Combination of bone marrow mesenchymal stem cells and brain-derived neurotrophic factor for treating spinal cord injury

BACKGROUND:Because bone marrow mesenchymal stem cells (BMSCs) do not secrete sufficient brain-derived neurotrophic factor (BDNF), the use of exogenous BDNF could improve microenvironments in injured regions for BMSCs differentiation. OBJECTIVE:To analyze recovery of the injured spinal cord following BMSCs venous transplantation in combination with consecutive injections of BDNF. DESIGN, TIME AND SETTING:A randomized, controlled animal experiment was performed at the Central Laboratory of First Hospital and Anatomical Laboratory, Fujian Medical University from October 2004 to May 2006.MATERIALS:Human BDNF was purchased from Sigma, USA. METHODS:A total of 44 New Zealand rabbits were randomly assigned to model (n = 8), BDNF (n = 12), BMSC (n = 12), and BMSC+BDNF (n = 12) groups. Spinal cord (L2) injury was established with the dropping method. The model group rabbits were injected with 1 mL normal saline via the ear margin vein; the BDNF group was subdurally injected with 100 μg/d human BDNF for 1 week; the BMSC group was injected with 1 mL BMSCs suspension (2 × 106/mL) via the ear margin vein; and the BMSC+BDNF group rabbits were subdurally injected with 100 μg/d BDNF for 1 week, in addition to BMSCs suspension via the ear margin vein. MAIN OUTCOME MEASURES:BMSCs surface markers were detected by flow cytometry. BMSCs differentiation in the injured spinal cord was detected by immunofluorescence histochemistry. Functional and structural recovery, as well as morphological changes, in the injured spinal cord were respectively detected by Tarlov score, horseradish peroxidase retrograde tracing, and hematoxylin & eosin staining methods at 1, 3, and 5 weeks following transplantation. RESULTS:Transplanted BMSCs differentiated into neuronal-like cells in the injured spinal cord at 3 and 5 weeks following transplantation. Neurological function and pathological damage improved following BMSC + BDNF treatment compared with BDNF or BMSC alone (P < 0.01 or P < 0.05). CONCLUSION:BMSCs venous transplantation in combination with BDNF subdural injection benefits neuronal-like cell differentiation and significantly improves structural and function of injured spinal cord compared with BMSCs or BDNF alone.     

Protective effects of human umbilical cord mesenchymal stem cell vein transplantation against spinal cord ischemia/reperfusion injury in rats

BACKGROUND: The majority of studies addressing spinal cord ischemia/reperfusion injury (SCIRI) have focused on drugs, proteins, cytokines, and various surgical techniques. A recent study reports that human umbilical cord mesenchymal stem cell (hUCMSC) transplantation achieves good therapeutic effects, but the mechanisms underlying nerve protection remain poorly understood.OBJECTIVE: To observe survival of transplanted hUCMSCs in SCIRI rat models and the influence on motor function in the hind limbs, to determine interleukin-8 expression and cellular apoptosis in spinal cord tissues, and to verify the hypothesis that hUCMSC transplantation exhibits protective effects on SCIRI.DESIGN, TIME AND SETTING: A randomized, controlled, animal experiment was performed at the Laboratory of the Department of Orthopedics in the First Affiliated Hospital of Soochow University,China between January 2007 and December 2008.MATERIALS: hUCMSCs were harvested from umbilical cord blood of healthy pregnant women after parturition in the Obstetrical Department of the First Affiliated Hospital of Soochow University, China. Rabbit anti-human BrdU monoclonal antibody was provided by DAKO, USA. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) Kit and enzyme-linked immunosorbent assay (ELISA) Kit were purchased by Wuhan Boster, China. METHODS: A total of 72 healthy, Wistar, adult rats were randomly assigned to three groups: sham-surgery, model, and transplantation, with 24 rats in each group. SCIRI was induced in the model and transplantation groups via the abdominal aorta block method. The inf rarenal abdominal aorta was not blocked in the sham-surgery group. Prior to abdominal aorta occlusion, 0.2-0.3 mL bromodeoxyuridine (BrdU)-labeled hUCMSCs suspension (cell concentration 5 × 10~3/μL) was injected through the great saphenous vein of the hind limb, and an equal volume of physiological saline was administered to the model and sham-surgery groups.MAIN OUTCOME MEASURES: Pathological observation of rat spinal cord tissues was performed by hematoxylin-eosin staining at 6, 24, and 48 hours post-surgery. Immunohistochemistry was applied to determine hUCMSCs survival in the spinal cord. The amount of cellular apoptosis and interleukin-8 expression in spinal cord tissues was assayed utilizing the TUNEL and ELISA methods, respectively. Motor function in the hind limbs was evaluated according to Jacob's score. RESULTS: Numerous BrdU-positive cells were observed in spinal cord tissues from the transplantation group. The number of apoptotic cells and interleukin-8 levels significantly decreased in the transplantation group (P < 0.05), pathological injury was significantly ameliorated, and motor function scores significantly increased (P < 0.05) compared with the model group. CONCLUSION: Via vein transplantation, hUCMSCs were shown to reach and survive in the injury area. Results suggested that the transplanted hUCMSCs contributed to significantly improved pathological changes in the injured spinal cord, as well as motor function, following SCIRI. The protective mechanism correlated with inhibition of cellular apoptosis and reduced production of inflammatory mediators.     

