Effect of the histone deacetylase inhibitor trichostatin A on the responsiveness of rat hepatocytes to dioxin.
Effect of the histone deacetylase inhibitor trichostatin A on the responsiveness of rat hepatocytes to dioxin.
复制标题
组蛋白脱乙酰酶抑制剂曲古抑菌素 A 对大鼠肝细胞对二恶英反应性的影响。
DOI：
10.1016/s0006-2952(97)00113-5
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发表时间：
1997
影响因子：
5.8
通讯作者：
Ruh,MF
中科院分区：
文献类型：
--
作者：
Xu,L;Ruh,TS;Ruh,MF
由于组蛋白乙酰化与特定基因转录的促进有关，我们研究了通过抑制historie脱乙酰酶来增加historic乙酰化对2，3，7，8-四氯二苯并-p-二恶英（TCDD）诱导培养大鼠肝细胞中P4501 A活性的影响。组蛋白脱乙酰化的抑制通过向孵育培养基中加入阿司他丁A（TSA）来完成，并且通过测定乙氧基试卤灵-O-脱乙基酶（EROD）形成试卤灵的速率来用荧光分光光度法测量P4501 A活性。虽然TSA单独（5-200 ng/mL）对EROD活性没有影响，但TSA增强了不同浓度（10− 12至10− 10 M）的TCDD的作用。与TCDD单独相比，添加200 ng TSA/mL TCDD导致EROD活性增加约200%。当TSA在不同的孵育时间（2、6、24小时）后通过用不含TSA的培养基连续洗涤从细胞中除去时，确定需要TSA 24小时以增强与TCDD孵育48小时的效果。除了EROD活性的测量，P4501 A1和1A 2微粒体蛋白通过蛋白质免疫印迹分析测定。虽然在单独存在TSA的情况下无法检测到P4501 A1和1A 2，但在存在或不存在TSA的情况下将细胞与TCDD孵育后，均存在P4501 A1。TCDD加TSA也导致P4501 A2的形成。本研究的结果表明，组蛋白乙酰化的作用TCDD诱导P4501 A酶的重要作用。
Since histone acetylation has been implicated in the facilitation of specific gene transcription, we investigated the effect of increasing historic acetylation through inhibition of historie deacetylase on 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) induction of P4501A activity in cultured rat hepatocytes. Inhibition of histone deacetylation was accomplished with addition of trichostatin A (TSA) to the incubation medium, and P4501A activity was measured spectrofluorometrically by determination of the rate of resorufin formation by ethoxyresorufin-O-deethylase (EROD). While TSA alone (5–200 ng/mL) had no effect on EROD activity, TSA potentiated the effect of various concentrations (10−12to 10−10M) of TCDD. Addition of 200 ng TSA/mL with TCDD resulted in an increased EROD activity of ~200% compared with TCDD alone. When TSA was removed from the cells after various incubation times (2, 6, 24 hr) by successive washings with TSA-free medium, it was determined that TSA was required for 24 hr in order to potentiate the effects of a 48-hr incubation with TCDD. In addition to measurement of EROD activity, P4501A1 and 1A2 microsomal protein were determined by western immunoblotting analysis. While neither P4501A1 nor 1A2 was detectable in the presence of TSA alone, P4501A1 was present after incubation of cells with TCDD in the presence or absence of TSA. TCDD plus TSA also resulted in the formation of P4501A2. The results of this study suggest an important role for histone acetylation in the action of TCDD on induction of P4501A enzymes.