RESUMO
During human pregnancy, iron requirements gradually increase, leading to higher amounts of erythropoietin (EPO) and reticulocytes, and changes in erythrocyte size and density. Women with pregestational obesity experience "obesity hypoferremia" during pregnancy, which alters iron homeostasis. In this study we aimed to describe the relationship between EPO and iron nutrition status during nonanemic pregnancy, and to explore whether obesity and inflammation influence erythropoiesis and red cell indices. We conducted a secondary analysis of a cohort followed throughout pregnancy. Participants were nonanemic women assigned to two study groups based on pregestational body mass index (pgBMI): adequate weight (AW, n = 53) or obesity (Ob, n = 40). All received a multivitamin supplement. At gestational ages (GA) 13, 21, 28 and 34, we measured hemoglobin and red cell indices with an ACT-5DIFF hematology counter, and reticulocyte percentage by manual cell counting. EPO, interleukin (IL-6) and markers of iron status, i.e., hepcidin, serum transferrin receptor (sTfr) and ferritin, were measured by ELISA. Bivariate correlations showed that EPO was positively associated with pgBMI, GA, sTfr and IL-6, but negatively associated with hepcidin, ferritin and hemoglobin, and unrelated to iron intake. Generalized linear models adjusted for confounding factors showed that EPO and erythrocyte concentrations were significantly higher in women in the Ob group, while mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH) and red cell distribution width (RDW) were lower; reticulocytes and mean corpuscular hemoglobin concentration (MCHC) were not different. Differences were not altered when controlling for inflammation (IL-6). These changes suggest that, in addition to altering iron metabolism, a larger maternal body size during pregnancy results in higher erythropoiesis without increasing hemoglobin, which is exhibited in the latter being distributed among more and smaller erythrocytes.
Assuntos
Tamanho Corporal , Índices de Eritrócitos , Eritropoese/fisiologia , Fenômenos Fisiológicos da Nutrição Materna , Obesidade Materna/sangue , Gravidez/sangue , Gravidez/fisiologia , Adulto , Eritrócitos/patologia , Eritropoetina/sangue , Feminino , Humanos , Inflamação/sangue , Mediadores da Inflamação/sangue , Interleucina-6/sangue , Ferro/metabolismo , Adulto JovemRESUMO
In contrast to steady-state erythropoiesis, which generates new erythrocytes at a constant rate, stress erythropoiesis rapidly produces a large bolus of new erythrocytes in response to anemic stress. In this study, we illustrate that Yes-associated protein (Yap1) promotes the rapid expansion of a transit-amplifying population of stress erythroid progenitors in vivo and in vitro. Yap1-mutated erythroid progenitors failed to proliferate in the spleen after transplantation into lethally irradiated recipient mice. Additionally, loss of Yap1 impaired the growth of actively proliferating erythroid progenitors in vitro. This role in proliferation is supported by gene expression profiles showing that transiently amplifying stress erythroid progenitors express high levels of genes associated with Yap1 activity and genes induced by Yap1. Furthermore, Yap1 promotes the proliferation of stress erythroid progenitors in part by regulating the expression of key glutamine-metabolizing enzymes. Thus, Yap1 acts as an erythroid regulator that coordinates the metabolic status with the proliferation of erythroid progenitors to promote stress erythropoiesis.
Assuntos
Proteínas Adaptadoras de Transdução de Sinal/fisiologia , Proteínas de Ciclo Celular/fisiologia , Células Precursoras Eritroides/fisiologia , Eritropoese/fisiologia , Regeneração/fisiologia , Proteínas Adaptadoras de Transdução de Sinal/genética , Alelos , Animais , Divisão Celular , Células Cultivadas , Indução Enzimática , Células Precursoras Eritroides/citologia , Deleção de Genes , Perfilação da Expressão Gênica , Regulação da Expressão Gênica , Camundongos , Camundongos Endogâmicos C57BL , RNA Mensageiro/biossíntese , Quimera por Radiação , Tolerância a Radiação , Proteínas Recombinantes/metabolismo , Baço/citologia , Estresse Fisiológico/genética , Fatores de Transcrição/genética , Proteínas de Sinalização YAPRESUMO
The lack of copper has been associated with anemia, myelodysplastic syndromes and leukemia as well as with a loss in complex IV activity and an enlarged mitochondrial morphology. Mitochondria play a key role during the differentiation of hematopoietic stem cells by regulating the passage from a glycolytic to oxidative metabolism. The former is associated with cell proliferation and the latter with cell differentiation. Oxidative metabolism, which occurs inside mitochondria, is sustained by the respiratory chain, where complex IV is copper-dependent. We have hypothesized that a copper deficiency induces a mitochondrial metabolic reprogramming, favoring cell expansion over cell differentiation in erythropoiesis. Erythroid progression analysis of the bone marrow of mice fed with a copper deficient diet and of the in vitro erythropoiesis of human CD34+ cells treated with a bathocuproine - a copper chelator - showed a major expansion of progenitor cells and a decreased differentiation. Under copper deficiency, mitochondria switched to a higher membrane potential, lower oxygen consumption rate and lower ROS levels as compared with control cells. In addition, mitochondrial biomass was increased and an up-regulation of the mitochondrial fusion protein mitofusin 2 was observed. Most copper-deficient phenotypes were mimicked by the pharmacological inhibition of complex IV with azide. We concluded that copper deficiency induced a mitochondrial metabolic reprogramming, making hematopoietic stem cells favor progenitor cell expansion over cell differentiation.