骨髓间充质干细胞尾静脉移植脊髓损伤大鼠脑源性神经营养因子及神经生长因子的表达

背景：骨髓间充质干细胞移植对脊髓损伤有治疗作用,但其机制尚不完全清楚。 目的：应用免疫组织化学方法观察骨髓间充质干细胞静脉移植损伤脊髓局部脑源性神经营养因子及神经生长因子的表达,分析骨髓间充质干细胞移植治疗大鼠脊髓损伤的作用途径。 方法：运用改良Allen法制备T10脊髓外伤性截瘫大鼠模型,假手术组6只,脊髓损伤组24只随机分为对照组和骨髓间充质干细胞移植组。骨髓间充质干细胞移植组、假手术组接受骨髓间充质干细胞单细胞悬液1 mL(1×106 cells)自大鼠尾静脉缓慢注射移植,对照组静脉注射PBS 1 mL。 结果与结论：脊髓损伤后损伤局部的脑源性神经营养因子、神经生长因子表达增加,骨髓间充质干细胞静脉注射移植后能促进脊髓损伤局部脑源性神经营养因子、神经生长因子更进一步的表达,这可能是促进神经结构及神经功能恢复的因素之一。     

高压氧联合神经干细胞移植治疗大鼠脊髓损伤

背景：单纯神经干细胞移植已应用于对受损脊髓组织的修复。 目的：以神经干细胞移植同时应用高压氧治疗大鼠脊髓损伤,观察联合作用对脊髓损伤大鼠运动功能恢复的影响。 方法：雌性SD大鼠60只,以半切法制成胸段脊髓半横断大鼠模型。随机分成单纯损伤组、神经干细胞移植组及高压氧治疗组,每组20只。伤后第4周取材行病理切片苏木精-伊红染色及BrdU免疫组织化学染色,第8周取材行辣根过氧化物酶示踪,透射电镜观察轴突的再生情况,通过体感诱发电位观察神经电生理恢复情况。造模后1,2,4,6,8周进行BBB评分和斜板实验等运动功能检测。 结果与结论：观察伤后4周病理切片,单纯损伤组未见神经轴索通过,神经干细胞移植组可见少量神经轴索样结构,高压氧治疗组可见较多神经轴索样结构。BrdU的阳性细胞数及辣根过氧化物酶阳性神经纤维数,高压氧治疗组最多,神经干细胞移植组次之,单纯损伤组最少,且各组之间差异有显著性意义(P < 0.05)。透射电镜下神经干细胞移植组、高压氧治疗组正中横断面可见新生的无髓及有髓神经纤维。高压氧治疗组大鼠体感诱发电位的潜伏期短于神经干细胞移植组,波幅高于神经干细胞移植组(P < 0.05),明显优于单纯损伤组(P < 0.01)。伤后4周神经干细胞移植组、高压氧治疗组大鼠后肢运动功能均有较明显恢复,高压氧治疗组较神经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。提示神经干细胞移植对于脊髓损伤大鼠后肢功能的恢复有促进作用,联合应用高压氧有协同效果。     

Bone marrow mesenchymal stem cells stimulated with low‐intensity pulsed ultrasound: Better choice of transplantation treatment for spinal cord injury

