Amita M et al. (MAR 2013)
Proceedings of the National Academy of Sciences of the United States of America 110 13 E1212--E1221
Complete and unidirectional conversion of human embryonic stem cells to trophoblast by BMP4
Human ES cells (hESC) exposed to bone morphogenic protein 4 (BMP4) in the absence of FGF2 have become widely used for studying trophoblast development,but the soundness of this model has been challenged by others,who concluded that differentiation was primarily toward mesoderm rather than trophoblast. Here we confirm that hESC grown under the standard conditions on a medium conditioned by mouse embryonic fibroblasts in the presence of BMP4 and absence of FGF2 on a Matrigel substratum rapidly convert to an epithelium that is largely KRT7+ within 48 h,with minimal expression of mesoderm markers,including T (Brachyury). Instead,they begin to express a series of trophoblast markers,including HLA-G,demonstrate invasive properties that are independent of the continued presence of BMP4 in the medium,and,over time,produce extensive amounts of human chorionic gonadotropin,progesterone,placental growth factor,and placental lactogen. This process of differentiation is not dependent on conditioning of the medium by mouse embryonic fibroblasts and is accelerated in the presence of inhibitors of Activin and FGF2 signaling,which at day 2 provide colonies that are entirely KRT7+ and in which the majority of cells are transiently CDX2+. Colonies grown on two chemically defined media,including the one in which BMP4 was reported to drive mesoderm formation,also differentiate at least partially to trophoblast in response to BMP4. The experiments demonstrate that the in vitro BMP4/hESC model is valid for studying the emergence and differentiation of trophoblasts.
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产品类型:
产品号#:
05850
05857
05870
05875
07923
85850
85857
85870
85875
产品名:
Dispase (1 U/mL)
mTeSR™1
mTeSR™1
Khorashad JS et al. (JUN 2009)
Haematologica 94 6 861--4
The level of BCR-ABL1 kinase activity before treatment does not identify chronic myeloid leukemia patients who fail to achieve a complete cytogenetic response on imatinib.
Imatinib is currently the first line therapy for newly diagnosed patients with chronic myeloid leukemia. However,20-25% of patients do not achieve durable complete cytogenetic responses. The mechanism underlying this primary resistance is unknown,but variations in BCR-ABL1 kinase activity may play a role and can be investigated by measuring the autophosphorylation levels of BCR-ABL1 or of a surrogate target such as Crkl. In this study we used flow cytometry to investigate the in vitro inhibition of Crkl phosphorylation by imatinib in CD34(+) cells in diagnostic samples from two groups of patients distinguished by their cytogenetic response. No difference in inhibition of Crkl phosphorylation was observed in the two groups. The observation that increasing the dose of imatinib in vivo did not increase the level of cytogenetic response in some non-responders suggests that in at least a proportion of patients imatinib resistance may be due to activation of BCR-ABL1-independent pathway.
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产品类型:
产品号#:
18056
18056RF
产品名:
Ueno NT et al. (NOV 2003)
Blood 102 10 3829--36
Rapid induction of complete donor chimerism by the use of a reduced-intensity conditioning regimen composed of fludarabine and melphalan in allogeneic stem cell transplantation for metastatic solid tumors.
We evaluated the feasibility and efficacy of a reduced-intensity conditioning (RIC) regimen of fludarabine and melphalan to achieve rapid complete donor chimerism after allogeneic stem cell transplantation (SCT) in patients with metastatic solid tumors. Between January 1999 and January 2003,8 patients with metastatic breast cancer (BC) and 15 with metastatic renal cell carcinoma (RCC) underwent allogeneic SCT after an RIC regimen of 5 days of fludarabine and 2 days of melphalan. Filgrastim-mobilized stem cells from HLA-identical related or unrelated donors were infused. Prophylaxis for graft-versus-host disease (GVHD) consisted of tacrolimus and methotrexate. All 22 evaluable patients had 100% donor chimerism at day 30 and at all measurement times thereafter. One patient died 19 days after SCT. Nine patients (39%) had grades II to IV acute GVHD and 10 patients (43%) had chronic GVHD. Five patients (22%) died of nonrelapse treatment-related complications. Treatment-related disease response was seen in 10 patients (45%),with 3 complete responses,2 partial responses,and 5 minor responses. Fludarabine-melphalan is a feasible and effective RIC regimen for allogeneic SCT in metastatic BC and RCC. It induces rapid complete donor chimerism without the need for donor lymphocyte infusion. Tumor regression associated with GVHD is consistent with graft-versus-tumor effect.
