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1.
Arch Insect Biochem Physiol ; 102(1): e21592, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-31276235

RESUMO

Ferritin, which is ubiquitous among all living organisms, plays a crucial role in maintaining iron homeostasis, immune response, and detoxification. In the present research, we identified an iron-binding protein, ferritin heavy chain subunit, from Papilio xuthus and named PxFerHCH. The complete complementary DNA of PxFerHCH was 1,252 bp encoding a sequence of 211 amino acids, which includes an iron-responsive element. Phylogenetic analysis showed that PxFerHCH is clustered with Manduca sexta and Galleria mellonella ferritin heavy chain subunits. Expression levels of PxFerHCH in various tissues were analyzed by reverse transcription quantitative polymerase chain reaction, and the results exhibited that PxFerHCH was expressed in all tissues with the highest expression in the fat body. The relative expression level of PxFerHCH in response to bacterial (Escherichia coli and Staphylococcus aureus) challenges sharply increased by about 12 hr postinfection (hpi) and then decreased at 24 hpi. In addition, the iron-binding capacity and antioxidation activity of recombinant PxFerHCH protein were also investigated. These results reveal that PxFerHCH might play an important role in defense against bacterial infection.


Assuntos
Apoferritinas/metabolismo , Borboletas/metabolismo , Ferro/metabolismo , Sequência de Aminoácidos , Animais , Apoferritinas/genética , Apoferritinas/isolamento & purificação , Sequência de Bases , Borboletas/genética , Borboletas/imunologia , Escherichia coli , Proteínas de Insetos/genética , Proteínas de Insetos/metabolismo , Staphylococcus aureus
2.
Gene ; 710: 399-405, 2019 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-31200088

RESUMO

Iron-responsive elements (IREs) are ~35-nucleotide (nt) stem-loop RNA structures located in 5' or 3' untranslated regions (UTRs) of mRNAs that mediate post-transcriptional regulation by their association with IRE-binding proteins (IRPs). IREs are characterized by their apical 6-nt loop motif 5'-CAGWGH-3' (W = A or U and H = A, C or U), the so-called pseudotriloop, of which the loop nts C1 and G5 are paired, and the none-paired C between the two stem regions. In this study, the yeast three-hybrid (Y3H) system was used to investigate the relevance of the pseudotriloop structure of ferritin light chain (FTL) for the IRE-IRP interaction and the binding affinities between variant IRE(-like) structures and the two IRP isoforms, IRP1 and 2. Destabilization of the pseudotriloop structure by a G5-to-A mutation reduced binding of IRP1 and 2, while restoring the pseudotriloop conformation by the compensatory C1-to-U mutation, restored binding to both IRPs. In particular, IRP1 showed even stronger binding to the C1U-G5A mutant than to the wildtype FTL IRE. On the other hand, deletion of the bulged-out U6 of the pseudotriloop did not significantly affect its binding to either IRP1 or 2, but substitution with C particularly enhanced the binding to IRP1. In comparison to FTL IRE, IRE-like structures of 5'-aminolevulinate synthase 2 (ALAS2) and SLC40A1 (also known as ferroportin-1) showed similar or, in the case of endothelial PAS domain protein 1 (EPAS1) IRE, slightly weaker binding affinity to IRPs. SLC11A2 (a.k.a. divalent metal transporter-1) IRE exhibited relatively weak binding to IRP1 and medium binding to IRP2. Notably, the IRE-like structure of α-synuclein showed no detectable binding to either IRP under the conditions used in this Y3H assay. Our results indicate that Y3H can be used to characterize binding between IRPs and various IRE-like structures in vivo.


Assuntos
Apoferritinas/química , Apoferritinas/genética , Proteína 1 Reguladora do Ferro/metabolismo , Proteína 2 Reguladora do Ferro/metabolismo , 5-Aminolevulinato Sintetase/química , 5-Aminolevulinato Sintetase/genética , 5-Aminolevulinato Sintetase/metabolismo , Animais , Apoferritinas/metabolismo , Fatores de Transcrição Hélice-Alça-Hélice Básicos/química , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Proteínas de Transporte de Cátions/química , Proteínas de Transporte de Cátions/genética , Proteínas de Transporte de Cátions/metabolismo , Proteína 1 Reguladora do Ferro/genética , Proteína 2 Reguladora do Ferro/genética , Mutação , Conformação de Ácido Nucleico , Técnicas do Sistema de Duplo-Híbrido , Regiões não Traduzidas
3.
Int J Mol Sci ; 20(10)2019 May 16.
Artigo em Inglês | MEDLINE | ID: mdl-31100837

RESUMO

Ferritin is a spherical iron storage protein composed of 24 subunits and an iron core. Using biomimetic mineralization, magnetic iron oxide can be synthesized in the cavity of ferritin to form magnetoferritin (MFt). MFt, also known as a superparamagnetic protein, is a novel magnetic nanomaterial with good biocompatibility and flexibility for biomedical applications. Recently, it has been demonstrated that MFt had tumor targetability and a peroxidase-like catalytic activity. Thus, MFt, with its many unique properties, provides a powerful platform for tumor diagnosis and therapy. In this review, we discuss the biomimetic synthesis and biomedical applications of MFt.


