两种阿尔茨海默病树鼩模型的探究

Study of two kinds of Alzheimer's disease tree shrew models

目的比较两种不同的阿尔茨海默病(Alzheimer’s disease,AD)树鼩模型大脑神经病理改变,探索优化的AD树鼩模型。方法 50只树鼩随机分为5组:D-半乳糖复合鹅膏蕈氨酸(IBO)高、低剂量组(腹腔注射D-半乳糖复合双侧大脑基底注射IBO),Aβ_(25-35)复合IBO高、低剂量组(双侧基底前脑注射)及对照组,10只/组。HE染色法观察各组树鼩大脑神经细胞形态;免疫组化法检测各组树鼩大脑胆碱乙酰基转移酶(Ch AT)和突触素(SYP)的表达;免疫印迹法检测β淀粉样蛋白1-42(Aβ_(1-42))、淀粉样蛋白前体蛋白(APP)和磷酸化tau蛋白(p-tau)的表达。结果 HE染色显示,造模树鼩大脑神经细胞均出现程度不同的形态损伤改变,以D-半乳糖复合IBO高剂量组和Aβ_(25-35)复合IBO高剂量组改变明显;免疫组化染色结果显示,造模组的Ch AT和SYP的表达均明显下降(P<0.01),其中以Aβ_(25-35)复合IBO高剂量组下降明显。免疫印迹检测结果显示,造模组的Aβ_(1-42)、APP和p-tau的表达均明显升高(P<0.05或P<0.01),其中以Aβ_(25-35)复合IBO高剂量组升高明显。结论 Aβ_(25-35)合并IBO注射Meynert核损毁造模方法更适合构建AD树鼩模型。

Aim To explore the optimized tree shrews model of Alzheimer's disease through comparison of the pathology changes of brain neurons between the two kinds of tree shrew models.Methods Fifty tree shrews were randomly divided into five groups with 10 in each group: control group,high dose D-galactose combined with ibotenic acid( IBO) group,low dose D-galactose combined with IBO group [intraperitoneal injection D-galactose combined with IBO injection into bilateral basal nucleus of Meynert( BNM) ], high dose Aβ_(25-35) combined with IBO group,and low dose Aβ_(25-35) combined with IBO group( injection into bilateral BNM). Hematoxylin and eosin( HE) staining was used to observe the morphological changes of brain neurons. The expressions of choline acetyltransterase( Ch AT) and synaptophysin( SYP) in the brains were detected by immunohistochemical staining. Western blot was used to detect the expression of amyloid beta 1-42( Aβ_(1-42)),amyloid precursor protein( APP)and phosphorylated tau protein( p-tau). Results The HE staining showed there were different degrees of morphological changes in the brains of model groups. The changes in the high dose D-galactose and high dose Aβ_(25-35) combined with IBO group were more obvious than those in low dose D-galactose and Aβ_(25-35)combined with IBO group. Immunohistochemical staining revealed that the levels of Ch AT and SYP in the model groups decreased compared with control group,and the decline in high dose Aβ_(25-35)combined with IBO group was more marked than that in low dose Aβ_(25-35) combined with IBO group( P < 0. 01).Western blot revealed that the levels of Aβ_(1-42),APP,p-tau in the model groups increased compared with control group,and the rise in high dose Aβ_(25-35)combined with IBO group was more apparent than that in low dose Aβ25-35 combined with IBO group( P < 0. 05 or P < 0. 01). Conclusion The method of modeling by Aβ_(25-35) combined with IBO injection into bilateral BNM is more suitable for the establishment of Alzheimer's disease model.