bluuebunny/crossref_metadata_2025_split huggingface dataset:
Elimination of Platelet Factor 4 (PF4) from Platelets Reduces Atherosclerosis and Increases HDL Cholesterol in C57Bl/6 and ApoE−/− Mice.
Authors: Sachais Bruce S. , Turrentine Tiffany , Dawicki-McKenna Jeanine M. , Rader Daniel J. , Kowalska M. Anna 
Published: April 2020

Abstract
There is a presence of circulating, activated platelets in blood of patients with atherosclerosis, coronary disease and hypercholesterolemia. Upon activation, platelets release a large amount of platelet factor 4 (PF4), a platelet specific chemokine. Our laboratory has previously demonstrated several potentially proatherogenic properties of PF4 including alteration of LDL metabolism and cellular trafficking, and activation of NFkB, a proinflammatory transcription factor involved in atherosclerosis. We have also localized PF4 to human atherosclerotic lesions. However, to date, no direct in vivo evidence for the involvement of PF4 in atherogenesis. In the current study, we have bred PF4−/− mice onto two athero-susceptible backgrounds, WT-C57Bl/6(WT) and apoE−/−, to examine the importance of PF4 in atherogenesis. PF4−/− and PF4−/−apoE−/− (DKO) mice are viable and healthy, with no spontaneous bleeding disorders. In order to induce atherosclerosis, WT and PF4−/− mice were fed an atherogenic Paigen diet for 30 weeks (Study 1), while apoE−/− and DKO mice were fed a high fat Western style diet for 10 weeks (Study 2). Examination of lesions in the aortic roots of Study 1 animals demonstrated a 5-fold reduction in PF4−/− compared to WT mice (p = 0.008). Measurement of cholesterol levels demonstrated similar total and non-HDL cholesterol levels in WT and PF4−/− mice. However, HDL cholesterol was significantly increased in PF4−/− mice compared to WT (2.5-fold, p = 0.001). Examination of apoE−/− mice (Study 2) demonstrated similar changes, with DKO mice demonstrating a 2.7-fold reduction in aortic atherosclerosis (measured by the en face method; p = 0.03) and a 1.7-fold increase in HDL cholesterol (p = 0.02) compared to apoE−/− mice. Although platelet counts were increased by ~30% in mice lacking PF4, the activation state of the platelets in our mice at sacrifice (WT vs PF4−/− and apoE−/− vs DKO) were similar as measured by both p-selectin expression and annexin V binding. These data demonstrate, for the first time, that the platelet specific chemokine PF4 promotes atherosclerotic lesion development in vivo.
Therapeutic Potential of Ovarian Monocyte Progenitor Cells (MPCs) in SLE-Murine Model.
Authors: El-Badri (Dajani) Nagwa S. , Cajera Vaishali , Hakki Amal , Baldwin Margaret , Sanberg Paul R. 
Published: April 2020

Abstract
We have previously shown that the progeny of resident ovarian stromal progenitor cells is restricted to the production of cells of the monocyte-macrophage lineage. These ovarian monocyte progenitor cells (MPCs) formed hematopoietic colonies on methyl cellulose, and were CD45+, CD11b+, CD11c+, and Ly6-Gr-1. A distinct CD45low population within these cells reacted with CD117 (C-kit) surface marker, suggestive of a primitive hematopoietic progenitor. To determine the therapeutic potential of MPCs, we transplanted 50,000 cells into normal and autoimmune BXSB autoimmune mouse model for SLE. MPCs did not rescue lethally irradiated mice from the consequences of irradiation, and were not engrafted in MHC-mismatched mouse strains. However, murine SLE-like symptoms were improved, and substantial reduction in inflammatory infiltrate was observed in tissue sections from transplanted mice including kidneys, lungs, and spleen. Restructuring of renal glomerural sclerosis was also observed in the transplant recipients. To determine whether glomerular vascular regeneration was directly mediated by donor MPCs, we tested the hypothesis that MPCs co-express markers for endothelial progenitor cells and monocytes. After culture in conditions permissible to endothelial cell differentiation, large percentage of MPCs (73%) expressed endothelial cell marker CD106. When their culture supernatant was applied to a rat aortic ring in matrigel tube forming assay, robust tube formation was observed in the experimental group. However, similar tube formation was also observed in the control well containing 20% FBS, and cultured MPCs failed to produce tube formation in matrigel assay. Interestingly, phenotypic analysis showed that only 52% of MPCs express MHC class I suggesting that these cells may induce less rejection when transplanted in mismatched hosts. These data suggest that vascular tissue repair initiated by MPCs is mediated by anti-inflammatory factors, and not by direct contribution to the reconstruction of glomeular vasculature.
Microarray Analysis of Thrombopoietin Induced Lineage Commitment of Bi-Potential Cell Line HU-3.
Authors: Morgan Doris A. , Jost Monika , Bender Patrick , Mayo Kelly , Kriete Andres 
Published: April 2020

