Therapeutic Potent. of e-sarcoglycan in LGMD Type 2D

治疗功效强。

• 批准号: 6881444
• 负责人: KEVIN P. CAMPBELL
• 金额: $ 34.66万
• 依托单位: UNIVERSITY OF IOWA
• 依托单位国家: 美国
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-04-01 至 2009-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6881444
• 关键词: cytoskeletal proteins; dystrophin; gene expression; gene therapy; genetic disorder; genetically modified animals; glycoproteins; laboratory mouse; muscle proteins; muscular dystrophy; nonhuman therapy evaluation; protein isoforms; transfection /expression vector

DESCRIPTION (provided by applicant): The long-term goal of this project is to design a therapy for autosomal recessive limb-girdle muscular dystrophy type 2D (LGMD-2D), which is due to aberrations in the (-sarcoglycan gene (Sgca), and affects mainly limb and girdle muscles to lead to progressive muscle fiber necrosis and weakness, Alpha-Sarcoglycan interacts with beta-, gamma-, and delta-sarcoglycan to form a subcomplex that increases the overall stability of the dystrophin-glycoprotein complex (DGC). Epsilon-Sarcoglycan is a ubiquitously expressed homologue of the muscle-specific alpha- sarcoglycan, sharing 43% identity and a similar protein structure. Epsilon-Sarcoglycan expression is detected as early as day E8.5 in mouse embryos before the detection of alpha-sarcoglycan at E15, and preliminary data shows increased detection during muscle regeneration suggesting that epsilon-sarcoglycan is embryonic or developmental form of alpha-sarcoglycan. This project focuses on exploring the therapeutic potential of upregulating epsilon-sarcoglycan levels for the treatment of LGMD-2D. The First Aim hypothesizes that increased expression of epsilon-sarcoglycan will replace alpha-sarcoglycan within the DGC. Characterization of transgenic mice with targeted overexpression of epsilon-sarcoglycan to muscle will test this hypothesis. The Second Aim hypothesizes that increased expression of epsilon-sarcoglycan will compensate for an aberrant alpha-sarcoglycan to prevent the onset of muscular dystrophy. Analysis of Sgca-null mice overexpressing epsilon-sarcoglycan will test this hypothesis. The Final Aim hypothesizes that increased and sustained epsilon-sarcoglycan expression in alpha-sarcoglycan deficiency will prevent further muscle pathology and repair the primary membrane defect to allow for normal muscle function. Adult Sgca-null mice will be intramuscularly injected with rAAVl epsilon-sarcoglycan and analyzed. This project will investigate the functional and physiological consequences of increased levels of epsilon-sarcoglycan to prevent and treat muscular dystrophy in alpha-sarcoglycan deficiency. The overall results of these experiments will develop the possibility of increased epsilon-sarcoglycan expression to compensate for (-sarcoglycan in LGMD-2D patients. Focusing on an endogenous protein like epsilon-sarcoglycan will bypass any acquired therapeutic immune response, and provides a platform for new targets for therapy and drug treatments aimed at up-regulating epsilon-sarcoglycan

描述（由申请人提供）：该项目的长期目标是设计一种治疗常染色体隐性肢带型肌营养不良症 2D 型（LGMD-2D）的疗法，该病是由于 α-肌聚糖基因（Sgca）的畸变引起的，主要影响肢和带肌肉，导致进行性肌纤维坏死和无力，α-肌聚糖 与 β-、γ- 和 δ-肌聚糖相互作用形成亚复合物，提高肌营养不良蛋白-糖蛋白复合物 (DGC) 的整体稳定性。 Epsilon-肌聚糖是肌肉特异性 α-肌聚糖的普遍表达的同源物，具有 43% 的同一性和相似的蛋白质结构。 早在 E8.5 天，小鼠胚胎中就检测到了 ε-肌聚糖表达，然后在 E15 检测到 α-肌聚糖，初步数据显示，在肌肉再生过程中检测量增加，表明 ε-肌聚糖是 α-肌聚糖的胚胎或发育形式。该项目的重点是探索上调的治疗潜力 用于治疗 LGMD-2D 的ε-肌聚糖水平。第一个目标假设 DGC 内 ε-肌聚糖表达的增加将取代 α-肌聚糖。对肌肉定向过度表达ε-肌聚糖的转基因小鼠的表征将检验这一假设。第二个目标假设增加ε-肌聚糖的表达将 补偿异常的α-肌聚糖以预防肌营养不良症的发生。对过度表达ε-肌聚糖的 Sgca 缺失小鼠的分析将检验这一假设。最终目标假设，α-肌聚糖缺乏症中ε-肌聚糖表达的增加和持续将防止进一步的肌肉病理学并修复初级膜缺陷，以允许正常的肌肉 功能。将rAAV1ε-肌聚糖肌肉注射到成年Sgca-null小鼠并进行分析。该项目将研究增加ε-肌聚糖水平的功能和生理后果，以预防和治疗α-肌聚糖缺乏症引起的肌营养不良。这些实验的总体结果将开发增加ε-肌聚糖表达的可能性 补偿 LGMD-2D 患者中的 (-肌聚糖)。专注于像 epsilon-肌聚糖这样的内源性蛋白质将绕过任何获得性治疗性免疫反应，并为旨在上调 epsilon-肌聚糖的治疗和药物治疗的新靶标提供平台