Distribution And Expression Of Amylin In The Brain Of Alzheimer’s Disease Model Mice And Wild-type Controls

Objective:To examine the distribution and expression of amylin in the brain of Alzheimer’s disease model mice and wild-type controls, and the relationship between amylin and senile plaques, so as to investigate the relationship between amylin and the pathology of AD.Methods: Different ages of APP/PS1 double transgenic male mice model(2xTgAD) and wild-type controls(WT) at the age of 5 month, 9 month and 12 month were selected for this study. Each group is 5 mice. Immunofluorescence staining was used to detect the distribution and expression of amylin, and the relationship between amylin and GFAP、NeuN and senile plaques in the brain. Western blot was acquired to investigate the change of the level of amylin protein in the brain.Results: Firstly, amylin-positive cells were most expressed in the mature neurons. Secondly, amylin-positive neurons were widely distributed and expressed throughout almost all the regions of brain in the mice, while the distribution is different in various areas of the brain. Amylin were strongly labeled in the cortex, whereas moderately expressed in the hippocampus and few expressed in the thalamus. Thirdly, the number of amylin positive cells in the cortex of 2×TgAD was obviously higher than WT, while was not significantly different in the hippocampus. With age, its expressed level was gradually increased. Fourthly, amylin positive substances were gathered and formed some distinct plaques in the brain of 2xTgAD with age. The number and area of senile plaques was gradually increased with age. The distribution of amylin was much more extensive than that of senile plaques in the 2xTgAD brain. There was the phenomenon of coexpression amylin with 4G8 in the cortex and hippocampus of 2xTgAD. Finally, expressed level of amylin protein in the brain of 2xTgAD was obviously higher than of WT, and its expressed level was gradually increased with age by the technology of western blot. The expression of amylin Mrna in the brain of 2xTgAD was higher than of WT.Conclusion: The distribution and expression of amylin is obviously different in the brain of 2xTgAD and WT mice at different ages. These differences suggest that deposition of amylin in the brain of AD may be associated with the formation of SP and the progression of AD pathogenesis.