Objective To observe the expression of β-amyloid(Aβ)in pancreas and brain of type 2 diabetes mellitus(T2DM)mice during the progression of T2DM.Methods A total of 36 control mice and 36 T2DM mice were randomly divided into 6 groups(13 weeks,16 weeks,19 weeks,22 weeks,25 weeks,28 weeks).One group of mice was sacrificed at 3-week intervals starting at 13 weeks of age,and the total observation period was from 13 weeks to 28 weeks.Immunohistochemical analysis and enzyme-linked immunosorbent assay(ELISA)were used to observe the distribution and expression of Aβ in pancreas and brain tissue of T2DM mice.Western blotting and ELISA were used to detect the expression of amyloid precursor protein(APP)and β-site amyloid precursor protein cleavage-1(BACE-1).The t-test was used for comparison between two groups,and one-way analysis of variance was used for comparison between multiple groups.Spearman correlation analysis was used to analyze the correlation between pancreatic Aβ content and homeostasis model assessment of insulin resistance index(HOMA-IR)and insulin/proinsulin ratio.Results With the progression of T2DM,the deposition of Aβ in pancreatic islets and brain hippocampus gradually worsened compared with control mice(P＜0.05).The expression of Aβ in pancreas and hippocampus of T2DM mice were gradually increased with the progress of T2DM(P＜0.05).The expression levels of APP and BACE-1 in the two tissues initially increased and then decreased with disease progression(P＜0.05).In addition,with the progression of the disease,the level of pancreatic islet function in the T2DM group gradually decreased,which was significantly correlated with the gradual increase of pancreatic Aβ deposition.Spearman correlation analysis showed that the correlation coefficients of HOMA-IR and insulin/proinsulin with pancreatic Aβdeposition were 0.837 0 and 0.728 1,respectively(P＜0.001).Conclusion The expression of Aβ in the pancreas and brain of T2DM mice changes in synchrony with disease progression.
维普
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