Mansur Abdallah, Adir Michal, Yerushalmi Gil, Hourvitz Ariel, Gitman Hila, Yung Yuval, Orvieto Raoul, Machtinger Ronit
Infertility and IVF Unit, Department of Obstetrics and Gynecology, Sheba Medical Center and Sackler School of Medicine, Tel-Aviv University, Tel Aviv-Yafo, Israel.
Infertility and IVF Unit, Department of Obstetrics and Gynecology, Sheba Medical Center and Sackler School of Medicine, Tel-Aviv University, Tel Aviv-Yafo, Israel
Hum Reprod. 2016 Jul;31(7):1562-9. doi: 10.1093/humrep/dew088. Epub 2016 Apr 24.
Does Bisphenol A (BPA) impair steroid hormone production in human luteinized granulosa cells in vitro?
At supra-physiological concentrations, BPA alters progesterone and estradiol synthesis in vitro and significantly reduces the mRNA and protein expression levels of three genes encoding steroidogenesis enzymes.
In IVF patients, the effects of BPA exposure on cycle outcome are controversial. Previous animal studies have shown that granulosa cell steroid hormone synthesis is compromised after BPA exposure, but their findings have been difficult to replicate in humans due, in part, to the low availability of discarded biological material.
STUDY DESIGN, SIZE, DURATION: Luteinized granulosa cells obtained from 44 fertile and infertile patients undergoing in vitro fertilization were cultured for 48 h with different concentrations of BPA (0, 0.2, 0.02, 2.0, 20 µg/ml).
PARTICIPANTS/MATERIALS, SETTING, METHODS: Culture medium and total RNA extracted from the luteinized granulosa cells were examined for estradiol and progesterone levels as well as mRNA and protein expression of steroidogenesis enzymes, using enzyme immunoassays, real-time PCR and western blots.
Treatment of granulosa cells with 2 or 20 µg/ml BPA for 48 h resulted in significantly lower progesterone biosynthesis (P < 0.005 and <0.001, respectively). Estradiol production was significantly altered only after incubation with 20 µg/ml of BPA (P < 0.001). These concentrations also significantly reduced the mRNA levels of 3β-hydroxysteroid dehydrogenase (3β-HSD), CYP11A1 and CYP19A1 without affecting StAR and 17β-hydroxysteroid dehydrogenase mRNA expression. Similarly, 3β-HSD, CYP11A1 and CYP19A1 protein levels were reduced after administration of 20 µg/ml BPA. Lower BPA concentrations similar to, and up to 100 times, the concentrations measured in human follicular fluid, serum and urine did not alter steroidogenesis in primary granulosa cell cultures.
LIMITATIONS, REASONS FOR CAUTION: This was an in vitro study investigating the effects of acute exposure (48 h) of BPA on discarded material. As such, the model may not accurately reflect the effect of BPA on the physiological events of follicular steroid hormone synthesis in vivo.
Our results show that in vitro exposure to BPA at low doses does not affect granulosa cells steroidogenesis. Combined with recent in vivo studies, these data can be reassuring but further studies are needed to assess the effects of chronic exposure to BPA on ovarian steroidogenesis.
This study was supported by grant number 1936/12 from the Israeli Science Foundation (ISF). The authors have no conflict of interest.
双酚A（BPA）是否会在体外损害人黄素化颗粒细胞中的类固醇激素生成？
在超生理浓度下，双酚A在体外改变孕酮和雌二醇的合成，并显著降低编码类固醇生成酶的三个基因的mRNA和蛋白质表达水平。
在体外受精患者中，双酚A暴露对周期结局的影响存在争议。先前的动物研究表明，双酚A暴露后颗粒细胞类固醇激素合成受到损害，但部分由于废弃生物材料的可得性低，他们的研究结果难以在人体中重复。
研究设计、规模、持续时间：从44名接受体外受精的可育和不育患者中获得的黄素化颗粒细胞，用不同浓度的双酚A（0、0.2、0.02、2.0、20μg/ml）培养48小时。
参与者/材料、环境、方法：使用酶免疫测定、实时PCR和蛋白质印迹法，检测从黄素化颗粒细胞中提取的培养基和总RNA中的雌二醇和孕酮水平，以及类固醇生成酶的mRNA和蛋白质表达。
用2或20μg/ml双酚A处理颗粒细胞48小时导致孕酮生物合成显著降低（分别为P < 0.005和<0.001）。仅在与20μg/ml双酚A孵育后，雌二醇生成显著改变（P < 0.001）。这些浓度也显著降低了3β-羟基类固醇脱氢酶（3β-HSD）、CYP11A1和CYP19A1的mRNA水平，而不影响类固醇生成急性调节蛋白（StAR）和17β-羟基类固醇脱氢酶的mRNA表达。同样，给予20μg/ml双酚A后，3β-HSD、CYP11A1和CYP19A1的蛋白质水平降低。与在人卵泡液、血清和尿液中测得的浓度相似且高达100倍的较低双酚A浓度，并未改变原代颗粒细胞培养中的类固醇生成。
局限性、谨慎原因：这是一项体外研究，调查双酚A急性暴露（48小时）对废弃材料的影响。因此，该模型可能无法准确反映双酚A对体内卵泡类固醇激素合成生理事件的影响。
我们的结果表明，体外低剂量暴露于双酚A不会影响颗粒细胞类固醇生成。结合最近的体内研究，这些数据可能令人安心，但需要进一步研究以评估长期暴露于双酚A对卵巢类固醇生成的影响。
本研究由以色列科学基金会（ISF）的1936/12号资助。作者没有利益冲突。
