PPIA, HPRT1, and YWHAZ Genes Are Suitable for Normalization of mRNA Expression in Long-Term Expanded Human Mesenchymal Stem Cells
Figure 1
Characterization of UCB-MSCs and BM-MSCs in early passage, and alteration of their features in middle and late passages under defined culture conditions. (a) Morphology of long-term expanded BM-MSCs and UCB-MSCs at early, middle and late passages. Scale bar = 50 μm. (b) Cell surface marker analysis of MSC-positive markers (CD44, CD105, and Vimentin) and negative markers (CD34 and CD45) in long-term expanded BM-MSCs and UCB-MSCs. (c) Lineage-specific differentiation of long-term expanded BM-MSCs and UCB-MSCs. The calcium-rich mineral deposits by osteogenic induction or proteoglycan synthesis by chondrogenic induction or intracellular accumulations of lipid droplets by adipogenic induction was identified by staining with 5% sliver nitrate or alcian blue or Oil-Red O, respectively. Scale bar = 50 μm. (d) In vitro proliferation capability of long-term expanded BM-MSCs and UCB-MSCs. Absorbance of MTT metabolite (formazan) was measured at 540 nm every other day from day 2 to day 14. The data were presented as mean ± SD. P < 0.05 vs E-BM-MSCs. (e) Senescence-associated β-galactosidase (SA-β-gal) activity in long-term expanded BM-MSCs and UCB-MSCs. Absorbance was measured at 405 nm. The data were presented as mean ± SD, P < 0.05 vs E-BM-MSCs. E-/M-/L-BM-MSCs, bone marrow-derived mesenchymal stem cells at early passage (passage 2-4)/middle passage (passage 10-12)/late passage (passage 18-20); E-/M-/L-UCB-MSCs, umbilical cord blood mesenchymal stem cell at early passage (passage 2-4)/middle passage (passage 10-12)/late passage (passage 18-20).