人脐带间充质干细胞的分离培养与鉴定

目的:建立并优化人脐带间充质干细胞分离纯化方法,并对其表面标志与多向分化潜能进行鉴定。方法:收集健康足月产胎儿脐带组织,采用组织块贴壁法进行原代培养,流式细胞仪对其表面标志进行检测,通过向成骨成脂分化对其多向分化潜能进行鉴定,RT-PCR对其干细胞特性基因Oct4、Nanog、Sox2、Nestin进行检测。结果:采用组织块贴壁法可在2周左右获得大量间充质干细胞,培养的细胞经流式细胞仪检测,高表达CD29、CD44、CD105、CD106,低表达CD34、CD45;经成骨成脂诱导2周后可分化为成骨细胞和成脂细胞,RT-PCR检测发现原代细胞表达Oct4、Nanog、Sox2、Nestin基因。结论:人脐带间充质干细胞可在体外扩增培养,具有多向分化潜能,可作为组织工程种子细胞来源。     

长期传代培养对人脐带间充质干细胞生物学特性的影响

该课题研究长期体外传代培养对人脐带间充质干细胞重要生物学属性的影响。采用组织块法分离人脐带间充质干细胞,体外反复传代培养后比较第5、10、20代细胞的主要生物学属性:采用细胞计数法与流式细胞仪检测不同代次细胞增殖活性和表面免疫标志物;染色体常规核型分析和微阵列分析检测其基因稳定性;成脂、成骨诱导分化检测其多向分化潜能;定量RT-PCR检测端粒酶反转录基因hTERT的表达; SA-β-gal活性确定细胞老化状态。第5、10、20代脐带间充质干细胞呈现相同的增殖曲线,各代次干细胞的增殖速率无显著性差异。不同培养代次的脐带间充质干细胞表面均呈现CD105、CD90、CD44、CD73高表达, CD19、CD34、CD45及HLA-DR不表达或低表达。基因稳定性分析证实三个代次干细胞均为正常二倍体核型,染色体基因组未发生基因拷贝数缺失、重复和大片段纯合子现象。成脂和成骨分化潜能以及hTERT表达均未见显著性差异。SA-β-gal活性检测显示,随培养代次的增加,脐带间充质干细胞开始呈现衰老征象,尤以第20代明显。体外反复传代长期培养对人脐带间充质干细胞的基本生物学属性、基因稳定性及其多向分化潜能均无显著性影响。过度长期培养有可能导致干细胞老化,活性降低。     

比较两种不同来源间充质干细胞的生物学特性及多向分化潜能

该文旨在比较人脂肪间充质干细胞(hADSCs)和脐带间充质干细胞(hUMSCs)的生物学特性,并鉴定其多向分化潜能。体外扩增培养hADSCs和hUMSCs,绘制细胞生长曲线并计算群体倍增时间,通过细胞集落实验比较两种细胞的增殖能力,流式细胞仪和RT-PCR方法分别检测细胞表面抗原和多能性相关基因的表达,采用成脂、成骨诱导分化试剂盒比较两种细胞的分化潜能。hADSCs和hUMSCs表达CD34、CD44、CD45、CD105的比例分别为2.7% vs 6.2%、92.3% vs 93.4%、1.3% vs 3.1%、99.4% vs 98.0%,均表达Oct4和Nanog基因;生长曲线均呈"S"型,两种细胞的群体倍增时间差异不显著(P0.05);随着代数的增加,两种细胞的增殖能力均变弱,但P7的hADSCs的增殖能力要显著优于hUMSCs(P0.05);经油红O、茜素红染色及RT-PCR和细胞免疫荧光方法检测特异基因的表达,表明两种细胞均具备成脂、成骨分化的能力,hADSCs的成脂能力优于hUMSCs,但两种间充质干细胞的成骨分化能力没有显著性差异。hADSCs和hUMSCs具有相似的生物学特性,但hADSCs可能具备更强的增殖能力和成脂分化潜能。     

脐带间充质干细胞——组织工程的新视角

目的 从脐带中分离培养脐带间充质干细胞(mesenchymal stem cell, MSC) 并进行鉴定,阐明其多向分化的潜在作用.方法 收集健康胎儿脐带,分离培养脐带中的间充质干细胞,以流式细胞仪对培养的间充质干细胞进行细胞表面标志检测,多种成分联合诱导其向脂肪、成骨方向分化,细胞化学染色检测诱导后的细胞变化.结果 脐带中分离培养的间充质干细胞不表达造血细胞系的标志CD34、CD45、HLA-DR,强表达CD105、CD44、CD90,在适当的诱导条件下可向脂肪及成骨方向分化.结论 脐带中存在具有多向分化潜能的间充质干细胞.     

