Human umbilical cord Wharton’s jelly-derived oligodendrocyte precursor-like cells for axon and myelin sheath regeneration

Human umbilical mesenchymal stem cells from Wharton’s jelly of the umbilical cord were induced to differentiate into oligodendrocyte precursor-like cells in vitro. Oligodendrocyte precursor cells were transplanted into contused rat spinal cords. Immunofluorescence double staining indicated that transplanted cells survived in injured spinal cord, and differentiated into mature and immature oligodendrocyte precursor cells. Biotinylated dextran amine tracing results showed that cell transplantation promoted a higher density of the corticospinal tract in the central and caudal parts of the injured spinal cord. Luxol fast blue and toluidine blue staining showed that the volume of residual myelin was significantly increased at 1 and 2 mm rostral and caudal to the lesion epicenter after cell transplantation. Furthermore, immunofluorescence staining verified that the newly regenerated myelin sheath was derived from the central nervous system. Basso, Beattie and Bresnahan testing showed an evident behavioral recovery. These results suggest that human umbilical mesenchymal stem cell-derived oligodendrocyte precursor cells promote the regeneration of spinal axons and myelin sheaths.     

脐血间充质干细胞与帕金森病

间充质干细胞(mesenchymal stem cells,MSCs)作为一种成体干细胞,具有未分化细胞的特性,能高效率的自我更新,并且有着向多种成熟细胞分化的潜能,在生物医学和组织工程中具有巨大的科研价值[1].骨髓是第一个被报道含有MSCs的组织来源,也是如今临床应用的主要来源,但获取过程有创,易导致感染、出血、慢性疼痛,并且其增殖、分化潜能均随年龄的增长而降低,因此对于老年患者的效果得不到保证.     

Human umbilical cord blood cell therapy blocks the morphological change and recruitment of CD11b‐expressing,isolectin‐binding proinflammatory cells after middle cerebral artery occlusion

Secondary neurodegeneration resulting from stroke is mediated by delayed proinflammatory signaling and immune cell activation. Although it remains unknown which cell surface markers signify a proinflammatory phenotype, increased isolectin binding occurs on CD11b‐expressing immune cells within injured brain tissue. Several reports have confirmed the efficacy of human umbilical cord blood (HUCB) cell therapy in reducing ischemic injury in rat after middle cerebral artery occlusion (MCAO), and these effects were attributed in part to dampened neuroinflammation. The present study examined the time course of lectin binding to cells of microglia/macrophage lineage within 96 hr after MCAO and whether delayed HUCB cell treatment alters the migration and/or morphological characteristics of these cells throughout the period of infarct expansion. Isolectin binding was up‐regulated in response to injury, was maximal at 96 hr, and colocalized with cells that expressed the putative proinflammatory markers MMP‐9 and nitric oxide. Isolectin‐tagged fluorescence was also significantly increased at 72 hr and localized to greater numbers of amoeboid, CD11b‐expressing cells relative to 51 hr. Treatment with 1 × 10⁶ HUCB cells significantly reduced total lectin binding at 72 hr, as well as the total area occupied by lectin‐tagged fluorescence at both 51 and 72 hr, relative to vehicle‐treated controls. This effect was accompanied by a shift in the morphology of CD11b‐positive cells from amoeboid to ramified shape. These data indicate that HUCB cell therapy suppressed the recruitment of proinflammatory, isolectin‐binding cells during the period of infarct expansion, thus offering a potential mechanism for the protective effects of HUCB cell therapy. © 2009 Wiley‐Liss, Inc.     

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.     

