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Faerber G, Schwarzer M, Schrepper A, Mohr FW, Doenst T. Chronic pressure overload in rats reduces mitochondrial respiratory capacity but not coupling to ATP-production. Thorac Cardiovasc Surg 2010. [DOI: 10.1055/s-0029-1246858] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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127
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Schöpe M, Schwarzer M, Schrepper A, Doenst T, Mohr FW, Amorim PA. Does exercise always cause physiological hypertrophy? Thorac Cardiovasc Surg 2010. [DOI: 10.1055/s-0029-1246867] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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128
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Schwarzer M, Koch LG, Britton SL, Mohr FW, Wisloff U, Doenst T. Normal insulin sensitivity and substrate oxidation in hearts from rats with low intrinsic aerobic exercise capacity and systemic insulin resistance. Thorac Cardiovasc Surg 2010. [DOI: 10.1055/s-0029-1246795] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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129
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Schrepper A, Schwarzer M, Amorim PA, Schöpe M, Mohr FW, Doenst T. Temporal effects of pressure overload on mitochondrial respiratory capacity during the development of heart failure. Thorac Cardiovasc Surg 2010. [DOI: 10.1055/s-0029-1246647] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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130
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Shingu Y, Nguyen TD, Amorim PA, Köppen A, Schwarzer M, Mohr FW, Doenst T. Oleate controls the effects of GLP-1 and exendin-4 on myocardial glucose utilization and contractile function. Thorac Cardiovasc Surg 2010. [DOI: 10.1055/s-0029-1246646] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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131
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Doenst T, Pytel G, Schrepper A, Amorim P, Färber G, Shingu Y, Mohr FW, Schwarzer M. Decreased rates of substrate oxidation ex vivo predict the onset of heart failure and contractile dysfunction in rats with pressure overload. Cardiovasc Res 2009; 86:461-70. [PMID: 20035032 DOI: 10.1093/cvr/cvp414] [Citation(s) in RCA: 189] [Impact Index Per Article: 12.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
AIMS Left ventricular hypertrophy is a risk factor for heart failure. However, it also is a compensatory response to pressure overload, accommodating for increased workload. We tested whether the changes in energy substrate metabolism may be predictive for the development of contractile dysfunction. METHODS AND RESULTS Chronic pressure overload was induced in Sprague-Dawley rats by aortic arch constriction for 2, 6, 10, or 20 weeks. Contractile function in vivo was assessed by echocardiography and by invasive pressure measurement. Glucose and fatty acid oxidation as well as contractile function ex vivo were assessed in the isolated working heart, and respiratory capacity was measured in isolated cardiac mitochondria. Pressure overload caused progressive hypertrophy with normal ejection fraction (EF) at 2, 6, and 10 weeks, and hypertrophy with dilation and impaired EF at 20 weeks. The lung-to-body weight ratio, as marker for pulmonary congestion, was normal at 2 weeks (indicative of compensated hypertrophy) but significantly increased already after 6 and up to 20 weeks, suggesting the presence of heart failure with normal EF at 6 and 10 weeks and impaired EF at 20 weeks. Invasive pressure measurements showed evidence for contractile dysfunction already after 6 weeks and ex vivo cardiac power was reduced even at 2 weeks. Importantly, there was impairment in fatty acid oxidation beginning at 2 weeks, which was associated with a progressive decrease in glucose oxidation. In contrast, respiratory capacity of isolated mitochondria was normal until 10 weeks and decreased only in hearts with impaired EF. CONCLUSION Pressure overload-induced impairment in fatty acid oxidation precedes the onset of congestive heart failure but mitochondrial respiratory capacity is maintained until the EF decreases in vivo. These temporal relations suggest a tight link between impaired substrate oxidation capacity in the development of heart failure and contractile dysfunction and may imply therapeutic and prognostic value.
