Molecular and functional signature of heart hypertrophy during pregnancy.

Journal Article (Journal Article)

During pregnancy, the heart develops a reversible physiological hypertrophic growth in response to mechanical stress and increased cardiac output; however, underlying molecular mechanisms remain unknown. Here, we investigated pregnancy-related changes in heart structure, function, and gene expression of known markers of pathological hypertrophy and cell stretching in mice hearts. In late pregnancy, hearts show eccentric hypertrophy, as expected for a response to volume overload, with normal left ventricular diastolic function and a moderate reduction in systolic function. Pregnancy-related physiological heart hypertrophy does not induce expression changes of known markers of pathological hypertrophy like: alpha- and beta-myosin heavy chain, atrial natriuretic factor, phospholamban, and sarcoplasmic reticulum Ca2+-ATPase. Instead, it induces the remodeling of Kv4.3 channel and increased c-Src tyrosine kinase activity, a stretch-responsive kinase. Cardiac Kv4.3 channel gene expression was downregulated by approximately 3- to 5-fold, both at the mRNA and protein levels, and was paralleled by a reduction in transient outward K+ currents, a longer action potential and by prolongation of the QT interval. Downregulation of cardiac Kv4.3 transcripts was mimicked by estrogen treatment in ovariectomized mice, and was prevented by the estrogen receptor antagonist ICI 182,780. c-Src activity increased by approximately 2-fold in late pregnancy and after estrogen treatment. We propose that, in addition to mechanical stress, the rise of estrogen toward the end of pregnancy contributes to pregnancy-related heart hypertrophy by increased c-Src activity and that the rise of estrogen is one factor that down regulates cardiac Kv4.3 gene expression providing a molecular correlate for a longer QT interval in pregnancy.

Full Text

Duke Authors

Cited Authors

  • Eghbali, M; Deva, R; Alioua, A; Minosyan, TY; Ruan, H; Wang, Y; Toro, L; Stefani, E

Published Date

  • June 10, 2005

Published In

Volume / Issue

  • 96 / 11

Start / End Page

  • 1208 - 1216

PubMed ID

  • 15905459

Electronic International Standard Serial Number (EISSN)

  • 1524-4571

Digital Object Identifier (DOI)

  • 10.1161/01.RES.0000170652.71414.16

Language

  • eng

Conference Location

  • United States