Utility of a bacterial infection model to study epithelial-mesenchymal transition, mesenchymal-epithelial transition or tumorigenesis.
Utility of a bacterial infection model to study epithelial-mesenchymal transition, mesenchymal-epithelial transition or tumorigenesis.
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DCLK 1和Lgr 5最近已被确定为静止和循环的干细胞在小肠隐窝，分别标记。上皮-间充质转化（EMT）是一个关键的发育程序，通常在癌症侵袭和转移期间被激活，并且还赋予扩散癌细胞自我更新能力。利用啮齿类柠檬酸杆菌（CR）诱导的可传染性小鼠结肠增生（TMCH）模型，我们观察到结肠隐窝中DCLK 1表达的相对降低，在高峰（感染后12天）增生时向基质染色显著转变，而Lgr 5和Msi-1的染色增加数倍。当增生消退时（第20-34天），与未感染的对照相比，记录到CR感染的隐窝中DCLK 1 +ve细胞的扩增。纯化的结肠隐窝细胞在感染后12或34天表现出转化生长因子-β（TGFβ）、Wnt和Notch途径的表观遗传调节，在体外形成单层，并转分化为成纤维细胞样细胞，其对波形蛋白、纤连蛋白和DCLK 1染色呈阳性。当胰蛋白酶消化并在软琼脂中再生长时，这些细胞形成结肠球/类器官，其在基质胶中发育成隐窝样结构（结肠样）并对DCLK 1染色呈阳性。表现出12或34天的TMCH的小鼠给予氧化偶氮甲烷一次，持续8小时（Gp 1）或每周一次，持续3周（Gp 2），并进行隐窝分离。来自Gp 1动物的隐窝细胞在软琼脂中形成单层以及结肠球，在裸鼠中形成结节/肿瘤。从Gp 2动物中分离的隐窝细胞不能形成单层，但在软琼脂中发育成结肠球，在裸鼠中发育成结节/肿瘤。因此，增生和增加的DCLK 1 +ve细胞的存在促进细胞转化，以响应第二次打击。因此，TMCH模型提供了一个很好的模板来研究肠道干细胞的改变如何促进细菌感染后的转分化、隐窝再生或结肠癌发生。
DCLK1 and Lgr5 have recently been identified as markers of quiescent and cycling stem cells in the small intestinal crypts, respectively. Epithelial–mesenchymal transition (EMT) is a key development program that is often activated during cancer invasion and metastasis, and also imparts a self-renewal capability to disseminating cancer cells. Utilizing the Citrobacter rodentium (CR)-induced transmissible murine colonic hyperplasia (TMCH) model, we observed a relative decrease in DCLK1 expression in the colonic crypts, with significant shift towards stromal staining at peak (12 days post infection) hyperplasia, whereas staining for Lgr5 and Msi-1 increased several fold. When hyperplasia was regressing (days 20–34), an expansion of DCLK1 +ve cells in the CR-infected crypts compared with that seen in uninfected control was recorded. Purified colonic crypt cells exhibiting epigenetic modulation of the transforming growth factor-β (TGFβ), Wnt and Notch pathways on 12 or 34 days post infection formed monolayers in vitro, and underwent trans-differentiation into fibroblast-like cells that stained positive for vimentin, fibronectin and DCLK1. These cells when trypsinized and regrown in soft agar, formed colonospheres/organoids that developed into crypt-like structures (colonoids) in Matrigel and stained positive for DCLK1. Mice exhibiting 12 or 34 days of TMCH were given azoxymethane once for 8 h (Gp1) or weekly for 3 weeks (Gp2), and subjected to crypt isolation. Crypt cells from Gp1 animals formed monolayers as well as colonospheres in soft agar and nodules/tumors in nude mice. Crypt cells isolated from Gp2 animals failed to form the monolayers, but developed into colonospheres in soft agar and nodules/tumors in nude mice. Thus, both hyperplasia and increased presence of DCLK1 +ve cells promote cellular transformation in response to a second hit. The TMCH model, therefore, provides an excellent template to study how alterations in intestinal stem cells promote trans-differentiation, crypt regeneration or colon carcinogenesis following bacterial infection.
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DOI：
10.1038/nrgastro.2010.39
发表时间：
2010-05
期刊：
Nature reviews. Gastroenterology & hepatology
影响因子：
--
作者：
通讯作者：
--
影响因子：
21.3
作者：
Batlle, E;Sancho, E;de Herreros, AG
通讯作者：
de Herreros, AG
影响因子：
5.4
作者：
Ali, Naushad;Allam, Heba;Houchen, Courtney W.
通讯作者：
Houchen, Courtney W.
影响因子：
3.1
作者：
Bétis, F;Brest, P;Hofman, P
通讯作者：
Hofman, P
DOI：
10.1016/j.ejpb.2010.11.008
发表时间：
2011-01-01
影响因子：
4.9
作者：
Cun, Dongmei;Jensen, Ditte Krohn;Nielsen, Hanne Morck
通讯作者：
Nielsen, Hanne Morck