I’d like to share excellent review about identity of mouse multipotent mesenchymal progenitors (mesenchymal stem cells – MSCs).
Some controversial issues highlighted in the review:
- Can we call MSCs “Stem Cells”?
- MSCs heterogeneity.
- What surface antigens could aid the isolation of mouse bone marrow-derived MSCs?
- Sca-1, the best marker in the mouse system?
- What is topographical and cellular relationships of MSCs with adventitial reticulocytes, pericytes and vascular smooth muscle cells?
- How can we dissect putative MPCs or immature mesenchymal cells from typical pericytes?
In summary, we currently believe that the murine BM stromal compartment is largely unexplored compared to their human equivalent. The phenotype of the potential BM MPC is still vague but most probably confine to the Sca-1+PDGFRβ+ fraction. Moreover, the data available points to the idea that MSCs are related to both progenitors from adventitia and pericytes, (perhaps slightly closer to the former) but further apart from classical VSMCs. We might hypothesise that in adult BM the primitive mesenchymal compartment is composed of a myriad of cell-types with similar phenotypes and differentiation potentials and even perhaps with the capacity of lineage inter-convertibility in vivo rather than one identifiable mesenchymal progenitor population, thus explaining the challenges/hurdles that this field had faced over the years trying to identify/isolate these putative cells in vivo.
Great review! Highly recommended!