Assuntos
Apoferritinas/metabolismo , Apoferritinas/uso terapêutico , Ferro/metabolismo , Ferro/uso terapêutico , Óxidos/metabolismo , Óxidos/uso terapêutico , Animais , Fenômenos Biomecânicos , Meios de Contraste , Sistemas de Liberação de Medicamentos , Compostos Férricos , Ferritinas , Humanos , Imagem por Ressonância Magnética , Nanopartículas de Magnetita , Neoplasias/diagnóstico por imagem , Neoplasias/tratamento farmacológico , Neoplasias/patologia
4.
Proc Natl Acad Sci U S A ; 116(12): 5681-5686, 2019 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-30833408

RESUMO

Malaria, the disease caused by Plasmodium spp. infection, remains a major global cause of morbidity and mortality. Host protection from malaria relies on immune-driven resistance mechanisms that kill Plasmodium However, these mechanisms are not sufficient per se to avoid the development of severe forms of disease. This is accomplished instead via the establishment of disease tolerance to malaria, a defense strategy that does not target Plasmodium directly. Here we demonstrate that the establishment of disease tolerance to malaria relies on a tissue damage-control mechanism that operates specifically in renal proximal tubule epithelial cells (RPTEC). This protective response relies on the induction of heme oxygenase-1 (HMOX1; HO-1) and ferritin H chain (FTH) via a mechanism that involves the transcription-factor nuclear-factor E2-related factor-2 (NRF2). As it accumulates in plasma and urine during the blood stage of Plasmodium infection, labile heme is detoxified in RPTEC by HO-1 and FTH, preventing the development of acute kidney injury, a clinical hallmark of severe malaria.


Assuntos
Heme/metabolismo , Rim/metabolismo , Malária/fisiopatologia , Animais , Apoferritinas/metabolismo , Linhagem Celular , Progressão da Doença , Células Epiteliais/metabolismo , Ferritinas/metabolismo , Ferritinas/fisiologia , Heme Oxigenase-1/metabolismo , Heme Oxigenase-1/fisiologia , Humanos , Tolerância Imunológica/fisiologia , Camundongos , Camundongos Endogâmicos C57BL , Fator 2 Relacionado a NF-E2/metabolismo , Fator 2 Relacionado a NF-E2/fisiologia , Plasmodium berghei/metabolismo , Plasmodium berghei/parasitologia , Regulação para Cima
5.
Fertil Steril ; 111(6): 1226-1235.e1, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30922653

RESUMO

OBJECTIVE: To identify the genetic cause of a pedigree with four patients with 46,XY pure gonadal dysgenesis (PGD). DESIGN: Genetic mutation study. SETTING: Academic medical center. PATIENT(S): Four first cousins, from three households of a Chinese pedigree, affected by 46,XY PGD. INTERVENTION(S): None. MAIN OUTCOME MEASURE(S): The patients were studied from clinical and genetic perspectives. Whole-genome sequencing was conducted in family members. RESULT(S): Four first cousins in the third generation were affected by 46,XY PGD. A specific familial characteristic was the prevalence of as high as 100% of gonadal tumors in patients. Whole-genome sequencing identified a new ferritin heavy chain-like 17 (FTHL17) mutation, c.GA442_443TT (p.E148L), which has the potential to interfere with protein function and cause 46,XY PGD. Moreover, the location (Xp21.2) of the FTHL17 gene proves that the family is X-linked recessive. In vitro functional study revealed that the perturbation of FTHL17 caused the decrease of protein expression and cell proliferation. CONCLUSION(S): We describe the first 46,XY PGD pedigree that may be attributed to mutations of the FTHL17 gene. We speculated that the FTHL17 gene is involved in the testis-determining pathway and tumorigenesis.


Assuntos
Apoferritinas/genética , Disgenesia Gonadal 46 XY/genética , Mutação , Neoplasias de Tecido Gonadal/genética , Adolescente , Adulto , Apoferritinas/metabolismo , Proliferação de Células , Análise Mutacional de DNA , Feminino , Predisposição Genética para Doença , Disgenesia Gonadal 46 XY/diagnóstico , Disgenesia Gonadal 46 XY/metabolismo , Disgenesia Gonadal 46 XY/cirurgia , Células HEK293 , Hereditariedade , Humanos , Neoplasias de Tecido Gonadal/diagnóstico , Neoplasias de Tecido Gonadal/metabolismo , Neoplasias de Tecido Gonadal/cirurgia , Linhagem , Fenótipo
6.
Nat Commun ; 10(1): 1121, 2019 03 08.
Artigo em Inglês | MEDLINE | ID: mdl-30850661

