洗心汤对T2D合并AD小鼠模型中JAK2/STAT3通路和IDE蛋白表达的影响

Effect of Xixin Decoction on JAK2/STAT3 pathway and IDE protein expression in T2D combined AD mouse model

目的探究洗心汤对2型糖尿病(type 2 diabetes mellitus,T2D)合并阿尔茨海默病(Alzheimer’s disease,AD)小鼠模型中JAK2/STAT3通路和胰岛素降解酶(insulin degrading enzyme,IDE)蛋白表达的影响,阐明其缓解AD相关症状的分子机制。方法通过对APP/PS1小鼠腹腔注射链脲佐菌素(streptozotocin,STZ)构建T2D-AD小鼠模型,然后分别给予安理申和洗心汤灌胃治疗。共分为4组:对照组、T2D-AD组、安理申组和洗心汤组。通过定位航行实验和空间探索实验考察小鼠的空间记忆能力;通过qRT-PCR检测IDE mRNA的表达水平;ELISA检测各组小鼠脑组织中炎症因子(TNF-α、IL-6、IL-8)的水平;Western blot检测各组小鼠脑组织中JAK2、STAT3、IDE和β淀粉样蛋白(amyloid-βpeptides,Aβ)的表达水平。结果与对照组相比,T2D-AD组小鼠的逃避潜伏期显著增加(P<0.05),目标平台象限滞留时间与穿越平台次数均显著减少(P<0.05);与T2D-AD组相比,安理申组和洗心汤组小鼠逃避潜伏期均显著缩短(P<0.05),小鼠目标平台象限滞留时间与穿越平台次数均显著增加(P<0.05)。与对照组相比,T2D-AD组小鼠脑组织中炎症因子(TNF-α、IL-6、IL-8)的水平显著升高(P<0.05);与T2D-AD组相比,安理申组和洗心汤组小鼠脑组织中炎症因子(TNF-α、IL-6、IL-8)的水平显著降低(P<0.05)。与对照组相比,T2D-AD组小鼠脑组织中磷酸化JAK2和STAT3水平显著升高(P<0.05);洗心汤组小鼠脑组织中磷酸化JAK2和STAT3水平显著低于T2D-AD组(P<0.05)。与对照组相比,T2D-AD组小鼠脑组织中IDE mRNA和蛋白水平显著降低(P<0.05),Aβ蛋白表达显著升高(P<0.05);与T2D-AD组比较,洗心汤组小鼠脑组织中IDE mRNA和蛋白水平显著升高(P<0.05),Aβ蛋白表达显著降低(P<0.05)。结论洗心汤能够通过抑制T2D-AD小鼠模型中JAK2/STAT3通路的激活缓解小鼠大脑中的炎症反应,并促进IDE蛋白表达,促进Aβ蛋白的降解。

Objective To investigate the effect of Xixin Decoction on JAK2/STAT3 pathway and insulin degrading enzyme(IDE)protein expression in mice with type 2 diabetes mellitus(T2D)combined with Alzheimer's disease(AD),and to elucidate the molecular mechanism of its reduction of AD-related symptoms.Methods T2D-AD mouse model was established by intraperitoneal injection of streptozotocin(STZ)to APP/PS1 mice,and then aricept and Xixin Decoction were given by intragastric administration.They were divided into four groups:control group,T2D-AD group,aricept group and Xixin Decoction group.The spatial memory ability of mice was investigated by navigation experiment and space exploration experiment.The expression level of IDE mRNA was detected by qRT-PCR.The inflammatory factor levels(TNF-α,IL-6 and IL-8)were detected in the brain tissues of each group by ELISA.Western blot was used to detect the protein expression levels of JAK2,STAT3,IDE and Aβ in the brain tissues of mice in each group.Results Compared with the control group,the escape latency of mice in T2D-AD group was significantly increased(P<0.05),and the retention time of target platform quadrant and the times of crossing platform were significantly decreased(P<0.05);compared with T2D-AD group,the escape latency of mice in aricept group and Xixin Decoction group was significantly shortened(P<0.05),and the retention time of mice in target platform quadrant and times of crossing platform were significantly increased(P<0.05).Compared with control group,the inflammatory factor levels(TNF-α,IL-6 and IL-8)were significantly increased in brain tissues of T2D-AD group(P<0.05);compared with T2D-AD group,the inflammatory factor levels(TNF-α,IL-6 and IL-8)were significantly decreased in aricept group and Xixin Decoction group(P<0.05).Compared with the control group,the levels of phosphorylated JAK2 and STAT3 in brain tissues of mice in T2D-AD group were significantly increased(P<0.05);the levels of phosphorylated JAK2 and STAT3 in the brain tissues of mice in Xixin Decoction group were significantly lower than those in T2D-AD group(P<0.05).Compared with control group,IDE mRNA and protein levels in T2D-AD group were significantly decreased(P<0.05),and Aβ protein level was significantly increased(P<0.05);compared with T2D-AD group,the mRNA and protein levels of IDE in Xixin Decoction group were significantly increased(P<0.05),and the protein level of Aβ was significantly decreased(P<0.05).Conclusion Xixin Decoction can inhibit the activation of JAK2/STAT3 pathway in T2D-AD mouse model,alleviate the inflammatory response in mouse brain,promote the expression of IDE protein and the degradation of Aβ protein.