The role of the Grb2-p38 MAPK signaling pathway in cardiac hypertrophy and fibrosis.

Journal Article (Journal Article)

Cardiac hypertrophy is a common response to pressure overload and is associated with increased mortality. Mechanical stress in the heart can result in the integrin-mediated activation of focal adhesion kinase and the subsequent recruitment of the Grb2 adapter molecule. Grb2, in turn, can activate MAPK cascades via an interaction with the Ras guanine nucleotide exchange factor SOS and with other signaling intermediates. We analyzed the role of the Grb2 adapter protein and p38 MAPK in cardiac hypertrophy. Mice with haploinsufficiency of the Grb2 gene (Grb2(+/-) mice) appear normal at birth but have defective T cell signaling. In response to pressure overload, cardiac p38 MAPK and JNK activation was inhibited and cardiac hypertrophy and fibrosis was blocked in Grb2(+/-) mice. Next, transgenic mice with cardiac-specific expression of dominant negative forms of p38alpha (DN-p38alpha) and p38beta (DN-p38beta) MAPK were examined. DN-p38alpha and DN-p38beta mice developed cardiac hypertrophy but were resistant to cardiac fibrosis in response to pressure overload. These results establish that Grb2 action is essential for cardiac hypertrophy and fibrosis in response to pressure overload, and that different signaling pathways downstream of Grb2 regulate fibrosis, fetal gene induction, and cardiomyocyte growth.

Full Text

Duke Authors

Cited Authors

  • Zhang, S; Weinheimer, C; Courtois, M; Kovacs, A; Zhang, CE; Cheng, AM; Wang, Y; Muslin, AJ

Published Date

  • March 2003

Published In

Volume / Issue

  • 111 / 6

Start / End Page

  • 833 - 841

PubMed ID

  • 12639989

Pubmed Central ID

  • PMC153766

International Standard Serial Number (ISSN)

  • 0021-9738

Digital Object Identifier (DOI)

  • 10.1172/JCI16290

Language

  • eng

Conference Location

  • United States