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BACKGROUND: Tropospheric ozone is an air pollutant that causes negative effects on vegetation, leading to significant losses in crop productivity. It is generated by chemical reactions in the presence of sunlight between primary pollutants resulting from human activity, such as nitrogen oxides and volatile organic compounds. Due to the constantly increasing emission of ozone precursors, together with the influence of a warming climate on ozone levels, crop losses may be aggravated in the future. Therefore, the search for solutions to mitigate these losses becomes a priority. Ozone-induced abiotic stress is mainly due to reactive oxygen species generated by the spontaneous decomposition of ozone once it reaches the apoplast. In this regard, compounds with antioxidant activity offer a viable option to alleviate ozone-induced damage. Using enzymatic technology, we have developed a process that enables the production of an extract with biostimulant properties from okara, an industrial soybean byproduct. The biostimulant, named as OEE (Okara Enzymatic Extract), is water-soluble and is enriched in bioactive compounds present in okara, such as isoflavones. Additionally, it contains a significant fraction of protein hydrolysates contributing to its functional effect. Given its antioxidant capacity, we aimed to investigate whether OEE could alleviate ozone-induced damage in plants. For that, pepper plants (Capsicum annuum) exposed to ozone were treated with a foliar application of OEE. RESULTS: OEE mitigated ozone-induced damage, as evidenced by the net photosynthetic rate, electron transport rate, effective quantum yield of PSII, and delayed fluorescence. This protection was confirmed by the level of expression of genes associated with photosystem II. The beneficial effect was primarily due to its antioxidant activity, as evidenced by the lipid peroxidation rate measured through malondialdehyde content. Additionally, OEE triggered a mild oxidative response, indicated by increased activities of antioxidant enzymes in leaves (catalase, superoxide dismutase, and guaiacol peroxidase) and the oxidative stress index, providing further protection against ozone-induced stress. CONCLUSIONS: The present results support that OEE protects plants from ozone exposure. Taking into consideration that the promotion of plant resistance against abiotic damage is an important goal of biostimulants, we assume that its use as a new biostimulant could be considered.
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Antioxidantes , Glycine max , Ozônio , Estresse Fisiológico , Ozônio/farmacologia , Glycine max/efeitos dos fármacos , Glycine max/fisiologia , Glycine max/metabolismo , Estresse Fisiológico/efeitos dos fármacos , Antioxidantes/metabolismo , Capsicum/efeitos dos fármacos , Capsicum/fisiologia , Capsicum/metabolismo , Fotossíntese/efeitos dos fármacos , Extratos Vegetais/farmacologiaRESUMO
Chromosomal translocations that generate in-frame oncogenic gene fusions are notable examples of the success of targeted cancer therapies. We have previously described gene fusions of FGFR3-TACC3 (F3-T3) in 3% of human glioblastoma cases. Subsequent studies have reported similar frequencies of F3-T3 in many other cancers, indicating that F3-T3 is a commonly occuring fusion across all tumour types. F3-T3 fusions are potent oncogenes that confer sensitivity to FGFR inhibitors, but the downstream oncogenic signalling pathways remain unknown. Here we show that human tumours with F3-T3 fusions cluster within transcriptional subgroups that are characterized by the activation of mitochondrial functions. F3-T3 activates oxidative phosphorylation and mitochondrial biogenesis and induces sensitivity to inhibitors of oxidative metabolism. Phosphorylation of the phosphopeptide PIN4 is an intermediate step in the signalling pathway of the activation of mitochondrial metabolism. The F3-T3-PIN4 axis triggers the biogenesis of peroxisomes and the synthesis of new proteins. The anabolic response converges on the PGC1α coactivator through the production of intracellular reactive oxygen species, which enables mitochondrial respiration and tumour growth. These data illustrate the oncogenic circuit engaged by F3-T3 and show that F3-T3-positive tumours rely on mitochondrial respiration, highlighting this pathway as a therapeutic opportunity for the treatment of tumours with F3-T3 fusions. We also provide insights into the genetic alterations that initiate the chain of metabolic responses that drive mitochondrial metabolism in cancer.
