Mechanistic role of cytochrome P450 (CYP)1B1 in oxygen-mediated toxicity in pulmonary cells: A novel target for prevention of hyperoxic lung injury.
Mechanistic role of cytochrome P450 (CYP)1B1 in oxygen-mediated toxicity in pulmonary cells: A novel target for prevention of hyperoxic lung injury.
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DOI：
10.1016/j.bbrc.2016.05.125
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发表时间：
2016-08-05
影响因子：
3.1
通讯作者：
Moorthy B
中科院分区：
文献类型：
--
作者：
Dinu D;Chu C;Veith A;Lingappan K;Couroucli X;Jefcoate CR;Sheibani N;Moorthy B
补充氧气是早产儿肺功能不全的常规治疗，会导致这些早产儿的支气管肺发育不良(BPD)。高氧还会导致成人的急性肺损伤(ALI)和急性呼吸窘迫综合征(ARDS)。氧介导的肺毒性的机制尚不完全清楚。最近的研究表明细胞色素P450(CYP)1A1/1A2在保护高氧性肺损伤中起重要作用。CYP1B1在氧介导的肺毒性中的作用还没有研究。在本研究中，我们验证了细胞色素P4501B1在体外肺细胞氧毒中起机制作用的假说。在人支气管上皮细胞系BEAS-2B中，高氧处理1-3天，细胞存活率下降约50-80%。高氧细胞毒性伴随着活性氧(ROS)水平增加高达110%，TUNEL阳性细胞增加高达4.8倍。Western印迹分析显示，高氧可显著下调细胞色素P4501B1蛋白水平。此外，细胞色素P1B1基因的表达水平下降了38%，其启动子活性下降了65%。另一方面，CyP1B1 siRNA对高氧应激下的细胞活力有明显的挽救作用，过表达的CyP1B1可显著减轻高氧培养48h后的细胞毒性。在细胞色素P4501B1基因缺失的永生化肺内皮细胞和野生型小鼠肺内皮细胞中，高氧诱导的caspase3/7活性呈时间依赖性升高，而缺乏细胞色素P1B1基因的内皮细胞培养48h和72h后caspase3/7活性显著降低，提示高氧应激可促进野生型肺内皮细胞的凋亡。综上所述，我们的研究结果支持了细胞色素P450 1B1在肺氧中毒中起机制作用的假说，并且细胞色素P1B1介导的细胞凋亡可能是氧中毒的机制之一。因此，CYP1B1可能成为预防和/或治疗婴儿BPD和成人ALI/ARDS的新靶点。
Supplemental oxygen, which is routinely administered to preterm infants with pulmonary insufficiency, contributes to bronchopulmonary dysplasia (BPD) in these infants. Hyperoxia also contributes to the development of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) in adults. The mechanisms of oxygen-mediated pulmonary toxicity are not completely understood. Recent studies have suggested an important role for cytochrome P450 (CYP)1A1/1A2 in the protection against hyperoxic lung injury. The role of CYP1B1 in oxygen-mediated pulmonary toxicity has not been studied. In this investigation, we tested the hypothesis that CYP1B1 plays a mechanistic role in oxygen toxicity in pulmonary cells in vitro. In human bronchial epithelial cell line BEAS-2B, hyperoxic treatment for 1–3 days led to decreased cell viability by about 50–80%. Hyperoxic cytotoxicity was accompanied by an increase in levels of reactive oxygen species (ROS) by up to 110%, and an increase of TUNEL-positive cells by up to 4.8-fold. Western blot analysis showed hyperoxia to significantly down-regulated CYP1B1 protein level. Also, there was a decrease of CYP1B1 mRNA by up to 38% and Cyp1b1 promoter activity by up to 65%. On the other hand, CYP1B1 siRNA appeared to rescue the cell viability under hyperoxia stress, and overexpression of CYP1B1 significantly attenuated hyperoxic cytotoxicity after 48 h of incubation. In immortalized lung endothelial cells derived from Cyp1b1-null and wild-type mice, hyperoxia increased caspase 3/7 activities in a time-dependent manner, but endothelial cells lacking the Cyp1b1 gene showed significantly decreased caspase 3/7 activities after 48 and 72 h of incubation, implying that CYP1B1 might promote apoptosis in wild type lung endothelial cells under hyperoxic stress. In conclusion, our results support the hypothesis that CYP1B1 plays a mechanistic role in pulmonary oxygen toxicity, and CYP1B1-mediated apoptosis could be one of the mechanisms of oxygen toxicity. Thus, CYP1B1 could be a novel target for preventative and/or therapeutic interventions against BPD in infants and ALI/ARDS in adults.