骨髓间充质干细胞在组织工程研究中的应用进展

背景：骨髓间充质干细胞作为良好的种子细胞在组织工程中发挥着重要的作用。 目的：描述骨髓间充质干细胞在在骨、软骨、肝、肌腱及心脏组织工程应用的实验现状,阐明骨髓间充质干细胞在组织工程中发挥的作用。 方法：以检索词“bone marrow mesenchymal stem cells,mesenchymal stem cells,tissue engineering”,应用计算机检索NCBI、PubMed数据库 2000-01/2010-10关于骨髓间充质干细胞应用于组织工程方面文章,并限定文章语言种类为English,排除重复性研究和缺乏原创性的研究。 结果与结论：共纳入33篇文献进行归纳分析。骨髓间充质干细胞增殖活跃、且具有多向分化潜能,在特定的条件下可以分化为成骨细胞、软骨细胞、肝细胞、肌腱细胞及心肌细胞。因此,骨髓间充质干细胞可作为良好的种子细胞应用于组织工程,治疗临床相关疾病。结果证实骨髓间充质干细胞在组织工程中有很高的应用价值,希望在相关疾病的治疗上能应用组织工程解决存在的难题。     

BMP12诱导恒河猴骨髓间充质干细胞定向分化为腱细胞

目的：研究骨髓间充质干细胞定向分化为腱细胞的可能性。方法：通过电穿孔法将外源基因BMF12导入骨髓间充质干细胞中，诱导骨髓间充质干细胞定向分化为腱细胞；在形态学和分子生物学水平上对诱导后的细胞加以鉴定。结果：光镜下，诱导后的细胞形态发生明显改变；RT-PCR结果表明，诱导后的细胞有BMP12和Collagen Ⅰ的mRNA的表达，而没有Collagen Ⅲ的mRNA表达；诱导后细胞呈CD44^ 为98．39％，HLA-DR^-。结论：BMF12能够诱导骨髓间充质干细胞定向分化为腱细胞，间充质干细胞有可能成为肌腱组织工程种子细胞来源之一。     

组织工程血管种子细胞的研究进展

组织工程血管种子细胞的来源、制取、培养分化、验证及种植已成为组织工程血管研究的关键步骤。目前常用的种子细胞是血管内皮细胞，干细胞如内皮前体细胞、间充质干细胞、脂肪干细胞等，尤其是间充质干细胞及脂肪干细胞具有易于分离培养、增殖能力强和可定向分化为内皮细胞及平滑肌细胞的特点而成为热点研究的种子细胞，干细胞的研究进展将会促进组织工程血管的临床应用。     

骨髓间充质干细胞在骨组织工程中的研究进展

近20年来，组织工程取得了迅猛发展，为骨缺损修复提供了新的思路和治疗途径，要构建理想的的组织工程化骨其前提就是要有生物学特性良好的种子细胞和适合的支架材料，随着干细胞研究的不断深入，给组织工程种子细胞的选择带来了新的希望。目前，可应用于骨组织工程的种子细胞中，骨髓间充质干细胞（bone marrow mesenchymal stem cells，MSCs），因其可通过体外贴壁培养分离，扩增迅速，是一类具有分化潜能的细胞，在特定条件下可以分化为多种组织细胞，如成骨细胞、软骨细胞、肌腱、脂肪细胞、成纤维细胞以及神经星状细胞等，且具有极强的自我复制能力，是一种重要组织工程种子细胞。本文就骨髓间充质干细胞作为骨组织工程的种子细胞的国内外研究进展简要做一综述。     

骨髓间充质干细胞及其在骨/软骨缺损修复中的应用进展

间充质干细胞是一类多能干细胞，在胚胎形成过程中分化为骨、软骨、肌腱、肌肉、脂肪和髓基质等多种间充质组织。近年，研究者成功地分离到人和多种动物骨髓间充质干细胞并发现其在体外仍保持干细胞特性，能够诱导分化为成骨细胞、软骨细胞、成肌细胞和脂肪细胞等细胞系。动物实验表明，骨髓间充质干细胞能够修复具有临床意义的软骨缺损。其在肌腱缺损修复中的应用价值与巳初步得到证实。此外，由于具有多能性，间充质干细胞还是很好的基因载体。在创伤修复的基因治疗中有广阔的应用前景。     

