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1.
Med Sci Monit ; 26: e926178, 2020 Sep 26.
Artigo em Inglês | MEDLINE | ID: mdl-32978363

RESUMO

BACKGROUND The aim of this study was to assess the diagnostic utility of iron homeostasis determinations for prediction of severity of COVID-19. MATERIAL AND METHODS This was a retrospective study enrolling a total of 50 patients diagnosed with the novel coronavirus disease-19 (COVID-19) from February 27, 2020 to March 30, 2020, including a severe group (12 patients) and a mild group (38 patients). For the control group, 50 healthy people were examined during the same period. We compared clinical laboratory data and iron homeostasis biomarkers among the 3 groups. ROC curve analysis was used to assess diagnoses. RESULTS Patients diagnosed with severe COVID-19 had higher hepcidin and serum ferritin levels than in other groups (p<0.001). A combination test of hepcidin and serum ferritin provided the best specificity and sensitivity in the prognosis of COVID-19 severity. Logistic regression analysis showed hepcidin and serum ferritin independently contributed to the severity of COVID-19. Hepcidin and serum ferritin tandem testing predicted COVID-19 severity with 94.6% specificity, while hepcidin and serum ferritin parallel testing had a sensitivity of 95.7%. CONCLUSIONS Iron homeostasis had a robust association with the occurrence of severe COVID-19. Iron homeostasis determinations were specific and sensitive for the early prediction of disease severity in COVID-19 patients and thus have clinical utility.


Assuntos
Betacoronavirus , Infecções por Coronavirus/sangue , Ferritinas/sangue , Hepcidinas/sangue , Pandemias , Pneumonia Viral/sangue , Adulto , Idoso , Área Sob a Curva , Biomarcadores , Feminino , Homeostase , Humanos , Ferro/metabolismo , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Prognóstico , Curva ROC , Estudos Retrospectivos , Sensibilidade e Especificidade
2.
PLoS One ; 15(8): e0237104, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32750083

RESUMO

BACKGROUND: Vitamins and minerals are routinely administered by total parenteral nutrition (TPN). However, in Japan, adjustments in iron dosage are difficult because blended mineral preparations are often used. It is therefore unclear whether the iron content is appropriate in cases of long-term TPN. The aim of the study was to assess the influence of iron administration by long-term TPN on iron deposition in post-mortem liver samples isolated from older deceased patients. METHODS: Liver tissues were collected from post-mortem autopsies of 187 patients over a period of 15 years. Samples were stained with Prussian blue and histologically evaluated from Grade 0-V by at least three different observers. Specimens with positive and negative iron staining were compared, and positive samples were grouped according to the level and distribution of the staining. Post-mortem blood obtained from the subclavian vein during autopsy was also analysed. Samples were collected for the measurement of unsaturated serum iron, serum iron, albumin, prealbumin, hepcidin, and IL-6 concentrations. RESULTS: Iron accumulation in the liver was significantly higher in male patients (p = 0.005) with a history of surgery (p = 0.044) or central vein administration of iron (p<0.001). Additionally, the duration of TPN in the iron-positive group was significantly longer than in the iron-negative group (p = 0.038). Serum analysis revealed that unsaturated serum iron was significantly higher in the iron-negative group and that ferritin and serum iron were significantly higher in the iron-positive group. No other statistically significant differences were observed between the two groups. CONCLUSIONS: Chronic intravenous administration of iron was associated with iron deposition in the liver, even when given the minimum recommended dosage. In long-term TPN patients, the iron dose should therefore be carefully considered.


Assuntos
Ferro/administração & dosagem , Fígado/metabolismo , Idoso , Idoso de 80 Anos ou mais , Autopsia , Feminino , Humanos , Infusões Intravenosas , Ferro/sangue , Ferro/metabolismo , Fígado/patologia , Masculino , Nutrição Parenteral
3.
PLoS One ; 15(8): e0235551, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32833964

RESUMO

VPS34 is a key regulator of endomembrane dynamics and cargo trafficking, and is essential in cultured cell lines and in mice. To better characterize the role of VPS34 in cell growth, we performed unbiased cell line profiling studies with the selective VPS34 inhibitor PIK-III and identified RKO as a VPS34-dependent cellular model. Pooled CRISPR screen in the presence of PIK-III revealed endolysosomal genes as genetic suppressors. Dissecting VPS34-dependent alterations with transcriptional profiling, we found the induction of hypoxia response and cholesterol biosynthesis as key signatures. Mechanistically, acute VPS34 inhibition enhanced lysosomal degradation of transferrin and low-density lipoprotein receptors leading to impaired iron and cholesterol uptake. Excess soluble iron, but not cholesterol, was sufficient to partially rescue the effects of VPS34 inhibition on mitochondrial respiration and cell growth, indicating that iron limitation is the primary driver of VPS34-dependency in RKO cells. Loss of RAB7A, an endolysosomal marker and top suppressor in our genetic screen, blocked transferrin receptor degradation, restored iron homeostasis and reversed the growth defect as well as metabolic alterations due to VPS34 inhibition. Altogether, our findings suggest that impaired iron mobilization via the VPS34-RAB7A axis drive VPS34-dependence in certain cancer cells.


