Pre- and post-alloSCT CD146⁺MSC harbor the entire CFU-F capacity and similarly support the progenitor phenotype in hematopoietic cells. (A) Frequency of CFU-F in the CD146⁺ and CD146^- subpopulation of the CD45^-/HLA-DR^- fraction of BM-MNC. (B-C) Post-alloSCT–derived CD146⁺CD45^-HLA-DR^- cells were expanded and analyzed for their surface antigen expression (B) by flow cytometry (a representative sample shown) and for their differentiation potential (C) through culture in growth medium (undifferentiated) or specific osteogenic and adipogenic differentiation media (representative sample, staining with alizarin pH4 and oil red for calcium deposition and lipid droplets, light microscopy, phase contrast, original magnification ×100). (D-E) CD146⁺MSC derived pre- and post-alloSCT (paired patient samples) were directly cocultured with CB CD34⁺ cells and proliferation (D) through cell counting (n = 3) as well as expression of CD34 and CD45RA (E) by flow cytometry (representative sample) was determined in separated (CD105^-) hematopoietic cells at day 7 of coculture compared with culture without MSC. (F) Frequencies of hematopoietic subpopulations according to their expression of CD34 and CD45RA from the cocultures (paired patient samples, n = 3) described in (D) and (E) given as mean percentage of cells.