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Ogita H, Node K, Asanuma H, Sanada S, Kim J, Takashima S, Minamino T, Hori M, Kitakaze M. Raloxifene Improves Coronary Perfusion, Cardiac Contractility, and Myocardial Metabolism in the Ischemic Heart: Role of Phosphatidylinositol 3-Kinase/Akt Pathway. J Cardiovasc Pharmacol 2004; 43:821-9. [PMID: 15167276 DOI: 10.1097/00005344-200406000-00012] [Citation(s) in RCA: 17] [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
The purpose of this study is to examine whether raloxifene, one of the selective estrogen receptor modulators, could improve myocardial ischemia and to assess the mechanisms involved. In open-chest beagle dogs anesthetized by intravenous infusion of sodium pentobarbital, the left anterior descending coronary artery (LAD) was perfused from the left carotid artery through an extracorporeal bypass tube. Raloxifene was infused into the LAD through the bypass tube under either ischemic or non-ischemic conditions. In the non-ischemic heart, raloxifene had no effect on coronary blood flow, fractional shortening, and myocardial metabolism. However, raloxifene caused an acute increase in both coronary blood flow and fractional shortening, and also improved myocardial anaerobic metabolism in the ischemic heart. These effects were partially attenuated by pretreatment with either L-NAME or wortmannin and were completely abolished by ICI182780 (an estrogen receptor antagonist) or L-NAME plus charybdotoxin (a blocker of Ca-activated K channels). Raloxifene also increased both Akt activity and the NO level, with these changes being completely abrogated by pretreatment with wortmannin. These results demonstrated that raloxifene improves coronary perfusion, cardiac contractility, and myocardial metabolism by release of NO and opening of Ca-activated K channels in the ischemic heart, and that NO production is mediated by the phosphatidylinositol 3-kinase/Akt pathway.
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Asanuma H, Minamino T, Sanada S, Takashima S, Ogita H, Ogai A, Asakura M, Liao Y, Asano Y, Shintani Y, Kim J, Shinozaki Y, Mori H, Node K, Kitamura S, Tomoike H, Hori M, Kitakaze M. Beta-adrenoceptor blocker carvedilol provides cardioprotection via an adenosine-dependent mechanism in ischemic canine hearts. Circulation 2004; 109:2773-9. [PMID: 15148268 DOI: 10.1161/01.cir.0000130917.12959.04] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
BACKGROUND Carvedilol is a beta-adrenoceptor blocker with a vasodilatory action that is more effective for the treatment of congestive heart failure than other beta-blockers. Recently, carvedilol has been reported to reduce oxidative stress, which may consequently reduce the deactivation of adenosine-producing enzymes and increase cardiac adenosine levels. Therefore, carvedilol may also have a protective effect on ischemia and reperfusion injury, because adenosine mediates cardioprotection in ischemic hearts. METHODS AND RESULTS In anesthetized dogs, the left anterior descending coronary artery was occluded for 90 minutes, followed by reperfusion for 6 hours. Carvedilol reduced the infarct size (15.0+/-2.8% versus 40.9+/-4.2% in controls), and this effect was completely reversed by the nonselective adenosine receptor antagonist 8-sulfophenyltheophylline (45.2+/-5.4%) or by an inhibitor of ecto-5'-nucleotidase (44.4+/-3.6%). There were no differences of either area at risk or collateral flow among the various groups. When the coronary perfusion pressure was reduced in other dogs so that coronary blood flow was decreased to 50% of the nonischemic level, carvedilol increased coronary blood flow (49.4+/-5.6 to 73.5+/-7.5 mL x 100 g(-1) x min(-1); P<0.05) and adenosine release (112.3+/-22.2 to 240.6+/-57.1 nmol/L; P<0.05) during coronary hypoperfusion. This increase of coronary blood flow was attenuated by either 8-sulfophenyltheophylline or superoxide dismutase. In human umbilical vein endothelial cells cultured with or without xanthine and xanthine oxidase, carvedilol caused an increase of ecto-5'-nucleotidase activity. CONCLUSIONS Carvedilol shows a cardioprotective effect against ischemia and/or reperfusion injury via adenosine-dependent mechanisms.
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Asanuma H, Sanada S, Ogai A, Minamino T, Takashima S, Asakura M, Ogita H, Shinozaki Y, Mori H, Node K, Tomoike H, Hori M, Kitakaze M. Methotrexate and MX-68, a New Derivative of Methotrexate, Limit Infarct Size via Adenosine-Dependent Mechanisms in Canine Hearts. J Cardiovasc Pharmacol 2004; 43:574-9. [PMID: 15085069 DOI: 10.1097/00005344-200404000-00013] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Methotrexate, an anti-rheumatic agent, has recently been reported to show an anti-inflammatory action via ecto-5'-nucleotidase- and adenosine-dependent mechanisms. Because ecto-5'-nucleotidase contributes to the production of adenosine and adenosine has a potent cardioprotective effect against ischemia/reperfusion injury, we investigated whether methotrexate or MX-68 [N-1-((2,4-diamino-6-pteridinyl) methyl)-3,4-dihydro-2H-1,4-benzothiazine-7- carbonyl]-N-2- aminoadipic acid] could reduce infarct size via adenosine-dependent mechanisms. In beagle dogs, the left anterior descending coronary artery was perfused through a bypass tube, which was occluded for 90 minutes followed by 6 hours of reperfusion. The size of infarcts was assessed by TTC staining. MX-68 reduced infarct size compared with that in untreated dogs (13.7 +/- 1.9 versus 38.6 +/- 5.3%, P < 0.01). This effect was completely blunted by either the adenosine receptor antagonist 8-sulfophenyltheophylline (8-SPT) (45.0 +/- 4.6% and 46.8 +/- 5.8% in the 8-SPT and MX-68 + 8-SPT groups, respectively) or by the ecto-5'-nucleotidase inhibitoralpha,beta-methylenadenosine 5'-diphosphate (AMP-CP) (44.0 +/- 4.5% and 46.7 +/- 5.8% in the AMP-CP and MX-68 + AMP-CP groups, respectively). Methotrexate also reduced infarct size to a level comparable with that in the MX-68 group, and its effect was also blunted by 8-SPT. There were no significant differences of collateral blood flow or risk area between the groups. We conclude that methotrexate and its derivative (MX-68) both limit infarct size via adenosine-dependent mechanisms.
