活性氧和钙信号参与铅对酵母细胞的毒性作用

发布时间：2018-09-11 15:02

【摘要】：以模式生物酵母菌为材料,研究铅对细胞的毒性效应,探讨胞内活性氧(ROS)和Ca~(2+)在铅诱导细胞死亡中的作用。结果显示,浓度为5~100 mg·L~(-1)的硝酸铅可降低酵母细胞活性,诱导酵母细胞死亡,随着铅浓度的提高和作用时间的延长,细胞死亡率增高。在铅处理组酵母细胞中,ROS和Ca~(2+)水平显著升高,线粒体膜电位明显下降;用1 mmol·L~(-1)的外源抗坏血酸(AsA)能降低铅引发的酵母细胞死亡,0.5 mmol·L~(-1)的钙离子螯合剂乙二醇双四乙酸(EGTA)或0.1 mmol·L~(-1)的质膜Ca~(2+)通道特异性抑制剂氯化镧(LaCl_3)亦可明显抑制铅引起的酵母细胞死亡。研究结果表明,铅诱发的酵母细胞死亡与处理组胞内ROS和Ca~(2+)升高有关,高浓度的Ca~(2+)可能通过诱导线粒体膜通透性转变孔道开放,或者高水平ROS可能损伤线粒体膜,致线粒体膜电位下降,继而激活相关下游信号导致细胞死亡。
[Abstract]:The toxic effects of lead on cells were studied by using model biological yeast, and the role of reactive oxygen species (ROS) and Ca~ (2) in lead-induced cell death was investigated. The results showed that lead nitrate at the concentration of 5 ~ 100 mg / L ~ (-1) could decrease the activity of yeast cells and induce the death of yeast cells. With the increase of lead concentration and the prolongation of the time of action, the cell death rate increased. The levels of Ros and Ca~ _ (2) in the yeast cells treated with lead increased significantly, and the mitochondrial membrane potential decreased significantly. Using 1 mmol L ~ (-1) exogenous ascorbic acid (AsA) to reduce the lead induced death of yeast cells (0.5 mmol L ~ (-1), the calcium chelator, ethylene glycol ditetraacetic acid (EGTA), or the plasmalemma Ca~ (2) channel specific inhibitor of 0.1 mmol L ~ (-1), lanthanum chloride (LaCl_3), also significantly inhibited lead-induced cell death. The yeast cells die. The results showed that the lead induced death of yeast cells was related to the increase of intracellular ROS and Ca~ (2) in the treatment group. High concentration of Ca~ (2) might open the pathway by inducing mitochondrial membrane permeability transition, or high level ROS might damage the mitochondrial membrane. Mitochondrial membrane potential decreases, which activates related downstream signals and results in cell death.
【作者单位】：山西大学生命科学学院;
【基金】：国家自然科学基金项目(No.30870454,30470318,31371868) 山西省科技攻关计划(No.20120322008-02) 山西省回国留学人员科研项目(No.2012013)
【分类号】：X171.5

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