骨髓间充质干细胞在全身照射大鼠体内分布实验研究

目的 用荧光定量RT-PCR方法探讨骨髓间充质干细胞在大鼠经过全身照射后其体内分布的状况.为进一步研究骨髓间充质干细胞(MSCs)对正常组织器管放射性损伤的治疗提供理论依据.方法 培养MSCs细胞,用绿色荧光蛋白标记.分别对大鼠行全身照射及全身照射+全脑照射,经尾静脉注入标记的MSCs,荧光显微镜观察MSCs在各器官的分布,荧光定量RT-PCR检测MSCs在不同组织器官的分布.结果 获得绿色荧光标记MSCs,经尾静脉注入各实验组大鼠体内后显示,未行照射时MSCs仅少量分布在肺、骨髓、脾中;6 Gy全身照射后各器官MSCs的分布明显增加,小肠、骨髓等早反应组织增加的更显著;7 Gy全身照射进一步增加了各器官MSCs数量;6 Gy全身照射+全脑照射20 Gy后MSCs在大脑的分布明显增多,在其他器官的发布也明显增加.结论 放射损伤可诱导MSCs产生趋化作用;MSCs在各器官分布随照射剂量及放射损伤程度增加而增多;局部照射可增加局部及其他器官MSCs分布.

The distribution of mesenchymal stem cells after total-body irradiation in rats

Objective To detect the distribution of mesenchymal stem cells(MSCs) after total-body irradiation in rats. Methods MSCs were cultured and labeled with green fluorescent protein(GFP). Rats were exposed to total-body irradiation(TB1) or TBI plus total brain irradiation, and then MSCs were injected through the tail vein. The Fluorescent MSCs were observed by fluorescence microscope. The MSCs numbers in different organs were determined by quantitative RT-PCR method. Results GFP-labeled MSCs were ob-tained. After MSCs were infused to the rats,few of them were observed in the organs of nonirradiated group except for a very low number in the lungs,bone marrow(BM) and spleen. TBI of 6 Gy increased the engraft-ment of MSCs in almost all the organs, especially in early response tissues such as the small intestine and BM. TBI of 7 Gy further increased the number of MSCs. The MSCs numbers in the brain and other organs were significantly increased after 20 Gy total brain irradiation in addition to 6 Gy TBI. Conclusions Radi-ation injury can induce the aggregation of MSCs. With the increase of radiation dose and severity of radiation injury,a significant increase of MSCs in different organs were observed. Local irradiation can increase the MSCs distribution in the radiation field as well as other organs.