Evolution of expression of cardiac phenotypes over a 4-year period in the β-myosin heavy chain-Q403 transgenic rabbit model of human hypertrophic cardiomyopathy

Sherif Nagueh, Suetnee Chen, Rajnikant Patel, Natalia Tsybouleva, Silvia Lutucuta, Helen A. Kopelen, William A. Zoghbi, Miguel A. Quiñones, Robert Roberts, A. J. Marian

Research output: Contribution to journalArticle

37 Scopus citations

Abstract

Hypertrophic cardiomyopathy (HCM), the most common cause of sudden cardiac death in the young, is characterized by a diverse array of cardiac phenotypes evolving over several decades. We have developed transgenic rabbits that fully recapitulate the phenotype of human HCM and provide for the opportunity to delineate the sequence of evolution of cardiac phenotypes, and thus, the pathogenesis of HCM. We determined evolution of biochemical, molecular, histological, structural and functional phenotypes at 4 age-periods in 47 β-myosin heavy chain-glutamine (MyHC-Q)-403 transgenic rabbits. Ca +2 sensitivity of myofibrillar ATPase activity was reduced very early and in the absence of other discernible phenotypes. Myocyte disarray also occurred early, prior to, and independent of hypertrophy and fibrosis. The latter phenotypes evolved predominantly during puberty in conjunction with activation of stress-related signaling kinases. Myocardial contraction and relaxation velocities were decreased early despite normal global cardiac function and in the absence of histological phenotype. Global cardiac function declined with aging, while left atrial size was increased along with Doppler indices of left ventricular filling pressure. Thus, Ca+2 sensitivity of myofibrillar ATPase activity is a primary phenotype expressed early and independent of the ensuing phenotypes. Pathogenesis of myocyte disarray, which exhibits age-independent penetrance, differs from those of hypertrophy and fibrosis, which show age-dependent expression. Myocardial dysfunction is an early marker that predicts subsequent development of hypertrophy. These findings in an animal model that recapitulates the phenotype of human HCM, implicate involvement of multiple independent mechanisms in the pathogenesis of cardiac phenotypes in HCM.

Original languageEnglish (US)
Pages (from-to)663-673
Number of pages11
JournalJournal of Molecular and Cellular Cardiology
Volume36
Issue number5
DOIs
StatePublished - May 2004

Keywords

  • ATPase
  • Cardiomyopathy
  • Echocardiography
  • Genetics
  • Hypertrophy
  • Tissue Doppler
  • Transgenic animal models

ASJC Scopus subject areas

  • Molecular Biology
  • Cardiology and Cardiovascular Medicine

Fingerprint Dive into the research topics of 'Evolution of expression of cardiac phenotypes over a 4-year period in the β-myosin heavy chain-Q403 transgenic rabbit model of human hypertrophic cardiomyopathy'. Together they form a unique fingerprint.

Cite this