bluuebunny/crossref_metadata_2025_split huggingface dataset:
Characterization of Signal Transduction Pathways in Human Bone Marrow Endothelial Cells
Authors: Liu Zhong-Ying , Ganju Ramesh K. , Wang Jian-Feng , Schweitzer Karin , Weksler Babette , Avraham Shalom , Groopman Jerome E. 
Published: October 2019

AbstractHuman bone marrow endothelial cells immortalized with the T antigen of SV40 (TrHBMEC) have previously been characterized by us with regard to their properties that are similar to primary marrow endothelial cells and their utility as a model system. We now report that TrHBMEC express a recently discovered signal transduction molecule termed RAFTK (related adhesion focal tyrosine kinase), also called Pyk2 or CAK-β. RAFTK, the second member of the focal adhesion kinase (FAK) family, is known to be activated in response to calcium flux in neuronal cells and integrin stimulation in megakaryocytes and B cells. We have studied the effects of cytokines on RAFTK activation in TrHBMEC. Treatment of TrHBMEC with the vascular endothelial growth factor (VEGF ), as well as the VEGF-related protein (VRP), the recently identified ligand for the FLT-4 receptor, resulted in enhanced tyrosine phosphorylation of RAFTK. Similar changes in RAFTK phosphorylation were observed upon stimulation of TrHBMEC with basic fibroblast growth factor (bFGF ) or oncostatin M (OSM). Stimulation of these cells with growth factors also resulted in an increase in RAFTK activity and the c-Jun NH2 -terminal kinase (JNK). RAFTK coimmunoprecipitated with the cytoskeletal protein paxillin through its C-terminal proline-rich domain in TrHBMEC. These results suggest that, in marrow endothelium, activation of RAFTK by VEGF, VRP, OSM, and bFGF represents a new element in the signal transduction pathways used by these growth factors and likely acts to coordinate signaling from their surface receptors to the cytoskeleton, thereby modulating cell growth and function.
Increased Recruitment of Hematopoietic Progenitor Cells Underlies the Ex Vivo Expansion Potential of FLT3 Ligand
Authors: Haylock David N. , Horsfall Martyn J. , Dowse Tracey L. , Ramshaw Hayley S. , Niutta Silvana , Protopsaltis Sandra , Peng Li , Burrell Christopher , Rappold Irene , Buhring Hans-Jorg , Simmons Paul J. 
Published: October 2019

AbstractThe ligand for flt-3 (FLT3L) exhibits striking structural homology with stem cell factor (SCF ) and monocyte colony-stimulating factor (M-CSF ) and also acts in synergy with a range of other hematopoietic growth factors (HGF ). In this study, we show that FLT3L responsive hematopoietic progenitor cells (HPC) are CD34+CD38−, rhodamine 123dull, and hydroperoxycyclophosphamide (4-HC) resistant. To investigate the basis for the capacity of FLT3L to augment the de novo generation of myeloid progenitors from CD34+CD38− cells, single bone marrow CD34+CD38− cells were sorted into Terasaki wells containing serum-free medium supplemented with interleukin-3 (IL-3), IL-6, granulocyte colony-stimulating factor (G-CSF ), SCF (4 HGF ) ± FLT3L. Under these conditions, FLT3L recruited approximately twofold more CD34+CD38− cells into division than 4 HGF alone. The enhanced proliferative response to FLT3L was evident by day 3 and was maintained at all subsequent time points examined. In accord with these findings, we also show that transduction of CD34+CD38− cells with the LAPSN retrovirus is enhanced by FLT3L. The results of these experiments therefore indicate that increased recruitment of primitive HPC into cell cycle underlies the ex vivo expansion potential of FLT3L and also its ability to improve retroviral transduction of HPC.
CD34 Expression Patterns During Early Mouse Development Are Related to Modes of Blood Vessel Formation and Reveal Additional Sites of Hematopoiesis
Authors: Wood Heather B. , May Gillian , Healy Lyn , Enver Tariq , Morriss-Kay Gillian M. 
Published: October 2019

