re-arrangements of atrial cardiomyocytes, thus favoring the onset and progression of AF. Serine proteases are a large and heterogeneous class of proteases involved in several processes that are important for cardiac function and are involved in cardiac diseases, such as (i) coagulation, (ii) fibrinolysis, (iii) extracellular matrix degradation, (iv) activation of receptors (i.e., protease-activated receptors [PPARs]), and (v) modulation of the activity of endogenous signals. The recognition of serine proteases substrates and their involvement in inflammatory/profibrotic mechanisms allowed the identification of novel cardio-protective mechanisms for commonly used drugs that inhibit serine proteases. The aim of this review is to summarize knowledge on the role of inflammation and fibrosis as determinants of AF. Moreover, we will recapitulate current findings on the role of serine proteases in the pathogenesis of AF and the possible beneficial effects of drugs inhibiting serine proteases in reducing the risk of AF through decrease of cardiac inflammation and fibrosis. These drugs include thrombin and factor Xa inhibitors (used as oral anticoagulants), dipeptidyl-peptidase 4 (DPP4) inhibitors, used for type-2 diabetes, as well as novel experimental inhibitors of mast cell chymases.
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Affiliation(s)
- Raffaele Coppini
- Section of Pharmacology, Department of Neurology, Psychology, Drug Sciences and Child Health, University of Florence, Florence, Italy
| | - Lorenzo Santini
- Section of Pharmacology, Department of Neurology, Psychology, Drug Sciences and Child Health, University of Florence, Florence, Italy
| | - Chiara Palandri
- Section of Pharmacology, Department of Neurology, Psychology, Drug Sciences and Child Health, University of Florence, Florence, Italy
| | - Laura Sartiani
- Section of Pharmacology, Department of Neurology, Psychology, Drug Sciences and Child Health, University of Florence, Florence, Italy
| | - Elisabetta Cerbai
- Section of Pharmacology, Department of Neurology, Psychology, Drug Sciences and Child Health, University of Florence, Florence, Italy
| | - Laura Raimondi
- Section of Pharmacology, Department of Neurology, Psychology, Drug Sciences and Child Health, University of Florence, Florence, Italy
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Michel MC, Brunner HR, Foster C, Huo Y. Angiotensin II type 1 receptor antagonists in animal models of vascular, cardiac, metabolic and renal disease. Pharmacol Ther 2016; 164:1-81. [PMID: 27130806 DOI: 10.1016/j.pharmthera.2016.03.019] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Accepted: 03/30/2016] [Indexed: 02/07/2023]
Abstract
We have reviewed the effects of angiotensin II type 1 receptor antagonists (ARBs) in various animal models of hypertension, atherosclerosis, cardiac function, hypertrophy and fibrosis, glucose and lipid metabolism, and renal function and morphology. Those of azilsartan and telmisartan have been included comprehensively whereas those of other ARBs have been included systematically but without intention of completeness. ARBs as a class lower blood pressure in established hypertension and prevent hypertension development in all applicable animal models except those with a markedly suppressed renin-angiotensin system; blood pressure lowering even persists for a considerable time after discontinuation of treatment. This translates into a reduced mortality, particularly in models exhibiting marked hypertension. The retrieved data on vascular, cardiac and renal function and morphology as well as on glucose and lipid metabolism are discussed to address three main questions: 1. Can ARB effects on blood vessels, heart, kidney and metabolic function be explained by blood pressure lowering alone or are they additionally directly related to blockade of the renin-angiotensin system? 2. Are they shared by other inhibitors of the renin-angiotensin system, e.g. angiotensin converting enzyme inhibitors? 3. Are some effects specific for one or more compounds within the ARB class? Taken together these data profile ARBs as a drug class with unique properties that have beneficial effects far beyond those on blood pressure reduction and, in some cases distinct from those of angiotensin converting enzyme inhibitors. The clinical relevance of angiotensin receptor-independent effects of some ARBs remains to be determined.
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Affiliation(s)
- Martin C Michel
- Dept. Pharmacology, Johannes Gutenberg University, Mainz, Germany; Dept. Translational Medicine & Clinical Pharmacology, Boehringer Ingelheim, Ingelheim, Germany.
| | | | - Carolyn Foster
- Retiree from Dept. of Research Networking, Boehringer Ingelheim Pharmaceuticals Inc., Ridgefield, CT, USA
| | - Yong Huo
- Dept. Cardiology & Heart Center, Peking University First Hospital, Beijing, PR China
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Wang H, Teng Y, Wang K, Xia Z, Tian Y, Li C. The M235T polymorphism in the angiotensinogen gene and atrial fibrillation: A meta-analysis. J Renin Angiotensin Aldosterone Syst 2014; 16:647-52. [PMID: 25172907 DOI: 10.1177/1470320313513482] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2013] [Accepted: 08/21/2013] [Indexed: 11/17/2022] Open
Affiliation(s)
- HuiXuan Wang
- Laboratory Medicine Department, Kunming General Hospital of PLA, Kunming, China
| | - Yi Teng
- Laboratory Medicine Department, Kunming General Hospital of PLA, Kunming, China
| | - Ke Wang
- Laboratory Medicine Department, Kunming General Hospital of PLA, Kunming, China
| | - ZhengWu Xia
- Laboratory Medicine Department, Kunming General Hospital of PLA, Kunming, China
| | - YuanYuan Tian
- Laboratory Medicine Department, Kunming General Hospital of PLA, Kunming, China
| | - CuiJuan Li
- Laboratory Medicine Department, Kunming General Hospital of PLA, Kunming, China
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Mishra A, Srivastava A, Mittal T, Garg N, Mittal B. Genetic predisposition to left ventricular dysfunction: a multigenic and multi-analytical approach. Gene 2014; 546:309-17. [DOI: 10.1016/j.gene.2014.05.060] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 05/19/2014] [Accepted: 05/26/2014] [Indexed: 12/29/2022]
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Artom N, Montecucco F, Mach F, Dallegri F, Pende A. Angiotensin II receptor antagonists in acute coronary syndromes. Eur J Clin Invest 2014; 44:219-30. [PMID: 24289238 DOI: 10.1111/eci.12198] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Accepted: 11/01/2013] [Indexed: 12/25/2022]
Abstract
BACKGROUND It is well known that inappropriate or exaggerated activity of the renin-angiotensin system might contribute to the development of systemic hypertension with consequent organ injury and associated increased risk of acute cardiovascular (CV) diseases. This review will discuss evidence form basic research and clinical studies, investigating the efficacy of angiotensin II receptor blockers (ARBs) in the management of acute coronary syndromes (ACS). MATERIALS AND METHODS This narrative review is based on the material found on MEDLINE and PubMed up to June 2013. We looked for the terms 'angiotensin, AT1 receptor, ACE inhibitors' in combination with 'acute coronary syndromes, acute myocardial infarction, pathophysiology'. RESULTS Preclinical studies showed relevant protective effects of ARBs to reduce adverse cardiac remodelling in animal models of acute cardiac ischaemia. However, although recommended in Consensus guidelines as a good alternative to angiotensin-converting enzyme inhibitors (ACEIs), clinical studies did not confirm a superior efficacy of the ARBs as compared to ACEIs. As a matter of fact for some authors, these drugs might potentially have deleterious effects increasing the CV risk. CONCLUSIONS Emerging evidence from clinical trials suggests that the use of ARBs in ACS might be controversial, and caution should be used for their clinical use to replace ACEIs in ACS.
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Affiliation(s)
- Nathan Artom
- First Clinic of Internal Medicine, Department of Internal Medicine, University of Genoa School of Medicine, IRCCS Azienda Ospedaliera Universitaria San Martino-IST Istituto Nazionale per la Ricerca sul Cancro, Genoa, Italy
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Zhang H, Zhong H, Everett TH, Wilson E, Chang R, Zeng D, Belardinelli L, Olgin JE. Blockade of A2B adenosine receptor reduces left ventricular dysfunction and ventricular arrhythmias 1 week after myocardial infarction in the rat model. Heart Rhythm 2013; 11:101-9. [PMID: 24120874 DOI: 10.1016/j.hrthm.2013.10.023] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/17/2013] [Indexed: 11/30/2022]
Abstract
BACKGROUND Remodeling occurs after myocardial infarction (MI), leading to fibrosis, dysfunction, and ventricular tachycardias (VTs). Adenosine via the A2B adenosine receptor (A2BAdoR) has been implicated in promoting fibrosis. OBJECTIVE To determine the effects of GS-6201, a potent antagonist of the A2BAdoR, on arrhythmogenic and functional cardiac remodeling after MI. METHODS Rats underwent ischemia-reperfusion MI and were randomized into 4 groups: control (treated with vehicle), angiotensin-converting enzyme inhibitor (treated with enalapril 1 day after MI), GS-6201-1d (treated with GS-6201 1 day after MI), GS-6201-1w (treated with GS-6201 administered 1 week after MI) . Echocardiography was performed at baseline and 1 and 5 weeks after MI. Optical mapping, VT inducibility, and histologic analysis were conducted at follow-up. RESULTS Treatment with the angiotensin-converting enzyme inhibitor improved ejection fraction (57.8% ± 2.5% vs 43.3% ± 1.7% in control; P < .01), but had no effect on VT inducibility. Treatment with GS-6201 improved ejection fraction (55.6% ± 2.6% vs 43.3% ± 1.7% in control; P < .01) and decreased VT inducibility (9.1% vs 68.4% in control; P < .05). Conduction velocities were significantly higher at border and infarct zones in hearts of rats treated with GS-6201 than in those of other groups. The conduction heterogeneity index was also significantly lower in hearts of rats treated with GS-6201. Histologic analysis showed that while both GS-6201 and enalapril decreased fibrosis in the noninfarct zone, only GS-6201 reduced the heterogeneity of fibrosis at the border, which is consistent with its effect on VT reduction. CONCLUSIONS Treatment with an A2BAdoR antagonist at 1 week results in the improvement in cardiac function and decreased substrate for VT. The inhibition of fibrogenesis by A2BAdoR antagonists may be a new target for the prevention of adverse remodeling after MI.
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Affiliation(s)
- Hao Zhang
- Cardiac Electrophysiology and Cardiovascular Research Institute, University of California, San Francisco, California
| | | | - Thomas H Everett
- Cardiac Electrophysiology and Cardiovascular Research Institute, University of California, San Francisco, California
| | - Emily Wilson
- Cardiac Electrophysiology and Cardiovascular Research Institute, University of California, San Francisco, California
| | - Roger Chang
- Cardiac Electrophysiology and Cardiovascular Research Institute, University of California, San Francisco, California
| | - Dewan Zeng
- Gilead Sciences, Inc, Foster City, California
| | | | - Jeffrey E Olgin
- Cardiac Electrophysiology and Cardiovascular Research Institute, University of California, San Francisco, California.