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Asano Y, Takashima S, Asakura M, Shintani Y, Liao Y, Minamino T, Asanuma H, Sanada S, Kim J, Ogai A, Fukushima T, Oikawa Y, Okazaki Y, Kaneda Y, Sato M, Miyazaki JI, Kitamura S, Tomoike H, Kitakaze M, Hori M. Lamr1 functional retroposon causes right ventricular dysplasia in mice. Nat Genet 2004; 36:123-30. [PMID: 14730304 DOI: 10.1038/ng1294] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2003] [Accepted: 12/29/2003] [Indexed: 11/08/2022]
Abstract
Arrhythmogenic right ventricular dysplasia (ARVD) is a hereditary cardiomyopathy that causes sudden death in the young. We found a line of mice with inherited right ventricular dysplasia (RVD) caused by a mutation of the gene laminin receptor 1 (Lamr1). This locus contained an intron-processed retroposon that was transcribed in the mice with RVD. Introduction of a mutated Lamr1 gene into normal mice by breeding or by direct injection caused susceptibility to RVD, which was similar to that seen in the RVD mice. An in vitro study of cardiomyocytes expressing the product of mutated Lamr1 showed early cell death accompanied by alteration of the chromatin architecture. We found that heterochromatin protein 1 (HP1) bound specifically to mutant LAMR1. HP1 is a dynamic regulator of heterochromatin sites, suggesting that mutant LAMR1 impairs a crucial process of transcriptional regulation. Indeed, mutant LAMR1 caused specific changes to gene expression in cardiomyocytes, as detected by gene chip analysis. Thus, we concluded that products of the Lamr1 retroposon interact with HP1 to cause degeneration of cardiomyocytes. This mechanism may also contribute to the etiology of human ARVD.
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Ogita H, Node K, Liao Y, Ishikura F, Beppu S, Asanuma H, Sanada S, Takashima S, Minamino T, Hori M, Kitakaze M. Raloxifene prevents cardiac hypertrophy and dysfunction in pressure-overloaded mice. Hypertension 2003; 43:237-42. [PMID: 14676219 DOI: 10.1161/01.hyp.0000109320.25921.b1] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
17beta-estradiol reduces myocardial hypertrophy and left ventricular mass, suggesting that the selective estrogen receptor modulator raloxifene may have similar effects. However, it is not clear whether raloxifene inhibits both cardiac hypertrophy and dysfunction. We used transverse aortic-banded mice to produce pressure-overload cardiac hypertrophy and used neonatal rat ventricular cardiomyocytes to investigate the cellular mechanisms of raloxifene on cardiac hypertrophy. Left ventricular mass and fractional shortening of mice hearts were measured by transthoracic echocardiography. Protein synthesis of cardiomyocytes was evaluated by incorporation of [3H]leucine into cardiomyocytes exposed to angiotensin II. Phosphorylation of mitogen-activated protein (MAP) kinase was also observed in cardiomyocytes. Raloxifene prevented increases in left ventricular mass and decreases of fractional shortening at 4 weeks after aortic banding. Pretreatment with raloxifene before angiotensin II stimulation inhibited the increase in [3H]leucine incorporation into neonatal rat cardiomyocytes in a concentration-dependent manner. This inhibition was partially but not significantly attenuated by N(G)-nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide synthase, and completely abolished by ICI182780, an estrogen receptor antagonist. Although the phosphorylation of p38 MAP kinase, c-Jun N-terminal kinase (JNK), or extracellular signal-regulated protein kinase (ERK) in cardiomyocytes was significantly increased by angiotensin II stimulation as compared with the control, pretreatment with raloxifene attenuated p38 MAP kinase phosphorylation, but neither JNK nor ERK phosphorylation. We conclude that raloxifene inhibits cardiac hypertrophy and dysfunction and that the inhibition of p38 MAP kinase phosphorylation after the stimulation of estrogen receptors may be involved in the cellular mechanisms of this agent.
