RESUMO
INTRODUCTION: The treatment landscape of polycythemia vera (PV) has seen major advancements within the last decade including approval of ruxolitinib in the second line setting after hydroxyurea, ropegylated interferon-α2b, and advanced clinical development of a novel class of agents called hepcidin mimetics. AREAS COVERED: We provide a comprehensive review of the evidence discussing the risk stratification, treatment indications, role and limitations of phlebotomy only approach and pivotal trials covering nuances related to the use of interferon-α (IFN-α), ruxolitinib, hepcidin mimetics, and upcoming investigational agents including HDAC and LSD1 inhibitors. EXPERT OPINION: The research paradigm in PV is slowly shifting from the sole focus on hematocrit control and moving toward disease modification. The discovery of hepcidin mimetics has come as a breakthrough in restoring iron homeostasis, achieving phlebotomy-independence and may lead to improved thrombosis-free survival with stricter hematocrit control. On the other hand, emerging data with IFN- α and ruxolitinib as well as combination of the two agents suggests the potential for achieving molecular remission in a subset of PV patients and long-term follow-up is awaited to validate the correlation of molecular responses with clinically relevant outcomes of progression-free and thrombosis-free survival.
Assuntos
Interferon-alfa , Nitrilas , Flebotomia , Policitemia Vera , Pirazóis , Policitemia Vera/tratamento farmacológico , Humanos , Nitrilas/uso terapêutico , Pirazóis/uso terapêutico , Interferon-alfa/uso terapêutico , Pirimidinas/uso terapêutico , Hepcidinas/metabolismo , Interferon alfa-2/uso terapêutico , HematócritoRESUMO
BACKGROUND: Iron (Fe) supplementation is a critical component of anemia therapy for patients with chronic kidney disease (CKD). However, serum Fe, ferritin, and transferrin saturation, used to guide Fe replacement, are far from optimal, as they can be influenced by malnutrition and inflammation. Currently, there is a trend of increasing Fe supplementation to target high ferritin levels, although the long-term risk has been overlooked. METHODS: We prospectively enrolled 28 patients with CKD on hemodialysis with high serum ferritin (> 1000 ng/ml) and tested the effects of 1-year deferoxamine treatment, accompanied by withdrawal of Fe administration, on laboratory parameters (Fe status, inflammatory and CKD-MBD markers), heart, liver, and iliac crest Fe deposition (quantitative magnetic resonance imaging [MRI]), and bone biopsy (histomorphometry and counting of the number of Fe positive cells in the bone marrow). RESULTS: MRI parameters showed that none of the patients had heart iron overload, but they all presented iron overload in the liver and bone marrow, which was confirmed by bone histology. After therapy, ferritin levels decreased, although neither hemoglobin levels nor erythropoietin dose was changed. A significant decrease in hepcidin and FGF-23 levels was observed. Fe accumulation was improved in the liver and bone marrow, reaching normal values only in the bone marrow. No significant changes in turnover, mineralization or volume were observed. CONCLUSIONS: Our data suggest that treatment with deferoxamine was safe and could improve Fe accumulation, as measured by MRI and histomorphometry. Whether MRI is considered a standard tool for investigating bone marrow Fe accumulation requires further investigation. Registry and the registration number of clinical trial: ReBEC (Registro Brasileiro de Ensaios Clinicos) under the identification RBR-3rnskcj available at: https://ensaiosclinicos.gov.br/pesquisador.
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Medula Óssea , Desferroxamina , Ferritinas , Sobrecarga de Ferro , Ferro , Fígado , Diálise Renal , Humanos , Masculino , Feminino , Sobrecarga de Ferro/tratamento farmacológico , Sobrecarga de Ferro/etiologia , Sobrecarga de Ferro/metabolismo , Medula Óssea/metabolismo , Medula Óssea/efeitos dos fármacos , Medula Óssea/patologia , Ferritinas/sangue , Ferritinas/metabolismo , Fígado/metabolismo , Fígado/efeitos dos fármacos , Fígado/patologia , Fígado/diagnóstico por imagem , Pessoa de Meia-Idade , Desferroxamina/uso terapêutico , Desferroxamina/administração & dosagem , Ferro/metabolismo , Idoso , Imageamento por Ressonância Magnética , Estudos Prospectivos , Insuficiência Renal Crônica/terapia , Insuficiência Renal Crônica/complicações , Insuficiência Renal Crônica/tratamento farmacológico , Insuficiência Renal Crônica/metabolismo , Insuficiência Renal Crônica/sangue , Fator de Crescimento de Fibroblastos 23 , Hepcidinas/metabolismoRESUMO
Subarachnoid hemorrhage (SAH) significantly compromises the blood-brain barrier (BBB) and impairs patient recovery. This study elucidates the critical role of astrocytic Neogenin-1 (NEO1) in BBB integrity post-SAH and examines the regulatory effects of hepcidin on endothelial cell (EC) function amid NEO1-mediated disruptions in iron homeostasis. Proteomic analyses of cerebrospinal fluid (CSF) from SAH patients revealed a substantial decrease in NEO1 expression, identifying it as a key factor in BBB integrity. 111 CSF proteins were significantly reduced in early SAH stages (days 1-3), with NEO1 among the most significantly altered. This dysregulation was linked to poorer patient outcomes, as indicated by a negative correlation between NEO1 levels and Modified Rankin Scale scores six months post-SAH (R = -0.4743, P < 0.0001). Experimental models further highlighted the importance of NEO1: SAH model and NEO1GFAP-Cre mice exhibited exacerbated EC dysfunction and increased BBB permeability, evidenced by significant Evans Blue retention and dextran leakage in the parietal cortex, effects that were mitigated by hepcidin administration. Our findings highlight the complex interplay between astrocytic signaling and endothelial function in SAH pathophysiology. The loss of astrocytic NEO1 led to increased EC proliferation and altered BBB structure, as confirmed by transmission electron microscopy and immunostaining for PECAM-1, indicating heightened blood vessel density in the affected cortex. Hepcidin treatment effectively reversed the EC dysfunction and BBB disruption in both NEO1-cKO mice and the SAH model, highlighting its potential as a therapeutic agent to enhance recovery and improve prognosis following SAH.
