脐血间充质干细胞移植后帕金森病大鼠纹状体内多巴胺含量的变化

背景：目前干细胞移植对帕金森病动物模型的研究多集中在骨髓间充质干细胞和胚胎干细胞方面,关于脐血间充质干细胞移植对帕金森病动物模型的研究相对较少,且未见测量脐血间充质干细胞移植前后多巴胺含量变化的报道。 目的：观察脐血干细胞移植对帕金森病大鼠纹状体内多巴胺含量的影响。 方法：帕金森病模型大鼠随机分成实验组和对照组。将第3代脐血间充质干细胞用Hoechst33258标记后植入实验组大鼠纹状体内,对照组注射磷酸盐缓冲溶液。移植后2,4,8周用免疫荧光双标法检测间充质干细胞的存活、迁移以及胶质纤维酸性蛋白、神经元特异性烯醇化酶、酪氨酸羟化酶和突触素的表达。移植后8周利用高效液相色谱-电化学检测仪检测纹状体多巴胺含量。 结果与结论：脐血间充质干细胞移植后可在大鼠脑内存活,随时间延长迁移范围扩大,分布于纹状体、胼胝体和皮质;胶质纤维酸性蛋白、神经元特异性烯醇化酶、酪氨酸羟化酶都有表达,突触素无表达。多巴胺水平与对照组相比有明显提高 (P < 0.05)。     

神经干细胞转基因移植治疗帕金森病的可能与可行*

背景：神经干细胞分化为何种类型的神经细胞,不仅取决于细胞自身基因调控,更受所处环境中外来信号的影响。 目的：就神经干细胞生物学特性、分化以及转基因移植治疗帕金森病的研究进展进行综述。 方法：由第一作者应用计算机检索PubMed数据库1992-01/2009-12及中国期刊网全文数据库2003-01/2010-12有关神经干细胞生物学特性、分化以及转基因移植治疗帕金森病的文章,英文检索词为“neural stem cell(NSCs), neural stem cell transplant, Parkinson’s disease(PD)”,中文检索词为“神经干细胞,干细胞移植,帕金森病”。排除重复性研究及Meta分析,共保留30篇文献进行综述。 结果与结论：转基因神经干细胞移植治疗帕金森病是目前公认的最有前景的治疗方案。在低氧条件下转基因培养的神经干细胞,能高效地诱导分化为多巴胺能神经元,为移植治疗帕金森病提供细胞源。但神经干细胞的生物学特性、诱导分化等还有待进一步分析。同时应用于人体治疗的生物安全性问题也逐渐引起人们的重视,如致瘤性等问题均在进一步探索中。     

人神经干细胞移植在大鼠帕金森病模型中的神经保护机制

神经干细胞（neural stem cells，NSCs）具有自我更新和神经分化的能力。我们在此探讨移植转染了v-myc基因的HB1.F3细胞克隆是否为治疗帕金森病的一个可行手段。体内绿色荧光蛋白标记的HB1．F3细胞（200，000个活细胞每3μL）立体定向移植（即日病灶移除范例）与对照组（营养因子或灭活细胞移植）相比帕金森病行为症状明显减轻的病鼠模型的6-羟基多巴胺毁损纹状体。此移植的影响来自酪氨酸羟化酶（tyrosine hydroxylase，TH）免疫反应性在黑质-纹状体通路上的保护作用。移植的HB1.F3细胞在神经元标志丝裂素活化蛋白2标记及突触体素阳性反应端标记的受损大脑中能够存活。而且，内源性神经发生在移植大鼠脑室下区被激活。为了进一步研究HB1．F3细胞移植后的神经保护机制，研究人员进行了细胞培养研究．发现大量HB1．F3细胞都是酪氨酸羟化酶、多巴胺和环磷酸腺苷调节的磷酸化蛋白32表达阳性细胞，同时大多数细胞也呈巢蛋白阳性表达，表明这一群细胞为成熟和未成熟细胞的混合体。[第一段]     

神经干细胞移植治疗帕金森病的研究进展

帕金森病(PD)是一种常见的中枢神经系统变性疾病，发病率约为1％，其病理特征主要是中脑黑质．纹状体通路多巴胺能神经元进行性变性，造成纹状体内多巴胺含量减少，当黑质纹状体多巴胺能神经元丢失70％时出现典型的临床症状。PD的最初药物治疗给许多患者带来了益处，但疗效是暂时的，因为左旋多巴并不能阻止多巴胺能神经元的进行性     

