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: Peter V Usatyuk, Panfeng Fu, Vijay Mohan, Yulia Epshtein, Jeffrey R Jacobson, Julian Gomez-Cambronero, Kishore K Wary, Vytas Bindokas, Steven M Dudek, Ravi Salgia, Joe G N Garcia, Viswanathan Natarajan
• Journal: The Journal of biological chemistry (J Biol Chem) Vol. 289 Issue 19 Pg. 13476-91 (May 09 2014) ISSN: 1083-351X [Electronic] United States
• PMID: 24634221 (Publication Type: Journal Article, Research Support, N.I.H., Extramural, Research Support, Non-U.S. Gov't)

Chemical References

• HGF protein, human
• HGF protein, mouse
• Reactive Oxygen Species
• Hepatocyte Growth Factor
• NADPH Oxidases
• neutrophil cytosolic factor 1
• Phosphatidylinositol 3-Kinases
• Proto-Oncogene Proteins c-met
• Proto-Oncogene Proteins c-akt

Topics

• Animals
• Cells, Cultured
• Endothelial Cells (cytology, metabolism)
• Hepatocyte Growth Factor (genetics, metabolism)
• Humans
• Lung (cytology, metabolism)
• Mice
• NADPH Oxidases (genetics, metabolism)
• Phosphatidylinositol 3-Kinases (genetics, metabolism)
• Proto-Oncogene Proteins c-akt (genetics, metabolism)
• Proto-Oncogene Proteins c-met (genetics, metabolism)
• Pseudopodia (genetics, metabolism)
• Reactive Oxygen Species (metabolism)
• Signal Transduction (physiology)