骨髓间充质干细胞移植对阿尔茨海默病大鼠行为学的影响*☆

背景：目前研究表明,骨髓间充质干细胞作为包括阿尔茨海默病在内的神经退行性疾病的细胞替代治疗,可能是一种有应用前景的工程细胞,但其对阿尔茨海默病的治疗效果尚不明确。 目的：观察定向诱导骨髓间充质干细胞移植对阿尔茨海默病大鼠行为学的影响,试图发现有效治疗阿尔茨海默病的策略。 设计、时间及地点：随机对照动物实验,于2009-03在武警医学院生理学与病理生理学教研室完成。 材料：健康雄性Wistar大鼠40只,鼠龄24个月,体质量450 g左右。 方法：自然衰老痴呆模型大鼠是通过迷宫试验筛选,将大鼠随机数字表法分为4组,每组10只。对照组大鼠双侧海马注射生理盐水;骨髓间充质干细胞移植组大鼠注射骨髓间充质干细胞;常氧分化移植组大鼠注射常氧环境下向神经元样细胞诱导的骨髓间充质干细胞;低氧分化移植组大鼠注射低氧环境下向神经元样细诱导的骨髓间充质干细胞。 主要观察指标：阿尔茨海默病大鼠的学习和记忆能力在移植前及实验后8周通过Y迷宫试验测定,记忆能力测定在学习能力测定48 h后进行。 结果：对照组阿尔茨海默病大鼠术后学习记忆成绩均下降,与术前相比,差异无显著性意义(P > 0.05);骨髓间充质干细胞移植组大鼠学习记忆成绩提高,与移植前相比差异无显著性意义(P > 0.05);常氧分化移植组和低氧分化移植组大鼠学习记忆成绩均较移植前提高;与对照组相比,其他3组大鼠学习记忆成绩均提高(P < 0.01)。 结论：骨髓间充质干细胞移植可以改善阿尔茨海默病模型大鼠的学习记忆能力,提示骨髓间充质干细胞移植对痴呆大鼠的认知功能障碍有治疗作用,且定向诱导分化的骨髓间充质干细胞移植治疗优于未分化的骨髓间充质干细胞,低氧诱导分化的骨髓间充质干细胞移植治疗效果最佳。     

多巴胺神经元联合中脑神经干细胞移植治疗帕金森病

目的探讨多巴胺神经元联合中脑神经干细胞移植治疗帕金森病大鼠的作用效果。方法体外分离大鼠胚胎腹侧中脑神经干细胞并行增强型绿色荧光蛋白(EGFP)修饰。分离大鼠胚胎多巴胺神经元,并用CM-Di I染料标记。构建经典的6-羟多巴胺毁损帕金森病大鼠模型。采用立体定向注射技术,将细胞移植到帕金森病大鼠纹状体区,阿朴吗啡(APO)腹腔注射诱导其偏侧旋转,评估细胞移植后运动障碍改善情况。采用免疫荧光组织化学鉴定移植细胞的定植存活、迁移及分化。结果细胞移植能显著改善帕金森病大鼠的运动障碍,以多巴胺神经元联合中脑神经干细胞移植(联合移植组)治疗最为显著,有更多的神经干细胞分化为多巴胺神经元。绝大多数移植细胞停留在移植部位,仅极少数向周围脑区迁移。结论多巴胺神经元联合神经干细胞移植治疗帕金森病大鼠可显著改善其运动障碍,其具体相关分子机制还有待进一步研究。     

