基于干细胞移植的联合治疗策略治疗脊髓损伤的实验研究进展

脊髓损伤是一种中枢神经系统的灾难性疾病,预后极差,至今缺乏有效的治疗措施。由于脊髓损伤病理过程的复杂性,目前认为任何单一的治疗措施都不足以修复损伤的脊髓。因此,各种基于干细胞移植的联合治疗策略被提出并应用于实验研究当中,且日益受到重视。联合治疗的效果优于单一组分治疗,有望成为一种治疗脊髓损伤的有效途径。     

干细胞移植治疗脊髓损伤的研究进展**

背景：干细胞移植作为治疗脊髓损伤最具前景的方法,已经在大量的动物实验和临床试验中得到证实。 目的：综述干细胞移植治疗脊髓损伤的相关研究进展。 方法：应用计算机检索2006-01/2010-12中国知网、Medline数据库相关文章,中文检索词“干细胞,脊髓损伤,细胞移植”,英文检索词“stem cells,spinal cord injury,cells transplantation”,共检索到文献494篇,最终纳入符合标准的文献24篇。 结果与结论：研究发现,移植的干细胞可以在脊髓内迁移、分化为神经元并分泌神经营养物质,促进神经组织的修复,改善神经功能。胚胎干细胞最早用于治疗脊髓损伤,但潜在的致瘤性等成为其临床应用的障碍;神经干细胞理论上是治疗脊髓损伤的首选干细胞,由于分离纯化技术要求严格,费用昂贵等使其在研究中进展缓慢;骨髓间充质干细胞来源丰富、取材方便,可行自体移植,避开了伦理学和移植后排斥等问题,目前被认为是一种理想的自体干细胞移植来源。随着细胞联合移植、基因修饰及组织工程支架移植治疗脊髓损伤的研究不断取得进展,许旺细胞、嗅鞘细胞的应用范围和治疗效果也得到提升。     

神经干细胞修复脊髓损伤

背景：神经生物学和干细胞技术的发展．使通过细胞移植增加脊髓神经数量、减少胶质瘢痕和空洞的形成成为可能。 目的：复习相关文献,就神经干细胞的鉴定及特性、神经干细胞修复脊髓损伤的可能机制、临床前研究及临床应用方面进行综述。 方法：以 “neural stem cells,transplant,spinal cord injury”为英文检索词,以“神经干细胞,移植,脊髓损伤” 为中文检索词,由第一作者检索1997/2010 PubMed数据库及万方数据库有关神经干细胞鉴定、特性、神经干细胞修复脊髓损伤的可能机制、临床前研究及临床应用方面等方面的文章。排除发表时间较早、重复及类似研究,对29篇符合标准的文献进行归纳总结。 结果与结论：神经干细胞有产生神经元、少突胶质细胞、星形胶质细胞,并替代受损的神经细胞功能等。文章从神经干细胞的鉴定及特性,神经干细胞修复脊髓损伤的可能机制,神经干细胞治疗脊髓损伤的实验研究及临床应用等方面进行了讨论。关于干细胞来源的神经元或胶质细胞移植后的长期生存及表型稳定性,以及逃脱分化及选择性程序的很少部分胚胎干细胞,可能会自在移植后的移植位点扩增并形成肿瘤等问题有待进一步解决。     

神经干细胞移植在脊髓损伤修复中的作用

近年来神经干细胞的发现及其相关研究,为脊髓损伤的治疗提供了一种新的策略.目前多通过应用单纯的神经干细胞移植、携带外源性基因的神经干细胞移植以及联合生物材料的神经干细胞移植等方法来治疗实验性脊髓损伤,取得了可喜的成绩.这些移植方式各有优缺点,为治疗和修复脊髓损伤开拓了思路,带来了希望.     

