目的 探讨TgAPPswePS1转基因小鼠角膜上皮的病理学和超微结构改变.方法 TgAPPswePS1转基因小鼠分为实验组及对照组,其中实验A组为15 ～18月龄APPswe(+)和PSEN1dE9(+)的阿尔茨海默病(Alzheimer's disease,AD)转基因鼠15只,实验B组为8月龄APPswe(+)和PSEN1dE9(+)的AD转基因小鼠15只,对照组为8月龄野生型小鼠10只.分别观察各组小鼠角膜上皮细胞的病理学改变、超微结构改变、β淀粉样蛋白(amyloidβ-protein,Aβ)的表达情况,并行TUNEL染色检测角膜上皮细胞凋亡情况.结果 实验B组和实验A组角膜上皮厚度分别为(20.104±1.763) μm和(15.456±1.439)μm,均较对照组的(23.567±2.123) μm减少,差异均有统计学意义(均为P＜0.05).实验B组和实验A组均较对照组角膜上皮细胞数减少,层数减少,细胞形态不规则.透射电子显微镜检测示,实验B组和实验A组均较对照组角膜上皮表面微绒毛明显减少,平坦.实验B组和实验A组角膜上皮铺片Aβ免疫阳性反应产物均较对照组明显增多、增强.TUNEL染色结果示,实验B组角膜上皮细胞凋亡数为(5.631±2.471)个,少于实验A组的(16.329±3.542)个,差异有统计学意义(P＜0.05).结论 TgAPPswePS1转基因小鼠较野生型小鼠角膜上皮病理学、超微结构及角膜上皮细胞内Aβ的表达均有改变,以上变化与小鼠月龄有相关性.%Objective To investigate the histopathological and ultrastructural changes in the corneal epithelium in TgAPPswePS1 transgenic mice.Methods TgAPPswePS1 transgenic mice were randomly divided into experimental group (A and B sub-group) and control group.There were 15 APPswe/PSEN1dE9 transgenic mice (15-18 months old) with Alzheimer's disease (AD) in the experimental A group,and 15 APPswe/PSEN1 dE9 transgenic AD mice (8 months old) mice in the experimental B group,as well as 10 wild-type mice (8 months old) in the control group.Then,the histopathological and ultrastructural changes and the expression of amyloid β-protein (Aβ) in the corneal epithelium of the mice were detected,and finally,the apoptosis of corneal epithelial cells were observed by TUNEL assay.Results The thickness of corneal epithelium in the control group,A and B sub-group of the experimental group was (23.567 ± 2.123) μm,(15.456 ± 1.439) μm and (20.104 ± 1.763) μm,respectively.Meanwhile,murine corneal epithelial cells presented the histopathological changes of disorderly arrangement,decreased layers of cells and irregular morphology in the experimental group compared with the control group.Under transmission electron microscope,the microvilli on the surface of corneal epithelium was flat and significantly decreased in the A and B sub-group when compared with the control group.Moreover,Aβ positive expression in the experimental group was significantly upregulated compared with the control group;and the apoptotic number of the corneal epithelium in the B sub-group [(5.631 ± 2.471) cells] was smaller than that in the A sub-group [(16.329 ±3.542) cells],with the significant difference(P ＜ 0.05).Conclusion There are changes in the histopathology and ultrastructure of the corneal epithelium and the expression of Aβ in TgAPPswePS1 transgenic mice compared with wild-type mice,which are associated with the age of mice.
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