Assuntos
Astrócitos , Barreira Hematoencefálica , Hepcidinas , Hemorragia Subaracnóidea , Hemorragia Subaracnóidea/metabolismo , Barreira Hematoencefálica/metabolismo , Barreira Hematoencefálica/patologia , Barreira Hematoencefálica/efeitos dos fármacos , Animais , Hepcidinas/metabolismo , Hepcidinas/genética , Astrócitos/metabolismo , Humanos , Camundongos , Masculino , Camundongos Endogâmicos C57BL , Células Endoteliais/metabolismo , Modelos Animais de Doenças , Feminino , Pessoa de Meia-Idade , Proteínas de Membrana/metabolismoRESUMO
Psoriasis is a multifactorial, chronic inflammatory skin disease with unresolved questions on its primary events. Iron overload has been described in the epidermis of psoriasis patients, but its relevance remains unknown. We found that the key iron regulatory hormone hepcidin was highly expressed in the epidermis of psoriasis patients, especially the pustular variants resistant to treatments. In a murine model of acute skin inflammation, keratinocyte-derived hepcidin was required for iron retention in keratinocytes, leading to hyperproliferation of the epidermal layer and neutrophil recruitment, two main features of psoriatic skin lesions. Keratinocytes overexpressing hepcidin were sufficient to elicit these psoriasiform features in a transgenic mouse model. Furthermore, transcriptome analysis of these keratinocytes revealed canonical pathways found in human psoriasis, pointing to a causal role for hepcidin in the pathogenesis of the disease. Altogether, our data suggest that hepcidin could be an actionable target for skin psoriasis treatment, in addition to current therapeutics, or targeted as maintenance therapy during remission to prevent recurrence.
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Proliferação de Células , Hepcidinas , Ferro , Queratinócitos , Camundongos Transgênicos , Infiltração de Neutrófilos , Psoríase , Pele , Hepcidinas/metabolismo , Hepcidinas/genética , Psoríase/metabolismo , Psoríase/patologia , Animais , Queratinócitos/metabolismo , Humanos , Ferro/metabolismo , Camundongos , Pele/metabolismo , Pele/patologia , Modelos Animais de Doenças , Masculino , Feminino , Epiderme/metabolismo , Epiderme/patologia , Camundongos Endogâmicos C57BL , Inflamação/metabolismo , Inflamação/patologiaRESUMO
Cardiac arrest is a common and fatal emergency situation. Recently, an increasing number of studies have shown that anemia in patients with cardiac arrest is closely related to high mortality rates and poor neurological outcomes. Anemia is prevalent among patients with post-cardiac arrest syndrome (PCAS), but its specific pathogenesis remains unclear. The mechanisms may involve various factors, including reduced production of erythropoietin, oxidative stress/inflammatory responses, gastrointestinal ischemic injury, hepcidin abnormalities, iatrogenic blood loss, and malnutrition. Measures to improve anemia related to cardiac arrest may include blood transfusions, administration of erythropoietin, anti-inflammation and antioxidant therapies, supplementation of hematopoietic materials, protection of gastrointestinal mucosa, and use of hepcidin antibodies and antagonists. Therefore, exploring the latest research progress on the mechanisms and treatment of anemia related to cardiac arrest is of significant guiding importance for improving secondary brain injury caused by anemia and the prognosis of patients with cardiac arrest.
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Anemia , Parada Cardíaca , Humanos , Anemia/etiologia , Anemia/terapia , Parada Cardíaca/terapia , Parada Cardíaca/etiologia , Parada Cardíaca/complicações , Eritropoetina/uso terapêutico , Hepcidinas/metabolismo , Estresse Oxidativo , Síndrome Pós-Parada Cardíaca/complicações , Síndrome Pós-Parada Cardíaca/etiologia , Síndrome Pós-Parada Cardíaca/terapiaRESUMO
The significance of iron in myocardial mitochondria function cannot be underestimated, because deviations in iron levels within cardiomyocytes may have profound detrimental effects on cardiac function. In this study, we investigated the effects of ferroportin 1 (FPN1) on cardiac iron levels and pathological alterations in mice subjected to chronic intermittent hypoxia (CIH). The cTNT-FPN1 plasmid was administered via tail vein injection to induce the mouse with FPN1 overexpression in the cardiomyocytes. CIH was established by exposing the mice to cycles of 21%-5% FiO2 for 3 min, 8 h per day. Subsequently, the introduction of hepcidin resulted in a reduction in FPN1 expression, and H9C2 cells were used to establish an IH model to further elucidate the role of FPN1. First, FPN1 overexpression ameliorated CIH-induced cardiac dysfunction, myocardial hypertrophy, mitochondrial damage and apoptosis. Second, FPN1 overexpression attenuated ROS levels during CIH. In addition, FPN1 overexpression mitigated CIH-induced cardiac iron accumulation. Moreover, the administration of hepcidin resulted in a reduction in FPN1 levels, further accelerating the CIH-induced levels of ROS, LIP and apoptosis in H9C2 cells. These findings indicate that the overexpression of FPN1 in cardiomyocytes inhibits CIH-induced cardiac iron accumulation, subsequently reducing ROS levels and mitigating mitochondrial damage. Conversely, the administration of hepcidin suppressed FPN1 expression and worsened cardiomyocyte iron toxicity injury.
