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Several redox modifications have been described during viral infection, including influenza virus infection, but little is known about glutathionylation and this respiratory virus. Glutathionylation is a reversible, post-translational modification, in which protein cysteine forms transient disulfides with glutathione (GSH), catalyzed by cellular oxidoreductases and in particular by glutaredoxin (Grx). We show here that (i) influenza virus infection induces protein glutathionylation, including that of viral proteins such as hemagglutinin (HA); (ii) Grx1-mediated deglutathionylation is important for the viral life cycle, as its inhibition, either with an inhibitor of its enzymatic activity or by siRNA, decreases viral replication. Overall these data contribute to the characterization of the complex picture of redox regulation of the influenza virus replication cycle and could help to identify new targets to control respiratory viral infection.
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Influenza Humana , Infecções por Orthomyxoviridae , Humanos , Glutationa/metabolismo , Oxirredução , Oxirredutases/metabolismo , Replicação Viral , Processamento de Proteína Pós-TraducionalRESUMO
BACKGROUND/AIMS: Community-based assessment and management of chronic liver disease (CLD) in people who are homeless (PWAH) remain poorly described. We aimed to determine prevalence/predictors of CLD in PWAH and assess the performance of non-invasive liver fibrosis and injury markers. METHODS: The Vulnerable Adult LIver Disease (VALID) study provided a "one-stop" liver service based at homeless hostels. Our primary outcome was the prevalence of clinically significant hepatic fibrosis (CSHF; liver stiffness measurement (LSM) ≥8 kPa). RESULTS: Total individuals recruited were 127, mean ± SD age 47 ± 9.4 years, 50% (95% CI 41%-59%) and 39% (95% CI 31%-48%) having alcohol dependence and a positive HCV RNA respectively. CSHF was detected in 26% (95% CI 17%-35%), independent predictors being total alcohol unit/week (OR 1.01, 95% CI 1.00-1.02, P = .002) and HCV RNA positivity (OR 2.93, 95% CI 1.12-7.66, P = .029). There was moderate agreement between LSM and Enhanced Liver Fibrosis (ELF) score (kappa 0.536, P < .001) for CSHF as assessed by LSM ≥8 kPa. Those with CSHF had significantly higher levels of IFN-γ (P = .002), IL-6 (P = .001), MMP-2 (P = .006), ccCK-18 (P < .001) and ELF biomarkers (P < .001), compared to those without CSHF. Service uptake was ≥95%. Direct acting antiviral (DAA) treatment completion was 93% (95% CI 77%-99%), sustained virological response (SVR) being 83% (95% CI 64%-94%). CONCLUSION: There is a significant liver disease burden from HCV and alcohol in PWAH. Non-invasive liver fibrosis and injury markers can help in identifying such individuals in the community. Despite a challenging cohort, excellent service uptake and high DAA-based SVRs can be achieved.
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Técnicas de Imagem por Elasticidade , Hepatite C Crônica , Adulto , Antivirais/uso terapêutico , Biomarcadores , Hepacivirus/genética , Hepatite C Crônica/complicações , Hepatite C Crônica/tratamento farmacológico , Hepatite C Crônica/epidemiologia , Humanos , Fígado/patologia , Cirrose Hepática/patologia , Pessoa de Meia-IdadeRESUMO
An amendment to this paper has been published and can be accessed via the original article.
