中文摘要：

目的通过低氧条件下培养骨髓间充质干细胞（bone marrow mesenchymal stemcells，BMSCs），观察其对百草枯（paraquat，PQ）中毒导致急性肺损伤大鼠细胞因子的干预效果。方法供体SD雄性大鼠的BMSCs分离传代后，分低氧培养组（5％O2）和常氧培养对照组（20％O2），两组分别置于低氧和常氧培养箱中培养，并进行细胞鉴定与增殖能力测定。雌性受体大鼠随机分四组：PQ组、常氧培养BMSCs组、低氧培养BMSCs组和正常对照组，观察14d内各组大鼠存活率、血浆中IL-1β、TNF—α、MDA、SOD和GSH—PX水平变化。结果①在低氧条件下培养的BMSCs部分发生分化，但大部分细胞仍保持BMSCs特点，稳定性较好；②与常氧细胞培养方法比较，在低氧条件下培养的BMSCs增殖能力明显提高（P≤0．05），增殖速度更快，集落形成数量更多（P≤0．01）；③与PQ组比较，常氧培养BMSCs组、低氧培养BMSCs组中大鼠14d内均存活；④与常氧培养BMSCs组比较，在染毒后7d内低氧培养BMSCs组中血浆IL-1β和TNF-α的水平明显降低（P≤0．01），MDA水平明显减少（P≤0．05），SOD和GSH—PX水平明显升高（P≤0．05）。结论在低氧微环境下培养的BMSCs更适应临床病理生理环境，抑制炎症介质释放，清除自由基，其抗脂质过氧化损伤的能力更强。

英文摘要：

Objective To investigate the effects of hypoxic cultured bone marrow mesenchymal stein cells （BMSCs） on changes of cytokines in paraquat - induced acute lung injury in rats. Methods BMSCs were isolated from SD rats and divided into normoxic culture group（20% O2 ） and hypoxie culture group（ 5% O2 ）. The proliferation and determination were observed and compared between the both groups. Sixty SD rats were randomly divided into four groups： a PQ group, a normoxic cultured BMSCs treatment group, ahypoxic cuhuredBMSCs treatment group and a normal control group. The rats＇ survival time were calculated during 14 days after PQ injections in each group. At the same time, the levels of Interleukin - 1β （ IL - 1β ） , tumor necrosis factor - α （ TNF - α ） , malondialdehyde （ MDA ） , superoxide dismutase （SOD）, glutathione peroxidase （GSH- PX） in plasma were detected, Results （1）The BMSCs cultured under hypoxic condition appeared differentiation partly. But most of the cells remained the characteristics of BMSCs, and the stability was good. （2）Compared with the normoxic cultured BMSCs, the proliferation of the hypoxic cultured BMSCs increased markedly （P〈0. 05 ）, and the numbers of colony formation increased significantly （P〈0.01）. （3）Compared with PQ group, the rats were all alive within 14 days in normoxic cultured BMSCs treatment group and hypoxic cultured BMSCs treatment group. （4）Compared with normoxic cultured BMSCs treatment group during 7 days after PQ Poisoning, the levels of IL - 1β and TNF - α in plasma in hypoxic cultured BMSCs treatment group were decreased significantly （P〈0. 01 ）, the levels of MDA in plasma decreased markedly （P〈0. 05）, and the activities of SOD, GSH - PX in plasma increased obviously （ P〈0.05）. Conclusion The hypoxic cultured BMSCs are more adapt to clinical pathological physiological environment than the cells cultured in normoxia, which have stronger ability of inhibiting inflammatory mediator levels, sc