Assuntos
Apoptose , Cardiomegalia , Proteínas de Transporte de Cátions , Hipóxia , Ferro , Miócitos Cardíacos , Espécies Reativas de Oxigênio , Animais , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Cardiomegalia/metabolismo , Cardiomegalia/genética , Cardiomegalia/patologia , Cardiomegalia/etiologia , Proteínas de Transporte de Cátions/metabolismo , Proteínas de Transporte de Cátions/genética , Hipóxia/metabolismo , Hipóxia/complicações , Camundongos , Espécies Reativas de Oxigênio/metabolismo , Ferro/metabolismo , Masculino , Hepcidinas/metabolismo , Hepcidinas/genética , Linhagem Celular , Camundongos Endogâmicos C57BL , Modelos Animais de Doenças , RatosRESUMO
The microbiota significantly impacts digestive epithelium functionality, especially in nutrient processing. Given the importance of iron for both the host and the microbiota, we hypothesized that host-microbiota interactions fluctuate with dietary iron levels. We compared germ-free (GF) and conventional mice (SPF) fed iron-containing (65 mg/Kg) or iron-depleted (<6 mg/Kg) diets. The efficacy of iron privation was validated by iron blood parameters. Ferritin and Dmt1, which represent cellular iron storage and transport respectively, were studied in tissues where they are abundant: the duodenum, liver and lung. When the mice were fed an iron-rich diet, the microbiota increased blood hemoglobin and hepcidin and the intestinal ferritin levels, suggesting that the microbiota helps iron storage. When iron was limiting, the microbiota inhibited the expression of the intestinal Dmt1 transporter, likely via the pathway triggered by Hif-2α. The microbiota assists the host in storing intestinal iron when it is abundant and competes with the host by inhibiting Dmt1 in conditions of iron scarcity. Comparison between duodenum, liver and lung indicates organ-specific responses to microbiota and iron availability. Iron depletion induced temporal changes in microbiota composition and activity, reduced α-diversity of microbiota, and led to Lactobacillaceae becoming particularly more abundant after 60 days of privation. By inoculating GF mice with a simplified bacterial mixture, we show that the iron-depleted host favors the gut fitness of Bifidobacterium longum.
Assuntos
Proteínas de Transporte de Cátions , Duodeno , Microbioma Gastrointestinal , Hepcidinas , Ferro da Dieta , Fígado , Animais , Camundongos , Microbioma Gastrointestinal/fisiologia , Ferro da Dieta/metabolismo , Ferro da Dieta/administração & dosagem , Proteínas de Transporte de Cátions/metabolismo , Proteínas de Transporte de Cátions/genética , Fígado/metabolismo , Fígado/microbiologia , Duodeno/metabolismo , Duodeno/microbiologia , Hepcidinas/metabolismo , Ferritinas/metabolismo , Vida Livre de Germes , Interações entre Hospedeiro e Microrganismos , Pulmão/microbiologia , Pulmão/metabolismo , Ferro/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Bactérias/classificação , Bactérias/metabolismo , Bactérias/genética , Bactérias/isolamento & purificação , Camundongos Endogâmicos C57BL , Hemoglobinas/metabolismo , MasculinoRESUMO
Impaired self-renewal of Kupffer cells (KCs) leads to inflammation in metabolic dysfunction-associated steatohepatitis (MASH). Here, we identify neutrophil cytosolic factor 1 (NCF1) as a critical regulator of iron homeostasis in KCs. NCF1 is upregulated in liver macrophages and dendritic cells in humans with metabolic dysfunction-associated steatotic liver disease and in MASH mice. Macrophage NCF1, but not dendritic cell NCF1, triggers KC iron overload, ferroptosis, and monocyte-derived macrophage infiltration, thus aggravating MASH progression. Mechanistically, elevated oxidized phospholipids induced by macrophage NCF1 promote Toll-like receptor (TLR4)-dependent hepatocyte hepcidin production, leading to increased KC iron deposition and subsequent KC ferroptosis. Importantly, the human low-functional polymorphic variant NCF190H alleviates KC ferroptosis and MASH in mice. In conclusion, macrophage NCF1 impairs iron homeostasis in KCs by oxidizing phospholipids, triggering hepatocyte hepcidin release and KC ferroptosis in MASH, highlighting NCF1 as a therapeutic target for improving KC fate and limiting MASH progression.
