骨髓间质干细胞的分离培养、生物学特性及应用

骨髓间质干细胞(Marrow stromal cells,MSCs)来源于中胚层间质,形成于发育中的骨髓腔,是骨髓内除造血干细胞(hematopoieti stem cells,HSCs)之外的另一类干细胞。于1968年由Friedenstein首次从骨髓中分离出来,称为成纤维集落生成细胞(Colony- forming units-fibroblastic,CFUF),能分化为类似骨和软骨聚集物样集落。目前,人、猪、大鼠、小鼠、兔和狗等动物的MSCs已被成功地分离培养。作为组织工程研究的热点种子细胞之一,MSCs在创伤修复、组织功能重建及人工器官再造与移植等研究领域中有广阔的应用前景。     

兔骨髓间充质干细胞向心肌细胞分化的研究

旨在研究5-氮杂胞苷(5-Aza)诱导兔骨髓间充质干细胞(Mesenchymal stem cells,MSCs)向心肌细胞分化的作用及适宜浓度.取兔股骨骨髓,分离并培养骨髓间充质干细胞,用5-Aza定向诱导向心肌样细胞分化.用倒置显微镜、免疫细胞化学法鉴定诱导后的细胞是否能表达心肌特异性蛋白α-横纹肌肌动蛋白(α-actin)和肌钙蛋白T(Cardiac troponin T,cTnT),计算各组细胞向心肌样细胞的诱导分化率.结果,5-Aza诱导MSCs后,细胞明显变宽,诱导1个月后的MSCs呈长杆状,走向趋于一致,相邻细胞间连接较紧密,相互融合.心肌细胞特异性蛋白α-actin和cTnT呈阳性表达,不同浓度的5-Aza诱导的MSCs心肌细胞特异性蛋白的表达率不一样,其中以10 μmol·L-1组表达率最高.5-Aza作用兔MSCs体外培养可以诱导其向心肌样细胞分化,最佳浓度为10μmol· L-1.     

猪骨髓间充质干细胞分离培养和诱导分化脂肪细胞

采用全骨髓培养法分离猪骨髓间充质干细胞(Mesenchymal stem cells,MSCs)并传代培养;取第4代纯化的MSCs在成脂诱导培养基中诱导分化;分化的成脂细胞用形态学和油红O染色法进行鉴定;用实时荧光定量PCR(Real-time PCR)检测成脂分化标志基因PPARγ2和LPL mRNA的表达情况。结果显示,分离培养的猪MSCs细胞经连续传代形态上无明显改变;MSCs在成脂分化培养液中诱导分化2d开始有少量脂滴出现,油红O染色成阳性,诱导18d成脂转化率可达59.8%;在诱导分化第5、10、15天时,PPARγ2mRNA相对表达量分别是(5.065±0.159)、(6.268±0.340)、(9.277±0.261),LPL mRNA的相对表达量分别是(10.995±1.473)、(13.130±0.712)、(15.762±0.934)。结果表明,用本诱导条件诱导猪MSCs向脂肪细胞分化,经形态学和油红O染色鉴定,成脂细胞分化率可达60%,且随分化时间的延长,脂肪细胞标志基因表达增加。     

兔脂肪间质干细胞的分离培养与鉴定

取兔腹股沟皮下脂肪组织，用Ⅰ型胶原酶消化，分离培养脂肪间质干细胞（MSCs），并用免疫组化和体外诱导分化方法对其表面分子标志和多向分化潜能进行鉴定。结果显示，兔脂肪组织中能够分离培养出脂肪MSCs，该类细胞表达CD29、CD44和CD105，不表达CD34、CD45及HLA—DR表面分子标志，并具有可分化为脂肪细胞、神经细胞和成骨细胞的多向分化潜能，证实兔脂肪组织中存在具有多向分化潜能的MSCs。     

生长因子对兔骨髓间充质干细胞增殖的影响

旨在研究碱性成纤维细胞生长因子(bFGF)对兔骨髓间充质干细胞(BMSCs)体外生长及增殖的影响。体外培养并鉴定兔BMSCs,用不同浓度的bFGF(5、10、20、40、80和100μg.L-1)作用于兔BMSCs,用四甲基偶氮唑盐比色法(MTT)、流式细胞仪观察细胞的生长及增殖情况。结果,经免疫细胞化学法和分化反推法鉴定所分离培养的细胞为兔骨髓间充质干细胞;MTT法结果显示,bFGF浓度为80μg.L-1时细胞的增殖能力最强(P<0.01),在培养第3天即出现显著的促增殖作用(P<0.01);流式细胞仪结果显示,bFGF组BMSCs的增殖指数明显高于对照组(P<0.01)。说明bFGF有促进体外培养兔BMSCs增殖的作用,浓度为80μg.L-1时促增殖能力最强,可以作为体外扩增培养兔骨髓间充质干细胞的最佳培养条件。     

