Effect of a dominant negative ras on myocardial hypertrophy by using adenoviral-mediated gene transfer.

Journal Article

BACKGROUND: The small guanosine triphosphate-binding protein ras regulates a signal transduction cascade linking cell surface receptors to mitogen-activated protein kinase (MAPK). Because the molecular signaling mechanisms underlying cardiac hypertrophy remain unclear, the current study examined the regulatory role of ras in both the biochemical and morphologic aspects of hypertrophy. METHODS: Adenoviral-mediated gene transfer was used to express a dominant negative mutant of ras (rasN17) at high efficiency in primary neonatal ventricular myocytes. Beta-galactosidase staining and Western blot analysis confirmed successful transfection and expression of the rasN17 gene product. MAPK activity was measured by an in vitro kinase assay resulting in radioactive phosphorus labeled product. Morphologic hypertrophy was assessed by fluorescein-conjugated phalloidin. RESULTS: Compared with uninfected or control adenoviral-infected cells, myocytes infected with rasN17 demonstrated attenuated basal MAPK activity. In contrast, rasN17 expression did not affect endothelin 1-induced MAPK activation. Morphologic studies showed that although rasN17 produced a phenotypic difference in the basal state, the ability of cardiac myocytes to morphologically respond to endothelin 1 stimulation, as manifested by sarcomeric reorganization, remained unaltered by the expression of the rasN17 gene product. CONCLUSIONS: Endothelin 1-stimulated MAPK activation and endothelin 1-induced morphologic hypertrophy are ras-independent processes.

Full Text

Duke Authors

Cited Authors

  • Pracyk, JB; Hegland, DD; Tanaka, K

Published Date

  • August 1997

Published In

Volume / Issue

  • 122 / 2

Start / End Page

  • 404 - 410

PubMed ID

  • 9288147

International Standard Serial Number (ISSN)

  • 0039-6060

Language

  • eng

Conference Location

  • United States