Assuntos
Ferroptose , Células de Kupffer , Camundongos Endogâmicos C57BL , Espécies Reativas de Oxigênio , Ferroptose/genética , Células de Kupffer/metabolismo , Animais , Humanos , Camundongos , Espécies Reativas de Oxigênio/metabolismo , Masculino , Ferro/metabolismo , NADPH Oxidases/metabolismo , Macrófagos/metabolismo , Hepcidinas/metabolismo , Hepcidinas/genéticaRESUMO
Hepcidin is a crucial regulator of iron homeostasis with protective effects on liver fibrosis. Additionally, gut microbiota can also affect liver fibrosis and iron metabolism. Although the hepatoprotective potential of Akkermansia muciniphila and Faecalibacterium duncaniae, formerly known as F. prausnitzii, has been reported, however, their effects on hepcidin expression remain unknown. We investigated the direct and macrophage stimulation-mediated effects of active, heat-inactivated, and cell-free supernatant (CFS) forms of A. muciniphila and F. duncaniae on hepcidin expression in HepG2 cells by RT-qPCR analysis. Following stimulation of phorbol-12-myristate-13-acetate (PMA) -differentiated THP-1 cells with A. muciniphila and F. duncaniae, IL-6 concentration was assessed via ELISA. Additionally, the resulting supernatant was treated with HepG2 cells to evaluate the effect of macrophage stimulation on hepcidin gene expression. The expression of genes mediating iron absorption and export was also examined in HepG2 and Caco-2 cells via RT-qPCR. All forms of F. duncaniae increased hepcidin expression while active and heat-inactivated/CFS forms of A. muciniphila upregulated and downregulated its expression, respectively. Active, heat-inactivated, and CFS forms of A. muciniphila and F. duncaniae upregulated hepcidin expression, consistent with the elevation of IL-6 released from THP-1-stimulated cells as a macrophage stimulation effect in HepG2 cells. A. muciniphila and F. duncaniae in active, inactive, and CFS forms altered the expression of hepatocyte and intestinal iron-mediated absorption /exporter genes, namely dcytb and dmt1, and fpn in HepG2 and Caco-2 cells, respectively. In conclusion, A. muciniphila and F. duncaniae affect not only directly but also through macrophage stimulation the expression of hepcidin gene in HepG2 cells. These findings underscore the potential of A. muciniphila and F. duncaniae as a potential therapeutic target for liver fibrosis by modulating hepcidin and intestinal and hepatocyte iron metabolism mediated gene expression.
Assuntos
Akkermansia , Faecalibacterium , Hepcidinas , Macrófagos , Humanos , Células CACO-2 , Microbioma Gastrointestinal , Células Hep G2 , Hepcidinas/genética , Hepcidinas/metabolismo , Interleucina-6/metabolismo , Interleucina-6/genética , Ferro/metabolismo , Ativação de Macrófagos , Macrófagos/imunologia , Macrófagos/microbiologia , Macrófagos/metabolismo , Células THP-1RESUMO
BACKGROUND: The interaction between iron status and malaria is incompletely understood. We evaluated longitudinal changes in iron homeostasis in volunteers enrolled in malaria volunteer infection studies (VIS) and in Malaysian patients with falciparum and vivax malaria. METHODS: We retrieved data and samples from 55 participants (19 female) enrolled in malaria VIS, and 171 patients (45 female) with malaria and 30 healthy controls (13 female) enrolled in clinical studies in Malaysia. Ferritin, hepcidin, erythropoietin, and soluble transferrin receptor (sTfR) were measured by ELISA. FINDINGS: In the VIS, participants' parasitaemia was correlated with baseline mean corpuscular volume (MCV), but not iron status (ferritin, hepcidin or sTfR). Ferritin, hepcidin and sTfR all increased during the VIS. Ferritin and hepcidin normalised by day 28, while sTfR remained elevated. In VIS participants, baseline ferritin was associated with post-treatment increases in liver transaminase levels. In Malaysian patients with malaria, hepcidin and ferritin were elevated on admission compared to healthy controls, while sTfR increased following admission. By day 28, hepcidin had normalised; however, ferritin and sTfR both remained elevated. INTERPRETATION: Our findings demonstrate that parasitaemia is associated with an individual's MCV rather than iron status. The persistent elevation in sTfR 4 weeks post-infection in both malaria VIS and clinical malaria may reflect a causal link between malaria and iron deficiency. FUNDING: National Health and Medical Research Council (Program Grant 1037304, Project Grants 1045156 and 1156809; Investigator Grants 2016792 to BEB, 2016396 to JCM, 2017436 to MJG); US National Institute of Health (R01-AI116472-03); Malaysian Ministry of Health (BP00500420).
Assuntos
Ferritinas , Hepcidinas , Homeostase , Ferro , Malária , Humanos , Feminino , Ferro/metabolismo , Ferro/sangue , Masculino , Adulto , Hepcidinas/sangue , Hepcidinas/metabolismo , Malária/sangue , Malária/parasitologia , Malária/metabolismo , Ferritinas/sangue , Receptores da Transferrina/metabolismo , Receptores da Transferrina/sangue , Pessoa de Meia-Idade , Malásia/epidemiologia , Adulto Jovem , Estudos Longitudinais , Malária Falciparum/parasitologia , Malária Falciparum/sangue , Malária Falciparum/metabolismo , Eritropoetina/metabolismo , Eritropoetina/sangue , Biomarcadores , Parasitemia/sangueRESUMO
Disruption of any stage of iron homeostasis, including uptake, utilization, efflux, and storage, can cause progressive damage to peripheral organs. The health hazards associated with occupational exposure to inhalation anesthetics (IA) in combination with chronic iron overload are not well documented. This study aimed to investigate changes in the concentration of essential metals in the peripheral organs of rats after iron overload in combination with IA. The aim was also to determine how iron overload in combination with IA affects tissue metal homeostasis, hepcidin-ferritin levels, and MMP levels according to physiological, functional, and tissue features. According to the obtained results, iron accumulation was most pronounced in the liver (19×), spleen (6.7×), lungs (3.1×), and kidneys (2.5×) compared to control. Iron accumulation is associated with elevated heavy metal levels and impaired essential metal concentrations due to oxidative stress (OS). Notably, the use of IA increases the iron overload toxicity, especially after Isoflurane exposure. The results show that the regulation of iron homeostasis is based on the interaction of hepcidin, ferritin, and other proteins regulated by inflammation, OS, free iron levels, erythropoiesis, and hypoxia. Long-term exposure to IA and iron leads to the development of numerous adaptation mechanisms in response to toxicity, OS, and inflammation. These adaptive mechanisms of iron regulation lead to the inhibition of MMP activity and reduction of oxidative stress, protecting the organism from possible damage.
