Department of Zoology, Panjab University, Chandigarh, India.
Department of Dermatology, Fiona Stanley Hospital, Perth, Western Australia, Australia.
Int J Dermatol. 2018 May;57(5):559-565. doi: 10.1111/ijd.13960. Epub 2018 Mar 8.
Idiopathic guttate hypomelanosis (IGH) is a pigmentary disorder of unknown pathogenesis characterized by small discrete white macules. In the skin, epidermal melanin unit between melanocytes and keratinocytes is responsible for melanin synthesis and equal distribution of melanin pigment.
Therefore, this study was designed to check the role of melanocytes in the pathogenesis of IGH.
For this study, six IGH patients and six controls were enrolled. Melanin content was checked in the skin sections and in the cultured melanocytes. Senescence was checked in the lesional skin of IGH patients by comparing the mRNA and protein expression of senescence markers p16, hp1, and p21.
Cultured melanocytes from the IGH patients showed morphological changes in comparison to the control melanocytes. Melanocytes from IGH patients were bigger in size with very small and retracted dendrites as compared to the control melanocytes. Melanin accumulation was more in the IGH patients as compared to the controls. Our results showed that expression of p16, p21, and hp1 was significantly higher in lesional skin of IGH patient as compared to healthy controls.
This study revealed large-sized melanocytes with small and retracted dendrites in IGH patients. Accumulation of more melanin in the IGH melanocytes might be due to problem in the transfer of melanin from melanocytes to keratinocytes. Accumulation of melanin can lead to the senescence in the melanocytes of IGH patients.
特发性点状色素减退症（IGH）是一种病因不明的色素障碍性疾病，其特征为小而离散的白色斑片。在皮肤中，黑素细胞与角质形成细胞之间的表皮黑素单位负责黑色素的合成和黑色素色素的均匀分布。
因此，本研究旨在检查黑素细胞在 IGH 发病机制中的作用。
本研究纳入了 6 名 IGH 患者和 6 名对照者。检查了皮肤切片和培养的黑素细胞中的黑色素含量。通过比较 IGH 患者皮损中衰老标志物 p16、hp1 和 p21 的 mRNA 和蛋白表达，检查 IGH 患者皮损中的衰老情况。
与对照组相比，IGH 患者培养的黑素细胞形态发生改变。IGH 患者的黑素细胞体积较大，与对照组相比，树突非常小且回缩。IGH 患者的黑色素积累比对照组更多。我们的结果表明，IGH 患者皮损中 p16、p21 和 hp1 的表达明显高于健康对照组。
本研究显示 IGH 患者的黑素细胞体积较大，树突较小且回缩。IGH 黑素细胞中黑色素的积累可能是由于黑色素从黑素细胞向角质形成细胞转移出现问题所致。黑色素的积累可导致 IGH 患者黑素细胞衰老。
