Gene Therapy and Seizures

描述(申请人提供)：理论上，病毒载体基因疗法在癫痫的治疗中具有很大的前景，在体内表达外源基因可能潜在地抑制局灶性癫痫发作的敏感性。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，而到目前为止，这种模式还不能预先预测。绕过这一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细胞分泌。甘丙肽(Gal)和神经肽Y(NPY)这两种内源性多肽都能有效地抑制边缘癫痫发作。最近对腺相关病毒载体(AAV)的初步研究表明，层状蛋白的分泌信号序列FN在体外可以分泌载体衍生的基因产物，当放置在GAL编码序列之前时，以可调节的方式抑制体内局灶性癫痫的敏感性，并减轻海人藻酸诱导的海马细胞死亡。因此，本方案将验证载体衍生的GAL或NPY体内分泌将抑制急性癫痫活动，减少红藻氨酸癫痫相关细胞死亡，并延缓匹罗卡品后的自发癫痫活动的假说。首先，将在GAL或NPY编码序列前含有纤维连接蛋白分泌序列的重组AAV载体注入下丘，评估其对癫痫发作的持续抑制和基因表达的调节能力。然后，这些相同的重组AAV载体将在红藻氨酸癫痫模型中进行测试，评估海马门神经元的转导是否可以改变急性癫痫敏感性和癫痫诱导的细胞损伤。随后，将确定这些AAV载体是否能够防止匹罗卡品诱发癫痫后的自发性癫痫的发展。这些研究的发现可能会导致一种治疗癫痫的新的基因治疗方法。

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.