Osteopontin (Eta-1) and fibroblast growth factor-2 cross-talk in angiogenesis.
The cytokine/extracellular matrix protein osteopontin (OPN/Eta-1) is an important component of cellular immunity and inflammation. It also acts as a survival, cell-adhesive, and chemotactic factor for endothelial cells. Here, subtractive suppression hybridization showed that serum-deprived murine aortic endothelial (MAE) cells transfected with the angiogenic fibroblast growth factor-2 (FGF2) overexpress OPN compared with parental cells. This was confirmed by Northern blotting and Western blot analysis of the conditioned media in different clones of endothelial cells overexpressing FGF2 and in endothelial cells treated with the recombinant growth factor. In vivo, FGF2 caused OPN expression in newly formed endothelium of the chick embryo chorioallantoic membrane (CAM) and of murine s.c. Matrigel plug implants. Recombinant OPN (rOPN), the fusion protein GST-OPN, and the deletion mutant GST-DeltaRGD-OPN were angiogenic in the CAM assay. Angiogenesis was also triggered by OPN-transfected MAE cells grafted onto the CAM. OPN-driven neovascularization was independent from endothelial alpha(v)beta(3) integrin engagement and was always paralleled by the appearance of a massive mononuclear cell infiltrate. Accordingly, rOPN, GST-OPN, GST-DeltaRGD-OPN, and the conditioned medium of OPN-overexpressing MAE cells were chemotactic for isolated human monocytes. Also, rOPN triggered a proangiogenic phenotype in human monocytes by inducing the expression of the angiogenic cytokines TNF-alpha and IL-8. OPN-mediated recruitment of proangiogenic monocytes may represent a mechanism of amplification of FGF2-induced neovascularization during inflammation, wound healing, and tumor growth.
Leali
Daria
D
Unit of General Pathology and Immunology, Department of Biomedical Sciences and Biotechnology, University of Brescia, Brescia, Italy.
Dell'Era
Patrizia
P
Stabile
Helena
H
Sennino
Barbara
B
Chambers
Ann F
AF
Naldini
Antonella
A
Sozzani
Silvano
S
Nico
Beatrice
B
Ribatti
Domenico
D
Presta
Marco
M
D043925:Angiogenesis Inducing Agents / Q000378:metabolism / Q000502:physiology; D000818:Animals; D002460:Cell Line; D002461:Cell Line, Transformed; D002465:Cell Movement / Q000276:immunology; D002642:Chick Embryo; D002823:Chorion / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D004730:Endothelium, Vascular / Q000378:metabolism; D016222:Fibroblast Growth Factor 2 / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D006801:Humans; D016130:Immunophenotyping; D039302:Integrin alphaVbeta3 / Q000378:metabolism / Q000502:physiology; D015850:Interleukin-6 / Q000096:biosynthesis; D016209:Interleukin-8 / Q000096:biosynthesis; D051379:Mice; D008807:Mice, Inbred BALB C; D009000:Monocytes / Q000166:cytology / Q000276:immunology / Q000378:metabolism; D018919:Neovascularization, Physiologic / Q000235:genetics; D053495:Osteopontin; D011994:Recombinant Proteins / Q000494:pharmacology; D012795:Sialoglycoproteins / Q000096:biosynthesis / Q000235:genetics / Q000378:metabolism / Q000502:physiology*; D014409:Tumor Necrosis Factor-alpha / Q000096:biosynthesis; D015854:Up-Regulation / Q000235:genetics
D043925:Angiogenesis Inducing Agents; D039302:Integrin alphaVbeta3; D015850:Interleukin-6; D016209:Interleukin-8; D011994:Recombinant Proteins; C506895:SPP1 protein, human; D012795:Sialoglycoproteins; C506896:Spp1 protein, mouse; D014409:Tumor Necrosis Factor-alpha; D016222:Fibroblast Growth Factor 2; D053495:Osteopontin