Effect of Glucose on Adherence of Neutrophils to Endothelial Cells

Son, Seok Man; Yoo, Seok Dong; Kim, In Ju; Kim, Yong Ki; Park, Hee Bag; Kim, Chi Dae; Hong, Ki Whan

Abstract

BACKGROUND: Accelerated atherosclerotic vascular disease is the leading cause of mortality in patients with diabetes mellitus. To clarify the mechanisms that cause macrovascular dysfunction in diabetes, we examined the effect of high glucose on the adhesion of neutrophils to the endothelial cells and release of TNF-a from cultured rabbit aortic endotheIial cells.
METHODS
Rabbit aortic endothelial cells in primary culture were prepared by the collagenase digestion method. Cells were incubated for various time upto 24 hours to evaluate TNF-a response to different glucose concentrations(0, 5.5, 11, 22mmol/L). Isolated rabbit neutrophils were incubated with monolayers of rabbit aortic endothelial cells under different glucose condition.
RESULTS
After 24 hrs incubation with various concentrations of glucose, neutrophil adherence to high concentration of glucose(11 and 22mM)-treated endothelium was significantly increased(46+/-7 and 64 +/-6%, respectively) compared with adhesion to low concentration of glucose(0 or 5.5mM)-treated endothelium(3l +/-5 and 30+/-3%, respectively), In addition, when TNF-a imrnunoreactivity in the culture medium was measured by enzyme-linked immunoassay after 24 hours of incubation with various concentration of glucose, the secretion of TNF-a from endothelial cells was significantly increased in a concentration-dependent manner upon exposure to high concentration of glucose,
CONCLUSION
The results of this study ciemonstrate tht high concentration of glucose stimulates neutrophil adhesion to endothelial cells in association with increased production of TNF-a from endothelial cells. These results suggest that glucose directly causes increased interaction between neutrophil and endothelial cell through a TNF-a-dependent mechaniasm,