脑源性神经营养因子及神经干细胞移植治疗新生大鼠缺氧缺血性脑损伤的实验研究

目的 观察脑源性神经营养因子(BDNF)及神经干细胞(NSCs)联合移植对缺氧缺血性脑损伤(HIBD)的治疗效果.方法 取新生24 h的Wistar大鼠海马NSCs进行培养、鉴定.选7日龄Wistar大鼠制备HIBD动物模型,模型制备后7 d行损伤侧侧脑室移植.将实验大鼠随机分为6组:正常组、模型组、假移植组、NSCs移植组、BDNF组、BDNF+NSCs移植组(联合移植组).移植后4周进行功能实验,取脑组织进行免疫组化免疫荧光检测.结果 从新生大鼠海马可成功培养出NSCs.Y迷宫实验结果:NSCs移植组达到学会的次数及正确记忆次数(163±11.60,5.00±1.13)n;BDNF组(150.00±8.94,5.17±1.47)n;BDNF+NSCs移植组(111.25±13.56,6.23±1.60)n.悬吊实验结果:NSCs移植组平均(30.10±11.8)s;BDNF组(36.25±10.98)s;BDNF+NSCs移植组(43.6±10.56)s.斜坡试验结果:NSCs移植组(20.3±8.25)s;BDNF组(14.33±2.88)s;BDNF+NSCs移植组(11.17±2.48)s.表明联合移植组大鼠学习记忆能力及神经功能与NSCs移植组比较明显改善(P＜0.05),而NSCs移植组大鼠学习记忆能力及神经功能与HIBD组比较,差异无统计学意义(P＞0.05).联合移植组损伤侧额叶皮层、海马存活的NSCs数量(9.31±0.71个,10.10±1.65个)与NSCs移植组(3.33±0.24个,4.22±0.33个)比较差异具有统计学意义(P＜0.01),且NSCs分化为神经元的比例明显增多,与NSCs移植组比较,差异有统计学意义(P＜0.05).结论 BDNF与NSCs联合移植较单独NSCs移植对HIBD有更好的疗效.

Brain-derived neurotrophic factor and neural stem cells transplantation in treatment of hypoxic-ischemic brain injury in rats

Objective To investigate the effects of brain-derived neurotrophic factor(BDNF)on survival,migration and differentiation on of neural stem cells(NSCs)transplanted into the brain of newborn rats with hypoxic.ischeroic brain damage and the recovery of nervous functions.Methods The NSCs were separated from hippocampus of neonatal Wistar rats within 24 h after birtk Brdu.NSE and GFAP were used as markers of differentiation and proliferation of NSCs.The newborn rats were subjected to hypoxic-ischemic condition to induce brain damage.Seven days later,NSCs transplantation wag performed for the animals The rats wera divided into normal control group,HIBD group,PBS group,NSCs transplantation group,BDNF group and BDNF+NSCs transplantation group randomly.At4 weeks after Uznsplantation the nervous function of rats was observed bv Y-maze and nerve behavior test.After they were sacrificed.the rat brains were examined by immunocytochemistry for Brdu and by immunofluorescence for NSE/Brdu.Results The hippocampus NSCs of newborn rat could be well cultured and thev expressed nestin and they could differentiate into NSE.GFAP.Most of NSCs survived in cerebral ventricle 4 weeks after transplantation in brain through Brdu innnunocytochemistry and they migrated into regions of brain extensively,especially to the injured side of cortex and hippocampus.The number of living NSCs in the injured side of cortex and hippocampus of BDNF+NSCs transplantation group increased evidently and the percentage of NSCs differentiated into NSE was higher than that in the NSCs transplantation group(P＜0.05).The nerve function recovery of the rats in BDNF and NSCs treated group Wna significantly better than that in the other groups(P＜0.05).The NSCs group had no prominent changes as compared with the model groups(P＞0.05).Conclusions NSCs can beisolatedfrom newborn rats hippocampus and cultured in vivo.NSCs Can survive.migrate and differentiate into neurons through cerebral ventricle. BDNF could significantly accderate proliferation and differentiation of NSCs transplanted into the brain ofrats with HIBD.The nervous function recovery Was improved prominently by transplantation of NSCs with BDNF application,which may become a potentiatly effective method to treat HIBD.