bluuebunny/crossref_metadata_2025_split huggingface dataset:
Loss of PTEN expression leading to high Akt activation in human multiple myelomas
Authors: Hyun Teresa , Yam Alan , Pece Salvatore , Xie Xiaozhen , Zhang Jie , Miki Toru , Gutkind J. Silvio , Li Weiqun 
Published: October 2019

AbstractMouse plasma cell tumor (PCT) and human multiple myeloma (MM) are terminal B-cell malignancies sharing many similarities. Our recent work demonstrated that activation of the insulin-like growth factor receptor (IGF-IR)/insulin receptor substrate (IRS)/phosphatidylinositol 3′ kinase (PI 3′K) pathway was evident in the tumor lines derived from both species. Although PI 3′K activity was higher in mouse tumor lines than that in human tumors, activation of Akt serine/threonine kinase was markedly lower in mouse lines. This discrepancy prompted us to test the status of PTEN tumor suppressor gene, as it has been shown to be a negative regulator of PI 3′K activity. Although all the mouse lines expressed intact PTEN, 2 of the 4 human lines (Δ47 and OPM2) possessing the highest Akt activity lost PTEN expression. Sequencing analysis demonstrated that the PTEN gene contains a deletion spacing from exon 3 to exon 5 or 6 in the Δ47 line and from exon 3 to 7 in the OPM2 line. Restoration of PTEN expression suppressed IGF-I–induced Akt activity, suggesting that loss of PTEN is responsible for uncontrolled Akt activity in these 2 lines. Despite the expression of PTEN with the concomitant low Akt activity in all mouse PCT lines, their p70S6K activities were generally higher than those in 3 human MM lines, arguing for specific negative regulation of Akt, but not p70S6K by PTEN. These results suggest that p70S6K and Akt may be differentially used by the plasma cell tumors derived from mice and humans, respectively.
o-Raffinose cross-linked hemoglobin improves the hemostatic defect associated with anemia and thrombocytopenia in rabbits
Authors: Lee David H. , Bardossy Leslie , Peterson Nichole , Blajchman Morris A. 
Published: October 2019

Abstract
Several different preparations of cross-linked hemoglobin (CLHb) are being evaluated for their efficacy and safety as red cell substitutes in a variety of preclinical and clinical settings. Because CLHb is known to sequester nitric oxide (NO) and inhibit NO-mediated processes, we hypothesized that CLHb would have a hemostatic effect by enhancing platelet reactivity, inducing vasoconstriction, or both. Infusion of o-raffinose CLHb shortened the prolonged microvascular bleeding time and decreased blood loss from ear incisions in rabbits rendered anemic and thrombocytopenic. Moreover, this hemostatic effect persisted for at least 24 hours after infusion. Phenylephrine induced a degree of vasoconstriction similar to that induced by CLHb but did not shorten the bleeding time or decrease blood loss, suggesting that vasoconstriction alone cannot account for the hemostatic effect of CLHb. There was no evidence of CLHb-induced activation of coagulation in vivo, since infusion of CLHb did not increase circulating levels of thrombin-antithrombin complex. In vitro, CLHb abolished the inhibitory effect of the NO donor 3-morpholinosydnonimine on platelet aggregation and enhanced the aggregation of stimulated but not resting platelets. This potentiating effect was not attenuated by the addition of superoxide dismutase or catalase. To evaluate the potential arterial thrombogenicity of CLHb, a model of carotid artery thrombosis was developed in rabbits without thrombocytopenia or anemia. Compared with albumin infusion, CLHb infusion shortened the time to complete carotid occlusion. These data suggest that CLHb may shift the thromboregulatory balance toward clot formation, resulting in decreased bleeding in anemic and thrombocytopenic rabbits and possibly increasing arterial thrombogenicity in normal rabbits.
An open-label study of the role of adjuvant hemostatic support with protein C replacement therapy in purpura fulminans–associated meningococcemia
Authors: White Barry , Livingstone Wendy , Murphy Ciaran , Hodgson Andrew , Rafferty Marie , Smith Owen P. 
Published: October 2019