RESUMO

Human transferrin receptor 1 (CD71) guarantees iron supply by endocytosis upon binding of iron-loaded transferrin and ferritin. Arenaviruses and the malaria parasite exploit CD71 for cell invasion and epitopes on CD71 for interaction with transferrin and pathogenic hosts were identified. Here, we provide the molecular basis of the CD71 ectodomain-human ferritin interaction by determining the 3.9 Å resolution single-particle cryo-electron microscopy structure of their complex and by validating our structural findings in a cellular context. The contact surfaces between the heavy-chain ferritin and CD71 largely overlap with arenaviruses and Plasmodium vivax binding regions in the apical part of the receptor ectodomain. Our data account for transferrin-independent binding of ferritin to CD71 and suggest that select pathogens may have adapted to enter cells by mimicking the ferritin access gate.


Assuntos
Antígenos CD/química , Apoferritinas/química , Proteínas de Protozoários/química , Receptores da Transferrina/química , Receptores Virais/química , Transferrina/química , Proteínas do Envelope Viral/química , Antígenos CD/genética , Antígenos CD/metabolismo , Apoferritinas/genética , Apoferritinas/metabolismo , Arenavirus do Novo Mundo/genética , Arenavirus do Novo Mundo/metabolismo , Sítios de Ligação , Clonagem Molecular , Microscopia Crioeletrônica , Escherichia coli/genética , Escherichia coli/metabolismo , Expressão Gênica , Vetores Genéticos/química , Vetores Genéticos/metabolismo , Células HeLa , Proteína da Hemocromatose/química , Proteína da Hemocromatose/genética , Proteína da Hemocromatose/metabolismo , Humanos , Plasmodium vivax/genética , Plasmodium vivax/metabolismo , Ligação Proteica , Conformação Proteica em alfa-Hélice , Conformação Proteica em Folha beta , Domínios e Motivos de Interação entre Proteínas , Proteínas de Protozoários/genética , Proteínas de Protozoários/metabolismo , Receptores da Transferrina/genética , Receptores da Transferrina/metabolismo , Receptores Virais/genética , Receptores Virais/metabolismo , Proteínas Recombinantes/química , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Especificidade por Substrato , Transferrina/genética , Transferrina/metabolismo , Proteínas do Envelope Viral/genética , Proteínas do Envelope Viral/metabolismo
7.
Biometals ; 32(2): 251-264, 2019 04.
Artigo em Inglês | MEDLINE | ID: mdl-30756217

RESUMO

Rimicaris exoculata (Decapoda: Bresiliidae) is one of the dominant species among hydrothermal vent communities along the Mid-Atlantic Ridge. This shrimp can tolerate high concentrations of heavy metals such as iron, but the mechanisms used for detoxification and utilization of excess metals remain largely unknown. Ferritin is a major iron storage protein in most living organisms. The central heavy subunit of ferritin (H-ferritin) possesses ferroxidase activity and converts iron from Fe2+ to Fe3+, the non-toxic form used for storage. In the present study, the H-ferritin RexFrtH was identified in the hydrothermal vent shrimp R. exoculata, and found to be highly expressed in the gill, the main organ involved in bioaccumulation of metals, at both RNA and protein levels. Accumulation of RexFrtH decreased from efferent to afferent vessels, coinciding with the direction of water flow through the gills. Fe3+ was localized with RexFrtH, and in vitro iron-binding and ferroxidase assays using recombinant RexFrtH confirmed the high affinity for iron. Based on these results, we propose a model of iron metabolism in R. exoculata gills; ferrous iron from ambient hydrothermal water accumulates and is converted and stored in ferric form by RexFrtH as an iron reservoir when needed for metabolism, or excreted as an intermediate to prevent iron overload. The findings expand our understanding of the adaptation strategies used by shrimps inhabiting extreme hydrothermal vents to cope with extremely high heavy metal concentrations.


Assuntos
Apoferritinas/metabolismo , Decápodes (Crustáceos)/metabolismo , Fontes Hidrotermais , Ferro/metabolismo , Animais
8.
Semin Nephrol ; 39(1): 76-84, 2019 01.
Artigo em Inglês | MEDLINE | ID: mdl-30606409

RESUMO

Iron is required for key aspects of cellular physiology including mitochondrial function and DNA synthesis and repair. However, free iron is an aberration because of its ability to donate electrons, reduce oxygen, and generate reactive oxygen species. Iron-mediated cell injury or ferroptosis is a central player in the pathogenesis of acute kidney injury. There are several homeostatic proteins and pathways that maintain critical balance in iron homeostasis to allow iron's biologic functions yet avoid ferroptosis. Hepcidin serves as the master regulator of iron homeostasis through its ability to regulate ferroportin-mediated iron export and intracellular H-ferritin levels. Hepcidin is a protective molecule in acute kidney injury. Drugs targeting hepcidin, H-ferritin, and ferroptosis pathways hold great promise to prevent or treat kidney injury. In this review we discuss iron homeostasis under physiological and pathologic conditions and highlight its importance in acute kidney injury.


