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1.
Nat Commun ; 10(1): 4596, 2019 10 10.
Artigo em Inglês | MEDLINE | ID: mdl-31601799

RESUMO

Many of the regulatory features governing erythrocyte specification, maturation, and associated disorders remain enigmatic. To identify new regulators of erythropoiesis, we utilize a functional genomic screen for genes affecting expression of the erythroid marker CD235a/GYPA. Among validating hits are genes coding for the N6-methyladenosine (m6A) mRNA methyltransferase (MTase) complex, including, METTL14, METTL3, and WTAP. We demonstrate that m6A MTase activity promotes erythroid gene expression programs through selective translation of ~300 m6A marked mRNAs, including those coding for SETD histone methyltransferases, ribosomal components, and polyA RNA binding proteins. Remarkably, loss of m6A marks results in dramatic loss of H3K4me3 marks across key erythroid-specific KLF1 transcriptional targets (e.g., Heme biosynthesis genes). Further, each m6A MTase subunit and a subset of their mRNAs targets are required for human erythroid specification in primary bone-marrow derived progenitors. Thus, m6A mRNA marks promote the translation of a network of genes required for human erythropoiesis.


Assuntos
Adenosina/análogos & derivados , Eritropoese/genética , Biossíntese de Proteínas , Adenosina/genética , Antígenos CD34/genética , Antígenos CD34/metabolismo , Células da Medula Óssea/fisiologia , Sistemas CRISPR-Cas , Proteínas de Ciclo Celular/genética , Linhagem Celular Tumoral , Regulação da Expressão Gênica , Histonas/genética , Histonas/metabolismo , Humanos , Fatores de Transcrição Kruppel-Like/genética , Fatores de Transcrição Kruppel-Like/metabolismo , Leucemia Eritroblástica Aguda/genética , Metiltransferases/genética , Regiões Promotoras Genéticas , Fatores de Processamento de RNA/genética , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Regulon
2.
BMC Med Genet ; 20(1): 140, 2019 08 16.
Artigo em Inglês | MEDLINE | ID: mdl-31420016

RESUMO

BACKGROUND: Severe malarial anemia (SMA) is a leading cause of malaria-related morbidity and mortality in children. The genetic factors that influence development of SMA and inefficient erythropoiesis, a central pathogenic feature of SMA, are only partially understood. METHODS: We performed a pilot Genome-wide Association Study (GWAS) on children with Plasmodium falciparum. The GWAS was performed using the Illumina® Infinium® HD Super Assay in conjunction with Illumina's® Human Omni2.5-8v1 BeadChip (with > 2.45 M markers). Data were analyzed using single SNP logistic regression analysis with an additive model of inheritance controlling for covariates. Results from our pilot global genomics study identified that variation in interleukin (IL)-7 was associated with enhanced risk of SMA. To validate this finding, we investigated the relationship between genotypes and/or haplotypes of two single nucleotide polymorphisms (SNPs) in IL7 [72194 T/C and - 2440 A/G] and susceptibility to both SMA and inefficient erythropoiesis [i.e., reticulocyte production index (RPI) < 2.0 in anemic children (Hb < 11.0 g/dL). Children presenting with P. falciparum malaria (< 3 years, n = 883) were stratified into two groups: Uncomplicated malaria (UM, n = 718) and SMA (n = 165). RESULTS: Regression modeling, controlling for anemia-related confounders, revealed that carriage of the TC genotype at position 72194 T/C was associated with enhanced susceptibility to inefficient erythropoiesis (OR = 1.90; 95% CI 1.09-3.30; P = 0.02) as was homozygous CC (OR 5.14; 95% CI = 1.20-21.99; P = 0.03). Consistent with this finding, individuals with the CA (72194C/-2440A) haplotype had an increased risk of inefficient erythropoiesis (OR = 1.90; 95% CI = 1.10-3.30; P = 0.02), whereas TA haplotype carriers had marginal protection against inefficient erythropoiesis (OR = 0.24; 95% CI = 0.06-1.21; P = 0.05). These observations were supported by Cochran-Armitage trend test for inefficient erythropoiesis (CA > TA > CG; P < 0.01). Although none of the genotype and/or haplotypic variants were significantly associated with SMA, the direction of the risk profiles were consistent with the erythropoiesis results. CONCLUSION: Taken together, variation in IL7 is associated with erythropoietic responses in children with falciparum malaria, a central physiological feature contributing to development of SMA.


