Aryl hydrocarbon receptor mediates laminar fluid shear stress-induced CYP1A1 activation and cell cycle arrest in vascular endothelial cells
Aryl hydrocarbon receptor mediates laminar fluid shear stress-induced CYP1A1 activation and cell cycle arrest in vascular endothelial cells
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DOI：
10.1093/cvr/cvm095
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发表时间：
2008-03-01
影响因子：
10.8
通讯作者：
Sasaguri, Toshiyuki
中科院分区：
文献类型：
--
作者：
Han, Zhiyi;Miwa, Yoshikazu;Sasaguri, Toshiyuki
目的 我们研究了剪切应力 (SS) 诱导的细胞色素 P450 (CYP) W 激活和细胞周期停滞与芳烃受体 (AhR) 的作用有关的机制，因为 AhR 介导多环芳烃 (PAH) 诱导的 CYP1A1 表达，并被认为参与细胞生长和分化的调节。 方法和结果 将人脐静脉内皮细胞 (EC) 暴露于层流随后收集SS以评估CYP1A1的表达、活性和转录以及AhR和细胞周期相关蛋白的表达。生理水平的层流SS（15达因/厘米（2））显着增加CYP1A1的表达水平和酶活性。 SS 刺激 CYP1A1 启动子活性而不影响 mRNA 稳定性。 CYP1A1 基因 5' 侧翼区域两个功能性外源反应元件 (XRE) 的丢失抑制了 SS 诱导的 CYP1A1 转录。层流 SS 刺激 AhR 的表达和核转位。 α-萘黄酮、AhR 拮抗剂和 AhR 的小干扰 RNA (siRNA) 显着抑制 SS 诱导的 CYP1A1 表达。 siRNA 还消除了 SS 诱导的细胞周期停滞、细胞周期蛋白依赖性激酶抑制剂 p21(Cip1) 的表达以及视网膜母细胞瘤蛋白的去磷酸化。结论 Laminar SS 通过激活 AhR 刺激 CYP1A1 的转录，其方式与 PAH 的作用类似。 AhR 还参与 SS 诱导的细胞周期停滞。我们的结果表明，暴露于血流的 AhR 持续激活在 EC 功能的调节中发挥着重要作用。
Aims We investigated the mechanisms of shear stress (SS)-induced activation of cytochrome P450 (CYP) W and cell cycle arrest with regard to the role of the aryl hydrocarbon receptor (AhR), since AhR mediates the expression of CYP1A1 induced by polycyclic aromatic hydrocarbons (PAHs) and is thought to be involved in the regulation of cell growth and differentiation.Methods and results Human umbilical vein endothelial cells (ECs) were exposed to laminar SS and thereafter collected to evaluate the expression, activity, and transcription of CYP1A1 and the expression of AhR and cell cycle-related proteins. A physiological level of laminar SS (15 dynes/cm(2)) markedly increased the expression level and enzymatic activity of CYP1A1. SS stimulated CYP1A1 promoter activity without influencing mRNA stability. Loss of two functional xenobiotic response elements (XREs) in the 5'-flanking region of the CYP1A1 gene suppressed the SS-induced transcription of CYP1A1. Laminar SS stimulated the expression and nuclear translocation of AhR. a-Naphthoflavone, an AhR antagonist, and a small interfering RNA (siRNA) for AhR significantly suppressed SS-induced CYP1A1 expression. The siRNA also abolished SS-induced cell cycle arrest, the expression of the cyclin-dependent kinase inhibitor p21(Cip1), and dephosphorytation of retinoblastoma protein.Conclusion Laminar SS stimulated the transcription of CYP1A1 through the activation of AhR in a way that is similar to the effects of PAHs. AhR was also involved in cell cycle arrest induced by SS. Our results suggest that sustained activation of AhR exposed to blood flow plays an important role in the regulation of EC functions.