GM-CSF increases AP-1 DNA binding and Ref-1 amounts in human alveolar macrophages.
Alveolar macrophages have been implicated in the pathogenesis of a number of acute and chronic lung disorders. A characteristic feature of many of the chronic lung diseases is that the types of macrophages in the lung change, and in most instances, the cells resemble monocyte-like cells. We have previously shown that normal human alveolar macrophages have a decreased capacity to express protein kinase C (PKC)-induced DNA binding activity of the transcription factor activator protein (AP)-1 compared with monocytes. This decrease in AP-1 DNA binding appears to be due to a defect in redox regulation of AP-1 proteins via a decrease in the redox active protein Ref-1. The hypothesis for this study is that there are factors generated during the development of chronic lung disease that increase AP-1 DNA binding activity and Ref-1 production in human alveolar macrophages. We have focused specifically on granulocyte-macrophage colony-stimulating factor (GM-CSF) as a prototype mediator that can be released by alveolar macrophages and is related to the fibrotic process in the lung. We found that after a 24-h incubation with GM-CSF, AP-1 DNA binding was significantly increased in both unstimulated, interleukin (IL)-13, and phorbol myristate acetate (PMA)-stimulated alveolar macrophages and that there was a corresponding increase in Ref-1 protein by Western blot analysis in the PMA-stimulated group. This suggests that disease-related cytokines such as GM-CSF and IL-13 may modulate AP-1 DNA binding activity in alveolar macrophages.
Flaherty
D M
DM
Department of Internal Medicine, University of Iowa College of Medicine and Veterans Administration Medical Center, Iowa City, Iowa 52242, USA. flahertydm@mail.medicine.uiowa.edu
Monick
M M
MM
Carter
A B
AB
Peterson
M W
MW
Hunninghake
G W
GW
D001483:Base Sequence; D019757:Carbon-Oxygen Lyases / Q000378:metabolism*; D004247:DNA / Q000235:genetics / Q000378:metabolism*; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase; D016178:Granulocyte-Macrophage Colony-Stimulating Factor / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D066298:In Vitro Techniques; D018793:Interleukin-13 / Q000008:administration & dosage / Q000494:pharmacology; D016676:Macrophages, Alveolar / Q000187:drug effects* / Q000378:metabolism*; D010084:Oxidation-Reduction; D016760:Proto-Oncogene Proteins c-fos / Q000378:metabolism; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D018808:Transcription Factor AP-1 / Q000235:genetics / Q000378:metabolism*
D018793:Interleukin-13; D016760:Proto-Oncogene Proteins c-fos; D016755:Proto-Oncogene Proteins c-jun; D018808:Transcription Factor AP-1; D016178:Granulocyte-Macrophage Colony-Stimulating Factor; D004247:DNA; D019757:Carbon-Oxygen Lyases; C085108:APEX1 protein, human; D043603:DNA-(Apurinic or Apyrimidinic Site) Lyase; D013755:Tetradecanoylphorbol Acetate