Neuronal chemorepellent Slit2 inhibits vascular smooth muscle cell migration by suppressing small GTPase Rac1 activation
Neuronal chemorepellent Slit2 inhibits vascular smooth muscle cell migration by suppressing small GTPase Rac1 activation
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DOI：
10.1161/01.res.0000205764.85931.4b
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发表时间：
2006-03-03
影响因子：
20.1
通讯作者：
De Leon, H
中科院分区：
文献类型：
--
作者：
Liu, D;Hou, J;De Leon, H
这些狭缝是分泌的蛋白质，在轴突引导和白细胞迁移中起作用。在与Robo受体结合时，Slit2排斥发育中的轴突并抑制白细胞趋化性。Slit2被切割成与细胞膜紧密结合的蛋白质Slit2- n和可扩散的片段Slit2- c。在本研究中，我们表征了Slit2-N在血管平滑肌细胞（VSMCs）中的功能作用，以及2个截断版本的Slit2-N的细胞关联特性。在这里，我们首次证明了Slit2-N是VSMCs的化学驱避剂。免疫组织化学和实时荧光定量PCR证实，完整血管表达Slit2和Robo受体。重组Slit2-N阻止血小板衍生生长因子（PDGF）刺激的VSMCs迁移。Slit2-N也取消了pdgf介导的小鸟苷三磷酸酶（GTPase） Rac1的激活，Rho GTPase超家族的成员参与调节肌动蛋白细胞骨架。此外，Slit2-N抑制pdgf诱导的板足形成，这是细胞运动的关键细胞骨架重组事件。Slit2- n对pdgf介导的[H-3]胸腺嘧啶摄取测定的DNA合成增加没有影响，表明Slit2不影响VSMC的生长。对2个基因工程的Slit2-N片段（Slit2-N/1118和Slit2-N/1121）的分析表明，Slit2-N与细胞膜结合的过程中有3个氨基酸（Arg1121, Thr1122）参与裂解位点上游。我们的数据表明Slit2在血管功能中具有新的功能作用，并表明在发育中的中枢神经系统中起作用的细胞引导机制在VSMCs中是保守的。
The Slits are secreted proteins with roles in axonal guidance and leukocyte migration. On binding to Robo receptors, Slit2 repels developing axons and inhibits leukocyte chemotaxis. Slit2 is cleaved into Slit2-N, a protein tightly binding to cell membranes, and Slit2-C, a diffusible fragment. In the present study, we characterized the functional role of Slit2-N in vascular smooth muscle cells (VSMCs) and the cell association properties of 2 truncated versions of Slit2-N. Here, we document for the first time that Slit2-N is a chemorepellent of VSMCs. Intact blood vessels expressed Slit2 and Robo receptors as demonstrated by immunohistochemistry and quantitative real time PCR. Recombinant Slit2-N prevented the platelet-derived growth factor (PDGF)-stimulated migration of VSMCs. Slit2-N also abrogated PDGF-mediated activation of small guanosine triphosphatase (GTPase) Rac1, a member of the Rho GTPase superfamily of proteins involved in regulating the actin cytoskeleton. Furthermore, Slit2-N inhibited the PDGF-induced formation of lamellipodia, a crucial cytoskeletal reorganization event for cell motility. Slit2-N had no effect on the PDGF-mediated increase in DNA synthesis determined by [H-3] thymidine uptake, suggesting that VSMC growth is unaffected by Slit2. Analysis of 2 engineered Slit2-N fragments (Slit2-N/1118 and Slit2-N/1121) indicated that 3 amino acids upstream of the putative cleavage site (Arg1121, Thr1122) are involved in the association of Slit2-N to the cell membrane. Our data assign a novel functional role to Slit2 in vascular function and show that cell guidance mechanisms that operate in the developing central nervous system are conserved in VSMCs.