Regulation of NF-kappaB activation by protein phosphatase 2B and NO, via protein kinase A activity, in human monocytes.
It has been reported previously that a short synthetic immunomodulating peptide (Pa) and the neuropeptide beta-endorphin modulate the immune system. We have found now that NF-kappaB participates in the stimulation of monocytes by both peptides and we investigated the molecular mechanism by which these stimuli activate NF-kappaB. Pa and beta-endorphin induce accumulation of cyclic 3('),5(')-adenosine monophosphate (cAMP) in a calcium/calmodulin-dependent fashion since it was completely inhibited by the calmodulin antagonist W-7. The effect of these complexes seems to be mediated, at least in part, by nitric oxide (NO) synthesized by constitutive NO synthase since the NO synthase inhibitor N-methyl-L-arginine (NMLA) reduced the elevation of cAMP. Furthermore, the NO donor SIN-1 provoked nitration of G(S)alpha, leading to the cAMP elevation that was suppressed by the G(S)alpha-selective antagonist NF-449. Interestingly, the rapid degradation of NF-kappaB inhibitor IkappaBalpha induced by Pa- and beta-endorphin was reversed by a pretreatment with H-89 and cyclosporin A, inhibitors of protein kinase A (PKA) and protein phosphatase 2B (PP2B), respectively. These observations are consistent with the inhibition caused by W-7, NMLA, H-89, and cyclosporin A on NF-kappaB induction by these agonists, indicating the involvement of PKA and PP2B in the regulation of NF-kappaB in human monocytes.
Bengoechea-Alonso
M Teresa
MT
Department of Biochemistry, University of Navarra, 31080 Pamplona, Spain.
Pelacho
Beatriz
B
Osés-Prieto
Juan A
JA
Santiago
Esteban
E
López-Moratalla
Natalia
N
López-Zabalza
María J
MJ
D000595:Amino Acid Sequence; D015153:Blotting, Western; D019703:Calcineurin / Q000378:metabolism*; D002478:Cells, Cultured; D017868:Cyclic AMP-Dependent Protein Kinases / Q000378:metabolism*; D004789:Enzyme Activation; D019205:GTP-Binding Protein alpha Subunits, Gs / Q000378:metabolism; D006801:Humans; D008969:Molecular Sequence Data; D009000:Monocytes / Q000201:enzymology / Q000378:metabolism*; D016328:NF-kappa B / Q000378:metabolism*; D009566:Nitrates / Q000378:metabolism; D009569:Nitric Oxide / Q000378:metabolism*; D021122:Protein Subunits / Q000378:metabolism; D015398:Signal Transduction / Q000187:drug effects; D001615:beta-Endorphin / Q000494:pharmacology
D016328:NF-kappa B; D009566:Nitrates; D021122:Protein Subunits; D009569:Nitric Oxide; D001615:beta-Endorphin; D017868:Cyclic AMP-Dependent Protein Kinases; D019703:Calcineurin; D019205:GTP-Binding Protein alpha Subunits, Gs