Neuronal differentiation of human umbilical cord blood neural stem-like cell line

The expanding population of neural stem/progenitor cells can be selected from human cord blood nonhematopoietic (CD34-negative) mononuclear fraction. Due to repeated expansion and selection of these cells we have established the first clonogenic, nonimmortalized human umbilical cord blood neural stem-like cell (HUCB-NSC) line. This line can be maintained at different stages of neural progenitor development by the presence of trophic factors, mitogens and neuromorphogens in culture media. Neurogenic potential of HUCB-NSC was established for serum-free and low-serum cultured cells. Commitment of HUCB-NSC by serum was shown to be important for the optimal response to the signals provided by surrounding environment in vitro. Enhanced neuronal differentiation induced by dBcAMP treatment was accompanied by expression of several functional proteins including glutamatergic, GABAergic, dopamine, serotonin and acetylcholine receptors, which was shown by microarray, immunocytochemistry and electrophysiology. Electrophysiological studies, whole-cell patch-clamp recordings, revealed in differentiated HUCB-NSC two types of voltage-sensitive and several ligand-gated currents typical for neuronal cells. The above HUCB-NSC characteristic conceivably implicates that cord blood-derived progenitors could be effectively differentiated into functional neuron-like cells in vitro.     

人脐血单个核细胞体外定向诱导向神经干细胞分化

背景：有文献报道应用不同的诱导剂如细胞生长因子和神经营养因子等，可将人脐血单个核细胞体外诱导为神经干细胞和/或成熟神经细胞，但诱导剂的使用方法以及剂量却各不相同。 目的: 联合应用不同的诱导剂将人脐血单个核细胞体外诱导分化为神经干细胞，并进行形态学观察和鉴定，以确定最佳诱导剂组合及最佳浓度。 设计、时间及地点：观察对比实验，于2007-05/2008-09在辽宁省血液中心输血医学研究所细胞研究中心完成。 材料：新鲜脐血来源于足月分娩的健康孕妇。 方法:体外分离培养人脐血单个核细胞，在无血清DMEM/F12培养液中添加不同组合的诱导因子进行单个核细胞的诱导，以确定最佳诱导因子组合：①10μg/L神经生长因子(nerve growth factor，NGF)+ 体积分数为0.01 神经营养因子N2+体积分数为0.02 神经营养因子B27。②10μg/L NGF+ 10μg/L碱性成纤维细胞生长因子(basic fibroblast growth factor，bFGF)+体积分数为0.01 神经营养因子N2+体积分数为0.02 神经营养因子B27。③10μg/L bFGF+10μg/L表皮生长因子(epidermal growth factor，EGF)+体积分数为0.01 神经营养因子N2+体积分数为0.02神经营养因子B27。④10μg/L bFGF+10μg/L EGF。同时在无血清DMEM/F12培养液中添加不同浓度的bFGF和EGF进行单个核细胞的诱导，以确定最佳诱导浓度：①5μg/L bFGF+ 5μg/L EGF组。②10μg/L bFGF和10 μg/L EGF组。③20μg/L bFGF和20μg/L EGF组。 主要观察指标：①倒置荧光显微镜下观察脐血单个核细胞及各诱导剂组诱导分化为神经干细胞的形态特征。②免疫荧光检测10 μg/L bFGF和10μg/L EGF组神经干细胞巢蛋白nestin的表达情况。③流式细胞仪检测10μg/L bFGF和10μg/L EGF组诱导第7天和第15天的细胞nestin表达情况。 结果：①分离培养的脐血单个核细胞呈散在的圆形生长。②至诱导第7天，分化细胞出现突触样结构和生长端样结构，并可见多个细胞之间形成网络，符合神经干细胞样形态特征。③不同的细胞因子组合诱导的神经干细胞增殖和分化情况不同，含NGF实验组细胞长势相对最差，含bFGF和EGF实验组的细胞长势最旺盛，胞体较大而圆，细胞突起也粗大，呈三角形或锥形，突触样结构和生长端样结构明显可见，为最佳诱导因子组合。④10μg/L bFGF+10μg/L EGF组的细胞密度适中，伸出突起明显，神经细胞形态最特异，培养周期最短，为最适实验浓度。⑤细胞免疫荧光检测10μg/L bFGF+10μg/L EGF组诱导第7天细胞nestin阳性。⑥流式细胞仪分别检测对照组和10μg/L bFGF+10μg/L EGF组诱导第7天、第15天nestin阳性细胞数，差异均具有统计学意义（P < 0.05）。 结论：联合应用10μg/L bFGF和10μg/L EGF可较短时间内定向将人脐血单个核细胞体外诱导分化为神经干细胞。     