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Respiração Celular , Proteínas Associadas aos Microtúbulos/genética , Mitocôndrias/metabolismo , Neoplasias/genética , Neoplasias/metabolismo , Proteínas de Fusão Oncogênica/genética , Receptor Tipo 3 de Fator de Crescimento de Fibroblastos/genética , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Encéfalo/patologia , Linhagem Celular Tumoral , Respiração Celular/efeitos dos fármacos , Transformação Celular Neoplásica/efeitos dos fármacos , Feminino , Glioblastoma/tratamento farmacológico , Glioblastoma/genética , Glioblastoma/metabolismo , Glioblastoma/patologia , Humanos , Masculino , Camundongos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/genética , Peptidilprolil Isomerase de Interação com NIMA/química , Peptidilprolil Isomerase de Interação com NIMA/metabolismo , Neoplasias/tratamento farmacológico , Neoplasias/patologia , Biogênese de Organelas , Fosforilação Oxidativa/efeitos dos fármacos , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Peroxissomos/efeitos dos fármacos , Peroxissomos/metabolismo , Fosforilação , Biossíntese de Proteínas , Espécies Reativas de Oxigênio/metabolismo , Receptores de Estrogênio/metabolismo , Transcrição Gênica , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
Mechanisms that maintain cancer stem cells are crucial to tumour progression. The ID2 protein supports cancer hallmarks including the cancer stem cell state. HIFα transcription factors, most notably HIF2α (also known as EPAS1), are expressed in and required for maintenance of cancer stem cells (CSCs). However, the pathways that are engaged by ID2 or drive HIF2α accumulation in CSCs have remained unclear. Here we report that DYRK1A and DYRK1B kinases phosphorylate ID2 on threonine 27 (Thr27). Hypoxia downregulates this phosphorylation via inactivation of DYRK1A and DYRK1B. The activity of these kinases is stimulated in normoxia by the oxygen-sensing prolyl hydroxylase PHD1 (also known as EGLN2). ID2 binds to the VHL ubiquitin ligase complex, displaces VHL-associated Cullin 2, and impairs HIF2α ubiquitylation and degradation. Phosphorylation of Thr27 of ID2 by DYRK1 blocks ID2-VHL interaction and preserves HIF2α ubiquitylation. In glioblastoma, ID2 positively modulates HIF2α activity. Conversely, elevated expression of DYRK1 phosphorylates Thr27 of ID2, leading to HIF2α destabilization, loss of glioma stemness, inhibition of tumour growth, and a more favourable outcome for patients with glioblastoma.
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Glioblastoma/metabolismo , Glioblastoma/patologia , Proteína 2 Inibidora de Diferenciação/metabolismo , Células-Tronco Neoplásicas/metabolismo , Proteína Supressora de Tumor Von Hippel-Lindau/antagonistas & inibidores , Animais , Fatores de Transcrição Hélice-Alça-Hélice Básicos/metabolismo , Hipóxia Celular , Linhagem Celular Tumoral , Proteínas Culina/metabolismo , Humanos , Prolina Dioxigenases do Fator Induzível por Hipóxia/metabolismo , Masculino , Camundongos , Células-Tronco Neoplásicas/patologia , Oxigênio/metabolismo , Fosforilação , Fosfotreonina/metabolismo , Ligação Proteica , Proteínas Serina-Treonina Quinases/antagonistas & inibidores , Proteínas Serina-Treonina Quinases/metabolismo , Proteínas Tirosina Quinases/antagonistas & inibidores , Proteínas Tirosina Quinases/metabolismo , Ubiquitinação , Proteína Supressora de Tumor Von Hippel-Lindau/metabolismo , Ensaios Antitumorais Modelo de Xenoenxerto , Quinases DyrkRESUMO
INTRODUCTION: In the context of the COVID-19 pandemic, there is concern regarding the impact of the influenza season. OBJECTIVE: To analyze the impact of influenza immunization history on patients with SARS-CoV-2 infection. METHODS: Patients older than 18 years with COVID-19, registered between March and August 2020, were included. Data were analyzed using Fisher's exact test and Student's t-test. To evaluate the impact on mortality, a logistic regression model was used; the relationship between the percentage of patients who received the influenza vaccine and mortality was determined with Pearson's correlation coefficient. RESULTS: 16,879 participants were included; 17 % had a history of influenza vaccination. Mortality was lower in the group with a history of vaccination (3.5 % vs. 7 %, p < 0.0001). The vaccination rate had an inverse relationship with the mortality rate (Pearson's r: -0.922, p = 0.026). CONCLUSIONS: Previous influenza immunization was an independent protective factor for mortality in patients with COVID-19. Although further studies are needed to determine a causal relationship, it would be reasonable to increase influenza immunization in the general population.
INTRODUCCIÓN: En el contexto de la pandemia de COVID-19 existe inquietud en cuanto al impacto de la temporada de influenza. OBJETIVO: Analizar el impacto del antecedente de inmunización contra influenza en pacientes con infección por SARS-CoV-2. MÉTODOS: Se incluyeron pacientes mayores de 18 años con COVID-19, registrados entre marzo y agosto de 2020. Los datos fueron analizados mediante las pruebas exacta de Fisher y t de Student. Para evaluar el impacto en la mortalidad se utilizó un modelo de regresión logística; la relación entre el porcentaje de pacientes a quienes se aplicó la vacuna contra la influenza y la mortalidad fue determinada con el coeficiente de correlación de Pearson. RESULTADOS: Se incluyeron 16 879 participantes; 17 % tuvo antecedente de vacunación contra influenza. La mortalidad fue menor en el grupo con historia de vacunación (3.5 % versus 7 %, p < 0.0001). El porcentaje de vacunación presentó una relación inversa con el porcentaje de mortalidad (r de Pearson 0.922, p = 0.026). CONCLUSIONES: La inmunización contra la influenza fue un factor protector independiente de mortalidad en pacientes con COVID-19. Aunque son necesarios más estudios para determinar la relación causal, será razonable incrementar la inmunización contra influenza en la población general.