Assuntos
Classe III de Fosfatidilinositol 3-Quinases/metabolismo , Ferro/metabolismo , Neoplasias/metabolismo , Hipóxia Celular , Linhagem Celular Tumoral , Proliferação de Células , Colesterol/biossíntese , Colesterol/genética , Classe III de Fosfatidilinositol 3-Quinases/genética , Endossomos/metabolismo , Células HEK293 , Humanos , Lisossomos/metabolismo , Receptores de LDL/metabolismo , Transferrina/metabolismo , Proteínas rab de Ligação ao GTP/genética , Proteínas rab de Ligação ao GTP/metabolismo
5.
Nature ; 585(7823): 113-118, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32814895

RESUMO

Cancer cells, including melanoma cells, often metastasize regionally through the lymphatic system before metastasizing systemically through the blood1-4; however, the reason for this is unclear. Here we show that melanoma cells in lymph experience less oxidative stress and form more metastases than melanoma cells in blood. Immunocompromised mice with melanomas derived from patients, and immunocompetent mice with mouse melanomas, had more melanoma cells per microlitre in tumour-draining lymph than in tumour-draining blood. Cells that metastasized through blood, but not those that metastasized through lymph, became dependent on the ferroptosis inhibitor GPX4. Cells that were pretreated with chemical ferroptosis inhibitors formed more metastases than untreated cells after intravenous, but not intralymphatic, injection. We observed multiple differences between lymph fluid and blood plasma that may contribute to decreased oxidative stress and ferroptosis in lymph, including higher levels of glutathione and oleic acid and less free iron in lymph. Oleic acid protected melanoma cells from ferroptosis in an Acsl3-dependent manner and increased their capacity to form metastatic tumours. Melanoma cells from lymph nodes were more resistant to ferroptosis and formed more metastases after intravenous injection than did melanoma cells from subcutaneous tumours. Exposure to the lymphatic environment thus protects melanoma cells from ferroptosis and increases their ability to survive during subsequent metastasis through the blood.


Assuntos
Ferroptose , Linfa/metabolismo , Melanoma/patologia , Metástase Neoplásica/patologia , Animais , Sobrevivência Celular , Coenzima A Ligases/metabolismo , Feminino , Ferroptose/efeitos dos fármacos , Glutationa/metabolismo , Humanos , Ferro/metabolismo , Masculino , Melanoma/sangue , Melanoma/metabolismo , Camundongos , Metástase Neoplásica/tratamento farmacológico , Ácido Oleico/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Fosfolipídeo Hidroperóxido Glutationa Peroxidase/metabolismo , Análise de Componente Principal
6.
PLoS One ; 15(8): e0231514, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32785261

RESUMO

Iron Overload Disorder (IOD) is a syndrome developed by captive browsing rhinoceroses like black rhinoceroses (Diceros bicornis), in which hemosiderosis develops in vital organs while free iron accumulates in the body, potentially predisposing to various secondary diseases. Captive grazing species like white rhinoceroses (Ceratotherium simum) do not seem to be affected. The authors hypothesized that inflammation and oxidative stress may be implicated in the pathogenesis of IOD in captive black rhinoceroses, making this syndrome a potential common denominator to various diseases described in captivity in this species. In this prospective study, 15 black (BR) and 29 white rhinoceroses (WR) originating from 22 European zoos were blood-sampled and compared for their iron status (serum iron), liver/muscle biochemical parameters (AST, GGT, cholesterol), inflammatory status (total proteins, protein electrophoresis) and oxidative stress markers (SOD, GPX, dROMs). Results showed higher serum iron and liver enzyme levels in black rhinoceroses (P < 0.01), as well as higher dROMs (P < 0.01) and a trend for higher GPX (P = 0.06) levels. The albumin/globulin ratio was lower in black rhinoceroses (P < 0.05) due to higher α2-globulin levels (P < 0.001). The present study suggests a higher inflammatory and oxidative profile in captive BR than in WR, possibly in relation to iron status. This could be either a consequence or a cause of iron accumulation. Further investigations are needed to assess the prognostic value of the inflammatory and oxidative markers in captive black rhinoceroses, particularly for evaluating the impact of reduced-iron and antioxidant-supplemented diets.


