Fig. 5.

Induction of human hair growth in immune-deficient nude mice. a, b Engraftment of high follicle-density HSCs onto immune-deficient nude mice led to hair growth in the grafts after 4–6 weeks (b), which was not observed in the HSCs prepared with FB aggregates as a control (a) (n = 10; five biological and two technical replicates per each condition). c, d Human-specific nuclear staining (green) indicated that the de novo hair follicles marked with K71 (c) (HF boundaries circled in dashed line) and DPCs marked with VCAN (d) are comprised of human cells (DPs circled in dashed line). e Low magnification image of the explanted grafts revealed the boundaries (dashed line) between the mouse and human tissues as marked by the human nuclear staining. Bright-field microscopy of unpigmented terminal human hair (f), engineered human hair in the grafts (g), and unpigmented human vellus hair (h) showed morphological similarities between human hair and engineered hair. i PCR was performed with two sets of primers specific to human and mouse cells using the RNA of the laser captured hair follicles from the grafts in comparison to whole grafts, mouse skin, and cultured human KCs. Scale bars for (a, b), (c−e) and (f−h) are 2 mm, 200 µm, and 50 µm respectively