Assuntos
Lesão Renal Aguda/fisiopatologia , Hepcidinas , Homeostase , Ferro/sangue , Rim/metabolismo , Lesão Renal Aguda/sangue , Animais , Apoferritinas/metabolismo , Heme Oxigenase-1/metabolismo , Hepcidinas/uso terapêutico , Hepcidinas/urina , Humanos , Ferro/metabolismo , Rim/fisiologia , Lipocalina-2/metabolismo
9.
Clin Sci (Lond) ; 133(1): 135-148, 2019 01 15.
Artigo em Inglês | MEDLINE | ID: mdl-30552136

RESUMO

OBJECTIVE: Ferritin, an iron-binding protein, is ubiquitous and highly conserved; it plays a crucial role in inflammation, which is the main symptom of periodontitis. Full-length cDNA library analyses have demonstrated abundant expression of ferritin in human periodontal ligament. The aims of the present study were to explore how ferritin is regulated by local inflammation, and to investigate its functions and mechanisms of action in the process of periodontitis. METHODS: Human gingival tissues were collected from periodontitis patients and healthy individuals. Experimental periodontitis was induced by ligature of second molars in mice. The expression of ferritin light polypeptide (FTL) and ferritin heavy polypeptide (FTH) were assessed by immunohistochemistry. Meanwhile, after stimulating human periodontal ligament cells (HPDLCs) with P. gingivalis-lipopolysaccharide (LPS), interleukin (IL)-6, and tumor necrosis factor-α (TNF-α), the expression of FTH and FTL were measured. Then, IL-6 and IL-8 were measured after incubation with different concentrations of apoferritin (iron-free ferritin) and several intracellular signaling pathway inhibitors, or after knockdown of the transferrin receptor. RESULTS: Both FTH and FTL were substantially higher in inflamed periodontal tissues than in healthy tissues. The location of the elevated expression correlated well with the extent of inflammatory infiltration. Moreover, expression of FTH and FTL were enhanced after stimulation with P. gingivalis-LPS, IL-6, TNF-α. Apoferritin induced the production of IL-6 and IL-8 in a dose-dependent manner partly through binding to the transferrin receptor and activating ERK/P38 signaling pathways in HPDLCs. CONCLUSIONS: Ferritin is up-regulated by inflammation and exhibits cytokine-like activity in HPDLCs inducing a signaling cascade that promotes expression of pro-inflammatory cytokines associated with periodontitis.


Assuntos
Antígenos CD/metabolismo , Apoferritinas/metabolismo , Citocinas/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Ferritinas/metabolismo , Mediadores da Inflamação/metabolismo , Ligamento Periodontal/enzimologia , Periodontite/enzimologia , Receptores da Transferrina/metabolismo , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Antígenos CD/genética , Apoferritinas/genética , Estudos de Casos e Controles , Células Cultivadas , Modelos Animais de Doenças , Ferritinas/genética , Humanos , Interleucina-6/metabolismo , Interleucina-8/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Ligamento Periodontal/patologia , Periodontite/genética , Periodontite/patologia , Receptores da Transferrina/genética , Transdução de Sinais , Fator de Necrose Tumoral alfa/metabolismo , Regulação para Cima
10.
Food Funct ; 9(4): 2015-2024, 2018 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-29541738

RESUMO

The effect of chitosan decoration on the transport of epigallocatechin (EGC)-encapsulated ferritin cage across the Caco-2 cells was investigated. After the encapsulation of EGC in apo-red bean (adzuki) ferritin (apoRBF), the EGC-loaded apoRBF nanoparticle (ER) was fabricated with an encapsulation ratio of 11.6% (w/w). The results indicated that different chitosan molecules (with molecular weights of 980, 4600, 46 000, and 210 000 Da) could attach onto the apoRBF via electrostatic interactions to form ER-chitosan complexes (ERCs) (ERCs980, ERCs4600, ERCs46000, and ERCs210000). ERCs980 and ERCs4600 retained the typical shell-like morphology of ferritin with a size distribution of 12 nm and showed weak negative zeta-potentials at pH 6.7, while ERCs46000 and ERCs210000 significantly aggregated. Furthermore, the transport of EGC in ERCs980 and ERCs4600 across the Caco-2 cells was enhanced by the transferrin receptor 1 (TfR-1)-mediated absorption pathway, demonstrating that chitosan molecules with low molecular weights of 980 and 4600 Da were beneficial to the absorption of EGC based on the ferritin cage. This study will facilitate the application of ferritin-chitosan materials for fabricating the core-shell platform for encapsulation and bioavailability enhancement of bioactive molecules.


