Isolation of mesenchymal stem cells from equine umbilical cord blood

Background  

There are no published studies on stem cells from equine cord blood although commercial storage of equine cord blood for future autologous stem cell transplantations is available. Mesenchymal stem cells (MSC) have been isolated from fresh umbilical cord blood of humans collected non-invasively at the time of birth and from sheep cord blood collected invasively by a surgical intrauterine approach. Mesenchymal stem cells isolation percentage from frozen-thawed human cord blood is low and the future isolation percentage of MSCs from cryopreserved equine cord blood is therefore expectedly low. The hypothesis of this study was that equine MSCs could be isolated from fresh whole equine cord blood.     

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.     

Mesenchymal stem cells from cryopreserved human umbilical cord blood

Umbilical cord blood (UCB) is well known to be a rich source of hematopoietic stem cells with practical and ethical advantages, but the presence of mesenchymal stem cells (MSCs) in UCB has been disputed and it remains to be validated. In this study, we examined the ability of cryopreserved UCB harvests to produce cells with characteristics of MSCs. We were able to obtain homogeneous plastic adherent cells from the mononuclear cell fractions of cryopreserved UCB using our culture conditions. These adherent cell populations exhibited fibroblast-like morphology and typical mesenchymal-like immunophenotypes (CD73+, CD105+, and CD166+, etc.). These cells presented the self-renewal capacity and the mesenchymal cell-lineage potential to form bone, fat, and cartilage. Moreover, they expressed mRNAs of multi-lineage genes including SDF-1, NeuroD, and VEGF-R1, suggesting that the obtained cells had the multi-differentiation capacity as bone marrow-derived MSCs. These results indicate that cryopreserved human UCB fractions can be used as an alternative source of MSCs for experimental and therapeutic applications.     

Proteomic profiling of human stem cells derived from umbilical cord blood

CD34+ preparations from five different umbilical cord samples were compared with respect to their proteome profile using 2-D gel electrophoresis. Fifty-two protein spots were found to match in all preparations referring to the high heterogeneity of such samples indicating a not fully developed (or instable) proteome of stem cells. All matching spots were subjected to in-gel digestion and nano-LC-MS/MS sequence analysis, from which 22 proteins were unambiguously identified.     

Characteristics of hematopoietic stem cells of umbilical cord blood

Umbilical cord blood collected from the postpartum placenta and cord is a rich source of hematopoietic stem cells (HSCs) and is an alternative to bone marrow transplantation. In this review we wanted to describe the differences (in phenotype, cytokine production, quantity and quality of cells) between stem cells from umbilical cord blood, bone marrow and peripheral blood. HSCs present in cord blood are more primitive than their counterparts in bone marrow or peripheral blood, and have several advantages including high proliferation. With using proper cytokine combination, HSCs can be effectively developed into different cell lines. This process is used in medicine, especially in hematology.     

Isolation,characterisation and comparative analysis of human umbilical cord vein perivascular cells and cord blood mesenchymal stem cells

Perivascular cells are known to be ancestors of mesenchymal stem cells (MSCs) and can be obtained from heart, skin, bone marrow, eye, placenta and umbilical cord (UC). However detailed characterization of perivascular cells around the human UC vein and comparative analysis of them with MSCs haven’t been done yet. In this study, our aim is to isolate perivascular cells from human UC vein and characterize them versus UC blood MSCs (UCB-MSCs). For this purpose, perivascular cells around the UC vein were isolated enzymatically and then purified with magnetic activated cell sorting (MACS) method using CD146 Microbead Kit respectively. MSCs were isolated from UCB by Ficoll density gradient solution. Perivascular cells and UCB-MSCs were characterized by osteogenic and adipogenic differentiation procedures, flow cytometric analysis [CD146, CD105, CD31, CD34, CD45 and alpha-smooth muscle actin (α-SMA)], and immunofluorescent staining (MAP1B and Tenascin C). Alizarin red and Oil red O staining results showed that perivascular cells and MSCs had osteogenic and adipogenic differentiation capacity. However, osteogenic differentiation capacity of perivascular cells were found to be less than UCB-MSCs. According to flow cytometric analysis, CD146 expression of perivascular cells were appeared to be 4.8-fold higher than UCB-MSCs. Expression of α-SMA, MAP1B and Tenascin-C from perivascular cells was determined by flow cytometry analysis and immunfluorescent staining. The results appear to support the fact that perivascular cells are the ancestors of MSCs in vascular area. They may be used as alternative cells to MSCs in the field of vascular tissue engineering.     

