Rippa Alexandra, Terskikh Vasily, Nesterova Anastasia, Vasiliev Andrey, Vorotelyak Ekaterina
Department of Regenerative Medicine, Pirogov Russian National Research Medical University, 1 Ostrovityanova, Moscow, 117997, Russian Federation.
Histochem Cell Biol. 2015 May;143(5):481-96. doi: 10.1007/s00418-014-1291-1. Epub 2014 Nov 4.
Mice with skin and hair follicle (HF) defects are common models of human skin disorders. A mutant strain with the we/we wal/wal genotype develops alopecia. We found the hair shaft structure in the pelage of mutant mice to have significant defects. Although these mice lose their hair at 21 days, a label-retaining cell population persists in HFs until at least day 54. Depilation-induced anagen was accomplished in we/we wal/wal mutants but the resulting hair shafts were short and extremely deformed. Serious abnormalities in epidermis stratification and HF morphogenesis exist in we/we wal/wal homozygous E18.5 embryos. There were significantly fewer HF primordia in this mutant compared with wild type. We discovered specific structures, identified as invalid placodes, positive for ectodysplasin A1 receptor, nuclear β-catenin, and LEF1, which failed to invaginate, produced a double basal-like layer of epidermal cells, and lacked cylindrical keratinocytes. Specification of dermal papillae (DP) was impaired, and the papillary dermis expressed alkaline phosphatase and LEF1. We also detected DP-like groups of intensively stained cells in the absence of visible signs of folliculogenesis in the epidermis. We showed differentiation disturbances in the mutant embryonic E18.5 epidermis and HFs: The cornified layer was absent, the width of the spinous layer was reduced, and HFs lacked LEF1-positive precortex cells. In this study, we used a very interesting and useful mouse model of alopecia. The presence of symptoms of skin disorders in we/we wal/wal murine embryos correlates with the postnatal skin phenotype. This correlation may help to evaluate reasons of alopecia.
皮肤和毛囊（HF）存在缺陷的小鼠是人类皮肤疾病的常见模型。具有we/we wal/wal基因型的突变品系会出现脱发症状。我们发现突变小鼠体表的毛干结构存在明显缺陷。尽管这些小鼠在21天时开始脱毛，但毛囊中存在一个标记保留细胞群体，至少持续到第54天。在we/we wal/wal突变体中可实现脱毛诱导的生长期，但长出的毛干短且极度变形。在we/we wal/wal纯合E18.5胚胎中，表皮分层和毛囊形态发生存在严重异常。与野生型相比，该突变体中的毛囊原基明显减少。我们发现了一些特定结构，被确定为无效基板，对外胚层发育不良蛋白A1受体、核β-连环蛋白和淋巴样增强因子1呈阳性，这些结构无法内陷，产生了双层基底样表皮细胞层，且缺乏柱状角质形成细胞。真皮乳头（DP）的特化受损，乳头真皮表达碱性磷酸酶和淋巴样增强因子1。在表皮没有明显毛囊发生迹象的情况下，我们还检测到了密集染色的DP样细胞群。我们发现突变胚胎E18.5的表皮和毛囊存在分化紊乱：角质层缺失，棘层宽度减小，毛囊缺乏淋巴样增强因子1阳性的前皮质细胞。在本研究中，我们使用了一种非常有趣且有用的脱发小鼠模型。we/we wal/wal小鼠胚胎中皮肤疾病症状的存在与出生后的皮肤表型相关。这种相关性可能有助于评估脱发的原因。
