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

PURPOSE Imatinib,the breakpoint cluster region protein (BCR)/Abelson murine leukemia viral oncogene homolog (ABL) inhibitor,is widely used to treat chronic myeloid leukemia (CML). However,imatinib resistance develops in many patients. Therefore,new drugs with improved therapeutic effects are urgently needed. Berberine (BBR) is a potent BCR-ABL inhibitor for imatinib-sensitive and -resistant CML. EXPERIMENTAL DESIGN Protein structure analysis and virtual screening were used to identify BBR targets in CML. Molecular docking analysis,surface plasmon resonance imaging,nuclear magnetic resonance assays,and thermoshift assays were performed to confirm the BBR target. The change in BCR-ABL protein expression after BBR treatment was assessed by Western blotting. The effects of BBR were assessed in vitro in cell lines,in vivo in mice,and in human CML bone marrow cells as a potential strategy to overcome imatinib resistance. RESULTS We discovered that BBR bound to the protein tyrosine kinase domain of BCR-ABL. BBR inhibited the activity of BCR-ABL and BCR-ABL with the T315I mutation,and it also degraded these proteins via the autophagic lysosome pathway by recruiting E3 ubiquitin-protein ligase LRSAM1. BBR inhibited the cell viability and colony formation of CML cells and prolonged survival in CML mouse models with imatinib sensitivity and resistance. CONCLUSIONS The results show that BBR directly binds to and degrades BCR-ABL and BCR-ABL T315I via the autophagic lysosome pathway by recruiting LRSAM1. The use of BBR is a new strategy to improve the treatment of patients with CML with imatinib sensitivity or resistance. View Publication

Cell fate can be reprogrammed by modifying intrinsic and extrinsic cues. Here we show that two small molecules (forskolin and dorsomorphin) enable the transcription factor Neurogenin 2 (NGN2) to convert human fetal lung fibroblasts into cholinergic neurons with high purity (textgreater90%) and efficiency (up to 99% of NGN2-expressing cells). The conversion is direct without passing through a proliferative progenitor state. These human induced cholinergic neurons (hiCN) show mature electrophysiological properties and exhibit motor neuron-like features,including morphology,gene expression and the formation of functional neuromuscular junctions. Inclusion of an additional transcription factor,SOX11,also efficiently converts postnatal and adult skin fibroblasts from healthy and diseased human patients to cholinergic neurons. Taken together,this study identifies a simple and highly efficient strategy for reprogramming human fibroblasts to subtype-specific neurons. These findings offer a unique venue for investigating the molecular mechanisms underlying cellular plasticity and human neurodegenerative diseases. View Publication

Leukemic stem cells (LSCs) are considered a major cause of relapse in acute myeloid leukemia (AML). Defining pathways that control LSC self-renewal is crucial for a better understanding of underlying mechanisms and for the development of targeted therapies. However,currently available culture conditions do not prevent spontaneous differentiation of LSCs,which greatly limits the feasibility of cell-based assays. To overcome these constraints we conducted a high-throughput chemical screen and identified small molecules that inhibit differentiation and support LSC activity in vitro. Similar to reports with cord blood stem cells,several of these compounds suppressed the aryl-hydrocarbon receptor (AhR) pathway,which we show to be inactive in vivo and rapidly activated ex vivo in AML cells. We also identified a compound,UM729,that collaborates with AhR suppressors in preventing AML cell differentiation. Together,these findings provide newly defined culture conditions for improved ex vivo culture of primary human AML cells. View Publication

