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

This systematic umbrella review and meta-meta-analysis aims to explore the role of hair follicle fibroblasts, specifically dermal papilla and dermal sheath cells, in the development of androgenetic alopecia (AGA). The study focuses on how these fibroblasts are involved in androgen signal transduction, paracrine signaling, stem cell niche disruption, inflammation, and fibrosis. The researchers anticipate finding evidence that dermal papilla cells have high levels of androgen receptors and 5α-reductase, leading to a shift in signaling balance that affects hair growth. Dysfunctional fibroblasts are expected to alter their secretory profiles, disrupt stem cell activation, and promote perifollicular fibrosis. The review will also summarize current therapies that indirectly affect fibroblasts and discuss emerging strategies that directly target these cells, aiming to fill research gaps and guide future therapeutic developments for AGA.