Nishie Tomomi, Taya Tomoki, Omori Shunichi, Ueno Kenya, Okamoto Yoshinori, Higaki Shogo, Oka Marina, Mitsuishi Yachiyo, Tanaka Taiga, Nakamoto Mana, Kawahara Hideaki, Teraguchi Natsuki, Kotaka Tomoyuki, Sawabe Misaki, Takahashi Miu, Kitaike Shoko, Wada Minori, Iida Keiko, Yamashita Akihiro, Jinno Hideto, Ichimura Atsuhiko, Tooyama Ikuo, Sakai Noriyoshi, Hibi Masahiko, Hirasawa Akira, Takada Tatsuyuki
Department of Pharmaceutical Sciences, Ritsumeikan University, Shiga, Japan.
Department of Genomic Drug Discovery Science, Graduate School of Pharmaceutical Sciences, Kyoto University, Kyoto, Japan.
Environ Health Perspect. 2025 Jun;133(6):67012. doi: 10.1289/EHP15574. Epub 2025 Jun 13.
Developing human fetuses may be exposed to the chemical compound bisphenol A (BPA), and retinoic acid (RA) has been detected at low levels in water sources. RA signaling regulates key developmental genes and is essential for organ development, including the brain. We previously reported that RA/BPA coexposure of mouse embryonic stem cells potentiates RA signaling, which warrants further investigation.
This study was undertaken in human induced pluripotent stem cells (iPSCs) and zebrafish embryos to investigate whether coexposure to BPA and exogenous RA could potentiate gene expression and exert pleiotropic effects on RA signaling.
Human iPSCs and zebrafish embryos were exposed to exogenous RA (0, 7.5, 10, 12.5, 100, 200 or ) or BPA () alone or coexposed to BPA () and exogenous RA (). Postexposure changes in genes were assessed by quantitative polymerase chain reaction and/or transcriptome analyses. RA receptor antagonists were used to identify the receptor responsible for signaling. In zebrafish, spatial expression of and was evaluated by whole-mount hybridization. Mauthner cell and craniofacial cartilage anomalies were studied by immunostaining and Alcian blue staining, respectively. Transcriptome was compared between iPSCs and zebrafish to identify alterations of common biological processes. Gradient curves of RA signal were calculated to simulate the effects of exogenous RA and BPA in zebrafish.
In both iPSCs and zebrafish, RA/BPA coexposure had higher expression of 3' genes in comparison with RA alone; BPA alone had no effect. Addition of RA receptor antagonists abolished these changes. In zebrafish, RA/BPA coexposure, in comparison with RA alone, resulted in a significant rostral shift in expression and increased rate of anomalies in Mauthner cells and craniofacial cartilage. Transcriptome comparison and correlations between the experimental results and gradient curve simulations strengthened these observations.
Our findings suggest a mechanistic link between chemical exposure and neurodevelopmental impairments and demonstrate involvement of exogenous RA signaling in endocrine disruption. Further investigation is needed to explore why BPA alone did not affect endogenous RA signaling, whereas exogenous RA signaling was potentiated with RA/BPA coexposure. https://doi.org/10.1289/EHP15574.
发育中的人类胎儿可能会接触到化合物双酚A（BPA），并且在水源中已检测到低水平的视黄酸（RA）。RA信号传导调节关键的发育基因，对包括大脑在内的器官发育至关重要。我们之前报道过，小鼠胚胎干细胞同时暴露于RA/BPA会增强RA信号传导，这值得进一步研究。
本研究在人诱导多能干细胞（iPSC）和斑马鱼胚胎中进行，以调查同时暴露于BPA和外源性RA是否会增强基因表达并对RA信号传导产生多效性影响。
将人iPSC和斑马鱼胚胎单独暴露于外源性RA（0、7.5、10、12.5、100、200或）或BPA（），或同时暴露于BPA（）和外源性RA（）。暴露后通过定量聚合酶链反应和/或转录组分析评估基因的变化。使用RA受体拮抗剂来确定负责信号传导的受体。在斑马鱼中，通过整体原位杂交评估和的空间表达。分别通过免疫染色和阿尔新蓝染色研究Mauthner细胞和颅面软骨异常。比较iPSC和斑马鱼之间的转录组，以确定常见生物学过程的改变。计算RA信号的梯度曲线，以模拟外源性RA和BPA在斑马鱼中的作用。
在iPSC和斑马鱼中，与单独暴露于RA相比，同时暴露于RA/BPA时3'基因的表达更高；单独暴露于BPA没有影响。添加RA受体拮抗剂消除了这些变化。在斑马鱼中，与单独暴露于RA相比，同时暴露于RA/BPA导致表达出现明显的向头侧移位，并增加了Mauthner细胞和颅面软骨的异常发生率。转录组比较以及实验结果与梯度曲线模拟之间的相关性强化了这些观察结果。
我们的研究结果表明化学物质暴露与神经发育障碍之间存在机制联系，并证明外源性RA信号传导参与内分泌干扰。需要进一步研究以探讨为什么单独暴露于BPA不会影响内源性RA信号传导，而同时暴露于RA/BPA会增强外源性RA信号传导。https://doi.org/10.1289/EHP15574。
