Targeted Therapy for Pompe Disease

7.项目总结/摘要 庞贝氏症是一种致命的神经肌肉疾病，其起因于编码酸的基因突变。 α-葡糖苷酶（GAA）-溶酶体糖原水解所必需的酶。通气不足和呼吸 不足是庞贝氏症突出特征，其导致未经治疗的婴儿呼吸衰竭。 虽然呼吸问题传统上被归因于呼吸肌和运动神经元 病理学，我们最近描述了平滑肌（SM）病理学在呼吸系统中的重要作用， 这种疾病的相关发病率。目前，Pompe患者唯一获得FDA批准的治疗方法是 酶替代疗法（ERT）。ERT显著提高了生存率，但随着患者寿命的延长， 威胁性SM病理，如破裂的血管动脉瘤和气道虚弱，已被揭露。 ERT后残留SM受累和细胞功能障碍的程度仍不清楚， 这个项目的重点。此外，我们还将研究腺相关病毒（AAV）基因治疗在 治疗庞贝氏症AAV基因疗法对于单基因疾病如庞贝氏症是理想的， 然而，靶向SM、骨骼、心脏和运动神经元的用于婴儿庞贝氏症的AAV的证据 仍然缺乏。我们提出了一系列的临床前实验，直接解决SM溶酶体糖原 本发明的目的是为了研究AAV载体在庞贝氏症中的累积，并探索AAV载体靶向所有受影响的肌肉群的功效。 和运动神经元。我们将重点关注靶向SM溶酶体糖原的腺相关病毒血清型和启动子 蓄积以及心脏、骨骼和运动神经元病理学。总体看 推动这一建议的基本假设是，广泛的平滑肌糖原积累 尽管有ERT，仍然存在庞贝氏症，并且新的AAV载体是治疗光滑， 骨骼、心脏和运动神经元病理学。我们的假设是基于 在庞贝氏症小鼠模型中的数据以及在我们的庞贝氏症患者中观察到的临床证据。三 将使用已建立的庞贝氏症小鼠模型来实现特定的目的：目的1： 全面检查呼吸和血管SM参与庞贝氏症和这种影响， 自噬失调的病理学目的2：比较早期和晚期ERT对呼吸和血管SM的影响 功能和糖原积累。目的3：检查新的合理设计的AAV 8 g9-GAA的能力 有效地抑制和清除SM、骨骼肌和运动神经元糖原积累， AAV 8和AAV 9。该项目将解决关于平滑肌功能障碍的知识差距， 确定新型腺相关病毒疗法治疗婴儿庞贝氏症的潜力，以显着降低发病率， mortality.

7. PROJECT SUMMARY/ABSTRACT Pompe disease is a fatal neuromuscular disorder that results from mutations in the gene encoding acid α-glucosidase (GAA) - an enzyme necessary for lysosomal glycogen hydrolysis. Hypoventilation and respiratory insufficiency are prominent features of Pompe disease that result in respiratory failure in untreated infants. Although breathing problems have traditionally been attributed to respiratory muscle and motor neuron pathology, we recently described the significant role of smooth muscle (SM) pathology in the respiratory- related morbidity of this disease. Currently, the only FDA approved therapy available to Pompe patients is enzyme replacement therapy (ERT). ERT has significantly increased survival but as patients live longer, life threatening SM pathology such as ruptured vascular aneurysms and airway weakness, has been unmasked. The extent of residual SM involvement and cellular dysfunction following ERT remains unknown and will be a focus of this project. In addition, we will study the efficacy of adeno-associated viral (AAV) gene therapy in treating Pompe SM involvement. AAV gene therapy is ideal for monogenetic disorders such as Pompe disease, however evidence of an AAV for infantile Pompe disease that targets SM, skeletal, cardiac and motor neurons is still lacking. We propose a series of pre-clinical experiments that directly address SM lysosomal glycogen accumulation in Pompe disease and explore the efficacy of AAV vectors in targeting all affected muscle groups and motor neurons. We will focus on an AAV serotype and promoter that targets SM lysosomal glycogen accumulation as well as cardiac, skeletal and motor neuron pathology in Pompe disease. Overall, the fundamental hypothesis driving this proposal is that extensive smooth muscle glycogen accumulation persists in Pompe disease despite ERT and that a novel AAV vector is necessary to treat smooth, skeletal, cardiac, and motor neuron pathology. Our hypothesis has been formulated based on preliminary data in the Pompe disease mouse model as well as clinical evidence seen in our Pompe disease patients. Three specific aims will be accomplished using an established mouse model of Pompe disease: Aim 1: To comprehensively examine respiratory and vascular SM involvement in Pompe disease and the impact of this pathology on autophagic dysregulation. Aim 2: To compare early and late ERT on respiratory and vascular SM function and glycogen accumulation. Aim 3: To examine the ability of a novel rationally designed AAV8g9-GAA to effectively transduce and clear SM, skeletal muscle, and motor neuron glycogen accumulation in comparison to AAV8 and AAV9. This project will address a gap in knowledge regarding smooth muscle dysfunction and will identify the potential of a novel AAV therapy for infantile Pompe disease to significantly reduce morbidity and mortality.