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

• 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
• 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

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：微绒毛包涵体病（MVID）是一种先天性腹泻， 肌球蛋白Vb（MYO 5 B）失活突变。MVID患者可用的治疗方案包括 终身全胃肠外营养或全肠移植。MVID患者经常出现 胆汁淤积这种胆汁淤积以前被认为是由于长期给予全胃肠外 营养然而，最近的出版物已经描述了MYO 5 B中的突变，其不导致MVID，但 相反，患者具有孤立的胆汁淤积。鉴于MVID的复杂性和有限的治疗选择 了解MYO 5 B突变引起的胆汁淤积的发病机制， 需要解决的重要科学问题。这项研究的核心假设是 MYO 5 B突变导致顶端/小管膜转运蛋白的异常表达， 胆汁盐的正常分泌。我们的假设基于我们的小鼠产生的初步数据， MVID的猪模型，证明BSEP和其他小管转运蛋白的错误定位。我们 MYO 5 B突变患者的已发表报告反映了这一发现， 胆盐输出蛋白（BSEP）在肝细胞中的表达。迄今为止，没有实验动物模型 已被用于定义MVID背景下胆汁淤积的机制。K 01职业发展 奖，我建议使用生殖系MYO 5 B KO小鼠，MVID猪模型和一种新的小鼠模型， MYO 5 B点突变可解决肝细胞顶端转运蛋白突变引起的缺陷 MYO5B。特异性目标1将定义MYO 5 B在维持肝细胞极性中的功能， 体内平衡特异性目的2将确定MYO 5 B中C266 R突变的机制， 导致胆汁淤积，但不导致MVID。在完成这些研究后，我希望 阐明了MYO 5 B在体内和体外调节肝细胞中蛋白质运输的作用。这 该提案强调需要更好地了解MYO 5 B在肝细胞中的功能， 最终目标是改善目前MVID的治疗方法。长期目标和宗旨： K 01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、消化系统疾病和肾脏疾病，因为它与消化系统和肝脏疾病有关。范德比尔特 大学医学中心提供完成此提案所需的所有科学资源。我有 召集了一群著名的科学家作为我的导师和导师委员会， 合作者此外，我还制定了一个训练计划，以提高我的科学技能，增加我的 出版记录并获得独立资金。这将确保成功地获得一个独立的 在完成该奖项后，我们将开始新的实验室。