超氧化物歧化酶融合蛋白改善阿尔茨海默病小鼠大脑白质超微结构实验研究  

Experimental study of superoxide dismutase fusion protein improving ultrastructure of cerebral white matter in mice with Alzheimer’s disease

作　　者：程艳 郭建伟 李扬[1] 薛荣亮 CHENG Yan;GUO Jianwei;LI Yang;XUE Rongliang(Department of Anesthesiology,Shaanxi Provincial People’s Hospital,Xi’an 710068,China)

机构地区：[1]陕西省人民医院麻醉科,陕西西安710068 [2]西安国际医学中心医院麻醉与舒适化医疗中心,陕西西安710100

出　　处：《陕西医学杂志》2022年第9期1049-1054,共6页Shaanxi Medical Journal

基　　金：国家自然科学基金资助项目(81471131)。

摘　　要：目的:观察超氧化物歧化酶(SOD)融合蛋白对阿尔茨海默病(AD)小鼠大脑白质超微结构的影响,探究大脑白质超微结构改变与脑内氧化应激水平之间的关系。方法:选用32只昆明雄性小鼠,适应性饲养7 d后,随机分为假手术组(S组)、模型组(M组)、SOD干预模型组(SM组)和SOD融合蛋白干预模型组(PM组),每组8只。在实验第9~23天,通过小鼠连续腹腔内注射等量0.9%氯化钠溶液(S和M组)、6 mg/(kg·d)SOD(SM组)或6 mg/(kg·d)SOD融合蛋白(PM组)进行预防干预。其中,在实验第16天,通过5μl微量注射器将0.9%氯化钠溶液(S组,2μl/只)及β-淀粉样蛋白(Aβ)1-42寡聚体(M组、SM组及PM组,2μl/只)注射于小鼠右侧脑室,以制备AD模型。在实验第32天,随机选取一侧大脑半球用ELISA法测定脑组织匀浆中的SOD活力和丙二醛(MDA)水平,另一侧大脑半球固定于2%甲醛+2.5%戊二醛溶液中,应用现代体视学方法定量分析小鼠脑白质及其超微结构变化。结果:四组小鼠在实验第8、24、31天体重比较差异无统计学意义(均P>0.05)。M组SOD活力低于S组,PM组SOD活力高于M组(均P<0.05)。M组MDA水平高于S组,PM组MDA水平低于M组(均P<0.05)。M组小鼠脑白质总体积、有髓神经纤维总长度、有髓神经纤维总体积、髓鞘总体积低于S组,PM组小鼠脑白质总体积、有髓神经纤维总长度、有髓神经纤维总体积、髓鞘总体积高于M组(均P<0.05)。M组小鼠髓鞘内直径及外直径低于S组,PM组小鼠髓鞘内直径及外直径高于M组(均P<0.05)。一侧脑白质总体积、有髓神经纤维总长度、有髓神经纤维总体积、髓鞘总体积与脑组织匀浆中SOD活力呈正相关,而与MDA水平呈负相关(均P<0.05)。结论:SOD融合蛋白外源性补充可明显减轻Aβ1-42诱导的氧化应激,改善AD小鼠脑白质及其超微结构变化。AD小鼠脑内氧化水平及白质超微结构改变之间有相关关系。Objective:To observe the effect of superoxide dismutase(SOD)fusion protein on the ultrastructure of cerebral white matter in mice with Alzheimer’s disease(AD),and to explore the relationship between the changes of cerebral white matter ultrastructure and the level of oxidative stress in the brain.Methods:Thirty-two Kunming male mice were randomly divided into sham operation group(group S),model group(group M),SOD intervention model group(group SM)and SOD fusion protein intervention model group(group PM)after 7 days normal feeding for adaptation,with 8 mice in each group.From the 9th to the 23rd day of the experiment,mice were injected with the same amount of 0.9%sodium chloride solution(group S and M),6 mg/(kg·d)SOD(group SM)or 6 mg/(kg·d)SOD fusion protein(group PM).On the 16th day of the exper iment,0.9%sodium chloride solution(group S,2μl/rat)and Aβ1-42 oligomer(group M,group SM and group PM,2μl/rat)were injected into the right ventricle of mice through a 5μl microsyringe to prepare AD model.On the 32nd day of the experiment,SOD activity and MDA level in brain homogenate were measured by ELISA in one hemisphere,while the other hemisphere was fixed in 2%formaldehyde and 2.5%glutaraldehyde solution for modern stereological study of white matter.Results:There was no significant difference in body weight among the four groups on days 8,24 and 31(all P>0.05).SOD activity in group M was lower than that in group S,while SOD activity in group PM was higher than that in group M(all P<0.05).MDA level in group M was higher than that in group S,while MDA level in group PM was lower than that in group M(all P<0.05).The total volume of white matter,total length of myelinated nerve fiber,total volume of myelinated nerve fiber and total volume of myelin sheath in group M were lower than those in group S,while the total volume of white matter,total length of myelinated nerve fiber,total volume of myelinated nerve fiber and total volume of myelin sheath in group PM were higher than those in group M(all P<0.05).The inter

关 键 词：阿尔茨海默病 超氧化物歧化酶融合蛋白 丙二醛 脑白质超微结构 现代体视学 氧化应激 

分 类 号：R749.16[医药卫生—神经病学与精神病学]