Replication Data for: Aggregation chimeras provide evidence of in vivo intercellular correction in ovine CLN6 neuronal ceroid lipofuscinosis (Batten disease)

The neuronal ceroid lipofuscinoses (NCLs; Batten disease) are fatal, mainly childhood, inherited neurodegenerative lysosomal storage diseases. Sheep affected with a CLN6 form display progressive regionally defined glial activation and subsequent neurodegeneration, indicating that neuroinflammation may be causative of pathogenesis. In this study, aggregation chimeras were generated from homozygous unaffected normal and CLN6 affected sheep embryos, resulting in seven chimeric animals with varied proportions of normal to affected cells. These sheep were classified as affected-like, recovering-like or normal-like, based on their cell-genotype ratios and their clinical and neuropathological profiles. Neuropathological examination of the affected-like animals revealed intense glial activation, prominent storage body accumulation and severe neurodegeneration within all cortical brain regions, along with vision loss and decreasing intracranial volumes and cortical thicknesses consistent with ovine CLN6 disease. In contrast, intercellular communication affecting pathology was evident at both the gross and histological level in the normal-like and recovering-like chimeras, resulting in a lack of glial activation and rare storage body accumulation in only a few cells. Initial intracranial volumes of the recovering-like chimeras were below normal but progressively recovered to about normal by two years of age. All had normal cortical thicknesses, and none went blind. Extended neurogenesis was evident in the brains of all the chimeras. This study indicates that although CLN6 is a membrane bound protein, the consequent defect is not cell intrinsic. The lack of glial activation and inflammatory responses in the normal-like and recovering-like chimeras indicate that newly generated cells are borne into a microenvironment conducive to maturation and survival.

神经元蜡样脂褐质沉积症（neuronal ceroid lipofuscinoses，NCLs；又称巴滕病，Batten disease）是一类致命的、主要累及儿童的遗传性神经退行性溶酶体贮积病。罹患CLN6型的绵羊会出现进行性、区域性明确的胶质细胞激活及后续的神经退行性变，提示神经炎症可能是其发病的诱因。本研究从纯合未受累的正常胚胎与CLN6型受累绵羊胚胎中构建聚合嵌合体，最终获得7只嵌合动物，其正常细胞与受累细胞的比例各不相同。根据细胞基因型比例、临床及神经病理特征，这些绵羊被分为受累样型、恢复样型与正常样型三类。对受累样型动物的神经病理检查显示，其全大脑皮层区域均存在显著的胶质细胞激活、大量贮积体蓄积及严重的神经退行性变，同时伴随视力丧失、颅内体积与皮层厚度进行性下降，与绵羊CLN6病的表型一致。与之相反，在正常样型与恢复样型嵌合体中，细胞间通讯可影响病理进程，这一点在大体及组织学水平均有体现：这类动物未出现胶质细胞激活，仅极少数细胞存在罕见的贮积体蓄积。恢复样型嵌合体的初始颅内体积低于正常水平，但在2岁时可逐渐恢复至接近正常水平，所有此类动物均具有正常的皮层厚度，且未出现失明。所有嵌合体的大脑中均观察到持续性神经发生现象。本研究表明，尽管CLN6是一种膜结合蛋白，其所导致的缺陷并非细胞自主性的。正常样型与恢复样型嵌合体中缺乏胶质细胞激活与炎症反应，提示新生细胞所处的微环境有利于其成熟与存活。