Millipore Sigma Vibrant Logo
 

ssea


1547 Results Búsqueda avanzada  
Mostrar
Productos (15)
Documentos (1,376)
Páginas (156)

Acote sus resultados Utilice los filtros siguientes para refinar su búsqueda

Tipo de documento

  • (799)
  • (560)
  • (13)
  • (1)
  • (1)
  • Mostrar más
¿No encuentra lo que está buscando?
Póngase en contacto con
el Servicio de Atención
al Cliente

 
¿Necesita ayuda para encontrar un documento?

  • An antibody against SSEA-5 glycan on human pluripotent stem cells enables removal of teratoma-forming cells. 21841799

    An important risk in the clinical application of human pluripotent stem cells (hPSCs), including human embryonic and induced pluripotent stem cells (hESCs and hiPSCs), is teratoma formation by residual undifferentiated cells. We raised a monoclonal antibody against hESCs, designated anti-stage-specific embryonic antigen (SSEA)-5, which binds a previously unidentified antigen highly and specifically expressed on hPSCs--the H type-1 glycan. Separation based on SSEA-5 expression through fluorescence-activated cell sorting (FACS) greatly reduced teratoma-formation potential of heterogeneously differentiated cultures. To ensure complete removal of teratoma-forming cells, we identified additional pluripotency surface markers (PSMs) exhibiting a large dynamic expression range during differentiation: CD9, CD30, CD50, CD90 and CD200. Immunohistochemistry studies of human fetal tissues and bioinformatics analysis of a microarray database revealed that concurrent expression of these markers is both common and specific to hPSCs. Immunodepletion with antibodies against SSEA-5 and two additional PSMs completely removed teratoma-formation potential from incompletely differentiated hESC cultures.
    Tipo de documento:
    Referencia
    Referencia del producto:
    MABD88

  • Efficient integration of transgenes into a defined locus in human embryonic stem cells. 20071742

    Random integration is one of the more straightforward methods to introduce a transgene into human embryonic stem (ES) cells. However, random integration may result in transgene silencing and altered cell phenotype due to insertional mutagenesis in undefined gene regions. Moreover, reliability of data may be compromised by differences in transgene integration sites when comparing multiple transgenic cell lines. To address these issues, we developed a genetic manipulation strategy based on homologous recombination and Cre recombinase-mediated site-specific integration. First, we performed gene targeting of the hypoxanthine phosphoribosyltransferase 1 (HPRT) locus of the human ES cell line KhES-1. Next, a gene-replacement system was created so that a circular vector specifically integrates into the targeted HPRT locus via Cre recombinase activity. We demonstrate the application of this strategy through the creation of a tetracycline-inducible reporter system at the HPRT locus. We show that reporter gene expression was responsive to doxycycline and that the resulting transgenic human ES cells retain their self-renewal capacity and pluripotency.
    Tipo de documento:
    Referencia
    Referencia del producto:
    MAB5552
    Nombre del producto:

  • Generation and Characterization of LIF-dependent Canine Induced Pluripotent Stem Cells from Adult Dermal Fibroblasts. 22221227

    Dogs provide a more clinically relevant model of human disease than rodents, particularly with respect to hereditary diseases. Thus, the availability of canine stem cells will greatly facilitate the use of the dog in the development of stem cell-based gene therapies and regenerative medicine. In this study we describe the production of canine induced pluripotent stem cells (ciPSCs) from adult dermal fibroblasts. These cells have a morphology resembling previously described canine embryonic stem cells, a normal karyotype, and express pluripotency markers including alkaline phosphatase, Nanog, Oct4, Telomerase, SSEA1, SSEA4, TRA1-60, TRA1-81, and Rex1. Furthermore, the inactive X chromosome is reactivated indicating a ground-state pluripotency. In culture they readily form embryoid bodies, which in turn give rise to cell types from all 3 embryonic germ layers, as indicated by expression of the definitive endoderm markers Cxcr4 and α-fetoprotein, mesoderm markers Collagen IIA and Gata2, and ectoderm markers βIII-tubulin, Enolase, and Nestin. Of particular significance is the observation that these ciPSCs are dependent only on leukemia inhibitory factor (LIF), making them similar to mouse and canine embryonic stem cells, but strikingly unlike the ciPSCs recently described in two other studies, which were dependent on both basic fibroblast growth factor and LIF in order to maintain their pluripotency. Thus, our ciPSCs closely resemble mouse ESCs derived from the inner cell mass of preimplantation embryos, while the previously described ciPSCs appear to be more representative of cells from the epiblast of mouse postimplantation embryos.
    Tipo de documento:
    Referencia
    Referencia del producto:
    MAB4304
    Nombre del producto:
    Anti-Stage-Specific Embryonic Antigen-4 Antibody, clone MC-813-70

