咪唑类离子液体处理对草鱼CYP3A和PXR基因表达的影响

Effects of the Treatment of Imidazolium Ionic Liquids on Gene Expression of Cytochrome P450 3A and Pregrane X Receptor(PXR) in Ctenopharyngodon idellus

细胞色素P450是一类含有亚铁血红素的超家族单加氧酶,参与许多外源物质(包括药物、环境化合物等)和内源性物质(如激素)的代谢转化。CYP3A是I相解毒酶系P450家族中的重要成员,在肝脏对外源毒物解毒和内源激素的代谢过程中发挥重要作用。为探讨草鱼(Ctenopharyngodon idellus)肝脏CYP3A在溴化1-辛基-3-甲基咪唑离子液体([C8mim]Br)的解毒过程作用以及鱼体对[C8mim]Br的解毒是否通过PXR-CYP3A转录调控途径作用,通过预试验获取[C8mim]Br对草鱼的急性毒性效应,选取22 mg/L(1/10 LC50)和109 mg/L(1/2LC50)浓度组[C8mim]Br对草鱼染毒24 h,荧光定量PCR检测CYP3A和PXR的表达情况。结果表明,草鱼肝脏CYP3A水平与对照组相比极显著上升(P<0.01),PXR基因表达量与对照组相比也极显著升高(P<0.01),CYP3A与PXR基因表达水平呈现出一定的相关性;推测在草鱼体内PXR可能就是[C8mim]Br作用于CYP3A的受体。

Cytochrome P450 （CYPs） enzymes, which was a kind of superfamily monooxygena with heme, joined the metabolic transformation of several exogenous materials （ included medicine, environmental compounds and so on） and endogenous materials （such as hormones）. CYP3A was an important member of the phrase I of detoxifica- tion enzymes P450, and it played a critical role in detoxifying exogenous toxicant and metabolizing endogenous hor- mone in liver. The study aimed to evaluate the function of CYP3A in the detoxification process of brominating the 1- oetyl-3-methylimidazolium ionic liquid （ [ Cs mim ] Br） and to determine whether the dctoxifieation of [ Cs mim ] Br through the PXR-CYP3A transcriptional regulatory pathway or not in Ctenopharyngodon idellus. According to the results of acute toxicity tests, the [ C8mimj Br-exposure concentrations were designed to be 22 mg/L and 109 mg/ L for Ctenopharyngodon idellus for 24 hours, and the expression situation of CYR3A and PXR was detected by fluo- rescent quantitative PC R. The result indicated that [ Csmim ] Br significantly up-regulate the expression of CYP3A and PXR at mRNA level in fish liver（P 〈0.01 ） , and the gene expression level of CYP 3A and PXR presented a certain correlation. This result assumed that the PXR in Ctenopharyngodon idellus maybe the receptor of [ Csmim] Br on CYP3A