Graduate School of Medical Science, Kumamoto Health Science University, Kumamoto, Japan; Graduate School of Medical Science, Kumamoto University Medical School, Kumamoto, Japan.
Graduate School of Medical Science, Kumamoto Health Science University, Kumamoto, Japan.
Heliyon. 2016 Feb 23;2(2):e00080. doi: 10.1016/j.heliyon.2016.e00080. eCollection 2016 Feb.
Interferon (IFN)-gamma is highly expressed in atherosclerotic lesions and may have an important role in atherogenesis. Myeloperoxidase (MPO), the most abundant protein in neutrophils, is a marker of plaque vulnerability and a possible bridge between inflammation and cardiovascular disease. Granulocyte-macrophage colony-stimulating factor (GM-CSF) has also been implicated in the pathogenesis of atherosclerosis. The present study investigated the role of neutrophil activation in atherosclerosis. Adherent macrophages were obtained from primary cultures of human mononuclear cells. Expression of IFN-gamma protein by GM-CSF-dependent-macrophages was investigated by enzyme-linked immunosorbent assay after stimulation with MPO. GM-CSF enhanced macrophage expression of the mannose receptor (CD206), which is involved in MPO uptake. MPO increased IFN-gamma production by GM-CSF-dependent macrophages in a concentration-dependent manner. Pretreatment of macrophages with small interfering RNA (siRNA) for CD206 or extracellular signal-regulated kinase (ERK)-2 attenuated IFN-gamma production, while siRNA for ERK-1 did not. GAPDH is known to bind to adenylate/uridylate (AU)-rich elements of RNA and may influence IFN-gamma protein expression by binding to the AU-rich element of IFN-gamma mRNA. Interestingly, pretreatment with siRNA for GAPDH significantly reduced IFN-gamma production by macrophages, while it did not affect TF protein expression. In conclusion, MPO upregulates IFN-gamma production by GM-CSF-dependent-macrophages via the CD206/ERK-2 signaling pathway, while silencing GAPDH reduces IFN-gamma production.
干扰素 (IFN)-γ在动脉粥样硬化病变中高度表达，可能在动脉粥样硬化形成中起重要作用。髓过氧化物酶 (MPO) 是中性粒细胞中最丰富的蛋白质，是斑块易损性的标志物，也是炎症与心血管疾病之间的可能桥梁。粒细胞-巨噬细胞集落刺激因子 (GM-CSF) 也与动脉粥样硬化的发病机制有关。本研究探讨了中性粒细胞激活在动脉粥样硬化中的作用。从人单核细胞的原代培养物中获得贴壁巨噬细胞。用 MPO 刺激后，通过酶联免疫吸附试验检测 GM-CSF 依赖性巨噬细胞中 IFN-γ 蛋白的表达。GM-CSF 增强了巨噬细胞甘露糖受体 (CD206) 的表达，该受体参与 MPO 的摄取。MPO 以浓度依赖的方式增加 GM-CSF 依赖性巨噬细胞中 IFN-γ 的产生。用 CD206 或细胞外信号调节激酶 (ERK)-2 的小干扰 RNA (siRNA) 预处理巨噬细胞可减弱 IFN-γ 的产生，而 ERK-1 的 siRNA 则没有。众所周知，GAPDH 与 RNA 的腺嘌呤/尿嘧啶 (AU) 丰富元件结合，通过与 IFN-γ mRNA 的 AU 丰富元件结合，可能影响 IFN-γ 蛋白的表达。有趣的是，用 GAPDH 的 siRNA 预处理可显著降低巨噬细胞中 IFN-γ 的产生，而不影响 TF 蛋白的表达。总之，MPO 通过 CD206/ERK-2 信号通路上调 GM-CSF 依赖性巨噬细胞中 IFN-γ 的产生，而沉默 GAPDH 可降低 IFN-γ 的产生。
