bluuebunny/crossref_metadata_2025_split huggingface dataset:
Reactive Oxygen Species Might Have Important Roles On Angiogenesis of Endothelial Progenitor Cells Derived From HCB(Human Cord Blood) Which Are Stimulated by VEGF.
Authors: Yoo Eun-Sun , Mun Yeung-Chul , Lee Kyoung-Eun , Nam Eunmi , Ahn Jee-Young , Oh Soo-Ah , Seong Chu-Myong 
Published: October 2019

Abstract
Abstract 1445
Poster Board I-468

Purpose
VEGF is a key angiogenic growth factor stimulating proliferation, migration, and tube formation on endothelial cells (ECs), that works through the VEGF receptor type 2 (VEGR2, KDR/Flk1). Reactive oxygen species (ROS) such as superoxide and H2O2 have roles signaling for molecules on angiogenesis. In present study, the aim is to investigate the roles of reactive oxygen species on neovascularization in endothelial progenitor cells.

Methods
Mononuclear cells isolated from UCB were cultured using EGM-2 medium with VEGF, IGF-1 and FGF or basal medium in presence or absence of VEGF for 7 days. Outgrowing endothelail progenitor cells (Yoo et al, STEM CELLS 21:228-235, 2003) at first week of culture were analyzed ROS production by dichlorofluorescein (DCF) fluorescence by use of 2,7-dichlorodihydro-fluoresceine-diacetate (H2DCF-DA). In order to determine that ROS production might involve in EPC proliferation and migration, we had analyzed the impact of N-acetyl-L-cysteine (NAC), broad spectrum ROS scavenger, and NAD(P)H oxidase inhibitor, diphenylene iodonium (DPI) using the proliferation, in vitro tube formation matrigel assay, migration assay with SDF-1/VEGF. We also analyzed the expression of NOX2-based NADPH oxidase (gp91phox) and activation of ERK2 and Akt (Thr308 and Ser473) using VEGF with or without DPI.

Results
Intracellular ROS level were increased during endothelial progenitor cell culture and were higher in UCB compared to that of BM and increased by VEGF treatment. Proliferation, in vitro tube formation matrigel assay and migration assay on endothelial progenitor cells using SDF-1/VEGF were decreased with additions of ROS scavenger DPI when compared with that of control group. In western blot data, NOX2-based NADPH oxidase(gp91phox) was increased by VEGF and decreased by addition of DPI. VEGF induced pERK2 expression was also decreased by DPI and that finding was correlated on down-regulation of endothelial cell proliferation by DPI. Activation of Ser473 Akt was found in control group and decreased by VEGF and rebounded by VEGF and DPI. But Thr308 Akt was not activated in our experiments.

Conclusions
These results suggested that NOX2-based NADPH oxidase(gp91phox)-induced ROS might play important roles on EPCs migration and proliferation by VEGF. Namely, manipulating the level of ROS biochemically may alter the pathogenesis in cardiovascular and in ischemic limb diseases. In results, these data may be useful to develop new therapeutic strategies.

Disclosures
No relevant conflicts of interest to declare.
The Role of HDAC1 Acetylation in Hematopoiesis and GATA-1 Function.
Authors: Luo Yi , Bungert Jorg , Huang Suming , Qiu Yi 
Published: October 2019

