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1.
Am J Physiol Gastrointest Liver Physiol ; 326(3): G330-G343, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38226933

RESUMO

Alterations in endoplasmic reticulum (ER)-mitochondria associations and in mitochondria-associated ER membrane (MAM) behavior have been reported in the brain in several neurodegenerative diseases. Despite the emerging role of the gut-brain axis in neurodegenerative disorders, the biology of MAM in the enteric nervous system (ENS) has not previously been studied. Therefore, we set out to characterize the MAM in the distal colon of wild-type C57BL/6J mice and senescence-accelerated mouse prone 8 (SAMP8), a mouse model of age-related neurodegeneration. We showed for the first time that MAMs are widely present in enteric neurons and that their association is altered in SAMP8 mice. We then examined the functions of MAMs in a primary culture model of enteric neurons and showed that calcium homeostasis was altered in SAMP8 mice when compared with control animals. These findings provide the first detailed characterization of MAMs in the ENS under physiological conditions and during age-associated neurodegeneration. Further investigation of MAM modifications in the ENS in disease may provide valuable information about the possible role of enteric MAMs in neurodegenerative diseases.NEW & NOTEWORTHY Our work shows for the first time the presence of contacts between endoplasmic reticulum and mitochondria in the enteric neurons and that the dynamic of these contacts is affected in these cells from an age-related neurodegeneration mouse model. It provides new insights into the potential role of enteric mitochondria-associated endoplasmic reticulum membrane in neurodegenerative disorders.


Assuntos
Sistema Nervoso Entérico , Doenças Neurodegenerativas , Camundongos , Animais , Membranas Associadas à Mitocôndria , Camundongos Endogâmicos C57BL , Retículo Endoplasmático , Modelos Animais de Doenças
2.
EMBO J ; 37(4)2018 02 15.
Artigo em Inglês | MEDLINE | ID: mdl-29351914

RESUMO

Transcription termination delimits transcription units but also plays important roles in limiting pervasive transcription. We have previously shown that transcription termination occurs when elongating RNA polymerase II (RNAPII) collides with the DNA-bound general transcription factor Reb1. We demonstrate here that many different DNA-binding proteins can induce termination by a similar roadblock (RB) mechanism. We generated high-resolution transcription maps by the direct detection of RNAPII upon nuclear depletion of two essential RB factors or when the canonical termination pathways for coding and non-coding RNAs are defective. We show that RB termination occurs genomewide and functions independently of (and redundantly with) the main transcription termination pathways. We provide evidence that transcriptional readthrough at canonical terminators is a significant source of pervasive transcription, which is controlled to a large extent by RB termination. Finally, we demonstrate the occurrence of RB termination around centromeres and tRNA genes, which we suggest shields these regions from RNAPII to preserve their functional integrity.


Assuntos
Proteínas de Ligação a DNA/metabolismo , RNA Polimerase II/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo , Saccharomyces cerevisiae/genética , Terminação da Transcrição Genética , Transcrição Gênica , Proteínas de Ligação a DNA/genética , Genoma Fúngico , RNA Polimerase II/genética , RNA Fúngico , Proteínas de Saccharomyces cerevisiae/genética
3.
Metabolomics ; 18(3): 18, 2022 03 15.
Artigo em Inglês | MEDLINE | ID: mdl-35290545