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Liao Y, Takashima S, Asano Y, Asakura M, Ogai A, Shintani Y, Minamino T, Asanuma H, Sanada S, Kim J, Ogita H, Tomoike H, Hori M, Kitakaze M. Activation of adenosine A1 receptor attenuates cardiac hypertrophy and prevents heart failure in murine left ventricular pressure-overload model. Circ Res 2003; 93:759-66. [PMID: 12970111 DOI: 10.1161/01.res.0000094744.88220.62] [Citation(s) in RCA: 102] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/23/2023]
Abstract
Sympathomimetic stimulation, angiotensin II, or endothelin-1 is considered to be an essential stimulus mediating ventricular hypertrophy. Adenosine is known to protect the heart from excessive catecholamine exposure, reduce production of endothelin-1, and attenuate the activation of the renin-angiotensin system. These findings suggest that adenosine may also attenuate myocardial hypertrophy. To verify this hypothesis, we examined whether activation of adenosine receptors can attenuate cardiac hypertrophy and reduce the risk of heart failure. Our in vitro study of neonatal rat cardiomyocytes showed that 2-chloroadenosine (CADO), a stable adenosine analogue, inhibits protein synthesis of cardiomyocytes induced by phenylephrine, endothelin-1, angiotensin II, or isoproterenol, which were mimicked by the stimulation of adenosine A1 receptors. For our in vivo study, cardiac hypertrophy was induced by transverse aortic constriction (TAC) in C57BL/6 male mice. Four weeks after TAC, both heart to body weight ratio (6.80+/-0.18 versus 8.34+/-0.33 mg/g, P<0.0001) as well as lung to body weight ratio (6.23+/-0.27 versus 10.03+/-0.85 mg/g, P<0.0001) became significantly lower in CADO-treated mice than in the TAC group. Left ventricular fractional shortening and left ventricular dP/dtmax were improved significantly by CADO treatment. Similar results were obtained using the selective adenosine A1 agonist N6-cyclopentyladenosine (CPA). A nonselective adenosine antagonist, 8-(p-sulfophenyl)-theophylline, and a selective adenosine A1 antagonist, 8-cyclopentyl-1,3-dipropylxanthine, eliminated the antihypertrophic effect of CADO and CPA, respectively. The plasma norepinephrine level was decreased and myocardial expression of regulator of G protein signaling 4 was upregulated in CADO-treated mice. These results indicate that the stimulation of adenosine receptors attenuates both the cardiac hypertrophy and myocardial dysfunction via adenosine A1 receptor-mediated mechanisms.
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MESH Headings
- 2-Chloroadenosine/pharmacology
- 2-Chloroadenosine/therapeutic use
- Animals
- Aorta/surgery
- Cells, Cultured
- Constriction
- Cyclic AMP-Dependent Protein Kinases/antagonists & inhibitors
- Heart Failure/etiology
- Heart Failure/prevention & control
- Heterotrimeric GTP-Binding Proteins/metabolism
- Hypertrophy, Left Ventricular/drug therapy
- Hypertrophy, Left Ventricular/etiology
- Hypertrophy, Left Ventricular/pathology
- Hypertrophy, Left Ventricular/physiopathology
- Male
- Mice
- Mice, Inbred C57BL
- Myocytes, Cardiac/cytology
- Myocytes, Cardiac/drug effects
- Myocytes, Cardiac/metabolism
- Purinergic P1 Receptor Agonists
- Purinergic P1 Receptor Antagonists
- Receptors, Cell Surface/agonists
- Ventricular Pressure
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Asakura M, Takashima S, Asano Y, Honma T, Asanuma H, Sanada S, Shintani Y, Liao Y, Kim J, Ogita H, Node K, Minamino T, Yorikane R, Agai A, Kitamura S, Tomoike H, Hori M, Kitakaze M. Canine DNA array as a potential tool for combining physiology and molecular biology. Circ J 2003; 67:788-92. [PMID: 12939556 DOI: 10.1253/circj.67.788] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The combining of molecular biology and physiology is essential for the further development of cardiovascular medicine, and DNA microarray is a useful tool for assessing multiple gene expressions. A canine DNA microarray has been designed and tested. Approximately 60 cardiovascular-related genes were cloned from newly developed canine cDNA libraries and spotted on slides. Using the arrays, the gene expression profiles of canine myocardium in were analyzed 2 protocols: (1). ischemic myocardium by 50% reduction of the coronary blood flow, and (2). necrotic myocardium caused by coronary artery ligation. Three hours after 50% flow reduction, cardiovascular-related genes, including ecto-5'-nucleotidase, endothelin-1, PAI-1, and AT receptors, exhibited rapid alteration and there were many more altered genes than with the complete coronary occlusion. Irreversible ischemic damage without necrosis more strongly affected gene expressions in surviving myocardium than in fatally damaged myocardium. The canine DNA microarray is a useful tool for assessing the precise molecular events following changes in the pathophysiological conditions of the heart.
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Ogita H, Node K, Asanuma H, Sanada S, Takashima S, Minamino T, Soma M, Kim J, Hori M, Kitakaze M. Eicosapentaenoic acid reduces myocardial injury induced by ischemia and reperfusion in rabbit hearts. J Cardiovasc Pharmacol 2003; 41:964-9. [PMID: 12775977 DOI: 10.1097/00005344-200306000-00020] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Intake of fish oil is known to have cardioprotective effects and reduce cardiovascular mortality. However, it is not widely recognized that eicosapentaenoic acid (EPA), one of the n-3 polyunsaturated fatty acids (PUFAs), exerts beneficial effects against myocardial ischemia/reperfusion injury. The purpose of this study is to investigate whether EPA attenuates the severity of myocardial ischemia/reperfusion injury and which cellular mechanism is involved. Rabbits were treated with or without EPA (600 mg/kg/day) for 2 weeks. Infarct size was measured in open-chest rabbits after 30-minute occlusion of the left anterior descending coronary artery (LAD) and after the subsequent 3-hour reperfusion. In several groups, NG-nitro-L-arginine methyl ester (L-NAME), an inhibitor of nitric oxide (NO) synthase, or charybdotoxin, a blocker of calcium-activated potassium (K(Ca)) channels, was infused intravenously beginning 20 minutes before LAD occlusion and continuing during reperfusion. Infarct size was reduced in the group treated with EPA compared with the control group (7.2 +/- 1.0% vs 24.6 +/- 2.3%; P < 0.01). The occurrence of ventricular arrhythmias in the reperfusion period tended to decrease in the EPA group. Either L-NAME or charybdotoxin partially blunted or completely abolished the infarct size-limiting effect of EPA, respectively. Eicosapentaenoic acid significantly increased the n-3:n-6 ratio of PUFA. Eicosapentaenoic acid reduces myocardial infarct size, mainly via the opening of K(Ca) channel-mediated and partially NO-mediated mechanisms in rabbit hearts.
