基于斑马鱼胚胎研究阻燃剂的生物有效性和内分泌干扰分子机制

The link between novel emerging flame retardants exposure and toxicity is complicated by numerous factors such as exposure route, absorb, uptake kinetics, bioaccumulation, and metabolism behavior. Their toxicity and mechanism need detail research. Accumulation and biotransformation of BDE-47 by zebrafish larvae and teratogenicity and expression of genes along the hypothalamus-pituitary-thyroid axis were studied. 6-HO-BDE47 and 6-MeO-BDE-47 affected the thyroid hormone pathway in different way. BDE-47 and 6-MeO-BDE-47 were accumulated more than 6-HO-BDE-47. 6-MeO-BDE-47 was transformed into 6-HO-BDE-47 but BDE-47 was not transformed into it. The overall objective is to conduct zebrafish embryos in ovo bioconcentration on several Polybrominated diphenyl ethers (PBDEs) and their derivates and other novel emerging flame retardents. An integrative approach will be applied to test and assess these chemicals for their potential development effects of embryos. The egg nanoinjection method is further used to assess the relationship between early life stage mortality in zebrafish. Embryos will be observed through matching up to 144 hour post fertilization (hpf) and rates of survival and abnormalities recorded. Receptor-associated mRNA expression involved in peroxisome proliferator-activated receptor (PPAR)-, aryl hydrocarbon receptors (AhRs)-, hyroid hormone receptor (TR)-, estrogenic receptors (ERs)-, androgenic receptors (AR)-, tglucocorticoid receptor (GR)-, and mineralocorticoid receptor (MR)-, and pregnane X receptor (PxR)- centered gene networks effects using zebrafish embryos/larvae will be further studied. We will explore the molecular mechanisms of endocrine signaling effects of PBDEs and their derivates in zebrafish. This study will be useful for scientific understanding of impact of emerging environmental contaminants of global interest both in ecosystem and possibly human health.

阻燃剂的生物膜吸收、体内迁移、分配、富集、代谢过程和产生的危害以及内分泌作用机制有待深入研究。申请者研究水暴露下多溴联苯醚及其衍生物对斑马鱼幼鱼下丘脑-垂体-甲状腺（HPT）轴上相关基因变化的影响，发现它们不同的调控机制且体内浓度测定发现富集和代谢不同。 拟借助斑马鱼胚胎研究水暴露多溴联苯醚及衍生物和有机磷阻燃剂在生物活体膜吸附、迁移、分配、富集和代谢的化学行为，结合显微注射技术研究系列阻燃剂对鱼胚胎的体内in ovo发育危害，比较水暴露（表观）剂效关系；进一步利用过氧化物酶体增殖物激活受体(PPAR)、芳香受体（AhRs）、甲状腺受体(TR)、雌激素受体（ERs）、雄激素受体(AR)、糖皮质激素受体（GR）、盐皮质激素受体（MR）和孕烷X受体（PxR）介导的内分泌系统干扰甄别的技术和方法，筛选并整合其不同类别的特异性表达基因，分析其致毒机制，为阻燃剂的生态危害评价和风险预测提供科学支撑。

溴系阻燃剂及其衍生物的水暴露在生物活体膜吸附、迁移、分配、富集和代谢等化学行为研究是比较复杂的,基于不同类别的基因特异性表达机理的内分泌系统干扰甄别的技术和手段需要致毒机制基础的研究支撑；溴阻燃剂的替代系列有机磷阻燃剂亟需毒理研究。本项目围绕这溴和磷阻燃剂开展了系列研究,发表 SCI 文章 14篇,中文核心3篇，专利 1 项,培养7 名研究生,取得主要研究成果: （1）基于斑马鱼胚胎，多溴联苯醚及其衍生物（BDE-28、BDE-99、BDE-47、6-OH-BDE-47、6-MeO-BDE-47）、四溴双酚A（TBBPA）和有机磷阻燃剂（TDCPP、TPP、TBOEP、TCEP）对其内分泌干扰重要启动事件——受体结合，参与介导调控下游基因的编码机理讨论，并结合AhR受体对接和动力学模拟（MD）来拓展和解释BDE-99受体表达基因交互作用；BDE-28、BDE-99、TBOEP对内分泌轴的影响效应；基于MD研究TCEP的多受体动力学结合过程解释多聚化的生成机理。（2）应用广义相加模型研究BDE-47及其羟基化和甲氧基化（6-OH-BDE-47、6-MeO-BDE-47）代谢和富集规律。结合显微注射技术，研究这三个化合物对斑马鱼胚胎内剂量与可观察效应的剂量关系；并通过构建不同暴露途径：水暴露、显微注射、多代暴露，用PFOS、6-OH-BDE-47作目标物，进一步解析实际内暴露剂量对斑马鱼早期生命阶段的效应关系；并通过建立目标化合物暴露液和鱼卵／幼鱼体内分析方法，动态监测暴露液（体外）和斑马鱼胚胎（体内）目标化合物的浓度水平，获得化合物的吸附、吸收、代谢动力学规律；研究四溴双酚A（TBBPA）的内剂量，以及代谢物效应关系。