AbstractCD34 is a cell surface glycoprotein that is selectively expressed within the human hematopoietic system on stem and progenitor cells, and in early blood vessels. To elucidate its functions during early blood vessel formation and hematopoiesis, we analyzed the expression patterns, in day 8 to day 10 mouse embryos, of CD34 RNA by in situ hybridization and protein by immunohistochemistry using the monclonal antibody RAM 34. Levels of expression in embryonic blood vessels were correlated with the mode of vessel formation, being high in pre-endothelial cells and in vessels forming by vasculogenesis (particularly the dorsal aortae) or angiogenesis, but low in vessels forming by coalescence (the cardinal veins). CD34+ erythroid cells, presumably of yolk sac origin, were present in the liver of day 10 embryos; at the same stage, putative definitive hematopoietic cells, strongly CD34+, were present in the para-aortic mesenchyme. Possible sites of hemangioblastic differentiation were detected in the form of CD34+ endothelium-attached hematopoietic cells in the dorsal aorta and in two previously unreported locations, the proximal umbilical and vitelline arteries. These observations suggest functions for CD34 in relation to specific modes of blood vessel formation, and a hemangioblastic role in both embryonic and extraembryonic sites.
Soluble Monomeric P-Selectin Containing Only the Lectin and Epidermal Growth Factor Domains Binds to P-Selectin Glycoprotein Ligand-1 on Leukocytes
Authors: Mehta Padmaja , Patel Kamala D. , Laue Thomas M. , Erickson Harold P. , McEver Rodger P. 
Published: October 2019

AbstractUnder shear stress, leukocytes use P-selectin glycoprotein ligand-1 (PSGL-1) to tether to and roll on P-selectin expressed on activated platelets or endothelial cells. P-selectin has an NH2-terminal lectin domain, an epidermal growth factor (EGF)-like motif, nine consensus repeats (CRs), a transmembrane domain, and a cytoplasmic tail. To determine whether the CRs are required for P-selectin to bind PSGL-1, we expressed a soluble protein (Lec-EGF) that contained only the lectin and EGF domains, plus a short C-terminal epitope tag. Electron microscopy and hydrodynamic analysis confirmed that Lec-EGF was monomeric, as previously shown for soluble P-selectin (sPS) that contained the lectin and EGF domains plus all nine CRs. Fluid-phase Lec-EGF or sPS inhibited binding of oligomeric125I-labeled membrane-derived P-selectin (mPS) to PSGL-1 on neutrophils and binding of 125I-PSGL-1 to immobilized mPS. The IC50 for inhibiting binding of mPS to neutrophils was fivefold greater for Lec-EGF than for sPS, whereas the IC50 for inhibiting binding of mPS to purified PSGL-1 was indistinguishable for Lec-EGF and sPS. Under static or shear conditions, neutrophils used PSGL-1 to tether to or roll on Lec-EGF that was captured by an immobilized monoclonal antibody to the C-terminal epitope. These data show that P-selectin requires only the lectin and EGF domains to bind to PSGL-1.
Immunohistochemical Analysis of Interleukin-1β–Converting Enzyme/Ced-3 Family Protease, CPP32/Yama/Caspase-3, in Hodgkin's Disease
Authors: Chhanabhai Mukesh , Krajewski Stanislaw , Krajewska Maryla , Wang Hong-Gang , Reed John C. , Gascoyne Randy D. 
Published: October 2019

