title: Functional overlap and cooperativity among alphav and beta1 integrin subfamilies during skin angiogenesis.
abstract: Angiogenesis requires endothelial cell survival and proliferation, which depend upon cytokine stimulation together with integrin-mediated cell adhesion to extracellular matrix; however, the question of which specific integrins are the best targets for suppressing neovascularization is controversial and unresolved. Therefore, we designed experiments to compare contributions of individual integrins from both the alphav and beta1 integrin subfamilies. With immobilized antibodies, we determined that adhesion through integrins alpha1beta1, alpha2beta1, alphavbeta3, and alphavbeta5 each individually supported dermal microvascular endothelial cell survival. Also, substratum coated with collagen I (which binds alpha1beta1 and alpha2beta1) and vitronectin (which binds alphavbeta3 and alphavbeta5) each supported survival. Importantly, substratum coated with combinations of collagen I and vitronectin were most effective at promoting survival, and survival on three-dimensional collagen I gels was strongly enhanced by vitronectin. Vascular endothelial growth factor activation of the p44/p42 mitogen-activated protein kinase pathway, which is required for angiogenesis, was supported by adhesion through either alpha1beta1, alpha2beta1, alphavbeta3, or alphavbeta5, and pharmacologic inhibition of this pathway blocked proliferation and suppressed survival. Therefore, these studies establish that the alpha1beta1, alpha2beta1, alphavbeta3, and alphavbeta5 integrins each support dermal microvascular endothelial cell viability, and that each collaborate with vascular endothelial growth factor to support robust activation of the mitogen-activated protein kinase pathway which mediates both proliferation and survival. Moreover, survival is supported most significantly by extracellular matrices, which engage all of these integrins in combination. Consistent with important complementary and overlapping functions, combined antagonism of these integrins provided superior inhibition of angiogenesis in skin, indicating that multiplicity of integrin involvement should be considered in designing strategies for controlling neovascularization.
authors.affiliation: Department of Pathology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, Massachusetts 02215, USA.
authors.forename: Carole A
authors.initials: CA
authors.lastname: Perruzzi
authors.forename: Antonin R
authors.initials: AR
authors.lastname: de Fougerolles
authors.forename: Victor E
authors.initials: VE
authors.lastname: Koteliansky
authors.forename: Mary C
authors.initials: MC
authors.lastname: Whelan
authors.forename: William F
authors.initials: WF
authors.lastname: Westlin
authors.forename: Donald R
authors.initials: DR
authors.lastname: Senger
mesh_terms: D000818:Animals; D002460:Cell Line; D002470:Cell Survival / Q000502:physiology; D024042:Collagen Type I / Q000502:physiology; D004338:Drug Combinations; D016228:Endothelial Growth Factors / Q000502:physiology; D004730:Endothelium, Vascular / Q000502:physiology; D004789:Enzyme Activation; D006801:Humans; D039222:Integrin alpha1beta1 / Q000502:physiology; D038982:Integrin alpha2beta1 / Q000502:physiology; D039564:Integrin alphaV / Q000502:physiology*; D039302:Integrin alphaVbeta3 / Q000502:physiology; D019012:Integrin beta1 / Q000502:physiology*; D016023:Integrins / Q000502:physiology; D036341:Intercellular Signaling Peptides and Proteins / Q000502:physiology; D008222:Lymphokines / Q000502:physiology; D008833:Microcirculation; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism; D018919:Neovascularization, Physiologic / Q000502:physiology*; D019030:Receptors, Vitronectin / Q000502:physiology; D012867:Skin / Q000098:blood supply*; D018411:Spodoptera; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D019096:Vitronectin / Q000502:physiology
chemical_list: D024042:Collagen Type I; D004338:Drug Combinations; D016228:Endothelial Growth Factors; D039222:Integrin alpha1beta1; D038982:Integrin alpha2beta1; D039564:Integrin alphaV; D039302:Integrin alphaVbeta3; D019012:Integrin beta1; D016023:Integrins; D036341:Intercellular Signaling Peptides and Proteins; D008222:Lymphokines; D019030:Receptors, Vitronectin; D042461:Vascular Endothelial Growth Factor A; D042442:Vascular Endothelial Growth Factors; D019096:Vitronectin; C064660:integrin alphaVbeta5; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D020928:Mitogen-Activated Protein Kinases