RESUMO
Lactoferrin is a natural cationic iron-binding glycoprotein of the transferrin family found in bovine milk and other exocrine secretions, including lacrimal fluid, saliva, and bile. Lactoferrin has been investigated for its numerous powerful influences, including anticancer, anti-inflammatory, anti-oxidant, anti-osteoporotic, antifungal, antibacterial, antiviral, immunomodulatory, hepatoprotective, and other beneficial health effects. Lactoferrin demonstrated several nutraceutical and pharmaceutical potentials and have a significant impact on improving the health of humans and animals. Lactoferrin plays a critical role in keeping the normal physiological homeostasis associated with the development of pathological disorders. The current review highlights the medicinal value, nutraceutical role, therapeutic application, and outstanding favorable health sides of lactoferrin, which would benefit from more exploration of this glycoprotein for the design of effective medicines, drugs, and pharmaceuticals for safeguarding different health issues in animals and humans.
Assuntos
Proteínas de Ligação ao Ferro , Lactoferrina , Animais , Humanos , Lactoferrina/farmacologia , Transferrina , Glicoproteínas , Antioxidantes , Suplementos NutricionaisRESUMO
Friedreich's ataxia is an incurable disease caused by frataxin (FXN) protein deficiency, which is mostly induced by GAA repeat expansion in intron 1 of the FXN gene. Here, we identified antisense oligonucleotides (ASOs), complementary to two regions within the first intron of FXN pre-mRNA, which could increase FXN mRNA by â¼2-fold in patient fibroblasts. The increase in FXN mRNA was confirmed by the identification of multiple overlapping FXN-activating ASOs at each region, two independent RNA quantification assays, and normalization by multiple housekeeping genes. Experiments on cells with the ASO-binding sites deleted indicate that the ASO-induced FXN activation was driven by indirect effects. RNA sequencing analyses showed that the two ASOs induced similar transcriptome-wide changes, which did not resemble the transcriptome of wild-type cells. This RNA-seq analysis did not identify directly base-paired off-target genes shared across ASOs. Mismatch studies identified two guanosine-rich motifs (CCGG and G4) within the ASOs that were required for FXN activation. The phosphorodiamidate morpholino oligomer analogs of our ASOs did not activate FXN, pointing to a PS-backbone-mediated effect. Our study demonstrates the importance of multiple, detailed control experiments and target validation in oligonucleotide studies employing novel mechanisms such as gene activation.
Assuntos
Ataxia de Friedreich , Regulação da Expressão Gênica , Oligonucleotídeos Antissenso , Humanos , Ataxia de Friedreich/genética , Proteínas de Ligação ao Ferro/genética , Proteínas de Ligação ao Ferro/metabolismo , Oligonucleotídeos Antissenso/genética , Oligonucleotídeos Antissenso/farmacologia , Oligonucleotídeos Antissenso/metabolismo , RNA Mensageiro/metabolismo , Células Cultivadas , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , FrataxinaRESUMO
Acrylamide (ACR) is a surprisingly common chemical due to its widespread use in industry and various other applications. However, its toxicity is a matter of grave concern for public health. Even worse, ACR is frequently detected in numerous fried or baked carbohydrate-rich foods due to the Maillard browning reaction. Herein, this study intends to delineate the underlying molecular mechanisms of Fe ions released from iron-binding protein transferrin (TF) after acrylamide binding by combining multiple methods, including multiple complementary spectroscopic techniques (UV-Vis, fluorescence, and circular dichroism spectroscopy), isothermal titration calorimetry, ICP-MS measurements, and modeling simulations. Results indicated that free Fe was released from TF only under high-dose ACR exposure (>100 µM). Acrylamide binding induced the loosening and unfolding of the backbone and polypeptide chain and destroyed the secondary structure of TF, thereby leading to protein misfolding and denaturation of TF and forming a larger size of TF agglomerates. Of which, H-binding and van der Waals force are the primary driving force during the binding interaction between ACR and TF. Further modeling simulations illustrated that ACR prefers to bind to the hinge region connecting the C-lobe and N-lobe, after that it attaches to the Fe binding sites of this protein, which is the cause of free Fe release from TF. Moreover, ACR interacted with the critical fluorophore residues (Tyr, Trp, and Phe) in the binding pocket, which might explain such a phenomenon of fluorescence sensitization. The two binding sites (Site 2 and Site 3) located around the Fe (III) ions with low-energy conformations are more suitable for ACR binding. Collectively, our study demonstrated that the loss of iron in TF caused by acrylamide-induced structural and conformational changes of transferrin.
