Study of Gene Expression Alteration in Male Androgenetic Alopecia: Evidence of Predominant Molecular Signaling Pathways

This document is a compilation of several studies that analyzed gene expression in male androgenetic alopecia (AGA) patients to identify molecular signaling pathways involved in hair loss. The studies found evidence of immune and inflammatory responses being strongly up-regulated, as well as an inhibition of certain signaling pathways and an alteration of vitamin D biosynthesis. The Wnt/β-catenin signaling pathway, which plays an important role in hair follicle development and maintenance, was inhibited in AGA patients. The dysregulated expression of proopiomelanocortin (POMC) and lower expression of CYP27B1 in AGA subjects were also identified. The studies provide compelling evidence for distinct molecular events contributing to alopecia that may pave the way for new therapeutic approaches.