细胞移植治疗脊髓损伤的研究进展

干细胞修复脊髓损伤是目前研究的一个热点。具有发育全能性的胚胎干细胞、神经系统来源的细胞(神经 干细胞、嗅鞘细胞、雪旺氏细胞)和成体干细胞(骨髓间充质干细胞、脐带血干细胞)各有其优缺点。移植方式和移 植时间窗的选择也对细胞的迁移和分化以及动物神经功能的恢复有重要影响,新技术的开展为细胞移植疗法提供 了新思路。     

神经干细胞移植治疗脊髓损伤

目的:探讨神经干细胞移植对脊髓损伤大鼠后肢运动功能修复的影响。方法:SD大鼠36只,制成T10脊髓全横断损伤模型。于造模成功后1周采用局部微量注射法移植。随机分三组：A损伤对照组（n=12）仅打开椎管暴露脊髓;B移植对照组（n=12）：注射10μl DMEM/F12培养液;C细胞移植组（n=12）：移植1.0?06/ml的神经干细胞悬液10μl。移植后通过不同时间点BBB行为评分、病理组织学、免疫荧光技术评价大鼠大鼠脊髓功能修复情况及移植细胞在体内的存活、迁移、分化。 结果:在体外成功建立SD大鼠海马源性神经干细胞培养体系;B、C两组大鼠随着时间延长BBB评分均不同程度提高,从移植后2W起C组大鼠评分明显高于B组,两组比较差异有统计学意义（P<0.05）;神经干细胞移植后能够在体内继续存活、迁移并且分化为NF-200、GFAP表达阳性的神经元及星形胶质细胞。 结论:神经干细胞移植治疗脊髓损伤是一种有效的方法。     

骨髓间充质干细胞移植联合吡拉西坦修复大鼠脊髓损伤

背景：单纯的干细胞移植对脊髓损伤的修复作用并不理想,主要是因为脊髓损伤后损伤区域神经组织的水肿、缺血、缺氧等引起继发性损伤造成的。 目的：在骨髓间充质干细胞移植治疗大鼠脊髓损伤的同时应用吡拉西坦,观察两者对大鼠脊髓损伤恢复的影响。 方法：雌性Wistar大鼠参照改良Allen打击法制备大鼠脊髓损伤模型。随机分成3组,即单纯损伤组、骨髓间充质干细胞移植组及骨髓间充质干细胞移植联合吡拉西坦组。于伤后1,2,4,6,8周进行BBB评分和斜板实验等运动功能检测。第4周取材行病理切片苏木精-伊红染色,通过SRY-PCR检测雄性大鼠Y染色体上特有的基因SRY,从而得知移植骨髓间充质干细胞是否存活。8周后取材,行辣根过氧化物酶示踪观察,并通过透射电镜观察轴突的再生情况。 结果与结论：伤后4周,骨髓间充质干细胞移植组、联合治疗组大鼠后肢运动功能均有较明显恢复,联合治疗组较骨髓间充质干细胞移植组恢复快(P < 0.05)。单纯损伤组亦有所恢复,但程度较轻。病理切片单纯损伤组未见神经轴索通过;骨髓间充质干细胞移植组可见少量神经轴索样结构;联合治疗组可见较多神经轴索样结构。骨髓间充质干细胞移植组、联合治疗组有SRY基因表达,单纯损伤组未检测到SRY基因。辣根过氧化物酶阳性神经纤维数联合治疗组﹥骨髓间充质干细胞移植组>单纯损伤组,差异具有显著性意义(P < 0.05)。透射电镜下,骨髓间充质干细胞移植组、联合治疗组正中横断面可见新生的无髓及有髓神经纤维。提示骨髓间充质干细胞移植联合吡拉西坦促进大鼠损伤脊髓结构和功能恢复的效果明显优于单纯细胞移植组,两者联用具有协同效应。     