RESUMO

INTRODUCTION: Marine biofilms are the most widely distributed mode of life on Earth and drive biogeochemical cycling processes of most elements. Phosphorus (P) is essential for many biological processes such as energy transfer mechanisms, biological information storage and membrane integrity. OBJECTIVES: Our aim was to analyze the effect of a gradient of ecologically relevant phosphate concentrations on the biofilm-forming capacity and the metabolome of the marine bacterium Pseudoalteromonas lipolytica TC8. METHODS: In addition to the evaluation of the effect of different phosphate concentration on the biomass, structure and gross biochemical composition of biofilms of P. lipolytica TC8, untargeted metabolomics based on liquid chromatography-mass spectrometry (LC-MS) analysis was used to determine the main metabolites impacted by P-limiting conditions. Annotation of the most discriminating and statistically robust metabolites was performed through the concomitant use of molecular networking and MS/MS fragmentation pattern interpretation. RESULTS: At the lowest phosphate concentration, biomass, carbohydrate content and three-dimensional structures of biofilms tended to decrease. Furthermore, untargeted metabolomics allowed for the discrimination of the biofilm samples obtained at the five phosphate concentrations and the highlighting of a panel of metabolites mainly implied in such a discrimination. A large part of the metabolites of the resulting dataset were then putatively annotated. Ornithine lipids were found in increasing quantity when the phosphate concentration decreased, while the opposite trend was observed for oxidized phosphatidylethanolamines (PEs). CONCLUSION: This study demonstrated the suitability of LC-MS-based untargeted metabolomics for evaluating the effect of culture conditions on marine bacterial biofilms. More precisely, these results supported the high plasticity of the membrane of P. lipolytica TC8, while the role of the oxidized PEs remains to be clarified.


Assuntos
Metabolômica , Pseudoalteromonas , Biofilmes , Metaboloma , Metabolômica/métodos , Fosfatos/farmacologia , Espectrometria de Massas em Tandem/métodos
4.
Eur Heart J ; 42(17): 1687-1695, 2021 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-33289793

RESUMO

AIMS: Risk stratification of sudden cardiac arrest (SCA) in Brugada syndrome (Brs) remains the main challenge for physicians. Several scores have been suggested to improve risk stratification but never replicated. We aim to investigate the accuracy of the Brs risk scores. METHODS AND RESULTS: A total of 1613 patients [mean age 45 ± 15 years, 69% male, 323 (20%) symptomatic] were prospectively enrolled from 1993 to 2016 in a multicentric database. All data described in the risk score were double reviewed for the study. Among them, all patients were evaluated with Shanghai score and 461 (29%) with Sieira score. After a mean follow-up of 6.5 ± 4.7 years, an arrhythmic event occurred in 75 (5%) patients including 16 SCA, 11 symptomatic ventricular arrhythmia, and 48 appropriate therapies. Predictive capacity of the Shanghai score (n = 1613) and the Sieira (n = 461) score was, respectively, estimated by an area under the curve of 0.73 (0.67-0.79) and 0.71 (0.61-0.81). Considering Sieira score, the event rate at 10 years was significantly higher with a score of 5 (26.4%) than with a score of 0 (0.9%) or 1 (1.1%) (P < 0.01). No statistical difference was found in intermediate-risk patients (score 2-4). The Shanghai score does not allow to better stratify the risk of SCA. CONCLUSIONS: In the largest cohort of Brs patient ever described, risk scores do not allow stratifying the risk of arrhythmic event in intermediate-risk patient.


Assuntos
Síndrome de Brugada , Desfibriladores Implantáveis , Adulto , Síndrome de Brugada/complicações , China , Morte Súbita Cardíaca/epidemiologia , Morte Súbita Cardíaca/etiologia , Eletrocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Medição de Risco
5.
Environ Microbiol ; 23(11): 6777-6797, 2021 11.
Artigo em Inglês | MEDLINE | ID: mdl-34490980

RESUMO

In the context of global warming, this study aimed to assess the effect of temperature and irradiance on the macroalgal Taonia atomaria holobiont dynamics. We developed an experimental set-up using aquaria supplied by natural seawater with three temperatures combined with three irradiances. The holobiont response was monitored over 14 days using a multi-omics approach coupling algal surface metabolomics and metabarcoding. Both temperature and irradiance appeared to shape the microbiota and the surface metabolome, but with a distinct temporality. Epibacterial community first changed according to temperature, and later in relation to irradiance, while the opposite occurred for the surface metabolome. An increased temperature revealed a decreasing richness of the epiphytic community together with an increase of several bacterial taxa. Irradiance changes appeared to quickly impact surface metabolites production linked with the algal host photosynthesis (e.g. mannitol, fucoxanthin, dimethylsulfoniopropionate), which was hypothesized to explain modifications of the structure of the epiphytic community. Algal host may also directly adapt its surface metabolome to changing temperature with time (e.g. lipids content) and also in response to changing microbiota (e.g. chemical defences). Finally, this study brought new insights highlighting complex direct and indirect responses of seaweeds and their associated microbiota under changing environments.


