Xue Zhiqiang, Yuan Wei, Li Jing, Zhou Hong, Xu Lihua, Weng Jiayi, Li Xiaoyang, Zhang Xinru, Wang Zhongqun, Yan Jinchuan
Department of Cardiology, Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu Province, People's Republic of China.
Department of Cardiology, Affiliated Hospital of Jiangsu University, Zhenjiang, Jiangsu Province, People's Republic of China.
Int J Cardiol. 2017 Mar 1;230:142-148. doi: 10.1016/j.ijcard.2016.12.042. Epub 2016 Dec 19.
Oxidized low-density lipoprotein (ox-LDL) is the most common inflammatory factor that mediates the activation and apoptosis of macrophages. Cyclophilin A (CyPA) is expressed following oxidative stress, hypoxia, and infection. However, the role of CyPA in the activation and apoptosis of macrophages is unclear. The aims of the study were to determine whether CyPA mediates the ox-LDL-induced activation and apoptosis in RAW264.7 cells and to analyze potential mechanisms.
Through Western blot and ELISA test, the expression of CyPA induced by ox-LDL is time-dependent in RAW264.7 cells. Gene silencing of CyPA reduced the generation of lipid droplets in the cytoplasm and downregulated the expression of the surface markers of macrophage activation, namely, CD80, CD86, and major histocompatibility complex class 2 antigen. Cell apoptosis is significantly decreased and the level of anti-apoptosis protein bcl-2 is increased in CyPA silent cells compared with the control group. Finally, autophagy-related protein LC3-II/LC3-I ratio level significantly decreased in CyPA silent cells with less autophagosome formation while the blocked autophagy flux was recovered. The differences in the activation and apoptosis between CyPA silent cells and the control cells were inhibited by pre-treatment with class III PI 3-kinase inhibitor 3-MA.
These results indicate that CyPA mediates the ox-LDL-induced activation and apoptosis in RAW264.7 cells by regulating autophagy.
氧化型低密度脂蛋白（ox-LDL）是介导巨噬细胞活化和凋亡的最常见炎症因子。亲环素A（CyPA）在氧化应激、缺氧和感染后表达。然而，CyPA在巨噬细胞活化和凋亡中的作用尚不清楚。本研究的目的是确定CyPA是否介导ox-LDL诱导的RAW264.7细胞活化和凋亡，并分析潜在机制。
通过蛋白质免疫印迹法和酶联免疫吸附测定试验，ox-LDL诱导的CyPA在RAW264.7细胞中的表达呈时间依赖性。CyPA基因沉默减少了细胞质中脂滴的生成，并下调了巨噬细胞活化表面标志物即CD80、CD86和主要组织相容性复合体II类抗原的表达。与对照组相比，CyPA沉默细胞中的细胞凋亡显著减少，抗凋亡蛋白bcl-2水平升高。最后，CyPA沉默细胞中自噬相关蛋白LC3-II/LC3-I比值水平显著降低，自噬体形成减少，而受阻的自噬流得以恢复。用III类磷脂酰肌醇3-激酶抑制剂3-MA预处理可抑制CyPA沉默细胞与对照细胞之间活化和凋亡的差异。
这些结果表明，CyPA通过调节自噬介导ox-LDL诱导的RAW264.7细胞活化和凋亡。