基因修饰的神经干细胞脑内移植后TH表达和神经递质的变化

目的：探讨经TH基因修饰的神经干细胞脑内移植后，PD模型动物脑内TH表达和神经递质的变化。方法：构建pN2ATH逆转录病毒载体质粒，用PA317细胞包装，G418筛选阳性克隆，病毒上清感染神经干细胞，将神经干细胞和表达TH的神经干细胞植入PD大鼠纹状体内，观察移植后TH的表达情况以及DA和DOPAC含量变化。结果：TH基因修饰的神经干细胞移植2月内，TH在纹状体内的表达增加，纹状体DA和DOPAC含量增高，好于单纯神经干细胞移植组和对照组，但比正常水平低，结论：TH基因修饰的神经干细胞，脑内移植能增加纹状体内TH的表达以及DA和DOPAC含量，为其脑内移植治疗PD提供了理论基础。     

干细胞移植治疗帕金森病研究进展

帕金森病(Parkinson's disease,PD)是一种人类常见的中枢神经系统退行性疾病,主要病理变化是黑质内多巴胺神经元损伤,是干细胞治疗的最佳适应证之一.动物模型的研究证实,干细胞移植可以替代丧失的神经元,恢复脑功能和促进脑的自我修复.临床试验显示干细胞移植在PD病人脑部也可达到类似的结果.这些研究展示了干细胞移植临床应用治疗PD的良好前景.然而,这样的治疗是否可以永久和完全恢复PD的脑功能仍是一个疑问.     

干细胞移植治疗帕金森病研究进展

帕金森病 (Parkinson’sdisease,PD)是一种人类常见的中枢神经系统退行性疾病 ,主要病理变化是黑质多巴胺神经元损伤 ,是干细胞治疗的最佳适应证之一。动物模型的研究证实 ,干细胞移植可以替代丧失的神经元 ,恢复脑功能和促进脑的自我修复。临床试验显示干细胞移植在PD病人脑部也可达到类似的结果。这些研究展示了干细胞移植临床应用治疗PD的良好前景。然而 ,这样的治疗是否可以永久和完全恢复PD的脑功能仍是一个疑问。     

GFP转基因小鼠神经干细胞移植治疗大鼠帕金森病的实验研究

目的观察GFP(绿色荧光蛋白)转基因小鼠胚胎神经干细胞植入帕金森病大鼠纹状体后的存活、分化情况及治疗作用。方法建立PD模型大鼠及体外培养神经干细胞,然后将GFP转基因小鼠神经干细胞定向植入帕金森病大鼠毁损侧纹状体内,于移植后不同时间诱发旋转行为,并与对照组相比,观察症状的改善,并用酪氨酸羟化酶(TH)免疫组织化学染色方法检测移植GFP转基因小鼠神经干细胞的存活及分化状况。结果 GFP转基因小鼠神经干细胞脑内移植后,帕金森病大鼠的旋转行为明显改善。移植后2至4周时可检测到成片或散在的TH免疫阳性细胞。结论 GFP转基因小鼠神经干细胞移植至帕金森病大鼠纹状体后,可分化为多巴胺能神经元并能改善旋转症状。     

雪旺细胞和神经干细胞共移植治疗大鼠帕金森病的实验研究

目的 研究雪旺细胞（SCs）和神经干细胞（NSCs）共移植治疗大鼠帕金森病（PD）的疗效。方法 18只PD模型的SD大鼠随机平均分成3组：对照组、NSCs组及共移植组。PBS、NSCs及SCs加NSCs分别植入PD大鼠右侧纹状体内。NSCs来源于孕14～16d胎鼠中脑腹侧的脑组织．SCs来源于1～3dSD新生鼠的坐骨神经。结果 移植10周后NSCs组及共移植组中纹状体区都出现TH染色阳性的神经元，与NSCs组相比，共移植组中的神经元体积及细胞核均较大。细胞数量多（P〈0．05）。与对照组相比，NSCs组及共移植组中大鼠的行为学均有明显的好转（P〈0．01），但NSCs组和共移植组相比，行为学的改变无明显差异（P〉0．05）。结论 SCs和NSCs共移植能有效治疗PD模型大鼠。     

Neurturin基因转染c17.2神经干细胞移植保护帕金森病大鼠模型的实验研究

目的探讨neurturin（NTN）基因转染c17．2神经干细胞脑内移植后对帕金森病大鼠模型的保护作用。方法构建高表达NTN蛋白的NTN-c17．2细胞克隆。实验分成NTN（12只）、空质粒（Mock，9只）和PBS组（9只），分别在各组大鼠的纹状体区移植入NTN-c17．2、Mock-c17．2和PBS，16d后再注入6-羟多巴胺（6-OHDA）。通过免疫组化、原位杂交、旋转行为和神经递质变化观察c17．2神经干细胞的分化，NTN基因的表达和NTN蛋白的保护作用。结果NTN-c17．2细胞移植后，细胞分化但仍持续分泌NTN蛋白。NTN蛋白可逆向运输到黑质，保护酪氨酸羟化酶（TH）阳性神经元免受6-OHDA的损害。动物模型旋转行为动态观测显示NTN的保护作用至少持续了4个月，NTN组要明显好于Mock和PBS组。移植后10个月，NTN和Mock组动物移植侧与健侧纹状体的神经递质如多巴胺浓度比值分别为95％（P〈0．05）和93％（P〈0．05），PBS组为75％。结论用带有NTN基因的神经干细胞移植治疗帕金森病，显示出良好的保护效果。     

