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This Article Full Text Full Text (PDF) All Versions of this Article: 297/5/C1249    most recent 00188.2009v1 Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in Web of Science Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Google Scholar Articles by Galluzzo, P. Articles by Marino, M. PubMed PubMed Citation Articles by Galluzzo, P. Articles by Marino, M.

Receptors and Signal Transduction

17β-Estradiol regulates the first steps of skeletal muscle cell differentiation via ER--mediated signals

Department of Biology, University Roma Tre, Rome, Italy

Submitted 30 April 2009 ; accepted in final form 1 September 2009

17β-Estradiol (E₂) mediates a wide variety of complex biological processes determining the growth and development of reproductive tract as well as nonreproductive tissues of male and female individuals. While E₂ effects on the reproductive system, bone, and cardiovascular system are quite well established, less is known about how it affects the physiology of other tissues. Skeletal muscle is a tissue that is expected to be E₂ responsive since both isoforms of estrogen receptor (ER- and ER-β) are expressed. Significant sex-related differences have been described in skeletal muscle, although the role played by E₂ and the mechanisms underlying it remain to be determined. Here, we demonstrate that E₂ increases the glucose transporter type 4 translocation at membranes as well as the expression of well-known differentiation markers of myogenesis (i.e., myogenin and myosin heavy chain) in rat myoblast cells (L6). These E₂-induced effects require rapid extranuclear signals and the presence of ER-, whereas no contribution of IGF-I receptor has been observed. In particular, ER--dependent Akt activation participates in regulating the first step of myogenic differentiation. Moreover, both receptors mediate the E₂-induced activation of p38, which, in turn, affects the expression of myogenin and myosin heavy chain. All together, these data indicate that E₂ should be included in the list of skeletal muscle trophic factors.

estrogen receptors; signal transduction pathways