Can quercetin increase claudin-4 and improve esophageal barrier function in

槲皮素能否增加claudin-4并改善食管屏障功能

基本信息

批准号：
8766644
负责人：
Roy Charles Orlando
金额：
$ 25.73万
依托单位：
UNIV OF NORTH CAROLINA CHAPEL HILL
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-07-01 至 2016-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8766644
关键词：
Achievement Acids Adult Adverse effects Affect American Barrett Esophagus Cell Line Cells Chronic Chronic Disease Clostridium difficile Colitis Controlled Clinical Trials Data Development Disease Electrical Resistance Epithelial Cells Epithelium Esophageal Esophageal Squamous Cell Esophagitis Extracellular Space Fluorescein Gastric Acid Gastric Parietal Cells Gastroesophageal reflux disease Health Heartburn Hip Fractures Human Hyperplasia In Vitro Infection Intestines Malignant Neoplasms Medical Methods Microscopy Modeling Movement Oral Osteoporosis Peptic Esophagitis Performance Physiological Plants Population Proteins Proton Pump Inhibitors Public Health Quality of life Quercetin Rattus Reflux Resistance Risk Risk Factors Running Sleep Squamous Epithelium Symptoms Testing Tight Junctions Tissues Withdrawal Work base claudin 4 cost design dietary supplements flavanoid impaired productivity improved in vivo public health relevance

项目摘要

DESCRIPTION (provided by applicant): Gastroesophageal reflux disease (GERD) is one of the most common chronic disorders in Americans, affecting 20% of the adult population. It causes heartburn and acid damage to the esophageal squamous epithelium (ESE). These symptoms and/or signs are of concern because they interfere with sleep and work, impairing productivity and quality of life; can cause erosions that progress to stricture and/or Barrett's esophagus, the latter a risk factor for cancer; and are costly to treat, generally requiring chroni acid- suppression with proton pump inhibitors (PPIs) whose U.S. costs run ~ $13.9 billion/year. Treatment with PPIs, however, is suboptimal, not only because of cost, but because of lack of symptom relief in a sizable population (25%) with the non-erosive form of GERD, as well as side effects that increase the risk of infections, including Clostridia difficile colitis, osteoporosis nd hip fracture, and hypergastrinemia that promotes gastric parietal cell hyperplasia and rebound hyperacidity making PPI withdrawal difficult. Therefore, alternative medical therapy for GERD is greatly needed, especially with agents that are safe, inexpensive, and effective in non-erosive reflux disease, the most common form of GERD. One method for treating GERD that remains untapped is by development of an agent that improves mucosal defense. One means of improving this defense is by improving the barrier function of ESE. Improvement of barrier function now appears feasible based on our understanding of how refluxed gastric acid attacks and damages ESE, leading to heartburn and erosive esophagitis. Acidic refluxates alter the tight junctions (TJs) that serve as barriers to the paracellular movement of luminal acid into ESE. Consequently, ESE of both erosive and non-erosive forms of GERD develop 'leaky' tight junctions, evidenced by low transepithelial electrical resistance (RT), high transepithelial fluorescein flux and dilated intercellular spaces on microscopy. Recently, we determined that the 'leaky' tight junctions in GERD were characterized by a selective reduction in claudin-4 and that these same physiologic pertubations were replicated in the HET-1A human esophageal squamous cell line. Specifically, HET-1A cells, when grown to confluence on permeable supports, lacked significant barrier function (undetectable RT and high fluorescein flux) and had low claudin-4 levels. Quercetin, a flavanoid widely available in plants and as an over-the-counter nutritional supplement, is known to raise claudin-4 levels and improve TJ barrier function in Caco2, an intestinal epithelial cell line. Therefore, we exposed HET-1A cells to quercetin and found that it raised claudin-4 and improved both barrier function and acid resistance of the TJ in vitro. Moreover, it did so at concentrations (5-10 ¿M) that approximate those achievable in vivo. These observations combined with data demonstrating that in vivo quercetin reduces esophageal damage in a rat model of reflux esophagitis provides strong conceptual support for a mechanistic study testing the hypotheses that: 'Oral quercetin can increase claudin-4 levels in vivo in the claudin-4 deficient ESE in GERD and by so doing increase both its barrier function and acid resistance.' Based on the above, then, the specific aims of this proposal are to: (1) Determine if oral quercetin increases the expression of claudin-4 in ESE of GERD in vivo; and (2) Determine whether the increase in claudin-4 by oral quercetin is accompanied by improvement in the barrier function and acid resistance of ESE in GERD. The achievement of these aims would provide strong support for performance of a controlled clinical trial to determine the value of oral quercetin for the treatment of GERD.

