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：
10581503
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 2025-02-28
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10581503
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 Cells Epithelium 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 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 Treatment Protocols Visualization Water Work apical membrane base bile canaliculus structure bile salts biliary tract chronic liver disease experimental study gastrointestinal transplantation human disease improved in vivo 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.

项目摘要背景和目的：微伏氏融合疾病（MVID）是由先天性腹泻的一种形式肌球蛋白VB（肌5b）中的灭活突变。 MVID个人的可用治疗选择是终身肠胃外营养或全肠移植。 MVID患者经常出现胆汁淤积。以前认为这种胆汁淤积是由总肠胃外的长时间施用引起的营养。但是，最近的出版物描述了Myo5b中没有导致MVID的突变，但相反，患者患有孤立的胆汁淤积。鉴于MVID的复杂性和有限的治疗选择可用，了解肌5b突变引起的胆汁淤积的发病机理代表需要解决的重要科学问题。该研究建议的核心假设是肌5b中的突变导致顶端/管膜转运蛋白的异常表达胆汁盐的正常分泌。我们以鼠标生成的初步数据为基础 MVID的猪模型表现出BSEP和其他管状转运蛋白的错误定位。我们的从Myo5b中突变患者的已发表报告反映了发现，表明异常肝细胞中胆汁盐输出蛋白（BSEP）的表达。迄今为止，没有实验动物模型用于定义MVID环境中胆汁淤积的机理。对于这个K01职业发展奖项，我建议使用种系Myo5b KO小鼠，MVID猪模型和一种新颖的鼠标模型 myo5b点突变，以解决由肝细胞中的顶型转运蛋白缺陷，这些肝细胞是由突变引起的 myo5b。具体目标1将定义肌5b在保持肝细胞极性和稳态。特定的目标2将确定Myo5b中C266R突变的机制有助于胆汁淤积，但不会导致MVID。完成这些研究后，我希望阐明了MyO5b在体内和体外肝细胞中蛋白质运输调节中的作用。这提案强调需要更好地理解Myo5b在肝细胞中的功能改善当前MVID治疗治疗的最终目标。长期目标和目标：成为获得K01职业发展奖的获得者将为必要的指导，培训和支持提供实现成为成为独立调查员的目标。这项研究非常适合美国国家研究所与消化和肝脏疾病有关的糖尿病，消化和肾脏疾病。范德比尔特大学医学中心提供完成该建议所需的所有科学资源。我有组建了一群著名的科学家，担任我的导师和指导委员会，并合作者。此外，我制定了一个培训计划来增强我的科学曲目，增加我的出版记录并获得独立资金。这将确保成功确保独立该奖项完成的职位是启动新实验室的职位。