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BACKGROUND: Vitamin D deficiency increases the risk of developing multiple sclerosis (MS) but it is unclear whether vitamin D supplementation improves the clinical course of MS, and there is uncertainty about the dose and form of vitamin D (D2 or D3) to be used. The mechanisms underlying the effects of vitamin D in MS are not clear. Vitamin D3 increases the rate of differentiation of primary oligodendrocyte precursor cells (OPCs), suggesting that it might help remyelination in addition to modulating the immune response. Here we analyzed the transcriptome of differentiating rat CG4 OPCs treated with vitamin D2 or with vitamin D3 at 24 h and 72 h following onset of differentiation. METHODS: Gene expression in differentiating CG4 cells in response to vitamin D2 or D3 was quantified using Agilent DNA microarrays (n = 4 replicates), and the transcriptome data were processed and analysed using the R software environment. Differential expression between the experimental conditions was determined using LIMMA, applying the Benjamini and Hochberg multiple testing correction to p-values, and significant genes were grouped into co-expression clusters by hierarchical clustering. The functional significance of gene groups was explored by pathway enrichment analysis using the clusterProfiler package. RESULTS: Differentiation alone changed the expression of about 10% of the genes at 72 h compared to 24 h. Vitamin D2 and D3 exerted different effects on gene expression, with D3 influencing 1272 genes and D2 574 at 24 h. The expression of the vast majority of these genes was either not changed in differentiating cells not exposed to vitamin D or followed the same trajectory as the latter. D3-repressed genes were enriched for Gene Ontology (GO) categories including transcription factors and the Notch pathway, while D3-induced genes were enriched for the Ras pathway. CONCLUSIONS: This study shows that vitamin D3, compared with D2, changes the expression of a larger number of genes in OLs. Identification of genes affected by D3 in OLs should help to identify mechanisms mediating its action in MS.
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Colecalciferol/farmacologia , Ergocalciferóis/farmacologia , Regulação da Expressão Gênica/efeitos dos fármacos , Células Precursoras de Oligodendrócitos/efeitos dos fármacos , Células Precursoras de Oligodendrócitos/metabolismo , Animais , Biomarcadores , Diferenciação Celular/genética , Linhagem Celular , Células Cultivadas , Biologia Computacional , Perfilação da Expressão Gênica , Ratos , TranscriptomaRESUMO
An amendment to this paper has been published and can be accessed via the original article.
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BACKGROUND: Endothelial injury is an early and enduring feature of cardiovascular disease. Inflammation and hypoxia may be responsible for this, and are often associated with the up-regulation of several transcriptional factors that include Hypoxia Inducible Factor-1 (HIF-1). Although it has been reported that HIF-1α is detectable in plasma, it is known to be unstable. Our aim was to optimize an assay for HIF-1α to be applied to in vitro and in vivo applications, and to use this assay to assess the release kinetics of HIF-1α following endothelial injury. METHODS: An ELISA for the measurement of HIF-1α in cell-culture medium and plasma was optimized, and the assay was used to determine the best conditions for sample collection and storage. The results of the ELISA were validated using Western blotting and immunohistochemistry (IHC). In vitro, a standardized injury was produced in a monolayer of rat aortic endothelial cells (RAECs) and intracellular HIF-1α was measured at intervals over 24 h. In vivo, a rat angioplasty model was used. The right carotid artery was injured using a 2F Fogarty balloon catheter. HIF-1α was measured in the plasma and in the arterial tissue (0, 1, 2, 3 and 5 days post injury). RESULTS: The HIF-1α ELISA had a limit of detection of 2.7 pg/mL and was linear up to 1000 pg/ mL. Between and within-assay, the coefficient of variation values were less than 15%. HIF-1α was unstable in cell lysates and plasma, and it was necessary to add a protease inhibitor immediately after collection, and to store samples at -80 °C prior to analysis. The dynamics of HIF-1α release were different for the in vitro and in vivo models. In vitro, HIF-1α reached maximum concentrations approximately 2 h post injury, whereas peak values in plasma and tissues occurred approximately 2 days post injury, in the balloon injury model. CONCLUSION: HIF-1α can be measured in plasma, but this requires careful sample collection and storage. The carotid artery balloon injury model is associated with the transient release of HIF-1α into the circulation that probably reflects the hypoxia induced in the artery wall.
