title: Temporal activation of c-Jun N-terminal kinase in adult transgenic heart via cre-loxP-mediated DNA recombination.
abstract: Using a cre-loxP-mediated gene-switch approach, we achieved targeted JNK activation in adult hearts. A transgenic model is established carrying a floxed gene-switch construct that directs GFP marker gene expression in the absence of DNA recombination between two loxP sites. A tamoxifen-inducible Cre recombinase was introduced in the transgenic heart by breeding with previously established Mer-Cre-Mer transgenic mice. Upon tamoxifen administration in double transgenic adult animals, cre-loxP-mediated DNA recombination efficiently switches "off" the loxP-flanked GFP expression unit in cardiomyocytes and switches "on" the expression of the target gene, MKK7D, a constitutively activated upstream activator of c-Jun N-terminal kinases (JNK). Expression of MKK7D in adult hearts resulted in significant activation of JNK activities and causes progressive cardiomyopathy in transgenic animals. This unique animal model of cardiac-specific and temporally regulated JNK activation will provide a powerful tool to investigate the functional role of the JNK pathway in the development of heart failure. Our data also demonstrated that the inducible gene-switch approach reported here may also be applicable in other studies to achieve efficient, tissue-specific, and temporally regulated genetic manipulation in intact animals.
authors.affiliation: Department of Physiology, University of Maryland School of Medicine, 655 W. Baltimore Street, Baltimore, MD 21201, USA.
authors.forename: Brian G
authors.initials: BG
authors.lastname: Petrich
authors.forename: Jeffery D
authors.initials: JD
authors.lastname: Molkentin
authors.forename: Yibin
authors.initials: Y
authors.lastname: Wang
mesh_terms: D000818:Animals; D004789:Enzyme Activation / Q000187:drug effects; D005786:Gene Expression Regulation / Q000187:drug effects; D049452:Green Fluorescent Proteins; D019426:Integrases / Q000235:genetics / Q000378:metabolism*; D048031:JNK Mitogen-Activated Protein Kinases; D008164:Luminescent Proteins / Q000235:genetics / Q000378:metabolism; D051379:Mice; D008822:Mice, Transgenic; D020928:Mitogen-Activated Protein Kinases / Q000235:genetics / Q000378:metabolism*; D009206:Myocardium / Q000378:metabolism* / Q000473:pathology; D032383:Myocytes, Cardiac / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000235:genetics / Q000378:metabolism; D011995:Recombination, Genetic / Q000187:drug effects / Q000235:genetics*; D013629:Tamoxifen / Q000494:pharmacology; D013997:Time Factors; D014764:Viral Proteins / Q000235:genetics / Q000378:metabolism*
chemical_list: D008164:Luminescent Proteins; D011993:Recombinant Fusion Proteins; D014764:Viral Proteins; D013629:Tamoxifen; D049452:Green Fluorescent Proteins; D048031:JNK Mitogen-Activated Protein Kinases; D020928:Mitogen-Activated Protein Kinases; C045073:Cre recombinase; D019426:Integrases