脑缺血大鼠骨髓间质干细胞移植后脑内分布与迁移

目的观察骨髓间质干细胞移植后在脑缺血大鼠脑内的存活、分布及迁移情况。方法Fieoll-Paque分离液梯度离心分离大鼠骨髓间质干细胞（rat bone mesenchymal stem cells，rMSCs），经体外培养扩增并流式细胞术鉴定；线拴法制作大鼠大脑中动脉闭塞（MCAO）脑局灶缺血模型，Hoechst33342标记细胞，分别通过静脉移植及立体定向局部移植到大鼠缺血侧纹状体。经过1、3、5周处死大鼠，取脑组织切片，在倒置荧光显微镜下观察细胞在脑内的存活、分布及迁移情况。结果应用梯度离心方法可以分离得到rMSCs，经过体外扩增可得到足够细胞数量用于移植，流式细胞术检测CD34、CD45表达阴性，CD29、CD90表达阳性。大鼠脑缺血后，无论静脉还是局部移植，rMSCs在脑内均能较长时间存活，移植细胞与宿主有很好组织相容性。静脉移植的细胞集中于脑缺血灶及其周围，缺血灶对侧脑组织移植的细胞较少（P〈0．05）；局部移植的细胞随着时间的推移向缺血灶不断迁移，分布在两侧大脑的差别都具有统计学意义（P〈0．05）。结论rMSCs通过静脉及立体定向两条途径进行移植后，能够在宿主缺血的脑中存活，向损伤部位迁移。rMSCs的这种迁移现象很可能与缺血灶的细胞信号改变有关，在临床上具有很大的潜在价值。

Distribution and migration of transplanted rat bone marrow stromal cells in the ischemic brain in vivo.

Objective To investigate the survival,distribution and migration of transplanted bone stromal cells in the ischemic brain in vivo.Methods Rat bone mesenchymal stem cells were isolated from adult rats bone marrow by Ficoll-Paque density gradients,cultured and amplified in vitro,and then identified by flow cytometry;Middle cerebral artery occlusion model of regional cerebral ischemia in rats were made by thread embolizing.24 hours later,rMSCs labeled by Hoechst 33342 were administrated into the adult rats through intravenous transplantation or stereotaxis infusion.Fluorescent microscope was used to observe the survival,distribution and migration of transplanted rMSCs 1,3,5 weeks later.Results rMSCs could be isolated from adult rats bone marrow by Ficoll-Paque density gradients,and the amplified rMSCs were enough for transplantation.FCM showed that rMSCs were negative for CD34,CD45,positive for CD29,CD71.Regardless of intravenous or local transplantation,rMSCs could survived and had compatibility with host.rMSCs intravenously administrated migrated and surrounded the ischemic focus,and the number of the transplanted rMSCs distributed in opposite hemicerebrum was fewer(P<0.05);and rMSCs locally administrated migrated to ischemic focus unceasingly.there was significant difference in the number of the transplanted rMSCs distributed in the hemicerebrum(P<0.05).Conclusion rMSCs are able to survive and migrate to ischemic brain tissue through two different administrations.rMSCs may provide an autoplastic therapy for ischemic stroke via intravenous transplantation.