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An morphological analysis of the intestinal pacemaker cells by connexin45 knock-out mice

Connexin45敲除小鼠肠道起搏细胞的形态学分析

基本信息

批准号：
12670019
负责人：
NAKAMURA Kei-ichiro
金额：
$ 2.43万
依托单位：
KYUSHU UNIVERSITY
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2000
资助国家：
日本
起止时间：
2000 至 2001
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/grant/KAKENHI-PROJECT-12670019/
关键词：
connexin 45 gap junction knockout mice smooth muscle central nervous system LacZ confocal laser scanning microscopy confocal laser scanning microscopy intestinal motility confocal laser scannning microscopy

项目摘要

By using heterozygous animals of our Cx45 knockout mice, in which Cx45 exon was replaced with Lac-Z gene as a marker, we analyzed the distribution pattern in organs and tissues of the whole body. The homozygous animals of the mutated gene die at around the embryonic day 10 because of malformation of the heart and heart failure, however, heterozygous animals are viable and fertile with normal structure. We have already reported that Cx45 was expressed in fibroblast-like cells, supposedly pacemaker cells for intestinal movements, at DMP of the small intestine. Adding to those cells, we have observed that smooth muscle cells around the pacemaker cells are expressing Cx45. Other smooth muscle cells, such as viscelral smooth muscle cells surrounding air way, urinary tract, sphincter and dilator muscle cells of the iris, ciliary body as well as vascular smooth muscle cells are also Lac-Z positive. It is important that we could detect Cx45 expressing cells that we used to be unable to identify because of their small amount of Cx45 expression. In the central nervous system, at least two types of morpholocally identified neurons were Lac-Z positive. We developed a new technique to observe three dimensional distribution pattern effectively in a thick slice. We identified 5 and 6th layers of cerebral cortex, thalamic nuclei, lateral and medial geniculate bodies, transition area of cortex to hippocampus, and habenular nuclei. Lac-Z positive neurons were distributed continuously along those nuclei. Further analysis is required for the understanding functional significance of those Cx45 expressing cells and their distribution pattern.

以我们的Cx45基因敲除小鼠的杂合子动物为研究对象，以Lac-Z基因替换Cx45外显子为标记，分析了Cx45基因敲除小鼠在全身器官组织中的分布规律。由于心脏畸形和心力衰竭，突变基因的纯合子动物在胚胎第10天左右死亡，然而，杂合子动物是活的和有生育能力的，结构正常。我们已经报道，在小肠的DMP处，Cx45在成纤维细胞样细胞中表达，这些细胞被认为是肠道运动的起搏细胞。加上这些细胞，我们观察到起搏细胞周围的平滑肌细胞正在表达Cx45。其他平滑肌细胞，如呼吸道、尿路周围粘液平滑肌细胞、虹膜括约肌和扩张肌细胞、睫状体平滑肌细胞以及血管平滑肌细胞也呈Lac-Z阳性。重要的是，我们可以检测到表达Cx45的细胞，而我们过去因为Cx45的少量表达而无法识别这些细胞。在中枢神经系统中，至少有两种形态定位的神经元呈Lac-Z阳性。我们开发了一种新的技术，可以有效地在厚切片上观察三维分布规律。我们确定了大脑皮质的第5层和第6层，丘脑的核，外侧和内侧膝状体，皮质到海马区的过渡区，以及缰核。Lac-Z阳性神经元沿这些核团连续分布。这些表达Cx45的细胞的功能意义及其分布规律还需要进一步的分析。