TY - JOUR
T1 - Heterogeneity and hierarchy of hematopoietic stem cells
AU - Ema, Hideo
AU - Morita, Yohei
AU - Suda, Toshio
N1 - Funding Information:
We thank Connie Eaves for suggesting that we compare differently defined HSC classes, and Aled O'Neill and Keiyo Takubo for critical reading of the manuscript. This work was supported in part by Grants-in-Aid for Scientific Research (A) and (C), Grants-in-Aid for Scientific Research on Innovative Areas in Japan, and the European Union's Seventh Framework Programme ( FP7/2007-2013 ) under grant agreement number 306240 (SyStemAge).
PY - 2014/2
Y1 - 2014/2
N2 - Hematopoietic stem cells (HSCs) are a more heterogeneous population than previously thought. Extensive analysis of reconstitution kinetics after transplantation allows a new classifications of HSCs based on lineage balance. Previously unrecognized classes of HSCs, such as myeloid- and lymphoid-biased HSCs, have emerged. However, varying nomenclature has been used to describe these cells, promoting confusion in the field. To establish a common nomenclature, we propose a reclassification of short-, intermediate-, and long-term (ST, IT, and LT) HSCs defined as: ST < 6 months, IT > 6 months, and LT > 12. We observe that myeloid-biased HSCs or α cells overlap with LT-HSCs, whereas lymphoid-biased HSCs or γ/δ cells overlap with ST-HSCs, suggesting that HSC lifespan is linked to cell differentiation. We also suggest that HSC heterogeneity prompts reconsideration of long-term (>4 months) multilineage reconstitution as the gold standard for HSC detection. In this review, we discuss relationships among ST-, IT-, and LT-HSCs relevant to stem cell heterogeneity, hierarchical organization, and differentiation pathways.
AB - Hematopoietic stem cells (HSCs) are a more heterogeneous population than previously thought. Extensive analysis of reconstitution kinetics after transplantation allows a new classifications of HSCs based on lineage balance. Previously unrecognized classes of HSCs, such as myeloid- and lymphoid-biased HSCs, have emerged. However, varying nomenclature has been used to describe these cells, promoting confusion in the field. To establish a common nomenclature, we propose a reclassification of short-, intermediate-, and long-term (ST, IT, and LT) HSCs defined as: ST < 6 months, IT > 6 months, and LT > 12. We observe that myeloid-biased HSCs or α cells overlap with LT-HSCs, whereas lymphoid-biased HSCs or γ/δ cells overlap with ST-HSCs, suggesting that HSC lifespan is linked to cell differentiation. We also suggest that HSC heterogeneity prompts reconsideration of long-term (>4 months) multilineage reconstitution as the gold standard for HSC detection. In this review, we discuss relationships among ST-, IT-, and LT-HSCs relevant to stem cell heterogeneity, hierarchical organization, and differentiation pathways.
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U2 - 10.1016/j.exphem.2013.11.004
DO - 10.1016/j.exphem.2013.11.004
M3 - Review article
C2 - 24269919
AN - SCOPUS:84896727582
SN - 0301-472X
VL - 42
SP - 74-82.e2
JO - Experimental Hematology
JF - Experimental Hematology
IS - 2
ER -
