Cardiac transgenesis with the tetracycline transactivator changes myocardial function and gene expression

McCloskey, DT; Turnbull, L; Swigart, PM; Zambon, AC; Turcato, S; Joho, S; Grossman, W; Conklin, BR; Simpson, PC; Baker, AJ

Cardiac transgenesis with the tetracycline transactivator changes myocardial function and gene expression

McCloskey, DT Turnbull, L

Swigart, PM Zambon, AC Turcato, S Joho, S Grossman, W Conklin, BR Simpson, PC Baker, AJ

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Publication Type:: Journal Article
Citation:: Physiological Genomics, 2005, 22 pp. 118 - 126
Issue Date:: 2005-10-01

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Field	Value	Language
dc.contributor.author	McCloskey, DT	en_US
dc.contributor.author	Turnbull, L https://orcid.org/0000-0002-9255-9033	en_US
dc.contributor.author	Swigart, PM	en_US
dc.contributor.author	Zambon, AC	en_US
dc.contributor.author	Turcato, S	en_US
dc.contributor.author	Joho, S	en_US
dc.contributor.author	Grossman, W	en_US
dc.contributor.author	Conklin, BR	en_US
dc.contributor.author	Simpson, PC	en_US
dc.contributor.author	Baker, AJ	en_US
dc.date.issued	2005-10-01	en_US
dc.identifier.citation	Physiological Genomics, 2005, 22 pp. 118 - 126	en_US
dc.identifier.issn	1531-2267	en_US
dc.identifier.uri	http://hdl.handle.net/10453/9715
dc.description.abstract	The cardiac-specific tetracycline-regulated gene expression system (tet-system) is a powerful tool using double-transgenic mice. The cardiac α-myosin heavy chain promoter (αMHC) drives lifetime expression of a tetracycline-inhibited transcription activator (tTA). Crossing αMHC-tTA mice with mice containing a tTA-responsive promoter linked to a target gene yields double-transgenic mice having tetracycline-repressed expression of the target gene in the heart. Using the tet-system, some studies use nontransgenic mice for the control group, whereas others use single-transgenic αMHC-tTA mice. However, previous studies found that high-level expression of a modified activator protein caused cardiomyopathy. Therefore, we tested whether cardiac expression of tTA was associated with altered function of αMHC-tTA mice compared with wild-type (WT) littermates. We monitored in vivo and in vitro function and gene expression profiles for myocardium from WT and αMHC-tTA mice. Compared with WT littermates, αMHC-tTA mice had a greater heart-to-body weight ratio (≈10%), ventricular dilation, and decreased ejection fraction, suggesting mild cardiomyopathy. In vitro, submaximal contractions were greater compared with WT and were associated with greater myofilament Ca2+ sensitivity. Gene expression profiling revealed that the expression of 153 genes was significantly changed by >20% when comparing αMHC-tTA with WT myocardium. These findings demonstrate that introduction of the αMHC-tTA construct causes significant effects on myocardial gene expression and major functional abnormalities in vivo and in vitro. For studies using the tet-system, these results suggest caution in the use of controls, since αMHC-tTA myocardium differs appreciably from WT. Furthermore, the results raise the possibility that the phenotype conferred by a target gene may be influenced by the modified genetic background of αMHC-tTA myocardium.	en_US
dc.relation.ispartof	Physiological Genomics	en_US
dc.relation.isbasedon	10.1152/physiolgenomics.00016.2005	en_US
dc.subject.classification	Biochemistry & Molecular Biology	en_US
dc.subject.mesh	Myocardium	en_US
dc.subject.mesh	Heart	en_US
dc.subject.mesh	Cytosol	en_US
dc.subject.mesh	Animals	en_US
dc.subject.mesh	Mice, Transgenic	en_US
dc.subject.mesh	Mice	en_US
dc.subject.mesh	Body Weight	en_US
dc.subject.mesh	Calcium	en_US
dc.subject.mesh	Doxycycline	en_US
dc.subject.mesh	Tetracycline	en_US
dc.subject.mesh	Ventricular Myosins	en_US
dc.subject.mesh	Actin Cytoskeleton	en_US
dc.subject.mesh	Gene Expression Profiling	en_US
dc.subject.mesh	Gene Expression Regulation	en_US
dc.subject.mesh	Genotype	en_US
dc.subject.mesh	Organ Size	en_US
dc.subject.mesh	Phenotype	en_US
dc.subject.mesh	Trans-Activators	en_US
dc.title	Cardiac transgenesis with the tetracycline transactivator changes myocardial function and gene expression	en_US
dc.type	Journal Article
utslib.citation.volume	22	en_US
utslib.for	0606 Physiology	en_US
utslib.for	1116 Medical Physiology	en_US
dc.location.activity	ISI:000230987700014	en_US
pubs.embargo.period	Not known	en_US
pubs.organisational-group	/University of Technology Sydney
pubs.organisational-group	/University of Technology Sydney/Faculty of Science
pubs.organisational-group	/University of Technology Sydney/Strength - ithree - Institute of Infection, Immunity and Innovation
utslib.copyright.status	closed_access
pubs.publication-status	Published	en_US
pubs.volume	22	en_US

Abstract:

The cardiac-specific tetracycline-regulated gene expression system (tet-system) is a powerful tool using double-transgenic mice. The cardiac α-myosin heavy chain promoter (αMHC) drives lifetime expression of a tetracycline-inhibited transcription activator (tTA). Crossing αMHC-tTA mice with mice containing a tTA-responsive promoter linked to a target gene yields double-transgenic mice having tetracycline-repressed expression of the target gene in the heart. Using the tet-system, some studies use nontransgenic mice for the control group, whereas others use single-transgenic αMHC-tTA mice. However, previous studies found that high-level expression of a modified activator protein caused cardiomyopathy. Therefore, we tested whether cardiac expression of tTA was associated with altered function of αMHC-tTA mice compared with wild-type (WT) littermates. We monitored in vivo and in vitro function and gene expression profiles for myocardium from WT and αMHC-tTA mice. Compared with WT littermates, αMHC-tTA mice had a greater heart-to-body weight ratio (≈10%), ventricular dilation, and decreased ejection fraction, suggesting mild cardiomyopathy. In vitro, submaximal contractions were greater compared with WT and were associated with greater myofilament Ca2+ sensitivity. Gene expression profiling revealed that the expression of 153 genes was significantly changed by >20% when comparing αMHC-tTA with WT myocardium. These findings demonstrate that introduction of the αMHC-tTA construct causes significant effects on myocardial gene expression and major functional abnormalities in vivo and in vitro. For studies using the tet-system, these results suggest caution in the use of controls, since αMHC-tTA myocardium differs appreciably from WT. Furthermore, the results raise the possibility that the phenotype conferred by a target gene may be influenced by the modified genetic background of αMHC-tTA myocardium.

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http://hdl.handle.net/10453/9715