Assuntos
Acrilamida , Proteínas de Ligação ao Ferro , Carboidratos , Humanos , Ferro/metabolismo , Proteínas de Ligação ao Ferro/metabolismo , Ligação Proteica , Transferrina/química , Transferrina/metabolismoRESUMO
Cyanobacteria are characterized by high iron content. This study investigated the effects of varying iron concentrations (1, 5, and 10 mg L-1) in the culture media on the biochemical composition and the iron bioaccumulation and speciation in Arthrospira platensis F&M-C256. Iron content measured in biomasses varied from 0.35 to 2.34 mg g-1 dry weight depending on the iron concentration in the culture media. These biomasses can be considered of interest for the production of spirulina-based supplements with low and high iron content. Iron speciation was studied using size exclusion chromatography followed by atomic absorption spectrometry and proteomic analysis. The role of C-phycocyanin as an iron binding protein was also investigated. Overall, the present results provide a better understanding of iron metabolism in cyanobacteria and a foundation for further studies.
Assuntos
Spirulina , Meios de Cultura/metabolismo , Ferro/metabolismo , Proteínas de Ligação ao Ferro/metabolismo , Proteômica , Spirulina/químicaRESUMO
Uranium is a naturally occurring radionuclide. Its redistribution, primarily due to human activities, can have adverse effects on human and non-human biota, which poses environmental concerns. The molecular mechanisms of uranium tolerance and the cellular response induced by uranium exposure in bacteria are not yet fully understood. Here, we carried out a comparative analysis of four actinobacterial strains isolated from metal and radionuclide-rich soils that display contrasted uranium tolerance phenotypes. Comparative proteogenomics showed that uranyl exposure affects 39-47% of the total proteins, with an impact on phosphate and iron metabolisms and membrane proteins. This approach highlighted a protein of unknown function, named UipA, that is specific to the uranium-tolerant strains and that had the highest positive fold-change upon uranium exposure. UipA is a single-pass transmembrane protein and its large C-terminal soluble domain displayed a specific, nanomolar binding affinity for UO22+ and Fe3+. ATR-FTIR and XAS-spectroscopy showed that mono and bidentate carboxylate groups of the protein coordinated both metals. The crystal structure of UipA, solved in its apo state and bound to uranium, revealed a tandem of PepSY domains in a swapped dimer, with a negatively charged face where uranium is bound through a set of conserved residues. This work reveals the importance of UipA and its PepSY domains in metal binding and radionuclide tolerance.
Assuntos
Urânio , Bactérias/genética , Bactérias/metabolismo , Ferro/metabolismo , Proteínas de Ligação ao Ferro , SoloRESUMO
BACKGROUND: New strategies are needed to combat multidrug-resistant bacteria. The restriction of iron uptake by bacteria is a promising way to inhibit their growth. We aimed to suppress the growth of Vibrio bacterial species by inhibiting their ferric ion-binding protein (FbpA) using food components. METHODS: Twenty spices were selected for the screening of FbpA inhibitors. The candidate was applied to antibacterial tests, and the mechanism was further studied. RESULTS: An active compound, rosmarinic acid (RA), was screened out. RA binds competitively and more tightly than Fe3+ to VmFbpA, the FbpA from V. metschnikovii, with apparent KD values of 8 µM vs. 17 µM. Moreover, RA can inhibit the growth of V. metschnikovii to one-third of the control at 1000 µM. Interestingly, sodium citrate (SC) enhances the growth inhibition effect of RA, although SC only does not inhibit the growth. The combination of RA/SC completely inhibits the growth of not only V. metschnikovii at 100/100 µM but also the vibriosis-causative pathogens V. vulnificus and V. parahaemolyticus, at 100/100 and 1000/100 µM, respectively. However, RA/SC does not affect the growth of Escherichia coli. CONCLUSIONS: RA/SC is a potential bacteriostatic agent against Vibrio species while causing little damage to indigenous gastrointestinal bacteria.
