Verchier Yann, Lardy Bernard, Nguyen Minh Vu Chuong, Morel Françoise, Arbault Stéphane, Amatore Christian
Laboratoire PASTEUR, Ecole Normale Supérieure, CNRS UMR 8640, Département de Chimie, 24 rue Lhomond, 75005 Paris, France.
Biochem Biophys Res Commun. 2007 Sep 21;361(2):493-8. doi: 10.1016/j.bbrc.2007.07.041. Epub 2007 Jul 20.
Oxidative stress is a metabolic situation used by immune cells to provide protection against infection. Under activation by threatening elements, phagocytes produce chemically toxic molecules, namely the reactive oxygen species (ROS) and reactive nitrogen species (RNS). This mechanism involves two types of enzymes: NAPDH oxidases (NOX) and NO synthases (NOS), which activities are versatile and not fully understood yet. In this regard, we studied in real-time the release of bursts of ROS and RNS by single PLB-985 cells, originating from a myeloid cell line prone to differentiate into neutrophil or monocyte-like phagocytes. A selective electrochemical detection of each ROS or RNS was conducted at platinized carbon fiber microelectrodes positioned at micrometric distances from single cells. Our results show (1) the existence of a NO synthase activity in PLB-985 cells and (2) the ability of NO synthases to provide a NOX activity in cells where NADPH oxidase (NOX2) is knocked out.
氧化应激是免疫细胞用来提供抗感染保护的一种代谢状态。在受到威胁因素激活时，吞噬细胞会产生化学毒性分子，即活性氧（ROS）和活性氮（RNS）。这一机制涉及两种类型的酶：烟酰胺腺嘌呤二核苷酸磷酸氧化酶（NOX）和一氧化氮合酶（NOS），它们的活性具有多样性且尚未完全被了解。在这方面，我们实时研究了源自易于分化为中性粒细胞或单核细胞样吞噬细胞的髓系细胞系的单个PLB - 985细胞释放ROS和RNS的爆发情况。在距离单个细胞微米级距离处放置的镀铂碳纤维微电极上对每种ROS或RNS进行了选择性电化学检测。我们的结果表明：（1）PLB - 985细胞中存在一氧化氮合酶活性；（2）在烟酰胺腺嘌呤二核苷酸磷酸氧化酶（NOX2）被敲除的细胞中，一氧化氮合酶具有提供NOX活性的能力。
