From blood monocytes to adipose tissue-resident macrophages: induction of diapedesis by human mature adipocytes.
Obesity has been suggested to be a low-grade systemic inflammatory state,therefore we studied the interaction between human adipocytes and monocytes via adipose tissue (AT)-derived capillary endothelium. Cells composing the stroma-vascular fraction (SVF) of human ATs were characterized by fluorescence-activated cell sorter (FACS) analysis and two cell subsets (resident macrophages and endothelial cells [ECs]) were isolated using antibody-coupled microbeads. Media conditioned by mature adipocytes maintained in fibrin gels were applied to AT-derived ECs. Thereafter,the expression of endothelial adhesion molecules was analyzed as well as the adhesion and transmigration of human monocytes. FACS analysis showed that 11% of the SVF is composed of CD14(+)/CD31(+) cells,characterized as resident macrophages. A positive correlation was found between the BMI and the percentage of resident macrophages,suggesting that fat tissue growth is associated with a recruitment of blood monocytes. Incubation of AT-derived ECs with adipocyte-conditioned medium resulted in the upregulation of EC adhesion molecules and the increased chemotaxis of blood monocytes,an effect mimicked by recombinant human leptin. These results indicate that adipokines,such as leptin,activate ECs,leading to an enhanced diapedesis of blood monocytes,and suggesting that fat mass growth might be linked to inflammatory processes.
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产品类型：
产品号#：
18058
18058RF
18056
18056RF
产品名：
Hoebeke I et al. (APR 2006)
Blood 107 7 2879--81
Overexpression of HES-1 is not sufficient to impose T-cell differentiation on human hematopoietic stem cells.
By retroviral overexpression of the Notch-1 intracellular domain (ICN) in human CD34+ hematopoietic stem cells (HSCs),we have shown previously that Notch-1 signaling promotes the T-cell fate and inhibits the monocyte and B-cell fate in several in vitro and in vivo differentiation assays. Here,we investigated whether the effects of constitutively active Notch-1 can be mimicked by overexpression of its downstream target gene HES1. Upon HES-1 retroviral transduction,human CD34+ stem cells had a different outcome in the differentiation assays as compared to ICN-transduced cells. Although HES-1 induced a partial block in B-cell development,it did not inhibit monocyte development and did not promote T/NK-cell-lineage differentiation. On the contrary,a higher percentage of HES-1-transduced stem cells remained CD34+. These experiments indicate that HES-1 alone is not able to substitute for Notch-1 signaling to induce T-cell differentiation of human CD34+ hematopoietic stem cells.
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产品类型：
产品号#：
18056
18056RF
产品名：
Menon MP et al. (MAR 2006)
The Journal of clinical investigation 116 3 683--94
Signals for stress erythropoiesis are integrated via an erythropoietin receptor-phosphotyrosine-343-Stat5 axis.
Anemia due to chronic disease or chemotherapy often is ameliorated by erythropoietin (Epo). Present studies reveal that,unlike steady-state erythropoiesis,erythropoiesis during anemia depends sharply on an Epo receptor-phosphotyrosine-343-Stat5 signaling axis. In mice expressing a phosphotyrosine-null (PY-null) Epo receptor allele (EpoR-HM),severe and persistent anemia was induced by hemolysis or 5-fluorouracil. In short-term transplantation experiments,donor EpoR-HM bone marrow cells also failed to efficiently repopulate the erythroid compartment. In each context,stress erythropoiesis was rescued to WT levels upon the selective restoration of an EpoR PY343 Stat5-binding site (EpoR-H allele). As studied using a unique primary culture system,EpoR-HM erythroblasts exhibited marked stage-specific losses in Epo-dependent growth and survival. EpoR-H PY343 signals restored efficient erythroblast expansion,and the selective Epo induction of the Stat5 target genes proviral integration site-1 (Pim-1) and oncostatin-M. Bcl2-like 1 (Bcl-x),in contrast,was not significantly induced via WT-EpoR,EpoR-HM,or EpoR-H alleles. In Kit+ CD71+ erythroblasts,EpoR-PY343 signals furthermore enhanced SCF growth effects,and SCF modulation of Pim-1 kinase and oncostatin-M expression. In maturing Kit- CD71+ erythroblasts,oncostatin-M exerted antiapoptotic effects that likewise depended on EpoR PY343-mediated events. Stress erythropoiesis,therefore,requires stage-specific EpoR-PY343-Stat5 signals,some of which selectively bolster SCF and oncostatin-M action.
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产品类型：
产品号#：
19756
19756RF
产品名：
Uhmann A et al. (SEP 2007)
Blood 110 6 1814--23
The Hedgehog receptor Patched controls lymphoid lineage commitment.
A first step in hematopoiesis is the specification of the lymphoid and myeloid lineages from multipotent progenitor cells in the bone marrow. Using a conditional ablation strategy in adult mice,we show that this differentiation step requires Patched (Ptch),the cell surface-bound receptor for Hedgehog (Hh). In the absence of Ptch,the development of T- and B-lymphoid lineages is blocked at the level of the common lymphoid progenitor in the bone marrow. Consequently,the generation of peripheral T and B cells is abrogated. Cells of the myeloid lineage develop normally in Ptch mutant mice. Finally,adoptive transfer experiments identified the stromal cell compartment as a critical Ptch-dependent inducer of lymphoid versus myeloid lineage commitment. Our data show that Ptch acts as a master switch for proper diversification of hematopoietic stem cells in the adult organism.
