The role of Myosin Vb in Hepatocyte Protein Trafficking

肌球蛋白 Vb 在肝细胞蛋白质运输中的作用

基本信息

批准号：
10401609
负责人：
Amy C Engevik
金额：
$ 13.35万
依托单位：
MEDICAL UNIVERSITY OF SOUTH CAROLINA
依托单位国家：
美国
项目类别：
财政年份：
2019
资助国家：
美国
起止时间：
2019-08-07 至 2024-02-29
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10401609
关键词：
AGFG1 gene Academic Medical Centers Actins Address Affect Albumins Animal Model Apical Award Bile Acids Binding Biological Assay Biological Models CRISPR/Cas technology Characteristics Cholestasis Common bile duct structure Complex Congenital Disorders Data Defect Development Diarrhea Digestive System Disorders Disease Disease model Endosomes Engineering Ensure Enterocytes Epithelial Epithelial Cells Experimental Animal Model Family suidae Feces Funding Future Generations Goals Hela Cells Hepatocyte Homeostasis Human Image Immunofluorescence Immunologic In Vitro Individual Injections Ink Intestines K-Series Research Career Programs Knockout Mice Laboratories Lead Life Liver Liver diseases Low-Density Lipoproteins MYO5A gene Measures Membrane Membrane Transport Proteins Mentors Mentorship Metabolism Microvillus inclusion disease Midazolam Modeling Molecular Motor Mus Mutation Myosin ATPase National Institute of Diabetes and Digestive and Kidney Diseases Nature Neonatal Organoids Parenteral Nutrition Pathogenesis Patients Point Mutation Positioning Attribute Production Protein Export Pathway Proteins Publications Publishing Pump Recycling Regulation Reporting Research Research Personnel Research Proposals Resources Role Scientist Secure Structure System Testing Therapeutic Total Parenteral Nutrition Training Training Support Treatment Protocols Water Work apical membrane base bile canaliculus structure bile salts biliary tract chronic liver disease experimental study gastrointestinal transplantation human disease improved in vivo individual patient innovation live cell imaging liver biopsy liver function mouse model neonatal mice novel porcine model prevent programs protein expression protein transport success tool trafficking uptake

项目摘要

PROJECT SUMMARY Background and aims: Microvillus Inclusion Disease (MVID) is a form of congenital diarrhea caused by inactivating mutations in Myosin Vb (MYO5B). The available treatment options for individuals with MVID are either lifelong total parenteral nutrition or full intestinal transplantation. MVID patients frequently present with cholestasis. This cholestasis was previously thought to arise from prolonged administration of total parenteral nutrition. However, recent publications have described mutations in MYO5B that do not result in MVID, but instead patients have isolated cholestasis. Given the complex nature of MVID and the limited treatment options available, understanding the pathogenesis of cholestasis resulting from mutations in MYO5B represents an important scientific question which needs to be addressed. The central hypothesis of this research proposal is that mutations in MYO5B result in aberrant expression of apical/canalicular membrane transporters preventing the normal secretion of bile salts. We base our hypothesis on preliminary data generated from our mouse and pig models of MVID which demonstrate mislocalization of BSEP and other canalicular transporters. Our findings are mirrored by published reports from patients with mutations in MYO5B, demonstrating aberrant expression of the bile salt export protein (BSEP) in hepatocytes. To date, no experimental animal model has been used to define the mechanism of cholestasis in the setting of MVID. For this K01 Career Development Award, I propose the use of germline MYO5B KO mice, an MVID pig model and a novel mouse model of MYO5B point mutation to address deficits in apical transporters in hepatocytes that arise from mutations in MYO5B. Specific Aim 1 will define the function of MYO5B in maintaining hepatocyte polarity and homeostasis. Specific Aim 2 will determine the mechanism by which the C266R mutation in MYO5B contributes to cholestasis, but does not result in MVID. At the completion of these studies I expect to have elucidated the role of MYO5B in the regulation of protein trafficking in hepatocytes in vivo and in vitro. This proposal highlights the need for a better understanding of the function of MYO5B in hepatocytes with the ultimate goal of improving current therapeutic treatments for MVID. Long-term objective and aims: Being the recipient of a K01 Career Development Award would provide the mentorship, training and support necessary to achieve my goal of becoming an independent investigator. This research is well suited for the National Institute of Diabetes and Digestive and Kidney Diseases as it relates to digestive and liver disorders. Vanderbilt University Medical Center offers all of the scientific resources required to complete this proposal. I have assembled a group of renowned scientists to serve as my mentors and mentorship committee, and as collaborators. Additionally, I have developed a training plan to enhance my scientific repertoire, increase my publication record and secure independent funding. This will ensure success in securing an independent position to start a new laboratory by the completion of this award.

项目概要背景和目的：微绒毛包涵体病（MVID）是一种由以下原因引起的先天性腹泻：肌球蛋白 Vb (MYO5B) 失活突变。 MVID 患者可用的治疗方案有终身全肠外营养或全肠移植。 MVID 患者经常出现胆汁淤积。以前认为这种胆汁淤积是由于长期注射全胃肠外药物引起的。营养。然而，最近的出版物描述了 MYO5B 的突变不会导致 MVID，但相反，患者有孤立性胆汁淤积。鉴于 MVID 的复杂性和有限的治疗选择现有的研究表明，了解 MYO5B 突变导致的胆汁淤积的发病机制代表了需要解决的重要科学问题。本研究提案的中心假设是 MYO5B 的突变导致心尖/小管膜转运蛋白的异常表达，从而阻止胆盐的正常分泌。我们的假设基于我们的鼠标生成的初步数据 MVID 猪模型显示 BSEP 和其他小管转运蛋白的错误定位。我们的已发表的来自 MYO5B 突变患者的报告也反映了这一发现，证明了异常肝细胞中胆汁盐输出蛋白（BSEP）的表达。迄今为止，尚无实验动物模型用于定义 MVID 情况下胆汁淤积的机制。对于本次K01职业发展奖，我建议使用种系 MYO5B KO 小鼠、MVID 猪模型和新型小鼠模型 MYO5B 点突变可解决因突变引起的肝细胞顶端转运蛋白缺陷 MYO5B。具体目标 1 将定义 MYO5B 在维持肝细胞极性和体内平衡。具体目标 2 将确定 MYO5B 中 C266R 突变的机制导致胆汁淤积，但不会导致 MVID。完成这些研究后，我希望能够阐明了 MYO5B 在体内和体外肝细胞蛋白质运输调节中的作用。这该提案强调需要更好地了解 MYO5B 在肝细胞中的功能最终目标是改善当前 MVID 的治疗方法。长期目标和目标：成为 K01 职业发展奖的获得者将提供必要的指导、培训和支持实现我成为一名独立调查员的目标。这项研究非常适合国家研究所糖尿病、消化和肾脏疾病，因为它与消化和肝脏疾病有关。范德比尔特大学医学中心提供完成该提案所需的所有科学资源。我有召集了一批著名的科学家作为我的导师和指导委员会，并作为合作者。此外，我还制定了一项培训计划，以增强我的科学能力，提高我的能力。出版记录并确保独立资金。这将确保成功确保独立该奖项完成后将启动一个新的实验室。