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产品类型:
产品号#:
15271HLA
产品名:
RosetteSep™ HLA 淋系细胞富集试剂盒
Lannutti BJ et al. (FEB 2009)
Blood 113 8 1778--85
Incomplete restoration of Mpl expression in the mpl-/- mouse produces partial correction of the stem cell-repopulating defect and paradoxical thrombocytosis.
Expression of Mpl is restricted to hematopoietic cells in the megakaryocyte lineage and to undifferentiated progenitors,where it initiates critical cell survival and proliferation signals after stimulation by its ligand,thrombopoietin (TPO). As a result,a deficiency in Mpl function in patients with congenital amegakaryocytic thrombocytopenia (CAMT) and in mpl(-/-) mice produces profound thrombocytopenia and a severe stem cell-repopulating defect. Gene therapy has the potential to correct the hematopoietic defects of CAMT by ectopic gene expression that restores normal Mpl receptor activity. We rescued the mpl(-/-) mouse with a transgenic vector expressing mpl from the promoter elements of the 2-kb region of DNA just proximal to the natural gene start site. Transgene rescued mice exhibit thrombocytosis but only partial correction of the stem cell defect. Furthermore,they show very low-level expression of Mpl on platelets and megakaryocytes,and the transgene-rescued megakaryocytes exhibit diminished TPO-dependent kinase phosphorylation and reduced platelet production in bone marrow chimeras. Thrombocytosis is an unexpected consequence of reduced Mpl expression and activity. However,impaired TPO homeostasis in the transgene-rescued mice produces elevated plasma TPO levels,which serves as an unchecked stimulus to drive the observed excessive megakaryocytopoiesis.
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产品类型:
产品号#:
03434
03444
04960
04902
04900
04963
04962
04970
产品名:
MethoCult™ GF M3434
MethoCult™ GF M3434
MegaCult™-C胶原和无细胞因子培养基
胶原蛋白溶液
MegaCult™-C无细胞因子培养基
双室载玻片套件
MegaCult™-C CFU-Mk染色试剂盒
MegaCult™-C无细胞因子全套试剂盒
Nagaoka M et al. (JAN 2010)
BMC developmental biology 10 60
Culture of human pluripotent stem cells using completely defined conditions on a recombinant E-cadherin substratum.
BACKGROUND: To maintain pluripotency of human embryonic stem (huES) cells in feeder-free culture it has been necessary to provide a Matrigel substratum,which is a complex of poorly defined extracellular matrices and growth factors derived from mouse Engelbreth-Holm-Swarm sarcoma cells. Culture of stem cells under ill-defined conditions can inhibit the effectiveness of maintaining cells in a pluripotent state and reduce reproducibility of differentiation protocols. Moreover recent batches of Matrigel have been found to be contaminated with the single stranded RNA virus,Lactate Dehydrogenase Elevating Virus (LDEV),raising concerns regarding the safety of using stem cells that have been cultured on Matrigel in a therapeutic setting. To circumvent such concerns,we attempted to identify a recombinant matrix that could be used as an alternative to Matrigel for the culture of human pluripotent stem cells. huES and human induced pluripotent stem (hiPS) cells were grown on plates coated with a fusion protein consisting of E-cadherin and the IgG Fc domain using mTeSR1 medium.backslashnbackslashnRESULTS: Cells grown under these conditions maintained similar morphology and growth rate to those grown on Matrigel and retained all pluripotent stem cell features,including an ability to differentiate into multiple cell lineages in teratoma assays. We,therefore,present a culture system that maintains the pluripotency of huES and hiPS cells under completely defined conditions.backslashnbackslashnCONCLUSIONS: We propose that this system should facilitate growth of stem cells using good manufacturing practices (GMP),which will be necessary for the clinical use of pluripotent stem cells and their derivatives.
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产品类型:
产品号#:
05850
05857
05870
05875
85850
85857
85870
85875
产品名:
mTeSR™1
mTeSR™1
Liu C et al. (DEC 2010)
Blood 116 25 5518--27
Progenitor cell dose determines the pace and completeness of engraftment in a xenograft model for cord blood transplantation.
