GEO Accession viewer

NCBI > GEO > Accession Display

Not logged in | Login

GEO help: Mouse over screen elements for information.

Series GSE5500

Query DataSets for GSE5500

Status

Public on Aug 12, 2006

Title

Gata4 is required for postnatal cardiac function and protection from pressure overload-induced heart failure

Organism

Mus musculus

Experiment type

Expression profiling by array

Summary

An important event in the pathogenesis of heart failure is the development of pathological cardiac hypertrophy. In cultured cardiac cardiomyocytes, the transcription factor Gata4 is required for agonist-induced cardiomyocyte hypertrophy. We hypothesized that in the intact organism Gata4 is an important regulator of postnatal heart function and of the hypertrophic response of the heart to pathological stress. To test this hypothesis, we studied mice heterozygous for deletion of the second exon of Gata4 (G4D). At baseline, G4D mice had mild systolic and diastolic dysfunction associated with reduced heart weight and decreased cardiomyocyte number. After transverse aortic constriction (TAC), G4D mice developed overt heart failure and eccentric cardiac hypertrophy, associated with significantly increased fibrosis and cardiomyocyte apoptosis. Inhibition of apoptosis by overexpression of the insulin-like growth factor 1 receptor prevented TAC-induced heart failure in G4D mice. Unlike WT-TAC controls, G4D-TAC cardiomyocytes hypertrophied by increasing in length more than width. Gene expression profiling revealed upregulation of genes associated with apoptosis and
fibrosis, including members of the TGF? pathway. Our data demonstrate that Gata4 is essential for cardiac function in the postnatal heart. After pressure overload, Gata4 regulates the pattern of cardiomyocyte hypertrophy and protects the heart from load-induced failure.
Keywords: genetic modification, pressure overload stress response

Overall design

We reasoned that if Gata4 was a crucial regulator of pathways necessary for cardiac hypertrophy, then modest reductions of Gata4 activity should result in an observable cardiac phenotype. To test this hypothesis, we used gene targeted mice that express reduced levels of Gata4. We characterized these mice at baseline and after pressure
overload.

Contributor(s)