甘露醇促进人脐血CD34^+细胞通过血脑屏障静脉迁移至高血压脑梗死大鼠脑组织

Mannitol improves the efficacy of intravenous transplantation of human umbilical cord blood CD34^+ cells for cerebral infarction in hypertensive rats

背景:单纯脐血细胞经静脉移植治疗脑梗死疗效有限,移植细胞经血脑屏障迁入脑内数量不足为重要原因之一。目的:观察血脑屏障开放剂甘露醇对人脐血CD34+细胞经静脉移植治疗高血压大鼠脑梗死疗效的影响。方法:分离人脐血CD34+细胞,脂质体方法转染pEGFPF质粒,制备pEGFP-CD34+细胞;45只雄性SD大鼠经线栓法建立大脑中动脉栓塞模型,造模后24h随机分为3组:实验组注射1×106GFP-CD34+细胞,继之注射20%甘露醇2g/kg;阳性对照组注射1×106GFP-CD34+细胞;空白对照组注射等量生理盐水。结果与结论:①荧光显微镜下实验组每张切片脑组织GFP标记阳性的绿色荧光细胞计数平均值显著多于阳性对照组。②移植后第7天治疗组与其他各组神经功能损害评分差异无显著性意义;移植后28d,各组神经功能均有不同程度恢复,实验组神经功能恢复明显优于阳性对照组和空白对照组(P<0.05)。③实验组与其他两组相比,大鼠脑梗死体积均显著减少。④实验组脑组织匀浆胶质细胞源性神经营养因子水平较阳性对照组、空白对照组明显增高。提示血脑屏障开放剂甘露醇促进静脉移植CD34+细胞通过血脑屏障迁入至脑组织,并增强静脉移植CD34+细胞治疗脑梗死的疗效。

BACKGROUND：Intravenous transplantation of human umbilical cord blood cells（HUCBCs） in treatment of cerebral infarction is limited.Only a small fraction of the grafted cells appears to survive at the damaged brain and the behavioral recovery is only partial.OBJECTIVE：To evaluate the ability of Mannitol,a blood brain barrier（BBB） permeabilizer,to enhance neuroprotective effects of intravenously administered HUCBCs for cerebral infarction in spontaneous hypertensive rats.METHODS：CD34＋ cells isolated from HUCB were transfected by GFP plasmid with liposome method.Forty-five adult male spontaneous hypertensive rats with middle cerebral artery occlusion were randomly divided into three groups at 24 hours after modeling,each of 15：Experimental group,GFP-CD34＋ cells（1×106） and 20% Mannitol（2 g/kg） were administrated intravenously at 24 hours after modeling;Positive control group,GFP-CD34＋ cells（1×106） were only injected intravenously at same time;Blank control group,normal saline was injected at same time.RESULTS AND CONCLUSION：①The number of GFP positive cells in cerebral tissues in the experimental group was increased significantly compared to the positive control group.②No significant difference was found in the neurologic function scores at day 7 after transplantation among the three groups;but at day 28 after transplantation,the neurologic function in the experimental group was improved significantly compared with the positive or blank control group（P〈0.05）.③The cerebral infarct volume in the experimental group was significantly decreased compared with the positive or blank control group.④The glial cell line-derived neurotrophic factor level in cerebral tissue in the experimental group was significantly increased compared with the positive and blank control groups.The results suggested that Mannitol enhanced CD34＋ cells to migrate into ischemic-injured cerebral tissues,and to improve the efficacy of CD34＋ cells delivered intravenously for cerebral infarction in spontaneous hypertensive rats.