Rahman I, Bel A, Mulier B, Lawson M F, Harrison D J, Macnee W, Smith C A
Rayne Laboratory, Respiratory Medicine Unit, University of Edinburgh, Teviot Place, Edinburgh, Scotland, EH8 9AG, United Kingdom.
Biochem Biophys Res Commun. 1996 Dec 24;229(3):832-7. doi: 10.1006/bbrc.1996.1888.
We studied the regulation of glutathione (GSH) synthesis and characterised the 5'-promoter region of the gamma-glutamylcysteine synthetase-heavy subunit (gammaGCS-HS) gene in human alveolar type II cells (A549) following exposure to menadione (MQ) and hydrogen peroxide (H2O2). Both MQ (100 microM) and H2O2 (100 microM) exposure increased intracellular GSH levels associated with increased gammaGCS activity. This was concomitant with enhanced expression of gammaGCS-HS mRNA. Transfection of deletion constructs of the gammaGCS-HS promoter (-1050 to +82 bp) in a chloramphenicol acetyl transferase (CAT) reporter system revealed that an human antioxidant response element (hARE), present within the proximal region of the promoter (-1050 to -818 bp), is not required for oxidant-mediated gene induction. We conclude that oxidant stress-induced gammaGCS-HS mRNA expression is associated with AP-1 or AP-1 like responsive elements (-817 to +45 bp).
我们研究了谷胱甘肽（GSH）合成的调节，并对人II型肺泡细胞（A549）暴露于甲萘醌（MQ）和过氧化氢（H2O2）后γ-谷氨酰半胱氨酸合成酶重亚基（γGCS-HS）基因的5'-启动子区域进行了表征。暴露于MQ（100μM）和H2O2（100μM）均增加了细胞内GSH水平，并伴有γGCS活性增加。这与γGCS-HS mRNA表达增强同时发生。在氯霉素乙酰转移酶（CAT）报告系统中对γGCS-HS启动子（-1050至+82 bp）的缺失构建体进行转染显示，启动子近端区域（-1050至-818 bp）内存在的人抗氧化反应元件（hARE）对于氧化剂介导的基因诱导不是必需的。我们得出结论，氧化应激诱导的γGCS-HS mRNA表达与AP-1或AP-1样反应元件（-817至+45 bp）相关。
