CAJ | 학술논문

目的：探讨β淀粉样蛋白（ Aβ）对维甲类X受体α（ RXRα）、孤儿核受体 Nur77的生成和亚细胞定位的影响。方法用 Aβ25～35处理小鼠脑神经瘤细胞（N2a）细胞，并以阿尔茨海默病（AD）模型小鼠的大脑皮层和海马组织为研究对象。应用实时荧光 RT-PCR和蛋白免疫印迹法检测N2a细胞和皮层、海马组织中RXRα、Nur77 mRNA表达和蛋白表达，应用核质分离结合Western印迹检测 N2a细胞中 RXRα、Nur77蛋白在细胞核与细胞质中的含量，应用免疫荧光技术观察N2a细胞与皮层、海马细胞中RXRα、Nur77的亚细胞定位；流式细胞仪检测N 2a细胞凋亡情况，Western印迹检测Bcl-2和Bax表达量。结果 N2a 细胞经 Aβ处理24 h 后，RXRαmRNA 表达水平下降了16.47％，Nur77 mRNA 表达水平无明显变化；RXRα、Nur77总蛋白量无明显变化，但RXRα与Nur77在细胞质中的含量分别由对照组的2.99％、3.91％增至处理组的21.4％、24.2％；Bcl-2蛋白表达下降，Bax表达量上升，细胞凋亡率从对照组1.23％增至Aβ25～35处理组18.69％；与对照小鼠比较，AD小鼠中 RXRα、Nur77 mRNA 表达水平在大脑皮层无明显差异，但在海马中分别增加了8.67％、11.73％；RXRα、Nur77总蛋白量变化无明显差异，但亚细胞定位发生改变，从细胞核迁移至细胞质增加并伴有凋亡发生。结论 Aβ可能诱导RXRα与Nur77从细胞核迁移至细胞质，诱发凋亡。
목적：탐토β정분양단백（ Aβ）대유갑류X수체α（ RXRα）、고인핵수체 Nur77적생성화아세포정위적영향。방법용 Aβ25～35처리소서뇌신경류세포（N2a）세포，병이아이자해묵병（AD）모형소서적대뇌피층화해마조직위연구대상。응용실시형광 RT-PCR화단백면역인적법검측N2a세포화피층、해마조직중RXRα、Nur77 mRNA표체화단백표체，응용핵질분리결합Western인적검측 N2a세포중 RXRα、Nur77단백재세포핵여세포질중적함량，응용면역형광기술관찰N2a세포여피층、해마세포중RXRα、Nur77적아세포정위；류식세포의검측N 2a세포조망정황，Western인적검측Bcl-2화Bax표체량。결과 N2a 세포경 Aβ처리24 h 후，RXRαmRNA 표체수평하강료16.47％，Nur77 mRNA 표체수평무명현변화；RXRα、Nur77총단백량무명현변화，단RXRα여Nur77재세포질중적함량분별유대조조적2.99％、3.91％증지처리조적21.4％、24.2％；Bcl-2단백표체하강，Bax표체량상승，세포조망솔종대조조1.23％증지Aβ25～35처리조18.69％；여대조소서비교，AD소서중 RXRα、Nur77 mRNA 표체수평재대뇌피층무명현차이，단재해마중분별증가료8.67％、11.73％；RXRα、Nur77총단백량변화무명현차이，단아세포정위발생개변，종세포핵천이지세포질증가병반유조망발생。결론 Aβ가능유도RXRα여Nur77종세포핵천이지세포질，유발조망。
Objective To investigate the effect of Aβon the expression and translocation of RXRαN/ur77.Methods In vitro,the N2a cells were treated with Aβ25~35 and ddH 2O respectively.The mRNA and protein expression levels of RXR α/Nur77,which were extrac-ted from cells of N2a/cerebral cortex/hippocampus ,were detected by real-time RT-PCR and Western blot,respectively.The protein expres-sion levels of RXRα/Nur77 in the cells/nucleus/cytoplasm were detected by nucleoplasm separation combined with Western blot.The trans-location of RXRα/Nur77 were observed by staining the seeded cells and frozen brain tissue sections.Cell apoptosis were detected by flow cy-tometry.Results The mRNA level of RXRαin N2a cells was increased 16.47%after 24 h treatment with Aβ25~35 ,but Nur77 remained al-most the same compared with that of control cells;the treatment with Aβ25~35 had no significant effect on the RXRα/Nur77 protein expression levels,but the ratio of RXRα/Nur77 in cytoplasm was increased from 2.99%,3.91%(in control group) to 21.4%,24.2%(in Aβgroup) respectively ;and there was higher expression of Bax and lower expression of Bcl-2 in Aβgroup,and the ratio of cells apoptosis(in control group) was increased from1 .23%to 18.69%(in Aβgroup).In Alzheimer's disease(AD) mice,the mRNA expression levels of RXRα/Nu7r7 had no significant difference in the cerebral cortex compared with those of control mice,and the expression levels of RXRα/Nur77 mR-NA increased8.67%and 11.73%respectively in the hippocampus compared with those of control mice .The RXRαN/ur77 protein levels remained the same as those of control mice.While RXRα/Nur77 protein was exported into cytoplasm significantly in the cerebral cortex and hippocampus cells compared with those of control mice,accompanied with cells apoptosis.Conclusions Either exogenous Aβ or increased Aβin the impact of brain pathology might affect RXRα/Nur77 nuclear exporting,thus induce cell apoptosis.