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1.
Chemosphere ; 265: 129136, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33276998

RESUMO

Cadmium (Cd) is a biologically non-essential and toxic heavy metal leaking to the environment via natural emission or anthropogenic activities, thereby contaminating crops and threatening human health. Metallothioneins (MTs) are a group of metal-binding proteins playing critical roles in metal allocation and homeostasis. In this study, we identified a novel function of OsMT1e from rice plants. OsMT1e was dominantly expressed in roots at all developmental stages and, to less extent, expressed in leaves at vegetative and seed filling stages. OsMT1e was mainly targeted to the nucleus and substantially induced by Cd exposure. Expression of OsMT1e in a yeast Cd-sensitive strain ycf1 conferred cellular tolerance to Cd, even though the ycf1 + OsMT1e cells accumulated more Cd than the control cells (ycf1 + pYES2). Both transgenic rice overexpressing (OX) and repressing OsMT1e by RNA interference (RNAi) were developed. Phenotypic analysis revealed that OsMT1e overexpression enhanced the rice growth concerning the increased shoot or root elongation, dry weight and chlorophyll contents, whereas the RNAi lines displayed a sensitive growth phenotype compared to wild-type. Assessment with 0.5, 2 and 10 µM Cd for two weeks revealed that the RNAi lines accumulated less Cd, while the OX lines had an increased Cd accumulation in root and shoot tissues. The contrasting Cd accumulation phenotypes between the OX and RNAi lines were further confirmed by a long-term study with 0.5 µM Cd for one month. Overall, the study unveiled a new function of OsMT1e in rice, which can be potentially used for engineering genotypes for phytoremediation or minimizing Cd in rice crops.


Assuntos
Cádmio , Oryza , Biodegradação Ambiental , Cádmio/toxicidade , Humanos , Metalotioneína/genética , Oryza/genética , Folhas de Planta , Raízes de Plantas/genética , Plantas Geneticamente Modificadas/genética
2.
PLoS Pathog ; 16(8): e1008778, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32841292

RESUMO

EBV-associated gastric cancer (EBVaGC) is characterized by high frequency of DNA methylation. In this study, we investigated how epigenetic alteration of host genome contributes to pathogenesis of EBVaGC through the analysis of transcriptomic and epigenomic datasets from NIH TCGA (The Cancer Genome Atlas) consortium. We identified that immune related genes (IRGs) is a group of host genes preferentially silenced in EBV-positive gastric cancers through DNA hypermethylation. Further functional characterizations of selected IRGs reveal their novel antiviral activity against not only EBV but also KSHV. In particular, we showed that metallothionein-1 (MT1) and homeobox A (HOXA) gene clusters are down-regulated via EBV-driven DNA hypermethylation. Several MT1 isoforms suppress EBV lytic replication and release of progeny virions as well as KSHV lytic reactivation, suggesting functional redundancy of these genes. In addition, single HOXA10 isoform exerts antiviral activity against both EBV and KSHV. We also confirmed the antiviral effect of other dysregulated IRGs, such as IRAK2 and MAL, in scenario of EBV and KSHV lytic reactivation. Collectively, our results demonstrated that epigenetic silencing of IRGs is a viral strategy to escape immune surveillance and promote viral propagation, which is overall beneficial to viral oncogenesis of human gamma-herpesviruses (EBV and KSHV), considering that these IRGs possess antiviral activities against these oncoviruses.


Assuntos
Biomarcadores/metabolismo , Epigênese Genética , Gammaherpesvirinae/isolamento & purificação , Regulação Viral da Expressão Gênica , Infecções por Herpesviridae/complicações , Interações Hospedeiro-Patógeno , Neoplasias Gástricas/genética , Biomarcadores/análise , Metilação de DNA , Gammaherpesvirinae/genética , Células HEK293 , Infecções por Herpesviridae/virologia , Proteínas Homeobox A10/genética , Humanos , Incidência , Metalotioneína/genética , Neoplasias Gástricas/epidemiologia , Neoplasias Gástricas/metabolismo , Neoplasias Gástricas/virologia , Ativação Viral , Replicação Viral
3.
Ecotoxicol Environ Saf ; 202: 110917, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32800252

RESUMO

Cadmium (Cd) is an extremely toxic environmental pollutant with high mobility in soils, which can contaminate groundwater, increasing its risk of entering the food chain. Yeast biosorption can be a low-cost and effective method for removing Cd from contaminated aqueous solutions. We transformed wild-type Saccharomyces cerevisiae (WT) with two versions of a Populus trichocarpa gene (PtMT2b) coding for a metallothionein: one with the original sequence (PtMT2b 'C') and the other with a mutated sequence, with an amino acid substitution (C3Y, named here: PtMT2b 'Y'). WT and both transformed yeasts were grown under Cd stress, in agar (0; 10; 20; 50 µM Cd) and liquid medium (0; 10; 20 µM Cd). Yeast growth was assessed visually and by spectrometry OD600. Cd removal from contaminated media and intracellular accumulation were also quantified. PtMT2b 'Y' was also inserted into mutant strains: fet3fet4, zrt1zrt2 and smf1, and grown under Fe-, Zn- and Mn-deficient media, respectively. Yeast strains had similar growth under 0 µM, but differed under 20 µM Cd, the order of tolerance was: WT < PtMT2b 'C' < PtMT2b 'Y', the latter presenting 37% higher growth than the strain with PtMT2b 'C'. It also extracted ~80% of the Cd in solution, and had higher intracellular Cd than WT. Mutant yeasts carrying PtMT2b 'Y' had slightly higher growth in Mn- and Fe-deficient media than their non-transgenic counterparts, suggesting the transgenic protein may chelate these metals. S. cerevisiae carrying the altered poplar gene offers potential for bioremediation of Cd from wastewaters or other contaminated liquids.


