Institute of Medical Physics and Biophysics, Medical Faculty, Leipzig University, 04 107 Leipzig, Germany.
Int J Mol Sci. 2020 Oct 29;21(21):8057. doi: 10.3390/ijms21218057.
The heme protein myeloperoxidase (MPO) is a major constituent of neutrophils. As a key mediator of the innate immune system, neutrophils are rapidly recruited to inflammatory sites, where they recognize, phagocytose, and inactivate foreign microorganisms. In the newly formed phagosomes, MPO is involved in the creation and maintenance of an alkaline milieu, which is optimal in combatting microbes. Myeloperoxidase is also a key component in neutrophil extracellular traps. These helpful properties are contrasted by the release of MPO and other neutrophil constituents from necrotic cells or as a result of frustrated phagocytosis. Although MPO is inactivated by the plasma protein ceruloplasmin, it can interact with negatively charged components of serum and the extracellular matrix. In cardiovascular diseases and many other disease scenarios, active MPO and MPO-modified targets are present in atherosclerotic lesions and other disease-specific locations. This implies an involvement of neutrophils, MPO, and other neutrophil products in pathogenesis mechanisms. This review critically reflects on the beneficial and harmful functions of MPO against the background of immune response.
髓过氧化物酶（MPO）是一种血红素蛋白，是中性粒细胞的主要组成部分。作为先天免疫系统的关键介质，中性粒细胞被迅速募集到炎症部位，在那里它们识别、吞噬和失活外来微生物。在新形成的吞噬体中，MPO 参与碱性环境的产生和维持，这对对抗微生物是最佳的。MPO 也是中性粒细胞细胞外陷阱的关键组成部分。这些有益的特性与 MPO 及其他中性粒细胞成分从坏死细胞中释放或由于吞噬作用受阻有关。虽然 MPO 被血浆蛋白铜蓝蛋白失活，但它可以与血清和细胞外基质的负电荷成分相互作用。在心血管疾病和许多其他疾病情况下，活性 MPO 和 MPO 修饰的靶标存在于动脉粥样硬化病变和其他疾病特异性部位。这意味着中性粒细胞、MPO 和其他中性粒细胞产物参与了发病机制。本综述在免疫反应的背景下批判性地反映了 MPO 的有益和有害功能。