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Sanada S, Kitakaze M. [Renin-angiotensin system as a potential target for the treatment with heart failure: ACE inhibitors, angiotensin-II receptor blockers and aldosterone antagonists]. NIHON RINSHO. JAPANESE JOURNAL OF CLINICAL MEDICINE 2003; 61:821-6. [PMID: 12755009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
Abstract
Recent experimental studies and clinical trials have revealed that the modulation of either systemic or regional(cardiovascular) renin-angiotensin systems(RAS) is one of the potential targets to prevent the progression of heart failure. Either ACE inhibitor, angiotensin-II receptor blocker or aldosterone antagonist differently block RAS. Many clinical trials told us that each of them improves heart failure and might promise the better prognosis. Now, some experimental studies are encouraging us to test the comparative effects or the effects in combination of them. Here we will summarize the current outcomes from the experimental and clinical studies, and discuss the future direction.
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Sanada S, Node K, Minamino T, Takashima S, Ogai A, Asanuma H, Ogita H, Liao Y, Asakura M, Kim J, Hori M, Kitakaze M. Long-acting Ca2+ blockers prevent myocardial remodeling induced by chronic NO inhibition in rats. Hypertension 2003; 41:963-7. [PMID: 12629037 DOI: 10.1161/01.hyp.0000062881.36813.7a] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
Chronic inhibition of nitric oxide (NO) synthesis induces cardiac remodeling independent of systemic hemodynamic changes in rats. We examined whether long-acting dihydropyridine calcium channel blockers block myocardial remodeling and whether the activation of 70-kDa S6 kinase (p70S6K) and extracellular signal-regulated kinase (ERK) are involved. Ten groups of Wistar-Kyoto rats underwent 8 weeks of drug treatment consisting of a combination of NO synthase inhibitor NG-nitro-l-arginine methyl ester (L-NAME), an inactive isomer (D-NAME), amlodipine (1 or 3 mg/kg per day), or benidipine (3 or 10 mg/kg per day). In other groups, L-NAME was also used in combination with a p70S6K inhibitor (rapamycin), a MEK inhibitor (PD98059), and hydralazine. Systolic blood pressure (SBP), heart rate, and left ventricular weight (LVW) were measured, together with histological examinations and kinase assay. L-NAME increased SBP and LVW (1048+/-22 versus 780+/-18 mg, P<0.01) compared with the control, showing a significant increase in cross-sectional area of cardiomyocytes after 8 weeks. Amlodipine, benidipine, or hydralazine equally attenuated the increase in SBP induced by L-NAME. However, both amlodipine and benidipine but not hydralazine attenuated the increase in LVW by L-NAME (789+/-27, 825+/-20 mg, P<0.01, and 1118+/-29 mg, NS, respectively), also confirmed by histological analysis. L-NAME caused a 2.2-fold/1.8-fold increase in p70S6K/ERK activity in myocardium compared with the control, both of which were attenuated by both amlodipine and benidipine but not hydralazine. Both rapamycin and PD98059 attenuated cardiac hypertrophy in this model. Thus, long-acting dihydropyridine calcium channel blockers inhibited cardiac hypertrophy induced by chronic inhibition of NO synthesis by inhibiting both p70S6K and ERK in vivo.
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Asanuma H, Node K, Minamino T, Sanada S, Takashima S, Ueda Y, Sakata Y, Asakura M, Kim J, Ogita H, Tada M, Hori M, Kitakaze M. Celiprolol increases coronary blood flow and reduces severity of myocardial ischemia via nitric oxide release. J Cardiovasc Pharmacol 2003; 41:499-505. [PMID: 12658050 DOI: 10.1097/00005344-200304000-00001] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Celiprolol is a selective beta(1)-adrenoceptor antagonist with antihypertensive actions, which causes renal vasodilation by increasing tissue nitric oxide (NO) levels. The authors tested whether celiprolol increases coronary blood flow (CBF) by increasing cardiac NO release in the ischemic heart in vivo. In open-chest dogs, coronary perfusion pressure of the left anterior descending coronary artery was reduced so that CBF decreased to 60% of control levels, and thereafter, coronary perfusion pressure was maintained constant. Ten minutes after the reduction of coronary perfusion pressure, we infused celiprolol into the left anterior descending coronary artery and measured fractional shortening and lactate extraction ratio as indices of regional myocardial contractility and metabolism. CBF significantly increased from 51.5 mL/100 g/min +/- 1.9 to 67.0 mL/100 g/min +/- 5.1 20 minutes after celiprolol infusion without changes in coronary perfusion pressure, while fractional shortening and lactate extraction ratio increased. Celiprolol also increased cardiac NO release. The L omega-nitroarginine methyl ester, the inhibitor of NO synthase, attenuated the increases in CBF, fractional shortening, lactate extraction ratio, and cardiac NO release due to celiprolol. ICI 118551, a beta(2)-adrenoceptor antagonist, did not blunt the effects of celiprolol and a nonselective beta-adrenoceptor antagonist, propranolol, increased neither CBF nor cardiac NO release, indicating that the effect of celiprolol is independent of beta-adrenoceptor blockade. It was concluded that celiprolol mediates coronary vasodilation and improves myocardial ischemia through NO-dependent mechanisms.