Assuntos
Sobrecarga de Ferro/imunologia , Sobrecarga de Ferro/metabolismo , Perissodáctilos/metabolismo , Animais , Animais de Zoológico/metabolismo , Suscetibilidade a Doenças/metabolismo , Feminino , Inflamação/metabolismo , Ferro/metabolismo , Fígado/metabolismo , Masculino , Estresse Oxidativo/fisiologia , Estudos Prospectivos
7.
Eur J Epidemiol ; 35(8): 763-773, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32816244

RESUMO

Iron metabolism and anemia may play an important role in multiple organ dysfunction syndrome in Coronavirus disease 2019 (COVID-19). We conducted a systematic review and meta-analysis to evaluate biomarkers of anemia and iron metabolism (hemoglobin, ferritin, transferrin, soluble transferrin receptor, hepcidin, haptoglobin, unsaturated iron-binding capacity, erythropoietin, free erythrocyte protoporphyrine, and erythrocyte indices) in patients diagnosed with COVID-19, and explored their prognostic value. Six bibliographic databases were searched up to August 3rd 2020. We included 189 unique studies, with data from 57,563 COVID-19 patients. Pooled mean hemoglobin and ferritin levels in COVID-19 patients across all ages were 129.7 g/L (95% Confidence Interval (CI), 128.51; 130.88) and 777.33 ng/mL (95% CI, 701.33; 852.77), respectively. Hemoglobin levels were lower with older age, higher percentage of subjects with diabetes, hypertension and overall comorbidities, and admitted to intensive care. Ferritin level increased with older age, increasing proportion of hypertensive study participants, and increasing proportion of mortality. Compared to moderate cases, severe COVID-19 cases had lower hemoglobin [weighted mean difference (WMD), - 4.08 g/L (95% CI - 5.12; - 3.05)] and red blood cell count [WMD, - 0.16 × 1012 /L (95% CI - 0.31; - 0.014)], and higher ferritin [WMD, - 473.25 ng/mL (95% CI 382.52; 563.98)] and red cell distribution width [WMD, 1.82% (95% CI 0.10; 3.55)]. A significant difference in mean ferritin levels of 606.37 ng/mL (95% CI 461.86; 750.88) was found between survivors and non-survivors, but not in hemoglobin levels. Future studies should explore the impact of iron metabolism and anemia in the pathophysiology, prognosis, and treatment of COVID-19.


Assuntos
Anemia/diagnóstico , Infecções por Coronavirus , Coronavirus/metabolismo , Ferro/metabolismo , Pandemias , Pneumonia Viral , Betacoronavirus , Biomarcadores/análise , Biomarcadores/sangue , Técnicas de Laboratório Clínico , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/epidemiologia , Eritropoetina , Ferritinas/sangue , Hemoglobinas/análise , Hemoglobinas/metabolismo , Hepcidinas/sangue , Hepcidinas/metabolismo , Humanos , Ferro/sangue , Pneumonia Viral/epidemiologia , Receptores da Transferrina/sangue , Transferrina/análise , Transferrina/metabolismo
8.
Chem Biol Interact ; 329: 109217, 2020 Sep 25.
Artigo em Inglês | MEDLINE | ID: mdl-32750324

RESUMO

Developing brain is very sensitive to the influence of environmental factors during gestation and the neonatal period. The aim of the study is to assess cobalt and iron accumulation in the brain as well as changes in the expression of iron-regulatory proteins transferrin receptor 1, hepcidin, and ferroportin in suckling mice. Perinatal exposure to cobalt chloride increased significantly cobalt content in brain tissue homogenates of 18-day-old (d18) and 25-day-old (d25) mice inducing alterations in brain iron homeostasis. Higher degree of transferrin receptor 1 expression was demonstrated in cobalt chloride-exposed mice with no substantial changes between d18 and d25 mice. A weak ferroportin expression was found in 18-day-old control and cobalt-treated mouse brain. Cobalt exposure of d25 mice resulted in increased ferroportin expression in brain compared to the untreated age-matched control group. Hepcidin level in cobalt-exposed groups was decreased in d18 mice and slightly increased in d25 mice. The obtained data contribute for the better understanding of metal toxicity impact on iron homeostasis in the developing brain with further possible implications in neurodegeneration.


