Sphingosine kinase activity is required for myogenic differentiation of C2C12 myoblasts
Sphingosine kinase activity is required for myogenic differentiation of C2C12 myoblasts
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DOI：
10.1002/jcp.21187
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发表时间：
2008-01-01
影响因子：
5.6
通讯作者：
Bruni, Paola
中科院分区：
文献类型：
--
作者：
Meacci, Elisabetta;Nuti, Francesca;Bruni, Paola
鞘氨醇激酶 (SphK) 是一种保守的脂质激酶，可催化 1-磷酸鞘氨醇 (S 1 P) 的形成，这是一种重要的脂质介质，可调节基本的生物过程。在这里，我们提供的证据表明，SphK 是实现细胞生长停滞以及 C2C12 成肌细胞的肌原性分化所必需的。事实上，在汇合的成肌细胞以及分化细胞中，SphK 活性、SphK 1 蛋白含量和 S1P 形成均得到增强。 SphK1 的强制表达降低了成肌细胞增殖率，增强了肌源性分化标记物的表达，并预测了分化肌肉表型的出现。相反，通过 RNA 干扰或催化失活的 SphK1 过度表达来特异性沉默 SphK I 的下调，显着增加细胞生长并延迟肌生成的开始；值得注意的是，外源添加 SIP 挽救了生物过程。重要的是，SphK1 过度表达的成肌细胞中对肌生成的刺激可通过 S1P(2) 受体特异性短干扰 RNA 的治疗而消除。这是内源性 SphK I 通过形成 SIP (通过 S1P(2) 的参与充当形态发生因子) 在成肌细胞生长停滞和刺激肌生成中的作用的首次报道。
Sphingosine kinase (SphK) is a conserved lipid kinase that catalyzes the formation of sphingosine 1-phosphate (S 1 P), an important lipid mediator, which regulates fundamental biological processes. Here, we provide evidence that SphK is required for the achievement of cell growth arrest as well as myogenic differentiation of C2C12 myoblasts. Indeed, SphK activity, SphK 1 protein content and S1P formation were found to be enhanced in myoblasts that became confluent as well as in differentiating cells. Enforced expression of SphK1 reduced the myoblast proliferation rate, enhanced the expression of myogenic differentiation markers and anticipated the onset of differentiated muscle phenotype. Conversely, down-regulation of SphK I by specific silencing by RNA interference or overexpression of the catalytically inactive SphK1, significantly increased cell growth and delayed the beginning of myogenesis; noticeably, exogenous addition of SIP rescued the biological processes. Importantly, stimulation of myogenesis in SphK1-overexpressing myoblasts was abrogated by treatment with short interfering RNA specific for S1P(2) receptor. This is the first report of the role of endogenous SphK I in myoblast growth arrest and stimulation of myogenesis through the formation of S I P that acts as morphogenic factor via the engagement of S1P(2).