AAV mediated gene knockdown of PIK3C2B as a therapeutic strategy for X-linked myotubular myopathy and fatty liver disease

AAV 介导的 PIK3C2B 基因敲低作为 X 连锁肌管肌病和脂肪肝的治疗策略

• 批准号: 10753786
• 负责人: JAMES J DOWLING
• 金额: $ 19.66万
• 依托单位: RESEARCH INST NATIONWIDE CHILDREN'S HOSP
• 依托单位国家: 美国
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-07-18 至 2025-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10753786
• 关键词: 1-Phosphatidylinositol 4-Kinase; Adult; Affect; American; Animals; Birth; Body Weight decreased; C2 Domain; Cessation of life; Charcot-Marie-Tooth Disease; Chemicals; Childhood; Cirrhosis; Clinical; Data; Dependence; Deposition; Development; Diet; Disease; Endosomes; Enteral Feeding; Enzyme Inhibition; Exercise; Exploratory/Developmental Grant; Facioscapulohumeral; Facioscapulohumeral Muscular Dystrophy; Fatty Liver; Fatty acid glycerol esters; Functional disorder; Genes; Genetic; Goals; Hepatobiliary; Human; In Vitro; Individual; Knock-out; Knockout Mice; Life; Liver; Liver Failure; Liver diseases; Malignant Neoplasms; Malignant neoplasm of liver; Mediating; Metabolism; MicroRNAs; Modeling; Molecular; Mus; Muscle; Muscle hypotonia; Natural History; Neuromuscular Diseases; Organ; PIK3CG gene; PMP22 gene; Pathology; Patients; Phenocopy; Phenotype; Phosphotransferases; Positioning Attribute; Pre-Clinical Model; Process; Proteins; RNA; Reducing diet; Regulation; Reporting; Risk; Role; Skeletal Muscle; Survivors; Symptoms; Testing; Therapeutic; Therapeutic Uses; Time; Translating; Translations; Ventilator; Vesicle; Weight Gain; Wheelchairs; Wild Type Mouse; X-linked myotubular myopathy; clinical translation; comorbidity; delivery vehicle; disability; disease-causing mutation; efficacy evaluation; fatty liver disease; gene therapy; genetic approach; improved; in vivo; infancy; inhibitor; insulin sensitivity; knock-down; knockout gene; metabolic phenotype; metabolic profile; mouse model; neurogenetics; non-alcoholic; non-alcoholic fatty liver disease; nonalcoholic steatohepatitis; novel; novel therapeutics; overexpression; patient subsets; phosphatidylinositol phosphate 4-kinase; prevent; promoter; rare condition; success; therapy development; trafficking

PROJECT SUMMARY/ABSTRACT PIK3C2B encodes the class II PI3 kinase Phosphatidylinositol-4-phosphate 3-kinase C2 domain-containing beta (PIK3C2B) protein, a regulator of vesicle trafficking through the endosome. Mouse knockout of Pik3c2b has no overtly deleterious phenotype, but instead promotes a beneficial metabolic profile that includes reduced weight gain, improved insulin sensitivity, and, most relevant for this proposal, reduced fat deposition in the liver. In addition, we have previously shown that genetic reduction of Pik3c2b can both prevent and reverse the skeletal muscle phenotype, as well as extend survival, of the mouse model of X-linked myotubular myopathy (XLMTM). XLMTM is rare neurogenetic condition with onset in infancy that is associated with profound muscle related disabilities and early death. In addition to affecting the skeletal muscle, an emerging XLMTM phenotype is hepatobiliary disease, which progresses to liver failure in a subset of patients. There are no treatments for XLMTM. Importantly, liver disease has not previously been identified in pre-clinical models of XLMTM, a significant barrier for disease understanding and treatment. To overcome this barrier, in new data, we have developed the first mouse model of XLMTM liver disease. Non-alcoholic fatty liver disease (NAFLD) is a highly prevalent condition that affects nearly 25% of American adults. It can lead to non-alcoholic hepatosteatosis (NASH), which in turn can progress to cirrhosis, liver failure, liver cancer, and death. There are no adequate therapies for these common and severe conditions. The scientific premise of this proposal is that reduction of PIK3C2B in mice promotes reduction of diet induced fatty liver and amelioration of disease relevant XLMTM phenotypes. The overall goal of the project is to develop therapies for XLMTM and NAFLD/NASH using a RNA knockdown based gene therapy. We hypothesize the following: (1) PIK3C2B knockdown in muscle and liver can be specifically, lastingly, and safely achieved with a synthetic miRNA delivered in vivo with AAV8 (AAV-miR-PIK3C2B); (2) AAV-miR- PIK3C2B can ameliorate both muscle and liver and phenotypes of the XLMTM mouse model; and (3) AAV-miR- PIK3C2B can prevent the development and progression of diet induce mouse NAFLD/NASH. These hypotheses will be rigorously evaluated in 3 aims. Aim 1 will develop AAV-miR-PIK3C2B, Aim 2 will test it in XLMTM mice, and Aim 3 will study it in a diet induced model of NASH. If successful, this proposal will be of high significance and impact because it will identify a single therapy suitable for clinical translation for both a rare, fatal paediatric condition and for a prevalent disease affecting millions of adults.

