Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 15.565
Filtrar
1.
Appl Microbiol Biotechnol ; 104(19): 8089-8104, 2020 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-32813065

RESUMO

Interspecies transmissions of viruses between animals and humans may result in unpredictable pathogenic potential and new transmissible diseases. This mechanism has recently been exemplified by the discovery of new pathogenic viruses, such as the novel severe acute respiratory syndrome corona virus-2 (SARS-CoV-2) pandemic, Middle-East respiratory syndrome-coronavirus epidemic in Saudi Arabia, and the deadly outbreak of Ebola in West Africa. The. SARS-CoV-2 causes coronavirus disease-19 (COVID-19), which is having a massive global impact in terms of economic disruption, and, above all, human health. The disease is characterized by dry cough, fever, fatigue, myalgia, and dyspnea. Other symptoms include headache, sore throat, rhinorrhea, and gastrointestinal disorders. Pneumonia appears to be the most common and severe manifestation of the infection. Currently, there is no vaccine or specific drug for COVID-19. Further, the development of new antiviral requires a considerable length of time and effort for drug design and validation. Therefore, repurposing the use of natural compounds can provide alternatives and can support therapy against COVID-19. In this review, we comprehensively discuss the prophylactic and supportive therapeutic role of probiotics for the management of COVID-19. In addition, the unique role of probiotics to modulate the gut microbe and assert gut homeostasis and production of interferon as an antiviral mechanism is described. Further, the regulatory role of probiotics on gut-lung axis and mucosal immune system for the potential antiviral mechanisms is reviewed and discussed.Key points• Gut microbiota role in antiviral diseases• Factors influencing the antiviral mechanism• Probiotics and Covid-19.


Assuntos
Betacoronavirus/fisiologia , Infecções por Coronavirus/terapia , Pneumonia Viral/terapia , Probióticos/uso terapêutico , Animais , Infecções por Coronavirus/prevenção & controle , Infecções por Coronavirus/transmissão , Trato Gastrointestinal/microbiologia , Humanos , Imunidade nas Mucosas , Pulmão/imunologia , Pulmão/microbiologia , Pulmão/virologia , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Pneumonia Viral/transmissão , Probióticos/metabolismo , Infecções Respiratórias/microbiologia , Viroses/prevenção & controle , Viroses/terapia , Viroses/transmissão , Vitamina D/fisiologia , Zinco/metabolismo
2.
PLoS Biol ; 18(7): e3000811, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-32735558

RESUMO

One of the earliest and most prevalent barriers to successful reproduction is polyspermy, or fertilization of an egg by multiple sperm. To prevent these supernumerary fertilizations, eggs have evolved multiple mechanisms. It has recently been proposed that zinc released by mammalian eggs at fertilization may block additional sperm from entering. Here, we demonstrate that eggs from amphibia and teleost fish also release zinc. Using Xenopus laevis as a model, we document that zinc reversibly blocks fertilization. Finally, we demonstrate that extracellular zinc similarly disrupts early embryonic development in eggs from diverse phyla, including Cnidaria, Echinodermata, and Chordata. Our study reveals that a fundamental strategy protecting human eggs from fertilization by multiple sperm may have evolved more than 650 million years ago.


Assuntos
Fertilização , Oócitos/metabolismo , Zinco/metabolismo , Ambystoma mexicanum , Animais , Feminino , Hidrozoários , Masculino , Strongylocentrotus purpuratus , Xenopus laevis , Peixe-Zebra
3.
Ecotoxicol Environ Saf ; 204: 111086, 2020 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-32781345

RESUMO

In the present research, Silene vulgaris as a representative species growing on both unpolluted and heavy metal (HM) polluted terrains were used to identify ecotype-specific responses to metallic stress. Growth, cell ultrastructure and element accumulations were compared between non-metallicolous (NM), calamine (CAL) and serpentine (SER) specimens untreated with HMs and treated with Pb, Cd and Zn ions under in vitro conditions. Moreover, proteins' modifications related to their level, carbonylation and degradations via vacuolar proteases were verified and linked with potential mechanisms to cope with ions toxicity. Our experiment revealed diversified strategy of HM uptake in NM and both metallicolous ecotypes, in which antagonistic relationship of Zn and Pb/Cd ions provided survival benefits for the whole organism. Despite this similarity, growth rate and metabolic pathways induced in CAL and SER shoots varied significantly. Exposition to HMs in CAL culture led to drop in protein level by approximately 16% compared to the control. This parameter nearly correlated with the enhanced activity of proteases at pH 5.2 as well as possible glutamate changes to proline and reduced glutathione, resulting in intensified growth and first signs of cell senescence. In turn, SER shoots were characterized by growth retardation (to 53% of the control), although protein level and carbonylation were not modified, while a deeper insight into protein network showed its remodeling towards production of polyamines and 2-oxoglutarate delivered to the Krebs cycle. Contrary, an uncontrolled HM influx in NM shoots contributed to morpho-structural disorders accompanied by an increase activity of proteases involved in the degradation of oxidized proteins, what pointed to metal-induced autophagy. Taken together, S. vulgaris ecotypes respond to stress by triggering various mechanisms engaged their survival and/or death under HM treatment.


