胞浆内非聚集型突变亨廷顿蛋白影响神经细胞的分化  

Cytoplasmic non-aggregated mutant huntingtin influencing differentiation of neural cell

作　　者：叶翠芳[1] 李和[1] 汪薇曦[1] 张亦农[1] 

机构地区：[1]华中科技大学同济医学院解剖学系组织胚胎学室

出　　处：《解剖学杂志》2004年第3期244-248,F003,共6页Chinese Journal of Anatomy

基　　金：国家杰出青年科学基金资助项目 (30 2 2 5 0 2 4 )

摘　　要：目的 :探讨胞浆内非聚集型突变亨廷顿蛋白 (huntingtin ,Htt)对神经细胞分化的影响。 方法 :利用磷酸钙沉淀法在培养的小鼠成神经瘤细胞 (N2a细胞 )瞬时或稳定转染编码正常或突变Htt的氨基末端片段的cDNA ,观察突变Htt对视黄酸 (retinoicacid ,RA)和无血清培养刺激N2a细胞突起生长的影响。结果 :在瞬时转染的N2a细胞中 ,2 0Q的正常Htt氨基末端片段弥散分布在胞浆内 ,1 5 0Q的突变Htt氨基末端片段在多数细胞胞浆内形成聚集物。在稳定表达 1 5 0Q的N2a细胞部分克隆中 ,1 5 0Q弥散分布在胞浆内。无论是含突变Htt聚集物的瞬时转染细胞还是仅在胞浆中表达非聚集型突变Htt的稳定转染细胞 ,其突起生长能力均较表达正常Htt的瞬时转染细胞和稳定转染细胞差。结论 :胞浆内非聚集型突变Htt也能影响神经细胞的分化。Objective: To explore if cytoplasmic nonaggregated mutant huntingtin (Htt) influence differentiation of the neural cell. Methods: By using calcium phosphate precipitation method, cultured neuroblastoma N2a cells were transiently or stably and the effect of mutant huntingtin on the growth of the neurite of N2a cell transfected with cDNA coding amino terminal fragments of normal or mutant huntingtin caused by the stimulation of retinoic acid (RA) or serum free culture was observed. Results: In transiently transfected N2a cells that expressed amino fragments of normal huntingtin containing 20 glutamine repeats (20Q), 20Q was diffusely distributed in the cytoplasm, whereas in most of cells that expressed mutant huntingtin containing 150 glutamine repeats (150Q), aggregates of the mutant Htt were formed in the cytoplasm. On the other hand, in some clones of stably transfected N2a cells expressing 150Q, the mutant Htt was diffused in the cytoplasm, no or few, if any, aggregates being formed, which was similar to normal huntingtin in the cells that stably expressed 20Q. It was notable that after stimulation with retinoic acid (RA) or serum deprivation, the growth of the neurites of both transient cells that contained aggregated mutant huntingtin and stable cells that expressed non aggreagated mutant huntingtin only in the cytoplasm was significantly worse than cells expressing normal huntingtin, whatever normal huntingtin was transiently or stably transfected. Conclusion: Cytoplasmic nonaggregated mutant huntingtin can also influence differentiation of neural cell.

关 键 词：胞浆 非聚集型突变 亨廷顿蛋白 神经细胞 HTT N2A细胞 

分 类 号：R361[医药卫生—病理学]