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132
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Bugger H, Schwarzer M, Chen D, Schrepper A, Amorim PA, Schoepe M, Nguyen TD, Mohr FW, Khalimonchuk O, Weimer BC, Doenst T. Proteomic remodelling of mitochondrial oxidative pathways in pressure overload-induced heart failure. Cardiovasc Res 2009; 85:376-84. [DOI: 10.1093/cvr/cvp344] [Citation(s) in RCA: 162] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
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133
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Schwarzer M, Doenst T. Letter to the editor: "Does a reduction in ADP-limited respiration indicate impaired mitochondrial function?". Am J Physiol Heart Circ Physiol 2009; 297:H889; author reply 890. [PMID: 19635850 DOI: 10.1152/ajpheart.00434.2009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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134
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Nguyen TD, Schwarzer M, Amorim P, Schrepper A, Mohr FW, Doenst T. Mitochondrial function in pressure-overload and exercise-induced hypertrophy: Time makes the difference. Thorac Cardiovasc Surg 2009. [DOI: 10.1055/s-0029-1191631] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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135
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Sauer M, Tews J, Schwarzer M, Seeburger J, Adams V, Falk V, Dhein S, Mohr FW. Rapid detection of the R389G polymorphism of ADRB1 by real time PCR using fluorescence resonance energy transfer. Clin Lab 2009; 55:128-136. [PMID: 19462935] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
The beta1-adrenoceptor plays a crucial role in the regulation of myocardial contractility and heart rate. A functionally important polymorphism at codon 389 has been associated with heart failure and hypertension. The conventional method of detecting this polymorphism is a PCR-assay followed by digestion with specific restriction enzyme (PCR-RFLP) polymorphism. We aimed to establish an alternative, fast genotyping method by real time PCR, which combines high speed DNA-amplification and real time fluorescence monitoring using fluorescence resonance energy transfer. Venous blood of 50 healthy volunteers was examined for the Arg389Gly polymorphism using both methods. The results from PCR-RFLP were compared to those obtained with real time fluorescence PCR and showed a 100% correlation. DNA sequencing confirmed a 100% concordance. This alternative technique is significantly less time consuming than traditional PCR-RFLP and facilitates the analysis of a large numbers of samples.
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136
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Schrepper A, Schwarzer M, Amorim P, Mohr FW, Doenst T. Effect of heart failure on mitochondrial function in cardiac and skeletal muscles. Thorac Cardiovasc Surg 2009. [DOI: 10.1055/s-0029-1191645] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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137
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Schwarzer M, Schrepper A, Amorim P, Pytel G, Mohr FW, Doenst T. Mitochondrial dysfunction in heart failure affects interfibrillar but not subsarcolemmal mitochondria. Thorac Cardiovasc Surg 2009. [DOI: 10.1055/s-0029-1191420] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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138
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Schwarzer M, Schrepper A, Pytel G, Mohr FW, Doenst T. The development of heart failure in rats is associated with impaired insulin response and mitochondrial dysfunction. Thorac Cardiovasc Surg 2009. [DOI: 10.1055/s-0029-1191641] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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139
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Faerber G, Pytel G, Schwarzer M, Schrepper A, Amorim P, Gielen S, Mohr FW, Doenst T. Decreased rates of substrate oxidation in vitro predict the onset of heart failure in rat hearts with pressure overload in vivo. Thorac Cardiovasc Surg 2009. [DOI: 10.1055/s-0029-1191597] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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140
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Schrepper A, Schwarzer M, Amorim P, Schoepe M, Nguyen TD, Mohr FW, Doenst T. Moderate exercise training in rats is associated with myocardial hypertrophy but normal metabolic geno- and phenotype. Thorac Cardiovasc Surg 2009. [DOI: 10.1055/s-0029-1191630] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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141
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Bugger H, Schwarzer M, Schrepper A, Pytel G, Mohr FW, Doenst T. Mitochondrial dysfunction outweighs beneficial effects of altered substrate selection in heart failure. Thorac Cardiovasc Surg 2009. [DOI: 10.1055/s-0029-1191335] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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142
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Doenst T, Bugger H, Schwarzer M, Faerber G, Borger MA, Mohr FW. Three good reasons for heart surgeons to understand cardiac metabolism. Eur J Cardiothorac Surg 2008; 33:862-71. [PMID: 18353669 DOI: 10.1016/j.ejcts.2008.02.015] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/26/2007] [Revised: 02/10/2008] [Accepted: 02/11/2008] [Indexed: 11/30/2022] Open
Abstract
It is the principal goal of cardiac surgeons to improve or reinstate contractile function with, through or after a surgical procedure on the heart. Uninterrupted contractile function of the heart is irrevocably linked to the uninterrupted supply of energy in the form of ATP. Thus, it would appear natural that clinicians interested in myocardial contractile function are interested in the way the heart generates ATP, i.e. the processes generally referred to as energy metabolism. Yet, it may appear that the relevance of energy metabolism in cardiac surgery is limited to the area of cardioplegia, which is a declining research interest. It is the goal of this review to change this trend and to illustrate the role and the therapeutic potential of metabolism and metabolic interventions for management. We present three compelling reasons why cardiac metabolism is of direct, practical interest to the cardiac surgeon and why a better understanding of energy metabolism might indeed result in improved surgical outcomes: (1) To understand cardioplegic arrest, ischemia and reperfusion, one needs a working knowledge of metabolism; (2) hyperglycemia is an underestimated and modifiable risk factor; (3) acute metabolic interventions can be effective in patients undergoing cardiac surgery.
