Figure 3

Cell senescence, apoptosis and surface antigens expression in STRO-1 ⁺ /CD34 ⁻ hDPSCs and STRO-1 ⁺ /c-Kit ⁺ /CD34 ⁺ hDPSCs. A: β-Galactosidase activity staining in confluent cultures of STRO-1⁺/c-Kit⁺/CD34- hDPSCs and STRO-1⁺/c-Kit⁺/CD34⁺ hDPSCs grown for 5 passages. Blue labeling indicates cells positive to β-galactosidase activity staining. Bar: 50 μm. B: Western blot analysis of active caspase 3 expression by STRO-1⁺/c-Kit⁺/CD34⁻ hDPSCs and STRO-1⁺/c-Kit⁺/CD34⁺ hDPSCs at passages 1 and 6. Blasts treated with etoposide were loaded as positive control of the presence of active caspase 3. Actin bands were presented as control of the protein loading. Densitometry of caspase 3 bands was shown at the bottom of western blot images. [***p<0,001 DPSC STRO-1⁺/c-Kit⁺/CD34⁺ (P6) vs DPSC STRO-1⁺/c-Kit⁺/CD34⁺ (P1), unpaired t-test; n=3]. C: Immunofluorescence labeling shows signals from c-Kit (red), STRO-1 (blue) and CD34 (green) in both the subpopulations of hDPSCs, analyzed at passages 1 and 6. DAPI staining is shown in grey. Yellow asterisks indicate the presence of pyknotic nuclei. Bar: 10 μm.