Laboratory of Evolutionary and Adaptive Physiology - Institute of Life, Earth and Environment - University of Namur, 61 Rue de Bruxelles, B5000 Namur, Belgium.
Department of Animal Sciences, University of California, Davis, Davis, CA 95616, USA.
J Proteomics. 2019 Mar 1;194:112-124. doi: 10.1016/j.jprot.2018.12.008. Epub 2018 Dec 12.
Early-life represents a critically sensitive window to endocrine disrupting chemicals, potentially leading to long-term repercussions on the phenotype later in life. The mechanisms underlying this phenomenon, referred to as the Developmental Origins of Health and Disease (DOHaD), are still poorly understood. To gain molecular understanding of these effects, we exposed mangrove rivulus (Kryptolebias marmoratus) for 28 days post hatching (dph) to 4 and 120 ng/L 17-α-ethinylestradiol, a model xenoestrogen. After 28 days, fish were raised for 140 days in clean water and we performed quantitative label-free proteomics on brain, liver and ovotestis of 168 dph adults. A total of 820, 888 and 420 proteins were robustly identified in the brain, liver and ovotestis, respectively. Effects of 17-α-ethinylestradiol were tissue and dose-dependent: a total of 31, 51 and 18 proteins were differentially abundant at 4 ng/L in the brain, liver and ovotestis, respectively, compared to 20, 25 and 39 proteins at 120 ng/L. Our results suggest that estrogen-responsive pathways, such as lipid metabolism, inflammation, and the innate immune system were affected months after the exposure. In addition, the potential perturbation of S-adenosylmethionine metabolism encourages future studies to investigate the role of DNA methylation in mediating the long-term effects of early-life exposures. SIGNIFICANCE: The Developmental Origins of Health and Disease (DOHaD) states that early life stages of humans and animals are sensitive to environmental stressors and can develop health issues later in life, even if the stress has ceased. Molecular mechanisms supporting DOHaD are still unclear. The mangrove rivulus is a new fish model species naturally reproducing by self-fertilization, making it possible to use isogenic lineages in which all individuals are highly homozygous. This species therefore permits to strongly reduce the confounding factor of genetic variability in order to investigate the effects of environmental stress on the phenotype. After characterizing the molecular phenotype of brain, liver and ovotestis, we obtained true proteomic reaction norms of these three organs in adults after early life stages have been exposed to the common endocrine disruptor 17-α-ethinylestradiol (EE2). Our study demonstrates long-term effects of early-life endocrine disruption at the proteomic level in diverse estrogen-responsive pathways 5 months after the exposure. The lowest tested and environmentally relevant concentration of 4 ng/L had the highest impact on the proteome in brain and liver, highlighting the potency of endocrine disruptors at low concentrations.
早期生命是内分泌干扰物的一个关键敏感窗口，可能会对以后的生活产生长期影响。这种现象的机制，即健康与疾病的发育起源 (DOHaD)，仍然知之甚少。为了从分子水平上了解这些影响，我们在孵化后 28 天（dph）用 4 和 120ng/L 的 17-α-乙炔基雌二醇（一种模型外源性雌激素）处理红树林鲷（Kryptolebias marmoratus）28 天。28 天后，鱼在清洁水中饲养 140 天，我们对 168dph 成年鱼的大脑、肝脏和卵睾进行了定量无标记蛋白质组学分析。在大脑、肝脏和卵睾中分别有 820、888 和 420 个蛋白质被可靠地鉴定出来。17-α-乙炔基雌二醇的影响具有组织和剂量依赖性：与 120ng/L 相比，4ng/L 时大脑、肝脏和卵睾中分别有 31、51 和 18 个蛋白质丰度差异，而 120ng/L 时大脑、肝脏和卵睾中分别有 20、25 和 39 个蛋白质丰度差异。我们的结果表明，雌激素反应途径，如脂质代谢、炎症和先天免疫系统，在暴露数月后受到影响。此外，S-腺苷甲硫氨酸代谢的潜在扰动鼓励未来的研究调查 DNA 甲基化在介导早期生活暴露的长期影响中的作用。意义：健康与疾病的发育起源 (DOHaD) 表明，人类和动物的早期生命阶段对外界环境压力很敏感，并可能在以后的生活中出现健康问题，即使压力已经停止。支持 DOHaD 的分子机制仍不清楚。红树林鲷是一种新型的鱼类模式物种，通过自体受精自然繁殖，因此可以使用高度纯合的同系物系来进行研究。因此，这种物种可以极大地减少遗传变异的混杂因素，以便研究环境压力对表型的影响。在对大脑、肝脏和卵睾的分子表型进行了特征描述之后，我们在早期生活阶段暴露于常见的内分泌干扰物 17-α-乙炔基雌二醇 (EE2) 5 个月后，获得了这些三个器官在成年期的真正蛋白质组反应规范。我们的研究表明，在暴露后 5 个月，在各种雌激素反应途径中，早期生活内分泌干扰的蛋白质组学水平存在长期影响。在大脑和肝脏中，最低测试的和环境相关的浓度 4ng/L 对蛋白质组的影响最大，这突出了内分泌干扰物在低浓度下的效力。
