Changes in histopathology and ultrastructure of corneal epithelium in TgAPPswePS1 transgenic mice / 眼科新进展

ABSTRACT

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.