MPTP小鼠脑沉默信息调节因子1和缺氧诱导因子-1α的表达及行为学检测

Expression of silent information regulator 1 and hypoxia-inducible factor 1&alpha|and behavioral changes in MPTP mice

摘要:

目的 本研究旨在研究MPTP模型小鼠中沉默信息调节因子1（SIRT1）和缺氧诱导因子1α（HIF-1α）的表达情况以及行为学的变化。方法 选用MPTP处理C57BL/6小鼠构建PD动物模型，采用行为学实验、高效液相色谱（HPLC）、免疫组化等方法检验模型的建立是否成功，并在小鼠模型中检测SIRT1和HIF-1α的表达情况。结果 MPTP处理的小鼠表现出显著的行为学异常，主要体现在自主活动减少（P<0.001）、步距缩短（P<0.001），且有显著运动迟缓（P<0.001）。HPLC结果发现，模型组小鼠纹状体区域多巴胺（DA）及其代谢产物减少（P<0.001）。免疫组化结果提示黑质区域多巴胺能神经元标志物酪氨酸羟化酶（TH）和多巴胺转运体（DAT）的表达明显下调（P<0.01）。分子生物学方面，PD模型小鼠的SIRT1表达降低（P<0.05），HIF-1α表达增加（P<0.05）。结论 PD模型小鼠表现出明显的行为学异常，多巴胺能神经元标志物检测提示成功复制PD动物模型，同时发现模型小鼠的SIRT1/HIF-1α的表达异常，提示该信号通路可能参与了PD的疾病过程。

Abstract:

Objective To investigate the expression of silent information regulator 1 (SIRT1) and hypoxia-inducible factor 1α (HIF-1α) and behavioral changes in 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) mice.Methods C57BL/6 mice were treated with MPTP to establish a Parkinson's disease (PD) model. The successful establishment of PD model was confirmed by behavioral test, high-performance liquid chromatography (HPLC), and immunohistochemistry. The expression of SIRT1 and HIF-1α in PD model mice was determined by Western blot.Results The mice treated with MPTP showed significant behavioral abnormalities:reduced autonomic activity, shortened step length, and bradykinesia (all P<0.001). The HPLC results showed that the PD model mice had significantly lower levels of dopamine and its metabolites in the striatum than the control mice (P<0.001). The immunohistochemistry results showed that the levels of tyrosine hydroxylase and dopamine transporter (dopaminergic neuron markers) in the substantia nigra of PD model mice were significantly down-regulated (P<0.01). The PD model mice had a significantly lower level of SIRT1 and a significantly higher level of HIF-1α compared with the control mice (P<0.05). Conclusions The PD model mice have significant behavioral abnormalities. The decrease in levels of dopaminergic neuron markers suggests that the PD model is successfully established. The abnormal expression of SIRT1/HIF-1α in the PD model mice indicates that the SIRT1/HIF-1 signaling pathway may be involved in the development of PD.