Assuntos
Eritropoese/genética , Variação Genética , Interleucina-7/genética , Malária Falciparum/complicações , Anemia/etiologia , Anemia/genética , Estudos de Casos e Controles , Feminino , Predisposição Genética para Doença , Estudo de Associação Genômica Ampla , Genótipo , Haplótipos , Humanos , Lactente , Quênia , Masculino , Projetos Piloto , Plasmodium falciparum/patogenicidade , Polimorfismo de Nucleotídeo Único
3.
Anticancer Res ; 39(8): 4495-4502, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31366551

RESUMO

BACKGROUND/AIM: In mice, fetal liver is the first tissue of definitive erythropoiesis for definitive erythroid expansion and maturation. ZFAT, originally identified as a candidate susceptibility gene for autoimmune thyroid disease, has been reported to be involved in primitive hematopoiesis and T cell development. The aim of this study was to examine whether or not Zfat is involved in definitive erythropoiesis in the fetal liver during mammalian development. MATERIALS AND METHODS: The role of Zfat during mouse fetal erythropoiesis in the fetal liver was examined using tamoxifen-inducible CreERT2 Zfat-deficient mice. RESULTS: Zfat-deficient mice exhibit moderate anemia with small and pale fetal liver through a decreased number of erythroblasts by E12.5. Apoptosis sensitivity in fetal liver erythroid progenitors was enhanced by Zfat-deficiency ex vivo. Moreover, Zfat knockdown partially inhibited CD71-/lowTer119- to CD71highTer119- transition of fetal liver erythroid progenitors with impairment in the elevation of CD71 expression. CONCLUSION: Zfat plays a critical role for erythropoiesis in the fetal liver.


Assuntos
Antígenos CD/genética , Eritropoese/genética , Fígado/crescimento & desenvolvimento , Receptores da Transferrina/genética , Fatores de Transcrição/genética , Animais , Apoptose/genética , Diferenciação Celular/genética , Células Eritroides/metabolismo , Células Eritroides/patologia , Desenvolvimento Fetal/genética , Feto , Regulação da Expressão Gênica no Desenvolvimento , Técnicas de Silenciamento de Genes , Humanos , Fígado/metabolismo , Camundongos , Linfócitos T/citologia , Linfócitos T/metabolismo , Tireoidite Autoimune/genética , Tireoidite Autoimune/patologia
4.
Hemoglobin ; 43(1): 73-75, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-31104519

RESUMO

A regulatory single nucleotide polymorphism (rSNP), the Aγ (+25 G>A) (rs368698783) (NG_000007.3: g47783G>A) located in the HBG1 proximal promoter, is a significant predictor of clinical severity by elevating Hb F levels in ß-thalassemia (ß-thal). In this study, the presence of the Aγ (+25 G>A) and Aγ (+25 A>A) genotypes was investigated in four subgroups from a total of 611 subjects, including 88 α-thalassemia (α-thal) carriers (group A), 162 ß-thal carriers of point mutations (group B), 57 carriers of ß-thal deletions (group C) and 152 non thalassemic individuals (group D). The result is that the genotypes G>A and A>A exhibit significantly high levels of Hb F compared with the genotype G>G in both groups B and C, while no significant difference was observed in both groups A and D. We assume that the effect of Aγ (+25 G>A) polymorphism on Hb F production is only under erythropoietic stress characteristic for ß-globin chain deficiency.


Assuntos
Alelos , Eritropoese/genética , Hemoglobina Fetal/genética , Genes Modificadores , Polimorfismo de Nucleotídeo Único , Globinas beta/genética , Talassemia beta/diagnóstico , Talassemia beta/genética , Índices de Eritrócitos , Feminino , Genótipo , Humanos , Fatores de Transcrição Kruppel-Like/genética , Masculino , Análise de Sequência de DNA , Talassemia alfa/diagnóstico , Talassemia alfa/genética
5.
Blood ; 134(5): 480-491, 2019 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-31101625

RESUMO

The erythroblastic island (EBI), composed of a central macrophage and surrounding erythroid cells, was the first hematopoietic niche discovered. The identity of EBI macrophages has thus far remained elusive. Given that Epo is essential for erythropoiesis and that Epor is expressed in numerous nonerythroid cells, we hypothesized that EBI macrophages express Epor so that Epo can act on both erythroid cells and EBI macrophages simultaneously to ensure efficient erythropoiesis. To test this notion, we used Epor-eGFPcre knockin mouse model. We show that in bone marrow (BM) and fetal liver, a subset of macrophages express Epor-eGFP. Imaging flow cytometry analyses revealed that >90% of native EBIs comprised F4/80+Epor-eGFP+ macrophages. Human fetal liver EBIs also comprised EPOR+ macrophages. Gene expression profiles of BM F4/80+Epor-eGFP+ macrophages suggest a specialized function in supporting erythropoiesis. Molecules known to be important for EBI macrophage function such as Vcam1, CD169, Mertk, and Dnase2α were highly expressed in F4/80+Epor-eGFP+ macrophages compared with F4/80+Epor-eGFP- macrophages. Key molecules involved in iron recycling were also highly expressed in BM F4/80+Epor-eGFP+ macrophages, suggesting that EBI macrophages may provide an iron source for erythropoiesis within this niche. Thus, we have characterized EBI macrophages in mouse and man. Our findings provide important resources for future studies of EBI macrophage function during normal as well as disordered erythropoiesis in hematologic diseases such as thalassemia, polycythemia vera, and myelodysplastic syndromes.


