N-WASP and WAVE2 acting downstream of phosphatidylinositol 3-kinase are required for myogenic cell migration induced by hepatocyte growth factor
N-WASP and WAVE2 acting downstream of phosphatidylinositol 3-kinase are required for myogenic cell migration induced by hepatocyte growth factor
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DOI：
10.1074/jbc.m408057200
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发表时间：
2004-12-24
影响因子：
4.8
通讯作者：
Endo, T
中科院分区：
文献类型：
--
作者：
Kawamura, K;Takano, K;Endo, T
在损伤引起的骨骼肌再生过程中，肌肉卫星细胞增殖并向肌肉损伤部位迁移。这种迁移主要是由完整肌纤维分泌的肝细胞生长因子（HGF）诱导的，也可从受损肌肉中释放。然而，卫星细胞迁移的细胞内机制尚未阐明。为了研究卫星细胞迁移的机制，我们利用卫星细胞来源的小鼠C2 C12骨骼肌细胞。HGF诱导C2 C12成肌细胞肌动蛋白骨架重组形成板状伪足。HGF处理促进成肌细胞在吞噬动力学追踪试验中的非定向迁移和在三维迁移室试验中向HGF的定向趋化迁移。内源性N-WASP和WAVE 2集中在迁移细胞前缘的板状伪足中。此外，野生型N-WASP或WAVE 2的外源性表达促进板状伪足的形成和迁移。与此相反，显性负突变体的N-WASP或WAVE 2的表达和敲低N-WASP或WAVE 2表达的RNA干扰阻止了HGF诱导的板状伪足的形成和迁移。当细胞用磷脂酰肌醇3-激酶抑制剂LY 294002处理时，HGF诱导的片状脂质体形成和迁移被废除。这些结果表明，N-WASP和WAVE 2，这是激活的磷脂酰肌醇3-激酶下游，所需的迁移通过肝细胞生长因子诱导的C2 C12细胞的板状伪足形成。
During skeletal muscle regeneration caused by injury, muscle satellite cells proliferate and migrate toward the site of muscle injury. This migration is mainly induced by hepatocyte growth factor (HGF) secreted by intact myofibers and also released from injured muscle. However, the intracellular machinery for the satellite cell migration has not been elucidated. To examine the mechanisms of satellite cell migration, we utilized satellite cell-derived mouse C2C12 skeletal muscle cells. HGF induced reorganization of actin cytoskeleton to form lamellipodia in C2C12 myoblasts. HGF treatment facilitated both nondirectional migration of the myoblasts in phagokinetic track assay and directional chemotactic migration toward HGF in a three-dimensional migration chamber assay. Endogenous N-WASP and WAVE2 were concentrated in the lamellipodia at the leading edge of the migrating cells. Moreover, exogenous expression of wild-type N-WASP or WAVE2 promoted lamellipodial formation and migration. By contrast, expression of the dominant-negative mutant of N-WASP or WAVE2 and knockdown of N-WASP or WAVE2 expression by the RNA interference prevented the HGF-induced lamellipodial formation and migration. When the cells were treated with LY294002, an inhibitor of phosphatidylinositol 3-kinase, the HGF-induced lamellipodial formation and migration were abrogated. These results imply that both N-WASP and WAVE2, which are activated downstream of phosphatidylinositol 3-kinase, are required for the migration through the lamellipodial formation of C2C12 cells induced by HGF.