Activation of endothelial NO synthase by a xanthine derivative ameliorates hypoxia-induced apoptosis in endothelial progenitor cells

J Pharm Pharmacol. 2016 Jun;68(6):810-8. doi: 10.1111/jphp.12555. Epub 2016 Apr 25.

Abstract

Objectives: Endothelial damage is strongly associated with cardiovascular diseases such as atherosclerosis, thrombosis and hypertension. Endothelial progenitor cells (EPCs) are primitive bone marrow (BM) cells that possess the capacity to mature into endothelial cells and play a role in neovascularization and vascular remodelling. This study aimed to investigate whether KMUP-1, a synthetic xanthine-based derivative, atorvastatin and simvastatin, can prevent endothelial dysfunction and apoptosis induced by hypoxia and to elucidate the underlying mechanisms.

Methods: Mononuclear cells were separated and were induced to differentiate into EPCs. KMUP-1, atorvastatin or simvastatin were administered prior to hypoxia.

Key findings: We found that EPCs exposed to hypoxia increased apoptosis as well as diminished proliferation. Pretreatment with KMUP-1, atorvastatin and simvastatin significantly prevented hypoxia-induced EPCs death and apoptosis, with associated increased of the Bcl-2/Bax ratio, and reduced caspase-3 and caspase-9 expression. We also assessed the nitrite production and Ser(1177)-phospho-eNOS expression and found that KMUP-1, atorvastatin and simvastatin not only increased the secretion of NO compared with the hypoxia group but also upregulated the eNOS activation.

Conclusions: KMUP-1 inhibited hypoxia-induced dysfunction and apoptosis in EPCs, which may be mediated through suppressing oxidative stress, upregulating eNOS and downregulating the caspase-3 signalling pathway.

Keywords: apoptosis; endothelial nitric oxide synthase; endothelial progenitor cells; hypoxia.

MeSH terms

  • Animals
  • Apoptosis / drug effects*
  • Apoptosis Regulatory Proteins / metabolism
  • Atorvastatin / pharmacology
  • Cell Hypoxia
  • Cell Proliferation / drug effects
  • Cells, Cultured
  • Cytoprotection
  • Endothelial Progenitor Cells / drug effects*
  • Endothelial Progenitor Cells / enzymology
  • Endothelial Progenitor Cells / pathology
  • Enzyme Activation
  • Enzyme Activators / pharmacology*
  • Nitric Oxide / metabolism
  • Nitric Oxide Synthase Type III / metabolism*
  • Nitrites / metabolism
  • Oxidative Stress / drug effects
  • Phosphorylation
  • Piperidines / pharmacology*
  • Rats, Sprague-Dawley
  • Signal Transduction / drug effects
  • Simvastatin / pharmacology
  • Xanthines / pharmacology*

Substances

  • Apoptosis Regulatory Proteins
  • Enzyme Activators
  • Nitrites
  • Piperidines
  • Xanthines
  • KMUP 1
  • Nitric Oxide
  • Atorvastatin
  • Simvastatin
  • Nitric Oxide Synthase Type III
  • Nos3 protein, rat