Induction of mice adult bone marrow mesenchymal stem cells into functional motor neuron-like cells

The differentiation of mesenchymal stem cells (MSC) into acetylcholine secreted motor neuron-like cells, followed by elongation of the cell axon, is a promising treatment for spinal cord injury and motor neuron cell dysfunction in mammals. Differentiation is induced through a pre-induction step using Beta- mercaptoethanol (BME) followed by four days of induction with retinoic acid and sonic hedgehog. This process results in a very efficient differentiation of BM-MSCs into motor neuron-like cells. Immunocytochemistry showed that these treated cells had specific motor neural markers: microtubule associated protein-2 and acetylcholine transferase. The ability of these cells to function as motor neuron cells was assessed by measuring acetylcholine levels in a culture media during differentiation. High-performance liquid chromatography (HPLC) showed that the differentiated cells were functional. Motor neuron axon elongation was then induced by adding different concentrations of a nerve growth factor (NGF) to the differentiation media. Using a collagen matrix to mimic the natural condition of neural cells in a three-dimensional model showed that the MSCs were successfully differentiated into motor neuron-like cells. This process can efficiently differentiate MSCs into functional motor neurons that can be used for autologous nervous system therapy and especially for treating spinal cord injuries.     

椎间盘微环境下椎间盘源性干细胞和髓核间充质干细胞的活性

文题释义：椎间盘微环境：在正常情况下,髓核组织缺乏血液供应,其营养代谢主要依赖渗透。由于代谢产物等影响,椎间盘组织内部的pH值为6.9-7.2,被认为是人体内最恶劣的环境之一,在这种条件下细胞正常代谢能力受到很大抑制,即使是特化的髓核细胞其代谢率也仅为正常的32%。当椎间盘退变后,葡萄糖及氧浓度进一步下降,乳酸堆积,pH值降低和代谢产物进行性增加。 髓核间充质干细胞：经过前期实验发现髓核间充质干细胞经自体移植于椎间盘局部,可以分化为纤维环细胞和髓核细胞,或者通过旁分泌细胞因子来促进组织细胞的再生,但髓核间充质干细胞在椎间盘微环境中存活量级并不清楚。椎间盘源性干细胞和髓核间充质干细胞在椎间盘微环境下的生存变化差异性也还是未知。 背景：椎间盘微环境对干细胞生物学行为具有重要作用,拟通过微环境调节作用来实现不依赖种子细胞的椎间盘组织修复。 目的：探讨椎间盘微环境下椎间盘源性干细胞和髓核间充质干细胞活性的差异。 方法：健康雄性SD大鼠10只,按照解剖区分离椎间盘骨组织,用Ⅱ型胶原酶消化后进行体外培养椎间盘源性干细胞;分离髓核组织,采用酶消化法体外培养髓核间充质干细胞。将获得的椎间盘源性干细胞和髓核间充质干细胞在体外进行正常条件、椎间盘微环境条件下培养扩增,培养第1-6天采用MTT法测定细胞增殖情况,培养第1,3,6天采用流式细胞技术检测CD29阳性表达水平。 结果与结论：①在不同环境的培养条件下,椎间盘源性干细胞和髓核间充质干细胞增殖情况呈相反趋势。在正常培养条件下,椎间盘源性干细胞和髓核间充质干细胞呈增殖状态,第4-6天为对数增殖期,两者差异无显著性意义(P > 0.05);在椎间盘微环境条件下,髓核间充质干细胞的增殖活性明显低于椎间盘源性干细胞,差异有显著性意义(P < 0.05);②在椎间盘微环境条件下培养第3,6天,椎间盘源性干细胞表面CD29阳性抗原表达水平明显高于髓核间充质干细胞,差异有显著性意义(P < 0.05);③结果表明,在椎间盘微环境条件下,髓核间充质干细胞和椎间盘源性干细胞活性受到一定程度的抑制,但椎间盘源性干细胞较髓核间充质干细胞保留更多的细胞活性。 ORCID: 0000-0002-3582-5630(胡炜) 中国组织工程研究杂志出版内容重点：干细胞;骨髓干细胞;造血干细胞;脂肪干细胞;肿瘤干细胞;胚胎干细胞;脐带脐血干细胞;干细胞诱导;干细胞分化;组织工程     

Specification of a dopaminergic phenotype from adult human mesenchymal stem cells