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.     

香丹注射液诱导人脐血间充质干细胞向神经细胞的分化

背景：选择一种高效、细胞损伤低的诱导人脐血间充质干细胞分化为神经细胞的方法是其应用于临床的前提。 目的：拟采用传统中药香丹注射液联合生长因子诱导脐血间充质干细胞向神经细胞方向分化,并且与单纯生长因子的诱导作用进行比较。 设计、时间及地点：免疫细胞化学水平的细胞观察实验,于2006-09/2008-04在潍坊医学院组织胚胎学教研室完成。 材料：人脐血标本取自潍坊市妇幼保健院,香丹注射液的有效成分为丹参素。 方法：采用密度梯度离心法分离人脐血单个核细胞,贴壁法筛选出人脐血间充质干细胞,体外扩增,以免疫荧光方法检测表面抗原。分为2组进行诱导分化,香丹注射液联合生长因子诱导组采用30 g/L香丹注射液联合表皮生长因子和碱性成纤维细胞生长因子诱导脐血间充质干细胞向神经细胞方向分化,并且与单纯生长因子诱导组进行比较。 主要观察指标：采用免疫细胞化学方法和免疫荧光方法检测诱导前后神经元特异性标志（神经元核抗原、β-TubulinⅢ）和神经胶质纤维酸性蛋白的表达。 结果：香丹注射液联合生长因子诱导法对脐血间充质干细胞损伤作用小,诱导效率高。脐血间充质干细胞经香丹注射液诱导后出现类似神经细胞的形态改变,胞体呈椭圆形,伸出长突起。免疫组织化学和免疫荧光方法鉴定显示,诱导后的细胞能特异性表达神经元核抗原和β-TubulinⅢ,而神经胶质纤维酸性蛋白阳性细胞较少。香丹注射液联合生长因子诱导组的 β-TubulinⅢ和神经元核抗原的阳性细胞率显著高于生长因子诱导组（P < 0.05）,神经胶质纤维酸性蛋白阳性细胞率明显低于生长因子诱导组（P < 0.05）。 结论：香丹注射液联合生长因子诱导对脐血间充质干细胞损伤作用小,诱导效率高,优于生长因子诱导法。且体外诱导后细胞主要分化为神经元样细胞,而非星形胶质细胞。     

无血清培养条件诱导人脐血间充质干细胞向神经细胞的分化

于2005-06/2007-09在南昌大学第二附属医院江西省分子医学重点实验室拟建立一种在无血清培养条件下诱导脐血间充质干细胞向神经细胞分化的方法。所用无血清培养基血清替代物是将纯化人转铁蛋白直接溶于DMEM培养基中,再将去毒后的BSA、超声波粉碎后的胆固醇、胰岛素及过氧化氢酶直接加入DMEM培养基中稀释至所需浓度。体外分离的脐血单个核细胞以1×109 L-1接种,加入含氢化可的松、纤维连接蛋白的无血清培养基,7 d后消化传代。取传至2,5,8代的脐血间充质干细胞,达60%~70%融合时以含β-巯基乙醇、丁化羟基苯甲醚的无血清培养基诱导其向神经细胞分化。结果在无血清条件下能培养扩增出大量脐血间充质干细胞,融合后可继续传代扩增;不表达CD34、CD13和CD45,强表达CD166、CD29、CD105,较强表达CD54,80%以上细胞处于G0/G1期;脐血间充质干细胞经诱导后,能形成具有典型神经元形态的神经细胞,神经元特异性烯醇化酶、神经丝蛋白、神经胶质元纤维酸性蛋白均呈阳性表达。提示在自行研制的无血清培养条件下可成功诱导脐血间充质干细胞向神经细胞分化。     

