Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 52
Filtrar
Más filtros

Tipo del documento
Intervalo de año de publicación
1.
J Cell Physiol ; 236(7): 4997-5011, 2021 07.
Artículo en Inglés | MEDLINE | ID: mdl-33305427

RESUMEN

The epidermal growth factor receptor (EGFR) harbors a calmodulin (CaM)-binding domain (CaM-BD) and a CaM-like domain (CaM-LD) upstream and downstream, respectively, of the tyrosine kinase (TK) domain. We demonstrate in this paper that deletion of the positively charged CaM-BD (EGFR/CaM-BD∆) inactivated the TK activity of the receptor. Moreover, deletion of the negatively charged CaM-LD (EGFR/CaM-LD∆), leaving a single negative residue (glutamate), reduced the activity of the receptor. In contrast, substituting the CaM-LD with a histidine/valine-rich peptide (EGFR/InvCaM-LD) caused full inactivation. We also demonstrated using confocal microscopy and flow cytometry that the chimera EGFR-green fluorescent protein (GFP)/CaM-BD∆, the EGFR/CaM-LD∆, and EGFR/InvCaM-LD mutants all bind tetramethylrhodamine-labelled EGF. These EGFR mutants were localized at the plasma membrane as the wild-type receptor does. However, only the EGFR/CaM-LD∆ and EGFR/InvCaM-LD mutants appear to undergo ligand-dependent internalization, while the EGFR-GFP/CaM-BD∆ mutant seems to be deficient in this regard. The obtained results and in silico modelling studies of the asymmetric structure of the EGFR kinase dimer support a role of a CaM-BD/CaM-LD electrostatic interaction in the allosteric activation of the EGFR TK.


Asunto(s)
Calmodulina/metabolismo , Membrana Celular/metabolismo , Animales , Células CHO , Señalización del Calcio/fisiología , Línea Celular , Cricetulus , Activación Enzimática/fisiología , Factor de Crecimiento Epidérmico/metabolismo , Receptores ErbB/genética , Receptores ErbB/metabolismo , Humanos , Unión Proteica/fisiología , Dominios Proteicos/fisiología , Proteínas Tirosina Quinasas/metabolismo
2.
Arch Biochem Biophys ; 697: 108680, 2021 01 15.
Artículo en Inglés | MEDLINE | ID: mdl-33220265

RESUMEN

The study of calmodulin (CaM) functions in living cells has been tackled up to date using cell-permeant CaM inhibitors or interference-RNA methods. CaM inhibitors may lack specificity and the siRNA interference approach is challenging, as all three CaM genes expressing an identical protein in mammals have to be blocked. Therefore, we recently introduced a novel genetic system using CRISPR/Cas9-mediated gene deletion and conditional CaM expression to study the function of CaM in HeLa cells. Here, we describe the effect of CaM downregulation on the basal and epidermal growth factor (EGF)-dependent 2D- and 3D-migration in HeLa cells. CaM downregulation inhibited cell migration on a 2D-surface in the absence but not in the presence of EGF. In contrast, CaM downregulation led to inhibition of 3D-migration across a porous membrane both in the absence and presence of EGF. CaM downregulation decreased the expression of Rac1, Cdc42 and RhoA, all known to play crucial roles in cell migration. These results show that EGF-dependent 2D- and 3D-migration utilize distinct CaM-regulated systems and identify several essential migratory proteins directly or indirectly regulated by CaM.


Asunto(s)
Calmodulina/deficiencia , Calmodulina/genética , Movimiento Celular/genética , Regulación hacia Abajo , Técnicas de Inactivación de Genes , Factor de Crecimiento Epidérmico/metabolismo , Células HeLa , Humanos , Proteína de Unión al GTP cdc42/metabolismo , Proteína de Unión al GTP rac1/metabolismo , Proteína de Unión al GTP rhoA/metabolismo
3.
Cell Mol Life Sci ; 76(12): 2299-2328, 2019 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-30877334