Assuntos
Apoferritinas/metabolismo , Catequina/análogos & derivados , Quitosana/metabolismo , Enterócitos/metabolismo , Absorção Intestinal , Nanoconjugados/química , Receptores da Transferrina/metabolismo , Absorção Fisiológica , Algoritmos , Apoferritinas/química , Apoferritinas/ultraestrutura , Catequina/administração & dosagem , Catequina/química , Catequina/metabolismo , Quitosana/química , Suplementos Nutricionais/análise , Difusão Dinâmica da Luz , Humanos , Microscopia Eletrônica de Transmissão , Peso Molecular , Nanoconjugados/ultraestrutura , Tamanho da Partícula , Proteínas de Vegetais Comestíveis/metabolismo , Sementes/química , Eletricidade Estática , Propriedades de Superfície , Vigna/química
11.
Glia ; 66(7): 1317-1330, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-29457657

RESUMO

Deficiency of trophic factors relating to the survival of oligodendrocytes, combined with direct interactions with the immune system, are favored paradigms that are increasingly implicated in demyelinating diseases of the central nervous system. We and others have previously shown that Sema4A and H-ferritin interact through the T-cell immunoglobulin and mucin domain (Tim-2) receptor in mice. H-ferritin has been identified as the iron delivery protein for oligodendrocytes, whereas Sema4A causes a direct cytotoxic effect. However, the expression of Tim-2 has not been detected in humans. Here, we demonstrate that, similar to rodents, human oligodendrocytes undergo apoptosis when exposed to Sema4A and take up H-ferritin for meeting iron requirements and that these functions are mediated via the Tim-1 receptor. Moreover, we also demonstrate the ability of H-ferritin to block Sema4A-mediated cytotoxicity. Furthermore, we show in a series of pilot studies that Sema4A is detectable in the CSF of multiple sclerosis patients and HIV-seropositive persons and can induce oligodendrocyte cell death. Together, these results identify a novel iron uptake mechanism for human oligodendrocytes and a connection between oligodendrocytes and the immune system.


Assuntos
Apoferritinas/metabolismo , Receptor Celular 1 do Vírus da Hepatite A/metabolismo , Oligodendroglia/metabolismo , Semaforinas/metabolismo , Apoptose/fisiologia , Linhagem Celular , Sobrevivência Celular/fisiologia , Escherichia coli , Infecções por HIV/metabolismo , Receptor Celular 2 do Vírus da Hepatite A/metabolismo , Humanos , Esclerose Múltipla/metabolismo , Oligodendroglia/citologia , Proteínas Recombinantes/metabolismo , Semaforinas/administração & dosagem , Lobo Temporal/metabolismo
12.
Biometals ; 31(1): 139-146, 2018 02.
Artigo em Inglês | MEDLINE | ID: mdl-29330752

RESUMO

The interactions of iron regulatory proteins (IRPs) with mRNAs containing an iron-responsive element (IRE) is a major means through which intracellular iron homeostasis is maintained and integrated with cellular function. Although IRE-IRP interactions have been proposed to modulate the expression of a diverse number of mRNAs, a transcriptome analysis of the interactions that form within the native mRNA structure and cellular environment has not previously been described. An RNA-CLIP study is described here that identified IRP-1 interactions occurring within a primary cell line expressing physiologically relevant amounts of mRNA and protein. The study suggests that only a small subset of the previously proposed IREs interact with IRP-1 in situ. Identifying authentic IRP interactions is not only important to a greater understanding of iron homeostasis and its integration with cell biology but also to the development of novel therapeutics that can compensate for iron imbalances.


Assuntos
Regulação da Expressão Gênica , Proteína 1 Reguladora do Ferro/genética , Ferro/metabolismo , RNA Mensageiro/genética , Elementos de Resposta , Antígenos CD/genética , Antígenos CD/metabolismo , Apoferritinas/genética , Apoferritinas/metabolismo , Pareamento de Bases , Fatores de Transcrição Hélice-Alça-Hélice Básicos/genética , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Sítios de Ligação , Proteínas de Transporte de Cátions/genética , Proteínas de Transporte de Cátions/metabolismo , Ferritinas/genética , Ferritinas/metabolismo , Homeostase , Células Endoteliais da Veia Umbilical Humana , Humanos , Proteína 1 Reguladora do Ferro/metabolismo , Ligação Proteica , Mapeamento de Interação de Proteínas/métodos , RNA Mensageiro/metabolismo , Receptores da Transferrina/genética , Receptores da Transferrina/metabolismo
13.
Acta Ophthalmol ; 96(1): 95-99, 2018 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-28636169

RESUMO

PURPOSE: To present a novel Finnish double nucleotide variant in the iron-responsive element (IRE) of the ferritin L-chain gene (FTL) leading to hyperferritinaemia-cataract syndrome (HHCS). METHODS: Genomic DNA extracted from peripheral blood leucocytes and synthetized with three different primers flanking the IRE in the FTL 5'-untranslated region of the FTL was used in polymerase chain reaction (PCR). Thereafter, Sanger sequencing was performed on the 487-bp and 602-bp PCR amplification products with specific primers to reveal FTL IRE mutations. RESULTS: A 58-year-old female patient with elevated serum ferritin level (1339 µg/l) was diagnosed with HHCS after extensive workup. Genetic testing identified a novel double point mutation g.48965355G>C (chr19, hg19) and g.48965356G>T (chr19, hg19) in the lower stem region of the IRE canonical structure of the FTL. CONCLUSION: After excluding other causes, elevated serum ferritin level in a person with early onset cataract is indicative for HHCS, a genetic disorder caused by mutation in the IRE of the FTL.


