Blood Lipid Mediator Sphingosine 1-Phosphate Potently Stimulates Platelet-derived Growth Factor-A and -B Chain Expression through S1P1-Gi-Ras-MAPK-dependent Induction of Krüppel-like Factor 5*
Blood Lipid Mediator Sphingosine 1-Phosphate Potently Stimulates Platelet-derived Growth Factor-A and -B Chain Expression through S1P1-Gi-Ras-MAPK-dependent Induction of Krüppel-like Factor 5*
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DOI：
10.1074/jbc.m305025200
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发表时间：
2004-03
影响因子：
4.8
通讯作者：
S. Usui;N. Sugimoto;N. Takuwa;S. Sakagami;S. Takata;S. Kaneko;Y. Takuwa
中科院分区：
文献类型：
--
作者：
S. Usui;N. Sugimoto;N. Takuwa;S. Sakagami;S. Takata;S. Kaneko;Y. Takuwa
血小板源性生长因子（PDGFs）是间充质细胞的有丝分裂原和趋化因子，在血管、肾和肺等多种器官的发育过程中发挥重要作用，也参与动脉粥样硬化和恶性肿瘤的发病机制。血脂介质鞘氨醇1-磷酸（S1 P）通过Edg家族的多个G蛋白偶联受体调节多种细胞类型的迁移、增殖和凋亡，并且是发育阶段血管形成所必需的。我们发现，在本研究中，S1 P诱导血管平滑肌细胞和新生内膜细胞中的PDGF-A和-B链的mRNA和蛋白水平的数倍增加。靶向S1 P1/Edg 1受体亚型的小干扰RNA双链体消除了S1 P对PDGF mRNA和蛋白表达的刺激。S1 P以Gi依赖性方式激活小GT3 Ras，以Gi和Ras依赖性方式激活ERK和p38 MAPK。百日咳毒素预处理、腺病毒介导的Asn 17 Ras表达、MEK抑制剂PD 98059或p38 MAPK抑制剂SB 203580显著抑制PDGF mRNA和蛋白的上调，表明Gi-Ras-ERK/p38 MAPK参与S1 P刺激PDGF表达。S1 P以依赖于Gi、Ras和ERK/p38 MAPK的方式刺激转录因子KLF 5的表达。通过小干扰RNA双链体下调KLF 5，可消除S1 P诱导的PDGF-A和-B链表达。另一方面，过度表达KLF 5刺激基础和S1 P诱导的PDGF表达。无论是S1 P刺激或KLF 5过表达增加PDGF-B启动子活性的顺式元件依赖的方式。这些结果揭示了血管平滑肌细胞中S1 P1触发的、Gi-Ras-ERK/p38 MAPK-KLF 5依赖的PDGF基因转录的刺激性调节。
Platelet-derived growth factors (PDGFs), potent mitogens and chemoattractants for mesenchymal cell types, play essential roles in development of several organs including blood vessels, kidney, and lung, and are also implicated in the pathogenesis of atherosclerosis and malignancies. Blood lipid mediator sphingosine 1-phosphate (S1P) regulates migration, proliferation, and apoptosis in a variety of cell types through multiple G protein-coupled receptors of the Edg family, and is necessary for vascular formation at the developmental stage. We found in the present study that S1P induced severalfold increases in the mRNA and protein levels of PDGF-A and -B chains in vascular smooth muscle cells and neointimal cells. S1P stimulation of PDGF mRNA and protein expression was abolished by the small interfering RNA duplexes targeting S1P1/Edg1 receptor subtype. S1P stimulated the small GTPase Ras in a Gi-dependent manner, and activated ERK and p38 MAPK in Gi- and Ras-dependent manners. Pertussis toxin pretreatment, adenovirus-mediated Asn17Ras expression, the MEK inhibitor PD98059, or the p38 MAPK inhibitor SB203580 markedly suppressed PDGF mRNA and protein up-regulation, indicating the involvement of Gi-Ras-ERK/p38 MAPK in S1P stimulation of PDGF expression. S1P stimulated expression of the transcription factor KLF5 in manners dependent on Gi, Ras, and ERK/p38 MAPK. Down-regulation of KLF5 by small interfering RNA duplexes abolished S1P-induced PDGF-A and -B chain expression. On the other hand, overexpression of KLF5 stimulated basal and S1P-induced PDGF expression. Either S1P stimulation or KLF5 overexpression increased the PDGF-B promoter activity in a cis-element-dependent manner. These results reveal the S1P1-triggered, Gi-Ras-ERK/p38 MAPK-KLF5-dependent, stimulatory regulation of PDGF gene transcription in vascular smooth muscle cells.