Dexamethasone enhances insulin-like growth factor-I effects on skeletal muscle cell proliferation. Role of specific intracellular signaling pathways

The Journal of Clinical Investigation
F Giorgino, R J Smith

Abstract

IGF-I stimulation of cell proliferation and c-Fos expression in skeletal muscle cells is markedly enhanced by dexamethasone. The effect of dexamethasone is not mediated by changes in IGF-binding proteins, as evidenced by similar effects of dexamethasone on the actions of insulin, PDGF-BB, and the IGF-I analogue long R3IGF-I. Dexamethasone also does not alter autocrine IGF-II secretion by muscle cells. To investigate the mechanism of the augmentation of IGF-I action, the effects of dexamethasone on intracellular IGF-I signaling pathways were determined. In dexamethasone-treated cells, the levels of IGF-I receptor tyrosine phosphorylation and receptor-associated phosphatidylinositol 3-kinase activity were increased. Dexamethasone-treated cells also showed increased and prolonged tyrosine phosphorylation of the Shc proteins. In contrast, dexamethasone decreased both tyrosine phosphorylation and expression of insulin receptor substrate 1 (IRS-1) and IRS-1-associated phosphatidylinositol 3-kinase activity. Thus, distinct signaling pathways activated by the IGF-I receptor in skeletal muscle cells are differentially regulated by dexamethasone. Potentiation of IGF-I action correlates with increased IGF-I receptor-associated phosphatidy...Continue Reading

References

Apr 1, 1978·Proceedings of the National Academy of Sciences of the United States of America·J B BakerD D Cunningham
Oct 1, 1992·Proceedings of the National Academy of Sciences of the United States of America·J McGladeT Pawson
Jan 25, 1991·Cell·L C CantleyS Soltoff
Jun 1, 1989·In Vitro Cellular & Developmental Biology : Journal of the Tissue Culture Association·C A ConoverR L Hintz
Jan 1, 1985·Annual Review of Physiology·E R FroeschJ Zapf
Jan 1, 1988·Annual Review of Biochemistry·Y Yarden, A Ullrich
Sep 1, 1987·Muscle & Nerve·J R Florini
Nov 1, 1974·Proceedings of the National Academy of Sciences of the United States of America·D Gospodarowicz, J S Moran
Mar 12, 1993·Cell·Z SongyangR J Lechleider
May 14, 1993·Biochemical and Biophysical Research Communications·K S Kovacina, R A Roth
Jul 1, 1994·Trends in Biochemical Sciences·M G MyersM F White
Jan 18, 1994·Proceedings of the National Academy of Sciences of the United States of America·D W RoseJ M Olefsky
Jul 1, 1993·Proceedings of the National Academy of Sciences of the United States of America·J Blenis
Sep 1, 1993·Proceedings of the National Academy of Sciences of the United States of America·D E LarsonL I Rothblum

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Citations

Dec 28, 1999·Molecular and Cellular Endocrinology·E V Páez-EspinosaM J Saad
Oct 27, 2007·Antioxidants & Redox Signaling·Benjamin D BringardnerClay B Marsh
Sep 13, 2000·Growth Hormone & IGF Research : Official Journal of the Growth Hormone Research Society and the International IGF Research Society·C Laurino, R Cordera
Apr 22, 2014·Research in Veterinary Science·S PegoloL Bargelloni
Mar 24, 2011·Journal of Proteome Research·Roberto StellaIgino Andrighetto
May 27, 2015·Molecules : a Journal of Synthetic Chemistry and Natural Product Chemistry·Sachchida Nand PandeyYi-Wen Chen
Aug 10, 2007·American Journal of Physiology. Regulatory, Integrative and Comparative Physiology·Cheng-Hui FangSulaiman Sheriff
Aug 23, 2007·The Journal of Clinical Endocrinology and Metabolism·Laura L GathercoleJeremy W Tomlinson
Mar 7, 1997·The Journal of Biological Chemistry·S A CoolicanJ R Florini
Jan 17, 2002·American Journal of Physiology. Regulatory, Integrative and Comparative Physiology·K R KritschD M Ney
Feb 10, 1999·The American Journal of Physiology·D G BurrinX Chang
Jul 10, 1998·The Proceedings of the Nutrition Society·J M BrameldJ M Harper
Aug 9, 2001·Neurobiology of Disease·J R Singleton, E L Feldman

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