  • Reprogramming factors involved in hybrids and cybrids of human embryonic stem cells fused with hepatocytes. 20936904

    Embryonic stem cells (ESCs) have the potential to reprogram somatic cells into ESC-like cells through cell fusion. In the present study, the potential of human (h)ESC cytoplasts and karyoplasts to reprogram human hepatocytes was evaluated. Green fluorescent protein (GFP) transfected hESCs (ENVY cells) were fused with SNARF-1 (CellTracker)-labeled human hepatocytes using polyethylene glycol (PEG) and fluorescence-activated cell sorting (FACS) to produce hESC-hepatocyte hybrids. Immunocytochemical analysis of ESC markers showed that the hybrids expressed OCT4, TRA-1-60, TRA-1-81, SSEA-4, and GCTM-2. However, SSEA-1, which is typically low or absent on hESCs, was detected on hESC–hepatocyte hybrids. Moreover, reverse transcriptase polymerase chain reaction (RT-PCR) showed that alpha-fetoprotein, which is highly expressed in hepatocytes, was erased in the hybrids. These results indicated that hESCs have the potential to reprogram hepatocyte phenotype to a relatively undifferentiated state, but such hybrid cells are not identical to hESCs. Although hESC–hepatocyte hybrids were aneuploid, they were able to differentiate into embryoid bodies and some types of somatic cells. Furthermore, cybrids of enucleated hESCs and hepatocytes were produced by cell fusion, but the cybrids were unable to self-renew in the same way as hESCs. Presumably, the reprogramming factors are associated with the karyoplast and not the cytoplast of hESCs.
    Tipo de documento:
    Referencia
    Referencia del producto:
    Múltiplo
    Nombre del producto:
    Múltiplo

  • Reprogramming of human fibroblasts to induced pluripotent stem cells under xeno-free conditions. 19890879

    The availability of induced pluripotent stem cells (iPSCs) has created extraordinary opportunities for modeling and perhaps treating human disease. However, all reprogramming protocols used to date involve the use of products of animal origin. Here, we set out to develop a protocol to generate and maintain human iPSC that would be entirely devoid of xenobiotics. We first developed a xeno-free cell culture media that supported the long-term propagation of human embryonic stem cells (hESCs) to a similar extent as conventional media containing animal origin products or commercially available xeno-free medium. We also derived primary cultures of human dermal fibroblasts under strict xeno-free conditions (XF-HFF), and we show that they can be used as both the cell source for iPSC generation as well as autologous feeder cells to support their growth. We also replaced other reagents of animal origin (trypsin, gelatin, matrigel) with their recombinant equivalents. Finally, we used vesicular stomatitis virus G-pseudotyped retroviral particles expressing a polycistronic construct encoding Oct4, Sox2, Klf4, and GFP to reprogram XF-HFF cells under xeno-free conditions. A total of 10 xeno-free human iPSC lines were generated, which could be continuously passaged in xeno-free conditions and maintained characteristics indistinguishable from hESCs, including colony morphology and growth behavior, expression of pluripotency-associated markers, and pluripotent differentiation ability in vitro and in teratoma assays. Overall, the results presented here demonstrate that human iPSCs can be generated and maintained under strict xeno-free conditions and provide a path to good manufacturing practice (GMP) applicability that should facilitate the clinical translation of iPSC-based therapies.
    Tipo de documento:
    Referencia
    Referencia del producto:
    Múltiplo
    Nombre del producto:
    Múltiplo