Assuntos
Encéfalo/metabolismo , Cobalto/farmacologia , Regulação da Expressão Gênica no Desenvolvimento/efeitos dos fármacos , Proteínas Reguladoras do Ferro/metabolismo , Animais , Peso Corporal/efeitos dos fármacos , Encéfalo/efeitos dos fármacos , Encéfalo/crescimento & desenvolvimento , Proteínas de Transporte de Cátions/genética , Proteínas de Transporte de Cátions/metabolismo , Cobalto/metabolismo , Feminino , Hepcidinas/genética , Hepcidinas/metabolismo , Ferro/metabolismo , Proteínas Reguladoras do Ferro/genética , Camundongos , Camundongos Endogâmicos ICR , Gravidez , Efeitos Tardios da Exposição Pré-Natal , Receptores da Transferrina/genética , Receptores da Transferrina/metabolismo
9.
Exp Parasitol ; 217: 107962, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32763249

RESUMO

Trypanosoma cruzi is a parasitic protozoan that infects various species of domestic and wild animals, triatomine bugs and humans. It is the etiological agent of American trypanosomiasis, also known as Chagas Disease, which affects about 17 million people in Latin America and is emerging elsewhere in the world. Iron (Fe) is a crucial micronutrient for almost all cells, acting as a cofactor for several metabolic enzymes. T. cruzi has a high requirement for Fe, using heminic and non-heminic Fe for growth and differentiation. Fe occurs in the oxidized (Fe3+) form in aerobic environments and needs to be reduced to Fe2+ before it enters cells. Fe-reductase, located in the plasma membranes of some organisms, catalyzes the Fe3+⇒ Fe2+ conversion. In the present study we found an amino acid sequence in silico that allowed us to identify a novel 35 kDa protein in T. cruzi with two transmembrane domains in the C-terminal region containing His residues that are conserved in the Ferric Reductase Domain Superfamily and are required for catalyzing Fe3+ reduction. Accordingly, we named this protein TcFR. Intact epimastigotes from the T. cruzi DM28c strain reduced the artificial Fe3+-containing substrate potassium ferricyanide in a cell density-dependent manner, following Michaelis-Menten kinetics. The TcFR activity was more than eightfold higher in a plasma membrane-enriched fraction than in whole homogenates, and this increase was consistent with the intensity of the 35 kDa band on Western blotting images obtained using anti-NOX5 raised against the human antigen. Immunofluorescence experiments demonstrated TcFR on the parasite surface. That TcFR is part of a catalytic complex allowing T. cruzi to take up Fe from the medium was confirmed by experiments in which DM28c was assayed after culturing in Fe-depleted medium: (i) proliferation during the stationary growth phase was five times slower; (ii) the relative expression of TcFR (qPCR) was 50% greater; (iii) intact cells had 120% higher Fe-reductase activity. This ensemble of results indicates that TcFR is a conserved enzyme in T. cruzi, and its catalytic properties are modulated in order to respond to external Fe fluctuations.


Assuntos
FMN Redutase/metabolismo , Ferro/metabolismo , Trypanosoma cruzi/enzimologia , Sequência de Aminoácidos , Animais , Western Blotting , Membrana Celular/enzimologia , Doença de Chagas/parasitologia , Colorimetria , FMN Redutase/análise , FMN Redutase/química , Imunofluorescência , Humanos , Filogenia , Distribuição de Poisson , Reação em Cadeia da Polimerase em Tempo Real , Alinhamento de Sequência , Trypanosoma cruzi/classificação , Trypanosoma cruzi/crescimento & desenvolvimento , Trypanosoma cruzi/metabolismo , Regulação para Cima
10.
Science ; 369(6501): 276-282, 2020 07 17.
Artigo em Inglês | MEDLINE | ID: mdl-32675368

RESUMO

The tumor microenvironment plays a critical regulatory role in cancer progression, especially in central nervous system metastases. Cancer cells within the cerebrospinal fluid (CSF)-filled leptomeninges face substantial microenvironmental challenges, including inflammation and sparse micronutrients. To investigate the mechanism by which cancer cells in these leptomeningeal metastases (LM) overcome these constraints, we subjected CSF from five patients with LM to single-cell RNA sequencing. We found that cancer cells, but not macrophages, within the CSF express the iron-binding protein lipocalin-2 (LCN2) and its receptor SCL22A17. These macrophages generate inflammatory cytokines that induce cancer cell LCN2 expression but do not generate LCN2 themselves. In mouse models of LM, cancer cell growth is supported by the LCN2/SLC22A17 system and is inhibited by iron chelation therapy. Thus, cancer cells appear to survive in the CSF by outcompeting macrophages for iron.


