APP/PS1转基因鼠中阿尔茨海默病对听功能的影响

Effect of Alzheimer’s disease on auditory function in APP/PS1 transgenic mice

目的探究在阿尔茨海默病(Alzheimer’s disease,AD)进程中APP/PS1转基因鼠的听力和耳蜗组织形态学变化情况,判断AD发生发展是否会影响其听功能。方法选择4、8和12月龄的APP/PS1转基因鼠和同窝野生型小鼠,通过免疫荧光染色法以及听性脑干反应(ABR)等方法检测,比较分析不同月龄APP/PS1转基因鼠的听功能变化情况。结果与对照组相比,4、8和12月龄APP/PS1转基因鼠海马中Aβ斑块显著增多,且随着年龄的增加APP/PS1转基因鼠海马组织中β淀粉样蛋白斑块沉积显著增加,表明随年龄的增加APP/PS1转基因鼠AD呈加重趋势;在4、8和12月龄,与同窝野生型小鼠相比APP/PS1转基因鼠的各频率听力阈值均未见显著差异。耳蜗组织形态学检测结果显示,两种小鼠耳蜗毛细胞、螺旋神经节等内耳关键细胞均无显著差异。APP/PS1转基因鼠和同窝野生型小鼠ABR检测结果显示,随着年龄增长两种小鼠的听力阈值均显著上升,均表现为年龄相关性听力损失。结论APP/PS1转基因鼠的发病进程中存在年龄相关性听力损失,但AD发生发展几乎不会对APP/PS1转基因鼠的听功能产生影响。

Objective To explore the hearing and cochlear histomorphological changes in APP/PS1 transgenic mice during the process of AD and to determine whether the occurrence and development of AD affect their hearing function.Methods APP/PS1 transgenic mice and wild type littermates were selected at the ages of 4,8 and 12 months.Changes to the auditory function of APP/PS1 transgenic mice over time were detected by immunofluorescence staining and auditory brainstem response(ABR)test.Results Compared with the control group,the 4-month-old APP/PS1 transgenic mice had a significantly increased number of Aβplaques in the hippocampus,indicating that AD symptoms were already present at this time.At the ages of 4,8 and 12 months,there was no significant difference in the hearing threshold between APP/PS1 transgenic mice and wild type mice.Histomorphological examination of the cochlea showed no significant difference in key cells of the inner ear,such as cochlear hair cells and spiral ganglion,between the two groups of mice.An ABR test showed that the hearing threshold of both APP/PS1 transgenic mice and wild type littermates increased significantly with age,and both groups showed age-related hearing loss.Conclusions There was age-related hearing loss in APP/PS1 transgenic mice,but the occurrence and development of AD had little effect on their auditory functions.