HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Full Text Full Text (PDF) Purchase Article View Shopping Cart Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Leng, Y. Articles by Zierath, J. R. Search for Related Content PubMed PubMed Citation Articles by Leng, Y. Articles by Zierath, J. R. Social Bookmarking                What's this?

Effects of Insulin, Contraction, and Phorbol Esters on Mitogen-Activated Protein Kinase Signaling in Skeletal Muscle From Lean and ob/ob Mice

¹ Department of Surgical Sciences, Section for Integrative Physiology, Karolinska Institutet, Stockholm, Sweden
² Department of Physiology and Pharmacology, Section for Integrative Physiology, Karolinska Institutet, Stockholm, Sweden

Effects of diverse stimuli, including insulin, muscle contraction, and phorbol 12-myristate-13-acetate (PMA), were determined on phosphorylation of mitogen-activated protein kinase (MAPK) signaling modules (c-Jun NH₂-terminal kinase [JNK], p38 MAPK, and extracellular signal-related kinase [ERK1/2]) in skeletal muscle from lean and ob/ob mice. Insulin increased phosphorylation of JNK, p38 MAPK, and ERK1/2 in isolated extensor digitorum longus (EDL) and soleus muscle from lean mice in a time- and dose-dependent manner. Muscle contraction and PMA also elicited robust effects on these parallel MAPK modules. Insulin action on JNK, p38 MAPK, and ERK1/2 phosphorylation was significantly impaired in EDL and soleus muscle from ob/ob mice. In contrast, muscle contraction-mediated JNK, p38 MAPK, and ERK1/2 phosphorylation was preserved. PMA effects on phosphorylation of JNK and ERK1/2 were normal in ob/ob mice, whereas effects on p38 MAPK were abolished. In conclusion, insulin, contraction, and PMA activate MAPK signaling in skeletal muscle. Insulin-mediated responses on MAPK signaling are impaired in skeletal muscle from ob/ob mice, whereas the effect of contraction is generally well preserved. In addition, PMA-induced phosphorylation of JNK and ERK1/2 are preserved, whereas p38 MAPK pathways are impaired in skeletal muscle from ob/ob mice. Thus, appropriate MAPK responses can be elicited in insulin-resistant skeletal muscle via an insulin-independent mechanism.

CiteULike    Del.icio.us    Digg    Reddit    Technorati    What's this?

This article has been cited by other articles:

				H. F. Kramer and L. J. Goodyear Exercise, MAPK, and NF-{kappa}B signaling in skeletal muscle J Appl Physiol, July 1, 2007; 103(1): 388 - 395. [Abstract] [Full Text] [PDF]

				K. Strle, S. R. Broussard, R. H. McCusker, W.-H. Shen, J. M. LeCleir, R. W. Johnson, G. G. Freund, R. Dantzer, and K. W. Kelley C-Jun N-Terminal Kinase Mediates Tumor Necrosis Factor-{alpha} Suppression of Differentiation in Myoblasts Endocrinology, September 1, 2006; 147(9): 4363 - 4373. [Abstract] [Full Text] [PDF]

				C. Huang, A. C. P. Thirone, X. Huang, and A. Klip Differential Contribution of Insulin Receptor Substrates 1 Versus 2 to Insulin Signaling and Glucose Uptake in L6 Myotubes J. Biol. Chem., May 13, 2005; 280(19): 19426 - 19435. [Abstract] [Full Text] [PDF]