- Email: [email protected]
bilirubin oxidative metabolites pathway in acute myocardial infarction
Mon&ty, June 19, 2006: Poster Session P2 Pathophysiology of thrombosis
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CHOLESTEROL CONTENT OF ERYTHROCYTE MEMBRANES - A NEW MARKER OF CAD INSTABILITY - MAY INDUCE SYSTEMIC INFLAMMATORY RESPONSES
D.N. Tziakas 1 , J.C. Kaski 2 , G.K. Chalikias 1 , C. Romero 3 , S. Fredericks 3 , I.K. Tentes 4, A.X. Kortsaris 4, D.I. Hatseras 1, D.W. Holt 3. 1 Universi~
Cardiology Department, Democritus Unh,ersi~ of Thrace, AlexatMroupolis, Greece." 2Cardiovascular Biology Researeh Centre, St Geroge's Universi~ of London, London, United Kingdom." 3Analytical Unit, St Geroge's Universi~ of London, LotMon, United Kingdom." 4 Universi~ Biochemistry Department, Alexandroupolis, Greece I n t r o d u c t i o n : Erythrocyte membranes are present within lipid cores of ruptured coronary atherosclerotic plaques. Cholesterol contained in erythrocyte membranes contributes to lipid core growth and plaque vulnerability. Total cholesterol content of erythrocyte membranes (TCEM) is a novel emerging marker of coronary artery disease (CAD) instability. Erythrocyte phagocytosis by macrophages within atherosderotic plaques apart from foam cell formation, triggers an inflammatory response. We investigated the association between C-reactive protein (CRP) levels and TCEM in CAD patients. M e t b o d s : We studied 332 patients (240 men, 654-11 years) of whom 84 had unstable CAD and 248 had stable angina. TCEM was measured on erythrocyte membrane ghosts using an enzymatic assay, while protein content was measured by the Bradford method. Results: We observed a positive linear assodation between CRP levels and TCEM (r=0.203, p<0.001). Patients with low TCEM levels (_< 103.4 ug/mg) had lower (p<0.001) levels of CRP (2.7 mg/L IQ 1.3-5.7) compared to patients with high TCEM levels (> 103.4 ug/mg) (5 mg/L IQ 2.5-10.1). In linear regression model, after adjusting for all the variables that could act as cofounders, CRP levels remained positively associated with TCEM (b=0.092, p=0.05) Conclusions The present study showed that TCEM levels are positively associated with circulating CRP levels, suggesting that TCEM may induce a systemic inflammatory response in CAD patients. Further studies are required to investigate the mechanisms by which erythrocyte membranes axe capable of initiating inflammatory cascades within atherosclerotic plaques.
I Mo-P2:185 I ENOS- AND INOS-DERIVED NITRIC OXIDE I R E G U L A T E S IN V I V O O X Y G E N C O N S U M P T I O N IN THE POSTISCHEMIC MYOCARDIUM G. He, X. Zhao, Y. Chen, J.L. Zweier. The Ohio State Universi~, Columbus,
USA Objective: NO production has been shown to regulate mitochondrial 0 2 consumption in vitro. We determine if NO production by eNOS and iNOS regulates in vivo myocardial 0 2 consumption. M e t h o d s : Myocardial tissue pO2 was monitored by EPR oximetry in WT, L - N A M E treated and eNOS-/- mice subjected to 30 rain regional ischemia followed by 60 rain and 35 days of reperfusion. Results: Myocardial tissue pO2 increased significantly after reperfusion in all groups. However, pO2 in L - N A M E and eNOS-/- mice was lower than in WT. The reperfusion-induced hyperoxygenation lasted for 30 days with lower pO2 in eNOS-/- mice compared to WT. At 60 rain of reperfusion, there was no alteration in cytochrome c oxidase (CcO) activity. However, CcO mRNA expression was up-regulated in WT. NADH dehydrogenase (NADHDH) activity was reduced in W T compared to L - N A M E and eNOS-/- mice with no difference in NADH-DH mRNA expression. At 48 h of reperfusion, expressions of iNOS mRNA, protein, and production of peroxynitrite were lower in eNOS-/- mice than in WT. The protein levels of CcO and NADH-DH were not affected, however the activity of CcO and NADH-DH were decreased in WT. The infarct size was found lower in eNOS-/- mice than in W T at 48 h of reperfusion. Conclusions: Thus in vivo, eNOS- and iNOS-derived NO suppressed 0 2 consumption in the postischemic myocardium through regulation of CcO and NADH-DH on mitochondrial respiration. The results suggest that deficiency of eNOS exerted a beneficial effect on postischemic myocardium mediated by limited generation of NO from the less expressed iNOS. Funding: NIH 1R01ItL081630-01 and A H A 0435299N.