Abstract
HU-3 is a cytokine dependent cell line derived from a patient with megakaryoblastic leukemia. The cells have
a strong megakaryocytic phenotype when cultured in GM-CSF and undergo terminal erythropoiesis when switched to stem cell factor and erythropoietin. (Morgan, 1997).
HU-3 cells are equally responsive to thrombopoietin (TPO), but no longer can be induced into the erythroid pathway nor do they advance along the megakaryocyte differentiation pathway. Microarray analysis of the bi-potential and unipotential cells using arrays with genome-wide coverage and bioinformatics software identified a panel of genes associated with the loss of erythroid potentiality and with an apparent commitment to the megakaryocytic lineage. Down-regulation of erythroid-specific genes expressed in the bi-potential cells was the predominant effect of the TPO microenvironment.
Expression Readouts of Globin and Other Erythroid Genes HU-3 alpha globin beta globin gamma globin zeta globin epsilon globin Rh factor GlycophorinA GM 187 32 258 17 94 46 80 TPO 50 4 130 2 9 4 2
HU-3 (TPO) did not show an enhanced megakaryocyte phenotype nor increased expression of CD41 (GpIIb), CD42 (Gp Ib) CD61 (GpIIIa), CD62 (P-selectin); Gp V, Gp IX, VEGF, and PDGF; however, several megakaryocyte-linked genes were up-regulated: pro-collagen lysine, annexin A1, angiopoietin 2, beta 1 integrin, and galactin 1 among others. Interleukin 8 expression increased approximately 30-fold in the TPO cultures. AML1 (RUNX1), GATA-1, and SPi-1/PU.1 are reported to be required for megakaryocyte and erythroid maturation, but were expressed at low levels and were not up-regulated by TPO. This observation may explain the block in the ability of HU-3 to enter the maturation pathway once unipotentiality had been achieved. The HU-3 cell line is a biologically relevant in vitro system for exploring the genetic program at the onset of megakaryocyte commitment and identifying genes necessary for entry into the maturation pathway.
N-Acetyl Cysteine Reduces von Willebrand Factor Multimer Size In Vitro and In Vivo.
Authors: Chen Junmei , Gushiken Francisca C. , Nolasco Leticia , Moake Joel F. , Lopez Jose A. 
Published: April 2020