Assuntos
Biodegradação Ambiental , Cádmio/metabolismo , Metalotioneína/genética , Proteínas de Plantas/genética , Populus/genética , Saccharomyces cerevisiae/genética , Poluentes do Solo/metabolismo , Cádmio/toxicidade , Metalotioneína/metabolismo , Metais Pesados/análise , Populus/metabolismo , Saccharomyces cerevisiae/metabolismo , Solo
4.
Sci Rep ; 10(1): 11707, 2020 07 16.
Artigo em Inglês | MEDLINE | ID: mdl-32678125

RESUMO

Neurodegenerative disorders (ND) like Alzheimer's (AD), Parkinson's (PD), Huntington's or Prion diseases share similar pathological features. They are all age dependent and are often associated with disruptions in analogous metabolic processes such as protein aggregation and oxidative stress, both of which involve metal ions like copper, manganese and iron. Bush and Tanzi proposed 2008 in the 'metal hypothesis of Alzheimer's disease' that a breakdown in metal homeostasis is the main cause of NDs, and drugs restoring metal homeostasis are promising novel therapeutic strategies. We report here that metallothionein (MT), an endogenous metal detoxifying protein, is increased in young amyloid ß (Aß) expressing Caenorhabditis elegans, whereas it is not in wild type strains. Further MT induction collapsed in 8 days old transgenic worms, indicating the age dependency of disease outbreak, and sharing intriguing parallels to diminished MT levels in human brains of AD. A medium throughput screening assay method was established to search for compounds increasing the MT level. Compounds known to induce MT release like progesterone, ZnSO4, quercetin, dexamethasone and apomorphine were active in models of AD and PD. Thioflavin T, clioquinol and emodin are promising leads in AD and PD research, whose mode of action has not been fully established yet. In this study, we could show that the reduction of Aß and α-synuclein toxicity in transgenic C. elegans models correlated with the prolongation of MT induction time and that knockdown of MT with RNA interference resulted in a loss of bioactivity.


Assuntos
Envelhecimento/metabolismo , Peptídeos beta-Amiloides/metabolismo , Proteínas de Caenorhabditis elegans/metabolismo , Caenorhabditis elegans/metabolismo , Metalotioneína/metabolismo , alfa-Sinucleína/metabolismo , Doença de Alzheimer/tratamento farmacológico , Doença de Alzheimer/metabolismo , Animais , Animais Geneticamente Modificados , Benzotiazóis/administração & dosagem , Benzotiazóis/farmacologia , Clioquinol/administração & dosagem , Clioquinol/farmacologia , Modelos Animais de Doenças , Emodina/administração & dosagem , Emodina/farmacologia , Técnicas de Silenciamento de Genes , Homeostase/efeitos dos fármacos , Metalotioneína/genética , Metais/metabolismo , Fármacos Neuroprotetores/administração & dosagem , Fármacos Neuroprotetores/farmacologia , Doença de Parkinson/tratamento farmacológico , Doença de Parkinson/metabolismo , Quercetina/administração & dosagem , Quercetina/farmacologia , Transdução de Sinais/efeitos dos fármacos
5.
Aquat Toxicol ; 226: 105555, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32645607

RESUMO

Fish strongly rely on olfaction as a variety of essential behaviors such as foraging and predator avoidance are mediated by the olfactory system. Cadmium (Cd) is known to impair olfaction and accumulate in the olfactory epithelium (OE) and bulb (OB) of fishes. In the present study, the acute toxicity of Cd on olfaction in zebrafish (Danio rerio) was characterized on the molecular and behavioral level. To this end, quantitative real-time PCR was performed in order to analyze the expression of selected genes in both the OE and OB. Moreover, the response of zebrafish to an alarm cue was investigated. Following 24 h of exposure to Cd, the expression of genes associated with olfactory sensory neurons was reduced in the OE. Furthermore, the antioxidant genes peroxiredoxin 1 (prdx1) and heme oxygenase 1 (hmox1), as well as the metallothionein 2 gene (mt2) were upregulated in the OE, whereas hmox1 and the stress-inducible heat shock protein 70 gene (hsp70) were upregulated in the OB upon exposure to Cd. Following stimulation with a conspecific skin extract, zebrafish displayed a considerable disruption of the antipredator behavior with increasing Cd concentration. Taken together, Cd impaired olfaction in zebrafish, thereby disrupting the antipredator response, which is crucial for the survival of individuals. Cellular stress followed by disruption of olfactory sensory neurons may have contributed to the observed behavioral deficits.


Assuntos
Comportamento Animal/efeitos dos fármacos , Cádmio/toxicidade , Regulação da Expressão Gênica/efeitos dos fármacos , Olfato/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Peixe-Zebra , Animais , Antioxidantes/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Metalotioneína/genética , Metalotioneína/metabolismo , Mucosa Olfatória/efeitos dos fármacos , Olfato/genética , Peixe-Zebra/genética , Peixe-Zebra/fisiologia
6.
Environ Res ; 187: 109703, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32480025