Assuntos
Microbiota , Phaeophyceae , Alga Marinha , Bactérias/genética , Alga Marinha/microbiologia , Temperatura
6.
Mol Ecol ; 30(12): 2891-2904, 2021 06.
Artigo em Inglês | MEDLINE | ID: mdl-33887078

RESUMO

Free-living (FL) marine microbial communities differ from those attached to particles (PA). Likewise, biofilms (B) colonizing artificial surfaces, including plastics or ship hulls, hardly resemble their planktonic surroundings. However, few studies have examined the effect of the environment on these lifestyles and on the source of organisms colonizing marine surfaces. Using 16S rRNA gene metabarcoding, we identified specificities of marine prokaryotic community lifestyles (FL, PA or B) sampled in three coastal polluted locations with dissimilar environmental conditions: the North-Western Mediterranean Sea and the Atlantic and Indian Oceans. Biofilms developed over polyvinyl chloride (PVC) were found to be significantly different from FL or PA collected during the immersions. Alpha-diversity increased from FL to PA and to B, illustrating the integrative aspect of the latter, with little proportion of operational taxonomic units shared with the first two. Beta-diversity clustered first the lifestyles and then the sites. FL and PA were more affected by water quality, especially by trace metal contamination, whereas B were as sensitive to trace metals as to nutrients. Although biofilms should be supplied by the planktonic (ultra) rare biosphere, source tracking could only detect small contributions of FL or PA taxa to B communities.


Assuntos
Biofilmes , Microbiota , Oceano Índico , Mar Mediterrâneo , Microbiota/genética , RNA Ribossômico 16S/genética
7.
Biofouling ; 36(4): 378-388, 2020 04.
Artigo em Inglês | MEDLINE | ID: mdl-32425065

RESUMO

Poly(dimethylsiloxane) (PDMS) elastomer coatings containing an amphiphilic hydrolyzable diblock copolymer additive were prepared and their potential as marine antifouling and antiadhesion materials was tested. The block copolymer additive consisted of a PDMS first block and a random poly(trialkylsilyl methacrylate (TRSiMA, R = butyl, isopropyl)-co-poly(ethyleneglycol) methacrylate (PEGMA) copolymer second block. PDMS-b-TRSiMA block copolymer additives without PEGMA units were also used as additives. The amphiphilic character of the coating surface was assessed in water using the captive air bubble technique for measurements of static and dynamic contact angles. The attachment of macro- and microorganisms on the coatings was evaluated by field tests and by performing adhesion tests to the barnacle Amphibalanus amphitrite and the green alga Ulva rigida. All the additive-based PDMS coatings showed better antiadhesion properties to A. amphitrite larvae than to U. rigida spores. Field tests provided meaningful information on the antifouling and fouling release activity of coatings over an immersion period of 23 months.


Assuntos
Incrustação Biológica , Polietilenoglicóis , Animais , Dimetilpolisiloxanos , Metacrilatos , Propriedades de Superfície
8.
Environ Microbiol ; 21(9): 3346-3363, 2019 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-30945796

RESUMO

An integrative multi-omics approach allowed monthly variations for a year of the surface metabolome and the epibacterial community of the Mediterranean Phaeophyceae Taonia atomaria to be investigated. The LC-MS-based metabolomics and 16S rDNA metabarcoding data sets were integrated in a multivariate meta-omics analysis (multi-block PLS-DA from the MixOmic DIABLO analysis) showing a strong seasonal covariation (Mantel test: p < 0.01). A network based on positive and negative correlations between the two data sets revealed two clusters of variables, one relative to the 'spring period' and a second to the 'summer period'. The 'spring period' cluster was mainly characterized by dipeptides positively correlated with a single bacterial taxon of the Alteromonadaceae family (BD1-7 clade). Moreover, 'summer' dominant epibacterial taxa from the second cluster (including Erythrobacteraceae, Rhodospirillaceae, Oceanospirillaceae and Flammeovirgaceae) showed positive correlations with few metabolites known as macroalgal antifouling defences [e.g. dimethylsulphoniopropionate (DMSP) and proline] which exhibited a key role within the correlation network. Despite a core community that represents a significant part of the total epibacteria, changes in the microbiota structure associated with surface metabolome variations suggested that both environment and algal host shape the bacterial surface microbiota.