Abstract
Abstract 1459
Poster Board I-482
Histone deacetylases (HDACs) play important roles in transcriptional regulation in eukaryotic cells. Several lines of evidence also link HDACs to cancer. HDAC inhibitors have shown preclinical promise when combined with other therapeutic agents in the treatments of leukemia and solid tumors. HDAC1 often presents in repressor complexes, such as Sin3, NuRD and CoREST complexes. We previously found that HDAC1 can be acetylated in vivo by acetyltransferase p300 and that acetylated HDAC1 completely loses its deacetylase activity (Qiu et al, 2006). In this study, we investigate the role of HDAC1 during erythroid differentiation. HDAC1 deacetylase activity gradually reduced upon the induction of differentiation. However, the HDAC1 protein level remains unchanged, suggesting that HDAC1 deacetylase activity, but not its protein level, is regulated. To further test the role of HDAC1 in erythroid differentiation, stable cell lines that overexpress HDAC1 and mutants mimicking acetylated or unacetylated HDAC1 were established. We also generated stable HDAC1 and HDAC2 knock down cell lines. The results showed that HDAC1 deacetylase activity is required to promote erythroid proliferation and to inhibit differentiation. Next, we studied whether HDAC1 modulates erythroid differentiation through regulating the activity of key erythroid transcription factor GATA-1. GATA-1 interacts with many other key hematopoietic transcription factors, as well as chromatin remodeling/modifying coactivators and corepressors. It is suggested that GATA-1 mediates gene activation through its association with coactivator complexes. However, recent studies indicated that GATA-1 associates with HDAC1/2 containing corepressor complexes (NuRD) throughout differentiation of erythroid cells. We investigated the deacetylase activity of the GATA-1 associated NuRD complex during erythroid differentiation. We found that the deacetylase activity of the complex decreased and further diminished at day 5 of DMSO induced MEL cells. Accordingly, the acetylated form of HDAC1 within the GATA-1 complex increased during erythroid differentiation. We further demonstrated the role of HDAC1 in GATA-1 mediated gene transcription in transient transfection assays. These studies indicate that HDAC1 plays an important role in regulating GATA-1 activity and the deacetylase activity of the GATA-1 associated NuRD complex is also regulated. This complex may play different roles in undifferentiated and differentiated erythroid cells. Thus, our results suggest a novel but rather general regulatory mechanism of histone deacetylase containing protein complexes.

Disclosures
No relevant conflicts of interest to declare.
Klf1 Regulatory Networks in Primary Erythroid Cells.
Authors: Tallack Michael , Whitington Thomas , Gardiner Brooke , Wainwright Eleanor , Keys Janelle , Monet Marion , Nourbakhsh Ehsan , Cloonan Nicole , Grimmond Sean , Bailey Timothy , Perkins Andrew Charles 
Published: October 2019

Abstract
Abstract 1462
Poster Board I-485
Klf1/Eklf regulates a diverse suite of genes to direct erythroid cell differentiation from bi-potent progenitors. To determine the local cis-regulatory contexts and transcription factor networks in which Klf1 works, we performed Klf1 ChIP-seq using the SOLiD deep sequencing platform. We mapped more than 10 million unique 35mer tags and found ∼1500 sites in the genome of primary fetal liver erythroid cells are occupied by endogenous Klf1. Many reside within well characterised erythroid gene promoters (e.g. b-globin) or enhancers (e.g. E2f2 intron 1), but some are >100kb from any known gene. We tested a number of Klf1 bound promoter and intragenic sites for activity in erythroid cell lines and zebrafish. Our data suggests Klf1 directly regulates most aspects of terminal erythroid differentiation including synthesis of the hemoglobin tetramer, construction of a deformable red cell membrane and cytoskeleton, bimodal regulation of proliferation, and co-ordination of anti-apoptosis and enucleation pathways. Additionally, we suggest new mechanisms for Klf1 co-operation with other transcription factors such as those of the gata, ets and myb families based on over-representation and spatial constraints of their binding motifs in the vicinity of Klf1-bound promoters and enhancers. Finally, we have identified a group of ∼100 Klf1-occupied sites in fetal liver which overlap with Klf4-occupied sites in ES cells defined by Klf4 ChIP-seq. These sites are associated with genes controlling the cell cycle and proliferation and are Klf4-dependent in skin, gut and ES cells, suggesting a global paradigm for Klfs as regulators of differentiation in many, if not all, cell types.

Disclosures
No relevant conflicts of interest to declare.
The MiR-23a MicroRNA Cluster Inhibits B Cell Development.
Authors: Mullenix Jason , Kong Kimi Y , Owens Kristin Severns , Rogers Jason , FitzPatrick Shannon , Dahl Richard E. 
Published: October 2019

