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1.
Int J Mol Sci ; 23(3)2022 Jan 21.
Artigo em Inglês | MEDLINE | ID: mdl-35163110

RESUMO

A deficiency of vitamin A (VAD) and iron is the most common nutritional problem affecting people worldwide. Given the scale of the problem, the interactions between vitamin A and iron levels are widely studied. However, the exact mechanism of the impact of vitamin A on the regulation of iron metabolism remains unclear. An extremely significant issue becomes a better understanding of the nature of the studied biological phenomenon, which is possible by using a systems approach through developing and analyzing a mathematical model based on a Petri net. To study the considered system, the t-cluster analysis, the significance analysis, and the analysis of the average number of transition firings were performed. The used analyses have allowed distinguishing the most important mechanisms (both subprocesses and elementary processes) positively and negatively regulating an expression of hepcidin and allowed to distinguish elementary processes with a higher frequency of occurrence compared to others. The analysis also allowed to resolve doubts about the discrepancy in literature reports, where VAD leads to positive regulation of hepcidin expression or to negative regulation of hepcidin expression. The more detailed analyses have shown that VAD more frequently positively stimulates hepcidin expression and this mechanism is more significant than the mechanism inhibiting hepcidin expression indirectly by VAD.


Assuntos
Algoritmos , Anemia Ferropriva/metabolismo , Hepcidinas/metabolismo , Ferro/metabolismo , Análise de Sistemas , Deficiência de Vitamina A/metabolismo , Vitamina A/metabolismo , Anemia Ferropriva/complicações , Anemia Ferropriva/patologia , Simulação por Computador , Humanos , Modelos Teóricos , Deficiência de Vitamina A/complicações , Deficiência de Vitamina A/patologia
2.
Sheng Li Xue Bao ; 74(4): 639-647, 2022 Aug 25.
Artigo em Zh | MEDLINE | ID: mdl-35993215

RESUMO

Anemia of chronic disease (ACD), complicated by various chronic inflammatory diseases, is the second most prevalent type of anemia after iron deficiency anemia in the world. ACD significantly reduces the life quality of patients with chronic diseases, and represents an independent poor prognostic factor in certain chronic diseases. A large body of studies has demonstrated that most of anemia is related to abnormal iron metabolism. In the past decade, hepcidin, as a key factor in regulating iron metabolism, has attracted enormous attention due to its important role in the pathogenesis of ACD. This article reviews the research progress on the role and underlying regulatory mechanisms of hepcidin in ACD. We also discuss the potential of hepcidin as an effective therapeutic target for ACD treatment, in order to provide a new maneuver for improving the quality of ACD patients' life.


Assuntos
Anemia Ferropriva , Anemia , Anemia Ferropriva/complicações , Anemia Ferropriva/metabolismo , Anemia Ferropriva/patologia , Doença Crônica , Hepcidinas , Humanos , Ferro/metabolismo
3.
Br J Haematol ; 193(5): 882-893, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33316086

RESUMO

The discovery of hepcidin has provided a solid foundation for understanding the mechanisms of systemic iron homeostasis and the aetiologies of iron disorders. Hepcidin assures the balance of circulating and stored iron levels for multiple physiological processes including oxygen transport and erythropoiesis, while limiting the toxicity of excess iron. The liver is the major site where regulatory signals from iron, erythropoietic drive and inflammation are integrated to control hepcidin production. Pathologically, hepcidin dysregulation by genetic inactivation, ineffective erythropoiesis, or inflammation leads to diseases of iron deficiency or overload such as iron-refractory iron-deficiency anaemia, anaemia of inflammation, iron-loading anaemias and hereditary haemochromatosis. In the present review, we discuss recent insights into the molecular mechanisms governing hepcidin regulation, how these pathways are disrupted in iron disorders, and how this knowledge is being used to develop novel diagnostic and therapeutic strategies.


Assuntos
Anemia Ferropriva , Eritropoese , Hemocromatose , Hepcidinas , Fígado , Anemia Ferropriva/genética , Anemia Ferropriva/metabolismo , Anemia Ferropriva/patologia , Anemia Ferropriva/fisiopatologia , Animais , Hemocromatose/genética , Hemocromatose/metabolismo , Hemocromatose/patologia , Hemocromatose/fisiopatologia , Hepcidinas/sangue , Hepcidinas/genética , Humanos , Fígado/metabolismo , Fígado/patologia , Fígado/fisiopatologia
4.
Blood ; 133(4): 344-355, 2019 01 24.
Artigo em Inglês | MEDLINE | ID: mdl-30538134

