Gene-based Neuromodulation: A New Paradigm for Functional Neurosurgery

描述(由申请人提供)：本提案将继续Boulis博士作为功能神经外科领域的临床医生和科学家的职业发展，专注于现有神经调节策略的替代方案。神经调节，即在解剖上离散的靶点内操纵神经活动，是功能神经外科的主要工具，在运动障碍、疼痛、痉挛、癫痫和精神疾病的治疗中得到应用。它已经在很大程度上取代了神经组织的破坏，成为治疗难治性功能障碍的一种手段。尽管如此，电流的集中传递不能具有药理学特异性，并且需要带有显著并发症发生率的电子神经假体。与植入设备相比，病毒基因疗法在治疗功能性神经疾病方面有几个优势。通过微创立体定向注射可以实现神经元基因的表达。此外，病毒载体的趋向性可以通过操纵病毒表面来改变，以针对个别细胞类型的载体，以及限制和指导基因表达的传播。最后，病毒基因可以在神经元中以持续的方式表达，而不会破坏它们的结构或突触结构。因此，基因转移可以用来操纵功能性神经结构，这是目前的外科手术无法实现的，提供了药理学和解剖学特异性的双重优势。下面的建议探索了利用最好的可诱导基因表达系统来实现突触功能的受控调节的载体的开发，以调节梭状芽胞杆菌破伤风毒素光(LC)基因和内向整流钾通道(Kir2.1)基因的释放。目前提议的目的将检验以下假设：1)AAV介导的LC突触抑制是持久的，并且比腺病毒介导的传递更具免疫原性，并且持久的表达可以由Tet-on系统调节。2)表达盒修饰、运动神经元靶向表达和轴突转基因传递可提高LC基因神经抑制的效力和特异性。3)RheoSwitch(R)可诱导表达系统将改善受控LC递送。4)神经元Kir2.1基因的表达可安全地抑制神经元的活动，其抑制作用强于LC介导的突触抑制。

DESCRIPTION (provided by applicant): The present proposal will continue the career development of Dr. Boulis as a clinician-scientist in the field of Functional Neurosurgery, focusing on an alternative to existing strategies for Neuromodulation. Neuromodulation, the manipulation of neural activity within anatomically discrete targets, is the principle tool of Functional Neurosurgery, finding application in the treatment of movement disorders, pain, spasticity, epilepsy and psychiatric disease. It has largely replaced the destruction of neural tissue as a means to treat refractory functional disorders. Nonetheless, the focused delivery of electric current is incapable of pharmacological specificity and requires electronic neural prostheses that carry a significant complication rate. Viral gene therapy has several advantages over implanted devices for the treatment of functional neural disorders. Neuronal gene expression can be achieved through minimally invasive stereotactic injection. Moreover, the tropism of viral vectors can be engineered through manipulation of the virus surface to target the vectors to individual cell types as well as limit and direct the spread of gene expression. Finally, viral gene expression can be achieved in a sustained fashion in neurons without disrupting their architecture or synaptic structure. Thus, gene transfer can be used to manipulate functioning neural structures in a fashion that current surgical procedures cannot achieve, providing the dual advantage of both pharmacologic and anatomic specificities. The following proposal explores the development of vectors to achieve controlled modulation of synaptic function using the best available inducible gene expression systems for regulated release of the clostridial tetanus toxin light (LC) gene and the inwardly rectifying potassium channel (Kir2.1) gene. Aims of the current proposal will test the following hypotheses: 1) AAV mediated LC synaptic inhibition is durable and less immunogenic than delivery mediated by Adenovirus, and that durable expression can be regulated by the Tet-on system. 2) Expression cassette modification, targeting expression to motor neurons and transgene delivery to axons, can improve the potency and specificity of LC gene-based neural inhibition. 3) The Rheoswitch(r) inducible expression system will improve controlled LC delivery. 4) Neuronal Kir2.1 gene expression can safely inhibit neuronal activity with potency exceeding that of LC mediated synaptic inhibition.