人脐带血单核细胞中的神经样细胞研究

目的 研究人脐带血单核细胞(HUBMNCs)中是否存在神经样细胞.方法 采集30例新生儿的脐带血,从中分离出单核细胞.采用免疫荧光染色法观察其神经巢蛋白和神经元特异性烯醇化酶(NSE)的表达,并对HUBMNCs进行体外培养,用倒置相差显微镜观察细胞形态.结果 HUBMNCs经免疫荧光染色后,在1个高倍视野(HP,×200)下分别可见(2.67±1.29)个、(7.37 ±2.46)个散在分布的nestin、NSE阳性的细胞.培养10 ～ 12 d时,出现3～5个/HP胞体较大、有数个类似轴突和树突状粗长突起的神经样细胞.结论 HUBMNCs中有少数神经样细胞.     

脐血来源AC133+细胞在不同诱导条件下神经分化标志物的表达

背景：近年来，在啮齿类动物中发现，造血干细胞具有向神经分化的塑型性，而在人类，这种造血的塑型性仍然具有争议。 目的:检测人脐血来源的AC133+造血干细胞是否具有向神经分化的潜能。 设计、时间及地点：本实验为成组对照设计实验，于2005-08/2007-12在天津血液学研究所和清华大学玉泉医院神经中心实验室完成。 材料：人脐带取自健康足月新生儿。胎脑滋养层细胞来源于22周流产胎儿脑组织。 方法：应用免疫磁珠分选人脐血AC133+细胞，流式细胞仪检测其纯度为99%以上。同时以机械分离及酶消化法制备胎脑滋养层细胞。选用4种培养条件对脐血来源AC133+造血干细胞进行诱导分化：①生长培养液DMEM/F12加上皮生长因子和碱性成纤维生长因子。②DMEM/F12 加上皮生长因子和碱性成纤维生长因子并联合使用脑源性生长因子，其间用全反式维甲酸处理3 d。③非细胞接触的共培养体系，先将制备的胎脑滋养层细胞生长在培养板内插件的半透膜上，与培养板内的脐血来源的AC133+细胞进行共培养。④细胞直接接触共培养，将预先用BrdU标记的脐血来源的AC133+细胞直接种在胎脑滋养层细胞上进行共培养。 主要观察指标： 1，2，4周收集诱导分化的脐血细胞，以RT-PCT检测是否有巢蛋白、骨形态生成蛋白2及神经细胞黏附分子的表达，免疫细胞化学方法检测细胞分型特异性抗原。 结果：部分脐血来源的AC133+细胞，在体外存在生长必需的因子上皮生长因子和碱性成纤维生长因子时，能表达一些与神经细胞分化有关的基因，如巢蛋白、骨形态生成蛋白，条件不同时，这些基因出现下调和关闭。在DMEM/F12 加上皮生长因子和碱性成纤维生长因子联合使用脑源性生长因子诱导培养液中，上述基因表达在2周时可检测到，同时可检测到神经发育过程中出现的另一分子神经细胞黏附分子，这一分子在造血过程中并不出现，在使用内插件的胎脑滋养层细胞共培养的脐血细胞中也检测到相同结果。在优化的非细胞接触条件中主要表达胶质酸性蛋白，在细胞直接接触的共培养体系中出现神经元分化的标志物Ⅲ β-tubulin蛋白的表达。这种基因表达变化提示，在特定的培养环境下，脐血来源的AC133+细胞内可能出现了基因重排，使造血潜能的干细胞表达神经细胞发育分子。 结论：脐血来源的AC133+细胞包含部分具有向神经分化潜能的多能干细胞，在适合条件下，表达神经分化相关抗原。     

