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）：巴雷特食管（BE）是正常鳞状食管上皮被肠化柱状上皮替代。它是对慢性胃酸和胆汁反流的反应，是食管腺癌 (EAC) 发展的重要危险因素。 BE被认为是对慢性组织损伤和促炎性前列腺素和细胞因子释放的适应性反应。然而，由于缺乏实验动物模型，人们对 BE 发病机制的了解仍知之甚少。开发创新的、基于遗传的和生理相关的 BE 小鼠模型是我实验室的一个重要的长期目标。 Cox-1和Cox-2是前列腺素生物合成的限速酶。 Cox-2 的表达是由胃酸反流在食道中诱导的，在大鼠胆汁反流模型中，Cox-2 的抑制可减少 BE 和癌症的进展。 Cox-2 还可以增加细胞内氧化应激并损伤 DNA。然而，Cox-2 在 BE 和 EAC 发病机制中的作用尚未得到测试。我们利用新型 3D 体外细胞培养系统来模拟 BE 发病机制。当我们在正常人食管角质形成细胞中表达 Cox-2 时，我们观察到肠道粘蛋白填充囊肿的形成。这表明 Cox-2 表达足以诱导角质形成细胞发生细胞谱系改变，该细胞谱系具有与 BE 细胞一致的粘蛋白分泌特征。因此，我们假设小鼠食管中 Cox-2 的表达导致慢性食管炎，通过引发氧化应激、DNA 损伤以及化生和发育不良的发展来模拟 GERD 食管炎。拟议研究的基本原理是，虽然临床观察数据表明 Cox-2 在巴雷特食管发病机制中的作用，但尚未在动物模型中得到证实。一旦确定，就可以更多地考虑药理学方法来预防 BE 的发生并限制向癌症的进展。在强有力的初步数据指导下，该假设将通过以下相互关联的具体目标进行检验：1) K14-Cox2 小鼠食道中的慢性 Cox-2 活性是否会导致炎症、氧化应激、DNA 损伤以及采用改变的分化计划？ 2) 抗氧化反应减弱或 DNA 修复缺陷能否与食管 Cox-2 表达协同作用，加速 DNA 损伤、化生和发育不良的发生？摘要 BE 是一种日益常见的癌前疾病，也是美国新出现的健康问题。我们的研究意义重大，因为它们从机制上探讨了 Cox2 对 BE 发病机制的贡献，并且我们预计我们的方法将产生改进的 BE 小鼠模型。此外，作为职业生涯中期研究员奖，这项研究将为 PI 提供一个突出的重点：1）提高他在小鼠病理学研究和综合表型分析方面的技能； 2）作为指导这些领域的初级研究者的基础； 3) 在小鼠病理学领域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.

幽门螺杆菌感染与胃癌患者胃中Lgr5阳性上皮干细胞的DNA损伤有关。

DOI：
发表时间：
2013-01
期刊：
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