局部注射骨髓间充质干细胞治疗大鼠脊髓损伤：运动功能有改善吗？

背景：目前研究多为骨髓间充质干细胞的体外培养及细胞移植对颅内疾病的治疗,对植入细胞在损伤脊髓中的成活、分化、迁移、结构重建等了解有限。 目的：探讨局部骨髓间充质干细胞移植在脊髓损伤修复中的作用和骨髓间充质干细胞替代治疗的可行性。 方法：成年健康雌性SD大鼠随机分为细胞移植组和对照组,建立SD大鼠脊髓横断损伤模型,伤后即刻分别向损伤区局部移植大鼠骨髓间充质干细胞悬液或无钙镁磷酸缓冲液。在术前和术后1 d,1周,2周,3周,4周和8周进行BBB评分,观测大鼠的运动功能,并于移植后1周免疫组织化学染色法观察BrdU标记的骨髓间充质干细胞在脊髓损伤处的存活情况,移植后4周进行损伤脊髓的大体观察和组织学检测。 结果与结论：移植后第1~8周细胞移植组BBB评分均髙于对照组;术后1周免疫组织化学染色结果显示在细胞移植组大鼠脊髓远端检测到BrdU阳性细胞,术后4周脊髓损伤处发现有神经纤维。证实通过损伤后立即局部注射的方式将骨髓间充质干细胞移植进大鼠脊髓损伤区,细胞可在损伤区存活;存活的骨髓间充质干细胞可分化为神经元,在损伤局部形成神经元通路,从而促进脊髓神经纤维传导功能的恢复,并促进高位脊髓损伤后大鼠后肢运动功能恢复。     

神经营养因子3基因修饰神经干细胞移植脊髓损伤的相关蛋白表达☆

背景：研究表明神经干细胞和神经营养因子3基因修饰的神经细胞联合移植能够在移植后存活并有效促进脊髓横断后脊髓的功能恢复,但神经营养因子3基因修饰的神经干细胞能否在脊髓受损部位发挥功能并促进脊髓损伤大鼠的功能恢复? 目的：观察神经营养因子3基因修饰胚胎脊髓神经干细胞移植后脊髓损伤大鼠的功能恢复情况及损伤局部的基因表达。 方法：将30只SD大鼠在T9水平进行脊髓半切后,随机分为3组,分别在受损脊髓内植入细胞培养液、神经干细胞及神经营养因子3基因修饰神经干细胞。另取10只仅行椎板切除设置为空白对照。移植后通过行为学测试评价脊髓功能的恢复,RT-PCR和Western blot检测脊髓损伤部位神经营养因子3和髓鞘碱性蛋白的表达。 结果与结论：移植神经营养因子3基因修饰神经干细胞组行为学测试结果最好,移植细胞培养液组行为学测试最差。与移植细胞培养液组相比,移植神经干细胞及神经营养因子3基因修饰神经干细胞组大鼠脊髓组织中神经营养因子3基因和髓鞘碱性蛋白基因的mRNA水平明显上调,在蛋白水平也有类似的结果,且神经营养因子3基因修饰神经干细胞组效果更明显。提示移植神经营养因子3基因修饰神经干细胞能促进脊髓受损部位出现更多向少突胶质细胞分化的细胞,并能更强的表达神经营养因子3。     

BDNF-GFP转染神经干细胞修复大鼠脊髓损伤：发挥干细胞与神经因子的双重效应？

摘要 背景：神经干细胞移植入大鼠脊髓损伤模型可以促进功能恢复,基因治疗已被广泛用于治疗脊髓损伤。 目的：确定BDNF-GFP转染后神经干细胞移植对大鼠脊髓损伤的修复效果。 设计,时间和背景：本实验是在中国医科大学基础医学院发育生物学实验室与2009年5月至2010年1月完成。 材料：10只新生Wistar大鼠和88只2-3个月大,雌雄不限的Wistar大鼠。 方法：以携带BDNF-GFP基因的腺病毒转染神经干细胞。88只Wistar大鼠中假手术组8只, 80只大鼠制成T9左侧横断模型,并随机分成四组：BDNF和GFP修饰的神经干细胞移植组,GFP修饰的神经干细胞移植组;单纯神经干细胞移植组和模型组。在各神经干细胞移植组,脊髓损伤后向横断处显微注射等体积细胞,模型组在相同的部位注射等体积的PBS。 主要观察指标： BBB评分检测脊髓损伤模型运动功能恢复情况;制备脊髓损伤模型2周后取材,免疫组化评估BDNF-GFP转染的神经干细胞移植后的细胞学特点;制备脊髓损伤模型2、4、6、8周Real-time PCR检测脊髓横断处BDNF表达情况。 结果： BDNF-GFP转染后神经干细胞在脊髓半切模型中存活并表达BDNF和GFP,移植该细胞后的大鼠体内高表达具有生物活性的BDNF,且脊髓损伤动物运动功能较对照组明显恢复。 结论：移植BDNF-GFP转染后神经干细胞可能是一种修复脊髓损伤的有效的方法。 关键词：神经干细胞,脑源性神经营养因子;绿色荧光蛋白;脊髓损伤;移植。     