9.
Anal Chem ; 90(8): 4978-4981, 2018 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-29611700

RESUMO

Several alternatives are currently investigated to prevent and control the natural process of colonization of any seawater submerged surfaces by marine organisms. Since few years we develop an approach based on addressable electroactive coatings containing conducting polymers or polymers with lateral redox groups. In this article we describe the use of a screen-printed plate formed by 96 three-electrode electrochemical cells to assess the potential of these electroactive coatings to prevent the adhesion of marine bacteria. This novel platform is intended to control and record the redox properties of the electroactive coating in each well during the bioassay (15 h) and to allow screening its antiadhesion activity with enough replicates to support significant conclusions. Validation of this platform was carried out with poly(ethylenedioxythiophene) (PEDOT) as electroactive coating obtained by electropolymerization of EDOT monomer in artificial seawater electrolyte on the working electrode of each electrochemical cell of the 96-well microplate.

10.
Biofouling ; 34(6): 657-672, 2018 07.
Artigo em Inglês | MEDLINE | ID: mdl-30185057

RESUMO

Metabarcoding and metabolomics were used to explore the taxonomic composition and functional diversity of eukaryotic biofouling communities on plates with antifouling paints at two French coastal sites: Lorient (North Eastern Atlantic Ocean; temperate and eutrophic) and Toulon (North-Western Mediterranean Sea; mesotrophic but highly contaminated). Four distinct coatings were tested at each site and season for one month. Metabarcoding showed biocidal coatings had less impact on eukaryotic assemblages compared to spatial and temporal effects. Ciliophora, Chlorophyceae or Cnidaria (mainly hydrozoans) were abundant at Lorient, whereas Arthropoda (especially crustaceans), Nematoda, and Ochrophyta dominated less diversified assemblages at Toulon. Seasonal shifts were observed at Lorient, but not Toulon. Metabolomics also showed clear site discrimination, but these were associated with a coating and not season dependent clustering. The meta-omics analysis enabled identifications of some associative patterns between metabolomic profiles and specific taxa, in particular those colonizing the plates with biocidal coatings at Lorient.


Assuntos
Incrustação Biológica , Metabolômica , Cilióforos/fisiologia , Estações do Ano
11.
Biofouling ; 34(9): 1055-1063, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-30626214

RESUMO

Much current research is focused on preventing and controlling the natural process of colonization by marine organisms of surfaces submerged in seawater. Previously, the authors' laboratory has reported the synthesis and the full physico-chemical characterization of homopolymers obtained from 1-ferrocenylmethyl methacrylate (FMMA), 2-(ferrocenylmethoxy)ethyl methacrylate (FMOEMA), and 3-(ferrocenylmethoxy)propyl methacrylate (FMOPMA). Here, the bacterial anti-adhesion activity of these homopolymers (pFMMA, pFMOEMA and pFMOPMA) is reported when stimulated in 96-well microplates containing a printed electrochemical cell in each well. Polymers were deposited on the printed carbon working electrode of each well in two columns each comprising eight wells. Their electrochemical anti-adhesion properties were evaluated by inoculating a marine biofilm forming bacterial strain, Pseudoalteramonas lipolytica, in each well and then applying recurrent scans for 15 h. The results revealed an intrinsic anti-adhesion activity of all the polymers. This activity was amplified by a factor of 10 when potential recurrent scans were applied.


