School of Public Health, Xinxiang Medical University, Xinxiang 453003, China.
Henan Provincial Key Laboratory of Children's Genetics and Metabolic Diseases/Henan Neural Development Engineering Research Center for Children, Department of Nephrology and Rheumatology, Children's Hospital Affiliated to Zhengzhou University, Zhengzhou 450018, China.
Ecotoxicol Environ Saf. 2021 Jan 15;208:111487. doi: 10.1016/j.ecoenv.2020.111487. Epub 2020 Oct 28.
Combined toxicity is a critical issue in risk assessment of contaminants. However, very little is known about the joint effects of graphene oxide (GO, a crucial 2-dimensional carbon material) and hexavalent chromium (Cr, a widespread heavy metal), particularly with respect to the critical period of embryogenesis. In this study, the combined toxicity of GO and Cr was evaluated through embryo-larval toxicity test in Danio rerio (zebrafish). Results indicated that the co-exposure of Cr (1 mg/L) and GO (0.01 mg/L) inhibited hatching and spontaneous movement of embryos, but no significant changes were found in the single Cr or GO group. Compared with the single GO or Cr exposure, their co-exposure (GO+Cr) significantly enhanced the teratogenicity in a concentration-dependent pattern, and the spinal curvature was observed as the main deformity. GO+Cr changed the protein secondary structures of embryos result of the generation of ROS and oxidative stress. The degradations of vertical myosepta and cartilages were observed in co-exposure group, suggesting that GO+Cr disrupted the development of musculoskeletal system. The genes col11a1a, col2a1a and postnb were down-regulated but the genes acta1b and mmp9 were up-regulated by GO+Cr. The interactions between Cr and GO demonstrated that the morphology, structure, and surface properties of GO were modified by Cr. The enhanced defects and O-containing groups of GO could trap more β-sheets, induced oxidative stress, disturbed the development of skeletal muscles and cartilages in zebrafish. These data suggested that GO+Cr enhanced their joint toxicity due to the variation of nanoparticle properties. This finding is important for assessing the ecological risk of graphene family nanomaterials in the natural environment.
联合毒性是污染物风险评估中的一个关键问题。然而，人们对于氧化石墨烯（GO，一种重要的二维碳材料）和六价铬（Cr，一种广泛存在的重金属）的联合效应知之甚少，特别是在胚胎发生的关键时期。在这项研究中，通过斑马鱼胚胎-幼虫毒性试验评估了 GO 和 Cr 的联合毒性。结果表明，Cr（1mg/L）和 GO（0.01mg/L）的共同暴露抑制了胚胎的孵化和自发运动，但在单一 Cr 或 GO 组中没有发现显著变化。与单一 GO 或 Cr 暴露相比，它们的共同暴露（GO+Cr）以浓度依赖的方式显著增强了致畸性，并且观察到脊柱弯曲是主要的畸形。GO+Cr 通过产生 ROS 和氧化应激改变了胚胎的蛋白质二级结构。共同暴露组观察到垂直肌隔和软骨的降解，表明 GO+Cr 破坏了肌肉骨骼系统的发育。GO+Cr 下调了 col11a1a、col2a1a 和 postnb 基因的表达，但上调了 acta1b 和 mmp9 基因的表达。Cr 与 GO 的相互作用表明，GO 的形貌、结构和表面性质发生了变化。GO 增强的缺陷和含氧基团可以捕获更多的β-折叠，诱导氧化应激，扰乱斑马鱼骨骼肌肉和软骨的发育。这些数据表明，由于纳米颗粒性质的变化，GO+Cr 增强了它们的联合毒性。这一发现对于评估自然环境中石墨烯家族纳米材料的生态风险具有重要意义。