Assuntos
Cádmio/toxicidade , Chumbo/toxicidade , Proteínas de Plantas/metabolismo , Silene/efeitos dos fármacos , Poluentes do Solo/toxicidade , Zinco/toxicidade , Autofagia/efeitos dos fármacos , Bioacumulação/efeitos dos fármacos , Cádmio/metabolismo , Ecótipo , Glutationa/metabolismo , Chumbo/metabolismo , Modelos Teóricos , Estresse Oxidativo/efeitos dos fármacos , Brotos de Planta/efeitos dos fármacos , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/metabolismo , Brotos de Planta/ultraestrutura , Silene/crescimento & desenvolvimento , Silene/metabolismo , Silene/ultraestrutura , Poluentes do Solo/metabolismo , Zinco/metabolismo
4.
PLoS Pathog ; 16(8): e1008707, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32780778

RESUMO

Proteus mirabilis, a Gram-negative uropathogen, is a major causative agent in catheter-associated urinary tract infections (CAUTI). Mannose-resistant Proteus-like fimbriae (MR/P) are crucially important for P. mirabilis infectivity and are required for biofilm formation and auto-aggregation, as well as for bladder and kidney colonization. Here, the X-ray crystal structure of the MR/P tip adhesin, MrpH, is reported. The structure has a fold not previously described and contains a transition metal center with Zn2+ coordinated by three conserved histidine residues and a ligand. Using biofilm assays, chelation, metal complementation, and site-directed mutagenesis of the three histidines, we show that an intact metal binding site occupied by zinc is essential for MR/P fimbria-mediated biofilm formation, and furthermore, that P. mirabilis biofilm formation is reversible in a zinc-dependent manner. Zinc is also required for MR/P-dependent agglutination of erythrocytes, and mutation of the metal binding site renders P. mirabilis unfit in a mouse model of UTI. The studies presented here provide important clues as to the mechanism of MR/P-mediated biofilm formation and serve as a starting point for identifying the physiological MR/P fimbrial receptor.


Assuntos
Adesinas Bacterianas/metabolismo , Biofilmes , Proteínas de Fímbrias/metabolismo , Proteus mirabilis/metabolismo , Infecções Urinárias/microbiologia , Zinco/metabolismo , Adesinas Bacterianas/química , Adesinas Bacterianas/genética , Sequência de Aminoácidos , Proteínas de Fímbrias/química , Proteínas de Fímbrias/genética , Humanos , Infecções por Proteus/metabolismo , Infecções por Proteus/microbiologia , Proteus mirabilis/química , Proteus mirabilis/genética , Alinhamento de Sequência , Infecções Urinárias/metabolismo , Zinco/química
5.
Aquat Toxicol ; 225: 105524, 2020 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-32610223

RESUMO

In the present research, the effects of exposure to a sublethal concentration of zinc (Zn) on metal and ion homeostasis, and the regulation and the localization of various Zn transporters (i.e., the Zrt-Irt Like Protein (ZIP) family of Zn transporters), were investigated in zebrafish (Danio rerio) during early development. Exposure to an elevated level of Zn [4 µM (high) vs. 0.25 µM (control)] from 0 day post-fertilization (dpf) resulted in a significant increase in the whole body content of Zn at 5 dpf. A transient decrease in the whole body calcium (Ca) level was observed in 3 dpf larvae exposed to high Zn. Similarly, whole body nickel (Ni) and copper (Cu) contents were also reduced in 3 dpf larvae exposed to high Zn. Importantly, the magnitude of reduction in whole body Ni and Cu contents following Zn exposure was markedly higher than that in Ca content, suggesting that internal Ni and Cu balance were likely more sensitive to Zn exposure in developing zebrafish. Exposure to high Zn altered the mRNA expression levels of specific zip transporters, with an increase in zip1 (at 3 dpf) and zip8 (at 5 dpf), and a decrease in zip4 (at 5 dpf). The expression levels of most zip transporters tended to decrease from 3 dpf to 5 dpf with the exception of zip4 and zip8. Results from in situ hybridization revealed that several zip transporters exhibited distinct spatial distribution (e.g., zip8 in the intestinal tract, zip14 in the pronephric tubules). Overall, our findings suggested that exposure to sublethal concentrations of Zn disrupts the homeostasis of essential metals during early development and that different ZIP transporters may play unique roles in regulating Zn homeostasis in various organs in developing zebrafish.


Assuntos
Proteínas de Transporte de Cátions/genética , Homeostase/efeitos dos fármacos , Poluentes Químicos da Água/toxicidade , Proteínas de Peixe-Zebra/genética , Peixe-Zebra , Zinco/toxicidade , Animais , Cálcio/metabolismo , Cobre/metabolismo , Relação Dose-Resposta a Droga , Larva/efeitos dos fármacos , Larva/metabolismo , Nível de Efeito Adverso não Observado , Poluentes Químicos da Água/metabolismo , Peixe-Zebra/fisiologia , Zinco/metabolismo
6.
PLoS One ; 15(7): e0234770, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32645004

RESUMO

BACKGROUND: Zinc (Zn) deficiency is one of the most common micronutrient deficiencies worldwide. Accurate estimates of Zn intake would facilitate the design and implementation of effective nutritional interventions. OBJECTIVE: We sought to improve estimates of dietary Zn intake by evaluating staple crop Zn content and dietary Zn consumption by children under the age of 5 in 9 rural districts of Uganda. METHODS: We measured the Zn content of 581 crop samples from household farms and 167 crop samples from nearby markets, and administered food frequency questionnaires to the primary caretakers of 237 children. We estimated Zn consumption using 3 sources of crop Zn content: (i) the HarvestPlus food composition table (FCT) for Uganda, (ii) measurements from household crops, and (iii) measurements from market crops. RESULTS: The Zn content of staple crops varied widely, resulting in significantly different estimates of dietary Zn intake. 41% of children appeared to be at risk when estimates were based on market-sampled crops, 23% appeared at risk when estimates were based on the HarvestPlus FCT, and 16% appeared at risk when estimates were based on samples from household farms. CONCLUSION: The use of FCTs to calculate Zn intake overestimated the risk of dietary inadequacy for children who primarily consumed staple crops that were produced on household farms, but underestimated the risk for children who primarily consumed staple crops that were purchased at market. More information on the Zn content of staple crops in developing countries could lead to more accurate estimates of dietary intake and associated deficiencies.


