Smad4 binds Hoxa9 in the cytoplasm and protects primitive hematopoietic cells against nuclear activation by Hoxa9 and leukemia transformation.
We studied leukemic stem cells (LSCs) in a Smad4(-/-) mouse model of acute myelogenous leukemia (AML) induced either by the HOXA9 gene or by the fusion oncogene NUP98-HOXA9. Although Hoxa9-Smad4 complexes accumulate in the cytoplasm of normal hematopoietic stem cells and progenitor cells (HSPCs) transduced with these oncogenes,there is no cytoplasmic stabilization of HOXA9 in Smad4(-/-) HSPCs,and as a consequence increased levels of Hoxa9 is observed in the nucleus leading to increased immortalization in vitro. Loss of Smad4 accelerates the development of leukemia in vivo because of an increase in transformation of HSPCs. Therefore,the cytoplasmic binding of Hoxa9 by Smad4 is a mechanism to protect Hoxa9-induced transformation of normal HSPCs. Because Smad4 is a potent tumor suppressor involved in growth control,we developed a strategy to modify the subcellular distribution of Smad4. We successfully disrupted the interaction between Hoxa9 and Smad4 to activate the TGF-β pathway and apoptosis,leading to a loss of LSCs. Together,these findings reveal a major role for Smad4 in the negative regulation of leukemia initiation and maintenance induced by HOXA9/NUP98-HOXA9 and provide strong evidence that antagonizing Smad4 stabilization by these oncoproteins might be a promising novel therapeutic approach in leukemia.
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产品类型：
产品号#：
03434
03444
03236
产品名：
MethoCult™GF M3434
MethoCult™GF M3434
MethoCult™SF M3236
Wang JC et al. (JUN 1997)
Blood 89 11 3919--24
Primitive human hematopoietic cells are enriched in cord blood compared with adult bone marrow or mobilized peripheral blood as measured by the quantitative in vivo SCID-repopulating cell assay.
We have previously reported the development of in vivo functional assays for primitive human hematopoietic cells based on their ability to repopulate the bone marrow (BM) of severe combined immunodeficient (SCID) and nonobese diabetic/SCID (NOD/SCID) mice following intravenous transplantation. Accumulated data from gene marking and cell purification experiments indicate that the engrafting cells (defined as SCID-repopulating cells or SRC) are biologically distinct from and more primitive than most cells that can be assayed in vitro. Here we demonstrate through limiting dilution analysis that the NOD/SCID xenotransplant model provides a quantitative assay for SRC. Using this assay,the frequency of SRC in cord blood (CB) was found to be 1 in 9.3 x 10(5) cells. This was significantly higher than the frequency of 1 SRC in 3.0 x 10(6) adult BM cells or 1 in 6.0 x 10(6) mobilized peripheral blood (PB) cells from normal donors. Mice transplanted with limiting numbers of SRC were engrafted with both lymphoid and multilineage myeloid human cells. This functional assay is currently the only available method for quantitative analysis of human hematopoietic cells with repopulating capacity. Both CB and mobilized PB are increasingly being used as alternative sources of hematopoietic stem cells in allogeneic transplantation. Thus,the findings reported here will have important clinical as well as biologic implications.
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产品类型：
产品号#：
28600
产品名：
L-Calc™有限稀释软件
Gerrits A et al. (APR 2010)
Blood 115 13 2610--8
Cellular barcoding tool for clonal analysis in the hematopoietic system.
Clonal analysis is important for many areas of hematopoietic stem cell research,including in vitro cell expansion,gene therapy,and cancer progression and treatment. A common approach to measure clonality of retrovirally transduced cells is to perform integration site analysis using Southern blotting or polymerase chain reaction-based methods. Although these methods are useful in principle,they generally provide a low-resolution,biased,and incomplete assessment of clonality. To overcome those limitations,we labeled retroviral vectors with random sequence tags or barcodes." On integration�
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产品类型：
产品号#：
09600
09650
产品名：
StemSpan™ SFEM
StemSpan™ SFEM
Liberski AR et al. (JUL 2013)
Journal of Proteome Research 12 7 3233--3245
Adaptation of a Commonly Used, Chemically Defined Medium for Human Embryonic Stem Cells to Stable Isotope Labeling with Amino Acids in Cell Culture
Metabolic labeling with stable isotopes is a prominent technique for comparative quantitative proteomics,and stable isotope labeling with amino acids in cell culture (SILAC) is the most commonly used approach. SILAC is,however,traditionally limited to simple tissue culture regimens and only rarely employed in the context of complex culturing conditions as those required for human embryonic stem cells (hESCs). Classic hESC culture is based on the use of mouse embryonic fibroblasts (MEFs) as a feeder layer,and as a result,possible xenogeneic contamination,contribution of unlabeled amino acids by the feeders,interlaboratory variability of MEF preparation,and the overall complexity of the culture system are all of concern in conjunction with SILAC. We demonstrate a feeder-free SILAC culture system based on a customized version of a commonly used,chemically defined hESC medium developed by Ludwig et al. and commercially available as mTeSR1 [mTeSR1 is a trade mark of WiCell (Madison,WI) licensed to STEMCELL Technologies (Vancouver,Canada)]. This medium,together with adjustments to the culturing protocol,facilitates reproducible labeling that is easily scalable to the protein amounts required by proteomic work flows. It greatly enhances the usability of quantitative proteomics as a tool for the study of mechanisms underlying hESCs differentiation and self-renewal. Associated data have been deposited to the ProteomeXchange with the identifier PXD000151.