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Lesões das Artérias Carótidas/metabolismo , Células Endoteliais/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Angioplastia com Balão , Animais , Linhagem Celular , Ensaio de Imunoadsorção Enzimática , Masculino , Ratos Sprague-Dawley , Fator A de Crescimento do Endotélio Vascular/genéticaRESUMO
BACKGROUND: The pro-myelinating effects of leukemia inhibitory factor (LIF) and other cytokines of the gp130 family, including oncostatin M (OSM) and ciliary neurotrophic factor (CNTF), have long been known, but controversial results have also been reported. We recently overexpressed erythropoietin receptor (EPOR) in rat central glia-4 (CG4) oligodendrocyte progenitor cells (OPCs) to study the mechanisms mediating the pro-myelinating effects of erythropoietin (EPO). In this study, we investigated the effect of co-treatment with EPO and LIF. METHODS: Gene expression in undifferentiated and differentiating CG4 cells in response to EPO and LIF was analysed by DNA microarrays and by RT-qPCR. Experiments were performed in biological replicates of N ≥ 4. Functional annotation and biological term enrichment was performed using DAVID (Database for Annotation, Visualization and Integrated Discovery). The gene-gene interaction network was visualised using STRING (Search Tool for the Retrieval of Interacting Genes). RESULTS: In CG4 cells treated with 10 ng/ml of EPO and 10 ng/ml of LIF, EPO-induced myelin oligodendrocyte glycoprotein (MOG) expression, measured at day 3 of differentiation, was inhibited ≥4-fold (N = 5, P < 0.001). Inhibition of EPO-induced MOG was also observed with OSM and CNTF. Analysis of the gene expression profile of CG4 differentiating cells treated for 20 h with EPO and LIF revealed LIF inhibition of EPO-induced genes involved in lipid transport and metabolism, previously identified as positive regulators of myelination in this system. In addition, among the genes induced by LIF, and not by differentiation or by EPO, the role of suppressor of cytokine signaling 3 (SOCS3) and toll like receptor 2 (TLR2) as negative regulators of myelination was further explored. LIF-induced SOCS3 was associated with MOG inhibition; Pam3, an agonist of TLR2, inhibited EPO-induced MOG expression, suggesting that TLR2 is functional and its activation decreases myelination. CONCLUSIONS: Cytokines of the gp130 family may have negative effects on myelination, depending on the cytokine environment.
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Eritropoetina/farmacologia , Fator Inibidor de Leucemia/farmacologia , Bainha de Mielina/genética , Oligodendroglia/efeitos dos fármacos , Animais , Linhagem Celular , Oligodendroglia/metabolismo , Análise de Sequência com Séries de Oligonucleotídeos , Ratos , Receptores da Eritropoetina/genética , Transcriptoma/efeitos dos fármacosRESUMO
The mechanism by which oxidative stress induces inflammation and vice versa is unclear but is of great importance, being apparently linked to many chronic inflammatory diseases. We show here that inflammatory stimuli induce release of oxidized peroxiredoxin-2 (PRDX2), a ubiquitous redox-active intracellular enzyme. Once released, the extracellular PRDX2 acts as a redox-dependent inflammatory mediator, triggering macrophages to produce and release TNF-α. The oxidative coupling of glutathione (GSH) to PRDX2 cysteine residues (i.e., protein glutathionylation) occurs before or during PRDX2 release, a process central to the regulation of immunity. We identified PRDX2 among the glutathionylated proteins released in vitro by LPS-stimulated macrophages using mass spectrometry proteomic methods. Consistent with being part of an inflammatory cascade, we find that PRDX2 then induces TNF-α release. Unlike classical inflammatory cytokines, PRDX2 release does not reflect LPS-mediated induction of mRNA or protein synthesis; instead, PRDX2 is constitutively present in macrophages, mainly in the reduced form, and is released in the oxidized form on LPS stimulation. Release of PRDX2 is also observed in human embryonic kidney cells treated with TNF-α. Importantly, the PRDX2 substrate thioredoxin (TRX) is also released along with PRDX2, enabling an oxidative cascade that can alter the -SH status of surface proteins and thereby facilitate activation via cytokine and Toll-like receptors. Thus, our findings suggest a model in which the release of PRDX2 and TRX from macrophages can modify the redox status of cell surface receptors and enable induction of inflammatory responses. This pathway warrants further exploration as a potential novel therapeutic target for chronic inflammatory diseases.