人脂肪间充质干细胞静脉移植修复脊髓损伤：相关因子及行为学评价

背景：研究证实脂肪间充质干细胞在体外经丹参等诱导剂诱导后可分化为神经元样细胞,因此有可能成为治疗脊髓损伤新的种子细胞。 目的：探讨脂肪间充质干细胞尾静脉移植后,对急性闭合性脊髓损伤大鼠行为学及损伤脊髓组织中各因子表达的影响。 方法：无菌条件下体外分离培养人脂肪间充质干细胞,传至第4代,将细胞收集并制成浓度为1×109 L-1细胞悬液。盐水对照组、细胞移植组大鼠建立脊髓损伤模型,造模成功后1周,细胞移植组经尾静脉注射1 mL干细胞悬液,盐水对照组同法注射等体积的生理盐水,模型对照组不做任何处理。 结果与结论：与模型对照组和盐水对照组比较,细胞移植组大鼠后肢运动功能明显恢复,BBB评分明显升高(P < 0.05);胶质纤维酸性蛋白阳性表达明显减少(P < 0.05),神经元特异性烯醇化酶、巢蛋白的阳性表达均明显升高(P < 0.05)。移植后3 d及1周,在损伤区及临近的脊髓节段可见经荧光染料标记的脂肪间充质干细胞,主要聚集在受损伤脊髓节段1 cm范围内,呈不均匀分布。提示急性闭合性脊髓损伤大鼠经尾静脉移植人脂肪间充质干细胞后,其行为学得到改善,受损脊髓节段局部神经元细胞分化明显增多,修复速度加快。     

脐血间充质干细胞定向诱导分化为神经细胞的研究进展

脐血间充质干细胞是一类能自我更新、能向3个胚层分化的成体干细胞,具有免疫源性低、来源广泛、伦理争议少等优点,是神经干细胞和骨髓间充质干细胞理想的替代细胞.如何在体外高效诱导脐血间充质干细胞向神经元方向定向分化为该领域的研究热点,现阶段诱导方式有:抗氧化诱导、细胞因子诱导、共培养诱导、基因转染诱导等.     

大鼠骨髓间充质干细胞体外培养及分化为神经干细胞的实验研究

目的研究大鼠骨髓间充质干细胞(bone marrow mesenchymal stemcells,MSCs)体外分化为神经干细胞(neural stemcells,NSCs)的可能性。方法取4～6周SD大鼠双侧股骨和胫骨骨髓细胞进行体外培养,通过传代得到纯化的MSCs后换用分化液诱导,通过形态学观察诱导后细胞形态变化,并用免疫荧光检测不同天数细胞nestin的表达率;NSCs分化实验对所诱导的NSC的分化潜能进行检测。结果MSCs诱导后的细胞nestin表达率随天数增加逐渐升高,1周后形成高表达nestin的神经干细胞球形细胞团;在含血清培养基中可自然分化为神经元和神经胶质样细胞。结论MSCs能于体外分化出神经干细胞,且具有进一步的分化能力,骨髓来源的神经干细胞将可能作为种子细胞用于神经系统疾病的治疗。     

小鼠胚胎干细胞诱导的神经前体细胞纹状体移植对PD大鼠的治疗作用

目的 观察来源于小鼠胚胎干细胞的神经前体细胞移植PD大鼠纹状体后的存活、分化以及细胞移植对PD大鼠的治疗作用。方法 采用无血清方法将小鼠胚胎干细胞定向诱导为神经前体细胞，免疫组化技术观察移植细胞的存活、分化。结果 胚胎体在N2选择性培养基选择生长5d后，85％以上的小鼠胚胎干细胞分化为nestin阳性的神经前体细胞。移植到PD大鼠纹状体后大部分神经前体细胞存活良好，移植细胞分别保持为未分化的nestin阳性的神经前体细胞和TH阳性的神经元。移植后3周，PD大鼠的旋转次数明显减少。结论 胚胎干细胞来源的神经前体细胞移植PD大鼠纹状体后能分化为TH阳性的神经细胞，对PD有治疗作用。     

