The Changes Of Aβ And Autophagy In The Brain Of Alzheimer’s Disease Transgenic Mice

Objective To observe the expression changes of β-amyloid（Aβ） andMicrotubuleassociated protein Light chain3（LC3） in different brain regions ofAlzheimer’s Disease transgenic mice, And analysis the correlation of Aβ andLC3,further investigate the changes of Autophagy in the brain of AD.Methods：1. Congo red staining, improvement Bielshowsky dyeing, mmunohi-stochemistry and immune fluorescent histochemical method were used to detectthe distribution of Morphological methods were used to detect the distribution ofAβ and LC3in the brains of AD transgenic mice.2. Westert blotting were used todetect the ratio of LC3Ⅱ/LC3Ⅰand the expression changes of Beclin-1.3. stereol-ogical metrology was applied in counting the amounts of positive staining objects.We also calculated the optical density value of positive staining objects with theIPP software. Finally the correlation of the quantity and optical density values bet-ween Aβ and LC3respectively was analyzed statistically with SPSS11.0.Result1. The search strategy of the mutant mice application is less than that ofwild-type mice, the difference was statistically significant （P＜0.05）; But therewas no statistically significant to average escape latency(M_mutant=38S，M_wild=29S，P＞0.05).2. Senile plaques were widely distributed in the regions of M1、M2、DG、CA1、CA3、CPu of the mutant mouse brain, but A β positive witch were homogen-eous shape were only present in the cytoplasm reactants of the cerebellum purki-nje cell layer.3. LC3were granular accumulate into a circular distribution of theM1、M2、DG、CA1、CA3、CPu of mutant mice; but they were Only homogenizingshaped distribution in the wild-type mouse brain, as well as mutant mice CbDistrict in the cytoplasm.4. there were statistically significant to expressionnumber and optical density of Aβ and LC3between mutant mice and wild-typemice of AD transfe（P＜0.05）.5. The expression levels of Aβ and LC3in specific brain regions of mutant type mice such as M1、M2、DG、CA1、CA3、CPu werehigher than the corresponding regions of wild type（P＜0.05）.6. No significantdifferences were found among the DG，CA1and CA3regions of hippocampus onthe expression of Aβ and LC3in mutant mice（P＞0.05）. There were also nosignificant differences among the M1，M2and hippocampus on the expression ofAβ and LC3in brains of mutant type（P＞0.05）. However，the expression levels ofAβ and LC3in above regions of mutant brains were higher than those in CPu（P＜0.05）. While the expression of Aβ and LC3in Cb were the least.7. There was apositively correlation（r=0.228，P＜0.01） between the expression of senile plaquesand Aβ in mutant group.8. There was a positively correlation（r=0.486, P <0.05）between the expression of LC3and Aβ in mutant group.9. The expression levels ofB e c l i n-1i n mu t a n t b r ai n s we r e h i gh er t ha n t ho s e i n w i l d t y p e.Conclusion1. It is reliable model to study AD that AD transgenic mice can be used.2.There was significant difference of Aβ expression in various brain regions of ADtransgenic mice.3. It is enhancement that autophagy in AD brain,and beclin-1regulatory pathway may play an important role.