搜索结果: 'methocult media formulations for mouse hematopoietic cells serum containing'

The human ATP-binding cassette superfamily G (White) member 2 (ABCG2) gene and its murine homologue breast cancer resistance protein 1 (Bcrp1) are recently described ATP-binding cassette transporters associated with drug resistance in tumor cell lines,including the MCF-7 cell line,selected for its resistance to mitoxantrone (MCF-7/MitoR). Infection of MCF-7 cells with the retroviral vector containing ABCG2 cDNA (G1-ABCG2) resulted in cells (MCF-7/ABCG2) that were resistant to mitoxantrone at levels similar to those observed in MCF-7/MitoR cells. Previous studies have shown that pluripotent hematopoietic stem cells overexpress the multidrug-resistant transport (MDR1) gene and efflux rhodamine,a substrate for the MDR1 transporter. Other studies have identified a primitive hematopoietic stem cell population,or side population (SP) cells,which are identified by their efflux of the fluorescent dye,Hoechst 33342. In an attempt to identify the transport genes responsible for this phenotype,we examined the uptake of Hoechst 33342 into MCF-7,MCF-7/MitoR,and MCF-7 cells infected with a retroviral vector expressing the ABCG2 gene (MCF-7/ABCG2). MCF-7/MitoR cells as well as MCF-7/ABCG2 cells demonstrated lower levels of Hoechst 33342 uptake compared with the parental MCF-7 cells. We also examined the level of the mouse Bcrp1 RNA in SP cells and non-SP cells isolated from mouse hematopoietic cells. Mouse SP cells expressed relatively high levels of Bcrp1 mRNA relative to non-SP cells. These results suggest that Hoechst 33342 is a substrate for the ABCG2 transporter and that ABCG2/Bcrp1 expression may serve as a marker for hematopoietic stem cells in hematopoietic cells. View Publication

Hematopoietic stem cells (HSCs) are the basis of bone marrow transplantation and are attractive target cells for hematopoietic gene therapy,but these important clinical applications have been severely hampered by difficulties in ex vivo expansion of HSCs. In particular,the use of cord blood for adult transplantation is greatly limited by the number of HSCs. Previously we identified angiopoietin-like proteins and IGF-binding protein 2 (IGFBP2) as new hormones that,together with other factors,can expand mouse bone marrow HSCs in culture. Here,we measure the activity of multipotent human severe combined immunodeficient (SCID)-repopulating cells (SRCs) by transplantation into the nonobese diabetic SCID (NOD/SCID) mice; secondary transplantation was performed to evaluate the self-renewal potential of SRCs. A serum-free medium containing SCF,TPO,and FGF-1 or Flt3-L cannot significantly support expansion of the SRCs present in human cord blood CD133+ cells. Addition of either angiopoietin-like 5 or IGF-binding protein 2 to the cultures led to a sizable expansion of HSC numbers,as assayed by NOD/SCID transplantation. A serum-free culture containing SCF,TPO,FGF-1,angiopoietin-like 5,and IGFBP2 supports an approximately 20-fold net expansion of repopulating human cord blood HSCs,a number potentially applicable to several clinical processes including HSC transplantation. View Publication

The anti-My-10 mouse monoclonal antibody was raised against the immature human myeloid cell line KG-1a and was selected for nonreactivity with mature human granulocytes. Anti-My-10 immunoprecipitated a KG-1a cell surface protein with an apparent Mr of approximately 115 kD. We describe the binding of this antibody to human hematopoietic cell types and show that My-10 is expressed specifically on immature normal human marrow cells,including hematopoietic progenitor cells. My-10 is also expressed by leukemic marrow cells from a subpopulation of patients. Thus,this antibody allows the identification and purification of hematopoietic progenitor cells from normal human marrow and the subclassification of leukemia. View Publication

