Effect of human umbilical cord blood derived CD34+ cells transpantation on the neurological recovery of rats with cerebral ischemia

Abstract

AIM：CD34+ stem cells are unique primitive cell populations with the characters of self-renewal, multi-differentiation and reconstruction of hematopoietic and immune function. Recent studies have indicated that it has significant effect on myocardial ischemia and physically vascular occlusion. It is known that for a long time the clinical effects of cerebral ischemia were poor, so, we observe the neurological functional recovery after transplanting human umbilical cord blood derived CD34+ cells into rats with middle cerebral artery occlusion (MCAO), and detect the survival, migration and neural differentiation of CD34+ cells.

METHODS： The experiment was performed in the Institute of Hematology, Chinese Academy of Medical Sciences and Peking Union Medical College since May 2002. ①Sixty adult male SD rats of 250-350 g were provided by the Fourth Department of Academy of Military Medical Sciences. All experimental procedures were accorded with the standards of animal ethics. Human umbilical cord blood was provided by cord blood stem cell bank of Tianjin and its application was agreed by the puerperas. ②Rats were randomly divided into three groups (n =20): CD34+ cells group, in which CD34+ cells were transplanted 24 hours after the establishment of models of MCAO using intraluminal thread approach; normal saline group, in which normal saline was injected 24 hours after the establishment of models; sham operation group, in which only models of MCAO were established. ③Functional outcome measurements were performed using the modified neurological severity score after transplantation. Meanwhile, the survival and migration of BrdU-labeled CD34+ cells and the expression of astrocytic marker-GFAP (glial fibriliary acidic protein) and the neuron marker-NeuN (neuronal nuclei) were detected by immunohistochemical and immunofluorescent staining.

RESULTS: ①There was no significant difference in the modified neurological severity score 24 hours after transplantation between CD34+ cell group and other groups (P > 0.05). From 1 to 4 weeks after operation, the neurological function of three groups showed improvement in different degrees, but the rats in CD34+ group had the best recovery (P < 0.05). ②The infarct volume of rats in CD34+ group had no significant decrease compared with the other two groups. ③Transplanted CD34+ cells survived in cerebral tissues of rats, and partial of them expressed GFAP or NeuN maker and migrated towards ischemic tissue.

CONCLUSION:CD34+ cells can survive,migrate and differentiate towards astrocytes or neurons after transplantation. Moreover, they improve the neurological recovery after MCAO.

Liu HY, Li JF, Li HJ, Zhang QJ, Han ZC.Effect of human umbilical cord blood derived CD34+ cells transplantation on the neurological recovery of rats with cerebral ischemia.Zhongguo Zuzhi Gongcheng Yanjiu yu Linchuang Kangfu 2008;12(3):451-455(China) [www.zglckf.com/zglckf/ejournal/upfiles/08-3/3k-451(ps).pdf]

摘要
目的：CD34+造血干细胞具有自我更新、多向分化及重建长期造血和免疫的生物学功能，针对心肌缺血性损伤、肢体血管闭塞引起的组织缺血等治疗有显著的疗效。由于中枢神经系统缺血性损伤临床治疗康复效果不佳，观察人脐带血CD34+细胞移植对大鼠大脑中动脉栓塞后神经功能恢复的影响及CD34+细胞的存活、迁移以及向神经细胞分化的情况。
方法：实验于2002-05起在天津市中国医学科学院中国协和医科大学血液学研究所进行。①实验材料：雄性SD大鼠由解放军军事医学科学院第四研究所提供，体质量250~350 g，实验过程中对动物处置符合动物伦理学标准。人脐带血由天津脐血干细胞库提供，产妇及家属对实验知情同意，并符合医学伦理学标准。②实验方法：将大鼠随机分为3组：CD34+细胞移植组：用线栓法建立大鼠左侧大脑中动脉栓塞模型后24 h移植CD34+细胞；生理盐水组：左侧大脑中动脉栓塞后24 h后注射等量的生理盐水；假手术组：仅行左侧大脑中动脉栓塞。③实验评估：采用改良神经功能损害评分观察大鼠神经功能恢复情况，应用免疫组织化学和免疫荧光双标记技术检测BrdU标记的CD34+细胞存活、迁移及其GFAP蛋白和NeuN蛋白的表达。
结果：①CD34+细胞移植组与其它各组在移植完成24 h 改良神经功能损害评分差异无显著性（P > 0.05）; 移植后1周到第4周，各组动物均有神经功能不同程度的恢复，CD34+细胞移植组神经功能恢复明显优于另两组（P < 0.05）。②CD34+细胞移植组与另两组比较，大鼠脑梗死体积无明显变化。③移植的CD34+细胞可在大鼠脑组织中存活，部分CD34+细胞同时表达GFAP蛋白或NeuN蛋白，并向缺血区域迁移。
结论：CD34+细胞可在大鼠脑缺血区域中存活、迁移并向星形胶质细胞或神经元分化，同时促进神经功能恢复。
关键词：胎血；CD34+细胞；脑缺血；移植；大鼠

刘海英，李建峰，李洪均，张庆俊，韩忠朝.人脐血CD34+细胞移植对局灶性脑缺血大鼠神经功能恢复的影响[J].中国组织工程研究与临床康复，2008，12(3):451-455 [www.zglckf.com/zglckf/ejournal/upfiles/08-3/3k-451(ps).pdf]