Assuntos
Eritroblastos/metabolismo , Perfilação da Expressão Gênica , Macrófagos/metabolismo , Transcriptoma , Animais , Biomarcadores , Biologia Computacional/métodos , Eritropoese/genética , Expressão Gênica , Humanos , Imunofenotipagem , Camundongos , Monócitos/metabolismo , Receptores da Eritropoetina/genética , Receptores da Eritropoetina/metabolismo , Nicho de Células-Tronco/genética , Estresse Fisiológico
6.
In Silico Biol ; 13(1-2): 55-69, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31006682

RESUMO

The in vivo erythropoiesis, which is the generation of mature red blood cells in the bone marrow of whole organisms, has been described by a variety of mathematical models in the past decades. However, the in vitro erythropoiesis, which produces red blood cells in cultures, has received much less attention from the modelling community. In this paper, we propose the first mathematical model of in vitro erythropoiesis. We start by formulating different models and select the best one at fitting experimental data of in vitro erythropoietic differentiation obtained from chicken erythroid progenitor cells. It is based on a set of linear ODE, describing 3 hypothetical populations of cells at different stages of differentiation. We then compute confidence intervals for all of its parameters estimates, and conclude that our model is fully identifiable. Finally, we use this model to compute the effect of a chemical drug called Rapamycin, which affects all states of differentiation in the culture, and relate these effects to specific parameter variations. We provide the first model for the kinetics of in vitro cellular differentiation which is proven to be identifiable. It will serve as a basis for a model which will better account for the variability which is inherent to the experimental protocol used for the model calibration.


Assuntos
Eritropoese , Modelos Teóricos , Algoritmos , Animais , Diferenciação Celular/genética , Embrião de Galinha , Células Precursoras Eritroides/citologia , Células Precursoras Eritroides/efeitos dos fármacos , Células Precursoras Eritroides/metabolismo , Eritropoese/efeitos dos fármacos , Eritropoese/genética , Humanos , Cinética , Modelos Biológicos , Reprodutibilidade dos Testes
7.
Int J Mol Sci ; 20(8)2019 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-31027199

RESUMO

Preeclampsia (PE) has been associated with placental dysfunction, resulting in fetal hypoxia, accelerated erythropoiesis, and increased erythroblast count in the umbilical cord blood (UCB). Although the detailed effects remain unknown, placental dysfunction can also cause inflammation, nutritional, and oxidative stress in the fetus that can affect erythropoiesis. Here, we compared the expression of surface adhesion molecules and the erythroid differentiation capacity of UCB hematopoietic stem/progenitor cells (HSPCs), UCB erythroid profiles along with the transcriptome and proteome of these cells between male and female fetuses from PE and normotensive pregnancies. While no significant differences were observed in UCB HSPC migration/homing and in vitro erythroid colony differentiation, the UCB HSPC transcriptome and the proteomic profile of the in vitro differentiated erythroid cells differed between PE vs. normotensive samples. Accordingly, despite the absence of significant differences in the UCB erythroid populations in male or female fetuses from PE or normotensive pregnancies, transcriptional changes were observed during erythropoiesis, particularly affecting male fetuses. Pathway analysis suggested deregulation in the mammalian target of rapamycin complex 1/AMP-activated protein kinase (mTORC1/AMPK) signaling pathways controlling cell cycle, differentiation, and protein synthesis. These results associate PE with transcriptional and proteomic changes in fetal HSPCs and erythroid cells that may underlie the higher erythroblast count in the UCB in PE.


Assuntos
Células Eritroides/metabolismo , Feto/patologia , Pré-Eclâmpsia/genética , Proteômica , Caracteres Sexuais , Transcrição Genética , Diferenciação Celular/genética , Movimento Celular/genética , Eritropoese/genética , Feminino , Regulação da Expressão Gênica , Células-Tronco Hematopoéticas/metabolismo , Humanos , Masculino , Pré-Eclâmpsia/patologia , Gravidez , Resultado da Gravidez/genética , Biossíntese de Proteínas , Transcriptoma/genética , Cordão Umbilical/patologia
8.
Blood ; 133(23): 2518-2528, 2019 06 06.
Artigo em Inglês | MEDLINE | ID: mdl-30971389

RESUMO

The microRNA (miRNA) locus miR-144/451 is abundantly expressed in erythrocyte precursors, facilitating their terminal maturation and protecting against oxidant stress. However, the full repertoire of erythroid miR-144/451 target messenger RNAs (mRNAs) and associated cellular pathways is unknown. In general, the numbers of mRNAs predicted to be targeted by an miRNA vary greatly from hundreds to thousands, and are dependent on experimental approaches. To comprehensively and accurately identify erythroid miR-144/451 target mRNAs, we compared gene knockout and wild-type fetal liver erythroblasts by RNA sequencing, quantitative proteomics, and RNA immunoprecipitation of Argonaute (Ago), a component of the RNA-induced silencing complex that binds miRNAs complexed to their target mRNAs. Argonaute bound ∼1400 erythroblast mRNAs in a miR-144/451-dependent manner, accounting for one-third of all Ago-bound mRNAs. However, only ∼100 mRNAs were stabilized after miR-144/451 loss. Thus, miR-144 and miR-451 deregulate <10% of mRNAs that they bind, a characteristic that likely applies generally to other miRNAs. Using stringent selection criteria, we identified 53 novel miR-144/451 target mRNAs. One of these, Cox10, facilitates the assembly of mitochondrial electron transport complex IV. Loss of miR-144/451 caused increased Cox10 mRNA and protein, accumulation of complex IV, and increased mitochondrial membrane potential with no change in mitochondrial mass. Thus, miR-144/451 represses mitochondrial respiration during erythropoiesis by inhibiting the production of Cox10.


