不同缺氧时间对大鼠骨髓间充质干细胞摄糖力和凋亡的影响

Influence of Hypoxia on Apoptosis and Glucose Intake in Bone Marrow Derived Mesenchymal Stem Cells in Rats

为探讨缺氧对大鼠间充质干细胞(MSC)凋亡和摄取葡萄糖能力的影响,将大鼠骨髓源细胞置于1%O2条件下培养不同时间,利用流式细胞技术分析细胞凋亡率(apoptotic rate,AR)和死亡率(death rate,DR),用放射同位素法检测细胞对3H标记-葡萄糖(3H-G)的摄取量,并应用透射电镜观察细胞超微结构的改变。结果表明:培养细胞呈成纤维细胞样,且在适当条件下可分化为成骨和成脂肪细胞;短暂缺氧即可引起MSC超微结构的改变,如微绒毛脱落、线粒体肿胀等;各缺氧时间点3H-G摄取量较常氧组均显著性降低(p<0.01),而各缺氧时间点之间没有统计学意义(p>0.05);低氧处理后MSC凋亡或死亡,1、4和8小时时的AR分别为(13.7±2.26)%、(14.1±2.78)%和(14.7±4.01)%,均较常氧组(0.09±2.03)%显著增高(p<0.01);DR分别为(3.11±2.14)%、(4.72±2.05)%和(4.91±3.72)%,亦较常氧组(0.04±1.79%)显著增高(p<0.05)。结论:短暂缺氧可引起MSC摄取葡萄糖能力下降,且部分细胞发生病理改变和凋亡。

To investigate the effects of hypoxia on the apoptosis and glucose intake of mesenchymal stem cells （MSCs）, MSCs derived from bone marrow of rats were incubated in the atmosphere of 1% O2 for a series of time points and their glucose-intaking capacity, ultrastructural changes and apoptotic proportions were analyzed by 3H-labeling assay, electron microscopy and flow cytometry, respectively. The results showed that the cultured cells took the fibroblast-like morphology and could be induced into osteoblasts and adipocytes under appropriate conditions. The proportions of apoptotic cells after hypoxia treatment for 1, 4 and 8 hours were 13.7 ±2.26%, 14. 1 ±2.78% and 14.7 ±4.01%, respectively, all of which were significantly higher than that observed in normoxic counterparts （ 0.09 ± 2.03 %, p 〈 0. 05）. Also, cell death occurred after hypoxia treatment and the death rates were 3.11 ±2.14%, 4.72 ±2.05% and 4. 91 ± 3.72% for 1,4 and 8 hours incubation respectively . Under hypoxia culture in vitro, cell membrane microvillus began to fall off and the mitochondrias became swelling at 1 hour, and the above changes increasingly aggravated along with hypoxia time prolongation. The 3H-glucose intaking ratios of MSCs at different hypoxia time points significantly decreased than those in normoxic cells （p 〈 0.01 ）. It is concluded that the acute hypoxia can induce down-regulation of glucose-intaking capacity, ultrastructural changes and apoptosis of MSCs.