AbstractActivated protein C (APC) is a natural anticoagulant that plays a pivotal role in coagulation homeostasis. Severe inherited or acquired deficiency results in a clinical syndrome called purpura fulminans. In addition, APC also appears to have potent cytokine-modifying properties and is protective in animal models of sepsis. The dual functional properties of APC are particularly relevant to severe meningococcemia, where acquired PC deficiency is accompanied by multiorgan failure and purpura fulminans. The authors conducted an open-label prospective study assessing the efficacy of PC replacement therapy in patients with severe meningococcal septicemia, purpura fulminans, and multiorgan failure. The morbidity and mortality were compared with predicted morbidity using the Glasgow Meningococcal Septicemia Prognostic Score. Thirty-six patients with a mean age of 12 years (range 3 months to 72 years) were enrolled in the study. The mean ± SD for plasma PC was 18 ± 7 IU/mL. PC was significantly lower than antithrombin or protein S and was also significantly lower than PC levels in a cohort of patients who developed meningococcemia without multiorgan failure and purpura fulminans. A total of 3 of 36 (8%) patients died, which compares favorably with predicted mortality of 18 of 36 (50%). Amputations were required in 4 of 33 (12%) survivors and in 2 of 31 (6.5%) patients who received PC within 24 hours of admission into the hospital, in comparison with the predicted amputation rate of 11 of 33 (30%). In conclusion, PC replacement therapy in severe meningococcal septicemia was associated with a reduction in predicted morbidity and mortality. The beneficial effect of PC replacement may reflect both the anticoagulant and anti-inflammatory properties of the PC pathway.
Ontogenic emergence of the hematon, a morphogenetic stromal unit that supports multipotential hematopoietic progenitors in mouse bone marrow
Authors: Blazsek Istvàn , Chagraoui Jalila , Péault Bruno 
Published: October 2019

AbstractDevelopment of the full repertoire of hematopoietic-lymphopoietic cells from a single stem cell requires specific contacts with stromal cells. The spatio-temporal organization of these cell associations in the bone marrow in ontogeny is, however, not well understood. In the adult, 10% of marrow cells form a cohort of compact aggregates, the hematon. In the hematon mesenchymal cells (Stro-1+), perivascular lipocytes (desmin+), endothelial cells (CD34+, Flk-1+, Sca-1+), and macrophages amalgamate with the hematopoietic progenitors long-term culture-initiating cells (LTC-IC), cobblestone area–forming cell (CAFC), high-proliferative-potential colony-forming unit (HPP-CFU), granulocyte-macrophage (GM)–CFU, and burst-forming unit–erythroid (BFU-E). During endochondral ossification of the femur, GM-CFU and day 7 CAFC numbers increased progressively from day 17 of gestation, but primitive, day 35 LTC-IC appeared from postnatal day 2. Unexpectedly, bone marrow (BM) taken between embryonic day 17 and day 5 was unable to support myeloid cell production in long-term cultures or to support day 35 LTC-IC growth. However, a gain in stromal cell competence occurred between days 7 and 10, which was correlated with the emergence of hematon in the BM. Thus, acquisition of hematopoietic competence by BM lags behind for approximately 10 days after the initial hematopoietic cell influx. In the adult, the hematon fraction was 3.7-fold enriched in day 35 LTC-IC over the buffy coat. It produced more GM-CFU and HPP-CFU in myeloid culture and more B cells in lymphopoietic “switch” cultures. It is reported that stromal hematopoietic units named hematons are specific morphogenetic structures that emerge at a well-defined postnatal stage of development in long bones, delineate discrete territories for hematopoietic stem cell seeding and development, embody the most productive hematogenous compartment in the BM, and probably enclose a morphogenetic organizer.
VEGF-C signaling pathways through VEGFR-2 and VEGFR-3 in vasculoangiogenesis and hematopoiesis
Authors: Hamada Koichi , Oike Yuichi , Takakura Nobuyuki , Ito Yasuhiro , Jussila Lotta , Dumont Daniel J. , Alitalo Kari , Suda Toshio 
Published: October 2019

AbstractSignaling by vascular endothelial growth factors (VEGFs) through VEGF receptors (VEGFRs) plays important roles in vascular development and hematopoiesis. The authors analyzed the function of VEGF-C signaling through both VEGFR-2 and VEGFR-3 in vasculoangiogenesis and hematopoiesis using a coculture of para-aortic splanchnopleural mesoderm (P-Sp) explants from mouse embryos with stromal cells (OP9). Vasculogenesis and angiogenesis were evaluated by the extent of vascular bed and network formation, respectively. Addition of VEGF-C to the P-Sp culture enhanced vascular bed formation and suppressed definitive hematopoiesis. Both vascular bed and network formations were completely suppressed by addition of soluble VEGFR-1–Fc competitor protein. Formation of vascular beds but not networks could be rescued by VEGF-C in the presence of the competitor, while both were rescued by VEGF-A. VEGFR-3–deficient embryos show the abnormal vasculature and severe anemia. Consistent with these in vivo findings, vascular bed formation in the P-Sp from the VEGFR-3–deficient embryos was enhanced to that in wild-type or heterozygous embryos, and hematopoiesis was severely suppressed. When VEGFR-3–Fc chimeric protein was added to trap endogenous VEGF-C in the P-Sp culture of the VEGFR-3–deficient embryos, vascular bed formation was suppressed and hematopoiesis was partially rescued. These results demonstrate that because VEGF-C signaling through VEGFR-2 works synergistically with VEGF-A, the binding of VEGF-C to VEGFR-3 consequently regulates VEGFR-2 signaling. In VEGFR-3–deficient embryos, an excess of VEGF-C signals through VEGFR-2 induced the disturbance of vasculogenesis and hematopoiesis during embryogenesis. This indicates that elaborated control through VEGFR-3 signaling is critical in vasculoangiogenesis and hematopoiesis.
Up-regulation of costimulatory/adhesion molecules by histone deacetylase inhibitors in acute myeloid leukemia cells
Authors: Maeda Takahiro , Towatari Masayuki , Kosugi Hiroshi , Saito Hidehiko 
Published: October 2019