Dopamine (DA) neurons derived from stem cells are a valuable source for cell replacement therapy in Parkinson disease, to study the molecular mechanisms of DA neuron development, and for screening pharmaceutical compounds that target DA disorders. Compared with other stem cells, MSCs derived from the adult human bone marrow (BM) have significant advantages and greater potential for immediate clinical application. We report the identification of in vitro conditions for inducing adult human MSCs into DA cells. Using a cocktail that includes sonic hedgehog and fibroblast growth factors, human BM-derived MSCs were induced in vitro to become DA cells in 12 days. Based on tyrosine hydroxylase (TH) expression, the efficiency of induction was determined to be approximately 67%. The cells develop a neuronal morphology expressing the neuronal markers NeuN and beta III tubulin, but not glial markers, glial fibrillary acidic protein and Olig2. As the cells acquire a postmitotic neuronal fate, they downregulate cell cycle activator proteins cyclin B, cyclin-dependent kinase 2, and proliferating cell nuclear antigen. Molecular characterization revealed the expression of DA-specific genes such as TH, Pitx3, Nurr1, DA transporter, and vesicular monoamine transporter 2. The induced MSCs also synthesize and secrete DA in a depolarization-independent manner. The latter observation is consistent with the low expression of voltage gated Na(+) and Ca(2+) channels in the induced MSCs and suggests that the cells are at an immature stage of development likely representing DA neuronal progenitors. Taken together, the results demonstrate the ability of adult human BM-derived MSCs to form DA cells in vitro.     

Immunogenicity of adult mesenchymal stem cells: lessons from the fetal allograft

Herein we review recent data that support host tolerance of allogeneic adult mesenchymal stem cells (MSC). Evidence is emerging that donor MSC deploy a very powerful array of mechanisms that allow escape from host allogeneic responses. These mechanisms include limited expression of alloantigen by the stem cell and cell contact-dependent and -independent mechanisms. MSC modulate host dendritic cell and T cell function, promoting induction of suppressor or regulatory T cells. These effects are complemented by the induction of divisional arrest anergy in T cells and by stem cell production of soluble immunomodulatory factors, including interleukin-10, transforming growth factor-beta, prostaglandin E2, and hepatocyte growth factor. In addition, MSC express the enzyme indoleamine 2,3-dioxygenase, which creates a tryptophan-depleted milieu that promotes immunosuppression. We propose that these observations show striking similarity to emerging data on the maternal acceptance of the fetal allograft. This comparison suggests new approaches to determine the contribution of different mechanisms to the successful use of MSC in regenerative medicine.     

大鼠MSCs体外诱导分化为神经元样细胞过程中发生细胞凋亡的机制研究

目的： 探讨体外诱导大鼠骨髓间充质干细胞(MSCs)向神经元样细胞分化过程中凋亡发生的机制。方法：分离纯化大鼠骨髓间充质干细胞,随机分为3组：对照组为单纯β-巯基乙醇诱导分化组; NEK1/2抑制剂1,4-二氨基-2,3-氰基-1,4-双［2-氨基苯基硫代］丁二烯（U0126）组为自预诱导开始在加入β-巯基乙醇的同时加入10 μmol/L U0126;蛋白激酶PKC激动剂氟波酯(PMA)组为自预诱导开始在加入β-巯基乙醇的同时分别加入30 nmol/L、120 nmol/L与300 nmol/L PMA。诱导5 h后终止反应,MTT法检测细胞活性,免疫细胞化学检测神经元特异性巢蛋白nestin及凋亡相关蛋白caspase、Bcl-2、Bax的表达情况,TUNEL法检测细胞凋亡指数。结果： 诱导后5 h与对照组相比,U0126组神经元样细胞的活性、nestin的表达、Bcl-2蛋白阳性表达率均出现增强或升高(P<0.05),细胞凋亡指数降低(P<0.05);300 nmol/L PMA组则显著抑制神经元样细胞的活性和nestin的表达(P<0.05),增强Bax并降低Bcl-2的表达(P<0.05),细胞凋亡指数明显升高(P<0.05)。结论： 大鼠MSCs诱导分化为神经元样细胞过程中发生凋亡机制涉及MAPK及PKC信号途径。     

