Characterization of human placental multipotent mesenchymal stromal cells (hPMSCs).
(A) Flow cytometry analysis of cell-marker expression by hPMSCs. The cells express CD13, CD29, CD44, CD54, CD73, CD90, CD105, CD166, HLA-ABC, Oct-4, and SSEA-4, but are negative for HLA-DR, CD34, CD45, and SSEA-1. The shaded area shows the profile of the cells stained by a control antibody of matching isotype. Ten thousand cells were counted from each sample. (B) Analysis of stem cell markers on hPMSCs by RT-PCR analysis. Three different strains of hPMSCs are shown in lane 1 to 3. Lane 4 was RNA obtained from a human embryonic stem cell line (hES 6; ES Cell International, USA) and served as a positive control. PCR was performed for 35 cycles to demonstrate Oct-4 and Sox-2 transcripts, and 30 cycles for Nanog. (C) The expression of integrin subunits on hPMSCs determined by flow cytometry. The data shown are representative of 3 different experiments. (D) Osteogenic differentiation of hPMCs resulted in positive staining for Alizarin Red S, indicating the presence of calcium salt deposition associated with the matrix. (E) Adipocyte differentiation resulted in cytoplasmic lipid droplets that were Oil Red O–positive. (F) Undifferentiated hPMSCs used as a control for Oil Red O staining. The cells were counterstained with Mayer's hematoxylin (E, F). Scale bar: 100 µm.