Castanheira Paula, Torquetti Leonardo Torquetti, Magalhãs Débora Rodrigues Soares, Nehemy Marcio B, Goes Alfredo M
Department of Biochemistry and Immunology, Biological Sciences Institute, Federal University of Minas Gerais, Belo Horizonte, Brazil.
Cell Transplant. 2009;18(4):423-31. doi: 10.3727/096368909788809811.
To evaluate DAPI (4',6-diamidino-2-phenylindole) as a nuclear tracer of stem cell migration and incorporation it was observed the pattern of retinal integration and differentiation of mesenchymal stem cells (MSCs) injected into the vitreous cavity of rat eyes with retinal injury. For this purpose adult rat retinas were submitted to laser damage followed by transplantation of DAPI-labeled BM-MSCs grafts and double-labeled DAPI and quantum dot-labeled BM-MSCs. To assess a possible DAPI diffusion as well as the integration and differentiation of DAPI-labeled BM-MSCs in laser-injured retina, host retinas were evaluated 8 weeks after injury/transplantation. It was demonstrated that, 8 weeks after the transplant, most of the retinal cells in all neural retinal presented nuclear DAPI labeling, specifically in the outer nuclear layer (ONL), inner nuclear layer (INL), and ganglion cell layer (GCL). Meanwhile, at this point, most of the double-labeled BM-MSCs (DAPI and quantum dot) remained in the vitreous cavity and no retinal cells presented the quantum dot marker. Based on these evidences we concluded that DAPI diffused to adjacent retinal cells while the nanocrystals remained labeling only the transplanted BM-MSCs. Therefore, DAPI is not a useful marker for stem cells in vivo tracing experiments because the DAPI released from dying cells in moment of the transplant are taken up by host cells in the tissue.
为了评估4',6-二脒基-2-苯基吲哚（DAPI）作为干细胞迁移和整合的核示踪剂，观察了注射到视网膜损伤大鼠眼玻璃体内的间充质干细胞（MSC）的视网膜整合和分化模式。为此，对成年大鼠视网膜进行激光损伤，然后移植用DAPI标记的骨髓间充质干细胞移植物以及用DAPI和量子点双重标记的骨髓间充质干细胞。为了评估DAPI可能的扩散以及DAPI标记的骨髓间充质干细胞在激光损伤视网膜中的整合和分化，在损伤/移植后8周对宿主视网膜进行评估。结果表明，移植后8周，所有神经视网膜中的大多数视网膜细胞呈现核DAPI标记，特别是在外核层（ONL）、内核层（INL）和神经节细胞层（GCL）。同时，此时，大多数双重标记的骨髓间充质干细胞（DAPI和量子点）仍留在玻璃体内，没有视网膜细胞呈现量子点标记。基于这些证据，我们得出结论，DAPI扩散到相邻的视网膜细胞，而纳米晶体仅保持对移植的骨髓间充质干细胞的标记。因此，DAPI在体内追踪实验中不是干细胞的有用标记物，因为移植时从死亡细胞释放的DAPI会被组织中的宿主细胞摄取。
