bluuebunny/crossref_metadata_2025_split huggingface dataset:
A GATA-1-Regulated microRNA Cluster That Is Essential for Erythropoiesis.
Authors: Dore Louis C. , dos Santos Camila O. , Amigo Julio , Dorman Christine , Wu Weisheng , Hardison Ross C. , Paw Barry H. , Weiss Mitchell J. 
Published: April 2020

Abstract
The nuclear factor GATA-1 controls erythropoiesis by regulating transcription of numerous protein-encoding genes. Here we show that GATA-1 also activates the expression of a critical erythroid microRNA (miR) locus. MicroRNAs regulate gene expression and tissue differentiation by binding the 3′ untranslated regions of mRNA transcripts to inhibit their translation or stability. We used an oligonucleotide-based microarray to analyze miR expression in G1E cells, a GATA-1-null erythroid line that undergoes terminal maturation when GATA-1 activity is restored. We identified 8 miRs that are significantly upregulated during GATA-1-induced erythroid maturation. Two of the most highly induced miRs, 144 and 451, are encoded in tandem on mouse chromosome 11 and are transcribed on the same primary microRNA transcript. Northern blot studies showed that the miR144/451 locus is strongly induced by GATA-1 and specifically expressed at high levels in human and murine erythroid precursors. Bioinformatic analysis of the miR144/451 locus identified a conserved region containing three closely-spaced GATA binding motifs located about 2.7 kb upstream of the transcriptional start. In erythroid cells, this region exhibits enhancer activity and binds GATA-1 and its cofactor FOG-1, as determined by chromatin immunoprecipitation studies. MicroRNAs 144 and 451 are conserved between mammals and zebrafish, facilitating further in vivo studies. Whole mount in situ hybridization of zebrafish embryos showed both miRs to be exclusively expressed in the developing blood islands (intermediate cell mass) at 24h post-fertilization (hpf), colocalizing with gata-1 and β-globinE1 expression. Both miRs are deficient in the gata-1 null mutant, vlad tepes, consistent with their epistatic relationship to gata-1. Transient inactivation of miR-451 function using anti-sense morpholino oligomers selectively ablated hemoglobin staining cells in embryos at 48 hpf. These morphant embryos also exhibited dramatically reduced β-globinE1 mRNA expression. In contrast, there were no quantitative effects on thrombocytes (platelet-equivalent cells) in morphant embryos. Together, our data define a new regulatory axis through which GATA-1 promotes red cell development by directly activating the transcription of miR144/451, a critical erythroid-specific microRNA locus.
Usual Clinical Parameters Underestimate the Incidence and Significance of Erythropoietin Deficiency as a Risk Factor for Death in Sickle Cell Disease.
Authors: Saraf Santosh , Sidhwani Seema , Farooqui Mohammed , Vara Stephen , DeSimone Joseph , Molokie Robert , Saunthararajah Yogenthiran 
Published: April 2020

Abstract
A robust reticulocytosis is necessary to maintain hemoglobin levels compatible with life in patients with sickle cell disease. Relative reticulocytopenia, defined as a absolute reticulocyte count less than 250 x 109/L despite hemoglobin &lt;9g/dl, has been identified as a risk factor for early death. RR could result from chronic bone marrow vaso-occlusive insult or a renal endocrine defect leading to erythropoietin (EPO) deficiency. In non-SCD patients, EPO levels and creatinine clearance are clinical parameters that are used to define patients with anemia from EPO deficiency. The normal ranges for these parameters may not apply to SCD, and therefore the incidence and significance of EPO deficiency in SCD may have been underestimated, compromising rational EPO replacement therapy. In a retrospective analysis of 417 patients with HbSS or S-β-thalassemia, confirming previous findings, RR was a risk factor for early death. There was a significant association between RR and proteinuria. Usually, there is an inverse correlation between hemoglobin and EPO levels (negative feed-back), this was seen in patients without RR. However, in patients with proteinuria, the correlation between hemoglobin and EPO levels was a positive one, suggesting hemoglobin dependence on EPO levels. Proteinuria or increased creatinine levels were a risk factor for early death but not if RR was included in the model, suggesting the increased risk of death associated with proteinuria and creatinine was mediated by RR. RR was also associated with decreased platelet and WBC counts, suggesting a contribution by cumulative vaso-occlusive bone marrow damage to RR. However, platelet and WBC counts were not risk factors for early death within the cohort. Damage to renal endocrine function/EPO deficiency should be added to the list of clinically significant chronic organ damage in SCD. EPO deficiency may precede and be causative of other end-organ damage, such as cardiac diastolic dysfunction and renal exocrine failure. Proteinuria should be recognized as a clinical parameter that should prompt consideration of EPO deficiency. Since EPO replacement is clinically feasible, renal endocrine dysfunctiton is a cause of symptoms, clinical deterioration and death that could be rationally addressed.
Clinical Utility and Safety of Methacholine Challenge in Children with Sickle Cell Disease.
Authors: Brown Michael S. , Boyd Jessica H. , Bates Pamela , DeBaun Michael R. , Strunk Robert C. 
Published: April 2020

