Cytochrome P450-dependent metabolism of eicosapentaenoic acid in the nematode Caenorhabditis elegans
Cytochrome P450-dependent metabolism of eicosapentaenoic acid in the nematode Caenorhabditis elegans
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DOI：
10.1016/j.abb.2008.02.002
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发表时间：
2008-04-01
影响因子：
3.9
通讯作者：
Menzel, Ralph
中科院分区：
文献类型：
--
作者：
Kulas, Jana;Schmidt, Cosima;Menzel, Ralph
秀丽隐杆线虫基因组中含有75个全长细胞色素P450（CYP 450）基因，其功能尚不清楚。我们测试的假设，其中一些可能参与二十碳五烯酸（EPA），主要的多不饱和脂肪酸的这种线虫的代谢。从蠕虫分离的微粒体含有光谱活性的NADPH还原酶（CPR）蛋白，并显示NADPH还原酶（CPR）的活动。它们代谢EPA，并且以较低的活性将花生四烯酸（AA）代谢成特定的区域异构环氧基和ω-/（ω-1）-羟基衍生物。17（R），18（S）-环氧二十碳四烯酸是EPA的主要代谢产物，对映体纯度为72%。环氧合酶和羟化酶反应是NADPH依赖性的，需要CPR编码的emb-8基因的功能表达，并被17-ODYA和PPOH抑制，这两种化合物已知是哺乳动物AA代谢的EMB亚型。多个随后是单个RNAi基因沉默实验鉴定了EPA-29 A3和EPA-33 E2作为C.优美的液相色谱/质谱分析表明，EPA和AA的区域异构环氧和羟基衍生物是C.优雅的。用非诺贝特处理蠕虫，内源性EPA代谢产物水平增加，这也诱导微粒体环氧合酶和羟化酶活性。这些结果首次证明了C.秀丽线虫与哺乳动物一样具有产生CYP依赖性类花生酸的能力，因此可能有助于今后对这类重要信号分子作用机制的研究。(c)2008年爱思唯尔公司All rights reserved.
The genome of Caenorhabditis elegans contains 75 full length cytochrome P450 (CYP) genes whose individual functions are largely unknown yet. We tested the hypothesis that some of them may be involved in the metabolism of eicosapentaenoic acid (EPA), the predominant polyunsaturated fatty acid of this nematode. Microsomes isolated from adult worms contained spectrally active CYP proteins and showed NADPH-CYP reductase (CPR) activities. They metabolized EPA and with lower activity also arachidonic acid (AA) to specific sets of regioisomeric epoxy- and omega-/(omega-1)-hydroxy-derivatives. 17(R),18(S)-epoxyeicosatetraenoic acid was produced as the main EPA metabolite with an enantiomeric purity of 72%. The epoxygenase and hydroxylase reactions were NADPH-dependent, required the functional expression of the CPR-encoding emb-8 gene, and were inhibited by 17-ODYA and PPOH, two compounds known to inactivate mammalian AA-metabolizing CYP isoforms. Multiple followed by single RNAi gene silencing experiments identified CYP-29A3 and CYP-33E2 as the major isoforms contributing to EPA metabolism in C. elegans. Liquid chromatography/mass spectrometry revealed that regioisomeric epoxy- and hydroxy-derivatives of EPA and AA are endogenous constituents of C. elegans. The endogenous EPA metabolite levels were increased by treating the worms with fenofibrate, which also induced the microsomal epoxygenase and hydroxylase activities. These results demonstrate for the first time that C. elegans shares with mammals the capacity to produce CYP-dependent eicosanoids and may thus facilitate future studies on the mechanisms of action of this important class of signaling molecules. (c) 2008 Elsevier Inc. All rights reserved.