Particulate Matter Exposure Induces Maternal Scalp Hair Loss After Birth in C57/B6 Mouse via Alteration of Inflammatory and Apoptotic Pathways

This study investigates the impact of PM2.5 exposure on postpartum hair loss in a mouse model, revealing that PM2.5 exposure leads to significant postpartum scalp hair loss. The study found that PM2.5 exposure alters inflammatory and apoptotic pathways, with increased expression of inflammatory markers (IL-6, IL-1β, TNF-α, p-NF-κB) and apoptotic markers (Caspase-3, BAX/Bcl-2 ratio) in exposed mice. Additionally, PM2.5 exposure resulted in morphological changes in scalp tissues, such as thickened stratum corneum and decreased hair follicle numbers. In vitro experiments with HaCaT cells and fibroblasts showed similar pathway alterations. The study concludes that PM2.5 exposure exacerbates postpartum hair loss by downregulating progesterone receptors and reducing hair follicle stem cell populations.