Assuntos
Proliferação de Células/fisiologia , Leucócitos Mononucleares/metabolismo , Animais , Western Blotting , Proliferação de Células/genética , Células Cultivadas , Cobre/metabolismo , Eritropoese/genética , Eritropoese/fisiologia , Citometria de Fluxo , Humanos , Camundongos , Camundongos Endogâmicos BALB C , Microscopia Confocal , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismoRESUMO
Copper is essential in cell physiology, participating in numerous enzyme reactions. In mitochondria, copper is a cofactor for respiratory complex IV, the cytochrome c oxidase. Low copper content is associated with anemia and the appearance of enlarged mitochondria in erythropoietic cells. These findings suggest a connection between copper metabolism and bioenergetics, mitochondrial dynamics and erythropoiesis, which has not been explored so far. Here, we describe that bathocuproine disulfonate-induced copper deficiency does not alter erythropoietic cell proliferation nor induce apoptosis. However it does impair erythroid differentiation, which is associated with a metabolic switch between the two main energy-generating pathways. That is, from mitochondrial function to glycolysis. Switching off mitochondria implies a reduction in oxygen consumption and ROS generation along with an increase in mitochondrial membrane potential. Mitochondrial fusion proteins MFN2 and OPA1 were up-regulated along with the ability of mitochondria to fuse. Morphometric analysis of mitochondria did not show changes in total mitochondrial biomass but rather bigger mitochondria because of increased fusion. Similar results were also obtained with human CD34+, which were induced to differentiate into red blood cells. In all, we have shown that adequate copper levels are important for maintaining proper mitochondrial function and for erythroid differentiation where the energy metabolic switch plus the up-regulation of fusion proteins define an adaptive response to copper deprivation to keep cells alive.
Assuntos
Cobre/deficiência , Metabolismo Energético , Células Eritroides/metabolismo , Eritropoese/fisiologia , GTP Fosfo-Hidrolases/biossíntese , Dinâmica Mitocondrial/genética , Proteínas Mitocondriais/biossíntese , Regulação para Cima , Apoptose/genética , Morte Celular/genética , Diferenciação Celular/genética , Proliferação de Células , Células Cultivadas , Cobre/metabolismo , Metabolismo Energético/genética , Células Eritroides/citologia , Células Eritroides/patologia , Eritropoese/genética , Humanos , Células K562 , Mitocôndrias/genética , Mitocôndrias/patologia , Simulação de Dinâmica Molecular , Regulação para Cima/genéticaRESUMO
To analyze the interconnection between erythropoiesis and iron metabolism, one of the issues raised in this study was to know iron bioavailability under physiopathological conditions. Our aim was to understand the functional axis response composed of erythropoietin (Epo)-hepcidin-ferroportin (FPN), when 2 dysfunctional states coexist, using an animal model of iron overload followed by hypoxia. FPN and prohepcidin were assessed by immunohistochemistry using rabbit anti-mouse FPN polyclonal and prohepcidin monoclonal antibodies. Goat-labeled polymer - horseradish peroxidase anti-rabbit EnVision + System (DAB) was used as the secondary antibody. Epo levels were measured by ELISA. Tissue iron was studied by Prussian blue iron staining. Erythropoietic response was assessed using conventional hematological tests. Iron overload increased prohepcidin that remained high in hypoxia, coexisting with high levels of Epo in hypoxia, with or without iron overload. In hypoxia, FPN was clearly evident in reticuloendothelial macrophages, more than in hypoxia with iron overload. Interestingly, duodenal FPN was clearly identified on the basolateral membrane in hypoxia, with or without iron overload. Our data indicate that 2 signals could induce the cell-specific response as follows: (i) iron signal, induced prohepcidin, which reduced reticuloendothelial FPN and reduced iron availability; and (ii) hypoxia signal, stimulated Epo, which affected iron absorption by stabilizing duodenal FPN and allowed iron supply to erythropoiesis independently of store size.