Assuntos
Cinamatos/farmacologia , Depsídeos/farmacologia , Ferro/metabolismo , Citrato de Sódio/farmacologia , Vibrio parahaemolyticus/efeitos dos fármacos , Proteínas de Bactérias/química , Proteínas de Bactérias/metabolismo , Sítios de Ligação , Cinamatos/química , Cinamatos/metabolismo , Depsídeos/química , Depsídeos/metabolismo , Sinergismo Farmacológico , Proteínas de Ligação ao Ferro/química , Proteínas de Ligação ao Ferro/metabolismo , Simulação de Acoplamento Molecular , Extratos Vegetais/química , Ligação Proteica , Vibrio parahaemolyticus/metabolismo , Ácido RosmarínicoRESUMO
Ferrous sulphate (FS) is a cost effective, readily available iron supplement for iron deficiency (ID). The pro-oxidant effect of oral ferrous iron is known to induce inflammation, causing gastric side-effects and resulting in poor compliance. Curcumin is a potent antioxidant and has also been shown to exhibit iron chelation in-vitro, although it is not established whether these effects are retained in-vivo. The aim of this study was therefore to assess the influence of a formulated bioavailable form of curcumin (HydroCurcTM; 500 mg) on acute iron absorption and status in a double blind, placebo-controlled randomized trial recruiting 155 healthy participants (79 males; 26.42 years ± 0.55 and 76 females; 25.82 years ± 0.54). Participants were randomly allocated to five different treatment groups: iron and curcumin placebo (FS0_Plac), low dose (18 mg) iron and curcumin placebo (FS18_Plac), low dose iron and curcumin (FS18_Curc), high dose (65 mg) iron and curcumin placebo (FS65_Plac), and high dose iron and curcumin (FS65_Curc). Participants were provided with the supplements according to their relevant treatment groups at baseline (0 min), and blood collection was carried out at 0 min and at 180 min following supplementation. In the treatment groups, significant difference was observed in mean serum iron between baseline (0 min) and at end-point (180 min) (F (1, 144) = 331.9, p < 0.0001) with statistically significant intra-group increases after 180 min (p < 0.0001) in the FS18_Plac (8.79 µmol/L), FS18_Curc (11.41 µmol/L), FS65_Plac (19.09 µmol/L), and FS65_Curc (16.39 µmol/L) groups. A significant difference was also observed between the two time points in serum TIBC levels and in whole blood haemoglobin (HGB) in the treatment groups, with a significant increase (1.55%/2.04 g/L) in HGB levels from baseline to end-point observed in the FS65_Curc group (p < 0.05). All groups receiving iron demonstrated an increase in transferrin saturation (TS%) in a dose-related manner, demonstrating that increases in serum iron are translated into increases in physiological iron transportation. This study demonstrates, for the first time, that regardless of ferrous dose, formulated curcumin in the form of HydroCurc™ does not negatively influence acute iron absorption in healthy humans.
Assuntos
Absorção Fisiológica/efeitos dos fármacos , Curcumina/administração & dosagem , Suplementos Nutricionais , Compostos Ferrosos/administração & dosagem , Ferro/sangue , Administração Oral , Adulto , Disponibilidade Biológica , Método Duplo-Cego , Feminino , Ferritinas/sangue , Voluntários Saudáveis , Hemoglobinas/análise , Humanos , Proteínas de Ligação ao Ferro/sangue , Masculino , Transferrina/análiseRESUMO
We aimed to analyze the chemical compositions in Arabica coffee bean extracts, assess the relevant antioxidant and iron-chelating activities in coffee extracts and instant coffee, and evaluate the toxicity in roasted coffee. Coffee beans were extracted using boiling, drip-filtered and espresso brewing methods. Certain phenolics were investigated including trigonelline, caffeic acid and their derivatives, gallic acid, epicatechin, chlorogenic acid (CGA) and their derivatives, p-coumaroylquinic acid, p-coumaroyl glucoside, the rutin and syringic acid that exist in green and roasted coffee extracts, along with dimethoxycinnamic acid, caffeoylarbutin and cymaroside that may be present in green coffee bean extracts. Different phytochemicals were also detected in all of the coffee extracts. Roasted coffee extracts and instant coffees exhibited free-radical scavenging properties in a dose-dependent manner, for which drip coffee was observed to be the most effective (p < 0.05). All coffee extracts, instant coffee varieties and CGA could effectively bind ferric ion in a concentration-dependent manner resulting in an iron-bound complex. Roasted coffee extracts were neither toxic to normal mononuclear cells nor breast cancer cells. The findings indicate that phenolics, particularly CGA, could effectively contribute to the iron-chelating and free-radical scavenging properties observed in coffee brews. Thus, coffee may possess high pharmacological value and could be utilized as a health beverage.
Assuntos
Coffea/química , Sequestradores de Radicais Livres/análise , Proteínas de Ligação ao Ferro/análise , Alcaloides , Antioxidantes/farmacologia , Linhagem Celular Tumoral , Ácido Clorogênico/farmacologia , Cromatografia Líquida de Alta Pressão/métodos , Coffea/toxicidade , Café/química , Café/toxicidade , Temperatura Alta , Humanos , Ferro/análise , Espectrometria de Massas/métodos , Fenóis/farmacologia , Compostos Fitoquímicos/análise , Compostos Fitoquímicos/química , Extratos Vegetais/análise , Extratos Vegetais/química , Sementes/químicaRESUMO
Friedreich ataxia (FA) is a neurodegenerative disease caused by the deficiency of frataxin, a mitochondrial protein. In primary cultures of dorsal root ganglia neurons, we showed that frataxin depletion resulted in decreased levels of the mitochondrial calcium exchanger NCLX, neurite degeneration and apoptotic cell death. Here, we describe that frataxin-deficient dorsal root ganglia neurons display low levels of ferredoxin 1 (FDX1), a mitochondrial Fe/S cluster-containing protein that interacts with frataxin and, interestingly, is essential for the synthesis of calcitriol, the active form of vitamin D. We provide data that calcitriol supplementation, used at nanomolar concentrations, is able to reverse the molecular and cellular markers altered in DRG neurons. Calcitriol is able to recover both FDX1 and NCLX levels and restores mitochondrial membrane potential indicating an overall mitochondrial function improvement. Accordingly, reduction in apoptotic markers and neurite degeneration was observed and, as a result, cell survival was also recovered. All these beneficial effects would be explained by the finding that calcitriol is able to increase the mature frataxin levels in both, frataxin-deficient DRG neurons and cardiomyocytes; remarkably, this increase also occurs in lymphoblastoid cell lines derived from FA patients. In conclusion, these results provide molecular bases to consider calcitriol for an easy and affordable therapeutic approach for FA patients.
