title: Hypoxia-induced mitogenic factor enhances angiogenesis by promoting proliferation and migration of endothelial cells.
abstract: Our previous studies have indicated that hypoxia-induced mitogenic factor (HIMF) has angiogenic properties in an in vivo matrigel plug model and HIMF upregulates expression of vascular endothelial growth factor (VEGF) in mouse lungs and cultured lung epithelial cells. However, whether HIMF exerts angiogenic effects through modulating endothelial cell function remains unknown. In this study, mouse aortic rings cultured with recombinant HIMF protein resulted in enhanced vascular sprouting and increased endothelial cell spreading as confirmed by Dil-Ac-LDL uptake, von Willebrand factor and CD31 staining. In cultured mouse endothelial cell line SVEC 4-10, HIMF dose-dependently enhanced cell proliferation, in vitro migration and tubulogenesis, which was not attenuated by SU1498, a VEGFR2/Flk-1 receptor tyrosine kinase inhibitor. Moreover, HIMF stimulation resulted in phosphorylation of Akt, p38 and ERK1/2 kinases in SVEC 4-10 cells. Treatment of mouse aortic rings and SVEC 4-10 cells with LY294002, but not SB203580, PD098059 or U0126, abolished HIMF-induced vascular sprouting and angiogenic responses. In addition, transfection of a dominant-negative mutant of phosphatidylinositol 3-kinase (PI-3K), Deltap85, blocked HIMF-induced phosphorylation of Akt, endothelial activation and tubulogenesis. These results indicate that HIMF enhances angiogenesis by promoting proliferation and migration of endothelial cells via activation of the PI-3K/Akt pathways.
authors.affiliation: Division of Pulmonary, Critical Care, and Sleep Medicine, Department of Internal Medicine, Saint Louis University, Desloge Towers, 7th Floor, 3635 Vista Avenue, Saint Louis, MO 63110-0250, USA.
authors.forename: Qiangsong
authors.initials: Q
authors.lastname: Tong
authors.forename: Liduan
authors.initials: L
authors.lastname: Zheng
authors.forename: Bo
authors.initials: B
authors.lastname: Li
authors.forename: Danming
authors.initials: D
authors.lastname: Wang
authors.forename: Chuanshu
authors.initials: C
authors.lastname: Huang
authors.forename: George M
authors.initials: GM
authors.lastname: Matuschak
authors.forename: Dechun
authors.initials: D
authors.lastname: Li
mesh_terms: D000818:Animals; D001011:Aorta / Q000166:cytology / Q000378:metabolism; D002465:Cell Movement / Q000502:physiology*; D049109:Cell Proliferation; D002478:Cells, Cultured; D002934:Cinnamates / Q000378:metabolism; D042783:Endothelial Cells / Q000166:cytology / Q000502:physiology*; D004789:Enzyme Activation; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D036341:Intercellular Signaling Peptides and Proteins; D051379:Mice; D008810:Mice, Inbred C57BL; D018919:Neovascularization, Physiologic / Q000502:physiology*; D020932:Nerve Growth Factor / Q000235:genetics / Q000378:metabolism; D019869:Phosphatidylinositol 3-Kinases / Q000235:genetics / Q000378:metabolism; D011506:Proteins / Q000235:genetics / Q000378:metabolism*; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism; D011994:Recombinant Proteins / Q000235:genetics / Q000378:metabolism; D015398:Signal Transduction / Q000502:physiology; D042461:Vascular Endothelial Growth Factor A / Q000378:metabolism; D040301:Vascular Endothelial Growth Factor Receptor-2 / Q000037:antagonists & inhibitors; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism
chemical_list: D002934:Cinnamates; D036341:Intercellular Signaling Peptides and Proteins; D011506:Proteins; D011994:Recombinant Proteins; C413576:Retnla protein, mouse; C483044:SU 1498; D042461:Vascular Endothelial Growth Factor A; D020932:Nerve Growth Factor; D019869:Phosphatidylinositol 3-Kinases; D040301:Vascular Endothelial Growth Factor Receptor-2; D051057:Proto-Oncogene Proteins c-akt; D048049:Extracellular Signal-Regulated MAP Kinases; D048051:p38 Mitogen-Activated Protein Kinases