人骨髓间充质干细胞移植老年性痴呆大鼠认知能力和海马超微结构的变化

背景：因发病机制不明,目前尚无治愈老年性痴呆的有效方法。现临床上主要是采用药物治疗,而骨髓间充质干细胞的替代治疗尚处于基础研究阶段,其海马移植后对老年性痴呆认知能力的影响未见报道。 目的：探讨人骨髓间充质干细胞移植对老年性痴呆大鼠认知能力和海马超微结构的影响。 方法：老年雄性Wistar大鼠30只,制备自然衰老痴呆模型,造模后随机分为3组,选取双侧海马为移植区,分化细胞移植组注射定向神经细胞诱导分化的人骨髓间充质干细胞悬液4 μL(2×105个细胞),干细胞移植组注射等量常规培养的人骨髓间充质干细胞,模型组注射等量生理盐水。通过Y迷宫试验测定大鼠的学习、记忆能力,透射电镜观察海马区超微结构。 结果与结论：与移植前大鼠学习、记忆分数比较,移植后12周模型组均显著下降(P < 0.01),干细胞移植组均有所提高(P > 0.05),分化细胞移植组均显著提高(P < 0.01)。移植后12周与模型组比较,干细胞移植组、分化细胞移植组大鼠学习、记忆分数均显著提高(P < 0.01)。电镜观察模型组大鼠海马区神经细胞可见明显损伤,干细胞移植组损伤减轻,分化细胞移植组多数神经细胞结构正常。证实骨髓间充质干细胞移植可以提高老年性痴呆大鼠的认知能力,且定向神经诱导分化的骨髓间充质干细胞移植治疗效果优于未分化的骨髓间充质干细胞,提示骨髓间充质干细胞减少海马组织神经细胞变性坏死可能是其改善老年性痴呆大鼠认知功能障碍的作用机制之一。     

骨髓间充质干细胞诱导分化为神经样细胞的离子通道：是否有电生理特性？

背景：以往研究证实,骨髓间充质干细胞经体外诱导先分化为神经干细胞,然后分化为神经样细胞,但是对于分化的神经样细胞是否具有电生理特性尚不明确。 目的：观察骨髓间充质干细胞诱导分化为神经样细胞的离子通道是否具有电生理特性？ 设计、时间及地点：观察性实验,于2005-03在华中科技大学同济医学院附属同济医院神经内科实验室完成。 材料：4周龄Wistar大鼠37只,雌雄不拘,体质量150 g左右。 方法：取Wistar大鼠股骨和胫骨,进行骨髓间充质干细胞原代培养,传至第15~20代融合状态的间充质干细胞置于预诱导培养基中培养24 h后,换用诱导培养基。在倒置显微镜下连续观察间充质干细胞的形态变化,分别采用免疫组织化学和Western Blot对未经诱导分化的间充质干细胞和诱导后第3天的间充质干细胞进行检测。利用电生理膜片箝技术检测50个骨髓间充质干细胞诱导分化后的神经样细胞。 主要观察指标：记录到的钾电流、GABA电流。 结果：①诱导分化前呈梭形细胞,在加入预诱导培养基后未出现明显的形态变化,换用诱导培养基1 h,胞体开始收缩,出现少数较小的卵圆形或纺锤形细胞,诱导24 h后,约60%细胞变成双极形、多极形和锥形,出现类似神经元细胞的形态。②免疫细胞化学检测未经诱导分化的间充质干细胞无NeuN、Nestin、GFAP表达,诱导分化后第3天的间充质干细胞NeuN表达明显增强,有Nestin表达,无GFAP表达。③Western Blot检测在未诱导分化时和预诱导24 h,无NeuN、Nestin表达,Nestin表达在诱导分化后6 h呈强阳性,在诱导分化24 h和48 h逐渐减弱。NeuN在诱导分化后6 h有表达,在诱导分化后24 h和48 h表达增强。④在检测的50个细胞中,共有25个细胞检测到ATP电流(50%)、GABA电流13个(26%)、总钾电流46(92%)、复极化钾电流46(92%)。 结论：在诱导分化的神经样细胞上存在功能性离子通道,具有电生理特性。     

兔间充质干细胞诱导纹状体神经干细胞分化为神经细胞的研究

目的研究兔纹状体间充质干细胞诱导神经干细胞分化为神经细胞的可行性和机制。方法培养骨髓间充质干细胞(BMSCs)融合达90%时,更换培养基无血清培养24h,收集细胞培养液即为其条件培养基。取成年兔纹状体细胞进行神经干细胞培养,加BMSC条件培养基进行神经干细胞的诱导分化。结果2～4h后神经干细胞开始贴壁,随后有突起从干细胞长出,7d后出现大量不同形态的分裂增殖新生神经细胞,较对照组神经元数量增加,有显著性差异,细胞折光性强,突起长,生存时间延长。结论间充质干细胞能提高神经干细胞诱导分化为神经元的数量,并能延长神经元的生存时间。     