Assuntos
Produtos Agrícolas/química , Zinco/análise , Zinco/deficiência , Pré-Escolar , Dieta , Feminino , Humanos , Lactente , Masculino , Micronutrientes/deficiência , Minerais , Avaliação Nutricional , Estado Nutricional , Valor Nutritivo , Uganda , Zinco/metabolismo
7.
Ecotoxicol Environ Saf ; 202: 110856, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32629202

RESUMO

To explore the mechanisms underlying the action of the heavy metals Cd and Zn on the photosynthetic function of plant leaves, the effects of 100 µmol L-1 Cd and 200 µmol L-1 Zn stress (the exposure concentrations of Cd and Zn in the culture medium were 2.24 mg kg-1 and 5.36 mg kg-1) on the chlorophyll and carotenoid contents as well as the photosynthetic function of tobacco leaves (Long Jiang 911) were studied. The key proteins in these physiological processes were quantitatively analyzed using a TMT-based proteomics approach. Cd stress was found to inhibit the expression of key enzymes during chlorophyll synthesis in leaves, resulting in a decrease of the Chl content. However, Zn stress did not significantly influence the chlorophyll content. Leaves adapted to Zn stress by upregulating CAO expression and increase the Chl b content. Although the Car content in leaves did not significantly change under either Cd or Zn stress, the expressions of ZE and VDE during Car metabolism decreased significantly under Cd stress. This was accompanied by damages to the xanthophyll cycle and the NPQ-dependent energy dissipation mechanism. In contrast, under Zn stress, leaves adapted to Zn stress by increasing the expression of VDE, thus improving NPQ. Under Cd stress, the expressions of three sets of proteins were significantly down-regulated, including PSII donor-side proteins (PPD3, PPD6, OEE1, OEE2-1, OEE2-2, OEE2-3, and OEE3-2), receptor-side proteins (D1, D2, CP43, CP47, Cyt b559α, Cyt b559ß, PsbL, PsbQ, PsbR, Psb27-H1, and Psb28), and core proteins of the PSI reaction center (psaA, psaB, psaC, psaD, psaE-A, PsaE-B, psaF, psaG, psaH-1, psaK, psaL, psaN, and psaOL). In comparison, only eight of the above proteins (PPD6, OEE3-2, PsbL, PsbQ, Psb27-H1, psaL, and psaOL) were significantly down-regulated by Zn stress. Under Cd stress, both the donor side and the receptor side of PSII were damaged, and PSII and PSI experienced severe photoinhibition. However, Zn stress did not decrease either PSII or PSI activities in tobacco leaves. In addition, the expression of electron transport-related proteins (cytb6/f complex, PC, Fd, and FNR), ATPase subunits, Rubisco subunits, and RCA decreased significantly in leaves under Cd stress. However, no significant changes were observed in any of these proteins under Zn stress. Although Cd stress was found to up-regulate the expressions of PGRL1A and PGRL1B and induce an increase of PGR5/PGRL1-CEF in tobacco leaves, NDH-CEF was significantly inhibited. Under Zn stress, the expressions of ndhH and PGRL1A in leaves were significantly up-regulated, but there were no significant changes in either NDH-CEF or PGR5/PGRL-CEF. Under Cd stress, the expressions of proteins related to Fd-dependent nitrogen metabolism and reactive oxygen species (ROS) scavenging processes (e.g., FTR, Fd-NiR, and Fd-GOGAT) were significantly down-regulated in leaves. However, no significant changes of any of the above proteins were identified under Zn stress. In summary, Cd stress could inhibit the synthesis of chlorophyll in tobacco leaves, significantly down-regulate the expressions of photosynthesis-related proteins or subunits, and suppress both the xanthophyll cycle and NDH-CEF process. The expressions of proteins related to the Fd-dependent nitrogen metabolism and ROS scavenging were also significantly down-regulated, which blocked the photosynthetic electron transport, thus resulting in severe photoinhibition of both PSII and PSI. However, Zn stress had little effect on the photosynthetic function of tobacco leaves.


