A Zebrafish Model to Study the Role of the Microbiota in the Etiology of Intestin

项目总结 人类的胃肠道内有大量复杂的微生物群落，这些微生物群落很重要。 对于正常的健康来说，但也会导致胃肠道癌症等疾病。在本提案中，我们将 使用斑马鱼模型来研究肠道微生物产生的因素如何与宿主遗传因素相互作用 推动了肠癌的发展。我们将利用容易感染肠道的斑马鱼线 由Wnt信号通路过度激活、慢性炎症或DNA修复缺失引起的癌症 机制，所有这些都通常与人类的胃肠道癌症有关。我们的第一个目标是 将表征一些由人类和斑马鱼相关细菌产生的分泌蛋白质， 调节与胃肠道癌症发展相关的宿主程序，包括上皮细胞 增殖和炎症。我们将确定促增殖蛋白是否协同作用。 具有易患癌症的遗传背景，扰乱正常的肠道上皮细胞更新程序，并导致 此外，抗炎蛋白是否对增殖具有保护作用。在……里面 我们的第二个目标是鉴定一个表达细菌癌基因CagA的转基因斑马鱼品系， 来自与胃癌相关的病原体幽门螺杆菌。我们将确定宿主的基因 在这些转基因鱼发展到增殖和癌症的过程中被激活的程序，我们 将测试这些途径中哪些是CagA致癌特性所必需的。我们还将测试 CagA的表达以促进肠道病理的方式改变了肠道微生物群落。在我们的 第三个目标，我们将调查自发性肠癌暴发背后的微生物病原学。 斑马鱼设施，我们已经证明它是可以传播的。我们将使用以下实验框架 传染性疾病，以确定与肠道病理有关的微生物。我们将利用我们的癌症- 易患斑马鱼品系表征疾病相关微生物群落的致癌潜力 以及单个候选微生物的数量。这项研究将提供对机制的新见解 肠道微生物有助于癌症的发展，并最终将导致新的诊断方法， 治疗和预防人类的胃肠道癌症。

PROJECT SUMMARY The human gastrointestinal tract houses large and complex communities of microorganisms that are important for normal health, but can also contribute to diseases such as gastrointestinal cancer. In this proposal we will use a zebrafish model to investigate how factors produced by gut microbes interact with host genetic factors to drive the progression of intestinal cancer. We will make use of zebrafish lines that are predisposed to intestinal cancer due to over-activation of the Wnt signaling pathway, chronic inflammation, or loss of DNA repair mechanisms, all of which are commonly associated with gastrointestinal cancers in humans. In our first aim we will characterize a number of secreted proteins, produced by both human and zebrafish-associated bacteria, that modulate host programs associated with gastrointestinal cancer development, including epithelial cell proliferation and inflammation. We will determine whether the pro-proliferative proteins interacts synergistically with cancer-prone genetic backgrounds to disrupt normal programs of intestinal epithelial renewal and cause hyperplasia, and furthermore whether the anti-inflammatory proteins confer protection against hyperplasia. In our second aim we will characterize a transgenic zebrafish line that expresses the bacterial oncogene, CagA, from the stomach cancer-associated pathogen Helicobacter pylori. We will determine the host genetic programs that are activated during the progression of these transgenic fish to hyperplasia and cancer, and we will test which of these pathways are required for CagA's carcinogenic properties. We will also test whether CagA expression alters the intestinal microbial community in ways that promote intestinal pathology. In our third aim we will investigate the microbial etiology behind an outbreak of spontaneous intestinal cancers in our zebrafish facility, which we have shown to be transmissible. We will use the experimental framework of transmissible disease to identify microbes associated with intestinal pathology. We will employ our cancer- prone zebrafish lines to characterize the carcinogenic potential of disease-associated microbial communities and of individual candidate microbes. This research will provide new insight into the mechanisms by with intestinal microbes contribute to cancer development and will ultimately lead to new approaches to diagnose, treat and prevent gastrointestinal cancers in humans.