不同饲养层对牛胚胎干细胞培养的影响

本研究建立牛胚胎干细胞(Bovine Embryonic Stem Cells ESCs)的分离培养体系,摸索牛ESCs的培养条件。对牛运用FSH减量注射法进行超数排卵获取胚胎。从获得的胚胎中分离ESCs,在不同的饲养层(牛骨髓间充质干细胞、牛成纤维细胞、牛乳腺干细胞)上培养,对牛ESCs进行形态学观察及鉴定。牛MSCs做饲养层与牛SFCs、牛MaSCs相比差异显著,牛MSCs的效果最佳(P0.05)。牛ESCs在牛MSCs做饲养层的条件下更易生长。分析了不同饲养层对牛ESCs分离培养的影响,建立了一种分离培养牛ESCs的饲养层体系,为进一步深入研究ESCs的诱导分化和应用打下基础。     

白来航鸡不同来源间充质干细胞的比较研究

【目的】以禽类间充质干细胞(MSCs)为研究对象,探讨不同来源MSCs生物学特性上的差异及其临床应用潜力。【方法】培养白来航鸡4种不同组织器官骨髓(BM)、脂肪(AT)、脐带(UC)和脾脏(S)衍生的MSCs,通过实时荧光定量PCR技术检测细胞表面标记物的表达,采用细胞生长曲线观察种群倍增时间变化,利用噻唑蓝细胞毒性检测法(MTT)确定基质细胞衍生因子1(SDF-1)对不同来源MSCs的细胞毒性,并选用细胞小室检测MSCs体外迁移情况,通过蛋白质印迹法方法确定MSCs体外迁移影响因素,最后选用成骨分化和成脂分化观察不同来源MSCs的体外分化情况。【结果】不同来源的MSCs细胞形态基本一致;细胞表面标记物CD29、CD44、CD71、CD90和CD105等基因呈阳性表达;不同来源的MSCs表面标记物的相对表达量不同,CD29基因的相对表达量基本相同,CD44基因在AT-MSCs中的相对表达量显著高于BM-MSCs(P<0.05),CD71基因在UC-MSCs中的相对表达量显著低于BM-MSCs(P<0.05),CD90基因在UC-MSCs和S-MSCs中的相对表达量极显著低于...     

用免疫荧光技术检测细胞培养物中兔出血症病毒

用本实验室制备的兔出血症病毒（rabbit hemorrhagic disease virus,RHDV）高免血清,按常规方法提纯出抗体（IgG）,用异硫氰酸荧光素（FITC）标记IgG。在细胞培养时,培养瓶中放入玻片,当细胞长成单层时,按常规方法接种病毒液,培养24、48、96、120h时取出玻片,用荧光抗体染色,在荧光显微镜下观察不同代次的细胞毒。经观察：兔肾上皮细胞（RK）毒培养到36—48h,羊睾丸细胞（ST）毒培养到72—96h时可观察到特异性荧光,随着培养时间的延长,荧光亮度增强,胞浆内充满特异性荧光。用肝组织强毒病料触片,呈特异性荧光,对照细胞培养48h无荧光出现,证实了两株细胞培养物中有大量的兔出血症病毒存在,从而成功的分离培养出了兔出血症病毒细胞毒。     

犬骨髓间充质干细胞的分离培养与鉴定

为了证明全骨髓贴壁法分离培养犬骨髓间充质干细胞的可行性,为后续移植试验提供活性良好的种子细胞,试验采用全骨髓贴壁法分离纯化犬骨髓间充质干细胞,并通过细胞形态观察、表面标记流式分析、体外诱导分化对细胞进行鉴定。结果表明:分离培养的原代骨髓间充质干细胞呈梭形、集落样生长,表面标记CD44呈阳性,CD34、CD45呈阴性,能够向成骨细胞和心肌样细胞分化。说明全骨髓贴壁法便捷可行,获得的犬骨髓间充质干细胞纯度高,增殖旺盛,分化能力良好。     