Assuntos
Ferro/metabolismo , Lipocalina-2/líquido cefalorraquidiano , Neoplasias Meníngeas , Animais , Humanos , Macrófagos/metabolismo , Neoplasias Meníngeas/metabolismo , Neoplasias Meníngeas/patologia , Neoplasias Meníngeas/secundário , Camundongos , Microambiente Tumoral
11.
Metabolism ; 110: 154306, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32621820

RESUMO

BACKGROUND: Iron is finely regulated due to its vital roles in organisms and the peroxidase reactivity if excess. Solute Carrier Family 46 Member 1 (SLC46A1), also named PCFT or HCP1, is the main importer of heme­iron in the intestine, but has a high abundance in the liver. Since the liver has a central role in iron homeostasis, whether SLC46A1 regulates hepatic iron metabolism is of interest to be identified. METHODS: The recombinant adeno-associated virus vectors were used to hepatic-specifically inhibit SLC46A1 expression to observe its effects on hepatic iron metabolism. Then the abilities of SLC46A1 in importing heme and folate, and consequent alterations of iron content in hepatocytes were determined. Furthermore, effects of iron on SLC46A1 expression were investigated both in vitro and in vivo. RESULTS: The hepatocyte-specific inhibition of SLC46A1 decreases iron content in the liver and increases iron content in serum. Expressions of iron-related molecules, transferrin receptor 1, hepcidin and ferroportin, are correspondingly altered. Interestingly, free heme concentration in serum is increased, indicating a decreased import of heme by the liver. In hepatocytes, SLC46A1 is capable of importing hemin, increasing intracellular iron content. The import of hemin by SLC46A1 is unaffected by its other substrate, folate. Instead, hemin treatment decreases SLC46A1 expression, reducing the import of folate. In addition, SLC46A1 itself shows to be iron-responsive both in vivo and in vitro, making it available for regulating iron metabolism. CONCLUSION: The results elucidate that SLC46A1 regulates iron metabolism in the liver through a folate-independent manner of importing heme. The iron-responsive characters of SLC46A1 give us a new clue to link heme or iron overload with folate deficiency diseases.


Assuntos
Heme/metabolismo , Ferro/metabolismo , Fígado/metabolismo , Transportador de Folato Acoplado a Próton/fisiologia , Animais , Células Cultivadas , Hemina/metabolismo , Hepatócitos/metabolismo , Humanos , Camundongos , Camundongos Endogâmicos C57BL , Transportador de Folato Acoplado a Próton/antagonistas & inibidores
12.
Zhejiang Da Xue Xue Bao Yi Xue Ban ; 49(1): 58-70, 2020 May 25.
Artigo em Chinês | MEDLINE | ID: mdl-32621410

RESUMO

Iron homeostasis plays an important role for the maintenance of human health. It is known that iron metabolism is tightly regulated by several key genes, including divalent metal transport-1(DMT1), transferrin receptor 1(TFR1), transferrin receptor 2(TFR2), ferroportin(FPN), hepcidin(HAMP), hemojuvelin(HJV) and Ferritin H. Recently, it is reported that DNA methylation, histone acetylation, and microRNA (miRNA) epigenetically regulated iron homeostasis. Among these epigenetic regulators, DNA hypermethylation of the promoter region of FPN, TFR2, HAMP, HJV and bone morphogenetic protein 6 (BMP6) genes result in inhibitory effect on the expression of these iron-related gene. In addition, histone deacetylase (HADC) suppresses HAMP gene expression. On the contrary, HADC inhibitor upregulates HAMP gene expression. Additional reports showed that miRNA can also modulate iron absorption, transport, storage and utilization via downregulation of DMT1, FPN, TFR1, TFR2, Ferritin H and other genes. It is noteworthy that some key epigenetic regulatory enzymes, such as DNA demethylase TET2 and histone lysine demethylase JmjC KDMs, require iron for the enzymatic activities. In this review, we summarize the recent progress of DNA methylation, histone acetylation and miRNA in regulating iron metabolism and also discuss the future research directions.