RESUMO

BACKGROUND: Genetic variations in glutathione (GSH)-related and metallothionein (MT) genes, which are involved in producing enzymes in the methylmercury (MeHg) metabolism pathway, have been proposed as one of the reasons for the individual variability in MeHg toxicokinetics. OBJECTIVE: To investigate the impact of genetic variations in MT and GSH-related genes on the association of fish consumption with body burden of MeHg, as measured by hair Hg concentrations among young children and women of childbearing age. METHODS: A total of 179 unrelated children and 165 mothers with either high or low fish consumption were recruited from the community. Their hair total Hg (tHg) and MeHg levels and genotypes for SNPs located on the GCLC, GCLM, GPX1, GSTA1, GSTP1, MT1A, MT2A, and MT4 genes were determined. Based on their 14-day food records, the amounts of fish consumed and their MeHg intakes were estimated. The impact of genetic variations on hair Hg concentrations was examined by using Mann-Whitney tests and multivariable linear regression analyses. RESULTS: The presence of minor alleles of GCLC-129 (rs17883901), GPX1-198 (rs1050450) and MT1M (rs9936741) were associated with significantly lower hair tHg levels in mothers whereas mothers with minor alleles of GSTP1-105(rs1695) and MT1M (rs2270836) have significantly higher hair tHg levels. After adjustment for fish consumption and other confounding factors, apart from MT1M (rs2270836), all of the above SNPs remain significant in the multivariable linear regression models. CONCLUSIONS: Our results in a group of children and women show that genetic variants of GSH-related and MT genes are associated with hair Hg concentrations. These genetic variations are likely to significantly affect MeHg metabolism and thus influence the accumulation of Hg in the human body.


Assuntos
Mercúrio , Compostos de Metilmercúrio , Animais , Criança , Pré-Escolar , Feminino , Peixes , Contaminação de Alimentos/análise , Variação Genética , Glutationa , Humanos , Mercúrio/análise , Metalotioneína/genética , Compostos de Metilmercúrio/análise , Projetos Piloto
7.
Sci Rep ; 10(1): 9603, 2020 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-32541800

RESUMO

Metallothionein (MT) is a protein with function of heavy metal detoxification. However, studies about how single nucleotide polymorphisms (SNPs) of MT genes influence lead nephropathy are relatively scarce. Therefore, our aim is to investigate the association between blood lead levels and renal biomarkers and to study whether this association is influenced by the combination of MT1A and MT2A SNPs. Blood lead, urinary uric acid (UA), and urinary N-acetyl-beta-d-glucosaminidase (NAG) levels were analyzed from 485 participants. Genotyping were performed on MT1A SNPs (rs11640851 and rs8052394) and MT2A SNPs (rs10636 and rs28366003). The combined MT1A 2A SNPs were divided into 16 groups. Among renal biomarkers, urinary UA was negatively significant associated with the time-weighted index of cumulative blood lead (TWICL), while urinary NAG was positively significant with TWICL. Furthermore, the association between urinary UA and TWICL was significantly modified by group 6 of combined SNPs (MT1A 2 A SNPs combination were AAAGGGAA, ACAGGGAA, and ACGGGGAA). In conclusion, the negative association of urinary UA and TWICL is modified by group 6, which means participants of group 6 are more susceptible to lead nephrotoxicity.


Assuntos
Rim/efeitos dos fármacos , Intoxicação por Chumbo/genética , Chumbo/sangue , Metalotioneína/genética , Polimorfismo de Nucleotídeo Único/genética , Acetilglucosaminidase/urina , Adulto , Biomarcadores/urina , Feminino , Humanos , Masculino , Metalotioneína/metabolismo , Pessoa de Meia-Idade , Ácido Úrico/urina
8.
Chemosphere ; 259: 127258, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32585458

RESUMO

This is the first study to investigate the reduction mechanism of Tl (III) to Tl(I) in the presence of plants, especially rice. Smaller plant density could effectively reduce the content of organic acids in the hydroponic system to keep the stability of Tl(III). As the plant density was reduced from 40 seedlings to 10 seedlings in 100 mL Tl(III) solution, the content of oxalate was declined to one-third of the original, and the ratio of Tl(III)/total Tl was increased from 39.6% to 81.0% in the first 2 h treatment. Then the differences in antioxidant capacity of rice exposed to the two Tl species were studied. The contents of malondialdehyde (MDA), hydrogen peroxide (H2O2) and superoxide anion (O2˙-) of rice roots exposed to Tl(III) were all higher than those to Tl(I). Meanwhile, the catalase (CAT) activity was significantly depressed and peroxidase (POD) was increased by Tl(III), whereas superoxide dismutase (SOD) showed a rise in both Tl(I) and Tl(III) with no significant difference between them. The expression of metallothionein gene OsMT1a to Tl(I) was upregulated to 255.5 times of Tl(III) though OsMT2c was downregulated to 0.39 times of Tl(III). Overall, the different responses in metallothionein gene expression and antioxidative enzyme activation might result in more ROS accumulation to rice roots by Tl(III) treatment than those by Tl(I).


Assuntos
Metalotioneína/genética , Oryza/fisiologia , Espécies Reativas de Oxigênio/metabolismo , Tálio/toxicidade , Antioxidantes/metabolismo , Catalase/metabolismo , Peróxido de Hidrogênio/metabolismo , Hidroponia , Malondialdeído/metabolismo , Metalotioneína/metabolismo , Oryza/genética , Oryza/metabolismo , Peroxidase/metabolismo , Peroxidases/metabolismo , Raízes de Plantas/metabolismo , Plântula/metabolismo , Superóxido Dismutase/metabolismo , Superóxidos/metabolismo
9.
Ecotoxicol Environ Saf ; 201: 110861, 2020 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-32544748

