High glucose enhances CD39 expression in vascular endothelial cells

Abstract

Abstract Background: Diabetes mellitus (DM) patients lose their ability to control normal blood glucose levels, resulting in high blood glucose levels (hyperglycemia). Hyperglycemia causes DM complications. This involves responses of vascular endothelial cells (VECs) to hyperglycemia, affecting inflammatory process and platelet activity. Ecto-enzyme CD39 is expressed on VECs, catalyzing the hydrolysis of ATP and ADP to AMP and, consequently, regulating inflammatory process and platelet activation. Objective: We studied whether high glucose concentration has an effect on CD39 expression on VECs. Methods: Cultured human umbilical vein endothelial cells (HUVEC) were used as a model of study. HUVEC were cultured in different glucose conditions (4, 9, 24, and 34 mM) for 24 hours. Cell viability was assessed using a 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT)-based assay and expression of CD39 was examined by using SDS-PAGE and western blot techniques. Results: HUVEC were cultured in normal (4 and 9 mM) or high (24 and 34 mM) glucose concentrations for short term (24 hours). The results showed that high glucose (24 and 34 mM) reduced cell viability to 89.5 ± 11.3 and 86.3 ± 13.5 (mean ± SD), compared with control (4 mM), respectively. High glucose also induced increases in CD39 expression in HUVEC. Conclusion: High glucose decreases cell viability and increases CD39 expression in HUVEC, suggesting involvement of CD39 in cell responses to high glucose.