Superoxide auto-augments superoxide formation and upregulates gp91phox expression in porcine pulmonary artery endothelial cells:: Inhibition by iloprost
Superoxide auto-augments superoxide formation and upregulates gp91phox expression in porcine pulmonary artery endothelial cells:: Inhibition by iloprost
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DOI：
10.1016/j.ejphar.2006.03.047
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发表时间：
2006-05-24
影响因子：
5
通讯作者：
Jeremy, Jamie Y.
中科院分区：
文献类型：
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作者：
Muzaffar, Saima;Shukla, Nilima;Jeremy, Jamie Y.
急性呼吸窘迫综合征（ARDS）的主要病因是超氧化物，其主要来源是烟酰胺腺嘌呤二核苷酸磷酸氧化酶（NADPH氧化酶）。为探讨超氧阴离子是否直接影响NADPH氧化酶的表达，用猪肺组织孵育超氧阴离子。研究了动脉内皮细胞对gp 91（phox）（NADPH氧化酶的催化亚基）表达和超氧化物形成的影响。将肺动脉内皮细胞与产生超氧化物的黄嘌呤/黄嘌呤氧化酶或肿瘤坏死因子α（TNF α）或血栓烷A（2）类似物U46619（超氧化物歧化酶[SOD]或过氧化氢酶或伊洛前列素）孵育16小时。然后洗涤细胞，通过分光光度法评估超氧化物形成，并使用蛋白质印迹法评估gp 91（phox）表达。超氧化物、TNF α和U46619在16 μ l孵育后引起肺动脉内皮细胞中超氧化物形成的增加并诱导gp 91（phox）表达，这种作用被SOD和夹竹桃素的持续存在所阻断，但不被过氧化氢酶阻断。夹竹桃素完全抑制超氧化物的形成诱导黄嘌呤/黄嘌呤氧化酶孵育16小时后。鱼藤酮和别嘌呤醇没有影响。伊洛前列素抑制超氧化物的形成和gp 91（phox）的表达。这些数据表明，超氧化物上调肺动脉内皮细胞gp 91（phox）的表达，从而增加超氧化物的形成，伊洛前列素阻断这种作用。这构成了一种新的机制，通过这种机制，血管超氧化物产生了一种自我维持的级联反应，这种级联反应可能对ARDS和其他血管病的病因学具有重要意义。(c)2006 Elsevier B. V.保留所有权利。
Central to the aetiology of Acute Respiratory Distress Syndrome (ARDS) is superoxide, the principal source of which is nicotinamide adenine dinucleotide phosphate oxidase (NADPH oxidase). To test whether superoxide may influence NADPH oxidase expression directly, the effect of incubation of superoxide with porcine pulmonary. arterial endothelial cells on the expression of gp91(phox) (a catalytic subunit of NADPH oxidase) and superoxide formation was investigated. Since iloprost has been purported to be potentially effective in treating ARDS, the effect of iloprost on superoxide-mediated effects was also studied.Pulmonary artery endothelial cells were incubated with xanthine/xanthine oxidase which generates superoxide, or tumour necrosis factor a (TNF alpha) or thromboxane A(2) analogue, U46619 ( superoxide dismutase [SOD] or catalase or iloprost) for 16 h. Cells were then washed and superoxide formation assessed spectrophometrically and gp91(phox) expression using Western blotting. The role of NADPH oxidase was also studied in the above settings using apocynin, an NADPH oxidase inhibitor.Superoxide, TNFa and U46619 elicited an increase in the formation of superoxide and induced gp91(phox) expression in pulmonary artery endothelial cells following a 16 It incubation an effect blocked by the continual presence of SOD and apocynin but not catalase. Apocynin completely inhibited superoxide formation induced with xanthine/xanthine oxidase after the 16 h incubation. Rotenone and allopurinol were without effect. Iloprost inhibited the formation of superoxide and gp91(phox) expression.These data demonstrate that superoxide upregulates gp91(phox) expression in pulmonary artery endothelial cells and thus augments superoxide formation, an effect blocked by iloprost. This constitutes a novel mechanism by which vascular superoxide creates a self-perpetuating cascade that may be of importance to the etiology of ARDS and other vasculopathies. (c) 2006 Elsevier B.V. All rights reserved.