Overexpression of miR‐122 promotes apoptosis of dermal papilla cells by directly targeting IGF1R in androgenetic alopecia.

Androgenetic alopecia (AGA) is the most common pattern of hair loss resulting from the effects of androgen on hair follicles. MicroRNAs (miRs) serve imperative roles in the regulation of many biological processes of hair follicles. However, the exact molecular mechanism of AGA remains to be elucidated. In the present study, we found miR‐122, which is mainly recognized as a tumor suppressor, was highly overexpressed in the bulb of balding hair follicles in comparison with nonbalding ones in AGA. Moreover, miR‐122 induces apoptosis of human dermal papilla cells (hDPCs) with miR‐122 mimics in vitro, and the expression of insulin‐like growth factor 1 receptor (IGF1R) in hDPCs was reduced following upregulation of miR‐122. Mechanistically, dual‐luciferase reporter assay confirmed that miR‐122 directly targeted the 3′‐untranslated region of IGF1R. These findings suggested that upregulation of miR‐122 induces apoptosis, potentially via the repression of IGF1R in hDPCs of AGA, providing a novel insight into the potential pathological mechanism of miR‐122 in AGA DPCs. [ABSTRACT FROM AUTHOR]