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Diniz GP, Takano AP, Barreto-Chaves MLM. MiRNA-208a and miRNA-208b are triggered in thyroid hormone-induced cardiac hypertrophy - role of type 1 Angiotensin II receptor (AT1R) on miRNA-208a/α-MHC modulation. Mol Cell Endocrinol 2013; 374:117-24. [PMID: 23623871 DOI: 10.1016/j.mce.2013.04.010] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Revised: 03/21/2013] [Accepted: 04/17/2013] [Indexed: 02/04/2023]
Abstract
Hyperthyroidism promotes cardiac hypertrophy and the Angiotensin type 1 receptor (AT1R) has been demonstrated to mediate part of this response. Recent studies have uncovered a potentially important role for the microRNAs (miRNAs) in the control of diverse aspects of cardiac function. Then, the objective of the present study was to investigate the action promoted by hyperthyroidism on β-MHC/miR-208b expression and on α-MHC/miR-208a expression, as well as the possible contribution of the AT1R in this event. The findings of this study confirmed that AT1R is a key mediator of the cardiac hypertrophy induced by hyperthyroidism. Additionally, we demonstrated that like β-MHC, miR-208b was down-regulated in the hyperthyroid group. Similarly, like the expression of its host gene, α-MHC, miR-208a expression was up-regulated in response to hyperthyroidism. Finally, our data suggest for the first time that AT1R mediates the hyperthyroidism-induced increase on cardiac miRNA-208a/α-MHC levels, while does not influence on the reduction of miRNA-208b/β-MHC levels.
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Affiliation(s)
- Gabriela Placoná Diniz
- Laboratory of Cell Biology and Functional Anatomy, Department of Anatomy, Institute of Biomedical Sciences, University of São Paulo, São Paulo 05508-900, Brazil.
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Kim HS, No CW, Goo SH, Cha TJ. An Angiotensin receptor blocker prevents arrhythmogenic left atrial remodeling in a rat post myocardial infarction induced heart failure model. J Korean Med Sci 2013; 28:700-8. [PMID: 23678261 PMCID: PMC3653082 DOI: 10.3346/jkms.2013.28.5.700] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2012] [Accepted: 04/01/2013] [Indexed: 12/19/2022] Open
Abstract
This study investigated the role of angiotensin II receptor blocker in atrial remodeling in rats with atrial fibrillation (AF) induced by a myocardial infarction (MI). MIs were induced by a ligation of the left anterior descending coronary artery. Two days after, the rats in the losartan group were given losartan (10 mg/kg/day for 10 weeks). Ten weeks later, echocardiography and AF induction studies were conducted. Ejection fraction was significantly lower in the MI rats. Fibrosis analysis revealed much increased left atrial fibrosis in the MI group than sham (2.22 ± 0.66% vs 0.25 ± 0.08%, P = 0.001) and suppression in the losartan group (0.90 ± 0.27%, P 0.001) compared with the MI group. AF inducibility was higher in the MI group than sham (39.4 ± 43.0% vs 2.0 ± 6.3%, P = 0.005) and significantly lower in losartan group (12.0 ± 31.6%, P = 0.029) compared with the MI. The left atrial endothelial nitric oxide synthase (NOS) and sarco/endoplasmic reticulum Ca(2+)-ATPase levels were lower in the MI group and higher in the losartan group significantly. The atrial inducible NOS and sodium-calcium exchanger levels were higher in the MI and lower in the losartan group significantly. Losartan disrupts collagen fiber formation and prevents the alteration of the tissue eNOS and iNOS levels, which prevent subsequent AF induction.
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Affiliation(s)
- Hyun-Su Kim
- Division of Cardiology, Department of Internal Medicine, Kosin University Gospel Hospital, Busan, Korea
| | - Chi-Wan No
- Division of Cardiology, Department of Internal Medicine, Kosin University Gospel Hospital, Busan, Korea
| | - Sang-Ho Goo
- Division of Cardiology, Department of Internal Medicine, Kosin University Gospel Hospital, Busan, Korea
| | - Tae-Joon Cha
- Division of Cardiology, Department of Internal Medicine, Kosin University Gospel Hospital, Busan, Korea
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Cliff B, Younis N, Hama S, Soran H. The role of the renin-angiotensin system blocking in the management of atrial fibrillation. J Drug Assess 2012; 1:55-64. [PMID: 27536429 PMCID: PMC4980732 DOI: 10.3109/21556660.2012.672353] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/29/2012] [Indexed: 12/02/2022] Open
Abstract
OBJECTIVE To review current available evidence for the role of renin-angiotensin system blockade in the management of atrial fibrillation. METHOD We conducted a PubMed and Medline literature search (January 1980 through July 2011) to identify all clinical trials published in English concerning the use of angiotensin converting enzyme inhibitors or angiotensin II receptor blockers for primary and secondary prevention of atrial fibrillation. We also discussed renin-angiotensin system and its effects on cellular electrophysiology. CONCLUSION The evidence from the current studies discussed does not provide a firm definitive indication for the use of angiotensin converting enzyme inhibitors or angiotensin II receptor blockers in the primary or secondary prevention of atrial fibrillation. Nevertheless, modest benefits were observed in patients with left ventricular dysfunction. In view of the possible benefits and the low incidence of side-effects with angiotensin converting enzyme inhibitors and angiotensin II receptor blockers, they can be given to patients with recurrent AF, specifically those with hypertension, heart failure and diabetes mellitus.
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Affiliation(s)
- Brett Cliff
- University Department of Medicine, Central Manchester University Hospitals NHS Foundation Trust, ManchesterUK
| | - Naveed Younis
- Department of Diabetes and Endocrinology, South Manchester University Hospitals NHS Foundation Trust, ManchesterUK
| | - Salam Hama
- Cardiovascular Research Group, School of Biomedicine, Core Technology Facility (3rd Floor), University of Manchester, ManchesterUK
| | - Handrean Soran
- University Department of Medicine, Central Manchester University Hospitals, ManchesterUK
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Goudis CA, Kallergis EM, Vardas PE. Extracellular matrix alterations in the atria: insights into the mechanisms and perpetuation of atrial fibrillation. Europace 2012; 14:623-30. [PMID: 22237583 DOI: 10.1093/europace/eur398] [Citation(s) in RCA: 49] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Atrial fibrillation is the most common arrhythmia in clinical practice and is associated with increased cardiovascular morbidity and mortality. Atrial fibrosis, a detrimental process that causes imbalance in extracellular matrix deposition and degradation, has been implicated as a substrate for atrial fibrillation, but the precise mechanisms of structural remodelling and the relationship between atrial fibrosis and atrial fibrillation are not completely understood. A large number of experimental and clinical studies have shed light on the mechanisms of atrial fibrosis at the molecular and cellular level, including interactions between matrix metalloproteinases and their endogenous tissue inhibitors, and profibrotic signals through specific molecules and mediators such as angiotensin II, transforming growth factor-β1, connective tissue growth factor, and platelet-derived growth factor. This review focuses on the mechanisms of atrial fibrosis and highlights the relationship between atrial fibrosis and atrial fibrillation.
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Affiliation(s)
- Christos A Goudis
- Department of Cardiology, University General Hospital, Heraklion, Crete, Voutes 71110, Greece
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Miyagawa S, Sakaguchi T, Nishi H, Yoshikawa Y, Fukushima S, Saito S, Sawa Y. Recent clinical and experimental advances in atrial fibrillation. ISRN CARDIOLOGY 2011; 2011:958189. [PMID: 22347664 PMCID: PMC3262506 DOI: 10.5402/2011/958189] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2011] [Accepted: 05/13/2011] [Indexed: 12/03/2022]
Abstract
Atrial fibrillation (AF) is the most common arrhythmia in clinical settings (Fuster et al., 2001), and it is often associated with congestive heart diseases (Issac et al., 2007). Many studies in both laboratory and clinical settings have sought to analyze the mechanisms of AF, develop treatments based on these mechanisms, and examine atrial remodeling in chronic AF. The aim of this paper is to analyze recent findings regarding the atrial remodeling that occurs in AF. In particular, we will describe the electrical and structural changes that involve atrial myocytes and the extracellular matrix. We will also describe the general classification and basic pathophysiology of AF and its surgical treatments.
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Affiliation(s)
- Shigeru Miyagawa
- Department of Cardiovascular Surgery, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka 565-0871, Japan
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Topal NP, Ozben B, Hancer VS, Tanrikulu AM, Diz-Kucukkaya R, Fak AS, Basaran Y, Yesildag O. Polymorphisms of the angiotensin-converting enzyme and angiotensinogen gene in patients with atrial fibrillation. J Renin Angiotensin Aldosterone Syst 2011; 12:549-56. [PMID: 21436211 DOI: 10.1177/1470320311399605] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Activation of the renin-angiotensin system (RAS) is associated with atrial fibrillation (AF). The aim of this study was to investigate the relation between AF and polymorphisms in RAS. One hundred and fifty patients with AF, 100 patients with no documented episode of AF and 100 healthy subjects were consecutively recruited into the study. The angiotensin-converting enzyme (ACE) insertion/deletion (I/D) polymorphism, and the M235T, A-20C, and G-6A polymorphisms of the angiotensinogen gene were genotyped. Patients with AF had significantly lower frequency of II genotype of ACE I/D and higher frequency of angiotensinogen M235T polymorphism T allele and TT genotype and G-6A polymorphism G allele and GG genotype compared with the controls. AF patients had significantly larger left atrium, higher left ventricular mass index (LVMI) and higher frequency of significant valvular pathology. ACE I/D polymorphism II genotype, angiotensinogen M235T polymorphism TT genotype and G allele and GG genotype of angiotensinogen G-6A polymorphism were still independently associated with AF when adjusted for left atrium, LVMI and presence of significant valvular pathology. Genetic predisposition might be underlying the prevalence of acquired AF. Patients with a specific genetic variation in the RAS genes may be more liable to develop AF.
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Affiliation(s)
- Nurdan Papila Topal
- Marmara University, Faculty of Medicine, Department of Cardiology, Istanbul, Turkey
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Du J, Xie J, Zhang Z, Tsujikawa H, Fusco D, Silverman D, Liang B, Yue L. TRPM7-mediated Ca2+ signals confer fibrogenesis in human atrial fibrillation. Circ Res 2010; 106:992-1003. [PMID: 20075334 DOI: 10.1161/circresaha.109.206771] [Citation(s) in RCA: 251] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
RATIONALE Cardiac fibrosis contributes to pathogenesis of atrial fibrillation (AF), which is the most commonly sustained arrhythmia and a major cause of morbidity and mortality. Although it has been suggested that Ca(2+) signals are involved in fibrosis promotion, the molecular basis of Ca(2+) signaling mechanisms and how Ca(2+) signals contribute to fibrogenesis remain unknown. OBJECTIVE To determine the molecular mechanisms of Ca(2+)-permeable channel(s) in human atrial fibroblasts, and to investigate how Ca(2+) signals contribute to fibrogenesis in human AF. METHODS AND RESULTS We demonstrate that the transient receptor potential (TRP) melastatin related 7 (TRPM7) is the molecular basis of the major Ca(2+)-permeable channel in human atrial fibroblasts. Endogenous TRPM7 currents in atrial fibroblasts resemble the biophysical and pharmacological properties of heterologous expressed TRPM7. Knocking down TRPM7 by small hairpin RNA largely eliminates TRPM7 current and Ca(2+) influx in atrial fibroblasts. More importantly, atrial fibroblasts from AF patients show a striking upregulation of both TRPM7 currents and Ca(2+) influx and are more prone to myofibroblast differentiation, presumably attributable to the enhanced expression of TRPM7. TRPM7 small hairpin RNA markedly reduced basal AF fibroblast differentiation. Transforming growth factor (TGF)-beta1, the major stimulator of atrial fibrosis, requires TRPM7-mediated Ca(2+) signal for its effect on fibroblast proliferation and differentiation. Furthermore, TGF-beta1-induced differentiation of cultured human atrial fibroblasts is well correlated with an increase of TRPM7 expression induced by TGF-beta1. CONCLUSIONS Our results establish that TRPM7 is the major Ca(2+)-permeable channel in human atrial fibroblasts and likely plays an essential role in TGF-beta1-elicited fibrogenesis in human AF.