Stem cell transplantation, especially treatment with bone marrow mesenchymal stem cells (BMSCs), has been considered a promising therapy for the locomotor and neurological recovery of spinal cord injury (SCI) patients. However, the clinical benefits of BMSCs transplantation remain limited because of the considerably low viability and inhibitory microenvironment. In our research, low‐intensity pulsed ultrasound (LIPUS), which has been widely applied to clinical applications and fundamental research, was employed to improve the properties of BMSCs. The most suitable intensity of LIPUS stimulation was determined. Furthermore, the optimized BMSCs were transplanted into the epicenter of injured spinal cord in rats, which were randomized into four groups: (a) Sham group (n = 10), rats received laminectomy only and the spinal cord remained intact. (b) Injury group (n = 10), rats with contused spinal cord subjected to the microinjection of PBS solution. (c) BMSCs transplantation group (n = 10), rats with contused spinal cord were injected with BMSCs without any priming. (d) LIPUS‐BMSCs transplantation group (n = 10), BMSCs stimulated with LIPUS were injected at the injured epicenter after contusion. Rats were then subjected to behavioral tests, immunohistochemistry, and histological observation. It was found that BMSCs stimulated with LIPUS obtained higher cell viability, migration, and neurotrophic factors expression in vitro. The rate of apoptosis remained constant. After transplantation of BMSCs and LIPUS‐BMSCs postinjury, locomotor function was significantly improved in LIPUS‐BMSCs transplantation group with higher level of brain‐derived neurotrophic factor (BDNF) and nerve growth factor (NGF) in the epicenter, and the expression of neurotrophic receptor was also enhanced. Histological observation demonstrated reduced cavity formation in LIPUS‐BMSCs transplantation group when comparing with other groups. The results suggested LIPUS can improve BMSCs viability and neurotrophic factors expression in vitro, and transplantation of LIPUS‐BMSCs could promote better functional recovery, indicating possible clinical application for the treatment of SCI.     

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.     

再程序化脂肪干细胞移植治疗大鼠脊髓损伤的机制

目的制备再程序化脂肪干细胞(ADSCs),并在体研究再程序化ADSCs移植入大鼠脊髓损伤模型后促进损伤脊髓神经功能恢复的作用和机制。方法体外培养、纯化和鉴定大鼠ADSCs,并利用慢病毒包装神经元生成素2(Ngn2)基因转染ADSCs制备再程序化干细胞。体内实验将48只雌性SD大鼠随机分成3组:SCI对照(A)组、单纯ADSCs移植(B)组和Ngn2-ADSCs移植(C)组。采用BBB评分评价大鼠运动功能,并通过HE染色、免疫组化和免疫荧光等方法检测脊髓组织学改变和相关蛋白的表达水平,进而观察实验动物脊髓功能恢复情况。结果 Ngn2-ADSCs移植组在运动功能评分、胶质瘢痕的形成、脊髓损伤后病理变化和分泌神经营养因子BDNF和VEGF蛋白含量明显优于其他组。结论 Ngn2-ADSCs移植后能有效地存活,并分化为神经细胞,抑制胶质瘢痕形成,减小脊髓损伤空洞,增加BDNF和VEGF表达,最终促进SCI大鼠的运动功能恢复,较单纯应用ADSCs能更好地促进SCI修复。     

大鼠骨髓间充质干细胞静脉移植对脊髓损伤的修复作用

目的初步探讨骨髓间充质干细胞（BMSCs）静脉移植对脊髓损伤后神经功能恢复和神经修复的影响。方法体外培养BMSCs，改良Allen法制备大鼠脊髓损伤模型，经尾静脉移植Brdu标记的BMSCs，损伤后24h、移植后1、3、5周评价实验动物的神经功能状况，并检测BMSCs在体内迁移、存活以及分化情况，电子显微镜观察组织形态学变化。结果移植的BMSCs在宿主损伤脊髓中聚集并存活，3～5周后有部分移植细胞表达神经元特异性烯醇化酶（NSE）、神经丝蛋白（NF）、微管相关蛋白（MAP2）；BMSCs静脉移植组大鼠运动功能改善，BBB评分高于对照组（P〈0．05）；5周后组织学观察，与对照组相比移植组损伤区脊髓结构较完整。结论BMSCs经静脉移植后可向脊髓损伤处聚集并存活分化，促进神经修复及神经功能的恢复。     

BDNF-expressing marrow stromal cells support extensive axonal growth at sites of spinal cord injury