RESUMO

Transferrin receptor 1 (Tfr1) mediates uptake of circulating transferrin-bound iron to developing erythroid cells and other cell types. Its critical physiological function is highlighted by the embryonic lethal phenotype of Tfr1-knockout (Tfrc-/-) mice and the pathologies of several tissue-specific knockouts. We generated TfrcAlb-Cre mice bearing hepatocyte-specific ablation of Tfr1 to explore implications in hepatocellular and systemic iron homeostasis. TfrcAlb-Cre mice are viable and do not display any apparent liver pathology. Nevertheless, their liver iron content (LIC) is lower compared with that of control Tfrcfl/fl littermates as a result of the reduced capacity of Tfr1-deficient hepatocytes to internalize iron from transferrin. Even though liver Hamp messenger RNA (mRNA) and serum hepcidin levels do not differ between TfrcAlb-Cre and Tfrcfl/fl mice, Hamp/LIC and hepcidin/LIC ratios are significantly higher in the former. Importantly, this is accompanied by modest hypoferremia and microcytosis, and it predisposes TfrcAlb-Cre mice to iron-deficiency anemia. TfrcAlb-Cre mice appropriately regulate Hamp expression following dietary iron manipulations or holo-transferrin injection. Holo-transferrin also triggers proper induction of Hamp mRNA, ferritin, and Tfr2 in primary TfrcAlb-Cre hepatocytes. We further show that these cells can acquire 59Fe from 59Fe-transferrin, presumably via Tfr2. We conclude that Tfr1 is redundant for basal hepatocellular iron supply but essential for fine-tuning hepcidin responses according to the iron load of hepatocytes. Our data are consistent with an inhibitory function of Tfr1 on iron signaling to hepcidin via its interaction with Hfe. Moreover, they highlight hepatocellular Tfr1 as a link between cellular and systemic iron-regulatory pathways.


Assuntos
Antígenos CD/metabolismo , Hepatócitos/metabolismo , Hepcidinas/metabolismo , Homeostase , Ferro/metabolismo , Receptores da Transferrina/metabolismo , Anemia Ferropriva/patologia , Animais , Ferritinas/metabolismo , Deleção de Genes , Regulação da Expressão Gênica/efeitos dos fármacos , Marcação de Genes , Hepatócitos/efeitos dos fármacos , Hepcidinas/genética , Homeostase/efeitos dos fármacos , Integrases/metabolismo , Ferro da Dieta/farmacologia , Camundongos Endogâmicos C57BL , Receptores da Transferrina/deficiência , Transferrina/metabolismo
5.
Pediatr Res ; 90(2): 341-346, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33469189

RESUMO

BACKGROUND: Iron deficiency anemia (IDA)-induced reactive thrombocytosis can occur in children and adults. The underlying mechanism for this phenomenon is indeterminate. Traditional cytokines such as thrombopoietin (TPO), interleukin-6 (IL-6), and IL-11 involved in megakaryopoiesis have not been shown to be the cause. Recent studies suggest that growth factors and signaling molecules involved with angiogenesis influence the proliferation and differentiation of megakaryocytes. METHODS: We investigated the possible association between angiogenic cytokines with reactive thrombocytosis due to IDA in an iron-deficient (ID) rat model. Complete blood count, iron panels, and TPO levels were measured at baseline and 5 weeks later in both control (C) and ID rats. Angiogenic cytokines were evaluated in the bone marrow in all rats. RESULTS: We successfully induced IDA in our rats by phlebotomy and reduced iron diet. We did not find an increase of TPO in ID rats. A review of the bone marrow showed an increase in the number of megakaryocytes, vascular structures, as well as increased intensity of stain for vascular endothelial growth factor (VEGF), and CXC chemokine receptor 4 (CXCR4) in rats with IDA compared to controls. CONCLUSIONS: Our results of histological bone marrow data suggest an important role for angiogenesis in the development of IDA-induced thrombocytosis. IMPACT: Thrombocytosis is common with IDA in both children and adults, but the mechanism is unclear. We confirmed that TPO is not the major driver of iron deficiency-associated thrombocytosis. We confirmed the increase in the number of megakaryocytes in the bone marrow despite stable TPO levels. We provided evidence supporting an important role of angiogenesis in megakaryocytopoiesis/thrombopoiesis with increased vascular structures and angiogenic cytokines in the bone marrow of iron-deficient rats. The demonstration that angiogenesis may play an important role in secondary thrombocytosis could lead to a new approach in treating symptomatic reactive thrombocytosis by targeting angiogenesis.


Assuntos
Anemia Ferropriva/complicações , Medula Óssea/irrigação sanguínea , Megacariócitos/metabolismo , Neovascularização Patológica , Receptores CXCR4/metabolismo , Trombocitose/etiologia , Trombopoese , Fator A de Crescimento do Endotélio Vascular/metabolismo , Anemia Ferropriva/sangue , Anemia Ferropriva/patologia , Animais , Modelos Animais de Doenças , Masculino , Megacariócitos/patologia , Ratos Sprague-Dawley , Transdução de Sinais , Trombocitose/sangue , Trombocitose/patologia , Trombopoetina/metabolismo
6.
Nephrol Dial Transplant ; 36(1): 111-120, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-32049331