脐血内皮祖细胞尾静脉与局部注射治疗糖尿病下肢缺血

背景：内皮祖细胞治疗糖尿病下肢缺血临床及动物实验多采用局部肌肉注射。 目的：比较脐血内皮祖细胞鼠尾静脉与局部注射治疗糖尿病下肢缺血效果的差异。 方法：取Wistar雄性大鼠分成5组：①糖尿病射线照射后结扎双后肢股动脉,尾静脉注射内皮祖细胞(DLV)。②糖尿病结扎双后肢股动脉左后肢局部肌肉注射PBS(DLC),右后肢局部肌肉注射内皮祖细胞(DLM)。③正常大鼠射线照射后结扎双后肢,尾静脉注射内皮祖细胞(NLV)。④糖尿病不结扎不注射内皮祖细胞(DC)。用绿色荧光示踪内皮祖细胞,苏木精-伊红染色检测肌纤维间毛细血管数,RT-PCR检测双后肢肌肉血管内皮生长因子mRNA水平。 结果与结论：DLV组与DLM组比较,右后肢腓肠肌溃疡及缺血好转明显,二者无明显区别;有明显荧光,差别不明显,Ⅷ因子免疫组织化学染色肌纤维间毛细血管数多,相互间无明显差别;腓肠肌血管内皮生长因子表达差异无显著性意义(P > 0.05)。提示脐血内皮祖细胞治疗糖尿病大鼠下肢缺血尾静脉注射与局部肌肉注射效果相当。     

Human umbilical cord blood-derived non-hematopoietic stem cells suppress lymphocyte proliferation and CD4, CD8 expression

One concern in the use of transplantation of non-hematopoietic stem cells from human umbilical cord blood (CB-nHSCs) is the possibility of rejection by the host's immune system. This study shows that both CB-nHSCs and their progenies after passaging, neuronal differentiation or IFN-gamma treatment have no significant effects on proliferation of xenogenic T lymphocytes. CB-nHSCs transplanted into the striatum of SD rat are shown to induce a lower level of CD4 and CD8 expression in the brain and in the peripheral blood and to survive better in the brain than SH-SY5Y cells. The results indicate that both undifferentiated and differentiated CB-nHSCs all have weak immunogenicity.     

体外诱导人脐带间充质干细胞分化为许旺细胞

背景：人脐带Wharton’s Jelly源间充质干细胞避免了伦理的限制,来源丰富,可以作为种子细胞进行组织修复。 目的：观察体外诱导脐带Wharton’s Jelly中间充质干细胞向许旺细胞分化的可行性。 方法：分离、培养脐带Wharton’s Jelly中间充质干细胞,流式细胞术鉴定细胞表面标志。利用神经细胞培养基、碱性成纤维生长因子、表皮生长因子、维甲酸、血小板源性生长因子等采用两步法将脐带间充质干细胞诱导分化为许旺细胞,倒置显微镜下观察细胞形态变化。利用免疫细胞化学染色法检测巢蛋白、S-100、纤维酸性蛋白的表达,反转录-聚合酶链反应、免疫印记技术检测许旺细胞特异性蛋白产物表达。 结果与结论：脐带细胞培养第7天形态发生变化,部分细胞变成梭形。原代细胞培养10 d左右可达80%~90%融合,细胞呈梭形。分离培养的细胞表达具有间充质干细胞表面特有标志：CD44(91.4%),CD29(91.3%),CD105(99.2%),不表达CD34(0.2%),CD45(0.9%),CD14(0.6%)。脐带Wharton’s Jelly中间充质干细胞经第一阶段诱导后,细胞由短梭形变成长梭形或纺锤形,并出现聚集现象,由形状规则、表面圆滑的球形细胞团形成。第二阶段诱导后,有长梭形细胞从球形细胞团爬出,96 h后细胞形态多为长梭形,伴有多极现象。免疫细胞化学染色结果示：长梭形多极细胞具有许旺细胞特异的纤维酸性蛋白、S100蛋白染色。结果表明脐带Wharton’s Jelly中间充质干细胞可在体外诱导分化为许旺细胞。     

人脐带间充质干细胞诱导成骨及治疗骨缺损

背景：人脐带间充质干细胞在成骨及组织器官修复方面具有更强的扩增能力及低免疫原性,其成集落生长潜能及成骨时间早于骨髓等其他来源间充质干细胞。 目的：观察脐带间充质干细胞诱导成骨及移植治疗骨缺损的临床效果。 方法：应用组织块贴壁法提取人脐带间充质干细胞,体外行成骨诱导并通过光镜观察、茜素红染色、碱性磷酸酶染色、Ⅰ型胶原的表达等证实其体外成骨能力;对临床骨缺损病例行人脐带间充质干细胞移植,移植后定期复查骨缺损部骨痂生长状况。 结果与结论：体外诱导证实人脐带间充质干细胞具有明确的成骨作用。骨缺损患者在人脐带源间充质干细胞移植后2个月X射线见左股骨髁上骨折部位骨块间隙模糊,骨折外周形成明显的骨痂,骨折断端相连,断端骨折线依然存在;移植后3个月见骨痂间已经形成明显骨性连接。证实脐带间充质干细胞具有体外诱导成骨及体内移植修复骨缺损作用。     

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.     

