Abstract

To investigate the expression and role of nicotinic acetylcholine α7 subunit (nAChRα7) in the hippocampus of rats with Parkinson's disease (PD) and Parkinson's disease dementia (PDD). PD model was established with 6-hydroxydopa. Then, methyllycaconitine was further used to prepare a PDD model. The behavioral indexes and malondialdehyde (MDA) and superoxide dismutase (SOD) levels were measured. The mRNA level and protein level of nAChRα7 in hippocampus was detected by reverse transcription quantitative polymerase chain reaction (RT-qPCR) and Western-blot, respectively. The α7nAchR and NeuN protein was detected by immunofluorescence. Compared with the PD model group, the escape latency of the PDD model group was significantly prolonged while the times of crossing platforms was significantly reduced (p < 0.05). The SOD level in the PDD and PD group decreased as compared with the control group (p < 0.05), while the MDA content increased (p < 0.05). The mRNA level and protein expression of nAChRα7 in the PDD and PD model group was significantly lower than that in the control group (p < 0.05). There was a significant difference in the nAChRα7 protein level between the PDD and PD model group (p < 0.05). Together, the nAChRα7 receptor level was significantly decreased in the PDD model group, indicating that the decrease in the nAChRα7 receptor levels is a possible mechanism of the pathogenesis of PDD.

摘要

探讨烟碱型乙酰胆碱α7亚基（nAChRα7）在帕金森氏病（PD）和帕金森氏病痴呆（PDD）大鼠海马中的表达和作用。用6-羟基多巴建立PD模型。然后，进一步使用甲基甘可卡因制备PDD模型。测量了行为指标以及丙二醛（MDA）和超氧化物歧化酶（SOD）的水平。通过逆转录定量聚合酶链反应（RT-qPCR）和Western-blot分别检测海马中nAChRα7的mRNA水平和蛋白水平。通过免疫荧光检测α7nAchR和NeuN蛋白。与PD模型组相比，PDD模型组的逃避潜伏期显着延长，而穿越平台的时间显着减少（p <0.05）。与对照组相比，PDD和PD组的SOD含量降低（p  <0.05），而MDA含量升高（p  <0.05）。在PDD和PD模型组中，nAChRα7的mRNA水平和蛋白表达显着低于对照组（p  <0.05）。PDD和PD模型组之间的nAChRα7蛋白水平存在显着差异（p  <0.05）。在一起，PDD模型组中的nAChRα7受体水平显着降低，表明nAChRα7受体水平的降低是PDD发病的可能机制。