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

CD154 (CD40 ligand) expression on CD4 T cells is normally tightly controlled,but abnormal or dysregulated expression of CD154 has been well documented in autoimmune diseases,such as systemic lupus erythematosus. Beyond regulation by NFAT proteins,little is known about the transcriptional activation of the CD154 promoter. We identified a species-conserved purine-rich sequence located adjacent to the CD154 transcriptional promoter proximal NFAT site,which binds early growth response (Egr) transcription factors. Gel shift assays and chromatin immunoprecipitation assays reveal that Egr-1,Egr-3,and NFAT1 present in primary human CD4 T cells are capable of binding this combinatorial site in vitro and in vivo,respectively. Multimerization of this NFAT/Egr sequence in the context of a reporter gene demonstrates this sequence is transcriptionally active upon T cell activation in primary human CD4 T cells. Overexpression of Egr-1,but not Egr-3,is capable of augmenting transcription of this reporter gene as well as that of an intact CD154 promoter. Conversely,overexpression of small interfering RNA specific for Egr-1 in primary human CD4 T cells inhibits CD154 expression. Similarly,upon activation,CD154 message is notably decreased in splenic CD4 T cells from Egr-1-deficient mice compared with wild-type controls. Our data demonstrate that Egr-1 is required for CD154 transcription in primary CD4 T cells. This has implications for selective targeting of Egr family members to control abnormal expression of CD154 in autoimmune diseases such as systemic lupus erythematosus. View Publication

Tristetraprolin (TTP,Zfp36,Nup475,Tis11) dramatically reduces the stability of target mRNAs by binding to AU-rich elements in their 3' untranslated regions. Through this mechanism,TTP functions as a rheostatic,temporal regulator of gene expression. TTP knockout (KO) mice exhibit completely penetrant granulocytic hyperplasia. We have shown that the hematopoietic stem-progenitor cell compartment in TTP KO mice is also altered. Although no change was detected in long-term hematopoietic stem cell (HSC) frequency or function,as assayed by immunophenotypic markers or limiting dilution transplants,we observed increases in the frequencies and numbers of short-term HSCs,multipotent progenitors,and granulocyte-monocyte progenitors. This pattern is consistent with reactive granulopoiesis� View Publication

Cancer-associated IDH mutations are characterized by neomorphic enzyme activity and resultant 2-hydroxyglutarate (2HG) production. Mutational and epigenetic profiling of a large acute myeloid leukemia (AML) patient cohort revealed that IDH1/2-mutant AMLs display global DNA hypermethylation and a specific hypermethylation signature. Furthermore,expression of 2HG-producing IDH alleles in cells induced global DNA hypermethylation. In the AML cohort,IDH1/2 mutations were mutually exclusive with mutations in the α-ketoglutarate-dependent enzyme TET2,and TET2 loss-of-function mutations were associated with similar epigenetic defects as IDH1/2 mutants. Consistent with these genetic and epigenetic data,expression of IDH mutants impaired TET2 catalytic function in cells. Finally,either expression of mutant IDH1/2 or Tet2 depletion impaired hematopoietic differentiation and increased stem/progenitor cell marker expression,suggesting a shared proleukemogenic effect. View Publication

OVERVIEW: All current antipsychotic medications work by binding to Gi-coupled dopamine (DA) D2 receptors. Such medications are thought to affect cellular function primarily by decreasing DA-mediated regulation of intracellular cyclic adenosine monophosphate (cAMP).However,several studies indicate that cAMP signal transduction abnormalities in schizophrenia may not be limited to D2-containing cells. The current study examines the potential of using non-receptor-based agents that modify intracellular signal transduction as potential antipsychotic medications. METHODS: The indirect DA agonist amphetamine has been used to model the auditory sensory processing deficits in schizophrenia. Such pharmacologically induced abnormalities are reversed by current antipsychotic treatments. This study examines the ability of the phosphodiesterase-4 inhibitor,rolipram,to reverse amphetamine-induced abnormalities in auditory-evoked potentials that are characteristic of schizophrenia. RESULTS: Rolipram reverses amphetamine-induced reductions in auditory-evoked potentials. CONCLUSION: This finding could lead to novel approaches to receptor-independent treatments for schizophrenia. View Publication

