Lactadherin promotes VEGF-dependent neovascularization

Vascular endothelial growth factor (VEGF)-induced blood vessel growth is involved in both physiological and pathological angiogenesis and requires integrin-mediated signaling. We now show that an integrin-binding protein initially described in milk-fat globule, MFG-E8 (also known as lactadherin), is expressed in and around blood vessels and has a crucial role in VEGF-dependent neovascularization in the adult mouse. Using neutralizing antibodies and lactadherin-deficient animals, we show that lactadherin interacts with αvβ3 and αvβ5 integrins and alters both VEGF-dependent Akt phosphorylation and neovascularization. In the absence of VEGF, lactadherin administration induced αvβ3- and αvβ5-dependent Akt phosphorylation in endothelial cells in vitro and strongly improved postischemic neovascularization in vivo. These results show a crucial role for lactadherin in VEGF-dependent neovascularization and identify lactadherin as an important target for the modulation of neovascularization.

[1]  R. Birge,et al.  The opsonin MFG-E8 is a ligand for the αvβ5 integrin and triggers DOCK180-dependent Rac1 activation for the phagocytosis of apoptotic cells , 2004 .

[2]  N. Aoki,et al.  Lactation-dependent expression of an mRNA splice variant with an exon for a multiply O-glycosylated domain of mouse milk fat globule glycoprotein MFG-E8. , 1999, Biochemical and biophysical research communications.

[3]  Keiko Miwa,et al.  Identification of a factor that links apoptotic cells to phagocytes , 2002, Nature.

[4]  E Ruoslahti,et al.  Integrin signaling. , 1999, Science.

[5]  Laurence Zitvogel,et al.  Molecular Characterization of Dendritic Cell-Derived Exosomes , 1999, The Journal of cell biology.

[6]  B. Lévy,et al.  Vascular Endothelial Growth Factor‐B Promotes In Vivo Angiogenesis , 2003, Circulation research.

[7]  R. Ogilvie,et al.  Basic fibroblast growth factor increases collateral blood flow in rats with femoral arterial ligation. , 1996, Circulation research.

[8]  Jingping Zhong,et al.  Neovascularization of ischemic tissues by gene delivery of the extracellular matrix protein Del-1. , 2003, The Journal of clinical investigation.

[9]  Michael R. Taylor,et al.  Role of human-milk lactadherin in protectoin against symptomatic rotavirus infection , 1998, The Lancet.

[10]  D. Taverna,et al.  Enhanced pathological angiogenesis in mice lacking beta3 integrin or beta3 and beta5 integrins. , 2002, Nature medicine.

[11]  Vishva Dixit,et al.  Vascular Endothelial Growth Factor Regulates Endothelial Cell Survival through the Phosphatidylinositol 3′-Kinase/Akt Signal Transduction Pathway , 1998, The Journal of Biological Chemistry.

[12]  R. Hynes,et al.  Beta3-integrin-deficient mice are a model for Glanzmann thrombasthenia showing placental defects and reduced survival. , 1999, The Journal of clinical investigation.

[13]  David A. Cheresh,et al.  Differential αv integrin–mediated Ras-ERK signaling during two pathways of angiogenesis , 2003, The Journal of cell biology.

[14]  S. Nagata,et al.  Autoimmune Disease and Impaired Uptake of Apoptotic Cells in MFG-E8-Deficient Mice , 2004, Science.

[15]  S. Nagata,et al.  Expression of milk fat globule epidermal growth factor 8 in immature dendritic cells for engulfment of apoptotic cells , 2004, European journal of immunology.

[16]  T. Doetschman,et al.  Targeted disruption of the Fgf2 gene does not affect vascular growth in the mouse ischemic hindlimb. , 2002, Journal of applied physiology.

[17]  B. Hogan,et al.  Cloning and characterization of developmental endothelial locus-1: an embryonic endothelial cell protein that binds the alphavbeta3 integrin receptor. , 1998, Genes & development.

[18]  R. Beddington,et al.  Capturing genes encoding membrane and secreted proteins important for mouse development. , 1995, Proceedings of the National Academy of Sciences of the United States of America.

[19]  P. Carmeliet.  Angiogenesis in health and disease , 2003, Nature Medicine.

[20]  J R Couto,et al.  Lactadherin (formerly BA46), a membrane-associated glycoprotein expressed in human milk and breast carcinomas, promotes Arg-Gly-Asp (RGD)-dependent cell adhesion. , 1997, DNA and cell biology.

[21]  B. Lévy,et al.  Angiotensin II Angiogenic Effect In Vivo Involves Vascular Endothelial Growth Factor- and Inflammation-Related Pathways , 2002, Laboratory Investigation.

[22]  I. Shiojima,et al.  The HMG-CoA reductase inhibitor simvastatin activates the protein kinase Akt and promotes angiogenesis in normocholesterolemic animals. , 2000, Nature Medicine.

[23]  N. Aoki,et al.  Secretion of a peripheral membrane protein, MFG-E8, as a complex with membrane vesicles. , 2002, European journal of biochemistry.

[24]  Paul Scherz,et al.  Functional analysis of secreted and transmembrane proteins critical to mouse development , 2001, Nature Genetics.

[25]  Bob S. Hu,et al.  Developmental Endothelial Locus-1 (Del-1), a Novel Angiogenic Protein: Its Role in Ischemia , 2004, Circulation.

[26]  R. Birge,et al.  The opsonin MFG-E8 is a ligand for the alphavbeta5 integrin and triggers DOCK180-dependent Rac1 activation for the phagocytosis of apoptotic cells. , 2004, Experimental cell research.

[27]  M. Ensslin,et al.  Identification of Mouse Sperm SED1, a Bimotif EGF Repeat and Discoidin-Domain Protein Involved in Sperm-Egg Binding , 2003, Cell.

[28]  A. Bui,et al.  cDNA cloning of a mouse mammary epithelial cell surface protein reveals the existence of epidermal growth factor-like domains linked to factor VIII-like sequences. , 1990, Proceedings of the National Academy of Sciences of the United States of America.

[29]  J. Hearder.  Physiological Effects of Ozone , 1874, Nature.

[30]  E. Ruoslahti,et al.  Platelet-derived Growth Factor Receptor β and Vascular Endothelial Growth Factor Receptor 2 Bind to the β3Integrin through Its Extracellular Domain* , 2000, The Journal of Biological Chemistry.

[31]  B. Lévy,et al.  Regulation of Matrix Metalloproteinase Activity in Ischemic Tissue by Interleukin-10: Role in Ischemia-Induced Angiogenesis , 2001, Circulation research.

[32]  B. Hogan,et al.  Cloning and characterization of developmental endothelial locus-1: An embryonic endothelial cell protein that binds the αvβ3 integrin receptor , 1997 .

[33]  E. Ruoslahti,et al.  Platelet-derived growth factor receptor beta and vascular endothelial growth factor receptor 2 bind to the beta 3 integrin through its extracellular domain. , 2000, The Journal of biological chemistry.

[34]  S. Fedosov,et al.  Functional analyses of two cellular binding domains of bovine lactadherin. , 2000, Biochemistry.