title: Pro-inflammatory responses in human monocytes are beta1-adrenergic receptor subtype dependent.
abstract: Stress induced circulating catecholamines are hypothesized to selectively activate adrenergic receptors (ARs) on immunocompetent cells modulating their inflammatory response to trauma or environmental toxins. We characterized changes in expression of a pro-inflammatory cytokine modulated by beta-AR activation in human primary and immortalized monocytes that had been simultaneously stimulated with lipopolysaccharide (LPS). Results from cytokine antibody arrays demonstrated that half-maximal effective concentrations of the selective beta-AR agonist isoproterenol (Iso) qualitatively increased LPS-mediated expression of the soluble cytokine, interleukin-1beta (IL-1beta). Semi-quantitative immunoblot techniques confirmed a synergistic increase of IL-1beta production in both LPS stimulated THP-1 cells and primary human monocytes co-incubated with Iso. Immunoblot techniques as well as radioligand binding studies were also used to characterize the heterogeneous expression of beta(1)- and beta(2)-AR subtypes on THP-1 cells. beta-AR activation is classically associated with generation of cAMP in many tissues and cell types. Therefore, using the method of Schild, we generated Iso concentration-response curves in the presence of fixed subtype-selective beta-AR antagonist concentrations to demonstrate that beta(1)-AR activation was exclusively linked with the generation of cAMP in THP-1 cells. Furthermore, use of a selective kinase inhibitor demonstrated that Iso potentiated the expression of soluble IL-1beta through activation of cAMP-dependent protein kinase A. Finally, discriminating concentrations of subtype-selective beta-AR antagonists revealed that beta(1)-AR stimulation alone accounted for the synergistic production of IL-1beta in LPS stimulated monocytes co-incubated with Iso. These results demonstrate a unique synergistic pro-inflammatory response mediated through a beta(1)-AR cAMP-dependent mechanism in LPS-challenged monocytic cells.
authors.affiliation: Department of Pharmacology, Physiology and Therapeutics, The University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND 58202-9037, USA.
authors.forename: Laurel A
authors.initials: LA
authors.lastname: Grisanti
authors.forename: Janel
authors.initials: J
authors.lastname: Evanson
authors.forename: Erica
authors.initials: E
authors.lastname: Marchus
authors.forename: Heather
authors.initials: H
authors.lastname: Jorissen
authors.forename: Andrew P
authors.initials: AP
authors.lastname: Woster
authors.forename: Wanda
authors.initials: W
authors.lastname: DeKrey
authors.forename: Edward R
authors.initials: ER
authors.lastname: Sauter
authors.forename: Colin K
authors.initials: CK
authors.lastname: Combs
authors.forename: James E
authors.initials: JE
authors.lastname: Porter
mesh_terms: D058671:Adrenergic beta-1 Receptor Antagonists; D001665:Binding Sites; D002457:Cell Extracts; D002460:Cell Line; D002462:Cell Membrane / Q000187:drug effects / Q000378:metabolism; D000242:Cyclic AMP / Q000096:biosynthesis; D017868:Cyclic AMP-Dependent Protein Kinases / Q000037:antagonists & inhibitors; D006801:Humans; D015151:Immunoblotting; D007249:Inflammation / Q000473:pathology*; D018836:Inflammation Mediators / Q000378:metabolism; D053583:Interleukin-1beta / Q000096:biosynthesis; D007700:Kinetics; D008070:Lipopolysaccharides / Q000494:pharmacology; D009000:Monocytes / Q000187:drug effects / Q000276:immunology* / Q000473:pathology*; D011412:Propanolamines / Q000494:pharmacology; D040081:Protein Array Analysis; D047428:Protein Kinase Inhibitors / Q000494:pharmacology; D018342:Receptors, Adrenergic, beta-1 / Q000378:metabolism*; D012044:Regression Analysis
chemical_list: D058671:Adrenergic beta-1 Receptor Antagonists; D002457:Cell Extracts; D018836:Inflammation Mediators; D053583:Interleukin-1beta; D008070:Lipopolysaccharides; D011412:Propanolamines; D047428:Protein Kinase Inhibitors; D018342:Receptors, Adrenergic, beta-1; C026777:ICI 118551; D000242:Cyclic AMP; D017868:Cyclic AMP-Dependent Protein Kinases