Immune regulation by mesenchymal stem cells derived from adult spleen and thymus

We show here that human and mouse mesenchymal stem cells (MSCs) can be obtained not only from bone marrow (BM), but also from adult spleen and thymus. In vitro, both human and mouse spleen- and thymus-derived MSCs exhibit immunophenotypic characteristics and differentiation potential completely comparable to BM-MSCs. In addition, they can inhibit immune responses mediated by activated T lymphocytes with efficiency comparable to BM-MSCs. In vivo, mouse MSCs from BM, spleen, and thymus, if injected together with a genetically modified tumor cell vaccine, can equally prevent the onset of an anti-tumor memory immune response, thus leading to tumor growth in normally resistant mice. Our data suggest that not only do spleen and thymus have a stem cell reservoir to build up their stromal architecture, but also contain microenviromental immunoregulatory cells with the same properties of BM-MSCs.     

成人骨髓间充质干细胞向甲状腺细胞的诱导分化

背景：促甲状腺素、胰岛素或类胰岛素生长因子等对甲状腺细胞的发育分化、特异基因的表达及功能的产生等起着重要作用,故实验模拟甲状腺的体内胚胎发生过程逐步加入以上刺激因子对骨髓间充质干细胞进一步诱导。 目的：探讨在特定环境下体外定向诱导成人骨髓间充质干细胞分化为甲状腺细胞的可行性。 方法：采用密度梯度法分离培养骨髓间充质干细胞,应用促甲状腺素、胰岛素等试剂进行诱导。利用倒置光学显微镜、透射电镜观察细胞分化过程的形态学变化,免疫荧光等检测方法研究成人骨髓间充质干细胞的分化情况。 结果与结论：诱导组培养第3天可见骨髓间充质干细胞由长梭形变为圆形、椭圆形或三角形,不规则形生长,边界欠清晰。从第8天开始可见贴壁的胚胎体逐渐呈扁平状。诱导培养第7天可见分化细胞中有甲状腺细胞的特有基因如TSHr的表达;第9天检测到分化细胞中甲状腺细胞标记物TTF-1的表达。结果初步表明骨髓间充质干细胞可以在体外诱导分化为甲状腺细胞,是研究甲状腺疾病组织工程治疗的理想种子细胞。     

恒河猴骨髓间充质干细胞的分离、培养及传代扩增

目的 建立成年恒河猴骨髓间充质干细胞(rMSC)体外分离、培养及传代扩增的有效体系,为探索新型人工生物骨替代材料提供种子细胞.方法 从恒河猴肋骨抽取骨髓,使用淋巴细胞分离液(Ficoll-Hypaque)密度梯度离心法分离骨髓细胞.用含10%胎牛血清(FCS)的低糖DMEM培养基贴壁培养、胰酶消化传代扩增.通过形态学及流式细胞技术对rMSC进行细胞周期分析及表型特征鉴定.结果 成年恒河猴骨髓来源的rMSC为成纤维样细胞群体,以梭形的成纤维样细胞为主.流式细胞技术结果 显示,rMSC表达CD29、CD44表面分子,不表达CD34、CD45等造血细胞特异性表面分子.结论 成年恒河猴骨髓来源的rMSC的分离、培养及传代扩增的细胞群中无造血系细胞污染且符合干细胞增殖特性,为探索新型人工生物骨替代材料的种子细胞提供了一个可靠来源.     

Temperature-responsive hydroxybutyl chitosan for the culture of mesenchymal stem cells and intervertebral disk cells

Temperature-responsive polymers are attractive candidates for applications related to injectable delivery of biologically active therapeutics, such as stem cells. In this study, we evaluate the potential of thermosensitive hydroxybutyl chitosan (HBC) as a biomaterial for the culture of human mesenchymal stem cells (hMSC) and cells derived from the intervertebral disk, with the eventual goal of using the HBC polymer as an injectable matrix/cell therapeutic. Conjugation of hydroxybutyl groups to chitosan renders the polymer water soluble and thermally responsive. Below its lower critical solution temperature, a solution of HBC can be maintained indefinitely in its solvated state. Upon exposure to a 37 degrees C environment, within 60 s, a 3.8 wt% HBC solution rapidly forms a gel that can be maneuvered with forceps. Upon cooling, the gel once again is able to revert to its solvated state. The gel exhibits a dramatic increase in both G' and G' with increasing temperature, signifying a temperature-dependent enhancement of gel mechanical properties. Although a solid structure upon gelation, due to its physical nature of polymer interaction and gel formation, the gel exhibits a fluid-like viscoelastic behavior when exposed to shear stresses of up to 10% strain, with both G' and G' approaching zero with increasing shear stress. Formulations of HBC gels presented in this study have gelation temperatures ranging from 13.0 to 34.6 degrees C and water contents of 67-95%. Minimal cytotoxicity in MSC and disk cell cultures was observed with these polymers up to a concentration of 5 wt%. Detection of metabolic activity, genetic analysis of synthesized mRNA, and histological staining of MSC and disk cell cultures in these gels collectively indicate cell proliferation without a loss in metabolic activity and extracellular matrix production. This study suggests the potential of HBC gel as an injectable carrier for future applications of delivering therapeutics to encourage a biologically relevant reconstruction of the degenerated disk.     