一种新的种子细胞——滑膜间充质干细胞

滑膜间充质干细胞作为一种新的间充质干细胞在组织工程中有着广阔的应用前景。滑膜间充质干细胞能够分化为软骨、骨、脂肪、骨骼肌，具有取材方便，供区并发症少等优点。因此，滑膜间充质干细胞是软骨、骨、脂肪及骨骼肌的种子细胞的理想来源。介绍了滑膜间充质干细胞的分离、获取以及其生物学特性，并对其在组织工程中应用的研究进展做一回顾。     

兔骨髓间充质干细胞体外培养定向诱导分化为软骨细胞

背景:骨髓间充质干细胞具有分化为骨、软骨、肌腱、脂肪等组织的多分化潜能.目的:体外培养兔骨髓间充质干细胞并定向诱导分化为软骨细胞,探讨体外诱导分化为软骨的方法和条件.方法:取兔股骨骨髓,全骨髓贴壁法分离培养骨髓间充质干细胞,碱性成纤维生长因子体外培养后,取第3 代细胞在培养基中添加不同质量浓度转化生长因子β1 的软骨分...     

骨髓间充质干细胞向血管内皮样细胞分化的研究进展

骨髓间充质干细胞是一类多潜能干细胞，具有自我增殖、多向分化潜能，可向中、外胚层细胞转化。作为组织工程种子细胞的新来源，具有广阔的应用前景。就骨髓间充质干细胞表型特征、分离鉴定和定向分化为内皮样细胞的理论基础及分化机制的研究进展作一综述。     

CD146阳性亚群有作为软骨组织工程种子细胞的应用潜力

文题释义：CD146：也称为MUC18,MCAM,Mel-CAM或S-Endo1,是一种跨膜糖蛋白,同时属于免疫球蛋白超级家族的一员。在人体组织中,CD146阳性细胞被认为是微血管的壁细胞,其具有较强的增殖、迁移及自我更新能力。 组织工程种子细胞：组织工程包括3个关键要素——种子细胞、支架和活性因子,其中种子细胞应具有良好的细胞活性、增殖能力、分化及合成基质等生物功能。 背景：再生医学的发展、组织工程技术的出现为软骨缺损重建提供了新的解决思路。在组织工程中,间充质干细胞是应用广泛的种子细胞,然而干细胞作为一个异质性的细胞群体其不同亚群发挥着不同的功能。因此,应用间充质干细胞关键功能亚群进行软骨修复具有广泛应用前景。 目的：从人脂肪间充质干细胞中分离出CD146阳性亚群细胞,验证其生物学特性及其作为软骨组织工程种子细胞的潜力。 方法：人脂肪间充质干细胞由浙江金时代生物技术有限公司提供,通过流式细胞术对人脂肪间充质干细胞表面标志物进行鉴定,应用免疫磁珠分选方法从人脂肪间充质干细胞中分选出CD146阳性表达的细胞亚群。通过基因芯片检测技术及生物信息学分析技术揭示2种细胞的分子特性;体外诱导2种细胞成软骨分化并进行鉴定;冻存复苏前后检测2种细胞的细胞活性及凋亡情况。 结果与结论：①人脂肪间充质干细胞表达高水平干细胞相关标志物CD73、CD90,不表达造血干细胞相关标志物CD34、CD45、HLA-DR;②生物信息分析结果表明CD146阳性亚群细胞与脂肪间充质干细胞相比在炎症通路及骨骼肌肉系统疾病有不同功能;③CD146阳性亚群细胞能够成球软骨分化,并且其成软骨分化能力要优于人脂肪间充质干细胞;④CD146阳性亚群细胞复苏后凋亡情况和活性均要优于人脂肪间充质干细胞;⑤结果表明,CD146阳性亚群细胞具有良好的成软骨分化潜力,是一种具有前景的软骨组织工程种子细胞。 ORCID: 0000-0003-4210-4708(眭翔) 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     