Assuntos
Anestésicos Inalatórios , Hepcidinas , Complexo Ferro-Dextran , Ferro , Estresse Oxidativo , Animais , Ratos , Hepcidinas/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Ferro/metabolismo , Masculino , Anestésicos Inalatórios/efeitos adversos , Anestésicos Inalatórios/toxicidade , Complexo Ferro-Dextran/administração & dosagem , Complexo Ferro-Dextran/toxicidade , Ferritinas/metabolismo , Sobrecarga de Ferro/metabolismo , Fígado/efeitos dos fármacos , Fígado/metabolismo , Fígado/patologia , Pulmão/efeitos dos fármacos , Pulmão/metabolismo , Pulmão/patologia , Rim/efeitos dos fármacos , Rim/metabolismo , Rim/patologia , Baço/efeitos dos fármacos , Baço/metabolismo , Baço/patologia , Ratos Wistar , Homeostase/efeitos dos fármacos , Isoflurano/efeitos adversosRESUMO
Iron is an essential element for proper cell functioning, but unbalanced levels can cause cell death. Iron metabolism is controlled at the blood-tissue barriers provided by microvascular endothelial cells. Dysregulated iron metabolism at these barriers is a factor in both neurodegenerative and cardiovascular diseases. Mammalian iron efflux is mediated by the iron efflux transporter ferroportin (Fpn). Inflammation is a factor in many diseases and correlates with increased tissue iron accumulation. Evidence suggests treatment with interleukin 6 (IL-6) increases intracellular calcium levels and calcium is known to play an important role in protein trafficking. We have shown that calcium increases plasma membrane localization of the iron uptake proteins ZIP8 and ZIP14, but if and how calcium modulates Fpn trafficking is unknown. In this article, we examined the effects of IL-6 and calcium on Fpn localization to the plasma membrane. In HEK cells expressing a doxycycline-inducible GFP-tagged Fpn, calcium increased Fpn-GFP membrane presence by 2 h, while IL-6 increased membrane-localized Fpn-GFP by 3 h. Calcium pretreatment increased Fpn-GFP mediated 55Fe efflux from cells. Endoplasmic reticulum calcium stores were shown to be important for Fpn-GFP localization and iron efflux. Use of calmodulin pathway inhibitors showed that calcium signaling is important for IL-6-induced Fpn relocalization. Studies in brain microvascular endothelial cells in transwell culture demonstrated an initial increase in 55Fe flux with IL-6 that is reduced by 6 h coinciding with upregulation of hepcidin. Overall, this research details one pathway by which inflammatory signaling mediated by calcium can regulate iron metabolism, likely contributing to inflammatory disease mechanisms.
Assuntos
Cálcio , Proteínas de Transporte de Cátions , Membrana Celular , Interleucina-6 , Ferro , Transporte Proteico , Proteínas de Transporte de Cátions/metabolismo , Proteínas de Transporte de Cátions/genética , Humanos , Interleucina-6/metabolismo , Interleucina-6/genética , Ferro/metabolismo , Membrana Celular/metabolismo , Cálcio/metabolismo , Células HEK293 , Animais , Células Endoteliais/metabolismo , Hepcidinas/metabolismo , Hepcidinas/genéticaRESUMO
Treatment with erythropoietin (EPO) can correct anaemia in chronic kidney disease (CKD) patients; however, up to 10% exhibit resistance or hyporesponsiveness to EPO. Non-alcoholic fatty liver disease (NAFLD), prevalent liver disease in CKD patients, may limit EPO response because of thrombopoietin deficiency, iron homeostasis disorder and inflammation. Therefore, we hypothesized NAFLD is a risk factor for EPO responsiveness. To test our hypothesis, we evaluated the effect of EPO in healthy rats and rats with NAFLD induced by a high-fat, high-carbohydrate (HFHC) diet. After 12 weeks on the HFHC diet, NAFLD rats showed lower erythroid response to EPO treatment than healthy rats. We, then, determined that the primary cause of EPO hyporesponsiveness could be iron deficiency associated with inflammation, which reduces erythroid cell production. Specifically, the concentrations of hepcidin, ferritin, transferrin and white blood cells in NAFLD rats were 12.8-, 16.4-, 2.51- and 1.40-fold higher than those in healthy rats, respectively. However, erythroid cell types in the bone marrow of NAFLD rats were significantly reduced. In conclusion, our data suggest that NAFLD could be a risk factor for EPO responsiveness, which is attributed to functional iron deficiency associated with inflammation.
