Angiotensin II induces p67phox mRNA expression and NADPH oxidase superoxide generation in rabbit aortic adventitial fibroblasts
Angiotensin II induces p67phox mRNA expression and NADPH oxidase superoxide generation in rabbit aortic adventitial fibroblasts
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DOI：
10.1161/01.hyp.32.2.331
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发表时间：
1998-08-01
期刊：
影响因子：
8.3
通讯作者：
Clark, JK
中科院分区：
文献类型：
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作者：
Pagano, PJ;Chanock, SJ;Clark, JK
超氧阴离子自由基(O-2(-))对内皮一氧化氮的生物活性起着至关重要的作用。在血管紧张素非依赖性高血压中，血管O-2(-)水平升高并阻碍内皮/一氧化氮依赖的血管松弛。我们已经报道了兔主动脉内的主要O-2(-)来源是外膜成纤维细胞吞噬细胞样的NADPH氧化酶，并表明血管紧张素II处理外膜成纤维细胞可引起培养的兔主动脉外膜成纤维细胞中依赖于NADPH的颗粒O-2(-)浓度依赖性增加。由于Ang II的拮抗剂[Sar(1)，Thr(8)]-Ang II能逆转Ang II(10nmol/L)诱导的依赖NADH和NADPH的O-2(-)至基础水平，我们检测了氨基肽酶N抑制剂阿司他丁(10mU/L)的作用，但对Ang II刺激的O-2(-)无影响。Ang(1-7)、Ang III和Ang IV在与Ang II相似的浓度下也不能有效地刺激O-2(-)水平，动力学分析表明Ang II使NADPH氧化酶O-2(-)的产生增加，在3小时达到高峰，16小时恢复到基础水平，胞浆因子p67(Phox)似乎在转录水平和蛋白质合成水平上都受到影响，因为放线菌素和放线菌酮分别抑制了这种作用。用逆转录酶从培养的兔主动脉外膜成纤维细胞中回收了p67(Phox)的部分序列。Northern分析和核糖核酸酶保护实验表明，Ang II可在NADPH氧化酶峰值之前诱导主动脉成纤维细胞p67(Phox)mRNA的转录。这些结果表明，Ang II通过转录激活p67(Phox)刺激主动脉外膜成纤维细胞产生NAD(P)H氧化酶O-2(-)。这些数据还为NADPH氧化酶因子的调节提供了初步证据，并可能提供一种新的方法来消除O2(-)依赖型高血压的发展。
Superoxide radical (O-2(-)) is ubiquitously critical to the bioactivity of endothelial nitric oxide. In angiotens-independent hypertension, vascular O-2(-) levels rise and impede endothelium/nitric oxide-dependent vascular relaxation. We have reported that the major O-2(-) source in the rabbit aorta is adventitial fibroblast phagocyte-like NADPH oxidase and shown that angiotensin (Ang) II treatment of adventitial fibroblasts causes a concentration-dependent increase in particulate NADPH-dependent O-2(-) From cultured rabbit aortic adventitial fibroblasts treated or not treated with Ang II, we prepared particulate fractions and measured lucigenin-enhanced chemiluminescence. Because [Sar(1),Thr(8)]-Ang II, a generalized antagonist of Ang II and plausible inhibitor of the conversion of Ang II, reversed Ang LI (10 nmol/L)-induced NADH- and NADPH-dependent O-2(-) to basal levels, we tested the effect of the inhibitor of aminopeptidase N, amastatin (10 mu mol/L), and found no effect on Ang II-stimulated O-2(-). Ang(1-7), Ang III, and Ang IV also were not effective in stimulating O-2(-) levels at concentrations similar to those of Ang II, Kinetic analysis showed a rise in NADPH oxidase O-2(-) production in response to Ang II, which peaks at 3 hours and returns to basal levels by 16 hours, p67(phox), a cytosolic factor, appears to be affected at both the level of transcription and protein synthesis because actinomycin and cycloheximide individually inhibited the observed effect. A partial sequence of p67(phox) was recovered by reverse transcriptase from mRNA harvested from cultured rabbit aortic adventitial fibroblasts. Furthermore, the p67(phox) mRNA transcript in aortic fibroblasts is induced by Ang II before the peak of NADPH oxidase by Northern analysis and ribonuclease protection assays. These data suggest that Ang II stimulates NAD(P)H oxidase O-2(-) generation in fibroblasts of aortic adventitia via transcriptional activation of p67(phox). These data also provide preliminary evidence for the regulation of factors of the NADPH oxidase and potentially provide a novel means by which to abrogate the development of O-2(-)-dependent hypertension.