Isolation and Characterisation of Mesenchymal Stem Cells from Rat Bone Marrow and the Endosteal Niche: A Comparative Study

Figure 4

Effect of continuous cell expansion on (a) telomere length analysis for CB-MSC and BM-MSC populations at cited PDs, by Southern blotting. Average telomere lengths were calculated from 3 blots, and averages and range of TRF values obtained are indicated in the associated table. Right-hand lane represents the separated DIG-labelled telomere length standard. (b) Expression of telomerase catalytic subunit, rTERT, was assessed by RT-PCR. Continued expression of rTERT at PD100 is consistent with minimal change in telomere length following expanded culture. (c) Staining of cell populations at PD100 with SA-β-galactosidase indicated the absence of senescent cells. (d) mRNA expression of cell cycle proteins regulating arrest in CM-MSCs and BM-MSCs was assessed by RT-PCR. p16^INK4A was only detected in CB-MSCs at PD15 and was lost with subsequent culture. Continued expression of p21^Waf1 and p53 was observed.

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