Repeated exposure to neurotoxic levels of chlorpyrifos alters hippocampal expression of neurotrophins and neuropeptides.
Repeated exposure to neurotoxic levels of chlorpyrifos alters hippocampal expression of neurotrophins and neuropeptides.
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DOI：
10.1016/j.tox.2016.01.001
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发表时间：
2016-01-18
期刊：
影响因子：
4.5
通讯作者：
Stallings JD
中科院分区：
文献类型：
--
作者：
Lee YS;Lewis JA;Ippolito DL;Hussainzada N;Lein PJ;Jackson DA;Stallings JD
毒死蜱（Chlorpyrifos，CPF）是一种有机磷农药，是世界上使用最广泛的农药之一。不引起胆碱能危象的亚慢性暴露于CPF与认知功能问题有关（即，学习和记忆缺陷），但这种关联的生物学机制仍然是推测性的。为了确定亚慢性CPF神经毒性的潜在机制，成年雄性Long Evans（LE）大鼠以3或10 mg/kg/d（s.c.）21天。我们通过RNA-seq、微阵列分析和小ncRNA测序技术定量海马CA 1区的mRNA和非编码RNA（ncRNA）表达谱。海马切片免疫组化用于确定CPF诱导的蛋白表达和定位模式的变化。两种剂量的CPF均未引起明显的胆碱能毒性临床体征，尽管在接触21天后，3或10 mg/kg/d组大鼠海马中的胆碱酯酶活性分别降至对照水平的58%或13%。仅在10 mg/kg/d剂量组中观察到海马CA 1区相对于对照组的差异基因表达。在通过RNA-seq和微阵列分析鉴定的1382个差异表达基因中，67个是两种方法共有的。在一项独立的CPF暴露研究中验证了其中6个基因（Bdnf、Cort、Crhbp、Nptx 2、Npy和Pnoc）的差异表达;免疫组织化学表明，在10 mg/kg/d CPF剂量下，海马CA 1区CRHBP和NPY升高。基因本体富集分析表明这些基因与受体介导的细胞存活信号通路相关。miR 132/212在CA 1海马区也升高，这可能在CPF给药后神经营养因子介导的认知过程中断中发挥作用。这些研究结果确定了CPF诱导的神经行为缺陷的潜在介质，亚慢性暴露于CPF的水平，抑制海马胆碱酯酶低于20%的控制。一个同样重要的发现是，亚慢性暴露于CPF的水平，产生更温和的抑制海马胆碱酯酶（约50%的控制）不会产生明显的变化，基因表达。
Chlorpyrifos (CPF), an organophosphorus pesticide (OP), is one of the most widely used pesticides in the world. Subchronic exposures to CPF that do not cause cholinergic crisis are associated with problems in cognitive function (i.e., learning and memory deficits), but the biological mechanism(s) underlying this association remain speculative. To identify potential mechanisms of subchronic CPF neurotoxicity, adult male Long Evans (LE) rats were administered CPF at 3 or 10 mg/kg/d (s.c.) for 21 days. We quantified mRNA and non-coding RNA (ncRNA) expression profiles by RNA-seq, microarray analysis and small ncRNA sequencing technology in the CA1 region of the hippocampus. Hippocampal slice immunohistochemistry was used to determine CPF-induced changes in protein expression and localization patterns. Neither dose of CPF caused overt clinical signs of cholinergic toxicity, although after 21 days of exposure, cholinesterase activity was decreased to 58% or 13% of control levels in the hippocampus of rats in the 3 or 10 mg/kg/d groups, respectively. Differential gene expression in the CA1 region of the hippocampus was observed only in the 10 mg/kg/d dose group relative to controls. Of the 1382 differentially expressed genes identified by RNA-seq and microarray analysis, 67 were common to both approaches. Differential expression of six of these genes (Bdnf, Cort, Crhbp, Nptx2, Npy and Pnoc) was verified in an independent CPF exposure study; immunohistochemistry demonstrated that CRHBP and NPY were elevated in the CA1 region of the hippocampus at 10 mg/kg/d CPF. Gene ontology enrichment analysis suggested association of these genes with receptor-mediated cell survival signaling pathways. miR132/212 was also elevated in the CA1 hippocampal region, which may play a role in the disruption of neurotrophin-mediated cognitive processes after CPF administration. These findings identify potential mediators of CPF-induced neurobehavioral deficits following subchronic exposure to CPF at a level that inhibits hippocampal cholinesterase to less than 20% of control. An equally significant finding is that subchronic exposure to CPF at a level that produces more moderate inhibition of hippocampal cholinesterase (approximately 50% of control) does not produce a discernable change in gene expression.