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.

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 signaling 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.但是，Notch信号的功能尚不清楚。因此，我们旨在阐明Notch信号在肠上皮细胞中的作用。首先，我们使用强力霉素引起的Notch细胞内结构域（NICD）的表达建立了Notch信号传导系统。此外，我们使用抑制NICD分离的γ-分泌酶抑制剂建立了Notch信号抑制系统。 NICD的表达引起了肠上皮细胞的去分化，例如粘蛋白2基因和HATH1基因的降低，在对比度上，Notch信号的抑制导致粘膜素2基因和HATH1基因的增加导致分化。因此，我们使用RNA微阵列分析阐明了几个直接靶向的基因，以阐明肠道功能。由于Notch信号调节了肠细胞系的分化，我们检查了NICD在人类肠道和人类炎中的表达。 NICD在下层地下室表示，而HES1和KI-67表示。此外，在IBD患者的肠道中，NICD以比正常肠道高的隐窝表达，这表明Notch信号的增加抑制了IBD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影响。 Notch信号的抑制导致小鼠中的杯状细胞增加，表明Notch信号可能是治疗IBD的新目标。