Rat hair follicle stem cells differentiate and promote recovery following spinal cord injury

Emerging studies of treating spinal cord injury （SCI） with adult stem cells led us to evaluate the effects of transplantation of hair follicle stem cells in rats with a compression-induced spinal cord lesion. Here, we proposed a hypothesis that rat hair follicle stem cell transplantation can promote the recovery of injured spinal cord. Compression-induced spinal cord injury was induced in Wistar rats in this study. The bulge area of the rat vibdssa follicles was isolated, cultivated and characterized with nestin as a stem cell marker. 5-Bromo-2＇-deoxyuridine （BrdU） labeled bulge stem cells were transplanted into rats with spinal cord injury. Immunohistochemical staining results showed that some of the grafted cells could survive and differentiate into oligodendrocytes （receptor-interacting protein positive cells） and neuronal-like cells （~lll-tubulin positive cells） at 3 weeks after transplantation. In addition, recovery of hind limb locomotor function in spinal cord injury rats at 8 weeks following cell transplantation was assessed using the Basso, Beattie and Bresnahan （BBB） locomotor rating scale. The results demon- strate that the grafted hair follicle stem cells can survive for a long time period in vivo and differentiate into neuronal- and glial-like cells. These results suggest that hair follicle stem cells can promote the recovery of spinal cord injury.     

Stem cell transplantation for treating spinal cord injury A literature comparison between studies of stem cells obtained from various sources

OBJECTIVE:To identify global research trends of stem cell transplantation for treating spinal cord injury using a bibliometric analysis of the Web of Science.DATA RETRIEVAL:We performed a bibliometric analysis of data retrievals for stem cell transplantation for treating spinal cord injury from 2002 to 2011 using the Web of Science.SELECTION CRITERIA:Inclusion criteria:(a) peer-reviewed articles on stem cell transplantation for treating spinal cord injury that were published and indexed in the Web of Science;(b) type of articles:original research articles,reviews,meeting abstracts,proceedings papers,book chapters,editorial material,and news items;and(c) year of publication:2002-2011.Exclusion criteria:(a) articles that required manual searching or telephone access;(b) documents that were not published in the public domain;and(c) a number of corrected papers from the total number of articles.MAIN OUTCOME MEASURES:(1) Annual publication output;(2) distribution according to country;(3) distribution according to institution;(4) distribution according to journals;(5) distribution according to funding agencies;and(6) top cited articles over the last 10 years.RESULTS:Bone marrow mesenchymal stem cells and embryonic stem cells have been widely used for treating spinal cord injury.In total,191 studies of bone marrow mesenchymal stem cell transplantation and 236 studies of embryonic stem cell transplantation for treating spinal cord injury appeared in the Web of Science from 2002 to 2011,and almost half of which were derived from American or Japanese authors and institutes.The number of studies of stem cell transplantation for treating spinal cord injury has gradually increased over the past 10 years.Most papers on stem cell transplantation for treating spinal cord injury appeared in journals with a particular focus on stem cell research,such as Stem Cells and Cell Transplantation.Although umbilical cord blood stem cells and adipose-derived stem cells have been studied for treating spinal cord injury,the number of published papers was much smaller,with only 21 and 17 records,respectively,in the Web of Science.CONCLUSION:Based on our analysis of the literature and research trends,we found that stem cells transplantation obtained from various sources have been studied for treating spinal cord injury;however,it is difficult for researchers to reach a consensus on this theme.     

