CAJ | 학술논문

目的研究高胆固醇血症诱导小鼠海马中tau蛋白磷酸化的作用以及阿托伐他汀对其中tau蛋白磷酸化水平的影响.方法雄性昆明小鼠,随机分为正常对照组、高胆固醇血症模型组、阿托伐他汀低剂量组(8mg·kg-1·d-1)、阿托伐他汀中剂量组(15mg·kg-1·d-1量)、阿托伐他汀高剂量组(20mg·kg-1·d-1),每组5只.饲以高脂饲料建立小鼠高胆固醇血症模型,用免疫印迹和免疫组织化学的方法检测小鼠海马中tau蛋白的磷酸化表达情况,分别用放射性配体结合实验和酶活性法检测小鼠海马中细胞分裂素活化蛋白激酶(MAPK)和细胞周期蛋白依赖性蛋白激酶5(Cdk-5)的酶活性.结果与正常对照组小鼠相比,高胆固醇血症模型组小鼠海马中tau蛋白磷酸化表达水平明显升高(F=14.761,P＜0.01),MAPK与Cdk-5活性明显升高(P＜0.01).与高胆固醇血症模型组相比,阿托伐他汀低剂量组(F=6.349,P＜0.05)、中剂量组(F=10.283,P＜0.01)及高剂量组(F=10.511,P＜0.01)的小鼠海马中tau蛋白Ser396/Ser404位点的过度磷酸化水平均呈现显著降低,MAPK与Cdk-5活性亦随着阿托伐他汀剂量的增加呈降低趋势.结论高胆固醇血症小鼠海马中tau蛋白发生过度磷酸化,异常的胆固醇代谢可能参与脑神经退行性变的病理过程;阿托伐他汀可通过阻断MAPK与Cdk-5的激活抑制tau蛋白磷酸化,对tau蛋白有保护作用.
목적 연구고담고순혈증유도소서해마중tau단백린산화적작용이급아탁벌타정대기중tau단백린산화수평적영향.방법 웅성곤명소서,수궤분위정상대조조、고담고순혈증모형조、아탁벌타정저제량조(8mg·kg-1·d-1)、아탁벌타정중제량조(15mg·kg-1·d-1량)、아탁벌타정고제량조(20mg·kg-1·d-1),매조5지.사이고지사료건립소서고담고순혈증모형,용면역인적화면역조직화학적방법검측소서해마중tau단백적린산화표체정황,분별용방사성배체결합실험화매활성법검측소서해마중세포분렬소활화단백격매(MAPK)화세포주기단백의뢰성단백격매5(Cdk-5)적매활성.결과 여정상대조조소서상비,고담고순혈증모형조소서해마중tau단백린산화표체수평명현승고(F=14.761,P＜0.01),MAPK여Cdk-5활성명현승고(P＜0.01).여고담고순혈증모형조상비,아탁벌타정저제량조(F=6.349,P＜0.05)、중제량조(F=10.283,P＜0.01)급고제량조(F=10.511,P＜0.01)적소서해마중tau단백Ser396/Ser404위점적과도린산화수평균정현현저강저,MAPK여Cdk-5활성역수착아탁벌타정제량적증가정강저추세.결론 고담고순혈증소서해마중tau단백발생과도린산화,이상적담고순대사가능삼여뇌신경퇴행성변적병리과정;아탁벌타정가통과조단MAPK여Cdk-5적격활억제tau단백린산화,대tau단백유보호작용.
Objective To investigate the phosphorylation of tau protein and the effect of atorvastatin on tau protein phosphorylation in hypercholesteremic mouse hippocampus. Methods Male Kunming mice were randomly divided into normal control group, hypercholesteremia group, and low-dose atorvastatin treatment group (8mg·kg-1·d-1), middle-dose group (15mg·kg-1·d-1),and high-dose group (20mg·kg-1·d-1) with five mice in each group. The hypercholesteremia mouse model was induced by cholesterol-enriched diets. The expression level of tau protein phosphorylation in mouse hippocampus was detected by Western blot and immunohistochemistry methods. The activities of mitogen-activated protein kinase (MAPK) and cyelin dependent kinase 5 (Cdk-5) were measured by liquid scintillation counting of the hippocampus incorporated radioactivity and immunoprecipetation activity assay respectively. Results In hypercholesteremic group, the expression level of tau protein phosphorylation in mouse hippocampus was significantly increased(F=14.761,P＜0.01)as compared with control group, and so were MAPK activity and Cdk-5 activity(all P＜0.01). Atorvastatin treatment group showed the decreased expression level of tau protein phosphorylation at ser396/404 site in low-dose group (F=6.349,P＜0.05),middle-dose group (F=10.283,P＜0.01) and high-dose group (F=10.511,P＜0.01) as compared with hypercholesteremia mouse group. The activities of MAPK and Cdk-5 were decreased along with the increasing atorvastatin doses. Conclusions Hypercholesteremia induces tau protein hyperphosphorylation in mouse hippocampus. Abnormal cholesterol metabolism may play an important role in the pathology process of neurodegeneration in brain. Atorvastatin might inhibit tau protein hyperphosphorylation by inhibiting the activations of MAPK and Cdk-5 in brain, atorvastatin may have the protect effect for tau protein.