AbstractThe Caenorhabditis elegans cell death gene, Ced-3, encodes a protein homologous to mammalian interleukin-1β–converting enzyme (ICE), a cysteine protease implicated in programmed cell death (PCD). CPP32, also known as Yama, apopain, and Caspase-3, is a member of this family, has substrate specificities similar to Ced-3, and has been shown to have an active role in PCD. Evidence suggests that these proteases act downstream of inhibitors of PCD such as Bcl-2 and Bcl-xL , which are frequently expressed in Reed-Sternberg (RS) cells of Hodgkin's disease (HD). To date there have been no studies examining the role of the ICE/Ced-3 family of proteins, in particular CPP32, in HD. We examined 24 cases of HD with a classical immunophenotype and 6 cases of nodular lymphocyte predominant HD (NLPHD) for the expression of CPP32 in the RS cells and lymphohistiocytic (L&H) cells as detected by immunohistochemistry. Twenty two of 24 cases (92%) of HD expressed the protein in the RS cells, whereas the L&H cells in all 6 cases of NLPHD lacked expression of CPP32. These results provide further evidence that NLPHD is a phenotypically different disease distinct from classical forms of HD. The differential expression of the cell death protein CPP32 may be an important factor contributing to the apparently different clinical behaviour of NLPHD in contrast to classical HD. The lack of expression of CPP32 in NLPHD shares similarities with low-grade B-cell non-Hodgkin's lymphomas and may explain their common clinical course. Further studies are required to elucidate the significance of CPP32 in HD.
A Markedly Disrupted Skeletal Network With Abnormally Distributed Intramembrane Particles in Complete Protein 4.1-Deficient Red Blood Cells (Allele 4.1 Madrid): Implications Regarding a Critical Role of Protein 4.1 in Maintenance of the Integrity of the Red Blood Cell Membrane
Authors: Yawata Ayumi , Kanzaki Akio , Gilsanz Florinda , Delaunay Jean , Yawata Yoshihito 
Published: October 2019

AbstractElectron microscopic (EM) studies were performed to clarify the interactions of membrane proteins in the red blood cell membrane structure in situ of a homozygous patient with total deficiency of protein 4.1 who carried a point mutation of the downstream translation initiation codon (AUG → AGG) of the protein 4.1 gene [the 4.1 (−) Madrid; Dalla Venezia et al, J Clin Invest 90:1713, 1992]. Immunologically, as expected, protein 4.1 was completely missing in the red blood cell membrane structure in situ. A markedly disrupted skeletal network was observed by EM using the quick-freeze deep-etching method and the surface replica method, although the number of spectrin molecules was only minimally reduced (395 ± 63/μm2; normal, 504 ± 36/μm2). The number of basic units in the skeletal network was strikingly reduced (131 ± 21/μm2; normal, 548 ± 39/μm2), with decreased small-sized units (17 ± 4/μm2; normal, 384 ± 52/μm2) and increased large-sized units (64% ± 14%; normal, 5% ± 1%). Concomitantly, immuno-EM disclosed striking clustering of spectrin molecules with aggregated ankyrin molecules in the red blood cell membrane structure in situ. Although no quantitative abnormalities in the number and size distribution of the intramembrane particles were observed, there was a disappearance of regular distribution, with many clusters of various sizes, probably reflecting the distorted skeletal network. Therefore, protein 4.1 suggests by EM to play a crucial role in maintenance of the normal integrity of the membrane structure in situ not only of the skeletal network but also of the integral proteins.
Neutropenia in Allogeneic Marrow Transplant Recipients Receiving Ganciclovir for Prevention of Cytomegalovirus Disease: Risk Factors and Outcome
Authors: Salzberger Bernd , Bowden Raleigh A. , Hackman Robert C. , Davis Chris , Boeckh Michael 
Published: October 2019

