NF-kappaB mediates alphavbeta3 integrin-induced endothelial cell survival.
The alphavbeta3 integrin plays a fundamental role during the angiogenesis process by inhibiting endothelial cell apoptosis. However, the mechanism of inhibition is unknown. In this report, we show that integrin-mediated cell survival involves regulation of nuclear factor-kappa B (NF-kappaB) activity. Different extracellular matrix molecules were able to protect rat aorta- derived endothelial cells from apoptosis induced by serum withdrawal. Osteopontin and beta3 integrin ligation rapidly increased NF-kappaB activity as measured by gel shift and reporter activity. The p65 and p50 subunits were present in the shifted complex. In contrast, collagen type I (a beta1-integrin ligand) did not induce NF-kappaB activity. The alphavbeta3 integrin was most important for osteopontin-mediated NF-kappaB induction and survival, since adding a neutralizing anti-beta3 integrin antibody blocked NF-kappaB activity and induced endothelial cell death when cells were plated on osteopontin. NF-kappaB was required for osteopontin- and vitronectin-induced survival since inhibition of NF-kappaB activity with nonphosphorylatable IkappaB completely blocked the protective effect of osteopontin and vitronectin. In contrast, NF-kappaB was not required for fibronectin, laminin, and collagen type I-induced survival. Activation of NF-kappaB by osteopontin depended on the small GTP-binding protein Ras and the tyrosine kinase Src, since NF-kappaB reporter activity was inhibited by Ras and Src dominant-negative mutants. In contrast, inhibition of MEK and PI3-kinase did not affect osteopontin-induced NF-kappaB activation. These studies identify NF-kappaB as an important signaling molecule in alphavbeta3 integrin-mediated endothelial cell survival.
Scatena
M
M
Department of Pathology, University of Washington, Seattle, Washington 98195, USA. mscatena@u.washington.edu
Almeida
M
M
Chaisson
M L
ML
Fausto
N
N
Nicosia
R F
RF
Giachelli
C M
CM
D000818:Animals; D015703:Antigens, CD / Q000502:physiology*; D001011:Aorta; D017209:Apoptosis / Q000502:physiology*; D002448:Cell Adhesion; D002470:Cell Survival / Q000187:drug effects / Q000502:physiology*; D002478:Cells, Cultured; D003094:Collagen / Q000494:pharmacology; D016895:Culture Media, Serum-Free; D004268:DNA-Binding Proteins / Q000096:biosynthesis / Q000378:metabolism; D004730:Endothelium, Vascular / Q000166:cytology* / Q000187:drug effects / Q000502:physiology*; D016326:Extracellular Matrix Proteins / Q000494:pharmacology; D020672:I-kappa B Proteins; D039661:Integrin beta3; D007700:Kinetics; D046911:Macromolecular Substances; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000037:antagonists & inhibitors / Q000378:metabolism*; D053495:Osteopontin; D010980:Platelet Membrane Glycoproteins / Q000502:physiology*; D011107:Polylysine / Q000494:pharmacology; D051381:Rats; D019030:Receptors, Vitronectin / Q000502:physiology*; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000494:pharmacology; D012795:Sialoglycoproteins / Q000494:pharmacology*; D015398:Signal Transduction; D014162:Transfection
D015703:Antigens, CD; D016895:Culture Media, Serum-Free; D004268:DNA-Binding Proteins; D016326:Extracellular Matrix Proteins; D020672:I-kappa B Proteins; D039661:Integrin beta3; D046911:Macromolecular Substances; D016328:NF-kappa B; C000606206:Nfkbia protein, rat; D010980:Platelet Membrane Glycoproteins; D019030:Receptors, Vitronectin; D011994:Recombinant Proteins; D012795:Sialoglycoproteins; C506897:Spp1 protein, rat; D053495:Osteopontin; D000072000:NF-KappaB Inhibitor alpha; D011107:Polylysine; D003094:Collagen