人羊膜间充质细胞定向分化的研究进展

人羊膜间充质细胞源自胎盘羊膜组织,具有间充质干细胞特性和多向分化潜能。在不同生长因子的调节下,人羊膜间充质细胞可分化成内、中、外三个胚层来源的细胞,如神经细胞、成骨细胞、软骨细胞、脂肪细胞、肝样细胞等。并且人羊膜间充质细胞具有比骨髓间充质干细胞更强的扩增能力和免疫原性低等优势,在组织工程及细胞替代治疗等再生医学领域具有广阔的应用前景。本文就人羊膜间充质细胞分离培养、生物学特性及多向分化潜能方面作一综述。     

Immunoregulatory function of mesenchymal stem cells

Mesenchymal stem cells (MSC) are a rare subset of stem cells residing in the bone marrow where they closely interact with hematopoietic stem cells and support their growth and differentiation. MSC can differentiate into multiple mesenchymal and non-mesenchymal lineages, providing a promising tool for tissue repair. In addition, MSC suppress many T cell, B cell and NK cell functions and may affect also dendritic cell activities. Due to their limited immunogenicity, MSC are poorly recognized by HLA-incompatible hosts. Based on these unique properties, MSC are currently under investigation for their possible use to treat immuno-mediated diseases. However, both their condition of immunoprivilege and their immunosuppressive function have recently been challenged when analyzed under particular experimental conditions. Thus, it is likely that MSC effects on the immune system may be deeply influenced not only by cell-to-cell interactions, but also by environmental factors shaping their phenotype and functions.     

CENTRAL TOLERANCE MECHANISMS IN CONTROL OF SUSCEPTIBILITY TO AUTOIMMUNE UVEITIC DISEASE

A family of dendritic cells has been identified in situ and in vitro by microscopy and immunolabeling. The members of this family include the dendritic cells isolated from lymphoid organs, Langerhans cells [LC] of the epidermis, veiled cells in afferent lymph, and interdigitating cells [IDC] in the T-cell areas. Some common features to all members of the family are high levels of MHC class II antigens, a lack of most B and T cell markers, and an absence or low levels of macrophage/granulocyte antigens. This review summarizes the markers of mouse dendritic cells as assessed by a panel of monoclonal antibodies, and stresses a few recent findings. 1) In spleen, there are two populations of dendritic cells. More than 75% of isolated cells are 33D1⁺, NLDC145^?, and JI1d^?, while the remainder have the reciprocal phenotype and thus share the NLDC145 antigen of IDC. Thymic dendritic cells, released by collagenase digestion, and epidermal LC also are 33DI^?, NLDC145⁺, J11d⁺. 2) When epidermal LC are placed in culture, there are changes in cell function and phenotype. There is a decrease in Fc-γ receptors and the F4/80 macrophage antigen, an increase in class I and II MHC products and p55 IL-2 receptors, and persistence of the NLDC145 IDC antigen. The cultured LC thereby resembles the IDC. 3) A new antibody N418 shows that dendritic cells express the p150/90 member of the leukocyte β₂ integrin family. Immunolabeling of tissue sections of spleen indicates that N418⁺ dendritic cells not only are present in the periarterial sheaths, the location of IDC, but also in “nests” at the periphery of the T area where 33D1 has been found. The peripheral collections interrupt the marginal zone of macrophages that separates white and red pulp, and places the dendritic cells in the path of T cells as they move through the white pulp. Therefore the members of the dendritic cell family have important markers in common, as well as differences that are associated with state of immunologic function and location.     

