不同年龄段雌性APP/PS1双转基因小鼠脑内病理特征的动态变化

Dynamic pathological changes in the brain of female APP/PS1 double transgenic mice with different ages

摘要:

目的：探讨不同年龄段雌性阿尔茨海默病（Alzheimer’s disease，AD）模型小鼠脑内特征性病理改变的动态变化。方法：选取3月龄、8月龄、12月龄、16月龄雌性APP/PS1双转基因AD模型小鼠各6只，断头取脑后进行石蜡包埋、切片、免疫组化染色，光镜下观察。结果：免疫组化结果显示，3月龄AD模型小鼠脑内神经细胞外偶尔可见β淀粉样蛋白（amyloidβ peptide，Aβ ）沉积形成的老年斑（senile plaque，SP），且SP体积很小；随着年龄的增长，AD模型小鼠脑内SP不仅数量增多，而且体积明显增大[M3=0.600±0.235，M8=8.933±1.730，M12=28.470±1.841，M16=94.130±4.287；P1=0.025，P2=０.000，P3=0.000（M3、M8、M12、M16分别代表3月龄、8月龄、12月龄、16月龄，P1、P2、P3分别代表M3同M8、M8同M12、M12同M16比较所得P值，下同）]；AD模型小鼠脑内神经元标志物NeuN的阳性细胞数量随年龄增长呈进行性下降的趋势（M3=1 919.00±58.21，M8=1 717.00±65.83，M12=1 689.00±45.66，M16=1 529.00±45.36；P1=0.011，P2=0.712，P3=0.043）；而星形胶质细胞（astrocyte，AC）标志物胶质纤维酸性蛋白（glial fibril－lary acidic protein，GFAP）的阳性细胞数量则随着年龄增长不断增多（M3=9.2±6.7，M8=1 053.0±171.3，M12=2 058.0±210.8，M16=3 283.0±240.30；P1=0.000，P2=0.000，P3=0.000）；而促进Aβ生成的关键酶β-分泌酶（β-site APP cleaving enzyme 1，BACE1）的阳性细胞数量随年龄不断增长增多（M3=2 183.00±85.43，M8=3 466.0±142.5，M12=4 555.00±83.23，M16=5 237.00±133.40；P1=０.000，P2=0.000，P3=0.000），蛋白质印迹（Western blot，WB）也得到同样的结果。结论：雌性APP/PS1双转基因小鼠3月龄开始出现典型AD病理改变，随着年龄的增长，病理改变逐渐加重，无逆转迹象。

Abstract:

Objective：To discuss the dynamic pathological changes in the brain of female Alzheimer’s disease（AD） mice with differ－ent ages. Methods：Totally 24 APP/PS1 double transgenic mice with AD of 3，8，12，16-month-age were chosen（6 mice for each age group）. Light microscopic observation was performed after Paraffin embedding，sectioning and immunohistochemical staining. Results Immunohistochemical results showed that，amyloidβ peptide（Aβ） and senile plaque（SP） can be occasionally observed. With the in－crease of the age，the volume and number of SP were increased（M3=0.600±0.235，M8=8.933±1.730，M12=28.470±1.841，M16=94.130±4.287；P1=0.025，P2=0.000，P3=0.000）（M3，M8，M12，M16 stands for 3，8，12，16 months respectively；P1，P2，P3 stands for the comparison of P value between M3 and M8，M8 and M12，M12 and M16）. Accordingly，NeuN positive cells in the brain of mice were in a declined trend（M3=1 919.00±58.21，M8=1 717.00±65.83，M12=1 689.00±45.66，M16=1 529.00±45.36，P1=0.011，P2=0.712，P3=0.043），glial fibrillary acidic protein-positive cells were increased（M3=9.2±6.7，M8=1 053.0±171.3，M12=2 058.0±210.8，M16=3 283.0±240.3；P1=0.000，P2=0.000，P3=0.000） and β-site APP cleaving enzyme 1 positive cells were increased（M3=2 183.00±85.43，M8=3 466.00±142.50，M12=4 555.00±83.23，M16=5 237.00±133.40；P1=0.000，P2=0.000，P3=0.000）. Similar results were achieved by Western blot. Conclusion：Female APP/PS1 double transgenic mice display typical AD pathological changes from the age of 3 months to 16 months. The pathological changes grad－ually increase with increasing of age，without reversal.