Assuntos
Alquil e Aril Transferases/biossíntese , Eritropoese/genética , Regulação da Expressão Gênica/genética , Proteínas de Membrana/biossíntese , MicroRNAs/genética , Alquil e Aril Transferases/genética , Animais , Proteínas de Membrana/genética , Camundongos , Camundongos Knockout
9.
Development ; 146(6)2019 03 21.
Artigo em Inglês | MEDLINE | ID: mdl-30837221

RESUMO

Hematopoiesis maintains the entire blood system, and dysregulation of this process can lead to malignancies (leukemia), immunodeficiencies or red blood cell diseases (anemia, polycythemia vera). We took advantage of the zebrafish model that shares most of the genetic program involved in hematopoiesis with mammals to characterize a new gene of unknown function, si:ch73-299h12.2, which is expressed in the erythroid lineage during primitive, definitive and adult hematopoiesis. This gene, required during primitive and definitive erythropoiesis, encodes a C2H2 zinc-finger protein that inhibits BMP signaling. We therefore named this gene blood-inducing factor 1 and BMP inhibitory factor 1 (bif1). We identified a bif1 ortholog in Sinocyclocheilus rhinocerous, another fish, and in the mouse genome. Both genes also inhibit BMP signaling when overexpressed in zebrafish. In conclusion, we have deorphanized a new zebrafish gene of unknown function: bif1 codes for a zinc-finger protein that inhibits BMP signaling and also regulates primitive erythropoiesis and definitive hematopoiesis.


Assuntos
Proteínas Morfogenéticas Ósseas/antagonistas & inibidores , Proteínas Morfogenéticas Ósseas/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Hematopoese , Peptídeos e Proteínas de Sinalização Intracelular/fisiologia , Proteínas de Peixe-Zebra/fisiologia , Animais , Animais Geneticamente Modificados , Linhagem da Célula , Núcleo Celular/metabolismo , Eritropoese/genética , Proteínas de Fluorescência Verde/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/genética , Camundongos , Transdução de Sinais , Fatores de Transcrição/metabolismo , Peixe-Zebra , Proteínas de Peixe-Zebra/genética , Dedos de Zinco
10.
Nat Biotechnol ; 37(4): 451-460, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30899105

RESUMO

Single-cell RNA sequencing studies of differentiating systems have raised fundamental questions regarding the discrete versus continuous nature of both differentiation and cell fate. Here we present Palantir, an algorithm that models trajectories of differentiating cells by treating cell fate as a probabilistic process and leverages entropy to measure cell plasticity along the trajectory. Palantir generates a high-resolution pseudo-time ordering of cells and, for each cell state, assigns a probability of differentiating into each terminal state. We apply our algorithm to human bone marrow single-cell RNA sequencing data and detect important landmarks of hematopoietic differentiation. Palantir's resolution enables the identification of key transcription factors that drive lineage fate choice and closely track when cells lose plasticity. We show that Palantir outperforms existing algorithms in identifying cell lineages and recapitulating gene expression trends during differentiation, is generalizable to diverse tissue types, and is well-suited to resolving less-studied differentiating systems.


Assuntos
Algoritmos , Diferenciação Celular/genética , Linhagem da Célula/genética , Análise de Sequência de RNA/estatística & dados numéricos , Análise de Célula Única/estatística & dados numéricos , Animais , Biotecnologia , Células da Medula Óssea/citologia , Células da Medula Óssea/metabolismo , Eritropoese/genética , Regulação da Expressão Gênica no Desenvolvimento , Hematopoese/genética , Humanos , Cadeias de Markov , Camundongos , Modelos Biológicos , Modelos Estatísticos
11.
Blood Cancer J ; 9(3): 33, 2019 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-30850577

RESUMO

The inv(16) acute myeloid leukemia-associated CBFß-MYH11 fusion is proposed to block normal myeloid differentiation, but whether this subtype of leukemia cells is poised for a unique cell lineage remains unclear. Here, we surveyed the functional consequences of CBFß-MYH11 in primary inv(16) patient blasts, upon expression during hematopoietic differentiation in vitro and upon knockdown in cell lines by multi-omics profiling. Our results reveal that primary inv(16) AML cells share common transcriptomic signatures and epigenetic determiners with megakaryocytes and erythrocytes. Using in vitro differentiation systems, we reveal that CBFß-MYH11 knockdown interferes with normal megakaryocyte maturation. Two pivotal regulators, GATA2 and KLF1, are identified to complementally occupy RUNX1-binding sites upon fusion protein knockdown, and overexpression of GATA2 partly induces a gene program involved in megakaryocyte-directed differentiation. Together, our findings suggest that in inv(16) leukemia, the CBFß-MYH11 fusion inhibits primed megakaryopoiesis by attenuating expression of GATA2/KLF1 and interfering with a balanced transcriptional program involving these two factors.