Two critical concerns in clinical cord blood transplantation are the initial time to engraftment and the subsequent restoration of immune function. These studies measured the impact of progenitor cell dose on both the pace and strength of hematopoietic reconstitution by transplanting nonobese diabetic/severe combined immunodeficiency/interleukin-2 receptor-gamma-null (NSγ) mice with lineage-depleted aldehyde dehydrogenase-bright CD34(+) human cord blood progenitors. The progress of each transplant was monitored over an extended time course by repeatedly analyzing the peripheral blood for human hematopoietic cells. In vivo human hematopoietic development was complete. After long-term transplantation assays (≥ 19 weeks),human T-cell development was documented within multiple tissues in 16 of 32 NSγ mice. Human T-cell differentiation was active within NSγ thymuses,as documented by the presence of CD4(+) CD8(+) T-cell progenitors as well as T-cell receptor excision circles. It is important to note that although myeloid and B-cell engraftment was detected as early as 4 weeks after transplantation,human T-cell development was exclusively late onset. High progenitor cell doses were associated with a robust human hematopoietic chimerism that accelerated both initial time to engraftment and subsequent T-cell development. At lower progenitor cell doses,the chimerism was weak and the human hematopoietic lineage development was frequently incomplete.
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产品类型:
产品号#:
01700
01705
01701
01702
14056
14066
28600
19056
19056RF
19756
19756RF
产品名:
ALDEFLUOR™ 试剂盒
ALDEFLUOR™ DEAB试剂, 1.5 mM, 1 mL
ALDEFLUOR™检测缓冲液
L-Calc™有限稀释软件
Gekas C et al. (APR 2009)
Blood 113 15 3461--71
Mef2C is a lineage-restricted target of Scl/Tal1 and regulates megakaryopoiesis and B-cell homeostasis.
The basic helix-loop-helix transcription factor stem cell leukemia gene (Scl) is a master regulator for hematopoiesis essential for hematopoietic specification and proper differentiation of the erythroid and megakaryocyte lineages. However,the critical downstream targets of Scl remain undefined. Here,we identified a novel Scl target gene,transcription factor myocyte enhancer factor 2 C (Mef2C) from Scl(fl/fl) fetal liver progenitor cell lines. Analysis of Mef2C(-/-) embryos showed that Mef2C,in contrast to Scl,is not essential for specification into primitive or definitive hematopoietic lineages. However,adult VavCre(+)Mef2C(fl/fl) mice exhibited platelet defects similar to those observed in Scl-deficient mice. The platelet counts were reduced,whereas platelet size was increased and the platelet shape and granularity were altered. Furthermore,megakaryopoiesis was severely impaired in vitro. Chromatin immunoprecipitation microarray hybridization analysis revealed that Mef2C is directly regulated by Scl in megakaryocytic cells,but not in erythroid cells. In addition,an Scl-independent requirement for Mef2C in B-lymphoid homeostasis was observed in Mef2C-deficient mice,characterized as severe age-dependent reduction of specific B-cell progenitor populations reminiscent of premature aging. In summary,this work identifies Mef2C as an integral member of hematopoietic transcription factors with distinct upstream regulatory mechanisms and functional requirements in megakaryocyte and B-lymphoid lineages.
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产品类型:
产品号#:
03234
03434
03444
04960
04902
04900
04961
04901
04963
04962
04970
04971
产品名:
MethoCult™ M3234
MethoCult™ GF M3434
MethoCult™ GF M3434
MegaCult™-C胶原和无细胞因子培养基
胶原蛋白溶液
MegaCult™-C无细胞因子培养基
MegaCult™-C胶原和含细胞因子培养基
MegaCult™-C含细胞因子培养基
双室载玻片套件
MegaCult™-C CFU-Mk染色试剂盒
MegaCult™-C无细胞因子全套试剂盒
MegaCult™-C含细胞因子全套试剂盒
Baran-Marszak F et al. (DEC 2010)
Blood 116 26 5961--71
Expression level and differential JAK2-V617F-binding of the adaptor protein Lnk regulates JAK2-mediated signals in myeloproliferative neoplasms.