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COVID-19/mortalidade , Vacinas contra Influenza , Vacinação/estatística & dados numéricos , Adolescente , Adulto , COVID-19/prevenção & controle , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Adulto JovemRESUMO
The phenotype of human placental extravillous trophoblast (EVT) at the end of pregnancy reflects both first trimester differentiation from villous cytotrophoblast (CTB) and later gestational changes, including loss of proliferative and invasive capacity. Invasion abnormalities are central to two major placental pathologies, preeclampsia and placenta accreta spectrum, so characterization of the corresponding normal processes is crucial. In this report, our gene expression analysis, using purified human CTB and EVT cells, highlights an epithelial-mesenchymal transition (EMT) mechanism underlying CTB-EVT differentiation and provides a trophoblast-specific EMT signature. In parallel, DNA methylation profiling shows that CTB cells, already hypomethylated relative to non-trophoblast cell lineages, show further genome-wide hypomethylation in the transition to EVT. However, a small subgroup of genes undergoes gains of methylation (GOM) in their regulatory regions or gene bodies, associated with differential mRNA expression (DE). Prominent in this GOM-DE group are genes involved in the EMT, including multiple canonical EMT markers and the EMT-linked transcription factor RUNX1, for which we demonstrate a functional role in modulating the migratory and invasive capacities of JEG3 trophoblast cells. This analysis of DE associated with locus-specific GOM, together with functional studies of an important GOM-DE gene, highlights epigenetically regulated genes and pathways acting in human EVT differentiation and invasion, with implications for obstetric disorders in which these processes are dysregulated.
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Regulation of proteasome abundance to meet cell needs under stress conditions is critical for maintaining cellular homeostasis. However, the effects of aging on this homeostatic response remain unknown. In this report, we analyzed in young and aged rat hippocampus, the dynamics of proteasome recovery induced by proteasome stress. Proteasome inhibition in young rats leads to an early and coordinate transcriptional and translational up-regulation of both the catalytic subunits of constitutive proteasome and the proteasome maturation protein. By contrast, aged rats up-regulated the inducible catalytic subunits and showed a lower and shorter expression of proteasome maturation protein. This resulted in a faster recovery of proteasome activity in young rats. Importantly, proteasome inhibition highly affected pyramidal cells, leading to the accumulation of ubiquitinated proteins in perinuclear regions of aged, but not young pyramidal neurons. These data strongly suggest that age-dependent differences in proteasome level and composition could contribute to neurodegeneration induced by proteasome dysfunction in normal and pathological aging.
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Envelhecimento , Hipocampo/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Regulação para Cima/fisiologia , Fatores Etários , Animais , Domínio Catalítico/fisiologia , Nucléolo Celular/metabolismo , Hipocampo/citologia , Imunoproteínas/metabolismo , Masculino , Neurônios/citologia , Neurônios/metabolismo , Ratos , Ratos WistarRESUMO
BACKGROUND: Neuroinflammation and protein accumulation are characteristic hallmarks of both normal aging and age-related neurodegenerative diseases. However, the relationship between these factors in neurodegenerative processes is poorly understood. We have previously shown that proteasome inhibition produced higher neurodegeneration in aged than in young rats, suggesting that other additional age-related events could be involved in neurodegeneration. We evaluated the role of lipopolysaccharide (LPS)-induced neuroinflammation as a potential synergic risk factor for hippocampal neurodegeneration induced by proteasome inhibition. METHODS: Young male Wistar rats were injected with 1 µL of saline or LPS (5 mg/mL) into the hippocampus to evaluate the effect of LPS-induced neuroinflammation on protein homeostasis. The synergic effect of LPS and proteasome inhibition was analyzed in young rats that first received 1 µL of LPS and 24 h later 1 µL (5 mg/mL) of the proteasome inhibitor lactacystin. Animals were sacrificed at different times post-injection and hippocampi isolated and processed for gene expression analysis by real-time polymerase chain reaction; protein expression analysis by western blots; proteasome activity by fluorescence spectroscopy; immunofluorescence analysis by confocal microscopy; and degeneration assay by Fluoro-Jade B staining. RESULTS: LPS injection produced the accumulation of ubiquitinated proteins in hippocampal neurons, increased expression of the E2 ubiquitin-conjugating enzyme UB2L6, decreased proteasome activity and increased immunoproteasome content. However, LPS injection was not sufficient to produce neurodegeneration. The combination of neuroinflammation and proteasome inhibition leads to higher neuronal accumulation of ubiquitinated proteins, predominant expression of pro-apoptotic markers and increased neurodegeneration, when compared with LPS or lactacystin (LT) injection alone. CONCLUSIONS: Our results identify neuroinflammation as a risk factor that increases susceptibility to neurodegeneration induced by proteasome inhibition. These results highlight the modulation of neuroinflammation as a mechanism for neuronal protection that could be relevant in situations where both factors are present, such as aging and neurodegenerative diseases.
