Sphingosine kinase is induced in mouse 3T3-L1 cells and promotes adipogenesis
Sphingosine kinase is induced in mouse 3T3-L1 cells and promotes adipogenesis
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DOI：
10.1194/jlr.m800206-jlr200
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发表时间：
2009-04-01
影响因子：
6.5
通讯作者：
Kosaka, Hiroaki
中科院分区：
文献类型：
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作者：
Hashimoto, Takeshi;Igarashi, Junsuke;Kosaka, Hiroaki
鞘氨醇1-磷酸（S1 P）是一种溶血磷脂介质，作为受体配体和细胞内第二信使发挥多种生物活性。在本研究中，我们探讨了鞘氨醇激酶（SphK），一种S1 P产生酶，在脂肪组织中的作用。我们利用小鼠3 T3-L1细胞作为体外脂肪生成模型，使用胰岛素/地塞米松/3-异丁基-1-甲基黄嘌呤（IBMX）的混合物诱导分化。实时定量PCR（qRT-PCR）分析显示，编码SphK-1和SphK-2两种亚型的转录本的表达水平在脂肪形成过程中上调（分别为基础水平的37.6倍和6.6倍，P <0.05）。同时，SphK-1/SphK-2蛋白丰度和S1 P含量增加，这些细胞在激素刺激后3天。通过药理学抑制SphK活性以及通过用针对SphK-1的小干扰RNA（siRNA）转染的功能丧失方法导致脂滴积累和脂肪细胞标志物基因表达的显著衰减。我们检测到13周龄肥胖表型ob/ob小鼠的脂肪组织中SphK-1 mRNA的表达明显高于同窝瘦小鼠。这些结果表明，SphK，一种S1 P产生酶，表达增加，在脂肪形成过程中起着重要作用，可能提供了一个新的控制点在脂肪组织。- 桥本，T.，J. Igarashi和H.科奇鞘氨醇激酶在小鼠3 T3-L1细胞中被诱导并促进脂肪生成。J. Lipid Res. 2009. 50：602-610。
Sphingosine 1-phosphate (S1P) is a lysophospholipid mediator that exerts numerous biological activities both as a receptor ligand and as an intracellular second messenger. In the present study, we explored roles of sphingosine kinase (SphK), an S1P-producing enzyme, in adipose tissue. We utilized mouse 3T3-L1 cells as an in vitro model of adipogenesis, using a mixture of insulin/dexamethasone/3-isobutyl-1-methylxanthine (IBMX) to induce differentiation. Real-time quantitative PCR (qRT-PCR) assays revealed that the expression levels of transcripts encoding both isoforms of SphK-1 and SphK-2 are up-regulated during adipogenesis (37.6- and 6.6-fold vs. basal, P, 0.05, respectively). Concomitantly, SphK-1/SphK-2 protein abundance and S1P contents of these cells increased at 3 days after hormonal stimulation. Loss-of-function approaches by pharmacological inhibition of SphK activity as well as by transfection with small interfering RNA (siRNA) against SphK-1 led to significant attenuation of lipid droplet accumulation and adipocyte marker gene expression. We detected marked elevation of SphK-1 mRNA in adipose tissue derived from 13-week-old ob/ob mice with obese phenotype than their lean littermates. These results suggest that increased expression of SphK, an S1P-producing enzyme, plays a significant role during adipogenesis, potentially providing a novel point of control in adipose tissue. -Hashimoto, T., J. Igarashi, and H. Kosaka. Sphingosine kinase is induced in mouse 3T3-L1 cells and promotes adipogenesis. J. Lipid Res. 2009. 50: 602-610.