Ligation of erythropoietin (EPO) receptor (EPOR) JAK2 kinase complexes propagates signals within erythroid progenitor cells (EPCs) that are essential for red blood cell production. To reveal hypothesized novel EPOR/JAK2 targets,a phosphotyrosine (PY) phosphoproteomics approach was applied. Beyond known signal transduction factors,32 new targets of EPO-modulated tyrosine phosphorylation were defined. Molecular adaptors comprised one major set including growth factor receptor-bound protein 2 (GRB2)-associated binding proteins 1-3 (GAB1-3),insulin receptor substrate 2 (IRS2),docking protein 1 (DOK1),Src homology 2 domain containing transforming protein 1 (SHC1),and sprouty homologue 1 (SPRY1) as validating targets,and SPRY2,SH2 domain containing 2A (SH2D2A),and signal transducing adaptor molecule 2 (STAM2) as novel candidate adaptors together with an ORF factor designated as regulator of human erythroid cell expansion (RHEX). RHEX is well conserved in Homo sapiens and primates but absent from mouse,rat,and lower vertebrate genomes. Among tissues and lineages,RHEX was elevated in EPCs,occurred as a plasma membrane protein,was rapidly PY-phosphorylated textgreater20-fold upon EPO exposure,and coimmunoprecipitated with the EPOR. In UT7epo cells,knockdown of RHEX inhibited EPO-dependent growth. This was associated with extracellular signal-regulated kinase 1,2 (ERK1,2) modulation,and RHEX coupling to GRB2. In primary human EPCs,shRNA knockdown studies confirmed RHEX regulation of erythroid progenitor expansion and further revealed roles in promoting the formation of hemoglobinizing erythroblasts. RHEX therefore comprises a new EPO/EPOR target and regulator of human erythroid cell expansion that additionally acts to support late-stage erythroblast development. View Publication

Outgrowth,long-term self-renewal,and terminal maturation of human erythroid progenitors derived from umbilical cord blood in serum-free medium can be modulated by steroid hormones. Homogeneous erythroid cultures,as characterized by flow cytometry and dependence on a specific mixture of physiologic proliferation factors,were obtained within 8 days from a starting population of mature and immature mononuclear cells. Due to previous results in mouse and chicken erythroblasts,the proliferation-promoting effect of glucocorticoids was not unexpected. Surprisingly,however,androgen had a positive effect on the sustained expansion of human female but not male erythroid progenitors. Under optimal conditions,sustained proliferation of erythroid progenitors resulted in a more than 10(9)-fold expansion within 60 days. Terminal erythroid maturation was significantly improved by adding human serum and thyroid hormone (3,5,3'-triiodothyronine [T3]) to the differentiation medium. This resulted in highly synchronous differentiation of the cells toward enucleated erythrocytes within 6 days,accompanied by massive size decrease and hemoglobin accumulation to levels comparable to those in peripheral blood erythrocytes. Thus,obviously,different ligand-activated nuclear hormone receptors massively influence the decision between self-renewal and terminal maturation in the human erythroid compartment. View Publication

Cardiovascular disease is a leading cause of death worldwide. The limited capability of heart tissue to regenerate has prompted methodological developments for creating de novo cardiomyocytes,both in vitro and in vivo. Beyond uses in cell replacement therapy,patient-specific cardiomyocytes may find applications in drug testing,drug discovery,and disease modeling. Recently,approaches for generating cardiomyocytes have expanded to encompass three major sources of starting cells: human pluripotent stem cells (hPSCs),adult heart-derived cardiac progenitor cells (CPCs),and reprogrammed fibroblasts. We discuss state-of-the-art methods for generating de novo cardiomyocytes from hPSCs and reprogrammed fibroblasts,highlighting potential applications and future challenges. View Publication

Pluripotent stem cell-derived cardiomyocyte grafts can remuscularize substantial amounts of infarcted myocardium and beat in synchrony with the heart,but in some settings cause ventricular arrhythmias. It is unknown whether human cardiomyocytes can restore cardiac function in a physiologically relevant large animal model. Here we show that transplantation of ∼750 million cryopreserved human embryonic stem cell-derived cardiomyocytes (hESC-CMs) enhances cardiac function in macaque monkeys with large myocardial infarctions. One month after hESC-CM transplantation,global left ventricular ejection fraction improved 10.6 ± 0.9{\%} vs. 2.5 ± 0.8{\%} in controls,and by 3 months there was an additional 12.4{\%} improvement in treated vs. a 3.5{\%} decline in controls. Grafts averaged 11.6{\%} of infarct size,formed electromechanical junctions with the host heart,and by 3 months contained ∼99{\%} ventricular myocytes. A subset of animals experienced graft-associated ventricular arrhythmias,shown by electrical mapping to originate from a point-source acting as an ectopic pacemaker. Our data demonstrate that remuscularization of the infarcted macaque heart with human myocardium provides durable improvement in left ventricular function. View Publication

