title: Conditional expression of a dominant-negative c-Myb in vascular smooth muscle cells inhibits arterial remodeling after injury.
abstract: Inhibiting activity of the c-Myb transcription factor attenuates G1 to S phase cell cycle transitions in vascular smooth muscle cells (SMCs) in vitro. To determine the effects of arterial SMC-specific expression of a dominant-negative c-Myb molecule (Myb-Engrailed) on vascular remodeling in vivo, we performed carotid artery wire-denudation in 2 independent lines of binary transgenic mice with SM22alpha promoter-defined Doxycycline-suppressible expression of Myb-Engrailed. Adult mice with arterial SMC-specific expression of Myb-Engrailed were overtly normal in appearance and did not display any changes in cardiovascular structure or physiology. However, bromodeoxyuridine-defined arterial SMC proliferation, neointima formation, medial hyperplasia, and arterial remodeling were markedly decreased in mice expressing arterial SMC-restricted Myb-Engrailed after arterial injury. These data suggest that c-Myb activity in arterial SMCs is not essential for arterial structure or function during development, but is involved in the proliferation of arterial SMCs as occurs in vascular pathology, and that the expression of a dominant-negative c-Myb can dramatically reduce adverse arterial remodeling in an in vivo model of restenosis. As such, this model represents a novel tissue-specific strategy for the potential gene therapy of diseases characterized by arterial SMC proliferation.
authors.affiliation: Division of Cellular and Molecular Biology, The Toronto General Hospital Research Institute, Ontario, Canada.
authors.forename: Xiao-Mang
authors.initials: XM
authors.lastname: You
authors.forename: Imran N
authors.initials: IN
authors.lastname: Mungrue
authors.forename: Waseem
authors.initials: W
authors.lastname: Kalair
authors.forename: Talat
authors.initials: T
authors.lastname: Afroze
authors.forename: Bheeshma
authors.initials: B
authors.lastname: Ravi
authors.forename: Al Muktafi
authors.initials: AM
authors.lastname: Sadi
authors.forename: Robert
authors.initials: R
authors.lastname: Gros
authors.forename: Mansoor
authors.initials: M
authors.lastname: Husain
mesh_terms: D000818:Animals; D001973:Bromodeoxyuridine; D016893:Carotid Stenosis / Q000473:pathology / Q000517:prevention & control*; D002455:Cell Division / Q000235:genetics; D004195:Disease Models, Animal; D015870:Gene Expression / Q000187:drug effects; D005799:Genes, Dominant; D018398:Homeodomain Proteins / Q000235:genetics; D051379:Mice; D008822:Mice, Transgenic; D008840:Microfilament Proteins / Q000235:genetics; D009124:Muscle Proteins / Q000235:genetics; D009131:Muscle, Smooth, Vascular / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D011401:Promoter Regions, Genetic; D020598:Proto-Oncogene Proteins c-myb / Q000096:biosynthesis* / Q000235:genetics / Q000494:pharmacology; D013752:Tetracycline / Q000494:pharmacology; D014157:Transcription Factors; D017539:Tunica Intima / Q000187:drug effects / Q000378:metabolism / Q000473:pathology
chemical_list: D018398:Homeodomain Proteins; D008840:Microfilament Proteins; D009124:Muscle Proteins; D020598:Proto-Oncogene Proteins c-myb; C058992:Tagln protein, mouse; D014157:Transcription Factors; C106185:engrailed homeobox proteins; C051615:transgelin; D013752:Tetracycline; D001973:Bromodeoxyuridine