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ROLES OF BILIRUBIN/BILIRUBIN OXIDATIVE M E T A B O L I T E S P A T H W A Y IN A C U T E M Y O C A R D I A L INFARCTION
K. Ishikawa 1, H. Kunii 1, T. Yamaguchi 2 , Y. Maxuyama 1 . 1Fukushima Medical Universi~, Fukushima, Japan: "~Tokyo Medical And Dental Universi~, Tokyo, Japan Objectives: Bilirubin, known as a waste product after heine degradation, has been recendy shown to exhibit antioxidative properties. We examined the roles of bilirubin and its oxidative metabolites biopyrrins in the patients with acute myocardial infarction (AMI). M e t h o d s : One hundred thirteen patients hospitalized for AMI were analyzed. Levels of serum bilirubin, plasma and urinary biopyrrins were measured. Relationships between bilirubin/biopyrrins and cardiac performance were analyzed. Immunohistochemical analyses were performed with the specimens from the autopsied patients. Results: The levels of serum bilirubin, plasma and urinary biopyrrins were significandy elevated within 24 hr, formed a peak on the day 3 and decreased by the day 14. The m a x i m u m levels of plasma and urinary biopyrrins were significandy higher in death cases. The degrees of biopyrrins were also higher in the patients with impaired left ventricular function. Immunohistochemical analyses revealed that abundant expressions of HO-1 and biopyrrins in the myocardium of the patient with AMI whereas there were little expression from non-caxdiac death. Renal tubular cells, aortic endothelium, pulmonary epithelium and macrophages also exhibited immunoreactivitve HO-1 and biopyrrins. C o n d u s i o n : Bilirubin and its oxidative metabolites biopyrrins were elevated in the patients with AMI and associated with acute phase mortality and morbidity. Activation of HO-1, an intrinsic defense system, seems to involve in the activation of bilirubin/biopyrrins pathway. Funding: Grant-in-aid 16590703 from the Ministry of Education, Science and Culture of Japan.
Mo-P2:187 ] L A M I N A R S H E A R S T R E S S S U P P R E S S E S T H E F I B R I N O L Y T I C C A P A C I T Y IN C U L T U R E D VASCULAR ENDOTHELIAL CELLS E. Ulfhammer, N. Bergh, L. Karlsson, M. Andersson, S. Jern. Clin. Eap. Res.
Lab., Sahlgrenskzt Universi~ Hospital/Ostra, GOteborg Universi~, GOteborg, Sweden Objective: Steady laminar shear stress is considered to be atheroprotective and to stimulate expression of the fibrinolytic key enzyme tissue-plasminogen activator (t-PA). This study aims at further examining how laminar shear stress of different magnitudes affects gene expression of t-PA and its main inhibitor PAI-1. M e t h o d s : Cultured human umbilical vein endothelial cells and human aortic endothelial cells were shear stress stimulated (2 or 25 dyn/cm 2) or kept static for 24 h in two different experimental perfusion systems. One of the systems employs the Streamer shear stress device (Flexercell) while the other is a novel computerized system developed at our laboratory. Effects on the gene expression of t-PA, PAI-1 and VCAM-1 were evaluated using real-time RT-PCR. Results: Both perfusion systems and both studied cell-types delivered almost identical shear stress responses on t-PA and VCAM-1. t-PA gene expression was suppressed by both low and high shear stress, with a more pronounced reduction by high shear (-50%). After an initial induction (6 h), shear stress was observed to repress VCAM-1 mRNA expression. Compared to high shear, VCAM-1 expression in low sheared cells was constantly higher. Only shear stimulations in the Streamer system affected the gene expression of PAI-1, resulting in a 3-fold induction with both magnitudes of shear stress. C o n d u s i o n s : By using two different experimental models for shear stress stimulation of cultured vascular endothelial cells, we hereby provide evidence for an anti-fibrinolytic effect of laminar shear stress. Funding: Swedish Research Council, Swedish Heaxt-Lung Foundation.
