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  • WEHI 164 subclone 13 assay for TNF: sensitivity, specificity, and reliability. 2110931

    Tumor necrosis factor alpha (TNF) is a peptide monokine involved in a number of immune reactions. To further understand the role of TNF in disease states it is critical to have an inexpensive, yet sensitive and specific assay. Additionally, the effects of prostaglandin E2 (PGE2), dexamethasone (dex), and cyclosporine A (CsA) on TNF gene expression have been studied, although little is known of the effects these compounds have on TNF containing samples. The aim of this study is to determine the sensitivity and specificity of a highly sensitive cell line to the actions of TNF, and to elucidate parameters which affect the stability of TNF in biological fluids. Dex and PGE2 at concentrations of 10(-5), 10(-7), and 10(-9) M, were shown not to effect the WEHI assay, and neither did CsA (10 ng/ml-1 ug/ml). The cells were not lysed by recombinant murine IL-1 alpha or beta, human recombinant IL-1 alpha or beta, human recombinant IL-2 or human recombinant IL-6 at concentrations ranging from 0.02 pg/ml to 1.0 ug/ml, or murine gamma-IFN from 100 pg/ml to 10 ng/ml. TNF containing samples with 1%-10% fetal calf serum maintained their cytolytic activity even after three freeze-thaw cycles. Serum samples did not lose any cytolytic activity with up to 11 cycles of freezing and thawing whereas, tissue culture media, containing TNF, lost significant activity with freeze-thawing. The WEHI assay has successfully detected cytolytic activity from lipopolysaccharide stimulated specimens from a number of different species. These data show the utility of this highly sensitive and specific assay. Furthermore, the WEHI assay showed a high degree of reproducibility in repeated assays.
    Document Type:
    Reference
    Product Catalog Number:
    01-164
  • Dosage and cell line dependent inhibitory effect of bFGF supplement in human pluripotent stem cell culture on inactivated human mesenchymal stem cells. 24465853

    Many different culture systems have been developed for expanding human pluripotent stem cells (hESCs and hiPSCs). In general, 4-10 ng/ml of bFGF is supplemented in culture media in feeder-dependent systems regardless of feeder cell types, whereas in feeder-free systems, up to 100 ng/ml of bFGF is required for maintaining long-term culture on various substrates. The amount of bFGF required in native hESCs growth niche is unclear. Here we report using inactivated adipose-derived human mesenchymal stem cells as feeder cells to examine long-term parallel cultures of two hESCs lines (H1 and H9) and one hiPSCs line (DF19-9-7T) in media supplemented with 0, 0.4 or 4 ng/ml of bFGF for up to 23 passages, as well as parallel cultures of H9 and DF19 in media supplemented with 4, 20 or 100 ng/ml bFGF for up to 13 passages for comparison. Across all cell lines tested, bFGF supplement demonstrated inhibitory effect over growth expansion, single cell colonization and recovery from freezing in a dosage dependent manner. In addition, bFGF exerted differential effects on different cell lines, inducing H1 and DF19 differentiation at 4 ng/ml or higher, while permitting long-term culture of H9 at the same concentrations with no apparent dosage effect. Pluripotency was confirmed for all cell lines cultured in 0, 0.4 or 4 ng/ml bFGF excluding H1-4 ng, as well as H9 cultured in 4, 20 and 100 ng/ml bFGF. However, DF19 demonstrated similar karyotypic abnormality in both 0 and 4 ng/ml bFGF media while H1 and H9 were karyotypically normal in 0 ng/ml bFGF after long-term culture. Our results indicate that exogenous bFGF exerts dosage and cell line dependent effect on human pluripotent stem cells cultured on mesenchymal stem cells, and implies optimal use of bFGF in hESCs/hiPSCs culture should be based on specific cell line and its culture system.
    Document Type:
    Reference
    Product Catalog Number:
    MAB4304
    Product Catalog Name:
    Anti-Stage-Specific Embryonic Antigen-4 Antibody, clone MC-813-70
  • A simple and efficient cryopreservation method for feeder-free dissociated human induced pluripotent stem cells and human embryonic stem cells. 19602515

