骨髓基质干细胞治疗骨不连的新进展

背景：骨髓基质干细胞体外培养增殖力强、易于向成骨细胞及软骨细胞方向分化且成骨性能稳定等特点,成为骨组织工程中合适的种子细胞。 目的：总结分析采用骨髓基质干细胞作为种子细胞,分析其直接移植于骨不连部位或复合支架或转基因治疗骨不连所具有的优劣势。 方法：检索1992/2011西文生物医学期刊文献数据及CNKI 数据库有关骨不连研究,骨髓基质干细胞分离、培养,在骨不连方面的应用,骨组织工程细胞支架方面的文献,英文检索词为“bone marrow stromal stem cells,nonunions, repairing,tissue engineering”,中文检索词为“骨髓基质干细胞,骨修复,骨不连,组织工程”。排除重复性研究,保留23篇进一步归纳总结。 结果与结论：利用骨髓基质干细胞作为种子细胞,直接植入骨不连部位,或与适当的支架材料结合,或用骨髓基质干细胞作为靶细胞,导入外源目的基因诱导成骨的基因治疗来修复骨缺损的方法,给骨缺损的治疗带来光明的前景。但同时也存在骨髓基质干细胞增殖、分化合适条件难以准确确定,经皮移植自体骨髓基质干细胞植入体内后容易流失,不能在植入部位形成有效的细胞浓度,支架材料尚不能完全符合临床要求,以及如何将骨组织工程与基因治疗的方法结合起来等问题,需要进一步的研究。     

Transplantation of bone marrow stromal cells for peripheral nerve repair

Cell transplantation using bone marrow stromal cells (BMSCs) to alleviate neurological deficits has recently become the focus of research in regenerative medicine. Evidence suggests that secretion of various growth-promoting substances likely plays an important role in functional recovery against neurological diseases. In an attempt to identify a possible mechanism underlying the regenerative potential of BMSCs, this study investigated the production and possible contribution of neurotrophic factors by transected sciatic nerve defect in a rat model with a 15 mm gap. Cultured BMSCs became morphologically homogeneous with fibroblast-like shape after ex vivo expansion. We provided several pieces of evidence for the beneficial effects of implanted fibroblast-like BMSCs on sciatic nerve regeneration. When compared to silicone tube control animals, this treatment led to (i) improved walking behavior as measured by footprint analysis, (ii) reduced loss of gastrocnemius muscle weight and EMG magnitude, and (iii) greater number of regenerating axons within the tube. Cultured fibroblast-like BMSCs constitutively expressed trophic factors and supporting substances, including nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), glial cell line-derived neurotrophic factor (GDNF), ciliary neurotrophic factor (CNTF), collagen, fibronectin, and laminin. The progression of the regenerative process after BMSC implantation was accompanied by elevated expression of neurotrophic factors at both early and later phases. These results taken together, in addition to documented Schwann cell-like differentiation, provide evidence indicating the strong association of neurotrophic factor production and the regenerative potential of implanted BMSCs.     

骨髓间质干细胞的分离培养及向神经细胞分化的研究

目的 研究骨髓间质干细胞的分离培养方法及其向神经元细胞分化的条件及可行性。方法 取大鼠骨髓，采用贴壁培养筛选法，分离培养骨髓问质干细胞，经β-巯基乙醇诱导，骨髓问质干细胞可向神经元样细胞分化，免疫细胞化学方法对分化细胞进行鉴定。结果 分离的骨髓间质干细胞可体外增殖，经β-巯基乙醇诱导，骨髓间质干细胞可向神经元细胞分化，细胞突起增多，具有神经元的形态学特征；分化后的细胞表达神经元标志物-神经元特异性烯醇化酶(NSE)和神经微丝(NF)。结论 骨髓组织中存在着骨髓间质干细胞，易分离和培养，体外可增殖，可横向分化为神经元，从而为中枢神经系统疾病的移植治疗提供了细胞来源。     