Assuntos
Epigênese Genética , Homeostase , Ferro , Regulação da Expressão Gênica/genética , Humanos , Ferro/metabolismo , Receptores da Transferrina
13.
Zhejiang Da Xue Xue Bao Yi Xue Ban ; 49(1): 44-57, 2020 May 25.
Artigo em Chinês | MEDLINE | ID: mdl-32621416

RESUMO

Recently, ferroptosis, an iron-dependent novel type of cell death, has been characterized as an excessive accumulation of lipid peroxides and reactive oxygen species. Emerging studies demonstrate that ferroptosis not only plays an important role in the pathogenesis and progression of chronic diseases, but also functions differently in the different disease context. Notably, it is shown that activation of ferroptosis could potently inhibit tumor growth and increase sensitivity to chemotherapy and immunotherapy in various cancer settings. As a result, the development of more efficacious ferroptosis agonists remains the mainstay of ferroptosis-targeting strategy for cancer therapeutics. By contrast, in non-cancerous chronic diseases, including cardiovascular & cerebrovascular diseases and neurodegenerative diseases, ferroptosis functions as a risk factor to promote these diseases progression through triggering or accelerating tissue injury. As a matter of fact, blocking ferroptosis has been demonstrated to effectively prevent ischemia-reperfusion heart disease in preclinical animal models. Therefore, it is a promising field to develope potent ferroptosis inhibitors for preventing and treating cardiovascular & cerebrovascular diseases and neurodegenerative diseases. In this article, we summarize the most recent progress on ferroptosis in chronic diseases, and draw attention to the possible clinical impact of this recently emerged ferroptosis modalities.


Assuntos
Doença Crônica , Ferroptose , Ferro , Animais , Ferroptose/fisiologia , Ferro/metabolismo , Espécies Reativas de Oxigênio
14.
Br J Radiol ; 93(1113): 20200552, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32614611

RESUMO

OBJECTIVE: T2 blackout (TBO) effect, which is a common finding in the brains of multiple sclerosis (MS) patients and older population that are imaged for other reasons on diffusion weighted imagings (DWI) and apparent diffusion coefficient (ADC) map show the existence of paramagnetic materials in the tissue. Because iron is known to accumulate in especially deep gray matter (DGM) structures in MS brains, we aimed to investigate the relationship between TBO and clinico-radiological parameters that may be iron-related in MS. METHODS: We retrospectively reviewed the latest MR images of MS patients on 3 Tesla MR scanner between 2018 and 2019. TBO existence and severity on DWI-ADC was assessed by two radiologists and its correlation with several outcomes of MS was investigated. RESULTS: No significant relationship was found between TBO and gender, subtype of MS whereas TBO was positively correlated with parameters such as black-hole lesions, cortical atrophy, duration of disease, age and extended disability status scale (EDSS) score. CONCLUSIONS: TBO shows correlation with the conditions which were revealed to be associated with iron accumulation in the brain of MS patients in the literature. Therefore, we concluded that TBO and its severity in DGM may represent iron accumulation in MS brains. ADVANCES IN KNOWLEDGE: TBO effect as a frequent imaging finding in daily practice may be used as predictor of the disease course of MS due to possible effects of iron accumulation in brain and thereby may be useful in modifying treatment strategies.


Assuntos
Encéfalo/diagnóstico por imagem , Encéfalo/metabolismo , Imagem de Difusão por Ressonância Magnética/métodos , Ferro/metabolismo , Esclerose Múltipla/diagnóstico por imagem , Adulto , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla/metabolismo , Variações Dependentes do Observador , Estudos Retrospectivos , Estatísticas não Paramétricas , Adulto Jovem
15.
Toxicol Lett ; 332: 130-139, 2020 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-32645461

RESUMO

Cadmium (Cd) is an environmental contaminant that triggers toxic effects in various tissues such as the kidney, liver, and lung. Cd can also cause abnormal iron metabolism, leading to anemia. Iron homeostasis is regulated by intestinal absorption. However, whether Cd affects the iron absorption pathway is unclear. We aimed to elucidate the relationship between the intestinal iron transporter system and Cd-induced iron deficiency anemia. C57BL/6J female and male mice, 129/Sv female mice, and DBA/2 female mice were given a single oral dose of CdCl2 by gavage. After 3 or 24 h, Cd decreased serum iron concentrations and inhibited the expression of iron transport-related genes in the duodenum. In particular, Cd decreased the levels of divalent metal transporter 1 and ferroportin 1 in the duodenum. In addition, human colon carcinoma Caco-2 cells were treated with CdCl2. After 72 h, Cd decreased the expression of iron transport-related factors in Caco-2 cells with a pattern similar to that seen in the murine duodenum. These findings suggest that Cd inhibits iron absorption through direct suppression of iron transport in duodenal enterocytes and contributes to abnormal iron metabolism.