Assuntos
Eritropoetina , Hepatopatia Gordurosa não Alcoólica , Animais , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/patologia , Ratos , Masculino , Ratos Sprague-Dawley , Dieta Hiperlipídica/efeitos adversos , Hepcidinas/metabolismoRESUMO
BACKGROUNDS & AIMS: Given its ability to inhibit HBV replication, Interferon alpha (IFN-α) treatment has been confirmed to be effective in managing Chronic Hepatitis B (CHB). However, its underlying mechanisms are incompletely understood. METHODS: Herein, we investigated the antiviral properties of IFN-α by introducing IFN-α expression plasmids into a well-established HBV Hydrodynamic Injection (HDI) mouse model and examined the impact of IFN-α or hepcidin treatment on macrophages derived from THP-1 cells. The cytokine profiles were analyzed using the cytometry microsphere microarray technology, and flow cytometry was used to analyze the polarization of macrophages. Additionally, the IL-6/JAK2/STAT3 signaling pathway and the hepcidin-ferroportin axis were analyzed to better understand the macrophage polarization mechanism. RESULTS: As evidenced by the suppression of HBV replication, injection of an IFN-α expression plasmid and supernatants of IFN-α-treated macrophages exerted anti-HBV effects. The IFN-α treatment up-regulated IL-6 in mice with HBV replication, as well as in IFN-α-treated HepG2 cells and macrophages. Furthermore, JAK2/STAT3 signaling and hepcidin expression was promoted, inducing iron accumulation via the hepcidin-ferroportin axis, which caused the polarization of M1 macrophages. Furthermore, under the effect of IFN-α, IL-6 silencing or blockade downregulated the JAK2/STAT3 signaling pathway and hepcidin, implying that increased hepcidin expression under IFN-α treatment was dependent on the IL-6/JAK2/STAT3 pathway. CONCLUSION: The IL-6/JAK2/STAT3 signaling pathway is activated by IFN-α which induces hepcidin expression. The resulting iron accumulation then induces the polarization of M1 macrophages via the hepcidin-ferroportin axis, yielding an immune response which exerts antiviral effects against HBV replication.
Assuntos
Antivirais , Vírus da Hepatite B , Hepcidinas , Interferon-alfa , Janus Quinase 2 , Macrófagos , Fator de Transcrição STAT3 , Hepcidinas/metabolismo , Hepcidinas/genética , Animais , Humanos , Interferon-alfa/farmacologia , Macrófagos/imunologia , Macrófagos/efeitos dos fármacos , Vírus da Hepatite B/fisiologia , Vírus da Hepatite B/efeitos dos fármacos , Vírus da Hepatite B/imunologia , Antivirais/farmacologia , Antivirais/uso terapêutico , Camundongos , Janus Quinase 2/metabolismo , Fator de Transcrição STAT3/metabolismo , Células Hep G2 , Transdução de Sinais/efeitos dos fármacos , Interleucina-6/metabolismo , Células THP-1 , Camundongos Endogâmicos C57BL , Replicação Viral/efeitos dos fármacos , Masculino , Hepatite B Crônica/imunologia , Hepatite B Crônica/tratamento farmacológico , Hepatite B Crônica/virologia , Modelos Animais de Doenças , Hepatite B/imunologia , Hepatite B/tratamento farmacológico , Hepatite B/virologia , Proteínas de Transporte de Cátions/metabolismo , Proteínas de Transporte de Cátions/genéticaRESUMO
Pathogenic variants in HFE and non-HFE genes have been identified in hemochromatosis in different patient populations, but there are still a certain number of patients with unexplained primary iron overload. We recently identified in Chinese patients a recurrent p.(Arg639Gln) variant in SURP and G-patch domain containing 2 (SUGP2), a potential mRNA splicing-related factor. However, the target gene of SUGP2 and affected iron-regulating pathway remains unknown. We aimed to investigate the pathogenicity and underlying mechanism of this variant in hemochromatosis. RNA-seq analysis revealed that SUGP2 knockdown caused abnormal alternative splicing of CIRBP pre-mRNA, resulting in an increased normal splicing form of CIRBP V1, which in turn increased the expression of BMPER by enhancing its mRNA stability and translation. Furthermore, RNA-protein pull-down and RNA immunoprecipitation assays revealed that SUGP2 inhibited splicing of CIRBP pre-mRNA by a splice site variant at CIRBP c.492 and was more susceptible to CIRBP c.492 C/C genotype. Cells transfected with SUGP2 p.(Arg639Gln) vector showed up-regulation of CIRBP V1 and BMPER expression and down-regulation of pSMAD1/5 and HAMP expression. CRISPR-Cas9 mediated SUGP2 p.(Arg622Gln) knock-in mice showed increased iron accumulation in the liver, higher total serum iron, and decreased serum hepcidin level. A total of 10 of 54 patients with hemochromatosis (18.5%) harbored the SUGP2 p.(Arg639Gln) variant and carried CIRBP c.492 C/C genotype, and had increased BMPER expression in the liver. Altogether, the SUGP2 p.(Arg639Gln) variant down-regulates hepcidin expression through the SUGP2/CIRBP/BMPER axis, which may represent a novel pathogenic factor for hemochromatosis.