Assuntos
Fator de Transcrição GATA2/metabolismo , Regulação Leucêmica da Expressão Gênica , Fatores de Transcrição Kruppel-Like/metabolismo , Megacariócitos/metabolismo , Proteínas de Fusão Oncogênica/genética , Sítios de Ligação , Diferenciação Celular , Linhagem Celular Tumoral , Proliferação de Células , Epigênese Genética , Células Eritroides/citologia , Células Eritroides/metabolismo , Eritropoese/genética , Perfilação da Expressão Gênica , Técnicas de Silenciamento de Genes , Humanos , Leucemia Mieloide Aguda/genética , Leucemia Mieloide Aguda/metabolismo , Megacariócitos/citologia , Proteínas de Fusão Oncogênica/metabolismo , Ligação Proteica , Trombopoese , Transcrição Genética
12.
Biomed Res Int ; 2019: 4504302, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30834265

RESUMO

Background: Extramedullary hematopoiesis (EMH) is common in non-transfusion-dependent thalassemia (NTDT) patients. Clinical presentations of EMH vary as MRI screening is not feasible. Hence, serum biomarkers are used to predict the risk of EMH. Materials and Methods: 52 NTDT patients, including 26 EMH (+) and 26 EMH (-), together with 26 healthy controls, were enrolled in this case-control study from 2013 to 2016. EMH was confirmed by computed tomography or MRI. Demographic, transfusion, genetic, laboratory, and liver iron concentration (LIC) data, as well as clinical complications, were analyzed. Results: EMH (+) patients had significantly higher serum ferritin (SF), growth differentiation factor 15 (GDF15), and erythropoietin (EPO) levels compared with EMH (-) patients and controls. The levels of erythroferrone (ERFE), hepcidin, and sTfR did not differ significantly between EMH (+) and EMH (-) patients (p>0.05). In NTDT patients, serum ERFE was not related to SF, LIC, hepcidin, sTfR, EPO, GDF15, and Hb levels. GDF15, EPO concentrations, and GDF15 to sTfR and GDF15 to EPO ratios are able to determine the presence of EMH with considerable sensitivity and specificity. Conclusions: GDF15, EPO, and GDF15 to EPO and GDF15 to sTfR ratios are potential biomarkers for the early prediction of NTDT in patients who are at risk for EMH.


Assuntos
Antígenos CD/sangue , Eritropoetina/sangue , Fator 15 de Diferenciação de Crescimento/sangue , Hematopoese Extramedular/genética , Receptores da Transferrina/sangue , Talassemia/sangue , Adulto , Biomarcadores/sangue , Estudos de Casos e Controles , Eritropoese/genética , Feminino , Ferritinas/sangue , Hematopoese Extramedular/fisiologia , Hepcidinas/sangue , Homeostase/genética , Humanos , Ferro/metabolismo , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Hormônios Peptídicos/sangue , Fatores de Risco , Talassemia/complicações , Talassemia/diagnóstico por imagem , Talassemia/fisiopatologia , Tomografia Computadorizada por Raios X
13.
Dev Cell ; 49(1): 118-129.e7, 2019 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-30827895

RESUMO

The nature of cell-state transitions during the transit-amplifying phases of many developmental processes-hematopoiesis in particular-is unclear. Here, we use single-cell RNA sequencing to demonstrate a continuum of transcriptomic states in committed transit-amplifying erythropoietic progenitors, which correlates with a continuum of proliferative potentials in these cells. We show that glucocorticoids enhance erythrocyte production by slowing the rate of progression through this developmental continuum of transit-amplifying progenitors, permitting more cell divisions prior to terminal erythroid differentiation. Mechanistically, glucocorticoids prolong expression of genes that antagonize and slow induction of genes that drive terminal erythroid differentiation. Erythroid progenitor daughter cell pairs have similar transcriptomes with or without glucocorticoid stimulation, indicating largely symmetric cell division. Thus, the rate of progression along a developmental continuum dictates the absolute number of erythroid cells generated from each transit-amplifying progenitor, suggesting a paradigm for regulating the total output of differentiated cells in numerous other developmental processes.