Abstract
Introduction: Lung disease is major cause of morbidity in children with sickle cell disease (SCD), yet understanding of lung pathophysiology is lacking. The diagnosis of asthma in children with asthma has become an important consideration in clinical management because of its association with a twice greater the rate of painful and acute chest syndrome (ACS) episodes when compared to children without asthma. Provocation challenges with methacholine have been used in both clinical and research settings to evaluate the presence of degree of airway hyperresponsiveness (AHR) in studies of asthma; however, no such evaluation has been described in children with SCD.
Methods: As part of routine clinical care, 21 children with SCD multiple or severe acute chest syndrome (ACS) episodes were challenged with methacholine to determine if AHR was a component of their recurrent respiratory tract symptoms.
Results: A total of fourteen of the children had a positive challenge, none of whom had evidence of obstruction or bronchodilator reactivity on spirometry. Ten of fourteen patients were previously on inhaled corticosteroids and had their asthma diagnosis confirmed and four were given a new diagnosis of asthma. In each positive challenge, forced expiratory volume in one second reversed to at least 90% of baseline after bronchodilator treatment. No patient developed a painful or ACS episode temporally related to the challenge.
Conclusion: Evaluation of AHR with methacholine challenge in patients with SCD appears to be well tolerated and may elucidate the basis of lung morbidity in a subgroup of children with repetitive or serious ACS episodes.
ADAMTS13 Antigen, Activity, Autoantibody and ADAMTS13/fXI Complex Levels May Be Useful Diagnostic Biomarkers for Patients with Sickle Cell Disease.
Authors: Fryer Hugh J.L. , Grafos Nicholas , Guinto Enriqueta R. , Wu Jogin , Bai Bing , Greenfield Robert S. 
Published: April 2020

Abstract
Severe reduction of ADAMTS13 activity or high titers of ADAMTS13 autoantibody levels have been implicated as causative factors in Thrombotic Thrombocytopenia Purpura (TTP). Ultralarge von Willebrand factor (UL-VWF) has been shown to mediate the binding of platelets and sickle red blood cells to the endothelium. Thus, ADAMTS13, which cleaves UL-VWF, may play a role in thrombotic events in patients with sickle cell disease (SCD). In this preliminary study, patients with SCD were compared with normal donors for plasma levels of ADAMTS13 antigen, activity, autoantibody, and ADAMTS13/fXI complex. ADAMTS13 antigen was measured using IMUBIND® ADAMTS13 ELISA, ADAMTS13 activity using the ACTIFLUOR™ ADAMTS13 FRET, ADAMTS13 autoantibody titers using IMUBIND® ADAMTS13 Autoantibody ELISA, and complex using IMUBIND ADAMTS13/fXI. Patients with SCD included in this study (n=10) exhibit a number of thrombotic symptoms including deep vein thrombosis, pulmonary embolism, and pulmonary hypertension. Some were found to have autoantibodies to Protein S or alloantibodies to red blood cell proteins. Patients were treated with hydroxyurea, coumadin, as well as various pain medications. Patients in a crisis stage of SCD were included in this study. The four ADAMTS13-related markers were found to be abnormal in patients with SCD compared with normal donors. Cutoff levels for each of the markers, determined based upon normal donor plasmas, were found to be as follows: for ADAMTS13 activity, values lower than 510 ng/ml were considered below normal; for ADAMTS13/fXI complex, values exceeding 360% of the normal were considered to be elevated; for ADAMTS13 autoantibody, values above 14.8 AU/ml were considered above normal. Using these cutoff levels, none of the normal donors (n=47) had abnormal activity or complex levels. One normal donor (2.1%) had elevated autoantibody levels. In comparison, for patients with SCD, 7/10 (70%) had reduced activity levels, 8/10 (80%) had elevated levels of ADAMTS13/fXI complex, and autoantibody was detected in 6/10 (60%) of the patients. These data suggest that ADAMTS13 may play a role in thrombotic complications associated with SCD. ADAMTS13-related biomarkers measured herein may aid in the diagnosis of patients with SCD and may prove useful in monitoring the treatment of SCD.
Specific Micro-RNA Expression Profile in Hodgkin Lymphoma.
Authors: Ping Tan Lu , Harms Geert , Blokzijl Tjasso , Schakel Rikst Nynke , Gibcus Johan , Möller Peter , Küppers Ralf , Reijmers Rogier M. , Pals Steven T. , Poppema Sibrand , Kroesen Bart-Jan , van den Berg Anke 
Published: April 2020

