Ankfy1损伤Purkinje细胞核内体导致常染色体隐性遗传性痉挛性共济失调Charlevoix-Saguenay的分子机制研究

Autosomal recessive spastic ataxia of Charlevoix-Saguenay (ARSACS) is an early-onset hereditary neurodegenerative disease characterized by cerebellar coordination disorders; the pathogenesis has not yet been identified. In 2017, we found that Ankfy1 mutation cause ARSACS. Ankfy1/+ transgenic mice had ataxia phenotype at early stage and apoptosis in Purkinje cells. Our previous study confirmed that Ankfy1 downregulation resulted in increased intracellular aggregates, axonal swelling in Purkinje cells, and was involved in PI3K/Akt signaling pathway. Studies have reported that Ankfy1 is related to the correct location of endosomes. Therefore the project intends to use immunohistochemistry, electrophysiological techniques, and molecular biological methods. Firstly, we will further to improve the pathophysiological effects of Ankfy1 on Purkinje cells. Secondly, we will elucidate Ankfy1 regulating the function of endosomes. Finally, we will clarify Ankfy1 mediated endosomes involvement in the adjusting of Purkinje cells. The results of our study will deepen the pathophysiology of ARSACS and reveal the etiology of Ankfy1 participates in ARSACS. At the same time, it will also provide new therapeutic targets for the clinical treatment and drug discovery of ARSACS.

常染色体隐性遗传性痉挛性共济失调Charlevoix-Saguenay（ARSACS）为一类以小脑协调障碍为主要特征的早发型遗传性神经退行性疾病，发病机制迄今未明。2017年课题组发现Ankfy1突变致ARSACS，Ankfy1/+转基因小鼠具有共济失调表型，且Purkinje细胞发生凋亡。本课题组前期研究证实下调Ankfy1导致细胞内聚集物增多、Purkinje细胞发生轴突肿胀，且PI3K/Akt信号通路参与其中。有研究报道Ankfy1参与核内体正确定位，因此本项目拟运用免疫组织化学、电生理及分子生物学等，完善Ankfy1对Purkinje细胞的病理生理影响及核内体功能调控；明确Ankfy1影响核内体参与调控Purkinje细胞功能活动的分子机制。结果将进一步深化ARSACS的病理生理，揭示疾病的病因学说，同时也将为ARSACS的临床治疗及药物研发提供新的分子靶标。

Charlevoix-Saguenay常染色体隐性痉挛性共济失调（ARSACS）是一种儿童期发病的神经退行性疾病。我们前期使用Ankfy1/+ 转基因小鼠证实Ankfy1 缺乏可导致ARSACS表型。我们目前的研究表明浦肯野细胞丢失主要发生在小脑前叶，而非后叶，同时伴有小脑深部核团逃逸。ARSACS细胞的自噬体形成在短期饥饿时减少，而长期饥饿后自噬通量增加。 ARSACS 小鼠浦肯野细胞出现线粒体自噬受损。雷帕霉素对线粒体结构及线粒体自噬有补救作用，说明在浦肯野细胞中抑制自噬可防止细胞功能障碍。这些结果证实Ankfy1在自噬中起非常重要的作用，Ankfy1/+小鼠小脑自噬的加强本身可能是一种稳态机制，自噬参与阻止浦肯野细胞丢失过程。