Activating mutations in signaling molecules,such as JAK2-V617F,have been associated with myeloproliferative neoplasms (MPNs). Mice lacking the inhibitory adaptor protein Lnk display deregulation of thrombopoietin/thrombopoietin receptor signaling pathways and exhibit similar myeloproliferative characteristics to those found in MPN patients,suggesting a role for Lnk in the molecular pathogenesis of these diseases. Here,we showed that LNK levels are up-regulated and correlate with an increase in the JAK2-V617F mutant allele burden in MPN patients. Using megakaryocytic cells,we demonstrated that Lnk expression is regulated by the TPO-signaling pathway,thus indicating an important negative control loop in these cells. Analysis of platelets derived from MPN patients and megakaryocytic cell lines showed that Lnk can interact with JAK2-WT and V617F through its SH2 domain,but also through an unrevealed JAK2-binding site within its N-terminal region. In addition,the presence of the V617F mutation causes a tighter association with Lnk. Finally,we found that the expression level of the Lnk protein can modulate JAK2-V617F-dependent cell proliferation and that its different domains contribute to the inhibition of multilineage and megakaryocytic progenitor cell growth in vitro. Together,our results indicate that changes in Lnk expression and JAK2-V617F-binding regulate JAK2-mediated signals in MPNs.
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产品类型:
产品号#:
03434
03444
04960
04902
04900
产品名:
MethoCult™ GF M3434
MethoCult™ GF M3434
MegaCult™-C胶原和无细胞因子培养基
胶原蛋白溶液
MegaCult™-C无细胞因子培养基
Goossens S et al. (MAY 2011)
Blood 117 21 5620--30
The EMT regulator Zeb2/Sip1 is essential for murine embryonic hematopoietic stem/progenitor cell differentiation and mobilization.
Zeb2 (Sip1/Zfhx1b) is a member of the zinc-finger E-box-binding (ZEB) family of transcriptional repressors previously demonstrated to regulate epithelial-to-mesenchymal transition (EMT) processes during embryogenesis and tumor progression. We found high Zeb2 mRNA expression levels in HSCs and hematopoietic progenitor cells (HPCs),and examined Zeb2 function in hematopoiesis through a conditional deletion approach using the Tie2-Cre and Vav-iCre recombination mouse lines. Detailed cellular analysis demonstrated that Zeb2 is dispensable for hematopoietic cluster and HSC formation in the aorta-gonadomesonephros region of the embryo,but is essential for normal HSC/HPC differentiation. In addition,Zeb2-deficient HSCs/HPCs fail to properly colonize the fetal liver and/or bone marrow and show enhanced adhesive properties associated with increased β1 integrin and Cxcr4 expression. Moreover,deletion of Zeb2 resulted in embryonic (Tie2-Cre) and perinatal (Vav-icre) lethality due to severe cephalic hemorrhaging and decreased levels of angiopoietin-1 and,subsequently,improper pericyte coverage of the cephalic vasculature. These results reveal essential roles for Zeb2 in embryonic hematopoiesis and are suggestive of a role for Zeb2 in hematopoietic-related pathologies in the adult.
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产品类型:
产品号#:
03434
03444
04960
04902
04900
产品名:
MethoCult™ GF M3434
MethoCult™ GF M3434
MegaCult™-C胶原和无细胞因子培养基
胶原蛋白溶液
MegaCult™-C无细胞因子培养基
Wernig G et al. (JUN 2006)
Blood 107 11 4274--81
Expression of Jak2V617F causes a polycythemia vera-like disease with associated myelofibrosis in a murine bone marrow transplant model.
An acquired somatic mutation,Jak2V617F,was recently discovered in most patients with polycythemia vera (PV),chronic idiopathic myelofibrosis (CIMF),and essential thrombocythemia (ET). To investigate the role of this mutation in vivo,we transplanted bone marrow (BM) transduced with a retrovirus expressing either Jak2 wild-type (wt) or Jak2V617F into lethally irradiated syngeneic recipient mice. Expression of Jak2V617F,but not Jak2wt,resulted in clinicopathologic features that closely resembled PV in humans. These included striking elevation in hemoglobin level/hematocrit,leukocytosis,megakaryocyte hyperplasia,extramedullary hematopoiesis resulting in splenomegaly,and reticulin fibrosis in the bone marrow. Histopathologic and flow cytometric analyses showed an increase in maturing myeloid lineage progenitors,although megakaryocytes showed decreased polyploidization and staining for acetylcholinesterase. In vitro analysis of primary cells showed constitutive activation of Stat5 and cytokine-independent growth of erythroid colony-forming unit (CFU-E) and erythropoietin hypersensitivity,and Southern blot analysis for retroviral integration indicated that the disease was oligoclonal. Furthermore,we observed strain-specific differences in phenotype,with Balb/c mice demonstrating markedly elevated leukocyte counts,splenomegaly,and reticulin fibrosis compared with C57Bl/6 mice. We conclude that Jak2V617F expression in bone marrow progenitors results in a PV-like syndrome with myelofibrosis and that there are strain-specific modifiers that may in part explain phenotypic pleiotropy of Jak2V617F-associated myeloproliferative disease in humans.
