Abstract:

Objective To investigate the effects of high glucose on expression of angiopoietin 2 (Ang2) and tyrosine kinase receptor (Tie2) in human umbilical vascular endothelial cells （HUVECs）cultured in vitro, and explore the possible mechanism of peritoneal angiogenesis in patients with peritoneal dialysis. Methods HUVECs cultured in vitro were treated with 4.25% glucose (high glucose group), 4.25% mannitol (mannitol group) and 800 μmol/L methylglyoxal (MGO) (MGO group), and blank control group was establishment. D(490 nm) was measured by MTT assay to compared the cell proliferation of HUVECs after incubation for 12 h, 24 h and 48 h in each group. The expression of Ang2 and Tie2 mRNA in HUVECs, the secretory volume of Ang2 in supernatant of cell culture and the expression of Tie2 protein in HUVECs were detected by RealTime PCR, ELISA and Western blotting respectively in each group. Results D(490 nm) of HUVECs in high glucose group, mannitol group and MGO group were significantly higher than that in blank control group after treatment for 12 h （P<0.05）, and D(490 nm) of HUVECs in high glucose group, mannitol group and MGO group were significantly lower than that in blank control group after treatment for 24 h （P<0.05）. The expression of Ang2 mRNA in HUVECs in high glucose group, mannitol group and MGO group was significantly higher than that in blank control group （P<0.05）, the secretory volumes of Ang2 in supernatant of cell culture in high glucose group and mannitol group were significantly higher than that in blank control group （P<0.05）, and the secretory volume of Ang2 in supernatant of cell culture in MGO group was significantly lower than that in blank control group （P<0.05）. The expression of Tie2 mRNA and protein in HUVECs in high glucose group, mannitol group and MGO group was significantly lower than that in blank control group （P<0.05）. Conclusion High glucose may promote angiogenesis in peritoneum through stimulating the endothelial cell proliferation and regulating the expression of Ang2.

Key words: angiogenesis, angiopoietin, tyrosine kinase receptor, peritoneal dialysis