Epidermal expression of Lgr6 is dependent on nerve endings and Schwann cells.

Lgr5/6 proteins are stem cell markers in various tissues. However, what determines their restricted expression pattern in these tissues remains unknown. We found that in skin, Lgr6 is not only expressed in the central isthmus, directly above the hair follicle bulge cells as reported previously, but also in the interfollicular epidermis. Lgr6 expression in skin is highly correlated with the innervation sites of cutaneous nerves. In the hair follicle, Lgr6 closely localizes with the surrounding nerve endings and their corresponding Schwann cells throughout the entire hair cycle. Furthermore, ablation of cutaneous nerves leads to degeneration of Schwann cells and diminished expression of Lgr6. Our results demonstrate that the nerve endings/Schwann cells control Lgr6 expression in skin, implying that they play a role in regulation of skin epithelial cells.