98%
921
2 minutes
20
Phenotypic markers associated with human hematopoietic stem cells (HSCs) were developed and validated using uncultured cells. Because phenotype and function can be dissociated during culture, better markers to prospectively track and isolate HSCs in ex vivo cultures could be instrumental in advancing HSC-based therapies. Using an expansion system previously shown to increase hematopoietic progenitors and SCID-repopulating cells (SRCs), we demonstrated that the rhodamine-low phenotype was lost, whereas AC133 expression was retained throughout culture. Furthermore, the AC133(+)CD38(-) subpopulation was significantly enriched in long-term culture-initiating cells (LTC-IC) and SRCs after culture. Preculture and postculture analysis of total nucleated cell and LTC-IC number, and limiting dilution analysis in NOD/SCID mice, showed a 43-fold expansion of the AC133(+)CD38(-) subpopulation that corresponded to a 7.3-fold and 4.4-fold expansion of LTC-ICs and SRCs in this subpopulation, respectively. Thus, AC133(+)CD38(-) is an improved marker that tracks and enriches for LTC-IC and SRC in ex vivo cultures.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1182/blood-2009-07-228106 | DOI Listing |
Blood
January 2010
Institute of Biomaterials and Biomedical Engineering, University of Toronto, Toronto, ON, Canada.
Phenotypic markers associated with human hematopoietic stem cells (HSCs) were developed and validated using uncultured cells. Because phenotype and function can be dissociated during culture, better markers to prospectively track and isolate HSCs in ex vivo cultures could be instrumental in advancing HSC-based therapies. Using an expansion system previously shown to increase hematopoietic progenitors and SCID-repopulating cells (SRCs), we demonstrated that the rhodamine-low phenotype was lost, whereas AC133 expression was retained throughout culture.
View Article and Find Full Text PDFCurr Opin Hematol
July 2006
Roger Williams Medical Center, Department of Research, Providence, Rhode Island 02908, USA.
Purpose Of Review: We review the continuum model of stem cell regulation. A series of studies on purified lineage negative rhodamine low Hoechst low murine stem cells driven through cell cycle by cytokine exposure have shown that many phenotypic features show reversible changes with cycle progression.
Recent Findings: We and others have shown that purified murine marrow stem cells are a cycling population.
Folia Histochem Cytobiol
March 2006
Department of Research, Roger Williams Medical Center, 825 Chalkstone Avenue, Providence, RI 02908, USA.
Traditional models of hematopoiesis have been hierarchical in nature. Over the past 10 years, we have developed data indicating that hematopoiesis is regulated in a continuum with deterministic and stochastic components. We have shown that the most primitive stem cells, as represented by lineage negative rhodamine(low) Hoechst(low) murine marrow cells are continuously or intermittently cycling as determined by in vivo BrdU labeling.
View Article and Find Full Text PDFImmunity
October 2003
Whitehead Institute for Biomedical Research, Nine Cambridge Center, Cambridge, MA 02142, USA.
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.
View Article and Find Full Text PDFJ Exp Med
June 2003
Department of Research, Roger Williams Medical Center, 825 Chalkstone Ave., Providence, RI 02908, USA.
We studied the genetic and engraftment phenotype of highly purified murine hematopoietic stem cells (lineage negative, rhodamine-low, Hoechst-low) through cytokine-stimulated cell cycle. Cells were cultured in interleukin (IL)-3, IL-6, IL-11, and steel factor for 0 to 48 h and tested for engraftment capacity in a lethally irradiated murine competitive transplant model. Engraftment showed major fluctuations with nadirs at 36 and 48 h of culture and recovery during the next G1.
View Article and Find Full Text PDF