Kidney Research Centre, Ottawa Hospital Research Institute, Ottawa, ON, Canada K1H 8M5.
Clin Sci (Lond). 2011 Feb;120(4):131-41. doi: 10.1042/CS20100384.
The Noxes (NADPH oxidases) are a family of ROS (reactive oxygen species)-generating enzymes. Of the seven family members, four have been identified as important sources of ROS in the vasculature: Nox1, Nox2, Nox4 and Nox5. Although Nox isoforms can be influenced by the same stimulus and co-localize in cellular compartments, their tissue distribution, subcellular regulation, requirement for cofactors and NADPH oxidase subunits and ability to generate specific ROS differ, which may help to understand the multiplicity of biological functions of these oxidases. Nox4 and Nox5 are the newest isoforms identified in the vasculature. Nox4 is the major isoform expressed in renal cells and appear to produce primarily H2O2. The Nox5 isoform produces ROS in response to increased levels of intracellular Ca2+ and does not require the other NADPH oxidase subunits for its activation. The present review focuses on these unique Noxes, Nox4 and Nox5, and provides novel concepts related to the regulation and interaction in the vasculature, and discusses new potential roles for these isoforms in vascular biology.
Noxes（NADPH 氧化酶）是一类产生 ROS（活性氧）的酶。在这七个家族成员中，有四个被确定为血管中 ROS 的重要来源：Nox1、Nox2、Nox4 和 Nox5。尽管 Nox 同工酶可能受到相同刺激的影响，并在细胞区室中共定位，但它们的组织分布、亚细胞调节、对辅助因子和 NADPH 氧化酶亚基的需求以及生成特定 ROS 的能力不同，这有助于理解这些氧化酶的多种生物学功能。Nox4 和 Nox5 是在血管中最新发现的同工酶。Nox4 是在肾脏细胞中表达的主要同工酶，似乎主要产生 H2O2。Nox5 同工酶在细胞内 Ca2+水平升高时产生 ROS，并且其激活不需要其他 NADPH 氧化酶亚基。本综述重点介绍了这些独特的 Noxes，即 Nox4 和 Nox5，并提供了与血管中调节和相互作用相关的新概念，并讨论了这些同工酶在血管生物学中的新的潜在作用。
