Uncovering cellular mechanisms to keep glycogen water-soluble

揭示保持糖原水溶性的细胞机制

• 批准号: 10621861
• 负责人: Felix Nitschke
• 金额: $ 40.99万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-05-15 至 2027-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10621861
• 关键词: Affect; Binding Proteins; Biochemistry; Biological Process; Cell physiology; Cells; Characteristics; Data; Deposition; Disease; Foundations; Genetic; Glycogen; Glycogen Branching Enzyme; Goals; Hand; Health; Heart; Impairment; In Vitro; Individual; Knowledge; Lafora Disease; Link; Liver; Modeling; Molecular; Mus; Muscle; Pathogenicity; Pathology; Phosphoric Monoester Hydrolases; Phosphorylation; Phosphotransferases; Physiological; Positioning Attribute; Precipitation; Prevention; Prevention approach; Proteome; Proteomics; Publishing; Rare Diseases; Regulation; Risk; Role; Solubility; Testing; Therapeutic; Water; Work; biochemical tools; brain tissue; genetic manipulation; glycogen metabolism; grasp; improved; in vivo; inorganic phosphate; mouse model; neuropathology; novel; novel therapeutic intervention; overexpression; polyglucosan; prevent; rare genetic disorder; reconstitution; tool; water solubility

Project Summary: Glycogen metabolism is impaired in >20 individual rare genetic diseases. Several of these diseases are caused by the formation of insoluble glycogen, which deposits in polyglucosan bodies (PBs). Without treatment currently available, PB accumulation causes pathology in liver, muscle, heart, and/or brain tissue. The mechanisms underlying the prevention of pathogenic insoluble glycogen are poorly understood. The PI’s work with established mouse models of polyglucosan body diseases links both glycogen phosphate and branching directly to glycogen solubility and imply a functional interdependence of phosphate and branching. The objective of this proposal is to identify how phosphate covalently linked to glycogen and glycogen branching impacts glycogen solubility in health and disease, and whether genetic modulation of each factor can decrease pathogenic PB accumulation in vivo. Utilizing novel in vitro and in vivo approaches, the proposed work will test the central hypothesis that glycogen phosphorylation and glycogen branching 1) are interrelated cellular processes that affect the solubility of glycogen, and 2) that when genetically manipulated can improve the physiological functionality of glycogen. Aim 1 characterizes the impact of glycogen phosphate, branching, and associated proteome on the precipitation risk of soluble glycogen in mouse models with insoluble glycogen accumulation. Analyses and experimental manipulation of these parameters will provide a mechanistic explanation for the structural changes in soluble glycogen that lead to glycogen insolubility. Aim 2 focuses on the impact and regulation of phosphorylation during glycogen synthesis, to interrogate glycogen phosphate as part of a GBE1-regulated protection mechanism of the cell to prevent glycogen insolubility. Aim3 determines the potential of enhanced branching in the prevention of insoluble glycogen. The impact of branching on glycogen precipitation risk will be characterized, and a new therapeutic approach for polyglucosan body diseases will be provided. This proposal uses established mouse models with PB-triggered pathology. In addition, two new mouse lines were generated, to separately modulate glycogen phosphate and branching in vivo. Combined with state-of-the-art glycogen biochemistry and proteomics, these new tools provide a unique opportunity to tease apart the interrelations of glycogen phosphate and branching and their effects on glycogen solubility. The proposed work can (1) shift the paradigm of glycogen phosphate being detrimental for glycogen solubility to phosphate as a protection mechanism from glycogen insolubility, (2) reveal regulatory connections between glycogen branching and phosphorylation, as well as (3) lead to the discovery of unknown glycogen kinases. It will (4) lay the ground work for new therapeutic approaches for polyglucosan body diseases and (5) provide a better grasp of vital cellular processes related to glycogen metabolism with implications for several rare diseases.

项目概要： 糖原代谢在超过 20 种罕见遗传性疾病中受损。 由不溶性糖原的形成引起，该糖原沉积在聚葡聚糖体 (PB) 中。 目前可用的治疗方法是，PB 积累会导致肝脏、肌肉、心脏和/或脑组织出现病变。 预防致病性不溶性糖原的机制尚不清楚。 与已建立的多聚葡萄糖体疾病小鼠模型的合作将磷酸糖原和 支化直接影响糖原溶解度，意味着磷酸盐和支化之间存在功能上的相互依赖性。 该提案的目的是确定磷酸盐如何与糖原和糖原共价连接 分支会影响健康和疾病中的糖原溶解度，以及每个因素的遗传调节是否 利用新颖的体外和体内方法，可以减少体内致病性 PB 的积累。 拟议的工作将检验糖原磷酸化和糖原分支 1) 的中心假设 影响糖原溶解度的相互关联的细胞过程，以及 2) 当基因操纵时 可以提高糖原的生理功能。 目标 1 描述了磷酸糖原、分支和相关蛋白质组对 具有不溶性糖原积累的小鼠模型中可溶性糖原的沉淀风险分析和。 这些参数的实验操作将为结构提供机械解释 目标 2 关注可溶性糖原的变化导致糖原不溶的影响和调节。 糖原合成过程中的磷酸化，以询问磷酸糖原作为 GBE1 调节的一部分 Aim3防止细胞糖原不溶的保护机制决定了增强的潜力。 分支对预防不溶性糖原的影响 分支对糖原沉淀的风险会产生影响。 对其进行表征，将为多聚葡萄糖体疾病提供一种新的治疗方法。 该提案使用已建立的具有 PB 触发病理学的小鼠模型。此外，还研究了两个新的小鼠品系。 产生，与最先进的技术相结合，分别调节磷酸糖原和体内分支。 糖原生物化学和蛋白质组学，这些新工具提供了一个独特的机会来梳理 磷酸糖原和支化的相互关系及其对糖原溶解度的影响。 工作可以（1）将磷酸糖原因糖原溶解度不佳而转变为磷酸盐 作为糖原不溶性的保护机制，(2) 揭示糖原之间的调节联系 分支和磷酸化，以及（3）导致未知糖原激酶的发现（4）。 为聚葡萄糖体疾病的新治疗方法奠定基础；(5) 提供更好的治疗方法 掌握与糖原代谢相关的重要细胞过程，对几种罕见疾病具有影响。