Assuntos
Cádmio/toxicidade , Carotenoides/metabolismo , Clorofila/metabolismo , Fotossíntese/efeitos dos fármacos , Tabaco/efeitos dos fármacos , Zinco/toxicidade , Cádmio/metabolismo , Transporte de Elétrons/efeitos dos fármacos , Complexo de Proteína do Fotossistema I/metabolismo , Complexo de Proteína do Fotossistema II/metabolismo , Folhas de Planta/metabolismo , Proteômica , Tabaco/metabolismo , Tabaco/fisiologia , Zinco/metabolismo
8.
Proc Natl Acad Sci U S A ; 117(32): 19528-19537, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32723821

RESUMO

Zinc starvation in mycobacteria leads to remodeling of ribosomes, in which multiple ribosomal (r-) proteins containing the zinc-binding CXXC motif are replaced by their motif-free paralogues, collectively called C- r-proteins. We previously reported that the 70S C- ribosome is exclusively targeted for hibernation by mycobacterial-specific protein Y (Mpy), which binds to the decoding center and stabilizes the ribosome in an inactive and drug-resistant state. In this study, we delineate the conditions for ribosome remodeling and hibernation and provide further insight into how zinc depletion induces Mpy recruitment to C- ribosomes. Specifically, we show that ribosome hibernation in a batch culture is induced at an approximately two-fold lower cellular zinc concentration than remodeling. We further identify a growth phase in which the C- ribosome remains active, while its hibernation is inhibited by the caseinolytic protease (Clp) system in a zinc-dependent manner. The Clp protease system destabilizes a zinc-bound form of Mpy recruitment factor (Mrf), which is stabilized upon further depletion of zinc, presumably in a zinc-free form. Stabilized Mrf binds to the 30S subunit and recruits Mpy to the ribosome. Replenishment of zinc to cells harboring hibernating ribosomes restores Mrf instability and dissociates Mpy from the ribosome. Finally, we demonstrate zinc-responsive binding of Mpy to ribosomes in Mycobacterium tuberculosis (Mtb) and show Mpy-dependent antibiotic tolerance of Mtb in mouse lungs. Together, we propose that ribosome hibernation is a specific and conserved response to zinc depletion in both environmental and pathogenic mycobacteria.


Assuntos
Mycobacterium tuberculosis/metabolismo , Ribossomos/metabolismo , Zinco/deficiência , Animais , Antibióticos Antituberculose/farmacologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Tolerância a Medicamentos/genética , Endopeptidase Clp/genética , Endopeptidase Clp/metabolismo , Camundongos , Mycobacterium tuberculosis/efeitos dos fármacos , Mycobacterium tuberculosis/genética , Mycobacterium tuberculosis/crescimento & desenvolvimento , Processamento de Proteína Pós-Traducional , Proteínas Ribossômicas/genética , Proteínas Ribossômicas/metabolismo , Subunidades Ribossômicas/metabolismo , Zinco/análise , Zinco/metabolismo
9.
Chemosphere ; 260: 127541, 2020 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-32688311

RESUMO

The present study explores the effect of ethylene diamine disuccinic acid (EDDS) and gibberellic acid (GA) application on the phytoextraction of copper and zinc ions by Lolium perenne. When Cu was individually applied, accumulation diminished over time with little translocation from roots to shoots. In contrast, Zn accumulation and damage to roots rapidly increased over 3 days with increase in Zn translocation to shoots. Co-application of Zn to Cu amended treatments enhanced Cu concentration in shoots. For the CuEDDS application, EDDS significantly increased Cu accumulation and the damage to root increased over time, while gibberellic acid applied with Cu and Zn generally lowered metal uptake and decreased cell membrane damage. The application of EDDS and GA-EDDS, by themselves or with Cu and Zn, lowered transpiration and increased translocation, while GA increased transpiration but decreased translocation. EDDS application typically increased metal ion uptake by causing more cell damage, while GA typically lowered the damage and decreased metal uptake even though the transpiration increased over time and plant growth occurred. Furthermore, the behaviour of metal uptake changed over time and, for some treatments, the short-term and long-term response differed greatly. These results show that EDDS can be successfully used in phytoextraction of both Cu and Zn ions by Lolium perenne while GA can resist damage and protect against plant stress.


Assuntos
Biodegradação Ambiental , Etilenodiaminas/química , Giberelinas/química , Lolium/metabolismo , Poluentes do Solo/metabolismo , Transporte Biológico , Cobre/metabolismo , Etilenos , Íons/metabolismo , Raízes de Plantas/metabolismo , Succinatos/metabolismo , Zinco/metabolismo
10.
Ecotoxicol Environ Saf ; 202: 110883, 2020 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-32570104

RESUMO

By exposing larvae of the holometabolous insect Spodoptera litura to the artificial diets supplemented with a range of Zinc (Zn) contents, we investigated Zn ingestion, excretion and accumulation in the insect throughout its life cycle. The effects of Zn stress on the survival, growth and food utilization of S. litura were also determined. Zn concentrations in the body (larvae, pupae, and adults), faeces, exuviates, puparium, eggs increased with the increasing Zn concentrations in the diets, while Zn excretion and accumulation by S. litura in 750 mg/kg Zn treatments was lower than the 600 mg/kg Zn treatment. In the 450 mg/kg Zn treatment, the Zn accumulation in S. litura at different developmental stages differed as follows: larvae > pupa > adult. S. litura ingested Zn via feeding and could excrete most of the Zn via faeces (compared with Zn excretion via exuviates) to reduce its internal Zn accumulation (compared with Zn ingestion). Survival and weight were significantly inhibited, and the prolonged period of development (larvae, pupae) and shortened longevity of adults were found in S. litura exposed to Zn stress greater than 450 mg Zn/kg. In the 150-450 mg/kg Zn treatments, the 6th instar larvae increased their relative consumption rate (RCR) and approximate digestibility (AD) (namely, food eaten) to gain weight, which resulted in greater Zn accumulation in the body. Therefore, below the threshold level (being close to 450 mg/kg Zn), S. litura seemed to have a strong homeostatic adjustment ability (increase the amount of food eaten, thereby increasing AD, RCR and Zn excretion via faeces and exuviates) to sustain their weight, and Zn was beneficial and harmless. Although larvae treated with 750 mg/kg Zn had a similar RCR and AD as the control, a reduced weight gain and prolonged larval period resulted in significantly lower relative growth rate (RGR), which indicated surviving insects may allocate more energy from foods for detoxification than for growth.


