title: Induction of ICAM-1 by Armillariella mellea is mediated through generation of reactive oxygen species and JNK activation.
abstract: BACKGROUND
  Armillariella mellea is an edible mushroom that has been traditionally used as an alternative medicine in many countries because of its anti-microbial and anti-cancer effects.
  
  
  OBJECTIVE
  In this study, we examined the ability of Armillariella mellea to induce the expression of intercellular adhesion molecule (ICAM)-1, an important cellular adhesion molecule for the recruitment of immune cells to regional inflammatory sites.
  
  
  METHODS
  A human monocytic cell line, THP-1 or human peripheral blood mononuclear cells (PBMC) were stimulated with Armillariella mellea extract (AME) and subjected to flow cytometry to examine the expression of ICAM-1 protein on the cell surface. Steady-state mRNA level of ICAM-1 was determined by real-time reverse transcription-polymerase chain reaction. The phosphorylation of JNK protein was examined by Western blot analysis using antibodies specific for non-phosphorylated and phosphorylated forms of JNK. For the analysis of transcription factors regulating ICAM-1 transcription, the nuclear fraction was extracted from AME-treated THP-1 cells and subjected to electrophoretic mobility shift assay.
  
  
  RESULTS
  AME induced expression of ICAM-1 and its mRNA in THP-1 cells in dose- and time-dependent manners. AME-induced ICAM-1 expression was also observed on CD14-positive monocytes in human PBMC. Interestingly, AME-induced ICAM-1 production was inhibited by the specific inhibitors of reactive oxygen species (ROS) and JNK, whereas no inhibitory effect was observed when inhibitors of ERK, p38 kinase, phosphatidylinositol 3-kinase, or protein kinase C were used. Concomitantly, AME increased phosphorylation of JNK in a time-dependent fashion. DNA binding activities of NF-kappaB, AP-1, SP-1, and STAT-1 were increased by AME treatment.
  
  
  CONCLUSIONS
  These results suggest that AME induces ICAM-1 expression in human monocytic cells through ROS/JNK-dependent signaling pathways leading to the activation of NF-kappaB, AP-1, SP-1, and STAT-1 transcription factors.
authors.affiliation: Department of Oral Microbiology and Immunology, Dental Research Institute, and BK21 Program, School of Dentistry, Seoul National University, Seoul 110-749, Republic of Korea.
authors.forename: Young Sook
authors.initials: YS
authors.lastname: Kim
authors.forename: Jintaek
authors.initials: J
authors.lastname: Im
authors.forename: Jung Nam
authors.initials: JN
authors.lastname: Choi
authors.forename: Seok-Seong
authors.initials: SS
authors.lastname: Kang
authors.forename: Yeo Jin
authors.initials: YJ
authors.lastname: Lee
authors.forename: Choong Hwan
authors.initials: CH
authors.lastname: Lee
authors.forename: Cheol-Heui
authors.initials: CH
authors.lastname: Yun
authors.forename: Chang Gue
authors.initials: CG
authors.lastname: Son
authors.forename: Seung Hyun
authors.initials: SH
authors.lastname: Han
mesh_terms: D000363:Agaricales; D001483:Base Sequence; D015153:Blotting, Western; D002460:Cell Line; D017931:DNA Primers; D004789:Enzyme Activation; D005434:Flow Cytometry; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D018799:Intercellular Adhesion Molecule-1 / Q000096:biosynthesis*; D048670:MAP Kinase Kinase 4 / Q000378:metabolism*; D017382:Reactive Oxygen Species / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction
chemical_list: D017931:DNA Primers; D017382:Reactive Oxygen Species; D018799:Intercellular Adhesion Molecule-1; D048670:MAP Kinase Kinase 4