周围神经细胞悬液对体外培养的骨髓基质干细胞诱导分化的影响

目的应用周围神经细胞悬液、中脑条件培养基与细胞因子联合诱导骨髓基质干细胞(MSCs)转化为多巴胺(DA)能神经元。探索体外诱导MSCs定向分化为DA能神经元的最佳条件。方法取雄性SD大鼠股骨和胫骨骨髓,进行MSCs的体外培养和传代扩增。碱性成纤维细胞生长因子预诱导后,依据处理因素不同分为对照组及实验组(周围神经细胞悬液组、周围神经细胞悬液 中脑条件培养基组)。倒置显微镜下观察细胞形态变化,在诱导第7天进行神经元特异烯醇化酶(NSE),酪氨酸羟化酶(TH)免疫细胞化学检测。计数NSE和TH阳性细胞数,并计算阳性细胞百分比。结果对照组及实验各组7d NSE阳性细胞数分别为2.304±0.767,37.411±2.89.37.836±2.836(细胞数/每视野)。各组以周围神经细胞悬液 中脑条件培养基组NSE阳性细胞率最高,差异有统计学意义(P<0.01)。对照组及实验各组7d TH阳性细胞数分别为0,10.44±0.511,16.671±0.544(细胞数/每视野)。以周围神经细胞悬液 中脑条件培养基组TH阳性细胞数量较多,差异非常显著(P<0.01)。结论周围神经细胞悬液、中脑条件培养基与细胞因子联合可明显促进MSCs向神经元样细胞分化,并促进细胞表达TH。     

Schwann cells induce neuronal differentiation of bone marrow stromal cells

Bone marrow stromal cells are multipotent stem cells that have the potential to differentiate into bone, cartilage, fat and muscle. Recently, bone marrow stromal cells have been shown to have the capacity to differentiate into neurons under specific experimental conditions, using chemical factors. We now describe how bone marrow stromal cells can be induced to differentiate into neuron-like cells when they are co-cultured with Schwann cells. When compared with chemical differentiation, expression of neuronal differentiation markers begins later, but one week after beginning co-culture, most bone marrow stromal cells showed a typical neuronal morphology. Our present findings support the transdifferentiation of bone marrow stromal cells, and the potential utility of these cells for the treatment of degenerative and acquired disorders of the nervous system.     

Peripheral nerve regeneration by bone marrow stromal cells

Adult bone marrow contains stem cells that have attracted interest through their possible use for cell therapy in neurological diseases. Bone marrow stromal cells (MSCs) were harvested from donor adult rats, cultured and pre-labeled with bromodeoxyuridine (BrdU) previously to be injected in the distal stump of transected sciatic nerve of the rats. Distal nerve stump of control rats received culture medium solution. MSCs-treated rats exhibit significant improvement on walking track test at days 18 and 33 compared to controls. Dual immunofluorescence labeling shows that BrdU reactive cells survive in the injected area of transected sciatic nerve at least 33 days after implantation, and almost 5% of BrdU cells express Schwann cell-like phenotype (S100 immunoreactivity). Because MSCs injected in a lesioned peripheral nerve can survive, migrate, differentiate in Schwann cells, and promote functional recovery, they may be an important source for cellular therapy in several neurological diseases.     

Expanding autologous multipotent mesenchymal bone marrow stromal cells

In this brief review, I will start by redefining the cells: mesenchymal stem cells should now be called multipotent mesenchymal stromal cells, with the same acronym (MSC). I will review the role of MSC as immunosuppressive and immunoprotected cells, and then go on to describe how cell culture strategies may depend on the desired functionality of MSC. In order to expand MSC in vitro, the cells have to be cultured as adherent cells on plastic surfaces. To obtain the best cell culture conditions, a number of methodological decisions have to be made. Special considerations are necessary if the cells are to be used for the treatment of patients.     