Propofol promotes spinal cord injury repair by bone marrow mesenchymal stem cell transplantation

Propofol is a neuroprotective anesthetic. Whether propofol can promote spinal cord injury repair by bone marrow mesenchymal stem cells remains poorly understood. We used rats to investigate spinal cord injury repair using bone marrow mesenchymal stem cell transplantation combined with propofol administration via the tail vein. Rat spinal cord injury was clearly alleviated; a large number of newborn non-myelinated and myelinated nerve fibers appeared in the spinal cord, the numbers of CM-Dil-labeled bone marrow mesenchymal stem cells and fluorogold-labeled nerve fibers were increased and hindlimb motor function of spinal cord-injured rats was markedly improved. These improvements were more prominent in rats subjected to bone marrow mesenchymal cell transplantation combined with propofol administration than in rats receiving monotherapy. These results indicate that propofol can enhance the therapeutic effects of bone marrow mesenchymal stem cell transplantation on spinal cord injury in rats.     

神经干细胞移植治疗脊髓损伤的研究与现状

近年来,神经干细胞的发现及其相关研究为脊髓损伤的治疗开辟了一条新途径,神经干细胞因与脊髓损伤区域的细胞同源而具有独特的治疗优势。随着研究的不断深入,胚胎源神经干细胞,永生化神经干细胞,胚胎和成体神经干细胞作为移植的供体细胞以及基因治疗的载体用于临床治疗。文章就脊髓损伤的机制、神经干细胞的基本特性、增殖和定向诱导分化机制及其在脊髓损伤修复中的应用问题进行系统的分析和综述,并对神经干细胞移植治疗脊髓损伤的应用及存在问题进行了展望。     

Human umbilical cord blood stem cell transplantation for the treatment of chronic spinal cord injury Electrophysiological changes and long-term efficacy

Stem cell transplantation can promote functional restoration following acute spinal cord injury (injury time < 3 months), but the safety and long-term efficacy of this treatment need further exploration. In this study, 25 patients with traumatic spinal cord injury (injury time > 6 months) were treated with human umbilical cord blood stem cells via intravenous and intrathecal injection. The follow-up period was 12 months after transplantation. Results found that autonomic nerve functions were restored and the latent period of somatosensory evoked potentials was reduced. There were no severe adverse reactions in patients following stem cell transplantation. These experimental findings suggest that the transplantation of human umbilical cord blood stem cells is a safe and effective treatment for patients with traumatic spinal cord injury.     

Intraspinal transplantation of motoneuron-like cell combined with delivery of polymer-based glial cell line-derived neurotrophic factor for repair of spinal cord contusion injury

To evaluate the effects of glial cell line-derived neurotrophic factor transplantation combined with adipose-derived stem cells-transdifferentiated motoneuron delivery on spinal cord con-tusion injury, we developed rat models of spinal cord contusion injury, 7 days later, injected adipose-derived stem cells-transdifferentiated motoneurons into the epicenter, rostral and caudal regions of the impact site and simultaneously transplanted glial cell line-derived neuro-trophic factor-gelfoam complex into the myelin sheath. Motoneuron-like cell transplantation combined with glial cell line-derived neurotrophic factor delivery reduced cavity formations and increased cell density in the transplantation site. The combined therapy exhibited superior promoting effects on recovery of motor function to transplantation of glial cell line-derived neurotrophic factor, adipose-derived stem cells or motoneurons alone. These ifndings suggest that motoneuron-like cell transplantation combined with glial cell line-derived neurotrophic factor delivery holds a great promise for repair of spinal cord injury.     

