Neutrophil Elastase-Generated Fragment of Vascular Endothelial Growth Factor-A Stimulates Macrophage and Endothelial Progenitor Cell Migration

PLoS One. 2015 Dec 16;10(12):e0145115. doi: 10.1371/journal.pone.0145115. eCollection 2015.

Abstract

Elastase released from neutrophils as part of the innate immune system has been implicated in chronic diseases such as emphysema and cardiovascular disease. We have previously shown that neutrophil elastase targets vascular endothelial growth factor-A (VEGF) for partial degradation to generate a fragment of VEGF (VEGFf) that has distinct activities. Namely, VEGFf binds to VEGF receptor 1 but not to VEGF receptor 2 and shows altered signaling compared to intact VEGF. In the present study we investigated the chemotactic function of VEGF and VEGFf released from cells by neutrophil elastase. We found that endothelial cells migrated in response to intact VEGF but not VEGFf whereas RAW 264.7 macrophages/monocytes and embryonic endothelial progenitor cells were stimulated to migrate by either VEGF or VEGFf. To investigate the role of elastase-mediated release of VEGF from cells/extracellular matrices, a co-culture system was established. High or low VEGF producing cells were co-cultured with macrophages, endothelial or endothelial progenitor cells and treated with neutrophil elastase. Elastase treatment stimulated macrophage and endothelial progenitor cell migration with the response being greater with the high VEGF expressing cells. However, elastase treatment led to decreased endothelial cell migration due to VEGF cleavage to VEGF fragment. These findings suggest that the tissue response to NE-mediated injury might involve the generation of diffusible VEGF fragments that stimulate inflammatory cell recruitment.

Publication types

  • Research Support, N.I.H., Extramural
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Cattle
  • Cell Movement*
  • Endothelial Progenitor Cells / drug effects*
  • Endothelial Progenitor Cells / physiology
  • Humans
  • Macrophages / drug effects*
  • Macrophages / physiology
  • Mice
  • Pancreatic Elastase / pharmacology
  • Peptide Fragments / chemistry
  • Peptide Fragments / pharmacology
  • Proteolysis
  • Rats
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / pharmacology
  • Sf9 Cells
  • Spodoptera
  • Vascular Endothelial Growth Factor A / chemistry
  • Vascular Endothelial Growth Factor A / pharmacology*

Substances

  • Peptide Fragments
  • Recombinant Proteins
  • Vascular Endothelial Growth Factor A
  • Pancreatic Elastase