Assuntos
Hemocromatose , Transdução de Sinais , Hemocromatose/genética , Humanos , Camundongos , Animais , Masculino , Proteínas de Ligação a RNA/genética , Hepcidinas/genética , Hepcidinas/metabolismo , FemininoRESUMO
BACKGROUND: Iron deficiency without anaemia is a common health problem, especially in young menstruating women. The efficacy of the usually recommended oral iron supplementation is limited due to increased plasma hepcidin concentration, which reduces iron absorption and leads to side effects such as intestinal irritation. This observation raises the question of how low-dose iron therapy may affect plasma hepcidin levels and whether oral iron intake dose-dependently affects plasma hepcidin production. METHODS: Fifteen non-anaemic women with iron deficiency (serum ferritin ≤30 ng/ml) received a single dose of 0, 6, 30, or 60 mg of elemental oral iron as ferrous sulfate on different days. Plasma hepcidin was measured before and seven hours after each dose. RESULTS: Subjects had an average age of 23 (standard deviation = 3.0) years and serum ferritin of 24 ng/ml (interquartile range = 16-27). The highest mean change in plasma hepcidin levels was measured after ingesting 60 mg of iron, increasing from 2.1 ng/ml (interquartile range = 1.6-2.9) to 4.1 ng/ml (interquartile range = 2.5-6.9; p < 0.001). Iron had a significant dose-dependent effect on the absolute change in plasma hepcidin (p = 0.008), where lower iron dose supplementation resulted in lower plasma hepcidin levels. Serum ferritin levels were significantly correlated with fasting plasma hepcidin levels (R2 = 0.504, p = 0.003) and the change in plasma hepcidin concentration after iron intake (R2 = 0.529, p = 0.002). CONCLUSION: We found a dose-dependent effect of iron supplementation on plasma hepcidin levels. Lower iron dosage results in a smaller increase in hepcidin and might thus lead to more efficient intestinal iron absorption and fewer side effects. The effectiveness and side effects of low-dose iron treatment in women with iron deficiency should be further investigated. This study was registered at the Swiss National Clinical Trials Portal (2021-00312) and ClinicalTrials.gov (NCT04735848).
Assuntos
Hepcidinas , Ferro , Feminino , Humanos , Anemia Ferropriva/tratamento farmacológico , Suplementos Nutricionais , Ferritinas , Hepcidinas/efeitos dos fármacos , Hepcidinas/metabolismo , Ferro/farmacologia , Ferro/uso terapêutico , Deficiências de Ferro/tratamento farmacológico , Estado NutricionalRESUMO
BACKGROUND: Iron deficiency anemia remains a significant public health issue in developing countries. The regulation of iron metabolism is primarily controlled by hepcidin, a key regulatory protein. During erythropoiesis, erythroferrone (ERFE), a hormone produced by erythroblasts in response to erythropoietin (EPO) synthesis, mediates the suppression of hepcidin. In this study, it was aimed to determine the correlation between erythroferrone (ERFE) and hepcidin levels in children with iron deficiency anemia. METHODS: This is a case-control study conducted at Kirsehir Ahi Evran University Training and Research Hospital Pediatrics Clinic between 1 and 31 September 2020. The study included 26 healthy children and 26 children with iron deficiency anemia. In order to evaluate iron status,whole blood count, serum iron, total iron binding capacity (TIBC), and ferritin levels were analyzed. The study measured the levels of hepcidin and erythroferrone in the serum of children diagnosed with iron deficiency before and after one month of iron treatment, as well as in a control group, using the ELISA method. Correlation between whole blood count, initial ferritin, hepcidin, ERFE and ferritin in the iron deficiency group was evaluated. RESULTS: Compared with healthy controls, the iron-deficient group had significantly lower haemoglobin (p < 0.001), MCV (p = 0.001), MCH (p < 0.001), MCHC (p < 0.001), iron (p < 0.001), ferritin (p < 0.001) and hepcidin (p = 0.001). Ferritin and hepcidin levels increased while erythroferrone levels remained unchanged after iron deficiency treatment. There was no correlation between hepcidin and ferritin levels in treatment group. CONCLUSIONS: The study found a strong and positive correlation between ferritin and hepcidin levels in iron-deficient children, but not between ERFE levels, suggesting that hepcidin is largely regulated by iron deposition levels. In addition, there was an increase in ferritin and hepcidin levels after iron treatment. The study found no significant difference in erythroferrone levels between the iron-deficient group and the control group. It is thought that this may be due to the short duration of iron treatment given to the patients with iron deficiency anemia included in the study.
Assuntos
Anemia Ferropriva , Deficiências de Ferro , Humanos , Criança , Hepcidinas/metabolismo , Estudos de Casos e Controles , Ferro , FerritinasRESUMO
BACKGROUND: Early studies in cellular models suggested an iron accumulation in Friedreich's ataxia (FA), yet findings from patients are lacking. OBJECTIVES: The objective is to characterize systemic iron metabolism, body iron storages, and intracellular iron regulation in FA patients. METHODS: In FA patients and matched healthy controls, we assessed serum iron parameters, regulatory hormones as well as the expression of regulatory proteins and iron distribution in peripheral blood mononuclear cells (PBMCs). We applied magnetic resonance imaging with R2*-relaxometry to quantify iron storages in the liver, spleen, and pancreas. Across all evaluations, we assessed the influence of the genetic severity as expressed by the length of the shorter GAA-expansion (GAA1). RESULTS: We recruited 40 FA patients (19 women). Compared to controls, FA patients displayed lower serum iron and transferrin saturation. Serum ferritin, hepcidin, mean corpuscular hemoglobin and mean corpuscular volume in FA inversely correlated with the GAA1-repeat length, indicating iron deficiency and restricted availability for erythropoiesis with increasing genetic severity. R2*-relaxometry revealed a reduction of splenic and hepatic iron stores in FA. Liver and spleen R2* values inversely correlated with the GAA1-repeat length. FA PBMCs displayed downregulation of ferritin and upregulation of transferrin receptor and divalent metal transporter-1 mRNA, particularly in patients with >500 GAA1-repeats. In FA PBMCs, intracellular iron was not increased, but shifted toward mitochondria. CONCLUSIONS: We provide evidence for a previously unrecognized iron starvation signature at systemic and cellular levels in FA patients, which is related to the underlying genetic severity. These findings challenge the use of systemic iron lowering therapies in FA. © 2024 The Authors. Movement Disorders published by Wiley Periodicals LLC on behalf of International Parkinson and Movement Disorder Society.
