Transcriptional regulation of human carboxylesterase 1A1 by nuclear factor-erythroid 2 related factor 2 (Nrf2)
Transcriptional regulation of human carboxylesterase 1A1 by nuclear factor-erythroid 2 related factor 2 (Nrf2)
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DOI：
10.1016/j.bcp.2009.08.019
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发表时间：
2010-01-15
影响因子：
5.8
通讯作者：
Yokoi, Tsuyoshi
中科院分区：
文献类型：
--
作者：
Maruichi, Taiga;Fukami, Tatsuki;Yokoi, Tsuyoshi
人羧酸酯酶(CES)1A主要在肝脏和肺中表达，在内源化合物和外源物质的降解中起着重要作用。据报道，CES1a在人肝细胞中由丁基羟基苯甲醚、噻氯匹定和双氯芬酸诱导，并被认为是由氧化应激引起的。然而，其分子机制仍有待进一步研究。在本研究中，我们试图研究CES1a是否受核因子-红系2相关因子2(Nrf2)的调控，Nrf2是一种由氧化应激激活的转录因子，并阐明其分子机制。实时定量逆转录-聚合酶链式反应(Real-Time RT-PCR)结果显示，在HepG2、Caco-2和HeLa细胞中，具有代表性的Nrf2激活剂叔丁基对苯二酚(TBHQ)和萝卜硫醚(SFN)可显著诱导CES1A1基因的表达。小干扰RNA可完全抑制NRF2的诱导作用。在HepG2细胞中，由CES1a特异性催化的CES1a蛋白水平和咪达普利水解酶活性也被TBHQ和SFN显著诱导。荧光素酶分析表明，CES1A1基因中的抗氧化反应元件(ARE)-2025负责Nrf2的反式激活。此外，电泳迁移率改变分析和染色质免疫沉淀分析表明，Nrf2与CES1A1基因中的ARE结合。这些发现清楚地表明，人类CES1A1是由Nrf2诱导的。这是首次揭示人CES1A1诱导调控的分子机制。(C)2009 Elsevier Inc.AM版权所有。
Human carboxylesterase (CES) 1A, which is predominantly expressed in liver and lung, plays an important role in the hydrolysis of endogenous compounds and xenobiotics. CES1A is reported to be induced in human hepatocytes by butylated hydroxyanisole, ticlopidine and diclofenac, and the induction is assumed to be caused by oxidative stress. However, the molecular mechanism remains to be determined. In this study, we sought to investigate whether CES1A is regulated by nuclear factor-erythroid 2 related factor 2 (Nrf2), which is a transcriptional factor activated by oxidative stress, and clarify the molecular mechanism. Real-time reverse transcription-PCR assays revealed that CES1A1 mRNA was significantly induced by tert-butylhydroquinone (tBHQ) and sulforaphane (SFN), which are representative activators of Nrf2 in HepG2, Caco-2 and HeLa cells. The induction was completely suppressed with small interfering RNA for Nrf2. In HepG2 cells, the CES1A protein level and imidapril hydrolase activity, which is specifically catalyzed by CES1A, were also significantly induced by tBHQ and SFN. Luciferase assays revealed that the antioxidant response element (ARE) at -2025 in the CES1A1 gene was responsible for the transactivation by Nrf2. In addition, electrophoretic mobility shift assays and chromatin immunoprecipitation assays revealed that Nrf2 binds to the ARE in the CES1A1 gene. These findings clearly demonstrated that human CES1A1 is induced by Nrf2. This is the first study to demonstrate the molecular mechanism of the inducible regulation of human CES1A1. (C) 2009 Elsevier Inc. AM rights reserved.