RNAi Targeting of Kv3 Channels in Basal Ganglia Disease

描述（由申请人提供）：帕金森病（PD）是一种以运动功能受损为特征的神经退行性疾病。它影响大约1/1000的成年人，在50岁以后呈指数上升。目前，尚无治疗PD的方法能明确减缓疾病进展。即使是暂时纠正症状，延长身体活动的时间也被认为是有价值的。 我们建议测试一种新的策略来缓解帕金森病的运动症状。PD患者苍白球（GP）和丘脑底核（ENA）的异常相关节律活动被认为是运动迟缓和震颤的基础。一组特定的膜电导在GP和ESTA神经元使这种活动。我们小组最近的工作表明，GP和DRG神经元的高频爆发放电依赖于它们的电压依赖性Kv 3 K+通道亚基的组合的表达。这些神经元形成含有Kv3.1和Kv3.4亚基的异聚体通道。这些异聚体通道非常有效地使峰电位复极化-使它们非常短暂-然后在峰电位后失活以允许下一个峰电位快速发生。从这些通道中消除Kv3.4亚基会降低通道的复极化效率，导致最大放电速率降低。因此，我们的目标是检验以下假设：GP/P2P神经元中Kv3.4亚基的抑制将显著减少病理性高频爆发放电，从而导致PD模型和患者的症状缓解。Kv3.4是基因治疗方法的极好靶标，因为它的表达对快速尖峰神经元具有高度特异性，并且GP/GP周围区域中的非靶向神经元的放电不应受到影响。 我们建议使用慢病毒载体，以提供小干扰RNA（siRNA）设计触发GP和DRG神经元中的Kv3.4 mRNA的降解。所提出的具体目标将允许开发在PD动物模型中测试我们的假设所需的技术。

DESCRIPTION (provided by applicant): Parkinson's disease (PD) is a neurodegenerative disorder characterized by impairment of motor function. It affects about 1 in 1000 adults, rising exponentially after the age of fifty. At present there is no treatment for PD shown to definitively attenuate disease progression. Even temporal correction of symptoms extending the period of physical mobility is considered valuable. We suggest to test a new strategy to relieve motor symptoms of the Parkinson's disease. The abnormal correlated rhythmic activity in the globus pallidus (GP) and subthalamic nucleus (STN) are believed to underlie bradykinesia and tremor of PD patients. A specific set of membrane conductances in GP and STN neurons enable such activity. Recent work by our group has shown that high frequency burst discharge in GP and STN neurons is dependent upon their expression of a combination of voltage-dependent Kv3 K+ channel subunits. These neurons form heteromeric channels containing Kv3.1 and Kv3.4 subunits. These heteromeric channels are very efficient at repolarizing spikes - keeping them very brief - and then deactivating after the spike to allow the next spike to occur quickly. Eliminating the Kv3.4 subunit from these channels diminishes the repolarizing efficiency of the channels, resulting in lower maximal discharge rates. Thus our goal is to test the hypothesis that the suppression of Kv3.4 subunit in GP/STN neurons will dramatically reduce pathological, high frequency burst discharge leading to symptomatic relief in PD models and patients. Kv3.4 is an excellent target for gene therapy approaches since its expression is highly specific for fast spiking neurons and the firing of non-targeted neurons in GP/STN surrounding areas should not be affected. We propose to use lentivirus vector to deliver small interfering RNA (siRNA) designed to trigger the degradation of Kv3.4 mRNA in GP and STN neurons. The proposed specific aims will allow development of the technology that is necessary for testing of our hypothesis in the animal models of PD.