In vitro differentiation of bone marrow stromal cells into neurons and glial cells and differential protein expression in a two-compartment bone marrow stromal cell/neuron co-culture system

This study was performed to establish a bone marrow stromal cell (BMSC)/neuron two-compartment co-culture model in which differentiation of BMSCs into neurons could occur without direct contact between the two cell types, and to investigate protein expression changes during differentiation of this entirely BMSC-derived population. Cultured BMSCs isolated from Wistar rats were divided into three groups: BMSC culture, BMSC/neuron co-culture and BMSC/neuron two-compartment co-culture. Cells were examined for neuron-specific enolase (NSE) and glial fibrillary acidic protein (GFAP) expression. The electrophysiological behavior of the BMSCs was examined using patch clamping. Proteins that had significantly different expression levels in BMSCs cultured alone and co-cultured with neurons were studied using a protein chip–mass spectroscopy technique. Expression of NSE and GFAP were significantly higher in co-culture cells than in two-compartment co-culture cells, and significantly higher in both co-culture groups than in BMSCs cultured alone. Five proteins showed significant changes in expression during differentiation: TIP39_RAT and CALC_RAT underwent increases, and INSL6_RAT, PNOC_RAT and PCSK1_RAT underwent decreases in expression. We conclude that BMSCs can differentiate into neurons during both contact co-culture with neurons and two-compartment co-culture with neurons. The rate at which BMSCs differentiated into neurons was higher in contact co-culture than in non-contact co-culture.     

GM-CSF enhances neural differentiation of bone marrow stromal cells

Recent reports suggest that bone marrow stromal cells may be induced into neural cells both in vivo and in vitro. The factors that regulate the neural differentiation and the mechanism involved, however, remains unclear. Here we demonstrated that granulocyte-macrophage colony-stimulating factor (GM-CSF), a potent hematopoietic factor, was able to enhance the neural differentiation of bone marrow stromal cells. Moreover, we found that GM-CSF receptors are abundantly distributed in the bone marrow stromal cells and GM-CSF significantly upregulated the phosphorylation of cAMP-responsive element binding protein in bone marrow stromal cells. These findings suggest that GM-CSF may activate its receptor and then enhance neural differentiation of bone marrow stromal cells by upregulating phosphorylation of cAMP-responsive element binding protein.     

体外培养骨髓基质细胞向成骨细胞的分化

背景：目前如何有效地诱导骨髓基质细胞向成骨细胞转化,建立稳定的体外培养诱导模式,研究诱导条件的作用机制是骨组织工程研究的重点。目的：建立一种兔骨髓基质细胞向成骨细胞分化的体外培养体系,观察其成骨过程。设计：对比观察。材料：4~8周龄新西兰大白兔,雌雄不拘,用于骨髓基质细胞的原代与传代培养。方法：将兔股骨骨髓基质细胞进行原代培养,待细胞铺满瓶底近80%后,加入2.5 g/L胰蛋白酶消化传代培养。取生长良好的对数期第2代细胞,以1×108 L-1的细胞浓度接种于预置盖玻片的6孔培养板内。细胞分为2组,实验组使用条件诱导培养基(RPMI 1640标准培养基加入地塞米松10-8 mol/L,β-甘油磷酸钠10 mmol/L,维生素C 50 μg/L),对照组继续使用标准培养基。两组细胞持续培养(常规两三天换液1次)进行细胞成骨分化观察。主要观察指标：倒置相差显微镜观察细胞生长及形态变化;苏木精-伊红染色、碱性磷酸酶染色、Ⅰ型胶原免疫组织化学染色、钙结节染色及扫描电镜观察骨髓基质细胞形态变化。结果：经诱导培养的细胞,在体外逐渐转化、增殖、分泌细胞外基质、最终形成了矿化基质。苏木精-伊红染色显示实验组传代细胞在接近融合为单层时形态多为梭形,多角形等。胞浆内可见颗粒;碱性磷酸酶染色可见实验组传代细胞染色呈强阳性,阳性率达83.2%,并能大量分泌Ⅰ型胶原;对照组仅有个别细胞染色呈阳性。四环素染色观察实验组骨髓基质细胞形成金黄色钙结节,甚至是骨样组织,与典型成骨细胞的生物学特性相似。扫描电镜观察实验组培养的传代细胞已接近融合为单层,细胞呈梭形或多角形表现,细胞表面及细胞间可见钙盐结晶沉积。结论：实验所建立的兔骨髓基质细胞体外诱导成骨转化体系,能够培养出生长活跃,增殖迅速,稳定、多量向成骨细胞转化的骨髓基质细胞培养模式,所培养的细胞可作为成骨细胞的一种来源,为构建组织工程化骨提供种子细胞。     

