糖尿病条件下钛-骨界面氧化应激对血管内皮细胞功能的影响及机制研究

Effects of titanium-bone interface oxidative stress on vascular endothelial cells and its mechanism under diabetic condition

目的研究在糖尿病条件下过度产生的活性氧簇(ROS)对钛-骨界面的血管内皮细胞功能的影响,并初步探讨改善血管内皮细胞功能以保持内植物稳定的方法。方法通过将人脐静脉血管内皮细胞(HUVECs)种植于钛片培养,建立体外模型,比较正常血清组(NS组),糖尿病血清组(DS组),DS+NAC(ROS抑制剂,20 mmol/L)组,NS+H_2O_2(300μmol/L)组血管内皮细胞的生物学功能、氧化应激水平及炎症介质水平。结果培养后第1、4、7天,DS组的细胞增殖活力明显低于NS组,DS+NAC组中细胞增殖活力较DS组显著提高但仍低于NS组,NS+H_2O_2组细胞增殖活力明显低于其他3组,差异均有统计学意义(P<0.05)。DS组MDA含量明显高于NS组,Mn SOD酶活性更低,早期细胞凋亡率更高,TNF-α含量更高。DS加入NAC之后,DS+NAC组MDA含量下降明显,Mn SOD酶活性升高,早期细胞凋亡率较显著下降,TNF-α含量明显降低,差异均有统计学意义(P<0.05)。在NS组中加入H_2O_2后,血管内皮细胞功能受损,氧化应激和炎症反应水平明显升高。结论糖尿病环境造成钛-骨界面血管内皮细胞氧化应激,过度产生ROS,对血管内皮细胞功能造成明显损伤,而抗氧化治疗可有效改善血管功能状态。

Objective To study the effect of overproduction of reactive oxygen species （ROS） on the human umbilical vein endothelial ceUs（HUVECs） under the diabetes condition and explore a method to improve the function of HUVECs to promote the treatment efficacy of titanium implants. Methods In vitro, HUVECs cultured on Ti sheet were subjected to different treatments： normal serum （NS）, diabetic serum （DS）, DS＋NAC （a ROS inhibitor） and NS＋H2O2. After a period of time, the biological behavior, oxidative stress and inflammatory mediators of the ceils were measured. Results After incubation on day 1, 4 and 7, the cell proliferation activity of DS group was significantly lower than that of NS group, and the cell proliferation activity in DS＋NAC group was significantly lower than that in NS group. The cell proliferation activity of NS＋H2O2 group was significantly lower than the other three groups, the difference was statistically significant （P 〈0.05）. In DS group, the MDA content, early apoptosis rate and TNF-a content was significantly higher than that in NS group, hut the MnSOD activity was lower than that in NS group, the difference was statistically significant （P 〈0.05）. Scavenging ROS by NAC markedly alleviated cell apoptosis and endothelial cell dysfunction. After H2O2 was added to the NS group, the function of vascular endothelial cells was impaired, and the levels of oxidative stress and inflammatory response were significantly increased. Conclusion The diabetes induced significant cell dysfunction and apoptosis of HUVECs, which was ameliorated by scavenging ROS with NAC.