Assuntos
Células Sanguíneas/metabolismo , Proliferação de Células/genética , Células Precursoras Eritroides/metabolismo , Hematopoese/genética , Animais , Células Sanguíneas/citologia , Diferenciação Celular/genética , Divisão Celular/genética , Células Cultivadas , Eritrócitos/citologia , Eritrócitos/metabolismo , Células Eritroides/citologia , Células Eritroides/metabolismo , Células Precursoras Eritroides/citologia , Eritropoese/genética , Glucocorticoides/genética , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Camundongos , Análise de Célula Única/métodos , Transcriptoma/genética
14.
Parasitol Res ; 118(4): 1147-1158, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30747294

RESUMO

Trypanosoma carassii is a flagellated bloodstream parasite of cyprinid fish with pathogenesis manifesting primarily as anemia in experimentally infected fish. This anemia is characterized by decreases in the number of circulating red blood cells (RBCs) during peak parasitemia. We examined changes in the key blood metrics and expression of genes known to be important in the regulation of erythropoiesis. Increasing parasitemia was strongly correlated with an overall decrease in the total number of circulating RBCs. Gene expression of key erythropoiesis regulators (EPO, EPOR, GATA1, Lmo2, and HIFα) and proinflammatory cytokines (IFNγ and TNFα) were measured and their expressions differed from those in fish made anemic by injections of phenylhydrazine (PHZ). Significant upregulation of pro-erythropoietic genes was observed in PHZ-induced anemia, but not during peak parasitic infection. Previously, we reported on functional characterization of goldfish erythropoietin (rgEPO) and its ability to induce survival and differentiation of erythroid progenitor cells in vitro. Treatment of goldfish during the infection with rgEPO reduced the severity of anemia but failed to fully prevent the onset of the anemic state in infected fish. Proinflammatory cytokines have been implicated in the suppression of erythropoiesis during trypanosomiasis, specifically the cytokines TNFα, IFNγ, and IL-1ß. Analysis of key proinflammatory cytokines revealed that mRNA levels of IFNγ and TNFα were upregulated in response to infection, but only TNFα increased in response to PHZ treatment. Synergistic activity of the proinflammatory cytokines may be required to sustain prolonged anemia. These findings provide insight into the relationship between T. carassii and host anemia and suggest that T. carassii may directly or indirectly suppress host erythropoiesis.


Assuntos
Anemia/genética , Citocinas/biossíntese , Eritropoese/genética , Regulação da Expressão Gênica/genética , Carpa Dourada/parasitologia , Parasitemia/patologia , Trypanosoma/classificação , Anemia/parasitologia , Animais , Contagem de Eritrócitos , Eritropoetina/biossíntese , Fator de Transcrição GATA1/biossíntese , Interferon gama/biossíntese , Proteínas com Domínio LIM/biossíntese , Fenil-Hidrazinas/farmacologia , RNA Mensageiro/genética , Receptores da Eritropoetina/biossíntese , Tripanossomíase/patologia , Fator de Necrose Tumoral alfa/biossíntese
15.
PLoS One ; 14(1): e0210515, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30653565

RESUMO

During erythropoiesis, haematopoietic stem cells (HSCs) differentiate in successive steps of commitment and specification to mature erythrocytes. This differentiation process is controlled by transcription factors that establish stage- and cell type-specific gene expression. In this study, we demonstrate that FUSE binding protein 1 (FUBP1), a transcriptional regulator important for HSC self-renewal and survival, is regulated by T-cell acute lymphocytic leukaemia 1 (TAL1) in erythroid progenitor cells. TAL1 directly activates the FUBP1 promoter, leading to increased FUBP1 expression during erythroid differentiation. The binding of TAL1 to the FUBP1 promoter is highly dependent on an intact GATA sequence in a combined E-box/GATA motif. We found that FUBP1 expression is required for efficient erythropoiesis, as FUBP1-deficient progenitor cells were limited in their potential of erythroid differentiation. Thus, the finding of an interconnection between GATA1/TAL1 and FUBP1 reveals a molecular mechanism that is part of the switch from progenitor- to erythrocyte-specific gene expression. In summary, we identified a TAL1/FUBP1 transcriptional relationship, whose physiological function in haematopoiesis is connected to proper erythropoiesis.


Assuntos
Diferenciação Celular/genética , Proteínas de Ligação a DNA/genética , Células Precursoras Eritroides/metabolismo , Regulação Neoplásica da Expressão Gênica , Proteínas de Ligação a RNA/genética , Proteína 1 de Leucemia Linfocítica Aguda de Células T/genética , Células A549 , Proteínas de Ligação a DNA/metabolismo , Eritropoese/genética , Fator de Transcrição GATA1/genética , Fator de Transcrição GATA1/metabolismo , Células HEK293 , Células HL-60 , Humanos , Proteínas de Ligação a RNA/metabolismo , Proteína 1 de Leucemia Linfocítica Aguda de Células T/metabolismo , Regulação para Cima
16.
Biochim Biophys Acta Mol Cell Res ; 1866(2): 214-224, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30395882

