Differential membrane marker expression in adult rodent bone marrow mesenchymal and neural crest stem cells.

Bone marrow stem cells are endowed with in vitro multi-lineage differentiation abilities, and constitute an attractive autologous source of material for cell therapy. With regards to recent findings, adult mesenchymal stem cells (MSC) are commonly assimilated to neural crest stem cells (NCSC), both isolated from adult bone marrow. The objective of this study was therefore to highlight significant differences for membrane markers between those two cell types. Using the minimal criteria for defining multipotent mesenchymal stromal cells as previously described by The International Society for Cellular Therapy, we were quite surprised that no significant difference could discriminate MSC from NCSC. To define new markers, we first performed a microarray comparison. Based on those results, we validated selected targets by RT-PCR, then by immunocytochemistry. In parallel, we observed that NCSC had the unique property (compared to MSC) to grow as spheres, which could also be used as a purification protocol for NCSC from adult bone marrow. Altogether, we demonstrated that P75NTR was the most significant discriminating marker between MSC and NCSC, isolated from mouse adult bone marrow, which could be used as selecting marker in an enrichment protocol. Sphere formation could then be used as a purification protocol for NCSC.