RESUMO

BACKGROUND: The optimal intravenous (IV) iron would allow safe correction of iron deficiency at a single infusion over a short time. The FERWON-NEPHRO trial evaluated the safety and efficacy of iron isomaltoside 1000/ferric derisomaltose (IIM) in patients with non-dialysis-dependent chronic kidney disease and iron deficiency anaemia. METHODS: In this randomized, open-label and multi-centre trial conducted in the USA, patients were randomized 2:1 to a single dose of 1000 mg IIM or iron sucrose (IS) administered as 200 mg IV injections up to five times within a 2-week period. The co-primary endpoints were serious or severe hypersensitivity reactions and change in haemoglobin (Hb) from baseline to Week 8. Secondary endpoints included incidence of composite cardiovascular adverse events (AEs). RESULTS: A total of 1538 patients were enrolled (mean estimated glomerular filtration rate 35.5 mL/min/1.73 m2). The co-primary safety objective was met based on no significant difference in the incidence of serious or severe hypersensitivity reactions in the IIM and IS groups [0.3% versus 0%; risk difference: 0.29% (95% confidence interval: -0.19; 0.77; P > 0.05)]. Incidence of composite cardiovascular AEs was significantly lower in the IIM versus IS group (4.1% versus 6.9%; P = 0.025). Compared with IS, IIM led to a more pronounced increase in Hb during the first 4 weeks (P ≤ 0.021), and change in Hb to Week 8 showed non-inferiority, confirming that the co-primary efficacy objective was met. CONCLUSIONS: Compared with multiple doses of IS, a single dose of IIM induced a non-inferior 8-week haematological response, comparably low rates of hypersensitivity reactions, and a significantly lower incidence of composite cardiovascular AEs.


Assuntos
Anemia Ferropriva/tratamento farmacológico , Dissacarídeos/administração & dosagem , Compostos Férricos/administração & dosagem , Óxido de Ferro Sacarado/administração & dosagem , Hematínicos/administração & dosagem , Insuficiência Renal Crônica/complicações , Administração Intravenosa , Adulto , Idoso , Idoso de 80 Anos ou mais , Anemia Ferropriva/etiologia , Anemia Ferropriva/patologia , Feminino , Hemoglobinas/análise , Humanos , Injeções Intravenosas , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Tempo
7.
Nephrol Dial Transplant ; 36(1): 129-136, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-31641775

RESUMO

BACKGROUND: Anemia is associated with adverse outcomes in those with chronic kidney disease (CKD). We examined the association of absolute and functional iron deficiency anemia (IDA) with adverse outcomes (cardiovascular hospitalization, dialysis and mortality) in those with nondialysis-dependent CKD. METHODS: Nondialysis-dependent CKD patients followed in the US Veterans Administration with hemoglobin level measured within 90 days of the date of the second estimated glomerular filtration rate <60 mL/min/1.73 m2 were included. Logistic regression, multivariate Cox proportional hazards and Poisson regression models adjusted for demographics and comorbidities were used to assess the prevalence and correlates of absolute [transferrin saturation (TSAT) ≤20%, ferritin <100 ng/mL] and functional (TSA T≤20%, ferritin >100-500 ng/mL) IDA and the associations of absolute and functional IDA with mortality, dialysis and cardiovascular hospitalization. RESULTS: Of 933 463 patients with CKD, 20.6% had anemia. Among those with anemia, 23.6% of patients had both TSAT and ferritin level measured, of whom 30% had absolute IDA and 19% had functional IDA. Absolute IDA in CKD was not associated with an increased risk of mortality or dialysis but was associated with a higher risk of 1-year {risk ratio [RR] 1.20 [95% confidence interval (CI) 1.12-1.28]} and 2-year cardiovascular hospitalization [RR 1.11 (95% CI 1.05-1.17)]. CKD patients with functional IDA had a higher risk of mortality [hazard ratio (HR) 1.11 (95% CI 1.07-1.14)] along with a higher risk of 1-year [RR 1.21 (95% CI 1.1-1.30)] and 2-year cardiovascular hospitalization [RR 1.13 (95% CI 1.07-1.21)]. Ferritin >500 ng/mL (treated as a separate category) was only associated with an increased risk of mortality [HR 1.38 (95% CI 1.26-1.51)]. CONCLUSIONS: In a large population of CKD patients with anemia, absolute and functional IDA were associated with various clinical covariates. Functional IDA was associated with an increased risk of mortality and cardiovascular hospitalization, but absolute IDA was associated only with a higher risk of hospitalization.


Assuntos
Anemia Ferropriva/epidemiologia , Doenças Cardiovasculares/mortalidade , Hospitalização/estatística & dados numéricos , Insuficiência Renal Crônica/complicações , Adulto , Idoso , Idoso de 80 Anos ou mais , Anemia Ferropriva/patologia , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/patologia , Feminino , Ferritinas/análise , Taxa de Filtração Glomerular , Humanos , Masculino , Pessoa de Meia-Idade , Razão de Chances , Prevalência , Prognóstico , Taxa de Sobrevida , Texas/epidemiologia
8.
J Pediatr Hematol Oncol ; 43(7): e941-e945, 2021 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-33661166

RESUMO

This study was performed to investigate the gene polymorphisms of the myeloperoxidase (MPO) enzyme and to determine whether MPO gene polymorphisms influence the response to iron therapy in pediatric patients with iron deficiency anemia (IDA). In this case-control study, 50 Turkish children with IDA and 50 healthy controls were enrolled. Three MPO gene alleles were selected for genotyping in the study: GG, AG, and AA. The relationships of alleles with IDA were analyzed and compared in patients and controls. Pretreatment and posttreatment laboratory parameters and gene polymorphisms were compared in the patient group. There was a significant difference between patients with IDA and controls regarding genotype frequencies of the AA, GG, and AG alleles (P=0.005). However, the AG allele was found to be associated with variations in hemoglobin, red blood cell, hematocrit, mean corpuscular volumes, and mean corpuscular Hb concentrations levels. The frequency of AA, GG, and AG alleles of the MPO gene was potentially associated with changes in iron metabolism and the AG allele led to variations in various hemogram parameters.


