全身照射大鼠骨髓提取液对真皮多能干细胞趋化作用的实验研究

目的　观察 5Gyγ射线全身照射后大鼠骨髓提取液对真皮多能干细胞 (dermalmultipotentstemcells ,dMSCs)的趋化作用 ,并定量分析尾静脉输注的dMSCs在大鼠体内的分布。方法　在Transwell培养体系中 ,观察骨髓提取液对dMSCs的趋化作用。3H TdR标记dMSCs ,经尾静脉输注到大鼠体内后 ,液闪法测量各组织内dMSCs的含量。结果　Transwell培养体系中 ,照射组骨髓提取液组从上层迁移到下层的细胞明显多于不照射的正常对照组和生理盐水组 (P <0 0 1)。照射后 1周始 ,照射组骨髓dMSCs含量明显高于正常对照组 (P <0 0 1) ;伤后 3周和 4周 ,照射组单位重量骨髓dMSCs含量也明显高于同组的肺脏、肝脏等组织。结论　全身照射大鼠骨髓提取液对dMSCs有很强的趋化作用 ,从而促进静脉输注的dMSCs偏向分布于损伤的骨髓。

Experimental study of chemotactic effects of total body irradiation in rat bone-marrow extracts on dermal multipotent stem cells

Objective To observe the effects of bone-marrow (BM) extracts from rats with total body irradiation (TBI) on the migration of dMSCs and to measure the distribution of transplanted dMSCs in rats quantitatively. Methods A microchemotaxis chamber, Transwell system, was used to observe the effects of BM extracts on the migration of dMSCs. Rat dMSCs labeled with 3H-TdR were transplanted into rats and the distribution in various organs were measured by liquid scintillation. Results BM extracts from TBI rats significantly increased dMSCs migration across the membrane of the microchemotaxis chamber as compared with those in the control group (P<0.01). From 1 week after injury, the amount of dMSCs in BM of TBI rats was larger than that of the non-injured rats (P<0.01). As far as per gram tissue was concerned, the amount of dMSCs in BM was greater than that of lung and liver in TBI rats at 3 and 4 weeks after TBI. Conclusions Our results suggest that BM extracts from TBI rats can enhance the migration of dMSCs, and thus promote the transplanted dMSCs to migrate to irradiation-injured BM.