Activated NKT cells increase dendritic cell migration and enhance CD8+ T cell responses in the skin

Activated NKT cells produce cytokines such as IL-4 and IFN-gamma that function locally to influence the strength and functional development of antigen-specific T cells. Here we identify an alternative mechanism by which NKT cells influence the strength of T cell responses: through modulation of peripheral dendritic cell (DC) trafficking. NKT cell activation with alpha-galactosylceramide induced high systemic levels of TNF-alpha that mediated increased DC migration from skin to draining lymph nodes. This increased DC trafficking led to a threefold increase in effector T cell priming and in the immune response elicited to antigen challenge when alpha-galactosylceramide was given at the time of immunization of the skin. These studies provide important implications for the use of NKT cell activation strategies to manipulate T cell-mediated responses including responses to cutaneous tumors and graft vs. host disease.     

Influences of the pia mater on the precursors of nerve cells

Summary In the developing cerebellum of 8-day old rats surgical lesions were made. During regeneration of the cerebellum the pia mater was found to penetrate inside the neural tissue. Partially differentiated Purkinje cells and granule cells, that were in close contact with the pial cells, were found atrophied. When the profilerative cells of external granular layer came into contact with the pial cells, they were reduced to a primitive type of epitheloid cells. In this instance epithelio-mesenchymal interaction was found deleterious to the precursors of neurons. However, when the epithelioid cells were freed from the contact with the pial cells by intervening basement membrane, they differentiated into ependymal cells. Such ependymal cells gave rise to small as well as large new ventriculer structures, and structures resembling chorioid plexus.This research was supported by NIH Research Grant NS08817-03. Acknowledgements are due to Sheila Anderson for histology and to Donna Whitehurst for photographic work.     

后肾细胞微环境诱导胚胎干细胞向肾系细胞分化的实验研究

目的: 探讨胚胎后肾细胞微环境诱导胚胎干细胞(ESCs)分化为肾系细胞的作用。方法: 小鼠D3系胚胎干细胞通过悬滴法制备拟胚体(EBs),将EBs细胞与取自孕12.5 d小鼠胚胎的后肾细胞通过间接共培养以诱导其分化,即为共培养诱导组,设EBs细胞自然分化为对照组;采用免疫荧光染色法检测共培养第3、5、7 d后的EBs细胞Pax2、WT-1蛋白表达情况,通过逆转录PCR法检测诱导3 d后的EBs细胞Pax2、WT-1、Lim1、Sall1、Emx2、GDNF、Wnt4、BMP7、Nephl、Nephrin、KSP和CD24 mRNA的表达情况。结果: EBs细胞在诱导的第3 d即出现了全部肾发育相关基因的表达,其中共培养组Pax2、WT-1、Emx2、GDNF、Nephl、Nephrin、KSP和CD24的表达强于对照组;免疫荧光结果显示在诱导3 d后的EBs细胞中可观察到Pax2阳性细胞,阳性细胞数在共培养第5、7 d增多;诱导5 d后可观察到WT-1阳性细胞,对照组未见Pax2或WT-1蛋白阳性细胞出现。结论: 后肾细胞微环境可促进ESCs分化为肾系细胞。     

脂肪来源干细胞诱导分化为神经元样细胞的实验研究

目的： 研究脂肪来源干细胞（ASCs）的分离、纯化、扩增以及在体外定向分化为神经元样细胞的能力。 方法: 获取并培养正常人的ASCs，倒置显微镜下观察其形态；流式细胞仪检测其免疫表型。全反式维甲酸（ATRA）诱导ASCs在体外分化为神经元样细胞，倒置显微镜观察神经元样细胞的形态，逆转录-聚合酶链反应（RT-PCR）检测巢蛋白基因的表达；免疫组织化学染色法和Western blotting法检测神经丝蛋白（NF）和神经元烯醇化酶（NSE）的表达。 结果: ASCs呈纤维样贴壁生长，体外培养易扩增；ASCs表达相关抗原CD29和CD105，不表达CD31、CD34、CD45和HLA-DR；不同扩增代数的ASCs经诱导剂的作用可呈现典型的神经元样细胞形态，巢蛋白基因及NF、NSE均呈阳性表达。 结论: 脂肪组织中分离培养的ASCs具有体外大量扩增并保持低分化状态的特性，以及定向分化为神经元样细胞的能力, 是一种可用于神经系统疾病治疗的种子细胞。     