X-box-binding protein 1-modified neural stem cells for treatment of Parkinson’s disease

X-box-binding protein 1-transfected neural stem cells were transplanted into the right lateral ventricles of rats with rotenone-induced Parkinson’s disease. The survival capacities and differentiation rates of cells expressing the dopaminergic marker tyrosine hydroxylase were higher in X-box-binding protein 1-transfected neural stem cells compared to non-transfected cells. Moreover, dopamine and 3,4-dihydroxyphenylacetic acid levels in the substantia nigra were significantly increased, α-synuclein expression was decreased, and neurological behaviors were significantly ameliorated in rats following transplantation of X-box-binding protein 1-transfected neural stem cells. These results indicate that transplantation of X-box-binding protein 1-transfected neural stem cells can promote stem cell survival and differentiation into dopaminergic neurons, increase dopamine and 3,4-dihydroxyphenylacetic acid levels, reduce α-synuclein aggregation in the substantia nigra, and improve the symptoms of Parkinson’s disease in rats.     

Protective effects of transplanted neural stem cells on the brain of Alzheimer's disease rats

BACKGROUND: To date, no drugs are able to halt the progression of Alzheimer's disease (AD). Neural stem cells (NSCs) transplantation has been widely used to treat AD, but the mechanism of AD treatment remains unclear.OBJECTIVE: To observe changes in protein and factors in the hippocampus and frontal lobe of AD rats following NSCs transplantation, and to understand mechanism of action of NSCs transplantation in AD treatment. DESIGN, TIME AND SETTING: A randomized, controlled animal study was conducted at the First Clinical Hospital, Jilin University, China from July 2007 to March 2009.MATERIALS: NSCs were harvested from the hippocampus of 10 E16 Wistar rats.METHODS: A total of 57 male adult Wistar rats were equally and randomly divided into normal control, AD model and NSCs groups. AD models were established in the AD model and NSCs groups by bilateral removal of hippocampus. At 2 weeks postsurgery, NSCs were transplanted into the hippocampus of rats from the NSCs group.MAIN OUTCOME MEASURES: Protein levels were measured in the hippocampus of rats from normal control, NSCs and AD model groups using proteomics. Expression of choline acetyl transferase mRNA, glial fibrillary acidic protein and S100β was measured in the hippocampus and frontal lobe of rats using in situ hybridization and immunohistochemistry.RESULTS: Expression of choline acetyl transferase mRNA, heat shock protein 70, heat shock protein 90, F-actin and actin was significantly higher in the NSCs group compared with AD model group. Glial fibrillary acidic protein and S100β expression was less in the NSCs group compared with AD model group.CONCLUSIOIN: NSCs implanted into the brain may generate new neural cells, which can relieve damage to the cholinergic system and resist apoptosis. NSCs transplantation plays a protective role in the cholinergic system in the AD rats to some extent.     

基因修饰骨髓源性神经元样干细胞治疗帕金森大鼠的研究

目的 观察大鼠酪氨酸羟化酶(tyrosinehydroxylase,TH)修饰的骨髓基质源性神经元样干细胞(neuronoid stem cells derived from bone marrow stem cells,NdSCs-D-BMSCs)在脑室移植途径下对帕金森病(Parkinson disease,PD)大鼠的治疗作用.方法 将酶切鉴定后的新构建质粒pEGFP-C2-TH经电穿孔法转染培养第8天NdSCs-D-BMSCs,注射到PD大鼠模型右侧脑室,观察大鼠行为学变化,移植细胞在大鼠脑组织内的迁移,以及高效液相方法检测脑内DA含量.结果 质粒pEGFP-C2-TH转染NdSCs-D-BMSCs移植后10周,PD大鼠症状显著改善,DA恢复至正常水平33.0%,移植细胞可以在PD大鼠脑内存活,并出现远处迁移.结论 TH修饰的大鼠NdSCs-D-BMSCs经脑室移植对PD大鼠具有明显的治疗作用,为临床中腰椎穿刺干细胞移植的应用提供实验依据.     