描述（由适用提供）：胃食管反射疾病（GERD）是美国人最常见的慢性疾病之一，影响了20％的成年人口。它会引起食道鳞状上皮（ESE）的胃灼热和酸损害。这些症状和/或迹象引起了人们的关注，因为它们会干扰睡眠和工作，损害生产力和生活质量；会导致侵蚀发展为狭窄和/或巴雷特食管，后者是癌症的危险因素；并且对治疗的昂贵，通常需要使用质子泵抑制剂（PPI）抑制Chroni酸，其成本约为139亿美元/年。 Treatment with PPIs, however, is suboptimal, not only because of cost, but because of lack of symptom relief in a sizable population (25%) with the non-erosive form of GERD, as well as side effects that increase the risk of infections, including Clostridia difficile colitis, osteoporosis nd hip fracture, and hypergastrinemia that promotes gastric parietal cell hyperplasia and rebound过度酸度使PPI撤离困难。因此，需要为GERD提供的替代药物疗法，尤其是对于安全，廉价且在非弱性反射疾病中有效的药物，这是GERD的最常见形式。治疗GERD尚未开发的一种方法是开发改善粘膜防御的代理。改善这种防御的一种方法是改善ESE的障碍功能。根据我们对反射胃酸攻击和损害ESE的理解，屏障功能的改善似乎是可行的，导致胃灼热和侵蚀性食管炎。酸性反映改变了紧密的连接（TJ），这是腔内酸到ESE的细胞细胞运动的障碍。因此，GERD的侵蚀性和非弱势形式的ESE形式形成了“漏水”的紧密连接，这是通过低经济上电阻（RT），高的经荧光荧光素通量和显微镜上扩张的细胞间空间证明的。最近，我们确定GERD中的“泄漏”紧密连接的特征是Claudin-4的选择性降低，并且这些相同的生理差异在HET-1A人类食管鳞状细胞系中被复制。具体而言，HET-1A细胞在可渗透的支撑上生长到汇合时，缺乏明显的屏障功能（无法检测到的RT和高荧光素通量），并且Claudin-4水平较低。槲皮素是一种在植物中广泛使用的类黄酮，作为一种非处方营养补充剂，可提高claudin-4水平并改善肠上皮细胞系Caco2中的TJ屏障功能。因此，我们将HET-1A细胞暴露于槲皮素中，发现它提高了Claudin-4并提高了TJ在体外的屏障功能和抗酸性。此外，它以近似体内成就的浓度（5-10€）的浓度（5-10€）这样做。这些观察结果与数据相结合，表明体内槲皮素在反射X炎的大鼠模型中降低了食道损害，为机械研究测试的假设提供了强有力的概念支持：“口服槲皮素可以增加claudin-4缺陷型在gerd中的耐药性ESE中的claudin-4水平，从而增加了它的抗抑郁症，并且可以使其脱颖而出和酸和功能抗性和酸和酸和功能性和功能性和功能性和功能性和功能性和酸性抗酸作用。因此，基于上述建议，该提案的具体目的是：（1）确定口服槲皮素是否会增加体内GERD ESE的Claudin-4的表达；（2）确定是否通过改善GERD中ESE的屏障功能和抗酸性来确定口服槲皮素的claudin-4增加。这些目标的实现将为对照临床试验的性能提供强有力的支持，以确定口服槲皮素在治疗GERD治疗方面的价值。