Abstract
von Willebrand factor (VWF) shares a similar domain structure with many polymeric mucins, including the presence of D domains and a C-terminal cysteine knot, which allows these molecules to form polymeric structures that can reach immense sizes. Precipitation of polymeric lung mucins complicates the clinical course of cystic fibrosis and chronic obstructive lung disease, and in both cases the viscosity of the inspissated mucus can be reduced by treatment with N-acetyl cysteine (NAC), which presumably reduces the size of the mucin polymers by reducing sensitive disulfide bonds. Because of the similarity of VWF and mucin multimers, we examined whether NAC could also reduce VWF multimer size both in vitro and in vivo. In vitro, we incubated NAC at different concentrations and for different times with ultra-large VWF multimers (ULVWF) isolated from endothelial cell supernatant and examined the effect on multimer size using agarose gel electrophoresis. NAC reduced ULVWF size in a time- and concentration-dependent manner, with the peak effect reached at 5 min and at concentration of 0.5 mM. We then examined the effect of NAC on ULVWF/platelet “strings” formed on the surface of histamine-activated endothelial cells by perfusing the strings with NAC solutions. At 1 mM, NAC eliminated almost all of the adherent strings within 5 minutes. We next examined the effect of NAC in vivo by following VWF multimer size with time in C57B/6 injected with NAC either intraperitoneally or intravenously. NAC, at a single dose of 500 mg/kg, induced a sustained reduction in VWF multimer size in the treated mice within 4 hours after injection. The effects lasted up to 8 hours. These results suggest that NAC may be a rapid, safe, and effective treatment for patients suspected of suffering from thrombotic thrombocytopenic purpura, a disorder characterized by a failure to process ULVWF.
Alternation of Cellular Morphology and Proliferation Induced by microRNA in Human Leukemia Cell Line, UT-7/EPO.
Authors: Kosaka Nobuyoshi , Yamamoto Yusuke , Nogawa Nami , Sugiura Keiichi , Miyazaki Hiroshi , Komatsu Norio , Ochiya Takahiro , Kato Takashi 
Published: April 2020

Abstract
Mature microRNA (miRNA) originated from primary miRNA (pri-miRNA) is a new group of potential regulator for cell differentiation, apoptosis, proliferation and oncogenesis. Some miRNAs were recently identified in hematopoietic cells, while the roles of miRNAs in erythrocytic and megakaryocytic cells had not been well examined. As a first step to explore for miRNAs specific for hematopoietic lineage, the expressions of several known primary microRNAs in erythrocytic and megakaryocytic cell lines, such as TF-1, HL-60, HEK293 and UT-7 leukemia cells, were examined by RT-PCR. We consequently focused on the pri-miR-10a, a primary transcript of miR-10a located within Hox gene clusters, and found the significant expression in TF-1 cells and UT-7/EPO cells. The UT-7/EPO cells were a subline established from the original UT-7 cells, as well as UT-7/GM and UT-7/TPO cells; therefore it was suitable for the further comparative analysis. Interestingly, in UT-7/EPO cells, the expression of pri-miR-10a increased under stimulation of erythropoietin (EPO; 1U/mL and 10U/mL). Based on these observations, it was postulated that pri-miR-10a might involve in modulating erythrocyte differentiation or proliferation. To clarify the role of pri-miR-10a in UT-7/EPO, we have established clonal cell lines by transfecting UT-7/EPO cells with either the control vector or the pri-miR-10a expression vector pCMV-pri-miR10a. Overexpression of pri-miR-10a in the UT-7/EPO cell line (miR10a-UT-7/EPO) was confirmed by RT-PCR. MiR10a-UT-7/EPO showed higher proliferation rate even at low concentration of EPO (0.1 mU/mL). Overexpression of pri-miR-10a did not appear to affect HOXB4 and HOXA1 expression, as similar mRNA levels were seen in both cell lines. It was notable that the cellular size of miR10a-UT-7/EPO became larger than its parental cells. Morphological studies of miR10a-UT-7/EPO were performed in detail. It is possible that miR-10a was capable to modulate morphological features particularly in cellular size relating to cell cycle regulation. For instance, loss of the E2F family members result in marked macrocytic anemia with megaloblastic features in adult mice (Mol Cell. 2000 Aug;6(2):281–91., Mol Cell Biol. 2003 May;23(10):3607–22., Blood. 2006 Aug 1;108(3):886–95.). Data presented here hypothesized that the roles of miR-10a in erythroid cells are tightly associated with cell cycle.
Novel Role for EKLF in Megakaryocyte-Erythroid Differential Lineage Commitment.
Authors: Frontelo Maria Pilar , Manwani Deepa , Galdass Mariann , Karsunky Holger , Gallagher Patrick G. , Bieker James J. 
Published: April 2020

