title: Identification of endoglin as a functional marker that defines long-term repopulating hematopoietic stem cells.
abstract: We describe a strategy to obtain highly enriched long-term repopulating (LTR) hematopoietic stem cells (HSCs) from bone marrow side-population (SP) cells by using a transgenic reporter gene driven by a stem cell enhancer. To analyze the gene-expression profile of the rare HSC population, we developed an amplification protocol termed "constant-ratio PCR," in which sample and control cDNAs are amplified in the same PCR. This protocol allowed us to identify genes differentially expressed in the enriched LTR-HSC population by oligonucleotide microarray analysis using as little as 1 ng of total RNA. Endoglin, an ancillary transforming growth factor beta receptor, was differentially expressed by the enriched HSCs. Importantly, endoglin-positive cells, which account for 20% of total SP cells, contain all the LTR-HSC activity within bone marrow SP. Our results demonstrate that endoglin, which plays important roles in angiogenesis and hematopoiesis, is a functional marker that defines LTR HSCs. Our overall strategy may be applicable for the identification of markers for other tissue-specific stem cells.
authors.affiliation: Whitehead Institute for Biomedical Research, Nine Cambridge Center, Cambridge, MA 02142, USA.
authors.forename: Chang-Zheng
authors.initials: CZ
authors.lastname: Chen
authors.forename: Min
authors.initials: M
authors.lastname: Li
authors.forename: David
authors.initials: D
authors.lastname: de Graaf
authors.forename: Stefano
authors.initials: S
authors.lastname: Monti
authors.forename: Berthold
authors.initials: B
authors.lastname: Göttgens
authors.forename: Maria-Jose
authors.initials: MJ
authors.lastname: Sanchez
authors.forename: Eric S
authors.initials: ES
authors.lastname: Lander
authors.forename: Todd R
authors.initials: TR
authors.lastname: Golub
authors.forename: Anthony R
authors.initials: AR
authors.lastname: Green
authors.forename: Harvey F
authors.initials: HF
authors.lastname: Lodish
mesh_terms: D000818:Animals; D020296:Animals, Congenic; D015703:Antigens, CD; D015415:Biomarkers; D001854:Bone Marrow Cells / Q000166:cytology; D019070:Cell Lineage; D003114:Colony-Forming Units Assay; D018076:DNA, Complementary / Q000235:genetics; D000071063:Endoglin; D005260:Female; D005434:Flow Cytometry; D020869:Gene Expression Profiling; D005786:Gene Expression Regulation; D018380:Hematopoietic Stem Cell Transplantation; D006412:Hematopoietic Stem Cells / Q000737:chemistry / Q000166:cytology*; D051379:Mice; D008810:Mice, Inbred C57BL; D016688:Mice, Inbred NOD; D016513:Mice, SCID; D008822:Mice, Transgenic; D020411:Oligonucleotide Array Sequence Analysis; D016133:Polymerase Chain Reaction / Q000379:methods; D011828:Radiation Chimera; D011956:Receptors, Cell Surface; D013382:Subtraction Technique; D019010:Vascular Cell Adhesion Molecule-1 / Q000235:genetics / Q000502:physiology*
chemical_list: D015703:Antigens, CD; D015415:Biomarkers; D018076:DNA, Complementary; C064206:ENG protein, human; D000071063:Endoglin; D011956:Receptors, Cell Surface; D019010:Vascular Cell Adhesion Molecule-1