High OCT4 and Low Expressions Determine In Vitro Lifespan of Mesenchymal Stem Cells

Figure 1

Morphological features and growth kinetics of BM-MSCs. (a) Representative images of BM-MSCs at an early passage (5th passage) showing that different morphology was observed in cells from different donors, ranging from a typical elongated and spindle-like shape (sample BM12) to an enlarged and irregular morphology (samples BM13 and BM16). Cells were stained with hematoxylin. Scale bar: 200 μm. (b) Cumulative population doublings (PD) of BM-MSCs from 6 young healthy donors until replicative senescence (growth arrest). Cell numbers were determined at every passage and cumulative PD was calculated. Each line represents BM-MSCs from one donor and each symbol represents one passage. (c) The mean PD time (PDT) of multiple donors at each passage, showing increased interindividual growth variability and greater PDT over time.

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