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Sanada S, Hori M, Node K, Kitakaze M. [The trend of research on the mechanism of reperfusion injury]. NIHON RINSHO. JAPANESE JOURNAL OF CLINICAL MEDICINE 2003; 61 Suppl 4:135-41. [PMID: 12734966] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Subscribe] [Scholar Register] [Indexed: 03/02/2023]
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Sanada S, Node K, Asanuma H, Ogita H, Takashima S, Minamino T, Asakura M, Hori M, Kitakaze M. [Opening of ATP-sensitive potassium channel attenuates cardiac remodeling induced by chronic inhibition of nitric oxide synthesis]. J Cardiol 2003; 41:43-4. [PMID: 12564115] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/28/2023]
Abstract
OBJECTIVES We examined whether the ATP-sensitive potassium(KATP) channel openers (KCOs) block myocardial hypertrophy, and whether the 70 kDa S6 kinase(p70S6K)-or extracellular signal-regulated kinase(ERK)-dependent pathway is involved. BACKGROUND Chronic inhibition of nitric oxide (NO) synthesis induces cardiac hypertrophy independent of blood pressure by increasing protein synthesis in vivo. KCOs attenuate calcium overload and confer cardioprotection against ischemic stress, and thereby prevent myocardial remodeling. METHODS Twelve Wistar-Kyoto rat groups underwent 8 weeks of the drug treatment in combination with NO synthase inhibitor N omega-nitro-L-arginine methyl ester (L-NAME), an inactive isomer D omega-nitro-L-arginine methyl ester(D-NAME), KCOs(nicorandil; 3 and 10 mg/kg/day, or JTV-506; 0.3 mg/kg/day), or a KATP channel blocker glibenclamide. L-NAME was also treated with hydralazine, p70S6K inhibitor (rapamycin) or MAP kinase kinase inhibitor(PD98059). Finally, left ventricular weight-to-body weight ratio(LVW/BW) was quantified followed by histological examinations and kinase assay. RESULTS L-NAME increased blood pressure and LVW/BW compared with the control. KCOs and hydralazine equally cancelled the increase in blood pressure, whereas only KCOs blocked the increase in LVW/BW and myocardial hypertrophy induced by L-NAME. The L-NAME group showed both p70S6K and ERK activation in the myocardium compared with the control(2.3-fold and 2.0-fold, respectively), which was not reversed by hydralazine. Selective inhibition of either P70S6K or ERK blocked myocardial hypertrophy. KCOs prevented the increase in activity only of p70S6K. Glibenclamide reversed the effect of nicorandil in the presence of L-NAME. CONCLUSIONS KCOs modulate p70S6K, not ERK, to attenuate myocardial hypertrophy induced by chronic inhibition of nitric oxide synthesis in vivo.
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Ogita H, Node K, Asanuma H, Sanada S, Liao Y, Takashima S, Asakura M, Mori H, Shinozaki Y, Hori M, Kitakaze M. Amelioration of ischemia- and reperfusion-induced myocardial injury by the selective estrogen receptor modulator, raloxifene, in the canine heart. J Am Coll Cardiol 2002; 40:998-1005. [PMID: 12225729 DOI: 10.1016/s0735-1097(02)02056-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVES We sought to investigate whether raloxifene reduces ischemia-reperfusion injury and what mechanisms are involved in the cardioprotective effects. BACKGROUND Estradiol-17-beta reduces myocardial infarct size in ischemia-reperfusion injury. Raloxifene, a selective estrogen receptor modulator, demonstrates immediate coronary artery vasorelaxing effects. METHODS The myocardial ischemia-reperfusion model included anesthetized open-chest dogs after 90-min occlusion of the left anterior descending coronary artery (LAD) and subsequent 6-h reperfusion. Raloxifene and/or other drugs were infused into the LAD from 10 min before coronary occlusion to 1 h after reperfusion without an occlusion period. RESULTS Infarct size was reduced in the raloxifene (5 microg/kg per min) group compared with the control group (7.2 +/- 2.5% vs. 40.9 +/- 3.9% of the area at risk, p < 0.01). Either N(G)-nitro-L-arginine methyl ester (L-NAME), the inhibitor of nitric oxide (NO) synthase, or charybdotoxin, the blocker of Ca(2+)-activated K+ (K(Ca)) channels, partially attenuated the infarct size-limiting effect, and both of them completely abolished the effect. The incidence of ventricular fibrillation was also less in the raloxifene group than in the control group (11% vs. 44%, p < 0.05). Activity of p38 mitogen-activated protein (MAP) kinase increased with 15-min ischemia, and raloxifene pretreatment inhibited the activity. Myeloperoxidase activity of the 6-h reperfused myocardium was also attenuated by raloxifene. CONCLUSIONS These data demonstrate that raloxifene reduces myocardial ischemia-reperfusion injury by mechanisms dependent on NO and the opening of K(Ca) channels in canine hearts. Deactivation of p38 MAP kinase and myeloperoxidase by raloxifene may be involved in the cellular mechanisms of cardioprotection.
