铅暴露对神经元和脉络丛上皮细胞的损伤机制研究  

Mechanisms of lead exposure-induced damages in neuron and choroidal epithelial cells

作　　者：刘杨[1] 宋晗[1] 官瑞丽 刘新秦[1] 沈学锋[1] 陈景元[1] 郑刚[1] 

机构地区：[1]中国人民解放军第四军医大学劳动与环境卫生学教研室,陕西西安710032

出　　处：《实用预防医学》2017年第6期641-645,共5页Practical Preventive Medicine

基　　金：国家重点基础研究发展计划(973计划)课题(2012C B525002);国家自然科学基金重点项目(81230063)

摘　　要：目的研究铅暴露对神经元和脉络丛上皮细胞的损伤作用及分子机制。方法大鼠嗜铬细胞瘤PC12细胞和脉络丛上皮Z310细胞体外培养。采用噻唑蓝法(MTT),通过暴露于0~50μmol/L醋酸铅24 h和48 h筛选适合剂量。两种细胞分别以醋酸铅10μmol/L处理,于48 h时间点用TUNEL法检测细胞凋亡水平,于24 h和48 h时间点用Western blot法检测bcl-2、bax及caspase-3蛋白水平。结果醋酸铅浓度为10μmol/L及以上时,PC12和Z310细胞活力均受到显著抑制,故选择10μmol/L为铅暴露剂量。与正常对照组相比,铅暴露后PC12细胞凋亡(TUNEL阳性)细胞数显著增多(P<0.05),Z310细胞凋亡细胞数无显著变化(P>0.05)。与正常对照组相比,醋酸铅10μmol/L处理PC12细胞24 h和48 h后,PC12细胞bax/bcl-2比值显著上升,cleaved caspase-3蛋白表达水平也显著增高(P<0.05),而Z310细胞bax/bcl-2比值及cleaved caspase-3蛋白水平均无显著改变(P>0.05)。结论铅暴露诱导不同类型大脑细胞损伤的方式和途径存在差异,通过线粒体途径诱导细胞凋亡参与了铅损伤PC12细胞的机制,但可能并不是铅诱导Z310细胞损伤的主要方式。Objective To investigate the effects of lead （ Pb ） exposure on neurons and choroid plexus epithelial cells and its molecular mechanisms. Methods Rat pheochromocytoma PC12 cells and choroidal epithelial Z310 cells were cultured in vitro. Methyl thiazolyl tetrazolium （ MTT） assay was performed to determine the proper Pb exposure dose （ the lowest dose affecting the cell viability） by treating the cells with 0-50μmol/L lead acetate for 24 and 48 hours. Cell apoptosis was determined by TUNEL assay following Pb exposure for 48 hours. Western blot was used to detect the protein levels of bcl-2, bax and caspase-3 at the 24th and 48th hours. Results The viability of both PC 12 and Z310 cell lines was significantly decreased when they were treated with 10μmol/L Pb and higher doses, so 10 μmol/L was chosen as the working concentration of Pb exposure. Compared with the normal controls, the number of TUNEL positive cells was significantly increased in PC12 cells following Pb exposure （P〈0. 05} , while no obvious cell apoptosis was observed in Pb-treated Z310 cells （P〉O.051. Western blot showed that 10 μmol/L Pb expo- sure resulted in increased ratio of bax/bcl-2 and elevated expression of cleaved caspase-3 protein in PC12 cells at both the 24th and 48th hours （P〈0.05） ; however, the bax/bcl-2 ratio and cleaved caspase-3 protein level were not significantly changed fol- lowing the Pb exposure （P〉0.05）. Conclusions Lead-induced damage in various brain cells may involve different pathways and mechanisms. It induces apoptosis in PC12 cells through mitochondrial pathway, but can not activate apoptosis signal in Z310 cells.

关 键 词：铅 PCI2细胞 脉络丛上皮细胞 细胞凋亡 CASPASE-3 

分 类 号：R741.02[医药卫生—神经病学与精神病学]