bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rsp1 Is Indispensable for mRNA Stability during Erythroid Terminal Differentiation
Authors: Tian Meng , Campagna Dean R. , Langer Nathaniel , Choe Seong-Kyu , Paw Barry H. , Justice Monica J. , Fleming Mark D. 
Published: April 2020

Abstract
Mouse models have proven invaluable for understanding erythropoiesis. Here, we describe an autosomal recessive inherited anemia in the mouse mutant hem6. Hematologic and transplantation analyses revealed a mild, congenital, hypochromic, microcytic anemia intrinsic to the hematopoietic system that is associated with a decreased red blood cell zinc protoporphyrin to heme ratio, indicative of porphyrin insufficiency. Iron uptake experiments showed that hem6 reticulocytes are defective in heme production, but not cellular iron uptake defects. Male hem6 mice are infertile due to defects in sperm structure and motility. Through positional cloning and BAC complementation, we identified the gene responsible for the hem6 anemia to be Rsp1 (RNAStabilityProtein1) on Chr.3. The anemia phenotype was reproduced by injecting zebrafish embryos with morpholinos specifically targeting the Rsp1 transcript. Multi-tissue, real-time PCR shows that Rsp1 is abundantly expressed in bone marrow and testis, which correlates with the anemia and infertility defects in the hem6 mutant. To further study the function of Rsp1, we conducted yeast two hybrid analysis, employing a human bone marrow library. We found that Rsp1 interacts with the poly (A)-binding protein cytoplasmic 1(PABPC1) and, using microarray analysis, showed that many abundant erythroid specific transcripts, including Hbb-b1, Hba-a1, Alas2, and Mitoferrin1, were significantly down regulated in hem6 reticulocytes. Since PABPC1 is responsible for stabilizing the Hba-a1 transcript [Wang et al. (1999) Mol Cell Biol19:4552–60 and Wang and Kiledjian (2000) Mol Cell Biol20:6334–41], we hypothesized that the relative deficiency in erythroid-specific mRNAs in hem6 reticulocytes might be due to decreased mRNA stability. Indeed, serial microarray analysis of reticulocytes aged in vitro showed that numerous, abundantly expressed erythroid-specific transcripts decayed at faster rates in hem6 reticulocytes compared to control reticulocytes. Furthermore, these mRNAs also have progressively shorter poly (A) tails, suggesting a mechanism for the increased rate of decay. In sum, the evidence supports the conclusion that Rsp1 is a regulator of mRNA stability and gene expression during the terminal differentiation of erythroid cells.
MicroRNA Profiling of EVI1 Deregulated Myeloid Leukemia
Authors: De Weer An , Poppe Bruce , Mestdagh Pieter , De Preter Katleen , Van Vlierberghe Pieter , Cauwelier Barbara , Van Roy Nadine , Verhasselt Bruno , Vandesompele Jo , Dastugue Nicole , Speleman Frank 
Published: April 2020

Abstract
Chromosomal rearrangements involving the EVI1 gene are a recurrent finding in malignant myeloid disorders. These translocations or inversions contribute to ectopic expression of, or to the formation of fusion genes involving the EVI1 gene. EVI1 transcriptional activation has been reported in up to 10% of acute myeloid leukemia (AML) patients, and is a prognostic marker predictive of a poor outcome. Recently, microRNA deregulation was identified as a major contributor to cancer initiation and progression. Furthermore, miRNA genes were shown to be directly regulated by activated proto-oncogenes. In this study, we investigated which miRNAs are implicated in the transcriptional pathways governed by the EVI1 oncogene as well as possible microRNAs regulating the expression of the EVI1 gene itself. A total of 384 miRNAs were profiled through automated qRT-PCR using high-throughput quantitative stem-loop RT-PCR. Our patient series consisted of 18 EVI1 rearranged and overexpressing samples confirmed by FISH, karyotyping and qRT-PCR, 11 normal bone marrow samples and 2 CD34+ cord blood fractions. Through integrated statistical analysis we were able to identify 36 significantly upregulated and 44 significantly downregulated miRNAs (p&lt;0.05) in EVI1 rearranged samples compared to normal bone marrow samples. Among these up- and downregulated miRNAs several have already been associated with leukemia or other types of cancer acting as oncogenes or tumor suppressor genes, respectively. Interestingly, in the panel of downregulated miRNAs, we found 3 miRNAs that have predicted binding sites on the 3′UTR of the EVI1 gene. Currently, no mechanism has been described to explain EVI1 overexpression, therefore loss of the inhibitory effect of miRNAs targeting the 3′UTR of EVI1 might be an important mechanism contributing to EVI1 ectopic expression. Further analyses will include vector based luminescence experiments to confirm the association between EVI1 and the 3 downregulated miRNAs. Functional studies will also be performed in order to assess the contribution of the differentially expressed miRNAs to the leukemic phenotype. Since patients with EVI1 involvement have a poor prognosis, elucidating the downstream EVI1 controlled miRNA targets and pathways could not only yield new insights into EVI1 etiogenesis, but could also add additional prognostic and diagnostic information. We anticipate that these findings could provide new targets for therapeutic intervention.
Bcl-2 Family Dysregulation in AML1-ETO-Expressing Human Hematopoietic Cells
Authors: Chou Fu-Sheng , Wunderlich Mark , Mulloy James C. 
Published: April 2020