Assuntos
Anemia Ferropriva/patologia , Biomarcadores/análise , Peroxidase/genética , Polimorfismo Genético , Adolescente , Alelos , Anemia Ferropriva/epidemiologia , Anemia Ferropriva/genética , Estudos de Casos e Controles , Criança , Feminino , Seguimentos , Genótipo , Humanos , Masculino , Prognóstico , Turquia/epidemiologia
9.
Anaesthesia ; 76 Suppl 4: 56-62, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33682094

RESUMO

Anaemia is common, particularly in women and the commonest underlying cause, iron deficiency, is often overlooked. Anaemia is associated with increased morbidity and mortality in patients undergoing anaesthesia; however, women are defined as being anaemic at a lower haemoglobin level than men. In this narrative review, we present the history of iron deficiency anaemia and how women's health has often been overlooked. Iron deficiency was first described as 'chlorosis' and a cause of 'hysteria' in women and initial treatment was by iron filings in cold wine. We present data of population screening demonstrating how common iron deficiency is, affecting 12-18% of apparently 'fit and healthy' women, with the most common cause being heavy menstrual bleeding; both conditions being often unrecognised. We describe a range of symptoms reported by women, that vary from fatigue to brain fog, hair loss and eating ice. We also describe experiments exploring the physical impact of iron deficiency, showing that reduced exercise performance is related to iron deficiency independent of haemoglobin concentration, as well as the impact of iron supplementation in women improving oxygen consumption and fitness. Overall, we demonstrate the need to single out women and investigate iron deficiency rather than accept the dogma of normality and differential treatment; this is to say, the need to change the current standard of care for women undergoing anaesthesia.


Assuntos
Anemia Ferropriva/patologia , Anemia Ferropriva/complicações , Anemia Ferropriva/tratamento farmacológico , Metabolismo Energético , Fadiga/etiologia , Feminino , Hemoglobinas/análise , Humanos , Ferro/administração & dosagem , Ferro/metabolismo , Consumo de Oxigênio , Desempenho Físico Funcional
10.
Anaesthesia ; 76 Suppl 4: 84-95, 2021 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-33682105

RESUMO

Iron deficiency and anaemia are global health problems and major causes of morbidity in women. Current definitions of anaemia in women are historic and have been challenged by recent data from observational studies. Menstrual loss, abnormal uterine bleeding and pregnancy put women at risk of developing iron deficiency which can result in severe fatigue, reduced exercise capacity and poor work performance. Iron deficiency and anaemia during pregnancy are associated with adverse maternal and fetal outcomes, including neurocognitive deficits in children born to iron-deficient mothers. Both iron deficiency and anaemia are common in women undergoing surgery but their association with poor outcomes remains uncertain. The enduring burden of iron deficiency and anaemia in women suggests that current strategies for recognition, prevention and treatment are limited in their utility. Improvements in our understanding of iron homeostasis and the development of new iron preparations, which are better absorbed with fewer side-effects, may improve therapeutic effectiveness of oral iron. Intravenous iron is efficacious for correcting anaemia rapidly but high-quality data on patient-centred outcomes and cost-effectiveness are currently lacking. Many recommendations for the treatment of iron deficiency and anaemia in national guidelines are not supported by high-quality evidence. There is a need for robust epidemiological data and well-designed clinical trials. The latter will require collaborative working between researchers and patients to design studies in ways that incorporate patients' perspectives on the research process and target outcomes that matter to them.


Assuntos
Anemia Ferropriva/patologia , Anemia/patologia , Administração Oral , Anemia/tratamento farmacológico , Anemia/terapia , Anemia Ferropriva/tratamento farmacológico , Anemia Ferropriva/terapia , Transfusão de Eritrócitos , Feminino , Hepcidinas/metabolismo , Antagonistas dos Receptores H2 da Histamina/uso terapêutico , Humanos , Ferro/administração & dosagem , Ferro/metabolismo , Saúde da Mulher
11.
Anaesthesia ; 76(5): 629-638, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33150612

