BACKGROUND: Endothelial progenitor cells (EPCs) are special types of stem cells and are a potential novel therapeutic approach in acute lung injury (ALI). Transplantation of EPCs can ameliorate the inflammatory state by reducing adhesion and exudation of inflammatory cells. However, the mechanism underlying the effect of EPCs on inflammatory response modulation remains unclear. The aim of the present study was to investigate the effect of EPCs on the modulation of neutrophils in vitro and in vivo.MATERIALS AND METHODS: EPCs were cocultured with neutrophils after lipopolysaccharide stimulation in vitro or transplanted into ALI rats, and neutrophil inflammatory mediators including tumor necrosis factor-á, interleukin-1â, neutrophil elastase, myeloperoxidase and matrix metalloproteinases-9 were detected by enzyme-linked immunosorbent assay, an myeloperoxidase detection kits, reverse transcription-polymerase chain reaction and western blotting.RESULTS: The results showed that EPCs significantly downregulated the expression of inflammatory mediators when cocultured with neutrophils in vitro or in vivo.CONCLUSIONS: These findings demonstrated that EPCs contributed to lung injury in ALI rats by downregulating neutrophil inflammatory mediators.
Acute Lung Injury Animals