title: Role of c-Met/phosphatidylinositol 3-kinase (PI3k)/Akt signaling in hepatocyte growth factor (HGF)-mediated lamellipodia formation, reactive oxygen species (ROS) generation, and motility of lung endothelial cells.
abstract: Hepatocyte growth factor (HGF) mediated signaling promotes cell proliferation and migration in a variety of cell types and plays a key role in tumorigenesis. As cell migration is important to angiogenesis, we characterized HGF-mediated effects on the formation of lamellipodia, a pre-requisite for migration using human lung microvascular endothelial cells (HLMVECs). HGF, in a dose-dependent manner, induced c-Met phosphorylation (Tyr-1234/1235, Tyr-1349, Ser-985, Tyr-1003, and Tyr-1313), activation of PI3k (phospho-Yp85) and Akt (phospho-Thr-308 and phospho-Ser-473) and potentiated lamellipodia formation and HLMVEC migration. Inhibition of c-Met kinase by SU11274 significantly attenuated c-Met, PI3k, and Akt phosphorylation, suppressed lamellipodia formation and endothelial cell migration. LY294002, an inhibitor of PI3k, abolished HGF-induced PI3k (Tyr-458), and Akt (Thr-308 and Ser-473) phosphorylation and suppressed lamellipodia formation. Furthermore, HGF stimulated p47(phox)/Cortactin/Rac1 translocation to lamellipodia and ROS generation. Moreover, inhibition of c-Met/PI3k/Akt signaling axis and NADPH oxidase attenuated HGF- induced lamellipodia formation, ROS generation and cell migration. Ex vivo experiments with mouse aortic rings revealed a role for c-Met signaling in HGF-induced sprouting and lamellipodia formation. Taken together, these data provide evidence in support of a significant role for HGF-induced c-Met/PI3k/Akt signaling and NADPH oxidase activation in lamellipodia formation and motility of lung endothelial cells.
authors.affiliation: From the Department of Pharmacology.
authors.forename: Peter V
authors.initials: PV
authors.lastname: Usatyuk
authors.forename: Panfeng
authors.initials: P
authors.lastname: Fu
authors.forename: Vijay
authors.initials: V
authors.lastname: Mohan
authors.forename: Yulia
authors.initials: Y
authors.lastname: Epshtein
authors.forename: Jeffrey R
authors.initials: JR
authors.lastname: Jacobson
authors.forename: Julian
authors.initials: J
authors.lastname: Gomez-Cambronero
authors.forename: Kishore K
authors.initials: KK
authors.lastname: Wary
authors.forename: Vytas
authors.initials: V
authors.lastname: Bindokas
authors.forename: Steven M
authors.initials: SM
authors.lastname: Dudek
authors.forename: Ravi
authors.initials: R
authors.lastname: Salgia
authors.forename: Joe G N
authors.initials: JG
authors.lastname: Garcia
authors.forename: Viswanathan
authors.initials: V
authors.lastname: Natarajan
mesh_terms: D000818:Animals; D002478:Cells, Cultured; D042783:Endothelial Cells / Q000166:cytology / Q000378:metabolism*; D017228:Hepatocyte Growth Factor / Q000235:genetics / Q000378:metabolism*; D006801:Humans; D008168:Lung / Q000166:cytology / Q000378:metabolism*; D051379:Mice; D019255:NADPH Oxidases / Q000235:genetics / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt / Q000235:genetics / Q000378:metabolism*; D019859:Proto-Oncogene Proteins c-met / Q000235:genetics / Q000378:metabolism*; D011554:Pseudopodia / Q000235:genetics / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology*
chemical_list: C066855:HGF protein, human; C553307:HGF protein, mouse; D017382:Reactive Oxygen Species; D017228:Hepatocyte Growth Factor; D019255:NADPH Oxidases; C060505:neutrophil cytosolic factor 1; D019869:Phosphatidylinositol 3-Kinases; D019859:Proto-Oncogene Proteins c-met; D051057:Proto-Oncogene Proteins c-akt
keywords: Akt; Cell Migration; Endothelial Cell; Hepatocyte Growth Factor; NADPH Oxidase