RESUMO

Pre-operative anaemia is associated with higher rates of transfusion and worse outcomes, including prolonged hospital stay, morbidity and mortality. Iron deficiency is associated with significantly lower haemoglobin levels throughout the peri-operative period and more frequent blood transfusion. Correction of iron stores before surgery forms part of the first pillar of patient blood management. We established a pre-operative anaemia clinic to aid identification and treatment of patients with iron deficiency anaemia scheduled for elective cardiac surgery. We present a retrospective observational review of our experience from January 2017 to December 2019. One-hundred and ninety patients received treatment with intravenous iron, a median of 21 days before cardiac surgery. Of these, 179 had a formal laboratory haemoglobin level measured before surgery, demonstrating a median rise in haemoglobin of 8.0 g.l-1 . Patients treated with i.v. iron demonstrated a significantly higher incidence of transfusion (60%) compared with the non-anaemic cohort (22%) during the same time period, p < 0.001. Significantly higher rates of new requirement for renal replacement therapy (6.7% vs. 0.6%, p < 0.001) and of stroke (3.7% vs. 1.2%, p = 0.010) were also seen in this group compared with those without anaemia, although there was no significant difference in in-hospital mortality (1.6% vs. 0.8%, p = 0.230). In patients where the presenting haemoglobin was less than 130 g.l-1 , but there was no intervention or treatment, there was no difference in rates of transfusion or of complications compared with the anaemic group treated with iron. In patients with proven iron deficiency anaemia, supplementation with intravenous iron showed only a modest effect on haemoglobin and this group still had a significantly higher transfusion requirement than the non-anaemic cohort. Supplementation with intravenous iron did not improve outcomes compared with patients with anaemia who did not receive intravenous iron and did not reduce peri-operative risk to non-anaemic levels. Questions remain regarding identification of patients who will receive most benefit, the use of concomitant treatment with other agents, and the optimum time frames for treatment in order to produce benefit in the real-world setting.


Assuntos
Anemia/patologia , Ferro/administração & dosagem , Administração Intravenosa , Adulto , Idoso , Idoso de 80 Anos ou mais , Anemia/mortalidade , Anemia/cirurgia , Anemia Ferropriva/mortalidade , Anemia Ferropriva/patologia , Anemia Ferropriva/cirurgia , Procedimentos Cirúrgicos Cardíacos , Transfusão de Eritrócitos , Feminino , Hemoglobinas/análise , Mortalidade Hospitalar , Humanos , Ferro/efeitos adversos , Ferro/sangue , Masculino , Pessoa de Meia-Idade , Cuidados Pré-Operatórios , Terapia de Substituição Renal , Estudos Retrospectivos , Acidente Vascular Cerebral/etiologia , Adulto Jovem
12.
Int J Mol Sci ; 22(22)2021 Nov 22.
Artigo em Inglês | MEDLINE | ID: mdl-34830468

RESUMO

Anemia is a common complication of chronic kidney disease (CKD). The prevalence of anemia in CKD strongly increases as the estimated Glomerular Filtration Rate (eGFR) decreases. The pathophysiology of anemia in CKD is complex. The main causes are erythropoietin (EPO) deficiency and functional iron deficiency (FID). The administration of injectable preparations of recombinant erythropoiesis-stimulating agents (ESAs), especially epoetin and darbepoetin, coupled with oral or intravenous(iv) iron supplementation, is the current treatment for anemia in CKD for both dialysis and non-dialysis patients. This approach reduces patients' dependence on transfusion, ensuring the achievement of optimal hemoglobin target levels. However, there is still no evidence that treating anemia with ESAs can significantly reduce the risk of cardiovascular events. Meanwhile, iv iron supplementation causes an increased risk of allergic reactions, gastrointestinal side effects, infection, and cardiovascular events. Currently, there are no studies defining the best strategy for using ESAs to minimize possible risks. One class of agents under evaluation, known as prolyl hydroxylase inhibitors (PHIs), acts to stabilize hypoxia-inducible factor (HIF) by inhibiting prolyl hydroxylase (PH) enzymes. Several randomized controlled trials showed that HIF-PHIs are almost comparable to ESAs. In the era of personalized medicine, it is possible to envisage and investigate specific contexts of the application of HIF stabilizers based on the individual risk profile and mechanism of action.


Assuntos
Anemia Ferropriva/tratamento farmacológico , Hematínicos/uso terapêutico , Falência Renal Crônica/tratamento farmacológico , Inibidores de Prolil-Hidrolase/uso terapêutico , Anemia Ferropriva/dietoterapia , Anemia Ferropriva/patologia , Diálise , Taxa de Filtração Glomerular/efeitos dos fármacos , Humanos , Ferro/uso terapêutico , Falência Renal Crônica/enzimologia , Insuficiência Renal Crônica/tratamento farmacológico , Insuficiência Renal Crônica/genética , Insuficiência Renal Crônica/patologia
13.
J Biol Chem ; 294(41): 14991-15002, 2019 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-31416832

RESUMO

Iron is a micronutrient fundamental for life. Iron homeostasis in mammals requires sustained postnatal intestinal iron absorption that maintains intracellular iron concentrations for central and systemic metabolism as well as for erythropoiesis and oxygen transport. More than 1 billion people worldwide suffer from iron deficiency anemia (IDA), a state of systemic iron insufficiency that limits the production of red blood cells and leads to tissue hypoxia and intracellular iron stress. Despite this tremendous public health concern, very few genetic models of IDA are available to study its progression. Here we developed and characterized a novel genetic mouse model of IDA. We found that tamoxifen-inducible deletion of the mammalian iron exporter ferroportin exclusively in intestinal epithelial cells leads to loss of intestinal iron absorption. Ferroportin ablation yielded a robust phenotype of progressive IDA that develops in as little as 3 months following disruption of intestinal iron absorption. We noted that, at end-stage IDA, tissue-specific transcriptional stress responses occur in which the heart shows little to no hypoxic and iron stress compared with other peripheral organs. However, morphometric and echocardiographic analysis revealed massive cardiac hypertrophy and chamber dilation, albeit with increased cardiac output at very low basal heart rates. We propose that our intestine-specific ferroportin knockout mouse model of end-stage IDA could be used in future studies to investigate IDA progression and cell-specific responses to hypoxic and iron stress.