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产品类型:
产品号#:
04960
04902
04900
04961
04901
04963
04962
04970
04971
产品名:
MegaCult™-C胶原和无细胞因子培养基
胶原蛋白溶液
MegaCult™-C无细胞因子培养基
MegaCult™-C胶原和含细胞因子培养基
MegaCult™-C含细胞因子培养基
双室载玻片套件
MegaCult™-C CFU-Mk染色试剂盒
MegaCult™-C无细胞因子全套试剂盒
MegaCult™-C含细胞因子全套试剂盒
Hisa T et al. (JAN 2004)
The EMBO journal 23 2 450--9
Hematopoietic, angiogenic and eye defects in Meis1 mutant animals.
Meis1 and Hoxa9 expression is upregulated by retroviral integration in murine myeloid leukemias and in human leukemias carrying MLL translocations. Both genes also cooperate to induce leukemia in a mouse leukemia acceleration assay,which can be explained,in part,by their physical interaction with each other as well as the PBX family of homeodomain proteins. Here we show that Meis1-deficient embryos have partially duplicated retinas and smaller lenses than normal. They also fail to produce megakaryocytes,display extensive hemorrhaging,and die by embryonic day 14.5. In addition,Meis1-deficient embryos lack well-formed capillaries,although larger blood vessels are normal. Definitive myeloerythroid lineages are present in the mutant embryos,but the total numbers of colony-forming cells are dramatically reduced. Mutant fetal liver cells also fail to radioprotect lethally irradiated animals and they compete poorly in repopulation assays even though they can repopulate all hematopoietic lineages. These and other studies showing that Meis1 is expressed at high levels in hematopoietic stem cells (HSCs) suggest that Meis1 may also be required for the proliferation/self-renewal of the HSC.
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产品类型:
产品号#:
04960
04902
04900
04961
04901
04963
04962
04970
04971
产品名:
MegaCult™-C胶原和无细胞因子培养基
胶原蛋白溶液
MegaCult™-C无细胞因子培养基
MegaCult™-C胶原和含细胞因子培养基
MegaCult™-C含细胞因子培养基
双室载玻片套件
MegaCult™-C CFU-Mk染色试剂盒
MegaCult™-C无细胞因子全套试剂盒
MegaCult™-C含细胞因子全套试剂盒
Berthier R et al. (MAR 1993)
Stem cells (Dayton,Ohio) 11 2 120--9
Serum-free medium allows the optimal growth of human megakaryocyte progenitors compared with human plasma supplemented cultures: role of TGF beta.
The growth of human megakaryocyte progenitors from human bone marrow (BM) cells was compared using a methylcellulose semisolid assay supplemented either by normal human plasma or by a serum-free medium. Far better growth of megakaryocyte colonies from CD34+ BM cells stimulated by interleukin 3 (IL-3) and interleukin 6 (IL-6) was observed in serum-free medium compared with human plasma supplemented cultures. These results were confirmed in liquid cultures using the same serum-free medium composition. The megakaryocytes were identified by using an immunocytochemical procedure after labeling with an anti-GPIIb-IIIa monoclonal antibody. High percentages (15 to 20%) of megakaryocytes were present in serum-free cultures stimulated by IL-3 alone or combined with IL-6. The absolute number of megakaryocytes in serum-free medium exceeds by 3.3 (IL-3 plus IL-6) to 4.4 (IL-3 alone) times the corresponding number of megakaryocytes observed in human plasma supplemented cultures. The optimal concentration of IL-3 alone was 5 ng/ml,and an optimal synergistic effect of IL-6 (5 ng/ml) was obtained when combined with a suboptimal dose of IL-3 (1 ng/ml). The poor growth of megakaryocyte colonies from CD34+ BM cells in human plasma suggested the presence of an inhibitory factor. When a neutralizing monoclonal antibody against transforming growth factor beta (TGF beta) is present in human plasma supplemented cultures of CD34+ BM cells,the number of megakaryocyte colonies is increased to the level observed in corresponding serum-free cultures. The high efficiency of this serum-free medium to promote the growth of human megakaryocytes will be useful to study the effects of regulators and platelet agonists acting on human megakaryocytes,without interference from factors in the serum.
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