Munesue Yoshiko, Ageyama Naohide, Kimura Nobuyuki, Takahashi Ichiro, Nakayama Shunya, Okabayashi Sachi, Katakai Yuko, Koie Hiroshi, Yagami Ken-Ichi, Ishii Kazuhiro, Tamaoka Akira, Yasutomi Yasuhiro, Shimozawa Nobuhiro
Division of Clinical Medicine, Department of Neurology, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan.
Tsukuba Primate Research Center, National Institutes of Biomedical Innovation, Health and Nutrition, 1-1 Hachimandai, Tsukuba, Ibaraki 305-0843, Japan.
Exp Neurol. 2023 May;363:114381. doi: 10.1016/j.expneurol.2023.114381. Epub 2023 Mar 12.
Neuronal ceroid lipofuscinoses (NCLs) are autosomal-recessive fatal neurodegenerative diseases that occur in children and young adults, with symptoms including ataxia, seizures and visual impairment. We report the discovery of cynomolgus macaques carrying the CLN2/TPP1 variant and our analysis of whether the macaques could be a new non-human primate model for NCL type 2 (CLN2) disease. Three cynomolgus macaques presented progressive neuronal clinical symptoms such as limb tremors and gait disturbance after about 2 years of age. Morphological analyses using brain MRI at the endpoint of approximately 3 years of age revealed marked cerebellar and cerebral atrophy of the gray matter, with sulcus dilation, gyrus thinning, and ventricular enlargement. Histopathological analyses of three affected macaques revealed severe neuronal loss and degeneration in the cerebellar and cerebral cortices, accompanied by glial activation and/or changes in axonal morphology. Neurons observed throughout the central nervous system contained autofluorescent cytoplasmic pigments, which were identified as ceroid-lipofuscin based on staining properties, and the cerebral cortex examined by transmission electron microscopy had curvilinear profiles, the typical ultrastructural pattern of CLN2. These findings are commonly observed in all forms of NCL. DNA sequencing analysis identified a homozygous single-base deletion (c.42delC) of the CLN2/TPP1 gene, resulting in a frameshifted premature stop codon. Immunohistochemical analysis showed that tissue from the affected macaques lacked a detectable signal against TPP1, the product of the CLN2/TPP1 gene. Analysis for transmission of the CLN2/TPP1 mutated gene revealed that 47 (49.5%) and 48 (50.5%) of the 95 individuals genotyped in the CLN2-affected macaque family were heterozygous carriers and homozygous wild-type individuals, respectively. Thus, we identified cynomolgus macaques as a non-human primate model of CLN2 disease. The CLN2 macaques reported here could become a useful resource for research and the development of drugs and methods for treating CLN2 disease, which involves severe symptoms in humans.
神经元蜡样脂褐质沉积症（NCLs）是一种常染色体隐性致命性神经退行性疾病，发生于儿童和青年成人，症状包括共济失调、癫痫发作和视力损害。我们报告了携带CLN2/TPP1变体的食蟹猴的发现，以及对这些食蟹猴是否可成为2型NCL（CLN2）疾病新的非人灵长类动物模型的分析。三只食蟹猴在约2岁后出现进行性神经元临床症状，如肢体震颤和步态障碍。在约3岁的终点使用脑部MRI进行的形态学分析显示，灰质有明显的小脑和大脑萎缩，伴有脑沟增宽、脑回变薄和脑室扩大。对三只患病食蟹猴的组织病理学分析显示，小脑和大脑皮质有严重的神经元丢失和变性，伴有胶质细胞活化和/或轴突形态改变。在整个中枢神经系统中观察到的神经元含有自发荧光的细胞质色素，根据染色特性鉴定为蜡样脂褐质，通过透射电子显微镜检查的大脑皮质有曲线形轮廓，这是CLN2的典型超微结构模式。这些发现常见于所有形式的NCL。DNA测序分析确定CLN2/TPP1基因存在纯合单碱基缺失（c.42delC），导致移码过早终止密码子。免疫组织化学分析表明，患病食蟹猴的组织缺乏针对CLN2/TPP1基因产物TPP1的可检测信号。对CLN2/TPP1突变基因传递的分析显示，在CLN2患病食蟹猴家族中进行基因分型的95个个体中，分别有47个（49.5%）和48个（50.5%）是杂合携带者和纯合野生型个体。因此，我们确定食蟹猴为CLN2疾病的非人灵长类动物模型。这里报告的CLN2食蟹猴可能成为研究以及开发治疗CLN2疾病（该病在人类中症状严重）的药物和方法的有用资源。
