Thrombin peptide TP508 stimulates rapid nitric oxide production in human endothelial cells

J Vasc Res. 2010;47(3):203-13. doi: 10.1159/000255963. Epub 2009 Nov 6.

Abstract

TP508, a 23-amino-acid peptide representing a portion of human thrombin, promotes tissue revascularization and repair. The molecular mechanisms of TP508 action, however, remain unclear. Nitric oxide (NO) plays a crucial role in regulation of angiogenesis and wound healing. We, therefore, investigated TP508 effects on NO production in human endothelial cells. TP508 stimulated a rapid, dose-dependent, 2- to 4-fold increase in NO production. TP508 induced NO release as early as 5 min. Continued exposure to TP508 for 1-24 h increased NO concentrations over controls by 100.5 +/- 9.6 and 463.3 +/- 24.2 nM, respectively. These levels of NO release were similar to those produced in response to vascular endothelial growth factor (VEGF). TP508- and VEGF-induced NO production was decreased by inhibitors of PI-3K (LY294002) and Src (PP2). TP508 stimulated early transient phosphorylation of Src and Akt. In contrast to VEGF, TP508 stimulation of NO release was inhibited by PKC inhibitor (Go6976) and was independent of intracellular calcium mobilization. These results demonstrate that TP508 and VEGF stimulate NO production to similar levels but through distinct pathways. This study provides new insights into the initial molecular mechanisms by which TP508 may stimulate diverse cellular effects leading to tissue revascularization and wound healing.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Calcium / metabolism
  • Cattle
  • Cells, Cultured
  • Dose-Response Relationship, Drug
  • Endothelial Cells / drug effects*
  • Endothelial Cells / metabolism
  • Humans
  • Nitric Oxide / metabolism*
  • Peptide Fragments / pharmacology*
  • Phosphatidylinositol 3-Kinases / metabolism
  • Phosphoinositide-3 Kinase Inhibitors
  • Phosphorylation
  • Protein Kinase C / antagonists & inhibitors
  • Protein Kinase C / metabolism
  • Protein Kinase Inhibitors / pharmacology
  • Proto-Oncogene Proteins c-akt / metabolism
  • Signal Transduction / drug effects
  • Thrombin / pharmacology*
  • Time Factors
  • Up-Regulation
  • Vascular Endothelial Growth Factor A / metabolism
  • src-Family Kinases / antagonists & inhibitors
  • src-Family Kinases / metabolism

Substances

  • Peptide Fragments
  • Phosphoinositide-3 Kinase Inhibitors
  • Protein Kinase Inhibitors
  • Vascular Endothelial Growth Factor A
  • Nitric Oxide
  • rusalatide acetate
  • src-Family Kinases
  • Proto-Oncogene Proteins c-akt
  • Protein Kinase C
  • Thrombin
  • Calcium