Fig 6. Enhanced apoptosis and DNA damage in the epidermis of Gclc-deficient mice.

(A,B) Immunofluorescence staining of skin sections at 3W for cleaved caspase-3 (N = 11/7/6/8) and γH2AX (N = 22/11/5/8) and quantification of positive cells per length epidermis. White dotted lines indicate the basement membrane. Scale bar: 20 μm. Scatter plots show the median with interquartile range. **P ≤ 0.01, ***P ≤ 0.001. (C,D) Electron microscopy of epidermis at 3W shows dermal-epidermal border with the basal and suprabasal layers of the epidermis. (C) Apoptotic keratinocytes in the basal and suprabasal layers have condensed nuclei separated by a small cleft from the cytosol (asterisk). Scale bar: 3 μm. (D) Basal keratinocytes from control mice show a well-organized mitochondrium (arrow) with well recognizable and lamellar organized cristae (left panel). The matrix of mitochondria in apoptotic (middle panel) and non-apoptotic (right panel) basal keratinocytes of ko^G mice lacks the typical cristae structure and reveals only small short cristae in disorganized orientation. Furthermore, the damaged mitochondrial matrix shows dense agglomeration (arrowheads). Scale bar: 170 nm. (E) OxyBlot of epidermal tissue lysates at 3W. Equal loading was confirmed by Ponceau S staining of the membrane. Shown is one representative sample for each genotype (N = 5).