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Sanada S, Node K, Asanuma H, Ogita H, Takashima S, Minamino T, Asakura M, Liao Y, Ogai A, Kim J, Hori M, Kitakaze M. Opening of the adenosine triphosphate-sensitive potassium channel attenuates cardiac remodeling induced by long-term inhibition of nitric oxide synthesis: role of 70-kDa S6 kinase and extracellular signal-regulated kinase. J Am Coll Cardiol 2002; 40:991-7. [PMID: 12225728 DOI: 10.1016/s0735-1097(02)02057-0] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVES We examined whether the adenosine triphosphate (ATP)-sensitive potassium (K(ATP)) channel openers (KCOs) block myocardial hypertrophy and whether the 70-kDa S6 kinase (p70S6K) or extracellular signal-regulated kinase (ERK)-dependent pathway is involved. BACKGROUND Long-term inhibition of nitric oxide (NO) synthesis induces cardiac hypertrophy independent of blood pressure, by increasing protein synthesis in vivo. The KCOs attenuate calcium overload and confer cardioprotection against ischemic stress, thereby preventing myocardial remodeling. METHODS Twelve Wistar-Kyoto rat groups underwent eight weeks of the drug treatment in combination with the NO synthase inhibitor N(omega)-nitro-L-arginine methyl ester (L-NAME), the inactive isomer D(omega)-nitro-L-arginine methyl ester, KCOs (nicorandil, 3 and 10 mg/kg per day, or JTV-506, 0.3 mg/kg per day), or the K(ATP) channel blocker glibenclamide. The L-NAME was also used with hydralazine, the p70S6K inhibitor rapamycin, or the mitogen-activated protein kinase inhibitor PD98059. Finally, the left ventricular weight (LVW) to body weight (BW) ratio was quantified, followed by histologic examination and kinase assay. RESULTS The L-NAME increased blood pressure and LVW/BW, as compared with the control agent. The KCOs and hydralazine equally cancelled the increase in blood pressure, whereas only KCOs blocked the increase in LVW/BW and myocardial hypertrophy induced by L-NAME. The L-NAME group showed both p70S6K and ERK activation in the myocardium (2.3-fold and 2.0-fold increases, respectively), as compared with the control group, which was not reversed by hydralazine. Selective inhibition of either p70S6K or ERK blocked myocardial hypertrophy. The KCOs prevented the increase in activity only of p70S6K. Glibenclamide reversed the effect of nicorandil in the presence of L-NAME. CONCLUSIONS The KCOs modulate p70S6K, not ERK, to attenuate myocardial hypertrophy induced by long-term inhibition of NO synthesis in vivo.
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Kitakaze M, Asanuma H, Funaya H, Node K, Takashima S, Sanada S, Asakura M, Ogita H, Kim J, Hori M. Angiotensin-converting enzyme inhibitors and angiotensin II receptor blockers synergistically increase coronary blood flow in canine ischemic myocardium: role of bradykinin. J Am Coll Cardiol 2002; 40:162-6. [PMID: 12103271 DOI: 10.1016/s0735-1097(02)01929-0] [Citation(s) in RCA: 19] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/20/2022]
Abstract
OBJECTIVES We examined whether the combination of an angiotensin-converting enzyme (ACE) inhibitor and an angiotensin II receptor blocker (ARB) synergistically mediates coronary vasodilation and improves myocardial metabolic and contractile dysfunction in ischemic hearts. BACKGROUND Either an ACE inhibitor or ARB mediates coronary vasodilation in ischemic hearts. METHODS In dogs with myocardial ischemia, we infused an ACE inhibitor (temocaprilat, 10 microg/kg/min) or ARB (RNH-6270, 10 microg/kg/min) into the coronary artery. RESULTS Perfusion pressure of the left anterior descending coronary artery was reduced from 104 +/- 8 to 42 +/- 2 mm Hg, so that coronary blood flow (CBF) decreased to one-third of the baseline value. Ten minutes after starting the infusion of temocaprilat, the cardiac bradykinin level increased (from 32 +/- 6 to 98 +/- 5 pg/ml). Coronary blood flow (29 +/- 2 to 44 +/- 3 ml/100 g/min) and the cardiac level of nitric oxide (NO) (7.8 +/- 1.9 to 17.5 +/- 3.2 microm) also increased, with these changes being attenuated by either N(omega)-nitro-L-arginine methyl ester or HOE140. RNH-6270 alone caused a modest increase in CBF (34 +/- 3 ml/100 g/min), with no increase in the cardiac NO or bradykinin levels. Both temocaprilat and RNH-6270 caused a further increase in both CBF (51 +/- 4 ml/100 g/min) and cardiac NO levels, without increasing the bradykinin level, and these changes were inhibited by HOE140. In the nonischemic heart, RNH-6270 augmented bradykinin-induced increases in CBF. CONCLUSIONS The combination of an ACE inhibitor and ARB mediates greater increases in CBF and more potent cardioprotective effects through bradykinin-dependent mechanisms than either drug alone.
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Liao Y, Ishikura F, Beppu S, Asakura M, Takashima S, Asanuma H, Sanada S, Kim J, Ogita H, Kuzuya T, Node K, Kitakaze M, Hori M. Echocardiographic assessment of LV hypertrophy and function in aortic-banded mice: necropsy validation. Am J Physiol Heart Circ Physiol 2002; 282:H1703-8. [PMID: 11959634 DOI: 10.1152/ajpheart.00238.2001] [Citation(s) in RCA: 107] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
We characterized the time course of the left ventricular (LV) geometric and functional changes after aortic banding, validated them by necropsy, and investigated the sensitivity of echocardiographic findings on LV hypertrophy. C57BL/6 mice were subjected to transverse aortic constriction (TAC) or sham operation; echocardiographic assessments were performed before or at 2, 4, 6, and 11 wk after surgery; and some of the mice were euthanized at the corresponding time points. There was a progressive increase in diastolic posterior wall thickness and LV systolic dimension; the percentage of LV fractional shortening (LV%FS) decreased progressively at 4 wk, whereas these parameters remained stable in sham-operated mice. Echo LV mass and LV%FS correlated well with actual whole heart mass and ratio of lung weight to body weight, respectively (r = 0.765 and -0.749, respectively; P < 0.0001). These results suggest that the development of myocardial hypertrophy and systolic dysfunction is a time-dependent process. Echocardiographic assessment of myocardial hypertrophy and functional changes correlate well with the actual heart mass and lung mass. Echocardiography is sensitive enough to assess myocardial hypertrophy and heart functional changes induced by pressure overload in mice.