Abstract
Megakaryocytes and erythroid cells are thought to derive from a common progenitor. Although a number of transcriptional regulators are important for this process, they do not explain the bipotential result. We have used gain- and loss-of-function studies, expression profiling, and molecular analyses to show that EKLF, a transcription factor whose crucial role in erythroid gene regulation is well established, plays an unexpected function in the lineage decision between megakaryopoiesis and erythropoiesis. It achieves this by inhibiting the formation of megakaryocytes derived from the common megakaryocyte-erythroid precursor (MEP) cell, while at the same time stimulating erythroid differentiation. Quantitative examination of EKLF expression during hematopoiesis reveals that, unlike genes whose presence is required for establishment of both lineages, EKLF expression is uniquely down-regulated in megakaryocytes after formation of the MEP. Microarray and molecular analyses support these observations and suggest that megakaryocytic inhibition is achieved, at least in part, by EKLF repression of Fli-1 message levels. These results reveal for the first time that EKLF plays a directive role in erythroid and megakaryocyte lineage decisions prior to establishment of the red cell compartment and suggest a model for transcription factor antagonism in MEP differential lineage commitment. Tests as predicted by this model will be discussed.
PU.1 Activity Determines Fate of Myeloid Progenitor Cells during Lineage Commitment.
Authors: Pospisil Vitek , Necas Emanuel , Stopka Tomas 
Published: April 2020

Abstract
Myeloid cell commitment is regulated by factors interacting with chromatin in a progenitor cell entering differentiation. PU.1 is an ETS family transcription factor that has been well characterized in inducing myelopoiesis and blocking erythroid differentiation. Conditionally activated PU.1-Estrogen Receptor transgene in mouse PU.1 knockout-derived hematopoietic progenitors is known to induce macrophage differentiation. We observed that manipulation of PU.1 activity by using different levels of PU.1-ER activator, tamoxifen, was capable of producing major populations of myeloid progeny including macrophages, granulocytes, lymphocytes and mastocytes. Gradual activation of PU.1 produce distinct committed populations that require presence of PU.1 activator. Withdrawal of tamoxifen from macrophages restored cycling and pluripotent potential resembling parental cell line. Furthermore, very low PU.1 activity induced frequent chromosomal aberations such as polyploidy. To determine that PU.1 directly caused these phenotypic changes we determined its occupancy at genes representing PU.1 targets by quantitative chromatin immunoprecipitation (ChIP). We demonstrate that PU.1 is enriched at regulatory regions of lineage restricted cell populations including promoters of CD11b, CD14, IL7R, PAX5, RAG1, Gelatinase, Lysozyme, and MCP. Different PU.1 levels promote distinct cell populations that have different localizations of PU.1 in chromatin. We also tested mRNA levels of PU.1 target genes in progenitor cell line induced by PU.1. Macrophage-specific target genes such as CD11b and CD14 are induced at high PU.1 levels and granulocytic PU.1 targets such as Gelatinase and Lysozyme are induced at intermediate and high PU.1 levels. B-cell specific mRNAs such as IL7-R, PAX5, and RAG1 were induced at low and high PU.1 levels. Our data suggest that PU.1 is recruited to and transactivates its lineage-restricted target genes differently at distinct PU.1 levels and such mechanism may be involved in myeloid cell commitment and leukemogenesis.
C-MYB and C/EBP Family Transcription Factors Regulate the Gfi-1 Promoter.
Authors: Dahl Richard , Owens Kristin S. 
Published: April 2020

