An Underlying Mechanism of Hair Loss in Acrodermatitis Enteropathica

The study explored the causes of hair loss in acrodermatitis enteropathica by examining zinc-adequate (ZA) and zinc-deficient (ZD) mice. It was found that ZD mice had sparser hair coats and their hair remained in the telogen stage, showing a disrupted hair cycle. These mice also did not experience hair regrowth after depilation, unlike ZA mice. Zinc supplementation, however, was able to restore the hair cycle and regrowth in ZD mice. The researchers discovered a lack of tissue-nonspecific alkaline phosphatase (TNAP) in the dermal papilla and P-cadherin in hair germ cells of ZD mice, with TNAP being a zinc-dependent enzyme essential for hair regeneration. Additionally, there was a downregulation of growth factor mRNA expression (pdgfa, pdgfß, fgf7, fgf10) in ZD mice, indicating that zinc deficiency leads to reduced production of these factors, decreased TNAP activity, and ultimately, impaired hair cycle and regrowth.