title: Hemangioblastic characteristics of fetal bone marrow-derived Flk1(+)CD31(-)CD34(-) cells.
abstract: OBJECTIVE
  To investigate whether Flk1(+)CD31(-)CD34(-) cells isolated from fetal bone marrow (BM) have characteristics of hemangioblasts, i.e., progenitors of endothelial and hematopoietic cells.
  
  
  METHODS
  Mononuclear cells from fetal BM were negatively sorted by CD45, GlyA, and CD34 micromagnetic beads, then cultured to form cell colonies. A single colony was harvested. Culture-expanded cells were seeded on ECM gel or semisolid media supplemented with endothelial and hematopoietic growth factors, respectively. Immunochemistry staining and RT-PCR were performed for cell characterization.
  
  
  RESULTS
  99% of cells from the single colony maintained Flk1(+) and CD31/CD34(-) during passaging. On ECM gel, Flk1(+)CD31(-)CD34(-) cells could grow into vascular structure that was positive for CD31 and vWF. There were round CD34(+) cells around the vascular structure. When angiogenesis inhibitor suramin was added before tube formation, formation of vascular structure was blocked. Additionally, Flk1(+)CD31(-)CD34(-) cells cultured on hematopoietic condition could differentiate into hematopoietic cells which expressed GATA-1, 2, and gamma, beta globin gene. After being replated in methylcellulose medium, they formed typical erythroid colonies.
  
  
  CONCLUSIONS
  Flk1(+)CD31(-)CD34(-) cells derived from fetal BM could differentiate into endothelial and hematopoietic cells. The results suggested that these Flk1(+)CD31(-)CD34(-) cells after embryo stage bear characteristics of hemangioblast and may have potential application for the hematopoietic and vascular diseases.
authors.affiliation: Sino-American Collaborative Laboratory, Stat Key Lab of Experimental Haematology, Institute of Haematology and Blood Diseases Hospital, Chinese Academy of Medical Sciences, Tianjin, China
authors.forename: Hong
authors.initials: H
authors.lastname: Guo
authors.forename: Baijun
authors.initials: B
authors.lastname: Fang
authors.forename: Lianming
authors.initials: L
authors.lastname: Liao
authors.forename: Zhigang
authors.initials: Z
authors.lastname: Zhao
authors.forename: Jiewen
authors.initials: J
authors.lastname: Liu
authors.forename: Huishu
authors.initials: H
authors.lastname: Chen
authors.forename: Steven H
authors.initials: SH
authors.lastname: Hsu
authors.forename: Qi
authors.initials: Q
authors.lastname: Cui
authors.forename: Robort Chunhua
authors.initials: RC
authors.lastname: Zhao
mesh_terms: D018952:Antigens, CD34 / Q000276:immunology*; D001483:Base Sequence; D001854:Bone Marrow Cells / Q000166:cytology / Q000276:immunology* / Q000378:metabolism; D002460:Cell Line; D017931:DNA Primers; D005786:Gene Expression Regulation; D006801:Humans; D007150:Immunohistochemistry; D018189:Immunomagnetic Separation; D019408:Platelet Endothelial Cell Adhesion Molecule-1 / Q000276:immunology*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D018952:Antigens, CD34; D017931:DNA Primers; D019408:Platelet Endothelial Cell Adhesion Molecule-1