Cortical transcriptional changes in a chemically-induced neuronopathic Gaucher disease mouse model

Great interest has been shown in understanding the pathology of Gaucher disease (GD) due to the recently-discovered genetic relationship with Parkinson’s disease. For such studies, suitable animal models of GD are required. Chemical induction of GD by inhibition of acid β-glucosidase (GCase) using the irreversible inhibitor, conduritol-B-epoxide (CBE), is particularly attractive, although few systematic studies examining the effect of CBE on development of symptoms associated with neurological forms of GD have been performed. We now demonstrate a correlation between the amount of CBE injected into mice and levels of accumulation of the GD substrates, glucosylceramide and glucosylsphingosine, and show that disease pathology, indicated by altered levels of pathological markers, depends on the dose of CBE and its time of injection. Gene array analysis shows a remarkable similarly in the gene expression profile of CBE-treated mice and a genetic GD mouse model, the Gbaflox/flox;nestin-Cre mouse, with 120 of the 144 genes up-regulated in CBE-treated mice also up regulated in Gbaflox/flox;nestin-Cre mice. Finally, we demonstrate that some aspects neuropathology and some behavioral abnormalities can be arrested upon cessation of CBE treatment during a specific time window. Together, our data demonstrate that injection of mice with CBE provides a rapid and relatively easy way to induce symptoms typical of neuronal forms of GD, which will prove particularly useful when examining the role of specific biochemical pathways in GD pathology, since CBE can be injected into mice defective in components of putative pathological pathways, alleviating the need for time consuming crossing of mice. C57BL/6JOlaHsd, SV129, C3H, FVB mice were i.p. treated with PBS or CBE 25mg/kg day from postnatal day 8-18. Cortex were removed with a spatula and RNA was extracted using the RNeasy mini kit (Qiagen GmbH, Hilden, Germany)

鉴于近期发现戈谢病（Gaucher disease, GD）与帕金森病存在遗传关联，学界对戈谢病的病理机制研究展现出浓厚兴趣。此类研究亟需适配的戈谢病动物模型。利用不可逆抑制剂环氧康多利糖醇B（conduritol-B-epoxide, CBE）抑制酸性β-葡萄糖苷酶（acid β-glucosidase, GCase）以化学诱导戈谢病的方法颇具吸引力，但目前针对CBE对戈谢病神经型症状影响的系统性研究仍较为匮乏。本研究证实，向小鼠注射的CBE剂量与戈谢病底物葡萄糖脑苷脂（glucosylceramide）、葡萄糖鞘氨醇（glucosylsphingosine）的积累水平呈显著相关；同时发现，以病理标志物水平变化表征的疾病病理进程，依赖于CBE的给药剂量与注射时机。基因芯片分析显示，经CBE处理的小鼠与遗传型戈谢病小鼠模型Gba flox/flox；巢蛋白-Cre小鼠的基因表达谱高度相似：CBE处理小鼠上调的144个基因中，有120个在Gba flox/flox；巢蛋白-Cre小鼠中同样呈上调表达。最后，本研究证实，在特定时间窗口内停止CBE给药，可阻断部分神经病理与行为异常进程。综上，本研究数据表明，向小鼠腹腔内注射CBE可快速且相对简便地诱导神经元型戈谢病的典型症状，该模型在探究特定生化通路在戈谢病病理中的作用时尤为实用：可直接向携带推定病理通路组分缺陷的小鼠注射CBE，无需耗时耗力的小鼠品系杂交繁育。本研究中，对C57BL/6JOlaHsd、SV129、C3H、FVB品系小鼠于出生后第8至18天，每日以25mg/kg剂量腹腔注射磷酸盐缓冲液（PBS）或CBE。采用解剖铲剥离皮层组织，使用RNeasy 微量试剂盒（德国希尔登Qiagen有限公司）提取RNA。