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Glutationa/metabolismo , Inflamação/metabolismo , Macrófagos/metabolismo , Estresse Oxidativo , Peroxirredoxinas/metabolismo , Animais , Western Blotting , Linhagem Celular , Humanos , Lipopolissacarídeos/farmacologia , Macrófagos/efeitos dos fármacos , CamundongosRESUMO
Erythropoietin (EPO) has both erythropoietic and tissue-protective properties. The EPO analogues carbamylated EPO (CEPO) and pyroglutamate helix B surface peptide (pHBSP) lack the erythropoietic activity of EPO but retain the tissue-protective properties that are mediated by a heterocomplex of EPO receptor (EPOR) and the ß common receptor (ßCR). We studied the action of EPO and its analogues in a model of wound healing where a bovine aortic endothelial cells (BAECs) monolayer was scratched and the scratch closure was assessed over 24 h under different oxygen concentrations. We related the effects of EPO and its analogues on repair to their effect on BAECs proliferation and migration (evaluated using a micro-Boyden chamber). EPO, CEPO and pHBSP enhanced scratch closure only at lower oxygen (5%), while their effect at atmospheric oxygen (21%) was not significant. The mRNA expression of EPOR was doubled in 5% compared with 21% oxygen, and this was associated with increased EPOR assessed by immunofluorescence and Western blot. By contrast, ßCR mRNA levels were similar in 5% and 21% oxygen. EPO and its analogues increased both BAECs proliferation and migration, suggesting that both may be involved in the reparative process. The priming effect of low oxygen tension on the action of tissue-protective cytokines may be of relevance to vascular disease, including atherogenesis and restenosis.
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Erythropoietin (EPO) is a neuroprotective cytokine in models of ischemic and nervous system injury, where it reduces neuronal apoptosis and inflammatory cytokines and increases neurogenesis and angiogenesis. EPO also improves cognition in healthy volunteers and schizophrenic patients. We studied the effect of EPO administration on the gene-expression profile in the ischemic cortex of rats after cerebral ischemia at early time points (2 and 6 h). EPO treatment up-regulated genes already increased by ischemia. Hierarchical clustering and analysis of overrepresented functional categories identified genes implicated in synaptic plasticity-Arc, BDNF, Egr1, and Egr2, of which Egr2 was the most significantly regulated. Up-regulation of Arc, BDNF, Dusp5, Egr1, Egr2, Egr4, and Nr4a3 was confirmed by quantitative PCR. We investigated the up-regulation of Egr2/Krox20 further because of its role in neuronal plasticity. Its elevation by EPO was confirmed in an independent in vivo experiment of cerebral ischemia in rats. Using the rat neuroblastoma B104, we found that wild-type cells that do not express EPO receptor (EPOR) do not respond to EPO by inducing Egr2. However, EPOR-expressing B104 cells induce Egr2 early upon incubation with EPO, indicating that Egr2 induction is a direct effect of EPO and that EPOR mediates this effect. Because these changes occur in vivo before decreased inflammatory cytokines or neuronal apoptosis is evident, these findings provide a molecular mechanism for the neuroreparative effects of cytokines and suggest a mechanism of neuroprotection by which promotion of a plastic phenotype results in decreased inflammation and neuronal death.
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Encéfalo/metabolismo , Eritropoetina/fisiologia , Perfilação da Expressão Gênica , Plasticidade Neuronal/genética , Acidente Vascular Cerebral/genética , Animais , Reação em Cadeia da Polimerase , RatosRESUMO
Erythropoietin (EPO) has protective effects in neurodegenerative and neuroinflammatory diseases, including in animal models of multiple sclerosis, where EPO decreases disease severity. EPO also promotes neurogenesis and is protective in models of toxic demyelination. In this study, we asked whether EPO could promote neurorepair by also inducing remyelination. In addition, we investigated whether the effect of EPO could be mediated by the classical erythropoietic EPO receptor (EPOR), since it is still questioned if EPOR is functional in nonhematopoietic cells. Using CG4 cells, a line of rat oligodendrocyte precursor cells, we found that EPO increases the expression of myelin genes (myelin oligodendrocyte glycoprotein [MOG] and myelin basic protein [MBP]). EPO had no effect in wild-type CG4 cells, which do not express EPOR, whereas it increased MOG and MBP expression in cells engineered to overexpress EPOR (CG4-EPOR). This was reflected in a marked increase in MOG protein levels, as detected by Western blot. In these cells, EPO induced by 10-fold the early growth response gene 2 (Egr2), which is required for peripheral myelination. However, Egr2 silencing with a siRNA did not reverse the effect of EPO, indicating that EPO acts through other pathways. In conclusion, EPO induces the expression of myelin genes in oligodendrocytes and this effect requires the presence of EPOR. This study demonstrates that EPOR can mediate neuroreparative effects.