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Affiliation(s)
- Jianyang Du
- Department of Cell Biology/Cardiology, ARB EG024, MC-3946, University of Connecticut Health Center, 263 Farmington Ave, Farmington, CT 06030, USA
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17
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Shen D, Tang Q, Huang Z, Chen Y, Xiong R, Wu H, Huang J, Feng S, Yan L, Bian Z. The effects of NK4 on viral myocarditis mice. Cardiovasc Pathol 2009; 18:323-31. [PMID: 19150247 DOI: 10.1016/j.carpath.2008.10.008] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2007] [Revised: 08/11/2008] [Accepted: 10/21/2008] [Indexed: 11/15/2022] Open
Abstract
NK4 may be a promising agent to inhibit tumor invasion and metastasis. To observe the effects of NK4 on the cardiovascular system with pathological injury and to discuss the mechanism, we established an experimental model of viral myocarditis (VCM) by coxsackievirus B3 infection in Balb/c mice on Day 0 and administered NK4 twice daily to the VCM and control mice from Day 20 to Day 45. We then evaluated the cardiac function by means of ultrasonic inspection. Hepatocyte growth factor, TNF (tumor necrosis factor)-alpha, and angiotensin II levels in the myocardial tissue were measured with enzyme-linked immunosorbent assay. Myocardium histopathology was examined with hematoxylin and eosin stain. Collagen deposition of the myocardium was detected through Masson staining. Microvessel staining with the RECA antibody and apoptosis detection with terminal deoxynucleotidyl transferase-mediated dUTP-biotin end labeling were performed in the myocardium. The changes in MMP3 (matrix metalloproteinase 3), MMP9, TIMP1 (tissue inhibitor of metalloproteinase 1), and TGF (transforming growth factor)-beta1 expression in the myocardium were measured by reverse-transcriptase polymerase chain reaction. We found that NK4 intervention increased TGF-beta and angiotensin II expression, suppressed MMPs, improved the activities of TIMPs, and then promoted collagen deposition in the myocardium. NK4 intervention also decreased the microvessels' density and increased the apoptotic cell count in the myocardia of VCM mice. However, we did not observe the obvious changes in the myocardia of control mice after NK4 intervention. These data suggest that NK4 made negative impacts on the restoration of cardiac function and the recovery from VCM in the experimental mice.
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Affiliation(s)
- Difei Shen
- Department of Cardiology, Renmin Hospital, Wuhan University, Wuhan, P.R. China
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18
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Membrane translocation of small GTPase Rac1 and activation of STAT1 and STAT3 in pacing-induced sustained atrial fibrillation. Heart Rhythm 2008; 5:1285-93. [DOI: 10.1016/j.hrthm.2008.05.012] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/23/2008] [Accepted: 05/14/2008] [Indexed: 11/20/2022]
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Novo G, Guttilla D, Fazio G, Cooper D, Novo S. The role of the renin-angiotensin system in atrial fibrillation and the therapeutic effects of ACE-Is and ARBS. Br J Clin Pharmacol 2008; 66:345-51. [PMID: 18782141 PMCID: PMC2526238 DOI: 10.1111/j.1365-2125.2008.03234.x] [Citation(s) in RCA: 52] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2008] [Accepted: 05/21/2008] [Indexed: 01/13/2023] Open
Abstract
Atrial fibrillation (AF) is the most common rhythm disturbance in medical practice and represents a very expensive health problem. AF can be managed with the prevention of thromboembolism and either a rate control of rhythm strategy. As both strategies have important limitations, probably a preventative strategy in patients at risk of developing arrhythmia can be a more attractive option. The renin-angiotensin system (RAS) seems to be involved in the genesis of arrhythmia by the following two mechanisms: 1. the induction of atrial fibrosis and structural remodelling by mitogen-activated protein kinase (MAPK) expression and reduction of collagenase activity; 2. the induction of electrical remodelling by shortening of the atrial effective refractory period (AERP) and of the action potential duration. For these reasons it has been hypothesized that angiotensin-converting enzyme inhibitors (ACE-Is) and angiotensin-II receptor blockers (ARBs) may play a role in preventing AF recurrence. The aim of the present review was to analyse evidence supporting the usefulness of RAS inhibition in patients with AF in order to focus on which specific subset of patients it would most favour. After reviewing the literature, we conclude that, although many studies and meta-analysis have supported the advantage of RAS block in preventing AF recurrence, it is premature to recommend the use of ACE-Is and ARBs specifically for the prevention of AF. However we believe that as these drugs are safe and manageable, they should be considered the drugs of choice in patients with AF and coexisting clinical conditions such as hypertension, coronary disease, heart failure and diabetes mellitus.
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Affiliation(s)
- Giuseppina Novo
- Division of Cardiology, Department of Internal Medicine and Cardiovascular Diseases, University of Palermo, Palermo, Italy.
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20
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Abstract
Atrial Fibrillation (AF) is one of the most frequent arrhythmias, especially in elderly patients. Cardiac overload increases the incidence of AF. Clinical presentation of atrial fibrillation can occur as nonsustained paroxysms, persistent episodes and in chronic-permanent form. The physio-pathological mechanisms are: • Circuit of multiple and anarchic re-entries • Atrial fibrillatory conduction • Re-entry circuit with fibrillatory conduction. Remodeling (electrical or structural) facilitates the appearance and persistence of AF: Neurovegetative changes and cytosolic Ca overload facilitate AF. Interstitial atrial fibrosis, in which Renin-Angiotensin System (RAS) hyperactivity is a main aspect of remodeling. There is clinical evidence that supports the antiatrial fibrillatory actions of RAS blockade. Potential mechanisms are: (a) direct modulation of ionic channels, (b) hemodynamic improvement, (c) reduction of atrial stretching, (d) antifibrotic effects. There is less clinical evidence with antialdosterone drugs, but theoretically these might also be useful.
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Affiliation(s)
- José Luis Serra
- Departamento de Arritmias, Sanatorio Allende, Córdoba, Argentina
| | - Mario Bendersky
- Department of Pharmacology, Chief Hypertension Unit, Instituto Modelo Cardiología, Córdoba University , Córdoba, Argentina,
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21
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Renin-angiotensin system component expression in the HL-1 atrial cell line and in a pig model of atrial fibrillation. J Hypertens 2008; 26:570-82. [PMID: 18300870 DOI: 10.1097/hjh.0b013e3282f34a4a] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
OBJECTIVES Local atrial tissue angiotensin II (AngII) level is elevated in atrial fibrillation (AF), but the mechanism is unknown. We hypothesized that atrial myocytes express all components of the renin-angiotensin system (RAS) and investigated whether rapid depolarization alone is sufficient to increase paracrine AngII production by up-regulating RAS component expression. METHODS In the HL-1 atrial cell line, rapid depolarization was induced by rapid field electrical stimulation (RES) at 1.0 V/cm and 600/min (10 Hz) in atrial HL-1 cells. In a pig model of AF, AF was induced by atrial pacing at 600/min in 10 adult pigs and 10 sham-operated pigs for comparison. RESULTS In atrial myocytes, RES induced a sustained elevation of intracellular calcium, and up-regulation of angiotensin-converting enzyme (ACE), chymase and angiotensinogen, resulting in increased AngII production. RES-induced AngII production was attenuated by enalapril [ACE inhibitor (ACEI)] and chymostatin (chymase inhibitor). Conditioned medium from RES-stimulated atrial myocytes increased [3H]leucine uptake and atrial natriuretic peptide expression in atrial myocytes, and [3H]proline uptake and collagen type 1 alpha 1 expression in atrial fibroblasts. Both were attenuated by co-incubation with the AngII type 1 receptor blocker (ARB) losartan. In the porcine model, significant structural changes and a similar pattern of changes of RAS components were noted in AF pigs. CONCLUSIONS Atrial cells expressed all components of RAS and rapid depolarization alone was sufficient to up-regulate RAS components, increase paracrine AngII production and induce atrial structural changes, which are attenuated by ACEI, ARB and chymase inhibitor.
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22
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Tsai CT, Hwang JJ, Chiang FT, Wang YC, Tseng CD, Tseng YZ, Lin JL. Renin-angiotensin system gene polymorphisms and atrial fibrillation: a regression approach for the detection of gene-gene interactions in a large hospitalized population. Cardiology 2008; 111:1-7. [PMID: 18239384 DOI: 10.1159/000113419] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/23/2006] [Accepted: 05/18/2007] [Indexed: 11/19/2022]
Abstract
OBJECTIVES To test the association between renin-angiotensin system gene variants and atrial fibrillation (AF) using a regression approach. METHODS A total of 1,236 consecutive patients (227 with AF and 1,009 with normal sinus rhythm as controls) were recruited. Angiotensin-converting enzyme (ACE) gene I/D polymorphism; T174M, M235T, G-6A, A-20C, G-152A and G-217A polymorphisms of the angiotensinogen (AGT) gene, and A1166C polymorphism of the angiotensin II type I receptor (AT1R) gene were genotyped. We used a regression approach based on a generalized linear model to evaluate haplotype effects and to detect gene-gene interactions by incorporating interaction terms in the model. RESULTS In single-locus analyses, no locus was associated with AF. After adjustment for AF risk factors, we found significant differences in the global AGT gene haplotype profile (the global score statistic = 30.364, p = 0.001) and individual haplotype frequencies between AF patients and controls. Furthermore, significant 2-way gene-gene interactions between ACE I/D polymorphism and AGT gene haplotypes and between AT1R A1166C polymorphism and AGT gene haplotypes, and 3-way interaction between ACE I/D, AT1R A1166C and AGT gene haplotypes were detected. CONCLUSIONS These results are compatible with the concept of multilocus and multigene effects in determining the risk of complex diseases such as AF, which would be missed with conventional single-locus approaches.
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Affiliation(s)
- Chia-Ti Tsai
- Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
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23
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Abstract
Atrial fibrillation (AF) is commonly associated with congestive heart failure (CHF), and CHF has been shown to be associated with atrial structural remodeling resulting in fibrosis. Atrial interstitial fibrosis has been seen in patients with CHF and in animal models of pacing-induced heart failure. With atrial fibrosis, conduction abnormalities result in increased AF vulnerability. The mechanism of AF associated with CHF is under debate, as both focal and reentrant mechanisms have been observed in animal models of CHF. However, recent studies using frequency-domain analysis have shown that the AF within this model is characterized by discrete, stable, high-frequency areas. The precise signaling processes involved in the development of atrial fibrosis are unknown. Angiotensin appears to play a role, as inhibition of angiotensin-converting enzyme (or angiotensin-receptor blocker) blunts atrial fibrosis in animal models of heart failure and decreases the incidence of AF in patients with heart failure. Transforming growth factor-beta (TGF-beta) also appears to play an important role. Mouse models that overexpress TGF-beta1 have profound atrial fibrosis and AF (with normal ventricles). Heart failure in canine models also produces increases in atrial TGF-beta1 expression, and inhibition of this expression prevents atrial fibrosis and the development of a substrate for AF. Atrial fibrosis appears to play a role in the development of a vulnerable substrate for AF, especially in the setting of CHF.
