Digitoxin elicits anti-inflammatory and vasoprotective properties in endothelial cells: Therapeutic implications for the treatment of atherosclerosis?

Atherosclerosis. 2009 Oct;206(2):390-6. doi: 10.1016/j.atherosclerosis.2009.03.019. Epub 2009 Mar 25.

Abstract

Pro-inflammatory processes initiated in the endothelium represent a crucial step in the pathogenesis of inflammatory cardiovascular disease, such as atherosclerosis. Recent observations pointed to potential anti-inflammatory properties of the cardiac glycoside digitoxin. Therefore, the present study investigated potential anti-inflammatory and vasoprotective properties of digitoxin as well as the underlying signaling pathways affected in endothelial cells (EC). Digitoxin, employing therapeutical concentrations used in patients (3-30nM), potently inhibited the IL-1beta-induced expression of MCP-1 and VCAM-1 in EC and the capacity of corresponding cell culture supernatants on monocyte migration as well as monocyte adhesion to endothelial monolayers, respectively. Furthermore, digitoxin prevented the IL-1beta-induced activation of p44/42-MAPK and NF-kappaB without affecting activation of JNK and p38-MAPK. Inhibition of NF-kappaB signaling but not p44/42-MAPK mimicked the observed inhibitory effects of digitoxin on MCP-1 expression and monocyte migration. Moreover, digitoxin inhibited NF-kappaB signaling at the level of TAK-1/IKK. Additionally, digitoxin prevented TNF-alpha-induced apoptosis in EC accompanied by activation of Akt. Blockade of PI-3-kinase, activator of Akt, prevented the anti-apoptotic properties of digitoxin and impaired its inhibitory action on NF-kappaB signaling and MCP-1 expression. Finally, digitoxin activated endothelial NO-synthase, which was blocked by inhibition of PI-3-kinase, Ca(2+)/Calmodulin-dependent-proteinkinase-II and chelation of intracellular calcium. Digitoxin elicits anti-inflammatory and vasoprotective properties by blocking NF-kappaB and activating PI-3-kinase/Akt signaling as well as Ca(2+)/Calmodulin-dependent-proteinkinase-II in EC. These observations indicate a potential therapeutical application of digitoxin in the treatment of cardiovascular diseases, such as atherosclerosis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Anti-Inflammatory Agents / pharmacology*
  • Atherosclerosis / metabolism
  • Cell Adhesion / drug effects
  • Cells, Cultured
  • Digitoxin / pharmacology*
  • Digoxin / pharmacology
  • Endothelial Cells / drug effects*
  • Enzyme Activation / drug effects
  • Humans
  • I-kappa B Kinase / antagonists & inhibitors
  • Interleukin-1beta / antagonists & inhibitors
  • Interleukin-1beta / pharmacology
  • JNK Mitogen-Activated Protein Kinases / metabolism
  • Mitogen-Activated Protein Kinase 1 / metabolism
  • Mitogen-Activated Protein Kinase 3 / metabolism
  • NF-kappa B / antagonists & inhibitors
  • Nitric Oxide Synthase Type III / metabolism
  • Vascular Cell Adhesion Molecule-1 / biosynthesis

Substances

  • Anti-Inflammatory Agents
  • Interleukin-1beta
  • NF-kappa B
  • Vascular Cell Adhesion Molecule-1
  • Digoxin
  • Digitoxin
  • Nitric Oxide Synthase Type III
  • I-kappa B Kinase
  • JNK Mitogen-Activated Protein Kinases
  • Mitogen-Activated Protein Kinase 1
  • Mitogen-Activated Protein Kinase 3