Pathogenesis of Tuberous Sclerosis Cortical Lesions

描述（由申请人提供）： 在皮质发生期间，放射状胶质细胞及其后代经历协调神经元产生和放置的定型的分裂和迁移模式，从而产生分层的大脑皮质。相反，结节性硬化症基因（TSC 1或TSC 2）杂合子个体大脑中的致癫痫性皮质病变是细胞过多的，并显示分层中断和灰白质边界扭曲。这些畸形被认为是由来自前体的克隆组成，其中次级突变消除了任一基因产物的表达。然而，这些皮质病变的发病机制与正常模式的皮质增殖和迁移尚未调查，TSC基因产物在皮质生成中的作用仍然未知。下面概述的实验提出通过模拟结节性硬化症的体内遗传缺陷来解决这些问题。靶向TSC 2转录本的RNAi载体将通过子宫内注射到大鼠胚胎的侧脑室中而被引入皮质祖细胞中。通过观察这些标记细胞与对照相比的增殖和迁移，将检查基因缺陷对皮质生成的影响。

DESCRIPTION (provided by applicant): During corticogenesis, radial glial cells and their progeny undergo stereotyped patterns of division and migration that coordinate neuronal production and placement, creating the layered cerebral cortex. In contrast, epileptogenic cortical lesions in the brains of individuals heterozygous for a tuberous sclerosis gene, TSC1 orTSC2, are hypercellular and display disrupted lamination and distorted gray-white matter boundaries. These malformations are thought to consist of clones derived from precursors in which a secondary mutation eliminates expression of either gene product. However, the pathogenesis of these cortical lesions in relation to normal patterns of cortical proliferation and migration has not been investigated, and the role of TSC gene products in corticogenesis remains unknown. Experiments outlined below propose to address these questions by mimicking the genetic deficiency of tuberous sclerosis in vivo. RNAi vectors targeting TSC2 transcript will be introduced into cortical progenitors through intrauterine injections into lateral ventricles of rat embryos. By observing the proliferation and migration of these labeled cells in comparison to controls, the influence of the gene defect on corticogenesis will be examined.