bluuebunny/crossref_metadata_2025_split huggingface dataset:
Single Adult Human CD34+/Lin−/CD38− Progenitors Give Rise to Natural Killer Cells, B-Lineage Cells, Dendritic Cells, and Myeloid Cells
Authors: Miller Jeffrey S. , McCullar Valarie , Punzel Michael , Lemischka Ihor R. , Moore Kateri A. 
Published: October 2019

AbstractMarrow stromal cultures support adult CD34+/Lin−/HLA-DR− or CD34+/Lin−/CD38− cell differentiation into natural killer (NK) or myeloid cells, but unlike committed lymphoid progenitors (CD34+/Lin−/CD45RA+/CD10+), no B cells are generated. We tested whether different microenvironments could establish a developmental link between the NK and B-cell lineages. Progenitors were cultured in limiting dilutions with interleukin-7 (IL-7), flt3 ligand (FL), c-kit ligand (KL), IL-3, IL-2, and AFT024, a murine fetal liver line, which supports culture of transplantable murine stem cells. NK cells, CD10+/CD19+ B-lineage cells and dendritic cells (DC) developed from the same starting population and IL-7, FL, and KL were required in this process. Single cell deposition of 3,872 CD34+/Lin−/CD38− cells onto AFT024 with IL-7, FL, KL, IL-2, and IL-3 showed that a one time addition of IL-3 at culture initiation was essential for multilineage differentiation from single cells. Single and double lineage progeny were frequently detected, but more importantly, 2% of single cells could give rise to at least three lineages (NK cells, B-lineage cells, and DC or myeloid cells) providing direct evidence that NK and B-lineage differentiation derive from a common lymphomyeloid hematopoietic progenitor under the same conditions. This study provides new insights into the role of the microenvironment niche, which governs the earliest events in lymphoid development.
Overexpression of A1, an NF-κB–Inducible Anti-Apoptotic Bcl Gene, Inhibits Endothelial Cell Activation
Authors: Stroka Deborah M. , Badrichani Anne Z. , Bach Fritz H. , Ferran Christiane 
Published: October 2019

AbstractA1 is an anti-apoptotic bcl gene that is expressed in endothelial cells (EC) in response to pro-inflammatory stimuli. We show that in addition to protecting EC from apoptosis, A1 inhibits EC activation and its associated expression of pro-inflammatory proteins by inhibiting the transcription factor nuclear factor (NF)-κB. This new anti-inflammatory function gives a broader dimension to the protective role of A1 in EC. We also show that activation of NF-κB is essential for the expression of A1. Taken together, our data suggest that A1 downregulates not only the pro-apoptotic and pro-inflammatory response, but also its own expression, thus restoring a quiescent phenotype to EC.
Constitutive Activation of Extracellular Signal-Regulated Kinase in Human Acute Leukemias: Combined Role of Activation of MEK, Hyperexpression of Extracellular Signal-Regulated Kinase, and Downregulation of a Phosphatase, PAC1
Authors: Kim Seong-Cheol , Hahn Jee-Sook , Min Yoo-Hong , Yoo Nae-Choon , Ko Yun-Woong , Lee Won-Jae 
Published: October 2019

AbstractExtracellular signal-regulated kinase (ERK) is an important intermediate in signal transduction pathways that are initiated by many types of cell surface receptors. It is thought to play a pivotal role in integrating and transmitting transmembrane signals required for growth and differentiation. Constitutive activation of ERK in fibroblasts elicits oncogenic transformation, and recently, constitutive activation of ERK has been observed in some human malignancies, including acute leukemia. However, mechanisms underlying constitutive activation of ERK have not been well characterized. In this study, we examined the activation of ERK in 79 human acute leukemia samples and attempted to find factors contributing to constitutive ERK activation. First, we showed that ERK and MEK were constitutively activated in acute leukemias by in vitro kinase assay and immunoblot analysis. However, in only one half of the studied samples, the pattern of ERK activation was similar to that of MEK activation. Next, by semiquantitative reverse transcriptase-polymerase chain reaction (RT-PCR) and immunoblot analysis, we showed hyperexpression of ERK in a majority of acute leukemias. In 17 of 26 cases (65.4%) analyzed by immunoblot, the pattern of ERK expression was similar to that of ERK activation. The fact of constitutive activation of ERK in acute leukemias suggested to us the possibility of an abnormal downregulation mechanism of ERK. Therefore, we examined PAC1, a specific ERK phosphatase predominantly expressed in hematopoietic tissue and known to be upregulated at the transcription level in response to ERK activation. Interestingly, in our study, PAC1 gene expression in acute leukemias showing constitutive ERK activation was significantly lower than that in unstimulated, normal bone marrow (BM) samples showing minimal or no ERK activation (P = .002). Also, a significant correlation was observed between PAC1 downregulation and phosphorylation of ERK in acute leukemias (P= .002). Finally, by further analysis of 26 cases, we showed that a complementary role of MEK activation, ERK hyperexpression, and PAC1 downregulation could contribute to determining the constitutive activation of ERK in acute leukemia. Our results suggest that ERK is constitutively activated in a majority of acute leukemias, and in addition to the activation of MEK, the hyperexpression of ERK and downregulation of PAC1 also contribute to constitutive ERK activation in acute leukemias.
Alteration of Actin Organization by Jaspamide Inhibits Ruffling, but not Phagocytosis or Oxidative Burst, in HL-60 Cells and Human Monocytes
Authors: Fabian Ina , Halperin Drora , Lefter Smadar , Mittelman Leonid , Altstock Rom T. , Seaon Osnat , Tsarfaty Ilan 
Published: October 2019