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Affiliation(s)
- Thomas H Everett
- Division of Cardiology and the Cardiovascular Research Institute, University of California San Francisco, San Francisco, California 94143-1354, USA
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24
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Abstract
While the remodeling process in myocardial failure involves changes in ventricular structure and performance, it is now appreciated that it is also associated with changes in thin filament composition and function. As is discussed, changes at the level thick filament may affect thin filament activation in heart failure. Alterations in actin, troponin and tropomyosin isoform composition do not appear to be significant factors in human heart failure. In contrast, proteolytic degradation of troponin subunits are likely to be playing a functional role in some forms of cardiomyopathy (e.g. ischemic). Finally, phosphorylation of troponin I and troponin T by kinases (most notably protein kinase C) substantially affect thin filament function in failing human myocardium. These findings indicate that functional deficits in thin filament function in failing myocardium are largely reversible and create the potential for future targeted therapies in the treatment of this deadly disease.
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Affiliation(s)
- Peter VanBuren
- Department of Medicine, College of Medicine, University of Vermont, VT 05405, USA.
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25
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Enomoto S, Yoshiyama M, Omura T, Matsumoto R, Kusuyama T, Kim S, Izumi Y, Akioka K, Iwao H, Takeuchi K, Yoshikawa J. Effects of eplerenone on transcriptional factors and mRNA expression related to cardiac remodelling after myocardial infarction. Heart 2005; 91:1595-600. [PMID: 15797934 PMCID: PMC1769240 DOI: 10.1136/hrt.2004.046540] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
OBJECTIVE To examine the effects of eplerenone, a selective aldosterone blocker, on cardiac function after myocardial infarction (MI) and myocardial remodelling related transcriptional factors and mRNA expression in non-infarcted myocardium. METHODS MI was induced by ligation of the coronary artery in Wistar rats. Rats were randomly assigned to a vehicle treated group or an eplerenone treated group (100 mg/kg/day). RESULTS At four weeks after MI, left ventricular (LV) end diastolic pressure, LV weight, and LV end diastolic dimension were increased in MI rats. Eplerenone significantly reduced the increase in LV end diastolic pressure, LV weight, and LV end diastolic dimension. In the MI rats the decreased ejection fraction indicated systolic dysfunction and the increased E wave to A wave ratio and E deceleration rate indicated diastolic dysfunction. Eplerenone significantly attenuated this systolic and diastolic dysfunction. Myocardial interstitial fibrosis, transcriptional activities of activator protein 1 and nuclear factor kappaB, and mRNA expression of monocyte chemoattractant protein 1, plasminogen activator inhibitor 1, atrial natriuretic peptide, brain natriuretic peptide, and collagen types I and III were significantly increased at four weeks after MI. Eplerenone significantly attenuated interstitial fibrosis and suppressed transcriptional activity and mRNA expression of these genes. CONCLUSIONS When administered after MI, eplerenone prevents cardiac remodelling accompanied by systolic and diastolic dysfunction and inhibits abnormal myocardial transcriptional activities and gene expression.
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Affiliation(s)
- S Enomoto
- Department of Internal Medicine and Cardiology, Osaka City University Medical School, Japan
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26
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Zhang J, Cheng X, Liao YH, Lu B, Yang Y, Li B, Ge H, Wang M, Liu Y, Guo Z, Zhang L. Simvastatin Regulates Myocardial Cytokine Expression and Improves Ventricular Remodeling in Rats after Acute Myocardial Infarction. Cardiovasc Drugs Ther 2005; 19:13-21. [PMID: 15883752 DOI: 10.1007/s10557-005-6893-3] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
PURPOSE Studies have showed that inflammatory cytokines were involved in the process of left ventricular (LV) remodeling after acute myocardial infarction (AMI), anti-inflammation treatment ameliorated LV remodeling and improved cardiac performance. Hydroxymethylglutary coenzyme A reductase inhibition (statins) could affect the expression of inflammatory cytokines. We hypothesized that statins have beneficial effects on early LV remodeling and cardiac performance in rats with AMI by modulating the production of inflammatory cytokines. METHODS Rats with AMI were treated with placebo or simvastatin (gastric gavage) for 4 weeks. The pro-inflammatory cytokines: tumor necrosis factor (TNF)-alpha, interleukin (IL)-1beta, IL-6 and the anti-inflammatory cytokine: IL-10 excreted by cardiac myocytes was examined. Echocardiography, hemodynamics and collagen type I production were measured to evaluate LV remodeling and cardiac function. RESULTS The mRNA expression and protein production of TNF-alpha, IL-1beta, IL-6 and IL-10 in AMI group were significantly elevated compared with sham rats. Simvastatin markedly attenuated the production of TNF-alpha, IL-1beta, IL-6 and increased IL-10 levels in the noninfarcted and infarcted regions, reduced collagen deposition in the noninfarcted myocardium and improved left ventricular function. However simvastatin did not alter plasma lipids. CONCLUSIONS Simvastatin ameliorates early LV remodeling and improve cardiac function after AMI. Simultaneously, it decreased pro-inflammatory and increased anti-inflammatory cytokines, which suggests, but does not prove, a causal relationship independent of plasma lipid-lowering effects.
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Affiliation(s)
- Jinying Zhang
- Laboratory of Cardiovascular Immunology, Institute of Cardiology, Union Hospital, Tongji Medical College of Huazhong University of Science and Technology, Wuhan, 430022, People's Republic of China
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27
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Pourdjabbar A, Parker TG, Nguyen QT, Desjardins JF, Lapointe N, Tsoporis JN, Rouleau JL. Effects of pre-, peri-, and postmyocardial infarction treatment with losartan in rats: effect of dose on survival, ventricular arrhythmias, function, and remodeling. Am J Physiol Heart Circ Physiol 2004; 288:H1997-2005. [PMID: 15539424 DOI: 10.1152/ajpheart.00671.2004] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Angiotensin receptor blockers (ARBs) reduce adverse left ventricular (LV) remodeling and improve LV function and survival when started postmyocardial infarction (MI). ARBs also reduce ventricular arrhythmias during ischemia-reperfusion injury when started pre-MI. No information exists regarding their efficacy and safety when started pre-MI and continued peri- and post-MI. We evaluated whether the ARB losartan improves the outcome when started pre-MI and continued peri- and post-MI. Male Wistar rats (n = 502) were treated for 7 days pre-MI with losartan at a high dose (30 mg.kg(-1).day(-1)), progressively increasing dose (3 mg.kg(-1).day(-1) increased to 10 mg.kg(-1).day(-1) 10 days and 30 mg.kg(-1).day(-1) 20 days post-MI), or no treatment. Ambulatory systolic blood pressure and Holter monitoring were performed for 24 h post-MI. Echocardiography was done 30 days post-MI, and LV remodeling, cardiac hemodynamics, and fetal gene expression were assessed 38 days post-MI. High-dose losartan reduced 24-h post-MI survival compared with the progressive dose and control (21.9% vs. 36.6% and 38.1%, P = 0.033 and P = 0.009, respectively). This was associated with greater hypotension in the high dose and no change in ventricular arrhythmias in all groups. In 24-h post-MI survivors, the progressive dose group had reduced mortality from 24 h to 38 days (8.5% vs. 28.6% for control vs. 38.9% for high dose, P = 0.032 and P = 0.01, respectively). Survivors of both losartan groups demonstrated improved LV remodeling, cardiac hemodynamics, preserved GLUT-4, and reduced cardiac fetal gene expression. Pretreatment with ARBs does not reduce 24-h post-MI ventricular arrhythmias or survival, and high doses increase mortality by causing excessive hypotension. In 24-h post-MI survivors, progressively increasing doses of losartan have multiple beneficial effects, including improved survival.
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Affiliation(s)
- Ali Pourdjabbar
- Division of Cardiology, St. Michael's Hospital, Rm. 6-044 Queen Wing, 30 Bond St., Toronto, Ontario M5B 1W8, Canada
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28
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Tsai CT, Lai LP, Lin JL, Chiang FT, Hwang JJ, Ritchie MD, Moore JH, Hsu KL, Tseng CD, Liau CS, Tseng YZ. Renin-Angiotensin System Gene Polymorphisms and Atrial Fibrillation. Circulation 2004; 109:1640-6. [PMID: 15023884 DOI: 10.1161/01.cir.0000124487.36586.26] [Citation(s) in RCA: 259] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND The activated local atrial renin-angiotensin system (RAS) has been reported to play an important role in the pathogenesis of atrial fibrillation (AF). We hypothesized that RAS genes might be among the susceptibility genes of nonfamilial structural AF and conducted a genetic case-control study to demonstrate this. METHODS AND RESULTS A total of 250 patients with documented nonfamilial structural AF and 250 controls were selected. The controls were matched to cases on a 1-to-1 basis with regard to age, gender, presence of left ventricular dysfunction, and presence of significant valvular heart disease. The ACE gene insertion/deletion polymorphism, the T174M, M235T, G-6A, A-20C, G-152A, and G-217A polymorphisms of the angiotensinogen gene, and the A1166C polymorphism of the angiotensin II type I receptor gene were genotyped. In multilocus haplotype analysis, the angiotensinogen gene haplotype profile was significantly different between cases and controls (chi2=62.5, P=0.0002). In single-locus analysis, M235T, G-6A, and G-217A were significantly associated with AF. Frequencies of the M235, G-6, and G-217 alleles were significantly higher in cases than in controls (P=0.000, 0.005, and 0.002, respectively). The odds ratios for AF were 2.5 (95% CI 1.7 to 3.3) with M235/M235 plus M235/T235 genotype, 3.3 (95% CI 1.3 to 10.0) with G-6/G-6 genotype, and 2.0 (95% CI 1.3 to 2.5) with G-217/G-217 genotype. Furthermore, significant gene-gene interactions were detected by the multifactor-dimensionality reduction method and multilocus linkage disequilibrium tests. CONCLUSIONS This study demonstrates the association of RAS gene polymorphisms with nonfamilial structural AF and may provide the rationale for clinical trials to investigate the use of ACE inhibitor or angiotensin II antagonist in the treatment of structural AF.