不同分离方法及首次换液时间对兔骨髓间充质干细胞生物活性的影响

探讨不同分离方法及首次换液时间对兔骨髓间充质干细胞(BMSCs)生物活性的影响。分别采用红细胞裂解法和全骨髓贴壁法分离纯化兔骨髓间充质干细胞,倒置显微镜观察细胞形态、台盼蓝染色检测细胞活性、记录首次传代时间、细胞免疫组化法鉴定CD90、CD44、CD34抗原表达;分别于培养12,24,48,72h首次换液,以后每2d换液1次,记录各组0~3代培养时间。结果显示,2种分离方法均能得到较均一的长梭形细胞,聚集成旋涡状均匀生长,CD90、CD44抗原表达阳性,CD34抗原表达阴性。其中红细胞裂解法所得细胞活性较全骨髓贴壁法高,首次传代时间短,差异显著(P0.05);24h首次换液各代达传代所需时间与其他各组比较差异极显著(P0.01),为最佳首次换液时间,可显著缩短细胞培养周期。这表明,采用红细胞裂解法,24h首次换液能够提高骨髓间充质干细胞的活性,缩短细胞培养周期。     

Marking of peripheral T-lymphocytes by retroviral transduction and transplantation of CD34+ cells in a canine X-linked severe combined immunodeficiency model

A retrovirus vector containing an enhanced green fluorescent protein complimentary DNA (EGFP cDNA) was used to mark and dynamically follow vector-expressing cells in the peripheral blood of bone marrow transplanted X-linked severe combined immunodeficient dogs. CD34(+) cells isolated from young normal dogs were transduced, using a 2 day protocol, with an amphotropic retroviral vector that expressed enhanced green fluorescent protein (EGFP) and the canine common gamma chain (gammac) cDNAs. Following transplantation of the transduced cells, normal donor peripheral blood lymphocytes (PBL) appeared by 1 month post-bone marrow transplant (BMT) and rescued three of five treated dogs from their lethal immunodeficiency. PCR and flow cytometric analysis of post-BMT PBL documented the peripheral EGFP expressing cells as CD3(+) T cells, which varied from 0% to 28%. Sorting of EGFP(+) and EGFP(-) peripheral blood T cells from two dogs, followed by vector PCR analysis, showed no evidence of vector shutdown. EGFP expression in B cells or monocytes was not detected. These marking experiments demonstrate that the transduction protocol did not abolish the lymphoid engraftment capability of ex vivo transduced canine CD34(+) cells and supports the potential utility of the MSCV retroviral vector for gene transfer to XSCID affected canine hematopoietic progenitor cells (HPC).     

Impact of the source and serial passaging of goat mesenchymal stem cells on osteogenic differentiation potential:implications for bone tissue engineering

Background: Adult mesenchymal stem cells(MSCs) can be conveniently sampled from bone marrow, peripheral blood, muscle, adipose and connective tissue, harvested from various species, including, rodents, dogs, cats, horses,sheep, goats and human beings. The MSCs isolated from adult tissues vary in their morphological and functional properties. These variations are further complicated when cells are expanded by passaging in culture. These differences and changes in MSCs must be considered prior to their application in the clinic or in a basic research study. Goats are commonly used as animal models for bone tissue engineering to test the potential of stem cells for bone regeneration. As a result, goat MSCs isolated from bone marrow or adipose tissue should be evaluated using in vitro assays, prior to their application in a tissue engineering project.Results: In this study, we compared the stem cell properties of MSCs isolated from goat bone marrow and adipose tissue. We used quantitative and qualitative assays with a focus on osteogenesis, including, colony forming unit, rate of cell proliferation, tri-lineage differentiation and expression profiling of key signal transduction proteins to compare MSCs from low and high passages. Primary cultures generated from each source displayed the stem cell characteristics,with variations in their osteogenic potentials. Most importantly, low passaged bone marrow MSCs displayed a significantly higher and superior osteogenic potential, and hence, will be the preferred choice for bone tissue engineering in future in vivo experiments. In the bone marrow MSCs, this process is potentially mediated by the p38 MAPK pathway. On the other hand, osteogenic differentiation in the adipose tissue MSCs may involve the p44/42 MAPK pathway.Conclusions: Based on these data, we can conclude that bone marrow and fat-derived MSCs undergo osteogenesis via two distinct signaling pathways. Even though the bone marrow MSCs are the preferred source for bone tissue engineering, the adipose tissue MSCs are an attractive alternative source and undergo osteo-differentiation differently from the bone marrow MSCs and hence, might require a cell-based enhancer/inducer to improve their osteogenic regenerative capacity.     

