High levels of dioxin-like potential in cigarette smoke evidenced by in vitro and in vivo biosensing
High levels of dioxin-like potential in cigarette smoke evidenced by in vitro and in vivo biosensing
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DOI：
10.1158/0008-5472.can-05-4541
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发表时间：
2006-07-15
期刊：
影响因子：
11.2
通讯作者：
Kitamura, Masanori
中科院分区：
文献类型：
--
作者：
Kasai, Ayumi;Hiramatsu, Nobuhiko;Kitamura, Masanori
香烟烟雾中含有低水平的芳香烃受体激动剂(AhR；也称为二恶英受体)。然而，人们对香烟烟雾激活AhR的全部潜力知之甚少。在这份报告中，我们使用体外和体内报告系统评估了香烟烟雾的总“二恶英样”活性。在7个卷烟牌号(焦油含量1~20 mg)前制备了卷烟烟雾提取物(CSE)，并以外源生物反应元件(XRE)为传感器，分泌型碱性磷酸酶(SEAP)为报告因子，进行了体外生物测定。报告细胞暴露于CSE以剂量依赖的方式触发XRE的激活，这种激活被AhR的功能抑制所抑制。将细胞直接、短暂地暴露在香烟烟雾中，同样会引起XRE的激活。以2，3，7，8-四氯二苯并-对二恶英(2，3，7，8-TCDD)为标准，定量评价了个体烟雾的XRE活化电位(XAP)。焦油含量与XAP值呈正相关。估计的XAP值非常高，每支香烟的XAP当量范围在18.5到51.2 ng 2，3，7，8-TCDD当量之间。以进一步估计香烟烟雾的XAP。在体内，我们产生了在X-RE对照下分泌SEAP的转基因报告鼠。小鼠暴露在烟雾中后，血清SEAP水平在12小时内显著升高，24小时达到峰值，之后下降。这些结果首次证明，在体外和体内，香烟烟雾具有出人意料的高二恶英样势，触发AhR-XRE途径。
Cigarette smoke contains low levels of agonists for the aryl hydrocarbon receptor (AhR; also called the dioxin receptor). However, little is understood about the whole potential of cigarette smoke for activating AhR. In this report, we evaluated the total "dioxin-like" activity of cigarette smoke using in vitro and in vivo, reporter systems. Cigarette smoke extract (CSE) was prepared front seven cigarette brands (1-20 mg tar content) and subjected to in vitro bioassay based on the xenobiotic-responsive element (XRE) as the sensor and secreted alkaline phosphatase (SEAP) as the reporter. Exposure of reporter cells to CSE triggered activation of XRE in a dose-dependent manner, which was suppressed by functional inhibition of AhR. Direct, brief exposure of the cells to cigarette smoke similarly induced activation of XRE. Using 2,3,7,8-tetrachlorodibenzo-p-dioxin (2,3,7,8-TCDD) as the standard, the XRE-activating potential (XAP) of individual smoke was evaluated quantitatively. Positive correlation was observed between the tar content and XAP values. The XAP values estimated were extremely high with a range front 18.5 to 51.2 ng 2,3,7,8-TCDD equivalent per cigarette. To further estimate XAP of cigarette smoke in. vivo, we generated transgenic reporter mice that secrete SEAP tinder the control of X-RE. After exposure of the mice to smoke, serum levels of SEAP were significantly elevated within 12 hours, peaked at 24 hours, and declined thereafter. These results evidenced for the first time that cigarette smoke has unexpectedly high dioxin-like potential that triggers the AhR-XRE pathway in vitro and in vivo.