Nox4 Is a Major Source of Superoxide Production in Human Brain Pericytes
Nox4 Is a Major Source of Superoxide Production in Human Brain Pericytes
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DOI：
10.1159/000369930
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发表时间：
2014-01-01
影响因子：
1.7
通讯作者：
Kitazono, Takanari
中科院分区：
文献类型：
--
作者：
Kuroda, Junya;Ago, Tetsuro;Kitazono, Takanari
背景：周细胞是毛细血管和毛细血管后微静脉周围的多功能细胞。在脑微血管系统中，周细胞通过产生活性氧（reactive oxygen species，ROS）在生理和病理条件下发挥重要作用，本研究旨在阐明人脑周细胞ROS的来源及其调控。方法：采用RT-PCR和western blot检测细胞中Nox酶的表达。超氧化物歧化酶-化学发光法测定超氧化物的产生。使用RNAi进行Nox 4的沉默，并使用3-（4，5-二甲基噻唑-2-基）-5-（3-羧基甲氧基苯基）-2-（4-磺基苯基）-2H-四唑鎓（MTS）测定评价细胞增殖。结果：Nox 4在人脑周细胞中占优势。细胞膜组分在NAD（P）H存在下产生超氧化物。用氮氧化物抑制剂diphenileneiodonium几乎消除了超氧化物的产生;然而，其他可能的超氧化物产生酶的抑制剂对NAD（P）H依赖的超氧化物的产生没有影响。周细胞表达血管紧张素II（Ang II）受体，和Ang II上调Nox 4的表达。低氧条件也增加了Nox 4的表达。Nox 4的沉默显著降低了ROS的产生并减弱了细胞增殖。结论：我们的研究表明，Nox 4是一种主要的超氧化物产生酶，其表达受血管紧张素II和缺氧应激的人脑周细胞。此外，Nox 4还可以促进细胞生长。(C)2015 S. Karger AG，巴塞尔
Background: Pericytes are multifunctional cells surrounding capillaries and postcapillary venules. In brain microvasculature, pericytes play a pivotal role under physiological and pathological conditions by producing reactive oxygen species (ROS).The aims of this study were to elucidate the source of ROS and its regulation in human brain pericytes. Methods: The expression of Nox enzymes in the cells was evaluated using RT-PCR and western blot. Superoxide production was determined by superoxide dismutase-inhibitable chemiluminescence. Silencing of Nox4 was performed using RNAi, and cell proliferation was evaluated using the 3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxyrnethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium (MTS) assay. Results: Nox4 was predominant among the Nox family in human brain pericytes. Membrane fractions of cells produced superoxide in the presence of NAD(P)H. Superoxide production was almost abolished with diphenileneiodonium, a Nox inhibitor; however, inhibitors of other possible superoxide-producing enzymes had no effect on NAD(P)H-dependent superoxide production. Pericytes expressed angiotensin II (Ang II) receptors, and Ang II upregulated Nox4 expression. Hypoxic conditions also increased the Nox4 expression. Silencing of Nox4 significantly reduced ROS production and attenuated cell proliferation. Conclusion: Our study showed that Nox4 is a major superoxide-producing enzyme and that its expression is regulated by Ang II and hypoxic stress in human brain pericytes. In addition, Nox4 may promote cell growth. (C) 2015 S. Karger AG, Basel