Assuntos
Proteínas de Transporte de Cátions/metabolismo , Eritropoetina/metabolismo , Hepcidinas/metabolismo , Animais , Disponibilidade Biológica , Duodeno/metabolismo , Enterócitos/metabolismo , Eritropoese/fisiologia , Feminino , Hipóxia/sangue , Hipóxia/embriologia , Hipóxia/metabolismo , Ferro/sangue , Ferro/metabolismo , Sobrecarga de Ferro/sangue , Sobrecarga de Ferro/metabolismo , Macrófagos/metabolismo , Camundongos , Baço/metabolismoRESUMO
The objective of this investigation was to assess the toxicological potential of nasal formulation of erythropoietin with low sialic acid content (Neuro EPO) after 28 days of intra-nasal dosing in rats besides to evaluate the immunogenicity and erythropoietic effect of the test substance. Healthy Wistar rats of both sexes were used for 28 days subacute toxicity and immunogenicity assays. Doses evaluated were 3450, 4830 and 6900 UI/kg/day. The toxicological endpoints examined included animal body weight, food consumption, hematological and biochemical patterns, antibodies determination, selected tissue weights and histopathological examination. Reversibility of toxic effects was evaluated at high dose 14 days after treatment period. Female B6D2F1 mice were used for evaluated erythropoietic effect of the nasal formulation. Hematological endpoints were examined every week during 28 days of intra-nasal dosing of 6900 UI/kg/day. Variations of hematological patterns were not observed after 28 days of intranasal dosing. A slight increase in glucose level of treated animals within the normal range was observed. This effect was not dose related and was reversible. Antibody formation was not observed in any of the test doses. Histopathological examination of organs and tissues did not reveal treatment induced changes. The administration of Neuro EPO in normocythaemic mice did not produce erythropoietic effect. These results suggest that Neuro EPO could be used as a neuroprotective agent, without significant systemic haematological side effects.
Assuntos
Eritropoese/fisiologia , Eritropoetina/administração & dosagem , Ácido N-Acetilneuramínico/administração & dosagem , Testes de Toxicidade Aguda , Administração Intranasal , Animais , Esquema de Medicação , Eritropoese/efeitos dos fármacos , Eritropoetina/toxicidade , Feminino , Masculino , Camundongos , Ácido N-Acetilneuramínico/toxicidade , Ratos , Ratos Wistar , Testes de Toxicidade Aguda/métodosRESUMO
OBJECTIVES: To evaluate whether hepcidin concentrations in serum (Hep((S))) and urine (Hep((U))) correlate with iron metabolism, erythropoiesis, and inflammation in preterm infants. STUDY DESIGN: Thirty-one preterm infants (23-32 weeks gestational age) were included. The concentration of the mature, 25 amino-acid form of hepcidin was determined by enzyme-linked immunosorbent assay in serum, urine, blood counts, reticulocytes, and iron measurements. RESULTS: Median (IQR) Hep((S)) was 52.4 (27.9-91.9) ng/mL. The highest values were measured in patients with systemic inflammation. Hep((S)) and Hep((U)) correlated strongly (P = .0007). Hep((S)) and Hep((U)) also correlated positively with ferritin (P = .005 and P = .0002) and with reticulocyte hemoglobin content (P = .015 and P = .015). Hep((S)) and Hep((U)) correlated negatively with soluble transferrin receptor/ferritin-ratio (P = .005 and P = .003). Infants with lower hemoglobin concentrations and higher reticulocyte counts had lower Hep((S)) (P = .0016 and P = .0089). CONCLUSION: In sick preterm infants, iron status, erythropoiesis, anemia, and inflammation correlated with the mature 25 amino-acid form of hepcidin. Further evaluation of Hep((U)) for non-invasive monitoring of iron status in preterm infants appears justified.
Assuntos
Peptídeos Catiônicos Antimicrobianos/sangue , Peptídeos Catiônicos Antimicrobianos/urina , Homeostase , Recém-Nascido Prematuro/metabolismo , Ferro/metabolismo , Ensaio de Imunoadsorção Enzimática , Eritropoese/fisiologia , Feminino , Idade Gestacional , Hepcidinas , Humanos , Recém-Nascido , Masculino , Prognóstico , Estudos RetrospectivosRESUMO
BACKGROUND: The bone marrow is considered to be an important storage of parasites in Leishmania-infected dogs, although little is known about cellular genesis in this organ during canine visceral leishmaniasis (CVL). METHODOLOGY/PRINCIPAL FINDINGS: The aim of the present study was to evaluate changes in erythropoiesis and leucopoiesis in bone marrow aspirates from dogs naturally infected with Leishmania chagasi and presenting different clinical statuses and bone marrow parasite densities. The evolution of CVL from asymptomatic to symptomatic status was accompanied by increasing parasite density in the bone marrow. The impact of bone marrow parasite density on cellularity was similar in dogs at different clinical stages, with animals in the high parasite density group. Erythroid and eosinophilic hypoplasia, proliferation of neutrophilic precursor cells and significant increases in lymphocytes and plasma cell numbers were the major alterations observed. Differential bone marrow cell counts revealed increases in the myeloid:erythroid ratio associated to increased numbers of granulopoietic cells in the different clinical groups compared with non-infected dogs. CONCLUSIONS: Analysis of the data obtained indicated that the assessment of bone marrow constitutes an additional and useful tool by which to elaborate a prognosis for CVL.