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Hipocampo/efeitos dos fármacos , Lipopolissacarídeos/toxicidade , Degeneração Neural/induzido quimicamente , Inibidores de Proteassoma/toxicidade , Acetilcisteína/análogos & derivados , Acetilcisteína/toxicidade , Envelhecimento/efeitos dos fármacos , Envelhecimento/fisiologia , Animais , Sinergismo Farmacológico , Hipocampo/enzimologia , Hipocampo/patologia , Inflamação/induzido quimicamente , Inflamação/epidemiologia , Inflamação/patologia , Masculino , Degeneração Neural/epidemiologia , Degeneração Neural/patologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Ratos , Ratos Wistar , Ubiquitinação/efeitos dos fármacos , Ubiquitinação/fisiologiaRESUMO
Ozone is a destructive pollutant, damaging crops, and decreasing crop yield. Therefore, there is great interest in finding strategies to alleviate ozone-induced crop losses. In plants, ozone enters leaves through the stomata and is immediately degraded into reactive oxygen species (ROS), producing ROS stress in plants. ROS stress can be controlled by ROS-scavenging systems that include enzymatic or non-enzymatic mechanisms. Our research group has developed a product from rice bran, a by-product of rice milling which has bioactive molecules that act as an antioxidant compound. This product is a water-soluble rice bran enzymatic extract (RBEE) which preserves all the properties and improves the solubility of proteins and the antioxidant components of rice bran. In previous works, the beneficial properties of RBEE have been demonstrated in animals. However, to date, RBEE has not been used as a protective agent against oxidative damage in agricultural fields. The main goal of this study was to investigate the ability of RBEE to be used as a biostimulant by preventing oxidative damage in plants, after ozone exposure. To perform this investigation, pepper plants (Capsicum annuum) exposed to ozone were treated with RBEE. RBEE protected the ozone-induced damage, as revealed by net photosynthetic rate and the content of photosynthetic pigments. RBEE also decreased the induction of antioxidant enzyme activities in leaves (catalase, superoxide dismutase, and ascorbate peroxidase) due to ozone exposure. ROS generation is a common consequence of diverse cellular traumas that also activate the mitogen-activated protein kinase (MAPK) cascade. Thus, it is known that the ozone damages are triggered by the MAPK cascade. To examine the involvement of the MAPK cascade in the ozone damage CaMPK6-1, CaMPK6-2, and CaMKK5 genes were analyzed by qRT-PCR. The results showed the involvement of the MAPK pathway in both, not only in ozone damage but especially in its protection by RBEE. Taken together, these results support that RBEE protects plants against ozone exposure and its use as a new biostimulant could be proposed.
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BACKGROUND: Mapping of allele-specific DNA methylation (ASM) can be a post-GWAS strategy for localizing regulatory sequence polymorphisms (rSNPs). The advantages of this approach, and the mechanisms underlying ASM in normal and neoplastic cells, remain to be clarified. RESULTS: We perform whole genome methyl-seq on diverse normal cells and tissues and three cancer types. After excluding imprinting, the data pinpoint 15,112 high-confidence ASM differentially methylated regions, of which 1838 contain SNPs in strong linkage disequilibrium or coinciding with GWAS peaks. ASM frequencies are increased in cancers versus matched normal tissues, due to widespread allele-specific hypomethylation and focal allele-specific hypermethylation in poised chromatin. Cancer cells show increased allele switching at ASM loci, but disruptive SNPs in specific classes of CTCF and transcription factor binding motifs are similarly correlated with ASM in cancer and non-cancer. Rare somatic mutations affecting these same motif classes track with de novo ASM. Allele-specific transcription factor binding from ChIP-seq is enriched among ASM loci, but most ASM differentially methylated regions lack such annotations, and some are found in otherwise uninformative "chromatin deserts." CONCLUSIONS: ASM is increased in cancers but occurs by a shared mechanism involving disruptive SNPs in CTCF and transcription factor binding sites in both normal and neoplastic cells. Dense ASM mapping in normal plus cancer samples reveals candidate rSNPs that are difficult to find by other approaches. Together with GWAS data, these rSNPs can nominate specific transcriptional pathways in susceptibility to autoimmune, cardiometabolic, neuropsychiatric, and neoplastic diseases.
