■已知内分泌干扰化学物质(EDC)会干扰内分泌稳态。它们对肾上腺皮质和类固醇生成的影响尚未得到充分阐明。这特别适用于普遍存在的双酚A(BPA),F(BPF),S(BPS)。
■NCI-H295R肾上腺皮质细胞暴露于不同浓度(1nM-1mM)的BPA,BPF,BPS,和它们的等摩尔混合物(BPmix)。72小时后,使用LC-MS/MS测量了15种内源性类固醇。计算CYP调节步骤的底物和产物的比率,以鉴定受影响最大的类固醇生成步骤。通过实时PCR确定类固醇生成酶的mRNA表达。
■双酚浓度低于250µM时,细胞活力不受影响。所有测试的双酚及其组合导致定量类固醇水平的广泛改变。雄烯二酮暴露于BPA(>10µM)后,类固醇浓度的最大倍数变化(FC)。例如,与媒介物处理的对照相比,在25µM(p≤0.0001)时下降了0.37±0.11倍。对于BPF,17-羟孕酮的水平显著增加了25µM(FC2.57±0.49,p≤0.001)和50µM(FC2.65±0.61,p≤0.0001).BPS治疗导致11-脱氧皮质酮在>1µM时的剂量依赖性下降(例如FC0.24±0.14,在10µM时p≤0.0001)。然而,当结合所有三种双酚时,加性效应被检测到:例如,11-脱氧皮质酮在剂量>10µM时降低(FC0.27±0.04,p≤0.0001,在25µM时),而21-脱氧皮质醇在10µM时增加了2.92±0.20(p≤0.01),在50µM下为3.21±0.45(p≤0.001)。虽然每个测量的雄激素(DHEA,DHEAS,雄烯二酮,睾丸激素,DHT)在所有实验中都降低了,雌二醇水平显着增加BPA,BPF,BPS,和BPmix(例如FC3.60±0.54,在100µMBPF时p≤0.0001)。计算的底物-产物比率表明CYP17A1-的抑制作用,和CYP21A2介导的转化,而CYP11B1和CYP19A1在双酚存在下显示出更高的活性。基于这些发现,分析了CYP基因最相关的mRNA表达。StAR的mRNA水平,CYP11B1和CYP17A1被BPF显著增高,BPS,还有BPmix.
■在细胞培养中,双酚在非细胞毒性水平上干扰类固醇生成,导致激素水平显著改变的化合物特异性模式。这些结果证明并要求进行其他体内研究以评估EDC对肾上腺功能的影响。
UNASSIGNED: Endocrine disrupting chemicals (EDCs) are known to interfere with endocrine homeostasis. Their impact on the adrenal cortex and steroidogenesis has not yet been sufficiently elucidated. This applies in particular to the ubiquitously available bisphenols A (BPA), F (BPF), and S (BPS).
UNASSIGNED: NCI-H295R adrenocortical cells were exposed to different concentrations (1nM-1mM) of BPA, BPF, BPS, and an equimolar mixture of them (BPmix). After 72 hours, 15 endogenous steroids were measured using LC-MS/MS. Ratios of substrate and product of CYP-regulated steps were calculated to identify most influenced steps of steroidogenesis. mRNA expression of steroidogenic enzymes was determined by real-time PCR.
UNASSIGNED: Cell viability remained unaffected at bisphenol concentrations lower than 250 µM. All tested bisphenols and their combination led to extensive alterations in the quantified steroid levels. The most profound fold changes (FC) in steroid concentrations after exposure to BPA (>10µM) were seen for androstenedione, e.g. a 0.37±0.11-fold decrease at 25µM (p≤0.0001) compared to vehicle-treated controls. For BPF, levels of 17-hydroxyprogesterone were significantly increased by 25µM (FC 2.57±0.49, p≤0.001) and 50µM (FC 2.65±0.61, p≤0.0001). BPS treatment led to a dose-dependent decrease of 11-deoxycorticosterone at >1µM (e.g. FC 0.24±0.14, p≤0.0001 at 10µM). However, when combining all three bisphenols, additive effects were detected: e.g. 11-deoxycortisosterone was decreased at doses >10µM (FC 0.27±0.04, p≤0.0001, at 25µM), whereas 21-deoxycortisol was increased by 2.92±0.20 (p≤0.01) at 10µM, and by 3.21±0.45 (p≤0.001) at 50µM. While every measured androgen (DHEA, DHEAS, androstenedione, testosterone, DHT) was lowered in all experiments, estradiol levels were significantly increased by BPA, BPF, BPS, and BPmix (e.g. FC 3.60±0.54, p≤0.0001 at 100µM BPF). Calculated substrate-product ratios indicated an inhibition of CYP17A1-, and CYP21A2 mediated conversions, whereas CYP11B1 and CYP19A1 showed higher activity in the presence of bisphenols. Based on these findings, most relevant mRNA expression of CYP genes were analysed. mRNA levels of StAR, CYP11B1, and CYP17A1 were significantly increased by BPF, BPS, and BPmix.
UNASSIGNED: In cell culture, bisphenols interfere with steroidogenesis at non-cytotoxic levels, leading to compound-specific patterns of significantly altered hormone levels. These results justify and call for additional in-vivo studies to evaluate effects of EDCs on adrenal gland functionality.