Figure 5.

Inhibition of Bak apoptotic activity but not degradation is required to regenerate epidermis in vitro. (A) Normal keratinocytes were transfected with either Bak or the ΔGD or ΔC mutants either alone or together with HPVE6/E7. EGFP was used as a marker of transfection. 16 h post-transfection the cells were monitored for morphological signs of apoptosis (membrane blebbing, nuclear condensation and fragmentation) (Magnification, 200×; inserts, 400×). (B) ΔGD and ΔGD/E6/E7 cells were seeded onto de-epidermalized dermis and allowed to reform an epithelium. The cells were irradiated with 45 mJcm⁻² UVB, harvested 8 h posttreatment and processed for immunohistochemistry. Sections were counterstained with haematoxylin. Positively stained cells are indicated by arrowheads. (Magnification, 200×)