Induction of neural tissue markers by micronized human spinal cord implants

The osteoinductive capacity of biological noncellular material has been widely recognized. Studies using bone morphogenetic proteins and acellular bone matrix demonstrate that host mesenchymal cells can be readily transformed into osteoprogenitor cells. The current study sought to determine whether another biological noncellular material, human spinal cord matrix, could induce transformation of host cells into a neural lineage. We demonstrate the formation of neural tissue and the expression of neural‐specific lineage markers in host cells colonizing implanted spinal cord fragments and adjacent tissue along with the lack of expression of nonneural lineage markers. These studies demonstrate that the inductive capacity of biological noncellular material is not limited to the osteogenic lineage and suggest that acellular spinal cord matrix could be used to generate host‐derived cells for use in neural repair and regeneration. © 2014 Wiley Periodicals, 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.     

人脐血干细胞移植修复大鼠脊髓损伤的功能评价

背景：在脊髓损伤模型的研究中，BBB评分系统和斜板试验均与脊髓损伤程度高度相关。 目的：建立改进大鼠脊髓全横断模型，对比观察BBB评分和斜板试验在人脐血干细胞移植术后功能评价中的作用。 设计、时间及地点：观察对比实验，于2007-04/2008-07在广东省组织构建与检测重点实验室完成。 材料：脐血来自健康足月产妇。实验动物为SPF级健康成年雌性SD大鼠50只，随机分为假手术对照组（n＝10）、磷酸盐注射组（n=20）、脐血干细胞移植组（n=20）。 方法：分离和体外培养人脐血干细胞。在显微镜下纵行剖开SD大鼠硬脊膜囊后，于硬脊膜内、蛛网膜外将超薄刀片刀尖直抵椎体骨质，将蛛网膜、脊髓、两侧壁和腹侧的硬脊膜作为一个整体完全划断，制作大鼠脊髓全横断模型，假手术对照组仅打开椎板，脐血干细胞移植组大鼠于脊髓两断端分别显微注射人脐血干细胞悬液6×109 ~7×109L-1，磷酸盐注射组注射等量磷酸盐缓冲液。 主要观察指标：术后12周内每2周分别应用BBB评分和斜板试验进行1次后肢运动功能评价。 结果：假手术对照组后肢运动功能于手术前后无显著变化。从术后第2周开始，磷酸盐注射组和脐血干细胞移植组逐渐恢复部分后肢运动功能，两组的BBB评分和斜板试验检测结果均表现出一致的增长趋势，呈线性正相关关系。从术后4周开始， BBB评分<13分的磷酸盐注射组和BBB评分≥13分的脐血干细胞移植组大鼠，在斜板试验中差异非常显著（P < 0.01）。到术后第12周时，磷酸盐注射组和脐血干细胞移植组斜板试验角度和恢复程度分别为34.25°和52.94％、53.85°和83.23％，并且脐血干细胞移植组高于磷酸盐注射组（P < 0.01），而同期磷酸盐注射组和脐血干细胞移植组对应的BBB评分和恢复程度仅分别为8.15和38.81％、13.90和66.19％，可见两组斜板试验角度恢复程度亦明显高于其自身对应的BBB评分结果。 结论：与BBB评分系统相比，斜板试验能更敏感地反映大鼠爪的功能恢复，但不能特异性地反映爪的精细运动。而作为主观评分体系的BBB评分系统，虽然特异性很高，但容易受主观因素的影响，敏感性较低。因此，联合应用BBB评分和斜板试验能更好地反映脊髓神经功能恢复情况。     

Trophic factor induction of human umbilical cord blood cells in vitro and in vivo