Abstract
Abstract 1465
Poster Board I-488
The miR-23a microRNA (miRNAs) cluster inhibits both [ITALIC]in vitro[/ITALIC] and [ITALIC]in vivo[/ITALIC] B cell development. When murine hematopoietic progenitor cells expressing the 23a cluster miRNAs were cultured in B cell promoting conditions we observed over a five-fold decrease in the generation of CD19+ B cells compared to control cultures. Conversely, we observed over a five-fold increase in CD11b+ myeloid cells. When irradiated mice were transplanted with bone marrow expressing the miR-23a cluster we observed a two-fold decrease in bone marrow and splenic B cells, 8 weeks post-transplant compared to control mice. The miR-23a cluster codes for a single pri-transcript, which when processed yields three mature miRNAs: miR-23a, miR-27a, and miR-24-2. All three mature miRNAs are more abundant in myeloid cells compared to other hematopoietic cells. In vitro miR-24 alone is necessary and sufficient to inhibit B cell development. The promoter for the cluster contains conserved binding sites for the essential myeloid transcription factors PU.1 and C/EBP alpha. Chromatin immunoprecipitations demonstrated that PU.1 and C/EBP alpha are associated with the promoter in myeloid cells. In addition, C/EBP alpha is bound to several highly conserved regions upstream of the promoter. Both PU.1 and C/EBP alpha promote myeloid development at the expense of lymphopoiesis. Our work suggests that the miR-23a cluster may be a critical downstream target of PU.1 and C/EBP alpha in the specification of myeloid cell fate. Although miRNAs have been identified downstream of PU.1 and C/EBP alpha in mediating the development of monocytes and granulocytes, the 23a cluster is the first downstream miRNA target implicated in the regulating lymphoid cell fate acquisition. We are currently identifying targets of miR-24 that may mediate the inhibitory effect on B lymphopoiesis.

Disclosures
No relevant conflicts of interest to declare.
Controlling Hematopoiesis through Sumoylation-Dependent Regulation of a GATA Factor.
Authors: Lee Hsiang-Ying , Johnson Kirby D. , Fujiwara Tohru , Boyer Meghan E. , Kim Shin-Il , Bresnick Emery H. 
Published: October 2019

Abstract
Abstract 1467
Poster Board I-490
GATA factors function via distinct modes to establish transcriptional networks that control fundamental developmental processes including hematopoiesis. Whereas the master regulator of hematopoiesis GATA-1 is subject to multiple posttranslational modifications, how these modifications influence GATA-1 activity at endogenous loci is poorly understood. GATA-1 is sumoylated at K137, which resides in the N-terminus, but how the N-terminus contributes to GATA-1 function remains unclear. Expression of a GATA-1 mutant lacking amino acids 1-83 of the N-terminus is linked to the development of acute megakaryoblastic leukemia [Wechsler et al. (2002) Nat. Genet. 32, 148], and deletion of the N-terminus preferentially deregulates a subset of target genes [Johnson et al. (2006) PNAS. 103, 15939]. We demonstrate that sumoylation at K137 promotes transcriptional activation only at a subset of its target genes – those requiring the cell type-specific coregulator, Friend of GATA-1 (FOG-1). Interestingly, a GATA-1 mutation that disrupts FOG-1 binding (V205G) and K137 mutations yielded similar phenotypes, although FOG-1 was not required for K137 sumoylation. Both V205 and K137 mutations dysregulated GATA-1 chromatin occupancy at select sites, FOG-1-dependent target gene expression, and were rescued by tethering SUMO-1. While FOG-1- and SUMO-1-dependent genes migrated away from the nuclear periphery upon erythroid maturation, FOG-1- and SUMO-1-independent genes localized at the periphery independent of maturation. These results illustrate how sumoylation of a critical developmental regulator selectively controls its function at specific loci, and members of a target gene ensemble with distinct coregulator and posttranslational modification requirements reside in different subnuclear compartments.

Disclosures:
No relevant conflicts of interest to declare.
High Incidence of Arterial Thrombosis in Young Patients Treated for Multiple Myeloma:Results of a Prospective Cohort Study.
Authors: Libourel Eduard J , Sonneveld P. , van der Holt Bronno , Leebeek F. W.G. 
Published: October 2019

