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1.
Curr Opin Hematol ; 31(2): 40-46, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-37982261

RESUMO

PURPOSE OF REVIEW: Myelodysplastic neoplasms (MDS) are diseases of stem cell aging associated with complications from inadequate hematopoiesis (red cells, neutrophils and platelets) and variable risk for transformation to acute myeloid leukemia. Those with low-risk disease also suffer and die from MDS-related complications. Among the most challenging is development of anemia and transfusion dependence, which impacts quality of life and is associated with reduced survival. Appreciating and measuring the quality-of-life impact, preventing (if possible), treating, and managing the complications from anemia in MDS are of critical importance. RECENT FINDINGS: Recent developments in basic science highlight the potential deleterious impact of iron overload within the developing red cell niche. Iron overload can compromise red cell maturation from healthy as well as malignant clones and produces an environment favoring expansion of mutant clonal cells, potentially driving disease progression. Observational studies in nontransfusion dependent MDS highlight that iron overload occurs even in the nontransfusion dependent. The newly approved (and established) therapies for management of MDS-related anemia work best when begun before patients become heavily transfusion-dependent. SUMMARY: Iron overload is detrimental to hematopoiesis. Understanding the benefit afforded by transfusion is critical to optimal application and patient reported outcomes can inform this. Recently developed therapies are active and optimized application may improve response.


Assuntos
Anemia , Sobrecarga de Ferro , Síndromes Mielodisplásicas , Neoplasias , Humanos , Qualidade de Vida , Sobrecarga de Ferro/terapia , Sobrecarga de Ferro/prevenção & controle , Síndromes Mielodisplásicas/terapia , Eritropoese , Neoplasias/complicações , Quelantes de Ferro
2.
Cochrane Database Syst Rev ; 11: CD011626, 2023 11 17.
Artigo em Inglês | MEDLINE | ID: mdl-37975597

RESUMO

BACKGROUND: Beta-thalassaemia is an inherited blood disorder that reduces the production of haemoglobin. The most severe form requires recurrent blood transfusions, which can lead to iron overload. Cardiovascular dysfunction caused by iron overload is the leading cause of morbidity and mortality in people with transfusion-dependent beta-thalassaemia. Iron chelation therapy has reduced the severity of systemic iron overload, but removal of iron from the myocardium requires a very proactive preventive strategy. There is evidence that calcium channel blockers may reduce myocardial iron deposition. This is an update of a Cochrane Review first published in 2018. OBJECTIVES: To assess the effects of calcium channel blockers plus standard iron chelation therapy, compared with standard iron chelation therapy (alone or with a placebo), on cardiomyopathy due to iron overload in people with transfusion-dependent beta thalassaemia. SEARCH METHODS: We searched the Cochrane Haemoglobinopathies Trials Register, compiled from electronic database searches and handsearching of journals and conference abstract books, to 13 January 2022. We also searched ongoing trials databases and the reference lists of relevant articles and reviews. SELECTION CRITERIA: We included randomised controlled trials (RCTs) of calcium channel blockers combined with standard chelation therapy versus standard chelation therapy alone or combined with placebo in people with transfusion-dependent beta thalassaemia. DATA COLLECTION AND ANALYSIS: We used standard Cochrane methods. We used GRADE to assess certainty of evidence. MAIN RESULTS: We included six RCTs (five parallel-group trials and one cross-over trial) with 253 participants; there were 126 participants in the amlodipine arms and 127 in the control arms. The certainty of the evidence was low for most outcomes at 12 months; the evidence for liver iron concentration was of moderate certainty, and the evidence for adverse events was of very low certainty. Amlodipine plus standard iron chelation compared with standard iron chelation (alone or with placebo) may have little or no effect on cardiac T2* values at 12 months (mean difference (MD) 1.30 ms, 95% confidence interval (CI) -0.53 to 3.14; 4 trials, 191 participants; low-certainty evidence) and left ventricular ejection fraction (LVEF) at 12 months (MD 0.81%, 95% CI -0.92% to 2.54%; 3 trials, 136 participants; low-certainty evidence). Amlodipine plus standard iron chelation compared with standard iron chelation (alone or with placebo) may reduce myocardial iron concentration (MIC) after 12 months (MD -0.27 mg/g, 95% CI -0.46 to -0.08; 3 trials, 138 participants; low-certainty evidence). The results of our analysis suggest that amlodipine has little or no effect on heart T2*, MIC, or LVEF after six months, but the evidence is very uncertain. Amlodipine plus standard iron chelation compared with standard iron chelation (alone or with placebo) may increase liver T2* values after 12 months (MD 1.48 ms, 95% CI 0.27 to 2.69; 3 trials, 127 participants; low-certainty evidence), but may have little or no effect on serum ferritin at 12 months (MD 0.07 µg/mL, 95% CI -0.20 to 0.35; 4 trials, 187 participants; low-certainty evidence), and probably has little or no effect on liver iron concentration (LIC) after 12 months (MD -0.86 mg/g, 95% CI -4.39 to 2.66; 2 trials, 123 participants; moderate-certainty evidence). The results of our analysis suggest that amlodipine has little or no effect on serum ferritin, liver T2* values, or LIC after six months, but the evidence is very uncertain. The included trials did not report any serious adverse events at six or 12 months of intervention. The studies did report mild adverse effects such as oedema, dizziness, mild cutaneous allergy, joint swelling, and mild gastrointestinal symptoms. Amlodipine may be associated with a higher risk of oedema (risk ratio (RR) 5.54, 95% CI 1.24 to 24.76; 4 trials, 167 participants; very low-certainty evidence). We found no difference between the groups in the occurrence of other adverse events, but the evidence was very uncertain. No trials reported mortality, cardiac function assessments other than echocardiographic estimation of LVEF, electrocardiographic abnormalities, quality of life, compliance with treatment, or cost of interventions. AUTHORS' CONCLUSIONS: The available evidence suggests that calcium channel blockers may reduce MIC and may increase liver T2* values in people with transfusion-dependent beta thalassaemia. Longer-term multicentre RCTs are needed to assess the efficacy and safety of calcium channel blockers for myocardial iron overload, especially in younger children. Future trials should also investigate the role of baseline MIC in the response to calcium channel blockers, and include a cost-effectiveness analysis.


