Pharmacology Division, CSIR-Central Drug Research Institute, Lucknow 226 001, India.
Cytometry A. 2012 Mar;81(3):238-47. doi: 10.1002/cyto.a.21178. Epub 2011 Dec 13.
Neutrophils expel extracellular traps (NETs) to entrap and exterminate the invaded micro-organisms. Acute/chronic inflammatory disorders are often observed with aberrantly enhanced NETs formation and high nitric oxide (NO) availability. Recent study from this laboratory demonstrated release of NETs from human neutrophils following treatment with SNP or SNAP. This study is an extension of our previous finding to explore the extracellular bacterial killing, source of DNA in the expelled NETs, their ability to induce proinflammatory cytokines release from platelets/THP-1 cells, and assessment of NO-mediated free radical formation by using a consistent NO donor, DETA-NONOate. NO-mediated NETs exhibited extracellular bacterial killing as determined by colony forming units. NO-mediated NETs formation was due to the activation of NADPH oxidase and myeloperoxidase. NO- or PMA-mediated NETs were positive for both nuclear and mitochondrial DNA as well as proteolytic enzymes. Incubation of NETs with human platelets enhanced the release of IL-1β and IL-8, while with THP-1 cells, release of IL-1β, IL-8, and TNFα was observed. This study demonstrates that NO by augmenting enzymatic free radical generation release NETs to promote extracellular bacterial killing. These NETs were made up of mitochondrial and nuclear DNA and potentiated release of proinflammatory cytokines.
中性粒细胞通过释放细胞外陷阱（NETs）来捕获和消灭入侵的微生物。急性/慢性炎症性疾病通常伴随着 NETs 形成异常增加和高一氧化氮（NO）可用性。本实验室最近的研究表明，SNP 或 SNAP 处理后，人中性粒细胞会释放 NETs。本研究是对我们之前发现的扩展，旨在探索细胞外细菌杀伤、释放的 NETs 中的 DNA 来源、它们诱导血小板/THP-1 细胞释放促炎细胞因子的能力，以及使用一致的 NO 供体 DETANONOate 评估 NO 介导的自由基形成。NO 介导的 NETs 通过菌落形成单位确定具有细胞外细菌杀伤作用。NO 介导的 NETs 形成是由于 NADPH 氧化酶和髓过氧化物酶的激活。NO 或 PMA 介导的 NETs 均为核 DNA 和线粒体 DNA 以及蛋白水解酶阳性。NETs 与人类血小板孵育可增强 IL-1β 和 IL-8 的释放，而与 THP-1 细胞孵育则观察到 IL-1β、IL-8 和 TNFα 的释放。这项研究表明，NO 通过增强酶促自由基生成来释放 NETs，以促进细胞外细菌杀伤。这些 NETs 由线粒体和核 DNA 组成，并增强了促炎细胞因子的释放。
