title: N-WASP and WAVE2 acting downstream of phosphatidylinositol 3-kinase are required for myogenic cell migration induced by hepatocyte growth factor.
abstract: 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 phosphati-dylinositol 3-kinase, are required for the migration through the lamellipodial formation of C2C12 cells induced by HGF.
authors.affiliation: Department of Biology, Faculty of Science, Graduate School of Science and Technology, Chiba University, Yayoicho, Inageku, Chiba 263-8522, Japan.
authors.forename: Kazuhiro
authors.initials: K
authors.lastname: Kawamura
authors.forename: Kazunori
authors.initials: K
authors.lastname: Takano
authors.forename: Shiro
authors.initials: S
authors.lastname: Suetsugu
authors.forename: Shusaku
authors.initials: S
authors.lastname: Kurisu
authors.forename: Daisuke
authors.initials: D
authors.lastname: Yamazaki
authors.forename: Hiroaki
authors.initials: H
authors.lastname: Miki
authors.forename: Tadaomi
authors.initials: T
authors.lastname: Takenawa
authors.forename: Takeshi
authors.initials: T
authors.lastname: Endo
mesh_terms: D000199:Actins / Q000648:ultrastructure; D000818:Animals; D002460:Cell Line; D002465:Cell Movement / Q000187:drug effects / Q000502:physiology*; D002867:Chromones / Q000494:pharmacology; D003599:Cytoskeleton / Q000648:ultrastructure; D004791:Enzyme Inhibitors / Q000494:pharmacology; D015870:Gene Expression; D017228:Hepatocyte Growth Factor / Q000494:pharmacology*; D006801:Humans; D015151:Immunoblotting; D051379:Mice; D008840:Microfilament Proteins / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D008856:Microscopy, Fluorescence; D009025:Morpholines / Q000494:pharmacology; D032342:Muscle Cells / Q000737:chemistry / Q000502:physiology* / Q000648:ultrastructure; D018482:Muscle, Skeletal / Q000737:chemistry / Q000648:ultrastructure; D009154:Mutation; D009419:Nerve Tissue Proteins / Q000032:analysis / Q000235:genetics / Q000502:physiology*; D019869:Phosphatidylinositol 3-Kinases / Q000378:metabolism*; D000081082:Phosphoinositide-3 Kinase Inhibitors; D011554:Pseudopodia / Q000737:chemistry / Q000648:ultrastructure; D034741:RNA, Small Interfering / Q000235:genetics; D011993:Recombinant Fusion Proteins; D014162:Transfection; D051300:Wiskott-Aldrich Syndrome Protein Family; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal
chemical_list: D000199:Actins; D002867:Chromones; D004791:Enzyme Inhibitors; D017228:Hepatocyte Growth Factor; D008840:Microfilament Proteins; D009025:Morpholines; D009419:Nerve Tissue Proteins; D019869:Phosphatidylinositol 3-Kinases; D000081082:Phosphoinositide-3 Kinase Inhibitors; D034741:RNA, Small Interfering; D011993:Recombinant Fusion Proteins; D051300:Wiskott-Aldrich Syndrome Protein Family; D051317:Wiskott-Aldrich Syndrome Protein, Neuronal; C495771:WASL protein, human; C495772:Wasl protein, mouse; C085911:2-(4-morpholinyl)-8-phenyl-4H-1-benzopyran-4-one