Christen Verena, Rusconi Manuel, Crettaz Pierre, Fent Karl
University of Applied Sciences and Arts Northwestern Switzerland, School of Life Sciences, Gründenstrasse 40, CH-4132, Muttenz, Switzerland.
Federal Office of Public Health, Division Chemical Products, 3003 Bern, Switzerland.
Toxicol Appl Pharmacol. 2017 Jun 15;325:25-36. doi: 10.1016/j.taap.2017.03.027. Epub 2017 Apr 3.
The detection of developmental neurotoxicity (DNT) of chemicals has high relevance for protection of human health. However, DNT of many pesticides is only little known. Furthermore, validated in vitro systems for assessment of DNT are not well established. Here we employed the rat phaeochromocytoma cell line PC-12 to evaluate DNT of 18 frequently used pesticides of different classes, including neonicotinoids, pyrethroids, organophosphates, organochlorines, as well as quaternary ammonium compounds, the organic compound used in pesticides, piperonyl butoxide, as well as the insect repellent diethyltoluamide (DEET). We determined the outgrowth of neurites in PC-12 cells co-treated with nerve growth factor and different concentrations of biocides for 5days. Furthermore, we determined transcriptional alterations of selected genes that may be associated with DNT, such as camk2α and camk2β, gap-43, neurofilament-h, tubulin-α and tubulin-β. Strong and dose- dependent inhibition of neurite outgrowth was induced by azamethiphos and chlorpyrifos, and dieldrin and heptachlor, which was correlated with up-regulation of gap-43. No or only weak effects on neurite outgrowth and transcriptional alterations occurred for neonicotinoids acetamiprid, clothianidin, imidacloprid and thiamethoxam, the pyrethroids λ-cyhalothrin, cyfluthrin, deltamethrin, and permethrin, the biocidal disinfectants C12-C14-alkyl(ethylbenzyl)dimethylammonium (BAC), benzalkonium chloride and barquat (dimethyl benzyl ammonium chloride), and piperonyl butoxide and DEET. Our study confirms potential developmental neurotoxicity of some pesticides and provides first evidence that azamethiphos has the potential to act as a developmental neurotoxic compound. We also demonstrate that inhibition of neurite outgrowth and transcriptional alterations of gap-43 expression correlate, which suggests the employment of gap-43 expression as a biomarker for detection and initial evaluation of potential DNT of chemicals.
化学物质发育神经毒性（DNT）的检测对保护人类健康具有高度相关性。然而，许多农药的DNT情况却鲜为人知。此外，用于评估DNT的经过验证的体外系统尚未很好地建立。在此，我们利用大鼠嗜铬细胞瘤细胞系PC - 12来评估18种不同类别的常用农药的DNT，这些农药包括新烟碱类、拟除虫菊酯类、有机磷类、有机氯类以及季铵化合物、农药中使用的有机化合物胡椒基丁醚，还有驱虫剂避蚊胺（DEET）。我们测定了在与神经生长因子和不同浓度杀生物剂共同处理5天的PC - 12细胞中神经突的生长情况。此外，我们还测定了可能与DNT相关的选定基因的转录变化，如钙/钙调蛋白依赖性蛋白激酶2α（camk2α）和钙/钙调蛋白依赖性蛋白激酶2β（camk2β）、生长相关蛋白43（gap - 43）、神经丝蛋白 - h、微管蛋白 - α和微管蛋白 - β。唑磷和毒死蜱以及狄氏剂和七氯可诱导强烈且剂量依赖性的神经突生长抑制，这与gap - 43的上调相关。新烟碱类的啶虫脒、噻虫胺、吡虫啉和噻虫嗪、拟除虫菊酯类的高效氯氟氰菊酯、氟氯氰菊酯、溴氰菊酯和氯菊酯、杀生物消毒剂C12 - C14 - 烷基（乙基苄基）二甲基铵（BAC）、苯扎氯铵和巴夸特（二甲基苄基氯化铵）以及胡椒基丁醚和避蚊胺对神经突生长和转录变化没有影响或只有微弱影响。我们的研究证实了某些农药存在潜在的发育神经毒性，并首次提供证据表明唑磷有可能作为一种发育神经毒性化合物。我们还证明神经突生长抑制与gap - 43表达的转录变化相关，这表明可将gap - 43表达用作检测和初步评估化学物质潜在DNT的生物标志物。