Assuntos
Cardiomiopatias , Sobrecarga de Ferro , Talassemia beta , Criança , Humanos , Talassemia beta/complicações , Talassemia beta/tratamento farmacológico , Bloqueadores dos Canais de Cálcio/efeitos adversos , Sobrecarga de Ferro/tratamento farmacológico , Sobrecarga de Ferro/prevenção & controle , Sobrecarga de Ferro/complicações , Ferro/uso terapêutico , Cardiomiopatias/etiologia , Cardiomiopatias/prevenção & controle , Anlodipino/efeitos adversos , Quelantes de Ferro/efeitos adversos , Ferritinas , Edema
3.
N Engl J Med ; 386(5): 415-427, 2022 02 03.
Artigo em Inglês | MEDLINE | ID: mdl-34891223

RESUMO

BACKGROUND: Betibeglogene autotemcel (beti-cel) gene therapy for transfusion-dependent ß-thalassemia contains autologous CD34+ hematopoietic stem cells and progenitor cells transduced with the BB305 lentiviral vector encoding the ß-globin (ßA-T87Q) gene. METHODS: In this open-label, phase 3 study, we evaluated the efficacy and safety of beti-cel in adult and pediatric patients with transfusion-dependent ß-thalassemia and a non-ß0/ß0 genotype. Patients underwent myeloablation with busulfan (with doses adjusted on the basis of pharmacokinetic analysis) and received beti-cel intravenously. The primary end point was transfusion independence (i.e., a weighted average hemoglobin level of ≥9 g per deciliter without red-cell transfusions for ≥12 months). RESULTS: A total of 23 patients were enrolled and received treatment, with a median follow-up of 29.5 months (range, 13.0 to 48.2). Transfusion independence occurred in 20 of 22 patients who could be evaluated (91%), including 6 of 7 patients (86%) who were younger than 12 years of age. The average hemoglobin level during transfusion independence was 11.7 g per deciliter (range, 9.5 to 12.8). Twelve months after beti-cel infusion, the median level of gene therapy-derived adult hemoglobin (HbA) with a T87Q amino acid substitution (HbAT87Q) was 8.7 g per deciliter (range, 5.2 to 10.6) in patients who had transfusion independence. The safety profile of beti-cel was consistent with that of busulfan-based myeloablation. Four patients had at least one adverse event that was considered by the investigators to be related or possibly related to beti-cel; all events were nonserious except for thrombocytopenia (in 1 patient). No cases of cancer were observed. CONCLUSIONS: Treatment with beti-cel resulted in a sustained HbAT87Q level and a total hemoglobin level that was high enough to enable transfusion independence in most patients with a non-ß0/ß0 genotype, including those younger than 12 years of age. (Funded by Bluebird Bio; HGB-207 ClinicalTrials.gov number, NCT02906202.).


Assuntos
Produtos Biológicos/uso terapêutico , Terapia Genética/métodos , Globinas beta/genética , Talassemia beta/terapia , Adolescente , Adulto , Produtos Biológicos/efeitos adversos , Bussulfano/uso terapêutico , Criança , Transfusão de Eritrócitos/efeitos adversos , Eritropoese , Feminino , Vetores Genéticos , Genótipo , Hemoglobinas/análise , Humanos , Sobrecarga de Ferro/prevenção & controle , Lentivirus/genética , Masculino , Pessoa de Meia-Idade , Agonistas Mieloablativos/uso terapêutico , Talassemia beta/sangue , Talassemia beta/genética
4.
Drug Chem Toxicol ; 45(6): 2814-2824, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-34663156

RESUMO

Morus nigra L. is a plant popularly known as 'amoreira preta', very used in folk medicine. Iron overload (hemochromatosis) is a clinical condition that causes damage to various tissues due to oxidative stress. Therapy to control iron overload is still unsatisfactory. The protective effect on oxidative stress induced by iron overload was verified. Phytochemical characterization was evaluated by UHPLC-MS/MS. The in silico toxicity predictions of the main phytochemicals were performed via computer simulation. To induce iron overload, the animals received iron dextran (50 mg/kg/day). The test groups received doses of 500 and 1000 mg/kg of M. nigra extract for six weeks. Body weight, organosomatic index, serum iron, hepatic markers, cytokines, interfering factors in iron metabolism, enzymatic and histopathological evaluations were analyzed. Vanillic acid, caffeic acid, 6-hydroxycoumarin, p-coumaric acid, ferulic acid, rutin, quercitrin, resveratrol, apigenin and kaempferol were identified in the extract. In addition, in silico toxic predictions showed that the main compounds presented a low probability of toxic risk. The extract of M. nigra showed to control the mediators of inflammation and to reduce iron overload in several tissues. Our findings illustrate a novel therapeutic action of M. nigra leaves on hemochromatosis caused by iron overload.