Assuntos
Anemia Ferropriva/induzido quimicamente , Cádmio/toxicidade , Duodeno/efeitos dos fármacos , Duodeno/metabolismo , Ferro/metabolismo , Animais , Transporte Biológico Ativo/efeitos dos fármacos , Células CACO-2 , Cádmio/farmacocinética , Cloreto de Cádmio/toxicidade , Proteínas de Transporte de Cátions/metabolismo , Feminino , Humanos , Fígado/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos DBA
16.
Life Sci ; 258: 118135, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32712297

RESUMO

In mammals, ferroportin (FPN) is the only known iron exporter, and it functions as a "water tap" in controlling iron absorption from the diet, iron egress from macrophages and other cells. However, its function is implemented not by itself but by a complex with many partners involved. In the current study, we elaborate on the direct partners in calibrating the capability of FPN in exporting iron out of cells, such as ceruloplasmin (CP), hephaestin (HP) and poly(rC)-binding protein 2 (PCBP2). We also recapitulate the current understandings of the regulation of FPN concentration at the post-transcriptional level. Considering the importance of FPN in finetuning iron homeostasis, a few therapeutic options are pursued to target FPN and its partners in treating iron diseases. Nonetheless, limited knowledge has been obtained on direct and indirect partners of FPN, so that more efforts should be invested including their therapeutic values.


Assuntos
Proteínas de Transporte de Cátions/metabolismo , Células/metabolismo , Distúrbios do Metabolismo do Ferro/metabolismo , Ferro/metabolismo , Animais , Humanos , Distúrbios do Metabolismo do Ferro/genética , Ligação Proteica , Transcrição Genética
17.
Proc Natl Acad Sci U S A ; 117(32): 19487-19496, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32723820

RESUMO

Alternative ribosome subunit proteins are prevalent in the genomes of diverse bacterial species, but their functional significance is controversial. Attempts to study microbial ribosomal heterogeneity have mostly relied on comparing wild-type strains with mutants in which subunits have been deleted, but this approach does not allow direct comparison of alternate ribosome isoforms isolated from identical cellular contexts. Here, by simultaneously purifying canonical and alternative RpsR ribosomes from Mycobacterium smegmatis, we show that alternative ribosomes have distinct translational features compared with their canonical counterparts. Both alternative and canonical ribosomes actively take part in protein synthesis, although they translate a subset of genes with differential efficiency as measured by ribosome profiling. We also show that alternative ribosomes have a relative defect in initiation complex formation. Furthermore, a strain of M. smegmatis in which the alternative ribosome protein operon is deleted grows poorly in iron-depleted medium, uncovering a role for alternative ribosomes in iron homeostasis. Our work confirms the distinct and nonredundant contribution of alternative bacterial ribosomes for adaptation to hostile environments.


Assuntos
Proteínas de Bactérias/metabolismo , Mycobacterium smegmatis/metabolismo , Ribossomos/metabolismo , Proteínas de Bactérias/genética , Ferro/metabolismo , Mycobacterium smegmatis/genética , Mycobacterium smegmatis/crescimento & desenvolvimento , Iniciação Traducional da Cadeia Peptídica/genética , Biossíntese de Proteínas , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/metabolismo , Subunidades Ribossômicas/metabolismo
18.
Am J Clin Nutr ; 112(3): 576-585, 2020 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-32614379

RESUMO

BACKGROUND: Maternal iron absorption during pregnancy can be evaluated using RBC incorporation of orally administered stable iron isotope. This approach underestimates true maternal absorption of iron as it does not account for absorbed iron that is transferred to the fetus or retained within the placenta. OBJECTIVE: Our objective was to re-evaluate maternal iron absorption after factoring in these losses and identify factors associated with iron partitioning between the maternal, neonatal, and placental compartments. METHODS: This study utilized data from stable iron isotope studies carried out in 68 women during the third trimester of pregnancy. Iron status indicators and stable iron isotopic enrichment were measured in maternal blood, umbilical cord blood, and placental tissue when available. Factors associated with iron isotope partitioning between the maternal, neonatal, and placental compartments were identified. RESULTS: On average, true maternal absorption of iron increased by 10% (from 19% to 21%) after accounting for absorbed iron present in the newborn (P < 0.001), and further increased by 7%, (from 39% to 42%, P < 0.001) after accounting for iron retained within the placenta. On average, 2% of recovered tracer was present in the placenta and 6% was found in the newborn. Net transfer of iron to the neonate was higher in women with lower total body iron (standardized ß = -0.48, P < 0.01) and lower maternal hepcidin (standardized ß = -0.66, P < 0.01). In women carrying multiple fetuses, neonatal hepcidin explained a significant amount of observed variance in net placental transfer of absorbed iron (R = 0.95, P = 0.03). CONCLUSIONS: Maternal RBC iron incorporation of an orally ingested tracer underestimated true maternal iron absorption. The degree of underestimation was greatest in women with low body iron. Maternal hepcidin was inversely associated with maternal RBC iron utilization, whereas neonatal hepcidin explained variance in net transfer of iron to the neonatal compartment.These trials were registered at clinicaltrials.gov as NCT01019096 and NCT01582802.