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Eritropoetina/farmacologia , Bainha de Mielina/genética , Oligodendroglia/efeitos dos fármacos , Receptores da Eritropoetina/metabolismo , Animais , Linhagem Celular , Linhagem Celular Tumoral , Regulação da Expressão Gênica/efeitos dos fármacos , Proteína Básica da Mielina/genética , Glicoproteína Mielina-Oligodendrócito/genética , Glicoproteína Mielina-Oligodendrócito/metabolismo , Oligodendroglia/metabolismo , RatosRESUMO
Objective: There is an association between frailty and arterial stiffness. However, arterial stiffness does not uniformly correlate with the spectrum of frailty states. Both oxidative stress and inflammaging contribute to vascular ageing. There are no human studies exploring links between arterial stiffness, oxidative stress, inflammaging and frailty. Our objective is to investigate arterial stiffness and inflammaging as predictors of frailty states. Methods: An observational longitudinal cohort study will be used to examine the association between arterial stiffness, oxidative stress and inflammation in 50 older adults (⩾70 years) with clinical frailty scores (CFS) ⩽6 over 6 months. All study measurements will be taken at baseline. Frailty assessment will include hand-grip strength, timed-up and go test, mini-mental state examination, geriatric depression scale and sarcopenia using body composition measurements with Tanita®. Arterial stiffness measurements will include carotid-femoral pulse wave velocity (cfPWV) and carotid-radial pulse wave velocity (crPWV) using Complior (Alam Medical, France). CAVI device will measure Cardio-ankle vascular index and ankle brachial index (ABI). Oxidative stress blood markers nitrotyrosine (NT) and 8-hydroxy-2'-deoxyguanosin (8-oxo-dG) and inflammation markers high-sensitive C-reactive protein (hs-CRP) and interlukin-6(IL-6) will be measured at baseline and 6 month along with lipid profile and glycated haemoglobin. Results data analysis plan: Descriptive statistics for continuous data using means and standard deviations for normality distributed variables or medians and inter-quartile ranges for skewed variables will be used. Participants will be categorised into CFS 1-3, and CFS 4-6. Categorical data will use frequencies and comparison between groups. Change in frailty between the groups over 6 months will be compared using paired t-test. Simple linear regression will be done between frailty measures, arterial stiffness, inflammation and oxidative stress biomarkers. Significance will be at P < .05. Conclusion: This study data will inform a larger, multi-centre study exploring further the interplay between frailty, biomarkers and arterial stiffness parameters.
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CNS neurons use robust cytoprotective mechanisms to ensure survival and functioning under conditions of injury. These involve pathways induced by endogenous neuroprotective cytokines such as erythropoietin (EPO). Recently, in contrast to its well known deleterious roles, TNF has also been shown to exhibit neuroprotective properties. In the present study, we investigated the molecular mechanisms by which TNF receptor (TNFR)I mediates neuroprotection by comparing the gene expression profiles of lesioned cortex from WT and TNFRI KO mice after permanent middle cerebral artery occlusion. Several known neuroprotective molecules were identified as TNFRI targets, notably members of the Bcl-2 family, DNA repair machinery and cell cycle, developmental, and differentiation factors, neurotransmitters and growth factors, as well as their receptors, including EPO receptor (EPOR), VEGF, colony-stimulating factor receptor 1, insulin-like growth factor (IGF), and nerve growth factor (NGF). Further analysis showed that induction of EPOR and VEGF expression in primary cortical neurons after glucose deprivation (GD) largely depended on TNFRI and was further up-regulated by TNF. Also, EPO- and VEGF-induced neuroprotection against GD, oxygen-glucose deprivation, and NMDA excitotoxicity depended significantly on TNFRI presence. Finally, EPO prevented neuronal damage induced by kainic acid in WT but not TNFRI KO mice. Our results identify cross-talk between tissue protective cytokines, specifically that TNFRI is necessary for constitutive and GD-induced expression of EPOR and VEGF and for EPO-mediated neuroprotection.
