基于斑马鱼胚胎/幼鱼研究新型溴代阻燃剂的发育影响及受体调控内分泌干扰交互作用机制

Key events (KEs) are measurements of change in biological state that are indicative of progression of a perturbation toward a specified adverse outcome, which could improve regulatory decision-making through greater integration and more meaningful use of mechanistic data. Toxic effects of these flame retardants on development mediated by nuclear receptors (NRs) has been suggested, but it has been difficult to assess the hazard posed by these novel brominated flame-retardants because of uncertainties of exposure and developmental toxicity is complicated by factors such as route of exposure, absorption, uptake kinetics, bioaccumulation, and metabolism. Thus, effects on the endocrine system as well as the associated factors are in need of additional research. .The overall objective of the proposed research is to assess receptor-mediated effects of three novel flame-retardants being used as replacements, 2-ethylhexyl-2,3,4,5 tetrabromobenzoate (TBB), bis(2-ethylhexyl)-2,3,4,5-tetrabromophthalate (TBPH), and 1,2,5,6-tetrabromocyclooctane (TBCO) detected in some environmental samples, by measuring expression of mRNA for genes involved nuclear receptor gene networks by use of the small model fish zebrafish embryos and integrated in silico approaches. Embryos/ larvae will be observed from 4 to 120 hours post fertilization (hpf) and rates of survival and abnormalities of individuals recorded. Studies of accumulation of these chemicals by zebrafish embryos /larvae as well as their in vivo metabolism will be determined. An integrative approach will be applied to explore the molecular and chemical bioaccumulation mechanisms of endocrine signaling effects of novel retardants in zebrafish by used of cytoscape software. This study will be useful for scientific understanding of impact of emerging environmental contaminants of global interest both in ecosystem and possibly human health.

由捕捉“潜在”分子启动事件来预测有害结局，指导快速“诊断”化学品关键致毒机制，可以为环境化学物质的风险管理提供大量有效而全面的毒理学依据。核受体(NRs)转录因子和胚胎的早期发育非常相关,建立分子对接和动力学模拟计算方法与体内受体介导转录因子调控测定方法，研究三个新溴代阻燃剂在核受体介导发育中的干扰作用,同时考虑生命早期快速发育不同阶段受体介导的各个基因启动、表达和对应鱼卵中的吸附、吸收、分配、富集和代谢、转化过程。拟采用系统生物学的方法,基于计算和斑马鱼幼体实验的内分泌相关核受体基因表达的动态链接发育过程的形态学变化方法,结合相应的化学行为,进行这三个新型溴代阻燃剂的潜在发育危害效应研究,为新型阻燃剂的可能生态危害评价和风险预测提供科学支撑。

基于不同类别特异性表达基因内分泌系统干扰甄别技术和手段来回答新型溴阻燃剂是否安全，整合多层次的效应结果来预测更多化合物潜在危害，可以为化学品的科学管理提供毒理学支撑。本项目围绕系列溴阻燃剂和其它几个结构、功能或用途相似的化合物，用斑马鱼不同生命阶段的多层次危害鉴别技术开展了系列研究，发表了文章19篇，其中SCI文章11篇，专利申请3项，培养9 名研究生，取得主要研究成果:（1）基于选用的模式化合物2-溴-4，6-二硝基苯胺（BDNA）的多代实验数据作为输入参数研究和预测TBB和TBPH个体水平到种群水平的负效应；并通过研究转录水平调控影响揭示其作用机理。（2）根据斑马鱼性腺发育过程的特点，设置80天的持续暴露实验，研究TBB、TBPH和TBCO对斑马鱼性腺发育及性别分化的影响。（3）基于不同实验同一化合物的效应结果不一致甚至相反这个问题，应用增强采样方法的分子动力学模拟手段研究TBB、TBPH和TBCO对激素受体激动和拮抗的定性区分和定量预测。（4）选择和TBPH结构类似的邻苯二甲酸二(2-乙基己基)酯（DEHP）研究斑马鱼F0代成年阶段、F1代全生命周期和F2代早期生命阶段斑马鱼的效应的生长发育、繁殖影响和性腺发育的影响和同为卤代杀菌剂三氯生（TCS）等化合物影响特定鱼尼丁（RyR1 receptor）受体及Ca2+的信号紊乱的机理，为以新型阻燃剂为代表更多的新型环境污染物提供效应通路机理看见。