大鼠骨髓间充质干细胞体外增殖与多向分化的能力

背景：生理条件下机体内多数骨髓间充质干细胞增殖并不明显,然而在一定刺激下可表现出旺盛的有丝分裂活动,具有很强的增殖倍增能力,且体外实验表明其具有多向分化潜能。 目的：进一步验证体外分离培养的大鼠骨髓间充质干细胞生长增殖与多向分化潜能。 方法：全骨髓法体外分离培养大鼠骨髓间充质干细胞,贴壁筛选法进行纯化,倒置相差显微镜下观察细胞形态及生长特征,MTT法绘制细胞生长曲线,免疫组化法对细胞表面干细胞标志CD44进行鉴定。取传至第4代细胞,分别用成骨、成软骨、成脂肪和成神经诱导剂予以培养,通过碱性磷酸酶染色、Ⅱ型胶原免疫组化染色、油红O染色、NeuN抗体免疫组化染色进行分化能力鉴定。 结果与结论：分离培养的细胞呈长梭形或多边形,细胞生长曲线呈S形,群体倍增时间约为31 h,免疫细胞化学染色后CD44呈阳性表达,CD34呈阴性。第4代骨髓间充质干细胞成骨诱导2周后出现钙盐沉积,成软骨诱导培养2周后Ⅱ型胶原检测呈阳性,成脂肪诱导培养2周后在细胞的胞浆内充满大量红色脂肪滴,成神经诱导6 h后细胞出现突起,类似神经元的轴突和树突纤维,NeuN免疫组化染色呈阳性。表明体外培养的大鼠骨髓间充质干细胞生长增殖能力旺盛,可向成骨细胞、软骨细胞、脂肪细胞、神经元样细胞方向分化。     

大鼠胚胎神经干细胞移植治疗脑出血的实验研究

目的 研究大鼠胚胎神经干细胞移植治疗脑出血的可行性。方法 从孕龄16天的大鼠胚胎脑组织中分离、培养神经干细胞并诱导其分化，通过免疫组化学技术研究其特性。制作大鼠脑出血模型，3天后将未分化的神经干细胞注入血肿同侧或对侧的尾状核内，记录损伤和移植后的大鼠运动功能。不同时间杀死大鼠，研究移植后的干细胞在体内分化和迁徙的情况。结果 实验中分离、培养的神经干细胞体外能够被诱导分化成神经元、光突胶质细胞和星形胶质细胞，血肿同侧移植干细胞的大鼠运动功能的改善显著好于血肿对侧移植干细胞组及未移植干细胞的对照组。免疫组化方法证实移植后的干细胞在体内可分化成神经元和胶质细胞，并向损伤区域迁徙。结论 大鼠胚胎神经干细胞体内、体外均具有多向分化潜能，其分化成各种类型神经细胞的比例与所处的外界环境有关，在脑内靠近损伤部位移植胚胎神经干细胞后能够有效改善脑出血动物的运动功能。     

神经干细胞和GABA能神经元治疗大鼠颞叶癫痫实验研究

目的探讨并比较神经干细胞(NSCs)和γ-氨基丁酸(GABA)能神经元移植治疗大鼠颞叶癫痫的疗效。方法取孕12 d SD大鼠胎鼠脑组织,分离培养NSCs并鉴定,取第3代NSCs定向诱导分化为GABA能神经元。48只SD大鼠随机分为4组,空白对照组、未移植组、NSCs移植组和GABA能神经元移植组,移植细胞用5-溴脱氧尿苷(BrdU)标记,在模型建立后的第4 d将上述两种细胞移植到癫痫大鼠右侧海马。分别在细胞移植后的4 w、8 w、12 w处死大鼠留取脑标本。常规HE染色和Nissl染色观察大鼠右侧海马的损伤与治疗情况并进行评价。结果 NSCs移植组和GABA能神经元移植组均于移植后第8 w时海马CA3(CA3)区神经元计数最多,组内比较时,与另外两个时间点之间的差异具有统计学意义(P<0.05)。进而取第8 w时间点进行组间比较,结果各组海马区神经元计数之间的差异均具有统计学意义(P<0.05)。结论两治疗组在移植后第8 w时海马区神经元计数最多,且NSC移植组的疗效优于GABA能神经元移植组。     