Assuntos
Calcitriol/farmacologia , Ferredoxinas/metabolismo , Ataxia de Friedreich/metabolismo , Proteínas de Ligação ao Ferro/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Neurônios/metabolismo , 25-Hidroxivitamina D3 1-alfa-Hidroxilase/metabolismo , Apoptose/efeitos dos fármacos , Calcitriol/biossíntese , Calcitriol/metabolismo , Proteínas de Transporte/metabolismo , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , Gânglios Espinais/citologia , Gânglios Espinais/metabolismo , Humanos , Proteínas dos Microfilamentos/metabolismo , Mitocôndrias/metabolismo , Proteínas Mitocondriais/metabolismo , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/metabolismo , Trocador de Sódio e Cálcio/metabolismo , Vitamina D/metabolismo , FrataxinaRESUMO
The increased interest in achieving, solely through diet, the same effect on iron levels with supplementation, leads to numerous studies on iron absorption of iron binding proteins (IBPs). The characteristics of IBPs from Tegillarca granosa (T. granosa) and its iron utilization were determined to analyze their relationship. The results showed in T. granosa, Fe(ÓÓ) was main iron form in hemoglobin (TH) and that Fe(ÓÓ) and Fe(ÓÓÓ) coexisted in ferritin (TF). After in vitro digestion, TH was easier to be digested than TF, bovine hemoglobin, and bovine ferritin. In caco-2 cells model, iron bioavailability of TH also was the best, which related to TH's superior fluid properties, higher ratios of α-helix to ß-sheet and amide I to amide II. These suggest TH could be used as a good source of organic iron and provide references for application of T. granosa in human nutrition. PRACTICAL APPLICATIONS: This research investigated the iron bioavailability and structural properties of iron-binding proteins from Tegillarca granosa (T. granosa). Moreover, the effects of iron absorption in bovine hemoglobin and ferritin were compared with those from T. granosa. The results showed the hemoglobin in T. granosa had better iron bioavailability and it could be a good source of iron. These data could provide a basic instruction of the application of T. granosa in functional food production.
Assuntos
Proteínas de Ligação ao Ferro , Ferro , Animais , Disponibilidade Biológica , Bivalves , Células CACO-2 , Bovinos , Humanos , ReologiaRESUMO
OBJECTIVE: To investigate whether levothyroxine is associated with improved live birth and other benefits in women with thyroid autoimmunity. DESIGN: Systematic review and meta-analysis. SETTING: Not applicable. PATIENT(S): Women positive for thyroid peroxidase antibody. INTERVENTION(S): MEDLINE, Embase, and the Cochrane Central Register of Controlled Trials were searched without any language restrictions. Pooled effect sizes were calculated using random-effects models. MAIN OUTCOME MEASURE(S): The primary outcome was the incidence of live birth, miscarriage, preterm birth, clinical pregnancy, ectopic pregnancy, neonatal admission, and birth weight. The summary measures were reported as relative risk (RR) with 95% confidence interval. RESULT(S): Levothyroxine supplementation was not associated with an increased rate of live birth or a decreased risk of miscarriage. Results were similar in subgroup analyses of live birth by age, baseline thyrotropin, baseline thyroid peroxidase antibody, body mass index, and use of assisted conception. For live birth, the effect estimate lay within the futility boundary for RR of 20% and 15%, but at a 10% RR, the effect estimate lay between the futility boundary and the inferior boundary. CONCLUSION(S): High- to moderate-quality evidence demonstrated that the use of levothyroxine was not associated with improvements in clinical pregnancy outcomes among women positive for thyroid peroxidase antibody. REGISTRATION NUMBER: PROSPERO CRD42019132976.