Transplantation of mesenchymal stem cells from human umbilical cord versus human umbilical cord blood for peripheral nerve regeneration

BACKGROUND: Mesenchymal stem cells (MSCs) appear to be a good alternative to Schwann cells in the treatment of peripheral nerve injury. Fetal stem cells, like umbilical cord blood (UCB) and umbilical cord (UC) stem cells, have several advantages over adult stem cells.OBJECTIVE: To assess the effects of UC-derived MSCs (UCMSCs) and UCB-derived MSCs (UCBMSCs) in repair of sciatic nerve defects. DESIGN, TIME AND SETTING: A randomized controlled animal experiment was performed at the laboratory of Department of Oral and Maxillofacial Surgery, Seoul National University Dental Hospital, from July to December 2009. MATERIALS: UCMSCs were provided by the Research Institute of Biotechnology, Dongguk University. UCBMSCs were provided by the Laboratory of Stem Cells and Tumor Biology, College of Veterinary Medicine, Seoul National University. Dulbecco's modified Eagle's medium (DMEM) was purchased from Gibco-BRL, USA. METHODS: Seven-week-old Sprague-Dawley rats were randomly and evenly divided into three groups: DMEM, UCBMSCs, and UCMSCs. A 10-mm defect in the left sciatic nerve was constructed in all rats. DMEM (15 μL) containing 1 × 106 UCBMSCs or UCMSCs was injected into the gap between nerve stumps, with the surrounding epineurium as a natural conduit. For the DMEM group, simple DMEM was injected. MAIN OUTCOME MEASURES: At 7 weeks after sciatic nerve dissection, dorsal root ganglia neurons were labeled by fluorogold retrograde labeling. At 8 weeks, electrophysiology and histomorphometry were performed. At 2, 4, 6, and 8 weeks after surgery, sciatic nerve function was evaluated using gait analysis.RESULTS: The UCBMSCs group and the UCMSCs group exhibited similar sciatic nerve function and electrophysiological indices, which were better than the DMEM group, as measured by gait analysis (P < 0.05). Fluorogold retrograde labeling of sciatic nerve revealed that the UCBMSCs group demonstrated a higher number of labeled neurons; however, the differences were not significant. Histomorphometric indices were similar in the UCBMSCs and UCMSCs groups, and total axon counts, particularly axon density (P < 0.05), were significantly greater in the UCBMSCs and UCMSCs groups than in the DMEM group. CONCLUSION: Transplanting either UCBMSCs or UCMSCs into axotomized sciatic nerves could accelerate and promote sciatic nerve regeneration over 8 weeks. Both treatments had similar effects on nerve regeneration.     

两种分离脐血间充质干细胞的方法比较*

背景：目前分离脐血间充质干细胞的方法很多,尚没有确定一种为最有效的方法。目的：寻找一种最为可靠的脐血间充质干细胞分离方法。方法：应用Percoll分离液法和羟乙基淀粉沉降法对脐血进行分离得到单核细胞,在含体积分数15%新生牛血清的DMEM/F12培养基中进行培养并传代。观察不同分离方法脐血单核细胞的回收率,每次传代的时间和细胞增值速度,培养过程中间充质干细胞形态的变化情况,并用流式细胞仪检测第3代细胞表面标志物CD90、CD44、CD34的表达。结果与结论：与Percoll分离液法相比羟乙基淀粉沉降法获得的单核细胞多,单核细胞回收率高(P < 0.01),第1次传代时间短(P < 0.01)。然而两种方法获得的细胞经培养在形态的变化和表面标志物CD90、CD44、CD34的表达上差异并无显著性意义(P > 0.05)。所以羟乙基淀粉沉降法的分离效率较高,培养时间短,但是并不能获得质量较高的脐血间充质干细胞。     

