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

Figure 6

The effect of PQQ on MMPs 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 immunohistochemically for (a) MMP-13 and (c) MMP-1. The percentage of (b) MMP-13-positive and (d) MMP-1-positive cells was calculated and presented using image analysis. (e) Western blot analysis of protein level for MMP-3 in the skin from the WT, Bmi-1^-/-, and Bmi-1^-/-+PQQ mice. β-Actin was used as a loading control. (f) MMP-3 protein levels relative to β-actin protein levels were determined using densitometric analysis and expressed relative to WT. (g) Schematic diagram of PQQ prevents Bmi-1 deficiency-induced skin aging by inhibiting oxidative stress and DNA damage. Values are shown as the of seven determinations per group. and versus WT mice; ^&& versus Bmi-1^-/- mice.

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