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Affiliation(s)
- Chia-Ti Tsai
- Division of Cardiology, Department of Internal Medicine, National Taiwan University Hospital, Taipei, Taiwan
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29
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Matsumoto R, Yoshiyama M, Omura T, Kim S, Nakamura Y, Izumi Y, Akioka K, Iwao H, Takeuchi K, Yoshikawa J. Effects of Aldosterone Receptor Antagonist and Angiotensin II Type I Receptor Blocker on Cardiac Transcriptional Factors and mRNA Expression in Rats With Myocardial Infarction. Circ J 2004; 68:376-82. [PMID: 15056838 DOI: 10.1253/circj.68.376] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
BACKGROUND Because the effects of an aldosterone receptor antagonist on transcriptional factors and mRNA expression have not been fully examined in myocardial infarction (MI), the present study examined the effects of spironolactone (SPIRO) and candesartan cilexitil (CAN) on activation of activator protein-1 (AP-1), nuclear factor-kappaB (NF-kappaB) and mRNA expression in the non-ischemic myocardium after MI. METHODS AND RESULTS MI was induced by ligation of the coronary artery in Wistar rats, which were separated into (1) vehicle-treated group, (2) CAN-treated group (10 mg/kg per day), (3) SPIRO-treated group (100 mg/kg per day) and (4) CAN + SPIRO-treated group. The activity of both AP-1 and NF-kappaB was significantly increased at 4 weeks after MI. CAN or SPIRO significantly prevented the cardiac remodeling and activity of AP-1 and NF-kappaB. Furthermore, CAN + SPIRO prevented the cardiac remodeling and activation of AP-1 and NF-kappaB, compared with CAN or SPIRO alone. Myocardial atrial natriuretic peptide, brain natriuretic peptide, collagen I and III mRNAs were enhanced by MI, and CAN or SPIRO alone significantly reduced the mRNAs. CAN + SPIRO significantly prevented these mRNAs, compared with CAN or SPIRO alone. CONCLUSIONS Both aldosterone and angiotensin II are involved in the myocardial transcriptional activation of AP-1, NF-kappaB and the cardiac remodeling-related mRNAs. The combination of CAN and SPIRO may be a potent therapeutic strategy for preventing cardiac remodeling after MI.
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Affiliation(s)
- Ryo Matsumoto
- Department of Internal Medicine and Cardiology, Osaka City University Medical School, Japan
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30
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Abstract
Circulating angiotensin (Ang) II has well-known endocrine properties in the cardiovasculature. AngII, produced de novo within the heart, has various autocrine and paracrine properties on resident cells expressed via AT(1) receptor-ligand binding. Herein, we review the heart's renin-angiotensin system and its role in connective tissue turnover involving heart valve leaflets and fibrous tissue that appears at sites of injury, such as following myocardial infarction.
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Affiliation(s)
- Yao Sun
- Department of Medicine, Division of Cardiovascular Diseases, University of Tennessee Health Science Center, Rm. 353 Dobbs Research Institute, 951 Court Avenue, Memphis, TN 38163, USA
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Nguyen QT, Colombo F, Clement R, Gosselin H, Rouleau JL, Calderone A. AT1 receptor antagonist therapy preferentially ameliorated right ventricular function and phenotype during the early phase of remodeling post-MI. Br J Pharmacol 2003; 138:1485-94. [PMID: 12721104 PMCID: PMC1573810 DOI: 10.1038/sj.bjp.0705212] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
1. The influence of AII on contractile dysfunction, regulation of the tyrosine kinase-dependent signaling molecule extracellular signal-regulated kinase (ERK), and natriuretic peptide gene expression were examined in the noninfarcted left ventricle (NILV) and right ventricle (RV) during the early phase of remodeling post-myocardial infarct (MI) in the rat. The selective AT(1) receptor antagonist irbesartan was administered <10 h following coronary artery ligation, and rats were killed either at 4-day or 2-week post-MI. 2. At 4 days post-MI, left ventricular systolic pressure (LVSP: sham=125+/-12, MI=91+/-4 mmHg) was decreased, whereas left ventricular end-diastolic pressure (LVEDP: sham=9+/-2, MI=17+/-2 mm Hg), right ventricular systolic (RVSP: sham=26+/-1, MI=34+/-2 mm Hg), and end-diastolic pressures (RVEDP: sham=3+/-0.5, MI=7+/-1 mm Hg) were increased. ERK phosphorylation was significantly elevated in the NILV and RV. 3. Irbesartan (40 mg x kg(-1)/day(-1)) administration did not improve left ventricular function, or suppress increased ERK phosphorylation in the 4-day post-MI rat. By contrast, irbesartan therapy normalized RVSP (MI+irbesartan=25+/-1 mm Hg), RVEDP (MI+irbesartan=3+/-0.3 mm Hg), and reduced ERK1 (MI=3.0+/-0.6, MI+irbesartan=2.0+/-0.3-fold increase), and ERK2 (MI=3.8+/-0.8, MI+irbesartan=2.2+/-0.5-fold increase) phosphorylation. 4. In 2-week post-MI rats, biventricular dysfunction was associated with increased prepro-ANP, and prepro-BNP mRNA expression. Irbesartan therapy normalized RVSP, attenuated RVEDP, and abrogated natriuretic peptide mRNA expression (prepro-ANP; MI=9+/-2, MI+irbesartan=2+/-1-fold increase, prepro-BNP; MI=6+/-2, MI+irbesartan=1+/-1-fold increase), whereas both transcripts remained elevated in the NILV despite the partial attenuation of LVEDP. 5. These data suggest that the therapeutic benefit of irbesartan treatment during the early phase of remodeling post-MI was associated with the preferential amelioration of RV contractile function and phenotype.
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Affiliation(s)
| | - Federico Colombo
- Dept. de Physiologie, Centre de Recherche de l'institut de Cardiologie de Montréal, Université de Montréal, Montréal, Québec, Canada
| | - Robert Clement
- Dept. de Physiologie, Centre de Recherche de l'institut de Cardiologie de Montréal, Université de Montréal, Montréal, Québec, Canada
| | - Hugues Gosselin
- Dept. de Physiologie, Centre de Recherche de l'institut de Cardiologie de Montréal, Université de Montréal, Montréal, Québec, Canada
| | | | - Angelino Calderone
- Dept. de Physiologie, Centre de Recherche de l'institut de Cardiologie de Montréal, Université de Montréal, Montréal, Québec, Canada
- Author for correspondence:
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Jin H, Yang R, Lu H, Ogasawara AK, Li W, Ryan A, Peale F, Paoni NF. Effects of early treatment with growth hormone on infarct size, survival, and cardiac gene expression after acute myocardial infarction. Growth Horm IGF Res 2002; 12:208-215. [PMID: 12175653 DOI: 10.1016/s1096-6374(02)00042-4] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
OBJECTIVE This study examined the effects of growth hormone (GH) on infarct size, survival, and cardiac gene expression in rats with acute myocardial infarction. DESIGN Animals randomly received sc injection of either saline vehicle (n = 98) or GH (2mg/kg/day, n = 105) for 14 days commencing the day of left coronary artery ligation. Infarct size was determined by morphometric analysis at the time of death or at 52 weeks post-surgery. Gene expression was analyzed by real-time RT-PCR after 2-week treatment. RESULTS GH decreased infarct size by 18% (P < 0.01) and increased survival by 36% at 52 weeks. GH also significantly reduced cardiac expression of atrial natriuretic factor, beta-myosin heavy chain, alpha-smooth muscle actin, collagen I, collagen III, fibronectin, and pro-inflammatory cytokines. CONCLUSIONS Treatment with GH for 2 weeks beginning on the day of myocardial infarction produced beneficial effects that were associated with reductions in cardiac gene expression symptomatic of pathological remodeling.
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Affiliation(s)
- Hongkui Jin
- Department of Cardiovascular Research, Genentech, Inc., South San Francisco, CA 94080, USA.
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Cowling RT, Gurantz D, Peng J, Dillmann WH, Greenberg BH. Transcription factor NF-kappa B is necessary for up-regulation of type 1 angiotensin II receptor mRNA in rat cardiac fibroblasts treated with tumor necrosis factor-alpha or interleukin-1 beta. J Biol Chem 2002; 277:5719-24. [PMID: 11600498 DOI: 10.1074/jbc.m107515200] [Citation(s) in RCA: 66] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Tumor necrosis factor-alpha (TNF-alpha) and interleukin-1 beta up-regulate type 1 angiotensin II receptor (AT(1)) mRNA and protein in cultured neonatal rat cardiac fibroblasts. The use of pharmacologic inhibitors and a degradation-resistant mutant I kappa B-alpha demonstrated that the transcription factor nuclear factor-kappa B (NF-kappa B) is necessary for cytokine-induced AT(1) up-regulation. The increase in AT(1) mRNA with TNF-alpha treatment is slow, reaching significance by 6-12 h and peaking by 24-48 h. Electrophoretic mobility shift assays revealed that NF-kappa B nuclear translocation was maintained for > or = 24 h with a single dose of TNF-alpha. Since prolonged NF-kappa B activation appeared necessary to maximize AT(1) up-regulation, the mechanism of persistent NF-kappa B activation was studied further. Stimulation with TNF-alpha induced a >10x increase in I kappa B kinase (IKK) activity that quickly diminished by 20 min. I kappa B-alpha and I kappa B-beta proteins were degraded during this time, and I kappa B-alpha was resynthesized subsequently by NF-kappa B-dependent transcription. However, I kappa B isoforms and IKK activity did not return completely to unstimulated values during a 12-h time course. These results suggest that low but persistent IKK activity and I kappa B degradation lead to prolonged NF-kappa B nuclear translocation and maximal AT(1) up-regulation in the continued presence of TNF-alpha.
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Affiliation(s)
- Randy T Cowling
- Department of Medicine, Division of Cardiology, University of California, San Diego Medical Center, San Diego, California 92103-8411, USA
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34
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Nakamura Y, Yoshiyama M, Omura T, Yoshida K, Kim S, Takeuchi K, Iwao H, Yoshikawa J. Transmitral inflow pattern assessed by Doppler echocardiography in angiotensin II type 1A receptor knockout mice with myocardial infarction. Circ J 2002; 66:192-6. [PMID: 11999647 DOI: 10.1253/circj.66.192] [Citation(s) in RCA: 18] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Many studies have suggested that the renin-angiotensin system plays an important role in the left ventricular (LV) remodeling and cardiac dysfunction that occurs after myocardial infarction (MI). Although angiotensin II type IA (AT1A) receptor knockout (KO) mice are reported to display less LV remodeling after MI, diastolic dysfunction has not been fully evaluated, so the present study measured transmitral inflow pattern in both AT1A receptor KO mice with MI (KO-MI) and wild type mice with MI (WT-MI). Cardiac geometry and function were examined by Doppler echocardiography and myocardial mRNA expression was determined by Northern blot analysis at 4 weeks after MI. The LV internal diastolic dimension of WT-MI was larger than that of the KO-MI (p<0.05). Marked increases in the E wave velocity and the ratio of the peak velocity of the E wave to the A wave were observed in the WT-MI (p<0.01). The deceleration rate of the E wave in KO-MI was lower than in WT-MI (p<0.05). mRNA expressions of ANP, BNP, collagen I and collagen III in the non-infarcted LV and RV of KO-MI were significantly lower than WT-MI. In conclusion, transmitral inflow abnormalities in KO-MI were attenuated compared with WT-MI.
