电离辐射对胎鼠皮肤间充质干细胞支持骨髓粒系造血作用的影响

目的：观察不同剂量的X射线照射对体外培养的胎鼠皮肤间充质干细胞(MSCs)支持造血细胞增殖作用的影响，为提高造血干细胞体外扩增效率提供一种更为有效的方法，进而为造血干细胞移植提供一个新的途径。 方法：分别用不同剂量的X射线照射培养的胎鼠皮肤MSCs层，然后将骨髓细胞种植于该细胞层上，扩增后不同时间(0~12 d)进行骨髓CFU-GM集落培养，同时取经X射线照射的皮肤MSCs的上清液进行骨髓CFU-GM、CFU-E及BFU-E培养，观察射线对胎鼠皮肤MSCs造血支持作用的影响。 结果：6、8和10 Gy剂量X射线照射胎鼠皮肤MSCs与骨髓细胞共同作用7 d时，骨髓祖细胞集落显著增加，其中6 Gy组增加最为明显，CFU-GM是0 Gy组的2.17倍。6、8和10 Gy剂量X射线照射培养皮肤的上清液体外亦可刺激骨髓CFU-GM、CFU-E、BFU-E的生长，与0 Gy组比较差异均有显著性(P<0.05)。其中6 Gy组增加最为明显，分别达0 Gy组的1.81倍、3.94倍和3.51倍，集落亦明显加大。 结论：一定剂量X射线照射胎鼠皮肤MSCs，其体外支持造血的作用增强，无论照射后的单纯MSCs细胞层还是上清液都可使骨髓细胞集落数增多。

Effects of irradiation on skin mesenchymal stem cells supporting hematopoiesis in fetal mice

Objective To apply skin mesenchymal stem cells (MSCs) irradiated with different dosages of X-rays, instead of MSCs in the bone marrow to promote the proliferation of hematopoietic stem cells in vitro. Methods The bone marrow cells were cultured on the skin MSCs layer irradiated with different dosages of X-rays in vitro. The number of bone marrow cells, the colony-forming-unit-macrophage-granulocyte (CFU-GM) were assayed after expansion and maintenance for 0-12 days. CFU-GM, colony-forming unit-erthroid(CFU-E), burst-forming-unit-erythroid (BFU-E)colony were assayed in the cultured supernatant of the skin MSCs. The effects of supporting hematopoiesis of irradiation on skin MSCs in fetal mice were observed.Results The CFU-GM colonies were increased after bone marrow cells were cultured together with fetal mice skin MSCs irradiated with 6,8, and 10 Gy X-rays, especially in 6 Gy X-rays group, it was 2.17 times as big as that in 0 Gy X-rays group. The cultured supernatant of skin MSCs irradiated with 6,8 and 10 Gy X-rays could stimulate the growth of CFU-GM, CFU-E, and BFU-E in vitro, there were significant differences compared with those in 0 Gy X-rays group (P<0.05), especially in 6 Gy X-rays group, they were 1.81,3.94,and 3.51 times as big as those in 0 Gy X-rays group,respectively.Conclusion Skin MSCs irradiated with certain dosage of X-rays in vitro have the function of sustaining the proliferation of hematopoietic cells,both irradiated MSCs layer and supernatant can increase the number of bone marrow cells colony.