Lavigne M C, Malech H L, Holland S M, Leto T L
Laboratory of Host Defenses, National Institutes of Health, National Institute of Allergy and Infectious Diseases, Bethesda, Md, USA.
Circulation. 2001 Jul 3;104(1):79-84. doi: 10.1161/01.cir.104.1.79.
Previous investigations provide evidence that an enzyme related to the phagocyte NADPH oxidase produces superoxide in the blood vessel wall. These data, however, are confounded by observations that both NADPH and NADH serve as substrates for superoxide production in vascular cells. To clarify this issue, we compared the superoxide-generating capabilities of vascular smooth muscle cells (VSMCs) derived from wild-type (p47phox(+/+); phagocyte oxidase) mice with those from mice that lack p47phox (p47phox(-/-); "knockout"), an essential component of the phagocyte NADPH oxidase.
VSMCs were derived from aortic explants harvested from p47phox(+/+) or p47phox(-/-) mice. VSMCs from p47phox(+/+) but not those from p47phox(-/-) mice produced superoxide after stimulation by phorbol myristate acetate. Consistent with this, p47phox was detected only in p47phox(+/+) VSMCs. p47phox-transduced p47phox(-/-) but not enhanced green fluorescent protein-transduced p47phox(-/-) VSMCs generated significant levels of superoxide after stimulation by angiotensin II or platelet-derived growth factor-BB (PDGF-BB). Enhanced expression of recombinant p47phox in p47phox-transduced p47phox(-/-) cells correlated with superoxide production in these cells.
These data provide direct functional proof that an oxidase requiring the p47phox component mediates superoxide release from VSMCs in the blood vessel wall in response to angiotensin II or PDGF-BB.
先前的研究表明，一种与吞噬细胞NADPH氧化酶相关的酶可在血管壁中产生超氧化物。然而，这些数据因以下观察结果而变得复杂：NADPH和NADH均可作为血管细胞中超氧化物产生的底物。为了阐明这一问题，我们比较了野生型（p47phox(+/+)；吞噬细胞氧化酶）小鼠来源的血管平滑肌细胞（VSMC）与缺乏p47phox（p47phox(-/-)；“敲除”）的小鼠来源的VSMC产生超氧化物的能力，p47phox是吞噬细胞NADPH氧化酶的一个重要组成部分。
VSMC取自p47phox(+/+)或p47phox(-/-)小鼠的主动脉外植体。佛波酯肉豆蔻酸酯刺激后，p47phox(+/+)小鼠的VSMC产生了超氧化物，而p47phox(-/-)小鼠的VSMC则未产生。与此一致的是，仅在p47phox(+/+) VSMC中检测到了p47phox。血管紧张素II或血小板衍生生长因子-BB（PDGF-BB）刺激后，转导p47phox的p47phox(-/-) VSMC产生了显著水平的超氧化物，而转导增强型绿色荧光蛋白的p47phox(-/-) VSMC则未产生。转导p47phox的p47phox(-/-)细胞中重组p47phox的表达增强与这些细胞中超氧化物的产生相关。
这些数据提供了直接的功能证据，表明一种需要p47phox成分的氧化酶可介导血管壁中的VSMC在血管紧张素II或PDGF-BB刺激下释放超氧化物。
