ABSTRACT

Background: In this study, we sought to provide an idea for establishing a novel mouse model for Parkinson’s disease (PD) through intranasal administration of paraquat instead of the conventional method of intraperitoneal injection. Intranasal administration has the potential to lower mortality caused by intraperitoneal paraquat administration.

Methods: A paraquat-loaded thermosensitive hydrogel composed of poloxamer 407 and poloxamer 188 was prepared. The survival rate of the animals was monitored upon paraquat administration nasally and intraperitoneally. The animals’ behavior was also observed. Immunofluorescence staining of tyrosine hydroxylase (TH) – positive cells and western blotting of α-synuclein (α-syn)in striatum were performed. HPLC method with electrochemical detection was used to quantify monoamine neurotransmitters in striatum. Real-time RT-PCR analysis of type 1 collagen, type 3 collagen and fibronectin expression was used to evaluate pulmonary fibrosis in mice after paraquat administration.

Results: The results indicated that intranasal administration of paraquat-loaded thermosensitive hydrogel can elicit Parkinsonism-like symptoms in mice. Relative to the conventional intraperitoneal injection, this strategy significantly improves survival when modeling PD and resulted in a higher loss of TH positive neurons in substantia nigra pars compacta (SNpc) and more aggregation of α-syn in striatum. Moreover, animals receiving paraquat hydrogel nasally exhibited motor disorder as well as lower levels of dopamine and dopamine metabolites in striatum when compared to those receiving paraquat intraperitoneally. The mRNA expression of collagen and fibronectinindicated that intranasal administration of paraquat was not associated with lung fibrosis.

Conclusion: This strategy provides a new idea and more convenient operation for the future study of mouse model of PD.

摘要

背景：在本研究中，我们试图通过鼻内给药百草枯代替传统的腹腔注射方法来建立一种新型帕金森病 (PD) 小鼠模型。鼻内给药有可能降低腹膜内给药百草枯引起的死亡率。

方法：制备由泊洛沙姆 407 和泊洛沙姆 188 组成的百草枯热敏水凝胶。在鼻腔和腹膜内施用百草枯后监测动物的存活率。还观察了动物的行为。进行酪氨酸羟化酶 (TH) 的免疫荧光染色 - 对纹状体中的阳性细胞和 α-突触核蛋白 (α-syn) 进行蛋白质印迹。使用带电化学检测的 HPLC 方法来量化纹状体中的单胺类神经递质。1 型胶原蛋白、3 型胶原蛋白和纤连蛋白表达的实时 RT-PCR 分析用于评估施用百草枯后小鼠的肺纤维化。

结果：结果表明，鼻内给药百草枯热敏水凝胶可引起小鼠帕金森样症状。相对于传统的腹腔注射，这种策略在模拟 PD 时显着提高了存活率，并导致黑质致密部 (SNpc) 中 TH 阳性神经元的损失更多，纹状体中 α-syn 的聚集更多。此外，与腹腔注射百草枯水凝胶的动物相比，鼻腔注射百草枯水凝胶的动物表现出运动障碍以及纹状体中多巴胺和多巴胺代谢物的水平较低。胶原蛋白和纤连蛋白的 mRNA 表达表明百草枯鼻内给药与肺纤维化无关。

结论：该策略为未来PD小鼠模型的研究提供了新的思路和更便捷的操作。