Abstract
Introduction Classical Hodgkin lymphoma (cHL) and nodular lymphocyte predominant Hodgkin lymphoma (NLPHL) differs not only in the form of histology and reactive background but also in the phenotypes of the tumor cells. Although tumor cells from both HL subtypes are originated from the germinal center (GC) B cell, gene expression studies show that lymphocytic and histiocytic (L&H) cells from NLPHL resembles normal B cells while Hodgkin/Reed-Sternberg cells (H/RS) from cHL demonstrate a loss of B cell phenotype and have significant overlap with primary mediastinal B cell lymphoma (PMBL). Recently, a new class of small RNAs, namely the micro-RNAs (miRNAs), has been identified. It is now known that at the post-transcriptional level, miRNAs negatively regulate gene expression in a sequence specific manner. Unique miRNAs expression patterns have been reported in various tissue types and also during a wide range of physiological states, such as cell proliferation, development, differentiation, apoptosis and hypoxia. As miRNAs play important roles in many cellular processes, it is proposed that there is a link between aberrant miRNA expression and loss of B cell phenotype in cHL.
Methods In this study, miRNA profiles from cell lines of various B cell lymphoma subtypes were examined by qRT-PCR. Also, several B cell subsets were sorted from tonsil by FACS and the miRNA profiles studied by qRT-PCR. Some of the miRNAs are analyzed by in situ hybridization (ISH) in both HL tissue and tonsil samples.
Results The miRNA profiling data indicated that cHL cell lines cluster together with PMBL while DEV, an NLPHL cell line, clusters together with CB. Upon validation of differentially expressed miRNAs on a cell line panel of 33 cell lines by monoplex qRT-PCR, 5/8 miRNAs identified as differentially expressed between cHL and GC B cells, were confirmed. Four out of six miRNAs differentially expressed between cHL and PMBL, were also confirmed as being differentially expressed in a larger cell panel. A high degree of overlap was observed between the most abundantly expressed miRNAs in the four HL cell lines. Expression of these miRNAs in HRS cells was verified by ISH in HL tissue samples. miRNA profiles of naive, GC and memory B cells display unique patterns. The overall miRNA expression levels were much lower than observed in the cell lines. Results of miRNA ISH in tonsil tissue demonstrated a specific staining pattern for each miRNA. These data indicate that miRNAs are particularly important for subsets of lymphocytes.
Conclusion Several miRNAs that are expressed specifically in Hodgkin lymphoma have been identified. However, the effect of the aberrant expressions of these miRNAs in HL is yet to be elucidated, as the targets of these miRNAs remain unknown.
Neutrophil Gelatinase-Associated Lipocalin Levels in Patients with Thalassemia Intermedia: Lack of Association with Erythropoiesis, Iron Metabolism, Renal Dysfunction and Inflammation.
Authors: Papassotiriou Ioannis , Margeli Alexandra , Drakatos Antonios , Delikou Sophia , Kassiou Korina , Kattamis Christos , Ladis Vassilios , Kattamis Antonios 
Published: April 2020