RESUMO

Marine biota have been co-challenged with ocean warming and mercury (Hg) pollution over many generations because of human activities; however, the molecular mechanisms to explain their combined effects are not well understood. In this study, a marine planktonic copepod Pseudodiaptomus annandalei was acutely exposed to different temperature (22 and 25 °C) and Hg (0 and 118 µg/L) treatments in a 24-h cross-factored experiment. Hg accumulation and its subcellular fractions were determined in the copepods after exposure. The expression of the genes of superoxide dismutase (SOD), glutathione peroxidase (GPx), metallothionein1 (mt1), heat shock protein 70 (hsp70), hsp90, hexokinase (hk), and pyruvate kinase (pk) was also analyzed. Both the Hg treatment alone and the combined exposure of warmer temperature plus Hg pollution remarkably facilitated Hg bioaccumulation in the exposed copepods. Compared with the Hg treatment alone, the combined exposure increased total Hg accumulation and also the amount of Hg stored in the metal-sensitive fractions (MSF), suggesting elevated Hg toxicity in P. annandalei under a warmer environment, given that the MSF is directly related to metal toxicity. The warmer temperature significantly up-regulated the mRNA levels of mt1, hsp70, hsp90, and hk, indicating the copepods suffered from thermal stress. With exposure to Hg, the mRNA level of SOD increased strikingly but the transcript levels of hsp90, hk, and pk decreased significantly, indicating that Hg induced toxic events (e.g., oxidative damage and energy depletion). Particularly, in contrast to the Hg treatment alone, the combined exposure significantly down-regulated the mRNA levels of SOD and GPx but up-regulated the mRNA levels of mt1, hsp70, hsp90, hk, and pk. Collectively, the results of this study indicate that ocean warming will potentially boost Hg toxicity in the marine copepod P. annandalei, which is information that will increase the accuracy of the projections of marine ecosystem responses to the joint effects of climate change stressors and metal pollution on the future ocean.


Assuntos
Copépodes/efeitos dos fármacos , Temperatura Alta , Mercúrio/toxicidade , Poluentes Químicos da Água/toxicidade , Animais , Copépodes/genética , Copépodes/metabolismo , Glutationa Peroxidase/genética , Glutationa Peroxidase/metabolismo , Proteínas de Choque Térmico HSP70/metabolismo , Proteínas de Choque Térmico HSP90/genética , Proteínas de Choque Térmico HSP90/metabolismo , Hexoquinase/genética , Hexoquinase/metabolismo , Mercúrio/farmacocinética , Metalotioneína/genética , Metalotioneína/metabolismo , Piruvato Quinase/genética , Piruvato Quinase/metabolismo , RNA Mensageiro/metabolismo , Superóxido Dismutase/genética , Superóxido Dismutase/metabolismo , Regulação para Cima , Poluentes Químicos da Água/farmacocinética
10.
Sci Rep ; 10(1): 7856, 2020 05 12.
Artigo em Inglês | MEDLINE | ID: mdl-32398691

RESUMO

Copper (Cu) is an essential, yet potentially toxic nutrient, as illustrated by inherited diseases of copper deficiency and excess. Elevated expression of the ATP7A Cu exporter is known to confer copper tolerance, however, the contribution of metal-binding metallothioneins is less clear. In this study, we investigated the relative contributions of ATP7A and the metallothioneins MT-I and MT-II to cell viability under conditions of Cu excess or deficiency. Although the loss of ATP7A increased sensitivity to low Cu concentrations, the absence of MTs did not significantly affect Cu tolerance. However, the absence of all three proteins caused a synthetic lethal phenotype due to extreme Cu sensitivity, indicating that MTs are critical for Cu tolerance only in the absence of ATP7A. A lack of MTs resulted in the trafficking of ATP7A from the trans-Golgi complex in a Cu-dependent manner, suggesting that MTs regulate the delivery of Cu to ATP7A. Under Cu deficiency conditions, the absence of MTs and / or ATP7A enhanced cell proliferation compared to wild type cells, suggesting that these proteins compete with essential Cu-dependent pathways when Cu is scarce. These studies reveal new roles for ATP7A and metallothioneins under both Cu deficiency and excess.


Assuntos
ATPases Transportadoras de Cobre/metabolismo , Cobre/farmacologia , Metalotioneína/metabolismo , Animais , Linhagem Celular , Sobrevivência Celular/efeitos dos fármacos , ATPases Transportadoras de Cobre/deficiência , ATPases Transportadoras de Cobre/genética , Relação Dose-Resposta a Droga , Regulação da Expressão Gênica/efeitos dos fármacos , Complexo de Golgi/efeitos dos fármacos , Complexo de Golgi/metabolismo , Metalotioneína/deficiência , Metalotioneína/genética , Camundongos , Mutação , Transporte Proteico/efeitos dos fármacos
11.
Diabetes ; 69(8): 1779-1792, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32404351

RESUMO

Diabetes-induced oxidative stress is one of the major contributors to dysfunction of endothelial progenitor cells (EPCs) and impaired endothelial regeneration. Thus, we tested whether increasing antioxidant protein metallothionein (MT) in EPCs promotes angiogenesis in a hind limb ischemia (HLI) model in endothelial MT transgenic (JTMT) mice with high-fat diet- and streptozocin-induced diabetes. Compared with littermate wild-type (WT) diabetic mice, JTMT diabetic mice had improved blood flow recovery and angiogenesis after HLI. Similarly, transplantation of JTMT bone marrow-derived mononuclear cells (BM-MNCs) stimulated greater blood flow recovery in db/db mice with HLI than did WT BM-MNCs. The improved recovery was associated with augmented EPC mobilization and angiogenic function. Further, cultured EPCs from patients with diabetes exhibited decreased MT expression, increased cell apoptosis, and impaired tube formation, while cultured JTMT EPCs had enhanced cell survival, migration, and tube formation in hypoxic/hyperglycemic conditions compared with WT EPCs. Mechanistically, MT overexpression enhanced hypoxia-inducible factor 1α (HIF-1α), stromal cell-derived factor (SDF-1), and vascular endothelial growth factor (VEGF) expression and reduced oxidative stress in ischemic tissues. MT's pro-EPC effects were abrogated by siRNA knockdown of HIF-1α without affecting its antioxidant action. These results indicate that endothelial MT overexpression is sufficient to protect against diabetes-induced impairment of angiogenesis by promoting EPC function, most likely through upregulation of HIF-1α/SDF-1/VEGF signaling and reducing oxidative stress.


