title: Acute alcohol exposure exerts anti-inflammatory effects by inhibiting IkappaB kinase activity and p65 phosphorylation in human monocytes.
abstract: Acute alcohol use is associated with impaired immune responses and decreased proinflammatory cytokine production. Our earlier studies have shown that acute alcohol intake inhibits NF-kappaB DNA binding in an IkappaBalpha-independent manner. We report using human peripheral blood monocytes and Chinese hamster ovary cells transfected with CD14 cells that acute alcohol treatment in vitro exerts NF-kappaB inhibition by disrupting phosphorylation of p65. Immunoprecipitation of p65 and IkappaBalpha revealed that acute alcohol exposure for 1 h decreased NF-kappaB-IkappaBalpha complexes in the cytoplasm. Phosphorylation of p65 at Ser(536) is mediated by IkappaB kinase (IKK)beta and is required for NF-kappaB-dependent cellular responses. We show that acute alcohol treatment decreased LPS-induced IKKalpha and IKKbeta activity resulting in decreased phosphorylation of p65 at Ser(536). Furthermore, nuclear expression of IKKalpha increased after alcohol treatment, which may contribute to inhibition of NF-kappaB. Decreased phosphorylation of nuclear p65 at Ser(276) was likely not due to alcohol-induced inhibition of protein kinase A and mitogen- and stress-activated protein kinase-1 activity. Although decreased IkappaBalpha phosphorylation after acute alcohol treatment was attributable to reduced IKKbeta activity, degradation of IkappaBalpha during alcohol exposure was IKKbeta-independent. Alcohol-induced degradation of IkappaBalpha in the presence of a 26S proteasome inhibitor suggested proteasome-independent IkappaBalpha degradation. Collectively, our studies suggest that acute alcohol exposure modulates IkappaBalpha-independent NF-kappaB activity primarily by affecting phosphorylation of p65. These findings further implicate an important role for IKKbeta in the acute effects of alcohol in immune cells.
authors.affiliation: Department of Medicine, University of Massachusetts Medical School, 364 Plantation Street, Worcester, MA 01605, USA.
authors.forename: Pranoti
authors.initials: P
authors.lastname: Mandrekar
authors.forename: Valentina
authors.initials: V
authors.lastname: Jeliazkova
authors.forename: Donna
authors.initials: D
authors.lastname: Catalano
authors.forename: Gyongyi
authors.initials: G
authors.lastname: Szabo
mesh_terms: D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors; D000431:Ethanol / Q000633:toxicity*; D006801:Humans; D051550:I-kappa B Kinase / Q000037:antagonists & inhibitors*; D007249:Inflammation / Q000276:immunology; D018950:Lipopolysaccharide Receptors / Q000235:genetics; D008070:Lipopolysaccharides / Q000494:pharmacology; D009000:Monocytes / Q000187:drug effects* / Q000378:metabolism; D016328:NF-kappa B / Q000187:drug effects; D010766:Phosphorylation / Q000187:drug effects; D051996:Transcription Factor RelA / Q000187:drug effects*
chemical_list: D018950:Lipopolysaccharide Receptors; D008070:Lipopolysaccharides; D016328:NF-kappa B; D051996:Transcription Factor RelA; D000431:Ethanol; D051550:I-kappa B Kinase; D017868:Cyclic AMP-Dependent Protein Kinases