Hematotoxicity is a significant issue for drug safety and can result from direct cytotoxicity toward circulating mature blood cell types as well as targeting of immature blood-forming stem cells/progenitor cells in the bone marrow. In vitro models for understanding and investigating the hematotoxicity potential of new test items/drugs are critical in early preclinical drug development. The traditional method,colony forming unit (CFU) assay,is commonly used and has been validated as a method for hematotoxicity screening. The CFU assay has multiple limitations for its application in investigative work. In this paper,we describe a detailed protocol for a liquid-culture,microplate-based in vitro hematotoxicity assay to evaluate lineage-specific (myeloid,erythroid,and megakaryocytic) hematotoxicity at different stages of differentiation. This assay has multiple advantages over the traditional CFU assay,including being suitable for high-throughput screening and flexible enough to allow inclusion of additional endpoints for mechanistic studies. Therefore,it is an extremely useful tool for scientists in pharmaceutical discovery and development. {\textcopyright} 2018 by John Wiley & Sons,Inc. View Publication

Ex vivo activation is a prerequisite to reaching adequate levels of gene editing by homology-directed repair (HDR) for hematopoietic stem and progenitor cell (HSPC)-based clinical applications. Here,we show that shortening culture time mitigates the p53-mediated DNA damage response to CRISPR-Cas9-induced DNA double-strand breaks,enhancing the reconstitution capacity of edited HSPCs. However,this results in lower HDR efficiency,rendering ex vivo culture necessary yet detrimental. Mechanistically,ex vivo activation triggers a multi-step process initiated by p38 mitogen-activated protein kinase (MAPK) phosphorylation,which generates mitogenic reactive oxygen species (ROS),promoting fast cell-cycle progression and subsequent proliferation-induced DNA damage. Thus,p38 inhibition before gene editing delays G1/S transition and expands transcriptionally defined HSCs,ultimately endowing edited cells with superior multi-lineage differentiation,persistence throughout serial transplantation,enhanced polyclonal repertoire,and better-preserved genome integrity. Our data identify proliferative stress as a driver of HSPC dysfunction with fundamental implications for designing more effective and safer gene correction strategies for clinical applications. View Publication

MicroRNAs (miRNA) are small noncoding RNAs that regulate gene expression by targeting mRNAs in a sequence specific manner,thereby determining their degradation or inhibiting translation. They are involved in processes such as proliferation,differentiation and apoptosis by fine-tuning the expression of genes underlying such events. The expression of specific miRNAs is involved in hematopoietic differentiation and their deregulation contributes to the development of hematopoietic malignancies such as acute myeloid leukemia (AML). miR-130a is over-expressed in AML. Here we show that miR-130a is physiologically expressed in myeloblasts and down-regulated during monocyte differentiation. Gain- and loss-of-function experiments performed on CD34+ human hematopoietic stem cells confirmed that expression of miR-130a inhibits monocyte differentiation by interfering with the expression of key transcription factors HOXA10,IRF8,KLF4,MAFB and PU-1. The data obtained in this study highlight that the correct modulation of miR-130a is necessary for normal differentiation to occur and confirming that deregulation of this miRNA might underlie the differentiation block occurring in AML. View Publication

Plasmacytoid dendritic cells (pDCs) are multifunctional immune cells with roles in both the innate and adaptive immune system. Their hallmark function is production of large amounts of type I interferons in response to viral infections,but they are also capable of producing a range of other cytokines,antigen presentation,and cytotoxicity. Their potential as an immunotherapy for cancer and infectious disease is being explored,but broad application of these cells is challenged by low frequency in the blood and low viability during ex vivo culturing. We have previously developed an effective in vitro differentiation protocol for producing pDCs from CD34+ hematopoietic stem and progenitor cells (HSPC-pDCs),which provides an attainable and large source of pDCs. HSPC-pDCs present pDC characteristics and functions,and like naturally occurring pDCs they exhibit large phenotypic and functional heterogeneity. Here,we characterize different cell subsets from in vitro pDC differentiation and identify a distinct population,which is the major producer of IFNα in response to TLR9 stimulation and display a transcriptomic profile similar to what is seen for pDCs circulating in the blood. We also investigate the possibility of rerouting subset specification during HSPCs-to-pDC differentiation by controlling gene expression of key master transcription factors (TFs). We identify TFs associated with the pDC differentiation trajectory that are essential for the development of TLR9-responsive HSPC-pDCs,and we also identify TFs that increase their frequency. In conclusion,we phenotypically and functionally characterize different cell subsets and modulate their relative frequencies by manipulating TF expression during pDC differentiation. These findings provide a deeper understanding of in vitro-differentiated pDC cultures that may spur further developments in their use as an immunomodulatory cell therapy. View Publication

