脐带间充质干细胞在颅脑损伤模型鼠体内的迁徙与定位

Migration and localization of umbilical cord mesenchymal stem cells implanted into brain injury model rats

背景:选择有效的手段,标记和追踪细胞在体内的分布、分化及转归,才能深入探讨细胞发挥治疗效果的具体机制。目的:了解BrdU标记脐带间充质干细胞在颅脑损伤大鼠体内的迁徙和定位情况。方法:分离培养人脐带间充质干细胞并进行细胞表面标志物鉴定,取第3代人脐带间充质干细胞采用BrdU进行标记,MTT法检测细胞增殖能力。将BrdU标记的人脐带间充质干细胞经尾静脉注射到颅脑损伤模型大鼠体内,移植后14 d取损伤处脑组织制备组织切片,倒置荧光显微镜下观察人脐带间充质干细胞的迁徙和定位情况。结果与结论:经流式细胞仪检测,细胞表达CD29、CD44、CD105,不表达造血细胞表面特异性标志CD34和CD45。通过生长曲线可以发现,细胞在接种1-3 d处于调整期,第3-5天进入对数生长期。移植后14 d在脑损伤部位可以观察到BrdU染色阳性细胞,表明移植的人脐带间充质干细胞在大鼠体内发生迁徙,经过大鼠的外周血液循环迁徙达到颅脑损伤部位,实现对损伤部位的有效修复。

BACKGROUND： Choosing an effective means to label and trace the distribution, differentiation and migration of cells in vivo help to further explore the specific mechanism of cells that exert a therapeutic effect. OBJECTIVE： To understand the migration and localization of Brd U-labeled human umbilical cord mesenchymal stem cells in brain injury model rats. METHODS： Human umbilical cord blood samples were obtained, and the isolation of human umbilical cord mesenchymal stem cells was carried out. The primary and passage culture were performed. The phenotype of cells was detected by flow cytometry. Passage 3 human umbilical cord mesenchymal stem cells were labeled using Brd U, and the cell proliferation was detected using MTT method. Brd U-labeled cells were injected into brain injury rats via the tail vein. At 14 days after transplantation, brain tissues in the injury region were cut into sections and the migration and location of the umbilical cord mesenchymal stem cells were observed under invertedfluorescence microscope. RESULTS AND CONCLUSION： Cell surface specific markers CD45 and CD34 were detected by flow cytometry, but the cells could not express CD44, CD105 and CD29. Based on the cell growth curve, the cells came into a conditioning period at 1-3 days of seeding and came into a logarithmic phase at 3-5 days. Brd U-positive cells were visible at the injury region after 14 days, indicating that in the rats, transplanted human umbilical cord mesenchymal stem cells migrated from the peripheral blood to the site of brain injury to achieve the effective repair of injured parts.