Effect of atorvastatin on tau protein phosphorylation in hippocampus of hypercholesteremic mouse / 中华老年医学杂志

ABSTRACT

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.