title: The endoglin(positive) sca-1(positive) rhodamine(low) phenotype defines a near-homogeneous population of long-term repopulating hematopoietic stem cells.
abstract: Endoglin, an ancillary TGF-beta receptor, is differentially expressed in long-term repopulating hematopoietic stem cells (LTR-HSC). Here, we describe simple and highly efficient purification schemes for mouse bone marrow LTR-HSCs using Endoglin as a marker. The Endoglin positive and Sca-1 positive (Endo(Pos) Sca-1(Pos)) population, which contains about 36% of "Side Population" (SP) cells, is highly enriched for LTR-HSCs. In long-term competitive reconstitution assays, 100 such cells reconstituted all lethally irradiated recipients. Interestingly, the Endo(Pos) Sca-1(Pos) population contains comparable LTR-HSC activity in both SP and non-SP fractions, indicating that many HSCs are not captured by the SP phenotype. Furthermore, LTR-HSCs are exclusively found in the Endo(Pos) Sca-1(Pos) Lin(Neg/Low) (lineage negative/low), but not in the Endo(Neg) Sca-1(Pos) Lin(Neg/Low) population, suggesting that the Endo(Pos) population may contain all LTR-HSCs in mouse bone marrow. Finally, we demonstrated that the Endo(Pos) Sca-1(Pos) Rh(Low) (Rhodamine-123 low) phenotype, without using CD34, c-Kit, or Lineage markers, defines a nearly homogenous population of LTR-HSCs.
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: Ling
authors.initials: L
authors.lastname: Li
authors.forename: Min
authors.initials: M
authors.lastname: Li
authors.forename: Harvey F
authors.initials: HF
authors.lastname: Lodish
mesh_terms: D000818:Animals; D015703:Antigens, CD; D018952:Antigens, CD34 / Q000378:metabolism; D000950:Antigens, Ly / Q000378:metabolism*; D000071063:Endoglin; D006412:Hematopoietic Stem Cells / Q000378:metabolism*; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D011956:Receptors, Cell Surface; D012235:Rhodamines / Q000378:metabolism*; D019010:Vascular Cell Adhesion Molecule-1 / Q000378:metabolism*
chemical_list: D015703:Antigens, CD; D018952:Antigens, CD34; D000950:Antigens, Ly; C064206:ENG protein, human; D000071063:Endoglin; C074650:Ly6a protein, mouse; D008565:Membrane Proteins; D011956:Receptors, Cell Surface; D012235:Rhodamines; D019010:Vascular Cell Adhesion Molecule-1