  • Establishment of rat embryonic stem cells and making of chimera rats. 18665239

    The rat is a reference animal model for physiological studies and for the analysis of multigenic human diseases such as hypertension, diabetes, neurological disorders, and cancer. The rats have long been used in extensive chemical carcinogenesis studies. Thus, the rat embryonic stem (rES) cell is an important resource for the study of disease models. Attempts to derive ES cells from various mammals, including the rat, have not succeeded. Here we have established two independent rES cells from Wister rat blastocysts that have undifferentiated characters such as Nanog and Oct3/4 genes expression and they have stage-specific embryonic antigen (SSEA) -1, -3, -4, and TRA-1-81 expression. The cells were successfully cultured in an undifferentiated state and can be possible over 18 passages with maintaining more than 40% of normal karyotype. Their pluripotent potential was confirmed by the differentiation into derivatives of the endoderm, mesoderm, and ectoderm. Most importantly, the rES cells are capable of producing chimera rats. Therefore, we established pluripotent rES cell lines that are widely used to produce genetically modified experimental rats for study of human diseases.
    Tipo de documento:
    Referencia
    Referencia del producto:
    Múltiplo
    Nombre del producto:
    Múltiplo

  • A novel embryonic stem cell line derived from the common marmoset monkey (Callithrix jacchus) exhibiting germ cell-like characteristics. 19251728

    Embryonic stem cells (ESC) hold great promise for the treatment of degenerative diseases. However, before clinical application of ESC in cell replacement therapy can be achieved, the safety and feasibility must be extensively tested in animal models. The common marmoset monkey (Callithrix jacchus) is a useful preclinical non-human primate model due to its physiological similarities to human. Yet, few marmoset ESC lines exist and differences in their developmental potential remain unclear.Blastocysts were collected and immunosurgery was performed. cjes001 cells were tested for euploidy by karyotyping. The presence of markers for pluripotency was confirmed by immunofluorescence staining and RT-PCR. Histology of teratoma, in vitro differentiation and embryoid body formation revealed the differentiation potential.cjes001 cells displayed a normal 46,XX karyotype. Alkaline phosphatase activity, expression of telomerase and the transcription factors OCT4, NANOG and SOX2 as well as the presence of stage-specific embryonic antigen (SSEA)-3, SSEA-4, tumor rejection antigens (TRA)-1-60, and TRA-1-81 indicated pluripotency. Teratoma formation assay displayed derivatives of all three embryonic germ layers. Upon non-directed differentiation, the cells expressed the germ cell markers VASA, BOULE, germ cell nuclear factor and synaptonemal complex protein 3 and showed co-localization of VASA protein within individual cells with the germ line stem cell markers CD9, CD49f, SSEA-4 and protein gene product 9.5, respectively.The cjes001 cells represent a new pluripotent ESC line with evidence for enhanced spontaneous differentiation potential into germ cells. This cjes001 line will be very valuable for comparative studies on primate ESC biology.
    Tipo de documento:
    Referencia
    Referencia del producto:
    AB5603
    Nombre del producto:
    Anti-Sox2 Antibody

  • A comparative study of induced pluripotent stem cells generated from frozen, stocked bone marrow- and adipose tissue-derived mesenchymal stem cells. 21706774

    Bone marrow-derived mesenchymal stem cells (BMSCs) and adipose tissue-derived mesenchymal stem cells (AMSCs) have been used clinically for tissue regeneration; however, their proliferation/differentiation potentials are limited. Recently, induced pluripotent stem cells (iPSCs), known to have nearly unlimited potential to proliferate and differentiate into cells of all three germ layers, have gained wide interest in regenerative medicine. Here, we generated iPSCs from frozen-stocked AMSCs and BMSCs and examined their biological characteristics by comparative analyses. Although the iPSCs were more challenging to generate from the BMSCs than the AMSCs, both iPSC populations expressed pluripotent markers, such as stage-specific embryonic antigen (SSEA)-3, SSEA-4, tumour-related antigens (TRAs) TRA-1-60 and TRA-1-81, OCT3/4 and NANOG. Furthermore, both cell populations differentiated well into three germ layer-derived cells, both in vitro and in vivo. These results indicate that iPSCs derived from frozen AMSCs/BMSCs exhibit equally acceptable iPSC characteristics and have potential in clinical applications as an alternative source of autogenous stem cells.
    Tipo de documento:
    Referencia
    Referencia del producto:
    MAB4304
    Nombre del producto:
    Anti-Stage-Specific Embryonic Antigen-4 Antibody, clone MC-813-70