Production of stem cells with embryonic characteristics from human umbilical cord blood

When will embryonic stem cells reach the clinic? The answer is simple -- not soon! To produce large quantities of homogeneous tissue for transplantation, without feeder layers, and with the appropriate recipient's immunological phenotype, is a significant scientific hindrance, although adult stem (ADS) cells provide an alternative, more ethically acceptable, source. The annual global 100 million human birth rate proposes umbilical cord blood (UCB) as the largest untouched stem cell source, with advantages of naive immune status and relatively unshortened telomere length. Here, we report the world's first reproducible production of cells expressing embryonic stem cell markers, - cord-blood-derived embryonic-like stem cells (CBEs). UCB, after elective birth by Caesarean section, has been separated by sequential immunomagnetic removal of nucleate granulocytes, erythrocytes and haemopoietic myeloid/lymphoid progenitors. After 7 days of high density culture in microflasks, (10(5) cells/ml, IMDM, FCS 10%, thrombopoietin 10 ng/ml, flt3-ligand 50 ng/ml, c-kit ligand 20 ng/ml). CBE colonies formed adherent to the substrata; these were maintained for 6 weeks, then were subcultured and continued for a minimum 13 weeks. CBEs were positive for TRA-1-60, TRA-1-81, SSEA-4, SSEA-3 and Oct-4, but not SSEA-1, indicative of restriction in the human stem cell compartment. The CBEs were also microgravity--bioreactor cultured with hepatocyte growth medium (IMDM, FCS 10%, HGF 20 ng/ml, bFGF 10 ng/ml, EGF 10 ng/ml, c-kit ligand 10 ng/ml). After 4 weeks the cells were found to express characteristic hepatic markers, cytokeratin-18, alpha-foetoprotein and albumin. Thus, such CBEs are a viable human alternative from embryonic stem cells for stem cell research, without ethical constraint and with potential for clinical applications.     

Optimization of cryopreservation condition for hematopoietic stem cells from umbilical cord blood

The conditions for cryopreservation of CD34⁺ hematopoietic stem cells (HSC) from umbilical cord blood (UCB) were optimized with a new cryo-medium containing 10% ethylene glycol (EG) and 2% dimethyl sulfoxide (Me₂SO) using a controlled-rate freezing (CRF) method. After the cryopreservation of mononuclear cells (MNC) from UCB, recoveries of MNC, CD34⁺ cells, and total colony-forming units (CFU) were significantly improved compared to those in the control cryo-medium containing 10% Me₂SO and 2% Dextran-40 (P < 0.05). This study shows that the new cryo-medium and CRF method provide better recoveries of MNC, HSC and total CFU than the control cryo-medium and isopropylalcohol freezing (IPA) method. Therefore, this cryo-medium, combined with the CRF method, is valuable for optimizing cryopreservation conditions for HSC from UCB to obtain satisfactory HSC recovery.     

Isolation and characterization of mesenchymal stem cells from caprine umbilical cord tissue matrix

Cord tissue fills the umbilical cord around the blood vessels and contains types of stem cells (mesenchymal stem cells or MSCs) that are not generally found in cord blood. MSCs are the stem cells that give rise to many of the “support tissues” in the body, including bone, cartilage, fat and muscle. Umbilical Cord Tissue cells (UCTs) possessing the capacity to differentiate into various cell types such as osteoblasts, chondrocytes and adipocytes have been previously isolated from different species including human, canine, murine, avian species etc. The present study documents the existence of similar multipotential stem cells in caprine UCTs having similar growth and morphological characteristics. The cells were isolated from caprine umbilical cord and cultivated in DMEM (low glucose) supplemented with 15% FBS, L-glutamine and antibiotics. Primary culture achieved confluence in 5–7 days having spindle shaped morphology. The cells were morphologically homogeneous, showed robust proliferation ability with a population doubled time of 92.07 h as well as normal karyotype. In vitro self-renewal capacity was demonstrated by colony-forming unit assay (CFU). The cells expressed MSC specific markers and showed multi-differentiation capability into adipogenic and osteogeneic. The results indicated that caprine UCTs (cUCTs) were isolated and characterized from umbilical cord tissue which can be used for tissue regeneration.     