    An essential prerequisite for the future widespread application of human induced pluripotent (hiPSCs) and embryonic stem cells (hESCs) is the development of efficient cryopreservation methods to facilitate their storage and transportation.We developed a simple and effective freezing/thawing method of single dissociated hESCs and hiPSCs in a feeder-free culture in the presence of Rho-associated kinase (ROCK) inhibitor Y-27632.Exposure to ROCK inhibitor Y-27632 in freezing solution alone does not significantly enhance the post-thaw survival rate of single dissociated hESCs and hiPSCs. However, when ROCK inhibitor was added to both pre- and post-thaw culture media, there was an enhancement in the survival rate, which further increased when ROCK inhibitor was added to Matrigel as well. Under these treatments, hESCs and hiPSCs retained typical morphology, stable karyotype, expression of pluripotency markers and the potential to differentiate into derivatives of all three germ layers after long-term culture.This method is an effective cryopreservation procedure for single dissociated hESCs in feeder-free culture, which is also applicable for single dissociated hiPSCs using a ROCK inhibitor. The cloning efficiency of hiPSCs and hESCs improves when ROCK inhibitor is added both in Matrigel and in medium in comparison with conventional addition to medium. Therefore, we believe this method would be useful for current and future applications of the pluripotent stem cells.
    Document Type:
    Reference
    Product Catalog Number:
    Multiple
    Product Catalog Name:
    Multiple
  • Derivation of mouse embryonic stem cells 17487198

    Here we describe a simple and efficient protocol for derivation of germline chimera-competent mouse embryonic stem cells (mESCs) from embryonic day 3.5 (E3.5) blastocysts. The protocol involves the use of early-passage mouse embryonic fibroblast feeders (MEF) and the alternation of fetal bovine serum- and serum replacement (SR)-containing media. As compared to other available protocols for mESCs derivation, our protocol differs in the combination of commercial availability of all reagents, technical simplicity and high efficiency. mESC lines are derived with approximately 50% efficiency (50 independent mESC lines derived from 96 blastocysts). We believe that this protocol could be a good starting point for (i) setting up the derivation of mESC lines in a laboratory and (ii) incorporating further steps to improve efficiency or adapt the protocol to other applications. The whole process (from blastocyst extraction to the freezing of mESC line) usually takes between 15 and 20 d.
    Document Type:
    Reference
    Product Catalog Number:
    Multiple
    Product Catalog Name:
    Multiple
  • Derivation of a new human embryonic stem cell line, Endeavour-2, and its characterization. 20178001

    Here, we describe the derivation of a novel human embryonic stem cell (hESC) line, Endeavour-2 (E-2), propagated on human fetal fibroblasts (HFF) in a serum-replacement media. The inner cell mass (ICM) was manually dissected from the blastocyst without using immunodissection and, therefore, antibodies from animal sources. A total of 20 embryos were thawed and cultured, eight embryos were hatched, and five ICMs were obtained. They were transferred onto HFF used as feeder layer, and one colony representing the initial cell proliferation of a new hESC line, E-2, was obtained. The newly emerged hESC colony was passaged first by physical dissection and subsequently by enzymatic dissociation. E-2 has been in culture for over 6 months and has been shown to possess typical features of a pluripotent hESC line including expression of stem cell surface markers (SSEA4, TRA-160, and integrin alpha-6), intracellular alkaline phosphatase, and pluripotency gene markers, OCT4 and NANOG. This hESC line shows lineage-specific differentiation into various representative cell types expressing markers characteristic of the three somatic germ layers under both in vitro and in vivo conditions. E-2 line shows a normal karyotype (46 XX) and has been successfully cryopreserved and thawed several times using slow-freezing procedures. E-2 adds to the repertoire of existing hESC lines for research and development purposes in the field of regenerative medicine.
    Document Type:
    Reference
    Product Catalog Number:
    MAB1982
    Product Catalog Name:
    Anti-Integrin α6 Antibody, clone MA6
  • The Arabidopsis mediator complex subunits MED16, MED14, and MED2 regulate mediator and RNA polymerase II recruitment to CBF-responsive cold-regulated genes. 24415770

    The Mediator16 (MED16; formerly termed SENSITIVE TO FREEZING6 [SFR6]) subunit of the plant Mediator transcriptional coactivator complex regulates cold-responsive gene expression in Arabidopsis thaliana, acting downstream of the C-repeat binding factor (CBF) transcription factors to recruit the core Mediator complex to cold-regulated genes. Here, we use loss-of-function mutants to show that RNA polymerase II recruitment to CBF-responsive cold-regulated genes requires MED16, MED2, and MED14 subunits. Transcription of genes known to be regulated via CBFs binding to the C-repeat motif/drought-responsive element promoter motif requires all three Mediator subunits, as does cold acclimation-induced freezing tolerance. In addition, these three subunits are required for low temperature-induced expression of some other, but not all, cold-responsive genes, including genes that are not known targets of CBFs. Genes inducible by darkness also required MED16 but required a different combination of Mediator subunits for their expression than the genes induced by cold. Together, our data illustrate that plants control transcription of specific genes through the action of subsets of Mediator subunits; the specific combination defined by the nature of the stimulus but also by the identity of the gene induced.
    Document Type:
    Reference
    Product Catalog Number:
    06-599
    Product Catalog Name:
    Anti-acetyl-Histone H3 Antibody
  • Main olfactory system mediates social buffering of conditioned fear responses in male rats. 19250440