Assuntos
Hemocromatose , Sobrecarga de Ferro , Morus , Animais , Morus/química , Morus/metabolismo , Quempferóis/análise , Quempferóis/farmacologia , Resveratrol/farmacologia , Hemocromatose/tratamento farmacológico , Apigenina/análise , Apigenina/farmacologia , Ácido Vanílico/farmacologia , Espectrometria de Massas em Tandem , Simulação por Computador , Dextranos/análise , Dextranos/metabolismo , Dextranos/farmacologia , Extratos Vegetais/uso terapêutico , Folhas de Planta/química , Estresse Oxidativo , Sobrecarga de Ferro/prevenção & controle , Compostos Fitoquímicos/análise , Rutina/farmacologia , Ferro/toxicidade , Ferro/análise , Citocinas/metabolismo , Mediadores da Inflamação/metabolismo
5.
Brain Res ; 1772: 147668, 2021 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-34592245

RESUMO

Cognitive deficits are among the most common comorbidities of temporal lobe epilepsy (TLE). Ferroptosis associated with the accumulation of iron overload-dependent lipid peroxidation produces significant cognitive deficits in TLE. The anti-aging protein, klotho, has been shown to exert neuroprotective effects while enhancing cognition in neurodegenerative disorders. However, the role of klotho in TLE progression has not been established. In this study, we evaluated the effects and underlying mechanisms of klotho in a rat model of TLE induced by lithium-chloride and pilocarpine (LiCl-Pilo). The expression of klotho was found to be inhibited in the hippocampus following LiCl-Pilo induced TLE in rats. An adeno-virus (AAV), which mediated klotho overexpression (AAV-KL) was injected into the bilateral hippocampus of the rat models. After 3 weeks, rats were treated through intraperitoneal injections of LiCl-Pilo. After 9 weeks, AAV-KL was found to have significantly induced klotho overexpression in the hippocampus, effectively ameliorated cognitive deficits and exerted neuroprotective effects in LiCl-Pilo induced TLE rat models. Klotho significantly prevented ferroptosis and iron overload. Meanwhile, klotho regulated the expressions of divalent metal transporter 1 (DMT 1) and ferroportin (FPN) that were associated with iron accumulation in the hippocampus. Furthermore, klotho significantly elevated glutathione peroxidase-4 (GPX-4) and glutathione (GSH) levels while suppressed reactive oxygen species (ROS) levels. In conclusion, klotho ameliorated cognitive deficits and exerted neuroprotective effects by inhibiting ferroptosis in LiCl-Pilo induced TLE rat models.


Assuntos
Disfunção Cognitiva/etiologia , Disfunção Cognitiva/terapia , Epilepsia do Lobo Temporal/complicações , Epilepsia do Lobo Temporal/terapia , Ferroptose/efeitos dos fármacos , Proteínas Klotho/genética , Animais , Antioxidantes/metabolismo , Disfunção Cognitiva/psicologia , Convulsivantes , Epilepsia do Lobo Temporal/psicologia , Terapia Genética , Hipocampo , Sobrecarga de Ferro/prevenção & controle , Lítio , Masculino , Neuroproteção , Pilocarpina , Ratos , Ratos Sprague-Dawley
6.
Food Funct ; 12(16): 7321-7328, 2021 Aug 21.
Artigo em Inglês | MEDLINE | ID: mdl-34173816

RESUMO

This study proposed to investigate the effect of Ilex paraguariensis infusion on the absorption of non-heme iron in hereditary hemochromatosis (HH) patients with the HFE genotype. A two-way randomized, controlled, crossover trial was conducted on patients, aged 29-69 years, undergoing maintenance therapy. Fourteen HFE-HH patients ingested a meal containing 11.4 mg iron and 200 mL either of water (control) or of Ilex paraguariensis leaf infusion. The beverages were offered in random order, at intervals separated by a washout period of 7 days. Active surveillance showed no adverse effects. Blood samples were drawn shortly before and 1, 2, 3, and 4 h after the meal for serum iron measurement. A significant reduction in the postprandial serum iron was observed for HH patients after intake of the Ilex paraguariensis infusion (area under the curve (AUC) expressed as mean ± SEM: 173.3 ± 44.7 µmol h-1 L-1) compared to water (1449.4 ± 241.5 µmol h-1 L-1) (p < 0.001). In summary, intake of Ilex paraguariensis leaf infusion significantly inhibited the absorption of iron in patients with HH and, therefore, should be considered as a potential adjuvant for iron overload control.


Assuntos
Hemocromatose/sangue , Ilex paraguariensis/metabolismo , Sobrecarga de Ferro/sangue , Sobrecarga de Ferro/prevenção & controle , Extratos Vegetais/farmacologia , Folhas de Planta/metabolismo , Adulto , Idoso , Bebidas , Estudos Cross-Over , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Extratos Vegetais/sangue
7.
Br J Haematol ; 194(1): 200-210, 2021 07.
Artigo em Inglês | MEDLINE | ID: mdl-33942901

RESUMO

Beta-thalassaemia is an inherited blood disorder characterised by ineffective erythropoiesis and anaemia. Consequently, hepcidin expression is reduced resulting in increased iron absorption and primary iron overload. Hepcidin is under the negative control of transmembrane serine protease 6 (TMPRSS6) via cleavage of haemojuvelin (HJV), a co-receptor for the bone morphogenetic protein (BMP)-mothers against decapentaplegic homologue (SMAD) signalling pathway. Considering the central role of the TMPRSS6/HJV/hepcidin axis in iron homeostasis, the inhibition of TMPRSS6 expression represents a promising therapeutic strategy to increase hepcidin production and ameliorate anaemia and iron overload in ß-thalassaemia. In the present study, we investigated a small interfering RNA (siRNA) conjugate optimised for hepatic targeting of Tmprss6 (SLN124) in ß-thalassaemia mice (Hbbth3/+ ). Two subcutaneous injections of SLN124 (3 mg/kg) were sufficient to normalise hepcidin expression and reduce anaemia. We also observed a significant improvement in erythroid maturation, which was associated with a significant reduction in splenomegaly. Treatment with the iron chelator, deferiprone (DFP), did not impact any of the erythroid parameters. However, the combination of SLN124 with DFP was more effective in reducing hepatic iron overload than either treatment alone. Collectively, we show that the combination therapy can ameliorate several disease symptoms associated with chronic anaemia and iron overload, and therefore represents a promising pharmacological modality for the treatment of ß-thalassaemia and related disorders.