Abstract
A subset of acute myeloid leukemia is caused by the chromosomal translocation (8;21), resulting in the expression of the AML1-ETO (AE) fusion protein. AE expression in human CD34+ umbilical cord blood (UCB) cells causes an expansion of the hematopoietic stem and progenitor cell (HSPC) compartment, but alone does not cause leukemia. We have recently shown that AE represses DNA damage repair genes, resulting in higher mutation frequency as well as p53 activation and increased basal apoptosis. Interestingly, we found that AE expression in CD34+ UCB cells was associated with high Bcl-xL levels, while control cells showed a gradual loss of Bcl-xL protein. Furthermore, expression of AE in aged HSPC that had already downregulated Bcl-xL also led to Bcl-xL protein upregulation. In addition, Bcl-xL protein, but not mRNA, was decreased by pharmacological and RNAi-mediated inhibition of p53 in AE cells and increased by low-intensity γ-irradiation, implying that Bcl-xL turnover may be post-translationally regulated by p53 levels. Bcl-xL knock-down by short-hairpin RNA in AE cells resulted in even higher p53 activity and growth disadvantage, suggesting that AE cells depend largely upon Bcl-xL for survival in the context of p53 activation. AE cells are also more sensitive than long-term cultured UCB cells to GX15-070, a BH3-mimetic drug that binds and inhibits all anti-apoptotic Bcl-2 family proteins. The sensitivity of AE cells to Bcl-xL inhibition and GX15-070 treatment may be due to upregulation of various pro-apoptotic Bcl-2 family proteins. Surprisingly, p53-upregulated modulator of apoptosis (PUMA) mRNA levels were decreased or remained unchanged in association with AE expression, even in the context of an upregulated p53 signaling pathway. Chromatin immunoprecipitation assay revealed that AE binds to and AML1 binding site in the putative promoter of PUMA, in a region distinct from the p53 consensus binding site. Indeed, PUMA expression is increased in response to γ-irradiation in cells expressing AE. This suggests that AE may directly repress PUMA gene expression, but does not prevent p53 binding. Taken together, our data indicate that AE expression may lead to re-establishment of a new balance between the pro-apoptotic signals conveyed by the activated p53 signaling pathway and the pro-survival signals, presumably Bcl-xL upregulation and PUMA repression, within the Bcl-2 family proteins to ensure cell survival and propagation.
Endocytosis and Erythroblast Enucleation Are Linked by the Action of a Survivin-EPS15-Clathrin Complex
Authors: Keerthivasan Ganesan , Small Sara , Liu Hui , Wickrema Amittha , Crispino John 
Published: April 2020

Abstract
The mechanisms that drive the final step in the development of reticulocytes from nucleated erythroblasts remain largely undefined. We recently reported that the chromosome passenger complex (CPC) protein survivin is required for the maintenance of hematopoietic stem cells and for the proliferation and survival of erythroid progenitors. Several lines of evidence suggest that survivin also plays an additional role late in erythropoiesis. First, 20% of survivin heterozygous mice showed a decrease in the proportion of enucleated cells relative to nucleated erythroblasts. Second, survivin is highly expressed in orthochromatic erythroblasts undergoing enucleation, where it partially co-localizes with actin at the junction between the extruding nucleus and cytoplasm. Third, overexpression of survivin promoted enucleation during DMSO-induced murine erythroleukemia (MEL) cell differentiation. Since survivin plays an essential role during normal mitosis and because enucleation has been postulated to occur by asymmetric cytokinesis, we investigated the link between cytokinesis and enucleation. Using primary erythroblast cultures, we found that chemical inhibitors of cytokinesis failed to prevent enucleation. Furthermore, we could not detect co-localization of survivin with aurora-B or INCENP, two other members of the CPC, in enucleating primary human erythroblasts. To determine the mechanism by which survivin contributes to enucleation, we utilized an in vivo biotinylation strategy to isolate survivin protein complexes from extracts of MEL cells. Using mass spectrometry, we discovered that survivin complexes include clathrin and its partner EPS15 (EGFR pathway substrate clone 15). We confirmed the endogenous interaction between these three proteins by co-immunoprecipitation. Treatment of primary erythroblast cultures with an inhibitor of endocytosis led to a decrease in enucleation efficiency. In addition, siRNAs targeting survivin, EPS15, or clathrin each reduced the degree of enucleation of primary human erythroblasts, confirming a requirement for this protein complex in enucleation. Together, our data demonstrate that survivin promotes enucleation by a novel clathrin-mediated process. Furthermore, our data help explain electron microscopy (EM) observations that enucleation is accompanied by an accumulation of vesicles that coalesce to form U-shaped channels at the junction between the nucleus and plasmalemma of the erythroblast (Simpson and Kling, JCB35:237, 1967). These EM studies along with our new data suggest that vesicular trafficking may be one of the major driving forces in enucleating erythroblasts.
Aminoacids and Fatty Acids Levels in Patients with Thalassemia Major
Authors: Canatan Duran , Baykal Asli , Duman Handan , Balta Nihal 
Published: April 2020

