有机磷药物敌百虫(trichlorfon)用途非常广泛,在农业上一直被作为杀虫剂用于植物保护,在动物医学上则被用作驱虫剂治疗内外寄生虫病,而在医学临床上则被用作抗血吸虫病的治疗,在20世纪还一直被用于神经退行性疾病阿尔茨海默病的治疗。然而,最近的研究发现,敌百虫作为胆碱能抑制剂除了具有急性毒性外,还可引发迟发性神经毒性(OPIDN)及导致其他慢性毒性症状。动物试验显示,敌百虫可引起脑皮层神经细胞凋亡,但发生机制并不清楚。
近日,中国科学院动物研究所伍一军研究组利用培养神经细胞模型研究了敌百虫致神经细胞凋亡的机理,流式细胞术分析显示,敌百虫及其降解代谢物敌敌畏均可引起神经细胞凋亡,并呈浓度依赖关系,蛋白质印迹分析则显示,敌百虫引起细胞caspase-12降低而活化态的caspase-12增加,提示敌百虫引起的细胞凋亡可通过内质网途径触发,敌百虫处理后细胞内钙离子浓度增加,而在用钙通道阻断剂及钙相关受体抑制剂处理后不仅这种敌百虫诱导的细胞内钙增加减少,而且细胞凋亡率以及与内质网途径有关的凋亡蛋白caspase-12和活化态的caspase-3水平也大幅度降低。此外,敌百虫诱导的神经细胞凋亡可被PMA所抑制。上述结果表明,与钙相关的内质网应激是导致敌百虫细胞毒性的机制。
原始出处:
Chemico-Biological Interactions 14 September 2009 doi:10.1016/j.cbi.2009.03.004
Trichlorfon induces apoptosis in SH-SY5Y neuroblastoma cells via the endoplasmic reticulum?
Cheng-Yun Liua, b, Ping-An Changa and Yi-Jun Wua, ,
aLaboratory of Molecular Toxicology, State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Datunlu Road, Beijing 100101, PR China
bGraduate School of the Chinese Academy of Sciences, Beijing 100039, PR China
This study investigated the role of the endoplasmic reticulum pathway in apoptosis induced by trichlorfon in SH-SY5Y human neuroblastoma cells. Flow cytometric analysis demonstrated that trichlorfon and its degradation product dichlorvos-induced apoptosis in a dose-dependent manner and Hoechst 33342 staining experiments revealed trichlorfon/dichlorvos-induced nucleus condensation. Western blot analysis indicated decreased expression of caspase-12 and increased activated caspase-12 in trichlorfon-treated cells compared to a control, suggesting that trichlorfon may induce apoptosis in SH-SY5Y partly via the endoplasmic reticulum. Intracellular Ca2+ level ([Ca2+]i) in SH-SY5Y cells increased after treatment with trichlorfon but was significantly reduced by pre-treatment with a combination of a calcium channel blocker, an inositol trisphosphate receptor inhibitor, and a ryanodine receptor inhibitor. Percent apoptosis and activated caspase-3 and caspase-12 decreased in pre-treated cells compared to those treated with trichlorfon alone. Trichlorfon-induced apoptosis was also inhibited by the protein kinase C activator, phorbol 12-myristate 13-acetate (PMA). These results suggest that endoplasmic reticulum stress, which is related to calcium, may be involved in the cytotoxicity of trichlorfon.