AbstractTo determine risk factors, frequency, time patterns, and outcome of ganciclovir-related neutropenia in allogeneic marrow transplant recipients, 278 consecutive patients receiving ganciclovir from engraftment until day 100 were studied. In this cohort, 159 patients (57%) had absolute neutrophil counts (ANC) less than 1,500/μL, 112 (41%) had an ANC less than 1,000/μL, 87 (31%) less than 750/μL, and 56 (21%) less than 500/μL for at least 2 consecutive days. Statistically significant risk factors for neutropenia in a Cox model were low marrow cellularity between day 21 and 28 (relative risk [RR] 2.4, P = .0002), hyperbilirubinemia ≥6 mg/dL during the first 20 days (RR 2.5, P = .0001), and elevation of serum creatinine ≥2 mg/dL after day 21 after transplant (RR 2.1, P = .001). Restriction to factors present at engraftment resulted in a similar model with low marrow cellularity, hyperbilirubinemia ≥6 mg/dL, and elevated serum creatinine as significant risk factors. Patients with no risk factor had an incidence of neutropenia of 21%, an incidence of 31% for one risk factor, and of 57% for two or more risk factors (RR 3.8, P = .001). Neutropenia was a negative predictor of overall (RR 2.0, P = .0001) and event-free survival (RR 2.1, P < .0001), and a predictor of relapse (RR 1.7, P = .03) and nonrelapse mortality (RR 2.1, P = .003). Thus, early liver dysfunction, elevated serum creatinine, and low marrow cellularity are risk factors for ganciclovir-related neutropenia. Neutropenia in ganciclovir recipients after marrow transplantation is an independent risk factor for mortality.
Fusion of TEL, the ETS-Variant Gene 6 (ETV6), to the Receptor-Associated Kinase JAK2 as a Result of t(9; 12) in a Lymphoid and t(9; 15; 12) in a Myeloid Leukemia
Authors: Peeters Pieter , Raynaud Sophie D. , Cools Jan , Wlodarska Iwona , Grosgeorge Josiane , Philip Patrick , Monpoux Fabrice , Van Rompaey Luc , Baens Mathijs , Van den Berghe Herman , Marynen Peter 
Published: October 2019

Abstract
Translocations in hematologic disease of myeloid or lymphoid origin with breakpoints at chromosome band 12p13 frequently result in rearrangements of the Ets variant gene 6 (ETV6). As a consequence either the ETS DNA-binding domain or the Helix-Loop-Helix (HLH) oligomerization domain of ETV6 is fused to different partner genes. We show here that a t(9; 12)(p24; p13) in a case of early pre-B acute lymphoid leukemia and a t(9; 15; 12)(p24; q15; p13) in atypical chronic myelogenous leukemia in transformation involve the ETV6 gene at 12p13 and the JAK2 gene at 9p24. In each case different fusion mRNAs were found, with only one resulting in an open reading frame for a chimeric protein consisting of the HLH oligomerization domain of ETV6 and the protein tyrosine kinase (PTK) domain of JAK2. The cloning of the complete human JAK2 coding and genomic sequences and of the genomic junction fragments of the translocations allowed a characterization of the different splice events leading to the various mRNAs. JAK2 plays a central role in non–protein tyrosine kinase receptor signaling pathways, which could explain its involvement in malignancies of different hematologic lineages. Besides hop in Drosophila no member of the JAK family has yet been implicated in tumorigenesis.
The Efficacy of Single-Dose Administration of Thrombopoietin With Coadministration of Either Granulocyte/Macrophage or Granulocyte Colony-Stimulating Factor in Myelosuppressed Rhesus Monkeys
Authors: Neelis Karen J. , Hartong Simone C.C. , Egeland Torstein , Thomas G. Roger , Eaton Dan L. , Wagemaker Gerard 
Published: October 2019

