Graphene oxide (GO) is an increasingly important nanomaterial that exhibits great promise in the area of bionanotechnology and nanobiomedicine. However, the toxic effects of GO on the vertebrate developmental system are still poorly understood. Here, we aimed to investigate the toxic effects and molecular mechanisms of GO exposure in larval and adult zebrafish. The results showed that the major hepatotoxic phenotype induced by GO in zebrafish embryos was a significant decrease in liver area and a dose-dependent decrease in the hepatocytes. Moreover, the number of macrophages and neutrophils in zebrafish embryos were reduced but the expressions of pro-inflammatory cytokines were increased after GO treatment. High through-put RNA-Seq identified 314 differentially expressed genes (DEGs) in GO-induced zebrafish embryos including 192 up-regulated and 122 down-regulated. KEGG and GO functional analysis revealed that steroid hormone biosynthesis, lipoprotein metabolic process, and PPAR signaling pathway were significantly enriched. Most of the lipid metabolism genes were down-regulated while majority of the immune genes were up-regulated after GO treatment. Moreover, GO induced NF-κB p65 into the nucleus and increased the protein levels of NF-κB p65, JAK2, STAT3, and Bcl2 in adult zebrafish liver. In addition, pharmacological experiments showed that inhibition of ROS and blocking the MAPK signaling could rescue the hepatotoxic phenotypes induced by GO exposure. On the contrary, pharmacological activation of PPAR-α expression have increased the hepatotoxic effects in GO-induced larval and adult zebrafish. Taken together, these informations demonstrated that GO induced hepatic dysfunction mainly through the ROS and PPAR-α mediated innate immune signaling in zebrafish.

氧化石墨烯（GO）是一种越来越重要的纳米材料，在生物纳米技术和纳米生物医学领域具有广阔的前景。但是，GO对脊椎动物发育系统的毒性作用仍知之甚少。在这里，我们旨在研究GO暴露在幼虫和成年斑马鱼中的毒性作用和分子机制。结果表明，GO引起的斑马鱼胚胎的主要肝毒性表型是肝脏面积明显减少，肝细胞剂量依赖性减少。此外，GO处理后，斑马鱼胚胎中的巨噬细胞和嗜中性粒细胞数量减少，但促炎细胞因子的表达增加。高通量RNA-Seq在GO诱导的斑马鱼胚胎中鉴定出314个差异表达基因（DEG），其中包括192个上调和122个下调。KEGG和GO功能分析表明，类固醇激素的生物合成，脂蛋白代谢过程和PPAR信号通路均显着丰富。GO处理后，大多数脂质代谢基因被下调，而大多数免疫基因被上调。此外，GO诱导成年斑马鱼肝脏中的NF-κBp65进入细胞核，并增加了NF-κBp65，JAK2，STAT3和Bcl2的蛋白质水平。此外，药理实验表明，抑制ROS和阻断MAPK信号传导可以挽救GO暴露诱导的肝毒性表型。反之，PPAR-α表达的药理激活增加了GO诱导的幼虫和成年斑马鱼的肝毒性作用。综上所述，这些信息表明GO主要通过ROS和PPAR-α介导的斑马鱼的先天免疫信号转导肝功能障碍。