Mouse models for esophageal Cox-2 oxidative stress and DNA damage

食管 Cox-2 氧化应激和 DNA 损伤的小鼠模型

基本信息

批准号：
9245744
负责人：
JOHN P. LYNCH
金额：
$ 14.73万
依托单位：
UNIVERSITY OF PENNSYLVANIA
依托单位国家：
美国
项目类别：
财政年份：
2013
资助国家：
美国
起止时间：
2013-06-13 至 2017-08-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/9245744
关键词：
Achievement Acids Adoption Advisory Committees Anabolism Animal Model Antioxidants Area Award Barrett Esophagus Base Excision Repairs Bile Reflux Biomedical Research Cell Culture System Cell Lineage Cells Cellular Morphology Characteristics Chronic Clinical Columnar Epithelium Cyclooxygenase Inhibitors Cyst DNA Adducts DNA Damage DNA Repair Data Development Dysplasia Educational Curriculum Eicosanoids Enzymes Epithelial Cells Epithelium Esophageal Esophageal Adenocarcinoma Esophageal injury Esophageal mucous membrane Esophagitis Esophagus Experimental Animal Model GPX3 gene Gastric Acid Gene Expression Genes Goals Health Human Hydrogen Peroxide In Vitro Incidence Inflammation Inflammatory Inflammatory Response Injury Intestines Knowledge Lipid Peroxidation Lipid Peroxides Malignant Neoplasms Malignant neoplasm of esophagus Mentors Metaplasia Metaplastic Epithelial Cell Mission Modeling Molecular Mucins Mus Oncogenes Oxidative Stress Pathogenesis Patient Care Pennsylvania Peptic Esophagitis Pharmacology Phenotype Physiological Precancerous Conditions Prevention strategy Prostaglandin-Endoperoxide Synthase Prostaglandins Public Health Rattus Reflux Research Research Personnel Resources Risk Factors Role Testing Tissues Training Transgenic Mice Transgenic Model United States National Institutes of Health Universities Work antioxidant enzyme base cytokine experience glutathione peroxidase human disease improved innovation insight keratinocyte mouse model novel novel therapeutics online resource overexpression oxidative DNA damage oxidative damage pressure prevent programs public health relevance response response to injury skills translational impact wiki

项目摘要

DESCRIPTION (provided by applicant): Barrett's esophagus (BE) is the replacement of the normal squamous esophageal epithelium with an intestinalized columnar epithelium. It occurs in response to chronic acid and bile reflux and is an important risk factor for the development of esophageal adenocarcinoma (EAC). BE is thought to be an adaptive response to chronic tissue injury and the release of pro-inflammatory prostaglandins and cytokines. However, the mechanisms underpinning BE pathogenesis remain poorly understood in part due to the paucity of experimental animal models. The development of innovative, genetically based and physiologically relevant mouse models for BE is an important long-term objective of my lab. Cox-1 and Cox-2 are the rate-limiting enzymes in prostaglandin biosynthesis. Cox-2 expression is induced in the esophagus by acid reflux, and the inhibition of Cox-2 reduces the progression to BE and cancer in a rat bile reflux model. Cox-2 is also known to increase intracellular oxidative stress and damage DNA. Nevertheless, a role for Cox-2 in the pathogenesis of BE and EAC has not been tested. We have utilized a novel 3D in vitro cell culture system to model BE pathogenesis. When we express Cox-2 in normal human esophageal keratinocytes we observe the development of intestinal mucin-filled cysts. This suggests that Cox-2 expression is sufficient to induce an altered cell lineage from keratinocytes, one that has mucin-secretory features consistent with BE cells. We therefore hypothesize that Cox-2 expression in the murine esophagus results in a chronic esophagitis that models GERD esophagitis by provoking oxidative stress, DNA damage, and the development of metaplasia and dysplasia. The rationale for the proposed research is that while a role for Cox-2 in the pathogenesis of Barrett's esophagus is suggested by clinical observational data, this has not been proven in animal models. Once it is established, greater consideration can be given to pharmacological approaches to prevent the onset of BE and limit progression to cancer. Guided by strong preliminary data, this hypothesis will be tested by the following inter-related Specific Aims: 1) Does chronic Cox-2 activity in the esophagus of K14-Cox2 mice result in inflammation, oxidative stress, DNA damage, and the adoption of an altered differentiation program? 2) Can a diminished antioxidant response or defective DNA repair synergize with esophageal Cox-2 expression to accelerate the onset of DNA damage, metaplasia, and dysplasia? Summary BE is an increasingly common precancerous condition and an emerging U.S. health problem. Our studies are significant because they mechanistically explore the contributions of Cox2 to BE pathogenesis, and we anticipate our approaches will yield improved mouse models for BE. Additionally, as a Midcareer Investigator Award, this study will provide an outstanding focus for the PI to: 1) advance his skills in mouse pathobiology research and comprehensive phenotyping; 2) serve as a basis for mentoring of junior investigators in these areas; and 3) Conduct state-of-the-art biomedical research in mouse pathobiology.

