A systems toxicology approach reveals the Wnt-MAPK crosstalk pathway mediated reproductive failure in Caenorhabditis elegans exposed to graphene oxide (GO) but not to reduced graphene oxide (rGO)
A systems toxicology approach reveals the Wnt-MAPK crosstalk pathway mediated reproductive failure in Caenorhabditis elegans exposed to graphene oxide (GO) but not to reduced graphene oxide (rGO)
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DOI：
10.1080/17435390.2016.1267273
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发表时间：
2017-02-01
期刊：
影响因子：
5
通讯作者：
Choi, Jinhee
中科院分区：
文献类型：
--
作者：
Chatterjee, Nivedita;Kim, Youngho;Choi, Jinhee
通过氧化石墨烯（GO）和还原氧化石墨烯（rGO）对秀丽隐杆线虫（Caillichabditis elegans）进行暴露，研究了石墨烯纳米材料的潜在危害。纳米生物相互作用的基本机制，解决了与综合系统毒理学方法，使用全球转录组学，基于网络的途径分析，并在硅片衍生的假设的实验验证。发现氧化石墨烯比rGO更大程度地降低蠕虫的生殖健康，但它不影响存活率（24小时终点）。GO与rGO效应的比较分析发现，无翅型MMTV整合位点家族（Wnt）途径和丝裂原活化蛋白激酶（MAPK）途径在GO中被诱发，但在rGO暴露的蠕虫中没有。因此，我们假设Wnt和MAPK通路之间的串扰是导致C。线虫对GO暴露的生殖敏感性。通过靶向Wnt-MAPK串扰途径的各个组分（用qPCR基因表达和突变体繁殖分析），我们发现了信号级联：α-2-> β-5-> β-4-> LIT-1-> POP-1-> EGL-5。具体而言，POP-1（TCF蛋白同源物）的激活和随后Wnt/β-连环蛋白靶基因（EGL-5）的抑制，在POP-1突变体[pop-1（q645）]蠕虫中用靶基因特异性RNAi分析，是暴露于GO的蠕虫中生殖潜力降低的中心机制。我们的研究结果突出了GO和rGO暴露的不同生物学和分子机制以及Wnt-MAPK通路串扰在体内系统中调节GO诱导的生殖失败中的作用，它们将有助于开发高效和无害的石墨烯应用以及改进基于机制的风险评估。
The potential hazards of graphene nanomaterials were investigated by exposing the nematode Caenorhabditis elegans to graphene oxide (GO) and reduced graphene oxide (rGO). The underlying mechanisms of the nano-bio interaction were addressed with an integrated systems toxicology approach using global transcriptomics, network-based pathway analysis, and experimental validation of the in-silico-derived hypotheses. Graphene oxide was found to reduce the worms' reproductive health to a greater degree than rGO, but it did not affect survival (24h endpoint). Comparative analysis of GO vs. rGO effects found that the wingless-type MMTV integration site family (Wnt) pathway and the mitogen-activated protein kinase (MAPK) pathway were evoked in GO- but not in rGO-exposed worms. We therefore hypothesized that crosstalk between the Wnt and MAPK pathways is responsible for C. elegans' reproductive sensitivity to GO exposure. By targeting the individual components of the Wnt-MAPK crosstalk pathway (with qPCR gene expression and mutant reproduction analysis), we found a signaling cascade of MOM-2 -> MOM-5 -> MOM-4 -> LIT-1 -> POP-1 -> EGL-5. Specifically, the activation of POP-1 (the TCF protein homolog) and subsequent repression of the Wnt/beta-catenin target gene (EGL-5), analyzed with target-gene-specific RNAi in POP-1 mutant [pop-1(q645)] worms, were the central mechanisms of reduced reproductive potential in the worms exposed to GO. Our results highlight the distinct biological and molecular mechanisms of GO and rGO exposure and the role of Wnt-MAPK pathway crosstalk in regulating GO-induced reproductive failure in in vivo systems, and they will contribute to the development of efficient and innocuous graphene applications as well to improvements in mechanism-based risk assessment.