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产品类型：
产品号#：
07923
85850
85857
产品名：
Dispase (1 U/mL)
mTeSR™1
mTeSR™1
Fraga AM et al. (MAR 2011)
Cell Transplantation 20 3 431--40
Establishment of a Brazilian line of human embryonic stem cells in defined medium: implications for cell therapy in an ethnically diverse population.
Pluripotent human embryonic stem (hES) cells are an important experimental tool for basic and applied research,and a potential source of different tissues for transplantation. However,one important challenge for the clinical use of these cells is the issue of immunocompatibility,which may be dealt with by the establishment of hES cell banks to attend different populations. Here we describe the derivation and characterization of a line of hES cells from the Brazilian population,named BR-1,in commercial defined medium. In contrast to the other hES cell lines established in defined medium,BR-1 maintained a stable normal karyotype as determined by genomic array analysis after 6 months in continuous culture (passage 29). To our knowledge,this is the first reported line of hES cells derived in South America. We have determined its genomic ancestry and compared the HLA-profile of BR-1 and another 22 hES cell lines established elsewhere with those of the Brazilian population,finding they would match only 0.011% of those individuals. Our results highlight the challenges involved in hES cell banking for populations with a high degree of ethnic admixture.
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产品类型：
产品号#：
85850
85857
产品名：
mTeSR™1
mTeSR™1
Chanda B et al. (SEP 2013)
Cell 155 1 215--227
Retinoic acid signaling is essential for embryonic hematopoietic stem cell development.
Hematopoietic stem cells (HSCs) develop from a specialized subpopulation of endothelial cells known as hemogenic endothelium (HE). Although the HE origin of HSCs is now well established in different species,the signaling pathways that control this transition remain poorly understood. Here,we show that activation of retinoic acid (RA) signaling in aorta-gonad-mesonephros-derived HE ex vivo dramatically enhanced its HSC potential,whereas conditional inactivation of the RA metabolizing enzyme retinal dehydrogenase 2 in VE-cadherin expressing endothelial cells in vivo abrogated HSC development. Wnt signaling completely blocked the HSC inductive effects of RA modulators,whereas inhibition of the pathway promoted the development of HSCs in the absence of RA signaling. Collectively,these findings position RA and Wnt signaling as key regulators of HSC development and in doing so provide molecular insights that will aid in developing strategies for their generation from pluripotent stem cells.
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产品类型：
产品号#：
01700
01705
01702
产品名：
ALDEFLUOR™ 试剂盒
ALDEFLUOR™ DEAB试剂
ALDEFLUOR™测定缓冲液
Sumitomo A et al. (OCT 2010)
Molecular and cellular biology 30 20 4818--27
The transcriptional mediator subunit MED1/TRAP220 in stromal cells is involved in hematopoietic stem/progenitor cell support through osteopontin expression.
MED1/TRAP220,a subunit of the transcriptional Mediator/TRAP complex,is crucial for various biological events through its interaction with distinct activators,such as nuclear receptors and GATA family activators. In hematopoiesis,MED1 plays a pivotal role in optimal nuclear receptor-mediated myelomonopoiesis and GATA-1-induced erythropoiesis. In this study,we present evidence that MED1 in stromal cells is involved in supporting hematopoietic stem and/or progenitor cells (HSPCs) through osteopontin (OPN) expression. We found that the proliferation of bone marrow (BM) cells cocultured with MED1 knockout (Med1(-/-)) mouse embryonic fibroblasts (MEFs) was significantly suppressed compared to the control. Furthermore,the number of long-term culture-initiating cells (LTC-ICs) was attenuated for BM cells cocultured with Med1(-/-) MEFs. The vitamin D receptor (VDR)- and Runx2-mediated expression of OPN,as well as Mediator recruitment to the Opn promoter,was specifically attenuated in the Med1(-/-) MEFs. Addition of OPN to these MEFs restored the growth of cocultured BM cells and the number of LTC-ICs,both of which were attenuated by the addition of the anti-OPN antibody to Med1(+/+) MEFs and to BM stromal cells. Consequently,MED1 in niche appears to play an important role in supporting HSPCs by upregulating VDR- and Runx2-mediated transcription on the Opn promoter.
