Abstract
We have investigated the function of TIE2/TEK receptor tyrosine kinase in the development of definitive hematopoiesis. In the vitelline artery at 9.5 days postcoitum (d.p.c.), TIE2+ hematopoietic cells aggregated and adhered to TIE2+ endothelial cells. Soluble TIE2-Fc chimeric protein inhibited the development of hematopoiesis and angiogenesis in the para-aortic splanchnopleural mesoderm (P-Sp) explant culture, and TIE2-deficient mice showed severely impaired definitive hematopoiesis. An in vitro study revealed that Angiopoietin-1 but not Angiopoietin-2 promoted the adhesion to fibronectin (FN) through integrins in TIE2-transfected cells and primary TIE2+ cells sorted from 9.5 d.p.c. P-Sp. Adhesion of TIE2+ cells induced by Angiopoietin-1 enhanced the proliferation of hematopoietic progenitor cells.
Publication types
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Research Support, Non-U.S. Gov't
MeSH terms
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Angiopoietin-1
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Angiopoietin-2
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Animals
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Blood Vessels / embryology*
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Cell Adhesion / physiology
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Cell Line
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Endothelium, Vascular / enzymology*
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Endothelium, Vascular / ultrastructure*
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Female
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Fibronectins / metabolism
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Hematopoiesis / physiology*
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Hematopoietic Stem Cells / cytology
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Male
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Membrane Glycoproteins / pharmacology
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Membrane Glycoproteins / physiology
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Mesoderm / physiology
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Mice
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Mice, Inbred C57BL
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Proteins / pharmacology
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Proteins / physiology
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Proto-Oncogene Proteins c-kit / metabolism
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Receptor Protein-Tyrosine Kinases / physiology*
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Receptor, TIE-2
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Signal Transduction / physiology
Substances
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Angiopoietin-1
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Angiopoietin-2
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Angpt1 protein, mouse
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Fibronectins
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Membrane Glycoproteins
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Proteins
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Proto-Oncogene Proteins c-kit
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Receptor Protein-Tyrosine Kinases
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Receptor, TIE-2