Abstract
Gfi-1 −/− mice generate abnormal immature myeloid cells exhibiting characteristics of both monocytes and granulocytes. One of Gfi-1’s critical functions is to downregulate monocyte specific genes in order for granulocytes to develop properly. Since the transcription factors C/EBP alpha and C/EBP epsilon are needed for granulocyte development we hypothesized that these factors may regulate Gfi-1 expression. The Gfi-1 promoter contains several putative C/EBP binding sites and we show by electrophoretic mobility shift and chromatin immunoprecipitation that C/EBP family members can bind to some of these sites. However we were unable to see activation of the Gfi-1 promoter by C/EBP proteins in transient transfection reporter assays. Other groups have shown that C/EBP proteins can synergize with the transcription factor c-myb. We observed that the Gfi-1 promoter contains sites for the hematopoietic transcription factor c-myb. Sevral of these c-myb binding sites are adjacent to C/EBP binding sites. In reporter assays in non-hematopoietic cells c-myb activated the Gfi-1 promoter by itself and this activity was enhanced when we included either C/EBP alpha or epsilon in the transfection. Our data suggests that C/EBP proteins and c-myb regulate the transcription of Gfi-1 in myeloid cells.
PBI-1402: A Non-Toxic Immunorestorative Small Molecule for the Treatment of Anemia.
Authors: Lagraoui Mouna , Grouix Brigitte , Julien Nathalie , Asselin Michel , Gaudreau Dannyck , Sarra-Bournet François , Morin Marie-Josée , Krosl Gorazd , Roy Denis-Claude , Penney Christopher , Gagnon Lyne 
Published: April 2020

Abstract
Erythropoiesis is regulated by an intricated network of transcription factors and other molecules that mediate differentiation of stem cell progenitors into erythroid lineage. PBI-1402 is a non-toxic, well-defined chemo- and radio-protective orally active small molecule which stimulates erythropoiesis. In vivo studies demonstrate that PBI-1402 has an immunorestorative effect in anemia induced by phenylhydrazine or lethal irradiation. In phenylhydrazine-induced anemia, PBI-1402 treated mice had an increased number of hematopoietic progenitor cells compared to the control mice. This increase was more pronounced in the erythroid lineage (BFU-E and CFU-E). In myeloablated mice that received a syngeneic bone marrow transplant, oral treatment with PBI-1402 resulted in a significant increase in peripheral erythrocyte count and hemoglobin concentration. In conclusion, these results indicate that PBI-1402 plays an important role in the formation of red blood cells. Therefore, PBI-1402 may be useful for the treatment of anemia associated with chemotherapy, radiotherapy, bone marrow transplantation and cancer.
A New Role for Flavoproteins in the Control of Megakaryocyte Polyploidy.
Authors: Makitalo Maria , McCrann Donald J. , Liu Kenian , Ravid Katya 
Published: April 2020

Abstract
Megakaryocytes (MKs) can reach a ploidy level of greater than 32N (with 2N representing diploid chromosomes), while polyploidization is important for generating an adequate number of functional platelets. The MK population in the marrow intriguingly consists of a large fraction of 8N and 16N cells that are cell cycle arrested. Here, we examined the expression of different NADPH (NOX) oxidases in MKs, using Western blotting and immunohistochemistry, because of their known role in upregulating regulators of the G1 phase of the cell cycle and in promoting cell cycle progression. It was found that in thrombopoietin-treated mouse bone marrow cultures, NOX1 is highly expressed in many, but not all MKs, while NOX4 is expressed at lower levels than NOX1. Treatment of mouse bone marrow or fetal liver cultures with a NOX inhibitor, diphenylene iodonium (DPI) lead to accumulation of viable MKs at diploid and tetraploid levels, and to a significant reduction in the fraction of high ploidy MKs, as measured by Flow cytometry analysis with a MK specific marker as well as by immunostaining. MKs isolated by an albumin gradient were subjected to Western blotting, which indicated a decrease in the level of the G1 phase cyclin, cyclin E, in DPI-treated cells. Taken together, this study shows for the first time the expression of NOX isoforms in MKs and highlights the important role of flavoproteins in promoting polyploidy in this lineage. It is suggested that the population of cell cycle-arrested intermediate-ploidy MKs is prevented from reaching higher ploidy, partly because of diminished levels of G1 phase regulators via NOX downregulation.
The Role of Cyclin C on Hematopoietic Cells.
Authors: Miyata Yasuhiko , Lie Yan , Sashida Goro , Nimer Stephen 
Published: April 2020