Bone marrow stromal cells (MSCs) constitute a heterogeneous cell layer in the bone marrow, supporting the growth and differentiation of hematopoietic stem cells. Recently, it has been reported that MSCs harbor pluripotent stem cells capable of neural differentiation and that simple treatment of MSCs with chemical inducing agents leads to their rapid transdifferentiation into neural cells. We examined whether native or neurally induced MSCs would reconstitute an axonal growth-promoting milieu after cervical spinal cord injury (SCI), and whether such cells could act as vehicles of growth factor gene delivery to further augment axonal growth. One month after grafting to cystic sites of SCI, native MSCs supported modest growth of host sensory and motor axons. Cells "neurally" induced in vitro did not sustain a neural phenotype in vivo and supported host axonal growth to a degree equal to native MSCs. Transduction of MSCs to overexpress brain-derived neurotrophic factor (BDNF) resulted in a significant increase in the extent and diversity of host axonal growth, enhancing the growth of host serotonergic, coerulospinal, and dorsal column sensory axons. Measurement of neurotrophin production from implanted cells in the lesion site revealed that the grafts naturally contain nerve growth factor (NGF) and neurotrophin-3 (NT-3), and that transduction with BDNF markedly raises levels of BDNF production. Despite the extensive nature of host axonal penetration into the lesion site, functional recovery was not observed on a tape removal or rope-walking task. Thus, MSCs can support host axonal growth after spinal cord injury and are suitable cell types for ex vivo gene delivery. Combination therapy with other experimental approaches will likely be required to achieve axonal growth beyond the lesion site and functional recovery.     

负载脊髓匀浆蛋白的树突状细胞促进小鼠脊髓损伤功能恢复的作用研究

目的 研究负载脊髓匀浆蛋白的未成熟树突状细胞(hpDCs)对小鼠脊髓损伤的促修复作用.方法 通过局部或腹腔注射hpDCs,并设立对照,利用BBB功能评分及组织病理学方法,观察其对小鼠脊髓损伤神经功能恢复和局部病变范围、空洞大小、胶质瘢痕厚度等病理改变的影响.结果 注射后第84天,腹腔注射hpDCs组BBB评分为16.5,与对照组相比有显著统计学意义(P＜0.01).各组腹腔或局部注射效果无统计学意义(P＞0.05).同时hpDCs可延长Nestin表达时间,缩小损伤区范围、空洞面积、胶质瘢痕厚度.结论 腹腔或局部注射hpDCs均可改善局部环境并促进小鼠脊髓损伤神经功能恢复.     

Combined NgR vaccination and neural stem cell transplantation promote functional recovery after spinal cord injury in adult rats

C‐J. Xu, L. Xu, L‐D. Huang, Y. Li, P‐P. Yu, Q. Hang, X‐M. Xu and P‐H. Lu (2011) Neuropathology and Applied Neurobiology 37, 135–155
Combined NgR vaccination and neural stem cell transplantation promote functional recovery after spinal cord injury in adult rats Aims: After spinal cord injury (SCI), there are many adverse factors at the lesion site such as glial scar, myelin‐derived inhibitors, cell loss and deficiency of neurotrophins that impair axonal regeneration. Therefore, combination therapeutic strategies might be more effective than a single strategy for promoting functional recovery after SCI. In the present study, we investigated whether a Nogo66 receptor (NgR) vaccine, combined with neural stem cell (NSC) transplantation, could promote better functional recovery than when NgR vaccine or NSCs were used alone. Methods: Adult rats were immunized with NgR vaccine at 1 week after a contusive SCI at the thoracic level, and the NSCs, obtained from green fluorescent protein transgenic rats, were transplanted into the injury site at 8 weeks post injury. The functional recovery of the animals under various treatments was evaluated by three independent behavioural tests, that is, Basso, Beattie and Bresnahan locomotor rating scale, footprint analysis and grid walking. Results: The combined therapy with NgR vaccination and NSC transplantation protected more ventral horn motor neurones in the injured spinal cord and greater functional recovery than when they were used alone. Furthermore, NgR vaccination promoted migration of engrafted NSCs along the rostral‐caudal axis of the injured spinal cords, and induced their differentiation into neurones and oligodendrocytes in vivo. Conclusions: The combination therapy of NgR vaccine and NSC transplantation exhibited significant advantages over any single therapy alone in this study. It may represent a potential new therapy for SCI.     