Assuntos
Spodoptera/fisiologia , Zinco/metabolismo , Animais , Peso Corporal , Dieta , Alimentos , Larva/efeitos dos fármacos , Mariposas , Pupa , Spodoptera/efeitos dos fármacos , Ganho de Peso , Zinco/toxicidade
11.
Life Sci ; 256: 117912, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32504755

RESUMO

Histone deacetylase enzymes were prominent chromatin remodeling drug that targets in the pathophysiology of Alzheimer's disease associated with transcriptional dysregulation. In vitro and in vivo models of AD have demonstrated overexpression of HDAC activity. Non-specificity and non-selectivity of HDAC are the major problems of existing HDAC inhibitors. Hence, we aim to set up a methodology describing the rational development of isoform-selective HDAC inhibitor targeting class, I and class IIb. A convenient multistage virtual screening followed by machine learning and IC50 screenings were used to classify the 5064 compounds into inhibitors and non-inhibitors classes retrieved from the ChEMBL database. ADMET analysis identified the pharmacokinetics and pharmacodynamics properties of selected compounds. Molecular docking, along with mutational analysis of eleven compounds, characterized the inhibiting potency. Herein, for the first time, we reported ChEMBL1834473 (2-[[5-(4-chlorophenyl)-1,3,4-thiadiazol-2-yl]amino]-N-hydroxypyrimidine-5-carboxamide) as the isoform-selective HDAC inhibitor, which interact central Zn2+ atom. The negative energy and interacting residue of the ChEMBL1834473 with six HDAC isoform has also been tabulated and mapped. Moreover, our findings concluded histidine, glycine, phenylalanine, and aspartic acid as key residues in protein-ligand interaction and classify 2347 compounds as HDAC inhibitors. Later, a protein-protein interaction network of six HDAC with the key proteins involved in the progression of an AD and signaling pathway, which describes the relationship between ChEMBL1834473 and AD, has been demonstrated using PPI network where the chosen inhibitor will work. Altogether, we conclude that the compound ChEMBL1834473 may be capable of inhibiting all isoforms of class I and class IIb HDAC based on computational analysis for AD therapeutics.


Assuntos
Doença de Alzheimer/tratamento farmacológico , Inibidores de Histona Desacetilases/química , Inibidores de Histona Desacetilases/uso terapêutico , Pirimidinas/química , Pirimidinas/uso terapêutico , Ácido Aspártico/metabolismo , Bases de Dados de Compostos Químicos , Avaliação Pré-Clínica de Medicamentos , Glicina/metabolismo , Histona Desacetilases/metabolismo , Humanos , Aprendizado de Máquina , Simulação de Acoplamento Molecular , Estrutura Molecular , Terapia de Alvo Molecular , Fenilalanina/metabolismo , Isoformas de Proteínas/química , Termodinâmica , Zinco/metabolismo
12.
J Plant Physiol ; 250: 153185, 2020 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-32497866

RESUMO

The objective of this study was to assess the effect of metalliferous conditions on the functioning of photosynthetic electron transport in waste heap populations of a pseudometallophyte, Viola tricolor L. Measurements of chlorophyll a fluorescence and the absorbance changes at 830 nm enabled a non-invasive assessment of photosynthetic apparatus performance. This was complemented by the evaluation of the chlorophyll content. Low temperature chlorophyll fluorescence emission spectra were also recorded. Based on the OJIP test performed in situ, we demonstrated a disturbed condition of photosystem II (PSII) in three metalliferous populations in comparison with a non-metallicolous one. The combined effects of elevated concentrations of zinc, cadmium and lead in soil resulted in the decline of some parameters describing the efficiency and electron flow through PSII. The differences between waste heap populations seemed to be partly correlated with the concentration of heavy metals in the soil. The characteristic of electron transport at photosystem I (PSI) in the light-adapted state revealed increased values of PSI donor-side limitation (YND) and a declined PSI quantum efficiency (YI). It was also demonstrated that the waste heap conditions negatively affect the total chlorophyll content in leaves and led to an increased ratio of fluorescence emission at 77 K (F730/F685). The obtained data indicate that, regardless of the high adaptation of metallicolous populations, photosynthetic electron transport is hampered in V. tricolor plants at metal polluted sites.


Assuntos
Adaptação Biológica , Transporte de Elétrons , Metais Pesados/metabolismo , Fotossíntese , Viola/efeitos dos fármacos , Viola/metabolismo , Cádmio/metabolismo , Chumbo/metabolismo , Polônia , Solo/química , Zinco/metabolismo
13.
Environ Pollut ; 261: 114213, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32408418