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。     

Nogo-6受体基因沉默神经干细胞立体定向移植治疗重型脑损伤

Inhibition of neurite growth, which is mediated by the Nogo-66 receptor (NgR), affects nerve regeneration following neural stem cell (NSC) transplantation. The present study utilized RNA interference to silence NgR gene expression in NSCs, which were subsequently transplanted into rats with traumatic brain injury. Following transplantation of NSCs transfected with small interfering RNA, typical neural cell-like morphology was detected in injured brain tissues, and was accompanied by absence of brain tissue cavity, increased growth-associated protein 43 mRNA and protein expression, and improved neurological function compared with NSC transplantation alone. Results demonstrated that NSC transplantation with silenced NgR gene promoted functional recovery following brain injury.     

Stem cell transplantation for treatment of cerebral ischemia in rats Effects of human umbilical cord blood stem cells and human neural stem cells

BACKGROUND:Exogenous neural stem cell transplantation promotes neural regeneration. However, various types of stem cells transplantation outcomes remain controversial. OBJECTIVE:To explore distribution, proliferation and differentiation of human neural stem cells (hNSCs) and human umbilical cord blood stem cells (hUCBSCs) following transplantation in ischemic brain tissue of rats, and to compare therapeutic outcomes between hNSCs and hUCBSCs. DESIGN, TIME AND SETTING:Randomized controlled animal studies were performed at the Experimental Animal Center of Nanjing Medical University and Central Laboratory of Second Affiliated Hospital of Nanjing Medical University of China from September 2008 to April 2009. MATERIALS:hNSCs were harvested from brain tissue of 10-13 week old fetuses following spontaneous abortion, and hUCBSCs were collected from umbilical cord blood of full-term newborns at the Second Affiliated Hospital of Nanjing Medical University of China. hNSCs and hUCBSCs were labeled by 5-bromodeoxyuridine (BrdU) prior to transplantation. METHODS:Rat models of cerebral ischemia were established by the suture method. A total of 60 healthy male Sprague Dawley rats aged 7-9 weeks were randomly assigned to hNSC transplantation, hUCBSC transplantation and control groups. The rat models in the hNSC transplantation, hUCBSC transplantation and control groups were infused with hNSC suspension, hUCBSC suspension and saline via the caudal vein, respectively. MAIN OUTCOME MEASURES:The distribution, proliferation and differentiation of hNSCs and hUCBSCs in ischemic brain tissue were observed using immunohistochemical methods. Neurological function in rats was assessed using the neurological severity score. RESULTS:The number of BrdU-positive cells was significantly greater in the hNSC transplantation group compared with hUCBSC transplantation group at 14 days following transplantation (P < 0.05). The number of BrdU-positive cells reached a peak at 28 days following transplantation. Nestin-positive, glial fibrillary acidic protein-positive, cyclic nucleotide 3' phosphohydrolase-positive and neuron specific enolase-positive cells were visible following transplantation. No significant difference was determined in the constituent ratio of various cells between hNSC and hUCBSC transplantation groups (P > 0.05). The neurological severity score was significantly decreased in rats at 21 days following transplantation (P < 0.05). No significant difference was detected in neurological severity score between hNSC and hUCBSC transplantation groups at various time points (P > 0.05). CONCLUSION:The transplanted hNSCs and hUCBSCs can migrate into ischemic brain tissue, proliferate and differentiate into neuron-like, astrocyte-like and oligodendrocyte-like cells, and improve neurological function in rats with cerebral ischemia.     

Derivation of primitive neural stem cells from human-induced pluripotent stem cells

Human-induced pluripotent stem cells (hiPSCs) have facilitated studies on organ development and differentiation into specific lineages in in vitro systems. Although numerous studies have focused on cellular differentiation into neural lineage using hPSCs, most studies have initially evaluated embryoid body (EB) formation, eventually yielding terminally differentiated neurons with limited proliferation potential. This study aimed to establish human primitive neural stem cells (pNSCs) from exogene-free hiPSCs without EB formation. To derive pNSCs, we optimized N2B27 neural differentiation medium through supplementation of two inhibitors, CHIR99021 (GSK-3 inhibitor) and PD0325901 (MEK inhibitor), and growth factors including basic fibroblast growth factor (bFGF) and human leukemia inhibitory factor (hLIF). Consequently, pNSCs were efficiently derived and cultured over a long term. pNSCs displayed differentiation potential into neurons, astrocytes, and oligodendrocytes. These early NSC types potentially promote the clinical application of hiPSCs to cure human neurological disorders.     

神经干细胞的来源

神经干细胞是近年来神经科学领域研究的一个热点。神经干细胞可来源于胚胎干细胞和成年干细胞，前者包括早期胚胎细胞和胎儿神经组织细胞，由于从胚胎获取干细胞面l临伦理学的束缚，从成年来源的神经干细胞将是未来临床应用更具可行性的途径。成年来源的神经干细胞包括存在于成年神经组织中的干细胞和从其他组织中分化得到的干细胞，其中骨髓基质细胞具有多分化潜能，在适当的条件下可以诱导分化出神经干细胞，目前备受关注。