Effect of a synthetic lipid immunomodulator on the regulation of the transcription factor NF-kappaB.
Macrophage activation plays a central role in host defense against a variety of pathogens via inducible messengers. The transcription factor NF-kappaB controls the synthesis of cytokines involved in immune responses. In quiescent cells, NF-kappaB is located in the cytosol bound to an inhibitor IkappaB. Upon appropriate signal, NF-KB translocates to the nucleus and binds to DNA. The present study investigated the involvement of an immunomodulator, (diHDA-glycerol) on the NF-kappaB/IkappaB complex. Results were compared to those obtained with lipopolysaccharide (LPS) as a major virulence factor in bacterial sepsis. Data showed that exposure of J774.1 cells either to LPS or diHDA-glycerol substantially increased with time the nuclear levels of NF-kappaB complexes. Antibodies to various NF-kappaB proteins supershifted p50, p65 and to a lesser extent c-rel. Western blot analyses showed a rapid cytosolic IkappaB-alpha turn over following LPS exposure in contrast to diHDA-glycerol treatment. Further experiments investigated the involvement of protein kinase C (PKC) by using two inhibitors, staurosporine and H7. Pretreatment of J774.1 with either inhibitor prior to diHDA-glycerol or LPS exposure decreased NF-kappaB activation. Our results indicate that diHDA-glycerol was acting on NF-kappaB through IkappaB regulative mechanisms differing from those used by LPS. DiHDA-glycerol is likely acting on many other transcription factors targeting distinct genes implied in up regulation of the immune system.
Pollet
S
S
Centre de Recherches du Service de Santé des Armées, La Tronche, France.
Bottex-Gauthier
C
C
Picot
F
F
Potier
P
P
Vidal
D
D
Favier
A
A
D000276:Adjuvants, Immunologic / Q000494:pharmacology*; D000818:Animals; D001483:Base Sequence; D002460:Cell Line; D004268:DNA-Binding Proteins / Q000378:metabolism; D005995:Glyceryl Ethers / Q000494:pharmacology*; D020672:I-kappa B Proteins; D008070:Lipopolysaccharides / Q000494:pharmacology; D008262:Macrophage Activation / Q000187:drug effects; D008264:Macrophages / Q000187:drug effects / Q000276:immunology / Q000378:metabolism; D051379:Mice; D000072000:NF-KappaB Inhibitor alpha; D016328:NF-kappa B / Q000378:metabolism*; D015345:Oligonucleotide Probes / Q000235:genetics / Q000378:metabolism; D011493:Protein Kinase C / Q000378:metabolism
C421303:1-(2-methoxyethoxymethyl)-2,3-(10-hydroxy-2-decenoyl)glycerol; D000276:Adjuvants, Immunologic; D004268:DNA-Binding Proteins; D005995:Glyceryl Ethers; C083487:I kappa B beta protein; D020672:I-kappa B Proteins; D008070:Lipopolysaccharides; D016328:NF-kappa B; C000606205:Nfkbia protein, mouse; D015345:Oligonucleotide Probes; D000072000:NF-KappaB Inhibitor alpha; D011493:Protein Kinase C