Assuntos
Deferiprona/uso terapêutico , Eritropoese/efeitos dos fármacos , Hepcidinas/biossíntese , Quelantes de Ferro/uso terapêutico , Sobrecarga de Ferro/prevenção & controle , Proteínas de Membrana/antagonistas & inibidores , RNA Interferente Pequeno/uso terapêutico , Talassemia beta/tratamento farmacológico , Acetilgalactosamina/administração & dosagem , Animais , Deferiprona/administração & dosagem , Modelos Animais de Doenças , Quimioterapia Combinada , Feminino , Perfilação da Expressão Gênica , Hepcidinas/genética , Humanos , Ferro/sangue , Quelantes de Ferro/administração & dosagem , Sobrecarga de Ferro/etiologia , Fígado/metabolismo , Magnésio/metabolismo , Proteínas de Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Interferência de RNA , RNA Interferente Pequeno/administração & dosagem , Espécies Reativas de Oxigênio , Serina Endopeptidases/genética , Baço/metabolismo , Baço/ultraestrutura , Zinco/metabolismo , Talassemia beta/complicações , Talassemia beta/metabolismo , Talassemia beta/fisiopatologia
8.
Toxicol Appl Pharmacol ; 410: 115361, 2021 01 01.
Artigo em Inglês | MEDLINE | ID: mdl-33285147

RESUMO

Iron overload toxicity has been implicated in retinal pigment epithelial cell injury in age-related macular degeneration. This study investigates the effects of astragaloside IV (AS-IV), a potential retinal protective agent, on the toxicity process of retinal iron overload in vivo and in vitro. AS-IV partially restored the retinal expression of rhodopsin and retinal pigment epithelium-specific 65 kDa protein, suppressed oxidative stress and inflammatory markers, and alleviated iron deposition and retinal pathological changes in vivo. Also, AS-IV inhibited the phosphorylation of p38 and ERK mitogen-activated protein kinases (MAPKs), as well as the nuclear translocation of nuclear factor-kappa B (NF-κB). Furthermore, AS-IV prevented cell death by decreasing the ratio of Bax/Bcl-2, caspase-3, and cleaved caspase-3 expression in vitro. Although there are no chelation effects between AS-IV and iron, AS-IV can reduce intracellular iron by regulating iron-handling proteins in ARPE-19 cells (Cav1.2, divalent metal transporter-1, transferrin receptor 1, and heavy-chain ferritin). In conclusion, the results show that AS-IV has significant protective effects against retinal iron overload toxicity and suggest that iron regulation and the inhibition of MAPKs and NF-κB activation might be mechanisms underlying the effects of AS-IV.


Assuntos
Sobrecarga de Ferro/prevenção & controle , Ferro/toxicidade , Proteínas Quinases Ativadas por Mitógeno/antagonistas & inibidores , NF-kappa B/antagonistas & inibidores , Epitélio Pigmentado da Retina/efeitos dos fármacos , Saponinas/uso terapêutico , Triterpenos/uso terapêutico , Animais , Humanos , Sobrecarga de Ferro/metabolismo , Sobrecarga de Ferro/patologia , Masculino , Camundongos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , NF-kappa B/metabolismo , Epitélio Pigmentado da Retina/metabolismo , Epitélio Pigmentado da Retina/patologia , Saponinas/farmacologia , Triterpenos/farmacologia
9.
Arch Dis Child ; 105(11): 1041-1048, 2020 11.
Artigo em Inglês | MEDLINE | ID: mdl-32994214

RESUMO

OBJECTIVES: Cardiac T2* MRI (T2*CMR), for accurate estimation of myocardial siderosis, was introduced as part of a QI collaborative to optimise chelation therapy in order to improve cardiac morbidity in transfusion dependent thalassaemia (TDT) patients. We report the impact of this QI initiative from two thalassaemia centres from this collaborative. DESIGN AND SETTING: A key driver based quality initiative was implemented to improve chelation in TDT patients registered at these two centres in Karachi, Pakistan. Protocol optimisation and compliance to treatment through training, communication and feedback were used as the drivers for QI intervention. Preintervention variables (demographics, chelation history, T2*CMR, echocardiography and holters) were collected from January 2015 to December 2016) and compared with variables in the post implementation phase (January to December 2019). A standardised adverse event severity for chelators and its management was devised for safe drug therapy as well as ensuring compliance to the regimen. Preintervention and postintervention variables were compared using non-parametric test. P value<0.05 was statistically significant. RESULTS: 100 patients with TDT, median age 17 (9-34) years, were included. An increase or stabilisation of T2*CMR was documented in 82% patients in the postintervention phase especially in patients with severe myocardial iron overload (5.5 vs 5.3 ms, p <0.01). Significantly fewer patients had abnormal echocardiographic findings (3.5% vs 26%, p <0.05) in the postintervention versus preintervention period. CONCLUSION: This QI initiative improved the chelation therapy leading to improved cardiac status in TDT patients at the participating centres.


