A Small-Sized Population of Human Umbilical Cord Blood-Derived Mesenchymal Stem Cells Shows High Stemness Properties and Therapeutic Benefit

Figure 3

Proliferative ability and senescence of differently sized populations. (a) Growth kinetics of the three populations was assessed by monitoring PD until cell proliferation ceased. Black arrows indicate the point of isolation by size (, ; , ). (b) The senescent stage was evident based on positive SA β-gal staining in P9 and P12. Staining was quantified by positive cell counts. Error bars represent the , ; , . μm. (c) Expression of senescence-associated proteins (pho-p53, pho-Rb, p21, and p16) was measured at P12 by immunoblotting analysis. Expression levels were normalized to β-actin levels, with the expression levels in the heterogeneous group defined as 1-fold (, ; , ); PD: population doubling.

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