鼻黏膜间充质干细胞的培养、鉴定及诱导分化

目的建立Sprague Dawley(SD)大鼠鼻黏膜间充质干细胞(NM-MSCs)的获取、分离、培养方法,初步了解其生物学特性。方法通过SD大鼠鼻黏膜贴壁法体外分离、培养NM-MSCs,光镜下细胞形态学观察,用免疫荧光技术检测间充质干细胞和神经干细胞标记物,用流式细胞术检测细胞表面标记物,再诱导其向骨组织及脂肪组织方向分化,最后对其进行细胞周期检测及分析。结果分离培养的NM-MSCs光镜下以梭形与多角形细胞为主,呈放射状排列,且生长旺盛;免疫荧光染色显示NM-MSCs同时表达STRO-1和Nestin;第4代NM-MSCs不表达CD19、CD31、CD34、CD45及HLADR细胞表面标记物,但表达CD90、CD105基质细胞标记物;NM-MSCs经成骨、成脂诱导后,茜素红染色和油红O染色均呈阳性;细胞周期分析显示NM-MSCs符合干细胞生长的特性。结论 SD大鼠NM-MSCs组织块贴壁法获取容易,操作简单,且可大量扩增用于细胞实验研究,经体外诱导后具有多向分化潜能,具有间充质干细胞的一般生物学特性。SD大鼠鼻黏膜组织块贴壁法为组织细胞工程研究提供了充足的种子细胞来源。     

脐带间充质干细胞成脂分化的研究

目的:探讨脐带间充质干细胞向成脂细胞方向分化的潜能,为脂肪组织工程提供一种来源丰富的干细胞来源。方法:采用胰酶和胶原酶Ⅰ型联合消化法获得脐带间充质干细胞,通过免疫细胞化学法对其表面标志物进行鉴定,化学诱导方法诱导脐带间充质干细胞向成脂细胞方向分化,倒置显微镜观察其形态变化,油红O染色对诱导后的细胞进行染色。结果:胰酶和胶原酶Ⅰ联合消化法分离的细胞贴壁生长,呈现成纤维细胞形态,免疫细胞化学显示脐带间充质干细胞表达CD29、CD44和CD105,但不表达CD31、CD34和CD105,脐带间充质干细胞在成脂诱导培养基中细胞生长速度明显减慢,细胞形态转变为肥大、扁平、含有大量脂滴的脂肪细胞,油红O染色示胞浆充满了油滴空泡。结论:脐带间充质干细胞具有向成脂细胞方向分化的潜能,为脂肪组织工程提供了一种来源丰富、免疫力低和低分化的种子细胞。     

人脐带间充质干细胞在组织工程中的研究进展

人脐带间充质干细胞是一类具有自我更新、增殖和多向分化潜能的干细胞,具有来源广泛、易于采集、保存和运输、无异体排斥、避免伦理争议等诸多优点.流式细胞仪分析发现人脐带间充质干细胞高表达间质细胞标志(CD44、CD105)、整合素受体(CD29、CD49b、CD49c、CD51),不表达造血系标志(CD34、CD45)人白细胞抗原HLA-DR和内皮细胞标志CD31.人脐带间充质干细胞在体内外可以分化为骨细胞、软骨细胞、肝细胞、心肌细胞、骨骼肌细胞以及神经元细胞等.目前人脐带间充质干细胞在组织工程骨、人工血管以及基因治疗等临床应用研究中已逐渐深入,并已显示出广阔的应用前景.本文就人脐带间充质干细胞的生物学特性及其在组织工程中的研究作一综述.     