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MESH Headings
- Animals
- Atrial Natriuretic Factor/genetics
- Collagen Type I/genetics
- Collagen Type III/genetics
- Coronary Circulation/physiology
- Disease Models, Animal
- Echocardiography, Three-Dimensional
- Gene Expression Regulation
- Hemodynamics
- Mice
- Mice, Inbred C57BL
- Mice, Knockout
- Mitral Valve/physiopathology
- Myocardial Infarction/diagnostic imaging
- Myocardial Infarction/genetics
- Myocardial Infarction/physiopathology
- Natriuretic Peptide, Brain/genetics
- Receptor, Angiotensin, Type 1
- Receptors, Angiotensin/deficiency
- Receptors, Angiotensin/genetics
- Receptors, Angiotensin/physiology
- Transcription, Genetic
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Affiliation(s)
- Yasuhiro Nakamura
- Department of Internal Medicine and Cardiology, Graduate School of Medicine, Osaka City University, Osaka, Japan
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35
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Blais C, Lapointe N, Rouleau JL, Clément R, Bachvarov DR, Adam A. Effects of captopril and omapatrilat on early post-myocardial infarction survival and cardiac hemodynamics in rats: interaction with cardiac cytokine expression. Can J Physiol Pharmacol 2002; 80:48-58. [PMID: 11911226 DOI: 10.1139/y01-096] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The purpose of this study was to evaluate and compare the effects of simultaneous angiotensin-converting enzyme (ACE) and neutral endopeptidase 24.11 (NEP) inhibition by the vasopeptidase inhibitor omapatrilat (10 and 40 mg x kg(-1) x day(-1)) with those of the selective ACE inhibitor captopril (160 mg x kg(-1) x day(-1)) on survival, cardiac hemodynamics, and cytokine mRNA expression in left ventricular (LV) tissues 4 days after myocardial infarction (MI) in rats. The effects of the co-administration of both B1 and B2 kinin receptor antagonists (2.5 mg x kg(-1) x day(-1) each) with and without omapatrilat were also evaluated to assess the role of bradykinin (BK) during this post-MI period. Both omapatrilat and captopril treatments improve early (4 days) post-MI survival when started 4 h post-MI. The use of kinin receptor antagonists had no significant effect on survival in untreated MI rats and omapatrilat-treated MI rats. This improvement in survival with omapatrilat and captopril is accompanied by a reduced LV end-diastolic pressure (LVEDP) and pulmonary congestion. The use of kinin receptor antagonists had little effect on cardiac hemodynamics or morphologic measurements. Acute MI significantly increased the expression of cardiac cytokines (TNF-alpha, TGF-beta1, and IL-10). Captopril significantly attenuated this activation, while omapatrilat had variable effects: sometimes increasing but generally not changing activation depending on the cytokine measured and the dose of omapatrilat used. The co-administration of both kinin receptor antagonists attenuates the increase in expression of cardiac TNF-alpha and TGF-beta1 after omapatrilat treatment. Taken together, these results would suggest that despite very marked differences in the way these drugs modified the expression of cardiac cytokines, both omapatrilat and captopril improved early (4 days) post-MI survival and cardiac function to a similar extent.
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Affiliation(s)
- Charles Blais
- Faculté de Pharmacie, Université de Montréal, Centre-ville, QC, Canada
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36
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Li D, Shinagawa K, Pang L, Leung TK, Cardin S, Wang Z, Nattel S. Effects of angiotensin-converting enzyme inhibition on the development of the atrial fibrillation substrate in dogs with ventricular tachypacing-induced congestive heart failure. Circulation 2001; 104:2608-14. [PMID: 11714658 DOI: 10.1161/hc4601.099402] [Citation(s) in RCA: 448] [Impact Index Per Article: 19.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Atrial structural remodeling creates a substrate for atrial fibrillation (AF), but the underlying signal transduction mechanisms are unknown. This study assessed the effects of ACE inhibition on arrhythmogenic atrial remodeling and associated mitogen-activated protein kinase (MAPK) changes in a dog model of congestive heart failure (CHF). METHODS AND RESULTS Dogs were subjected to various durations of ventricular tachypacing (VTP, 220 to 240 bpm) in the presence or absence of oral enalapril 2 mg. kg(-1). d(-1). VTP for 5 weeks induced CHF, local atrial conduction slowing, and interstitial fibrosis and prolonged atrial burst pacing-induced AF. Atrial angiotensin II concentrations and MAPK expression were increased by tachypacing, with substantial changes in phosphorylated forms of c-Jun N-terminal kinase (JNK), extracellular signal-regulated kinase (ERK), and p38-kinase. Enalapril significantly reduced tachypacing-induced changes in atrial angiotensin II concentrations and ERK expression. Enalapril also attenuated the effects of CHF on atrial conduction (conduction heterogeneity index reduced from 3.1+/-0.4 to 1.9+/-0.2 ms/mm, P<0.05), atrial fibrosis (from 11.9+/-1.1% to 7.5+/-0.4%, P<0.01), and mean AF duration (from 651+/-164 to 218+/-75 seconds, P<0.05). Vasodilator therapy of a separate group of VTP dogs with hydralazine and isosorbide mononitrate did not alter CHF-induced fibrosis or AF promotion. CONCLUSIONS CHF-induced increases in angiotensin II content and MAPK activation contribute to arrhythmogenic atrial structural remodeling. ACE inhibition interferes with signal transduction leading to the AF substrate in CHF and may represent a useful new component to AF therapy.
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Affiliation(s)
- D Li
- Department of Medicine, Montreal Heart Institute and University of Montreal, Montreal, Quebec, Canada
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37
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Tzanidis A, Lim S, Hannan RD, See F, Ugoni AM, Krum H. Combined angiotensin and endothelin receptor blockade attenuates adverse cardiac remodeling post-myocardial infarction in the rat: possible role of transforming growth factor beta(1). J Mol Cell Cardiol 2001; 33:969-81. [PMID: 11343419 DOI: 10.1006/jmcc.2001.1361] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
A. Tzanidis, S. Lim, R. D. Hannan, F. See, A. M. Ugoni and H. Krum. Combined Angiotensin and Endothelin Receptor Blockade Attenuates Adverse Cardiac Remodeling Post-Myocardial Infarction in the Rat: Possible Role of Transforming Growth Factor beta(1). Journal of Molecular and Cellular Cardiology (2001) 33, 969-981. Myocardial infarction (MI) is associated with activation of the vasoconstrictor peptides, angiotensin II (AngII) and endothelin-1 (ET-1), which are thought to contribute to adverse cardiac remodeling and dysfunction. The present study sought to determine whether combined AngII and ET receptor blockade improves cardiac remodeling over individual treatments in an experimental model of left ventricular myocardial infarction (LVMI) in the rat. Groups of eight female Sprague-Dawley rats were randomized at 24 h post-LVMI to 1 week treatment with either vehicle, an ET(A/B)receptor antagonist (bosentan), an AT(1)receptor antagonist (valsartan), or combined treatment. Vehicle-treated animals developed LV dysfunction with extensive accumulation of collagen type I and increased alpha(1)(I) procollagen mRNA compared to sham controls. Whilst individual receptor blockade with either bosentan or valsartan reduced LVEDP towards sham control levels, there were no significant changes to myocardial collagen deposition in comparison to vehicle. In contrast, improved ventricular function by combined treatment was associated with reduced type I collagen deposition within left ventricular non-infarct regions, as well as reduced peptide distribution and cardiac gene expression of the profibrogenic peptide, transforming growth factor beta(1)(TGF beta(1)). These data demonstrate that combined AngII and ET receptor blockade has beneficial effects on myocardial fibrogenesis over individual treatments during adverse cardiac remodeling early post-MI.
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Affiliation(s)
- A Tzanidis
- Department of Medicine/Epidemiology and Preventive Medicine, Monash University Medical School, Alfred Hospital, Commercial Road, Prahran 3181, Victoria, Australia.
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38
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Fukui T, Yoshiyama M, Hanatani A, Omura T, Yoshikawa J, Abe Y. Expression of p22-phox and gp91-phox, essential components of NADPH oxidase, increases after myocardial infarction. Biochem Biophys Res Commun 2001; 281:1200-6. [PMID: 11243862 DOI: 10.1006/bbrc.2001.4493] [Citation(s) in RCA: 85] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Recent studies have shown that oxidative stress plays an important role in cardiovascular diseases. NADPH oxidase is one of the major sources of superoxide anions and a candidate for the initiation and development of atherosclerosis, which involves the remodeling of vasculature. However, the relevance of NADPH oxidase in ventricular remodeling has not been well-characterized. This is the first report showing that the expression of p22-phox and gp91-phox, essential components of NADPH oxidase, are increased in the infarcted sites after myocardial infarction. The levels of thiobarbituric acid reactive substance, which indicates the lipid peroxidation level, and nuclear factor-kappaB (NF-kappaB) DNA binding activity are also increased in infarcted sites. Our results suggest that the increased expression of NADPH oxidase may have an effect on left ventricular remodeling by increasing the redox-sensitive NF-kappaB DNA binding activity as well as the lipid peroxidation level.
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Affiliation(s)
- T Fukui
- Department of Pharmacology, Kagawa Medical University, Kagawa, Japan
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39
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Omura T, Yoshiyama M, Ishikura F, Kobayashi H, Takeuchi K, Beppu S, Yoshikawa J. Myocardial ischemia activates the JAK-STAT pathway through angiotensin II signaling in in vivo myocardium of rats. J Mol Cell Cardiol 2001; 33:307-16. [PMID: 11162135 DOI: 10.1006/jmcc.2000.1303] [Citation(s) in RCA: 42] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
There have been many studies concerning the hemodynamics and physiological mechanisms in ischemic heart disease, little is known about molecular mechanisms during myocardial ischemia in in vivo study. As the signal transduction pathway responsible for myocardial hypertrophy and apoptosis, janus kinase (JAK) and signal transducers and activators of transcription (STAT) are suggested to play an important role. However, whether in vivo activation of JAK-STAT pathway occurs during myocardial ischemia is still unknown. The purpose of this study was to determine whether myocardial JAK or STAT is activated in ischemic heart, and to evaluate the angiotensin blockade on the pathway. Myocardial infarction was produced by ligation of the coronary artery in Wistar rats. After myocardial ischemia, we analysed both activated levels and total amounts of JAK1, JAK2, STAT1 and STAT3 by Western blot analyses at 0, 5, 15, 30, 60, 120 and 240 min. Compared with JAK activities at 0 min, JAK1 activities were significantly increased at 60 and 120 min (3.0- and 3.7-fold, respectively, P<0.01). JAK2 and STAT1 activities of ischemic myocardium were unchanged through the time course. STAT3 activities were increased at 5 min (3.3-fold, P<0.01) and markedly enhanced at 30, 60 and 120 min (4.6-, 7.7- and 8.7-fold, respectively, P<0.01). Pretreatment with imidapril (ACE inhibitor) and candesartan cilexitil (AT1 receptor antagonist) significantly prevented the increase in the phosphorylation of JAK1 at 120 min and STAT3 at 30 and 120 min. Sis-inducing factor (SIF) DNA complex was supershifted by specific anti-STAT3 antibody, indicating that increased SIF complex at least contained activated STAT3 proteins in ischemic myocardium. Imidapril and candesartan cilexitil inhibited the activation of SIF DNA binding at 1 day after coronary ligation. In conclusion, we showed that JAK1 and STAT3 were activated by ischemia from the basal activities in in vivo rat myocardial ischemia model. Imidapril and candesartan cilexitil prevented the increase in phosphorylated JAK1 and STAT3, thereby suggesting that angiotensin II, especially angiotensin II type I receptor, partially mediates activation of myocardial JAK-STAT pathway in acute myocardial ischemia.
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Affiliation(s)
- T Omura
- First Department of Internal Medicine, Osaka City University Medical School, Osaka, Japan.