Assuntos
Ataxia de Friedreich , Ferro , Humanos , Ataxia de Friedreich/genética , Ataxia de Friedreich/sangue , Ataxia de Friedreich/metabolismo , Feminino , Masculino , Adulto , Ferro/metabolismo , Fígado/metabolismo , Fígado/patologia , Pessoa de Meia-Idade , Imageamento por Ressonância Magnética , Adulto Jovem , Baço/metabolismo , Leucócitos Mononucleares/metabolismo , Proteínas de Transporte de Cátions/genética , Proteínas de Transporte de Cátions/metabolismo , Ferritinas/sangue , Ferritinas/metabolismo , Hepcidinas/genética , Hepcidinas/sangue , Hepcidinas/metabolismo , Pâncreas/metabolismo , Pâncreas/patologiaRESUMO
BACKGROUND: Iron deficiency (ID) is a frequent comorbidity in patients with acute (AHF) and chronic heart failure (CHF) associated with morbidity and death. We aimed to better characterize iron homeostasis in patients with heart failure applying different biomarkers and to evaluate the accuracy of current ID definition by the European Society of Cardiology/American College of Cardiology/American Heart Association to indicate tissue iron availability and demand. METHODS AND RESULTS: We performed a retrospective cohort study investigating 277 patients with AHF and 476 patients with CHF between February 2021 and May 2022. Patients with AHF had more advanced ID than patients with CHF, reflected by increased soluble transferrin receptor and soluble transferrin receptor-ferritin index, and lower ferritin, serum iron, transferrin saturation, hepcidin, and reticulocyte hemoglobin. Decreased iron availability or increased tissue iron demand, reflected by increased soluble transferrin receptor-ferritin index and decreased reticulocyte hemoglobin, was found in 84.1% (AHF) and 28.0% (CHF) with absolute ID and in 50.0% (AHF) and 10.5% (CHF) with combined ID according to the current European Society of Cardiology/American College of Cardiology/American Heart Association-based ID definition. Low hepcidin expression as an indicator of systemic ID was found in 91.1% (AHF) and 80.4% (CHF) of patients with absolute ID and in 32.3% (AHF) and 18.8% (CHF) of patients with combined ID. ID definitions with higher specificity reduce the need for iron supplementation by 25.5% in patients with AHF and by 65.6% in patients with CHF. CONCLUSIONS: Our results suggest that the current European Society of Cardiology/American College of Cardiology/American Heart Association-based ID definition might overestimate true ID, particularly in CHF. More stringent thresholds for ID could more accurately identify patients with heart failure with reduced tissue iron availability who benefit from intravenous iron supplementation.
Assuntos
Biomarcadores , Insuficiência Cardíaca , Ferro , Humanos , Insuficiência Cardíaca/epidemiologia , Insuficiência Cardíaca/sangue , Insuficiência Cardíaca/metabolismo , Insuficiência Cardíaca/diagnóstico , Feminino , Masculino , Estudos Retrospectivos , Idoso , Ferro/metabolismo , Ferro/sangue , Biomarcadores/sangue , Ferritinas/sangue , Doença Crônica , Pessoa de Meia-Idade , Receptores da Transferrina/sangue , Anemia Ferropriva/sangue , Anemia Ferropriva/epidemiologia , Anemia Ferropriva/diagnóstico , Doença Aguda , Hepcidinas/sangue , Hepcidinas/metabolismo , Idoso de 80 Anos ou mais , Deficiências de FerroRESUMO
The anemia of inflammation (AI) is characterized by the presence of inflammation and abnormal elevation of hepcidin. Accumulating evidence has proved that Rocaglamide (RocA) was involved in inflammation regulation. Nevertheless, the role of RocA in AI, especially in iron metabolism, has not been investigated, and its underlying mechanism remains elusive. Here, we demonstrated that RocA dramatically suppressed the elevation of hepcidin and ferritin in LPS-treated mice cell line RAW264.7 and peritoneal macrophages. In vivo study showed that RocA can restrain the depletion of serum iron (SI) and transferrin (Tf) saturation caused by LPS. Further investigation showed that RocA suppressed the upregulation of hepcidin mRNA and downregulation of Fpn1 protein expression in the spleen and liver of LPS-treated mice. Mechanistically, this effect was attributed to RocA's ability to inhibit the IL-6/STAT3 pathway, resulting in the suppression of hepcidin mRNA and subsequent increase in Fpn1 and TfR1 expression in LPS-treated macrophages. Moreover, RocA inhibited the elevation of the cellular labile iron pool (LIP) and reactive oxygen species (ROS) induced by LPS in RAW264.7 cells. These findings reveal a pivotal mechanism underlying the roles of RocA in modulating iron homeostasis and also provide a candidate natural product on alleviating AI.