β-arrestin2 Mediates the Arginine Vasopressin-Induced Expression of IL-1β in Murine Hearts.

BACKGROUND Circulating levels of arginine vasopressin (AVP) are elevated during cardiac stress and this could be a factor in cardiac inflammation and fibrosis. Herein, we studied the effects of AVP on interleukin-1β (IL-1β) production and the role(s) of β-arrestin2-dependent signaling in murine heart. METHODS The levels of IL-1β mRNA and protein in adult rat cardiofibroblasts (ARCFs) was measured using quantitative PCR and ELISA, respectively. The activity of β-arrestin2 was manipulated using either pharmacologic inhibitors or through recombinant β-arrestin2 over-expression. These experiments were conducted to determine the roles of β-arrestin2 in the regulation of AVP-induced IL-1β and NLRP3 inflammasome production. The phosphorylation and activation of NF-κB induced by AVP was measured by immunoblotting. β-arrestin2 knockout (KO) mice were used to investigate whether β-arrestin2 mediated the AVP-induced production of IL-1β and NLRP3, as well as the phosphorylation of the NF-κB p65 subunitin mouse myocardium. Prism GraphPad software(version 8.0), was used for all statistical analyses. RESULTS AVP induced the expression of IL-1β in a time-dependent manner in ARCFs but not in cultured adult rat cardiomyocytes (ARCMs). The inhibition of NF-κB with pyrrolidinedithiocarbamic acid (PDTC) prevented the AVP-induced phosphorylation of NF-κB and production of IL-1β and NLRP3 in ARCFs. The deletion of β-arrestin2 blocked the phosphorylation of p65 and the expression of NLRP3 and IL-1β induced by AVP in both mouse hearts and in ARCFs. CONCLUSIONS AVP promotes IL-1β expression through β-arrestin2-mediated NF-κB signaling in murine heart.