Assuntos
Autoanticorpos/sangue , Autoantígenos/imunologia , Doenças Autoimunes/tratamento farmacológico , Iodeto Peroxidase/imunologia , Proteínas de Ligação ao Ferro/imunologia , Complicações na Gravidez/etiologia , Doenças da Glândula Tireoide/tratamento farmacológico , Tiroxina/uso terapêutico , Adulto , Doenças Autoimunes/sangue , Doenças Autoimunes/complicações , Doenças Autoimunes/imunologia , Biomarcadores/sangue , Peso ao Nascer , Feminino , Humanos , Recém-Nascido , Nascido Vivo , Gravidez , Complicações na Gravidez/imunologia , Ensaios Clínicos Controlados Aleatórios como Assunto , Medição de Risco , Fatores de Risco , Doenças da Glândula Tireoide/sangue , Doenças da Glândula Tireoide/complicações , Doenças da Glândula Tireoide/imunologiaRESUMO
Several rare neurodegenerative diseases, including chorea acanthocytosis, are caused by mutations in the VPS13A-D genes. Only symptomatic treatments for these diseases are available. Saccharomyces cerevisiae contains a unique VPS13 gene and the yeast vps13Δ mutant has been proven as a suitable model for drug tests. A library of drugs and an in-house library of natural compounds and their derivatives were screened for molecules preventing the growth defect of vps13Δ cells on medium with sodium dodecyl sulfate (SDS). Seven polyphenols, including the iron-binding flavone luteolin, were identified. The structure-activity relationship and molecular mechanisms underlying the action of luteolin were characterized. The FET4 gene, which encodes an iron transporter, was found to be a multicopy suppressor of vps13Δ, pointing out the importance of iron in response to SDS stress. The growth defect of vps13Δ in SDS-supplemented medium was also alleviated by the addition of iron salts. Suppression did not involve cell antioxidant responses, as chemical antioxidants were not active. Our findings support that luteolin and iron may target the same cellular process, possibly the synthesis of sphingolipids. Unveiling the mechanisms of action of chemical and genetic suppressors of vps13Δ may help to better understand VPS13A-D-dependent pathogenesis and to develop novel therapeutic strategies.
Assuntos
Produtos Biológicos/farmacologia , Descoberta de Drogas/métodos , Ensaios de Triagem em Larga Escala/métodos , Luteolina/farmacologia , Fármacos Neuroprotetores/farmacologia , Proteínas de Saccharomyces cerevisiae/metabolismo , Produtos Biológicos/química , Proliferação de Células/efeitos dos fármacos , Proteínas de Transporte de Cobre/genética , Proteínas de Transporte de Cobre/metabolismo , Ferro/metabolismo , Proteínas de Ligação ao Ferro/genética , Proteínas de Ligação ao Ferro/metabolismo , Luteolina/química , Fármacos Neuroprotetores/química , Saccharomyces cerevisiae , Proteínas de Saccharomyces cerevisiae/genética , Bibliotecas de Moléculas Pequenas/química , Bibliotecas de Moléculas Pequenas/farmacologia , Relação Estrutura-Atividade , Supressão GenéticaRESUMO
Iron sulfur (Fe-S) clusters rank among the most ancient and conserved prosthetic groups. Fe-S clusters containing proteins are present in most, if not all, organisms. Fe-S clusters containing proteins are involved in a wide range of cellular processes, from gene regulation to central metabolism, via gene expression, RNA modification or bioenergetics. Fe-S clusters are built by biogenesis machineries conserved throughout both prokaryotes and eukaryotes. We focus mostly on bacterial ISC machinery, but not exclusively, as we refer to eukaryotic ISC system when it brings significant complementary information. Besides covering the structural and regulatory aspects of Fe-S biogenesis, this review aims to highlight Fe-S biogenesis facets remaining matters of discussion, such as the role of frataxin, or the link between fatty acid metabolism and Fe-S homeostasis. Last, we discuss recent advances on strategies used by different species to make and use Fe-S clusters in changing redox environmental conditions.
Assuntos
Escherichia coli/fisiologia , Proteínas Ferro-Enxofre/fisiologia , Ferro/metabolismo , Enxofre/metabolismo , Proteína de Transporte de Acila/fisiologia , Ácidos Graxos/metabolismo , Regulação Bacteriana da Expressão Gênica , Homeostase , Humanos , Proteínas de Ligação ao Ferro , Proteínas Ferro-Enxofre/química , Oxirredução , Saccharomyces cerevisiae/fisiologia , FrataxinaRESUMO
Friedreich's Ataxia (FRDA) is an incurable genetic disease caused by an expanded trinucleotide AAG repeat within intronic RNA of the frataxin (FXN) gene. We have previously demonstrated that synthetic antisense oligonucleotides or duplex RNAs that are complementary to the expanded repeat can activate expression of FXN and return levels of FXN protein to near normal. The potency of these compounds, however, was too low to encourage vigorous pre-clinical development. We now report testing of "gapmer" oligonucleotides consisting of a central DNA portion flanked by chemically modified RNA that increases binding affinity. We find that gapmer antisense oligonucleotides are several fold more potent activators of FXN expression relative to previously tested compounds. The potency of FXN activation is similar to a potent benchmark gapmer targeting the nuclear noncoding RNA MALAT-1, suggesting that our approach has potential for developing more effective compounds to regulate FXN expression in vivo.
