【摘要】 背景:在需要进行干细胞治疗的缺血性心脏病移植的微环境中,长期存在着缺血缺氧环境,骨髓间充质干细胞移植到心肌后能否适应?目的:观察骨髓间充质干细胞对缺氧的耐受性。设计、时间及地点:对比观察实验,2005-03/2006-03在北京大学医学部心血管研究所完成。材料:成年雄性SD大鼠10只,体质量150g左右,SPF级。方法:采用密度梯度法分离培养大鼠骨髓间充质干细胞,在3种氧浓度中进行培养。体积分数为0.95的N2+体积分数为0.05的CO2为无氧组,体积分数为0.01的O2+体积分数为0.94的N2+体积分数为0.05的CO2为低氧组,体积分数为0.05的CO2+空气为正常氧浓度组。测定MTT值绘制生长曲线、用锥虫蓝和Hoechst33258染色计数细胞死亡和凋亡的数量。主要观察指标:细胞在不同氧浓度及不同培养时间点的死亡和凋亡百分数,以及细胞数目增长情况。结果:①生长曲线显示骨髓间充质干细胞在1%低氧浓度和无氧条件下的增殖能力较正常氧浓度条件下显著降低(P<0.05)。②在不同氧浓度条件下,连续培养5d内,各时间点骨髓间充质干细胞死亡百分率3组间差异无显著性。③通过检测细胞核碎裂发现缺氧未显著增加骨髓间充质干细胞凋亡,在不同氧浓度条件下,连续培养5d内,细胞凋亡率均低于8%(P>0.05)。结论:骨髓间充质干细胞在体外培养时对缺氧耐受性较好。更多还原

【Abstract】 BACKGROUND:Whether bone marrow mesenchymal stem cells(BMSCs)can accommodate after transplantation for ischemic heart disease in ischemia/hypoxia environment. OBJECTIVE:To investigate the hypoxia tolerance of BMSCs. DESIGN,TIME AND SETTING:A control observational experiment was performed at Peking University Institute of Cardiovascular Sciences from March 2005 to March 2006. MATERIALS:Ten adult male SD rats weighing 150 g of SPF grade were used in this study. METHODS:Rat BMSCs were isolated by density gradient method and cultured in 3 different concentrations of oxygen.There were anoxia group(N2 of 0.95 volume fraction+CO2 of 0.05 volume fraction),hypoxia group(O2 of 0.01 volume fraction+N2 of 0.94 volume fraction+CO2 of 0.05 volume fraction)and normoxia group(CO2 of 0.25 volume fraction+air).Cell viability was measured by MTT assay to draw growth curve.Trypan blue and Hoechst staining were used to count cell death and apoptosis. MAIN OUTCOME MEASURES:Cell death and apoptosis percentage under different oxygen concentrations at different time points,as well as cell number increase. RESULTS:Growth curve showed that the proliferation of BMSCs was significantly lower in hypoxia(1%)and anoxia groups than in the normoxia group(P<0.05).There was no significant difference in cell death rate among 3 groups under different oxygen concentrations at different time points in successive culture for 5 days.Hypoxia did not induce significant apoptosis in BMSCs by detecting the nuclear fragmentation.The apoptotic percentage of BMSCs was less than 8%after 5 days in different oxygen culture conditions(P>0.05). CONCLUSION:BMSCs present good hypoxia tolerance in vitro.更多还原