诱导剂共培养：谁更适宜骨髓间充质干细胞向神经细胞的分化？

背景：目前骨髓间充质干细胞向神经细胞分化的方法较多,采用不同诱导方法对骨髓充质干细胞分化成神经细胞的比例是不同的。 目的：比较化学诱导法和共培养法诱导大鼠骨髓间充质干细胞分化为神经细胞的差异。 方法：大鼠全骨髓血细胞分离纯化法培养骨髓间充质干细胞,分为化学诱导组和共培养组,分别采用加入化学诱导剂β-巯基乙醇和Transwell小室共培养方法诱导骨髓间充质干细胞向神经细胞分化。 结果与结论：诱导培养1周后从化学诱导和共培养组的骨髓间充质干细胞出现突起,且呈辐射生长,2周后均可见神经元特异性烯醇化酶阳性细胞。共培养组中第四五天可见星级神经细胞状结构,并形成更多的突起,神经元特异性烯醇化酶染色阳性率为(70.82±2.46)%。而在第六七天化学诱导组中神经细胞形态样细胞形成,并有连接,神经元特异性烯醇化酶染色阳性率为(52.37±1.83)%。提示细胞微环境在骨髓间充质干细胞分化成神经细胞发挥主导作用,且化学诱导法诱导效率低于共培养法。     

骨髓间充质干细胞向肝样细胞的诱导及分化

背景：研究表明,在体外提供肝细胞及成纤维细胞生长因子等多种因子可诱导骨髓间充质干细胞向肝样细胞分化,但对其诱导的最佳环境还处于摸索阶段。 目的：观察体外应用肝细胞生长因子和成纤维生长因子4等多种因子联合诱导骨髓间充质干细胞向肝样细胞的分化能力。 方法：采用全骨髓贴壁培养法分离、扩增大鼠骨髓间充质干细胞,培养第3代时用肝细胞生长因子、成纤维生长因子4、胰岛素铁硒传递蛋白及地塞米松等联合诱导其向肝样细胞的分化。于诱导7,14,21 d后观察细胞形态变化,RT-PCR检测细胞白蛋白、甲胎蛋白、细胞角蛋白的mRNA表达;于诱导14,21 d行PAS糖原染色检测,并采用免疫细胞荧光法检测细胞白蛋白表达。 结果与结论：随着诱导时间的延长,骨髓间充质干细胞表现为肝细胞样,并呈集落生长,肝细胞特异性标志物逐渐出现和成熟。细胞诱导至7 d出现甲胎蛋白mRNA表达,14 d表达增高,21 d时表达下降;14 d时细胞角蛋白18、白蛋白 mRNA和糖原出现表达,并随时间延长表达逐渐增加。细胞诱导14 d时,胞浆白蛋白出现表达,至21 d时表达增强。证实骨髓间充质干细胞在肝细胞生长因子、成纤维生长因子4等多种因子诱导作用下,具有强大的向肝细胞分化能力。     

