Triphenyl phosphate-induced developmental toxicity in zebrafish: potential role of the retinoic acid receptor.
Triphenyl phosphate-induced developmental toxicity in zebrafish: potential role of the retinoic acid receptor.
复制标题
DOI：
10.1016/j.aquatox.2015.02.009
复制
发表时间：
2015-04
期刊：
影响因子：
--
通讯作者：
Volz DC
中科院分区：
文献类型：
--
作者：
Isales GM;Hipszer RA;Raftery TD;Chen A;Stapleton HM;Volz DC
以斑马鱼为模型，我们之前报道了发育暴露于磷酸三苯酯（TPP）——一种高产的有机磷阻燃剂——会导致二恶英样的心脏环损伤，这种损伤与芳烃受体无关。利用药理学方法，本研究的目的是研究视黄酸受体(RAR) -一种调节脊椎动物心脏形态发生的核受体-在介导tpp诱导的斑马鱼发育毒性中的潜在作用。我们首先揭示了斑马鱼在受精后5-72小时（hpf）在无毒性浓度的RAR拮抗剂（BMS493）的存在下静态暴露于TPP显著增强了TPP诱导的毒性（相对于单独TPP），尽管相同的无毒性BMS493浓度减轻了视黄酸（RA）诱导的毒性。BMS493介导的TPP毒性增强不是TPP摄取或代谢差异的结果，因为在存在或不存在BMS493的情况下，TPP和二苯磷酸（DPP）的胚胎内剂量没有差异。利用实时PCR，我们量化了斑马鱼细胞色素P450 26a1 （cyp26a1）表达的相对变化，这是RA诱导RAR激活的主要靶基因，发现RA和TPP暴露导致cyp26a1表达分别比暴露于载体的胚胎增加和减少了5倍。为了研究TPP是否可能与人RARs相互作用，我们在RA存在的情况下，将转染嵌合人RARα-、RARβ-或RARγ的中国仓鼠卵巢细胞稳定暴露于TPP中，发现TPP以浓度依赖的方式显著抑制RA诱导的荧光素酶活性。总的来说，我们的研究结果表明斑马鱼RARs可能参与介导tpp诱导的发育毒性，这一作用机制可能与人类有关。
Using zebrafish as a model, we previously reported that developmental exposure to triphenyl phosphate (TPP) – a high-production volume organophosphate-based flame retardant – results in dioxin-like cardiac looping impairments that are independent of the aryl hydrocarbon receptor. Using a pharmacologic approach, the objective of this study was to investigate the potential role of retinoic acid receptor (RAR) – a nuclear receptor that regulates vertebrate heart morphogenesis – in mediating TPP-induced developmental toxicity in zebrafish. We first revealed that static exposure of zebrafish from 5-72 hours post-fertilization (hpf) to TPP in the presence of non-toxic concentrations of an RAR antagonist (BMS493) significantly enhanced TPP-induced toxicity (relative to TPP alone), even though identical non-toxic BMS493 concentrations mitigated retinoic acid (RA)-induced toxicity. BMS493-mediated enhancement of TPP toxicity was not a result of differential TPP uptake or metabolism, as internal embryonic doses of TPP and diphenyl phosphate (DPP) – a primary TPP metabolite - were not different in the presence or absence of BMS493. Using real-time PCR, we then quantified the relative change in expression of cytochrome P450 26a1 (cyp26a1) – a major target gene for RA-induced RAR activation in zebrafish – and found that RA and TPP exposure resulted in a ∼5-fold increase and decrease in cyp26a1 expression, respectively, relative to vehicle-exposed embryos. To address whether TPP may interact with human RARs, we then exposed Chinese hamster ovary cells stably transfected with chimeric human RARα-, RARβ-, or RARγ to TPP in the presence of RA, and found that TPP significantly inhibited RA-induced luciferase activity in a concentration-dependent manner. Overall, our findings suggest that zebrafish RARs may be involved in mediating TPP-induced developmental toxicity, a mechanism of action that may have relevance to humans.