Induction of GABAergic phenotype in a neural stem cell line for transplantation in an excitotoxic model of Huntington's disease

The implementation of cell replacement therapies for Huntington's disease using multipotent neural stem cells (NSCs) requires the specific differentiation into gamma-aminobutyric acid (GABA) neuronal subtype before transplantation. Here we present an efficient culture procedure that induces stable GABAergic neurons from the immortalized striatal neural stem cell line ST14A. This process requires sequential retinoic acid treatment and KCl depolarization. Initial addition of 10 microM retinoic acid increased cell survival and promoted neuronal differentiation. Subsequent stimulation with 40 mM KCl induced specific differentiation into GABAergic neurons, yielding 74% of total cultured cells. KCl-evoked Ca(2+) influx reduced cell proliferation and nestin expression, and induced neurite outgrowth and GABAergic markers as well as GABA contents, release, and uptake. Characterization of the integration, survival, and phenotype of these predifferentiated GABAergic neurons following transplantation into the adult brain in a model of Huntington's disease revealed long-term survival in quinolinate-lesioned striata. Under these conditions, cells maintained their GABAergic phenotype and elaborated neurite processes with synaptic contacts with endogenous neurons. In conclusion, we have generated a homogeneous population of functional GABAergic neurons from a neural stem cell line, which survive and maintain their acquired fate in vivo. These data may lend support to the possibility of cell replacement therapies for Huntington's disease using neural stem cells.     

神经干细胞移植治疗颞叶癫痫的近期效果研究

目的探讨神经干细胞移植治疗颞叶癫痫的疗效。方法首先建立大鼠的海人酸颞叶癫痫模型。然后从胚胎大鼠的海马中分离培养出神经干细胞,将预诱导的、向氨基丁酸能神经元方向分化的胚胎神经干细胞移植入颞叶癫痫模型的海马内,在移植后1w、2w、3w和4w分别进行移植癫痫大鼠的癫痫最低阂值的测定、海马中氨基丁酸的测定和移植的神经干细胞在体内分化情况的鉴定。结果移植后的癫痫最低阈值和海马中的氨基丁酸逐渐增加,接近但未达到正常值,预诱导的神经干细胞全部分化为氨基丁酸能神经元。结论神经干细胞移植治疗颞叶癫痫具有一定效果。     

红景天苷和脑源性神经营养因子与神经干细胞共移植对致鼠神经干细胞定向分化的研究

目的：探讨红景天苷和脑源性神经营养因子（BDNF）、神经干细胞（NSCs）共移植对致鼠NSCs定向分化影响。方法：将戊四氮致大鼠分为模型组、NSCs组、NSCs＋BDNF组和NSCs＋BDNF＋红景天苷组。取新生大鼠海马组织,将培养的NSCs与BDNF＋红景天苷＋BDNF和基础培养基分别移植至致鼠海马组织中,苏木精-伊红染色及免疫组化检测不同时间点5-溴脱氧尿嘧啶核苷（BrdU）、谷氨酸脱羧酶（GAD65）阳性细胞数,并观察大鼠行为学改变。结果：NSCs＋BDNF＋红景天苷共移植组与其他组比较,各时间点BrdU、GAD65阳性细胞数均增多（P〈0.05）。第3周开始,大鼠癫发作次数最少（P〈0.05）。结论：BDNF与红景天苷联合有利于神经干细胞向γ-氨基丁酸能神经元分化。两者联合移植至致鼠后能减少大鼠的癫发作次数。     

Glutamate decarboxylase (GAD67 and GAD65) gene expression is increased in a subpopulation of neurons in the putamen of parkinsonian monkeys

