title: Activation of AMPA receptor promotes TNF-α release via the ROS-cSrc-NFκB signaling cascade in RAW264.7 macrophages.
abstract: The relationship between glutamate signaling and inflammation has not been well defined. This study aimed to investigate the role of AMPA receptor (AMPAR) in the expression and release of tumor necrosis factor-alpha (TNF-α) from macrophages and the underlying mechanisms. A series of approaches, including confocal microscopy, immunofluorescency, flow cytometry, ELISA and Western blotting, were used to estimate the expression of AMPAR and downstream signaling molecules, TNF-α release and reactive oxygen species (ROS) generation in the macrophage-like RAW264.7 cells. The results demonstrated that AMPAR was expressed in RAW264.7 cells. AMPA significantly enhanced TNF-α release from RAW264.7 cells, and this effect was abolished by CNQX (AMPAR antagonist). AMPA also induced elevation of ROS production, phosphorylation of c-Src and activation of nuclear factor (NF)-κB in RAW264.7 cells. Blocking c-Src by PP2, scavenging ROS by glutathione (GSH) or inhibiting NF-κB activation by pyrrolidine dithiocarbamate (PDTC) decreased TNF-α production from RAW264.7 cells. We concluded that AMPA promotes TNF-α release in RAW264.7 macrophages likely through the following signaling cascade: AMPAR activation → ROS generation → c-Src phosphorylation → NF-κB activation → TNF-α elevation. The study suggests that AMPAR may participate in macrophage activation and inflammation.
authors: Department of Physiology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, China.
authors: Xiu-Li
authors: XL
authors: Cheng
authors: Office of Scientific R&D, Tsinghua University, Beijing, China.
authors: Fan
authors: F
authors: Ding
authors: Department of Physiology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, China.
authors: Hui
authors: H
authors: Li
authors: Department of Physiology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, China.
authors: Xiao-Qiu
authors: XQ
authors: Tan
authors: Department of Pathophysiology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, China.
authors: Xiao
authors: X
authors: Liu
authors: Department of Physiology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, China. Electronic address: caojimin@126.com.
authors: Ji-Min
authors: JM
authors: Cao
authors: Department of Pathophysiology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, China. Electronic address: longlongnose@163.com.
authors: Xue
authors: X
authors: Gao
mesh_terms: D000818:Animals; D000081247:CSK Tyrosine-Protein Kinase; D002460:Cell Line; D008262:Macrophage Activation; D008264:Macrophages / Q000166:cytology / Q000276:immunology*; D051379:Mice; D016328:NF-kappa B / Q000276:immunology*; D017382:Reactive Oxygen Species / Q000276:immunology*; D018091:Receptors, AMPA / Q000276:immunology*; D015398:Signal Transduction; D014409:Tumor Necrosis Factor-alpha / Q000276:immunology*; D019061:src-Family Kinases / Q000276:immunology*
chemical_list: D016328:NF-kappa B; D017382:Reactive Oxygen Species; D018091:Receptors, AMPA; D014409:Tumor Necrosis Factor-alpha; D000081247:CSK Tyrosine-Protein Kinase; D019061:src-Family Kinases
keywords: AMPA receptor; Inflammation; Macrophage; NF-κB; Reactive oxygen species; TNF-α