van den Driesche Sander, McKinnell Chris, Calarrão Ana, Kennedy Laura, Hutchison Gary R, Hrabalkova Lenka, Jobling Matthew S, Macpherson Sheila, Anderson Richard A, Sharpe Richard M, Mitchell Rod T
MRC Centre for Reproductive Health, The Queen's Medical Research Institute, The University of Edinburgh, Edinburgh, United Kingdom.
Environ Health Perspect. 2015 Mar;123(3):223-30. doi: 10.1289/ehp.1408248. Epub 2014 Dec 16.
Phthalate exposure induces germ cell effects in the fetal rat testis. Although experimental models have shown that the human fetal testis is insensitive to the steroidogenic effects of phthalates, the effects on germ cells have been less explored.
We sought to identify the effects of phthalate exposure on human fetal germ cells in a dynamic model and to establish whether the rat is an appropriate model for investigating such effects.
We used immunohistochemistry, immunofluorescence, and quantitative real-time polymerase chain reaction to examine Sertoli and germ cell markers on rat testes and human fetal testis xenografts after exposure to vehicle or di(n-butyl) phthalate (DBP). Our study included analysis of germ cell differentiation markers, proliferation markers, and cell adhesion proteins.
In both rat and human fetal testes, DBP exposure induced similar germ cell effects, namely, germ cell loss (predominantly undifferentiated), induction of multinucleated gonocytes (MNGs), and aggregation of differentiated germ cells, although the latter occurred rarely in the human testes. The mechanism for germ cell aggregation and MNG induction appears to be loss of Sertoli cell-germ cell membrane adhesion, probably due to Sertoli cell microfilament redistribution.
Our findings provide the first comparison of DBP effects on germ cell number, differentiation, and aggregation in human testis xenografts and in vivo in rats. We observed comparable effects on germ cells in both species, but the effects in the human were muted compared with those in the rat. Nevertheless, phthalate effects on germ cells have potential implications for the next generation, which merits further study. Our results indicate that the rat is a human-relevant model in which to explore the mechanisms for germ cell effects.
邻苯二甲酸酯暴露会在胎鼠睾丸中诱导生殖细胞效应。尽管实验模型表明人类胎儿睾丸对邻苯二甲酸酯的类固醇生成效应不敏感，但对生殖细胞的影响尚未得到充分研究。
我们试图在动态模型中确定邻苯二甲酸酯暴露对人类胎儿生殖细胞的影响，并确定大鼠是否是研究此类影响的合适模型。
我们使用免疫组织化学、免疫荧光和定量实时聚合酶链反应来检测暴露于赋形剂或邻苯二甲酸二丁酯（DBP）后的大鼠睾丸和人类胎儿睾丸异种移植中的支持细胞和生殖细胞标志物。我们的研究包括对生殖细胞分化标志物、增殖标志物和细胞粘附蛋白的分析。
在大鼠和人类胎儿睾丸中，DBP暴露均诱导了相似的生殖细胞效应，即生殖细胞丢失（主要是未分化的）、多核生殖母细胞（MNGs）的诱导以及分化生殖细胞的聚集，尽管后者在人类睾丸中很少发生。生殖细胞聚集和MNG诱导的机制似乎是支持细胞-生殖细胞膜粘附的丧失，可能是由于支持细胞微丝重新分布。
我们的研究结果首次比较了DBP对人类睾丸异种移植和大鼠体内生殖细胞数量、分化和聚集的影响。我们观察到两种物种对生殖细胞的影响具有可比性，但与大鼠相比，人类的影响较弱。尽管如此，邻苯二甲酸酯对生殖细胞的影响对下一代具有潜在影响，值得进一步研究。我们的结果表明，大鼠是探索生殖细胞效应机制的与人类相关的模型。
