The Central Role of Fibroblasts in Androgenic Alopecia: A Systematic Umbrella Review and Meta-Meta-Analysis

This systematic review investigates the role of fibroblasts, especially dermal papilla cells, in androgenetic alopecia (AGA). It examines how androgen exposure influences fibroblast functions and molecular pathways, including AR/5α-reductase expression and signaling pathways like Wnt/β-catenin and TGF-β/BMP. The study suggests that androgens may suppress Wnt/β-catenin signaling, enhance TGF-β/BMP signaling, and modify secretory profiles, contributing to hair loss. The review includes in vitro, animal, and human tissue studies but does not conduct a meta-analysis due to expected heterogeneity. The findings aim to highlight research gaps and guide future studies on fibroblast-mediated mechanisms in AGA.