Assuntos
Quimiocina CXCL12/metabolismo , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Experimental/prevenção & controle , Células Progenitoras Endoteliais/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Metalotioneína/metabolismo , Neovascularização Patológica/metabolismo , Neovascularização Patológica/prevenção & controle , Animais , Western Blotting , Sobrevivência Celular/genética , Sobrevivência Celular/fisiologia , Quimiocina CXCL12/genética , Ensaio de Imunoadsorção Enzimática , Feminino , Membro Posterior/patologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Isquemia/genética , Isquemia/metabolismo , Leucócitos Mononucleares/metabolismo , Masculino , Metalotioneína/genética , Camundongos , Estresse Oxidativo/genética , Estresse Oxidativo/fisiologia , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo
12.
Antioxid Redox Signal ; 33(2): 59-65, 2020 07 10.
Artigo em Inglês | MEDLINE | ID: mdl-32323565

RESUMO

Human lungs single-cell RNA sequencing data from healthy donors (elderly and young; GEO accession no. GSE122960) were analyzed to isolate and specifically study gene expression in alveolar type II cells. Colocalization of angiotensin-converting enzyme 2 (ACE2) and TMPRSS2 enables severe acute respiratory syndrome coronavirus 2 (SARS-CoV 2) to enter the cells. Expression levels of these genes in the alveolar type II cells of elderly and young patients were comparable and, therefore, do not seem to be responsible for worse outcomes observed in coronavirus disease 2019 (COVID-19) affected elderly. In cells from the elderly, 263 genes were downregulated and 95 upregulated. Superoxide dismutase 3 (SOD3) was identified as the top-ranked gene that was most downregulated in the elderly. Other redox-active genes that were also downregulated in cells from the elderly included activating transcription factor 4 (ATF4) and metallothionein 2A (M2TA). ATF4 is an endoplasmic reticulum stress sensor that defends lungs via induction of heme oxygenase 1. The study of downstream factors known to be induced by ATF4, according to Ingenuity Pathway Analysis™, identified 24 candidates. Twenty-one of these were significantly downregulated in the cells from the elderly. These downregulated candidates were subjected to enrichment using the Reactome Database identifying that in the elderly, the ability to respond to heme deficiency and the ATF4-dependent ability to respond to endoplasmic reticulum stress is significantly compromised. SOD3-based therapeutic strategies have provided beneficial results in treating lung disorders including fibrosis. The findings of this study propose the hypotheses that lung-specific delivery of SOD3/ATF4-related antioxidants will work in synergy with promising antiviral drugs such as remdesivir to further improve COVID-19 outcomes in the elderly.


Assuntos
Fator 4 Ativador da Transcrição/genética , Infecções por Coronavirus/genética , Pulmão/metabolismo , Pneumonia Viral/genética , Superóxido Dismutase/genética , Adulto , Idoso , Células Epiteliais Alveolares/patologia , Células Epiteliais Alveolares/virologia , Antioxidantes/uso terapêutico , Betacoronavirus/patogenicidade , Infecções por Coronavirus/terapia , Infecções por Coronavirus/virologia , Feminino , Regulação da Expressão Gênica/genética , Heme Oxigenase-1/genética , Humanos , Pulmão/patologia , Pulmão/virologia , Masculino , Metalotioneína/genética , Pessoa de Meia-Idade , Pandemias , Peptidil Dipeptidase A/genética , Pneumonia Viral/terapia , Pneumonia Viral/virologia , Serina Endopeptidases/genética
13.
Artigo em Inglês | MEDLINE | ID: mdl-32340109

RESUMO

Chronic exposure to lead is neurotoxic to the human peripheral sensory system. Variant vitamin D receptor (VDR) genes and polymorphisms of metallothioneins (MTs) are associated with different outcomes following lead toxicity. However, no evidence of a relationship between lead neurotoxicity and polymorphisms has previously been presented. In this study, we investigated the relationship between the polymorphisms of VDR, MT1A, and MT2A genes and lead toxicity following chronic occupational lead exposure. We measured vibration perception thresholds (VPT) and current perception thresholds (CPT) in 181 workers annually for five years. The outcome variables were correlated to the subject's index of long-term lead exposure. Polymorphisms of VDR, MT1A, and MT2A were defined. The potential confounders, including age, sex, height, smoking, alcohol consumption, and working life span, were also collected and analyzed using linear regression. The regression coefficients of some gene polymorphisms were at least 20 times larger than regression coefficients of time-weighted index of cumulative blood lead (TWICL) measures. All regression coefficients of TWICL increased slightly. MT1A rs11640851 (AA/CC) was associated with a statistically significant difference in all neurological outcomes except hand and foot VPT. MT1A rs8052394 was associated with statistically significant differences in hand and foot CPT 2000 Hz. In MT2A rs10636, those with the C allele showed a greater effect on hand CPT than those with the G allele. Among the VDR gene polymorphisms, the Apa rs7975232 (CC/AA) single nucleotide polymorphism was associated with the greatest difference in hand CPT. MT2A rs28366003 appeared to have a neural protective effect, whereas Apa (rs7975232) of VDR and MT2A rs10636 increased the neurotoxicity as measured by CPT in the hands. MT1A rs8052394 had a protective effect on large myelinated nerves. MT1A rs11640851 was associated with susceptibility to neurotoxicity.