The mononuclear fraction of human umbilical cord blood (HUCBmnf) is a mixed cell population that multiple research groups have shown contains cells that can express neural proteins. In these studies, we have examined the ability of the HUCBmnf to express neural antigens after in vitro exposure to defined media supplemented with a cocktail of growth and neurotrophic factors. It is our hypothesis that by treating the HUCBmnf with these developmentally-relevant factors, we can expand the population, enhance the expression of neural antigens and increase cell survival upon transplantation. Prior to growth factor treatment in culture, expression of stem cell antigens is greater in the non-adherent HUCBmnf cells compared to the adherent cells (p < 0.05). Furthermore, treatment of the non-adherent cells with growth factors, increases BrdU incorporation, especially after 14 days in vitro (DIV). In HUCBmnf-embryonic mouse striata co-culture, a small number of growth factor treated HUCBmnf cells were able to integrate into the growing neural network and express immature (nestin and TuJ1) and mature (GFAP and MAP2) neural markers. Treated HUCBmnf cells implanted in the subventricular zone predominantly expressed GFAP although some grafted HUCBmnf cells were MAP2 positive. While short-term treatment of HUCBmnf cells with growth and neurotrophic factors enhanced proliferative capacity in vitro and survival of the cells in vivo, the treatment regimen employed was not enough to ensure long-term survival of HUCBmnf-derived neurons necessary for cell replacement therapies for neurodegenerative diseases.     

Expression of transcription factor Oct-4 and other embryonic genes in CD133 positive cells from human umbilical cord blood

A significant number of hematopoietic stem/progenitor cells (HSPC) in human umbilical cord blood could serve as a reservoir for the placental vasculature, yet, their morphological and functional features are not completely understood. Here, we describe the characterization of purified CD133(+) progenitor cells from umbilical cord blood, a subset of CD34(+) hematopoietic progenitors that were grown in proliferation medium containing Flt3-ligand, thrombopoietin and stem cell factor. Following isolation and enrichment of the CD133(+) cells by immunomagnetic cell sorting, they remained non-adherent for up to 40 days in culture and expressed different pluripotency markers including Sox-1, Sox-2, FGF-4, Rex-1 and Oct-4.Oct-4 expression was confirmed by laser-assisted single cell picking with subsequent quantitative real-time RT-PCR. The expression of Oct-4 indicates a pluripotent phenotype of CD133(+) cells and appears to be of functional relevance: After three weeks in endothelial differentiation medium, suspended cells became adherent, developed an endothelial cell-like morphology, bound fluoresceine isothiocyanate-labeled Ulex europaeus agglutinin-1, took up acetylated Di-LDL, and expressed other endothelial markers such as PECAM-1 or VEGFR-2. Concomitantly, Oct-4 expression was significantly reduced. Moreover, following treatment with retinoic acid, CD133(+) cells exhibited neural morphology associated with the expression of beta-III-tubulin. CD133(+) cells were found to express the luteinizing hormone/human chorionic gonadotropin (LH/hCG) receptor, detected by RT-PCR and immunocytochemistry. The recombinant human chorionic gonadotropin induced proliferation of the CD133(+) cells in a dose-specific manner. Our results indicate that CD133(+) HSPC from umbilical cord blood may have a greater differentiation potential than previously recognized and give rise to proliferative endothelial cells participating in placental vasculogenesis.     

