title: Reactive oxygen species-activated p38/ERK 1/2 MAPK signaling pathway in the Mycobacterium bovis bacillus Calmette Guérin (BCG)-induced CCL2 secretion in human monocytic cell line THP-1.
abstract: OBJECTIVE
  CCL2 plays an important role in mycobacterial infection by inducing leukocyte recruitment and activation. Here we assess the role of reactive oxygen species (ROS) in the secretion of the CCL2 and the activation of mitogen-activated protein kinases (MAPKs) by human monocytic cells infected with Mycobacterium bovis bacillus Calmette Guérin (BCG).
  
  
  METHODS
  CCL2 mRNA and protein expression were measured by reverse transcriptase polymerase chain reaction (RT-PCR), quantitative PCR and ELISA. Kinase phosphorylation was determined by immunoblotting.
  
  
  RESULTS
  Treatment of human monocytic cells with M. bovis BCG activated rapid superoxide generation. mRNA expression of CCL2 was increased in M. bovis BCG-infected monocytic cells, and this increase was abrogated by administration of the nicotinamide adenine dinucleotide phosphate (NADPH) oxidase inhibitor diphenyleneiodonium (DPI). Importantly, M. bovis BCG-induced CCL2 protein secretion was also inhibited by the NADPH oxidase inhibitor DPI, the selective inhibitor of NADPH oxidase apocynin, the mitochondrial electron transfer chain subunit I inhibitor rotenone and H(2)O(2) scavenging enzyme catalase, indicating that the inhibition is through the NADPH/ROS pathway. Analysis of downstream signals showed that inhibition of NADPH oxidase inhibited M. bovis BCG-induced phosphorylation of MAPK (extracellular signal-regulated kinase (ERK) 1/2 and p38).
  
  
  CONCLUSIONS
  These results strongly suggest that NADPH oxidase-derived ROS-mediated activation of p38 and ERK 1/2 is essential for the M. bovis BCG-induced CCL2 production.
authors.affiliation: Departamento de Inmunología, Escuela Nacional de Ciencias Biológicas, Instituto Politecnico Nacional, IPN, México, D.F., México. pmendezs@bios.encb.ipn.mx
authors.forename: Patricia
authors.initials: P
authors.lastname: Méndez-Samperio
authors.forename: Aline
authors.initials: A
authors.lastname: Pérez
authors.forename: Laura
authors.initials: L
authors.lastname: Alba
mesh_terms: D000818:Animals; D001500:BCG Vaccine / Q000494:pharmacology*; D002460:Cell Line; D018932:Chemokine CCL2 / Q000235:genetics / Q000378:metabolism*; D004789:Enzyme Activation; D016166:Free Radical Scavengers / Q000378:metabolism; D006801:Humans; D020935:MAP Kinase Signaling System / Q000502:physiology*; D019950:Mitogen-Activated Protein Kinase 1 / Q000378:metabolism*; D048052:Mitogen-Activated Protein Kinase 3 / Q000378:metabolism*; D009000:Monocytes / Q000166:cytology / Q000187:drug effects / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism*; D048051:p38 Mitogen-Activated Protein Kinases / Q000378:metabolism*
chemical_list: D001500:BCG Vaccine; D018932:Chemokine CCL2; D016166:Free Radical Scavengers; D017382:Reactive Oxygen Species; D019950:Mitogen-Activated Protein Kinase 1; D048052:Mitogen-Activated Protein Kinase 3; D048051:p38 Mitogen-Activated Protein Kinases