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Takashima S, Kitakaze M, Asakura M, Asanuma H, Sanada S, Tashiro F, Niwa H, Miyazaki Ji JI, Hirota S, Kitamura Y, Kitsukawa T, Fujisawa H, Klagsbrun M, Hori M. Targeting of both mouse neuropilin-1 and neuropilin-2 genes severely impairs developmental yolk sac and embryonic angiogenesis. Proc Natl Acad Sci U S A 2002; 99:3657-62. [PMID: 11891274 PMCID: PMC122579 DOI: 10.1073/pnas.022017899] [Citation(s) in RCA: 301] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
Neuropilins (NP1 and NP2) are vascular endothelial growth factor (VEGF) receptors that mediate developmental and tumor angiogenesis. Transgenic mice, in which both NP1 and NP2 were targeted (NP1(-/-)NP2(-/-)) died in utero at E8.5. Their yolk sacs were totally avascular. Mice deficient for NP2 but heterozygous for NP1 (NP1(+/-)NP2(-/-)) or deficient for NP1 but heterozygous for NP2 (NP1(-/-)NP2(+/-)) were also embryonic lethal and survived to E10-E10.5. The E10 yolk sacs and embryos were easier to analyze for vascular phenotype than the fragile poorly formed 8.5 embryos. The vascular phenotypes of these E10 mice were very abnormal. The yolk sacs, although of normal size, lacked the larger collecting vessels and had less dense capillary networks. PECAM staining of yolk sac endothelial cells showed the absence of branching arteries and veins, the absence of a capillary bed, and the presence of large avascular spaces between the blood vessels. The embryos displayed blood vessels heterogeneous in size, large avascular regions in the head and trunk, and blood vessel sprouts that were unconnected. The embryos were about 50% the length of wild-type mice and had multiple hemorrhages. These double NP1/NP2 knockout mice had a more severe abnormal vascular phenotype than either NP1 or NP2 single knockouts. Their abnormal vascular phenotype resembled those of VEGF and VEGFR-2 knockouts. These results suggest that NRPs are early genes in embryonic vessel development and that both NP1 and NP2 are required.
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Asanuma H, Kitakaze M, Node K, Takashima S, Sakata Y, Asakura M, Sanada S, Shinozaki Y, Mori H, Tada M, Kuzuya T, Hori M. Benidipine, a long-acting Ca channel blocker, limits infarct size via bradykinin- and NO-dependent mechanisms in canine hearts. Cardiovasc Drugs Ther 2002; 15:225-31. [PMID: 11713890 DOI: 10.1023/a:1011964222712] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
Amlodipine increases NO levels in coronary vessels and aorta via bradykinin-dependent mechanisms in vitro. We have previously reported that a long-acting Ca channel blocker, benidipine, increases cardiac NO levels in ischemic canine hearts, suggesting that benidipine may also protect against ischemia and reperfusion injury via bradykinin- and NO-dependent mechanisms. We examined this possibility. In open chest dogs, the left anterior descending coronary artery was perfused with blood through a bypass tube and was occluded for 90 min followed by 6 hours of reperfusion. Infarct size was assessed by TTC staining at 6 hours of reperfusion. When benidipine doses of 50, 100, and 200 ng/kg/min were infused via the bypass tube between 10 min prior to the onset of ischemia and after 60 min of reperfusion, systemic blood pressure did not change significantly. Infarct size decreased with the administration of benidipine (50, 100, and 200 ng/kg/min) when compared to the untreated condition (24.8+/-2.5, 17.3+/-3.1, and 16.5+/-2.0 vs. 43.4+/-5.6%, respectively) associated with the increased release of NO and bradykinin in the coronary venous blood upon reperfusion. Myeloperoxidase activity of the myocardium increased after 6 hours of reperfusion, which was attenuated by benidipine. The limitation of infarct size and the increase in myeloperoxidase activity were completely blunted by either L-NAME or HOE140. There were no significant differences in collateral blood flow assessed by the microsphere method after 45 min of ischemia for any of the groups. Thus, we conclude that the Ca channel blocker, benidipine, limits infarct size via bradykinin- and NO-dependent mechanisms.