Small-molecule inhibitors of the serine dipeptidases DPP8 and DPP9 (DPP8/9) induce a lytic form of cell death called pyroptosis in mouse and human monocytes and macrophages1,2. In mouse myeloid cells,Dpp8/9 inhibition activates the inflammasome sensor Nlrp1b,which in turn activates pro-caspase-1 to mediate cell death3,but the mechanism of DPP8/9 inhibitor-induced pyroptosis in human myeloid cells is not yet known. Here we show that the CARD-containing protein CARD8 mediates DPP8/9 inhibitor-induced pro-caspase-1-dependent pyroptosis in human myeloid cells. We further show that DPP8/9 inhibitors induce pyroptosis in the majority of human acute myeloid leukemia (AML) cell lines and primary AML samples,but not in cells from many other lineages,and that these inhibitors inhibit human AML progression in mouse models. Overall,this work identifies an activator of CARD8 in human cells and indicates that its activation by small-molecule DPP8/9 inhibitors represents a new potential therapeutic strategy for AML. View Publication

New small molecules that regulate the step-wise differentiation of human pluripotent stem cells into dopaminergic neurons have been identified. The steroid,guggulsterone,was found to be the most effective inducer of neural stem cells into dopaminergic neurons. These neurons are extensively characterized and shown to be functional. We believe this new approach offers a practical route to creating neurons of sufficient quality to be used to treat Parkinson's disease patients. View Publication

The complete array of genes required for terminal erythroid differentiation remains unknown. To address this knowledge gap,we perform a genome-scale CRISPR knock-out screen in the human erythroid progenitor cell line HUDEP-2 and validate candidate regulators of erythroid differentiation in a custom secondary screen. Comparison of sgRNA abundance in the CRISPR library,proerythroblasts,and orthochromatic erythroblasts,resulted in the identification of genes that are essential for proerythroblast survival and genes that are required for terminal erythroid differentiation. Among the top genes identified are known regulators of erythropoiesis,underscoring the validity of this screen. Notably,using a Log2 fold change of <−1 and false discovery rate of <0.01,the screen identified 277 genes that are required for terminal erythroid differentiation,including multiple genes not previously nominated through GWAS. NHLRC2,which was previously implicated in hemolytic anemia,was a highly ranked gene. We suggest that anemia due to NHLRC2 mutation results at least in part from a defect in erythroid differentiation. Another highly ranked gene in the screen is VAC14,which we validated for its requirement in erythropoiesis in vitro and in vivo. Thus,data from this CRISPR screen may help classify the underlying mechanisms that contribute to erythroid disorders. Subject terms: Erythropoiesis,CRISPR-Cas9 genome editing,Haematopoietic stem cells View Publication

Throughout its history,chronic myeloid leukemia (CML) has set precedents for cancer research and therapy. These range from the identification of the first specific chromosomal abnormality associated with cancer to the development of imatinib as a specific,targeted therapy for the disease. The successful development of imatinib as a therapeutic agent for CML can be attributed directly to decades of scientific discoveries. These discoveries determined that the BCR-ABL tyrosine kinase is the critical pathogenetic event in CML and an ideal target for therapy. This was confirmed in clinical trials of imatinib,with imatinib significantly improving the long-term survival of patients with CML. Continuing in this tradition of scientific discoveries leading to improved therapies,the understanding of resistance to imatinib has rapidly led to strategies to circumvent resistance. Continued studies of hematologic malignancies will allow this paradigm of targeting molecular pathogenetic events to be applied to many additional hematologic cancers. View Publication

More recently,reprogramming of somatic cells to an embryonic stem cell-like state presents a milestone in the realm of stem cells,making it possible to derive all cell types from any patients bearing specific genetic mutations. With the development of induced pluripotent stem (iPS) cells,we are now able to use the derivatives of iPS cells to study the mechanisms of disease and to perform drug screening and toxicology testing. In addition,differentiated iPS cells are now close to be used in clinical practice. Here we review the progress of iPS technique and the possible application in the area of Parkinson's disease treatment. View Publication