常氧及缺氧培养对成骨细胞hFOB1.19增殖的影响

目的了解不同氧条件培养对成骨细胞增殖、凋亡的影响。方法将成骨细胞hfob1.19分别置于常氧条件（培养箱内含20%O₂），缺氧条件（培养箱内含1%O₂）培养120 h，并分别在24、48、72、96、120 h通过MTT检测细胞增殖，流式检测细胞凋亡，检测细胞内ROS。结果常氧培养72 h之前成骨细胞活性遂渐增加，增殖明显，72 h之后细胞增长趋于平缓。缺氧初期细胞活性有所降低，但降低趋势较平缓，72 h之后细胞活性急剧下降；常氧条件下成骨细胞凋亡不明显，缺氧条件下，随培养时间延长，凋亡细胞多，凋亡比例快速增加；常氧条件下细胞内活性氧水平较低，各个时间段活性氧水平差异不大（P<0.05）。缺氧条件下细胞内活性氧水平高，随着缺氧时间增长，活性氧水平快速升高（P<0.05）。结论实验表明长时间的缺氧导致成骨生长活性降低，细胞凋亡增加，伴随着大量的ROS产生，氧化应激在细胞凋亡过程中起了重要作用。

Effects of Normoxia and Hypoxic Culture Environment on Proliferation of hFOB1.19

Objective To explore the effects of different oxygen conditions on the proliferation and apoptosis of osteoblasts. Methods The hfob1.19 were cultured on normoxic conditions (20% O₂ in the incubator) and in hypoxic condition (containing 1% O₂ in the incubator) for 120 h. Cell proliferation were detected through MTT assay in 24 h, 48 h, 72 h, 96 h and 120 h, with flow cytometry apoptosis and detection of intracellular ROS. Results The activity of osteoblasts increased gradually after 72 h of normoxia(P<0.05). After 72 h the cell growth tended to be gentle. In the early stage of hypoxia, the cell viability decreased, but the decrease tended to be gentle. After 72 h, the cell viability decreased sharply. The apoptosis of osteoblasts was not significant on the condition of normoxia. However, on the condition of hypoxia, the proportion of apoptotic cells increased rapidly. The levels of reactive oxygen species (ROS) in cells on normoxia were lower than those in normoxic conditions(P<0.05). On hypoxic conditions, intracellular reactive oxygen species (ROS) levels were high, and the level of reactive oxygen species increased rapidly with hypoxia time prolonged. Conclusion Prolonged hypoxia lead to decreased osteoblast growth activity and increased apoptosis. It is accompanied by a large number of ROS generation.The oxidative stress plays an important role in the process of apoptosis.