辛伐他汀对老年糖尿病认知功能障碍大鼠脑组织Klotho蛋白表达影响及其相关研究

Effect of simvastatin on expression of brain tissue Klotho in elderly rats with diabetes-associated cognitive decline and its correlation study

目的探讨辛伐他汀对老年糖尿病认知功能障碍大鼠认知功能障碍的延缓作用及对Klotho蛋白表达的影响。方法实验将老年SD大鼠(18~22月龄)分为4组,分别为对照组:大鼠正常饮食,于第12周开始口服灌胃生理盐水8周;辛伐他丁组:大鼠正常饮食,于第12周口服灌胃辛伐他丁10 mg·kg^(-1)·d^(-1)8周;模型组:高脂饮食12周,于第4周腹腔注射链脲佐菌素(STZ,25 mg/kg),给药后8周检测血糖、认知功能,剔除不符合标准的大鼠,然后开始口服灌胃生理盐水8周;糖尿病+辛伐他丁组:按照模型组大鼠的方式建立糖尿病认知功能减退(DACD)模型并进行筛选后,于第12周开始口服灌胃辛伐他丁10 mg·kg^(-1)·d^(-1)。在持续灌胃辛伐他汀的第8周,取各组大鼠脑组织进行Neun免疫荧光染色并利用Western blot检测海马组织Klotho、Caspase-3蛋白表达水平的变化,检测血糖水平,并利用Morris水迷宫实验测定认知功能改变情况。结果与对照组比较,模型组和糖尿病+辛伐他汀组大鼠逃避潜伏期延长,Klotho、Neun蛋白表达水平下降,Caspase-3蛋白表达水平上升,差异均有统计学意义(P<0.05);与模型组比较,糖尿病+辛伐他丁组逃避潜伏期缩短、Klotho、Neun蛋白表达水平增加,Caspase-3蛋白表达水平下降,差异均有统计学意义(P<0.05)。结论长期使用辛伐他汀可缓解糖尿病认知功能障碍老年大鼠的海马区细胞凋亡、神经元损伤及认知功能障碍的持续恶化,以上作用可能与Klotho表达变化相关。

Objective To study the delay effect of simvastatin on the diabetes-associated cognitive decline and its effect on Klotho protein in the elderly rats with diabetes-associated cognitive decline.Methods The SD rats(18-22 months old)were divided into 4 groups:the control group,giving the normal diet and beginning to orally take normal saline by gavage at the time of 12th week;the simvastatin group;normal diet was given and beginning to orally take simvastatin 10 mg·kg^(-1)·d^(-1) by gavage;the diabetes group,high-fat diet was given for 12 weeks and was intraperitoneally injected by streptozotocin(STZ,25 mg/kg)at 4 weeks,blood sugar and cognitive function was detected at 8th week after taking medication,and the rats that did not meet the standard were exclucled,then the normal saline gavage was given for 8 weeks;the diabetes+simvastatin group:the diabetes-associated cognitive decline rat model according to the pattern of the rats in the diabetes group was constructed,10 mg·kg^(-1)·d^(-1) of simvastatin was begin to orally administered by gavage at 12th week.The brain tissues in each group were taken in 8 weeks by simvastatin continuous bavage for conducting the Neun immunofluorescent staining,Western blot was used to detect the expression levels of Klotho and Caspase-3 proteins.the blood sugar level was detected and the change of cognitive function was detected by the Morris water maze test.Results Compared with the control group,the escape latency was prolonged in the diabetes group and diabetes+simvastati group,the expression levels of Klotho and Neun proteins were decreased,the Caspase-3 protein expression level was increased,and the differences were statistically significant(P<0.05);compared with the diabetes group,the escape latent period in the diabetes+simvastatin group was shortened,the expression levels of Klotho and Neun proteins were increased,the Caspase-3 protein expression level was decreased,and the differences were statistically significant(P<0.05).Conclusion The long-term use of simvastatin could alleviate the cellular apoptosis in hippocampus area,neuron damage and diabetes-associated cognitive decline persistent deterioration in elderly rats with diabetes-associated cognitive decline,which may be correlated with the change of Klotho protein expression.