核糖糖基化BSA单体对SH-SY5Y细胞的毒性明显（英文）  

Ribosylated BSA Monomer is Severely Toxic to SH-SY5Y Cells

作　　者：魏艳[1] 王玉婧[1,2] 吴蓓蓓[1,2] 张英豪[1] 赫荣乔[1] 

机构地区：[1]中国科学院生物物理研究所,脑与认知科学国家重点实验室,北京100101 [2]中国科学院大学,北京100049

出　　处：《生物化学与生物物理进展》2016年第6期579-591,共13页Progress In Biochemistry and Biophysics

基　　金：supported by grants from National Basic Research Program of China(2012CB911004);The National Natural Scientific Foundation of China(31270868,31200601);The External Cooperation Program of BIC,Chinese Academy of Sciences(GJHZ201302)~~

摘　　要：研究显示,蛋白质异常修饰形成的寡聚体,与其多聚体、淀粉样纤维相比,具有更强的细胞毒性.这一发现被认为是蛋白质错误折叠和聚集研究领域中的重要进展.蛋白质的异常修饰如还原糖的非酶糖基化,是糖尿病最基本的病理特征.2型糖尿病患者尿液中的核糖浓度显著升高,表明糖尿病不仅与葡萄糖代谢紊乱相关,同时也与核糖代谢失调相关.以牛血清白蛋白(BSA)为研究对象,通过荧光分光光度计检测、原子力显微镜、透射电子显微镜观察以及分子排阻色谱分离,观察到核糖糖基化能够诱导BSA聚集,从单体、寡聚体逐渐形成多聚体.通过CCK-8 Kit、乳酸脱氢酶细胞活性检测、TUNEL染色、caspase-3活性检测以及流式细胞检测等方法,发现核糖糖基化的BSA单体对SH-SY5Y细胞(人神经母细胞瘤细胞系)具有明显的毒性,与此同时,糖化寡聚体和多聚体没有表现出显著的毒性.进一步研究发现,核糖糖基化的BSA单体通过与AGEs的受体RAGE相互作用,激活细胞内的MAPK通路,从而导致细胞凋亡.Oligomers, rather than polymers and fibrils, of protein aggregates are thought to be cytotoxic, which is a milestone in the study of protein misfolding and aggregation. Abnormally high level of uric ribose in type 2 diabetic patients and ribosylated animal models indicate that diabetes is not only correlated with metabolic dysfunction in glucose but also ribose. Here, using ribosylation of bovine serum albumin（BSA）, we show that ribosylated BSA aggregates and proceeds from a monomer and onto an oligomer and polymer, observed with fluorescence spectrophotometer, atomic force microscopy, transmission electron microscopy and size exclusion chromatography. Ribosylated monomer showed severely cytotoxic to SH-SY5 Y cells（a human neuroblastoma cell line） under the observations by assays of CCK-8, LDH activity, TUNEL staining, caspase-3 activity and flow-cytometry, whereas ribosylated oligomer and polymer did not. The cytotoxic effect of the ribosylated monomer likely occurs by inducing neuronal apoptosis through activation of the receptor of AGEs（RAGE） associated with mitogen-activated protein kinases（MAPK） pathways.

关 键 词：核糖 糖基化 核糖糖基化 单体 多聚体 细胞毒性 

分 类 号：Q25[生物学—细胞生物学]