Assuntos
Apoferritinas/genética , Catarata/congênito , DNA/genética , Distúrbios do Metabolismo do Ferro/congênito , Proteínas Reguladoras do Ferro/genética , Mutação , Mutação Puntual , Apoferritinas/metabolismo , Catarata/genética , Catarata/metabolismo , Análise Mutacional de DNA , Feminino , Finlândia , Testes Genéticos , Humanos , Distúrbios do Metabolismo do Ferro/genética , Distúrbios do Metabolismo do Ferro/metabolismo , Proteínas Reguladoras do Ferro/metabolismo , Pessoa de Meia-Idade , Linhagem , Reação em Cadeia da Polimerase
14.
J Neuropathol Exp Neurol ; 77(1): 21-39, 2018 Jan 01.
Artigo em Inglês | MEDLINE | ID: mdl-29186589

RESUMO

Misfolded protein in the amygdala is a neuropathologic feature of Alzheimer disease and many other neurodegenerative disorders. We examined extracts from human amygdala (snap-frozen at autopsy) to investigate whether novel and as yet uncharacterized misfolded proteins would be detectable. Polypeptides from the detergent-insoluble, urea-soluble protein fractions of amygdala were interrogated using liquid chromatography-electrospray ionization-tandem mass spectrometry. Among the detergent-insoluble proteins identified in amygdala of demented subjects but not controls were Tau, TDP-43, Aß, α-synuclein, and ApoE. Additional detergent-insoluble proteins from demented subjects in the high-molecular weight portion of SDS gels included NNT, TNIK, PRKDC (DNA-PK, or DNA-PKcs), ferritin light chain (FTL), AIFM1, SYT11, STX1B, EAA1, COL25A1, M4K4, CLH1, SQSTM, SYNJ1, C3, and C4. In follow-up immunohistochemical experiments, NNT, TNIK, PRKDC, AIFM1, and FTL were observed in inclusion body-like structures in cognitively impaired subjects' amygdalae. Double-label immunofluorescence revealed that FTL and phospho-PRKDC immunoreactivity colocalized partially with TDP-43 and/or Tau inclusion bodies. Western blots showed high-molecular weight "smears", particularly for NNT and PRKDC. A preliminary genetic association study indicated that rare NNT, TNIK, and PRKDC gene variants had nominally significant association with Alzheimer-type dementia risk. In summary, novel detergent-insoluble proteins, with evidence of proteinaceous deposits, were found in amygdalae of elderly, cognitively impaired subjects.


Assuntos
Doença de Alzheimer/metabolismo , Tonsila do Cerebelo/metabolismo , Disfunção Cognitiva/metabolismo , Corpos de Inclusão/metabolismo , Idoso , Idoso de 80 Anos ou mais , Doença de Alzheimer/patologia , Tonsila do Cerebelo/patologia , Apoferritinas/metabolismo , Fator de Indução de Apoptose/metabolismo , Cromatografia Líquida , Disfunção Cognitiva/patologia , Proteína Quinase Ativada por DNA/metabolismo , Proteínas de Ligação a DNA/metabolismo , Humanos , Corpos de Inclusão/patologia , Proteínas Mitocondriais/metabolismo , NADP Trans-Hidrogenase Específica para A ou B/metabolismo , Proteínas Nucleares/metabolismo , Proteômica , Espectrometria de Massas em Tandem
15.
J Cell Physiol ; 233(1): 30-37, 2018 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-28338217

RESUMO

The significant positive correlation between ghrelin and iron and hepcidin levels in the plasma of children with iron deficiency anemia prompted us to hypothesize that ghrelin may affect iron metabolism. Here, we investigated the effects of fasting or ghrelin on the expression of hepcidin, ferroportin 1 (Fpn1), transferrin receptor 1 (TfR1), ferritin light chain (Ft-L) proteins, and ghrelin, and also hormone secretagogue receptor 1 alpha (GHSR1α) and ghrelin O-acyltransferase (GOAT) mRNAs in the spleen and/or macrophage. We demonstrated that fasting induces a significant increase in the expression of ghrelin, GHSR1α, GOAT, and hepcidin mRNAs, as well as Ft-L and Fpn1 but not TfR1 proteins in the spleens of mice in vivo. Similar to the effects of fasting on the spleen, ghrelin induced a significant increase in the expression of Ft-L and Fpn1 but not TfR1 proteins in macrophages in vitro. In addition, ghrelin was found to induce a significant enhancement in phosphorylation of ERK as well as translocation of pERK from the cytosol to nuclei. Furthermore, the increased pERK and Fpn1 induced by ghrelin was demonstrated to be preventable by pre-treatment with either GHSR1α antagonist or pERK inhibitor. Our findings support the hypothesis that fasting upregulates Fpn1 expression, probably via a ghrelin/GHSR/MAPK signaling pathway.