Neural cell injury microenvironment induces neural differentiation of human umbilical cord mesenchymal stem cells

This study aimed to investigate the neural differentiation of human umbilical cord mesenchymal stem cells (hUCMSCs) under the induction of injured neural cells. After in vitro isolation and culture, passage 5 hUCMSCs were used for experimentation. hUCMSCs were co-cultured with normal or Aβ_1-40-injured PC12 cells, PC12 cell supernatant or PC12 cell lysate in a Transwell co-culture system. Western blot analysis and flow cytometry results showed that choline acetyltransferase and microtubule-associated protein 2, a specific marker for neural cells, were expressed in hUCMSCs under various culture conditions, and highest expression was observed in the hUCMSCs co-cultured with injured PC12 cells. Choline acetyltransferase and microtubule-associated protein 2 were not expressed in hUCMSCs cultured alone (no treatment). Cell Counting Kit-8 assay results showed that hUCMSCs under co-culture conditions promoted the proliferation of injured PC12 cells. These findings suggest that the microenvironment during neural tissue injury can effectively induce neural cell differentiation of hUCMSCs. These differentiated hUCMSCs likely accelerate the repair of injured neural cells.     

脐血单个核细胞体外诱导分化为肝样细胞的可行性**★

目的：细胞移植为重度肝损伤治疗提供了一条新的途径，但肝细胞来源仍是一个未解决的问题。实验采用体外培养体系，观察人脐血单个核细胞是否可以诱导分化为肝样细胞,以期为治疗肝脏疾病提供了新的细胞来源。 方法：实验于2006-10/2007-08在解放军第一二三医院南京军区肝病中心实验室完成。①实验材料：脐血由蚌埠解放军123医院妇产科提供，产妇及家属对实验知情同意,并经医院伦理委员会批准。②实验方法：分离获得脐血单个核细胞后，将其分组培养：对照组不加细胞因子，实验组加入重组人肝细胞生长因子、重组人成纤维生长因子4和重组人制瘤素。③实验评估：于诱导前及诱导后第7，14，21，28天采用免疫细胞化学染色检测甲胎蛋白、细胞角蛋白18、白蛋白和肝细胞抗体的表达，应用流式细胞仪检测细胞中白蛋白表达，放射免疫法检测细胞培养液中甲胎蛋白的分泌水平。 结果：①免疫细胞化学染色显示，实验组第7天可见甲胎蛋白染色阳性细胞，第21天后染色基本为阴性，第7天未检测到细胞角蛋白18和白蛋白阳性表达，随着诱导时间的延长，呈阳性表达，阳性率逐渐增高。对照组染色均呈阴性。② 实验组培养第21天时检测到糖原染色阳性细胞，28 d时呈强阳性表达。对照组糖原染色呈阴性。③流式细胞仪检测实验组白蛋白阳性细胞比例逐渐增高，第28天达80%。放射免疫法检测7 d的甲胎蛋白水平达到最高，与诱导前和对照组差异显著（P < 0.05）。 结论：在特定细胞生长因子诱导下，脐血单个核细胞能够分化为肝样细胞。     

人脐带血内皮祖细胞体外培养和鉴定

传统免疫磁珠法分选内皮祖细胞的方法操作复杂、费用大,细胞获得率较低,且内皮祖细胞的增生及分化受限。 目的：尝试改良人脐带血内皮祖细胞体外诱导分化及鉴定的方法,为实现内皮祖细胞移植、改善血管功能提供足量细胞来源。 方法：采用密度梯度离心方法获得人带血单个核细胞,体外进行诱导、分化和扩增,通过免疫组织化学、免疫荧光和流式细胞仪等技术对脐血来源的内皮祖细胞进行鉴定。 结果与结论：脐带血单个核细胞在培养过程中出现梭形贴壁和铺路石样等形态;在细胞培养至第7天,免疫组织化学显示：CD31、vWF在体外培养过程中的表达阳性;免疫荧光染色表明：(83.0±4.3)%的贴壁细胞双染呈阳性,并且DiI-acLDL标记的内皮祖细胞红色荧光在体外可以持续6周以上;第7天贴壁细胞流式细胞仪分析显示：CD34、CD133和KDR分别为(17.8±3.7)%、(22.1±4.4)%、(81.5±5.0)%。结果提示,实验成功从脐带血单个核细胞中分离培养出内皮祖细胞,在其体外可扩增并向为内皮细胞方向分化。     

