近日，《細胞—代謝》（Cell Metabolism）發(fā)表了法國國家健康和醫(yī)學研究院（INSERM）的一項新研究，為我們解釋了肌細胞是如何在負重運動時后變粗大的,。
肌肉變大的奧秘在于肌細胞在運動（如舉重）過程中會產生一種化學物質，這種化學物質會給肌肉干細胞發(fā)出信號,，使其分化從而承受負重,。名為血清反應因子(Srf)的物質激發(fā)了可以分化成肌細胞但處于休眠狀態(tài)下的肌肉干細胞，使其生長并形成肌纖維,，肌纖維越多就意味著肌肉和力量越大,。
研究員索蒂羅波羅斯（Athanassia Sotiropoulos）認為，來自肌纖維的信號可以控制干細胞的行為和參與肌肉的生長,，這是出乎意料且十分有趣的發(fā)現(xiàn),，這些研究結果將有助于人們找到，因年齡和疾病引發(fā)的肌肉萎縮問題的方法,。
研究人員對實驗小鼠進行了基因改造,，使它們的肌肉中缺少血清反應因子，之后研究人員發(fā)現(xiàn),，沒有這種因子,，就算小鼠進行負載運動肌肉也沒有增長。索蒂羅波羅斯說道,，血清反應因子通過基因網絡來釋放信號,，這其中包括一種名為Cox2的基因。消炎藥（如布洛芬）會阻礙Cox2的活動,，因此這些藥物有可能會抑制肌肉的生長,。她表示，以增長肌肉為目標的治療方法（比如長期臥床后的恢復）也可以把重心轉向血清反應因子復雜的化學網絡上來,。(生物谷Bioon.com)
doi:10.1016/j.cmet.2011.12.001
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Srf-Dependent Paracrine Signals Produced by Myofibers Control Satellite Cell-Mediated Skeletal Muscle Hypertrophy
Aline Guerci, Charlotte Lahoute, Sophie Hébrard, Laura Collard, Dany Graindorge, Maryline Favier, Nicolas Cagnard, Sabrina Batonnet-Pichon, Guillaume Précigout, Luis Garcia, David Tuil, Dominique Daegelen, Athanassia Sotiropoulos
Adult skeletal muscles adapt their fiber size to workload. We show that serum response factor (Srf) is required for satellite cell-mediated hypertrophic muscle growth. Deletion of Srf from myofibers and not satellite cells blunts overload-induced hypertrophy, and impairs satellite cell proliferation and recruitment to pre-existing fibers. We reveal a gene network in which Srf within myofibers modulates interleukin-6 and cyclooxygenase-2/interleukin-4 expressions and therefore exerts a paracrine control of satellite cell functions. In Srf-deleted muscles, in vivo overexpression of interleukin-6 is sufficient to restore satellite cell proliferation but not satellite cell fusion and overall growth. In contrast cyclooxygenase-2/interleukin-4 overexpression rescue satellite cell recruitment and muscle growth without affecting satellite cell proliferation, identifying altered fusion as the limiting cellular event. These findings unravel a role for Srf in the translation of mechanical cues applied to myofibers into paracrine signals, which in turn will modulate satellite cell functions and support muscle growth.
