Glucose-related reactive oxygen species formation and its influence on the expression of MCP-1 in passage endothelial cells

Objective To study the relationship between abnormal changes of reactive oxygen species (ROS) and the expression of monocyte chemoattractant protein-1 (MCP-1) in passage vein endothelial cells when these cells were exposed to high glucose and the underlying mechanisms of passage cells′ dysfunction under high glucose. Methods The human umbilical vein endothelial cells that isolated from newborn umbilical cord were cultured and verified as vascular endothelial cells by immunohistochemistry in vitro. Passage cells were divided into 4 groups: 5.5 mmol/L P2 group,passage 2 cells cultured in 5.5 mmol/L glucose; 5.5 mmol/L P6 group,passage 6 cells cultured in 5.5 mmol/L glucose; 16.5 mmol/L P2 group,passage 2 cells cultured in 16.5 mmol/L glucose; 16.5 mmol/L P6 group,passage 6 cells cultured in 16.5 mmol/L glucose. The endpoints for culture in each group were designed as 0,12,24 and 48 h. Levels of ROS were studied with flow cytometry and MCP-1 mRNA expression was assayed by reverse-transcription polymerase chain reaction. Results The levels of ROS stable in 5.5 mmol/L group were increased time-dependently in 16.5 mmol/L P2 group. For example,the levels of ROS were 56.5% or 69.2% times more at the time point of 24 h or 48 h than at the time point of 0 h in 16.5 mmol/L P2 group. The levels of ROS in 16.5 mmol/L P2 group increased significantly than in 5.5 mmol/L P2 group at the time point of 24 h and 48 h (all P 0.05). ROS also increased significantly in passage 6 cells compared to passage 2 cells in every point of time as these cells were treated by 5.5 mmol/L glucose or 16.5 mmol/L glucose. The expression of MCP-1 was increased time-dependently and dose-dependently by glucose at the point of 12,24 and 48 h. The expressions of MCP-1 were also increased significantly in passage 6 cells compare to passage 2 cells in every point of time. Conclusion The expression of MCP-1 increased by high glucose is probably mediated by increased formation of ROS in passage VECs.