Accessory phenotype and function of macrophages induced by cyclic adenosine monophosphate

Mature macrophages (Mph) differentiated in culture from normal human peripheral blood monocytes (Mo) exhibit low activity as accessory cells (antigen-presenting cells) in T lymphocyte stimulation. A test system was established based on mitogenicity to quantitate the accessory activity of Mph-derived cells and to follow its changes for several days. The system used accessory cells treated with the oxidative mitogen, sodium periodate. The cells were subsequently co-cultured with pooled human lymphocytes from a cryopreserved stock. DNA synthesis in these cells was used as an indicator of accessory activity. Mph could be converted within 5-6 days into highly active accessory cells if a continuous stimulus of exogenously added dibutyryl cyclic AMP (db-cAMP) was provided. Mph treated by db-cAMP retained a high degree of HLA-DR expression but typical Mph markers such as non-specific esterase, phagocytosis, and expression of Fc-receptors were down-regulated. Acid phosphatase and myeloperoxidase underwent only slight changes, while the monocyte marker 5'-nucleotidase remained undetectable. Morphologically, the cells rounded up and developed veils and dendritiform elongations. In contrast to dendritic cells, Mph-derived accessory cells retained the CD14 antigen characteristic of monocytes and Mph. It is concluded that Mph are able to respond to exogenous stimuli and to convert into a highly active accessory cell. This contrasts to the well-known state of the 'activated Mph' with respect to markers and function. Both states appear to be antagonistically controlled by intracellular second messengers, as the accessory cell phenotype is positively correlated with intracellular cyclic AMP increase, whereas Mph activation correlates with cyclic GMP increase.     

Identification of a CD8α Dendritic Cell Subpopulation in Rat Spleen and Evaluation of Its OX-62 Expression

Rat spleen DC and bone marrow-derived DC were isolated and characterized by morphology and flow cytometry. We found a CD8α⁺ DC subpopulation representing 19–48% (27.4 ± 12.0) of total spleen DC. The OX-62 expression on total spleen DC was 41–59% (51.8 ± 7.5). Myeloid bone marrow-derived DC were negative for CD8α and OX-62. We demonstrated the coexpression of CD8α and OX-62 molecules, at least in a portion CD8α⁺ spleen DC. Both CD8α⁺ and CD8α⁻ spleen DC subpopulations separated by MACS were able to induce an in vivo primary immune response to OVA. The immune response induced by the CD8α⁻ DC subpopulation was higher (P < 0.05). We identified a CD8α⁺ DC subpopulation in rat spleen less effective in inducing an immune response than CD8α⁻ DC. Moreover, our results suggest the presence of DC subpopulations with different lineages in DC preparations based on OX-62 expression.     

Human Osteogenic Sarcoma: Fine Structure of the Osteoblastic Type

The fine structure of representative regions of 13 osteoblastic osteogenic sarcomas was studied. These regions contained four morphologically distinguishable subtypes of osteoblastlike cells. In addition, fibroblastlike and chondroblastlike cells were present, along with multinucleated giant cells, leukocytes, macrophagelike cells, and small populations of histogenetically unclassifiable (but probably neoplastic) cells.

The morphologic evidence was compatible with the view that the variations in appearance among the subgroups of osteobl astlike cells reflected differences in maturation and differentiation of these cells. In at least one subgroup, the morphologic findings suggested that the ceils were capable of manufacturing a secretory product. The multinucleated giant cells occurring in genuine tumor areas appeared to be closely related to neoplastic osteoblasts.

The presence of chondroblastlike cells in the tissues illustrates that cells with a diverging differentiation can occur in an osteoblast-dominated cell population. This agrees with the view that the neoplastic cells originate from a mesenchymal stem cell with potential for multifaceted differentiation.