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B. Nowlan et al.
adult mouse tissues.36 In particular, SCA1 is known to be expressed by immature MSC in the BM and skeletal mus- cle, as well as by BM endothelial cells.30,37,38 The literature is conflicting as to whether SCA1 expression on stromal cells is dependent on the mouse strain. For instance, some
groups have identified that cultured plastic-adherent MSC derived from BALB/c mice39,40 and CBA mice40 are SCA1+ (both haplotype LY6.1 mice). In contrast, other groups reported that the SCA1 staining on MSC was restricted to plastic-adherent cultured MSC from the C57BL/6 and FVB/N strains whereas DBA1-derived MSC
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Figure 6. Comparative SCA1 expression in bone marrow endothelial and mesenchymal cells from C57BL/6 and NSG mice. (A-D) Live single cells (A) were gated for non-hematopoietic CD45- Ter119- cells (B). From these CD45- Ter119- cells, endothelial cells were gated as CD31+ (C). The remaining CD31- non-endothelial cells were gated for CD51+ mesenchymal cells (D). (E, F, I) SCA1 expression in bone marrow endothelial cells was similar in C57BL/6 (E) and NSG (F) mice as seen in the overlay histogram (I). (G, H, J) CD45- Ter119- CD31- CD51+ mesenchymal cells were further gated for PDGFRα and SCA1 expression. SCA1 expression in mesenchymal cells was comparable in C57BL/6 (G) and NSG (H) mice in dot-plots and the overlay histograms (J). (K) SCA1 expression in mesenchymal stromal cells (MSC) cultured from NSG mice. These plots represent data from four separate mice for each strain.
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haematologica | 2020; 105(1)