Antibody-mediated oligodendrocyte cell death requires an astrocyte-derived cosignal

We have described a monoclonal antibody (mAb), 2B10, that identifies a cell-surface protein expressed only on oligodendrocytes, the myelin-forming cells in the vertebrate central nervous system. To examine the effect of mAb 2B10 on oligodendrocyte development and survival, purified antibody was added to dissociated cultures of neonatal rat spinal cord. Addition of mAb 2B10 induced significant cell death, with a reduction of approximately 70% in the number of differentiated oligodendrocytes. The number of astrocytes was unaltered. Addition of mAb 2B10 did not affect the proliferation or differentiation of oligodendrocyte precursors. MAb 2B10-induced death of differentiated oligodendrocytes was independent of complement but did require an environmental signal. In purified oligodendrocyte cultures, binding of the antibody to oligodendrocytes did not induce cell death. Conditioned medium and transwell coculture experiments indicated that the required environmental signals were not soluble. By contrast, when oligodendrocytes were cocultured with astrocytes, addition of mAb 2B10 specifically induced cell death of differentiated oligodendrocytes, suggesting that a locally acting cosignal from astrocytes was required to facilitate the cell death. This cosignal was provided by live astrocytes but not by fixed astrocytes, microglia, or fibroblasts. Such antibody-induced oligodendrocyte cell death may explain in part the loss of myelin-forming cells in demyelination conditions, such as multiple sclerosis. J. Neurosci. Res. 52:137–148, 1998. © 1998 Wiley-Liss, Inc.     

Functional recovery and local microenviromental change after in vivo transplantion of human umbilical cord blood mesenchymal stem cells into spinal cord injury rats

目前的体内实验研究发现,成体干细胞移植是促进中枢神经系统损伤如脊髓损伤(spinal cord injury, SCI)等难治性疾病的有益尝试,成体干细胞如间充质干细胞具有可塑性,移植的细胞可以在损伤部位存活、整合入宿主组织中,分化出神经元、星形胶质细胞和少突胶质细胞,从而促使中枢神经系统的功能得到部分恢复。近年来也有一部分学者指出,成体干细胞具有可塑性证据不足,成体干细胞并不能跨胚层分化,而只是简单地与宿主细胞的融合。那么,如果并没有或极少有干细胞的转分化,还有哪些因素有助于干细胞移植后神经损伤功能的恢复呢？本文究其相关机制作了初步探讨     

脐血间充质干细胞在软骨组织工程中的应用**

背景：关节软骨修复再生能力较差,软骨缺损的修复与功能重建是关节外科的一大难题,也是近年研究热点之一,而软骨组织工程技术的发展为其提供了新的思路和方法。 目的：总结和分析脐血间充质干细胞的生物学特性及其在软骨组织工程中的研究与应用。 方法：通过计算机检索中国期刊全文数据库及PubMed数据库2000-01/2010-12的有关文献资料,分别以“脐血间充质干细胞,组织工程,软骨缺损”为中文检索词,“umbilical cord blood mesenchymal stem cells,tissue engineering,cartilage repair”为英文检索词,纳入脐血间充质干细胞和软骨组织工程的相关文献,排除重复性研究,共选取33篇文献做进一步分析。 结果与结论：脐血间充质干细胞以其固有的取材方便、免疫原性较弱、分化能力强以及被病毒细菌污染率低等特有的优势,成为软骨组织工程理想的种子细胞,将在未来软骨组织工程的研究及应用中发挥重要的作用。     

Transplantation of hNT neurons into the ischemic cortex: cell survival and effect on sensorimotor behavior