Assuntos
Anemia Ferropriva/genética , Anemia Ferropriva/patologia , Remodelamento Atrial/genética , Estresse Fisiológico/genética , Transcrição Gênica , Animais , Proteínas de Transporte de Cátions/deficiência , Proteínas de Transporte de Cátions/genética , Hipóxia Celular/genética , Modelos Animais de Doenças , Deleção de Genes , Intestinos/patologia , Camundongos , Miocárdio/patologia , Especificidade de Órgãos
14.
Blood ; 132(19): 2078-2087, 2018 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-30213870

RESUMO

Ferroportin (FPN), the only known vertebrate iron exporter, transports iron from intestinal, splenic, and hepatic cells into the blood to provide iron to other tissues and cells in vivo. Most of the circulating iron is consumed by erythroid cells to synthesize hemoglobin. Here we found that erythroid cells not only consumed large amounts of iron, but also returned significant amounts of iron to the blood. Erythroblast-specific Fpn knockout (Fpn KO) mice developed lower serum iron levels in conjunction with tissue iron overload and increased FPN expression in spleen and liver without changing hepcidin levels. Our results also showed that Fpn KO mice, which suffer from mild hemolytic anemia, were sensitive to phenylhydrazine-induced oxidative stress but were able to tolerate iron deficiency upon exposure to a low-iron diet and phlebotomy, supporting that the anemia of Fpn KO mice resulted from erythrocytic iron overload and resulting oxidative injury rather than a red blood cell (RBC) production defect. Moreover, we found that the mean corpuscular volume (MCV) values of gain-of-function FPN mutation patients were positively associated with serum transferrin saturations, whereas MCVs of loss-of-function FPN mutation patients were not, supporting that erythroblasts donate iron to blood through FPN in response to serum iron levels. Our results indicate that FPN of erythroid cells plays an unexpectedly essential role in maintaining systemic iron homeostasis and protecting RBCs from oxidative stress, providing insight into the pathophysiology of FPN diseases.


Assuntos
Anemia Ferropriva/genética , Proteínas de Transporte de Cátions/genética , Células Eritroides/patologia , Hemólise , Ferro/sangue , Mutação com Perda de Função , Estresse Oxidativo , Anemia Ferropriva/sangue , Anemia Ferropriva/patologia , Animais , Proteínas de Transporte de Cátions/análise , Células Eritroides/metabolismo , Mutação com Ganho de Função , Humanos , Ferro/análise , Deficiências de Ferro , Sobrecarga de Ferro/sangue , Sobrecarga de Ferro/genética , Sobrecarga de Ferro/patologia , Fígado/metabolismo , Fígado/patologia , Camundongos , Camundongos Knockout , Baço/metabolismo , Baço/patologia
15.
FASEB J ; 33(12): 13450-13464, 2019 12.
Artigo em Inglês | MEDLINE | ID: mdl-31569998

RESUMO

Iron is a necessary nutrient for humans and nearly all bacterial species. During Salmonella infection, macrophages limit the availability of iron to intracellular pathogens in one of the central components of nutritional immunity. However, Salmonella also have mechanisms to interfere with the antimicrobial effect of host iron withdrawal and meet their own nutrient requirements by scavenging iron from the host. Here, we provide what is, to our knowledge, the first report that SpvB, a pSLT-encoded cytotoxic protein whose function is associated with the intracellular stage of salmonellosis, perturbs macrophage iron metabolism, thereby facilitating Salmonella survival and intracellular replication. In investigating the underlying mechanism, we observed that the Salmonella effector SpvB down-regulated nuclear factor erythroid-derived 2-related factor 2 (NRF2), and its C-terminal domain was necessary and sufficient for NRF2 degradation via the proteasome pathway. Decreased NRF2 expression in the nucleus resulted in a decrease in its transcriptional target ferroportin, encoding the sole macrophage iron exporter, thus ultimately decreasing iron efflux and increasing the intracellular iron content. Additionally, SpvB contributes to the pathogenesis of Salmonella including severe serum hypoferremia, increased splenic and hepatic bacterial burden, and inflammatory injury in vivo. Together, our observations uncovered a novel contribution of SpvB to Salmonella pathology via interference with host intracellular iron metabolism.-Yang, S., Deng, Q., Sun, L., Dong, K., Li, Y., Wu, S., Huang, R. Salmonella effector SpvB interferes with intracellular iron homeostasis via regulation of transcription factor NRF2.


