Identification of the Notch signal in intestinal epithelial cells and the failure of the intestinal differentiation in chronic colitis.

慢性结肠炎肠上皮细胞Notch信号的鉴定和肠分化失败。

基本信息

批准号：
17590624
负责人：
OKADA Eriko
金额：
$ 2.24万
依托单位：
Tokyo Medical and Dental University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (C)
财政年份：
2005
资助国家：
日本
起止时间：
2005 至 2006
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-17590624/
关键词：
Notch Chronic colitis Regeneration Stem Cell Notchシグナル腸管分化転写因子

项目摘要

In this study, we demonstrated that Notch signaling plays a crucial role in the differentiation of intestinal epithelial cells, and then we revealed several genes directly targeted by Notch signal in intestinal epithelial cells.It has been reported that the deficient of HES1 gene via Notch signaling caused the differentiation of intestinal epithelial cells, indicating that Notch signaling regulates the dedifferentiation of intestinal epithelial cells. However the function of Notch signaling has been unknown. Therefore, we aimed to elucidate the effect of Notch signaling in intestinal epithelial cells. First, we established the system of Notch signal stimulation, using the expression of Notch intracellular domain (NICD) induced by doxycycline. Moreover, we established the system of Notch signal inhibition, using γ-secretase inhibitor that suppresses the separation of NICD. The expression of NICD caused the dedifferentiation of intestinal epithelial cells such as the decrease of Mucin2 gene and Hath1 gene, on the contrary, the inhibition of Notch signal caused the differentiation with the increase of Mucin2 gene and Hath1 gene. Therefore, we identified several genes directly targeted by Notch signal stimulation, using RNA micro array analysis for the clarification of Notch function in intestine.Because Notch signal regulates the differentiation of intestinal cell line, we examined the expression of NICD in human intestine and human colitis. NICD was expressed at the lower crypt, whereas Hes1 and Ki-67 were expressed. Moreover, in intestine of IBD patient, NICD was expressed at higher crypt than in normal intestine, suggesting that the increase of Notch signal suppress the differentiation of the intestinal epithelial cells in IBD. So we assessed the effect of γ-secretase inhibitor on intestinal epithelial cells. The inhibition of Notch signal caused the increase of goblet cells in mouse, indicating that Notch signal may be new target for the therapy of IBD.

在这项研究中，我们证明了Notch信号在肠上皮细胞的分化中起着至关重要的作用，然后我们揭示了肠上皮细胞中Notch信号直接靶向的几个基因。据报道，HES1基因的缺陷通过Notch信号传导引起肠上皮细胞的分化，表明Notch信号调节肠上皮细胞的去分化，但Notch信号的功能尚不清楚，因此，我们的目的是阐明Notch信号的作用。首先，我们利用多西环素诱导的Notch细胞内结构域（NICD）的表达建立了Notch信号刺激系统。此外，我们利用γ-分泌酶抑制剂抑制了Notch信号抑制系统。 NICD的表达引起肠上皮细胞的去分化，如Mucin2基因和Hath1基因的减少，相反，Notch信号分离的抑制则引起分化。随着Mucin2基因和Hath1基因的增加，我们鉴定了Notch信号刺激直接靶向的几个基因，利用RNA微阵列分析来阐明Notch在肠道中的功能。由于Notch信号调节肠道细胞系的分化，因此我们检查了Notch信号。 NICD在人肠道和人结肠炎中表达于下隐窝，而Hes1和Ki-67在IBD患者肠道中表达。隐窝信号的增加表明IBD中Notch信号的增加抑制了肠上皮细胞的分化，因此我们评估了γ-分泌酶抑制剂对肠上皮细胞的抑制作用。小鼠细胞，表明Notch信号可能成为治疗IBD的新靶点。