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Fator de Ligação a CCCTC/metabolismo , Metilação de DNA , Neoplasias/metabolismo , Fatores de Transcrição/metabolismo , Alelos , Ilhas de CpG , Impressão Genômica , Humanos , Desequilíbrio de Ligação , Neoplasias/genética , Polimorfismo de Nucleotídeo Único , Sequenciamento Completo do GenomaRESUMO
Alterations in the proteasome activity in the CNS have been described during aging. However, a detailed study of all proteasome subunits is actually lacking. We have analyzed, in vivo, the age-related modifications in the molecular composition of hippocampal proteasomes. We found that the immunoproteasome/proteasome ratio was increased in aged hippocampus. The processing of the low-molecular-mass protein (LMP)7/beta(5i) subunit, practically absent in young hippocampus, was increased in aged animals. Among the potential factors underlying these modifications we evaluated the neuroinflammation and the transcription factor Zif268. Lipopolysaccharide (LPS)-induced neuroinflammation in young rats, up-regulated the expression of immunoproteasome subunits and increased the processing of the LMP7/beta(5i) protein. Moreover, the hydrophobicity of cellular peptides, analyzed by liquid chromatography, increased in both, young LPS-injected animals and aged rats, suggesting that immunoproteasomes including the LMP7/beta(5i) subunit could, at least in part, account for this modification. Also, the mRNA expression of the transcription factor Zif268, which down-regulates the immunoproteasome subunit LMP7/beta(5i) by binding to sequences within the promoter regions, was decreased in both, aged hippocampus and young LPS-injected animals. Finally, we found that spatial memory training in young animals, a situation in which the expression of Zif268 is increased, modified the mRNA expression of the constitutive and catalytic subunits in an opposite manner. Based on present data, we propose that the age-related increases in the content of hippocampal immunoproteasome is mostly because of neuroinflammatory processes associated to aging.
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Envelhecimento/metabolismo , Regulação da Expressão Gênica/fisiologia , Hipocampo/metabolismo , Complexo de Endopeptidases do Proteassoma/metabolismo , Animais , Proteína 1 de Resposta de Crescimento Precoce/genética , Proteína 1 de Resposta de Crescimento Precoce/metabolismo , Regulação da Expressão Gênica/efeitos dos fármacos , Hipocampo/efeitos dos fármacos , Hipocampo/ultraestrutura , Imunoglobulinas/metabolismo , Lipopolissacarídeos/farmacologia , Masculino , Aprendizagem em Labirinto/fisiologia , Complexos Multienzimáticos/química , Complexos Multienzimáticos/genética , Complexos Multienzimáticos/metabolismo , Complexo de Endopeptidases do Proteassoma/química , Complexo de Endopeptidases do Proteassoma/genética , Subunidades Proteicas/genética , Subunidades Proteicas/metabolismo , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Frações Subcelulares/metabolismoRESUMO
This work presents a new bioprocess process for the extraction of bioactive components from soy pulp by-product (okara) using an enzymatic technology that was compared to a conventional water extraction. Okara is rich in fiber, fat, protein, and bioactive compounds such as isoflavones but its low solubility hampers the use in food and fertilizer industry. After the enzymatic attack with endoproteases half of the original insoluble proteins were converted into soluble peptides. Linked to this process occured the solubilization of isoflavones trapped in the insoluble protein matrix. We were able to extract up to 62.5% of the total isoflavones content, specially aglycones, the more bioactive isoflavone forms, whose values rose 9.12 times. This was probably due to the increased solubilization and interconversion from the original isoflavones. In conclusion, our process resulted in the formulation of a new functional product rich in aglycones and bioactive peptides with higher antioxidant potency than the original source. Therefore, we propose that the enzymatic extraction of okara bioactive compounds is an advantageous tool to replace conventional extraction.
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Proteostasis alteration and neuroinflammation are typical features of normal aging. We have previously shown that neuroinflammation alters cellular proteostasis through immunoproteasome induction, leading to a transient decrease of proteasome activity. Here, we further investigated the role of acute lipopolysaccharide (LPS)-induced hippocampal neuroinflammation in cellular proteostasis. In particular, we focused on macroautophagy (hereinafter called autophagy) and endoplasmic reticulum-associated protein degradation (ERAD). We demonstrate that LPS injection induced autophagy activation that was dependent, at least in part, on glycogen synthase kinase (GSK)-3ß activity but independent of mammalian target of rapamycin (mTOR) inhibition. Neuroinflammation also produced endoplasmic reticulum (ER) stress leading to canonical unfolded protein response (UPR) activation with a rapid activating transcription factor (ATF) 6α attenuation that resulted in a time-dependent down-regulation of ERAD markers. In this regard, the time-dependent accumulation of unspliced X-box binding protein (XBP) 1, likely because of decreased inositol-requiring enzyme (IRE) 1α-mediated splicing activity, might underlie in vivo ATF6α attenuation. Importantly, lactacystin-induced activation of ERAD was abolished in both the acute neuroinflammation model and in aged rats. Therefore, we provide a cellular pathway through which neuroinflammation might sensitize cells to neurodegeneration under stress situations, being relevant in normal aging and other disorders where neuroinflammation is a characteristic feature.
