β1,2-N-乙酰氨基葡萄糖-氧位-甘露糖基转移酶1基因参与了阿尔茨海默病模型小鼠的病理生理过程

Protein O-linked mannose β1,2-N-acetylglucosaminyltransferase 1 gene is involved in the pathogenic process of Alzheimer′s disease model mice

目的探讨β1,2-N-乙酰氨基葡萄糖-氧位-甘露糖基转移酶1(protein O-linked mannose β1,2-N-acetylglucosaminyltransferase1,POMGnT1)基因是否参与了阿尔茨海默病(Alzheimer′sdisease,AD)的病理生理过程。方法通过实时PCR和蛋白免疫印迹法,检测POMGnT1基因在AD模型细胞系[N2a/淀粉样前体蛋白(APP)695swe,n=3]和正常对照细胞系(N2a/wt,n=3)转录和翻译水平上的差异。利用免疫荧光染色比较POMGnT1基因在5个月龄AD模型小鼠(APP/PS1,n=3)和同月龄正常野生型对照小鼠脑组织(n=3)中的表达差异。通过免疫组织化学的方法,检测POMGnT1基因敲除小鼠2个月龄(n=3)和1岁龄(n=3)脑组织中β-淀粉样蛋白(Aβ)沉积的差异。结果POMGnT1基因在AD模型细胞系中mRNA(0.80±0.02)和蛋白质(0.50±0.02)的含量均显著低于正常对照细胞系(mRNA:1.00,t=10.52,P<0.01;蛋白质:1.31±0.04,t=18.64,P<0.01)。免疫荧光染色结果显示,POMGnT1在AD模型小鼠中的阳性表达率明显低于正常野生型对照小鼠。免疫组织化学结果显示,2个月龄(0.358±0.014和0.048±0.001,t=22.58,P<0.01)和1岁龄(0.266±0.004和0.229±0.003,t=7.771,P=0.002)POMGnT1-/-小鼠的脑中Aβ沉积均显著较同月龄正常野生型小鼠多。结论POMGnT1基因参与了AD的病理生理过程,并且起到了正向保护作用。

Objective To investigate the role of protein O-linked mannose β1, 2-N-acetylglucosaminyltransferase 1 (POMGnT1) in the pathogenic process of Alzheimer′s disease (AD). Methods The expression of POMGnT1 gene was examined in AD model cells (N2a/amyloid-precursor protein (APP) 695swe, n=3) and N2a/wt cells (n=3) using real-time PCR and Western blotting. This expression was also examined in AD model mice (APP/PS1, n=3) and wild-type mice (n=3) using immunofluorescence staining. Amyloid β-protein (Aβ) were examined in POMGnT1-gene-knockout mice (n=3) and wild-type mice (n=3) using immunochemistry. Results The expression of POMGnT1 gene decreased in mRNA and protein levels in N2a/APP695swe cells compared to N2a/wt cells (mRNA: 0.80±0.02 vs 1.00, t=10.52, P<0.01;protein: 0.50±0.02 vs 1.31±0.04, t=18.64, P<0.01). Immunofluorescence results showed the reduced expression of POMGnT1 protein in neurons of APP/PS1 mice. Immunochemistry results showed more Aβ deposits in POMGnT1-gene-knockout mice (2 months old: 0.358±0.014 vs 0.048±0.001, t=22.58, P<0.01;1 year old: 0.266±0.004 vs 0.229±0.003, t=7.771, P=0.002). Conclusion These findings suggest POMGnT1 gene may play an important role in the pathogenic process of AD.