AbstractJaspamide, a naturally occurring cyclic peptide isolated from the marine sponge Hemiastrella minor, has fungicidal and growth-inhibiting activities. Exposure of promyelocytic HL-60 cells and human monocytes to jaspamide induces a dramatic reorganization of actin from a typical fibrous network to focal aggregates. HL-60 cells exposed to 5 × 10−8 mol/L or 10−7 mol/L jaspamide exhibited a reduced proliferation rate. In addition, 10−7mol/L jaspamide induced maturation of HL-60 cells as indicated by the appearance of a lobulated nucleus in 55% ± 5% of the cells and immunophenotypic maturation of the leukemia cells (upregulation of CD16 and CD14 B antigens). Further characterization has shown that F-actin is aggregated both in HL-60 cells and in human monocytes exposed to 10−7 mol/L jaspamide. Well-spread cultured human monocytes contracted and adopted round shapes after treatment with jaspamide. Moreover, a dose-dependent increase in both total actin and de novo synthesized portions of the soluble actin was observed in jaspamide-treated HL-60 cells. Jaspamide treatment inhibits ruffling and intracellular movement in HL-60 cells and monocytes, but does not affect phagocytic activity or respiratory burst activity. The consequential effects of jaspamide-induced actin reorganization on ruffling, versus its negligible effect on phagocytosis and oxidative burst, may shed light on molecular mechanisms of actin involvement in these processes. Jaspamide disrupts the actin cytoskeleton of normal and malignant mammalian cells with no significant effect on phagocytic activity and may, therefore, be considered as a novel therapeutic agent.
Altered Multidrug Resistance Phenotype Caused by Anthracycline Analogues and Cytosine Arabinoside in Myeloid Leukemia
Authors: Hu Xiu F. , Slater Alison , Kantharidis Phillip , Rischin Danny , Juneja Surender , Rossi Ralph , Lee Grace , Parkin John D. , Zalcberg John R. 
Published: October 2019

AbstractThe expression of P-glycoprotein (Pgp) is often increased in acute myeloid leukemia (AML). However, little is known of the regulation of Pgp expression by cytotoxics in AML. We examined whether Pgp expression and function in leukemic blasts was altered after a short exposure to cytotoxics. Blasts were isolated from 19 patients with AML (15 patients) or chronic myeloid leukemia in blastic transformation (BT-CML, 4 patients). Pgp expression and function were analyzed by flow cytometric analysis of MRK 16 binding and Rhodamine 123 retention, respectively. At equitoxic concentrations, ex vivo exposure for 16 hours to the anthracyclines epirubicin (EPI), daunomycin (DAU), idarubicin (IDA), or MX2 or the nucleoside analogue cytosine arabinoside (AraC) differentially upregulated MDR1/Pgp expression in Pgp-negative and Pgp-positive blast cells. In Pgp-negative blasts, all four anthracyclines and AraC significantly increased Pgp expression (P = .01) and Pgp function (P = .03). In contrast, MX2, DAU, and AraC were the most potent in inducing Pgp expression and function in Pgp positive blasts (P &lt; .05). A good correlation between increased Pgp expression and function was observed in Pgp-negative (r = .90, P = .0001) and Pgp-positive blasts (r = .77,P = .0002). This increase in Pgp expression and function was inhibited by the addition of 1 μmol/L PSC 833 to blast cells at the time of their exposure to these cytotoxics. In 1 patient with AML, an increase in Pgp levels was observed in vivo at 4 and 16 hours after the administration of standard chemotherapy with DAU/AraC. Upregulation of Pgp expression was also demonstrated ex vivo in blasts harvested from this patient before the commencement of treatment. In 3 other cases (1 patient with AML and 2 with BT-CML) in which blasts were Pgp negative at the time of initial clinical presentation, serial samples at 1 to 5 months after chemotherapy showed the presence of Pgp-positive blasts. All 3 patients had refractory disease. Interestingly, in all 3 cases, upregulation of Pgp by cytotoxics was demonstrated ex vivo in blasts harvested at the time of presentation. These data suggest that upregulation of the MDR1 gene may represent a normal response of leukemic cells to cytotoxic stress and may contribute to clinical drug resistance.
Serum Hyaluronan in Patients With Multiple Myeloma: Correlation With Survival and Ig Concentration
Authors: Dahl Inger Marie S. , Turesson Ingemar , Holmberg Erik , Lilja Karin 
Published: October 2019