Abstract
Thrombopoietin (TPO) was evaluated for efficacy in a placebo-controlled study in rhesus monkeys with concurrent administration of either granulocyte/macrophage colony-stimulating factor (GM-CSF) or granulocyte CSF, (G-CSF). Rhesus monkeys were subjected to 5 Gy total-body irradiation (TBI), resulting in 3 weeks of profound pancytopenia, and received either TPO 5 μg/kg intravenously (IV) at day 1 (n = 4), GM-CSF 25 μg/kg subcutaneously (SC) for 14 days (n = 4), TPO and GM-CSF (n = 4), G-CSF 10 μg/kg/d SC for 14 days (n = 3), TPO and G-CSF (n = 4), or placebo (carrier, n = 4; historical controls, n = 8). Single-dose IV treatment with TPO 1 day after TBI effectively counteracted the need for thrombocyte transfusions (provided whenever thrombocyte levels were <40 × 109/L) and accelerated platelet reconstitution to normal levels 2 weeks earlier than placebo controls. TPO/GM-CSF was more effective than single-dose TPO alone in stimulating thrombocyte regeneration, with a less profound nadir and a further accelerated recovery to normal thrombocyte counts, as well as a slight overshoot to supranormal levels of thrombocytes. Monkeys treated with TPO/GM-CSF uniformly did not require thrombocyte transfusions, whereas those treated with GM-CSF alone needed two to three transfusions, similar to the placebo-treated monkeys, which required, on average, three transfusions. Also, reticulocyte production was stimulated by TPO and further augmented in monkeys treated with TPO/GM-CSF. TPO alone did not stimulate neutrophil regeneration, whereas GM-CSF shortened the period of neutrophil counts less than 0.5 × 109/L by approximately 1 week; TPO/GM-CSF treatment elevated the neutrophil nadir, but did not further accelerate recovery to normal values. TPO also augemented the neturophil response to G-CSF, resulting in similar patterns of reconstitution following TPO/G-CSF and TPO/GM-CSF treatment. TPO/GM-CSF resulted in significantly increased reconstitution of CD34+ bone marrow cells and progenitor cells such as GM-CFU and BFU-E. Adverse effects of combining TPO with the CSFs were not observed. It is concluded that (1) a single IV administration of TPO is sufficient to prevent severe thrombocytopenia following myelosuppression, (2) TPO/G-CSF and TPO/GM-CSF treatment result in distinct response patterns, with TPO/GM-CSF being superior to TPO/G-CSF in stimulating thrombocyte and erythrocyte recovery while being equivalent in stimulating neutrophil recovery; and (3) TPO significantly improves the performance of CSFs in alleviating severe neutropenia.
Interleukin-6 and the Granulocyte Colony-Stimulating Factor Receptor Are Major Independent Regulators of Granulopoiesis In Vivo But Are Not Required for Lineage Commitment or Terminal Differentiation
Authors: Liu Fulu , Poursine-Laurent Jennifer , Wu Huai Yang , Link Daniel C. 
Published: October 2019

AbstractMultiple hematopoietic cytokines can stimulate granulopoiesis; however, their relative importance in vivo and mechanisms of action remain unclear. We recently reported that granulocyte colony-stimulating factor receptor (G-CSFR)-deficient mice have a severe quantitative defect in granulopoiesis despite which phenotypically normal neutrophils were still detected. These results confirmed a role for the G-CSFR as a major regulator of granulopoiesis in vivo, but also indicated that G-CSFR independent mechanisms of granulopoiesis must exist. To explore the role of interleukin-6 (IL-6) in granulopoiesis, we generated IL-6 × G-CSFR doubly deficient mice. The additional loss of IL-6 significantly worsened the neutropenia present in young adult G-CSFR–deficient mice; moreover, exogenous IL-6 stimulated granulopoiesis in vivo in the absence of G-CSFR signals. Near normal numbers of myeloid progenitors were detected in the bone marrow of IL-6 × G-CSFR–deficient mice and their ability to terminally differentiate into mature neutrophils was observed. These results indicate that IL-6 is an independent regulator of granulopoiesis in vivo and show that neither G-CSFR or IL-6 signals are required for the commitment of multipotential progenitors to the myeloid lineage or for their terminal differentiation.
Involvement of Transcription Factor Encoded by the Mouse mi Locus (MITF ) in Expression of p75 Receptor of Nerve Growth Factor in Cultured Mast Cells of Mice
Authors: Jippo Tomoko , Morii Eiichi , Tsujino Kumiko , Tsujimura Tohru , Lee Young-Mi , Kim Dae-Ki , Matsuda Hiroshi , Kim Hyung-Min , Kitamura Yukihiko 
Published: October 2019

