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 (PV) 是一种自身免疫性水疱性皮肤病，由自身抗体与桥粒桥粒糖蛋白 3 (Dsg3) 结合引起。尽管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，但表皮中水疱形成改变自身抗体与自身抗原结合的机制尚未阐明。在本项目中，我们研究了使用产生抗Dsg3自身抗体的PV模型小鼠桥粒的分子变化，以及产生临床和组织学抗体的PV、Dsg3敲除(-/-)小鼠的临床、组织学和免疫学表型。表型模仿PV，以及各自的对照小鼠。使用包埋后免疫金电子显微镜对每只小鼠的桥粒成分进行免疫定位，包括 Dsg 1、桥粒胶蛋白 (Dsc) 1、Dsc3、斑珠蛋白 (PG)、亲斑蛋白 1 (Pp1)、桥粒斑蛋白 (DP)。所有标记均根据距质膜的距离和每个桥粒的标记数量进行测量，并进行统计分析。结果，在Dsg3 -/- 小鼠中，DP的定位向细胞内方向移动了11 nm，表明Dsg3和DP之间存在密切关系。此外，Dsg3 -/- 小鼠中的PG数量显着减少。这可能是由于缺乏 Dsg3 导致桥粒形成中 PG 的募集受到干扰。 DP的小幅移动可能是由于PG的减少引起的，PG是DP与桥粒附着斑块的主要配体。另一方面，在PV模型小鼠中，DP移动了24 nm，比Dsg3 -/- 小鼠更明显，但PG标记数量没有明显变化。这表明自身抗体与 Dsg3 的结合可能会将一些信号转移到细胞质，并且伴随 DP 可能会发生角蛋白收缩。总之，我们发现PV模型小鼠和Dsg3 -/- 小鼠水疱形成的分子机制不同，并且自身抗体结合后确实发生了细胞质变化。