人骨髓基质细胞分化为神经细胞潜力的研究

目的研究骨髓基质细胞在含血清培养基中向神经细胞分化的潜能.方法从健康人肋骨分离原代骨髓基质细胞,接种于含10%胎牛血清(FBS)的DMEM中,分为A组(3～4 d换液一次)、B组(不换液),在相差显微镜下观察生长情况.在培养的1,5,10 d用免疫荧光法检测两组骨髓基质细胞的各种表面标志物巢蛋白(nestin)、胶质纤维酸性蛋白(GFAP)、微管相关蛋白(MAP-2)、S-100表达情况.并在培养的第1,4,7,10,13 d用酶联免疫吸附法(ELISA)检测 B组培养细胞上清中的脑源性神经营养因子(BDNF)和神经生长因子(NGF)的分泌水平.结果 A组细胞分裂繁殖速度明显高于B组,在培养的第11～12 d,B组中部分细胞表现为胞体锥形并有长突起的神经元样形态,且形成网状.A组中随着培养时间的延长仅仅有nestin表达增加 ,B组中Nestin, GFAP, MAP-2的表达随时间的不同有差异,S-100在体积较小的细胞表达较强.B组细胞培养的第10d,检测到BDNF的表达,培养第7,10,13 d检测到NGF分泌.结论人骨髓基质细胞在含血清培养基中能够表达神经前体细胞和神经细胞的相关表面标志物,并且能够分泌一定水平的神经营养因子,表现出可分化成神经细胞的潜能.血清和骨髓基质细胞自身分泌物质的蓄积可能在其中起到了重要的作用.     

骨髓基质干细胞与骨缺损的修复

背景：骨髓基质干细胞来源广泛,分离方便,扩增迅速,具有多向分化潜能,适合自体移植的特点,同时是骨组织工程中合适的种子细胞。 目的：总结分析采用骨髓基质干细胞作为种子细胞,并利用转基因或其复合支架修复骨缺损所具有的优势。 方法：检索1990/2009 西文生物医学期刊文献数据及CNKI数据库有关骨髓基质干细胞分离、培养,在骨缺损方面的应用,骨组织工程方面的文献,英文检索词为“Bone marrow stem cells,Repairing,Bone defect”,中文检索词为“骨髓基质干细胞,修复,骨缺损”。排除重复性研究,保留28篇进一步归纳总结。 结果与结论：文章从骨髓基质干细胞作为种子细胞的优势,骨髓基质干细胞的分离和培养,骨髓基质干细胞的成骨诱导及骨髓基质干细胞修复骨缺损等方面进行了总结。利用骨髓基质干细胞作为种子细胞,与适当的支架材料结合,或用骨髓基质干细胞作为靶细胞,导入外源目的基因诱导成骨的基因治疗来修复骨缺损的方法,给骨缺损的治疗带来光明的前景。但同时也存在骨髓基质干细胞存化,骨髓基质干细胞的增殖、分化合适的条件,哪些因子能有效促进新骨形成,载体材料及体内植入方式,以及如何将骨组织工程与基因治疗的方法结合起来等问题需要进一步的研究。     

BMSC向神经干细胞诱导分化研究进展

骨髓基质细胞（bone marrow stromal cells，BMSC）是指存在于骨髓间质中具有自我复制能力，不仅可分化为造血细胞，在特定条件下还可分化为非造血组织细胞。BMSC具有多向分化潜能和强大的增殖能力，遗传背景稳定，体内植入反应弱，易于分离扩增纯化，是一种较理想的组织工程种子细胞。近年来，国内外学者广泛开展了BMSC向神经干细胞诱导分化的研究，本文就BMSC向神经干细胞及神经细胞诱导分化的研究进展分述如下。     