RESUMO

Elavl1 (also known as HuR), an RNA binding protein highly conserved between zebrafish and human, regulates gene expression by stabilizing target mRNA. Our previous studies have uncovered that the predominant isoform elavl1a is required for zebrafish embryonic erythropoiesis. However, the exact mechanism of how elav11 spatiotemporally stabilizes target mRNAs to regulate specific erythropoiesis is not yet understood. Here we show that phosphorylation of elavl1a at Ser219 and Ser316 by PKC is necessarily required for cytosolic shuttling from the nucleus to stabilize gata1 mRNA and thus promotes erythropoiesis. Knockdown of elavl1a resulted in the hindrance of erythropoiesis and Hemin-induced erythroid differentiation of human myeloid leukemia K562 cells. Interestingly, inhibition of PKC reproduced the phenotype seen during zebrafish embryogenesis and erythroid differentiation of myeloid leukemia. Mechanistically, Hemin induced elavl1a export from nuclear to cytoplasmic space in K562 cells in a manner dependent on phosphorylation on Ser219 and Ser316, as overexpression of elavl1a with mutations on Ser219 and Ser316 resulted in erythropoiesis failure. Additionally, co-administration of low doses of elavl1a morpholino (MO) and three PKC inhibitors showed a combined effect in zebrafish embryonic erythropoiesis dysplasia. In conclusion, our study reveals that PKC-mediated phosphorylation of elavl1a at Ser219 and Ser316 sites controls its nucleo-cytoplasmic translocation in zebrafish, thereby regulating embryonic erythropoiesis.


Assuntos
Proteína Semelhante a ELAV 1/metabolismo , Eritropoese/genética , Eritropoese/fisiologia , Animais , Diferenciação Celular , Linhagem Celular Tumoral , Proteína Semelhante a ELAV 1/fisiologia , Fator de Transcrição GATA1/genética , Fator de Transcrição GATA1/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/genética , Hemina/farmacologia , Humanos , Células K562 , Fosforilação , Proteína Quinase C/metabolismo , Proteína Quinase C/fisiologia , RNA Mensageiro/metabolismo , Proteínas de Ligação a RNA/genética , Proteínas de Ligação a RNA/metabolismo , Peixe-Zebra/metabolismo , Proteínas de Peixe-Zebra/genética , Proteínas de Peixe-Zebra/metabolismo
17.
Am J Hematol ; 94(1): 10-20, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30252956

RESUMO

The signaling cascade induced by the interaction of erythropoietin (EPO) with its receptor (EPO-R) is a key event of erythropoiesis. We present here data indicating that Fyn, a Src-family-kinase, participates in the EPO signaling-pathway, since Fyn-/- mice exhibit reduced Tyr-phosphorylation of EPO-R and decreased STAT5-activity. The importance of Fyn in erythropoiesis is also supported by the blunted responsiveness of Fyn-/- mice to stress erythropoiesis. Fyn-/- mouse erythroblasts adapt to reactive oxygen species (ROS) by activating the redox-related-transcription-factor Nrf2. However, since Fyn is a physiologic repressor of Nrf2, absence of Fyn resulted in persistent-activation of Nrf2 and accumulation of nonfunctional proteins. ROS-induced over-activation of Jak2-Akt-mTOR-pathway and repression of autophagy with perturbation of lysosomal-clearance were also noted. Treatment with Rapamycin, a mTOR-inhibitor and autophagy activator, ameliorates Fyn-/- mouse baseline erythropoiesis and erythropoietic response to oxidative-stress. These findings identify a novel multimodal action of Fyn in the regulation of normal and stress erythropoiesis.


Assuntos
Eritropoese/fisiologia , Estresse Oxidativo/fisiologia , Proteínas Proto-Oncogênicas c-fyn/fisiologia , Animais , Autofagia , Doxorrubicina/toxicidade , Eritroblastos/enzimologia , Eritropoese/efeitos dos fármacos , Eritropoese/genética , Feminino , Janus Quinase 2/metabolismo , Camundongos , Camundongos Knockout , Fator 2 Relacionado a NF-E2/metabolismo , Oxirredução , Fenil-Hidrazinas/toxicidade , Fosforilação , Processamento de Proteína Pós-Traducional , Proteínas Proto-Oncogênicas c-fyn/deficiência , Proteínas Proto-Oncogênicas c-fyn/genética , Espécies Reativas de Oxigênio , Receptores da Eritropoetina/metabolismo , Fator de Transcrição STAT5/metabolismo , Transdução de Sinais , Sirolimo/farmacologia , Serina-Treonina Quinases TOR/metabolismo
18.
J Infect Dis ; 219(1): 154-164, 2019 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-30060095

