摘要

草甘膦是许多除草剂配方中的活性成分。草甘膦在人类和动物模型中的神经毒性作用已有报道。然而，草甘膦在神经元发育中作用的详细机制仍不清楚。最近，一些研究报道了神经发育障碍（NDDs）与妊娠期草甘膦暴露有关的证据。目前的研究小组已经鉴定出与NDDs病因相关的microRNAs（miRNAs），但是它们在草甘膦暴露后大脑发育过程中的表达水平还没有被确定。在本研究中，我们评估了在怀孕和哺乳期间暴露于草甘膦后28天小鼠后代的前额叶皮质（PFC）中miRNA的表达模式。用miRNA微阵列检测了小鼠子代PFC中55个上调和19个下调的miRNA，并用定量聚合酶链反应（PCR）对20个解除调控的miRNA进行了进一步评价。利用生物信息学分析了11个靶点。与相关miRNAs相关的基因本体（GO）术语包括神经发生（GO:0050769）、神经元分化（GO:0030182）和大脑发育（GO:0007420）。基因Cdkn1a、Numbl、Notch1、Fosl1和Lef1参与Wnt和Notch信号通路，与神经发育密切相关。利用小鼠Wnt和Notch信号通路的PCR阵列验证草甘膦对Wnt和Notch信号通路相关基因表达模式的影响。妊娠期和哺乳期暴露草甘膦后，Nr4a2和Wnt7b表达下调，而小鼠后代的PFC中Dkk1、Dixdc1、Runx1、Shh、Lef‑1和Axin2表达上调。这些结果表明Wnt/β-catenin和Notch通路异常。这些发现对于理解草甘膦诱导的神经毒性机制，以及帮助阐明草甘膦与NDDs之间的联系可能具有特别的意义。

Glyphosate is the active ingredient in numerous herbicide formulations. The role of glyphosate in neurotoxicity has been reported in human and animal models. However, the detailed mechanism of the role of glyphosate in neuronal development remains unknown. Recently, several studies have reported evidence linking neurodevelopmental disorders (NDDs) with gestational glyphosate exposure. The current group previously identified microRNAs (miRNAs) that are associated with the etiology of NDDs, but their expression levels in the developing brain following glyphosate exposure have not been characterized. In the present study, miRNA expression patterns were evaluated in the prefrontal cortex (PFC) of 28 postnatal day mouse offspring following glyphosate exposure during pregnancy and lactation. An miRNA microarray detected 55 upregulated and 19 downregulated miRNAs in the PFC of mouse offspring, and 20 selected deregulated miRNAs were further evaluated by quantitative polymerase chain reaction (PCR). A total of 11 targets of these selected deregulated miRNAs were analyzed using bioinformatics. Gene Ontology (GO) terms associated with the relevant miRNAs included neurogenesis (GO:0050769), neuron differentiation (GO:0030182) and brain development (GO:0007420). The genes Cdkn1a, Numbl, Notch1, Fosl1 and Lef1 are involved in the Wnt and Notch signaling pathways, which are closely associated with neural development. PCR arrays for the mouse Wnt and Notch signaling pathways were used to validate the effects of glyphosate on the expression pattern of genes involved in the Wnt and Notch pathways. Nr4a2 and Wnt7b were downregulated, while Dkk1, Dixdc1, Runx1, Shh, Lef‑1 and Axin2 were upregulated in the PFC of mice offspring following glyphosate exposure during pregnancy and lactation. These results indicated abnormalities of the Wnt/β‑catenin and Notch pathways. These findings may be of particular interest for understanding the mechanism of glyphosate‑induced neurotoxicity, as well as helping to clarify the association between glyphosate and NDDs.