The homing of transplanted bone marrow mesenchymal stem cells to the thymus / 中国组织工程研究

ABSTRACT

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.