Mo-P2:188 ] I N V O L V E M E N T O F R A F / E R K P A T H W A Y IN PRODUCTION OF PLASMINOGEN ACTIVATOR I N H I B I T O R - 1 IN V A S C U L A R E N D O T H E L I A L C E L L S I N D U C E D BY O X I D I Z E D O R G L Y C A T E D L D L G. Sangle, F. Zhu, S. Ren, G. Shen. Universi~ of Manitoba, Witwipeg,
CaHgld~l Plasminogen activator inhibitor (PAI)-1 is the major physiological inhibitor for
XIV bztetTtational Symposium on Atherosclerosis, Rome, Italy, June 18-22, 2006
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CHOLESTEROL CONTENT OF ERYTHROCYTE MEMBRANES - A NEW MARKER OF CAD INSTABILITY - MAY INDUCE SYSTEMIC INFLAMMATORY RESPONSES
D.N. Tziakas 1 , J.C. Kaski 2 , G.K. Chalikias 1 , C. Romero 3 , S. Fredericks 3 , I.K. Tentes 4, A.X. Kortsaris 4, D.I. Hatseras 1, D.W. Holt 3. 1 Universi~
Cardiology Department, Democritus Unh,ersi~ of Thrace, AlexatMroupolis, Greece." 2Cardiovascular Biology Researeh Centre, St Geroge's Universi~ of London, London, United Kingdom." 3Analytical Unit, St Geroge's Universi~ of London, LotMon, United Kingdom." 4 Universi~ Biochemistry Department, Alexandroupolis, Greece I n t r o d u c t i o n : Erythrocyte membranes are present within lipid cores of ruptured coronary atherosclerotic plaques. Cholesterol contained in erythrocyte membranes contributes to lipid core growth and plaque vulnerability. Total cholesterol content of erythrocyte membranes (TCEM) is a novel emerging marker of coronary artery disease (CAD) instability. Erythrocyte phagocytosis by macrophages within atherosderotic plaques apart from foam cell formation, triggers an inflammatory response. We investigated the association between C-reactive protein (CRP) levels and TCEM in CAD patients. M e t b o d s : We studied 332 patients (240 men, 654-11 years) of whom 84 had unstable CAD and 248 had stable angina. TCEM was measured on erythrocyte membrane ghosts using an enzymatic assay, while protein content was measured by the Bradford method. Results: We observed a positive linear assodation between CRP levels and TCEM (r=0.203, p<0.001). Patients with low TCEM levels (_< 103.4 ug/mg) had lower (p<0.001) levels of CRP (2.7 mg/L IQ 1.3-5.7) compared to patients with high TCEM levels (> 103.4 ug/mg) (5 mg/L IQ 2.5-10.1). In linear regression model, after adjusting for all the variables that could act as cofounders, CRP levels remained positively associated with TCEM (b=0.092, p=0.05) Conclusions The present study showed that TCEM levels are positively associated with circulating CRP levels, suggesting that TCEM may induce a systemic inflammatory response in CAD patients. Further studies are required to investigate the mechanisms by which erythrocyte membranes axe capable of initiating inflammatory cascades within atherosclerotic plaques.
I Mo-P2:185 I ENOS- AND INOS-DERIVED NITRIC OXIDE I R E G U L A T E S IN V I V O O X Y G E N C O N S U M P T I O N IN THE POSTISCHEMIC MYOCARDIUM G. He, X. Zhao, Y. Chen, J.L. Zweier. The Ohio State Universi~, Columbus,
USA Objective: NO production has been shown to regulate mitochondrial 0 2 consumption in vitro. We determine if NO production by eNOS and iNOS regulates in vivo myocardial 0 2 consumption. M e t h o d s : Myocardial tissue pO2 was monitored by EPR oximetry in WT, L - N A M E treated and eNOS-/- mice subjected to 30 rain regional ischemia followed by 60 rain and 35 days of reperfusion. Results: Myocardial tissue pO2 increased significantly after reperfusion in all groups. However, pO2 in L - N A M E and eNOS-/- mice was lower than in WT. The reperfusion-induced hyperoxygenation lasted for 30 days with lower pO2 in eNOS-/- mice compared to WT. At 60 rain of reperfusion, there was no alteration in cytochrome c oxidase (CcO) activity. However, CcO mRNA expression was up-regulated in WT. NADH dehydrogenase (NADHDH) activity was reduced in W T compared to L - N A M E and eNOS-/- mice with no difference in NADH-DH mRNA expression. At 48 h of reperfusion, expressions of iNOS mRNA, protein, and production of peroxynitrite were lower in eNOS-/- mice than in WT. The protein levels of CcO and NADH-DH were not affected, however the activity of CcO and NADH-DH were decreased in WT. The infarct size was found lower in eNOS-/- mice than in W T at 48 h of reperfusion. Conclusions: Thus in vivo, eNOS- and iNOS-derived NO suppressed 0 2 consumption in the postischemic myocardium through regulation of CcO and NADH-DH on mitochondrial respiration. The results suggest that deficiency of eNOS exerted a beneficial effect on postischemic myocardium mediated by limited generation of NO from the less expressed iNOS. Funding: NIH 1R01ItL081630-01 and A H A 0435299N.
