An Underlying Mechanism of Hair Loss in Acrodermatitis Enteropathica

The study investigated the mechanisms of hair loss in acrodermatitis enteropathica (AE) using zinc-adequate (ZA) and zinc-deficient (ZD) mice. Although ZD mice did not show obvious hair loss, their hair was sparser compared to ZA mice, and their hair cycle was disrupted, remaining in the telogen stage. Depilation-induced anagen initiation was absent in ZD mice but restored with zinc supplementation, indicating reversible impairment of hair cycle functions due to zinc deficiency. Dermal papilla (DP) cells in ZD mice were atrophic and lacked tissue-nonspecific alkaline phosphatase (TNAP) activity, a zinc-dependent enzyme crucial for hair regeneration. Additionally, platelet-derived growth factor (PDGF) expression was significantly reduced in ZD dermis, suggesting that zinc deficiency led to decreased PDGF production and downregulated TNAP activity, causing hair cycle disruption and impaired hair regeneration.