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Asanuma H, Kitakaze M, Node K, Sanada S, Ogita H, Takashima S, Asakura M, Minamino T, Tada M, Hori M. Inhibitory effects of the novel antagonist of both GP IIb/IIIa and vitronectin receptors on the formation of coronary thromboemboli caused by an inhibition of adenosine receptors during coronary hypoperfusion in dogs. J Am Coll Cardiol 2002. [DOI: 10.1016/s0735-1097(02)81347-x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
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Asanuma H, Kitakaze M, Node K, Sanada S, Ogita H, Takashima S, Asakura M, Minamino T, Tada M, Hori M. Amlodipine increases coronary blood flow and reduces the severity of myocardial ischemia in canine hearts: roles of NO and adenosine. J Am Coll Cardiol 2002. [DOI: 10.1016/s0735-1097(02)81456-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
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97
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Sanada S, Kitakaze M, Node K, Asanuma H, Ogita H, Takashima S, Asakura M, Minamino T, Hori M. Selective serotonin 5HT 2A receptor inhibition attenuates myocardial ischemia through the increase in nitric oxide production: the alternative role of 5HT 1B receptor. J Am Coll Cardiol 2002. [DOI: 10.1016/s0735-1097(02)81310-9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Ogita H, Node K, Asanuma H, Sanada S, Takashima S, Asakura M, Kitakaze M, Hori M. [Amelioration of ischemia- and reperfusion-induced myocardial injury by the selective estrogen receptor modulator, raloxifene, in the canine heart]. J Cardiol 2002; 39:55-6. [PMID: 11828800] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/23/2023]
Abstract
BACKGROUND 17 beta-estradiol reduces myocardial infarct size which is mediated by nitric oxide (NO) and the opening of Ca (2+)-activated K+ (KCa) channels. Raloxifene, a selective estrogen receptor modulator, demonstrates acute coronary artery vasorelaxing effects. Whether raloxifene reduces ischemia/reperfusion injury and what mechanisms are involved in the cardioprotective effects were investigated. METHODS Infarct size was measured in open-chest dogs following occlusion of the left anterior descending coronary artery for 90 min and subsequent reperfusion for 6 hr. The incidence of ventricular fibrillations during reperfusion period was also observed. Infusion of raloxifene and/or other drugs into the left anterior descending coronary artery was initiated 10 min before coronary occlusion and continued until 1 hr after reperfusion started without an occlusion period. RESULTS Infarct size was reduced in the raloxifene (5 micrograms/kg/min) group compared with the control group (6.8 +/- 4.2% vs 40.9 +/- 3.9% of the area at risk, p < 0.01). Either NG-nitro-L-arginine methyl ester, the inhibitor of NO synthase (infarct size: 22.8 +/- 5.4%, p < 0.05 vs raloxifene or the control) or charbdotoxin, the blocker of KCa channels (infarct size: 23.5 +/- 5.1%, p < 0.05 vs raloxifene or the control), partially attenuated the infarct size-limiting effect, and combination of both agents completely abolished the effect (infarct size: 37.7 +/- 5.8%). The incidence of ventricular fibrillations was also less in the raloxifene group than in the control group(11% vs 44%, p < 0.05). CONCLUSIONS Raloxifene reduces myocardial infarct size and the incidence of ventricular fibrillations by NO- and the opening of KCa channels-dependent mechanisms in canine hearts.
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Asakura M, Kitakaze M, Sakata Y, Asanuma H, Sanada S, Kim J, Ogida H, Liao Y, Node K, Takashima S, Tada M, Hori M. Adenosine-induced cardiac gene expression of ischemic murine hearts revealed by cDNA array hybridization. Circ J 2002; 66:93-6. [PMID: 11999673 DOI: 10.1253/circj.66.93] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Because many endogenous substances, including adenosine, contribute to the pathophysiology of ischemic hearts, the present study was designed to investigate the transcription responses of murine hearts to ischemia with or without administration of an inhibitor of adenosine receptor, 8-sulfophenyltheophylline (8SPT). Sixty minutes after ligation of the proximal site of the left coronary artery with (n=9) or without (n=9) 8SPT, the hearts were excised to obtain mRNA for cDNA array analysis. In 18,376 cDNA, 2 known genes were upregulated over 10-fold, and 11 known genes were upregulated 5.0-9.9-fold. 8SPT reduced the expressed gene to the control levels. Furthermore, 32 unknown genes were also upregulated over 5.0-fold. In contrast, 11 known genes were downregulated below 0.2-fold, and 64% of the downregulated genes were restored by 8SPT. The 7 unknown genes were downregulated to levels below 0.2-fold. Therefore, it was concluded that the cardiac expression of 24 known and 39 unknown genes was modulated by ischemic stress, and that these genes appeared to be related to the pathophysiology of the ischemic heart because endogenous adenosine modulated their expression.
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Asakura M, Kitakaze M, Takashima S, Liao Y, Ishikura F, Yoshinaka T, Ohmoto H, Node K, Yoshino K, Ishiguro H, Asanuma H, Sanada S, Matsumura Y, Takeda H, Beppu S, Tada M, Hori M, Higashiyama S. Cardiac hypertrophy is inhibited by antagonism of ADAM12 processing of HB-EGF: metalloproteinase inhibitors as a new therapy. Nat Med 2002; 8:35-40. [PMID: 11786904 DOI: 10.1038/nm0102-35] [Citation(s) in RCA: 545] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
Abstract
G-protein-coupled receptor (GPCR) agonists are well-known inducers of cardiac hypertrophy. We found that the shedding of heparin-binding epidermal growth factor (HB-EGF) resulting from metalloproteinase activation and subsequent transactivation of the epidermal growth factor receptor occurred when cardiomyocytes were stimulated by GPCR agonists, leading to cardiac hypertrophy. A new inhibitor of HB-EGF shedding, KB-R7785, blocked this signaling. We cloned a disintegrin and metalloprotease 12 (ADAM12) as a specific enzyme to shed HB-EGF in the heart and found that dominant-negative expression of ADAM12 abrogated this signaling. KB-R7785 bound directly to ADAM12, suggesting that inhibition of ADAM12 blocked the shedding of HB-EGF. In mice with cardiac hypertrophy, KB-R7785 inhibited the shedding of HB-EGF and attenuated hypertrophic changes. These data suggest that shedding of HB-EGF by ADAM12 plays an important role in cardiac hypertrophy, and that inhibition of HB-EGF shedding could be a potent therapeutic strategy for cardiac hypertrophy.
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