RESUMO

Brassica juncea L. is an attractive species in PTMs contaminated soil remediation ascribing to its high tolerance under stress and great accumulation capacity of metals. To identify the potential Cd/Zn accumulators from numerous different Chinese mustard cultivars for practical phytoremediation is a promising strategy in China. In present work, a pot experiment involving elevated Cd/Zn concentrations was performed among 21 cultivars. Regarding physiological and biochemical indicators under Cd/Zn stress, principal component analysis and cluster analysis were used for cultivar tolerance evaluation and classification. Results showed that BJ (Bao Jie, var. involutus) cultivar was distinguished as a potential phytoremediation candidate comparing with other cultivars. Moreover, BJ accumulated the maximum Cd content of 63.85 and 77.29 mg kg-1 DW in shoots and roots, respectively, and the maximum Zn uptake by BJ were 6693 and 4777 mg kg-1 DW in shoots and roots, respectively. Accordingly, BJ had the highest Cd/Zn tolerance, remarkable accumulation and translocation capacity (accumulation factor (AF) > 1 for Cd and Zn; translocation factor (TF) > 0.8 for Cd and TF > 1 for Zn). In addition, the superoxide dismutase (SOD), peroxidase (POD) and catalase (CAT) activities of the mustard increased initially under low Cd/Zn stress as compared to the control and then declined dramatically with the increasing metals exposure concentration. Therefore, the antioxidant enzymes may play a protective role against reactive oxygen species (ROS) under low Cd/Zn stress, whereas the defense system might be collapsed under relatively high Cd/Zn stress. Furthermore, the enhanced Cd/Zn exposure led to an increase in malondialdehyde (MDA) content in the mustard cultivars, indicating that Cd/Zn had induced more severe oxidative stress and higher degree of lipid peroxidation had occurred. The present investigation results indicated that BJ (Bao Jie, var. involutus), as a native cultivar, can be further applied in the field trials of phytoremediation practices in contaminated soil.


Assuntos
Cádmio/metabolismo , Mostardeira/metabolismo , Poluentes do Solo/metabolismo , Zinco/metabolismo , Antioxidantes , Biodegradação Ambiental , Cádmio/análise , China , Raízes de Plantas , Poluentes do Solo/análise , Zinco/análise
14.
mSphere ; 5(3)2020 05 27.
Artigo em Inglês | MEDLINE | ID: mdl-32461278

RESUMO

Zinc supplementation in cell culture has been shown to inhibit various viruses, like herpes simplex virus, rotavirus, severe acute respiratory syndrome (SARS) coronavirus, rhinovirus, and respiratory syncytial virus (RSV). However, whether zinc plays a direct antiviral role in viral infections and whether viruses have adopted strategies to modulate zinc homeostasis have not been investigated. Results from clinical trials of zinc supplementation in infections indicate that zinc supplementation may be beneficial in a pathogen- or disease-specific manner, further underscoring the importance of understanding the interaction between zinc homeostasis and virus infections at the molecular level. We investigated the effect of RSV infection on zinc homeostasis and show that RSV infection in lung epithelial cells leads to modulation of zinc homeostasis. The intracellular labile zinc pool increases upon RSV infection in a multiplicity of infection (MOI)-dependent fashion. Small interfering RNA (siRNA)-mediated knockdown of the ubiquitous zinc uptake transporter ZIP1 suggests that labile zinc levels are increased due to the increased uptake by RSV-infected cells as an antiviral response. Adding zinc to culture medium after RSV infection led to significant inhibition of RSV titers, whereas depletion of zinc by a zinc chelator, N,N,N',N'-tetrakis(2-pyridinylmethyl)-1,2-ethanediamine (TPEN) led to an increase in RSV titers. The inhibitory effect of zinc was specific, as other divalent cations had no effect on RSV titers. Both RSV infection and zinc chelation by TPEN led to reactive oxygen species (ROS) induction, whereas addition of zinc blocked ROS induction. These results suggest a molecular link between RSV infection, zinc homeostasis, and oxidative-stress pathways and provide new insights for developing strategies to counter RSV infection.IMPORTANCE Zinc deficiency rates in developing countries range from 20 to 30%, and zinc supplementation trials have been shown to correct clinical manifestations attributed to zinc deficiency, but the outcomes in the case of respiratory infections have been inconsistent. We aimed at understanding the role of zinc homeostasis in respiratory syncytial virus (RSV) infection. Infection of lung epithelial cell lines or primary small-airway epithelial cells led to an increase in labile zinc pools, which was due to increased uptake of zinc. Zinc supplementation inhibited RSV replication, whereas zinc chelation had an opposing effect, leading to increases in RSV titers. Increases in labile zinc in RSV-infected cells coincided with induction of reactive oxygen species (ROS). Both zinc depletion and addition of exogenous ROS led to enhanced RSV infection, whereas addition of the antioxidant inhibited RSV, suggesting that zinc is part of an interplay between RSV-induced oxidative stress and the host response to maintain redox balance.


Assuntos
Infecções por Vírus Respiratório Sincicial/patologia , Vírus Sincicial Respiratório Humano/metabolismo , Replicação Viral/efeitos dos fármacos , Zinco/metabolismo , Zinco/farmacologia , Células A549 , Adolescente , Proteínas de Transporte de Cátions/genética , Linhagem Celular , Criança , Pré-Escolar , Células Epiteliais/metabolismo , Etilenodiaminas/farmacologia , Feminino , Interações Hospedeiro-Patógeno , Humanos , Pulmão/citologia , Pulmão/metabolismo , Masculino , Estresse Oxidativo/fisiologia , Interferência de RNA , RNA Interferente Pequeno/genética , Espécies Reativas de Oxigênio/metabolismo , Mucosa Respiratória/metabolismo , Mucosa Respiratória/virologia
15.
Arch Microbiol ; 202(7): 1957-1963, 2020 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-32462214

