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Molecular basis of keratinocyte desmosomes and acantholysis using imunoelectron microscopy

使用免疫电子显微镜研究角质形成细胞桥粒和棘层松解的分子基础

基本信息

批准号：
15591192
负责人：
ISHIKO Akira
金额：
$ 2.24万
依托单位：
Keio University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2003
资助国家：
日本
起止时间：
2003 至 2004
项目状态：
已结题

项目摘要

Pemphigus vulgaris(PV) is an autoimmune blistering skin disease caused by binding of autoantibodies to the desmosomal desmoglein 3 (Dsg3). Although it has been confirmed that the autoantibodies themselves are pathogenic and plays a central role of this disease, the mechanism of blister formation in the epidermis alter binding autoantibodies to the autoantigen has not been clarified, yet. In this project, we have investigated the molecular changes in the desmosomes using PV model mice, which produce anti-Dsg3 autoantibodies as well as clinical, histological and immunological phenotype of PV, Dsg3 knockout(-/-) mice, which produce clinical and histological phenotype mimicking PV, and respective control mice. Desmosomal components including Dsg 1, desmocollin(Dsc) 1, Dsc3, plakoglobin(PG), plakophilin 1(Pp1), desmoplakin (DP) were immunolocalized using post-embedding immunogold electron microscopy in each mouse. All the labeling was measured in terms of distance from plasma membrane and number of labeling per desmosome, and statistically analyzed. As results, in Dsg3 -/- mice, the localization of DP shifted 11 nm toward intracellular direction, suggesting a close relationship between Dsg3 and DP. In addition, number of PG in Dsg3 -/- mice decreased significantly. This might be due to the disturbed recruitment of PG in desmosomal formation by lacking Dsg3. The small shift of DP might be caused by the decrease of PG, which is a major ligand of DP to the desmosomal attachment plaque.On the other hand, in PV models mice, DP shifted 24 nm, more markedly than Dsg3 -/- mice, but the number of PG labeling showed no significant changes. This suggests that binding of autoantibody to the Dsg3 may transfer some signals to the cytoplasm and keratin retraction may occur accompanying DP. In conclusion, we have shown that molecular mechanism of blister formation underlying PV model mice and Dsg3 -/- mice is different and that cytoplasmic change did occur after autoantibody binding.

寻常型天疱疮（Pemphigus vulgaris， PV）是一种自身免疫性起泡性皮肤病，由自身抗体与桥粒蛋白3 （Dsg3）结合引起。虽然已证实自身抗体本身具有致病性，并在该疾病中起核心作用，但表皮中形成水疱的机制改变了自身抗体与自身抗原的结合，尚不清楚。在本项目中，我们使用产生抗Dsg3自身抗体的PV模型小鼠以及PV的临床、组织学和免疫学表型，产生临床和组织学表型模仿PV的Dsg3敲除（-/-）小鼠和各自的对照小鼠，研究桥粒的分子变化。利用包埋后免疫金电镜对每只小鼠的桥粒组成物dsg1、desmocolin (Dsc) 1、Dsc3、plakhemoglobin （PG）、plakophilin 1（Pp1）、desmoplakin （DP）进行免疫定位。以离质膜的距离和每个桥粒的标记数测量所有标记，并进行统计分析。结果显示，在Dsg3 -/-小鼠中，DP的定位向细胞内方向移动了11 nm，表明Dsg3与DP有密切的关系。此外，Dsg3 -/-小鼠PG数量明显减少。这可能是由于缺乏Dsg3干扰了PG在桥粒形成中的募集。DP的小位移可能是由于PG的减少引起的，PG是DP在桥粒体附着斑块上的主要配体。另一方面，在PV模型小鼠中，DP移位24 nm，比Dsg3 -/-小鼠更明显，但PG标记的数量没有明显变化。这表明自身抗体与Dsg3的结合可能会将一些信号传递到细胞质中，并可能伴随DP发生角蛋白收缩。总之，我们已经证明PV模型小鼠和Dsg3 -/-小鼠水疱形成的分子机制是不同的，并且自身抗体结合后确实发生了细胞质改变。