Bioreactor expansion of human adult bone marrow-derived mesenchymal stem cells

Supplementation of mesenchymal stem cells (MSCs) during hematopoietic stem cell (HSC) transplantation alleviates complications such as graft-versus-host disease, leading to a speedy recovery of hematopoiesis. To meet this clinical demand, a fast MSC expansion method is required. In the present study, we examined the feasibility of using a rotary bioreactor system to expand MSCs from isolated bone marrow mononuclear cells. The cells were cultured in a rotary bioreactor with Myelocult medium containing a combination of supplementary factors, including stem cell factor and interleukin-3 and -6. After 8 days of culture, total cell numbers, Stro-1(+)CD44(+)CD34(-) MSCs, and CD34(+)CD44(+)Stro-1(-) HSCs were increased 9-, 29-, and 8-fold, respectively. Colony-forming efficiency-fibroblast per day of the bioreactor-treated cells was 1.44-fold higher than that of the cells without bioreactor treatment. The bioreactor-expanded MSCs showed expression of primitive MSC markers endoglin (SH2) and vimentin, whereas markers associated with lineage differentiation, including osteocalcin (osteogenesis), type II collagen (chondrogenesis), and C/EBP-alpha (CCAAT/enhancer-binding protein-alpha) (adipogenesis), were not detected. Upon induction, the bioreactor-expanded MSCs were able to differentiate into osteoblasts, chondrocytes, and adipocytes. We conclude that the rotary bioreactor with the modified Myelocult medium reported in this study may be used to rapidly expand MSCs.     

The derivation of mesenchymal stem cells from human embryonic stem cells

Human embryonic stem cells (hESCs) hold promise for tissue regeneration therapies by providing a potentially unlimited source of cells capable of undergoing differentiation into specified cell types. Several preclinical studies and a few clinical studies use human bone marrow stromal cells (hBMSCs) to treat skeletal diseases and repair damaged tissue. However, hBMSCs have limited proliferation and differentiation capacity, suggesting that an alternate cell source is desirable, and hESCs may serve this purpose. Here we describe a protocol for the reproducible derivation of mesenchymal stem cells from hESCs (hES-MSCs). The hES-MSCs have a similar immunophenotype to hBMSCs, specifically they are CD73+, STRO-1+ and CD45-, and are karyotypically stable. The derived hES-MSCs are also capable of differentiating into osteoblasts and adipocytes. When the hES-MSCs were genetically modified with the lineage-specific Col2.3-GFP lentivirus and cultured in osteogenic medium, increased GFP expression was detected over time, indicating the hES-MSCs have the capacity to differentiate down the osteogenic lineage and had progressed toward a mature osteoblast phenotype.     

成人骨髓间充质干细胞对造血干细胞体外增殖的影响

目的研究骨髓间充质干细胞（MSC）对脐带血（CB）CD34^＋细胞体外增殖和造血重建能力的影响。方法取人骨髓单个核细胞贴壁培养．梭形细胞完全融合后传代，用流式细胞仪检测免疫表型；将CBCD34^＋细胞接种到MSC或其他培养液中．比较不同培养条件对造血干细胞扩增能力、集落形成能力及黏附分子表达的影响。结果在加入IL-3的培养体系中．在MSC和细胞因子作用下，CD34^＋细胞扩增7d和14d后，有核细胞（NC）、CD34^＋细胞和CDl33^＋细胞数，实验组均显著多于对照组。CD34＋细胞在未加入IL-3的培养体系中培养8d后，实验组NC、CD34^＋细胞、CD34^＋CD38-细胞和造血祖细胞集落扩增倍数均显著高于对照组。扩增后CD34^＋细胞的ALCAM、VLA-α4、VLA-α5、VLA-β1、HCAM、PECAM和LFA-1表达较扩增前无显著变化。结论MSC可为造血干细胞（HSC）体外扩增提供适宜的微环境，有助于CD34^＋细胞体外增殖并抑制HSC分化，保持其造血重建潜能和归巢能力。     

引产儿与正常成人骨髓间充质干细胞的比较

背景：骨髓间充质干细胞是多能干细胞,同时可参与免疫调节反应,而成人及引产胎儿骨髓均是间充质干细胞的重要来源。 目的：通过引产儿与正常成人骨髓间充质干细胞的细胞形态、免疫表型、增殖活性及分泌细胞因子的比较,揭示二者生物学特点的差异。 方法：采用密度梯度离心法分离引产儿与正常成人骨髓单个核细胞,通过贴壁法培养骨髓间充质干细胞,收集传3代后的骨髓间充质干细胞,流式细胞术鉴定其免疫表型、MTT比色法检测其增殖活性以及用ELISA法检测细胞培养上清液中白细胞介素6、血小板源性生长因子和表皮生长因子的水平。 结果与结论：引产儿组和正常成人组骨髓间充质干细胞形态相似、表型相同,分泌细胞因子水平无显著差异,但引产儿细胞增殖活性显著高于正常成人。提示引产儿与正常成人骨髓间充质干细胞除增殖活性有差异外,其余生物学特点相似,引产儿可以为间充质干细胞研究提供新的骨髓来源。