Abstract
Neutrophil Gelatinase-Associated Lipocalin (NGAL, 24p3, SIP24, lipocalin-2 or siderocalin) is a novel iron-carrier protein exerting pleiotropic properties. The physiological role of NGAL is not fully elucidated though a few pivotal functions, such as regulation of apoptosis of leukocytes have been described recently. It has also been demonstrated that NGAL is abundantly expressed in erythroid progenitor cells inducing apoptosis and inhibiting their differentiation. NGAL is reduced in the erythroid cells of mice with acute anemia and injection of recombinant lipocalin-2 delayed the recovery of red blood cells suggesting a negative effect of NGAL in accelerating erythropoiesis. The recently reported functions of NGAL on erythroid progenitor cells and its relation to iron transport prompted us to study the pattern of NGAL levels in Thalassemia Intermedia (TI), which is characterized by erythroid progenitor cells hyperactivity and irregularities in iron metabolism (especially iron transport). To this end we measured NGAL levels in 30 patients with TI and in 20 apparently healthy controls matched for age. We also evaluated other parameters that could be possibly related to NGAL’s functions as: soluble transferrin receptor (sTfR) for eythroid marrow activity; NTBI concentration for non-transferrin-bound mediate iron delivery pathway; creatinine, cystatin C and β2-microglobulin for renal dysfunction and CRP and IL-6 for low grade inflammation. The main results of the showed that: a) NGAL levels were significantly higher in patients with TI compared to controls (139.1±86.1 vs 51.2±11.8 μg/L, p&lt;0.0001), while 4 patients presented with NGAL levels within normal range, b) in patients with TI no correlation was found between NGAL and the erythropoiesis’ parameters Hb, Hb F and sTfR, (p&gt;0.66, p&gt;0.67 and p&gt;0.81 respectively), the parameters of iron metabolism, ferritin and NTBI (p&gt;0.90 and p&gt;0.95 respectively) the markers of renal dysfunction and/or those of low-grade inflammation (p&gt;0.50). The increased NGAL levels observed in TI patients in this study are in agreement with the elevated expression of NGAL observed in experimental models of thalassemia. We postulate that the induction of NGAL in these patients may represent either a response facilitating the survival of the less damaged thalassemic erythroid precursors, or a consequence due to the abnormal iron regulation in patients with TI.
Cucurbitacin D Upregulates Fetal Hemoglobin Expression in K562 Cells and Human Erythroid Progenitors.
Authors: Xing Hongtao , Zhang Siwei , Koeffler H. Phillip , Fung Ming Chiu 
Published: April 2020

Abstract
The search for novel therapeutic candidates causing reactivation of fetal hemoglobin (a2g2; HbF) to reduce the imbalance of globin gene expression is important in order to develop effective approach for the clinical management of sickle cell anemia and b-thalassemia. For the first time, we have identified cucurbitacin D (CuD), a naturally occurring oxygenated tetracyclic triterpenoid, as a molecular entity inducing g-globin gene expression and HbF synthesis in K562 cells and human erythroid progenitors from either peripheral blood or bone marrow. The upregulation of HbF induced by CuD was dose- and time- dependent. CuD was compared to hydroxyurea (HU), 5-azacytidine, amifostine, recombinant human erythropoietin (rhEPO), and sodium phenylbutyrate. At their optimal dosage, CuD (12.5 ng/mL) and HU (25.0 μg/mL) induced nearly 70% K562 cells to express total hemoglobin after 6 days culture, which was higher than the induction by Amifostine (30%), 5-azacytidine (36%), rhEPO (16%), sodium phenylbutyrate (23%) at their optimal concentrations and negative control (11%). Fetal hemoglobin ELISA showed that CuD (12.5 ng/mL) and 5-azacytidine (400 ng/mL) induced higher levels of fetal hemoglobin in K562 cells (15.4 ng/μL and 29.3 ng/μL, respectively), compared to HU (10.3 ng/μL), amifostine (7.8 ng/μL), rhEPO (10.9 ng/μL), sodium phenylbutyrate (9.9 ng/μL) at their optimal concentrations and negative control (5.3 ng/μL). CuD induced a significantly higher fetal cell percentage than HU in K562 cells (65% vs 37% maximum) and primary erythroid progenitors (36% vs 21% maximum) based on the immunofluorescence imaging and flow cytometry analysis. Real-time PCR results showed that the amount of γ-globin mRNA increased from 2.5-fold in CuD-optimal-treated cells (12.5 ng/mL, 48 hours) compared with 1.5-fold in HU-optimal-treated cells (25.0 μg/mL, 48 hours). Growth inhibition assay (MTT) demonstrated that CuD at its optimal γ-globin inducing dosage (12.5 ng/mL) inhibited proliferation of K562 by less than 10% of untreated control cells; while hydroxyurea at its optimal dosage (25.0 μg/mL) inhibited 80% of cell division. The in vitro therapeutic index (calculated by dividing the dose inhibiting 50% cell growth (IC50) by dose inducing 50% maximal HbF production (ED50)) of CuD was 40-fold greater than HU. Taken together, the results suggest that CuD has the potential to be a therapeutic agent for treatment of sickle cell anemia and b-thalassemia.
Idiopathic Hypereosinophilic Syndrome in a Child.
Authors: Ferrara Mara , Capozzi Laura , Save Giuseppina , Esposito Luigi 
Published: April 2020

