The role of beta-catenin in the pathophysiology of infantile spasms

项目总结 婴儿痉挛(IS)，又称West综合征，是一种灾难性的儿童癫痫综合征 以痉挛为特征的，在生命的后期发展为癫痫发作。痉挛以自发性痉挛为典型 头部、颈部和四肢的屈曲/伸展，发生在4-8月龄之间。目前的治疗方法 IS的选择通常是无效的，并与显著的副作用相关。因此，新的治疗方法 战略至关重要。寻找新的治疗方法的一个限制因素是缺乏临床前 动物模型。我们鉴定并鉴定了一种具有多种表型的新型啮齿动物模型。 人类的特点是。该模型是通过饲养雄性小鼠而产生的，这些雄性小鼠含有一种带牙线的 Cre重组酶基因在雌性小鼠体内的表达 钙/钙调蛋白依赖的蛋白激酶IIα(CaMKIIa)启动子的调控。这是它的后代 在CaMKIIa阳性神经元中缺乏APC的Cross被称为APC条件性敲除(APC CKO)。 APC CKO动物已被证明增加了兴奋性突触交流和增加了 海马区CA1区锥体神经元兴奋性棘细胞密度。APC是一种主要的抑制调节剂。 大的信号通路被称为？-连环蛋白/Wnt通路。APC是ç-catenin破坏的一部分 复杂的，以？连环蛋白为目标的降解。当APC丢失时，？-catenin水平升高，1)增加 转录一个大的基因家族，以及2)增加兴奋性突触的稳定性。我们是这样开始的 检查APC CKO动物的表型是否与人类一致。我们发现他们展示了 自发性行为痉挛从出生后第8天到第11天，它们的发作期脑电与痉挛行为相关 与人类在IS中的发作活动相似，成年后它们有自发的脑电和行为 癫痫发作。有趣的是，APC杂合突变与发育障碍和癫痫障碍都有关。 此外，许多与IS相关的基因要么是ç-连环蛋白/Wnt途径的一部分，要么是相互作用的 受它的监管。在这项建议中，我们将专门研究？连环蛋白在糖尿病的病理生理学中的作用。 婴儿痉挛。我们将研究通过删除APC来增加？连环蛋白的效果，并且独立于 对痉挛行为、癫痫发作和脑电活动的影响。接下来，我们将细心表演 肌钙蛋白操纵的药代动力学、药效学及副作用分析 发展。最后，我们将确定将？连环蛋白水平恢复到正常水平是否能减轻痉挛和癫痫发作 在以后的生活中。这项建议将解决？连环蛋白在痉挛的病理生理学中的作用，提供一个新的 小鼠模型进行临床前分析，并引入一大套新的潜在治疗靶点 IS的治疗。

Project summary Infantile spasms (IS, also known as West Syndrome) is a catastrophic childhood epilepsy syndrome characterized by spasms which progress into seizures later in life. Spasms are typified by spontaneous flexion/extension of the head, neck, and limbs and occur between 4-8 months of age. The current treatment options for IS are often ineffective and are associated with significant side effects. Therefore, novel treatment strategies are essential. One limiting factor in identifying new treatment approaches is a paucity of pre-clinical animal models. We have identified and characterized a novel rodent model with many phenotypic characteristics of human IS. The model was generated by breeding male mice containing a floxed version of the Adenomatous polyposis coli (APC) gene with female mice expressing the Cre-recombinase gene under the control of the Ca2+/calmodulin-dependent protein kinase II alpha (CaMKIIa) promoter. The offspring of this cross, which lack APC in CaMKIIa-positive neurons, are known as APC conditional knockouts (APC cKOs). APC cKO animals have been shown to have increased excitatory synaptic communication and an increased density of excitatory spines on hippocampal CA1 pyramidal neurons. APC is the main inhibitory regulator of a large signaling pathway known as the ß-catenin/Wnt pathway. APC is part of the ß-catenin destruction complex, targeting ß-catenin for degradation. When APC is lost, ß-catenin levels rise and 1) increase transcription of a large family of genes, and 2) increase the stability of excitatory synapses. We began by examining APC cKO animals for phenotypes consistent with human IS. We found that they exhibit spontaneous behavioral spasms from post-natal day 8-11, they have an ictal EEG correlate of spasm behavior similar to human ictal activity in IS, and as adults they have spontaneous electrographic and behavioral seizures. Interestingly, APC heterozygous mutations are linked to both developmental and seizure disorders. Furthermore, many of the genes linked to IS are either part of the ß-catenin/Wnt pathway or are reciprocally regulated by it. In this proposal we will specifically examine the role of ß-catenin in the pathophysiology of infantile spasms. We will examine the effects of increasing ß-catenin by deleting APC, and independently of APC, on spasms behavior, seizure, and electrographic brain activity. Next, we will perform careful pharmacokinetic, pharmacodynamic, and adverse effect analysis of manipulating ß-catenin during development. Lastly, we will determine if restoring ß-catenin levels to normal attenuates spasms and seizures later in life. This proposal will address the role of ß-catenin in the pathophysiology of spasms, provide a new mouse model for pre-clinical analysis, and introduce a large set of new potential therapeutic targets for the treatment of IS.