Assuntos
Terapia por Quelação/métodos , Cardiopatias/prevenção & controle , Coração/diagnóstico por imagem , Quelantes de Ferro/uso terapêutico , Sobrecarga de Ferro/prevenção & controle , Talassemia/terapia , Adolescente , Adulto , Transfusão de Sangue , Criança , Protocolos Clínicos , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Paquistão , Melhoria de Qualidade , Adulto Jovem
10.
Metallomics ; 12(10): 1494-1507, 2020 10 21.
Artigo em Inglês | MEDLINE | ID: mdl-32852491

RESUMO

Iron plays an essential role in preventing iron deficiency anemia and ensuring the healthy growth of animals. The special physiological condition of piglets is the main cause of iron deficiency. Iron metabolism in the intestine is the basis for understanding the effects of iron on the health of piglets. In order to scientifically evaluate dietary iron supplementation doses, it is necessary to recognize the effects of iron deficiency and iron overload on piglet intestinal health. Besides, iron as a cofactor is essential for the growth of microorganisms, and microorganisms compete with the host to absorb iron. Under the stress of iron deficiency and iron overload, various control schemes (such as precise nutrition, element balance, elimination of oxidation, etc.) are effective measures to eliminate adverse effects. In this review, we comprehensively review recent findings on the effects of iron deficiency and iron overload on intestinal health. This review will provide a rational design strategy to achieve a reasonable iron supplement, which will guide the use of iron in animal husbandry.


Assuntos
Anemia Ferropriva/veterinária , Sobrecarga de Ferro/veterinária , Ferro da Dieta/uso terapêutico , Ferro/metabolismo , Doenças dos Suínos/prevenção & controle , Suínos/fisiologia , Anemia Ferropriva/metabolismo , Anemia Ferropriva/prevenção & controle , Animais , Homeostase , Mucosa Intestinal/metabolismo , Sobrecarga de Ferro/metabolismo , Sobrecarga de Ferro/prevenção & controle , Ferro da Dieta/metabolismo , Doenças dos Suínos/metabolismo , Doenças dos Suínos/patologia
11.
Blood ; 136(17): 1968-1979, 2020 10 22.
Artigo em Inglês | MEDLINE | ID: mdl-32556142

RESUMO

ß-Thalassemia intermedia is a disorder characterized by ineffective erythropoiesis (IE), anemia, splenomegaly, and systemic iron overload. Novel approaches are being explored based on the modulation of pathways that reduce iron absorption (ie, using hepcidin activators like Tmprss6-antisense oligonucleotides [ASOs]) or increase erythropoiesis (by erythropoietin [EPO] administration or modulating the ability of transferrin receptor 2 [Tfr2] to control red blood cell [RBC] synthesis). Targeting Tmprss6 messenger RNA by Tmprss6-ASO was proven to be effective in improving IE and splenomegaly by inducing iron restriction. However, we postulated that combinatorial strategies might be superior to single therapies. Here, we combined Tmprss6-ASO with EPO administration or removal of a single Tfr2 allele in the bone marrow of animals affected by ß-thalassemia intermedia (Hbbth3/+). EPO administration alone or removal of a single Tfr2 allele increased hemoglobin levels and RBCs. However, EPO or Tfr2 single-allele deletion alone, respectively, exacerbated or did not improve splenomegaly in ß-thalassemic mice. To overcome this issue, we postulated that some level of iron restriction (by targeting Tmprss6) would improve splenomegaly while preserving the beneficial effects on RBC production mediated by EPO or Tfr2 deletion. While administration of Tmprss6-ASO alone improved the anemia, the combination of Tmprss6-ASO + EPO or Tmprss6-ASO + Tfr2 single-allele deletion produced significantly higher hemoglobin levels and reduced splenomegaly. In conclusion, our results clearly indicate that these combinatorial approaches are superior to single treatments in ameliorating IE and anemia in ß-thalassemia and could provide guidance to translate some of these approaches into viable therapies.


Assuntos
Eritropoetina/administração & dosagem , Eritropoetina/genética , Terapia Genética/métodos , Proteínas de Membrana/antagonistas & inibidores , Oligonucleotídeos Antissenso/administração & dosagem , Talassemia beta/terapia , Animais , Células Cultivadas , Eritropoese/efeitos dos fármacos , Eritropoese/genética , Regulação da Expressão Gênica/efeitos dos fármacos , Ferro/metabolismo , Sobrecarga de Ferro/genética , Sobrecarga de Ferro/prevenção & controle , Masculino , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Oligonucleotídeos Antissenso/farmacologia , Receptores da Transferrina/genética , Serina Endopeptidases/genética , Serina Endopeptidases/metabolismo , Talassemia beta/metabolismo
12.
Saudi J Kidney Dis Transpl ; 31(6): 1263-1272, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33565438

RESUMO

The evaluation of iron status in dialysis patients provides information essential to the planning of adequate recombinant human erythropoietin treatment. To diagnose iron deficiency in patients undergoing hemodialysis (HD), reticulocyte hemoglobin content and percentage of hypochromic red cells are incorporated into the European best practice guidelines on anemia management in chronic kidney disease (CKD), the mean reticulocyte hemoglobin content (Ret-HE) was proposed as alternatives to standard biochemical tests. Reticulocyte hemoglobin content and percentage of hypochromic red cells are incorporated into the European best practice guidelines on anemia management in CKD. Our aim was to assess the value of Ret-HE parameter, in terms of the sensitivity and specificity for detecting iron deficiency, in HD patients. We studied 50 patients undergoing HD three times weekly , to clarify the accuracy of Ret-HE in diagnosing iron deficiency in dialysis patients, we initially compared Ret-HE with such iron parameters as serum ferritin levels, transferrin saturation, and hypochromic red blood cell (Hypo%) which has been established as indicators of functional iron deficiency. Ret-HE mean value in anemic patients was (25.84 ± 4.23 pg) and had good correlation (P <0.001) between Ret-HE, serum iron, ferritin, transferrin, and transferin saturation in dialysis patients. Receiver operating characteristic curve analysis revealed, values of the area was 0.887, and at a cutoff value of 27.0 pg, a sensitivity of 90.4% and a specificity of 80.8% were achieved. The newly proposed Ret-HE can provide clinicians with information equivalent to iron deficiency anemia markers. Ret-HE is a new parameter that is easily measurable is suggested as reliable parameters for the study of erythropoiesis status in HD patients.


