Morphologic and proliferative changes and immunophenotype upon senescence
(A and E) Representative images of the fibroblast-like morphology of MSCs at P0 (A) and P4, P6, P8, P10, and P12 (E) are presented. Scale bars, 100 μm. (B) CCK-8 assay of MSCs at P4, P6, P8, P10, and P12. (C) NCPD of MSCs from P4 to P12. (D) The continuous increase in cell size is reflected by the increasing forward-scatter signal in flow cytometry (FSC). (F) Representative cell cycle diagrams of MSCs during long-term culture at P4, P6, P8, P10, and P12. (G) Surface marker expression on MSCs at P4 and P12 analyzed using flow cytometry. Black lines represent isotype control. Data are presented as the means ± SEM. ∗p < 0.05, ∗∗p < 0.01, ∗∗∗p < 0.001 compared with P4. n = 9 MSCs per passage.