The cellular distribution of the mRNAs encoding for the two isoforms of glutamate decarboxylase, GAD67 and GAD65, was analyzed by in situ hybridization histochemistry in the caudate nucleus and putamen of control and 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP)-treated parkinsonian squirrel monkeys. On brain sections processed with a radioactive and a digoxigenin-labeled cRNA probe, the GAD67 and GAD65 mRNAs were colocalized in virtually all labeled neurons of the caudate nucleus and putamen, in both control and MPTP-treated monkeys. Furthermore, neurons labeled with the GAD cRNAs constituted at least 90% of all striatal neurons, as estimated on adjacent Nissl-stained sections. In the two groups of monkeys, double-labeling experiments using a combination of radioactive GAD67 or GAD65 and digoxigenin-labeled preproenkephalin (PPE) cRNA probes showed that roughly half of all neurons labeled with the GAD cRNAs were also labeled with the PPE cRNA probe. When compared to controls, GAD67 and GAD65 mRNA levels were higher in the putamen, and to a lesser extent in the caudate nucleus, of MPTP-treated monkeys. Further analysis of labeling at the cellular level in a dorsolateral sector of the putamen revealed that GAD67 and GAD65 mRNA levels in MPTP-treated monkeys were increased in PPE-labeled (presumed striato-pallidal) neurons but not in PPE-unlabeled (presumed striato-nigral) neurons. Our results demonstrate that most neurons in the caudate nucleus and putamen of squirrel monkeys contain the mRNAs encoding for the two GAD isoforms. In addition, the selective increase in GAD mRNA levels in PPE-labeled neurons provides further evidence that striato-pallidal GABAergic neurons are hyperactive in MPTP-treated parkinsonian monkeys. Synapse 27:122–132, 1997. © 1997 Wiley-Liss, Inc.     

Castration Decreases Single Cell Levels of mRNA Encoding Glutamic Acid Decarboxylase in the Diagonal Band of Broca and the Sexually Dimorphic Nucleus of the Preoptic Area

Using quantitative in situ hybridization histochemistry (ISHH), we determined the effect of castration on single cell levels of glutamic acid decarboxylase (GAD) mRNA in discrete hypothalamic regions of the male rat brain associated with the control of gonadotropin secretion. A 48-base oligodeoxynucleotide probe was used to detect with equal affinity the two isoforms of GAD message, GAD₆₅ and GAD₆₇. GAD message also was quantitated in a number of selected areas of the brain to contrast GAD gene expression amongst several populations of GABAergic neurons. Comparison of 11 brain regions demonstrated a 9.3-fold range in the quantity of single cell GAD mRNA with levels being highest in the amygdala and the diagonal band of Broca, moderate in the piriform cortex, caudate nucleus, substantia innominata, globus pallidus, cingulate cortex and medial septal nucleus, and lowest in the lateral septal nucleus and the medial preoptic nucleus (MPN). Castration markedly reduced single cell GAD mRNA levels in the DBB and the MPN, two discrete hypothalamic structures known to contain dendritic fields, cell bodies, and axons of GnRH neurons projecting to the median eminence. A striking finding was a dense core of steroid-sensitive GABAergic neurons within the MPN comprising the sexually dimorphic nucleus of the preoptic area (SDN-POA). Similar to the MPN as a whole, the amount of GAD mRNA expressed by cells in the SDN-POA of sham operated control rats was greater than in castrated animals. GAD mRNA levels were inversely related to serum LH titers, suggesting a role for these neurons in the mechanism controlling gonadal steroid negative feedback on LH secretion. This report provides the basis for future work to determine if GAD₆₅, GAD₆₇ or whether both isoforms are affected by gonadal steroid input.     

Neuromodulation for Parkinson's disease]