AbstractHistone deacetylase inhibitors (HDACIs) have been used to focus on the effects of inducing gene expression through the acetylation of histones which results in chromatin remodeling. The study explored whether HDACIs could induce the expression of costimulatory/adhesion molecules on acute myeloid leukemia (AML) cells, thereby effectively inducing tumor immunity. The expression of CD80, CD86, human leukocyte antigen (HLA)-DR, HLA-ABC, and intracellular adhesion molecule–1 (ICAM-1) was tested in human AML cell lines after the addition of HDACI, sodium butyrate (SB). Generally, increased expression of CD86 was observed by SB treatment in a majority of cell lines, and ICAM-1 was expressed in fewer cell lines. Essentially the same results were obtained using other HDACIs such as FR901228, trichostatin A, and trapoxin A. Quantitation of transcripts of CD86 accompanied with RNA synthesis inhibition assay and nuclear run-on assay revealed that SB up-regulates the CD86 expression transcriptionally. Furthermore, chromatin immunoprecipitation experiments showed that HDACI treatment caused remarkable acetylation on histone H3 and H4 at CD86 promoter chromatin in vivo. In 30 clinical AML samples, CD86 expression was significantly increased (P &lt; .001) by SB treatment, and the expression of HLA-DR and ICAM-1 was moderately increased (P &lt; .05) by SB treatment. Finally, the allogeneic mixed leukocyte reaction (allo-MLR) against HL60 cells pretreated with SB was enhanced 4-fold compared with allo-MLR obtained with non-treated HL60 cells. These results suggest that the immunotherapeutic use of HDACIs may become a novel tool for treatment of AML.
The interleukin-6 receptor alpha-chain (CD126) is expressed by neoplastic but not normal plasma cells
Authors: Rawstron Andy C. , Fenton James A. L. , Ashcroft John , English Anne , Jones Richard A. , Richards Stephen J. , Pratt Guy , Owen Roger , Davies Faith E. , Child J. Anthony , Jack Andrew S. , Morgan Gareth 
Published: October 2019

Abstract
Interleukin-6 (IL-6) is reported to be central to the pathogenesis of myeloma, inducing proliferation and inhibiting apoptosis in neoplastic plasma cells. Therefore, abrogating IL-6 signaling is of therapeutic interest, particularly with the development of humanized anti–IL-6 receptor (IL-6R) antibodies. The use of such antibodies clinically requires an understanding of IL-6R expression on neoplastic cells, particularly in the cycling fraction. IL-6R expression levels were determined on plasma cells from patients with myeloma (n = 93) and with monoclonal gammopathy of undetermined significance (MGUS) or plasmacytoma (n = 66) and compared with the levels found on normal plasma cells (n = 11). In addition, 4-color flow cytometry was used to assess the differential expression by stage of differentiation and cell cycle status of the neoplastic plasma cells. IL-6R alpha chain (CD126) was not detectable in normal plasma cells, but was expressed in approximately 90% of patients with myeloma. In all groups, the expression levels showed a normal distribution. In patients with MGUS or plasmacytoma, neoplastic plasma cells expressed significantly higher levels of CD126 compared with phenotypically normal plasma cells from the same marrow. VLA-5− “immature” plasma cells showed the highest levels of CD126 expression, but “mature” VLA-5+ myeloma plasma cells also overexpressed CD126 when compared with normal subjects. This study demonstrates that CD126 expression is restricted to neoplastic plasma cells, with little or no detectable expression by normal cells. Stromal cells in the bone marrow microenvironment do not induce the overexpression because neoplastic cells express higher levels of CD126 than normal plasma cells from the same bone marrow in individuals with MGUS.
The role of apoptosis, proliferation, and the Bcl-2–related proteins in the myelodysplastic syndromes and acute myeloid leukemia secondary to MDS
Authors: Parker Jane E. , Mufti Ghulam J. , Rasool Feyrooz , Mijovic Aleksandar , Devereux Stephen , Pagliuca Antonio 
Published: October 2019