RESUMO

Some probiotic strains, such as Lactobacillus spp., are options for the removal of heavy metals from food, water and soil. Although copper or zinc are essential for use in many biochemical processes, they are toxic at high concentrations. The purpose of the current study was to evaluate two Lactobacillus strains for their application in the bioremediation of copper and zinc from aqueous solution. The biomass of Lactobacillus fermentum and Lactobacillus plantarum were treated with different concentrations of copper or zinc (0-200 mM). Minimum inhibitory concentration, biosorption capacity and kinetic biosorption behavior were determined. The results showed rapid biosorption of both metals and both species, removed zinc ions more efficient than copper. The highest removal rate of zinc reached 84% for the L.fermentum. Moreover, Freundlich and Langmuir model indicated that L.fermentum showed a higher capability to biosorp heavy metal compared to L.plantarum. It was concluded that L.fermentum biomass, a widely available and highly efficient biosorbant, could be applied for zinc or copper bioremediation from the aquatic environment.


Assuntos
Biodegradação Ambiental , Cobre/metabolismo , Lactobacillus fermentum/metabolismo , Lactobacillus plantarum/metabolismo , Zinco/metabolismo , Biomassa , Poluentes Ambientais/metabolismo , Cinética , Água
16.
Gene ; 750: 144759, 2020 Aug 05.
Artigo em Inglês | MEDLINE | ID: mdl-32423892

RESUMO

Zinc transporters play vital roles in regulating zinc content and localization by mobilizing zinc across cellular and intracellular membranes. Pacific oyster Crassostrea gigas is one of the most zinc-rich animals, which has been regarded as an excellent food for zinc supplement. But the information about zinc transporters and their involvements in zinc accumulation in oysters is still limited. In the present study, a total of 28 zinc transporter genes, including nine Zinc transporter genes (CgZnTs) and 19 Zrt/Irt-like protein genes (CgZIPs), were identified in C. gigas genome using a genome-wide search strategy. There were five ZIP10 homologs in C. gigas, which were much more than those in mammals, fish and other mollusks. Among oyster zinc transporters, immense variations were detected in their gene structure, protein length and physicochemical properties. Phylogenetic analysis showed that most of these transporters were distinctly clustered with their homologs from Homo sapiens, Danio rerio and other mollusks, and the most closely related transporters shared similar motif compositions. The highest zinc content was detected in the oyster mantle and gill, while the lowest level was found in the adductor muscle. The mRNA of all tested CgZnTs and CgZIPs were constitutively expressed in oyster tissues, and most of them were highly expressed in the gill or hepatopancreas. The analysis of RNA-seq data from gill and hepatopancreas showed that all the transporters exhibited divergent response patterns under zinc stress, except for CgZIP4 whose expression was almost undetectable in the two tissues. The results indicated that zinc transporters played important roles in the regulation of zinc homeostasis in C. gigas, which provided a solid foundation for further functional analysis of zinc transporters in oysters and other mollusks.


Assuntos
Proteínas de Transporte/metabolismo , Crassostrea/metabolismo , Zinco/metabolismo , Animais , Crassostrea/genética , Perfilação da Expressão Gênica/métodos , Genoma , Filogenia , Transcriptoma/genética
17.
PLoS One ; 15(5): e0233493, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32453778

RESUMO

Glyoxalase pathway is the major pathway of methylglyoxal detoxification and is ubiquitously present in all organisms ranging from prokaryotes to eukaryotes. Glyoxalase I (GLYI) and Glyoxalase II (GLYII), the two core enzymes of this pathway work together to neutralize methylglyoxal (MG), a dicarbonyl molecule with detrimental cytotoxicity at higher concentrations. The first step towards the detoxification of MG is catalyzed by GLYI, a metalloenzyme that requires divalent metal ions (either Zn2+ as seen in eukaryotes or Ni2+ as in prokaryotes). However, both Zn2+ and Ni2+ dependent GLYIs have been shown to co-exist in a higher eukaryote i.e. Arabidopsis thaliana. In the present study, we determine the role of both Zn2+ dependent (AtGLYI2) and Ni2+ dependent (AtGLYI3, AtGLYI6) GLYIs from Arabidopsis in salinity stress tolerance. AtGLYI2 overexpressing Arabidopsis plants showed better growth rate while maintaining lower levels of MG under high saline conditions. They were taller with more number of silique formation with respect to their Ni2+ dependent counterparts. Further, lack in germination of Arabidopsis AtGLYI2 mutants in presence of exogenous MG indicates the direct involvement of Zn2+ dependent GLYI in MG detoxification, suggesting Zn2+ dependent GLYI as the main enzyme responsible for MG detoxification and salinity stress tolerance.


Assuntos
Arabidopsis/crescimento & desenvolvimento , Lactoilglutationa Liase/genética , Lactoilglutationa Liase/metabolismo , Arabidopsis/enzimologia , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Regulação da Expressão Gênica no Desenvolvimento , Regulação da Expressão Gênica de Plantas , Germinação , Mutação , Aldeído Pirúvico/metabolismo , Estresse Salino , Zinco/metabolismo
18.
Ecotoxicol Environ Saf ; 200: 110728, 2020 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-32460048

