骨髓间充质干细胞移植治疗脑梗死大鼠的研究

Treatment of Intravenous Administration of Bone Marrow Stromal Cells in Cerebral Infarction Model Rats

目的研究静脉移植骨髓间充质干细胞(bone marrow stromal cells,BMSCs)对脑梗死模型大鼠的影响。方法对10只同种异体SD大鼠的BMSCs进行体外分离、培养、扩增、纯化后,用5-溴脱氧尿嘧啶核苷(5-bromodcexyurid ine,BrdU)进行标记;大脑中动脉线栓发制作脑梗死动物模型,制模后7 d,完全随机分为A、B、C 3组:A组22只,做为BMSCs移植组,经鼠尾静脉注射2.0×106/mL的BMSCs细胞悬液;B组22只,做为对照组,注射1.0 mL培养液;C组22只,做为空白手术对照组。注射后2、3、6周,免疫组织化学检测BMSCs在梗死周围区的存活、分布、分化并计数,观察损伤脑内生长相关蛋白-43(growth associatedprotein-43,GAP-43)、神经丝蛋白200(neurofilament 200,NF200)和巢蛋白的表达,注射后1、2、3、4、5、6周,进行评分。结果移植后2、3、6周,BrdU阳性的BMSCs主要分布于脑梗死周围区。计数发现,移植后2周,BrdU阳性的BMSCs约占移植细胞数的5.9%,3周占5.3%,6周占3.9%;移植后2周,BMSCs形态大多变为圆形或椭圆形,部分阳性标记的细胞长出神经元样突起,约12.6%表达胶质纤维酸性蛋白(glialfribrillary acid ic protein,GAFP),约6.3%表达神经元特异性核蛋白(neuronal nuclear antigen,NeuN);移植后2、3、6周,A组GAP-43、NF200、巢蛋白的表达,明显高于B、C组(P<0.05);移植后3周开始,A组的评分在各观察时间点明显高于B、C组(P<0.05)。结论通过静脉注射的BMSCs能向梗死病灶内迁徙、存活,表现出对梗死灶的趋化性,并向神经元和星形胶质细胞分化,上调GAP-43、NF200和巢蛋白的表达,改善神经功能,可应用于治疗脑梗死。

Objective To observe the effect of intravenous administration of bone marrow stromal cells（BMSCs） on the functional after cerebral infarction in rats.Methods BMSCs harvested from 10 donor adult Sprague-Dawley rats were isolated,cultured,purified,amplified and labeled with bromedeoxyuridine（BrdU）.A total of 66 adult Sprngue-Dawley rats were subjected to middle cerebral artery occlusion（MCAO） causing cerebral infarction and randomly divided into three groups seven days after MCAO.Group A（22 rats） was treated with 2.0×106 BMSCs cultured in 1.0 mL phosphate-buffered saline by tail vein,Group B（22 rats）was treated with 1.0 mL Dulbecco modified Eagle medium and Group C（22 rats）was set as blank control group.The distribution and differentiation of donor ceils in spinal cord were observed in recipient rats by using immunohistochemical staining and expressions of growth associated protein-43（GAP-43）.neurofilament 200（NF200）and nestin in the contused spinal cord measured at 2,3 and 6 weeks respectively after injection.The motor function of three groups was evaluated at 1,2,3,4,5 and 6 weeks respectively after injection.Results BrdU-reactive cells were mainly distributed near regions of infarction region at 2,3 and 6 weeks after injection.The survived cells in infarction region accounted for 5.9%,5.3%and 3.9%of the injection cells at 2,3 and 6 weeks respectively after injection.Two weeks after injection,BMSCs were mainly round or ellipse in shape.12.6% BrdU-reactive cells expressed glial fibrillary acidic protein（GFAP）and 6.3%expressed the neuronal nuclear antigen（NeuN）.The expressions of GAP-43.NF200 and nestin were detected at 2,3 and 6 weeks after injection,with significant higher level in Group A than that in Groups B and C（P0.05）.Score in Group A was significantly higher than that in Groups B and C 3~6 weeks after transplantation（P0.05）.Conclusion With intravenous administration after spinal cerebral infarction,BMSCs migrate and survive into infarction region,exhibit site-dependent differentiation,up-regulate the expressions of GAP-43,NF200 and nestin,ameliorate nerve function and can be used for treatment of cerebral infarction.