Alzheimer's disease (AD) involves the progressive degeneration of neurons critical for learning and memory. In addition,patients with AD typically exhibit impaired olfaction associated with neuronal degeneration in the olfactory bulb (OB). Because DNA base excision repair (BER) is reduced in brain cells during normal aging and AD,we determined whether inefficient BER due to reduced DNA polymerase-β (Polβ) levels renders OB neurons vulnerable to degeneration in the 3xTgAD mouse model of AD. We interrogated OB histopathology and olfactory function in wild-type and 3xTgAD mice with normal or reduced Polβ levels. Compared to wild-type control mice,Polβ heterozygous (Polβ+/- ),and 3xTgAD mice,3xTgAD/Polβ+/- mice exhibited impaired performance in a buried food test of olfaction. Polβ deficiency did not affect the proliferation of OB neural progenitor cells in the subventricular zone. However,numbers of newly generated neurons were reduced by approximately 25% in Polβ+/- and 3xTgAD mice,and by over 60% in the 3xTgAD/Polβ+/- mice compared to wild-type control mice. Analyses of DNA damage and apoptosis revealed significantly greater degeneration of OB neurons in 3xTgAD/Polβ+/- mice compared to 3xTgAD mice. Levels of amyloid β-peptide (Aβ) accumulation in the OB were similar in 3xTgAD and 3xTgAD/Polβ+/- mice,and cultured Polβ-deficient neurons exhibited increased vulnerability to Aβ-induced death. Olfactory deficit is an early sign in human AD,but the mechanism is not yet understood. Our findings in a new AD mouse model demonstrate that diminution of BER can endanger OB neurons,and suggest a mechanism underlying early olfactory impairment in AD. View Publication

IntroductionImmune cells that contribute to the pathogenesis of systemic lupus erythematosus (SLE) derive from adult hematopoietic stem and progenitor cells (HSPCs) within the bone marrow (BM). For this reason,we reasoned that fundamental abnormalities in SLE can be traced to a BM-derived HSPC inflammatory signature.MethodsBM samples from four SLE patients,six healthy controls,and two umbilical cord blood (CB) samples were used. CD34+ cells were isolated from BM and CB samples,and single-cell RNA-sequencing was performed.ResultsA total of 426 cells and 24,473 genes were used in the analysis. Clustering analysis resulted in seven distinct clusters of cell types. Mutually exclusive markers,which were characteristic of each cell type,were identified. We identified three HSPC subpopulations,one of which consisted of proliferating cells (MKI67 expressing cells),one T-like,one B-like,and two myeloid-like progenitor subpopulations. Differential expression analysis revealed i) cell cycle-associated signatures,in healthy BM of HSPC clusters 3 and 4 when compared with CB,and ii) interferon (IFN) signatures in SLE BM of HSPC clusters 3 and 4 and myeloid-like progenitor cluster 5 when compared with healthy controls. The IFN signature in SLE appeared to be deregulated following TF regulatory network analysis and differential alternative splicing analysis between SLE and healthy controls in HSPC subpopulations.DiscussionThis study revealed both quantitative—as evidenced by decreased numbers of non-proliferating early progenitors—and qualitative differences—characterized by an IFN signature in SLE,which is known to drive loss of function and depletion of HSPCs. Chronic IFN exposure affects early hematopoietic progenitors in SLE,which may account for the immune aberrancies and the cytopenias in SLE. View Publication

