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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
2011-8-31
pubmed:abstractText
Rac1-GTPase activation plays a key role in the development and progression of cardiac remodeling. Therefore, we engineered a transgenic mouse model by overexpressing cDNA of a constitutively active form of Zea maize Rac gene (ZmRacD) specifically in the hearts of FVB/N mice. Echocardiography and MRI analyses showed cardiac hypertrophy in old transgenic mice, as evidenced by increased left ventricular (LV) mass and LV mass-to-body weight ratio, which are associated with relative ventricular chamber dilation and systolic dysfunction. LV hypertrophy in the hearts of old transgenic mice was further confirmed by an increased heart weight-to-body weight ratio and histopathology analysis. The cardiac remodeling in old transgenic mice was coupled with increased myocardial Rac-GTPase activity (372%) and ROS production (462%). There were also increases in ?(1)-integrin (224%) and ?(1)-integrin (240%) expression. This led to the activation of hypertrophic signaling pathways, e.g., ERK1/2 (295%) and JNK (223%). Pravastatin treatment led to inhibition of Rac-GTPase activity and integrin signaling. Interestingly, activation of ZmRacD expression with thyroxin led to cardiac dilation and systolic dysfunction in adult transgenic mice within 2 wk. In conclusion, this is the first study to show the conservation of Rho/Rac proteins between plant and animal kingdoms in vivo. Additionally, ZmRacD is a novel transgenic model that gradually develops a cardiac phenotype with aging. Furthermore, the shift from cardiac hypertrophy to dilated hearts via thyroxin treatment will provide us with an excellent system to study the temporal changes in cardiac signaling from adaptive to maladaptive hypertrophy and heart failure.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
1522-1539
pubmed:author
pubmed:issnType
Electronic
pubmed:volume
301
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
H868-80
pubmed:meshHeading
pubmed-meshheading:21622832-Aging, pubmed-meshheading:21622832-Amino Acid Sequence, pubmed-meshheading:21622832-Analysis of Variance, pubmed-meshheading:21622832-Animals, pubmed-meshheading:21622832-Antigens, CD29, pubmed-meshheading:21622832-Echocardiography, pubmed-meshheading:21622832-Genotype, pubmed-meshheading:21622832-Hypertrophy, Left Ventricular, pubmed-meshheading:21622832-Integrin alpha1, pubmed-meshheading:21622832-MAP Kinase Signaling System, pubmed-meshheading:21622832-Magnetic Resonance Imaging, pubmed-meshheading:21622832-Male, pubmed-meshheading:21622832-Mice, pubmed-meshheading:21622832-Mice, Transgenic, pubmed-meshheading:21622832-Molecular Sequence Data, pubmed-meshheading:21622832-Mutation, pubmed-meshheading:21622832-Myocardium, pubmed-meshheading:21622832-Myosin Heavy Chains, pubmed-meshheading:21622832-Phenotype, pubmed-meshheading:21622832-Plant Proteins, pubmed-meshheading:21622832-Pravastatin, pubmed-meshheading:21622832-Promoter Regions, Genetic, pubmed-meshheading:21622832-Superoxides, pubmed-meshheading:21622832-Thyroxine, pubmed-meshheading:21622832-Ventricular Dysfunction, Left, pubmed-meshheading:21622832-Ventricular Function, Left, pubmed-meshheading:21622832-Ventricular Remodeling, pubmed-meshheading:21622832-rac1 GTP-Binding Protein
pubmed:year
2011
pubmed:articleTitle
Cardiac remodeling caused by transgenic overexpression of a corn Rac gene.
pubmed:affiliation
Department of Anesthesiology, The Ohio State University, Columbus, Ohio, USA.
pubmed:publicationType
Journal Article