AbstractThe mi locus of mice encodes a member of the basic-helix-loop-helix-leucine zipper (bHLH-Zip) protein family of transcription factors (hereafter called MITF ). Cultured mast cells (CMCs) of mi/mi genotype showed a poor response to nerve growth factor (NGF ). Addition of NGF to the suboptimal dose of interleukin-3 (IL-3) increased the plating efficiency of normal (+/+) CMCs but not mi/mi CMCs. Although +/+ CMCs were berberine sulfate–negative when cultured with IL-3, +/+ CMCs became berberine sulfate–positive when cultured in the presence of both IL-3 and NGF, which suggested increased heparin content. In contrast, NGF did not influence the phenotype of mi/mi CMCs. The poor response of mi/mi CMCs to NGF was attributed to the deficient expression of p75 NGF receptor. The purpose of the present study is to examine the effect of MITF on p75 gene transcription. Overexpression of +-MITF or mi-MITF was observed in mi/mi CMCs to which cDNA encoding each type of MITF had been introduced using the retroviral vector. Overexpression of +-MITF but not of mi-MITF normalized the expression of p75 and the above-mentioned poor responses of mi/mi CMCs to NGF, indicating the involvement of +-MITF in p75 gene transactivation. Then, we analyzed the promoter of the p75 gene. Two CANNTG motifs recognized by bHLH-Zip–type transcription factors were conserved between the mouse and rat p75 promoters. One of these two CANNTG motifs was specifically bound by +-MITF. When the luciferase gene under the control of the p75 promoter was cotransfected into NIH/3T3 fibroblasts with cDNA encoding +-MITF or mi-MITF, luciferase activity increased significantly only when +-MITF cDNA was cotransfected. The mutation of this CANNTG motif abolished the transactivation effect of +-MITF, indicating that +-MITF transactivated the p75 gene, at least in part, through direct binding.
Collagen But Not Fibrinogen Surfaces Induce Bleb Formation, Exposure of Phosphatidylserine, and Procoagulant Activity of Adherent Platelets: Evidence for Regulation by Protein Tyrosine Kinase-Dependent Ca2+ Responses
Authors: Heemskerk Johan W.M. , Vuist Wim M.J. , Feijge Marion A.H. , Reutelingsperger Chris P.M. , Lindhout Theo 
Published: October 2019

AbstractWith a combined phase-contrast and fluorescence video imaging system, changes in morphology and cytosolic [Ca2+]i were investigated of fura-2–loaded platelets during adhesion to fibrinogen or collagen matrices. The Ca2+ signals were, on the level of single platelets, compared to the secretion and procoagulant responses, using fluorescent-labeled AK-6 antibody against P-selectin and labeled annexin V for detection of surface-exposed phosphatidylserine (PS), respectively. Platelets in contact with fibrinogen developed filapods and spread over the matrix, in most of the cells without detectable Ca2+ signal. Thrombin induced repetitive spiking in [Ca2+]i , followed by the expression of P-selectin but not of PS on the platelet surface. Platelet interaction with collagen resulted in spreading and transformation of the cells into blebbing, “balloon”-like structures (diameter about 5 μm). The latter morphological changes were accompanied by high and prolonged increases in [Ca2+]i , by the exposure of both P-selectin and PS, and by the ability of the platelets to convert prothrombin into thrombin. Thrombin addition accelerated the onset of the Ca2+ signals and the appearance of surface-exposed PS. Collagen-induced PS exposure was slightly reduced by treatment of the platelets with aspirin, and strongly inhibited by suppression of the Ca2+ responses with prostaglandin E1 or the Ca2+ chelator, dimethyl-BAPTA. Inhibition of protein tyrosine phosphorylation with genistein, U73343, or wortmannin resulted in spiking Ca2+ responses in many of the platelets and in almost complete reduction of bleb formation and PS exposure. In contrast, genistein did not suppress bleb formation and PS exposure of platelets stimulated with the Ca2+ ionophore A23187. We conclude that a collagen but not fibrinogen matrix acts as a potent activator of the procoagulant response through activation of tyrosine kinases and subsequent generation of sustained intracellular Ca2+ signals.