Verderame Mariailaria, Scudiero Rosaria
Department of Biology, University of Naples Federico II, Via Mezzocannone 8, 80134 Napoli, Italy.
Department of Biology, University of Naples Federico II, Via Mezzocannone 8, 80134 Napoli, Italy.
C R Biol. 2017 Mar;340(3):139-144. doi: 10.1016/j.crvi.2017.01.005. Epub 2017 Feb 24.
In the last years, the hormonal balance is threatened by the interferences of substances with hormone-like action (endocrine disruptor chemicals, EDCs) that may harm animal reproduction. Most EDCs are resistant to environmental degradation and are considered ubiquitous contaminants. EDCs may have synthetic or natural origins. Pesticides used in intensive agriculture contain large amounts of chemicals with estrogenic properties, such as the alkylphenol nonylphenol (NP). Besides, animal feeding operations are important sources of natural estrogen metabolites introduced into the environment through manure application in organic farming. In both cases, EDCs can reach animals, including humans particularly at risk due to their position in the food chain. This is the reason for which it is important to use terrestrial vertebrates as sentinels in soil biomonitoring programmes. Today, the most validated biomarker of estrogenic exposure is the expression in male liver of the vitellogenin (VTG), an estrogen-dependent glycolipophosphoprotein naturally expressed only in the liver of oviparous females during the reproductive season. This report summarizes the data available on the EDC-dependent expression and the synthesis of VTG in male vertebrates, highlighting our latest studies that demonstrate the ability of testis and epididymis of the lacertid Podarcis sicula to synthesize VTG following estrogenic exposure. These findings provide, for the first time, evidence on an extrahepatic expression and synthesis of VTG in a terrestrial vertebrate and lay the groundwork for a new value of the VTG as a biomarker of environmental contamination. In addition, the results open a new scenario on the role of VTG in cells other than oocytes.
在过去几年中，激素平衡受到具有类激素作用的物质（内分泌干扰化学物质，EDCs）的干扰威胁，这些物质可能损害动物繁殖。大多数EDCs对环境降解具有抗性，被认为是普遍存在的污染物。EDCs可能有合成或天然来源。集约化农业中使用的农药含有大量具有雌激素特性的化学物质，如烷基酚壬基酚（NP）。此外，动物饲养作业是通过有机农业中粪便施用引入环境的天然雌激素代谢物的重要来源。在这两种情况下，EDCs都能到达动物体内，包括人类，由于其在食物链中的位置，人类尤其处于危险之中。这就是在土壤生物监测计划中使用陆生脊椎动物作为哨兵很重要的原因。如今，雌激素暴露最有效的生物标志物是雄性肝脏中卵黄蛋白原（VTG）的表达，卵黄蛋白原是一种雌激素依赖性糖脂磷蛋白，在繁殖季节仅在卵生雌性动物的肝脏中自然表达。本报告总结了关于雄性脊椎动物中EDC依赖性VTG表达和合成的现有数据，突出了我们的最新研究，这些研究表明，在雌激素暴露后，蜥蜴Podarcis sicula的睾丸和附睾能够合成VTG。这些发现首次提供了陆生脊椎动物肝外VTG表达和合成的证据，并为将VTG作为环境污染生物标志物的新价值奠定了基础。此外，这些结果为VTG在卵母细胞以外的细胞中的作用开启了新的局面。
