Figure 5.

Indirubin promotes wound healing via the activation of JNK signaling though PXR. (A) Unscratched or scratched HaCaT cells were further treated with DMSO (0.1%) or indirubin (100 nM) for 6 h and assessed for the phosphorylation of JNK. Representative images (left) and relative pJNK/JNK ratio (right) are shown (n = 3). Cropped blots are displayed and full-length blots are shown in Supplementary Fig. S6. (B,C) HaCaT cells were scratched and treated with DMSO (0.1%) or indirubin (100 nM) in the absence or presence of JNK inhibitor SP600125 (40 μM). Representative images (B, left), relative pJNK/JNK and pc-jun/c-jun ratios measured by western blotting (B, right, n = 3), and relative wound areas (C, n = 18) are shown. The statistical significances between DMSO and indirubin in the absence of SP600125 are indicated with purple asterisks in (C). Cropped blots are displayed and full-length blots are shown in Supplementary Fig. S8. (D,E) HaCaT cells were transfected with control or PXR siRNA. The transfected cells were then scratched or left unscratched, and were further treated with DMSO (0.1%) or indirubin (100 nM). At 6 h post-treatment, cells were harvested and the phosphorylation status of JNK was assessed by western blotting. Representative images (D), the relative pJNK/JNK ratio (E, upper), and the relative PXR/β-Actin ratio (E, lower) are shown (n = 3). Cropped blots are displayed and full-length blots are shown in Supplementary Fig. S9. The samples derive from the same experiment and that blots were processed in parallel for (A,B,D), respectively. Data are presented as mean ± SD (C) or SEM (A,B,E). *P < 0.05, **P < 0.01, and ***P < 0.001.