Odawara Mikiko, Mezaki Minori, Yoshimura Tomohisa, Takaoka Akiko, Oda Fumino, Saeki Hidehisa, Funasaka Yoko
R&D Laboratories, Self-Medication, Taisho Pharmaceutical Co. Ltd., Saitama, Japan.
Department of Dermatology, Nippon Medical School, Tokyo, Japan.
J Dermatol. 2024 Mar;51(3):453-457. doi: 10.1111/1346-8138.17034. Epub 2024 Jan 13.
Senile lentigo (SL) is a pigmentary disorder associated with disrupted epidermal turnover. Trace minerals in the skin are known to regulate keratinocyte proliferation and differentiation. To clarify the role of iron in SL, we compared the expression of molecules related to iron metabolism between SL lesion (lesion) and the surrounding normal skin (nonlesion). Our results revealed that proteins involved in iron uptake and utilization such as transferrin receptor 1, iron regulatory protein 1, mitoferrin 1, and divalent metal transporter 1 were expressed in the lower epidermis in the nonlesion, while expression of them was also observed in the upper epidermis in the lesion. Ferroportin (FPN), involved in iron export, was expressed in the upper epidermis in the nonlesion, but was only scarcely expressed in the upper epidermis in the lesion. Hepcidin, which promotes FPN degradation, was expressed in the lower epidermis in the nonlesion; however, its expression was also observed in the upper epidermis in the lesion. These changes in the expression of molecules involved in iron uptake/export/utilization might reflect the altered iron utilization state in SL, resulting in disruption of keratinocyte differentiation and disturbing epidermal turnover. Our results suggest that the metabolism of iron in keratinocytes in SL differs from that in the normal epidermis, and these changes could be associated with the abnormal epidermal turnover and decreased melanin excretion in SL.
老年雀斑（SL）是一种与表皮更替紊乱相关的色素沉着性疾病。已知皮肤中的微量元素可调节角质形成细胞的增殖和分化。为了阐明铁在SL中的作用，我们比较了SL皮损（皮损）和周围正常皮肤（非皮损）之间与铁代谢相关分子的表达。我们的结果显示，参与铁摄取和利用的蛋白质，如转铁蛋白受体1、铁调节蛋白1、线粒体铁转运蛋白1和二价金属转运体1，在非皮损的下表皮中表达，而在皮损的上表皮中也观察到它们的表达。参与铁输出的铁转运蛋白（FPN）在非皮损的上表皮中表达，但在皮损的上表皮中仅少量表达。促进FPN降解的铁调素在非皮损的下表皮中表达；然而，在皮损的上表皮中也观察到其表达。铁摄取/输出/利用相关分子表达的这些变化可能反映了SL中铁利用状态的改变，导致角质形成细胞分化紊乱并扰乱表皮更替。我们的结果表明，SL中角质形成细胞的铁代谢与正常表皮不同，这些变化可能与SL中表皮更替异常和黑色素排泄减少有关。