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Isquemia Encefálica/genética , Citoproteção/genética , Eritropoetina/genética , Agonistas de Aminoácidos Excitatórios/toxicidade , Neurônios/metabolismo , Receptores Tipo I de Fatores de Necrose Tumoral/fisiologia , Fator A de Crescimento do Endotélio Vascular/genética , Animais , Isquemia Encefálica/patologia , Morte Celular/genética , Perfilação da Expressão Gênica , Ácido Caínico/toxicidade , Masculino , Camundongos , Camundongos Knockout , N-Metilaspartato/toxicidade , Neurônios/efeitos dos fármacos , Neurônios/patologia , Análise de Sequência com Séries de Oligonucleotídeos , Receptores da Eritropoetina/genética , Receptores Tipo I de Fatores de Necrose Tumoral/genética , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Oxidative stress is defined as an imbalance between the levels of reactive oxygen species (ROS) and antioxidant defences. The view of oxidative stress as a cause of cell damage has evolved over the past few decades to a much more nuanced view of the role of oxidative changes in cell physiology. This is no more evident than in the field of immunity, where oxidative changes are now known to regulate many aspects of the immune response, and inflammatory pathways in particular. Our understanding of redox regulation of immunity now encompasses not only increases in reactive oxygen and nitrogen species, but also changes in the activities of oxidoreductase enzymes. These enzymes are important regulators of immune pathways both via changes in their redox activity, but also via other more recently identified cytokine-like functions. The emerging picture of redox regulation of immune pathways is one of increasing complexity and while therapeutic targeting of the redox environment to treat inflammatory disease is a possibility, any such strategy is likely to be more nuanced than simply inhibiting ROS production.
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Antioxidantes , Estresse Oxidativo , Oxirredução , Espécies Reativas de OxigênioRESUMO
Patients who have experienced a first cerebral ischemic event are at increased risk of recurrent stroke. There is strong evidence that low-level inflammation as measured by high sensitivity C-reactive protein (hs-CRP) is a predictor of further ischemic events. Other mechanisms implicated in the pathogenesis of stroke may play a role in determining the risk of secondary events, including oxidative stress and the adaptive response to it and activation of neuroprotective pathways by hypoxia, for instance through induction of erythropoietin (EPO). This study investigated the association of the levels of CRP, peroxiredoxin 1 (PRDX1, an indicator of the physiological response to oxidative stress) and EPO (a neuroprotective factor produced in response to hypoxia) with the risk of a second ischemic event. Eighty patients with a diagnosis of lacunar stroke or transient ischemic attack (TIA) were included in the study and a blood sample was collected within 14 days from the initial event. Hs-CRP, PRDX1, and EPO were measured by ELISA. Further ischemic events were recorded with a mean follow-up of 42 months (min 24, max 64). Multivariate analysis showed that only CRP was an independent predictor of further events with an observed risk (OR) of 1.14 (P = 0.034, 95% CI 1.01-1.29). No association was observed with the levels of PRDX1 or EPO. A receiver operating curve (ROC) determined a cut-off CRP level of 3.25 µg/ml, with a 46% sensitivity and 81% specificity. Low-level inflammation as detected by hs-CRP is an independent predictor of recurrent cerebrovascular ischemic events.
