NF-kB /Beta-catenin interaction during intestinal inflammation

肠道炎症期间 NF-kB /β-catenin 相互作用

• 批准号: 7906796
• 负责人: Jun Sun
• 金额: $ 13万
• 依托单位: UNIVERSITY OF ROCHESTER
• 依托单位国家: 美国
• 财政年份: 2007
• 资助国家: 美国
• 起止时间: 2007-09-01 至 2012-08-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7906796
• 关键词: Bacteria; Bacterial Proteins; Binding; Colitis; Cultured Cells; Cyclin D1; Data; Disease; Enterobacteriaceae; Environment; Epithelial Cells; Genes; Germ-Free; Health; IL8 gene; In Vitro; Inflammation; Inflammatory Bowel Diseases; Inflammatory disease of the intestine; Interleukin-10; Intestinal Mucosa; Intestines; Knowledge; Language; Maintenance; Modeling; Mono-S; Mus; NF-kappa B; Pathogenesis; Pathway interactions; Patients; Phosphorylation; Play; Property; Proteins; Research; Role; Signal Pathway; Ubiquitination; beta catenin; c-myc Genes; commensal microbes; in vivo; insight; microbial; novel strategies; response

DESCRIPTION (provided by applicant): Increasing evidence indicates that endogenous enteric bacteria play a crucial role in the pathogenesis of inflammatory bowel diseases (IBDs). It is clear that gut flora contribute to the elevated levels of activated NF-???in the intestinal mucosa of IBD patients. However, it is unclear which bacterial strain and/or bacterial ?products contribute to the pathogenesis and/or maintenance of IBD. Due to the complexity of the gut flora, identification of the specific causative microbial agents in IBD remains challenging, and the search for the causative microbial agents is intense. AvrA is a pathogenic gene of certain bacteria whose encoded protein is inserted into intestinal epithelial cells through a Type III secretory pathway. In previous studies, we demonstrated that AvrA stabilizes ?-catenin, which is a negative regulator of the NF-?? pathway in epithelial cells. We hypothesize that the bacterial effector AvrA inhibits the NF-???pathway and actives the ?-catenin pathway to inhibit intestinal inflammation. In this study, I will focus on the mechanism and effects of AvrA, using both in vitro and in vivo approaches. For in vitro studies, we will colonize epithelial cells with AvrA-sufficient or -deficient bacteria strains. We will determine how the bacterial effector AvrA actually regulates NF-??/?-catenin binding and identify post-transcriptional changes in regulators of the NF-?? and ?-catenin pathways induced by AvrA (e.g., phosphorylations, ubiquitinations). We will investigate expression changes induced by AvrA in downstream targets (i.e., IL-8, c-myc, cyclin D1) of the NF-?? and???-catenin pathways. For in vivo studies, we will employ IL-10-/- mice that develop spontaneous colitis, which has been shown to require colonic bacterial colonization for full expression. These IL-10-/- mice will initially be raised in germ-free environments, and will then be mono-associated with E.coli F18 or E.coli F18AvrA+ to determine the function of AvrA in inhibiting inflammation in vivo. Elucidating the mechanisms of AvrA regulating the NF-?? and ?-catenin signaling pathways will provide new insights into how bacteria-host interactions contribute to inflammation. These studies have direct relevance to a better understanding of diseases such as inflammatory bowel diseases and infectious colitis. Lay language: This proposal is aimed at understanding the mechanism and effects of the bacterial protein AvrA in inhibiting inflammation. We will focus on the mechanism and effects of AvrA in cultured cells colonized with bacterial strains (with or without AvrA expression) and in a mouse colitis model. The information obtained from our research will provide new insights into the way bacteria-host interactions contribute to inflammation. This has direct relevance to a better understanding of diseases such as inflammatory bowel diseases and infectious colitis.

描述（由申请人提供）：越来越多的证据表明内源性肠细菌在炎症性肠病的发病机理（IBD）中起着至关重要的作用。显然，肠道菌群在IBD患者的肠粘膜中有助于激活NF的水平升高。但是，目前尚不清楚哪种细菌菌株和/或细菌？产物有助于IBD的发病机理和/或维持。由于肠道菌群的复杂性，IBD中特定的因果微生物剂的鉴定仍然具有挑战性，并且对因果微生物剂的搜索非常强烈。 AVRA是某些细菌的致病基因，其编码的蛋白通过III型分泌途径插入肠上皮细胞中。在先前的研究中，我们证明了Avra可以稳定吗？-Catenin，哪个是NF-的负调节剂。上皮细胞中的途径。我们假设细菌效应子AVRA抑制了NF - ???途径，并活跃于抑制肠炎的途径。在这项研究中，我将使用体外和体内方法专注于AVRA的机制和影响。为了进行体外研究，我们将用AVRA足够的或缺乏细菌菌株定植上皮细胞。我们将确定细菌效应子Avra实际上如何调节NF - ??/？ - catenin结合并确定NF-调节剂的转录后变化。和？ - 由AVRA诱导的途径（例如，磷酸化，泛素化）。我们将研究NF-的下游靶标（即IL-8，C-MYC，Cyclin D1）引起的表达变化。和??? - catenin途径。对于体内研究，我们将采用发展自发性结肠炎的IL-10 - / - 小鼠，已证明需要结肠细菌定植才能充分表达。这些IL-10 - / - 小鼠最初将在无菌环境中升高，然后将与E.Coli F18或E.Coli F18avra+单一相关，以确定AVRA在体内抑制炎症中的功能。阐明调节NF- ?? AVRA的机制 - - 连蛋白信号通路将为细菌宿主相互作用如何促进炎症提供新的见解。这些研究直接与对炎症性肠道疾病和感染性结肠炎等疾病的更好理解有关。 外行语言：该建议旨在了解细菌蛋白AVRA在抑制炎症中的机制和影响。我们将重点关注AVRA在用细菌菌株（或不具有AVRA表达）和小鼠结肠炎模型中定居的培养细胞中的机制和作用。从我们的研究中获得的信息将为细菌 - 宿主相互作用促进炎症的方式提供新的见解。这与对炎症性肠道疾病和感染性结肠炎等疾病的更好理解具有直接的相关性。