脐血间充质干细胞诱导向神经元样细胞分化的实验研究

目的：研究脐血间充质干细胞生物学特性及向神经元样细胞分化的潜能。方法：采用密度梯度离心结合贴壁培养法自脐血中分离间充质干细胞,观察细胞生长情况,描绘生长曲线,流式细胞仪检测细胞表面标志物,分别向成骨细胞、脂肪细胞、神经元样细胞进行诱导分化,通过茜素红染色、油红O染色检测脐血间充质干细胞成骨、成脂肪细胞诱导分化能力,而以免疫组织化学检测诱导后细胞表面神经标志物的表达。结果：纯化的脐血间充质干细胞贴壁生长,呈均一梭形,生长曲线呈S型,并以P3代增殖能力最强,细胞表面不表达或弱表达CD34、CD35、CD106,高表达CD29、CD44、CD105。成骨诱导2周后,可检测到钙化基质的形成,成脂肪诱导3周后,可检测到脂滴的形成。向神经元样细胞诱导分化后,可观察到典型的神经元样形态改变,且NSE、NF、GFAP阳性表达。结论：分离纯化的脐血间充质干细胞具有较强的增殖能力与分化潜能,并在体外诱导条件下可以向神经元样细胞定向分化。     

人脐带间充质干细胞作为维持人胚胎干细胞生长饲养层细胞的研究

目的寻找可以维持人胚胎干细胞未分化生长的人源性细胞作为饲养层细胞,从而解决使用鼠源性细胞作为饲养层带来的安全问题。方法尝试以人脐带间充质干细胞作为饲养层细胞来培养人胚胎干细胞,检验其是否可以维持人胚胎干细胞的未分化生长状态。用胶原酶消化法分离人脐带间充质干细胞,光镜下观察细胞形态;流式细胞仪检测其表面标志;诱导人脐带间充质干细胞向成骨细胞和脂肪细胞进行分化。将人胚胎干细胞系H1接种于丝裂霉素C灭活后的人脐带间充质干细胞上,每隔5d进行一次传代。培养20代后,对人胚胎干细胞特性进行相关检测,包括细胞形态、碱性磷酸酶染色、相关多能性基因的表达、分化能力。结果从人脐带中分离出的间充质干细胞为梭形,呈平行排列生长或漩涡状生长;细胞高表达CD44、CD29、CD73、CD105、CD90、CD86、CD147、CD117,不表达CD14、CD38、CD133、CD34、CD45、HLA-DR;具有分化成脂肪细胞和成骨细胞的潜能。人胚胎干细胞在人脐带间充质干细胞饲养层上培养20代后,继续保持人胚胎干细胞的典型形态,碱性磷酸酶染色为阳性,免疫荧光染色显示OCT4、Nanog、SSEA4、TRA-1-81、TRA-1-60的表达为阳性,SSEA1表达为阴性,体外悬浮培养可以形成拟胚体。结论人脐带间充质干细胞可以作为人胚胎干细胞的饲养层细胞,支持其生长,并维持其未分化生长状态。     

人脐带和骨髓间充质干细胞体外分离培养及生物学特性比较

目的体外分离培养、扩增人脐带间充质干细胞(h UC-MSC)和人骨髓间充质干细胞(h BM-MSC),并对其生物学特性进行比较。方法采用组织块贴壁法从足月胎儿脐带分离、纯化和培养h UC-MSC,健康成人骨髓肝素抗凝后,采用密度梯度离心法分离、纯化和培养h BM-MSC;用倒置显微镜观察两种细胞的形态及细胞生长增殖情况,流式细胞仪分析检测第3代细胞表面标志的表达,Von?Kossa染色及油红O染色检测分化潜能。结果镜下两种细胞均为贴壁生长,形态为均一的成纤维细胞样,取相同数量的细胞传代接种后,h UC-MSC的增殖速率快于h BM-MSC,两种细胞具有均一的细胞表型,均表达CD29、CD44、CD105,不表达CD45、CD34、HLA-DR、HLA-G、CD80、CD86,两种细胞都有成骨、成脂分化潜能,但h UC-MSC的分化潜能更强。结论 h UC-MSC与h BM-MSC具有相似的生物学特性,且前者具有更强的增殖能力和分化潜能,h UC-MSC有望成为h BMMSC理想的替代来源。     

Mesenchymal stem cells derived from human placenta suppress allogeneic umbilical cord blood lymphocyte proliferation