Assuntos
Descoberta de Drogas , Ataxia de Friedreich/tratamento farmacológico , Proteínas de Ligação ao Ferro/genética , Oligonucleotídeos Antissenso/farmacologia , Células Cultivadas , Relação Dose-Resposta a Droga , Ataxia de Friedreich/genética , Ataxia de Friedreich/metabolismo , Humanos , Proteínas de Ligação ao Ferro/metabolismo , Estrutura Molecular , Oligonucleotídeos Antissenso/química , Relação Estrutura-Atividade , FrataxinaRESUMO
Friedreich ataxia (FA) is a cardioneurodegenerative disease caused by deficient frataxin expression. This mitochondrial protein has been related to iron homeostasis, energy metabolism, and oxidative stress. Previously, we set up a cardiac cellular model of FA based on neonatal rat cardiac myocytes (NRVM) and lentivirus-mediated frataxin RNA interference. These frataxin-deficient NRVMs presented lipid droplet accumulation, mitochondrial swelling and signs of oxidative stress. Therefore, we decided to explore the presence of protein thiol modifications in this model. With this purpose, reduced glutathione (GSH) levels were measured and the presence of glutathionylated proteins was analyzed. We observed decreased GSH content and increased presence of glutahionylated actin in frataxin-deficient NRVMs. Moreover, the presence of oxidized cysteine residues was investigated using the thiol-reactive fluorescent probe iodoacetamide-Bodipy and 2D-gel electrophoresis. With this approach, we identified two proteins with altered redox status in frataxin-deficient NRVMs: electron transfer flavoprotein-ubiquinone oxidoreductase and dihydrolipoyl dehydrogenase (DLDH). As DLDH is involved in protein-bound lipoic acid redox cycling, we analyzed the redox state of this cofactor and we observed that lipoic acid from pyruvate dehydrogenase was more oxidized in frataxin-deficient cells. Also, by targeted proteomics, we observed a decreased content on the PDH A1 subunit from pyruvate dehydrogenase. Finally, we analyzed the consequences of supplementing frataxin-deficient NRVMs with the PDH cofactors thiamine and lipoic acid, the PDH activator dichloroacetate and the antioxidants N-acetyl cysteine and Tiron. Both dichloroacetate and Tiron were able to partially prevent lipid droplet accumulation in these cells. Overall, these results indicate that frataxin-deficient NRVMs present an altered thiol-redox state which could contribute to the cardiac pathology.
Assuntos
Ataxia de Friedreich , Miócitos Cardíacos , Actinas/metabolismo , Animais , Ataxia de Friedreich/genética , Ataxia de Friedreich/metabolismo , Proteínas de Ligação ao Ferro , Miócitos Cardíacos/metabolismo , Oxirredução , Estresse Oxidativo , Oxirredutases/metabolismo , Piruvatos/metabolismo , Ratos , Compostos de Sulfidrila/metabolismo , FrataxinaRESUMO
Friedreich's ataxia (FA) is due to deficiency of the mitochondrial protein, frataxin, which results in multiple pathologies including a deadly, hypertrophic cardiomyopathy. Frataxin loss leads to deleterious accumulations of redox-active, mitochondrial iron, and suppressed mitochondrial bioenergetics. Hence, there is an urgent need to develop innovative pharmaceuticals. Herein, the activity of the novel compound, 6-methoxy-2-salicylaldehyde nicotinoyl hydrazone (SNH6), was assessed in vivo using the well-characterized muscle creatine kinase (MCK) conditional frataxin knockout (KO) mouse model of FA. The design of SNH6 incorporated a dual-mechanism mediating: (1) NAD+-supplementation to restore cardiac bioenergetics; and (2) iron chelation to remove toxic mitochondrial iron. In these studies, MCK wild-type (WT) and KO mice were treated for 4-weeks from the asymptomatic age of 4.5-weeks to 8.5-weeks of age, where the mouse displays an overt cardiomyopathy. SNH6-treatment significantly elevated NAD+ and markedly increased NAD+ consumption in WT and KO hearts. In SNH6-treated KO mice, nuclear Sirt1 activity was also significantly increased together with the NAD+-metabolic product, nicotinamide (NAM). Therefore, NAD+-supplementation by SNH6 aided mitochondrial function and cardiac bioenergetics. SNH6 also chelated iron in cultured cardiac cells and also removed iron-loading in vivo from the MCK KO heart. Despite its dual beneficial properties of supplementing NAD+ and chelating iron, SNH6 did not mitigate cardiomyopathy development in the MCK KO mouse. Collectively, SNH6 is an innovative therapeutic with marked pharmacological efficacy, which successfully enhanced cardiac NAD+ and nuclear Sirt1 activity and reduced cardiac iron-loading in MCK KO mice. No other pharmaceutical yet designed exhibits both these effective pharmacological properties.