Abstract
The regulation of pluripotent hematopoietic stem cells (HSCs) is essential for the maintenance of multilineage blood production throughout life. The ability to self-renew or differentiate is a critical factor in the regulation of HSC numbers and cell fate, but so is the ability to enter and reside in a quiescent state (G0 phase of the cell cycle). The regulation of the G0 stem cell compartment is important for maintaining an inexhaustible pool of HSCs, protected from cellular stress. We have recently shown that the ETS transcription factor MEF is an important regulator of HSC quiescence (H. D. Lacorazza, Cancer Cell, 2006). The mechanism by which MEF or cell cycle regulatory proteins like p21 control entry into (and exit from) the G0 stage of the cell cycle is poorly understood. Insights into the mechanisms of HSC regulation could have important therapeutic potential.
Recently, a Cyclin C/cdk3 interaction was reported to play an important role in cell cycle re-entry from quiescent state (G0 to G1) by phosphorylating the retinoblastoma protein (Rb) in human fibroblasts (S. Ren, Cell, 2004). To elucidate if cyclin C is involved in the regulation of cell cycle in hematopoietic cells, especially human CD34+ HSCs, we have optimized a FG12 lentivirus based shRNA strategy (kindly provided by D. Baltimore, PNAS, 2002). shRNA directed against cyclin C successfully decreased both cyclin C mRNA and protein expression levels. Using this vector, we have consistently achieved a 90 % transduction efficiency and a 60–70 % reduction of cyclin C levels in human CD34+ cells as evidenced by real time PCR. Now we are analyzing the cell cycle and biological effects of cyclin C knockdown and overexpression on hematopoietic cells using both human CD34+ cells and human leukemic cell lines.
Crosstalk between Murine Liver Sinusoidal Endothelial Cells (LSEC) and Hematopoietic Stem Cells during In Vitro Hematopoiesis.
Authors: Cardier Jose E. , Luna Gonzalo 
Published: April 2020

Abstract
Crosstalk between murine liver sinusoidal endothelial cells (LSEC) and hematopoietic stem cells during in vitro hematopoiesis. G. Luna, J. E. Cardier. Laboratorio de Patologia Celular y Molecular, Centro de Medicina Experimental, Instituto Venezolano de Investigaciones Científicas (IVIC). Apartado 21827, Caracas, Venezuela
We have showed that at the liver there is a specific hematopoietic microenvironment, constituted by the liver sinusoid endothelial cells (LSEC), which are capable to support, in vitro and in vivo, not only the proliferation but also the differentiation and survival of hematopoietic stem cells (HSC). The ability of LSEC to support hematopoiesis could be related to specific hematopoietic molecules expressed by these cells. In this study, we investigate the expression of some cell adhesion molecules (VCAM-1, ICAM-1, and the integrin a4b1 ), and early acting hematopoietic cytokines (IL-6 and GM-CSF), on LSEC cocultured with HSC. The expression of VCAM-1, ICAM-1, α4β1, IL6 and GM-SCF was increased on LSEC cocultured with HSC. In contrast, a significant decrease in the expression of IL-6 and GM-CSF in the HSC derived from the same cocultures was observed. The blockade of VCAM-1 on LSEC reduced significantly the adhesion of HSC to LSEC monolayers, suggesting that this molecule is involved in the binding of HSC to LSEC microenvironments. There were not changes in the expression of the molecules evaluated when the LSEC and HSC were co-cultured in non-contact conditions, suggesting that soluble factors do not participate in regulating the expression of these molecules. Our data shows that during in vitro hematopoiesis, LSEC are activated to express molecules associated with the hematopoiesis process. LSEC activation is regulated by the contact between these cells and HSC. By expressing critical hematopoietic microenvironment molecules, LSEC may regulate the proliferation and differentiation of HSC, during liver extramedullary hematopoiesis.