骨髓间充质干细胞立体定向移植治疗大鼠脊髓损伤*

摘要 背景：传统观念认为,神经组织损伤后几乎不能再生,以往对SCI的治疗缺乏有效手段,致使本病致残率高,疗效差。干细胞治疗关键在于移植具有再生能力的干细胞,通过多种作用机制,可以重建中枢神经系统的结构和功能,近年来引起了广泛的关注。 目的：探讨立体定向移植骨髓间充质干细胞（MSCs）对大鼠脊髓损伤修复的影响并探讨其机制 设计、时间及地点：随机对照动物实验,于2007-10/2008-6在天津市环湖医院完成。 材料：1月龄SD大鼠20只,用于制备骨髓间充质干细胞;健康成年Wistar大鼠45只,雌性、同系,体质量280±20 g。将动物随机分为对照组、假手术组与移植组,每组各15只。 方法：密度梯度离心法结合贴壁筛选法分离骨髓间充质干细胞,经流式细胞仪鉴定为MSCs。以动脉瘤夹夹闭法制备大鼠脊髓损伤（SCI）模型,在SCI大鼠致伤后第7天,通过立体定向途径移植MSCs到移植组大鼠脊髓损伤中心,移植等量生理盐水至假手术组大鼠脊髓损伤中心,对照组大鼠不做处理。 主要观察指标：SCI大鼠损伤前及损伤后第7天、14天、30天、60天、90天的BBB评分;损伤后第90天处死大鼠,观察其脊髓组织中有无BrdU阳性细胞、Brdu+NSE、Brdu+GFAP、Brdu+bFGF、Brdu+BDNF免疫组化双染阳性细胞并观察NSE、GFAP、bFGF、BDNF单染阳性细胞。 结果： ①BBB评分发现,MSCs移植组大鼠BBB后肢功能评分恢复优于对照组（p<0.05）;假手术组BBB评分在损伤后30天内恢复速度慢于对照组（p<0.05）,至第90天与对照组比较无显著差异（P>0.05）;②免疫组织化学染色发现,移植组大鼠脊髓内在损伤中心及头、尾端距离脊髓损伤中心1cm处均可见BrdU染色阳性细胞及Brdu+NSE、Brdu+GFAP、Brdu+bFGF、Brdu+BDNF免疫组化双染阳性细胞。移植组NSE、GFAP、bFGF、BDNF单染阳性细胞数明显高于对照组和假手术组（p<0.05）。 结论： MSCs移植可以促进SCI大鼠的神经功能的恢复,其机制可能与移植细胞分化为神经元样和神经胶质细胞样细胞,并分泌或促进宿主分泌神经营养因子有关。 关键词 脊髓损伤 骨髓间充质干细胞 立体定向 细胞移植     

胎鼠神经干细胞移植对大鼠脊髓损伤后神经细胞凋亡及凋亡抑制基因Bcl-2表达的影响

目的研究胎鼠神经干细胞(NSCs)移植对大鼠脊髓损伤(SCI)后神经细胞凋亡及凋亡抑制基因Bcl-2表达的影响。方法 40只SD大鼠随机分为正常对照组(Normal组),脊髓损伤组(SCI组),神经干细胞组(NSC组),神经干细胞标记组(BrdU+NSCs组)。采用电控脊髓损伤打击装置制作模型,5-溴脱氧尿嘧啶核苷(Br-dU)法标记处于对数生长期的NSCs,SCI后即刻进行NSCs移植。免疫组化法观察BrdU标记NSCs的存活、迁移及凋亡抑制基因Bcl-2的表达,TUNEL法标记凋亡细胞(免疫组化及免疫荧光显色),改良Rivlin法观察大鼠后肢运动功能的恢复情况。结果 BrdU+NSCs组在损伤脊髓区域可检测到BrdU标记的阳性NSCs。BrdU+NSC组与NSC组各时间点凋亡阳性细胞数均比SCI组减少(P<0.01),Bcl-2免疫阳性细胞光密度值比SCI组明显增加(P<0.01),且Bcl-2表达高峰延长至伤后7d;移植后7d、14d、28d后肢运动功能评分较SCI组明显升高(P<0.01)。Br-dU+NSC组与NSC组之间比较无明显差异(P>0.05)。结论体外培养的胚胎大鼠NSCs可在脊髓损伤区域存活、迁移,并能通过上调Bcl-2的表达来抑制大鼠脊髓损伤后神经细胞的凋亡,从而促进大鼠瘫痪肢体功能的恢复。     