Assuntos
Feto/metabolismo , Ferro/farmacocinética , Placenta/metabolismo , Adolescente , Adulto , Transporte Biológico , Feminino , Humanos , Recém-Nascido , Ferro/metabolismo , Isótopos de Ferro , Marcação por Isótopo , Gravidez , Adulto Jovem
19.
PLoS One ; 15(7): e0236405, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32702060

RESUMO

Regulatory small RNAs play an essential role in maintaining cell homeostasis in bacteria in response to environmental stresses such as iron starvation. Prokaryotes generally encode a large number of RNA regulators, yet their identification and characterisation is still in its infancy for most bacterial species. Burkholderia cenocepacia is an opportunistic pathogen with high innate antimicrobial resistance, which can cause the often fatal cepacia syndrome in individuals with cystic fibrosis. In this study we characterise a small RNA which is involved in the response to iron starvation, a condition that pathogenic bacteria are likely to encounter in the host. BrrF is a small RNA highly upregulated in Burkholderia cenocepacia under conditions of iron depletion and with a genome context consistent with Fur regulation. Its computationally predicted targets include iron-containing enzymes of the tricarboxylic acid (TCA) cycle such as aconitase and succinate dehydrogenase, as well as iron-containing enzymes responsible for the oxidative stress response, such as superoxide dismutase and catalase. Phenotypic and gene expression analysis of BrrF deletion and overexpression mutants show that the regulation of these genes is BrrF-dependent. Expression of acnA, fumA, sdhA and sdhC was downregulated during iron depletion in the wild type strain, but not in a BrrF deletion mutant. TCA cycle genes not predicted as target for BrrF were not affected in the same manner by iron depletion. Likewise, expression of sodB and katB was dowregulated during iron depletion in the wild type strain, but not in a BrrF deletion mutant. BrrF overexpression reduced aconitase and superoxide dismutase activities and increased sensitivity to hydrogen peroxide. All phenotypes and gene expression changes of the BrrF deletion mutant could be complemented by overexpressing BrrF in trans. Overall, BrrF acts as a regulator of central metabolism and oxidative stress response, possibly as an iron-sparing measure to maintain iron homeostasis under conditions of iron starvation.


Assuntos
Proteínas de Bactérias/genética , Burkholderia cenocepacia/genética , Ferro/metabolismo , Pequeno RNA não Traduzido/genética , Aconitato Hidratase/metabolismo , Burkholderia cenocepacia/metabolismo , Catalase/genética , Regulação Bacteriana da Expressão Gênica/efeitos dos fármacos , Humanos , Peróxido de Hidrogênio/farmacologia , Ferro/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Superóxido Dismutase/genética
20.
Med Sci (Paris) ; 36(6-7): 616-625, 2020.
Artigo em Francês | MEDLINE | ID: mdl-32614313

RESUMO

Iron has a fundamental role for cell physiology and especially in retina as a cofactor of many pathways of the visual transduction. A tightly regulated homeostasis avoids the accumulation of prooxidant and proinflammatory free iron. A dysfunction of iron retinal homeostasis is associated with many genetic or age-related degenerative diseases such as age-related macular degeneration (AMD). Here, we describe various mechanisms reported during AMD, enhanced by iron accumulation and its homeostasis dysregulation. We have investigated a local treatment with transferrin, the natural iron carrier, to control these pathological pathways and iron dysfunction, without side effects. Iron has a central role in pathogenesis of AMD and is a target for futures therapies.


Assuntos
Ferro/fisiologia , Degeneração Macular/etiologia , Homeostase/genética , Humanos , Ferro/metabolismo , Degeneração Macular/genética , Degeneração Macular/metabolismo , Degeneração Macular/terapia , Redes e Vias Metabólicas/genética , Retina/metabolismo , Retina/patologia , Terapias em Estudo/métodos , Terapias em Estudo/tendências , Transferrina/genética , Transferrina/fisiologia
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