RESUMO

Background: Among the severe malaria syndromes, severe malarial anemia (SMA) is the most common, whereas cerebral malaria (CM) is the most lethal. However, the mechanisms that lead to CM and SMA are unclear. Methods: We compared transcriptomic profiles of whole blood obtained from Ugandan children with acute CM (n = 17) or SMA (n = 17) and community children without Plasmodium falciparum infection (n = 12) and determined the relationships among gene expression, hematological indices, and relevant plasma biomarkers. Results: Both CM and SMA demonstrated predominantly upregulated enrichment of dendritic cell activation, inflammatory/Toll-like receptor/chemokines, and monocyte modules, but downregulated enrichment of lymphocyte modules. Nuclear factor, erythroid 2 like 2 (Nrf2)-regulated genes were overexpressed in children with SMA relative to CM, with the highest expression in children with both SMA and sickle cell disease (HbSS), corresponding with elevated plasma heme oxygenase-1 in this group. Erythroid and reticulocyte-specific signatures were markedly decreased in CM relative to SMA despite higher hemoglobin levels and appropriate increases in erythropoietin. Viral sensing/interferon-regulatory factor 2 module expression and plasma interferon-inducible protein-10/CXCL10 negatively correlated with reticulocyte-specific signatures. Conclusions: Compared with SMA, CM is associated with downregulation of Nrf2-related and erythropoiesis signatures by whole-blood transcriptomics. Future studies are needed to confirm these findings and assess pathways that may be amenable to interventions to ameliorate CM and SMA.


Assuntos
Anemia/metabolismo , Eritropoese/genética , Malária Cerebral/metabolismo , Malária Falciparum/sangue , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Anemia/complicações , Anemia Falciforme/complicações , Anemia Falciforme/metabolismo , Biomarcadores/sangue , Quimiocina CXCL10/metabolismo , Quimiocinas/metabolismo , Criança , Pré-Escolar , Células Dendríticas/metabolismo , Regulação para Baixo , Células Eritroides/metabolismo , Eritropoetina/metabolismo , Feminino , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Heme Oxigenase-1/sangue , Heme Oxigenase-1/metabolismo , Hemoglobinas , Humanos , Lactente , Fator Regulador 2 de Interferon/metabolismo , Malária Cerebral/complicações , Masculino , Monócitos , Plasmodium falciparum , Reticulócitos/metabolismo , Receptores Toll-Like/metabolismo , Transcriptoma , Uganda
19.
J Cell Physiol ; 234(3): 2373-2385, 2019 03.
Artigo em Inglês | MEDLINE | ID: mdl-30192008

RESUMO

Erythropoiesis is a multi-step process that involves the differentiation of hematopoietic stem cells into mature red blood cells (RBCs). This process is regulated by several signaling pathways, transcription factors and microRNAs (miRNAs). Many studies have shown that dysregulation of this process can lead to hematologic disorders. PI3K/AKT is one of the most important pathways that control many cellular processes including, cell division, autophagy, survival, and differentiation. In this review, we focus on the role of PI3K/AKT pathway in erythropoiesis and discuss the function of some of the most important genes, transcription factors, and miRNAs that regulate different stages of erythropoiesis which play roles in differentiation and maturation of RBCs, prevention of apoptosis, and autophagy induction. Understanding the role of the PI3K pathway in erythropoiesis may provide new insights into diagnosing erythrocyte disorders.


Assuntos
Diferenciação Celular/genética , Eritropoese/genética , Fosfatidilinositol 3-Quinases/genética , Proteínas Proto-Oncogênicas c-akt/genética , Apoptose/genética , Autofagia/genética , Eritrócitos/citologia , Eritrócitos/metabolismo , Células-Tronco Hematopoéticas/metabolismo , Humanos , MicroRNAs/genética , Transdução de Sinais/genética
20.
Nat Commun ; 9(1): 4386, 2018 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-30349036

RESUMO

In addition to serving as a prosthetic group for enzymes and a hemoglobin structural component, heme is a crucial homeostatic regulator of erythroid cell development and function. While lncRNAs modulate diverse physiological and pathological cellular processes, their involvement in heme-dependent mechanisms is largely unexplored. In this study, we elucidated a lncRNA (UCA1)-mediated mechanism that regulates heme metabolism in human erythroid cells. We discovered that UCA1 expression is dynamically regulated during human erythroid maturation, with a maximal expression in proerythroblasts. UCA1 depletion predominantly impairs heme biosynthesis and arrests erythroid differentiation at the proerythroblast stage. Mechanistic analysis revealed that UCA1 physically interacts with the RNA-binding protein PTBP1, and UCA1 functions as an RNA scaffold to recruit PTBP1 to ALAS2 mRNA, which stabilizes ALAS2 mRNA. These results define a lncRNA-mediated posttranscriptional mechanism that provides a new dimension into how the fundamental heme biosynthetic process is regulated as a determinant of erythrocyte development.


Assuntos
Heme/metabolismo , RNA Longo não Codificante/metabolismo , 5-Aminolevulinato Sintetase/genética , 5-Aminolevulinato Sintetase/metabolismo , Antígenos CD34/metabolismo , Diferenciação Celular/genética , Diferenciação Celular/fisiologia , Células Eritroides/metabolismo , Eritropoese/genética , Eritropoese/fisiologia , Ribonucleoproteínas Nucleares Heterogêneas/genética , Ribonucleoproteínas Nucleares Heterogêneas/metabolismo , Humanos , Proteína de Ligação a Regiões Ricas em Polipirimidinas/genética , Proteína de Ligação a Regiões Ricas em Polipirimidinas/metabolismo , Ligação Proteica , RNA Longo não Codificante/genética , RNA Mensageiro/metabolismo , Células-Tronco/metabolismo
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