AbstractSerum from 386 myeloma patients were analyzed for serum hyaluronan (HYA) at diagnosis. Median age was 68 years (range, 32 to 87 years). The distribution of Ig classes was typical (58% IgG, 21% IgA, 1% IgD, and 20% light chain disease). The patients comprised 58% in stage III, 33% in stage II, and 9% in stage I. The majority (82%) had HYA values within an intermediate range (10 to 120 μg/L), 13% had high values (&gt;120 μg/L), and 5% had abnormally low values (0 to 9 μg/L). For the first time, a patient group with abnormally low HYA serum values is reported. An inverse correlation between survival and HYA serum level was found (P = .015). When tested separately, patients with abnormally low or high HYA values had significantly shorter median survival (21.1 and 19.7 months, respectively) than those with an intermediate HYA concentration (32.6 months; P = .005). Patients with abnormally low or high HYA levels had more advanced disease as judged by staging and biochemical markers. Interestingly, there was an inverse correlation between the HYA value and the M-component concentration in serum. Fifty percent of patients with abnormally low HYA values had IgA myelomas. In conclusion, the serum concentration of HYA may be of prognostic value in selected cases of multiple myeloma. Further studies will be performed to elucidate possible explanations for our findings, especially those related to the HYA cell surface binding proteins.
Differentiation in Culture of Murine Primitive Lymphohematopoietic Progenitors Toward T-Cell Lineage
Authors: Hirayama Fumiya , Aiba Yuichi , Ikebuchi Kenji , Sekiguchi Sadayoshi , Ogawa Makio 
Published: October 2019

AbstractEarlier, we described a stromal cell-free two-step clonal culture system in which murine primitive lymphohematopoietic progenitors produce myeloid and B-lymphoid lineage cells. In the same culture T-cell potential of the progenitors was maintained. We now report that, in addition to myeloid and B-lymphoid cells, putative T-cell progenitors are also produced in culture. Lineage-negative (Lin−) Ly-6A/E+ c-kit+ bone marrow cells from 5-fluorouracil–treated mice were cultured in methylcellulose in the presence of SF (Steel factor), interleukin (IL)-11, and IL-7, and the resulting primary colonies were picked and pooled. When injected into severe combined immune deficiency (scid) mice, the pooled cells reconstituted the T-cell compartment of the scid mice earlier than freshly prepared primitive marrow cells. This reconstitution activity of the pooled primary colony cells was enriched in the Ly-6A/E+ and FcγRII/III−/low cell fractions. Reverse transcriptase-polymerase chain reaction (RT-PCR) and DNA-PCR analyses showed that some of the primary colony cells are differentiated sufficiently to express messenger RNA (mRNA) of T-cell receptor (TCR) β-chain and pre-TCR alpha (pT) and, although not frequently, to perform Dβ-Jβ rearrangement of the TCR gene. Micromanipulation studies confirmed the clonal origin of myeloid lineage cells and the cells positive for the T-cell–specific transcripts and D-J rearrangement of TCR β-chain. These results suggested that, in the presence of SF, IL-11, and IL-7, primitive lymphohematopoietic progenitors differentiate toward T-cell lineage in addition to myeloid and B-cell lineages.
Mpl Ligand Enhances the Transcription of the Cyclin D3 Gene: A Potential Role for Sp1 Transcription Factor
Authors: Wang Zhengyu , Zhang Ying , Lu Jun , Sun Shinnshin , Ravid Katya 
Published: October 2019

