Mechanisms of gallbladder smooth muscle dysfunction

胆囊平滑肌功能障碍的机制

基本信息

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
项目类别：
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

项目摘要

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，其标志性特征包括收缩力、炎症和胆结石形成减少。三个特征始终相关胆石病：（1）胆汁中胆固醇疏水盐和甘油三酯（TG）水平升高； (2) 胆囊炎症; (3)胆囊张力和收缩力受损。尽管如此，胆结石形成减少、炎症和收缩力之间的相互关系尚不清楚，这反映了我们对导致静息张力下降的细胞事件缺乏了解胆囊疾病的餐后收缩。本拨款申请旨在解决这些基本问题我们的知识差距。本次拨款申请的总体目标是：（1）阐明细胞和胆囊平滑肌 (GBSM) 收缩性在胆结石疾病中受到破坏的离子机制； (2)确定炎症在平滑肌功能障碍和胆结石相关胆汁淤滞中的作用疾病; (3)探索亲水性胆汁盐在通过预防胆囊功能保护中的应用。或扭转这些对 GBSM 的干扰。我们将使用野生型和转基因小鼠喂养生石（胆结石）形成）饮食来评估 GBSM 和 Cajal 间质细胞 (ICC) 期间发生的功能变化正常小鼠和未发生胆囊炎症的小鼠胆结石疾病的进展。我们还将评估在接受环氧合酶治疗的同时喂食生石饮食的小鼠的 GBSM 功能抑制剂，或保护性亲水性胆盐，熊去氧胆酸（UDCA）。第二个模型涉及评估体外应用的胆固醇和疏水性胆汁盐对胆囊肌层的影响制剂，无论是否预先施用 UDCA。这种方法使我们能够检查这些化合物单独或一起在受控环境中的 GBSM 和 ICC 上进行。该拨款提案涉及使用最先进技术进行调查的综合方法疾病进展过程中胆囊病理生理学从单分子到完整组织动物。使用的技术包括完整肌肉中 GBSM 细胞和 ICC 的光遗传学 Ca2+ 成像分别从完整和分离的 GBSM 细胞中进行束、细胞内和膜片钳记录，以及肌层张力测量。结合我们之前对平滑肌功能的研究，我们将提供关于胆囊运动功能如何被破坏导致胆汁淤滞的见解，以及运动功能受损与炎症之间的相互关系。此外，这些研究将阐明 UDCA 预防或逆转 GBSM/ICC 细胞变化的治疗潜力胆囊收缩力，并揭示介导胆囊活动的细胞机制。