Assuntos
Aldeídos/uso terapêutico , Cardiomiopatias/tratamento farmacológico , Ataxia de Friedreich/tratamento farmacológico , Hidrazonas/uso terapêutico , Quelantes de Ferro/uso terapêutico , NAD/metabolismo , Trifosfato de Adenosina/metabolismo , Aldeídos/farmacologia , Animais , Cardiomiopatias/metabolismo , Linhagem Celular , Creatina Quinase Forma MM/genética , Modelos Animais de Doenças , Ataxia de Friedreich/metabolismo , Hidrazonas/farmacologia , Ferro/metabolismo , Quelantes de Ferro/farmacologia , Proteínas de Ligação ao Ferro/genética , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mitocôndrias Cardíacas/efeitos dos fármacos , Mitocôndrias Cardíacas/metabolismo , Ratos , FrataxinaRESUMO
Mitochondrial dysfunction is a pivotal event in many neurodegenerative disease states including traumatic brain injury (TBI) and spinal cord injury (SCI). One possible mechanism driving mitochondrial dysfunction is glutamate excitotoxicity leading to Ca2+-overload in neuronal or glial mitochondria. Therapies that reduce calcium overload and enhance bioenergetics have been shown to improve neurological outcomes. Pioglitazone, an FDA approved compound, has shown neuroprotective properties following TBI and SCI, but the underlying mechanism(s) are unknown. We hypothesized that the interaction between pioglitazone and a novel mitochondrial protein called mitoNEET was the basis for neuroprotection following CNS injury. We discovered that mitoNEET is an important mediator of Ca2+-mediated mitochondrial dysfunction and show that binding mitoNEET with pioglitazone can prevent Ca2+-induced dysfunction. By utilizing wild-type (WT) and mitoNEET null mice, we show that pioglitazone mitigates mitochondrial dysfunction and provides neuroprotection in WT mice, though produces no restorative effects in mitoNEET null mice. We also show that NL-1, a novel mitoNEET ligand, is neuroprotective following TBI in both mice and rats. These results support the crucial role of mitoNEET for mitochondrial bioenergetics, its importance in the neuropathological sequelae of TBI and the necessity of mitoNEET for pioglitazone-mediated neuroprotection. Since mitochondrial dysfunction is a pathobiological complication seen in other diseases such as diabetes, motor neuron disease and cancer, targeting mitoNEET may provide a novel mitoceutical target and therapeutic intervention for diseases that expand beyond TBI.
Assuntos
Lesões Encefálicas Traumáticas/tratamento farmacológico , Metabolismo Energético/efeitos dos fármacos , Proteínas de Ligação ao Ferro/metabolismo , Proteínas de Membrana/metabolismo , Mitocôndrias/efeitos dos fármacos , Fármacos Neuroprotetores/uso terapêutico , Pioglitazona/uso terapêutico , Animais , Lesões Encefálicas Traumáticas/metabolismo , Modelos Animais de Doenças , Proteínas de Ligação ao Ferro/genética , Masculino , Proteínas de Membrana/genética , Camundongos , Camundongos Knockout , Mitocôndrias/metabolismo , Neuroproteção/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , Pioglitazona/farmacologia , Ratos , Ratos Sprague-DawleyRESUMO
OBJECTIVE: The purpose of this prospective study was to assess the effects of selenium supplementation on TSH and interferon-γ inducible chemokines (CXCL9, CXCL10 and CXCL11) levels in patients with subclinical hypothyroidism due to Hashimoto's thyroiditis. PATIENTS AND METHODS: Patients with subclinical hypothyroidism due to Hashimoto thyroiditis were prospectively enrolled in the SETI study. They received 83mcg of selenomethionine/day orally in a soft gel capsule for 4 months with water after a meal. No further treatment was given. All patients were measured thyroid hormone, TPOAb, CXCL9, CXCL10, CXCL11, iodine, and selenium levels at baseline and at study end. RESULTS: 50 patients (43/7 female/male, median age 43.9±11.8 years) were enrolled, of which five withdrew from the study. At the end of the study, euthyroidism was restored in 22/45 (48.9%) participants (responders), while 23 patients remained hypothyroid (non-responders). There were no significant changes in TPOAb, CXCL9, CXCL10, CXCL11, and iodine levels from baseline to the end of the study in both responders and non-responders. TSH levels were re-tested six months after selenomethionine withdrawal: 83.3% of responding patients remained euthyroid, while only 14.2% of non-responders became euthyroid. CONCLUSIONS: The SETI study shows that short-course supplementation with selenomethionine is associated to a normalization of serum TSH levels which is maintained 6 months after selenium withdrawal in 50% of patients with subclinical hypothyroidism due to chronic autoimmune thyroiditis. This TSH-lowering effect of selenium supplementation is unlikely to be related to changes in humoral markers of autoimmunity and/or circulating CXCL9.
