Faculty Opinions Recommendation of Targeted Skin Overexpression of the Mineralocorticoid Receptor in Mice Causes Epidermal Atrophy, Premature Skin Barrier Formation, Eye Abnormalities, and Alopecia

In this study, the authors developed a mouse model with conditional doxycycline-inducible overexpression of the human mineralocorticoid receptor (MR) in keratinocytes to explore MR's role in the skin. They found that overexpression of MR from birth for 4 months led to progressive alopecia and hair follicle cysts, which were reversible upon cessation of doxycycline. The abnormalities were specific to hair follicles, as other skin structures remained normal. The study suggested that these effects might be due to increased glucocorticoid signaling, as the enzyme 11bHSD2, which confers MR specificity, is not present in the epidermis. This model provides a tool for further investigation into non-classical MR signaling in skin and hair follicle physiology.