Assuntos
Intoxicação do Sistema Nervoso por Chumbo/sangue , Chumbo/toxicidade , Metalotioneína/genética , Exposição Ocupacional/estatística & dados numéricos , Receptores de Calcitriol/genética , Biomarcadores/metabolismo , Indústria Química , Exposição Ambiental , Feminino , Genótipo , Humanos , Chumbo/sangue , Intoxicação do Sistema Nervoso por Chumbo/diagnóstico , Masculino , Doenças Profissionais/induzido quimicamente , Doenças Profissionais/genética , Exposição Ocupacional/efeitos adversos , Exposição Ocupacional/prevenção & controle , Polimorfismo de Nucleotídeo Único
14.
Acta Neuropathol Commun ; 8(1): 35, 2020 03 19.
Artigo em Inglês | MEDLINE | ID: mdl-32192527

RESUMO

The choroid plexus (CP) is a key regulator of the central nervous system (CNS) homeostasis through its secretory, immunological and barrier properties. Accumulating evidence suggests that the CP plays a pivotal role in the pathogenesis of multiple sclerosis (MS), but the underlying mechanisms remain largely elusive. To get a comprehensive view on the role of the CP in MS, we studied transcriptomic alterations of the human CP in progressive MS and non-neurological disease controls using RNA sequencing. We identified 17 genes with significantly higher expression in progressive MS patients relative to that in controls. Among them is the newly described long non-coding RNA HIF1A-AS3. Next to that, we uncovered disease-affected pathways related to hypoxia, secretion and neuroprotection, while only subtle immunological and no barrier alterations were observed. In an ex vivo CP explant model, a subset of the upregulated genes responded in a similar way to hypoxic conditions. Our results suggest a deregulation of the Hypoxia-Inducible Factor (HIF)-1 pathway in progressive MS CP. Importantly, cerebrospinal fluid levels of the hypoxia-responsive secreted peptide PAI-1 were higher in MS patients with high disability relative to those with low disability. These findings provide for the first time a complete overview of the CP transcriptome in health and disease, and suggest that the CP environment becomes hypoxic in progressive MS patients, highlighting the altered secretory and neuroprotective properties of the CP under neuropathological conditions. Together, these findings provide novel insights to target the CP and promote the secretion of neuroprotective factors into the CNS of progressive MS patients.


Assuntos
Plexo Corióideo/metabolismo , Hipóxia/genética , Esclerose Múltipla Crônica Progressiva/genética , Esclerose Múltipla Recidivante-Remitente/genética , Neuroproteção/genética , Neurossecreção/genética , Adrenomedulina/líquido cefalorraquidiano , Adrenomedulina/genética , Adulto , Idoso , Estudos de Casos e Controles , Feminino , Perfilação da Expressão Gênica , Ontologia Genética , Glicoproteínas/líquido cefalorraquidiano , Glicoproteínas/genética , Humanos , Fator 1 Induzível por Hipóxia , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Peptídeos e Proteínas de Sinalização Intercelular/líquido cefalorraquidiano , Peptídeos e Proteínas de Sinalização Intercelular/genética , Ventrículos Laterais , Masculino , Metalotioneína/genética , Pessoa de Meia-Idade , Esclerose Múltipla Crônica Progressiva/líquido cefalorraquidiano , Esclerose Múltipla Recidivante-Remitente/líquido cefalorraquidiano , Inibidor 1 de Ativador de Plasminogênio/líquido cefalorraquidiano , Inibidor 1 de Ativador de Plasminogênio/genética , RNA Antissenso/genética , RNA Longo não Codificante , RNA-Seq
15.
Fish Shellfish Immunol ; 100: 146-151, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32165247

RESUMO

High temperature is an important environmental factor that affects the survival and immunity of aquatic animals. The intestine of crustaceans is their first line of defense, and the physiological homeostasis of this organ can be influenced by high temperature stress. The red swamp crayfish Procambarus clarkii is an important commercial aquaculture species in China, but little is known about its intestinal immune response to acute heat stress. In this study, we investigated the intestinal immune response of P. clarkii individuals that were assigned to the control (25 °C) and heat stress (35 °C) groups. Biochemical assays were conducted for the oxidative stress parameters ·O2- generation capacity, lipid peroxide content, and malondialdehyde content; the activities of the antioxidant enzymes superoxide dismutase, catalase, and glutathione peroxidase; and the activities of the immunity-related enzymes alkaline phosphatase, acid phosphatase, and lysozyme. The relative expression level of the antioxidant genes heat shock protein 70 (hsp70), ferritin (fer), and metallothione (met) was examined by RT-PCR. Based on the data obtained, all the parameters tended to increase, peak and then decrease with time, and were significantly different between the two groups (P < 0.05). These findings reveal that acute heat stress adversely affects the antioxidant status and immune function in the P. clarkii intestine. They lay the groundwork for future studies on the effect of rising water temperatures on immune function and survival of this species.


