Sidiropoulou Erasmia, Sachana Magdalini, Flaskos John, Harris Wayne, Hargreaves Alan J, Woldehiwet Zerai
Department of Veterinary Pathology, Faculty of Veterinary Science, University of Liverpool, Leahurst CH647TE, UK.
Arch Toxicol. 2009 Apr;83(4):373-80. doi: 10.1007/s00204-008-0339-1. Epub 2008 Jul 17.
The aim of this study was to assess the neurotoxicity of diazinon oxon (DZO), a major in vivo metabolite of the phosphorothionate insecticide diazinon (DZ), on differentiating mouse N2a neuroblastoma cells. When used at concentrations of 1, 5 and 10 microM, DZO did not cause cell death but it impaired the outgrowth of axon-like processes after 24 h. Densitometric scanning of Western blots of lysates of N2a cells revealed that exposure to 5 or 10 microM DZO for 24 h increased the expression of phosphorylated neurofilament heavy chain (NFH) compared to controls, while there was no significant change in total NFH. By contrast, treatment of N2a cells with 1-10 microM DZO resulted in marked reductions in the expression of the axon growth-associated protein GAP-43. DZO-treated cells also showed an increased expression of the heat shock protein HSP-70 compared to controls. The above biochemical changes were not temporally related to inhibition of acetylcholinesterase (AChE). These data suggest that biologically relevant, subcytotoxic levels of DZO may exert neurotoxic effects on differentiating cells and that the mechanisms involved are different from those attributed to its parent compound.
本研究的目的是评估二嗪磷氧（DZO）对分化中的小鼠N2a神经母细胞瘤细胞的神经毒性，DZO是硫代磷酸酯杀虫剂二嗪磷（DZ）的主要体内代谢产物。当以1、5和10微摩尔浓度使用时，DZO不会导致细胞死亡，但在24小时后会损害轴突样突起的生长。对N2a细胞裂解物的蛋白质印迹进行光密度扫描显示，与对照组相比，暴露于5或10微摩尔DZO 24小时会增加磷酸化神经丝重链（NFH）的表达，而总NFH没有显著变化。相比之下，用1-10微摩尔DZO处理N2a细胞会导致轴突生长相关蛋白GAP-43的表达显著降低。与对照组相比，DZO处理的细胞还显示热休克蛋白HSP-70的表达增加。上述生化变化与乙酰胆碱酯酶（AChE）的抑制在时间上无关。这些数据表明，生物学相关的亚细胞毒性水平的DZO可能对分化细胞产生神经毒性作用，并且所涉及的机制与归因于其母体化合物的机制不同。
