β-adrenergic stimulation induces interleukin-18 expression via β2-AR, PI3K, Akt, IKK, and NF-κB

We investigated whether beta-adrenergic receptor (beta-AR) stimulation induces the expression of interleukin (IL)-18, a proinflammatory cytokine, in myocardium and in cardiac-derived endothelial cells (CDEC) via activation of nuclear factor (NF)-kappaB. Our results indicate that isoproterenol (ISO) activates NF-kappaB DNA binding activity, and induces myocardial and systemic elaboration of IL-18 via beta(2)-AR signaling. Furthermore, in CDEC, ISO increased basal and inducible promoter activities, increased IL-18 gene transcription and mRNA stability, and induced IL-18 expression via beta(2)-AR agonism. Signaling required G(i), PI3K, Akt, IKK, and NF-kappaB. In conclusion, our results indicate for the first time that isoproterenol induces myocardial and systemic elaboration of IL-18 via a beta(2)-AR and NF-kappaB-dependent mechanism. Similar events may occur in heart failure, a disease state characterized by sustained beta-AR activation. (C) 2004 Elsevier Inc. All rights reserved.