A C-terminal fragment of fibulin-7 interacts with endothelial cells and inhibits their tube formation in culture.
We have previously demonstrated that fibulin-7 (Fbln7) is expressed in teeth by pre-odontoblast and odontoblast cells, localized in the basement membrane and dentin matrices, and is an adhesion molecule for dental mesenchyme cells and odontoblasts. Fbln7 is also expressed in blood vessels by endothelial cells. In this report, we show that a recombinant C-terminal Fbln7 fragment (Fbln7-C) bound to Human Umbilical Vein Endothelial Cells (HUVECs) but did not promote cell spreading and actin stress fiber formation. Fbln7-C binding to HUVECs induced integrin clustering at cell adhesion sites with other focal adhesion molecules, and sustained activation of FAK, p130Cas, and Rac1. In addition, RhoA activation was inhibited, thereby preventing HUVEC spreading. As endothelial cell spreading is an important step for angiogenesis, we examined the effect of Fbln7-C on angiogenesis using in vitro assays for endothelial cell tube formation and vessel sprouting from aortic rings. We found that Fbln7-C inhibited the HUVEC tube formation and the vessel sprouting in aortic ring assays. Our findings suggest potential anti-angiogenic activity of the Fbln7 C-terminal region.
Laboratory of Cell and Developmental Biology, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892-4370, United States; Research Institute for Diseases of Old Age, Juntendo University School of Medicine, Tokyo 113-8421, Japan.
Susana
S
de Vega
Laboratory of Cell and Developmental Biology, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892-4370, United States; Department of Biochemistry and Biophysics, Graduate School of Health Care Sciences, Tokyo Medical and Dental University, Tokyo 113-8510, Japan.
Nobuharu
N
Suzuki
Research Institute for Diseases of Old Age, Juntendo University School of Medicine, Tokyo 113-8421, Japan.
Risa
R
Nonaka
Department of Experimental Medicine, Nikolaus Fiebiger Center of Molecular Medicine, University of Erlangen-Nuernberg, Erlangen, Germany.
Takako
T
Sasaki
Laboratory of Cell and Developmental Biology, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892-4370, United States.
Patricia
P
Forcinito
Research Institute for Diseases of Old Age, Juntendo University School of Medicine, Tokyo 113-8421, Japan.
Eri
E
Arikawa-Hirasawa
Laboratory of Cell and Developmental Biology, National Institute of Dental and Craniofacial Research, National Institutes of Health, Bethesda, MD 20892-4370, United States. Electronic address: yoshi.yamada@nih.gov.
Yoshihiko
Y
Yamada
D000818:Animals; D002135:Calcium-Binding Proteins / Q000737:chemistry / Q000378:metabolism*; D002448:Cell Adhesion; D050719:Crk-Associated Substrate Protein / Q000378:metabolism; D004789:Enzyme Activation; D022001:Focal Adhesions / Q000378:metabolism / Q000648:ultrastructure; D061307:Human Umbilical Vein Endothelial Cells / Q000166:cytology / Q000378:metabolism*; D006801:Humans; D016023:Integrins / Q000378:metabolism; D051379:Mice; D018919:Neovascularization, Physiologic; D010766:Phosphorylation; D011485:Protein Binding; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D022502:Stress Fibers / Q000378:metabolism; D020830:rac1 GTP-Binding Protein / Q000378:metabolism; D020742:rhoA GTP-Binding Protein / Q000378:metabolism
D002135:Calcium-Binding Proteins; D050719:Crk-Associated Substrate Protein; C524759:FBLN7 protein, human; D016023:Integrins; C107953:RAC1 protein, human; D011994:Recombinant Proteins; D020830:rac1 GTP-Binding Protein; D020742:rhoA GTP-Binding Protein
Angiogenesis; Endothelial cells; Fibulin-7 fragment