Assuntos
Astacoidea/imunologia , Resposta ao Choque Térmico/imunologia , Temperatura Alta , Imunidade Inata , Intestinos/imunologia , Animais , Aquicultura , Ferritinas/genética , Proteínas de Choque Térmico HSP70/genética , Resposta ao Choque Térmico/genética , Hepatopâncreas/imunologia , Hepatopâncreas/patologia , Intestinos/patologia , Metalotioneína/genética , Estresse Oxidativo
16.
PLoS One ; 15(3): e0230572, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32210477

RESUMO

Chromatin structure plays a decisive role in gene regulation through the actions of transcriptional activators, coactivators, and epigenetic machinery. These trans-acting factors contribute to gene expression through their interactions with chromatin structure. In yeast INO1 activation, transcriptional activators and coactivators have been defined through intense study but the mechanistic links within these trans-acting factors and their functional implications are not yet fully understood. In this study, we examined the crosstalk within transcriptional coactivators with regard to the implications of Snf2p acetylation during INO1 activation. Through various biochemical analysis, we demonstrated that both Snf2p and Ino80p chromatin remodelers accumulate at the INO1 promoter in the absence of Snf2p acetylation during induction. Furthermore, nucleosome density and histone acetylation patterns remained unaffected by Snf2p acetylation status. We also showed that cells experience increased sensitivity to copper toxicity when remodelers accumulate at the INO1 promoter due to the decreased CUP1 expression. Therefore, our data provide evidence for crosstalk within transcriptional co-activators during INO1 activation. In light of these findings, we propose a model in which acetylation-driven chromatin remodeler recycling allows for efficient regulation of genes that are dependent upon limited co-activators.


Assuntos
Adenosina Trifosfatases/metabolismo , Metalotioneína/metabolismo , Mio-Inositol-1-Fosfato Sintase/genética , Proteínas de Saccharomyces cerevisiae/genética , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/metabolismo , Fatores de Transcrição/metabolismo , Acetilação , Adenosina Trifosfatases/genética , Sobrevivência Celular/efeitos dos fármacos , Cromatina/metabolismo , Montagem e Desmontagem da Cromatina , Cobre/metabolismo , Cobre/toxicidade , Histonas/metabolismo , Metalotioneína/genética , Mio-Inositol-1-Fosfato Sintase/metabolismo , Nucleossomos/metabolismo , Regiões Promotoras Genéticas , Fatores de Transcrição/genética , Ativação Transcricional
17.
Appl Environ Microbiol ; 86(9)2020 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-32111593

RESUMO

Metallothionein (MT) genes are valuable genetic materials for developing metal bioremediation tools. Currently, a limited number of prokaryotic MTs have been experimentally identified, which necessitates the expansion of bacterial MT diversity. In this study, we conducted a metagenomics-guided analysis for the discovery of potential bacterial MT genes from the soil microbiome. More specifically, we combined resistance gene enrichment through diversity loss, metagenomic mining with a dedicated MT database, evolutionary trace analysis, DNA chemical synthesis, and functional genomic validation to identify novel MTs. Results showed that Cu stress induced a compositional change in the soil microbiome, with an enrichment of metal-resistant bacteria in soils with higher Cu concentrations. Shotgun metagenomic sequencing was performed to obtain the gene pool of environmental DNA (eDNA), which was subjected to a local BLAST search against an MT database for detecting putative MT genes. Evolutional trace analysis led to the identification of 27 potential MTs with conserved cysteine/histidine motifs different from those of known prokaryotic MTs. Following chemical synthesis of these 27 potential MT genes and heterologous expression in Escherichia coli, six of them were found to improve the hosts' growth substantially and enhanced the hosts' sorption of Cu, Cd, and Zn, among which MT5 led to a 13.7-fold increase in Cd accumulation. Furthermore, four of them restored Cu and/or Cd resistance in two metal-sensitive E. coli strains.IMPORTANCE The metagenomics-guided procedure developed here bypasses the difficulties encountered in classic PCR-based approaches and led to the discovery of novel MT genes, which may be useful in developing bioremediation tools. The procedure used here expands our knowledge on the diversity of bacterial MTs in the environment and may also be applicable to identify other functional genes from eDNA.


Assuntos
Bactérias/genética , Cádmio/efeitos adversos , Cobre/efeitos adversos , Farmacorresistência Bacteriana/genética , Metagenoma , Metalotioneína/genética , Microbiota/genética , Bactérias/efeitos dos fármacos , Genes Bacterianos , Metagenômica , Metalotioneína/metabolismo , Microbiota/efeitos dos fármacos , Microbiologia do Solo , Poluentes do Solo/efeitos adversos
18.
Artigo em Inglês | MEDLINE | ID: mdl-32114524

RESUMO

Background The aim of this study was to investigate the effects of selenium, zinc, insulin, and metallothionein on oxidative damage and metallothionein (MT) gene expression levels in streptozotocin (STZ)-induced type 1 diabetic rats exposed to Cd. Methods Rats were categorized under eight groups (control, STZ, Cd, STZ + Cd, Group 5, Group 6, Group 7, and STZ + Cd + MT [n:8/group]) were used. After diabetes was induced by STZ (55 mg/kg, i.p.), Cd was administered (1 mg/kg CdCl, orally) for 4 weeks. In cadmium-treated groups selenium (Na2SeO3 1.5 mg/kg, i.p.), zinc (ZnSO4 10 mg/kg via oral gavage), insulin (insulin glargine, 2U/day, s.c.), and MT (1mg/kg, every other 10 days, s.c.) were administered. MT gene expression levels, MDA levels, GPx, SOD, and CAT activity levels were determined in liver and kidney tissues. Results MT gene expression and MDA levels increased (p < 0.05) while GPx and SOD activity levels decreased (p < 0.05) in STZ, Cd, and STZ + Cd groups. In Group 5, Group 6, Group 7, and Group 8 groups MT gene expression and MDA levels were decreased while GPx and SOD activity levels were increased (p < 0.05). CAT activity significantly increased (p < 0.05) in STZ + Cd group while there were no significance in other groups (p > 0.05). Compared to the control, Group 5, Group 6, Group 7, and Group 8 groups provided no difference for alanine aminotransferase, aspartate aminotransferase, blood urea nitrogen and creatinine levels (p > 0.05). Conclusions Our results suggest that Se, insulin, Zn and MT may have protective effects against hepatotoxicity and nephrotoxicity caused by Cd exposure in diabetic rats by reducing oxidative stress and MT gene expression levels.


