Repression of the Antioxidant Pyrroloquinoline Quinone in Skin Aging Induced by Bmi-1 Deficiency

Figure 3

The effect of PQQ on cell proliferation and senescence in the skin of Bmi-1^-/- mice. Representative micrographs of paraffin-embedded skin sections from 8-week-old WT, Bmi-1^-/-, and Bmi-1^-/-+PQQ mice stained for (a) PCNA and (c) SA-β-gal. The percentage of (b) PCNA-positive and (d) SA-β-gal-positive cells was calculated and presented using image analysis. (e) Western blot analysis of protein level for p53, p21, and p19 in the skin from the WT, Bmi-1^-/-, and Bmi-1^-/-+PQQ mice. β-Actin was used as a loading control. (f) p53, (g) p21, and (h) p19 protein levels relative to β-actin protein levels were determined using densitometric analysis and expressed relative to WT. Values are shown as the of seven determinations per group. , , and versus WT mice; ^&, ^&&, and ^&&& versus Bmi-1^-/- mice.

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