Sphingosine-1-phosphate lyase is involved in the differentiation of F9 embryonal carcinoma cells to primitive endoderm
Sphingosine-1-phosphate lyase is involved in the differentiation of F9 embryonal carcinoma cells to primitive endoderm
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DOI：
10.1074/jbc.m211416200
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发表时间：
2003-04-18
影响因子：
4.8
通讯作者：
Igarashi, Y
中科院分区：
文献类型：
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作者：
Kihara, A;Ikeda, M;Igarashi, Y
磷酸鞘氨醇（SIP）是一种具有生物活性的脂质分子，在细胞外和细胞内均有作用。SPL基因编码一种能降解SIP的哺乳动物SIP裂解酶。在这里，我们通过基因靶向破坏了小鼠F9胚胎癌细胞的SPL基因。这是关于哺乳动物SIP裂解酶基因破坏的首次报道。与野生型细胞相比，spll -null细胞没有SIP裂解酶活性，细胞内SIP增加了近2倍。维甲酸诱导F9胚胎癌细胞向原始内胚层（PrE）分化。在spll -null细胞中观察到这种预分化的加速。这种效应可能是由S1P的积累引起的，因为S1P合成抑制剂N，N-二甲基鞘氨醇对PrE分化有抑制作用。此外，稳定表达鞘氨醇激酶的F9细胞也表现出加速分化的趋势。外源性S1P对分化没有影响，表明细胞内而非细胞外的S1P参与其中。此外，我们确定SPL蛋白的表达在PrE的进展过程中上调。我们还发现鞘氨醇激酶活性在预分化细胞中增加。这些结果表明细胞内S1P在PrE分化中起作用，而SPL可能参与了分化过程中细胞内S1P水平的调节。
Sphingosine I-phosphate (SIP) is a bioactive lipid molecule that acts both extracellularly and intracellularly. The SPL gene encodes a mammalian SIP lyase that degrades SIP. Here, we have disrupted the SPL gene in mouse F9 embryonal carcinoma cells by gene targeting. This is the first report of gene disruption of mammalian SIP lyase. The SPL-null cells exhibited no SIP lyase activity, and intracellular SIP was increased similar to2-fold, compared with wild-type cells. Treatment of F9 embryonal carcinoma cells with retinoic acid induces differentiation to primitive endoderm (PrE). An acceleration in this PrE differentiation was observed in the SPL-null cells. This effect was apparently caused by the accumulated S1P, since N,N-dimethylsphingosine, a S1P synthesis inhibitor, had an inhibitory effect on the PrE differentiation. Moreover, F9 cells stably expressing sphingosine kinase also exhibited an acceleration in the differentiation. Exogenous S1P had no effect on differentiation, indicating that intracellular but not extracellular S1P is involved. Moreover, we determined that expression of the SPL protein is up-regulated during the progression to PrE. We also showed that sphingosine kinase activity is increased in PrE-differentiated cells. These results suggest that intracellular S1P has a role in the PrE differentiation and that SPL may be involved in the regulation of intracellular S1P levels during this differentiation.