人脐带血间充质干细胞分离培养体系的优化筛选

背景：目前所报道的脐带血间充质干细胞体外培养条件不尽相同,尚缺乏统一标准,且培养效率较低。 目的：拟对人脐带血间充质干细胞的分离方法、培养条件进行优化筛选。 设计、时间及地点：细胞学体外对照观察,于2007-05/2008-04在中国医学科学院北京协和医学院北京协和医院中心实验室完成。 材料：35份脐带血标本来源于北京协和医院妇产科顺产或剖宫产胎儿。 方法：应用淋巴细胞分离液法、羟乙基淀粉沉降法、羟乙基淀粉沉降与淋巴细胞分离液两步分离法分别从脐带血中获得单个核细胞。细胞接种后,应用含体积分数为10%胎牛血清的DMEM/F12、L-DMEM和MesencultTM不同培养基,在不同体积分数胎牛血清（5%,10%,20%）、不同细胞接种密度（5×106,1×107,5×107,1×108）下进行细胞培养。细胞传至第3代诱导成骨,行Von Kossa染色。 主要观察指标：不同分离方法、培养基、胎牛血清浓度、种植密度分离培养细胞的效果,脐带血间充质干细胞表面标记的表达及成骨情况。 结果：与淋巴细胞分离液法比较,羟乙基淀粉沉降法、羟乙基淀粉沉降与淋巴细胞分离液两步分离法获得的单个核细胞数量明显增多（P < 0.05,P < 0.01）,羟乙基淀粉沉降与淋巴细胞分离液两步分离法细胞原代培养时间显著短于另2种方法（P < 0.01）。应用含体积分数为10%胎牛血清的DMEM/F12或MesencultTM培养基,T25培养瓶中细胞接种密度为5×107时,培养效率高于其余各种条件组合（P < 0.01）。贴壁细胞表达CD29,CD105,不表达CD34,CD45,CD90及CD133,经成骨诱导培养21 d后Von Kossa染色可见黑色矿化结节。 结论：应用羟乙基淀粉沉降与淋巴细胞分离液两步分离法可以获得较多数量的脐带血单个核细胞,加入含体积分数为10%胎牛血清的DMEM/F12或MesencultTM培养基、细胞接种密度为5×107时可以提高脐带血间充质干细胞的培养效率。     

人脐血间充质干细胞与β-磷酸三钙的生物相容性

背景：体内实验显示,β-磷酸三钙多孔陶瓷是较为理想的骨组织工程支架材料,但由于体内植入实验受多种因素的影响,不能很好反映细胞的生长、增殖和表型变化。 目的：观察体外人脐血间充质干细胞与β-磷酸三钙多孔陶瓷的生物相容性。 方法：将培养的第6代人脐血间充质干细胞悬液滴注入β-磷酸三钙内部进行复合,然后将干细胞-支架材料复合物置入含体积分数为10%胎牛血清的α-MEM培养体系中培养,于培养第4,8,12天电镜下观察人脐血间充质干细胞在材料表面及内部生长情况,采用MTT测试法绘制细胞生长曲线,并进行DNA含量、蛋白质含量测定。 结果与结论：人脐血间充质干细胞与β-磷酸三钙体外复合后能够在β-磷酸三钙支架材料表面及内部的孔隙内贴附,且生长良好,其DNA复制和蛋白合成功能不受β-磷酸三钙的影响。说明人脐血间充质干细胞和β-磷酸三钙支架材料生物相容性良好,二者可作为种子细胞和支架材料用于组织工程化骨与软骨的构建。     

Genetically modified human umbilical cord blood cells as a promising strategy for treatment of spinal cord injury

正Spinal cord injury(SCI)continues to be a pressing health and social problem.The injury leads to neuronal and glial cell death accompanied by degeneration of nerve fibers.There are currently no particularly effective treatments.SCI causes profound disability of people affected and has attracted increased attention in the international field of neuroregeneration.For the past two decades,