EPITHELIAL CHANGE/GENE EXPRESSION IN CROHN'S DISEASE

肠上皮是粘膜免疫系统和肠道环境之间的主要接口。SAMP1/Yit小鼠是一种遗传近交系小鼠，在30周龄时发生与人类克罗恩病相似的回肠炎，几乎完全外显率。SAMP/Yit小鼠疾病的一个主要特征是在炎症和回肠炎发展的早期出现明显的回肠上皮结构异常。在无菌SAMP/Yit中不发生回肠炎，提示肠内细菌或环境产生的上皮损伤在慢性骨髓炎的发展中起作用。这些观察结果提出了一种假设，即SAMP1/Yit小鼠对损伤的上皮反应发生改变，从而导致异常，进而导致慢性骨髓炎。目的1将检验SAMP/Yit小鼠与对照小鼠相比是否对上皮损伤有改变的反应。我们将探讨上皮干细胞命运的关系。过继性转移技术将用于分离SAMP1/Yit上皮固有的损伤反应差异，以及活化t细胞和炎症反应引起的变化。调节隐窝上皮细胞凋亡的基因表达的变化也将被检查。在目的2中，我们将确定SAMP/Yit小鼠中上皮结构或分化的变化是否会诱导调节炎症反应的上皮分子产生的改变。上皮细胞源性细胞因子的产生将在从回肠炎小鼠中分离的上皮细胞和上皮细胞特性的遗传改变中进行检测，上皮细胞特性的改变或由炎症和持续的上皮损伤引起的改变。在目标3中，我们将研究可能参与SAMP/Yit小鼠回肠炎发展的上皮表达基因的遗传差异。这将使用cDNA微阵列技术来鉴定与易感性或疾病发展相关的染色体位点编码的差异表达基因，这些基因通过项目2中概述的遗传分析确定。

The intestinal epithelium represents the major interface between the mucosal immune system and the lumenal environment. The SAMP1/Yit mouse is a genetically inbred mouse line that develops ileitis that is similar to human Crohn's disease with near complete penetrance by 30 weeks of age. A major feature of disease in the SAMP/Yit mouse is the prominent architectural abnormalities of the ileal epithelium that occur early in the development of inflammation and ileitis. Ileitis does not develop in germ free SAMP/Yit suggesting a role for lumenal bacteria or environmentally-produced epithelial damage in the development of chronic iteal inflammation. These observations raise the hypothesis that SAMP1/Yit mice have an altered epithelial response to injury which results in abnormalities which, in turn, leads to chronic iteal inflammation. Aim 1 will examine whether SAMP/Yit mice have an altered response to epithelial damage compared to control mice. The relationship of epithelial stem cell fate will be examined. Adoptive transfer techniques will be used to separate differences in injury-response that are intrinsic to the SAMP1/Yit epithelium from changes induced by the presence of activated T-cells and an inflammatory response. Changes in the expression of genes which regulate crypt epithelial apoptosis will also be examined. In aim 2 we will determine whether the changes in epithelial architecture or differentiation present in the SAMP/Yit mouse induce alterations in epithelial production of molecules that regulate the inflammatory response. The production of epithelial derived cytokines will be examined in n epithelial cells isolated from mice with ileitis and from heritable alterations in the properties of the epithelial alterations in the properties of the epithelial cells or are induced by inflammation and ongoing epithelial damage. In aim 3 we will examine heritable differences in epithelial expressed genes that may be involved in the development of ileitis in the SAMP/Yit mouse. This will be accomplished using cDNA microarray technology to identify differentially expressed genes that are encoded with chromosomal loci associated with susceptibility or development of disease as determined through the genetic analysis outlined in project 2.