RESUMO

In this study, the effects of iron (Fe) nanoparticles (NPs) on Fe and heavy metal accumulations by castor (Ricinus communis L.) plants were investigated. The castor cultivar was planted in the soil contaminated with Pb and Zn for 48 days with Fe2O3 NPs treatments. The Fe and heavy metal concentrations in the plant tissues, the plant tissues' ultrastructures, and the Fe and heavy metal distributions in the soil aggregate were analyzed. The results of this study indicate that there is a mutual promotion relationship between Fe and heavy metals (Pb and Zn). The scanning electron microscopy (SEM) revealed ultrastructural differences in the xylem and phloem with Fe2O3 NPs addition, and the presence of Fe2O3 NPs may influence the synthesis of starch granules in response to heavy metal stress. Based on the analysis of the soil aggregate, α-Fe2O3 NPs and γ-Fe2O3 NPs changed the size distribution of the soil aggregate, that is, the macro-aggregate and the clay fraction contents increased and the micro-aggregate content decreased. Moreover, in the different size fractions of the soil aggregate, Fe2O3 NPs can change the Zn and Fe enrichment and migration between the macro-aggregate and clay fractions, and there is a synergistic effect between the Fe and Zn migration. In addition, in the castor organs (roots and shoots), the Zn accumulation was mainly determined by the Zn concentration of the macro-aggregate fraction, while the Fe accumulation was mainly determined by the Fe concentration of the micro-aggregate fraction. Overall, these direct observations help improve our understanding of the migration and transport characteristics of Fe and heavy metals in soil-plant systems when Fe nanoparticles are added to metal-contaminated soils.


Assuntos
Compostos Férricos , Ferro/metabolismo , Chumbo/metabolismo , Nanopartículas Metálicas , Ricinus/metabolismo , Poluentes do Solo/metabolismo , Zinco/metabolismo , Ferro/análise , Chumbo/análise , Ricinus/ultraestrutura , Solo/química , Poluentes do Solo/análise , Zinco/análise
19.
Sheng Wu Gong Cheng Xue Bao ; 36(3): 529-540, 2020 Mar 25.
Artigo em Chinês | MEDLINE | ID: mdl-32237546

RESUMO

To explore the effects of some chemical amendments on the plant growth and phytoextraction efficiencies of cadmium (Cd)/zinc (Zn) hyper accumulator Sedum plumbizincicola in acid soils with high aluminum (Al) toxicity, a greenhouse pot experiment was conducted. Different kinds and dosages of amendments including calciummagnesium-phosphorus fertilizer (CMP), magnesium carbonate (MgCO3), potassium dihydrogen phosphate (KH2POPO4 ) were added. The results showed that CMP and MgCO3 increased soil pH and decreased soil exchangeable Al concentration to some extent, while KH2PO4 reduced soil exchangeable Al concentration but had little effect on increasing soil pH. Proper application (9.39 mg/kg) of CMP could improve the biomass and Cd and Zn phytoextraction efficiencies by S. plumbizincicola but it would inhibit plant growth and phytoextraction performance when exceeding 9.39 mg/kg. MgCO3 addition enhanced plant metal uptake while KH2PO4 presented an opposite effect. It suggests that using CMP and MgCO3 could alleviate Al toxicity to S. plumbizincicola in acid soils and maintain relatively high metal extraction efficiency.


Assuntos
Alumínio , Cádmio , Fertilizantes , Sedum , Poluentes do Solo , Zinco , Alumínio/toxicidade , Biodegradação Ambiental , Cádmio/metabolismo , Sedum/efeitos dos fármacos , Sedum/metabolismo , Solo/química , Poluentes do Solo/metabolismo , Poluentes do Solo/toxicidade , Zinco/metabolismo
20.
Sheng Wu Gong Cheng Xue Bao ; 36(3): 549-559, 2020 Mar 25.
Artigo em Chinês | MEDLINE | ID: mdl-32237548

RESUMO

Sedum plumbizincicola is a native cadmium/zinc (Cd/Zn) hyperaccumulator in China. At present, it has been applied to remediation of Cd contaminated soils. As the large differences in the removal efficiency of Cd and Zn for different soil conditions, the enhancement measure is important for the phytoremediation process. There have been many studies on the effects of earthworms on plant growth. But the effects on the growth of S. plumbizincicola and heavy metal removal efficiency have been rarely reported. There were 2 pot experiments: S. plumbizincicola was planted on 3 types of soils: Perudic Luvisols, Stagnic Anthrosols, and Udic Cambisols inoculated with Eisenia foetida to explore the effect of Eisenia foetida on the growth and Cd/Zn absorption of S. plumbizincicola. Stagnic Anthrosols with higher Cd effectiveness was selected in the second season pot experiment for further research the combined effect of earthworm and rich straw. The results of the first pot experiment showed that the addition of earthworms in acidic Perudic Luvisols increased the shoot biomass of S. plumbizincicola by 106% compared with the control treatment, and the Cd and Zn uptake increased by 72.0% and 36.0%, respectively. The soil available Cd was reduced by the addition of earthworms. The other two soils inoculated with earthworms had no enhancement on phytoremediation, addition of earthworms together with straw could improve the growth of S. plumbizincicola and the Cd/Zn uptake in Stagnic Anthrosols. The above results indicated that adding earthworm can enhance the phytoremediation of Cd/Zn hyperaccumulator, and the addition of straw is an important synergistic technique for earthworm-enhanced phytoremediation of S. plumbizincicola.


Assuntos
Oligoquetos , Sedum , Poluentes do Solo , Animais , Biodegradação Ambiental , Cádmio/metabolismo , China , Oligoquetos/fisiologia , Sedum/metabolismo , Poluentes do Solo/metabolismo , Zinco/metabolismo
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA