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Connective tissue growth factor is a key regulator of fibrosis in pressure overloaded rat heart
The 8th Annual Scientific Meeting
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JHFS
S177
O-089
O-091
Combined Measurements of Cardiac Troponin T and N-Terminal Pro-Brain Natriuretic Peptide in Patients with Chronic Heart Failure TANIGUCHI RYOJI1, SATO YUKIHITO2, NISHIO YUKIKO1, OZASA NEIKO1, HARUNA YOSHISUMI1, TAMURA TOSHIHIRO1, MATSUMORI AKIRA1, KIMURA TAKESHI1, KITA TORU1 1 Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan, 2Division of Cardiology, Department of Internal Medicine, Hyogo Prefectural Amagasaki Hospital, Hyogo, Japan
Role of Endogenous Adrenomedullin System in Rat Cardiac Fibroblasts
Objective: To examine the prognostic contribution of combined cardiac troponin T(cTnT) and N-terminal pro-brain natriuretic peptide(NTproBNP) in patients with compensated and decompensated chronic heart failure(CHF) in absence of acute coronary syndrome. Design and patient population: Between July 2001 and March 2002, 73 consecutive patients (mean age ⫽ 68.2 ⫾ 1.4years,39men) hospitalised for decompensated or stable CHF were studied and followed until December 2002. Main outcome measures: Serum cTnT and NT-proBNP were measured on admission. Actuarial rates of adverse cardiac events, including sudden or CHF death, or rehospitalisation for CHF during follow-up were compared among patients grouped according to initial serum cTnT and NT-proBNP concentrations, singly or in combination. Results: The cut-off value for NT-proBNP predictive of cardiac decompensation was 1050pg/ml. NT-proBNP was significantly higher among 46 patients with, than among 27 patients without, decompensated CHF(7167 ⫾ 2318 vs.1360 ⫾ 286pg/ml, P ⬍ 0.01). The serum concentration of cTnT upon admission was ⬎ 0.02ng/ml in 22 of the 73 patients. High cTnT values were measured in 17 of 46 patients(37%)(0.037 ⫾ 0.004ng/ml) with, and in 5 of 27 patients(18.5%)(0.038 ⫾ 0.002ng/ml) without, cardiac decompensation. The 18 patients with high concentrations of both cTnT and NTproBNP had a lower adverse cardiac event-free rate than the 31 patients with low cTnT and low NT-proBNP on study entry(P ⬍ 0.005). Conclusions: Combined measurements of serum cTnT and NT-proBNP were reliable prognostic markers of adverse cardiac event in patients with CHF.
ISHIKAWA YAYOI, NISHIKIMI TOSHIO, ISHIMURA KIMIHIKO, TADOKORO KAZUYOSHI, MORI YOSUKE, AKIMOTO KAZUMI, MATSUOKA HIROAKI Department of Hypertension and Cardiorenal Medicine, Dokkyo University School of Medicine, Tochigi, Japan Background: We investigated the effects of interleukin 1-beta (IL-1b) on the adrenomedullin system in cardiac fibroblasts and also examined the role of it. Methods: With or without the presence of IL-1b in cultured rat neonatal cardiac fibroblasts, we measured; (1) two molecular forms of adrenomedullin in cultured medium by specific immunoradiometric assay, (2) gene expression of adrenomedullin, calcitonin receptor like receptor (CRLR), receptor activity modifying protein2 (RAMP2), and RAMP3, which are components of adrenomedullin receptor, by northern blot analysis or RTPCR, (3) cAMP levels in response to exogenous administered adrenomedullin, (4) 3H-proline incorporation with and without a specific antisense oligodeoxynucleotide. Results: (1) IL-1b dose-dependently increased the levels of two molecular forms of adrenomedullin, adrenomedullin-mature and adrenomedullin-glycine (P ⬍ 0.01). Adrenomedullin-mature form was a major molecular form in culture medium (85%). (2) IL-1b significantly increased gene expression of adrenomedullin and its receptor components (adrenomedullin: ⫹30%, CRLR: ⫹460%, RAMP2: ⫹25%, RAMP3: ⫹350%, all P ⬍ 0.01). (3) Preincubated IL-1b elevated the intracellular cAMP response to exogenous administered adrenomedullin at 10⫺7 M (⫹26%, P ⬍ 0.05). (4) AM antisense oligodeoxynucleotide treatment significantly lowered adrenomedullin levels in cultured medium (-50%). IL-1b significantly increased 3H-proline incorporation and adrenomedullin antisense oligodeoxynucleotide treatment further increased 3H-proline incorporation (⫹22%, P ⬍ 0.05). Conclusion: These results support a physiological role for adrenomedullin in the regulation of cell growth as an autocrine factor in cardiac fibroblasts.
O-090
O-092
Connective Tissue Growth Factor is a Key Regulator of Fibrosis in Pressure Overloaded Rat Heart KOITABASHI NORIMICHI1, ARAI MASASHI1, TAKIZAWA TAKAKO1, WATANABE ATAI1, HARA SHIROU1, NIWANO KAZUO1, KURABAYASHI MASAHIKO1, NISHIDA TAKASHI2, TAKIGAWA MASAHARU2 1 Department of Medicine and Biological Science, Gunma University, Graduate School of Medicine, Maebashi, Japan, 2Department of Biochemistry and Dentistry, Okayama University Graduate school of Medicine and Dentistry, Okayama, Japan
Fetal Gene Program Associated with Right Ventricular Hypertrophy/ Failure-is Left Ventricle Really Spared? USUI SHIN-ICHI, YAO ATSUSHI, KINUGAWA KOICHIRO, TAKAHASHI TOSHIYUKI, NAGAI RYOZO Department of Cardiovascular Medicine, University of Tokyo, Graduate School of Medicine, Tokyo, Japan
The myocardial fibrillar collagen deposition increases myocardial stiffness and exacerbates cardiac function in the pressure overloaded heart. Connective tissue growth factor (CTGF/CCN2/HCS24) is a profibrotic cytokine that promotes fibroblast proliferation and extracellular matrix production in connective tissues. Although, up-regulation of CTGF gene in human failing heart has been demonstrated, precise role of CTGF in maladaptive ventricular remodeling remains to be elucidate. In this study, we determined temporal changes in CTGF mRNA expression level and the correlation between markers of cardiac function during the cardiac hypertrophy induced by abdominal aortic banding in rat. Northern blot analysis showed that CTGF mRNA expression levels were up-regulated even 24 hours after banding. CTGF expression levels were closely correlated with levels of BNP expression (n ⫽ 45, r ⫽ 0.781, P ⬍ 0.001). At day7, the %area of myocardial fibrosis evaluated Masson-Trichrome staining and the abnormal left ventricular diastolic function evaluated by echocardiography strongly correlated with CTGF mRNA levels. Immunohistochemical analysis showed that CTGF protein expressed in cardiac myocytes and fibroblasts around myocardial fibrosis. In conclusion, we have demonstrated that CTGF was upregulated in pressure overloaded rat heart. Our results suggested that CTGF regulates collagen metabolism in myocardium and plays an important role in the development of diastolic dysfunction.
Left ventricular (LV) hypertrophy is usually associated with fetal gene program, but it remains unclear whether it is the case in right ventricular (RV) hypertrophy. Recently, an alkaloid toxin, monocrotaline (MCT), has been established to induce pulmonary hypertension and RV hypertrophy. Objective: To investigate myocyte-specific gene expression associated with RV hypertrophy/failure. Methods: Rats were injected with MCT (50mg/kg) and after 6 weeks levels of mRNA expression were determined. *P ⬍ 0.05 vs vehicle. Results: Approximately half of MCT-injected rats died after 6 weeks. MCT markedly increased RV weight (289%*) with modest increases in LV weight (148%*). In MCT-treated RV, the mRNA level of SERCA (34.6%*) or alpha-MHC (12.8%*) was decreased, while that of ANP (1100%*), BNP (1100%*), skeletal alpha-actin (462%*), or beta-MHC (313%*) was increased, i.e. fetal gene program activation. Interestingly, not only in septum but in separated LV free wall, MCT also activated significant fetal gene program except SERCA. Conclusion: MCT induced RV hypertrophy and failure, which was accompanied by typical fetal gene program in RV. Although MCT theoretically caused unloading of LV free wall, MCT-treated LV exhibited similar pattern of fetal gene activation. Thus, LV may also be affected in the case of severe pulmonary hypertension. The induction of fetal gene program in LV might be attributable to paracrine effects of neurohormonal factors produced by diseased pulmonary vasculature and/or RV.
•
JHFS
S177
O-089
O-091
Combined Measurements of Cardiac Troponin T and N-Terminal Pro-Brain Natriuretic Peptide in Patients with Chronic Heart Failure TANIGUCHI RYOJI1, SATO YUKIHITO2, NISHIO YUKIKO1, OZASA NEIKO1, HARUNA YOSHISUMI1, TAMURA TOSHIHIRO1, MATSUMORI AKIRA1, KIMURA TAKESHI1, KITA TORU1 1 Department of Cardiovascular Medicine, Graduate School of Medicine, Kyoto University, Kyoto, Japan, 2Division of Cardiology, Department of Internal Medicine, Hyogo Prefectural Amagasaki Hospital, Hyogo, Japan
Role of Endogenous Adrenomedullin System in Rat Cardiac Fibroblasts
Objective: To examine the prognostic contribution of combined cardiac troponin T(cTnT) and N-terminal pro-brain natriuretic peptide(NTproBNP) in patients with compensated and decompensated chronic heart failure(CHF) in absence of acute coronary syndrome. Design and patient population: Between July 2001 and March 2002, 73 consecutive patients (mean age ⫽ 68.2 ⫾ 1.4years,39men) hospitalised for decompensated or stable CHF were studied and followed until December 2002. Main outcome measures: Serum cTnT and NT-proBNP were measured on admission. Actuarial rates of adverse cardiac events, including sudden or CHF death, or rehospitalisation for CHF during follow-up were compared among patients grouped according to initial serum cTnT and NT-proBNP concentrations, singly or in combination. Results: The cut-off value for NT-proBNP predictive of cardiac decompensation was 1050pg/ml. NT-proBNP was significantly higher among 46 patients with, than among 27 patients without, decompensated CHF(7167 ⫾ 2318 vs.1360 ⫾ 286pg/ml, P ⬍ 0.01). The serum concentration of cTnT upon admission was ⬎ 0.02ng/ml in 22 of the 73 patients. High cTnT values were measured in 17 of 46 patients(37%)(0.037 ⫾ 0.004ng/ml) with, and in 5 of 27 patients(18.5%)(0.038 ⫾ 0.002ng/ml) without, cardiac decompensation. The 18 patients with high concentrations of both cTnT and NTproBNP had a lower adverse cardiac event-free rate than the 31 patients with low cTnT and low NT-proBNP on study entry(P ⬍ 0.005). Conclusions: Combined measurements of serum cTnT and NT-proBNP were reliable prognostic markers of adverse cardiac event in patients with CHF.
ISHIKAWA YAYOI, NISHIKIMI TOSHIO, ISHIMURA KIMIHIKO, TADOKORO KAZUYOSHI, MORI YOSUKE, AKIMOTO KAZUMI, MATSUOKA HIROAKI Department of Hypertension and Cardiorenal Medicine, Dokkyo University School of Medicine, Tochigi, Japan Background: We investigated the effects of interleukin 1-beta (IL-1b) on the adrenomedullin system in cardiac fibroblasts and also examined the role of it. Methods: With or without the presence of IL-1b in cultured rat neonatal cardiac fibroblasts, we measured; (1) two molecular forms of adrenomedullin in cultured medium by specific immunoradiometric assay, (2) gene expression of adrenomedullin, calcitonin receptor like receptor (CRLR), receptor activity modifying protein2 (RAMP2), and RAMP3, which are components of adrenomedullin receptor, by northern blot analysis or RTPCR, (3) cAMP levels in response to exogenous administered adrenomedullin, (4) 3H-proline incorporation with and without a specific antisense oligodeoxynucleotide. Results: (1) IL-1b dose-dependently increased the levels of two molecular forms of adrenomedullin, adrenomedullin-mature and adrenomedullin-glycine (P ⬍ 0.01). Adrenomedullin-mature form was a major molecular form in culture medium (85%). (2) IL-1b significantly increased gene expression of adrenomedullin and its receptor components (adrenomedullin: ⫹30%, CRLR: ⫹460%, RAMP2: ⫹25%, RAMP3: ⫹350%, all P ⬍ 0.01). (3) Preincubated IL-1b elevated the intracellular cAMP response to exogenous administered adrenomedullin at 10⫺7 M (⫹26%, P ⬍ 0.05). (4) AM antisense oligodeoxynucleotide treatment significantly lowered adrenomedullin levels in cultured medium (-50%). IL-1b significantly increased 3H-proline incorporation and adrenomedullin antisense oligodeoxynucleotide treatment further increased 3H-proline incorporation (⫹22%, P ⬍ 0.05). Conclusion: These results support a physiological role for adrenomedullin in the regulation of cell growth as an autocrine factor in cardiac fibroblasts.