项目总结/摘要 PIK 3C 2B编码II类PI 3激酶磷脂酰肌醇-4-磷酸3-激酶C2结构域的β （PIK 3C 2B）蛋白，其是囊泡通过内体运输的调节剂。敲除Pik 3c 2b的小鼠没有 明显有害的表型，而是促进有益的代谢特征，包括减轻体重 增加，改善胰岛素敏感性，并且与该提议最相关的是，减少肝脏中的脂肪沉积。在 此外，我们之前已经表明，Pik 3c 2b的遗传减少可以预防和逆转骨骼肌损伤， 肌肉表型，以及延长生存期，小鼠模型的X连锁肌管性肌病（XLM ™）。 XLMTM是一种罕见的神经遗传性疾病，在婴儿期发病，与深刻的肌肉相关 残疾和早逝。除了影响骨骼肌，一种新兴的XLMTM表型是 肝胆疾病，在一部分患者中进展为肝功能衰竭。没有治疗方法 XLMTM。重要的是，肝脏疾病以前没有被确定在临床前模型的XLMTM， 对疾病理解和治疗的重大障碍。为了克服这一障碍，在新的数据中，我们有 开发了第一个XLMTM肝病小鼠模型。 非酒精性脂肪肝（NAFLD）是一种高度流行的疾病，影响着近25%的美国人 成年人了它可以导致非酒精性脂肪肝（NASH），这反过来又可以进展为肝硬化，肝功能衰竭， 肝癌和死亡对于这些常见和严重的疾病没有适当的治疗方法。 该提议的科学前提是小鼠中PIK 3C 2B的减少促进了饮食诱导的PIK 3C 2B的减少。 脂肪肝和改善疾病相关的XLMTM表型。该项目的总体目标是开发 使用基于RNA敲低的基因疗法治疗XLMTM和NAFLD/NASH。 我们假设如下：（1）肌肉和肝脏中的PIK 3C 2B敲低可以是特异性的、持久的， 用AAV 8（AAV-miR-PIK 3C 2B）体内递送的合成miRNA安全地实现;（2）AAV-miR-PIK 3C 2B; PIK 3C 2B可以改善XLMTM小鼠模型的肌肉和肝脏以及表型;以及（3）AAV-miR-3C 2B可以改善XLMTM小鼠模型的肌肉和肝脏以及表型。 PIK 3C 2B可以阻止饮食诱导的小鼠NAFLD/NASH的发生和进展。 这些假设将在3个目标中进行严格评估。目标1将开发AAV-miR-PIK 3C 2B，目标2将测试 目的3将在饮食诱导的NASH模型中研究它。如果成功的话，这一提议将是 因为它将确定一种适用于临床转化的单一疗法， 罕见、致命的儿科疾病和影响数百万成年人的流行病。