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Autofagia/fisiologia , Estresse do Retículo Endoplasmático/fisiologia , Degradação Associada com o Retículo Endoplasmático/fisiologia , Inflamação/fisiopatologia , Proteostase/fisiologia , Fator 6 Ativador da Transcrição/metabolismo , Animais , Linhagem Celular , Regulação para Baixo/fisiologia , Endorribonucleases/metabolismo , Glicogênio Sintase Quinase 3 beta/metabolismo , Inflamação/metabolismo , Masculino , Camundongos , Ratos , Ratos Wistar , Transdução de Sinais/fisiologia , Serina-Treonina Quinases TOR/metabolismo , Resposta a Proteínas não Dobradas/fisiologia , Proteína 1 de Ligação a X-Box/metabolismoRESUMO
Aging represents the main risk factor to develop Alzheimer disease (AD) and protein aggregation constitutes a pathological hallmark thought to be involved in the etiology of this disease. Here, we show that, in basal conditions, the expression of chaperones calnexin, protein disulfide isomerase (PDI) and Grp78 was decreased in aged hippocampus, whereas the protein ubiquitination increased, suggesting the existence of age-related deficits in the systems involved in the defense against unfolded proteins. Interestingly, when cellular stress was induced by intra-hippocampal lactacystin injection, the aged rats were less efficient than young animals in alleviating the protein accumulation and, as an important factor, did not induce the expression of chaperones as young animals. However, the expression of the pro-apoptotic factor CHOP/GADD153 was induced and caspase-12 was activated in stressed aged rats but not in young animals. Current results demonstrated that unfolding protein response (UPR) is not correctly activated in aged rat hippocampus. Consequently, the up-regulation of apoptotic pathway mediators is increased in aged rats. Results might provide further understanding of the pathogenic mechanisms of age-related neurodegenerative disorders.
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Envelhecimento/metabolismo , Hipocampo/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Neurônios/metabolismo , Estresse Fisiológico/metabolismo , Envelhecimento/patologia , Doença de Alzheimer/metabolismo , Doença de Alzheimer/fisiopatologia , Animais , Apoptose/fisiologia , Calnexina/metabolismo , Chaperona BiP do Retículo Endoplasmático , Proteínas de Choque Térmico/metabolismo , Hipocampo/patologia , Masculino , Chaperonas Moleculares/metabolismo , Neurônios/patologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Isomerases de Dissulfetos de Proteínas/metabolismo , Dobramento de Proteína , Ratos , Transdução de Sinais/fisiologia , Estresse Fisiológico/fisiopatologia , Fator de Transcrição CHOP/metabolismo , Ubiquitina/metabolismo , Regulação para Cima/fisiologiaRESUMO
Resumen Introducción: En el contexto de la pandemia de COVID-19 existe inquietud en cuanto al impacto de la temporada de influenza. Objetivo: Analizar el impacto del antecedente de inmunización contra influenza en pacientes con infección por SARS-CoV-2. Métodos: Se incluyeron pacientes mayores de 18 años con COVID-19, registrados entre marzo y agosto de 2020. Los datos fueron analizados mediante las pruebas exacta de Fisher y t de Student. Para evaluar el impacto en la mortalidad se utilizó un modelo de regresión logística; la relación entre el porcentaje de pacientes a quienes se aplicó la vacuna contra la influenza y la mortalidad fue determinada con el coeficiente de correlación de Pearson. Resultados: Se incluyeron 16 879 participantes; 17 % tuvo antecedente de vacunación contra influenza. La mortalidad fue menor en el grupo con historia de vacunación (3.5 % versus 7 %, p < 0.0001). El porcentaje de vacunación presentó una relación inversa con el porcentaje de mortalidad (r de Pearson 0.922, p = 0.026). Conclusiones: La inmunización contra la influenza fue un factor protector independiente de mortalidad en pacientes con COVID-19. Aunque son necesarios más estudios para determinar la relación causal, será razonable incrementar la inmunización contra influenza en la población general.
Abstract Introduction: In the context of the COVID-19 pandemic, there is concern regarding the impact of the influenza season. Objective: To analyze the impact of influenza immunization history on patients with SARS-CoV-2 infection. Methods: Patients older than 18 years with COVID-19, registered between March and August 2020, were included. Data were analyzed using Fishers exact test and Students t-test. To evaluate the impact on mortality, a logistic regression model was used; the relationship between the percentage of patients who received the influenza vaccine and mortality was determined with Pearsons correlation coefficient. Results: 16,879 participants were included; 17 % had a history of influenza vaccination. Mortality was lower in the group with a history of vaccination (3.5 % vs. 7 %, p < 0.0001). The vaccination rate had an inverse relationship with the mortality rate (Pearsons r: -0.922, p = 0.026). Conclusions: Previous influenza immunization was an independent protective factor for mortality in patients with COVID-19. Although further studies are needed to determine a causal relationship, it would be reasonable to increase influenza immunization in the general population.
