超越危害识别：从斑马鱼ToxCast化学筛选中发现作用机制。
完整摘要 · 中文译文
大规模化学筛选是危害识别和化学品优先级排序的重要工具，但这类筛选很少能从表型鉴定进一步推进到机制鉴定。在本研究中，我们使用斑马鱼胚胎筛选了来自美国环保署ToxCast第三阶段文库的4，657种化学品，以检测其对胚胎发育的干扰作用，并通过使用原始文库储备、独立来源化学品、浓度-反应分析、转录组学和功能实验进行序贯验证，推进了选定的候选化合物。在61个经重复检测的主要阳性结果中，33个重现了原始表型，且在随后使用独立来源化学品进行检测的8个化合物中，有4个表现出可重现的浓度依赖性发育毒性。随后，我们研究了purpurin，一种研究尚不充分的蒽醌类色素，其可导致心包水肿、循环缺陷和体轴异常。对暴露于purpurin的胚胎进行的转录组学分析显示，涉及钙调节、离子转运和神经元信号传导的通路被协同抑制。增加细胞外钙浓度可产生对purpurin诱导的发育异常浓度依赖性挽救，而同等浓度的镁补充则无此作用，这支持钙可用性或钙稳态在purpurin发育毒性中发挥作用。这些结果表明，大规模体内毒性筛选可以与独立的化学验证和功能后续研究相结合，从而超越危害识别，迈向对环境相关化学品作用机制的理解。 环境化学物质会干扰胚胎发育。
完整摘要 · 英文原文
Large-scale chemical screens are important tools for hazard identification and chemical prioritization, but they less commonly progress from identifying a phenotype to identifying its mechanism. Here, we used zebrafish embryos to screen 4,657 chemicals from the U.S. EPA ToxCast Phase III library for disruption of embryonic development and advanced selected hits through sequential validation using original library stocks, independently sourced chemicals, concentration-response analysis, transcriptomics, and functional experiments. Of 61 primary hits subjected to repeat testing, 33 reproduced the original phenotype, and four of eight compounds subsequently tested using independently sourced chemicals exhibited reproducible concentration-dependent developmental toxicity. We then investigated purpurin, an understudied anthraquinone pigment that caused pericardial edema, circulation defects, and body-axis abnormalities. Transcriptomic analysis of purpurin-exposed embryos revealed coordinated suppression of pathways involved in calcium regulation, ion transport, and neuronal signaling. Increasing extracellular calcium produced a concentration-dependent rescue of purpurin-induced developmental abnormalities, whereas equivalent magnesium supplementation did not, supporting a role for calcium availability or homeostasis in purpurin developmental toxicity. These results demonstrate that large-scale in vivo toxicity screening can be integrated with independent chemical validation and functional follow-up to move beyond hazard identification toward mechanistic understanding of how environmental chemicals disrupt embryonic development.