Effect Of Apolipoprotein E Gene Knock-out And High-fat Diet On Mortalin Expression In Mice Hippocampal CA₃ Neurons

Objective Apolipoprotein E (apolipoprotein E, ApoE) is confirmed susceptibility to late familial, sporadic Alzheimer's disease (Alzheimer's disease, AD). From the cells, animal experiments to clinical, cholesterol which is regulationed by apolipoprotein E is closely linked with AD. We investigate the effect of Apolipoprotein E gene knock-out(ApoE KO) and high-fat diet on morphology and the expression of Mortalin in hippocampal CA3 neurons of mice, and explore the impact of these factors on memory and Alzheimer's disease. Methods Ten wild-type and 10 ApoE KO mice were fed with common chow as the control C group and the KO group respectively while 10 ApoE KO mice were fed with high fat diet as the KO-HF group.12 weeks later, the weight and the lid of these mice were measured. The brain tissues were observed using HE staining, protargol staining, nissl staining, immunohistochemistry staining and image analysis by computer. Results①The weight of C group (4.816±1.370),KO group (0.066±1.821),KO-HF group (23.631±5.215) is different (F=18.210,P<0.05).②The total cholesterol of C group (2.062±0.303),KO group (13.680±3.719),KO-HF group (31.821±2.933) is different (F=279.439,P<0.05).The triglyceride of C group (1.778±0.397), KO group (2.624±0.654), KO-HF group (3.006±0.238) is different (F=18.422,P<0.05).The low-density lipoprotein cholesterol of C group (0.697±0.550), KO group (2.367±0.571), KO-HF group (5.165±1.071) is different (F=73.820, P<0.05).③HE staining shows the pyramidal cells of KO group and KO-HF group are loose and irregular arrangement.④Protargol staining shows there is no Neurofibrillary tangle in KO group and KO-HF group.⑤Nissl staining shows the pyramidal cells of KO group and KO-HF group are loose and irregular arrangement. Image analysis shows the nissl of C group (0.341±0.035),KO group (0.301±0.031),KO-HF group (0.261±0.020) is different (F=18.068,P<0.05)⑥Immunohistochemistry staining shows the pyramidal cells of KO group and KO-HF group are up-regulated. Image analysis shows the Mortalin of C group (0.256±0.061),KO group (0.322±0.060),KO-HF group (0.391±0.041) is different (F=15.230, P<0.05).Conclusions ApoE KO and high-fat diet can reduce nissl, and improve the expression of Mortalin.