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Biomarcadores/sangue , Proteína C-Reativa/metabolismo , Ataque Isquêmico Transitório/patologia , Acidente Vascular Cerebral Lacunar/patologia , Idoso , Eritropoetina/sangue , Feminino , Humanos , Inflamação/sangue , Ataque Isquêmico Transitório/sangue , Masculino , Pessoa de Meia-Idade , Peroxirredoxinas/sangue , Recidiva , Sensibilidade e Especificidade , Acidente Vascular Cerebral Lacunar/sangueRESUMO
Inflammation is associated with production of reactive oxygen species (ROS) and results in the induction of thioredoxin (TXN) and peroxiredoxins (PRDXs) and activation of nuclear factor-like 2 (Nrf2). In this study we have used the mouse RAW 264.7 macrophage and the human THP-1 monocyte cell line to investigate the pattern of expression of three Nrf2 target genes, PRDX1, TXN reductase (TXNRD1) and heme oxygenase (HMOX1), by activation of different Toll-like receptors (TLRs). We found that, while the TLR4 agonist lipopolysaccharide (LPS) induces all three genes, the pattern of induction with agonists for TLR1/2, TLR3, TLR2/6 and TLR7/8 differs depending on the gene and the cell line. In all cases, the extent of induction was HMOX1>TXNRD1>PRDX1. Since LPS was a good inducer of all genes in both cell lines, we studied the mechanisms mediating LPS induction of the three genes using mouse RAW 264.7â¯cells. To assess the role of ROS we used the antioxidant N-acetylcysteine (NAC). Only LPS induction of HMOX1 was inhibited by NAC while that of TXNRD1 and PRDX1 was unaffected. These three genes were also induced by phorbol myristate acetate (PMA), a ROS-inducer acting by activation of protein kinase C (PKC). The protein kinase inhibitor staurosporine inhibited the induction of all three genes by PMA but only that of HMOX1 by LPS. This indicates that activation of these genes by inflammatory agents is regulated by different mechanisms involving either ROS or protein kinases, or both.
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Inflamação/genética , Fator 2 Relacionado a NF-E2/genética , Peroxirredoxinas/genética , Tiorredoxina Redutase 1/genética , Animais , Regulação da Expressão Gênica/efeitos dos fármacos , Heme Oxigenase-1/genética , Inflamação/metabolismo , Inflamação/patologia , Lipopolissacarídeos/farmacologia , Glicoproteínas de Membrana/genética , Proteínas de Membrana/genética , Camundongos , Proteína Quinase C/antagonistas & inibidores , Proteína Quinase C/genética , Células RAW 264.7 , Espécies Reativas de Oxigênio/metabolismo , Estaurosporina/farmacologia , Receptor 2 Toll-Like/genética , Receptor 3 Toll-Like/genética , Receptor 4 Toll-Like/genética , Receptor 7 Toll-Like/genéticaRESUMO
Peroxiredoxin 1 (PRDX1) is an antioxidant enzyme that, when secreted, can act as a proinflammatory signal. Here we studied the regulation of intracellular PRDX1 by lipopolysaccharide (LPS) and interferon-gamma (IFN-γ) in the RAW 264.7 mouse macrophage cell line. While LPS or IFN-γ alone did not affect PRDX1 protein levels, their combination led to an almost complete loss of the PRDX1 dimer. This was likely mediated by the increased production of nitric oxide (NO) as it was reversed by the NO synthase inhibitor L-N-methylarginine (L-NMMA), while a NO-releasing agent decreased PRDX1 levels. Inhibition of the proteasome with MG132 also prevented the loss of the PRDX1 dimer, suggesting that the decrease is due to a NO-activated proteasomal degradation pathway. By contrast with the decrease in protein levels, LPS increased PRDX1 mRNA and this effect was amplified by IFN-γ. Two other Nrf2 target genes, thioredoxin reductase (TXNRD1) and haem oxygenase (HMOX1), were also induced by LPS but IFN-γ did not increase their expression further. This study shows that inflammation differentially regulates PRDX1 at the levels of protein stability and gene expression, and that NO plays a key role in this mechanism.