Abstract
Bone marrow CD34+ cell apoptosis (annexin V), proliferation (Ki-67), and Bcl-2-related protein expression was evaluated by flow cytometry in 102 patients with myelodysplastic syndrome (MDS) and acute myeloid leukemia secondary to MDS (MDS-AML) and in 30 normal donors (NBM). Apoptosis was significantly increased in refractory anemia (RA)/RA with ringed sideroblasts (RARS) (56.9% [20.4%-93.6%]) and refractory anemia with excess blasts (RAEB) (51.2% [25.2%-76.6%]) compared with NBM (16.7% [3.4%-35.3%],P &lt; .0001). In RA/RARS, apoptosis always exceeded proliferation (Ki-67-positivity, 26.1% [9.5%-47.8%]; apoptosis:proliferation ratio 2.08 [1.15-3.63]); whereas in RAEB, this ratio equalized (1.14 [0.93-2.08]) due to increased proliferation (40.4% [22%-69.5%]). Progression to RAEB in transformation (RAEB-t)/MDS-AML was associated with a significant reduction in apoptosis (22.3% [2.1%-53.2%];P &lt; .0001) and proliferation (16.8% [1.9%-75.8%);P = .04; ratio 1.69 [0.16-12.21]). Pro-apoptotic (Bax/Bad) versus anti-apoptotic (Bcl-2/Bcl-X) Bcl-2-related protein ratios were increased in RA/RARS compared with NBM (2.57 [1.93-9.42] versus 1.89 [0.65-4.1]; P = .06), whereas disease progression was associated with significantly reduced ratios (1.16 [0.06-3.32]; P &lt; .0001) due primarily to increased Bcl-2 expression. Apoptosis and Bax/Bad:Bcl-2/Bcl-X ratio were inversely correlated with both International Prognostic Scoring System score and cytogenetic risk group; highest levels observed in patients with low score and/or good risk cytogenetics. There was a trend toward an association between Bcl-2–related protein expression and apoptosis (P = .07). This study indicates that MDS progression arises through multiple hits that alter levels of CD34+cell apoptosis and proliferation. Early disease is associated with excessive apoptosis and elevated ratio of apoptosis to proliferation. Increased proliferative rates are observed in RAEB, whereas leukemic transformation arises through inhibition of apoptosis rather than excessive cell growth. Although disease progression is accompanied by a fall in pro-apoptotic versus anti-apoptotic Bcl-2–related protein ratios, heterogeneity in patterns of protein expression indicates that factors additional to Bcl-2 family members play a role in the deregulated apoptosis in MDS.
High marrow seeding efficiency of human lymphomyeloid repopulating cells in irradiated NOD/SCID mice
Authors: Cashman Johanne D. , Eaves Connie J. 
Published: October 2019

Abstract
Transplantable human hematopoietic stem cells (competitive repopulating units [CRU]) can be quantitated based on their ability to produce large populations of lymphoid and myeloid progeny within 6 weeks in the marrow of intravenously injected, sublethally irradiated NOD/SCID mice. It is shown that the proportions of total injected human fetal liver and cord blood CRU in the marrow of mice 24 hours after transplantation are 5% and 7%, respectively, as determined by limiting-dilution assays in other primary and secondary NOD/SCID mice. The similarity in these 2 seeding efficiency values suggests that mechanisms regulating the ability of human hematopoietic stem cells to enter the marrow from the blood, at least in this xenotransplant model, do not change between fetal life and birth. In addition, it appears that previously reported human stem cell frequencies and their in vivo self-renewal activity measured in NOD/SCID mice have been markedly underestimated.
Primitive hematopoietic stem cell function in vivo is uniquely high in the CXB-12 mouse strain
Authors: Chen Jichun , Astle Clinton M. , Müller-Sieburg Christa E. , Harrison David E. 
Published: October 2019