Isolation and expansion of oligodendrocyte progenitor cells from cryopreserved human umbilical cord blood

Background aimsOligodendrocyte precursor cells (OPC) hold promise as a cellular therapy for demyelinating diseases. The feasibility of using OPC-based therapies in humans depends upon a reliable, readily available source. We have previously described the isolation, expansion and characterization of oligodendrocyte-like cells from fresh human umbilical cord blood (UCB). We now describe the isolation and expansion of OPC from thawed, cryopreserved UCBMethodsWe thawed cryopreserved UCB units employing a standard clinical protocol, then isolated and plated mononuclear cells under previously established culture conditions. All OPC cultures were trypsinized at 21 days, counted, then characterized by flow cytometry after fixation, permeablization and labeling with the following antibodies: anti-oligodendrocyte marker 4 (O4), anti-oligodendrocyte marker 1 (O1) and anti-myelin basic protein (MBP). OPC were also placed in co-culture with shiverer mouse neuronal cells then stained in situ for beta tubulin III (BT3) and MBP as a functional assay of myelination.ResultsThe average OPC yield per cryopreserved UCB unit was 64% of that seen with fresh UCB. On flow cytometric analysis, 74% of thawed UCB units yielded cells with an O4-expression level of at least 20% of total events, compared with 95% of fresh UCB units. We observed myelination of shiverer neurons in our functional assay, which could be used as a potency assay for release of OPC cells in phase I human clinical trials.ConclusionsOur results demonstrate that OPC can be derived reliably from thawed, cryopreserved UCB units, and support the feasibility of using these cells in human clinical trials.     

Human mesenchymal stem cells isolated from the umbilical cord

Mesenchymal stem cells (MSCs) are known as a population of multi-potential cells able to proliferate and differentiate into multiple mesodermal tissues including bone, cartilage, muscle, ligament, tendon, fat and stroma. In this study human MSCs were successfully isolated from the umbilical cords. The research characteristics of these cells, e.g., morphologic appearance, surface antigens, growth curve, cytogenetic features, cell cycle, differentiation potential and gene expression were investigated. After 2weeks of incubation, fibroblast-like cells appeared to be dominant. During the second passage the cells presented a homogeneous population of spindle fibroblast-like cells. After more than 4months (approximately 26 passages), the cells continued to retain their characteristics. Flow cytometry analysis revealed that CD29, CD44, CD95, CD105 and HLA-I were expressed on the cell surface, but there was no expression of hematopoietic lineage markers, such as CD34, CD38, CD71 and HLA-DR. Chromosomal analysis showed the cells kept a normal karyotype. The cell cycle at the third passage showed the percentage of G(0)/G(1), G(2)/M and S phase were 88.86%, 5.69% and 5.45%, respectively. The assays in vitro demonstrated the cells exhibited multi-potential differentiation into osteogenic and adipogenic cells. Both BMI-1 and nucleostemin genes, expressed in adult MSCs from bone marrow, were also expressed in umbilical cord MSCs. Here we show that umbilical cords may be a novel alternative source of human MSCs for experimental and clinical applications.     

Mesenchymal stromal cells from umbilical cord blood

Mesenchymal Stromal Cells (MSC) are key candidates for cellular therapies. Although most therapeutic applications have focused on adult bone marrow derived MSC, increasing evidence suggests that MSC are present within a wide range of tissues. Umbilical cord blood (CB) has been proven to be a valuable source of hematopoietic stem cells, but its therapeutic potential extends beyond the hematopoietic component suggesting regenerative potential in solid organs as well. There is evidence that other stem or progenitor populations, such as MSC, exist in CB which might be responsible for these effects. Many different stem and progenitor cell populations have been postulated with potential ranging from embryonic like to lineage-committed progenitor cells. Based on the confusing data, this review focuses on a human CB derived, plastic adherent fibroblastoid population expressing similar characteristics to bone marrow derived MSC. It concentrates especially on concepts of isolation and expansion, comparing the phenotype with bone marrow derived MSC, describing the differentiation capacity and finally in the last the therapeutic potential with regard to regenerative medicine, stromal support, immune modulation and gene therapy.     

Analysis and cryopreservation of hematopoietic stem and progenitor cells from umbilical cord blood