Abstract
The idiopathic hypereosinophilic syndrome (HSE) is a new heterogeneus disorder characterized by persistent unxplained hypereosinophilia (eosinophil count &gt; 1.5 x 10 9 /L) persisting at least 6 months with possibile organ involvment. The diagnosis of HSE is based on exclusion criteria of other causes of eosinophilia. We reporte a case of an atopic 3 year-old male child with a history of eczema since first years of life and hypereosinophilia. At admission he showed severe generalized eczema with pruritus pain in the jonts, fever, several athsma, mild hepatosplenomegaly and lymphoadenomegaly. Biological findings included mild hypochromic microcytic anemia (Hb 10.5 g/dl, MCV 65 μ3, MCH 23 pg) due to heterozygous α thalassemia -delection (α) −37-, hyperleukocitosis (WBC 45.5 x 10 3 / μL) and hypereosynophilia (20.9 x 10 3 / μL). Bone marrow aspiration revealed absence of blast cells, mild reduction of myeloid (40%) and erythroid cells (10%) with increased M/E ratio 6/1. The eosynophilic cells represented 35%. Some of these cells presented cytoplasmatic atypia. Blood lymphocyte immunophenotypical analysis showed increased values of T lymphocytes CD3+, B lymphocytes CD19+ and T helper lymphocytes CD3+CD4+ Serum IgE levels were increased. Cytokines serum levels were undectable. Karyotype was 46XY. Non cytogenetic abnormalities were found in myeloid cells. Specific viral antibodies as well as autoantibodies and parasitologic assessements were negative. Corticosteroids were used with mild clinical improvement, followed by worsenings when the drug was stopped. The absence of blast cells or cytogenetic abnormality favor the diagnosis of HSE. However some patients in whom a diagnosis of idiopathic HSE appears appropiate may subsequently develope malignancies. A systematic survey of a large group of patients with otherwise unexplained eosinophilia is needed as well as a prolonged follow up of patients to early evaluate in each case neoplastic risk.
Induction of Apoptosis in Neutrophils from Septic Patients by Proinflammatory Molecules.
Authors: Gomez Luz S. , Arango Julian C. , Matute Juan D. , Gomez Ivan D. , Lopez Juan A. , Toro Fabiola , Jaimes Fabian , Patino Pablo J. 
Published: April 2020

Abstract
Neutrophils are in part responsible of the tissue damage accompanying the systemic inflammatory response produced during sepsis. A mechanism to limit their activity is apoptosis, however neutrophil apoptosis appear to be delayed in sepsis, which could increase the abnormal inflammatory response. On the other hand, it has been described that the proinflammatory molecules involved in delaying neutrophil apoptosis can induce apoptosis in other cells. Moreover there is not studies evaluating early apoptotic response in neutrophils from septic patients. In order to study the early apoptic response (30, 60 and 180 min) of neutrophils isolated from septic patients and healthy volunteers, these cells were isolated from peripheral blood, cultured with not stimulus or with LPS or fMLP and then analyzed by flow cytometry using DiOC6 and Annexin V/propidium iodide. Our data show that spontaneous apoptosis in neutrophils isolated from septic patients is increased during the first 3 h of in vitro culture in comparison to apoptosis from healthy volunteers neutrophils; however, this response is delayed when neutrophils isolated from septic patients were cultured during 24 h. Furthermore neutrophils isolated from healthy controls and septic patients stimulated with LPS or fMLP evidenced an apoptotic response at early incubation times in comparison with untreated cells. Previous studies have demonstrated a delay of apoptotic response of neutrophils obtained from patients with sepsis, which has been explained by the induction of anti-apoptotic proteins or inhibition of expression of apoptotic genes by LPS and other proinflammatory mediators. On the contrary our results suggest that there is an early increase in apoptosis when neutrophils isolated from septic patients are cultured without stimulus or in presence of microbial molecules such as fMLP and LPS. This contradictory evidence might be explained if we take in account the heterogeneity of circulatory neutrophils. At early time after LPS incubation a susceptible population of neutrophils activates different apoptotic responses, however the cells that are resistant to this effect activate a cascade of intracellular events that finally induces the transcription of several genes with anti-apoptotic and inhibits the expression of those pro-apoptotic. As consequence of these differences new pathogenic processes and therapeutic targets should be considered in sepsis.