title: Cordycepin negatively modulates lipopolysaccharide-induced cytokine production by up-regulation of heme oxygenase-1.
abstract: OBJECTIVE
  The present study is to investigate the effect of cordycepin on the expression of heme oxygenase-1 (HO-1) in lipopolysaccharide (LPS)-activated microphages, as well as its mechanism of action.
  
  
  METHODS
  Mouse RAW264.7 cells were treated with different concentrations of cordycepin for 0-16h. Western blotting was used to determine the expression of HO-1 and the phosphorylation of c-Src and the p47phoxsubunit of NADPH oxidase. Intracellular reactive oxygen species (ROS) level was determined using H2DCFDA as fluorescent probe. Laser-scanning confocal microscopy was used to visualize the nuclear translocation of NF-E2-related factor 2 (Nrf2). Enzyme-linked immunosorbent assay was performed to measure the inhibitory effect of cordycepin on LPS-induced secretion of tumor necrosis factor-α and interleukin-6.
  
  
  RESULTS
  Cordycepin induced the phosphorylation of c-Src and p47phoxsubunit of NADPH oxidase in RAW264.7 cells. Cordycepin increased the secretion of ROS by activating NADPH oxidase. In addition, cordycepin enhanced the expression of HO-1 in RAW264.7 cells in both dose- and time-dependent manners. Of note, elevated HO-1 expression induced by cordycepin treatment was regulated by c-Src/NADPH oxidase/ROS pathway. HO-1 expression induced by cordycepin was dependent on the activation of Nrf2, which was regulated by c-Src/NADPH oxidase/ROS. Cordycepin reduced LPS-induced secretion of proinflammatory cytokines through up-regulation of HO-1.
  
  
  CONCLUSIONS
  The present study demonstrates that cordycepin induces the expression of HO-1 in RAW264.7 cells via c-Src/NADPH oxidase/ROS/Nrf2 pathway, and plays an anti-inflammatory role by inhibiting the secretion of cytokines from macrophages.
authors.affiliation: Division of Pathogenic Biology, Department of Laboratory Medicine, Shaoyang University, Shaoyang, PR China.
authors.forename: Rui
authors.initials: R
authors.lastname: Qing
authors.affiliation: Division of Pathogenic Biology, Department of Laboratory Medicine, Shaoyang University, Shaoyang, PR China.
authors.forename: Zezhi
authors.initials: Z
authors.lastname: Huang
authors.affiliation: Division of Pathogenic Biology, Department of Laboratory Medicine, Shaoyang University, Shaoyang, PR China.
authors.forename: Yufei
authors.initials: Y
authors.lastname: Tang
authors.affiliation: Division of Pathogenic Biology, Department of Laboratory Medicine, Shaoyang University, Shaoyang, PR China.
authors.forename: Qingke
authors.initials: Q
authors.lastname: Xiang
authors.affiliation: Department of Basic Medicine, Xiangnan University, Chenzhou, PR China. Electronic address: big_young@aliyun.com.
authors.forename: Fan
authors.initials: F
authors.lastname: Yang
mesh_terms: D000818:Animals; D000893:Anti-Inflammatory Agents / Q000494:pharmacology*; D000081247:CSK Tyrosine-Protein Kinase; D016207:Cytokines / Q000378:metabolism; D003839:Deoxyadenosines / Q000494:pharmacology*; D051547:Heme Oxygenase-1 / Q000235:genetics / Q000378:metabolism*; D008070:Lipopolysaccharides / Q000276:immunology; D008264:Macrophages / Q000187:drug effects / Q000276:immunology*; D051379:Mice; D009249:NADP / Q000378:metabolism; D051267:NF-E2-Related Factor 2 / Q000378:metabolism; D000067996:RAW 264.7 Cells; D017382:Reactive Oxygen Species / Q000378:metabolism; D015398:Signal Transduction; D015854:Up-Regulation; D019061:src-Family Kinases / Q000378:metabolism
chemical_list: D000893:Anti-Inflammatory Agents; D016207:Cytokines; D003839:Deoxyadenosines; D008070:Lipopolysaccharides; D051267:NF-E2-Related Factor 2; C495636:Nfe2l2 protein, mouse; D017382:Reactive Oxygen Species; D009249:NADP; D051547:Heme Oxygenase-1; D000081247:CSK Tyrosine-Protein Kinase; D019061:src-Family Kinases; C058120:cordycepin
keywords: Cordycepin; Heme oxygenase-1; Macrophages