Assuntos
ADP Ribose Transferases/metabolismo , Anemia Ferropriva/patologia , Homeostase , Ferro/metabolismo , Macrófagos/patologia , Fator 2 Relacionado a NF-E2/metabolismo , Infecções por Salmonella/patologia , Salmonella typhimurium , Fatores de Virulência/metabolismo , ADP Ribose Transferases/genética , Anemia Ferropriva/metabolismo , Anemia Ferropriva/microbiologia , Animais , Proteínas de Transporte de Cátions/antagonistas & inibidores , Proteínas de Transporte de Cátions/genética , Proteínas de Transporte de Cátions/metabolismo , Citoplasma/metabolismo , Regulação da Expressão Gênica , Humanos , Deficiências de Ferro , Macrófagos/metabolismo , Macrófagos/microbiologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Fator 2 Relacionado a NF-E2/genética , Infecções por Salmonella/metabolismo , Infecções por Salmonella/microbiologia , Baço/metabolismo , Baço/microbiologia , Baço/patologia , Fatores de Virulência/genética
16.
Nutr Cancer ; 72(5): 864-872, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-31474155

RESUMO

Anemia is a prevalent complication in patients with cancer, both at diagnosis and during treatment, with notable negative effects on quality of life and overall prognosis. Iron deficiency is the most common cause of anemia in the patients and can affect almost half of patients with solid and hematologic malignancies. The pathogenesis is complex and multifactorial, including bleeding, malnutrition, medications, and inflammation resulted from cancer and cancer treatment. In fact, either absolute or functional iron deficiency can occur. Most iron deficient cancer patients present with functional iron deficiency, a condition with adequate iron storage but insufficient iron supply for erythroblasts and other iron dependent tissues. Functional iron deficiency is the result of the cancer related cytokine release, but in absolute iron deficiency iron reserves are depleted leading to similar but often more severe symptoms of inadequate iron store. Current therapeutic options in cancer anemia consist of iron administration, erythropoietic stimulating agents, and blood transfusion. The latter should be administered to a minimum, because of problems regarding risks. Here, we present a review on the epidemiology, pathophysiology, clinical outcomes, and therapeutic options of iron deficiency as well as the effect of iron therapy on tumor progression in anemic cancer patients.


Assuntos
Anemia Ferropriva/tratamento farmacológico , Anemia Ferropriva/metabolismo , Deficiências de Ferro , Ferro/administração & dosagem , Neoplasias/metabolismo , Anemia Ferropriva/etiologia , Anemia Ferropriva/patologia , Humanos , Neoplasias/sangue , Ensaios Clínicos Controlados Aleatórios como Assunto
17.
Pediatr Blood Cancer ; 67(10): e28614, 2020 10.
Artigo em Inglês | MEDLINE | ID: mdl-32729200

RESUMO

OBJECTIVE: The objective of this single-center observational study was to determine the clinical and hematologic responses to intravenous ferric carboxymaltose (FCM) in a cohort of pediatric patients with poor response to oral iron therapy. The occurrence of adverse events was systematically recorded for up to 96 hours after infusion. STUDY DESIGN: A retrospective cohort of 144 consecutive patients aged 18 months to < 18 years with iron deficiency anemia (IDA) or iron deficiency (ID) without anemia was investigated. All patients had failed oral iron therapy. The assessments before and after FCM treatment followed a predefined protocol. RESULTS: One hundred of 117 (85 %) of patients with complete data achieved the target ferritin level ≥ 30 µg/L after a single FCM dose. Of 77 patients with IDA and complete data, 38 (49%) showed a complete hematological response within 6-12 weeks; a complete or partial response was achieved by 83%. Clinical symptoms improved in 85% of all patients. In 92% of patients (n = 133 /144), FCM infusion was uneventful. During the 96-hour follow-up, five patients reported potentially related symptoms. No serious adverse events occurred. CONCLUSION: The study confirms the safety and efficacy of FCM in children (aged 18 months and older) and adolescents unresponsive to oral therapy, in real-world experience. Single-dose FCM treatment was followed by clinical improvement with advantages of safety, compliance, and lower cost compared with previous generation parenteral iron preparations that had to be administered in fractionated sessions.


Assuntos
Anemia Ferropriva/tratamento farmacológico , Compostos Férricos/administração & dosagem , Distúrbios do Metabolismo do Ferro/tratamento farmacológico , Maltose/análogos & derivados , Administração Intravenosa , Adolescente , Anemia Ferropriva/patologia , Criança , Pré-Escolar , Feminino , Seguimentos , Humanos , Lactente , Distúrbios do Metabolismo do Ferro/patologia , Masculino , Maltose/administração & dosagem , Prognóstico , Estudos Retrospectivos
18.
J Pediatr Hematol Oncol ; 42(3): 208-213, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-31568184

RESUMO

INTRODUCTION: The most common causes of microcytic anemia are iron deficiency anemia (IDA) and thalassemia trait (TT). This study investigated the reliability of erythrocyte indices and formulas as screening tests in the differential diagnosis of IDA and TT before performing detailed tests for definitive diagnosis. MATERIALS AND METHODS: In total, 50 children with ß-TT, 31 with α-TT, 50 with IDA were included. For the 8 erythrocyte indices and formulas (red blood cells [RBC], red blood cell distribution width [RDW], red blood cell distribution width index [RDWI], Mentzer index [MI], Shine and Lal index [S&L], England and Fraser [E&F], Green and King index [G&K], Srivastava index) the sensitivity, specificity, positive and negative predictive values (PPVs and NPVs, respectively) were calculated according to the cutoff values in the literature and recalculated revised cutoff values. RESULTS: According to the cutoff values in the literature for the differential diagnosis of IDA and TT, the ranking of sensitivity, specificity, PPVs, and NPVs from the highest to the lowest was RDWI, RBC, E&F, G&K, MI, Srivastava, RDW, S&L. The sensitivity, specificity, PPVs, and NPVs of all the indices according to the revised cutoff values were higher than those according to the cutoff values in the literature. CONCLUSIONS: According to both the cutoff values in the literature and revised cutoff values, the most reliable indices were RBC and RDWI.