Assuntos
Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Tipo 1/tratamento farmacológico , Metalotioneína/genética , Estresse Oxidativo/efeitos dos fármacos , Animais , Cádmio/toxicidade , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Tipo 1/complicações , Regulação da Expressão Gênica/efeitos dos fármacos , Insulina/administração & dosagem , Insulina/farmacologia , Nefropatias/prevenção & controle , Hepatopatias/prevenção & controle , Masculino , Metalotioneína/administração & dosagem , Metalotioneína/farmacologia , Ratos , Ratos Wistar , Selênio/administração & dosagem , Selênio/farmacologia , Estreptozocina , Zinco/administração & dosagem , Zinco/farmacologia
19.
Int J Mol Sci ; 21(5)2020 Feb 27.
Artigo em Inglês | MEDLINE | ID: mdl-32120996

RESUMO

Terrestrial snails (Gastropoda) possess Cd-selective metallothioneins (CdMTs) that inactivate Cd2+ with high affinity. Most of these MTs are small Cysteine-rich proteins that bind 6 Cd2+ equivalents within two distinct metal-binding domains, with a binding stoichiometry of 3 Cd2+ ions per domain. Recently, unusually large, so-called multi-domain MTs (md-MTs) were discovered in the terrestrial door snail Alinda biplicata (A.b.). The aim of this study is to evaluate the ability of A.b. to cope with Cd stress and the potential involvement of md-MTs in its detoxification. Snails were exposed to increasing Cd concentrations, and Cd-tissue concentrations were quantified. The gene structure of two md-MTs (9md-MT and 10md-MT) was characterized, and the impact of Cd exposure on MT gene transcription was quantified via qRT PCR. A.b. efficiently accumulates Cd at moderately elevated concentrations in the feed, but avoids food uptake at excessively high Cd levels. The structure and expression of the long md-MT genes of A.b. were characterized. Although both genes are intronless, they are still transcribed, being significantly upregulated upon Cd exposure. Overall, our results contribute new knowledge regarding the metal handling of Alinda biplicata in particular, and the potential role of md-MTs in Cd detoxification of terrestrial snails, in general.


Assuntos
Cádmio/toxicidade , Gastrópodes/efeitos dos fármacos , Gastrópodes/metabolismo , Metalotioneína/metabolismo , Animais , Aprendizagem da Esquiva/efeitos dos fármacos , Transporte Biológico/genética , Cádmio/metabolismo , Evolução Molecular , Gastrópodes/genética , Metalotioneína/genética , Domínios Proteicos/genética , Estresse Fisiológico/genética , Ativação Transcricional/efeitos dos fármacos , Ativação Transcricional/genética , Regulação para Cima
20.
Exp Cell Res ; 390(1): 111949, 2020 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-32145254

RESUMO

Farnesoid X receptor (FXR) is a metabolic nuclear receptor, which protects liver from many endogenous and exogenous injuries. Metallothioneins (MTs) belong to a low-molecular-weight protein family involved in metal homeostasis and the regulation of hepatic oxidative stress. In the present study, we aimed to investigate the effect of FXR on hepatic MT1 expression and the underlying mechanism. C57BL/6 mice or primary cultured mouse hepatocytes were treated with the synthetic FXR ligand GW4064 or natural ligand CDCA. RNA-Sequencing (RNA-seq) analysis was performed to identify gene expression profile in the livers of mice treated with GW4064. Real-time PCR and Western blot were applied to determine the expression of MT1 and other FXR target genes in the livers of mice and primary hepatocytes treated with GW4064 and CDCA. Cellular and subcellular locations of MT1 in the livers of mice treated with GW4064 were examined using immunohistochemistry assay. FXR small interfering RNAs (siRNA) was transfected to silence FXR. Luciferase reporter and chromatin immunoprecipitation (ChIP) assays were utilized to confirm the regulation of MT1 gene promoter activity by FXR. RNA-seq analysis revealed that GW4064 treatment significantly induced MT1 expression in mouse liver. Consistently, MT1 expression in the hepatocytes of mouse livers and cultured hepatocytes was upregulated by GW4064 as well as CDCA. In addition, adenovirus-mediated overexpression of FXR markedly increased, while siRNA-mediated FXR silencing significantly suppressed MT1 expression in cultured hepatocytes. Luciferase reporter and ChIP assays further confirmed that the MT1 gene was under the direct control of FXR. Collectively, our findings demonstrate that MT1 is a novel target gene of FXR and may contribute to antioxidative capacity of FXR in liver diseases.


Assuntos
Fígado/metabolismo , Metalotioneína/genética , Receptores Citoplasmáticos e Nucleares/metabolismo , Animais , Células Cultivadas , Hepatócitos/metabolismo , Humanos , Masculino , Metalotioneína/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Receptores Citoplasmáticos e Nucleares/genética
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