Abstract
Introduction: The red blood cell(RBC) membrane is a complex of lipids an proteins. When thalassemic RBCs are challenged with oxidant stress, incorporation of fatty acids in RBC phospholipids is affected. We investigated the aminoacids, carnitine and fatty acid levels of thalassemic patients.
Material-Method: A total number of 40 thalassemia major patient aged between 7–30 years, who has been taken regular transfusion and deferasirox therapy are included. Serum lipid profil (trigliserit, cholesterol, HDL and LDL) and ferritin levels were measured. Serum levels of aminoacids (valine, leucine/isoluecine, methionine, phenylalanine, tyrosine, aspartat, glutamat, glysine, alanine, ornitine, sitrulline, carnitine and fatty acids (C2 asetil, C3 propionil, C4 butiril, C5:1 tigilil, C5 izovaleril, C4OH3Ohbutiril, C6 hekzanol, C5OH-3 hidroksiizovaleril, C8oktanol, C10 dekanol, C5DC glutaril, C12 dodekenoil, C14.1 metilglutaril, C1 miristoil, C14OH 3 hidoksimiristoil, C16 1-palmitoleil, C16 OH 3 hidroksipalmitoleil, C18 1 oleil, C18 stearoil, C18.1OH 3 hidrosioil) were measured by using tanden-mass spectrometry.
Results: There was found high level of phenylalanine in 7 (17.5%) and fatty acid: c18 oleil 1 patients (2.5%) and low level of glisin in 4 (10%), metionin 1 patients(2.5%), carnitin 1 patients (2.5%) and as fatty acids; C16 palmitol in 11 (27.5%), C3 propiponil in 8 (20%) and C2 asetil 2 patients. (5%). Other amino acids and fatty acids were normal levels. There was significant relationship between fatty acids such as C16 palmitol, C3 propiponil and lipid profil.
Conclusion: Normal lipid profil and fatty acids is changed in thalassemic cells which in turn leads to altered interactions.
Vascular Heme Oxygenase-1 Induction Suppresses Tissue Factor and Plasminogen Activator Inhibitor-1 Expressions
Authors: Morishita Eriko , Maruyama Keiko , Sekiya Akiko , Ohtake Shigeki , Nakao Shinji , Yachie Akihiro 
Published: April 2020