BACKGROUND: Circulating tumor cells (CTCs) in the peripheral blood of breast cancer patients may be an important indicator of metastatic disease and poor prognosis. However,the use of experimental models is required to fully elucidate the functional consequences of CTCs. The purpose of this study was to optimize the sensitivity of multiparameter flow cytometry for detection of human tumor cells in mouse models of breast cancer. METHODS: MDA-MB-468 human breast cancer cells were serially diluted in whole mouse blood. Samples were lysed and incubated with a fluorescein isothiocyanate-conjugated anti-human leukocytic antigen antibody and a phycoerythrin-conjugated anti-mouse pan-leukocyte CD45 antibody. Samples were then immunomagnetically depleted of CD45-positive leukocytes,fixed,permeabilized,and stained with propidium iodide before flow cytometric analysis. RESULTS: Human breast cancer cells could be differentiated from mouse leukocytes based on increased light scatter,cell surface marker expression,and aneuploid DNA content. The method was found to have a lower sensitivity limit of 10(-5) and was effective for detecting human breast cancer cells in vivo in the circulation of experimental mice carrying primary human mammary tumors. CONCLUSIONS: This technique has the potential to be a valuable and sensitive tool for investigating the biological relevance of CTCs in experimental mouse models of breast cancer. View Publication

Acute inflammatory bowel disease (AIBD) is a wide clinical entity including severe gastrointestinal pathologies with common histopathological basis. Epidemiologically increasing diseases,such as necrotizing enterocolitis (NEC),gastrointestinal graft versus host disease (GVHD),and the primary acute phase of chronic inflammatory bowel disease (CIBD),exhibit a high necessity for new therapeutic strategies. Mesenchymal stem cell (MSC) cellular therapy represents a promising option for the treatment of these diseases. In our study,we comparatively assess the efficacy of human MSCs derived from bone marrow (BM),umbilical cord blood (UCB),human embryonic stem cells (ESCs),or human-induced pluripotent stem cells (iPSCs) in a mouse model of chemically induced acute enterocolitis. The laboratory animals were provided ad libitum potable dextrane sulfate sodium solution (DSS) in order to reproduce an AIBD model and then individually exposed intraperitoneally to MSCs derived from BM (BM-MSCs),UCB (UCB-MSCs),ESCs (ESC-MSCs),or iPSCs (iPSC-MSCs). The parameters used to evaluate the cellular treatment efficacy were the animal survival prolongation and the histopathological-macroscopic picture of bowel sections. Although all categories of mesenchymal stem cells led to statistically significant survival prolongation compared to the control group,significant clinical and histopathological improvement was observed only in mice receiving BM-MSCs and UCB-MSCs. Our results demonstrated that the in vivo anti-inflammatory effect of ESC-MSCs and iPSC-MSCs was inferior to that of UCB-MSCs and BM-MSCs. Further investigation will clarify the potential of ESCs and iPSC-derived MSCs in AIBD treatment. View Publication

BACKGROUND: Persistent mixed chimerism represents a state in which recipient and donor cells stably co-exist after hematopoietic stem cell transplantation. However,since in most of the studies reported in literature the engraftment state was observed in the nucleated cells,in this study we determined the donor origin of the mature erythrocytes of patients with persistent mixed chimerism after transplantation for hemoglobinopathies. Results were compared with the engraftment state observed in singly picked out burst-forming unit - erythroid colonies and in the nucleated cells collected from the peripheral blood and from the bone marrow. DESIGN AND METHODS: The donor origin of the erythrocytes was determined analyzing differences on the surface antigens of the erythrocyte suspension after incubation with anti-ABO and/or anti-C,-c,-D,-E and -e monoclonal antibodies by a flow cytometer. Analysis of short tandem repeats was used to determine the donor origin of nucleated cells and burst-forming unit - erythroid colonies singly picked out after 14 days of incubation. RESULTS: The proportions of donor-derived nucleated cells in four transplanted patients affected by hemoglobinopathies were 71%,46%,15% and 25% at day 1364,1385,1314 and 932,respectively. Similar results were obtained for the erythroid precursors,analyzing the donor/recipient origin of the burst-forming unit - erythroid colonies. In contrast,on the same days of observation,the proportions of donor-derived erythrocytes in the four patients with persistent mixed chimerism were 100%,100%,73% and 90%. Conclusions Our results showed that most of the erythrocytes present in four long-term transplanted patients affected by hemoglobinopathies and characterized by the presence of few donor engrafted nucleated cells were of donor origin. The indication that small proportions of donor engrafted cells might be sufficient for clinical control of the disease in patients affected by hemoglobinopathies is relevant,although the biological mechanisms underlying these observations need further investigation. View Publication