Fig. 5

Rarα is required for baseline and dsRNA augmented WIHN. a, b Chemical inhibition of RARs (BMS493) decreases RA (left)- and Poly (I:C) (0.1 µg per ml) (right)-induced KRT15 and KRT19 expression in human scalp keratinocytes as detected by western blot with quantitation (n = 3 independent experiments, *P < 0.05, paired Student t-test). c Immunostaining of KRT15 (green), KRT19 (red) and nuclei (DAPI; blue). * Represents co-stained cells of KRT15 and KRT19. White scale bar = 100 µm. d BMS493 inhibited Krt15 and Wnt7b expression in healing wounds as detected by immunostaining. White dashed lines and arrows separate normal and wounded areas. White arrow heads indicate hair follicles (HF) in normal skin. White scale bar = 100 µm. e, BMS493 treatment inhibited WIHN, in untreated or Poly (I:C) (50 µl; 5 µg per mouse)-treated WT mice. Red dashed lines indicate area of WIHN. (n = 5 independent animals, *P < 0.05, paired Student t-test). f–h Conditional epithelial specific deletion of Rara (g; n = 4-9 independent animals, *P < 0.05, paired Student t-test) and global deletion of Rara (h; n = 4–11 independent animals, *P < 0.05, paired Student t-test) both inhibit baseline and Poly (I:C) (50 µl; 5 µg per mouse) augmented WIHN, while epithelial deletion of Rarg has minimal effects (f). Red dashed lines indicate area of WIHN. i Rejuvenating fractional ablative CO₂ laser induces RA synthesis in human scalp (n = 3 independent human samples, *P < 0.05, paired Student t-test; bottom). Clinical photos (top) and H&E histology (middle) of human subjects before and after CO₂ laser treatment. Black scale bar = 1 mm. Data are means ± SEM