ギャップ結合蛋白遺伝子変異マウスの分子解剖学的研究

间隙连接蛋白基因突变小鼠的分子解剖学研究

基本信息

批准号：
11470005
负责人：
SHIBATA Yosaburo
金额：
$ 8.83万
依托单位：
KYUSHU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B).
财政年份：
1999
资助国家：
日本
起止时间：
1999 至 2000
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-11470005/
关键词：
connexin gap junction gene targeting lacZ NFATC1 endocardial cushion heart A-V block Cre-loxP system NF-ATcl

项目摘要

We created mice harboring an nls-lacZ gene in place of connexin45, which encodes the only known gap junction protein in the primitive heart before embryonic dey 9, using the cre-loxPsystem. Heterologous recombinant mice revealed Lac Z signals in the nucleus in various tissues : some nuclei in the brain, retina, intestinal and vascular smooth muscles, endothelial cells of blood vessels and endocardium, and impulse conducting fibers of the heart. Connexin45-deficient mice died of heart failure at around embryonic day 10. They initiated heart contractions, but conduction block appeared ithin 24 hours after the first contractions. Their cardiac walls displayed an endocardial cushion defect, while the cardiac jelly was present. These abnormalities were caused by impairment of the epithelial-mesenchymal transformation of the cardiac endothelium. Activation of the endothelium depended on the presence of the connexin45 gap junctions since signaling through Ca^<2+>/calcineurin and NF-ATcl (originally named NF-ATc)was disrupted in the mutant hearts. These results indicate a requirement for gap junction intercellular channels during early cardiogenesis and hence implicate connexin in congenital heart diseases. This finding may be the first report to present the direct molecular mechanism of cell to cell communication through gap junction in the tissue development.

我们创建了带有NLS-LACZ基因的小鼠，代替了Connexin45，该小鼠使用Cre-loxpsystem在胚胎DEY 9之前编码了原始心脏中唯一已知的间隙连接蛋白。异源重组小鼠在各种组织中揭示了核中的Lac Z信号：大脑中的一些核，视网膜，肠道和血管平滑肌，血管和心内膜的内皮细胞，以及脉冲导致心脏的纤维。 Connexin45缺陷小鼠在胚胎第10天左右死于心力衰竭。它们发起了心脏收缩，但第一次收缩后24小时出现了Ithin的传导阻滞。他们的心脏墙显示出心内垫缺陷，而心脏果冻则出现。这些异常是由于心脏内皮的上皮间质转化损害引起的。内皮的激活取决于连接缝隙连接的存在，因为通过CA^<2+>/钙调蛋白和NF-ATCL（最初命名为NF-ATC）发出信号，在突变体心脏中破坏了。这些结果表明在早期心脏病发生过程中需要间隙连接间通道的要求，因此暗示了先天性心脏病中的连接蛋白。这一发现可能是第一个通过组织发育中的间隙连接来介绍细胞与细胞通信的直接分子机制的报告。