Assuntos
Células da Medula Óssea/parasitologia , Eritropoese/fisiologia , Leishmania/patogenicidade , Leishmaniose/parasitologia , Leucopoese/fisiologia , Animais , Cães , Feminino , Leishmaniose/patologia , MasculinoAssuntos
Adaptação Fisiológica/genética , Altitude , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Etnicidade/genética , Seleção Genética , Doença da Altitude/etnologia , Doença da Altitude/genética , Povo Asiático/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/fisiologia , China , Eritropoese/genética , Eritropoese/fisiologia , Eritropoetina/metabolismo , Evolução Molecular , Regulação da Expressão Gênica , Estudos de Associação Genética , Haplótipos , Humanos , Fator 1 Induzível por Hipóxia/genética , Fator 1 Induzível por Hipóxia/fisiologia , Prolina Dioxigenases do Fator Induzível por Hipóxia , Imunidade Inata , PPAR alfa/genética , PPAR alfa/fisiologia , Polimorfismo de Nucleotídeo Único , Pró-Colágeno-Prolina Dioxigenase/genética , Pró-Colágeno-Prolina Dioxigenase/fisiologia , América do Sul , TibetRESUMO
Objetivou-se avaliar os parâmetros hematológicos da tilápia-do-nilo alimentada com dietas suplementadas com níveis de levedura autolisada e zinco, anterior e posterior ao estímulo pelo frio. As dietas foram formuladas para conter 32,0% PD e 3.240 kcal ED/kg com adição de levedura autolisada (%) e zinco (mg/kg): 0,0:0,0; 0,0:79,5; 2,0:0,0; 0,795:79,5; 2,0:200; 4,0:400; 6,0:600; 12,0:1200 e 14,0:1400. Na fase I, 135 alevinos foram distribuídos em 27 aquários de 50L e alimentados quatro vezes/dia por 128 dias (26ºC). Posteriormente, iniciou-se a fase II. Nove peixes/tratamento foram transferidos para 27 aquários de 40L (três/aquário) e submetidos à baixa temperatura (13,0ºC) por sete dias. Antes e após o estímulo pelo frio avaliaramse: o número de eritrócitos, a porcentagem de hematócrito, a taxa de hemoglobina, o volume corpuscular médio, a concentração dehemoglobina corpuscular média, a proteína plasmática e leucócitos totais, a porcentagem de linfócitos, neutrófilos e monócitos. O número de eritrócitos foi influenciado (p<0,05) pela adição de levedura autolisada e zinco nas dietas. Após o estímulo pelo frio o maior prejuízo na eritropoiese ocorreu nos peixes que receberam dietas 0,795:79,50 (Lev:Zn) e 14:1.400 (Lev:Zn). A ausência dos nutrientes-testes determinou queda significativa no hematócrito, leucócitos e proteína plasmática total. O estresse pelo frio determina leucopenia, linfopenia, neutrofilia e monopenia.(AU)
Hematological parameters of Nile tilapia fed diets supplemented with increasing levels of autolised yeast and zinc, before and after cold stress, were analyzed. The diets were formulated to contain 32.0% DP and 3,240 kcal/kg DE with increasing levels of autolised yeast (%) and zinc (mg/kg), as: 0.0:0.0; 0.0:79.5; 2.0:0.0; 0.795:79.5; 2.0:200; 4.0:400; 6.0:600; 12.0:1.200; 14.0:1400 . In phase I, 135 fingerlings were distributed into 27 50l-aquaria and fed ad libitum four times a day during 128 days (26ºC). After that, phase II began and nine fish from each treatment were transferred to 27 40l-aquaria (three/aquarium) and submitted to cold temperature (13.0ºC) during seven days. Before and after cold stress, the following parameters were evaluated: erythrocytes number, hematocrit, hemoglobin, corpuscular volume, mean corpuscular volume, total plasmatic protein, total leucocytes, lymphocytes, neutrophils and monocytes percentage. The number of erythrocytes was significantly influenced by the addition of autolised yeast and zinc to the diets. After cold stress, fish fed diets supplemented with 0.795:79.50 (Lev:Zn) and 14:1400 (Lev:Zn) presented impaired erythrocyte synthesis. Absence of test nutrients determined significant decrease in hematocrit, total leukocyte and total plasmatic protein. Cold stress determines leukopenia, lymphopenia, neutrophylia and monopenia(AU)