侧脑室注射α-突触核蛋白对黑质和纹状体单胺氧化酶B表达的影响

EFFECT OF INTRACEREBROVENTRICULAR INJECTION OF Α-SYNUCLEIN ON THE EXPRESSION OF MONOAMINE OXIDASE B IN THE SUBSTANTIA NIGRA AND THE STRIATUM

目的探讨侧脑室注射α-突触核蛋白(α-syn)对小鼠黑质和纹状体区单胺氧化酶B(MAO-B)蛋白表达以及运动功能的影响。方法将8周龄雄性C57BL/6小鼠随机分为生理盐水组以及0.04、0.20和2.00 ng的α-syn组,给予侧脑室连续注射生理盐水或α-syn共7 d,采用转棒实验检测小鼠运动能力,采用免疫印迹法检测小鼠黑质和纹状体区酪氨酸羟化酶(TH)和MAO-B蛋白表达。结果与生理盐水组相比,0.20和2.00 ng的α-syn组小鼠在转棒上运动时间明显缩短(F=4.877,P<0.05),且纹状体区MAO-B蛋白表达水平显著升高(F=9.662,P<0.05),但0.04 ng的α-syn组小鼠运动水平和纹状体区MAO-B蛋白表达水平均没有明显变化(P>0.05)。各组小鼠黑质区TH和MAO-B蛋白表达水平比较差异均无显著性(P>0.05)。结论侧脑室注射α-syn可引起小鼠纹状体区MAO-B蛋白表达增加和运动功能障碍。

Objective To investigate the effect of intracerebroventricular injection of α-synuclein(α-syn) on the expression of monoamine oxidase B(MAO-B) in the substantia nigra and the striatum of mice. Methods Male C57 BL/6 mice, aged 8 weeks, were randomly divided into normal saline group and 0.04, 0.20, and 2.00 ng α-syn groups. After intracerebroventricular injection of normal saline or α-syn was given for 7 consecutive days, the rotarod test was used to evaluate motor ability, and Wes-tern blotting was used to measure the protein expression levels of tyrosine hydroxylase(TH) and MAO-B in the substantia nigra and the striatum of mice. Results Compared with the normal saline group, the 0.20 and 2.00 ng α-syn groups had a significant reduction in the time spent on the rotating rod(F=4.877,P<0.05) and a significant increase in the protein expression level of MAO-B in the striatum(F=9.662,P<0.05), while the 0.04 ng α-syn group had no significant changes in motor ability and the protein expression level of MAO-B in the striatum(P>0.05). There were no significant differences in the protein expression levels of TH and MAO-B in the substantia nigra between these groups(P>0.05). Conclusion Intracerebroventricular injection of α-syn can increase the protein expression of MAO-B in the striatum of mice and induce impairment of motor ability.