Control of oxidative stress by an amino-acid derivative

该项目测试了N-乙酰半胱氨酸，一种抗氧化剂，氨基酸衍生物(AAD)，在控制针对成骨细胞的氧化应激方面的保护潜力。从大鼠骨髓中提取成骨细胞进行培养。在培养基中加入H_2O_2诱导氧化应激。然后，将一些过氧化氢处理的培养物与AAD共处理。加入H_2O_2后，细胞数在第2天减少到未处理组的50%。在H_2O_2中加入AAD后，细胞数呈剂量依赖性增加，细胞数比H_2O_2组多50%。在第7天，I型胶原、骨桥蛋白和骨钙素的基因表达水平被H_2O_2下调3倍，经AAD共同处理后，H_2O_2抑制的基因表达完全恢复。第15天Von Kossa染色检测，AAD+H_2O_2联合处理组的矿化能力约为单独H_2O_2培养组的1.8倍。这些AAD介导的修复与AAD剂量依赖的细胞内谷胱甘肽增加和AAD剂量依赖的细胞内活性氧的减少有关。综上所述，过氧化氢诱导的氧化应激实质上损害了成骨细胞的增殖、分化和矿化。更重要的是，在培养中加入AAD后，由于氧化还原平衡的改善，这些损伤被发现恢复到接近正常的水平，这证明了进一步的体内研究，以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.