Parkinson's disease (PD) is a neurodegenerative disorder characterized by a progressive loss of midbrain dopaminergic (DA) neurons and a subsequent reduction in striatal dopamine. As a treatment for advanced Parkinson's disease, deep brain stimulation (DBS) of the thalamus was introduced in 1987 to treat tremor, and was applied in 1993 to the subthalamic nucleus. Now high-frequency stimulation of the subthalamic nucleus has become a surgical therapy of choice. Another surgical treatment is a cell replacement therapy. Transplantation of fetal dopaminergic (DA) neurons can produce symptomatic relief, however, the technical and ethical difficulties in obtaining sufficient and appropriate donor fetal brain tissue have limited the application of this therapy. Then, neural precursor cells and embryonic stem (ES) cells are expected to be candidates of potential donor cells for transplantation. We induced DA neurons from monkey ES cells, and analyzed the effect of transplantation of the DA neurons into MPTP-treated monkeys as a primate model of Parkinson's disease. Behavioral studies and functional imaging revealed that the transplanted cells functioned as DA neurons, attenuating the MPTP-induced neurological symptoms. DA neurons have also been generated from several human ES cell lines. Furthermore, functional recovery of rat PD models after transplantation was observed. One of the major problems in ES cell transplantation is tumor formation, which is caused by a small fraction of undifferentiated ES cells in the graft. So, it is essential for undifferentiated ES cells to be eliminated from the graft in order for transplantation to be feasible. These efforts will lead to clinical application of ES cell transplantation to the patients with PD.     

Human neural stem cells promote proliferation of endogenous neural stem cells and enhance angiogenesis in ischemic rat brain

Transplantation of human neural stem cells into the dentate gyrus or ventricle of rodents has been reportedly to enhance neurogenesis. In this study, we examined endogenous stem cell proliferation and angiogenesis in the ischemic rat brain after the transplantation of human neural stem cells. Focal cerebral ischemia in the rat brain was induced by middle cerebral artery occlusion. Human neural stem cells were transplanted into the subventricular zone. The behavioral performance of human neural stem cells-treated ischemic rats was significantly improved and cerebral infarct volumes were reduced compared to those in untreated animals. Numerous transplanted human neural stem cells were alive and preferentially localized to the ipsilateral ischemic hemisphere. Furthermore, 5-bromo-2′-deoxyuridine-labeled endogenous neural stem cells were observed in the subventricular zone and hippocampus, where they differentiated into cells immunoreactive for the neural markers doublecortin, neuronal nuclear antigen Neu N, and astrocyte marker glial fibrillary acidic protein in human neural stem cells-treated rats, but not in the untreated ischemic animals. The number of 5-bromo-2′-deoxyuridine-positive ? anti-von Willebrand factor-positive proliferating endothelial cells was higher in the ischemic boundary zone of human neural stem cells-treated rats than in controls. Finally, transplantation of human neural stem cells in the brains of rats with focal cerebral ischemia promoted the proliferation of endogenous neural stem cells and their differentiation into mature neural-like cells, and enhanced angiogenesis. This study provides valuable insights into the effect of human neural stem cell transplantation on focal cerebral ischemia, which can be applied to the development of an effective therapy for stroke.     

Transplantation of adipose tissue-derived stem cells for treatment of focal cerebral ischemia

The neurological functional disabilities caused by cerebral infarction significantly deteriorate life quality and increase the medical and socio-economic costs. Although some molecular agents show potential in acting against the pathological mechanisms in animal studies, none has been proven effective for cerebral ischemia treatment in human patients. New treatment strategy needs to be developed. Stem cell therapy is promising for neural regeneration and thus become one of the current trends. More evidence has shown stem cells, such as embryonic stem cells (ESCs), skeletal muscle satellite cells and mesenchymal stem cells, to be useful in tissue repair and regeneration. However all these stem cells mentioned above have limitations. Adipose tissue-derived stem cells (ADSCs) are an alternative autologous stem cell source for the characters as abundant, easy to obtain, immunological and ethic problem free. So far, this treatment strategy has been rarely adopted on ischemic brain injury. In this study, we investigated the transplantation effects of rat ADSCs for the treatment of cerebral ischemia in rats. ADSCs were isolated from rat adipose tissue and then induced to initiate neural differentiation. Following neural induction, ADSCs developed neural morphology and displayed molecular expression of Nestin, MAP2 and GFAP. We evaluate the neurobehavioral function, infarct volume and cell properties as apoptosis, survival, migration, proliferation, differentiation and immunogenicity. Treatment with i-ADSCs (induction from ADSCs) results in better functional recovery and more reduction in hemispheric atrophy then without i-ADSCs in other groups. Our study demonstrates that i-ADSCs therapy is promising in stroke treatment and finally leads to an efficacious therapeutic modalities for much better outcome in clinical patients.