Figure 1. Topical application of PAO induces erythema, edema, micro-vesicants (mv) and inflammatory cytokines in Ptch1+/−/SKH-1 mouse skin.
Dorsal skin of mice was treated topically with either 30 μL of ethanol (vehicle) or PAO (100 μg/mouse) in 30 μL ethanol on the dorsal skin area of 1.6 × 1.6 cm2 and animals were observed for PAO-induced effects/lesions at 0–16 h. (A) Mouse skin photographs showing time-dependent gross changes. (B) Effects of PAO on the development of erythema and edema using draize score as described in Supplementary Table S1. (C) Histochemical analysis of the skin sections (H&E) excised at various time intervals (0–16 h) following PAO treatment. Arrows show mv formation characterized by epidermal and dermal separation. (D) Time-dependent effects of PAO on size and number (D-II) of mv formation. (E) Histograms showing real time PCR analysis of pro-inflammatory cytokines. (F) Western blot analysis of IL-1β. Histogram showing dentiometric analysis of western blots. Data are expressed as mean ± SEM. *P < 0.05, **P < 0.01 and ***P < 0.001 when compared to controls (0 h).