Assuntos
Proteínas de Transporte de Cátions/metabolismo , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Jejum/metabolismo , Grelina/metabolismo , Macrófagos Peritoneais/enzimologia , Receptores de Grelina/metabolismo , Transdução de Sinais , Baço/enzimologia , Aciltransferases/genética , Aciltransferases/metabolismo , Animais , Apoferritinas/genética , Apoferritinas/metabolismo , Proteínas de Transporte de Cátions/genética , Células Cultivadas , MAP Quinases Reguladas por Sinal Extracelular/antagonistas & inibidores , Grelina/genética , Antagonistas de Hormônios/farmacologia , Macrófagos Peritoneais/efeitos dos fármacos , Masculino , Camundongos Endogâmicos C57BL , Fosforilação , Inibidores de Proteínas Quinases/farmacologia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Receptores de Grelina/antagonistas & inibidores , Receptores de Grelina/genética , Baço/efeitos dos fármacos , Regulação para Cima
17.
PLoS One ; 12(9): e0185260, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28945778

RESUMO

OBJECTIVE: The aim of the present work was to verify whether adenoviral vector mediated ferritin over-expression in mesenchymal stem cells could be detected by 7T MRI device, and to explore the relationship between ferritin content and MRI signal intensities. METHODS: A recombined adenoviral vector (rAdV) encoding ferritin heavy chain (FTH1) subunit was specially designed for the aim of infecting bone marrow mesenchymal stem cells (BMSCs). Ferritin over-expression in BMSCs was determined by cell immunocytochemistry and the ferritin content in cells was determined by ELISA assay. BMSCs were subjected to cell viability, proliferation and multi-differentiation analyses as well as 7T MRI test using fast spin-echo pulse sequence. The R2 value andδR2 were calculated according to T2 mapping images. RESULTS: As was confirmed by cell immunocytochemistry and ELISA assay, rAdV mediated ferritin was over-expressed in BMSCs. Ferritin over-expression did not interfere with stem cell viability or pluripotent differentiation but slowed cell proliferation. The R2 value of BMSCs-FTH1 vs control BMSCs from 1-4 weeks was16.65±1.28 s-1 vs 13.99±0.80 s-1, (t = 3.94, p = 0.004), 15.63±1.37 s-1 vs 13.87±0.83 s-1 (t = 2.47, p = 0.039), 15.53±0.88 s-1 vs 14.25±0.53 s-1 (t = 2.80, p = 0.023) and 14.61±1.28 s-1 vs 13.69±1.03 s-1 (t = 1.25, p = 0.24), respectively. δR2 gradually decreased from 1-4 weeks and the difference between the groups had statistical significance (F = 12.45, p<0.01).δR2 was positively correlated with OD value (r = 0.876, p<0.01) and ferritin concentration (r = 0.899, p<0.01) as determined by Pearson correlation. CONCLUSIONS: Our study confirms that ferritin could be over-expressed in BMSCs as a result of rAdV mediated infection and could be quantitatively detected by 7T MRI device. The differences in T2 signal intensities and R2 values stem from internal contrast generated by endogenous ferritin over-expression. The correlation between δR2, OD and ferritin concentration suggests that MRI can detect ferritin signal change accurately.


Assuntos
Apoferritinas/metabolismo , Imagem por Ressonância Magnética/métodos , Células-Tronco Mesenquimais/metabolismo , Adenoviridae/genética , Animais , Apoferritinas/genética , Diferenciação Celular , Proliferação de Células , Sobrevivência Celular , Células Cultivadas , Ensaio de Imunoadsorção Enzimática , Estudos de Viabilidade , Vetores Genéticos , Humanos , Imuno-Histoquímica , Células-Tronco Mesenquimais/citologia , Camundongos , Proteínas Recombinantes/genética , Proteínas Recombinantes/metabolismo , Regulação para Cima
18.
Neuroscience ; 362: 141-151, 2017 Oct 24.
Artigo em Inglês | MEDLINE | ID: mdl-28842186

RESUMO

Brain iron accumulation is a common feature shared by several neurodegenerative disorders including Parkinson's disease. However, what produces this accumulation of iron is still unknown. In this study, the 6-hydroxydopamine (6-OHDA) hemi-parkinsonian rat model was used to investigate abnormal iron accumulation in substantia nigra. We investigated three possible causes of iron accumulation; a compromised blood-brain barrier (BBB), abnormal expression of ferritin, and neuroinflammation. We identified alterations in the BBB subsequent to the injection of 6-OHDA using gadolinium-enhanced magnetic resonance imaging (MRI). Moreover, detection of extravasated IgG suggested that peripheral components are able to enter the brain through a leaky BBB. Presence of iron following dopamine cell degeneration was studied by MRI, which revealed hypointense signals in the substantia nigra. The presence of iron deposits was further validated in histological evaluations. Furthermore, iron inclusions were closely associated with active microglia and with increased levels of L-ferritin indicating a putative role for microglia and L-ferritin in brain iron accumulation and dopamine neurodegeneration.