Mo-P2:1861
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ROLES OF BILIRUBIN/BILIRUBIN OXIDATIVE M E T A B O L I T E S P A T H W A Y IN A C U T E M Y O C A R D I A L INFARCTION
K. Ishikawa 1, H. Kunii 1, T. Yamaguchi 2 , Y. Maxuyama 1 . 1Fukushima Medical Universi~, Fukushima, Japan: "~Tokyo Medical And Dental Universi~, Tokyo, Japan Objectives: Bilirubin, known as a waste product after heine degradation, has been recendy shown to exhibit antioxidative properties. We examined the roles of bilirubin and its oxidative metabolites biopyrrins in the patients with acute myocardial infarction (AMI). M e t h o d s : One hundred thirteen patients hospitalized for AMI were analyzed. Levels of serum bilirubin, plasma and urinary biopyrrins were measured. Relationships between bilirubin/biopyrrins and cardiac performance were analyzed. Immunohistochemical analyses were performed with the specimens from the autopsied patients. Results: The levels of serum bilirubin, plasma and urinary biopyrrins were significandy elevated within 24 hr, formed a peak on the day 3 and decreased by the day 14. The m a x i m u m levels of plasma and urinary biopyrrins were significandy higher in death cases. The degrees of biopyrrins were also higher in the patients with impaired left ventricular function. Immunohistochemical analyses revealed that abundant expressions of HO-1 and biopyrrins in the myocardium of the patient with AMI whereas there were little expression from non-caxdiac death. Renal tubular cells, aortic endothelium, pulmonary epithelium and macrophages also exhibited immunoreactivitve HO-1 and biopyrrins. C o n d u s i o n : Bilirubin and its oxidative metabolites biopyrrins were elevated in the patients with AMI and associated with acute phase mortality and morbidity. Activation of HO-1, an intrinsic defense system, seems to involve in the activation of bilirubin/biopyrrins pathway. Funding: Grant-in-aid 16590703 from the Ministry of Education, Science and Culture of Japan.
Mo-P2:187 ] L A M I N A R S H E A R S T R E S S S U P P R E S S E S T H E F I B R I N O L Y T I C C A P A C I T Y IN C U L T U R E D VASCULAR ENDOTHELIAL CELLS E. Ulfhammer, N. Bergh, L. Karlsson, M. Andersson, S. Jern. Clin. Eap. Res.
Lab., Sahlgrenskzt Universi~ Hospital/Ostra, GOteborg Universi~, GOteborg, Sweden Objective: Steady laminar shear stress is considered to be atheroprotective and to stimulate expression of the fibrinolytic key enzyme tissue-plasminogen activator (t-PA). This study aims at further examining how laminar shear stress of different magnitudes affects gene expression of t-PA and its main inhibitor PAI-1. M e t h o d s : Cultured human umbilical vein endothelial cells and human aortic endothelial cells were shear stress stimulated (2 or 25 dyn/cm 2) or kept static for 24 h in two different experimental perfusion systems. One of the systems employs the Streamer shear stress device (Flexercell) while the other is a novel computerized system developed at our laboratory. Effects on the gene expression of t-PA, PAI-1 and VCAM-1 were evaluated using real-time RT-PCR. Results: Both perfusion systems and both studied cell-types delivered almost identical shear stress responses on t-PA and VCAM-1. t-PA gene expression was suppressed by both low and high shear stress, with a more pronounced reduction by high shear (-50%). After an initial induction (6 h), shear stress was observed to repress VCAM-1 mRNA expression. Compared to high shear, VCAM-1 expression in low sheared cells was constantly higher. Only shear stimulations in the Streamer system affected the gene expression of PAI-1, resulting in a 3-fold induction with both magnitudes of shear stress. C o n d u s i o n s : By using two different experimental models for shear stress stimulation of cultured vascular endothelial cells, we hereby provide evidence for an anti-fibrinolytic effect of laminar shear stress. Funding: Swedish Research Council, Swedish Heaxt-Lung Foundation.
Mo-P2:188 ] I N V O L V E M E N T O F R A F / E R K P A T H W A Y IN PRODUCTION OF PLASMINOGEN ACTIVATOR I N H I B I T O R - 1 IN V A S C U L A R E N D O T H E L I A L C E L L S I N D U C E D BY O X I D I Z E D O R G L Y C A T E D L D L G. Sangle, F. Zhu, S. Ren, G. Shen. Universi~ of Manitoba, Witwipeg,
CaHgld~l Plasminogen activator inhibitor (PAI)-1 is the major physiological inhibitor for
XIV bztetTtational Symposium on Atherosclerosis, Rome, Italy, June 18-22, 2006