描述（由申请人提供）：Barrett的食管（BE）是替代正常的鳞状食管上皮，用肠道上的柱状上皮替换。它是对慢性酸和胆汁反流的响应而发生的，是食管腺癌（EAC）发展的重要危险因素。被认为是对慢性组织损伤以及促炎性前列腺素和细胞因子的释放的一种适应性反应。然而，由于实验动物模型的缺乏，部分原因是发病机理所基于的发病机理仍然很少理解。为BE创新，基于遗传和生理相关的小鼠模型的开发是我实验室的重要长期目标。 COX-1和COX-2是前列腺素生物合成中的速率限制酶。 COX-2通过胃酸反流诱导的COX-2表达，COX-2的抑制作用降低了大鼠胆汁反流模型中的BES和癌症的进展。已知COX-2会增加细胞内氧化应激和损伤DNA。然而，COX-2在BE和EAC的发病机理中的作用尚未进行测试。我们已经利用了一种新型的3D体外细胞培养系统来建模为发病机理。当我们在正常人类食管角质形成细胞中表达COX-2时，我们会观察到肠粘膜填充囊肿的发展。这表明COX-2表达足以诱导角质形成细胞的细胞谱系改变，该细胞具有与BE细胞一致的粘蛋白分泌特征。因此，我们假设鼠食管食管中的COX-2表达会导致慢性食管炎，该食管炎通过引起氧化应激，DNA损伤以及化生和发育不良的发展来对GERD食管炎进行建模。拟议研究的理由是，虽然COX-2在Barrett食管发病机理中的作用是通过临床观察数据提出的，但在动物模型中尚未证明这一点。一旦建立，就可以对防止BE发作的药理方法进行更大的考虑，并限制对癌症的进展。在强有力的初步数据的指导下，该假设将通过以下相关特定目的检验：1）K14-COX2小鼠食管中慢性COX-2活性是否会导致炎症，氧化应激，DNA损伤和采用改变的差异化计划？ 2）减少抗氧化剂反应或有缺陷的DNA修复能够与食道COX-2表达协同，以加速DNA损伤，化生和发育不良的发作？总结是越来越常见的癌前状况，也是美国新兴的美国卫生问题。我们的研究很重要，因为它们从机械上探讨了Cox2对发病机理的贡献，我们预计我们的方法将为BE提供改进的小鼠模型。此外，作为中级研究员奖，这项研究将为PI提供出色的重点：1）提高他在小鼠病理生物学研究和全面表型方面的技能； 2）作为指导这些领域初级调查人员的基础； 3）在小鼠病理生物学中进行最先进的生物医学研究。

项目成果

期刊论文数量（1）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

H. pylori infection is associated with DNA damage of Lgr5-positive epithelial stem cells in the stomach of patients with gastric cancer.

DOI：
10.1007/s10620-012-2360-8
发表时间：
2013-01
期刊：
DIGESTIVE DISEASES AND SCIENCES
影响因子：
3.1
作者：
Uehara, Takeshi;Ma, Deqin;Yao, Yuan;Lynch, John P.;Morales, Knashawn;Ziober, Amy;Feldman, Michael;Ota, Hiroyoshi;Sepulveda, Antonia R.
通讯作者：
Sepulveda, Antonia R.