纹状体多巴胺能神经元STX1A影响抽动障碍机制研究

Tic disorder (TD) is a common chronic neuromental disorder in childhood, and its pathogenesis is still not clear. Our previous study found that the levels of dopamine in the striatum and plasma of TD rats were higher than those in the control rats. STX1A is an important member of the presynaptic vesicle release. In the pre experiment, we found that the expression of STX1A in striatum of TD rats was significantly decreased at mRNA and protein levels, and the expression of STX1A positive area in dopaminergic neurons decreased significantly. Therefore we put forward the hypothesis that dopaminergic neurons STX1A expression, resulting in STX1A binding of dopamine transporter (DAT) play a dopamine reuptake function, which lead to increace of striatal dopamine concentration, exhibiting stereotypic behavior of TD increased. The aim of this study is to carry out in vitro cell experiments and in vivo animal experiments. We will use Western blot, RT-PCR and co-immunoprecipitation in our study to investigate the role of STX1A-DAT pathway in the pathogenesis of TD, and further explore the role of STX1A and DAT in the regulation of dopamine system in alleviating TD symptoms. There is no similar research report on the effect of STX1A on TD at home and abroad. This study will elucidate the role of dopaminergic neuron STX1A-DAT pathway in the pathogenesis of TD, further reveal the pathogenesis of TD, and provide a theoretical reference for the prevention and control of TD.

抽动障碍(Tic disorder, TD)是儿童期常见慢性神经精神障碍，其发病机制不清。我们前期研究发现TD大鼠纹状体及血浆多巴胺水平高于对照大鼠。STX1A是突触前囊泡释放的重要成员，预实验中我们发现TD大鼠纹状体STX1A表达在mRNA及蛋白水平显著下降，多巴胺能神经元表达STX1A阳性面积显著下降。由此提出假说：多巴胺能神经元STX1A表达下调，导致STX1A结合多巴胺转运体(DAT)发挥多巴胺重摄取功能减弱，多巴胺浓度上升、TD样刻板行为增多。本课题拟进行离体细胞实验和在体动物实验，采用Western blot、RT-PCR、免疫共沉淀等技术研究STX1A-DAT通路与TD发病的关系，探索调控多巴胺能系统STX1A和DAT在缓解TD症状中的作用。目前未见关于STX1A影响TD的报道。本课题将阐明多巴胺能神经元STX1A-DAT通路在TD发病中的作用，为防治TD提供理论参考。

抽动障碍的发病与多巴胺系统功能障碍相关。我们前期研究发现突触前SNARE复合物Syntaxin 1A（STX1A）在TD动物纹状体中的表达发生了变化。为阐明纹状体STX1A在TD中的生物学作用及其对多巴胺能系统的调节作用，本项目进行离体细胞实验和在体动物实验，采用Western blot、RT-PCR、免疫共沉淀等技术研究STX1A-DAT通路与TD发病的关系，探索调控多巴胺能系统STX1A和DAT在缓解TD症状中的作用。结果发现，TD模型纹状体STX1A的表达下降。在体外，STX1A过表达组上清液中的DA含量较低，而细胞内DA含量较高。STX1A的过度表达可以抵消IDPN诱导的TD样行为。同时，STX1A的体内敲除可加重TD样行为。此外，当DAT过表达时，TD样行为得到缓解。纹状体中DAT的过度表达导致STX1A表达增加。CO-IP分析显示DAT和STX1A的组合。纹状体STX1A表达在TD发育过程中降低，STX1A可能通过与DAT的相互作用发挥抗TD作用，DAT维持DA再摄取。STX1A抑制导致的过高DA信号驱动病理刻板行为。.本项目聚焦多巴胺能神经元STX1A-DAT通路在TD发病中的作用，验证了STX1A 与DAT 结合并影响多巴胺释放，STX1A 及DAT 过表达或沉默影响TD 症状，为防治TD提供理论参考，具有一定的医学意义。在项目执行期间，发表了高水平学术论文9篇，其中SCI收录4篇，培养了硕士研究生1名。