Striatal CaV1.3 Calcium Channels: An Overlooked Antidyskinetic Target for PD

纹状体 CaV1.3 钙通道：一个被忽视的 PD 抗运动障碍靶点

• 批准号: 9033414
• 负责人: KATHY Steece STEECE-COLLIER
• 金额: $ 19.19万
• 依托单位: MICHIGAN STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-09-15 至 2017-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9033414
• 关键词: Calcium Channel; Cardiovascular Physiology; Clinical; Clinical Research; Corpus striatum structure; Data; Development; Dihydropyridines; Dose; Dyskinetic syndrome; Exploratory/Developmental Grant; Gene Proteins; Genes; Intervention; Levodopa; Mediating; Messenger RNA; Outcome; Parkinson Disease; Pharmaceutical Preparations; Recombinant adeno-associated virus (rAAV); Severities; Testing; Time; design; dihydropyridine; innovation; preclinical study; public health relevance; research study; small hairpin RNA; subcutaneous

 DESCRIPTION (provided by applicant): Previous studies, including those in our lab have shown that subcutaneous, slow release pellets containing CaV1.2/1.3 channel antagonists can reduce the expression of levodopa-induced dyskinesias (LID) produced by low dose (6 mg/kg) and high dose levodopa (12.5 mg/kg), however, this effect is partial and lost over time. These data suggest that the CaV1.3 channel is a potential antidyskinetic target, yet whether the limitation in scope and loss of protection over time are related to pharmacological limitation remains unknown. There are several issues that limit validating the involvement of CaV1.3 channel antagonism for any use in Parkinson's disease (PD) with pharmacological agents, which includes: 1) there is no currently available pharmacological agent that can selectively silence CaV1.3 channels without impacting the CaV1.2 channels that are important in cardiovascular function; 2) CaV1.3 channels are incompletely inhibited even by high concentrations of currently available dihydropyridine (DHP) drugs ; and 3) pharmacological blockade traditionally employed results in non-continuous channel blockade, which we propose contributes to the variable or partial protective outcome of all previous clinical and preclinical studies. We posit that the previous studies provide strong and necessary rationale that the CaV1.3 channel is a potential antidyskinetic target and that development of an innovative approach to confirm its possible clinical utility is warranted. To provide unequivocal proof-of- principle evidence, devoid of pharmacological limitations, we propose three Specific Aims (SA) that will allow examination of the impact of continuous, high potency and target-selective, mRNA-level silencing of striatal CaV1.3 channel on LIDs, using the R21 mechanisms to assist in developing and executing these important studies. In SA 1, we will determine the time course of striatal CaV1.3 gene and protein silencing achieved with our recombinant adeno-associated virus (rAAV)-mediated expression of a short hairpin RNA (shRNA) designed against the CaV1.3 mRNA, which will guide the timing of interventions in SA 2 and 3. In SA 2, we will test the hypothesis that constitutive silencing of striatal CaV1.3 channels prior to levodopa exposure will provide potent and enduring amelioration of LIDs. In SA 3, we will test the hypothesis that constitutive silencing of striatal CaV1.3 channels in subjects already expressing LIDs will significantly decrease severity of established LIDs.

 描述（由申请人提供）：之前的研究，包括我们实验室的研究表明，含有CaV1.2/1.3通道拮抗剂的皮下缓释微丸可以减少低剂量（6 mg/kg）和高剂量左旋多巴引起的左旋多巴诱导的运动障碍（LID）的表达。（12.5 mg/kg），然而，这种作用是部分的，并且随着时间的推移而消失。这些数据表明，CaV1.3通道是一个潜在的抗运动障碍的目标，但范围的限制和随着时间的推移保护的损失是否与药理学限制仍然未知。有几个问题限制了用药理学试剂验证CaV1.3通道拮抗作用在帕金森病（PD）中的任何用途，包括：1）目前没有可选择性沉默CaV1.3通道而不影响在心血管功能中重要的CaV1.2通道的药理学试剂; 2）CaV 1.3通道即使被高浓度的目前可用的二氢吡啶（DHP）药物也不完全抑制;和3）传统使用的药理学阻断导致非连续通道阻断，我们认为这有助于所有以前的临床和临床前研究的可变或部分保护结果。我们认为，以前的研究提供了强有力的和必要的理由，CaV1.3通道是一个潜在的抗运动障碍的目标，并开发一种创新的方法，以确认其可能的临床效用是必要的。为了提供明确的原则性证据，没有药理学限制，我们提出了三个特定目的（SA），允许检查纹状体CaV1.3通道的连续，高效和靶向选择性，mRNA水平沉默对LID的影响，使用R21机制来协助开发和执行这些重要的研究。在SA 1中，我们将确定纹状体CaV1.3基因和蛋白质沉默的时间过程，这些沉默是通过我们的重组腺相关病毒（rAAV）介导的针对CaV1.3 mRNA设计的短发夹RNA（shRNA）表达实现的，这将指导SA 2和3中干预的时机。在SA 2中，我们将检验以下假设：左旋多巴暴露前纹状体CaV1.3通道的组成性沉默将提供LID的有效和持久的改善。在SA 3中，我们将检验以下假设：在已经表达LID的受试者中，纹状体CaV1.3通道的组成性沉默将显著降低已建立的LID的严重程度。