PKH67示踪骨髓间充质干细胞迁移至损伤脊髓的实验研究

目的 探讨SCI后体外移植PKH67标记的BMSCs迁移至脊髓损伤处并进行增值和分化的动员情况。方法 用梯度离心法分离和培养出SD 大鼠第3代BMSCs,用绿色荧光染料PKH67标记; 采用钳夹法制备脊髓损伤(SCI)模型,分为实验组(n=15)、对照组(n=16)、假手术组(n=16); SCI术后对脊髓损伤组织进行HE染色,实验组和假手术组于术后尾静脉移植含有1×10⁷个BMSCs的0.5 mL生理盐水,对照组注射等量生理盐水; 分别于术后1、7、14、21 d观察大鼠后肢运动功能恢复情况,并做BBB分; 术后21 d后取脊髓组织,行免疫荧光染色,观察BMSCs的迁移,增值和分化情况。结果(1)镜下可见损伤脊髓形成的空洞、坏死及炎性细胞的增多;(2)共聚焦荧光显微镜观察显示术后21 d实验组脊髓损伤部位可见移植的BMSCs, 部分BMSCs呈GFAP和Nestin阳性表达; 假手术组无 PKH67标记的BMSCs; 实验组GFAP和Nestin阳性细胞数较对照组和假手术组明显增加(P<0.05),对照组较假手术组增加不明显(P>0.05);(3)实验组和对照组BBB评分均有增加,但实验组BBB评分显著高于对照组(P<0.05)。结论 PKH67示踪的BMSCs可迁移至损伤脊髓部位,进行增值并分化为神经元样细胞,促进损伤脊髓的神经功能恢复。     

Combined transplantation of bone marrow mesenchymal stem cells and pedicled greater omentum promotes locomotor function and regeneration of axons after spinal cord injury in rats*★

BACKGROUND： According to previous studies, the neuroprotective effect of the pedicled greater omentum may be attributed to the secretion of neurotrophic factors and stimulation of angiogenesis. The neurotrophic factors released from the pedicled greater omentum, such as brain-derived neurotrophic factor and neurotrophin 3/4/5 could exert a neuroprotective effect on the damaged host neural and glial cells, and also could induce the transdifferentiation of transplanted bone marrow mesenchymal stem cells （BMSCs） into neural cells. OBJECTIVE： Based on the functions of the omentum of neuro-protection and vascularization, we hypothesize that the transplantation of BMSCs and pedicled greater omentum into injured rat spinal cord might improve the survival rate and neural differentiation of transplanted BMSCs and consequently gain a better functional outcome. DESIGN, TIME AND SETFING： A randomized, controlled animal experiment. The experiments were carried out at the Department of Anatomy, the Secondary Military Medical University of Chinese PLA between June 2005 and June 2007. MATERIALS： Fifteen male inbred Wistar rats, weighing （200±20） g, provided by the Experimental Animal Center of the Secondary Military Medical University of Chinese PLA were used and met the animal ethical standards. Mouse anti-BrdU and mouse anti-NF200 monoclonal antibody were purchased from Boster, China. METHODS： Cell culture： We used inbred Sprague-Dawley rats to harvest bone marrow for culture of BMSCs and transplantation to avoid possible immune rejection. BMSCs were cultured via total bone marrow adherence. Experimental grouping and intervention： The rats were randomly divided into a control group, cell group and combined group, five rats per group. Rats in the control group underwent spinal cord injury （SCI） only, during which an artery clamp with pressure force of 30 g was employed to compress the spinal cord at the Tl0 level for 30 seconds to produce the SCI model. 5 μ L PBS containing 10^5 BMSCs was injected in     

Schwann cell-like remyelination following transplantation of human umbilical cord blood (hUCB)-derived mesenchymal stem cells in dogs with acute spinal cord injury

Human umbilical cord blood derived mesenchymal stem cells (hUCB-MSCs) have significant therapeutic potential in cell-based therapies following spinal cord injury (SCI). To evaluate this potential, we conducted our preliminary investigations on the remyelination of injured spinal cords with hUCB-MSC transplantations and we observed its long term effects on dogs with SCI. Of the ten injured dogs, seven were transplanted with hUCB-MSCs 1 week after SCI, whereas the remaining three dogs were not transplanted. Two transplanted dogs died over the first month after transplantation because of urinary tract infection, bedsores and sepsis. The SCI dogs showed no improvement in motor and sensory functions and their urinary dysfunction persisted until they were euthanized (from 3 months to 1 year) while hind-limb recovery in 4 dogs among the five transplanted dogs was significantly improved. In the recovered dogs, functional recovery was sustained for three years following transplantation. Histological results from five transplanted dogs showed that many axons were remyelinated by P0-positive myelin sheaths after transplantation. Our results suggest that transplantation of hUCB-derived MSCs may have beneficial therapeutic effects. Furthermore, histological results provided the first in vivo evidence that hUCB-MSCs are able to enhance the remyelination of peripheral-type myelin sheaths following SCI.     