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40
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Jin H, Yang R, Li W, Lu H, Ryan AM, Ogasawara AK, Van Peborgh J, Paoni NF. Effects of exercise training on cardiac function, gene expression, and apoptosis in rats. Am J Physiol Heart Circ Physiol 2000; 279:H2994-3002. [PMID: 11087257 DOI: 10.1152/ajpheart.2000.279.6.h2994] [Citation(s) in RCA: 86] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
This study determined the effects of exercise training on cardiac function, gene expression, and apoptosis. Rats exposed to a regimen of treadmill exercise for 13 wk had a significant increase in cardiac index and stroke volume index and a concomitant decrease in systemic vascular resistance compared with both age-matched and body weight-matched sedentary controls in the conscious state at rest. In exercise-trained animals, there was no change in the expression of several marker genes known to be associated with pathological cardiac adaptation, including atrial natriuretic factor, beta-myosin heavy chain, alpha-skeletal and smooth muscle actins, and collagens I and III. Exercise training, however, produced a significant induction of alpha-myosin heavy chain, which was not observed in rats with myocardial infarction. No histological features of cardiac apoptosis were observed in the treadmill-trained rats. In contrast, apoptotic myocytes were detected in animals with myocardial infarction. In summary, exercise training improves cardiac function without evidence of cardiac apoptosis and produces a pattern of cardiac gene expression distinct from pathological cardiac adaptation.
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Affiliation(s)
- H Jin
- Department of Cardiovascular Research, Genentech Incorporated, South San Francisco, California 94080, USA
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41
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Hao J, Wang B, Jones SC, Jassal DS, Dixon IM. Interaction between angiotensin II and Smad proteins in fibroblasts in failing heart and in vitro. Am J Physiol Heart Circ Physiol 2000; 279:H3020-30. [PMID: 11087260 DOI: 10.1152/ajpheart.2000.279.6.h3020] [Citation(s) in RCA: 122] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Angiotensin II (angiotensin) and transforming growth factor (TGF)-beta(1) play an important role in cardiac fibrosis. We examined Smad proteins in 8-wk post-myocardial infarction (MI) rat hearts. AT(1) blockade (losartan) attenuated the activation of TGF-beta(1) in target tissues. Losartan administration (8 wk, 15 mg. kg(-1). day(-1)) normalized total Smad 2 overexpression in infarct scar and remnant heart tissue and normalized Smad 4 in infarct scar. Phosphorylated Smad 2 (P-Smad 2) staining decreased in cytosol from failing heart vs. the control, which was normalized by losartan, suggesting augmented P-Smad 2 movement into nuclei in untreated failing hearts. Using adult primary rat fibroblasts treated with angiotensin (10(-6) M), we noted rapid translocation (15 min) of P-Smad 2 into the nuclei from the cytosol. Nuclear P-Smad 2 protein level increased with angiotensin treatment, which was blocked by losartan. We conclude that angiotensin may influence total Smad 2 and 4 expression in post-MI heart failure and that angiotensin treatment is associated with rapid P-Smad 2 nuclear translocation in isolated fibroblasts. This study suggests that cross talk between angiotensin and Smad signaling is associated with fibrotic events in post-MI hearts.
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Affiliation(s)
- J Hao
- Laboratory of Molecular Cardiology, Institute of Cardiovascular Sciences, St. Boniface General Hospital Research Centre, Faculty of Medicine, University of Manitoba, Winnipeg, Manitoba, Canada R2H 2A6
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Akao M, Sakurai T, Horie M, Otani H, Takano M, Kouchi I, Murakami T, Sasayama S. Angiotensin II type 1 receptor blockade abolishes specific K(ATP)channel gene expression in rats with myocardial ischemia. J Mol Cell Cardiol 2000; 32:2239-47. [PMID: 11112999 DOI: 10.1006/jmcc.2000.1251] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The cardiac ATP-sensitive potassium (K(ATP)) channel is potentially composed of an inward rectifier potassium channel (Kir6.1 and/or Kir6.2) subunit and the cardiac type of sulfonylurea receptor (SUR2A). We reported that cardiac Kir6.1 mRNA and protein are specifically upregulated in the non-ischemic as well as the ischemic regions in rats with myocardial ischemia, suggesting that humoral and/or hemodynamic factors are responsible for this regulation. In the present study, pretreatment with TCV-116, an angiotensin (Ang) II type 1 receptor antagonist, completely inhibited the upregulation of Kir6.1 mRNA and protein expression in both regions of rat hearts subjected to 60 min of coronary artery occlusion followed by 24 h of reperfusion; whereas pretreatment with lisinopril, an Ang converting enzyme (ACE) inhibitor, partly inhibited this upregulation. Except for rats pretreated with TCV-116, Kir6.1 mRNA levels were positively correlated with those for brain natriuretic peptide (BNP), a molecular indicator of regional wall stress, in both the non-ischemic and the ischemic regions. Plasma Ang II levels were not elevated in rats with control myocardial ischemia compared with sham rats. Thus, the stress-related induction of cardiac Kir6.1 mRNA and protein expression under myocardial ischemia is inhibited by pretreatment with an AT1 antagonist, but also in part by an ACE inhibitor, suggesting that activation of local renin-angiotensin system may play a role.
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Affiliation(s)
- M Akao
- Department of Cardiovascular Medicine, Kyoto University Graduate School of Medicine, Kyoto, 606-8507, Japan
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Taniyama Y, Morishita R, Nakagami H, Moriguchi A, Sakonjo H, Matsumoto K, Nakamura T, Higaki J, Ogihara T. Potential contribution of a novel antifibrotic factor, hepatocyte growth factor, to prevention of myocardial fibrosis by angiotensin II blockade in cardiomyopathic hamsters. Circulation 2000; 102:246-52. [PMID: 10889138 DOI: 10.1161/01.cir.102.2.246] [Citation(s) in RCA: 136] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
BACKGROUND Because hepatocyte growth factor (HGF) prevented and/or regressed fibrosis in liver and pulmonary injury models, HGF may play an important role in the pathogenesis of fibrotic cardiovascular disease. Because angiotensin (Ang) II significantly decreased local HGF production, we performed (1) in vitro experiments using fibroblasts and (2) administration of an ACE inhibitor (temocapril) and an Ang II type 1 receptor antagonist (CS-866) to cardiomyopathic hamsters. METHODS AND RESULTS In human fibroblasts, HGF significantly increased the production of matrix metalloprotease-1 (MMP-1) and urokinase plasminogen activator, whereas HGF also significantly attenuated the reduction of MMP-1 activity induced by Ang II. In contrast, HGF significantly decreased transforming growth factor (TGF)-beta mRNA stimulated by Ang II, whereas HGF also decreased basal TGF-beta protein level without affecting growth. Similarly, in rat cardiac fibroblasts, HGF inhibited the expression and production of TGF-beta, whereas HGF upregulated its specific receptor, c-met. Conversely, in vivo experiments revealed that administration of temocapril and CS-866 to cardiomyopathic hamsters resulted in a significant decrease in fibrotic area and increase in cardiac HGF concentration and mRNA (P<0.01), whereas cardiac concentration and mRNA of HGF were significantly decreased in cardiomyopathic hamsters. In contrast, mRNA expression of collagen III was markedly decreased by treatment with temocapril and CS-866. CONCLUSIONS Here, we demonstrated that Ang II blockade prevented myocardial fibrosis in the cardiomyopathic hamster, accompanied by a significant increase in cardiac HGF. Overall, increase in local HGF expression may participate in the prevention of myocardial injury by Ang II blockade through its antifibrotic action.
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Affiliation(s)
- Y Taniyama
- Department of Geriatric Medicine, Osaka University Medical School, Suita, Japan
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Takeuchi K, Omura T, Yoshiyama M, Yoshida K, Otsuka R, Shimada Y, Ujino K, Yoshikawa J. Long-acting calcium channel antagonist pranidipine prevents ventricular remodeling after myocardial infarction in rats. Heart Vessels 2000; 14:111-9. [PMID: 10776803 DOI: 10.1007/bf02482294] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/24/2022]
Abstract
The purpose of this study was to examine the effects of the long-acting calcium channel antagonist pranidipine on ventricular remodeling, systolic and diastolic cardiac function, circulating humoral factors, and cardiac mRNA expression in myocardial infarcted rats. Myocardial infarction (MI) was produced by ligation of the coronary artery in Wistar rats. Three mg/kg per day of pranidipine was randomly administered to the infarcted rats. Hemodynamic measurements, Doppler echocardiographic examinations, analyses of the plasma levels of humoral factors, and myocardial mRNA expression were performed at 4 weeks after myocardial infarction. Left ventricular end-diastolic pressure (LVEDP) and central venous pressure (CVP) increased to 24.2 +/- 1.2mmHg and 5.4 +/- 0.6 mmHg. Pranidipine reduced LVEDP and CVP to 13.6 +/- 1.4mmHg (P < 0.01) and 2.5 +/- 0.4mmHg (P < 0.01). The weight of the left and right ventricles in MI was significantly higher than in the sham-operated rats (sham, 2.02 +/- 0.04 and 0.47 +/- 0.02g/kg; MI, 2.18 +/- 0.05 and 0.79 +/- 0.04g/ kg; P < 0.01). Left ventricular end-diastolic dimension (LVDd) in MI increased to 10.3 +/- 0.3mm (P < 0.01) (sham, 6.4 +/- 0.3mm). Pranidipine prevented an increase in the weight of the left and right ventricles (2.02 +/- 0.04 and 0.6 +/- 0.03g/kg, P < 0.01) and LVDd (7.9 +/-0.2mm, P < 0.01 to MI). Plasma renin activity (PRA), and plasma epinephrine, norepinephrine, and dopamine concentrations in MI were higher than those of the sham-operated rats. Pranidipine decreased the PRA and plasma cathecolamine levels of the myocardial infarcted rats to the level of the sham-operated rats. Moreover, the rats in MI showed systolic dysfunction, shown by decreased fractional shortening (sham, 31 +/- 2% vs MI, 15 +/- 1%; P < 0.01) and diastolic dysfunction shown by the E-wave deceleration rate (sham, 12.8 +/- 1.1 m/s2; MI, 32.6 +/- 2.1 m/s2; P < 0.01). Pranidipine significantly prevented systolic and diastolic dysfunction. The increases in beta-myosin heavy chain (MHC), alpha-skeletal actin, and atrial natriuretic polypeptide mRNAs in the noninfarcted left ventricle and right ventricle at 4 weeks after the myocardial infarction were significantly suppressed by the treatment with pranidipine. On the other hand, depressed alpha-MHC was restored to normal levels by pranidipine in both regions. In conclusion, pranidipine prevents the left ventricular remodeling process accompanied by systolic and diastolic dysfunction, and inhibits abnormal cardiac gene expression after myocardial infarction.