Successful engraftment of cultured autologous mesenchymal stem cells in a surgically repaired soft palate defect in an adult horse

The objective of this study was to graft autologous mesenchymal stem cells (MSCs) at the site of surgical repair of a soft palate defect in an adult horse in an attempt to improve wound healing and to investigate whether the transplanted MSCs would integrate into the soft palate structure and participate in regeneration. Bone marrow was collected from an adult horse with a full-thickness soft palate defect. The MSCs were isolated, cultured in monolayers, and labeled with 5-bromo-2-desoxymidine (BrdU) and chloromethylbenzamido-DiI-derived (cm-DiI) before transplantation. The soft palate defect was repaired by mandibular symphysiotomy, and the labeled MSCs were injected into the repaired soft palate. Postmortem examination revealed that 90% of the soft palate defect had been sutured. Staining by BrdU and cm-DiI was intense in the soft palate tissue. Labeled MSCs were detected in tissue slices from the injection sites. The cells were organized in a manner similar to that in native soft palate tissue, indicating successful engraftment.     

The canine epiphyseal-derived mesenchymal stem cells are comparable to bone marrow derived-mesenchymal stem cells

Mesenchymal stem cells (MSCs) hold great potential in cell therapy and have attracted increasing interests in a wide range of biomedical sciences. However, the scarcity of MSCs and the prolonged isolation procedure limited the clinical application. To address these 2 issues, we developed a method to isolate MSCs from bone biopsy tissues of euthanized canine body donors. Compared to the traditional method to isolate MSCs from aspirated bone marrow (BMSCs), the isolation procedure for MSCs from harvested epiphyseal cancellous bone (EMSCs) was less time-consuming. The isolated EMSCs had similar plastic-adherence, tri-lineage differentiation and consistent surface marker profiles compared to BMSCs. We harvested BMSCs and EMSCs from 24 euthanized cases from clinics and 42 euthanized donors from a local shelter. The successful rate for EMSC isolation is significantly higher compared to BMSC isolation, while the other properties of the isolated MSCs including the clonogenicity, proliferative potentials and molecular phenotypes were not discernibly different between the MSCs established by the two methods. In conclusion, we demonstrated a new procedure to harvest MSCs by bone biopsy at the epiphyseal region. This method is less time consuming and more reliable, and the resulting MSCs are comparable to those harvested by bone marrow aspiration. The combination of the two methods can greatly improve the efficiency to harvest MSCs.     

In vitro neuronal and osteogenic differentiation of mesenchymal stem cells from human umbilical cord blood

Mesenchymal stem cells (MSCs) have the capabilities for self-renewal and differentiation into cells with the phenotypes of bone, cartilage, neurons and fat cells. These features of MSCs have attracted the attention of investigators for using MSCs for cell-based therapies to treat several human diseases. Because bone marrow-derived cells, which are a main source of MSCs, are not always acceptable due to a significant drop in their cell number and proliferative/differentiation capacity with age, human umbilical cord blood (UCB) cells are good substitutes for BMCs due to the immaturity of newborn cells. Although the isolation of hematopoietic stem cells from UCB has been well established, the isolation and characterization of MSCs from UCB still need to be established and evaluated. In this study, we isolated and characterized MSCs. UCB-derived mononuclear cells, which gave rise to adherent cells, exhibited either an osteoclast or a mesenchymal-like phenotype. The attached cells with mesenchymal phenotypes displayed fibroblast-like morphologies, and they expressed mesenchym-related antigens (SH2 and vimentin) and periodic acid Schiff activity. Also, UCB-derived MSCs were able to transdifferentiate into bone and 2 types of neuronal cells, in vitro. Therefore, it is suggested that the MSCs from UCB might be a good alternative to bone marrow cells for transplantation or cell therapy.     

Molecular and Cellular Characterization of Buffalo Bone Marrow‐Derived Mesenchymal Stem Cells

Immune privileged mesenchymal stem cells (MSCs) can differentiate into multiple cell types and possess great potential for human and veterinary regenerative therapies. This study was designed with an objective to isolate, expand and characterize buffalo bone marrow‐derived MSCs (BM‐MSCs) at molecular and cellular level. Buffalo BM‐MSCs were isolated by Ficoll density gradient method and cultured in Dulbecco’s modified Eagle’s medium supplemented with fetal bovine serum (FBS). These cells were characterized through alkaline phosphatase (AP) staining, colony‐forming unit (CFU) assay, mRNA expression analysis (CD 73, CD 90, CD 105, Oct4 and Nanog), immunolocalization along with flow cytometry (Stro 1, CD 73, CD 105, Oct4, Sox2 and Nanog) and in situ hybridization (Oct4 and Sox2). Multilineage differentiation (osteogenic, adipogenic and chondrogenic) was induced in vitro, which was further assessed by specific staining. Buffalo BM‐MSCs have the capacity to form plastic adherent clusters of fibroblast‐like cells and were successfully maintained up to 16^th passage. These cells were AP positive, and further CFU assay confirmed their clonogenic property. RT‐PCR analysis and protein localization study showed that buffalo BM‐MSCs are positive for various cell surface markers and pluripotency markers. Cytoplasmic distribution of mRNA for pluripotency markers in buffalo BM‐MSCs and multilineage differentiation were induced in vitro, which was further assessed by specific staining. To the best of our knowledge, this is the first report of buffalo BM‐MSCs, which suggests that MSCs can be derived and expanded from buffalo bone marrow and can be used after characterization as a novel agent for regenerative therapy.     