Abstract
Abstract 149
It is well known that patients with multiple myeloma (MM) are at high risk for venous thromboembolism (VTE). Thrombotic complications are most frequently seen in patients treated with thalidomide based regimens. Several other risk factors for VTE have been identified including abnormalities in coagulation factors, such as high factor VIII levels, APC resistance and hypofibrinolysis. Recently a few cases of MM patients and arterial thromboembolism (ATE) have been reported. Therefore we prospectively studied the risk of ATE in 195 consecutive patients aged <66 years with previously untreated MM. All patients were treated according to the HOVON 50 study protocol, a prospective randomized phase III study on the effects of 3 courses of doxorubicin and dexamethasone with thalidomide (TAD) or vincristine (VAD) followed by high dose melphalan and thalidomide or interferon-alpha2 maintenance or the HOVON 65 study protocol, a prospective randomised phase III study on the effects of 3 courses doxorubicin and dexamethasone with vincristine (VAD) or bortezomib (PAD), followed by high dose melphalan and bortezomib or thalidomide maintenance. All patients treated with TAD courses received prophylaxis for VTE with low molecular-weight heparin. During a follow-up of 522.4 patient-years 11 patients (5.6%) developed ATE. Most events occurred within one year after start of treatment (64%). Median age at onset of ATE was 59 years (range 43–65). For myocardial infarction we demonstrated an annual incidence of 0.77% in men and 0.19% in women compared to an equal age group, 55–59 years, described by Parikh et al in the Framingham Heart Study population who reported annual incidences of 0.22% in men and 0.04% in women, respectively. For cerebral ischemic events we demonstrated an annual incidence of 0.77% in men and 0.19% in women compared to 0.29% in men and 0.22% in women in the general Dutch population, aged 55–59, as described by Gijsen and Poos. Of thrombophilic factors a statistically significant higher factor VIII:C (FVIII:C) was observed in symptomatic patients, 2.93 IU/ml (1.16–6.45) versus 2.15 (0.74–6.48) (p=0.03). FVIII:C correlated significantly with age (p=0.02) and ISS stage (p=0.001). Adjustment for age and ISS stage, revealed a RR for ATE of 11.67 (95% CI: 2.23–61.18) for hypertension, a RR of 15.17 (1.78–129.54) for smoking and a RR of 1.85 (0.99–3.47) for each IU/ml increase in FVIII level, respectively. In conclusion, MM patients are at high risk for arterial thrombotic events during and following induction chemotherapy. High factor VIII levels, which may reflect disease activity, contribute to the risk of ATE especially in patients with known risk factors for cardiovascular disease.

Disclosures:
Sonneveld: Johnson&Johnson: Consultancy.
Inhibition of HIV-1 in Sickle Cell Disease Peripheral Blood Mononuclear Cells.
Authors: Ammosova Tatiana , Charles Sharroya , Rotimi Jamie , Foster Altreisha , Diaz Sharmin , Kim Bak , Gordeuk Victor R. , Nekhai Sergei 
Published: October 2019

Abstract
Abstract 1509
Poster Board I-532

Background
The hypoxic response is an important component of the body 's reaction to impaired tissue oxygenation associated with the anemia and vasoocclusive episodes of sickle cell disease (SCD). It has been reported that HIV infection progresses relatively slowly in patients with SCD (Am J Hematol 1998; 59:199-207). We recently showed that HIV-1 transcription and replication is significantly reduced in cells cultured at 3% versus 21% oxygen (J Cell Physiol 2009; in press). Our previous studies indicated that protein phosphatase-1 (PP1) interacts with HIV-1 transcriptional activator, Tat, and thereby participates in the regulation of HIV-1 transcription. Sickle cell patients are in chronically hypoxic state and we hypothesized that HIV-1 replication in their peripheral blood mononuclear cells (PBMCs) would be slower then in controls.

Methods
We isolated PBMCs from patients with SCD and from normal subjects, activated the cells with phytohemagglutinin and IL-2 for 24 h, and infected with pseudotyped HIV-1 virus expressing Luciferase. The infected cells were cultured at 3% of oxygen for 72 h.

Results
We show here that PP1 association with cellular regulatory subunits is modified and that PP1 activity is significantly reduced by 20-40% in different cell lines at 3% versus 21% oxygen. One round of replication of pseudotyped HIV-1 Luciferase virus normalized to the number of the cells in culture was significantly reduced in SCD PBMCs comparing to normal controls.

Conclusions
Our results provide a direct evidence of that HIV-1 replication may be slower in SCD-derived PBMCs. In future, we will analyze PP1 activity and the association of PP1 with regulatory subunits in SCD PBMCs. Understanding of how oxygen status influences HIV-1 replication might open new possibilities for treatment of hidden HIV-1 reservoirs that harbor non-replicating HIV-1 virus.

Acknowledgments
This work was supported by NHLBI Research Grant 2 R25 HL003679-08 from the National Institutes of Health and The Office of Research on Minority Health.

