EFFECT OF THIOL ANTIOXIDANTS ON LIPOPOLYSACCHARIDE-INDUCED CYCLOOXYGENASE-2 EXPRESSION IN PULMONARY EPITHELIAL CELLS
EFFECT OF THIOL ANTIOXIDANTS ON LIPOPOLYSACCHARIDE-INDUCED CYCLOOXYGENASE-2 EXPRESSION IN PULMONARY EPITHELIAL CELLS
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DOI：
10.26402/jpp.2018.4.04
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发表时间：
2018-08-01
影响因子：
2.2
通讯作者：
Kim, H.
中科院分区：
文献类型：
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作者：
Choi, S.;Lim, J. W.;Kim, H.
环氧合酶-2(COX-2)在肺部炎症反应中起重要作用，其表达受多种转录因子的调节，包括核因子-kappaB(NF-kappa B)、激活蛋白-1(AP-1)和信号转导与转录激活因子-3(STAT-3)，这些转录因子受氧化应激激活。谷胱甘肽(GSH)和N-乙酰半胱氨酸(NAC)是清除活性氧(ROS)的硫醇抗氧化剂。本研究探讨脂多糖(LPS)诱导肺上皮细胞A549细胞COX-2表达是否通过产生ROS和激活氧化剂敏感的转录因子如核因子-kappaB、AP-1和STAT-3来实现。在内毒素刺激前用GSH或NAC处理细胞1h。检测细胞内ROS水平、核因子-kappaB、AP-1和STAT-3的DNA结合活性以及COX-2的mRNA和蛋白水平。我们的结果表明，内毒素使ROS水平升高，并在2小时内达到峰值。脂多糖以时间依赖的方式激活A549细胞中的NF-kappa B、AP-1和STAT-3，并诱导COX-2的表达。硫醇抗氧化剂GSH和NAC可降低A549细胞的ROS水平，抑制其ROS水平的升高，减轻其对核因子-kappaB、AP-1和STAT-3的激活以及对COX-2的表达。综上所述，GSH和NAC通过降低肺上皮A549细胞ROS水平和抑制肺上皮A549细胞中NF-kappa B、AP-1和STAT-3的活化来抑制COX-2的表达。用硫醇抗氧化剂GSH和NAC预处理可能有利于治疗与氧化应激相关的肺部炎症。
Cyclooxygenase-2 (COX-2) plays an important role in pulmonary inflammatory response, and its expression is regulated by several transcription factors including nuclear factor kappa-B (NF-kappa B), activator protein-1 (AP-1), and signal transducer and activator of transcription-3 (STAT-3), which are activated by oxidative stress. Glutathione (GSH) and N-acetyl cysteine (NAC) are thiol antioxidants that scavenge reactive oxygen species (ROS). The present study investigated whether lipopolysaccharide (LPS) induces COX-2 expression through ROS generation and the activation of oxidant-sensitive transcription factors such as NF-kappa B, AP-1, and STAT-3 in pulmonary epithelial A549 cells. The cells were pretreated with GSH or NAC for 1 hour prior to LPS stimulation. Intracellular ROS levels, DNA-binding activities of NF-kappa B, AP-1, and STAT-3, and mRNA and protein levels of COX-2 were determined. Our results showed that LPS increased ROS levels that peaked at 2 hours. LPS activated NF-kappa B, AP-1, and STAT-3 and induced the expression of COX-2 in A549 cells in a time-dependent manner. Pretreatment of thiol antioxidants GSH and NAC reduced ROS levels and attenuated the increase in ROS, the activation of NF-kappa B, AP-1, and STAT-3, and the expression of COX-2 in LPS-treated A549 cells. In conclusion, GSH and NAC suppress COX-2 expression by reducing ROS levels and inhibiting the activation of NF-kappa B, AP-1, and STAT-3 in pulmonary epithelial A549 cells exposed to LPS. Pretreatment with thiol antioxidants GSH and NAC may be beneficial for the treatment of pulmonary inflammation associated with oxidative stress.