Assuntos
Anemia Ferropriva/sangue , Anemia Ferropriva/diagnóstico , Hemoglobinas/metabolismo , Deficiências de Ferro , Reticulócitos/metabolismo , Idoso , Idoso de 80 Anos ou mais , Feminino , Ferritinas/sangue , Humanos , Ferro/sangue , Sobrecarga de Ferro/prevenção & controle , Masculino , Pessoa de Meia-Idade , Curva ROC , Diálise Renal , Insuficiência Renal Crônica/terapia , Transferrina/metabolismo
13.
Biol Trace Elem Res ; 194(1): 210-220, 2020 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-31236816

RESUMO

We aimed to evaluate the effect of grape seed proanthocyanidins (GSPCs) on neuronal apoptosis, particularly through their roles in maintaining divalent mineral element balance and resisting oxidation in rats with iron overload. A total of 40 Sprague-Dawley rats were randomly divided into control, iron overload, GSPCs, and iron overload + GSPCs groups. The iron, calcium, zinc, magnesium, and copper contents in the brain tissue of the rats were measured using inductively coupled plasma mass spectrometry. Their oxidative stress state was determined using the relevant kit. The number of apoptotic neurons was evaluated using the terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) assay, and synaptosome numbers were determined using the immunohistochemical approach. Fas, Bax, and Bcl-2 gene expressions in the cortex and hippocampus were detected using quantitative real-time polymerase chain reaction. After 7 weeks, compared with the control group, the zinc and magnesium contents; superoxide dismutase, glutathione peroxidase, and catalase activities; and synaptophysin and Bcl-2 gene expressions in the iron overload group were significantly decreased, whereas the iron, calcium contents, and malondialdehyde contents; TUNEL-positive cell numbers; and Fas and Bax gene expressions were significantly increased. There were no significant changes in the copper content. Conversely, the rats exhibited better recovery when GSPCs were used instead of iron alone. In summary, GSPCs protected against iron overload induced neuronal apoptosis in rats by maintaining the divalent mineral element balance, reducing oxidative stress, and regulating apoptotic genes expressions.


Assuntos
Apoptose/efeitos dos fármacos , Extrato de Sementes de Uva/farmacologia , Sobrecarga de Ferro/prevenção & controle , Neurônios/efeitos dos fármacos , Proantocianidinas/farmacologia , Animais , Dieta , Extrato de Sementes de Uva/administração & dosagem , Masculino , Proantocianidinas/administração & dosagem , Ratos , Ratos Sprague-Dawley
14.
Adv Chronic Kidney Dis ; 26(4): 292-297, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31477259

RESUMO

Patients with end-stage renal disease on dialysis commonly receive intravenous iron to treat anemia along with erythropoiesis-stimulating agents. While studies of intravenous iron have demonstrated efficacy in raising hemoglobin, the quantity of administered intravenous iron has raised concerns about iron overload leading to long-term toxicities. The goal of this review is to understand recent trends in intravenous iron use, potential mechanisms of iron toxicity, and to evaluate the available evidence in the literature for potential long-term cardiovascular and infectious complications. We include findings from the recently published landmark clinical trial of intravenous iron for patients receiving hemodialysis to contextualize treatment recommendations.


Assuntos
Anemia Ferropriva/tratamento farmacológico , Hematínicos/administração & dosagem , Hematínicos/efeitos adversos , Sobrecarga de Ferro/etiologia , Ferro/administração & dosagem , Ferro/efeitos adversos , Falência Renal Crônica/complicações , Administração Intravenosa , Anemia Ferropriva/etiologia , Doenças Cardiovasculares/etiologia , Doenças Cardiovasculares/prevenção & controle , Relação Dose-Resposta a Droga , Quimioterapia Combinada , Hematínicos/uso terapêutico , Humanos , Infecções/etiologia , Ferro/uso terapêutico , Sobrecarga de Ferro/prevenção & controle , Padrões de Prática Médica/tendências , Resultado do Tratamento
15.
Toxicol Appl Pharmacol ; 382: 114748, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31499193

RESUMO

Hepatic iron overload is one of the causative factors for chronic liver injury and fibrosis. The present study aimed to investigate the potential antifibrotic effect of the iron chelator; deferasirox (DFX) in experimentally-induced liver fibrosis in rats. Male Sprague-Dawley rats were administered concanavalin A (Con A) and/or DFX for 6 consecutive weeks. Con A injection induced significant hepatotoxicity as was evident by the elevated transaminases activity, and decreased albumin level. Also, it disturbed the iron homeostasis through increasing C/EBP homologous protein (CHOP), decreasing phosphorylated cAMP responsive element binding protein(P-CREB) and hepcidin levels leading to significant serum and hepatic iron overload. In addition, it induced an imbalance in the oxidative status of the liver via upregulating NADPH oxidase 4 (NOX4), together with a marked decrease in anti-oxidant enzymes' activities. As a consequence, upregulation of nuclear factor-kappa b (NF-κB) and the downstream inflammatory mediators was observed. Those events all together precipitated in initiation of liver fibrosis as confirmed by the elevation of alpha-smooth muscle actin (α-SMA) and liver collagen content. Co-treatment with DFX protected against experimentally-induced liver fibrosis in rats via its iron chelating, anti-oxidant, and anti-inflammatory properties. These findings imply that DFX can attenuate the progression of liver fibrosis.