骨髓基质细胞成年大鼠脑内移植

目的 研究骨髓基质细胞脑内移植后的分布和移行，为细胞移植治疗疾病奠定基础。方法 常规培养大鼠骨髓基质细胞，应用免疫组织学方法对细胞进行鉴定，Hoechst33258标记细胞，立体定向移植到大鼠的纹状体，经过一段时间后处死大鼠，脑组织切片，直接在荧光显微镜下检查存活的细胞。结果 细胞移植到大鼠脑内能够长时间存活，移植细胞与宿主细胞有很好的相容性，宿主脑组织的结构无破坏，移植细胞能够移行一段距离，说明脑内存在的信号诱导细胞向一定的方向迁徙。结论 骨髓基质细胞脑内移植后，能够与宿主脑组织整合在一起，无细胞过度增生和胶质瘢痕形成，这种细胞可能成为中枢神经系统自体移植的细胞来源。     

体外培养人体脂肪基质细胞和骨髓基质细胞的成骨活性对比

背景：目前组织工程骨构建研究中的种子细胞主要来源于骨、骨膜、骨髓及骨外组织,近年来的研究多集中于骨髓基质细胞。而脂肪中基质细胞的发现,有望取代骨髓基质细胞。 目的：观察体外培养脂肪基质细胞与骨髓基质细胞的生物学特性,并比较二者成骨诱导后的碱性磷酸酶活性,从成骨活性方面来评价脂肪基质细胞能否取代骨髓基质细胞。 方法：手术中收集同一人体的脂肪组织与骨髓组织。脂肪组织经机械切割后以Ⅰ型胶原酶消化获得脂肪基质细胞,骨髓组织以淋巴细胞分离液密度梯度离心法分离骨髓基质细胞;体外培养、传代后以诱导培养液行成骨诱导培养。诱导后第2,3周各检测1次细胞中的碱性磷酸酶活性,并行Von Kossa钙结节染色鉴定成骨细胞。 结果与结论：共获得15例患者的脂肪与骨髓组织,其中10例完成实验。与骨髓基质细胞相比,脂肪基质细胞更易培养成活,扩增速度快;二者细胞形态相似,诱导培养后细胞外基质中均有黑色的钙结节形成;碱性磷酸酶活性二者差异无显著性意义(P > 0.05)。结果提示脂肪组织来源丰富,脂肪基质细胞成活容易,具有与骨髓基质细胞相似的生物学性能,且易培养、增殖快,二者的成骨活性相似,脂肪基质细胞比骨髓基质细胞更具有优势。     

脂肪基质干细胞和骨髓基质干细胞的体外分化能力*☆

背景：脂肪基质干细胞和骨髓基质干细胞具有很多相似的生物学特性。 目的：比较脂肪基质干细胞和骨髓基质干细胞与受损PC12细胞分别共培养后定向分化能力的差异。 方法：分别分离培养脂肪组织来源和骨髓组织来源的基质干细胞,取第5代细胞进行实验,2种细胞分别与正常或受损PC12细胞培养上清液共培养,或仅单独培养。 结果与结论：脂肪基质干细胞和骨髓基质干细胞均表达较高水平的CD44和CD29,而后者表达的CD45、CD56在前者几乎未检测到。单独培养的2种细胞均表达较高水平的Nanog、Oct4、Sox2,不表达神经元特异性烯醇酶。其中经受损PC12细胞干预的2种细胞Nanog、Oct4、Sox2表达水平显著降低,而脂肪基质干细胞中神经元特异性烯醇酶阳性细胞数更多,提示受损PC12细胞对于脂肪基质干细胞可能具有更强的诱导分化作用。     

The future of bone marrow stromal cell transplantation for the treatment of spinal cord injury

<正>Bone marrow stromal cell(BMSC)transplantation therapy is a promising approach for treating spinal cord injury(SCI),based on a number of experimental and clinical reports(Wright et al.,2011).BMSCs are a source of neuroregenerative somatic stem cells that are without the potential for tumorigenicity.Although clinical studies of autologous BMSC transplantation have been reported in Asia(Jiang