Alimentary Tract Lipids in Health and Disease

描述（由申请人提供）：本应用程序的目的是利用生物物理和病理生理原理以及物理，化学，生化和分子生物学技术来推进对胆汁及其两种主要功能障碍的基本理解，即胆汁淤积和色素和胆固醇类型的胆结石。i)第一个目标将确定啮齿螺杆菌和肝杆菌的肠肝感染，包括人类和小鼠常见的肠胆病原体，是胆固醇-胆结石发病的最后共同诱因，通过胆固醇-过饱和胆汁成核。研究将在遗传胆结石易感小鼠身上进行，并结合模型胆汁和天然胆汁胆固醇成核的体外分析，以及对人类胆道组织中幽门螺杆菌感染的证据进行量化。ii)目标二将量化产石状态下管膜上磷脂酰乙醇胺三甲基化为磷脂酰胆碱的途径的活性，这可能与胆道胆固醇高分泌有关。该反应的副产物血浆和胆汁同型半胱氨酸的升高，可能作为一种产石标志，并揭示了邻近和远端器官功能障碍。iii)第三个目标将调查并明确证明，在Slc10a2小鼠严重胆汁盐吸收不良的情况下，胆红素和“黑色”色素胆结石的肠肝循环，并确定含有共价连接的胆酸（一种强胆红素粘合剂）的非吸收水凝胶的预防作用。或者-葡糖苷酸，1-4内酯，细菌-葡糖苷酸酶的有效抑制剂。iv)目标四将通过实验和分子动力学模拟计算出天然胆汁中共轭和非共轭胆红素的物理状态，并定义人类胆汁中“黑色”色素胆结石形成所需的热力学条件。v)第五个目标将探索与全肠外营养相关的胆汁淤积、色素“污泥”和胆结石形成，重点关注肠内饥饿导致的CCK和分泌素的缺乏。激素不足导致未结合胆红素的肠肝循环，从而产生高胆红素胆红素，也导致肝胆汁碱性降低，内源性-葡萄糖醛酸酶水解胆红素葡萄糖醛酸和胆红素钙沉淀发生。这些假设驱动的基础研究目标的结果将提供关联原生系统和模型系统的见解，并且应该很容易转化为预防和治疗人类这些常见的肝胆疾病。

DESCRIPTION (provided by applicant): The objectives of this application are to use biophysical and pathophysiologic rationale and physical, chemical, biochemical and molecular biologic techniques to advance fundamental understanding of bile and its two major dysfunctions, namely cholestasis and gallstones of both pigment and cholesterol types, i) The first aim will determine whether enterohepatic infection with Helicobacter rodentium and hepaticus, both common human and murine enterobiliary pathogens, is the final common trigger in cholesterol gallstone pathogenesis via nucleation of cholesterol supersaturated bile. Studies will be carried out on genetically gallstone-susceptible mice coupled with in vitro analysis of cholesterol nucleation from model and native biles as well as quantifying evidence of Helicobacter infection in human biliary tissues, ii) Aim two will quantify the activity of the pathway responsible for trimethylation of phosphatidylethanolamine to phosphatidylcholine on the canalicular membrane in the lithogenic state, which may be coupled with biliary cholesterol hypersecretion. Elevation of plasma and bile homocysteine, a by-product of this reaction, may serve as a lithogenic marker and shed light on vicinal and distal organ dysfunction, iii) The third aim will investigate, and unambiguously prove, enterohepatic cycling of bilirubin and 'black' pigment gallstones in the setting of severe bile salt malabsorption in the Slc10a2 null mouse and determine its prevention by nonabsorbed hydrogels containing covalently linked cholic acid, a strong bilirubin binder, or beta-glucaro,1-4 lactone, a potent inhibitor of bacterial beta-glucuronidase. iv) Aim four will work out, both experimentally and by molecular dynamic simulations, the physical states of conjugated and unconjugated bilirubins in native biles and define the thermodynamic conditions required for "black" pigment gallstone formation in human biles, v) The fifth aim will explore cholestasis and pigment "sludge" and gallstone formation associated with total parenteral nutrition, focusing on the lack of CCK and secretin from enteral starvation. The hormonal deficits cause enterohepatic cycling of unconjugated bilirubin which engenders hyperbilirubinbilia and also results in less alkaline hepatic bile, where endogenous beta-glucuronidase hydrolysis of bilirubin glucuronides and calcium bilirubinate precipitation occurs. The results of these hypothesis-driven basic research aims will provide insights that correlate native and model systems and should be readily translatable to prevent and treat these common hepatobiliarv diseases in humans.