Assuntos
Doença de Hashimoto/complicações , Hipotireoidismo/sangue , Selênio/sangue , Selenometionina/administração & dosagem , Administração Oral , Adulto , Idoso , Análise de Variância , Anticorpos/sangue , Autoantígenos/imunologia , Quimiocina CXCL10/sangue , Quimiocina CXCL11/sangue , Quimiocina CXCL2/sangue , Feminino , Doença de Hashimoto/sangue , Humanos , Hipotireoidismo/etiologia , Hipotireoidismo/terapia , Interferon gama , Iodeto Peroxidase/imunologia , Iodo/sangue , Proteínas de Ligação ao Ferro/imunologia , Modelos Logísticos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Curva ROC , Tireotropina/sangue , Resultado do Tratamento , Adulto JovemRESUMO
BACKGROUND: Thyroid gland is a probable goal tissue for radiation-related injury. Occupational exposure to ionizing radiation leads to thyroid dysfunction and exposure to high dose may lead to thyroid carcinoma. OBJECTIVE: Evaluation of the role of Thyroid peroxidase antibody as a predictor for thyroid dysfunction among nurses and technicians in the radiology department in Mansoura Specialized Medical hospital (MSMH). SUBJECTS AND METHODS: Subjects were Nurses and technicians who are working in (MSMH) with persistent daily duty in the last 3 years and fulfilling the inclusion and exclusion criteria. All subjects included in the study were recruited in one month and divided into two groups; Group 1: 50 subjects who were working in radiology, coronary angiography and ERCP unit, Radiation -exposed group. Group 2: 33 subjects who were working in In-patient departments and in out- patient clinics and not exposed to any type of radiation. Non fasting blood sample was taken from all enrolled subjects for measurement of TSH and Anti-TPO. RESULTS: TPO was positively and significantly correlated to age, TSH, duration of radiology/ y (r=0.388, 0.364, 0.342respectively) p value <0.05. Roc curve was done to detect the sensitivity and specificity of TSH in relation to TPO that revealed the cutoff value of TSH > 1.69 with Sensitivity and Specificity. PPV, NPV and accuracy at cutoff >1.69 were 70.6%, 51.5%, 42.8%, 77.3% and 58%. CONCLUSION: Working personnel with positive anti TPO and their TSH levels are more than 1.69 associated with symptoms of hypothyroidism, a trial of treatment is mandatory to relieve symptoms.
Assuntos
Autoantígenos/sangue , Pessoal de Saúde , Hospitais Especializados , Iodeto Peroxidase/sangue , Proteínas de Ligação ao Ferro/sangue , Exposição Ocupacional/efeitos adversos , Lesões por Radiação/sangue , Doenças da Glândula Tireoide/sangue , Adulto , Autoanticorpos/sangue , Autoanticorpos/efeitos da radiação , Autoantígenos/efeitos da radiação , Estudos Transversais , Egito/epidemiologia , Feminino , Humanos , Iodeto Peroxidase/efeitos da radiação , Proteínas de Ligação ao Ferro/efeitos da radiação , Masculino , Pessoa de Meia-Idade , Valor Preditivo dos Testes , Exposição à Radiação/efeitos adversos , Lesões por Radiação/diagnóstico , Doenças da Glândula Tireoide/epidemiologia , Adulto JovemRESUMO
Friedreich's ataxia (FA) is a neurodegenerative disease with no approved therapy that is the result of frataxin deficiency. The identification of human FA blood biomarkers related to disease severity and neuro-pathomechanism could support clinical trials of drug efficacy. To try to identify human biomarkers of neuro-pathomechanistic relevance, we compared the overlapping gene expression changes of primary blood and skin cells of FA patients with changes in the Dorsal Root Ganglion (DRG) of the KIKO FA mouse model. As DRG is the primary site of neurodegeneration in FA, our goal was to identify which changes in blood and skin of FA patients provide a 'window' into the FA neuropathomechanism inside the nervous system. In addition, gene expression in frataxin-deficient neuroglial cells and FA mouse hearts were compared for a total of 5 data sets. The overlap of these changes strongly supports mitochondrial changes, apoptosis and alterations of selenium metabolism. Consistent biomarkers were observed, including three genes of mitochondrial stress (MTIF2, ENO2), apoptosis (DDIT3/CHOP), oxidative stress (PREX1), and selenometabolism (SEPW1). These results prompted our investigation of the GPX1 activity as a marker of selenium and oxidative stress, in which we observed a significant change in FA patients. We believe these lead biomarkers that could be assayed in FA patient blood as indicators of disease severity and progression, and also support the involvement of mitochondria, apoptosis and selenium in the neurodegenerative process.