Beta-adrenergic stimulation induces interleukin-18 expression via beta2-AR, PI3K, Akt, IKK, and NF-kappaB.

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 beta2-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 beta2-AR agonism. Signaling required GiPI3K, 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 beta2-AR and NF-kappaB-dependent mechanism. Similar events may occur in heart failure, a disease state characterized by sustained beta-AR activation.