BACKGROUND: Umbilical cord blood (UCB) is an important source of hematopoietic stem and progenitor cells (HSC/HPC) for the reconstitution of the hematopoietic system after clinical transplantation. Cryopreservation of these cells is critical for UCB banking and transplantation as well as for research applications by providing readily available specimens. The objective of this study was to optimize cryopreservation conditions for CD34+ HSC/HPC from UCB. METHODS: Cryopreservation of CD34+ HSC/HPC from UCB after mononuclear cell (MNC) preparation was tested in a research-scale setup. Experimental variations were concentration of the cryoprotectant, the protein additive and cell concentration. In addition, protocols involving slow, serial addition and removal of DMSO were compared with standard protocols (fast addition and removal of DMSO) in order to avoid osmotic stress for the cryopreserved cells. Viability and recoveries of MNC, CD34+ cells and total colony-forming units (CFU) were calculated as read-outs. In addition, sterility testing of the collected UCB units before further processing was performed. RESULTS: The optimal conditions for cryopreservation of CD34+ HPC in MNC preparations were 10% DMSO and 2% human albumin at high cell concentrations (5 x 10(7) MNC/mL) with fast addition and removal of DMSO. After cryopreservation using a computer-controlled freezer, high viabilities (89%) and recoveries for CD34+ cells (89%) as well as for CFU (88%) were observed. Microbial contamination of the collected UCB samples was reduced to a rate of 6.4%. DISCUSSION: Optimized cryopreservation conditions were developed for UCB MNC in respect of the composition of the cryosolution. In addition, our results showed that fast addition of DMSO is essential for improved cryopreservation and post-thaw quality assessment results, whereas the speed of DMSO removal after thawing has little influence on the recoveries of CD34+ cells and CFU.     

人脐带血来源造血干细胞体外扩增的研究进展

造血干细胞（HSCs）是血液系统中的一类成体干细胞群,具有自我更新和多谱系分化两个基本特征。造血干细胞移植（HSCT）可以治疗退行性疾病和多种血液系统疾病。脐带血来源造血干细胞（CB HSCs）是降低HLA配型要求的突破点,但单份脐带血中HSCs数量不能满足使用要求,为了获得足够数量的CB HSCs,体外扩增是一种可行的方法。近几年,学者们探索了多种体外扩增方法,包括优化细胞生长因子混合物、与基质细胞共培养及加入小分子化合物（SMCs）激动剂等。目前应用细胞因子联合小分子的扩增方法在多个临床试验中获得成功。本文对目前体外扩增CB HSCs的研究进展做一综述。     

Phenotypical and functional characteristics of mesenchymal stem cells derived from equine umbilical cord blood

Mesenchymal stem cells (MSCs) offer promise as therapeutic aid in the repair of tendon and ligament injuries in race horses. Fetal adnexa is considered as an ideal source of MSCs due to many advantages, including non-invasive nature of isolation procedures and availability of large tissue mass for harvesting the cells. However, MSCs isolated from equine fetal adnexa have not been fully characterized due to lack of species-specific markers. Therefore, this study was carried out to isolate MSCs from equine umbilical cord blood (UCB) and characterize them using cross-reactive markers. The plastic-adherent cells could be isolated from 13 out of 20 (65 %) UCB samples. The UCB derived cells proliferated till passage 20 with average cell doubling time of 46.40 ± 2.86 h. These cells expressed mesenchymal surface markers but did not express haematopoietic/leucocytic markers by RT-PCR and immunocytochemistry. The phenotypic expression of CD29, CD44, CD73 and CD90 was shown by 96.36 ± 1.28, 93.40 ± 0.70, 73.23 ± 1.29 and 46.75 ± 3.95 % cells, respectively in flow cytometry, whereas, reactivity against the haematopoietic antigens CD34 and CD45 was observed only in 2.4 ± 0.20 and 0.1 ± 0.0 % of cells, respectively. Osteogenic and chondrogenic differentiation could be achieved using established methods, whereas the optimum adipogenic differentiation was achieved after supplementing media with 15 % rabbit serum and 20 ng/ml of recombinant human insulin. In this study, we optimized methodology for isolation, cultural characterization, differentiation and immunophenotyping of MSCs from equine UCB. Protocols and markers used in this study can be employed for unequivocal characterization of equine MSCs.     

Angiogenic potential difference between two types of endothelial progenitor cells from human umbilical cord blood

The hierarchy of endothelial progenitor cells (EPCs) in human umbilical cord blood has been disclosed. In this study we compare, for the first time, the angiogenic potential difference between two types of EPCs. We cultured mononuclear cells (MNCs) isolated from human umbilical cord blood using endothelial cell-conditioned medium and obtained two types of EPCs, referred to as circulating angiogenic cells (CACs) and high proliferative potential endothelial progenitor cells (HPP-EPCs). Both types of cells possess characteristics of EPCs, including expressing CD31, VE-cadherin, KDR and von Willebrand factor, uptake of Ac-LDL and binding to lectin. However, unlike CACs, which express CD14 but not CD133, HPP-EPCs express CD133 but not CD14. Also, unlike CACs, HPP-EPCs display stronger proliferation and clonogenic potential in vitro and show stronger ability to promote vascular growth in the hind-limb model of ischemia in mice (BALB/C-nu) in vivo.