O-090
O-092
Connective Tissue Growth Factor is a Key Regulator of Fibrosis in Pressure Overloaded Rat Heart KOITABASHI NORIMICHI1, ARAI MASASHI1, TAKIZAWA TAKAKO1, WATANABE ATAI1, HARA SHIROU1, NIWANO KAZUO1, KURABAYASHI MASAHIKO1, NISHIDA TAKASHI2, TAKIGAWA MASAHARU2 1 Department of Medicine and Biological Science, Gunma University, Graduate School of Medicine, Maebashi, Japan, 2Department of Biochemistry and Dentistry, Okayama University Graduate school of Medicine and Dentistry, Okayama, Japan
Fetal Gene Program Associated with Right Ventricular Hypertrophy/ Failure-is Left Ventricle Really Spared? USUI SHIN-ICHI, YAO ATSUSHI, KINUGAWA KOICHIRO, TAKAHASHI TOSHIYUKI, NAGAI RYOZO Department of Cardiovascular Medicine, University of Tokyo, Graduate School of Medicine, Tokyo, Japan
The myocardial fibrillar collagen deposition increases myocardial stiffness and exacerbates cardiac function in the pressure overloaded heart. Connective tissue growth factor (CTGF/CCN2/HCS24) is a profibrotic cytokine that promotes fibroblast proliferation and extracellular matrix production in connective tissues. Although, up-regulation of CTGF gene in human failing heart has been demonstrated, precise role of CTGF in maladaptive ventricular remodeling remains to be elucidate. In this study, we determined temporal changes in CTGF mRNA expression level and the correlation between markers of cardiac function during the cardiac hypertrophy induced by abdominal aortic banding in rat. Northern blot analysis showed that CTGF mRNA expression levels were up-regulated even 24 hours after banding. CTGF expression levels were closely correlated with levels of BNP expression (n ⫽ 45, r ⫽ 0.781, P ⬍ 0.001). At day7, the %area of myocardial fibrosis evaluated Masson-Trichrome staining and the abnormal left ventricular diastolic function evaluated by echocardiography strongly correlated with CTGF mRNA levels. Immunohistochemical analysis showed that CTGF protein expressed in cardiac myocytes and fibroblasts around myocardial fibrosis. In conclusion, we have demonstrated that CTGF was upregulated in pressure overloaded rat heart. Our results suggested that CTGF regulates collagen metabolism in myocardium and plays an important role in the development of diastolic dysfunction.
Left ventricular (LV) hypertrophy is usually associated with fetal gene program, but it remains unclear whether it is the case in right ventricular (RV) hypertrophy. Recently, an alkaloid toxin, monocrotaline (MCT), has been established to induce pulmonary hypertension and RV hypertrophy. Objective: To investigate myocyte-specific gene expression associated with RV hypertrophy/failure. Methods: Rats were injected with MCT (50mg/kg) and after 6 weeks levels of mRNA expression were determined. *P ⬍ 0.05 vs vehicle. Results: Approximately half of MCT-injected rats died after 6 weeks. MCT markedly increased RV weight (289%*) with modest increases in LV weight (148%*). In MCT-treated RV, the mRNA level of SERCA (34.6%*) or alpha-MHC (12.8%*) was decreased, while that of ANP (1100%*), BNP (1100%*), skeletal alpha-actin (462%*), or beta-MHC (313%*) was increased, i.e. fetal gene program activation. Interestingly, not only in septum but in separated LV free wall, MCT also activated significant fetal gene program except SERCA. Conclusion: MCT induced RV hypertrophy and failure, which was accompanied by typical fetal gene program in RV. Although MCT theoretically caused unloading of LV free wall, MCT-treated LV exhibited similar pattern of fetal gene activation. Thus, LV may also be affected in the case of severe pulmonary hypertension. The induction of fetal gene program in LV might be attributable to paracrine effects of neurohormonal factors produced by diseased pulmonary vasculature and/or RV.