Human placenta-derived mononuclear cells （MNC） were isolated by a Percoll density gradient and cultured in mesenchymal stem cell （MSC） maintenance medium. The homogenous layer of adherent cells exhibited a typical fibroblastlike morphology, a large expansive potential, and cell cycle characteristics including a subset of quiescent cells. In vitro differentiation assays showed the tripotential differentiation capacity of these cells toward adipogenic, osteogenic and chondrogenic lineages. Flow cytometry analyses and immunocytochemistry stain showed that placental MSC was a homogeneous cell population devoid of hematopoietic cells, which uniformly expressed CD29, CD44, CD73, CD105, CD166, laminin, fibronectin and vimentin while being negative for expression of CD31, CD34, CD45 and m-smooth muscle actin. Most importantly, immuno-phenotypic analyses demonstrated that these cells expressed class Ⅰ major histocompatibility complex （MHC-I）, but they did not express MHC-Ⅱ molecules. Additionally these cells could suppress umbilical cord blood （UCB） lymphocytes proliferation induced by cellular or nonspecific mitogenic stimuli. This strongly implies that they may have potential application in allograft transplantation. Since placenta and UCB are homogeneous, the MSC derived from human placenta can be transplanted combined with hematopoietic stem cells （HSC） from UCB to reduce the potential graft-versus-host disease （GVHD） in recipients.     

Production of endothelial progenitor cells obtained from human Wharton's jelly using different culture conditions

Endothelial progenitor cells (EPC) participate in revascularization and angiogenesis. EPC can be cultured in vitro from mononuclear cells of peripheral blood, umbilical cord blood or bone marrow; they also can be transdifferentiated from mesenchymal stem cells (MSC). We isolated EPCs from Wharton's jelly (WJ) using two methods. The first method was by obtaining MSC from WJ and characterizing them by flow cytometry and their adipogenic and osteogenic differentiation, then applying endothelial growth differentiating media. The second method was by direct culture of cells derived from WJ into endothelial differentiating media. EPCs were characterized by morphology, Dil-LDL uptake/UEA-1 immunostaining and testing the expression of endothelial markers by flow cytometry and RT-PCR. We found that MSC derived from WJ differentiated into endothelial-like cells using simple culture conditions with endothelium induction agents in the medium.     

Vitamin C treatment promotes mesenchymal stem cell sheet formation and tissue regeneration by elevating telomerase activity

Cell sheet engineering has been developed as an alternative approach to improve mesenchymal stem cell-mediated tissue regeneration. In this study, we found that vitamin C (Vc) was capable of inducing telomerase activity in periodontal ligament stem cells (PDLSCs), leading to the up-regulated expression of extracellular matrix type I collagen, fibronectin, and integrin β1, stem cell markers Oct4, Sox2, and Nanog as well as osteogenic markers RUNX2, ALP, OCN. Under Vc treatment, PDLSCs can form cell sheet structures because of increased cell matrix production. Interestingly, PDLSC sheets demonstrated a significant improvement in tissue regeneration compared with untreated control dissociated PDLSCs and offered an effective treatment for periodontal defects in a swine model. In addition, bone marrow mesenchymal stem cell sheets and umbilical cord mesenchymal stem cell sheets were also well constructed using this method. The development of Vc-mediated mesenchymal stem cell sheets may provide an easy and practical approach for cell-based tissue regeneration.     

Differentiation and migration properties of human foetal umbilical cord perivascular cells: potential for lung repair

Mesenchymal stem cells (MSC) have been derived from different cultured human tissues, including bone marrow, adipose tissue, amniotic fluid and umbilical cord blood. Only recently it was suggested that MSC descended from perivascular cells, the latter being defined as CD146⁺ neuro‐glial proteoglycan (NG)2⁺ platelet‐derived growth factor‐Rβ⁺ ALP⁺ CD34^– CD45^– von Willebrand factor (vWF)^– CD144^–. Herein we studied the properties of perivascular cells from a novel source, the foetal human umbilical cord (HUC) collected from pre‐term newborns. By immunohistochemistry and flow cytometry we show that pre‐term/foetal HUCs contain more perivascular cells than their full‐term counterparts (2.5%versus 0.15%). Moreover, foetal HUC perivascular cells (HUCPC) express the embryonic cell markers specific embryonic antigen‐4, Runx1 and Oct‐4 and can be cultured over the long term. To further confirm the MSC identity of these cultured perivascular cells, we also showed their expression at different passages of antigens that typify MSC. The multilineage differentiative capacity of HUCPC into osteogenic, adipogenic and myogenic cell lineages was demonstrated in culture. In the perspective of a therapeutic application in chronic lung disease of pre‐term newborns, we demonstrated the in vitro ability of HUCPC to migrate towards an alveolar type II cell line damaged with bleomycin, an anti‐cancer agent with known pulmonary toxicity. The secretory profile exhibited by foetal HUCPC in the migration assay suggested a paracrine effect that could be exploited in various clinical conditions including lung disorders.