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产品类型：
产品号#：
03334
03434
03444
09500
产品名：
MethoCult™M3334
MethoCult™GF M3434
MethoCult™GF M3434
BIT 9500血清替代物
Lianguzova MS et al. (APR 2007)
Cell biology international 31 4 330--7
Phosphoinositide 3-kinase inhibitor LY294002 but not serum withdrawal suppresses proliferation of murine embryonic stem cells.
Mouse embryonic stem (mES) cells have short duration of their cell cycle and are capable of proliferating in the absence of growth factors. To find out which signaling pathways contribute to the regulation of the mES cell cycle,we used pharmacological inhibitors of MAP and PI3 kinase cascades. The MAP kinase inhibitors as well as serum withdrawal did not affect mES cell cycle distribution,whereas the inhibitor of PI3K activity,LY294002,induced accumulation of cells in G(1) phase followed by apoptotic cell death. Serum withdrawal also causes apoptosis,but it does not change the content and activity of cell cycle regulators. In contrast,in mES cells treated with LY294002,the activities of Cdk2 and E2F were significantly decreased. Interestingly,LY294002had a much stronger effect on cell cycle distribution in low serum conditions,implying that serum can promote G(1)--textgreaterS transition of mES cells by a LY294002-resistant mechanism. Thus,proliferation of mES cells is maintained by at least two separate mechanisms: a LY294002-sensitive pathway,which is active even in the absence of serum,and LY294002-resistant,but serum-dependent,pathway.
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Myogenesis GRC 2017,Till and McCulloch Meeting 2017
产品号#：
05980
05982
05983
产品名：
MyoCult™-SF 扩增添加物试剂盒 (人)
MyoCult™-SF 扩增10X添加物（人）
MyoCult™-SF 贴附基质
Allan LL et al. (SEP 2009)
Blood 114 12 2411--6
Apolipoprotein-mediated lipid antigen presentation in B cells provides a pathway for innate help by NKT cells.
Natural killer T (NKT) cells are innate-like lymphocytes that recognize lipid antigens and have been shown to enhance B-cell activation and antibody production. B cells typically recruit T-cell help by presenting internalized antigens recognized by their surface antigen receptor. Here,we demonstrate a highly efficient means whereby human B cells present lipid antigens to NKT cells,capturing the antigen using apolipoprotein E (apoE) and the low-density lipoprotein receptor (LDL-R). ApoE dramatically enhances B-cell presentation of alpha-galactosylceramide (alphaGalCer),an exogenous CD1d presented antigen,inducing activation of NKT cells and the subsequent activation of B cells. B cells express the LDL-R on activation,and the activation of NKT cells by B cells is completely LDL-R dependent,as shown by blocking experiments and the complete lack of presentation when using apoE2,an isoform of apoE incapable of LDL-R binding. The dependence on apoE and the LDL-R is much more pronounced in B cells than we had previously seen in dendritic cells,which can apparently use alternate pathways of lipid antigen uptake. Thus,B cells use an apolipoprotein-mediated pathway of lipid antigen presentation,which constitutes a form of innate help for B cells by NKT cells.
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Phosphoinositide 3-kinase signaling is essential for ABL oncogene-mediated transformation of B-lineage cells.
BCR-ABL and v-ABL are oncogenic forms of the Abl tyrosine kinase that can cause leukemias in mice and humans. ABL oncogenes trigger multiple signaling pathways whose contribution to transformation varies among cell types. Activation of phosphoinositide 3-kinase (PI3K) is essential for ABL-dependent proliferation and survival in some cell types,and global PI3K inhibitors can enhance the antileukemia effects of the Abl kinase inhibitor imatinib. Although a significant fraction of BCR-ABL-induced human leukemias are of B-cell origin,little is known about PI3K signaling mechanisms in B-lineage cells transformed by ABL oncogenes. Here we show that activation of class I(A) PI3K and downstream inactivation of FOXO transcription factors are essential for survival of murine pro/pre-B cells transformed by v-ABL or BCR-ABL. In addition,analysis of mice lacking individual PI3K genes indicates that products of the Pik3r1 gene contribute to transformation efficiency by BCR-ABL. These findings establish a role for PI3K signaling in B-lineage transformation by ABL oncogenes.
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EasySep™小鼠TIL（CD45）正选试剂盒
科学海报A Serum-Free Workflow for the Isolation, Expansion and Differentiation of Human Myogenic Progenitors
科学海报Generation of T and NK Cells From Pluripotent Stem Cell-Derived Hematopoietic Progenitors in a Stroma-Free, Serum-Free Culture System
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