Assuntos
Concanavalina A/toxicidade , Deferasirox/uso terapêutico , Quelantes de Ferro/uso terapêutico , Sobrecarga de Ferro/prevenção & controle , Cirrose Hepática/prevenção & controle , Animais , Sobrecarga de Ferro/induzido quimicamente , Sobrecarga de Ferro/metabolismo , Cirrose Hepática/induzido quimicamente , Cirrose Hepática/metabolismo , Masculino , Ratos , Ratos Sprague-Dawley
16.
Biomed Res Int ; 2019: 3103946, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31428632

RESUMO

Suitable content of iron is essential for human body, but iron overload is associated with many kinds of diseases including chronic liver damage. Recently, researchers find that iron overload promotes hepatocyte autophagy and apoptosis. However, the mechanism of iron overload in liver damage remains unclear. In this study, Lo2 cells were selected as the research object, iron dextran was a model drug, and astragaloside IV was a therapeutic drug to explore the role of iron overload. MTT assay and Annexin/PI double staining were used to measure cell viability and apoptosis. Ultrastructure was observed by transmission electron microscopy. The expression levels of apoptosis and autophagy-related proteins were determined by real-time PCR and Western Blot. The results showed that iron dextran could significantly inhibit Lo2 cell viability and increase the apoptosis rate, while astragaloside IV could reverse the inhibition of Lo2 cell viability and decrease the apoptosis rate. Transmission electron microscopy showed a significant increase in the number of autophagosomes after administration of iron dextran, and the application of astragaloside IV reduced the production of autophagosomes. LC3II/I was significantly upregulated in the model group but decreased in the astragaloside IV treatment group, and P62 showed the opposite trend. Iron dextran significantly upregulated the expression of Bax and downregulated Bcl2, while astragaloside IV reversed this trend. Finally, the inhibition of hepcidin caused by iron dextran was counteracted by astragaloside IV. In conclusion, the experimental results show that the iron overload model mainly induces excessive autophagy and apoptosis of hepatocytes, thus causing damage to hepatocytes, but astragaloside IV plays a certain therapeutic role in reversing this damage.


Assuntos
Hepatócitos/metabolismo , Sobrecarga de Ferro/prevenção & controle , Fígado/lesões , Fígado/metabolismo , Saponinas/farmacologia , Triterpenos/farmacologia , Autofagossomos/metabolismo , Autofagossomos/patologia , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Hepatócitos/patologia , Humanos , Sobrecarga de Ferro/induzido quimicamente , Sobrecarga de Ferro/metabolismo , Sobrecarga de Ferro/patologia , Complexo Ferro-Dextran/efeitos adversos , Complexo Ferro-Dextran/farmacologia , Fígado/patologia , Proteínas Associadas aos Microtúbulos/metabolismo , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteínas de Ligação a RNA/metabolismo , Proteína X Associada a bcl-2/metabolismo
17.
Crit Rev Oncol Hematol ; 141: 54-72, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31228649

RESUMO

Myelodysplastic syndromes (MDS) are clonal hematopoietic stem cell disorders characterized by cytopenias and progression to acute myeloid leukemia (AML). Although several treatments for MDS are available, the mainstay of therapy for most patients remains supportive care. This includes red blood cell (RBC) transfusion to correct anemia, which leads to iron overload. RBC transfusion dependence and iron overload portend inferior overall survival. Some studies indicate that iron chelation therapy (ICT) may have beneficial effects on clinical endpoints in MDS; however, these data are from non-randomized trials and the validity of the results is vigorously debated. A consistent observation in clinical studies of ICT in MDS has been hematologic improvement (HI) in some patients, including a reduction in RBC transfusion requirements and even transfusion independence. Here, we review data on HI with ICT in lower risk MDS, preclinical data examining mechanisms by which HI may occur, and identify areas for future investigation.


Assuntos
Terapia por Quelação , Transfusão de Eritrócitos/efeitos adversos , Quelantes de Ferro/uso terapêutico , Sobrecarga de Ferro/prevenção & controle , Síndromes Mielodisplásicas/terapia , Anemia/tratamento farmacológico , Anemia/etiologia , Transfusão de Sangue/métodos , Terapia por Quelação/métodos , Transfusão de Eritrócitos/métodos , Humanos , Ferro/sangue , Sobrecarga de Ferro/etiologia , Síndromes Mielodisplásicas/sangue , Síndromes Mielodisplásicas/complicações , Síndromes Mielodisplásicas/tratamento farmacológico , Trombocitopenia/tratamento farmacológico , Trombocitopenia/etiologia , Reação Transfusional/sangue , Reação Transfusional/prevenção & controle
18.
Transfus Med Rev ; 33(3): 170-175, 2019 07.
Artigo em Inglês | MEDLINE | ID: mdl-31153715

RESUMO

Sickle cell disease (SCD) is a frequent indication for chronic transfusion, which can cause iron overload. Excess iron often affects the liver, but not the heart in SCD. Magnetic resonance (MR) is recommended to detect myocardial iron overload (MIO) but its elevated cost requires optimized indication. We aimed to compile all published data on MIO in SCD upon the description of a fatal case of severe MIO in our institution, and to determine associated risk factors. We performed a systematic review using the PRISMA guidelines in two databases (PubMed and Web of Science). Inclusion criteria were publication in English, patients diagnosed with SCD, and reporting ferritin and MIO by MR. Twenty publications reported on 865 SCD adult and pediatric patients, with at least 10 other cases of MIO. The prevalence of MIO in chronically transfused SCD patients can be estimated to be 3% or less, and is associated with high transfusion burden, top-up transfusions, and low adherence to iron chelation. Cardiac siderosis in SCD is rarely reported, and increased awareness with better use of the available screening tools are necessary. Prospective studies should define the recommended chelation regimens depending on the severity of MIO.