Human-pluripotent-stem-cell-derived kidney cells (hPSC-KCs) have important potential for disease modelling and regeneration. Whether the hPSC-KCs can reconstitute tissue-specific phenotypes is currently unknown. Here we show that hPSC-KCs self-organize into kidney organoids that functionally recapitulate tissue-specific epithelial physiology,including disease phenotypes after genome editing. In three-dimensional cultures,epiblast-stage hPSCs form spheroids surrounding hollow,amniotic-like cavities. GSK3β inhibition differentiates spheroids into segmented,nephron-like kidney organoids containing cell populations with characteristics of proximal tubules,podocytes and endothelium. Tubules accumulate dextran and methotrexate transport cargoes,and express kidney injury molecule-1 after nephrotoxic chemical injury. CRISPR/Cas9 knockout of podocalyxin causes junctional organization defects in podocyte-like cells. Knockout of the polycystic kidney disease genes PKD1 or PKD2 induces cyst formation from kidney tubules. All of these functional phenotypes are distinct from effects in epiblast spheroids,indicating that they are tissue specific. Our findings establish a reproducible,versatile three-dimensional framework for human epithelial disease modelling and regenerative medicine applications. View Publication

Human neocortex expansion likely contributed to the remarkable cognitive abilities of humans. This expansion is thought to primarily reflect differences in proliferation versus differentiation of neural progenitors during cortical development. Here,we have searched for such differences by analysing cerebral organoids from human and chimpanzees using immunohistochemistry,live imaging,and single-cell transcriptomics. We find that the cytoarchitecture,cell type composition,and neurogenic gene expression programs of humans and chimpanzees are remarkably similar. Notably,however,live imaging of apical progenitor mitosis uncovered a lengthening of prometaphase-metaphase in humans compared to chimpanzees that is specific to proliferating progenitors and not observed in non-neural cells. Consistent with this,the small set of genes more highly expressed in human apical progenitors points to increased proliferative capacity,and the proportion of neurogenic basal progenitors is lower in humans. These subtle differences in cortical progenitors between humans and chimpanzees may have consequences for human neocortex evolution. View Publication

Background: Human cytomegalovirus (CMV) is a major pathogen that poses significant risks to immunocompromised individuals and neonates. The tegument protein pp71,encoded by the UL82 gene,plays a pivotal role in initiating viral lytic replication and evading host immune responses. Despite its clinical relevance,standardized monoclonal antibodies (mAbs) for pp71 remain limited,prompting the need to expand the available repertoire of antibodies targeting this critical protein. Methods: In this study,we constructed a diverse human single-chain variable fragment (scFv) library using RNA derived from the B cells of four healthy donors. The library was expressed in Saccharomyces cerevisiae,and iterative rounds of magnetic-activated cell sorting (MACS) were performed against recombinant pp71. Clonal enrichment was monitored using flow cytometry. Results: Among the isolated clones,one designated ID2 exhibited high sensitivity and specificity for pp71,as demonstrated by flow cytometry,immunofluorescence,an enzyme-linked immunosorbent assay (ELISA),and biolayer interferometry (BLI). Conclusions: Collectively,these findings establish a novel pp71-specific mAb and underscore the utility of yeast surface display combined with MACS for expanding the antibody toolkit available for CMV research and diagnostics. View Publication

Syngeneic mouse tumor models have shown that senescence influences the tumor immune response in multiple ways,including the induction of an immunosuppressive microenvironment or the promotion of immune cell recruitment. Yet,the impact of senescence on the tumor immune response in a humanized setting remains largely unexplored. MethodsTo address this question,we employed a combination cells co-culture models,tumor spheroids and mice bearing tumors immunogenic to human immune cells derived from the same donor. Results: We found that senescent fibroblasts exert a dual effect by enhancing the recruitment of immune cells into the tumor microenvironment while simultaneously promoting the apoptosis of T and NK cells. Mechanistically,we demonstrate that this apoptosis is primarily due to increased Fas ligand (FasL) expression on the surface of senescent fibroblasts. Increased FasL expression was observed on different human fibroblast cell lines in response to different senescence inducers with a particular robust effect in response to RAS-induced senescence. Deletion of FasL on fibroblasts was sufficient to prevent immune cell death and increase tumor cell killing in mice. Discussion: Our results identified the expression of FasL expression as a novel component of the senescent tumor microenvironment and highlight the importance of evaluating the impact of therapy-induced senescence in humanized models to understand and predict the outcome of cancer treatments. View Publication