Wound Healing - A Proteomic Analysis of the Effect of Erythropoietin on Granulation Tissue Isolated from ePTFE Implants

Abstract

Bekka Christensen, Vibeke Koudahl, Bent Honore, Jens Overgaard, Tine Engberg Damsgaard, Henrik Vorum

Background: Erythropoietin is a multifunctional cytokine, with recent studies indicating a positive effect on wound healing in models of incisional and burn wounds. Objective: The objective of this study was to investigate the changes in protein expression after daily injections of recombinant human erythropoietin in granulation tissue isolated from subcutaneous implants of expanded polytetrafluoroethylene (ePTFE tube). Methods: ePTFE tubes were implanted subcutaneously in twelve C57bl6 mice. Six of the mice were treated with daily subcutaneous injection of recombinant human erythropoietin of 1000 IU/kg. The remaining six mice, the control group, were treated with injections of 0.9% saline. The implants were removed on day 9 after implantation. The granulation tissue was isolated and analyzed for protein expression using a proteomic approach including two-dimensional polyacrylamide gel electrophoresis and mass spectrometry. Some of the results were confirmed with Western Blotting. Results: We identified 33 differentially expressed proteins in the rhEPO-treated group. Three proteins involved in the glycolytic pathway — Glyceraldehyde-3-phosphate dehydrogenase, Alpha-enolase, and Triosephosphate isomerase — were altered in the granulation tissue from the rhEPO-treated group. Conclusion: Daily injection of recombinant human erythropoietin of 1000 IU/kg alters the protein expression of GAPDH, ENOA and TPIS in granulation tissue from wounds on postoperative day 9. The successful combination of proteomic analysis of wound tissue and the ePTFE wound model could advance our knowledge of the complex healing process.