Abstract
Objective - Heme oxygenase-1(HO-1), the rate-limiting enzyme of heme degradation, has recently been considered to have protective roles against various pathological conditions. 10 years have passed since we lost the first and the only patient of HO-1 deficiency. Since the patient of HO-1 deficiency showed endothelial cell injury and extremely enhanced coagulation and fibrinolytic parameters, we examined the effect of HO-1 modulation on tissue factor (TF) and plasminogen activator inhibitor-1 (PAI-1) expression on endothelial cells.
Methods and Results -
Human umbilical vein endothelial cell (HUVEC) was stimulated with hemin (100mM), HO-1 inducer, and mRNA and protein levels for HO-1, TF and PAI-1 were examined. Total RNA was extracted from HUVEC, and was analyzed by real time RT-PCR. Protein expression levels of HO-1, TF and PAI-1 were measured by ELISA. Hemin stimulation increased HO-1 mRNA levels by 20 times. On the other hand, TF mRNA and antigen levels were minimum even after 8 hours of stimulation. Importantly, hemin stimulation reduced PAI-1 mRNA more than half after 4 hours. After HO-1 induction by hemin (100 mM) for 6 hours, HUVEC cultures were exposed to 10 ng/ml tumor necrosis factor (TNF).
Prior exposure to hemin significantly increased HO-1 mRNA by 60 times in 30 minutes after stimulation with TNF. However, TNF alone could not induce HO-1 mRNA and protein levels in HUVEC. Although stimulation with TNF enhanced expressions of both TF and PAI-1 mRNA, they were significantly inhibited more than half by prior treatment with hemin. TF antigen levels were similarly decreased (5.0 to 0.7 pg/ml). PAI-1 antigen levels were also inhibited by prior treatment with hemin (1.8 to 0.1 ng/ml)(3) To see if hemin effect on HUVEC is due to HO-1 production, HO-1 inhibitor tin-protoporphyrin IX (SnPP-IX) was added to the cultures. The inhibitor effect of hemin on TF and PAI-1 productions was cancelled when HUVEC was cocultured with SnPP-IX.
Conclusions - These results indicate that hemin exert inhibitory effect on TF and PAI-1 expressions through HO-1 production. Induction of HO-1 may be beneficial in the prevention of thrombosis associated with inflammation.
Vasohibin Inhibits Large Blood Vessel Formation and Supports Development of Microvessels
Authors: Kern Johann , Steurer Michael , Gastl Gunther , Gunsilius Eberhard , Untergasser Gerold 
Published: April 2020

Abstract
Aims: The murine homolog of human vasohibin (mVASH1), a putative antiangiogenic protein, was investigated for its inhibitory effects on in vitro and in vivo angiogenesis. Cell growth and migration was analyzed in murine embryonic fibroblasts, smooth muscle cells and brain endothelial cells (bEND.3). Moreover, angiogenic sprouting was studied on human umbilical vein endothelial cells (HUVEC) in the spheroid sprouting assay. In vivo effects on blood vessel formation were investigated in the chorioallontoic membrane assay and in the murine B16F10 melanoma model.
Results: Purified mVASH1 protein inhibited cell growth and migration of murine endothelial cell and fibroblasts, but not of vascular aortic smooth muscle cells (AoSMC). Adenovial overexpression did not inhibit proliferation or VEGF/bFGF induced capillary sprouting of HUVEC in the spheroid assay. Murine VASH1 inhibited growth of large vessels in the chorioallantoic membrane assay and induced the formation of a dense, fine capillary network. Subcutaneous growth of VASH1 overexpressing B16F10 melanomas in C57BL/6 mice was not affected within the observed time frame, but there was a significant increase of microvessels and coverage of blood vessels with alpha-smooth muscle cell actin positive mural cells.
Conclusions: Our data implicate that the murine VASH1 causes angiogenic remodelling by inhibiting the growth of large vessels in vivo and by supporting the formation of microvessels and their coverage with smooth muscle cells. EG and GU contributed equally to this work.
Circulating Endothelial Progenitor Cells Is Increasing in Human T Cell Lymphotropic Virus Type 1 (HTLV1) Asymptomatic Carriers
Authors: Meireles Ana Luisa Langanke Pedroso , Chamone Dalton , Godoy Carla Rosa Teixeira , Pereira Juliana 
Published: April 2020

Abstract
The role of angiogenesis in metastasis of solid tumors is well established, but not in hematologic malignancies. Marwan et al demonstrated that Human T Cell Lymphotropic Virus Type 1 (HTLV1) transformed T cells secrete vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF) and induce angiogenesis in vitro. Adult T-cell leukemia-lymphoma (ATL) leukemic cells produce VEGF and bFGF proteins. Therefore, the role of angiogenesis in ATL development is under investigation. We interested whether endothelial progenitor cells (EPCs) and mature endothelial cells (ECs) contribute to tumor angiogenesis in ATL Thought, this cross-sectional study aimed at quantifying circulating endothelial cells in the blood of HTLV1 asymptomatic carriers in comparison to healthy individuals by flow cytometry. A sample of 30 HTLV1 carrier age and sex matched has been compared to the control group. We demonstrated that the EPCs values were greater in the asymptomatic HTLV1 carrier (median 0.8288 cells/mm3) rather than to the control group (median 0.4905 cells/mm3) (p = 0.035). We identified other pathway of the angiogenesis in HTLV1 carriers. However, others studies are necessary to confirm the role of EPCs in the ATL pathogenesis.
Bone Marrow Adipocytes Prevent Hematopoietic Expansion in Homeostasis and in Bone Marrow Transplantation
Authors: Naveiras Olaia , Nardi Valentina , Daley George Q. 
Published: April 2020

