Investigating the role of various extracellular matrix in androgenetic alopecia: Insights from immunostaining and quantitative analysis – A pilot study

Abstract Androgenetic alopecia (AGA) is the most common hair loss, characterized by miniaturization of hair follicles, shortened anagen, and prolonged telogen phases. Clinically, distinct patterns of hair loss distribution are evident between males and females. The pathogenesis of AGA is considered a mutual interplay of genetic, hormonal, and environmental factors. Mechanical properties of the scalp, for example, skin stiffness, have also been proposed as an important factor. To date, no comprehensive study has been conducted to demonstrate the density and distribution of various extracellular matrix (ECM) components at different dermal depths in AGA. To address this knowledge gap, we conducted immunohistochemical staining in patients with pattern hair loss to analyze the distribution of ECM components. Our findings reveal distinct distribution patterns of collagen I, collagen III, and elastin fibers within different dermal layers in male and female AGA cases. Notably, the intensity of elastin staining was significantly increased in all dermal layers in the male AGA skin, compared to the normal scalp skin. In summary, our study highlights the significance of ECM components in both male and female AGA.