摘要
背景:骨髓间充质干细胞在造血干细胞致死放射剂量下却能够存活,并且仍能维持典型的干细胞特性,促进放射后的造血恢复,而自噬是细胞在应激状态下重要的适应性调控机制,可能参与骨髓间充质干细胞的放射耐受。目的:探索放射诱导的自噬与人骨髓间充质干细胞在放射损伤过程中的关系。方法:取体外培养的处于对数生长期的第3代骨髓间充质干细胞,随机分为对照组、3-甲基腺嘌呤组、雷帕霉素组、照射组、照射联合3-甲基腺嘌呤组和照射联合雷帕霉素组,3-甲基腺嘌呤组和雷帕霉素组细胞分别使用5 mmol/L自噬抑制剂3-甲基腺嘌呤和200 nmol/L自噬激活剂雷帕霉素干预12 h,照射组细胞接受单剂量6 Gy X射线照射2 h,照射联合3-甲基腺嘌呤组和照射联合雷帕霉素组分别在接受相应药物干预12 h后,接受6 Gy X射线照射2 h。结果与结论:对照组中自噬泡阳性细胞及凋亡细胞所占比例均较低;照射组中自噬泡阳性细胞及凋亡细胞比例较对照组均明显升高,且可见较高比例的自噬+凋亡细胞;应用3-甲基腺嘌呤后,自噬泡阳性细胞比例明显下降,凋亡细胞比例明显升高,但自噬+凋亡细胞比例与照射组相比无显著差异;而给予雷帕霉素后发现自噬泡阳性细胞显著高于照射组,但凋亡细胞比例与照射组相比无明显差异,并且未观察到自噬+凋亡细胞。对照组与3-甲基腺嘌呤组微管相关蛋白1轻链3-Ⅱ蛋白表达水平均很低;雷帕霉素组与照射组微管相关蛋白1轻链3-Ⅱ蛋白表达水平较对照组均明显升高,但照射组低于雷帕霉素组;照射联合3-甲基腺嘌呤组微管相关蛋白1轻链3-Ⅱ蛋白表达明显低于照射组,但仍高于对照组,照射联合雷帕霉素组微管相关蛋白1轻链3-Ⅱ蛋白表达较照射组和雷帕霉素处理组均明显升高。提示自噬可能对骨髓间充质干细胞具有放射保护作用。
BACKGROUND：Bone marrow mesenchymal stem cells can survive under the lethal dose of radiation in response to hematopoietic stem cells, and stil maintain the typical characteristics of stem cells to promote hematopoietic recovery after radiation. However, autophagy is an important mechanism for cellular adaptation under stress, which may be involved in radiation tolerance of bone marrow mesenchymal stem cells. OBJECTIVE：To investigate the role of autophagy in human bone marrow mesenchymal stem cells in response to irradiation. METHODS：Passage 3 bone marrow mesenchymal stem cells cultured in vitro at logarithmic phase were col ected and randomized into control, 3-mehyladenine, rapamycin, irradiation, irradiation＋3-mehyladenine and irradiation＋rapamycin groups. The autophagy reactions of bone marrow mesenchymal stem cells were regulated by 5 mmol/L 3-mehyladenine and 200 nmol/L rapamycin for 12 hours in the 3-mehyladenine and rapamycin groups, respectively. Two-hour 6 Gy X-ray irradiation was performed in the irradiation group and two complication groups undergoing 12-hour corresponding drug intervention. RESULTS AND CONCLUSION：The proportions of cells with autophagic vacuoles and apoptotic cells were higher in the irradiation group than the control group, moreover, autophagic＋apoptotic cells were increased in the irradiation group. 3-mehyladenine intervention could decrease the proportion of cells with autophagic vacuoles,and increase the number of apoptotic cells. But there was no difference in the proportion of autophagic＋apoptotic cells between the 3-mehyladenine and irradiation groups. After rapamycin intervention, the proportion of autophagic cells was higher than that in the irradiation group, but no difference in the proportion of apoptotic cells between the two grups, as wel as there were no autophagic＋apoptotic cells. The expression of microtubule-associated protein 1 light chain 3-II was ranked as fol ows：the control and 3-mehyladenine groups＆lt;irradiation＋3-mehyladenine group＆lt
出处
《中国组织工程研究》
CAS
CSCD
2014年第28期4474-4478,共5页
Chinese Journal of Tissue Engineering Research