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Humanos , Masculino , Feminino , Adolescente , Adulto , Pessoa de Meia-Idade , Adulto Jovem , Vacinas contra Influenza , Vacinação/estatística & dados numéricos , COVID-19/mortalidade , Estudos Retrospectivos , COVID-19/prevenção & controleRESUMO
Autophagy plays a key role in the maintenance of cellular homeostasis, and autophagy deregulation gives rise to severe disorders. Many of the signaling pathways regulating autophagy under stress conditions are still poorly understood. Using a model of proteasome stress in rat hippocampus, we have characterized the functional crosstalk between the ubiquitin proteasome system and the autophagy-lysosome pathway, identifying also age-related modifications in the crosstalk between both proteolytic systems. Under proteasome inhibition, both autophagy activation and resolution were efficiently induced in young but not in aged rats, leading to restoration of protein homeostasis only in young pyramidal neurons. Importantly, proteasome stress inhibited glycogen synthase kinase-3ß in young but activated in aged rats. This age-related difference could be because of a dysfunction in the signaling pathway of the insulin growth factor-1 under stress situations. Present data highlight the potential role of glycogen synthase kinase-3ß in the coordination of both proteolytic systems under stress situation, representing a key molecular target to sort out this deleterious effect.
Assuntos
Envelhecimento/metabolismo , Envelhecimento/fisiologia , Autofagia/fisiologia , Quinase 3 da Glicogênio Sintase/fisiologia , Hipocampo/fisiologia , Lisossomos/fisiologia , Complexo de Endopeptidases do Proteassoma/fisiologia , Células Piramidais/metabolismo , Transdução de Sinais/fisiologia , Animais , Quinase 3 da Glicogênio Sintase/metabolismo , Glicogênio Sintase Quinase 3 beta , Homeostase , Fator de Crescimento Insulin-Like I/metabolismo , Masculino , Doenças Neurodegenerativas/genética , Inibidores de Proteassoma , Proteínas/metabolismo , Proteólise , Células Piramidais/fisiologia , Ratos Wistar , Ubiquitina/fisiologiaRESUMO
OBJECTIVE: Chronic low-grade inflammation in obesity is characterized by macrophage accumulation in white adipose tissue and adipokine production deregulation. Obesity also is characterized by oxidative stress related to inflammatory signaling. The aim of this study was to analyze whether dietary supplementation with a rice bran enzymatic extract (RBEE), rich in bioactive compounds with antioxidant and hypocholesterolemic properties, would ameliorate the inflammatory state existing in visceral adipose tissue of obese Zucker rats. METHODS: Obese Zucker rats and their littermate controls, lean Zucker rats ages 8 wk, were daily fed an enriched diet with either 1% or 5% RBEE supplementation over 20 wk. Measurement of adipocyte size and mRNA expression of proinflammatory molecules from visceral abdominal/epididymal tissue was performed. RESULTS: An RBEE-supplemented diet decreased the overproduction of tumor necrosis factor-α, interleukin (IL)-6, IL-1 ß, and inducible nitric oxide synthase (iNOS), as well as the overproduction of IL-6 and iNOs in visceral abdominal adipose tissue and visceral epididymal adipose tissue, respectively. An RBEE-supplemented diet modified the adipocyte-size distribution pattern in both abdominal and epididymal adipose tissue, shifting it toward smaller cell sizes. CONCLUSIONS: Chronic administration of a novel water-soluble RBEE, rich in polyphenols, tocotrienols and γ-oryzanol, could be a suitable treatment to ameliorate the obesity-associated proinflammatory response.
Assuntos
Tecido Adiposo/efeitos dos fármacos , Suplementos Nutricionais , Inflamação/tratamento farmacológico , Obesidade/complicações , Oryza/química , Fitoterapia , Extratos Vegetais/uso terapêutico , Adipócitos/efeitos dos fármacos , Animais , Anti-Inflamatórios/farmacologia , Anti-Inflamatórios/uso terapêutico , Antioxidantes/farmacologia , Antioxidantes/uso terapêutico , Biomarcadores/metabolismo , Citocinas/metabolismo , Epididimo/efeitos dos fármacos , Inflamação/metabolismo , Gordura Intra-Abdominal/metabolismo , Masculino , Óxido Nítrico Sintase Tipo II/metabolismo , Obesidade/metabolismo , Extratos Vegetais/farmacologia , RNA Mensageiro/metabolismo , Ratos , Ratos Wistar , Ratos Zucker , Sementes/químicaRESUMO
High-grade gliomas (HGGs) are incurable brain tumors that are characterized by the presence of glioma-initiating cells (GICs). GICs are essential to tumor aggressiveness and retain the capacity for self-renewal and multilineage differentiation as long as they reside in the perivascular niche. ID proteins are master regulators of stemness and anchorage to the extracellular niche microenvironment, suggesting that they may play a role in maintaining GICs. Here, we modeled the probable therapeutic impact of ID inactivation in HGG by selective ablation of Id in tumor cells and after tumor initiation in a new mouse model of human mesenchymal HGG. Deletion of 3 Id genes induced rapid release of GICs from the perivascular niche, followed by tumor regression. GIC displacement was mediated by derepression of Rap1gap and subsequent inhibition of RAP1, a master regulator of cell adhesion. We identified a signature module of 5 genes in the ID pathway, including RAP1GAP, which segregated 2 subgroups of glioma patients with markedly different clinical outcomes. The model-informed survival analysis together with genetic and functional studies establish that ID activity is required for the maintenance of mesenchymal HGG and suggest that pharmacological inactivation of ID proteins could serve as a therapeutic strategy.
