Oligonucleotides that Modulate AMPA Receptor Alternative Splicing as Drug Candida

作为药物念珠菌调节 AMPA 受体选择性剪接的寡核苷酸

• 批准号: 8199864
• 负责人: GORDON J LUTZ
• 金额: $ 31.5万
• 依托单位: LIFESPLICE PHARMA, LLC
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-08-01 至 2013-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8199864
• 关键词: AMPA Receptors; Age; Alternative Splicing; Amyotrophic Lateral Sclerosis; Blood - brain barrier anatomy; Bolus Infusion; Brain; Brain Stem; Candida; Cannulas; Cell Nucleus; Cessation of life; Clinical Trials; Diagnosis; Dose; Familial Amyotrophic Lateral Sclerosis; Glutamates; Infusion procedures; Injection of therapeutic agent; Intrathecal Injections; Ion Channel; Lead; Length; Longevity; Measures; Mediating; Mediator of activation protein; Membrane; Modality; Motor; Motor Cortex; Motor Neurons; Mus; Nerve Degeneration; Oligonucleotides; Onset of illness; Pathology; Patients; Pharmaceutical Preparations; Phase; Protein Isoforms; RNA; RNA Splicing; Resistance; Spinal; Spinal Canal; Spinal Cord; Spinal Injections; System; Therapeutic; Time; Toxicology; Transcript; Variant; Vertebral column; base; comparative efficacy; density; desensitization; design; drug candidate; drug development; excitotoxicity; improved; neuron loss; novel; product development; research study; response

DESCRIPTION (provided by applicant): Amyotrophic lateral sclerosis (ALS) is characterized by the progressive and selective loss of motor neurons (MNs) in the motor cortex, brainstem, and spinal cord, resulting in death of patients typically 2-5 years after diagnosis. Glutamate-mediated excitotoxicity in the CNS has been implicated as a major contributor to MN cell death in ALS. It is thought that the vulnerability of MNs to glutamate-mediated excitotoxicity is due to a combination of their high density of Ca2+ permeable ion channels, and their diminished capacity to handle excessive Ca2+ influx, which serves as a trigger for neurodegeneration. Why MNs of ALS patients are especially vulnerable to excitotoxicity remains unknown, but there is nearly universal acceptance that excitotoxicity contributes to selective death on MNs in ALS patients. Therefore, the development of drugs which lower Ca2+ influx during excitatory activity in the CNS, is a crucial focal point in the pursuit for therapeutics for ALS. Ionotropic AMPA receptors are glutamate-activated ion channels that are key mediators of Ca2+ influx in MNs. AMPA receptors are composed of four subunits termed GluR1-4. Two alternatively spliced variants of all four GluRs called "flip" and "flop" are normally expressed in the CNS and are known to modulate AMPA channel conductance. AMPA channels containing GluR-flip isoforms are 'higher gain' channels, which have greater current amplitudes and/or greater resistant to glutamate-desensitization than the 'lower gain' AMPA channels containing "flop" variants. Thus, when the flip/flop ratios of GluRs are elevated, AMPA receptors in MNs show enhanced excitatory activity, and greater Ca2+ influx. We recently developed several novel chemically-modified RNA oligonucleotides, called splice modulating oligomers (SMOs), which potently and specifically modulate GluR alternative splicing to reduce the flip/flop ratio of various GluR isoforms. Although SMOs do not cross the blood-brain-barrier, after direct delivery into the CSF they are broadly distributed throughout the CNS and have the extraordinary capacity to readily to cross the membrane and enter the nuclei of cells in the CNS, where their splice modulating activity persists for months. Here we propose a translational set of experiments to validate the potential of our SMOs as therapeutics for treating ALS. First, we will compare the efficacy of our lead SMO (LSP-GR3) in reducing GluR3-flip expression throughout the CNS, using (1) continuous ICV delivery, and (2) single bolus injection into the lumbar sac of the spinal column (Aim 1). We will then use the best delivery modality determined in Aim 1 and evaluate the efficacy of our two lead SMOs to improve motor function, and increase lifespan in ALS mice (Aim 2). PUBLIC HEALTH RELEVANCE: This proposal is designed to provide the 'proof of principle' that novel drug candidates developed by LifeSplice Pharma, LLC are efficacious at ameliorating pathology in ALS mice. These studies will lead to formal toxicology analysis, and ultimately an IND application and FDA approval for clinical trials in ALS patients.

描述（由申请人提供）： 肌萎缩侧索硬化症 (ALS) 的特点是运动皮层、脑干​​和脊髓中的运动神经元 (MN) 进行性和选择性丧失，通常导致患者在诊断后 2-5 年死亡。中枢神经系统中谷氨酸介导的兴奋性毒性被认为是 ALS 中 MN 细胞死亡的主要原因。据认为，MN 对谷氨酸介导的兴奋性毒性的脆弱性是由于其高密度的 Ca2+ 可渗透离子通道以及其处理过量 Ca2+ 流入的能力减弱，而过量 Ca2+ 流入会引发神经退行性变。为什么 ALS 患者的 MN 特别容易受到兴奋性毒性的影响尚不清楚，但几乎普遍认为兴奋性毒性会导致 ALS 患者的 MN 选择性死亡。因此，开发降低 CNS 兴奋活动期间 Ca2+ 流入的药物是 ALS 治疗方法的一个关键焦点。离子型 AMPA 受体是谷氨酸激活的离子通道，是 MN 中 Ca2+ 流入的关键介质。 AMPA 受体由四个称为 GluR1-4 的亚基组成。所有四种 GluR 的两种选择性剪接变体（称为“翻转”和“翻牌”）通常在 CNS 中表达，并且已知可调节 AMPA 通道电导。含有 GluR-flip 亚型的 AMPA 通道是“更高增益”通道，与含有“flop”变体的“低增益”AMPA 通道相比，其具有更大的电流幅度和/或对谷氨酸脱敏的更强抵抗力。因此，当 GluR 的翻转/翻转比率升高时，MN 中的 AMPA 受体表现出增强的兴奋活性和更多的 Ca2+ 流入。我们最近开发了几种新型化学修饰的 RNA 寡核苷酸，称为剪接调节寡聚体 (SMO)，它可以有效且特异性地调节 GluR 选择性剪接，以降低各种 GluR 同工型的翻转/翻转比率。尽管 SMO 不穿过血脑屏障，但在直接递送到 CSF 后，它们广泛分布在整个 CNS 中，并且具有轻松穿过细胞膜并进入 CNS 细胞核的非凡能力，它们的剪接调节活性在 CNS 中持续数月。在这里，我们提出了一组转化实验来验证我们的 SMO 作为治疗 ALS 的疗法的潜力。首先，我们将比较我们的主要 SMO (LSP-GR3) 在减少整个 CNS 中 GluR3-flip 表达方面的功效，使用 (1) 连续 ICV 输送，和 (2) 单次推注注射到脊柱的腰椎囊中（目标 1）。然后，我们将使用目标 1 中确定的最佳递送方式，并评估我们的两种主要 SMO 在改善 ALS 小鼠运动功能和延长寿命方面的功效（目标 2）。 公共卫生相关性： 该提案旨在提供“原理证明”，证明 LifeSplice Pharma, LLC 开发的新型候选药物可有效改善 ALS 小鼠的病理状况。这些研究将导致正式的毒理学分析，并最终获得 IND 申请并获得 FDA 批准在 ALS 患者中进行临床试验。