Fig. 4.

DP cells preconditioning promotes hair induction in mice. (a) H&E staining of the wound sites showing the formation of structures morphologically resembling HFs and SGs 6 weeks after grafting CM-precultured DP cells and KCs in immune-deficient mice. (b) Hair bulb formation (dashed circle) and hair shaft elongation (arrows) were observed in one of the seven co-grafted animals. (c) DP cells grafted alone led to the formation of less complex and less abundant structures which (d) were not observed in controls (dotted lines limit the wound area). (e) High magnification image of the recreated structures of the experimental condition demonstrating their complexity, including the presence of a differentiated core morphologically alike to hair shafts (arrowheads). (f) The folliculoid structures featured distinct epithelial layers, including (g) one layer expressing the IRS marker K25, (h) a layer co-expressing both K15 and K14 or layers only positive for K14. Arrowheads indicate K14 and K15 co-expression in HF-like (white) and SG-like structure (yellow). (i)K10 expression was limited to the skin epithelium, whereas (j) the sebocyte marker FABP4 was expressed in the structures resembling SG. Scale bars are 500 µm for (a-c), 100 µm for (d) and 50 µm for (e-j).