Propofol injection combined with bone marrow mesenchymal stem cell transplantation better improves electrophysiological function in the hindlimb of rats with spinal cord injury than monotherapy

The repair effects of bone marrow mesenchymal stem cell transplantation on nervous system damage are not satisfactory. Propofol has been shown to protect against spinal cord injury. Therefore, this study sought to explore the therapeutic effects of their combination on spinal cord injury. Rat models of spinal cord injury were established using the weight drop method. Rats were subjected to bone marrow mesenchymal stem cell transplantation via tail vein injection and/or propofol injection via tail vein using an infusion pump. Four weeks after cell transplantation and/or propofol treatment, the cavity within the spinal cord was reduced. The numbers of PKH-26-positive cells and horseradish peroxidase-positive nerve fibers apparently increased in the spinal cord. Latencies of somatosensory evoked potentials and motor evoked potentials in the hindlimb were noticeably shortened, amplitude was increased and hindlimb motor function was obviously improved. Moreover, the combined effects were better than cell transplantation or propofol injection alone. The above data suggest that the combination of propofol injection and bone marrow mesenchymal stem cell transplantation can effectively improve hindlimb electrophysiological function, promote the recovery of motor funtion, and play a neuroprotective role in spinal cord injury in rats.     

Biodegradable chitin conduit tubulation combined with bone marrow mesenchymal stem cell transplantation for treatment of spinal cord injury by reducing glial scar and cavity formation

We examined the restorative effect of modified biodegradable chitin conduits in combination with bone marrow mesenchymal stem cell transplantation after right spinal cord hemisection injury. Immunohistochemical staining revealed that biological conduit sleeve bridging reduced glial scar formation and spinal muscular atrophy after spinal cord hemisection. Bone marrow mesenchymal stem cells survived and proliferated after transplantation in vivo, and differentiated into cells double-positive for S100(Schwann cell marker) and glial fibrillary acidic protein(glial cell marker) at 8 weeks. Retrograde tracing showed that more nerve fibers had grown through the injured spinal cord at 14 weeks after combination therapy than either treatment alone. Our findings indicate that a biological conduit combined with bone marrow mesenchymal stem cell transplantation effectively prevented scar formation and provided a favorable local microenvironment for the proliferation, migration and differentiation of bone marrow mesenchymal stem cells in the spinal cord, thus promoting restoration following spinal cord hemisection injury.     

间充质干细胞移植修复脊髓损伤的研究现状

骨髓间充质干细胞在体外没有外界因素作用下连续传50代仍可保持原来的特性,亦可在一些条件的诱导下分化成神经细胞。实验研究表明,间充质干细胞移植能促进脊髓损伤的神经结构修复及神经功能恢复,其机制可能与替代作用、营养作用、诱导作用、桥接作用等有关。携带外源功能基因的骨髓间充质干细胞移植到体内存活、迁徙、分化并基因表达脑源性生长因子、神经生长因子等细胞因子,明显促进脊髓损伤的恢复,成为了新的研究热点。随着对间充质干细胞的生物学特性进一步深入研究,一些未解决的问题将会逐步得到解决,为脊髓损伤和其他神经系统疾病的患者带来新的希望。     

自体骨髓干细胞移植治疗脊髓损伤420例

目的：总结分析骨髓干细胞移植治疗脊髓损伤的效果。 方法：2003-09/2008-04解放军第四六三医院神经外科细胞治疗康复中心行干细胞移植的脊髓损伤患者420例,按病情分为2组：完全性脊髓损伤组42例,不完全性脊髓损伤组378例,两组患者在性别、年龄、受伤时间、损伤部位、损伤原因等方面比较差异无显著性意义(P > 0.05)。两组首先通过手术或立体定向的方法把干细胞直接移植在脊髓损伤部位,然后再根据患者病情经腰穿途径或经静脉途径移植,每次移植间隔为1周,干细胞移植量为(2~3)个×102/kg。移植过程中为促进干细胞的生长和分化,根据患者病情及身体状况给予相应的康复功能锻炼。 结果：与入院时比较,骨髓干细胞移植1,3,12个月后,不完全性脊髓损伤患者针刺觉评分、轻触觉评分、运动评分均有明显改善(P < 0.05或0.01),完全性脊髓损伤患者针刺觉评分、轻触觉评分、运动评分均无明显变化(P > 0.05),两组残损分级均无明显改善(P > 0.05)。 结论：骨髓干细胞移植治疗脊髓损伤有效可行。