AbstractCyclin D3 plays a major role in the development of polyploidy in megakaryocytes. The expression of cyclin D3 gene and the level of cyclin D3 protein are increased by the Mpl ligand in the Y10/L8057 megakaryocytic cell line, as indicated by Northern and Western blot analyses, and by nuclear run-on assays and transfection experiments with cyclin D3 promoter constructs. DNase I footprinting of the promoter region showed protected segments, at −75 to −60 bp and at −134 to −92 bp, which display binding sites for the Sp family of transcription factors. Gel mobility shift assay and supershifts with specific antibodies indicate that Sp1 binds to these regions in the cyclin D3 promoter and that Sp1 binding activity is significantly increased by Mpl ligand. Mutation of either Sp1 site both decreases the basal promoter activity and eliminates the induction by Mpl ligand. We find that the nonphosphorylated form of SP1 has greater affinity for the cyclin D3 promoter and that the majority of Sp1 in the cells is nonphosphorylated. Mpl ligand treatment results in increased levels of Sp1 protein, which also appears as nonphosphorylated. Okadaic acid, which inhibits protein phosphatase 1 (PP1) and shifts Sp1 to a phosphorylated form, decreases cyclin D3 gene expression and suppresses Mpl ligand induction. Our data point to the potential of Mpl ligand to activate at once several Sp1-dependent genes during megakaryopoiesis.
Interleukin-9 Regulates NF-κB Activity Through BCL3 Gene Induction
Authors: Richard Mélisande , Louahed Jamila , Demoulin Jean-Baptiste , Renauld Jean-Christophe 
Published: October 2019

AbstractBCL3 encodes a protein with close homology to IκB proteins and interacts with p50 NF-κB homodimers. However, the regulation and transcriptional activity of BCL3 remain ill-defined. We observed here that interleukin-9 (IL-9) and IL-4, but not IL-2 or IL-3, transcriptionally upregulated BCL3 expression in T cells and mast cells. BCL3 induction by IL-9 was detected as soon as 4 hours after stimulation and appeared to be dependent on the Jak/STAT pathway. IL-9 stimulation was associated with an increase in p50 homodimers DNA binding activity, which was mimicked by stableBCL3 expression. This contrasts with tumor necrosis factor (TNF)-dependent NF-κB activation, which occurs earlier, involves p65/p50 dimers, and is dependent on IκB degradation. Moreover, IL-9 stimulation or BCL3 transient transfection similarly inhibited NF-κB–mediated transcription in response to TNF. Taken together, our observations show a new regulatory pathway for the NF-κB transcription factors through STAT-dependent upregulation ofBCL3 gene expression.
Deletion of a Critical Internalization Domain in the G-CSFR in Acute Myelogenous Leukemia Preceded by Severe Congenital Neutropenia
Authors: Hunter Melissa G. , Avalos Belinda R. 
Published: October 2019

AbstractAcquired mutations in the granulocyte colony-stimulating factor receptor (G-CSFR) occur in a subset of patients with severe congenital neutropenia (SCN) who develop acute myelogenous leukemia (AML). These mutations affect one allele and result in hyperproliferative responses to G-CSF, presumably through a dominant-negative mechanism. Here we show that a critical domain in the G-CSFR that mediates ligand internalization is deleted in mutant G-CSFR forms from patients with SCN/AML. Deletion of this domain results in impaired ligand internalization, defective receptor downmodulation, and enhanced growth signaling. These results explain the molecular basis for G-CSFR mutations in the pathogenesis of the dominant-negative phenotype and hypersensitivity to G-CSF in SCN/AML.
Positive and Negative Cis-Acting Elements Are Required for Hematopoietic Expression of Zebrafish GATA-1
Authors: Meng Anming , Tang Hong , Yuan Baozheng , Ong Bruce A. , Long Qiaoming , Lin Shuo 
Published: October 2019

AbstractGATA-1 is a transcription factor required for development of erythroid cells. The expression of GATA-1 is tightly restricted to the hematopoietic lineage. Using transgene constructs containing zebrafish GATA-1 genomic sequences and the green fluorescent protein (GFP) reporter gene, we previously showed that a 5.6-kb enhancer/promoter fragment is sufficient to direct erythroid-specific expression of the GFP. In this study, we used enhancer/promoter fragments containing various deletion and point mutations to further characterize the cis-acting elements controlling tissue-specific GATA-1 expression. We report here the identification of distinct cis-acting elements that cooperate to confer on GATA-1 its hematopoietic expression pattern. A CACCC box, located 142 bp upstream of the translation start codon, is critical for the initiation of GATA-1 expression. A distal double GATA element is required for maintaining and enhancing the hematopoietic expression of GATA-1. The erythroid-specific activity of the GATA-1 promoter is also enhanced by a 49-bp sequence element located 218 bp upstream of the CACCC element and a CCAAT box adjacent to the double GATA motif. Finally, the hematopoietic specificity of the GATA-1 promoter is secured by a negative cis-acting element that inhibits expression in the notochord.
Identification of a Cellubrevin/Vesicle Associated Membrane Protein 3 Homologue in Human Platelets
Authors: Bernstein Audrey M. , Whiteheart Sidney W. 
Published: October 2019