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Inflamação , Macrófagos/metabolismo , Óxido Nítrico/metabolismo , Peroxirredoxinas/metabolismo , Animais , Regulação da Expressão Gênica , Interferon gama , Lipopolissacarídeos , Macrófagos/enzimologia , Camundongos , Peroxirredoxinas/genética , Proteólise , Células RAW 264.7 , Espécies Reativas de Nitrogênio/metabolismoRESUMO
INTRODUCTION: The ABSORB bioresorbable vascular scaffold (BVS) is associated with greater neointimal proliferation and thrombotic rate than metal stent. The role of inflammatory biomarkers on neointimal proliferation has not been studied in the setting of BVS implantation. PATIENTS AND METHODS: Thirty patients had arterial blood sampling before elective percutaneous coronary intervention with the ABSORB BVS and at 9-months follow-up. Plasma levels of interleukin-6, soluble CD40 ligand, monocyte chemotactic protein-1 and C-reactive protein were measured using enzyme-linked immunosorbent assay. Baseline and follow-up levels were compared for each biomarker. Optical frequency domain imaging was performed at follow-up and the neointimal burden was calculated as the ratio of neointimal area to scaffold area. The levels of inflammatory mediators were correlated with the neointimal burden. RESULTS: There was no significant increase in the levels of biomarkers from baseline to follow-up. Median C-reactive protein levels changed from 1.1 [interquartile range (IQR): 0.5-2.5] to 2.2 (IQR: 0.5-3.5) µg/ml, interleukin-6 from 1.0 (IQR: 0.6-1.4) to 1.0 (IQR: 0.6-1.4) pg/ml, monocyte chemotactic protein-1 from 120.4 (IQR: 86.0-153.4) to 102.0 (IQR: 70.3-148.1) pg/ml and soluble CD40 ligand from 108.3 (IQR: 74.1-173.7) to 112.0 (IQR: 71.0-225.9) pg/ml. The average neointimal burden in the cohort was 18±6%. Baseline, follow-up and change in plasma levels of inflammatory markers between these two time points did not correlate with the neointimal burden. CONCLUSION: Elective percutaneous coronary intervention with the ABSORB BVS does not provoke a chronic inflammatory response. The degree of neointimal proliferation after elective implantation of the ABSORB BVS is independent of the pre-existing inflammatory environment.
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Implantes Absorvíveis , Doença da Artéria Coronariana/terapia , Estenose Coronária/terapia , Vasos Coronários/patologia , Mediadores da Inflamação/sangue , Neointima , Intervenção Coronária Percutânea/instrumentação , Idoso , Biomarcadores/sangue , Proliferação de Células , Doença da Artéria Coronariana/sangue , Doença da Artéria Coronariana/diagnóstico por imagem , Doença da Artéria Coronariana/patologia , Estenose Coronária/sangue , Estenose Coronária/diagnóstico por imagem , Estenose Coronária/patologia , Vasos Coronários/diagnóstico por imagem , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Desenho de Prótese , Fatores de Tempo , Resultado do TratamentoRESUMO
[This corrects the article DOI: 10.3389/fimmu.2018.01215.].
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Erythropoietin (EPO) is of great interest as a therapy for many of the central nervous system (CNS) diseases and its administration is protective in experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). Endogenous EPO is induced by hypoxic/ischemic injury, but little is known about its expression in other CNS diseases. We report here that EPO expression in the spinal cord is induced in mouse models of chronic or relapsing-remitting EAE, and is prominently localized to motoneurons. We found a parallel increase of hypoxia-inducible transcription factor (HIF)-1 alpha, but not HIF-2 alpha, at the mRNA level, suggesting a possible role of non-hypoxic factors in EPO induction. EPO mRNA in the spinal cord was co-expressed with interferon (IFN)-gamma and tumor necrosis factor (TNF), and these cytokines inhibited EPO production in vitro in both neuronal and glial cells. Given the known inhibitory effect of EPO on neuroinflammation, our study indicates that EPO should be viewed as part of the inflammatory/anti-inflammatory network in MS.