Mechanisms of gallbladder smooth muscle dysfunction

胆囊平滑肌功能障碍的机制

• 批准号: 10667646
• 负责人: Brigitte Lavoie
• 金额: $ 54.25万
• 依托单位: UNIVERSITY OF VERMONT & ST AGRIC COLLEGE
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-07-18 至 2026-05-31
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10667646
• 关键词: AKT Signaling Pathway; Address; Agonist; Animal Model; Animals; Anti-Inflammatory Agents; Applications Grants; Bile fluid; Cholecystectomy; Cholecystitis; Cholelithiasis; Cholestasis; Cholesterol; Controlled Environment; Coupling; Cyclic AMP; Cyclic AMP-Dependent Protein Kinases; Cyclooxygenase Inhibitors; Data; Development; Diet; Digestive System Disorders; Disease; Disease Progression; Evaluation; Event; Experimental Models; Foundations; Functional disorder; Gall Bladder Diseases; Gallbladder; Gallbladder Emptying; Human; Hydrophobicity; Image; Impairment; In Vitro; Individual; Inflammation; Interstitial Cell of Cajal; Knowledge; Lead; Measurement; Mediating; Modeling; Morbidity - disease rate; Motor; Mus; Muscle; Muscle Cells; Muscle function; PIK3CG gene; Pacemakers; Pathway interactions; Periodicity; Play; Positioning Attribute; Preparation; Property; Research; Rest; Role; Signal Transduction; Smooth Muscle; Smooth Muscle Myocytes; Sodium Chloride; T-Lymphocyte; Techniques; Testing; Therapeutic; Tissues; Transgenic Mice; Triglycerides; Ursodeoxycholic Acid; bile salts; cell motility; cost; experimental study; gallstone disease; high risk; high risk population; hydrophilicity; in vivo Model; insight; motility disorder; novel strategies; optogenetics; patch clamp; prevent; protective effect; response; single molecule

Gallbladder disease is one of the most common digestive disorders, and hallmark properties include decreased contractility, inflammation, and gallstone formation. Three features are consistently associated with gallstone disease: (1) elevated cholesterol hydrophobic salt and triglyceride (TG) levels in the bile; (2) inflammation of the gallbladder; and (3) impairments in gallbladder tone and contractility. Nevertheless, the interrelationships between decreased gallstone formation, inflammation, and contractility are not understood, and this reflects our lack of understanding of the cellular events that lead to decreased resting tone and postprandial contractions in gallbladder disease. This grant application proposes to address these fundamental gaps in our knowledge. The overall objectives of this grant application are to: (1) elucidate the cellular and ionic mechanisms by which gallbladder smooth muscle (GBSM) contractility is disrupted in gallstone disease; (2) determine the role of inflammation in smooth muscle dysfunction and associated biliary stasis in gallstone disease; and (3) explore the utility of hydrophilic bile salts in the protection of gallbladder function by preventing or reversing these disruptions to GBSM. We will use wild type and transgenic mice fed a lithogenic (gallstone forming) diet to evaluate the functional changes that occur in GBSM and interstitial cells of Cajal (ICC) during the progression of gallstone disease in normal mice and mice that do not develop gallbladder inflammation. We will also evaluate GBSM function in mice fed a lithogenic diet while being treated with a cyclooxygenase inhibitor, or the protective hydrophilic bile salt, ursodeoxycholic acid (UDCA). The second model involves evaluation of the effects of cholesterol and hydrophobic bile salts applied in vitro to gallbladder muscularis preparations, with or without prior application of UDCA. This approach allows us to examine the actions of these compounds, individually or together, on GBSM and ICC in a controlled environment. This grant proposal involves an integrated approach using state-of-the-art techniques to investigate gallbladder pathophysiology from single molecules to intact tissue during the progression of disease in the animal. Techniques to be used include optogenetic Ca2+ imaging of GBSM cells and ICC in intact muscle bundles, intracellular and patch clamp recording from intact and isolated GBSM cells, respectively, and muscularis tension measurements. Together with our previous studies on smooth muscle function, we will provide insights on how gallbladder motor function is disrupted leading to biliary stasis, and the interrelationship between disrupted motor function and inflammation. Furthermore, these studies will elucidate the therapeutic potential of UDCA to prevent or reverse cellular changes in GBSM/ICC that underlie decreased gallbladder contractility, and uncover the cellular mechanisms that mediate their actions in the gallbladder.

胆囊疾病是最常见的消化系统疾病之一，标志性的特性包括 收缩性，炎症和胆结石形成降低。三个功能始终与 胆结石疾病：（1）胆汁中胆固醇疏水盐和甘油三酸酯（TG）水平升高； （2） 胆囊的炎症； （3）胆囊色调和收缩力的损害。然而， 胆结石形成，炎症和收缩性降低之间的相互关系尚不清楚， 这反映了我们对导致静息语调降低和的细胞事件的理解不足 胆囊疾病的餐后收缩。该赠款申请建议解决这些基本 我们的知识差距。该赠款应用程序的总体目标是：（1）阐明细胞和 胆结石疾病中胆囊平滑肌（GBSM）收缩力通过胆囊平滑肌（GBSM）的离子机制； （2）确定炎症在平滑肌功能障碍和胆结石中相关的胆道中的作用 疾病; （3）探索通过防止胆囊功能保护亲水性胆汁盐的效用 或将这些干扰逆转为GBSM。我们将使用饲喂岩性的野生型和转基因小鼠（胆结石 形成）饮食评估Cajal（ICC）GBSM和间质细胞中发生的功能变化 不引起胆囊炎症的正常小鼠和小鼠的胆结石疾病的进展。 我们还将评估喂养岩性饮食的小鼠中的GBSM功能，同时接受环氧合酶治疗 抑制剂，或保护性亲水性胆汁盐，ursexyoxycholic Acid（UDCA）。第二个模型涉及 评估胆固醇和疏水胆汁盐在体外应用于胆囊肌肉的作用 准备工作，有或没有事先应用UDCA。这种方法使我们能够检查 这些化合物在受控的环境中单独或一起在GBSM和ICC上。 该赠款提案涉及使用最先进的技术进行调查的集成方法 胆囊病理生理学从单分子到完整的组织在疾病进展过程中 动物。要使用的技术包括完整肌肉中GBSM细胞和ICC的光学遗传学CA2+成像 束，细胞内和斑块夹从完整和孤立的GBSM细胞记录，以及 肌肉张力测量。加上我们先前关于平滑肌功能的研究，我们将 提供有关胆囊运动功能如何中断导致胆道僵局的见解， 运动功能和炎症中断之间的相互关系。此外，这些研究将阐明 UDCA预防或反向GBSM/ICC的细胞变化的治疗潜力，其基础降低了 胆囊收缩性，并发现介导其在胆囊中作用的细胞机制。