Growth and differentiation characteristics of equine mesenchymal stromal cells derived from different sources

Multipotent mesenchymal stromal cells (MSCs) are a promising therapeutic tool for the treatment of equine tendon and other musculoskeletal injuries. While bone marrow is considered the ‘gold standard’ source of these cells, various other tissues contain MSCs with potentially useful features. The aim of this study was to compare clinically relevant characteristics of MSCs derived from bone marrow, umbilical cord blood and tissue and from adipose tissue and tendon. Cell yield, proliferation, migration, tendon marker expression and differentiation into adipocytes, chondrocytes and osteoblasts was assessed, quantified and compared.MSC numbers obtained from adipose, tendon or umbilical cord tissues were 222-fold higher than those obtained from bone marrow or cord blood. Cells derived from tendon and adipose tissues exhibited most rapid proliferation. Osteogenic differentiation was most prominent in MSCs derived from bone marrow, and was weak in MSCs derived from umbilical cord blood and tissue. In contrast, the highest levels of chondrogenic differentiation were observed in MSCs derived from these sources. Collagen 1A2 expression was highest in adipose- and tendon-derived MSCs, while scleraxis expression was highest in cord blood- and in tendon-derived MSCs. The findings indicate that MSCs from different sources display significantly diverse properties that may impact on their therapeutic application.     

Impact of source tissue and ex vivo expansion on the characterization of goat mesenchymal stem cells

Background: There is considerable interest in using goats as models for genetically engineering dairy animals and also for using stem cells as therapeutics for bone and cartilage repair. Mesenchymal stem cells(MSCs) have been isolated and characterized from various species, but are poorly characterized in goats.Results: Goat MSCs isolated from bone marrow(BM-MSCs) and adipose tissue(ASCs) have the ability to undergo osteogenic, adipogenic and chondrogenic differentiation. Cytochemical staining and gene expression analysis show that ASCs have a greater capacity for adipogenic differentiation compared to BM-MSCs and fibroblasts. Different methods of inducing adipogenesis also affect the extent and profile of adipogenic differentiation in MSCs. Goat fibroblasts were not capable of osteogenesis, hence distinguishing them from the MSCs. Goat MSCs and fibroblasts express CD90, CD105, CD73 but not CD45, and exhibit cytoplasmic localization of OCT4 protein. Goat MSCs can be stably transfected by Nucleofection, but, as evidenced by colony-forming efficiency(CFE), yield significantly different levels of progenitor cells that are robust enough to proliferate into colonies of integrants following G418 selection.BM-MSCs expanded over increasing passages in vitro maintained karyotypic stability up to 20 passages in culture,exhibited an increase in adipogenic differentiation and CFE, but showed altered morphology and amenability to genetic modification by selection.Conclusions: Our findings provide characterization information on goat MSCs, and show that there can be significant differences between MSCs isolated from different tissues and from within the same tissue. Fibroblasts do not exhibit trilineage differentiation potential at the same capacity as MSCs, making it a more reliable method for distinguishing MSCs from fibroblasts, compared to cell surface marker expression.     

生物素—亲和素法检测鸡实验性成髓细胞性白血病的研究

用生物素-亲和素法检测实验鸡雏47只。结果,感染后鸡雏骨髓的成髓细胞是鸡成髓细胞性白血病病毒最先攻击的靶细胞。死亡病例,阳性成髓细胞分布于骨髓、肝、脾、肾、心、肺、胸腺、法氏囊、盲肠扁桃体、翅羽髓等器官。60天病例,骨髓、肝、心壁内形成阳性成髓细胞结节。尸体的骨髓、肝脏和翅羽髓任一器官,在其血管内外检出阳性成髓细胞聚集和增生,可诊断为鸡成髓细胞性白血病。