Assuntos
Barreira Hematoencefálica/metabolismo , Ferro/metabolismo , Transtornos Parkinsonianos/metabolismo , Animais , Antígenos CD/metabolismo , Antígenos de Diferenciação Mielomonocítica/metabolismo , Apoferritinas/metabolismo , Astrócitos/metabolismo , Astrócitos/patologia , Barreira Hematoencefálica/diagnóstico por imagem , Barreira Hematoencefálica/patologia , Proteínas de Ligação ao Cálcio/metabolismo , Permeabilidade Capilar/fisiologia , Neurônios Dopaminérgicos/metabolismo , Neurônios Dopaminérgicos/patologia , Feminino , Imunoglobulina G/metabolismo , Proteínas dos Microfilamentos/metabolismo , Microglia/metabolismo , Microglia/patologia , Neuroimunomodulação/fisiologia , Oxidopamina , Transtornos Parkinsonianos/diagnóstico por imagem , Transtornos Parkinsonianos/patologia , Ratos Sprague-Dawley
19.
PLoS One ; 12(8): e0182954, 2017.
Artigo em Inglês | MEDLINE | ID: mdl-28837569

RESUMO

Astrocytic brain tumors are the most frequent primary brain tumors. Treatment with radio- and chemotherapy has increased survival making prognostic biomarkers increasingly important. The aim of the present study was to investigate the expression and prognostic value of transferrin receptor-1 (TfR1) as well as ferritin heavy (FTH) and light (FTL) chain in astrocytic brain tumors. A cohort of 111 astrocytic brain tumors (grade II-IV) was stained immunohistochemically with antibodies against TfR1, FTH, and FTL and scored semi-quantitatively. Double-immunofluorescence stainings were established to determine the phenotype of cells expressing these markers. We found that TfR1, FTH, and FTL were expressed by tumor cells in all grades. TfR1 increased with grade (p<0.001), but was not associated with prognosis in the individual grades. FTH and FTL were expressed by tumor cells and cells with microglial/macrophage morphology. Neither FTH nor FTL increased with malignancy grade, but low FTH expression by both tumor cells (p = 0.03) and microglia/macrophages (p = 0.01) correlated with shorter survival in patients anaplastic astrocytoma. FTL-positive microglia/macrophages were frequent in glioblastomas, and high FTL levels correlated with shorter survival in the whole cohort (p = 0.01) and in patients with anaplastic astrocytoma (p = 0.02). Double-immunofluorescence showed that TfR1, FTH, and FTL were co-expressed to a limited extent with the stem cell-related marker CD133. FTH and FTL were also co-expressed by IBA-1-positive microglia/macrophages. In conclusion, TfR1 was highly expressed in glioblastomas and associated with shorter survival in the whole cohort, but not in the individual malignancy grades. Low levels of FTH-positive tumor cells and microglia/macrophages were associated with poor survival in anaplastic astrocytomas, while high amounts of FTL-positive microglia/macrophages had a negative prognostic value. The results suggest that regulation of the iron metabolism in astrocytic brain tumors is complex involving both autocrine and paracrine signaling.


Assuntos
Antígenos CD/metabolismo , Apoferritinas/metabolismo , Astrocitoma/metabolismo , Neoplasias Encefálicas/metabolismo , Receptores da Transferrina/metabolismo , Astrocitoma/patologia , Encéfalo/metabolismo , Neoplasias Encefálicas/patologia , Pré-Escolar , Estudos de Coortes , Feminino , Imunofluorescência , Humanos , Lactente , Masculino , Prognóstico , Análise de Sobrevida
20.
J Chem Inf Model ; 57(9): 2112-2118, 2017 09 25.
Artigo em Inglês | MEDLINE | ID: mdl-28853891

RESUMO

We investigated the kinetics of the release of iron(II) ions from the internal cavity of human H-ferritin as a function of pH. Extensive molecular dynamics simulations of the entire 24-mer ferritin provided atomic-level information on the release mechanism. Double protonation of His residues at pH 4 facilitates the removal of the iron ligands within the C3 channel through the formation of salt bridges, resulting in a significantly lower release energy barrier than pH 9.


Assuntos
Apoferritinas/química , Apoferritinas/metabolismo , Ferro/metabolismo , Humanos , Ligações de Hidrogênio , Concentração de Íons de Hidrogênio , Simulação de Dinâmica Molecular , Conformação Proteica
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