β-抑制蛋白1/2在帕金森病小鼠中的表达及其与发病机制的关系

The expression level of β-arrestin 1/2 in mice with Parkinson's disease and its relationship with pathogenesis of Parkinson's disease

目的观察β-抑制蛋白1/2(β-arrestin1/2)在帕金森病(PD)小鼠脑组织中的表达情况, 分析其参与PD病理过程的可能机制。方法采用1-甲基-4-苯基-1, 2, 3, 6-四氢吡啶盐酸盐(MPTP)制备PD模型, 末次给药后3 d处死小鼠, 取脑组织。观察小鼠行为学和脑组织病理学变化, Western bolt法检测脑组织β-arrestin1/2表达, 免疫荧光双标记法检测β-arrestin1/2与小胶质细胞共定位情况, 分别运用限速酶酪氨酸羟化酶(TH)、Iba-1标记细胞, 采用免疫组化染色观察脑片多巴胺能神经元丢失和小胶质细胞活化情况。结果与空白对照组比较, PD小鼠脑组织中β-arrestin1蛋白相对表达水平升高, β-arrestin2蛋白相对表达水平降低(t=11.535、9.948, 均P=0.000), 且β-arrestin1/2与小胶质细胞均存在共同细胞定位。MPTP诱导PD后, β-arrestin1^(+/+)组和β-arrestin1^(-/-)组小鼠中脑SNc区Th^(+)神经元数量均减少(t=4.098、3.571, P=0.000、0.001), 中脑SNc区Iba-1^(+)细胞数量均增加(t=10.097、6.448, 均P=0.000)。MPTP诱导PD后, β-arrestin2^(+/+)组和β-arrestin2^(-/-)组小鼠中脑SNc区Th^(+)神经元数量均减少(t=3.512、5.237, P=0.001、0.000), 中脑SNc区Iba-1^(+)细胞数量均增加(t=5.816、8.402, 均P=0.000)。与β-arrestin1^(+/+)组比较, β-arrestin1^(-/-)组小鼠小胶质细胞TRAF6、NF-κB及COX-2表达上调(t=5.324、5.837、9.350, 均P=0.000)。与β-arrestin2+/+组比较, β-arrestin2-/-组小鼠小胶质细胞TRAF6、NF-κB及COX-2表达下调(t=5.094、6.318、9.466, 均P=0.000)。结论 PD小鼠脑组织β-arrestin1表达上调、β-arrestin2表达下调, β-arrestin1/2可能通过TRAF6/NF-κB/COX-2通路影响小胶质细胞增殖活化以及多巴胺能神经元丢失参与PD的病理过程。

Objective To observe the expression level of β-arrestin 1/2 in mice with Parkinson's disease(PD)and its relationship with pathogenesis of PD.Methods PD model was prepared by using 1-methyl-4-phenyl 1.2.3.6 tetrahydropyridine hydrochloride(MPTP).The mice were killed at 3 days after the last administration and the brain tissue was taken for observing brain histopathological changes.The colocalization of β-arrestin1/2 with microglia was detected by using immunofluorescence double-labeling ofβ-arrestinl/2 and microglia.Tyrosine hydroxylase(TH)and lba-1 were used to label cells,and then the loss of dopaminergic neurons and the activation of microglia were observed by immunohistochemistry.Results As compared with the blank control group,the relative expression level of β-arrestinl protein in brain tissue of PD mice was increased significantly,while the relative expression level of β-arrestin2 protein was decreased significantly(t=11.535.9.948,both P=0.000),and β-arrestin1/2 shared cell localization with microglia.After MPTP induced PD,the number of Tht neurons in SNc area of midbrain was decreased siguificantly in p-dllustin1^(+/+) g1vup aund β-arlestin1^(-/-) group(t=4.098,3.571.P=0.000,0.001),while the number of Iba-1^(+) cells in SNc area of midbrain was increased significantly(t=10.097、6.448.both P=0.000).After MPTP induced PD,the number of Th^(+) neurons in SNc area of midbrain was decreased significantly inβ-arrestin2^(+/+)group andβ-arrestin2^(-/-) group(t=3.512.5.237,P=0.001.0.000),while the number of Iba-1^(+) cells in SNc area of midbrain was increased significantly(t=5.816.8.402,P=0.000).Compared withβ-arrestin1^(+/+) group,the expressions of TRAF6,NF-κB and COX-2 in mouse microglia were significantly increased inβ-arrestin1^(-/-) group(t=5.324,5.837,9.350,all P=0.0000).Compared with β-arrestin2^(+/+)group,the expressions of TRAF6,NF-κB and COX-2 in mouse microglia were significantly down-regulated in β-arrestin2^(-/-)group(t=5.094.6.318.9.466,all P=0.000).Conclusions The expression ofβ-arrestinl is up-regulated andβ-arrestin2 is down-regulated in brain tissue of PD mice.β-arrestin1/2 may affect the proliferation and activation of microglia and the loss of dopaminergic neurons through TRAF6/NF-κB/COX-2 pathway,and participate in the pathological process of PD.