AbstractBone marrow cells (BMCs) from CXB-12/HiaJ (CXB-12) mice had 14 times the total long-term repopulating ability found in the best of 11 other CXB recombinant inbred (RI) lines. BMCs from each RI line donor were mixed with genetically marked standard competitor BMCs from the BALB/cBy×C57BL/6 F1 (CByB6F1) hybrid, the mice used to produce the RI lines, and the mixtures repopulated lethally irradiated CByB6F1 recipients. Percentages of donor-type erythrocytes and lymphocytes measured the actual long-term repopulating functions of the donor RI lines relative to the standard competitor. CXB-12 BMCs repopulated better after 3 or 6 months than after 1 month, suggesting that the most primitive precursors were involved. Compared to CByB6F1 standard competitor cells, CXB-12 cells repopulated 3 to 12 times as well, with their advantage increasing when higher doses of cells were transplanted, probably because of hybrid resistance of the recipient against low doses. This was far better than expected, because F1 cells normally function 2 to 3 times as well as cells from an inbred strain. In competitive dilution, the advantage resulted from 2 factors: more precursor cells and more function per precursor. In the model that best fit the data, CXB-12 donors had 2.4 times the concentration of hematopoietic stem cells (HSCs) as the CByB6F1 standard, and each HSC repopulated 1.4 times as well. CXB-12 mice did not have elevated erythrocyte and lymphocyte numbers in blood and marrow and did not have unusually elevated concentrations of colony-forming unit spleen, cobblestone colonies, and long-term colony-initiating cells in marrow.
During ontogeny primitive (CD34+CD38−) hematopoietic cells show altered expression of a subset of genes associated with early cytokine and differentiation responses of their adult counterparts
Authors: Oh Il-Hoan , Lau Aster , Eaves Connie J. 
Published: October 2019

AbstractComparison of gene expression profiles in closely related subpopulations of primitive hematopoietic cells offers a powerful first step to elucidating the molecular basis of their different biologic properties. Here we present the results of a comparative quantitative analysis of transcript levels for various growth factor receptors, ligands, and transcription factor genes in CD34+CD38− and CD34+CD38+ cells purified from first trimester human fetal liver, cord blood, and adult bone marrow (BM). In addition, adult BM CD34+CD38− cells were examined after short-term exposure to various growth factors in vitro. Transcripts for 19 of the 24 genes analyzed were detected in unmanipulated adult BM CD34+CD38− cells. Moreover, the levels of transforming growth factor beta (TGF-β), gp130, c-fos, and c-jun transcripts in these cells were consistently and significantly different (higher) than in all other populations analyzed, including phenotypically similar but biologically different cells from fetal or neonatal sources, as well as adult BM CD34+ cells still in G0 after 2 days of growth factor stimulation. We have thus identified a subset of early response genes whose expression in primitive human hematopoietic cells is differently regulated during ontogeny and in a fashion that is recapitulated in growth factor-stimulated adult BM CD34+CD38− cells, before their cell cycle progression and independent of their subsequent differentiation response. These findings suggest a progressive alteration in the physiology of primitive hematopoietic cells during development such that these cells initially display a partially “activated” state, which is not maximally repressed until after birth.
Vascular endothelial growth factor–stimulated endothelial cells promote adhesion and activation of platelets
Authors: Verheul Henk M. W. , Jorna Anita S. , Hoekman Klaas , Broxterman Henk J. , Gebbink Martijn F. B. G. , Pinedo Herbert M. 
Published: October 2019

AbstractCoagulation abnormalities, including an increased platelet turnover, are frequently found in patients with cancer. Because platelets secrete angiogenic factors on activation, this study tested the hypothesis that platelets contribute to angiogenesis. Stimulation with vascular endothelial growth factor (VEGF, 25 ng/mL) of human umbilical vein endothelial cells (HUVECs) promoted adhesion of nonactivated platelets 2.5-fold. In contrast, stimulation of HUVECs with basic fibroblast growth factor (bFGF) did not promote platelet adhesion. By blocking tissue factor (TF) activity, platelet adhesion was prevented and antibodies against fibrin(ogen) and the platelet-specific integrin, αIIbβ3, inhibited platelet adhesion for 70% to 90%. These results indicate that VEGF-induced platelet adhesion to endothelial cells is dependent on activation of TF. The involvement of fibrin(ogen) and the αIIbβ3 integrin, which exposes a high-affinity binding site for fibrin(ogen) on platelet activation, indicates that these adhering platelets are activated. This was supported by the finding that the activity of thrombin, a product of TF-activated coagulation and a potent platelet activator, was required for platelet adhesion. Finally, platelets at physiologic concentrations stimulated proliferation of HUVECs, indicative of proangiogenic activity in vivo. These results support the hypothesis that platelets contribute to tumor-induced angiogenesis. In addition, they may explain the clinical observation of an increased platelet turnover in cancer patients. Platelets may also play an important role in other angiogenesis-dependent diseases in which VEGF is involved, such as diabetes and autoimmune diseases.