Targeting Expression of the Human Vitamin D Receptor to the Keratinocytes of Vitamin D Receptor Null Mice Prevents Alopecia

The study demonstrated that targeting the expression of the human vitamin D receptor (VDR) specifically to keratinocytes in VDR null mice prevented the development of alopecia. VDR null mice typically developed several conditions, including alopecia, due to a defect in anagen initiation. By generating transgenic mice that expressed the human VDR under the control of the keratin 14 promoter, researchers were able to prevent alopecia in these mice. The hair follicle keratinocytes in these transgenic mice showed an enhanced proliferative response during anagen initiation compared to control littermates, indicating that VDR expression in keratinocytes was crucial for maintaining a normal hair cycle.