Development of a new drug delivery method by the use of occludin molecules

利用occludin分子开发新的药物递送方法

基本信息

批准号：
10557011
负责人：
TSUKITA Shoichiro
金额：
$ 7.81万
依托单位：
KYOTO UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
1998
资助国家：
日本
起止时间：
1998 至 1999
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-10557011/
关键词：
occludin tight junction embryonic stem cell ZO-1 embryoid body paracellular pathway drug delivery barrier ノックアウトドミナントネガティブ内皮細胞阻害ペプチド

项目摘要

Occludin is the only known integral membrane protein of tight junctions (TJ), and is now believed to be directly involved in the barrier and fence functions of TJ. Occludin-deficient embryonic stem (ES) cells were generated by targeted disruption of both alleles of the occludin gene. When these cells were subjected to suspension culture, they aggregated to form simple, and then cystic embryoid bodies (EBs) with the same time course as EB formation from wild-type ES cells. Immunofluorescence microscopy and ultrathin section electron microscopy revealed that polarized epithelial (visceral endoderm-like) cells were differentiated to delineate EBs not only from wild-type but also from occludin-deficient ES cells. Freeze fracture analyses indicated no significant differences in number or morphology of TJ strands between wild-type and occludin-deficient epithelial cells. Furthermore, ZO-1, a TJ-associated peripheral membrane protein, was still exclusively concentrated at TJ in occludin-deficient epithelial cells. In good agreement with these morphological observations, TJ in occludin-deficient epithelial cells functioned as a primary barrier to the diffusion of a low molecular mass tracer through the paracellular pathway. These findings indicate that there are as yet unidentified TJ integral membrane protein (s) which can form strand structures, recruit ZO-1, and function as barrier without occludin.

Occludin是紧密连接（TJ）的唯一已知的积分膜蛋白，现在据信直接参与TJ的屏障和围栏功能。通过靶向闭塞基因的两个等位基因的靶向破坏，产生闭合缺陷的胚胎干细胞（ES）细胞。当这些细胞受到悬浮培养的情况时，它们汇总形成简单，然后形成与野生型ES细胞相同的时间过程的囊性胚胎体（EB）。免疫荧光显微镜和超薄截面电子显微镜表明，极化上皮（内脏内胚层状）细胞不仅从野生型中，而且还从闭塞性缺乏的ES细胞中分化为EBS。冻结分析表明，野生型和缺陷型上皮细胞之间TJ链数的数量或形态没有显着差异。此外，ZO-1是一种与TJ相关的周围膜蛋白，在闭塞性上皮细胞中仍然只集中在TJ上。与这些形态学观察非常吻合，在咬合素缺陷的上皮细胞中TJ充当了低分子质量示踪剂通过副细胞途径扩散的主要障碍。这些发现表明，尚未确定的TJ积分膜蛋白（S）可以形成链结构，募集ZO-1，并充当没有闭合蛋白的屏障。