Assuntos
Glioma/metabolismo , Proteína 1 Inibidora de Diferenciação/metabolismo , Modelos Biológicos , Proteínas de Neoplasias/metabolismo , Proteínas de Ligação a Telômeros/metabolismo , Animais , Linhagem Celular Tumoral , Intervalo Livre de Doença , Proteínas Ativadoras de GTPase/genética , Proteínas Ativadoras de GTPase/metabolismo , Deleção de Genes , Glioma/genética , Glioma/mortalidade , Glioma/terapia , Células HEK293 , Humanos , Proteína 1 Inibidora de Diferenciação/genética , Camundongos , Camundongos Knockout , Proteínas de Neoplasias/genética , Complexo Shelterina , Taxa de Sobrevida , Proteínas de Ligação a Telômeros/genéticaRESUMO
Glioblastoma is one of the most challenging forms of cancer to treat. Here we describe a computational platform that integrates the analysis of copy number variations and somatic mutations and unravels the landscape of in-frame gene fusions in glioblastoma. We found mutations with loss of heterozygosity in LZTR1, encoding an adaptor of CUL3-containing E3 ligase complexes. Mutations and deletions disrupt LZTR1 function, which restrains the self renewal and growth of glioma spheres that retain stem cell features. Loss-of-function mutations in CTNND2 target a neural-specific gene and are associated with the transformation of glioma cells along the very aggressive mesenchymal phenotype. We also report recurrent translocations that fuse the coding sequence of EGFR to several partners, with EGFR-SEPT14 being the most frequent functional gene fusion in human glioblastoma. EGFR-SEPT14 fusions activate STAT3 signaling and confer mitogen independence and sensitivity to EGFR inhibition. These results provide insights into the pathogenesis of glioblastoma and highlight new targets for therapeutic intervention.
Assuntos
Neoplasias Encefálicas/genética , Genômica , Glioblastoma/genética , Cateninas/genética , Receptores ErbB/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Mutação , Fatores de Transcrição/genética , delta CateninaRESUMO
Neuroinflammation is an important contributor to pathogenesis of age-related neurodegenerative disorders such as Alzheimer's or Parkinson's disease. Accumulating evidence indicates that inhibition of microglia-mediated neuroinflammation may become a reliable protective strategy for neurodegenerative processes. Flavonoids, widely distributed in the vegetable kingdom and in foods such as honey, have been suggested as novel therapeutic agents for the reduction of the deleterious effects of neuroinflammation. The present study investigated the potential protective effect of a honey flavonoid extract (HFE) on the production of pro-inflammatory mediators by lipopolysaccharide-stimulated N13 microglia. The results show that HFE significantly inhibited the release of pro-inflammatory cytokines such as TNF-α and IL-1ß. The expressions of iNOS and the production of reactive oxygen intermediates (ROS) were also significantly inhibited. Accordingly, the present study demonstrates that HFE is a potent inhibitor of microglial activation and thus a potential preventive-therapeutic agent for neurodegenerative diseases involving neuroinflammation.
Assuntos
Anti-Inflamatórios/farmacologia , Flavonoides/farmacologia , Mel/análise , Lipopolissacarídeos/farmacologia , Microglia/efeitos dos fármacos , Animais , Linhagem Celular , Cromatografia Líquida de Alta Pressão , Citocinas/biossíntese , Citocinas/metabolismo , Flavonoides/isolamento & purificação , Camundongos , Microglia/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Espectrometria de Massas em TandemRESUMO
Stem-cell functions require activation of stem-cell-intrinsic transcriptional programs and extracellular interaction with a niche microenvironment. How the transcriptional machinery controls residency of stem cells in the niche is unknown. Here we show that Id proteins coordinate stem-cell activities with anchorage of neural stem cells (NSCs) to the niche. Conditional inactivation of three Id genes in NSCs triggered detachment of embryonic and postnatal NSCs from the ventricular and vascular niche, respectively. The interrogation of the gene modules directly targeted by Id deletion in NSCs revealed that Id proteins repress bHLH-mediated activation of Rap1GAP, thus serving to maintain the GTPase activity of RAP1, a key mediator of cell adhesion. Preventing the elevation of the Rap1GAP level countered the consequences of Id loss on NSC-niche interaction and stem-cell identity. Thus, by preserving anchorage of NSCs to the extracellular environment, Id activity synchronizes NSC functions to residency in the specialized niche.