Assuntos
Aderência Bacteriana/fisiologia , Incrustação Biológica/prevenção & controle , Técnicas Eletroquímicas/métodos , Compostos Ferrosos/química , Gammaproteobacteria/crescimento & desenvolvimento , Ácidos Polimetacrílicos/química , Biofilmes/crescimento & desenvolvimento , Carbono , Eletrodos , Metalocenos , Água do Mar/microbiologia
12.
Molecules ; 23(9)2018 Aug 29.
Artigo em Inglês | MEDLINE | ID: mdl-30158494

RESUMO

The evolution of regulations concerning biocidal products aimed towards an increased protection of the environment (e.g., EU Regulation No 528/2012) requires the development of new non-toxic anti-fouling (AF) systems. As the marine environment is an important source of inspiration, such AF systems inhibiting the adhesion of organisms without any toxicity could be based on molecules of natural origin. In this context, the antibiofilm potential of tropical microalgal extracts was investigated. The tropics are particularly interesting in terms of solar energy and temperatures which provide a wide marine diversity and a high production of microalgae. Twenty microalgal strains isolated from the Indian Ocean were studied. Their extracts were characterized in terms of global chemical composition by high resolution magic angle spinning (HR-MAS) and nuclear magnetic resonance (NMR) spectroscopy, toxicity against marine bacteria (viability and growth) and anti-adhesion effect. The different observations made by confocal laser scanning microscopy (CLSM) showed a significant activity of three extracts from Dinoflagellate strains against the settlement of selected marine bacteria without any toxicity at a concentration of 50 µg/mL. The Symbiodinium sp. (P-78) extract inhibited the adhesion of Bacillus sp. 4J6 (Atlantic Ocean), Shewanella sp. MVV1 (Indian Ocean) and Pseudoalteromonas lipolytica TC8 (Mediterranean Ocean) at 60, 76 and 52%, respectively. These results underlined the potential of using microalgal extracts to repel fouling organisms.


Assuntos
Antibacterianos/farmacologia , Aderência Bacteriana/efeitos dos fármacos , Metanol/farmacologia , Microalgas/química , Oceano Atlântico , Bactérias/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Oceano Índico , Mar Mediterrâneo , Microalgas/isolamento & purificação , Testes de Sensibilidade Microbiana , Microbiologia da Água
13.
Microb Ecol ; 74(3): 585-598, 2017 10.
Artigo em Inglês | MEDLINE | ID: mdl-28374061

RESUMO

Surface colonization in seawater first corresponds to the selection of specific microbial biofilm communities. By coupling flow cytometry, microscopy and high throughput sequencing (HTS, 454 pyrosequencing) with artificial surfaces and environmental analyses, we intend to identify the contribution of biofilm community drivers at two contrasted French sites, one temperate and eutrophic (Lorient, Atlantic coast) and the other at a mesotrophic but highly contaminated bay (Toulon, North-Western Mediterranean Sea). Microbial communities were shaped by high temperatures, salinity and lead at Toulon by but nutrients and DOC at Lorient. Coatings including pyrithione exhibited a significant decrease of their microbial densities except for nanoeukaryotes. Clustering of communities was mainly based on the surface type and secondly the site, whereas seasons appeared of less importance. The in-depth HTS revealed that γ- and α-proteobacteria, but also Bacteroidetes, dominated highly diversified bacterial communities with a relative low ß-diversity. Sensitivity to biocides released by the tested antifouling coatings could be noticed at different taxonomic levels: the percentage of Bacteroidetes overall decreased with the presence of pyrithione, whereas the α/γ-proteobacteria ratio decreased at Toulon when increased at Lorient. Small diatom cells (Amphora and Navicula spp.) dominated on all surfaces, whereas site-specific sub-dominant taxa appeared clearly more sensitive to biocides. This overall approach exhibited the critical significance of surface characteristics in biofilm community shaping.


