骨髓间充质干细胞移植后在胸腺内的定居

摘要

BACKGROUND:Bone marrow mesenchymal stem cels have low immunogenicity and can induce immune tolerance. At present, the mechanism of immune regulation of bone marrow mesenchymal stem cels is not completely understood. It has been rarely reported whether the bone marrow mesenchymal stem cels can migrate to the thymus after transplantation. OBJECTIVE:To observe the distribution and survival of bone marrow mesenchymal stem cels in the thymus of aging rats after transplantation. METHODS: Bone marrow mesenchymal stem cels cultured in vitrowere transfected by adenovirus vectors expressing green fluorescent protein. Transfected bone marrow mesenchymal stem cels were injected into the portal vein of aging rats. At days 3, 7, 14, 21 after transplantation, the survival of bone marrow mesenchymal stem cels homing to the thymus was observed under fluorescence microscope. At day 3 after transplantation, thymus tissues were taken and stained with hematoxylin-eosin for pathological observation. RESULTS AND CONCLUSION:Green fluorescent protein-labeled bone marrow mesenchymal stem cels had a strong green fluorescence at days 3 and 7 after transplantation, and the cel contour was clear. There was no significant difference in the mean absorbance values at days 3 and 7 (P> 0.05). Expression of green fluorescent protein was weakened significantly at days 14 and 21 compared with that at day 3 (P < 0.05). At 3 days after transplantation, the transplanted bone marrow mesenchymal stem cels were clearly visible in the thymus, and acute rejection was not observed. The results show that bone marrow mesenchymal stem cels can migrate to the damaged thymus tissue through the blood circulation, and can survive at least 1 week.%背景：骨髓间充质干细胞具有低免疫原性，并可诱导机体产生免疫耐受。目前对骨髓间充质干细胞发挥免疫调节作用的机制还不完全了解，对于骨髓间充质干细胞移植后能否迁移到免疫器官胸腺尚鲜有报道。　　目的：观察骨髓间充质干细胞移植后在衰老模型大鼠免疫器官胸腺组织内的存活情况。　　方法：以腺病毒介导绿色荧光蛋白基因体外转染骨髓间充质干细胞，通过大鼠尾静脉注射移植给衰老模型大鼠，于移植后第3，7，14，21天取材，荧光显微镜下观察骨髓间充质干细胞归巢到胸腺的存活情况。移植骨髓间充质干细胞第3天，取材胸腺组织，进行苏木精-伊红染色，观察移植细胞部位的组织病理变化。　　结果与结论：①骨髓间充质干细胞移植后第3，7天：绿色荧光蛋白荧光表达较强，细胞轮廓清晰，两者平均吸光度值比较，差异均无显著性意义(P>0.05)。②移植后第14，21天：绿色荧光蛋荧光表达较弱，与第3天平均吸光度值相比，差异有显著性意义(P<0.05)。③细胞移植后第3天：胸腺组织切片光镜显示无急性排斥反应特征出现。④结果表明骨髓间充质干细胞可通过血液循环迁移至受损胸腺组织，且至少能够存活1周。