  • Effective vitrification of human induced pluripotent stem cells using carboxylated ε-poly-l-lysine. 21621529

    Derivation of human induced pluripotent stem (iPS) cells could enable their widespread application in future. Establishment of highly efficient and reliable methods for their preservation is a prerequisite for these applications. In this study, we developed a vitrification solution comprising ethylene glycol (EG) and sucrose as well as carboxylated ε-poly-l-lysine (PLL); this solution inhibited devitrification. Human iPS cells were vitrified in 200-μL vitrification solutions comprised 6.5M EG, 0.75 M sucrose and 0 or 10%w/v carboxylated PLL with 65 mol% of the amino groups converted to carboxyl groups [PLL (0.65)] in a cryovial by directly immersing in liquid nitrogen. After warming, attached colony and recovery rates of human iPS cells vitrified by adding PLL (0.65) were significantly higher than those for cells without PLL (0.65) and vitrification solution (DAP213: 2M dimethyl sulfoxide, 1M acetamide and 3M propylene glycol). Furthermore, even after warming at room temperature, attached colony and recovery rates of iPS cells vitrified with PLL (0.65) were reduced to a lesser extent than those vitrified with either DAP213 or EG and sucrose without PLL (0.65). This could be attributed to inhibition of devitrification by PLL (0.65), as differential scanning calorimetry indicated less damage after vitrification with PLL (0.65). In addition, human iPS cells vitrified in the solution with PLL (0.65) had normal karyotypes and maintained undifferentiated states and pluripotency as determined by immunohistochemistry and teratoma formation. Addition of PLL (0.65) successfully vitrified human iPS cells with high efficiency. We believe that this method could aid future applications and increase utility of human iPS cells.
    Tipo de documento:
    Referencia
    Referencia del producto:
    MAB4303

  • Maternal embryonic leucine zipper kinase (MELK) reduces replication stress in glioblastoma cells. 23836907

    Maternal embryonic leucine zipper kinase (MELK) belongs to the subfamily of AMP-activated Ser/Thr protein kinases. The expression of MELK is very high in glioblastoma-type brain tumors, but it is not clear how this contributes to tumor growth. Here we show that the siRNA-mediated loss of MELK in U87 MG glioblastoma cells causes a G1/S phase cell cycle arrest accompanied by cell death or a senescence-like phenotype that can be rescued by the expression of siRNA-resistant MELK. This cell cycle arrest is mediated by an increased expression of p21(WAF1/CIP1), an inhibitor of cyclin-dependent kinases, and is associated with the hypophosphorylation of the retinoblastoma protein and the down-regulation of E2F target genes. The increased expression of p21 can be explained by the consecutive activation of ATM (ataxia telangiectasia mutated), Chk2, and p53. Intriguingly, the activation of p53 in MELK-deficient cells is not due to an increased stability of p53 but stems from the loss of MDMX (mouse double minute-X), an inhibitor of p53 transactivation. The activation of the ATM-Chk2 pathway in MELK-deficient cells is associated with the accumulation of DNA double-strand breaks during replication, as demonstrated by the appearance of γH2AX foci. Replication stress in these cells is also illustrated by an increased number of stalled replication forks and a reduced fork progression speed. Our data indicate that glioblastoma cells have elevated MELK protein levels to better cope with replication stress during unperturbed S phase. Hence, MELK inhibitors hold great potential for the treatment of glioblastomas as such or in combination with DNA-damaging therapies.
    Tipo de documento:
    Referencia
    Referencia del producto:
    Múltiplo
    Nombre del producto:
    Múltiplo