Fig. 1

Characterization of human induced pluripotent stem cell (iPSC)-derived mesenchymal stem cells (MSCs). a Morphology of iPSCs and iPSC-MSCs. Urine cell-derived iPSCs (U-iPSCs) and amniocyte-derived iPSCs (A-iPSCs) were characterized by embryonic stem cell-like morphology, and iPSC-MSCs from these clones of iPSCs had fibroblast-like morphology (original magnification, 100×). b Expression of the pluripotent markers OCT4, Sox-2, TRA-1-60, and TRA-1-81 in U-iPSCs, A-iPSCs, U-iPSC-MSCs, and A-iPSC-MSCs by flow cytometry, and SV40LT DNA in U-iPSCs and U-iPSC-MSCs. Gray histograms were negative isotypes. c Immunophenotype analysis of the MSC surface markers in U-iPSC-MSCs and A-iPSC-MSCs by flow cytometry. Cells were harvested at passage 4. d Representative images of the differentiation of U-iPSC-MSCs toward adipogenic, osteogenic, and chondrogenic lineages. e The representative pictures for the aging of U-iPSC-MSCs and bone marrow-derived MSCs (BM-MSCs) evaluated by β-galactosidase activity. Arrows show the positive staining. f Statistical analysis for the β-galactosidase-positive cells of U-iPSC-MSCs and BM-MSCs. Data are presented as mean ± SD. Three different batches of BM-MSCs were used. n = 3–5 replicates per condition. g Growth curves for iPSC-MSCs and BM-MSCs. Three different batches of BM-MSCs were used. *P < 0.05, ***P < 0.001, versus BM-MSCs at the same time point. nd not detectable, P passage