Creation and correction of Spinal Muscular Atrophy in the pig

猪脊髓性肌萎缩症的产生和矫正

基本信息

批准号：
8702801
负责人：
ARTHUR H. M. BURGHES
金额：
$ 37.95万
依托单位：
OHIO STATE UNIVERSITY
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-04-01 至 2016-03-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8702801
关键词：
Address Affect Age Animal Model Animals Atrophic Axon Birth Blood - brain barrier anatomy Blood Vessels Brain Cause of Death Cells Cerebrospinal Fluid Cessation of life Child Clinical Clinical Trials Dependovirus Detection Development Disease Ensure Family suidae Functional disorder Future Gait Gene Transduction Agent Genes Genetic Human Immunosuppression Infant Injection of therapeutic agent Intervention Intrathecal Injections Limb structure Longevity Messenger RNA Modeling Monkeys Motor Motor Neurons Mus Mutation Neoadjuvant Therapy Neurologic Neurons Pathology Patients Phenotype Production Ramp Route SMN protein (spinal muscular atrophy)SMN2 gene Series Severities Spinal Cord Spinal Ganglia Spinal Muscular Atrophy Staging Symptoms Testing Therapeutic Therapeutic Agents Therapeutic Intervention Time Transcript Treatment Efficacy Treatment Protocols Vascular System Ventilator Virus Walking cell type clinically relevant design gene therapy infant death knock-down mouse model neuron loss programs public health relevance research study restoration small hairpin RNA success transduction efficiency vector

项目摘要

DESCRIPTION (provided by applicant): Spinal muscular atrophy (SMA) is an autosomal recessive disorder which is the most common genetic cause of infant death. SMA is caused by loss or mutation of survival motor neuron 1 gene (SMN1) and retention of the SMN2 gene, which leads to insufficient levels of SMN for motor neurons. Introduction of scAAV9-SMN either through the vascular system or via intrathecal (CSF) delivery in SMA mice results in a marked correction of the phenotype. The advantage of intrathecal delivery is the lower titer of virus that can be used for correction, thus simplifying the production of scAAV9-SMN. While the efficiency of transduction of motor neurons has been investigated in pig and in monkeys, the ability to correct a SMA phenotype in a large animal model has not been investigated. This is due to fact that there is no large animal model of SMA currently available. A large animal model of SMA can be used to address the importance of high SMN levels in motor neurons, the efficiency of SMN transduction required to obtain a clinical benefit, and when SMN needs to be induced to obtain clinical benefit. We therefore propose to optimize scAAV9-SMN delivery to motor neurons in a clinically relevant large animal porcine model of SMA and develop gene therapy protocols for the treatment of SMA in this model. In particular, we will address transduction efficiency including repeat administration and when SMN must be introduced to correct a pig model of SMA. We will create the pig SMA model by reducing SMN in the required neurons using scAAV9- shRNA: SMN knockdown. The shRNA is specific for pig SMN and does not affect the levels of human SMN. The shRNA is delivered via intrathecal delivery of a scAAV9shRNA construct that expresses SMN and GFP. Injection is performed in 5-day-old piglets and EMG, clinical presentation, and a ramp test will be used to evaluate the affected pig. The GFP can be used to follow the efficiency of motor neuron transduction and EMG to follow the progression of functional motor neuron loss. We will then introduce scAAV9-SMN at various stages of the disease including pre-symptomatic, at the first signs of phenotype, and later stages when the hind limbs are severely weak. Furthermore, we will determine if restoration of SMN levels must occur prior to CMAP and MUNE reduction, which will in turn indicate when SMN needs to be restored in SMA patients to obtain the greatest clinical benefit. These experiments will set the parameters for all SMN induction therapies in SMA and allow determination of when to introduce a therapeutic agent.

描述（由申请人提供）：脊柱肌肉萎缩（SMA）是一种常染色体隐性疾病，是婴儿死亡的最常见遗传原因。 SMA是由生存运动神经1基因（SMN1）的丧失或突变引起的，SMN2基因的保留率导致运动神经元的SMN水平不足。通过血管系统或通过鞘内（CSF）递送在SMA小鼠中引入SCAAV9-SMN导致表型的明显校正。鞘内递送的优点是病毒的下滴度可用于校正，从而简化SCAAV9-SMN的产生。虽然已经在猪和猴子中研究了运动神经元转导的效率，但尚未研究大型动物模型中SMA表型的能力。这是由于目前没有SMA的大型动物模型。 SMA的大动物模型可用于解决运动神经元中高SMN水平的重要性，获得临床益处所需的SMN转导效率，以及需要引起SMN何时获得临床益处。因此，我们建议在SMA的临床大型动物猪模型中优化SCAAV9-SMN向运动神经元的传递，并在此模型中开发用于治疗SMA的基因治疗方案。特别是，我们将解决转导效率，包括重复给药，以及必须引入SMN以纠正SMA的猪模型。我们将使用SCAAV9-SHRNA：SMN敲除在所需的神经元中减少SMN来创建PIG SMA模型。 shRNA是特异性的，不影响人类SMN的水平。 shRNA是通过鞘内递送的SCAAV9SHRNA构建体传递的，该构建体表达SMN和GFP。注射在5天大的小猪和EMG，临床表现中进行，坡道测试将用于评估受影响的猪。 GFP可用于遵循运动神经元转导和EMG的效率，以跟随功能性运动神经元丧失的进展。然后，我们将在该疾病的各个阶段引入SCAAV9-SMN，包括症状前，在表型的第一迹象上，后来的后肢严重较弱。此外，我们将确定是否必须在CMAP和Mune降低之前进行SMN水平的恢复，这反过来又表明何时需要在SMA患者中恢复SMN以获得最大的临床益处。这些实验将设置SMA中所有SMN诱导疗法的参数，并确定何时引入治疗剂。