蛋白酶体功能障碍对多巴胺能PC12细胞的特异性损伤  

Specific Damage of Ubiquitin-Proteasome System Dysfunction to Dopaminergic PC12 Cells

作　　者：周海燕[1] 戚辰[1] 范国华[1] 王刚[1] 张宇红[1] 陈生弟[1] 

机构地区：[1]上海交通大学医学院瑞金医院神经内科神经病学研究所,上海200025

出　　处：《上海交通大学学报（医学版）》2006年第7期715-718,共4页Journal of Shanghai Jiao tong University:Medical Science

基　　金：国家自然科学基金(30471918);国家重点基础研究发展计划("973"计划)(2006cb500700)资助项目

摘　　要：目的探讨蛋白酶体抑制剂lactacystin对多巴胺能PC12细胞的特异性损伤。方法不同浓度的lactacystin(1、5、10、15和20μmol/L)分别处理多巴胺能PC12细胞和胶质瘤U251细胞24 h,MTT法检测细胞活力;50μmol/L的lactacystin处理U251细胞24 h,MTT法检测细胞活力;10、20μmol/L lactacystin处理PC12细胞,W estern B lot检测细胞内多泛素化蛋白含量;单胺氧化酶B抑制剂selegiline(500μmol/L)和特异性酪氨酸羟化酶抑制剂-αMT(1 mmol/L)提前4 h预处理PC12细胞,再与10μmol/Llactacystin共同作用24 h,MTT法检测细胞活力,W estern B lot检测多泛素化蛋白含量。结果Lactacystin呈剂量依赖性损伤多巴胺能PC12细胞,其对胶质瘤U251细胞无毒性作用,而且其毒性与细胞内多泛素化蛋白生成增加相关。用以增加细胞内多巴胺含量的selegiline和用以减少细胞内多巴胺含量的α-MT都导致lactacystin毒性增强。结论蛋白酶体功能障碍特异性损伤多巴胺能细胞,而其特征性的神经递质多巴胺在其易感性中的作用复杂。Objective To explore whether the selective inhibitor of ubiquitin-proteasome, lactacystin, specifically injures the dopaminergic PC12 cells. Methods Both dopaminergic PC12 cells and glioma U251 cells were treated with different concentrations of lactacystin （1, 5, 10, 15 and 20μmoL/L） for 24 h, then the cellular viability was assessed by MTT assay. U251 cells were further exposed to 50 μmoL/L lactacystin and the cellular viability was evaluated. 10 and 20 μmol/L lactacystin were chosen for treating PC12 cells, and the cellular polyubiquitinated proteins were detected by Western Blot. PC12 cells were treated with 500μmol/L selegiline, the selective monoamine oxidase B inhibitor or 1 mmol/L α-MT ,the highly selective inhibitor of tyrosine hydroxylase 4 h before exposure to 10 μmol/L lactacystin, then the cellular viability was evaluated by MTT assay, and the cellular polyubiquitinated proteins were detected by Western Blot. Results Lactacystin dose-dependently injured the dopaminergic PC12 cells, while did no harm to the glioma U251 cells. Moreover, the toxicity was associated with the increase of cellular polyubiquitinated proteins. Selegiline, which could increase the dopamine content, enhanced the toxic effect of lactacystin on PC12 cells. Paradoxically, α-MT, which could decrease the content of the dopamine, also aggravated the toxicity. Conclusion Ubiquitin-proteasome system dysfunction specifically injures the dopaminergic PC12 cells, and the neurotransmitter dopamine may be the key factor involved in the event of vulnerability, while the role is complicated.

关 键 词：蛋白酶体 多泛素化蛋白 多巴胺 单胺氧化酶B 酪氨酸羟化酶 

分 类 号：R742.5[医药卫生—神经病学与精神病学]