Assuntos
Fenômenos Fisiológicos Bacterianos , Biofilmes/crescimento & desenvolvimento , Incrustação Biológica , Diatomáceas/fisiologia , Água do Mar/microbiologia , Oceano Atlântico , Incrustação Biológica/prevenção & controle , Citometria de Fluxo , França , Mar Mediterrâneo , Estações do Ano , Análise de Sequência de DNA
14.
Biofouling ; 32(7): 801-13, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27353006

RESUMO

This study aimed to improve understanding of the strategies developed by the Mediterranean seaweed Taonia atomaria to chemically control bacterial epibiosis. An experimental protocol was optimized to specifically extract algal surface-associated metabolites by a technique involving dipping in organic solvents whilst the integrity of algal cell membranes was assessed by fluorescent microscopy. This methodology was validated using mass spectrometry-based profiles of algal extracts and analysis of their principal components, which led to the selection of methanol as the extraction solvent with a maximum exposure time of 15 s. Six compounds (A-F) were identified in the resulting surface extracts. Two of these surface-associated compounds (B and C) showed selective anti-adhesion properties against reference bacterial strains isolated from artificial surfaces while remaining inactive against epibiotic bacteria of T. atomaria. Such specificity was not observed for commercial antifouling biocides and other molecules identified in the surface or whole-cell extracts of T. atomaria.


Assuntos
Biofilmes/efeitos dos fármacos , Desinfetantes/isolamento & purificação , Phaeophyceae/metabolismo , Phaeophyceae/microbiologia , Alga Marinha/metabolismo , Alga Marinha/microbiologia , Bactérias/classificação , Aderência Bacteriana/efeitos dos fármacos , Desinfetantes/farmacologia , Mar Mediterrâneo , Metaboloma , Phaeophyceae/química , Alga Marinha/química , Propriedades de Superfície
15.
FASEB J ; 28(7): 2840-51, 2014 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-24671707

RESUMO

Autoantibodies to nuclear antigens arise in human autoimmune diseases, but a unifying pathogenetic mechanism remains elusive. Recently we reported that exposure of neutrophils to inflammatory conditions induces the citrullination of core histones by peptidylarginine deiminase 4 (PAD4) and that patients with autoimmune disorders produce autoantibodies that recognize such citrullinated histones. Here we identify histone H1 as an additional substrate of PAD4, localize H1 within neutrophil extracellular traps, and detect autoantibodies to citrullinated H1 in 6% of sera from patients with systemic lupus erythematosus and Sjögren's syndrome. No preference for deiminated H1 was observed in healthy control sera and sera from patients with scleroderma or rheumatoid arthritis. We map binding to the winged helix of H1 and determine that citrulline 53 represents a key determinant of the autoantibody epitope. In addition, we quantitate RNA for H1 histone subtypes in mature human neutrophils and identify citrulline residues by liquid chromatography and tandem mass spectrometry. Our results indicate that deimination of linker histones generates new autoantibody epitopes with enhanced potential for stimulating autoreactive human B cells.-Dwivedi, N., Neeli, I., Schall, N., Wan, H., Desiderio, D. M., Csernok, E., Thompson, P. R., Dali, H., Briand, J.-P., Muller, S., Radic, M. Deimination of linker histones links neutrophil extracellular trap release with autoantibodies in systemic autoimmunity.


Assuntos
Autoanticorpos/imunologia , Autoimunidade/imunologia , Histonas/imunologia , Neutrófilos/imunologia , Sequência de Aminoácidos , Autoantígenos/imunologia , Doenças Autoimunes/imunologia , Epitopos/imunologia , Humanos , Imunoglobulina G/imunologia , Dados de Sequência Molecular , Alinhamento de Sequência
16.
Appl Environ Microbiol ; 80(16): 4821-31, 2014 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-24907329

