高糖诱导人脐静脉内皮细胞衰老过程中活性氧与二甲基精氨酸二甲胺水解酶-非对称性二甲基精氨酸系统的变化

Objective To investigate the changes in reactive oxygen species (ROS) and dimethylarginine dimethylaminohydrolase-asymmetric dimethylarginine (DDAH-ADMA) system in the process of endothelial cell senescence after exposure to high glucose. Methods The human umbilical vein endothelial cells (HUVECs) were cultured with different concentrations of glucose, e.g. 5. 5 mmol/L (normal level),and high levels as 11. 0, 22. 0 and 33. 0 mmol/L. for 48 hours, respectively. Subsequently, SA-β-gal staining was used to evaluate senescence of cells. Telomerase activity was detected by polymerase chain reactionenzyme linked immunosorbent assay (PCR-ELISA). The intracellular ROS level was measured by flow cytometry. The ADMA concentration and DDAH activity were determined with high-performance liquid chromatography. Results Compared with normal glucose concentration group, after the endothelial cells were treated with high glucose concentration (11. 0 - 33. 0 mmol/L) for 48 hours, the number of SA-β-gal positive cells was increased significantly [(7.00±1. 73)%, (12. 67±2. 03)%, (16. 00±2. 26)% vs. (4. 00±1.33)%, P＞0.05, P＜0.05, P＜0.05] and the telomerase activity was inhibited dramatically [(91. 32±4.01)%, (78. 44±3. 78)%, (56. 04±3. 35)% vs. 100%, all P＜0. 05]. The ROS level (mfi) was increased in all high glucose groups (159. 84±27. 52, 188. 99±18. 77, 244. 56±20. 96 vs. 117.11±18. 76, P＜0. 05 or P＜0. 01). At the same time, the ADMA (μmol/L) production was increased (0. 78±0. 14, 0. 88±0.18,1. 08±0.15 vs. 0. 70±0. 12, P＞0. 05, P＜0. 05, P＜0. 05), and DDAH activity was decreased [(91. 32±4.01)%, (78.44±3.78)%, (56. 04± 3. 35)% vs. 100%, all P＜0.05]. Conclusion High glucose can accelerate endothelial cells senescence in dose-dependent manner and the underlying mechanism may be related to an increased oxidative stress and change in DDAH-ADMA system.

Alterations in reactive oxygen species and dimetbylarginine dimethylaminohydrolase-asymmetric dimethylarginine system in the process of endothelial cell senescence induced by high glucose