Two recent studies unveil the difference in DNA damage response to radiation between hematopoietic stem and progenitor cells in mouse and human. The study from Emmanuelle Passegue laboratory, demonstrates that, compared to progenitors mouse hematopoietic stem cells (HSCs) are radioresistant and using different mechanism of DNA damage repair. Second study, from John Dick laboratory, unexpectedly showed that human HSCs are more sensitive to ionizing radiation , compared to progenitors. Why human and mouse HSCs so different in terms of survival and resistance to radiation?
Andrew Lane and David Scadden in their commentary emphasizing that the difference between these two studies may have a methodological basis:
…markers for stem and progenitor populations are more refined in the mouse than in the human so somewhat different stem and progenitor cell populations may have been analyzed…
…slightly different doses of radiation were used…
…HSPCs from umbilical cord blood were transplanted into the mouse bone marrow niche, which may have provided less efficient survival signals for human cells than for mouse cells…
…human umbilical cord blood HSPCs have a different biology than the bone marrow HSPCs of mouse.
Taking in account general assumption that “stemness” associate with radioresistance, these data, seem to me quite interesting and conflicting.
Yet another commentary, noted that difference in results could be explained by anatomical location and ontogeny of HSCs:
Perhaps the most interesting possibility is that DDR differences seen in CB HSPCs from human versus bone marrow or mobilized HSPCs from young mice relate to the different anatomical locations, or to the stage of ontogeny from which the studied cells were derived, given that that both anatomical location and ontogeny are known to significantly impact HSC function.
What do you think about the difference in HSCs radioresistance between mouse and human showed in these studies?
P.S.: You can find both articles and commentaries in open access.
Related posts:
- Hematopoietic stem cells heterogeneity
- Mouse hematopoietic stem cell identification and analysis by flow cytometry
- FACS analysis of mouse hematopoietic stem cell subsets – gating strategy
- How ex vivo transduction of hematopoietic stem cells can affect transplant outcome
- Single cell clonal analysis for assessment of human hematopoietic progenitors and their hierarchy