RESUMO

When immersed in seawater, substrates are rapidly colonized by both micro- and macroorganisms. This process is responsible for important economic and ecological prejudices, particularly when related to ship hulls or aquaculture nets. Commercial antifouling coatings are supposed to reduce biofouling, i.e., micro- and macrofoulers. In this study, biofilms that primarily settled on seven different coatings (polyvinyl chloride [PVC], a fouling release coating [FRC], and five self-polishing copolymer coatings [SPC], including four commercial ones) were quantitatively studied, after 1 month of immersion in summer in the Toulon Bay (Northwestern Mediterranean Sea, France), by using flow cytometry (FCM), microscopy, and denaturing gradient gel electrophoresis. FCM was used after a pretreatment to separate cells from the biofilm matrix, in order to determine densities of heterotrophic bacteria, picocyanobacteria, and pico- and nanoeukaryotes on these coatings. Among diatoms, the only microphytobenthic class identified by microscopy, Licmophora, Navicula, and Nitzschia were determined to be the dominant taxa. Overall, biocide-free coatings showed higher densities than all other coatings, except for one biocidal coating, whatever the group of microorganisms. Heterotrophic bacteria always showed the highest densities, and diatoms showed the lowest, but the relative abundances of these groups varied depending on the coating. In particular, the copper-free SPC failed to prevent diatom settlement, whereas the pyrithione-free SPC exhibited high picocyanobacterial density. These results highlight the interest in FCM for antifouling coating assessment as well as specific selection among microbial communities by antifouling coatings.


Assuntos
Fenômenos Fisiológicos Bacterianos/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Incrustação Biológica/prevenção & controle , Diatomáceas/fisiologia , Polímeros/farmacologia , Água do Mar/microbiologia , Bactérias/classificação , Bactérias/efeitos dos fármacos , Bactérias/genética , Bactérias/isolamento & purificação , Diatomáceas/classificação , Diatomáceas/efeitos dos fármacos , Diatomáceas/isolamento & purificação , Mar Mediterrâneo , Cloreto de Polivinila/farmacologia , Navios
17.
Microorganisms ; 12(3)2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38543496

RESUMO

Plastics in the ocean create the "plastisphere", a diverse habitat hosting various life forms. Other than the pollution induced by plastics, the co-occurrence of primary producers, symbiotic organisms, decomposers, and pathogens within the plastisphere raises questions about how they influence the dynamics of marine ecosystems. Here, we used a shotgun DNA-sequencing approach to describe the species thriving on floating plastics collected in two Mediterranean sites. Our findings revealed many species of bacteria, eukaryotes, viruses, and archaea on each plastic. Proteobacteria was dominant (70% of reads in the entire dataset), with other groups such as Ascomycota fungi (11%) and Bacteroidetes (9%) also being represented. The community structure was not affected by the polymeric composition or the plastic shape. Notably, pathogenic Vibrio species, including V. campbelli, V. alginolyticus, and V. coralliilyticus, were among the most abundant species. Viruses, despite showing lower relative abundances, occurred in all samples, especially Herpesvirales, Caudovirales, and Poxviridae groups. A significant finding was the presence of the White Spot Syndrome virus (WSSV). This pathogen, responsible for devastating outbreaks in aquaculture systems, had not been previously reported in the marine plastisphere. Our study emphasizes the need for further investigation into the ecological and economic impacts of plastisphere organisms in the ocean.

18.
Environ Pollut ; 348: 123808, 2024 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-38521396

RESUMO

The term "Plastisphere" refers to the biofilm layer naturally formed by microorganisms attaching to plastic surfaces. This layer possesses the capability to adsorb persistent organic and inorganic pollutants, particularly trace metals, which are the focus of this research study. Immersion experiments were concurrently conducted in five locations spanning four European countries (France, Ireland, Spain, and Italy) utilising eight distinct polymers. These immersions, repeated every three months over a one-year period, aimed to evaluate the baseline bioaccumulation of 12 trace metals. The study underscores the intricate nature of metal bioaccumulation, influenced by both micro-scale factors (such as polymer composition) and macro-scale factors (including geographical site and seasonal variations). Villefranche Bay in France exhibited the lowest metals bioaccumulation, whereas Naples in Italy emerged as the site where bioaccumulation was often the highest for the considered metals. Environmental risk assessment was also conducted in the study. The lightweight nature of certain plastics allows them to be transported across significant distances in the ocean. Consequently, evaluating trace metal concentrations in the plastisphere is imperative for assessing potential environmental repercussions that plastics, along with their associated biota, may exert even in locations distant from their point of emission.


