Gene Therapy and Seizures

描述（由申请人提供）：理论上，病毒载体基因疗法对癫痫的治疗有很大的希望，在体内表达外源基因可能会抑制局灶性癫痫的敏感性。神经递质受体和离子通道提供了明显的基因治疗靶点，但成功的结果取决于病毒载体转导的模式，迄今为止还不能先验地预测。规避这种潜在障碍的一种方法是表达一种内源性抑制性神经肽，该神经肽随后从转导的细胞分泌出来。两种内源性肽，甘丙肽（GAL）和神经肽Y (NPY)，都能有效抑制边缘癫痫发作活动。最近对腺相关病毒载体（AAV）的初步研究表明，层状蛋白纤维连接蛋白的分泌信号序列可以在体外分泌载体衍生的基因产物，当将其置于GAL编码序列前面时，可以以可调节的方式抑制体内局灶性癫痫的敏感性，并减轻海马体中kainic酸诱导的细胞死亡。因此，本研究将验证以下假设：体内分泌载体衍生的GAL或NPY将抑制急性发作活动，减少kainic酸发作相关的细胞死亡，并延缓服用匹罗卡平后发生的自发发作活动。首先，将含有GAL或NPY编码序列前纤维连接蛋白分泌序列的重组AAV载体注入下丘脑，评估其抑制癫痫发作的持久性和调控基因表达的能力。然后，这些相同的重组AAV载体将在kainic酸发作模型中进行测试，评估海马门部神经元的转导是否可以改变急性发作敏感性和癫痫诱导的细胞损伤。随后，将确定这些AAV载体是否可以预防匹罗卡品诱发癫痫发作后自发性癫痫发作的发展。这些研究的发现可能会导致一种新的基因治疗方法来治疗癫痫。

DESCRIPTION (provided by applicant): Theoretically, viral vector gene therapy holds great promise for the treatment of epilepsy, where in vivo expression of foreign genes could potentially suppress focal seizure sensitivity. Neurotransmitter receptors and ion channels offer obvious gene therapy targets, but a successful outcome is dependent upon the pattern of viral Vector transduction which to date cannot be predicted a priori. One means to circumvent this potential impediment would be to express an endogenous inhibitory neuropeptide that is subsequently secreted from the transduced cell. Two endogenous peptides, galanin (GAL) and neuropeptide Y (NPY), both can potently suppress limbic seizure activity. Recent preliminary findings with adeno-associated virus vectors (AAV) show that the secretion signal sequence for the laminar protein, fibronectin, can secrete vector-derived gene product in vitro and when placed in front of the GAL coding sequence, suppresses in vivo focal seizure sensitivity in a regulatable fashion and attenuates kainic acid-induced cell death in the hippocampus. Therefore, the present proposal will test the hypothesis that in vivo secretion of vector derived GAL or NPY will suppress acute seizure activity, reduce kainic acid seizure associated cell death and retard the spontaneous seizure activity that develops after pilocarpine administration. First, recombinant AAV vectors containing fibronectin secretory sequence in front of GAL or NPY coding sequences will be infused into the inferior colliculus, and both the persistence of seizure suppression and the ability to regulate gene expression will be evaluated. Then, these same recombinant AAV vectors will be tested in the kainic acid seizure model, evaluating if transduction of hippocampal hilar neurons can alter acute seizure sensitivity and seizure-induced cell damage. Subsequently, it will be determined if these AAV vectors can prevent the development of spontaneous seizures following pilocarpine-induced seizures. The findings from these studies could lead to a novel gene therapeutic approach to the treatment of epilepsy.