Assuntos
Anemia Falciforme/terapia , Ferritinas/metabolismo , Sobrecarga de Ferro/diagnóstico , Sobrecarga de Ferro/etiologia , Miocárdio/metabolismo , Reação Transfusional/diagnóstico , Anemia Falciforme/metabolismo , Biomarcadores/metabolismo , Evolução Fatal , Feminino , Humanos , Sobrecarga de Ferro/epidemiologia , Sobrecarga de Ferro/prevenção & controle , Pessoa de Meia-Idade , Reação Transfusional/epidemiologia , Reação Transfusional/prevenção & controle
19.
Neurochem Res ; 44(4): 959-967, 2019 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-30694428

RESUMO

Iron overload is a common pathophysiological state underlying many diseases that has a detrimental influence on cells. The protective effects of Dexmedetomidine (Dex), a high selective alpha-2-adrenoceptor agonist, have been revealed through many experimental models, whereas no study reports its effects on an iron overload model. To elucidate these effects, we used FeCl2 with or without Dex to treat SH-SY5Y cells for 24 h and then detected indicators of oxidative stress, inflammation and apoptosis and investigated possible mechanisms further. After treatment with FeCl2 for 24 h, cell viability decreased in a dose dependent manner, and Dex promoted cell survival in FeCl2 incubation, also in a dose-dependent manner. Compared with the FeCl2 group, 20 µM Dex significantly attenuated ROS accumulation, reduced pro-inflammatory cytokine expression, and inhibited apoptosis. Furthermore, 20 µM concentration of Dex remarkably downregulated the expression of pro-apoptotic protein and activation of caspase 3 while increasing anti-apoptotic protein expression. Additionally, Dex also effectively suppressed the expression of NF-κB and its activation. In conclusion, Dex exerted anti-oxidative stress, anti-inflammation, and anti-apoptosis effects on FeCl2-treated SH-SY5Y cells, possibly by inhibiting NF-κB signaling pathway.


Assuntos
Agonistas de Receptores Adrenérgicos alfa 2/farmacologia , Cloretos/toxicidade , Dexmedetomidina/farmacologia , Compostos Férricos/toxicidade , Sobrecarga de Ferro/metabolismo , NF-kappa B/metabolismo , Linhagem Celular Tumoral , Sobrevivência Celular/efeitos dos fármacos , Sobrevivência Celular/fisiologia , Relação Dose-Resposta a Droga , Humanos , Sobrecarga de Ferro/prevenção & controle , NF-kappa B/antagonistas & inibidores , Espécies Reativas de Oxigênio/antagonistas & inibidores , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia
20.
Semin Dial ; 32(1): 22-29, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-29956370

RESUMO

Parenteral iron is used to restore the body's iron pool before and during erythropoiesis-stimulating agent (ESA) therapy; together these agents form the backbone of anemia management in end-stage renal disease (ESRD) patients undergoing hemodialysis. ESRD patients receiving chronic intravenous iron products, which exceed their blood loss are exposed to an increased risk of positive iron balance. Measurement of the liver iron concentration (LIC) reflects total body iron stores in patients with secondary hemosiderosis and genetic hemochromatosis. Recent studies of LIC in hemodialysis patients, measured by quantitative MRI and magnetic susceptometry, have demonstrated a high risk of iron overload in dialysis patients treated with IV iron products at doses advocated by current anemia management guidelines for dialysis patients. Liver iron overload causes increased production of hepcidin and elevated plasma levels, which can activate macrophages of atherosclerotic plaques. This mechanism may explain the results of 3 long-term epidemiological studies which showed the association of excessive IV iron doses with increased risk of cardiovascular morbidity and mortality among hemodialysis patients. A more physiological approach of iron therapy in ESRD is needed. Peritoneal dialysis patients, hemodialysis patients infected with hepatitis C virus, and hemodialysis patients with ferritin above 1000 µg/L without a concomitant inflammatory state, all require specific and cautious iron management. Two recent studies have shown that most hemodialysis patients will benefit from lower maintenance IV iron dosages; their results are applicable to American hemodialysis patients. Novel pharmacometric and economic approaches to iron therapy and anemia management are emerging which are designed to lessen the potential side effects of excessive IV iron while maintaining hemoglobin stability without an increase in ESA dosing.


Assuntos
Anemia Ferropriva/tratamento farmacológico , Compostos Férricos/administração & dosagem , Sobrecarga de Ferro/prevenção & controle , Diálise Renal/efeitos adversos , Administração Intravenosa , Idoso , Anemia Ferropriva/etiologia , Relação Dose-Resposta a Droga , Esquema de Medicação , Feminino , Compostos Férricos/efeitos adversos , Ferritinas/sangue , Hematínicos/administração & dosagem , Humanos , Falência Renal Crônica/sangue , Falência Renal Crônica/diagnóstico , Falência Renal Crônica/terapia , Masculino , Pessoa de Meia-Idade , Diálise Peritoneal/efeitos adversos , Diálise Peritoneal/métodos , Prognóstico , Diálise Renal/métodos , Medição de Risco , Fatores de Tempo , Resultado do Tratamento , Suspensão de Tratamento
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