Assuntos
Poluentes Ambientais , Metais Pesados , Oligoelementos , Poluentes Químicos da Água , Bioacumulação , Poluentes Químicos da Água/análise , Metais , França , Polímeros , Monitoramento Ambiental , Metais Pesados/análise , Plásticos
19.
J Biol Chem ; 287(52): 43685-93, 2012 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-23109338

RESUMO

Blockage of the metastasis process remains a significant clinical challenge, requiring innovative therapeutic approaches. For this purpose, molecules that inhibit matrix metalloproteinases activity or induce the expression of their natural inhibitor, the tissue inhibitor of metalloproteinases (TIMPs), are potentially interesting. In a previous study, we have shown that synthetic ligands binding to cell surface nucleolin/nucleophosmin and known as HB 19 for the lead compound and NucAnt 6L (N6L) for the most potent analog, inhibit both tumor growth and angiogenesis. Furthermore, they prevent metastasis in a RET transgenic mice model which develops melanoma. Here, we investigated the effect of N6L on the invasion capacity of MDA-MB-435 melanoma cells. Our results show that the multivalent pseudopeptide N6L inhibited Matrigel invasion of MDA-MB-435 cells in a modified Boyden chamber model. This was associated with an increase in TIMP-3 in the cell culture medium without a change in TIMP-3 mRNA expression suggesting its release from cell surface and/or extracellular matrix. This may be explained by our demonstrated N6L interaction with sulfated glycosaminoglycans and consequently the controlled bioavailability of glycosaminoglycan-bound TIMP-3. The implication of TIMP-3 in N6L-induced inhibition of cell invasion was evidenced by siRNA silencing experiments showing that the loss of TIMP-3 expression abrogated the effect of N6L. The inhibition of tumor cell invasion by N6L demonstrated in this study, in addition to its previously established inhibitory effect on tumor growth and angiogenesis, suggests that N6L represents a promising anticancer drug candidate warranting further investigation.


Assuntos
Antineoplásicos/farmacologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Chumbo/farmacologia , Proteínas de Neoplasias/biossíntese , Neoplasias/metabolismo , Peptídeos/farmacologia , Inibidor Tecidual de Metaloproteinase-3/biossíntese , Animais , Antineoplásicos/química , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica/genética , Humanos , Chumbo/química , Camundongos , Camundongos Transgênicos , Invasividade Neoplásica , Proteínas de Neoplasias/genética , Neoplasias/tratamento farmacológico , Neoplasias/genética , Neoplasias/patologia , Peptídeos/química , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , RNA Neoplásico/biossíntese , Inibidor Tecidual de Metaloproteinase-3/genética
20.
Environ Microbiol ; 15(11): 2879-93, 2013 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-23869714

RESUMO

The search for new antifouling (AF) coatings that are environmentally benign has led to renewed interest in the ways that micro-organisms colonize substrates in the marine environment. This review covers recently published research on the global species composition and dynamics of marine biofilms, consisting mainly of bacteria and diatoms found on man-made surfaces including AF coatings. Marine biofilms directly interact with larger organisms (macrofoulers) during colonization processes; hence, recent literature on understanding the basis of the biofilm/macrofouling interactions is essential and will also be reviewed here. Overall, differences have been identified in species composition between biofilm and planktonic forms for both diatoms and bacteria at various exposure sites. In most studies, the underlying biofilm was found to induce larval and spore settlement of macrofoulers; however, issues such as reproducibility, differences in exposure sites and biofilm composition (natural multispecies vs. monospecific species) may influence the outcomes.


Assuntos
Bactérias/efeitos dos fármacos , Biofilmes/efeitos dos fármacos , Diatomáceas/efeitos dos fármacos , Desinfetantes/farmacologia , Bactérias/crescimento & desenvolvimento , Biofilmes/classificação , Biofilmes/crescimento & desenvolvimento , Diatomáceas/crescimento & desenvolvimento , Desinfetantes/química , Esporos/efeitos dos fármacos , Esporos/crescimento & desenvolvimento , Propriedades de Superfície
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