Immunomolecular mapping of adherens junction and desmosomal components in normal human epidermis
Immunomolecular mapping of adherens junction and desmosomal components in normal human epidermis
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DOI：
10.1111/j.0906-6705.2003.00083.x
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发表时间：
2003-12-01
影响因子：
3.6
通讯作者：
Shimizu, H
中科院分区：
文献类型：
--
作者：
Ishiko, A;Matsunaga, Y;Shimizu, H
粘附连接（AJs）是细胞-细胞和细胞-基质连接，已知由与f-肌动蛋白细胞骨架相连的跨膜和细胞质成分组成。虽然AJs的存在已被证实存在于正常的人类表皮中，但先前的研究免疫定位AJs相关抗原一直存在争议。本研究的目的是对正常人类表皮角质形成细胞中AJs及其成分与桥粒的关系进行更精确的分子定位。使用电子显微镜（EM）方法来最佳固定质膜，AJ结构通常被视为两个角质形成细胞之间的细胞间隙变窄，与桥粒和间隙连接不同。这种结构在上表皮比在基底层更常见。免疫金电镜显示，在桥粒区域缺乏AJ成分（E-cadherin和β -catenin），但在桥粒间区域的紧密膜关联部位存在AJ成分。相反，桥粒组分血小板红蛋白和嗜血小板蛋白1仅局限于桥粒的外部附着斑块。这些结果进一步证实，AJs具有与桥粒不同的分子组成和分布，并且它们定期发生在沿角质形成细胞质膜的桥粒之间，提供了替代的细胞-细胞粘附机制。
Adherens junctions (AJs) are cell-cell and cell-matrix junctions that are known to comprise of transmembrane and cytoplasmic components linked to the f-actin cytoskeleton. Although the presence of AJs has been confirmed in normal human epidermis, previous studies immunolocalizing AJ-related antigens have been controversial. The purpose of this study was to produce a more precise molecular mapping of AJs and their constituents in relation to desmosomes in normal human epidermal keratinocytes. Using an electron microscopy (EM) method to optimally fix plasma membranes, AJ structures were typically seen as a narrowing of the intercellular space between two keratinocytes that was distinct from desmosomes and gap junctions. Such structures were consistently found more frequently in the upper epidermis than in the basal layer. Immunogold electron microscopy showed an absence of the AJ components (E-cadherin and beta-catenin) from desmosomal areas but they were present at interdesmosomal areas at sites of close membrane association. Conversely, the desmosomal components plakoglobin and plakophilin 1 were restricted only to the outer attachment plaque of the desmosome. These results further confirm that AJs have a distinct molecular composition and distribution from desmosomes and that they regularly occur between desmosomes along the keratinocyte plasma membrane to provide alternative cell-cell adhesion mechanisms.