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产品类型：
产品号#：
03434
03444
19756
19756RF
产品名：
MethoCult™ GF M3434
MethoCult™ GF M3434
Tenedini E et al. ( 2010)
Cell Death & Disease 1 e28
Integrated analysis of microRNA and mRNA expression profiles in physiological myelopoiesis: role of hsa-mir-299-5p in CD34+ progenitor cells commitment
Hematopoiesis entails a series of hierarchically organized events that proceed throughout cell specification and terminates with cell differentiation. Commitment needs the transcription factors' effort,which,in concert with microRNAs,drives cell fate and responds to promiscuous patterns of gene expression by turning on lineage-specific genes and repressing alternate lineage transcripts. We obtained microRNA profiles from human CD34+ hematopoietic progenitor cells and in vitro differentiated erythroblasts,megakaryoblasts,monoblasts and myeloblast precursors that we analyzed together with their gene expression profiles. The integrated analysis of microRNA-mRNA expression levels highlighted an inverse correlation between microRNAs specifically upregulated in one single-cell progeny and their putative target genes,which resulted in downregulation. Among the upregulated lineage-enriched microRNAs,hsa-miR-299-5p emerged as having a role in controlling CD34+ progenitor fate,grown in multilineage culture conditions. Gain- and loss-of-function experiments revealed that hsa-miR-299-5p participates in the regulation of hematopoietic progenitor fate,modulating megakaryocytic-granulocytic versus erythroid-monocytic differentiation.
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产品类型：
产品号#：
18058
18058RF
18099
18099RF
18086
18086RF
产品名：
Song W et al. (OCT 2016)
Journal of Biomedical Materials Research - Part A 104 3 678--687
Efficient generation of endothelial cells from human pluripotent stem cells and characterization of their functional properties
Although endothelial cells (ECs) have been derived from human pluripotent stem cells (hPSCs),large-scale generation of hPSC-ECs remains challenging and their functions are not well characterized. Here we report a simple and efficient three-stage method that allows generation of approximately 98 and 9500 ECs on day 16 and day 34,respectively,from each human embryonic stem cell (hESC) input. The functional properties of hESC-ECs derived in the presence and absence of a TGF$$-inhibitory molecule SB431542 were characterized and compared with those of human umbilical vein endothelial cells (HUVECs). Confluent monolayers formed by SB431542(+) hESC-ECs,SB431542(-) hESC-ECs,and HUVECs showed similar permeability to 10,000 Da dextran,but these cells exhibited striking differences in forming tube-like structures in 3D fibrin gels. The SB431542(+) hESC-ECs were most potent in forming tube-like structures regardless of whether VEGF and bFGF were present in the medium; less potent SB431542(-) hESC-ECs and HUVECs responded differently to VEGF and bFGF,which significantly enhanced the ability of HUVECs to form tube-like structures but had little impact on SB431542(-) hESC-ECs. This study offers an efficient approach to large-scale hPSC-EC production and suggests that the phenotypes and functions of hPSC-ECs derived under different conditions need to be thoroughly examined before their use in technology development. This article is protected by copyright. All rights reserved.
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Wognum AW et al. ( )
Archives of medical research 34 6 461--75
Identification and isolation of hematopoietic stem cells.
Hematopoietic stem cells (HSCs) are defined by their ability to repopulate all of the hematopoietic lineages in vivo and sustain the production of these cells for the life span of the individual. In the absence of reliable direct markers for HSCs,their identification and enumeration depends on functional long-term,multilineage,in vivo repopulation assays. The extremely low frequency of HSCs in any tissue and the absence of a specific HSC phenotype have made their purification and characterization a highly challenging goal. HSCs and primitive hematopoietic cells can be distinguished from mature blood cells by their lack of lineage-specific markers and presence of certain other cell-surface antigens,such as CD133 (for human cells) and c-kit and Sca-1 (for murine cells). Functional analyses of purified subpopulations of primitive hematopoietic cells have led to the development of several procedures for isolating cell populations that are highly enriched in cells with in vivo stem cell activity. Simplified methods for obtaining these cells at high yield have been important to the practical exploitation of such advances. This article reviews recent progress in identifying human and mouse HSCs and current techniques for their purification.
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产品类型：
产品号#：
18056
18056RF
产品名：
Hidalgo A et al. (JAN 2005)
Blood 105 2 567--75
Enforced fucosylation of neonatal CD34+ cells generates selectin ligands that enhance the initial interactions with microvessels but not homing to bone marrow.
Hematopoietic progenitor/stem cell homing to the bone marrow requires the concerted action of several adhesion molecules. Endothelial P- and E-selectins play an important role in this process,but their ligands on a large subset of neonate-derived human CD34+ cells are absent,leading to a reduced ability to interact with the bone marrow (BM) microvasculature. We report here that this deficiency results from reduced alpha1,3-fucosyltransferase (FucT) expression and activity in these CD34+ cells. Incubation of CD34+ cells with recombinant human FucTVI rapidly corrected the deficiency in nonbinding CD34+ cells and further increased the density of ligands for both P- and E-selectins on all cord blood-derived CD34+ cells. Intravital microscopy studies revealed that these FucTVI-treated CD34+ cells displayed a marked enhancement in their initial interactions with the BM microvasculature,but unexpectedly,homing into the BM was not improved by FucTVI treatment. These data indicate that,although exogenous FucT enzyme activity can rapidly modulate selectin binding avidity of cord blood CD34+ cells,further studies are needed to understand how to translate a positive effect on progenitor cell adhesion in bone marrow microvessels into one that significantly influences migration and lodgement into the parenchyma.
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EasySep™小鼠TIL（CD45）正选试剂盒
技术公告Endothelial Protein C Receptor (EPCR): A New Marker for Identification and Positive Selection of Mouse Hematopoietic Stem Cells
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