Cardiomyopathy in Irx4-deficient mice is preceded by abnormal ventricular gene expression.

ABSTRACT: To define the role of Irx4, a member of the Iroquois family of homeobox transcription factors in mammalian heart development and function, we disrupted the murine Irx4 gene. Cardiac morphology in Irx4-deficient mice (designated Irx4(Delta ex2/Delta ex2)) was normal during embryogenesis and in early postnatal life. Adult Irx4(Delta ex2/Delta ex2) mice developed a cardiomyopathy characterized by cardiac hypertrophy and impaired contractile function. Prior to the development of cardiomyopathy, Irx4(Delta ex2/Delta ex2) hearts had abnormal ventricular gene expression: Irx4-deficient embryos exhibited reduced ventricular expression of the basic helix-loop-helix transcription factor eHand (Hand1), increased Irx2 expression, and ventricular induction of an atrial chamber-specific transgene. In ne

SUBMITTER: Bruneau BG 

PROVIDER: S-EPMC86719 | biostudies-literature | 2001 Mar

REPOSITORIES: biostudies-literature