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Affiliation(s)
- K Takeuchi
- First Department of Internal Medicine, Osaka City University Medical School, Osaka, Japan
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Abstract
This study was designed to elaborate a molecular profile of expressed genes during ischemic injury to the mouse heart after surgical constriction of the left coronary artery without reperfusion. A mouse cDNA array containing 588 known genes was used to compare gene expression in heart RNA after 24-h ischemia with control tissue. Alterations in gene expression on the array were supported by relative reverse transcription-polymerase chain reaction analysis after timed periods of ischemia. Decreased levels of the cell cycle regulator p18ink4 and the oxidative responsive gene glutathione S-transferase were accompanied by an upregulation of the genes associated with cardiac muscle development, alpha-myosin heavy chain and fetal myosin alkali light chain. Other stress responses elicited by cardiac injury included an induction of Egr-1 and Egr-3 transcription factors, as well as the apoptotic regulator Bax. Altogether, these findings indicate that expression of genes associated with a fetal transcription program may be involved with the post ischemic remodeling process in heart ventricles.
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Affiliation(s)
- D Lyn
- Department of Biochemistry, and the Cardiovascular Institute, Morehouse School of Medicine, Atlanta, Georgia 30310, USA.
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46
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Graf K, Neuss M, Stawowy P, Hsueh WA, Fleck E, Law RE. Angiotensin II and alpha(v)beta(3) integrin expression in rat neonatal cardiac fibroblasts. Hypertension 2000; 35:978-84. [PMID: 10775572 DOI: 10.1161/01.hyp.35.4.978] [Citation(s) in RCA: 44] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
We recently demonstrated that alpha(v)beta(3) integrins are involved in the mechanisms of angiotensin II (Ang II)-induced DNA synthesis and collagen gel contractions in rat cardiac fibroblasts (CFBs), cellular mechanisms that are relevant for cardiac remodeling. The aim of the present study was to elucidate the effect of Ang II and other growth factors on the regulation of the alpha(v)beta(3) integrins in fibroblasts from neonatal rat hearts. The alpha(v)beta(3) integrin receptor expression was significantly increased (P<0.05) at the mRNA level after treatment with Ang II, transforming growth factor-beta(1) (TGF-beta(1)), and platelet-derived growth factor (PDGF) for 8 and 16 hours. The surface expression of the alpha(v) and beta(3) integrin subunits was elevated after 32 and 48 hours (P<0.05) as determined with flow cytometry. To investigate fibroblast motility, we performed chemotaxis experiments with transwell chambers. Ang II was chemotactic for CFBs, as tested with checkerboard experiments. The chemotactic effect was concentration dependent and was completely blocked by Ang II type 1 receptor blockers but not by Ang II type 2 receptor blocker PD 123319. Ang II- and PDGF-BB-mediated chemotaxis could be significantly inhibited by RGD peptides and the blocking antibodies against alpha(v)beta(3) integrin (both P<0.01). Adhesion of CFBs to vitronectin was partially inhibited by an antibody to alpha(v)beta(3) integrin but was mainly mediated by an alpha(v)beta(5) integrin. Relevant in vivo expression of alpha(v)beta(3) integrin by CFBs was confirmed with in situ hybridization with probes for alpha(v) and beta(3) mRNA in rat hearts. The present study demonstrates that the expression of alpha(v)beta(3) integrin is augmented by Ang II, PDGF, and TGF-beta(1) in neonatal CFBs. Furthermore, this integrin is involved in the chemotaxis, motility, and adhesion of CFBs. The present findings support the current concept that integrins participate in the control of fibroblast behavior during cardiac remodeling mechanisms.
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Affiliation(s)
- K Graf
- Division of Endocrinology, Diabetes and Hypertension, University of California Los Angeles, School of Medicine, Los Angeles, CA, USA
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47
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Omura T, Yoshiyama M, Takeuchi K, Kim S, Iwao H, Yamagishi H, Toda I, Teragaki M, Akioka K, Yoshikawa J. Angiotensin blockade inhibits SIF DNA binding activities via STAT3 after myocardial infarction. J Mol Cell Cardiol 2000; 32:23-33. [PMID: 10652187 DOI: 10.1006/jmcc.1999.1051] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The in vivo activation of transcription factors, which is important for cell regulation by gene expression, has not been well examined in myocardial infarcted heart. The purpose of this study was to determine whether myocardial signal transducer and activator of transcription (STAT) pathway is activated as sis-inducing factor (SIF) in infarcted heart, and to assess the angiotensin blockade on SIF activity in ischemic and non-ischemic myocardium of rat. Myocardial infarction was made by ligation of the coronary artery in Wistar rats. In electrophoretic mobility shift assay, myocardial SIF DNA binding activities gradually increased and reached to peak at 1 week in infarcted and non-infarcted regions after myocardial infarction. Imidapril and candesartan cilexitil significantly prevented the increase in SIF DNA binding activity in infarcted and non-infarcted regions. This increased SIF DNA complex was supershifted by specific anti-STAT3 antibody, indicating that increased SIF complex at least contained activated STAT3 proteins in myocardial infarcted heart. Furthermore, immunoprecipitation-Western blot analysis revealed that STAT3 of infarcted and non-infarcted regions were tyrosine-phosphorylated at 1 week after myocardial infarction. Imidapril and candesartan cilexitil prevented the increase in phosphorylated STAT3. Thus, the transcriptional activation of STAT3 through AT1 receptor may be partially involved in cardiac remodeling after myocardial infarction.
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Affiliation(s)
- T Omura
- First Department of Internal Medicine, Osaka City University Medical School, Osaka, Japan
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48
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Gurantz D, Cowling RT, Villarreal FJ, Greenberg BH. Tumor necrosis factor-alpha upregulates angiotensin II type 1 receptors on cardiac fibroblasts. Circ Res 1999; 85:272-9. [PMID: 10436170 DOI: 10.1161/01.res.85.3.272] [Citation(s) in RCA: 70] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Angiotensin II (Ang II) plays an important role in post-myocardial infarction (MI) remodeling. Most Ang II effects related to remodeling involve activation of the type 1 receptor (AT(1)). Although the AT(1) receptor is upregulated on cardiac fibroblasts post-MI, little is known about the mechanisms involved in the process. Consequently, we tested whether growth factors known to be present in the remodeling heart increased AT(1) mRNA levels. Using quantitative competitive reverse transcription-polymerase chain reaction, we found that norepinephrine, endothelin, atrial natriuretic peptide, and bradykinin had no significant effect on AT(1) mRNA levels. Ang II, transforming growth factor-beta(1), and basic fibroblast growth factor reduced AT(1) mRNA levels (P<0.02). Tumor necrosis factor-alpha (TNF-alpha), however, produced a marked increase in AT(1) mRNA. After 24 hours of TNF-alpha incubation, AT(1) mRNA increased by 5-fold above control levels (P<0.01). The EC(50) for the TNF-alpha effect was 4.6 ng/mL (0.2 nmol/L). Interleukin (IL)-1beta caused a 2.4-fold increase, whereas IL-2 and IL-6 had no significant effect. Studies of TNF-alpha enhancement of AT(1) mRNA levels demonstrate that the increase was not due to a change in transcript stability. TNF-alpha treatment for 48 hours also resulted in a 3-fold increase in AT(1) surface receptor and a 2-fold increase in Ang II-induced production of inositol phosphates. The present findings provide evidence for TNF-alpha regulation of AT(1) receptor density on cardiac fibroblasts. Because TNF-alpha concentration and AT(1) receptor density increase in the myocardium after MI, these results raise the possibility that TNF-alpha modulates post-MI remodeling by enhancing Ang II effects on cardiac fibroblasts.
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MESH Headings
- Angiotensin II/pharmacology
- Animals
- Cells, Cultured
- Dose-Response Relationship, Drug
- Drug Stability
- Fibroblasts/drug effects
- Fibroblasts/metabolism
- Inositol Phosphates/biosynthesis
- Myocardium/cytology
- Myocardium/metabolism
- RNA, Messenger/chemistry
- RNA, Messenger/metabolism
- Rats
- Rats, Sprague-Dawley
- Receptor, Angiotensin, Type 1
- Receptor, Angiotensin, Type 2
- Receptors, Angiotensin/drug effects
- Receptors, Angiotensin/genetics
- Receptors, Angiotensin/metabolism
- Tumor Necrosis Factor-alpha/pharmacology
- Up-Regulation/physiology
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Affiliation(s)
- D Gurantz
- Department of Medicine, Division of Cardiology, University of California, San Diego Medical Center, San Diego, CA, USA
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49
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Weber KT. Angiotensin II and connective tissue: homeostasis and reciprocal regulation. REGULATORY PEPTIDES 1999; 82:1-17. [PMID: 10458642 DOI: 10.1016/s0167-0115(99)00032-4] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
As a concept traditionally applied to integrative organ physiology, homeostasis likewise applies to self-regulated growth and structure of loose, dense and specialized connective tissues. De novo generation and co-induction of signals, either stimulatory or inhibitory to the formation of these tissues, provide for a reciprocal regulation of their composition; angiotensin (Ang) II is a growth stimulator. Components involved in AngII generation and its biological activity, including angiotensin converting enzyme (ACE) and AngII receptors, are expressed by mesenchymal cells responsible for connective tissue turnover. ACE inhibition or AT1 receptor antagonism attenuate the formation of these connective tissues. The concept of circulatory homeostasis, and the endocrine properties of plasma AngII involved in maintaining same, need each be broadened to encompass auto- and paracrine effects of AngII produced within connective tissues, where it contributes to their homeostatic regulation of structure and composition.
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Affiliation(s)
- K T Weber
- Division of Cardiology, University of Missouri Health Sciences Center, Columbia, USA.
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50
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Ambrose J, Pribnow DG, Giraud GD, Perkins KD, Muldoon L, Greenberg BH. Angiotensin type 1 receptor antagonism with irbesartan inhibits ventricular hypertrophy and improves diastolic function in the remodeling post-myocardial infarction ventricle. J Cardiovasc Pharmacol 1999; 33:433-9. [PMID: 10069680 DOI: 10.1097/00005344-199903000-00014] [Citation(s) in RCA: 22] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
To evaluate the role of angiotensin II (AII) on diastolic function during post-myocardial infarction (MI) ventricular remodeling, coronary ligation or sham operation was performed in male Sprague-Dawley rats. Experimental animals were maintained on either irbesartan, a selective AT1-receptor antagonist, or no treatment. Measurement of cardiac hypertrophy, diastolic function, and sarcoendoplasmic reticulum adenosine triphosphatase (ATPase; SERCA) and phospholamban (PLB) gene expression was assessed at 6 weeks after MI. Myocardial infarction caused a significant increase in myocardial mass and left ventricular (LV) filling pressure, whereas LV systolic pressure and +dP/dt were reduced. The time constant of isovolumic relaxation (tau) was markedly prolonged after MI. Post-MI hypertrophy was associated with substantial increases in the messenger RNA (mRNA) expression of atrial natriuretic peptide (ANP), but no significant changes in SERCA or PLB levels. Although irbesartan treatment did not significantly alter post-MI LV systolic or filling pressures, it nevertheless effectively decreased ventricular hypertrophy, improved tau, and normalized ANP expression. These results demonstrate that AT1-receptor antagonism has important effects on myocardial hypertrophy and ANP gene expression, which are independent of ventricular loading conditions. In addition, the improvement in diastolic function was not related to changes in SERCA and PLB gene expression, suggesting that enhanced myocardial relaxation was related to the blockade of AII effects on myocyte function or through a reduction of ventricular hypertrophy itself or both.
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Affiliation(s)
- J Ambrose
- Division of Cardiovascular Medicine, University of California, San Diego, USA
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