Disclosures
No relevant conflicts of interest to declare.
Cytoprotective Mechanisms of the Lung in Sickle Cell Disease.
Authors: Ghosh Samit , Tan Fang , Monsunjac Mario , Ofori-Acquah Solomon F 
Published: October 2019

Abstract
Abstract 1538
Poster Board I-561
Circulating plasma hemoglobin contributes to major vasculopathies including pulmonary hypertension in patients who have sickle cell disease (SCD). There is an emerging concept that such vasculopathies are relatively mild because of activation of several cytoprotective pathways in SCD. The biochemical profile of plasma and the transcriptome of peripheral blood cells in patients who have SCD offer indirect support for this concept. Indeed, heme oxygenase-1 (HO-1), an acute phase enzyme that degrades heme into intermediates and byproducts with vasculoprotective properties is markedly elevated in mononuclear leukocytes of patients who have SCD. Nonetheless, the scope of the cytoprotective mechanisms of the lung and other organs impacted directly by sickle vasculopathies remain poorly appreciated. We previously identified an array of cytoprotective enzymes in lung endothelial cells chronically exposed to non-toxic concentrations of hemin in vitro. In this study, we examined the expression of NAD(P)H oxidase and candidate cytoprotective enzymes in two models of transgenic mice with SCD, and examined HO-1 expression in sickle chronic lung disease. Although NAD(P)H oxidase catalyzes reactive oxygen species generation by heme and is responsible for increased adhesion of leukocytes to the endothelium in SCD mice, there was no elevation of any of its subunits (gp91Phox and p22Phox, p47Phox, p67Phox and p40 Phox) in sickle mice lungs compared to hemizygote control mice lungs. Quantitative RT-PCR analysis revealed unexpectedly no difference in HO-1 mRNA level in sickle and non-sickle control lungs. On the contrary, analysis of the same tissues showed significantly higher NAD(P)H quinone oxidoreductase-1 (NQO1) mRNA level in both Berkeley and Townes knock-in sickle mice compared to controls (p<0.001). Enhanced expression of NQO1 but not HO-1 in sickle mice lungs was confirmed at the protein level by western blot analysis and by immunohistochemistry. Finally, we studied cases of sickle chronic lung disease (n=17) and discovered that NQO1 is expressed in the pulmonary endothelium at significantly higher levels than in normal lung tissues (p<0.002). In agreement with the data in mice, we found no difference in HO-1 staining in sickle human lung and normal lung tissues. Our findings indicate that despite its established role in acute elimination of excess heme, HO-1 is not elevated in sickle lungs. This study highlights the importance of dissecting the cytoprotective phenotype of individual organs impacted by SCD towards a rationale approach to developing efficacious antioxidant therapy for this disorder.

Disclosures
No relevant conflicts of interest to declare.
Improved Patient Survival and Cure for Hodgkin Lymphoma: A Population-Based Study of 6,136 Patients Diagnosed in Sweden 1973-2005.
Authors: Sjoberg Jan , Halthur Cat , Kristinsson Sigurdur Y , Landgren Ola , Dickman Paul W , Bjorkholm Magnus 
Published: October 2019

Abstract
Abstract 1553
Poster Board I-576
We evaluated survival for all patients diagnosed with Hodgkin lymphoma (HL) in Sweden 1973-2005 (n=6,136; 3,515 men and 2,621 women; median age 40 years). Patients were categorized into six age groups and four calendar periods (1973-1980, 1981-1988, 1989-1996, and 1997-2005). Relative survival ratios (RSRs) were computed as measures of patient survival. Cumulative relative survival improved over time in all age groups with the greatest improvement in patients 51-65 years. Also in patients 66-80 years, significant improvements were recorded in both five- and ten year RSRs. Importantly, a plateau in relative survival was observed after 5 years in patients below ≤ 35 years of age during the last calendar period suggesting a lack of long-term treatment-related mortality. The ten-year RSRs in this calendar period were 0.95, 0.95, 0.92, 0.80, and 0.51 for the age groups 0-18, 19-35, 36-50, 51-65, and 66-80, respectively. Thus, despite this progress, age at diagnosis remains an important predictor of outcome. We also found a significantly better survival for women when adjusted for age and calendar period. During the study period, refined treatment options for patients with limited and advanced-stage HL have contributed to an increasing cure rate. In addition, our findings support that long-term mortality of HL therapy has decreased. Elderly patients still do poorly and targeted treatment options associated with fewer side effects will advance the clinical HL field.
Cumulative relative survival stratified by age at diagnosis and calendar period of diagnosis Cumulative relative survival stratified by age at diagnosis and calendar period of diagnosis

Disclosures
No relevant conflicts of interest to declare.