Control of oxidative stress by an amino-acid derivative

本项目检测了抗氧化剂氨基酸衍生物（AAD） n -乙酰半胱氨酸（N-acetyl半胱氨酸）控制成骨细胞氧化应激的保护潜力。从大鼠骨髓中提取成骨细胞进行培养。在培养基中加入H2O2诱导氧化应激。然后，将部分h2o2处理过的培养物与AAD共处理。在第2天，添加H2O2使细胞数量减少到未处理培养的50%。在H2O2培养物中加入AAD，细胞数量呈剂量依赖性增加，细胞数量比H2O2培养物中增加50%。第7天，H2O2使ⅰ型胶原、骨桥蛋白和骨钙素基因表达水平下调3倍。通过AAD共处理，h2o2抑制的基因表达完全恢复。第15天Von Kossa染色评估矿化能力约为1。AAD+H2O2共处理组比H2O2单独培养组高8倍。这些AAD介导的恢复与AAD剂量依赖性细胞内谷胱甘肽的增加和AAD剂量依赖性细胞内活性氧的减少有关。综上所述，H2O2诱导的氧化应激严重损害成骨细胞的增殖、分化和矿化。更重要的是，由于氧化还原平衡的改善，在培养物中添加AAD可以将这些损伤恢复到接近正常水平，这需要进一步的体内研究来测试其作为局部抗氧化应激药物的治疗潜力。

This project tested the protective potential of N-acetyl cysteine, an antioxidant, amino acid derivative(AAD), in controlling oxidative stress against osteoblasts. Osteoblastic cells extracted from rat bone marrow were cultured. Oxidative stress was induced by adding H2O2 into the culture media. Then, some H2O2-treated cultures were cotreated with AAD. Addition of H2O2 decreased the number of cells to 50% of untreated cultures at days 2. Addition of AAD into H2O2 cultures resulted in a dose-dependent increase in the number of cells, with the cell number being 50% greater than that in the H2O2 culture. The gene expression levels of type I collagen, osteopontin, and osteocalcin were downregulated threefold by H2O2 on day 7. The H2O2-suppressed gene expression was fully recovered by AAD cotreatment. The mineralizing capability, assessed by Von Kossa staining on day 15, were approximately 1. 8 times greater in the AAD+H2O2 cotreated group than in the culture with H2O2 alone. These AAD-mediated restorations were associated with an AAD dose-dependent increase of intracellular glutathione and a AAD dose-dependent decrease of intracellular reactive oxygen species. In conclusion, oxidative stress induced by H2O2 substantially impairs the proliferation, differentiation, and mineralization of osteoblasts. More importantly, the addition of AAD into the culture was found to restore these damages to a near normal level due to the improved redox balance, warranting further in vivo studies to test its therapeutic potential as a local antioxidative stress drug.