| Increased temperature, not cardiac load, activates heat shock transcription factor 1 and heat shock protein 72 expression in the heart. | |
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MedLine Citation:
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PMID: 16990482 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The expression of myocardial heat shock protein 72 (HSP72) postexercise is initiated by the activation of heat shock transcription factor 1 (HSF1). However, it remains unknown which physiological stimuli govern myocardial HSF1 activation during exercise. These experiments tested the hypothesis that thermal stress and mechanical load, concomitant with simulated exercise, provide independent stimuli for HSF1 activation and ensuing cardiac HSP72 gene expression. To elucidate the independent roles of increased temperature and cardiac workload in the exercise-mediated upregulation of left-ventricular HSP72, hearts from adult male Sprague-Dawley rats were randomly assigned to one of five simulated exercise conditions. Upon reaching a surgical plane of anesthesia, each experimental heart was isolated and perfused using an in vitro working heart model, while independently varying temperatures (i.e., 37 degrees C vs. 40 degrees C) and cardiac workloads (i.e., low preload and afterload vs. high preload and afterload) to mimic exercise responses. Results indicate that hyperthermia, independent of cardiac workload, promoted an increase in nuclear translocation and phosphorylation of HSF1 compared with normothermic left ventricles. Similarly, hyperthermia, independent of workload, resulted in significant increases in cardiac levels of HSP72 mRNA. Collectively, these data suggest that HSF1 activation and HSP72 gene transcriptional competence during simulated exercise are linked to elevated heart temperature and are not a direct function of increased cardiac workload. |
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Authors:
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Jessica L Staib; John C Quindry; Joel P French; David S Criswell; Scott K Powers |
Publication Detail:
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Type: In Vitro; Journal Article; Research Support, N.I.H., Extramural; Research Support, Non-U.S. Gov't Date: 2006-09-21 |
Journal Detail:
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Title: American journal of physiology. Regulatory, integrative and comparative physiology Volume: 292 ISSN: 0363-6119 ISO Abbreviation: Am. J. Physiol. Regul. Integr. Comp. Physiol. Publication Date: 2007 Jan |
Date Detail:
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Created Date: 2007-01-01 Completed Date: 2007-02-08 Revised Date: 2008-11-21 |
Medline Journal Info:
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Nlm Unique ID: 100901230 Medline TA: Am J Physiol Regul Integr Comp Physiol Country: United States |
Other Details:
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Languages: eng Pagination: R432-9 Citation Subset: IM |
Affiliation:
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Department of Applied Physiology and Kinesiology, University of Florida, Gainesville, Florida, USA. |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Animals Blood Pressure / physiology Blotting, Western Body Temperature / physiology Cell Nucleus / metabolism Coronary Circulation / physiology DNA-Binding Proteins / biosynthesis* Electrophoresis, Polyacrylamide Gel HSP72 Heat-Shock Proteins / biosynthesis* Heart / physiology* Heart Rate / physiology Hot Temperature* Male Myocardium / metabolism* Oxidation-Reduction Phosphorylation Physical Exertion / physiology Physical Stimulation Protein Transport Proteins / metabolism RNA / biosynthesis Rats Rats, Sprague-Dawley Reverse Transcriptase Polymerase Chain Reaction Transcription Factors / biosynthesis* |
| Grant Support | |
ID/Acronym/Agency:
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R01 HL072789/HL/NHLBI NIH HHS |
| Chemical | |
Reg. No./Substance:
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0/DNA-Binding Proteins; 0/HSP72 Heat-Shock Proteins; 0/Proteins; 0/Transcription Factors; 0/heat shock transcription factor; 63231-63-0/RNA |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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