Adiponectin blocks interleukin-18-mediated endothelial cell death via APPL1-dependent AMP-activated protein kinase (AMPK) activation and IKK/NF-κB/PTEN suppression

Academic Article

Abstract

  • The adipocyte-derived cytokine adiponectin is known to exert anti-inflammatory and anti-apoptotic effects. In patients with atherosclerotic cardiovascular disease, circulating levels of adiponectin correlate inversely with those of the proinflammatory, proapoptotic cytokine interleukin (IL)-18. The opposing actions of IL-18 and adiponectin on both cell survival and inflammation led us to investigate whether adiponectin signaling antagonizes IL-18-mediated endothelial cell death and to identify the underlying molecular mechanisms. Treatment with IL-18 suppressed Akt phosphorylation and its associated kinase activity, induced IκB kinase (IKK)-NF-κB-dependent PTEN activation, and promoted endothelial cell death. Pretreatment with adiponectin stimulated APPL1-dependent AMPK activation, reversed Akt inhibition in a phosphatidylinositol 3-kinase-dependent manner, blocked IKK-NF-κB-PTEN signaling, reduced caspase-3 activity, blocked Bax translocation, and inhibited endothelial cell death. The cytoprotective effect of adiponectin signaling was recapitulated by treatment with the pharmacological AMPK activator 5-aminoimidazole-4-carboxamide-1-β-riboside. Collectively, these results demonstrated that adiponectin reverses IL-18-mediated endothelial cell death through an AMPK-associated mechanism, which may thus have therapeutic potential for diminishing IL-18-dependent vascular injury and inflammation.
  • Authors

    Published In

    Digital Object Identifier (doi)

    Author List

  • Chandrasekar B; Boylston WH; Venkatachalam K; Webster NJG; Prabhu SD; Valente AJ
  • Start Page

  • 24889
  • End Page

  • 24898
  • Volume

  • 283
  • Issue

  • 36