Comparative characteristics of mesenchymal stem cells from human bone marrow and placenta: CD10, CD49d, and CD56 make a difference

It is well known that MSCs are characterized by a marked heterogeneity, being composed by bonafide stem cells; transit multipotent amplifying cells; osteo- chondro-, and adipoprogenitors; fat, cartilage, and bone precursors. We characterized by flow cytometry, a series of 10 MSC preparations obtained from five human full term placenta specimens and five bone marrow aspirates. hpMSCs were obtained from amniotic membrane and the nature of these cells was demonstrated on the basis of stringent criteria such as high proliferation potential, surface phenotype (CD324/E-Cadherin−, VLA4/CD49d+) adherence to plastic and cell morphology, differentiation potential towards osteogenic, adipogenic an chondrogenic lineage, and fetal origin, determined by sensitive molecular leukocyte antigen typing. We demonstrated that CD56 was consistently expressed on a cell subset of hpMSCs (ranging from 5 to 50% positive cells), whereas it was completely absent on hbmMSCs (p < 0.01, Mann–Whitney U-test). We demonstrated the striking differences as regard the expression of CD10, CD49d, and CD56. To our knowledge, our findings regarding the differential expression of CD10 and CD56 on hpMSC and hbmMSC are absolutely new.