Onishi Saki, Baba Yuta, Yokoi Fumika, Ide Kaori, Ohyama Manabu, Nishifuji Koji
Laboratory of Veterinary Internal Medicine, Division of Animal Life Science, Graduate School, Tokyo University of Agriculture and Technology, Tokyo, 183-8509, Japan.
Department of Dermatology, Kyorin University School of Medicine, Tokyo, 181-8611, Japan.
Vet Dermatol. 2019 Oct;30(5):365-e107. doi: 10.1111/vde.12771. Epub 2019 Jul 12.
Nestin, which was originally described as a neural crest stem cell marker, is known to be expressed in bulge follicle cells of human, canine and murine anagen hairs. However, the capacity of nestin-expressing cells to differentiate into the components of the hair follicle or the epidermis has been insufficiently investigated.
HYPOTHESIS/OBJECTIVES: To determine whether nestin-expressing cells are capable of differentiating into keratinocytes.
ANIMALS/MATERIALS: A double-transgenic mouse line Nes-Cre/CAG-CAT-EGFP, in which enhanced green fluorescent protein (EGFP) is expressed upon Cre-based recombination driven by the nestin promoter.
The tissue distribution of EGFP and nestin cells in the skin of the mouse line was analysed by immunofluorescence and immunohistochemical analyses.
EGFP cells were recognized in the outer epithelial cell layers of anagen and telogen hair follicles, but rarely seen in the interfollicular epidermis. The EGFP cells in the outer layers of the hair follicles coexpressed keratin 14, a marker of the outer root sheath (ORS) keratinocytes, but not trichohyalin granules, an inner root sheath keratinocyte cell marker. Immunostaining for nestin failed to detect its expression in the majority of hair follicle epithelial cells, suggesting that the EGFP cells in the ORS were derived from nestin-expressing progenitor cells that had become further committed along the epithelial cell lineage, where nestin is no longer expressed.
These results suggest that progenitor cells that differentiate into ORS keratinocytes are distinct from those for other hair follicle or epidermal components and provide implications for regenerative medicine and the molecular classification of hair follicle tumours.
巢蛋白最初被描述为神经嵴干细胞标志物，已知其在人、犬和小鼠生长期毛发的毛囊隆突细胞中表达。然而，表达巢蛋白的细胞分化为毛囊或表皮成分的能力尚未得到充分研究。
假设/目的：确定表达巢蛋白的细胞是否能够分化为角质形成细胞。
动物/材料：一种双转基因小鼠品系Nes-Cre/CAG-CAT-EGFP，其中增强型绿色荧光蛋白（EGFP）在巢蛋白启动子驱动的基于Cre的重组后表达。
通过免疫荧光和免疫组织化学分析对该小鼠品系皮肤中EGFP和巢蛋白细胞的组织分布进行分析。
在生长期和休止期毛囊的外上皮细胞层中可识别出EGFP细胞，但在毛囊间表皮中很少见到。毛囊外层的EGFP细胞共表达角蛋白14，这是外根鞘（ORS）角质形成细胞的标志物，但不表达内根鞘角质形成细胞标志物毛透明蛋白颗粒。巢蛋白免疫染色未能在大多数毛囊上皮细胞中检测到其表达，这表明ORS中的EGFP细胞来源于表达巢蛋白的祖细胞，这些祖细胞已沿着上皮细胞谱系进一步分化，在此过程中巢蛋白不再表达。
这些结果表明，分化为ORS角质形成细胞的祖细胞与其他毛囊或表皮成分的祖细胞不同，这为再生医学和毛囊肿瘤的分子分类提供了启示。