Transplantation of human neural stem cells for spinal cord injury in primates

Recent studies have shown that delayed transplantation of neural stem/progenitor cells (NSPCs) into the injured spinal cord can promote functional recovery in adult rats. Preclinical studies using nonhuman primates, however, are necessary before NSPCs can be used in clinical trials to treat human patients with spinal cord injury (SCI). Cervical contusion SCIs were induced in 10 adult common marmosets using a stereotaxic device. Nine days after injury, in vitro-expanded human NSPCs were transplanted into the spinal cord of five randomly selected animals, and the other sham-operated control animals received culture medium alone. Motor functions were evaluated through measurements of bar grip power and spontaneous motor activity, and temporal changes in the intramedullary signals were monitored by magnetic resonance imaging. Eight weeks after transplantation, all animals were sacrificed. Histologic analysis revealed that the grafted human NSPCs survived and differentiated into neurons, astrocytes, and oligodendrocytes, and that the cavities were smaller than those in sham-operated control animals. The bar grip power and the spontaneous motor activity of the transplanted animals were significantly higher than those of sham-operated control animals. These findings show that NSPC transplantation was effective for SCI in primates and suggest that human NSPC transplantation could be a feasible treatment for human SCI.     

Human umbilical cord blood stem cells upregulate matrix metalloproteinase-2 in rats after spinal cord injury

Matrix metalloproteinases (MMPs) are a large family of proteolytic enzymes involved in inflammation, wound healing and other pathological processes after neurological disorders. MMP-2 promotes functional recovery after spinal cord injury (SCI) by regulating the formation of a glial scar. In the present study, we aimed to investigate the expression and/or activity of several MMPs, after SCI and human umbilical cord blood mesenchymal stem cell (hUCB) treatment in rats with a special emphasis on MMP-2. Treatment with hUCB after SCI altered the expression of several MMPs in rats. MMP-2 is upregulated after hUCB treatment in spinal cord injured rats and in spinal neurons injured either with staurosporine or hydrogen peroxide. Further, hUCB induced upregulation of MMP-2 reduced formation of the glial scar at the site of injury along with reduced immunoreactivity to chondroitin sulfate proteoglycans. Blockade of MMP-2 activity in hUCB cocultured injured spinal neurons reduced the protection offered by hUCB which indicated the involvement of MMP-2 in the neuroprotection offered by hUCB. Based on these results, we conclude that hUCB treatment after SCI upregulates MMP-2 levels and reduces the formation of the glial scar thereby creating an environment suitable for endogenous repair mechanisms.     

尿动力学检查对干细胞移植治疗脊髓损伤后排尿障碍的临床疗效评估

目的 探讨通过尿动力学检查判断间充质干细胞移植治疗脊髓损伤后排尿障碍的临床疗效.方法 对20例胸10-腰1段脊髓损伤后遗症患者行脐带间充质干细胞移植,并进行术前和术后半年尿动力检查,ASIA损伤分级评分.结果 60％患者尿道括约肌功能、膀胱顺应性明显改善.结论 间充质干细胞移植可以显著改善胸腰段脊髓损伤后遗症患者排尿障碍,恢复尿道括约肌和膀胱功能,提高患者生活质量.     

Review of transplantation of neural stem/progenitor cells for spinal cord injury

Spinal cord injury (SCI) is a debilitating condition often resulting in paralysis, yet currently there is no effective treatment. Stem cell transplantation is a promising therapeutic strategy for promoting tissue repair after SCI. Stem cells offer a renewable source of cells with inherent plasticity for tissue regeneration. Neural stem/progenitor cells (NSPCs) are multipotent cells that self-renew and are committed to the neural lineage, and thus, they are especially suited to SCI repair. NSPCs may differentiate into neural cells after transplantation into the injured spinal cord, replacing lost or damaged cells, providing trophic support, restoring connectivity, and facilitating regeneration. Here, we review experimental studies and considerations for clinical translation of NSPC transplantation for SCI.