    We previously reported that the presence of a conspecific animal blocked freezing of a male rat in response to an auditory conditioned stimulus that had been paired with foot shocks, as well as associated Fos expression in the paraventricular nucleus. Here we investigated how this 'social buffering' is mediated by examining the contributions of both physical contact and the main olfactory system. Fear-conditioned rats exposed to the conditioned stimulus alone responded by freezing and increased Fos expression in the paraventricular nucleus. However, the presence of another rat, but not a guinea pig, dramatically mitigated these responses, even if the dyad was separated by a wire mesh or a pair of wire meshes 5 cm apart. In contrast, social buffering was absent when a transparent acrylic board was inserted between the double wire mesh. Lesioning of the main olfactory epithelium by injection of ZnSO(4) intranasally also abolished social buffering. Thus, we conclude that the main olfactory system is essential for the social buffering but does not require physical contact between the dyad.
    Document Type:
    Reference
    Product Catalog Number:
    MAB5406
    Product Catalog Name:
    Anti-GAD67 Antibody, clone 1G10.2
  • Chilling- and Freezing-Induced Alterations in Cytosine Methylation and Its Association with the Cold Tolerance of an Alpine Subnival Plant, Chorispora bungeana. 26270551

    Chilling (0-18°C) and freezing (less than 0°C) are two distinct types of cold stresses. Epigenetic regulation can play an important role in plant adaptation to abiotic stresses. However, it is not yet clear whether and how epigenetic modification (i.e., DNA methylation) mediates the adaptation to cold stresses in nature (e.g., in alpine regions). Especially, whether the adaptation to chilling and freezing is involved in differential epigenetic regulations in plants is largely unknown. Chorispora bungeana is an alpine subnival plant that is distributed in the freeze-thaw tundra in Asia, where chilling and freezing frequently fluctuate daily (24 h). To disentangle how C. bungeana copes with these intricate cold stresses through epigenetic modifications, plants of C. bungeana were treated at 4°C (chilling) and -4°C (freezing) over five periods of time (0-24 h). Methylation-sensitive amplified fragment-length polymorphism markers were used to investigate the variation in DNA methylation of C. bungeana in response to chilling and freezing. It was found that the alterations in DNA methylation of C. bungeana largely occurred over the period of chilling and freezing. Moreover, chilling and freezing appeared to gradually induce distinct DNA methylation variations, as the treatment went on (e.g., after 12 h). Forty-three cold-induced polymorphic fragments were randomly selected and further analyzed, and three of the cloned fragments were homologous to genes encoding alcohol dehydrogenase, UDP-glucosyltransferase and polygalacturonase-inhibiting protein. These candidate genes verified the existence of different expressive patterns between chilling and freezing. Our results showed that C. bungeana responded to cold stresses rapidly through the alterations of DNA methylation, and that chilling and freezing induced different DNA methylation changes. Therefore, we conclude that epigenetic modifications can potentially serve as a rapid and flexible mechanism for C. bungeana to adapt to the intricate cold stresses in the alpine areas.
    Document Type:
    Reference
    Product Catalog Number:
    MABE146
    Product Catalog Name:
    Anti-5-methylcytosine Antibody, clone 33D3
  • Extrasynaptic GABAA receptors in mediodorsal thalamic nucleus modulate fear extinction learning. 24886120

    The gamma-amino-butyric acid (GABA) system is a critical mediator of fear extinction process. GABA can induce "phasic" or "tonic" inhibition in neurons through synaptic or extrasynaptic GABAA receptors, respectively. However, role of the thalamic "tonic GABA inhibition" in cognition has not been explored. We addressed this issue in extinction of conditioned fear in mice.Here, we show that GABAA receptors in the mediodorsal thalamic nucleus (MD) modulate fear extinction. Microinjection of gabazine, a GABAA receptor antagonist, into the MD decreased freezing behavior in response to the conditioned stimulus and thus facilitated fear extinction. Interestingly, microinjection of THIP (4,5,6,7-tetrahydroisoxazolo[5,4-c]pyridin-3-ol), a preferential agonist for the δ-subunit of extrasynaptic GABAA receptors, into the MD attenuated fear extinction. In the opposite direction, an MD-specific knock-out of the extrasynaptic GABAA receptors facilitated fear extinction.Our results suggest that "tonic GABA inhibition" mediated by extrasynaptic GABAA receptors in MD neurons, suppresses fear extinction learning. These results raise a possibility that pharmacological control of tonic mode of GABAA receptor activation may be a target for treatment of anxiety disorders like post-traumatic stress disorder.
    Document Type:
    Reference
    Product Catalog Number:
    MAB3120
    Product Catalog Name:
    Anti-Cre Recombinase Antibody, clone 2D8