Abstract
Several studies suggest membrane trafficking events are mediated by integral, membrane proteins from both transport-vesicle and target membranes, called v- and t-SNAREs (SNAp REceptors), respectively. Previous experiments using antibodies to synaptobrevin/vesicle associated membrane protein (VAMP) 1, 2, or rat cellubrevin failed to detect these v-SNAREs in human platelets, although membrane proteins from these cells could support 20S complex formation. To identify v-SNAREs in platelets, we used a polymerase chain reaction (PCR) approach with degenerate primers to amplify potential VAMP-like v-SNAREs. A cDNA encoding a novel v-SNARE was isolated from a human megakaryocyte cDNA library. Termed human cellubrevin (Hceb), this protein has greater than 93% identity with human VAMP 1, 2, and rat cellubrevin over the conserved core region, but has a unique N–terminal domain. Northern blot analysis showed that the 2.5-kB mRNA encoding Hceb is expressed in every human tissue tested. Hceb from detergent-solubilized platelet membranes, participated in -SNAP–dependent 20S complex formation and adenosine triphosphate (ATP)-dependent disassembly, showing that Hceb can act as a v-SNARE in platelets. Immunofluorescence microscopy, using an anti-Hceb antibody showed a punctate, intracellular staining pattern in platelets, megakaryocytes, and HEK-293 cells. This same pattern was observed in surface-activated platelets even though all dense core and most -granule contents had been released. These data suggest that Hceb may reside on a platelet organelle that is not primarily involved in the exocytic pathway.
Functional Role of Interleukin-4 (IL-4) and IL-7 in the Development of X-Linked Severe Combined Immunodeficiency
Authors: Kumaki Satoru , Ishii Naoto , Minegishi Masayoshi , Tsuchiya Shigeru , Cosman David , Sugamura Kazuo , Konno Tasuke 
Published: October 2019

AbstractX-linked severe combined immunodeficiency (X-SCID) is characterized by an absent or diminished number of T cells and natural-killer (NK) cells with a normal or elevated number of B cells, and results from mutations of the γc chain. The γc chain is shared by interleukin-2 (IL-2), IL-4, IL-7, IL-9, and IL-15 receptors. Recently, a survival signal through the IL-7 receptor  (IL-7R) chain was shown to be important for T-cell development in mice and was suggested to contribute to the X-SCID phenotype. In the present study, we examined function of a mutant γc chain (A156V) isolated from an X-SCID patient and found that T cells expressing the mutant γc chain were selectively impaired in their responses to IL-4 or IL-7 compared with the wild-type γc chain expressing cells although responses to IL-2 or IL-15 were relatively maintained. The result shows that IL-4– and/or IL-7–induced signaling through the γc chain is critical for T-cell development and plays an important role in the development of the X-SCID phenotype.
Human Immunodeficiency Virus Type 1 Nef Protein Sensitizes CD4+ T Lymphoid Cells to Apoptosis via Functional Upregulation of the CD95/CD95 Ligand Pathway
Authors: Zauli Giorgio , Gibellini Davide , Secchiero Paola , Dutartre Hélène , Olive Daniel , Capitani Silvano , Collette Yves 
Published: October 2019

AbstractMany viruses have evolved genes encoding proteins that regulate cell death by apoptosis. The human immunodeficiency virus type 1 (HIV-1) Nef protein alters T-cell development and signaling and is required for optimal viral replication and pathogenicity in vivo. To analyze the interference of Nef with cell survival, we used both regulated and constitutively expressed nef alleles in stably transfected T-cell lines. Nef-expressing cells were sensitized to cell death by apoptosis, which was specifically exacerbated by an anti-CD95 IgM monoclonal antibody (MoAb). Flow cytometric analysis showed that the surface expression of both CD95 and CD95 ligand (CD95L) was upregulated by endogenous Nef expression. Nef-mediated apoptosis was almost completely suppressed by the addition in culture of an anti-CD95 Fab′ IgG MoAb, which specifically blocks CD95/CD95L interactions. Lastly, mutation of a proline motif in the core region of the nef gene, which disrupts its ability to interact with cellular kinases and reduces HIV-1 replication in vitro, completely abrogated the Nef-mediated induction of apoptosis as well as its ability to upregulate surface CD95 and CD95L. These findings may provide molecular insight into the role of endogenous Nef in the T-cell depletion observed in vivo, particularly HIV-specific cytotoxic CD8+ T cells.