Abstract
In mammalian bone marrow (BM), osteoblasts and endothelium constitute functional niches that support hematopoietic stem cells (HSC). Adult BM also contains numerous adipocytes, whose numbers correlate inversely with the hematopoietic activity of the marrow. As described by Neumann’s law in 1882, distal skeletal regions are adipocytic and thus non-hematopoietic in the adult. Fatty infiltration of the hematopoietic red marrow also occurs following irradiation or chemotherapy and is a diagnostic feature in biopsies from patients with marrow aplasia. However, whether adipocytes participate in hematopoietic regulation or simply expand to fill marrow space is unclear. We have found that murine hematopoiesis is reduced in adipocyte-rich marrow during homeostasis, and that adipocytes antagonize marrow recovery post-irradiation. By flow cytometry, colony forming assay, and competitive repopulation, we found a reduced frequency of HSCs and short-term hematopoietic progenitors in the adipocyte-rich vertebrae of the tail compared to the adipocyte-free vertebrae of the thorax. In A-ZIP/F1 “fatless” mice, which are genetically incapable of forming adipocytes, post-irradiation marrow engraftment is accelerated relative to wild type mice. Likewise, pharmacologic inhibition of adipocyte formation with the PPARg inhibitor Bisphenol-A-DiGlycidyl-Ether (BADGE) enhances hematopoietic recovery after BM transplant. Moreover, we have found that mice deficient in the adipocyte-specific protein adiponectin, which has been described to inhibit hematopoietic progenitor expansion in vitro, have increased progenitors in fatty marrow both during homeostasis and after BM transplant. Our data implicate adipocytes as negative regulators of the bone marrow microenvironment, and demonstrate that antagonizing adipogenesis is advantageous for enhancing hematopoietic recovery in the setting of bone marrow transplantation.
Minor Histocompatibility Antigen Mismatches and Graft Versus Host and Relapse in High-Resolution HLA-Matched Allogeneic Hematopoietic Stem Cell Transplantation
Authors: Cliquennois Manuel , Cracco Pascale , Becuwe Dominique , Salleron Julia , Dufossé Françoise , Duhamel Alain , Jouet Jean-Pierre , Dessaint Jean-Paul , Labalette Myriam , Yakoub-Agha Ibrahim 
Published: April 2020

Abstract
In a fully molecular HLA-matched setting, the outcome of allogeneic stem-cell transplantation (allo-SCT) can be affected by mismatches in minor histocompatibility antigens (mHAs) that might impact on the risk of graft-versus-host (GvH) and graft-versus-leukemia (GvL) effects. The association between mHA disparities and outcome was investigated in 96 consecutive patients who underwent myeloablative HLA-matched allo-SCT (from 69 HLA-identical siblings and 27 HLA-matched unrelated donors, all typed and matched at both allelic levels for HLA-A, -B, -Cw, -DRB1, and -DQB1 loci) for standard-risk hematological malignancy (AML n = 41; ALL n = 29; MDS n = 12; CML n = 8; others n = 6). All patients but 9 received bone marrow graft. Allelic mHAg typing was performed by PCR with sequence-specific primers for 9 autosomally encoded mHA and H-Y (PCR-SSP; Spierings et al. PLoS ONE. 2006 Dec 20; 1:e42). The distribution of autosomal mHAs among donor and recipients conformed to the expected frequencies for this population. As expected, the prevalence of mHAg mismatches was higher in unrelated compared to related recipient/donor pairs (p &lt; .003). In univariate analysis, patients who received a graft with more than 2 mHAg mismatches developed more often grade II-IV acute GvH disease (p = .01; HR=2.92 [1.28–6.64]). In multivariate analysis, HA2 mismatch emerged as an independent determinant of acute GvH disease (p = .05; HR = .42). When only mismatches in the GvL/GvH direction were considered, mismatch for HA-1, that is expressed mainly by the hematopoietic system, tended to influence the incidence of both acute and chronic GvH disease (p = .06; HR=1.47 [0.97–2.21] and p = .049; HR = 1.45 [1.00–2.10], respectively) but also to confer a reduced risk of relapse (p = .07; HR = .58 [0.32–1.05]). Mismatch for HA-8, that has a broad tissue distribution, emerged as an independent risk factor of grade II-IV acute GvH disease (p = .02; HR = 1.77 [1.08–2.89]). This study confirms the impact of mHAg mismatches on patients’ outcome after fully HLA-matched allo-SCT and highlights both the cumulative effect of mHAg disparities on outcome and the distinctive contribution of individual mHAs on GvH versus GvL effects of allo-SCT.