Cell transplantation offers a potential new treatment for stroke. Animal studies using models that produce ischemic damage in both the striatum and the frontal cortex have shown beneficial effects when hNT cells (postmitotic immature neurons) were transplanted into the ischemic striatum. In this study, we investigated the effect of hNT cells in a model of stroke in which the striatum remains intact and damage is restricted to the cortex. hNT cells were transplanted into the ischemic cortex 1 week after stroke induced by distal middle cerebral artery occlusion (dMCAo). The cells exhibited robust survival at 4 weeks posttransplant even at the lesion border. hNT cells did not migrate, but they did extend long neurites into the surrounding parenchyma mainly through the white matter. Neurite extension was predominantly toward the lesion in ischemic animals but was bidirectional in uninjured animals. Extension of neurites through the cortex toward the lesion was also seen when there was some surviving cortical tissue between the graft and the infarct. Prolonged deficits were obtained in four tests of sensory-motor function. hNT-transplanted animals showed a significant improvement in functional recovery on one motor test, but there was no effect on the other three tests relative to control animals. Thus, despite clear evidence of graft survival and neurite extension, the functional benefit of hNT cells after ischemia is not guaranteed. Functional benefit could depend on other variables, such as infarct location, whether the cells mature, the behavioral tests employed, rehabilitation training, or as yet unidentified factors.     

黄芩甙诱导人脐血间充质干细胞分化为神经元样细胞

目的探讨中药黄芩甙体外诱导人脐血间充质干细胞（MSCS）分化为神经元样细胞的可行性及其可能的机制。方法无菌条件下采集正常足月胎儿的脐带血,经肝素抗凝,用相对密度1．077的淋巴细胞分离液分离脐血单个核细胞,加入含黄芩甙50μmol/L的液体培养体系中进行扩增培养。取扩增培养2周的人脐血MSCS进行诱导实验。实验共分3组：诱导组（诱导液和维持液均含黄芩甙300～400μmol/L）；对照1组（诱导液和维持液均不含黄芩甙及其它抗氧化剂）；对照2组（诱导液和维持液均含3mmol/Lβ-巯基乙醇、20g/L二甲基亚砜和20mmol/L丁化羟基苯甲醚,不含黄芩甙）。诱导30min后开始在倒置显微镜下动态观察人脐血MSCS生长情况及诱导前后形态学变化。各组分别在诱导6h、24h、7d留取标本制作细胞爬片,用免疫细胞化学染色法评价神经细胞特异性烯醇化酶（NSE）和微管相关蛋白2（MAP-2）阳性细胞的表达率。用Hoechest 33258染色法评价各组细胞存活率。结果黄芩甙诱导7d后,人脐血MSCS形成较典型的神经元样细胞形态,免疫细胞化学染色显示黄芩甙诱导组NSE、MAP-2阳性细胞表达率及细胞存活率分别为77．2％±9．8％、76．6％±6．2％、86．5％±5．2％,显著高于对照1、2组（P＜0．01）。分别为4．6％±0．7％、0．7％±0．5％、45．7％±8．3％和68．9％±4．5％、51．5％±5．2％、71．6％±6．4％。结论黄芩甙能诱导人脐血MSCS分化为神经元样细胞,其诱导作用温和、稳定而持久,其诱导机制可能与黄芩甙的抗氧化、调控细胞NF-κB的活性从而刺激多种细胞因子的生成有关。     

Human umbilical cord blood-derived mesenchymal stem cells promote regeneration of crush-injured rat sciatic nerves

Several studies have demonstrated that human umbilical cord blood-derived mesenchymal stem cells can promote neural regeneration following brain injury. However, the therapeutic effects of human umbilical cord blood-derived mesenchymal stem cells in guiding peripheral nerve regeneration remain poorly understood. This study was designed to investigate the effects of human umbilical cord blood-derived mesenchymal stem cells on neural regeneration using a rat sciatic nerve crush injury model. Human umbilical cord blood-derived mesenchymal stem cells (1 × 10 6 ) or a PBS control were injected into the crush-injured segment of the sciatic nerve. Four weeks after cell injection, brain-derived neurotrophic factor and tyrosine kinase receptor B mRNA expression at the lesion site was increased in comparison to control. Furthermore, sciatic function index, Fluoro Gold-labeled neuron counts and axon density were also significantly increased when compared with control. Our results indicate that human umbilical cord blood-derived mesenchymal stem cells promote the functional recovery of crush-injured sciatic nerves.     

