Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
16
pubmed:dateCreated
1993-7-7
pubmed:abstractText
The molecular mechanisms by which overloaded cardiac myocytes increase the cell size (hypertrophy) remain unknown. We have previously shown that mechanical loading increased the protein synthesis and the expression of proto-oncogene c-fos mRNA (Komuro, I., Kaida, T., Shibazaki, Y., Kurabayashi, M., Katoh, Y. Hoh, E., Takaku, F., and Yazaki, Y. (1990) J. Biol. Chem. 265, 3595-3598; Komuro, I., Katoh, Y., Kaida, T., Shibazaki, Y., Kurabayashi, M., Hoh, E., Takaku, F., and Yazaki, Y. (1991) J. Biol. Chem. 266, 1265-1268). It has been known that both mitogen-activated protein (MAP) kinase and S6 kinase can be activated by many kinds of growth factors. To clarify whether MAP kinase(s) and S6 kinase(s) are associated with the intracellular signaling of cardiac hypertrophy induced by mechanical loading, we cultured neonatal rat cardiac myocytes in deformable dishes and imposed an in vitro mechanical loading by stretching the adherent myocytes. In this study, we demonstrated that 1) myocyte stretching maximally activated a kinase activity toward myelin basic protein (MBP) at 10 min after stretching, and the kinase activity returned to the control level at 30 min after stretching; 2) kinase assays in MBP-containing gel, after sodium dodecyl sulfate-polyacrylamide gel electrophoresis, revealed that stretch-induced MBP kinase activity mainly migrated at 42 kDa in the immunoprecipitated fraction of anti-MAP kinase antibody, suggesting that the stretching mainly increased the 42-kDa MAP kinase activity in cardiac myocytes; 3) phosphorylation of MAP kinase was induced after stretching cardiac myocytes; 4) when protein kinase C was depleted by preincubating myocytes with 100 nM 12-O-tetradecanoyl-phorbol-13-acetate for 24 h or 2 nM staurosporine for 30 min, stretch-induced MBP kinase activity was decreased by approximately 60-70% as compared with the kinase activity in myocytes without protein kinase C depletion; 5) although the receptor tyrosine kinases were depleted by preincubating myocytes with 50 microM tyrphostin or 20 microM genistein for 30 min, there was no change in the stretch-induced MBP kinase activity; 6) stretch-induced MBP kinase activity was partially dependent on transsarcolemmal influx of Ca2+; 7) myocyte stretching also increased S6 peptide (RRLSSLRA) kinase activity in the anti-S6 kinase II antibody immunoprecipitates. From these results, we conclude that myocyte stretching increases the activities of MAP kinase and S6 peptide kinase, which may play an important role in the induction of the specific genes and the increase in the protein synthesis.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
http://linkedlifedata.com/resource/pubmed/chemical/Alkaloids, http://linkedlifedata.com/resource/pubmed/chemical/Calcium-Calmodulin-Dependent..., http://linkedlifedata.com/resource/pubmed/chemical/Catechols, http://linkedlifedata.com/resource/pubmed/chemical/Genistein, http://linkedlifedata.com/resource/pubmed/chemical/Isoflavones, http://linkedlifedata.com/resource/pubmed/chemical/Myelin Basic Proteins, http://linkedlifedata.com/resource/pubmed/chemical/Nitriles, http://linkedlifedata.com/resource/pubmed/chemical/Protein Kinase C, http://linkedlifedata.com/resource/pubmed/chemical/Protein Kinases, http://linkedlifedata.com/resource/pubmed/chemical/Protein-Serine-Threonine Kinases, http://linkedlifedata.com/resource/pubmed/chemical/Protein-Tyrosine Kinases, http://linkedlifedata.com/resource/pubmed/chemical/Ribosomal Protein S6 Kinases, http://linkedlifedata.com/resource/pubmed/chemical/Staurosporine, http://linkedlifedata.com/resource/pubmed/chemical/Tetradecanoylphorbol Acetate, http://linkedlifedata.com/resource/pubmed/chemical/Tyrphostins, http://linkedlifedata.com/resource/pubmed/chemical/tyrphostin 47
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
5
pubmed:volume
268
pubmed:geneSymbol
c-fos
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
12069-76
pubmed:dateRevised
2009-11-19
pubmed:meshHeading
pubmed-meshheading:7685031-Alkaloids, pubmed-meshheading:7685031-Animals, pubmed-meshheading:7685031-Animals, Newborn, pubmed-meshheading:7685031-Calcium-Calmodulin-Dependent Protein Kinases, pubmed-meshheading:7685031-Catechols, pubmed-meshheading:7685031-Cells, Cultured, pubmed-meshheading:7685031-Electrophoresis, Polyacrylamide Gel, pubmed-meshheading:7685031-Enzyme Activation, pubmed-meshheading:7685031-Gene Expression, pubmed-meshheading:7685031-Genes, fos, pubmed-meshheading:7685031-Genistein, pubmed-meshheading:7685031-Isoflavones, pubmed-meshheading:7685031-Kinetics, pubmed-meshheading:7685031-Myelin Basic Proteins, pubmed-meshheading:7685031-Myocardium, pubmed-meshheading:7685031-Nitriles, pubmed-meshheading:7685031-Protein Kinase C, pubmed-meshheading:7685031-Protein Kinases, pubmed-meshheading:7685031-Protein-Serine-Threonine Kinases, pubmed-meshheading:7685031-Protein-Tyrosine Kinases, pubmed-meshheading:7685031-Rats, pubmed-meshheading:7685031-Rats, Wistar, pubmed-meshheading:7685031-Ribosomal Protein S6 Kinases, pubmed-meshheading:7685031-Staurosporine, pubmed-meshheading:7685031-Tetradecanoylphorbol Acetate, pubmed-meshheading:7685031-Tyrphostins
pubmed:year
1993
pubmed:articleTitle
Mechanical loading activates mitogen-activated protein kinase and S6 peptide kinase in cultured rat cardiac myocytes.
pubmed:affiliation
Third Department of Internal Medicine, Faculty of Medicine, University of Tokyo, Japan.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't