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143
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Schwarzer M, Riehle C, Pytel G, Bugger H, Blum D, Mohr F, Doenst T. Regulation of myocardial metabolic gene expression in pressure-overload and exercise-induced hypertrophy. Thorac Cardiovasc Surg 2008. [DOI: 10.1055/s-2008-1038011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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144
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Pytel G, Muehle A, Faerber G, Maks V, Schwarzer M, Dhein S, Mohr F, Doenst T. Exercise-induced- vs. pressure overload hypertrophy in rat heart: Substrate oxidation patterns and insulin sensitivity. Thorac Cardiovasc Surg 2008. [DOI: 10.1055/s-2008-1037877] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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145
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Faerber G, Barreto-Pereira HF, Gilsbach R, Schoepe M, Schwarzer M, Hein L, Doenst T. Induction of heart failure by minimally invasive aortic constriction in wild-type mice – respiratory capacity of isolated mitochondria and metabolic gene expression. Thorac Cardiovasc Surg 2008. [DOI: 10.1055/s-2008-1037870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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146
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Pytel G, Maks V, Schwarzer M, Kuntze T, Mohr F, Doenst T. Substrate oxidation in isolated working rat hearts is not different between clinically compensated hypertrophy and heart failure. Thorac Cardiovasc Surg 2008. [DOI: 10.1055/s-2008-1037959] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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147
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Schwarzer M, Pytel G, Bugger H, Schrepper A, Schoepe M, Riehle C, Mohr F, Doenst T. Cardiac metabolic adaptation during chronic exercise is independent of PGC-1 signaling. Thorac Cardiovasc Surg 2008. [DOI: 10.1055/s-2008-1037759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
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148
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Yada S, Loebbecke S, Ferstl W, Antes J, Boskovic D, Türcke T, Schwarzer M. Eco-friendly Method for Nitration of Aromatics. CHEM-ING-TECH 2007. [DOI: 10.1002/cite.200790103] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
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149
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Janietz S, Krüger H, Ferstl W, Schwarzer M, Löbbecke S. Einsatz von Mikroreaktoren zur Synthese. CHEM-ING-TECH 2007. [DOI: 10.1002/cite.200750258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022]
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150
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Reboll MR, Oumard A, Gazdag AC, Renger I, Ritter B, Schwarzer M, Hauser H, Wood M, Yamada M, Resch K, Nourbakhsh M. NRF IRES activity is mediated by RNA binding protein JKTBP1 and a 14-nt RNA element. RNA (NEW YORK, N.Y.) 2007; 13:1328-40. [PMID: 17592041 PMCID: PMC1924892 DOI: 10.1261/rna.545407] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
The mRNA of human NF-kappaB repressing factor (NRF) contains a long 5'-untranslated region (UTR) that directs ribosomes to the downstream start codon by a cap-independent mechanism. Comparison of the nucleotide (nt) sequences of human and mouse NRF mRNAs reveals a high degree of identity throughout a fragment of 150 nt proximal to the start codon. Here, we show that this region constitutes a minimal internal ribosome entry segment (IRES) module. Enzymatic RNA structure analysis reveals a secondary structure model of the NRF IRES module. Point mutation analysis of the module determines a short, 14-nt RNA element (nt 640-653) as a mediator of IRES function. Purification of IRES binding cellular proteins and subsequent ESI/MS/MS sequence analysis led to identification of the RNA-binding protein, JKTBP1. EMSA experiments show that JKTBP1 binds upstream to the 14-nt RNA element in the NRF IRES module (nt 579-639). Over-expression of JKTBP1 significantly enhances activity of the NRF IRES module in dicistronic constructs. Moreover, siRNA experiments demonstrate that down-regulation of endogenous JKTBP1 decreases NRF IRES activity and the level of endogenous NRF protein. The data of this study show that JKTBP1 and the 14-nt element act independently to mediate NRF IRES activity.
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