Assuntos
Anemia Ferropriva/diagnóstico , Biomarcadores/sangue , Índices de Eritrócitos , Talassemia/diagnóstico , Anemia Ferropriva/sangue , Anemia Ferropriva/patologia , Criança , Pré-Escolar , Diagnóstico Diferencial , Eritrócitos/patologia , Feminino , Humanos , Masculino , Sensibilidade e Especificidade , Talassemia/sangue , Talassemia/patologia
19.
Nanomedicine ; 26: 102178, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32145382

RESUMO

Iron deficiency is an important subclinical disease affecting over one billion people worldwide. A growing body of clinical records supports the use of intravenous iron-carbohydrate complexes for patients where iron replenishment is necessary and oral iron supplements are either ineffective or cannot be tolerated by the gastrointestinal tract. A critical characteristic of iron-carbohydrate drugs is the complexity of their core-shell structure, which has led to differences in the efficacy and safety of various iron formulations. This review describes parameters influencing the safety and effectiveness of iron-carbohydrate complexes during production, storage, handling, and clinical application. We summarized the physicochemical and biological assessments of commercially available iron carbohydrate nanomedicines to provide an overview of publicly available data. Further, we reviewed studies that described how subtle differences in the manufacturing process of iron-carbohydrate complexes can impact on the physicochemical, biological, and clinical outcomes of original product versus their intended copies or so-called iron "similar" products.


Assuntos
Anemia Ferropriva/tratamento farmacológico , Compostos de Ferro/uso terapêutico , Ferro/uso terapêutico , Nanopartículas/uso terapêutico , Administração Intravenosa , Anemia Ferropriva/patologia , Carboidratos/química , Carboidratos/uso terapêutico , Humanos , Ferro/metabolismo , Compostos de Ferro/química , Nanomedicina/tendências , Nanopartículas/química , Tamanho da Partícula
20.
Proc Natl Acad Sci U S A ; 114(48): 12669-12674, 2017 11 28.
Artigo em Inglês | MEDLINE | ID: mdl-29138321

RESUMO

Iron is an essential metal for all organisms, yet disruption of its homeostasis, particularly in labile forms that can contribute to oxidative stress, is connected to diseases ranging from infection to cancer to neurodegeneration. Iron deficiency is also among the most common nutritional deficiencies worldwide. To advance studies of iron in healthy and disease states, we now report the synthesis and characterization of iron-caged luciferin-1 (ICL-1), a bioluminescent probe that enables longitudinal monitoring of labile iron pools (LIPs) in living animals. ICL-1 utilizes a bioinspired endoperoxide trigger to release d-aminoluciferin for selective reactivity-based detection of Fe2+ with metal and oxidation state specificity. The probe can detect physiological changes in labile Fe2+ levels in live cells and mice experiencing iron deficiency or overload. Application of ICL-1 in a model of systemic bacterial infection reveals increased iron accumulation in infected tissues that accompany transcriptional changes consistent with elevations in both iron acquisition and retention. The ability to assess iron status in living animals provides a powerful technology for studying the contributions of iron metabolism to physiology and pathology.


Assuntos
Infecções por Acinetobacter/metabolismo , Anemia Ferropriva/metabolismo , Luciferina de Vaga-Lumes/análise , Corantes Fluorescentes/análise , Sobrecarga de Ferro/metabolismo , Ferro/metabolismo , 2,2'-Dipiridil/farmacologia , Infecções por Acinetobacter/genética , Infecções por Acinetobacter/microbiologia , Infecções por Acinetobacter/patologia , Acinetobacter baumannii/patogenicidade , Acinetobacter baumannii/fisiologia , Anemia Ferropriva/genética , Anemia Ferropriva/patologia , Animais , Proteínas de Transporte de Cátions/genética , Proteínas de Transporte de Cátions/metabolismo , Cátions Bivalentes , Modelos Animais de Doenças , Compostos Férricos/farmacologia , Luciferina de Vaga-Lumes/análogos & derivados , Luciferina de Vaga-Lumes/síntese química , Corantes Fluorescentes/síntese química , Regulação da Expressão Gênica , Hepcidinas/genética , Hepcidinas/metabolismo , Homeostase/genética , Sobrecarga de Ferro/genética , Sobrecarga de Ferro/patologia , Proteína 1 Reguladora do Ferro/genética , Proteína 1 Reguladora do Ferro/metabolismo , Proteína 2 Reguladora do Ferro/genética , Proteína 2 Reguladora do Ferro/metabolismo , Medições Luminescentes , Camundongos , Camundongos Transgênicos , Compostos de Amônio Quaternário/farmacologia , Receptores da Transferrina/genética , Receptores da Transferrina/metabolismo , Transdução de Sinais , Transferrina/genética , Transferrina/metabolismo
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