Intravenous human umbilical cord blood transplantation for stroke: impact on infarct volume and caspase-3-dependent cell death in spontaneously hypertensive rats

Transplantation of human umbilical cord blood cells (HUCBC) produces reliable behavioral and morphological improvements in animal models of stroke. However, the mechanisms of action still have not been fully elucidated. The aim of the present study is the evaluation of potential neuroprotective effects produced by HUCBC in terms of reduced infarct volume and caspase-3-dependent cell death. Permanent middle cerebral artery occlusion was induced in 90 spontaneously hypertensive rats. The animals were randomly assigned to the control group (n = 49) or the verum group (n = 41). The cell suspension (8 × 10⁶ HUCBC per kilogram bodyweight) or vehicle solution was intravenously administered 24 h after stroke onset. Fifty subjects (n = 25/25) were sacrificed after 25, 48, 72 and 96 h, and brain specimens were removed for immunohistochemistry for MAP2, cleaved caspase-3 (casp3) and GFAP. Another 42 animals (n = 26/16) were sacrificed after 0, 6, 24, 36 and 48 h and their brains processed for quantitative PCR for casp3 and survivin. The infarct volume remained stable over the entire experimental period. However, cleaved casp3 activity increased significantly in the infarct border zone within the same time frame. Numerous cleaved casp3-positive cells were colocalized with the astrocytic marker GFAP, whereas cleavage of neuronal casp3 was observed rarely. Neither the infarct volume nor casp3 activity was significantly affected by cell transplantation. Delayed systemic transplantation of HUCBC failed to produce neuroprotective effects in a permanent stroke model using premorbid subjects.     

人脐血干细胞移植治疗大鼠脑缺血的实验研究

目的研究人脐血干细胞(HUCBCs)移植治疗脑缺血大鼠的疗效及HUCBCs在缺血大鼠脑内的状况。方法采集足月新生儿脐带血60～100ml,分离出其中的单个核细胞,体外培养并予5溴脱氧嘧啶尿苷(Brdu)标记48h。采用线栓法制作大鼠脑缺血再灌注模型,1d后将3×106HUCBCs经缺血侧侧脑室注射入大鼠脑内。在移植后不同时间对大鼠进行神经损害严重程度评分(NSS),用免疫组化技术观察移植后的HUCBCs的存活、迁徙、分化状况。结果HUCBCs在体外具有增殖能力;移植组大鼠自移植后3周起其NSS显著低于对照组(均P<0.05);移植后2周、4周、6周脑组织切片中均可见Brdu染色阳性细胞,缺血侧明显多于对侧(均P<0.05),移植后4周、6周明显多于移植后2周(均P<0.05);移植组各时间点脑组织切片中均可见神经巢蛋白阳性细胞;植入的HUCBCs在大鼠脑内能向损伤区域迁徙并能分化为星形胶质细胞、少突胶质细胞和神经元。结论HUCBCs能在缺血大鼠脑内存活、迁徙和分化,并能改善其神经功能。HUCBCs移植可作为脑梗死的有效治疗手段。     

Evidence for high translational potential of mesenchymal stromal cell therapy to improve recovery from ischemic stroke

Although ischemic stroke is a major cause of morbidity and mortality, current therapies benefit only a small proportion of patients. Transplantation of mesenchymal stromal cells (MSC, also known as mesenchymal stem cells or multipotent stromal cells) has attracted attention as a regenerative therapy for numerous diseases, including stroke. Mesenchymal stromal cells may aid in reducing the long-term impact of stroke via multiple mechanisms that include induction of angiogenesis, promotion of neurogenesis, prevention of apoptosis, and immunomodulation. In this review, we discuss the clinical rationale of MSC for stroke therapy in the context of their emerging utility in other diseases, and their recent clinical approval for treatment of graft-versus-host disease. An analysis of preclinical studies examining the effects of MSC therapy after ischemic stroke indicates near-universal agreement that MSC have significant favorable effect on stroke recovery, across a range of doses and treatment time windows. These results are interpreted in the context of completed and ongoing human clinical trials, which provide support for MSC as a safe and potentially efficacious therapy for stroke recovery in humans. Finally, we consider principles of brain repair and manufacturing considerations that will be useful for effective translation of MSC from the bench to the bedside for stroke recovery.