RESUMEN

The appearance of modular proteins is a widespread phenomenon during the evolution of proteins. The combinatorial arrangement of different functional and/or structural domains within a single polypeptide chain yields a wide variety of activities and regulatory properties to the modular proteins. In this review, we will discuss proteins, that in addition to their catalytic, transport, structure, localization or adaptor functions, also have segments resembling the helix-loop-helix EF-hand motifs found in Ca2+-binding proteins, such as calmodulin (CaM). These segments are denoted CaM-like domains (CaM-LDs) and play a regulatory role, making these CaM-like proteins sensitive to Ca2+ transients within the cell, and hence are able to transduce the Ca2+ signal leading to specific cellular responses. Importantly, this arrangement allows to this group of proteins direct regulation independent of other Ca2+-sensitive sensor/transducer proteins, such as CaM. In addition, this review also covers CaM-binding proteins, in which their CaM-binding site (CBS), in the absence of CaM, is proposed to interact with other segments of the same protein denoted CaM-like binding site (CLBS). CLBS are important regulatory motifs, acting either by keeping these CaM-binding proteins inactive in the absence of CaM, enhancing the stability of protein complexes and/or facilitating their dimerization via CBS/CLBS interaction. The existence of proteins containing CaM-LDs or CLBSs substantially adds to the enormous versatility and complexity of Ca2+/CaM signaling.


Asunto(s)
Calmodulina/química , Motivos EF Hand , Proteínas/química , Actinina/química , Actinina/metabolismo , Secuencia de Aminoácidos , Animales , Sitios de Unión , Calcineurina/química , Calcineurina/metabolismo , Calcio/metabolismo , Señalización del Calcio , Calmodulina/metabolismo , Calpaína/química , Calpaína/metabolismo , Humanos , Modelos Moleculares , Unión Proteica , Dominios Proteicos , Proteínas Quinasas/química , Proteínas Quinasas/metabolismo , Proteínas/metabolismo
4.
Electrophoresis ; 2018 Feb 20.
Artículo en Inglés | MEDLINE | ID: mdl-29460953

RESUMEN

Cantharellus tubaeformis was processed by pressurized hot water extraction (80-240°C) with the aim of maximizing the extraction of oligomeric fractions, ß-glucans, and the in vitro antioxidant properties of the extracts. Increased severity of treatment enhanced the extraction yields above 62% at temperatures of 210ºC or higher, corresponding to the maximum ß-glucan yields. The highest antioxidant capacity was obtained at 170ºC, although the highest content of phenolic compounds was obtained at the highest severity studied. This hydrothermal treatment can be considered a suitable process to obtain extracts with antioxidant properties and rich in ß-glucans.

5.
J Proteome Res ; 14(9): 3530-40, 2015 Sep 04.
Artículo en Inglés | MEDLINE | ID: mdl-26216070

RESUMEN

A comprehensive study of the molecular active landscape of human cells can be undertaken to integrate two different but complementary perspectives: transcriptomics, and proteomics. After the genome era, proteomics has emerged as a powerful tool to simultaneously identify and characterize the compendium of thousands of different proteins active in a cell. Thus, the Chromosome-centric Human Proteome Project (C-HPP) is promoting a full characterization of the human proteome combining high-throughput proteomics with the data derived from genome-wide expression profiling of protein-coding genes. Here we present a full proteomic profiling of a human lymphoma B-cell line (Ramos) performed using a nanoUPLC-LTQ-Orbitrap Velos proteomic platform, combined to an in-depth transcriptomic profiling of the same cell type. Data are available via ProteomeXchange with identifier PXD001933. Integration of the proteomic and transcriptomic data sets revealed a 94% overlap in the proteins identified by both -omics approaches. Moreover, functional enrichment analysis of the proteomic profiles showed an enrichment of several functions directly related to the biological and morphological characteristics of B-cells. In turn, about 30% of all protein-coding genes present in the whole human genome were identified as being expressed by the Ramos cells (stable average of 30% genes along all the chromosomes), revealing the size of the protein expression-set present in one specific human cell type. Additionally, the identification of missing proteins in our data sets has been reported, highlighting the power of the approach. Also, a comparison between neXtProt and UniProt database searches has been performed. In summary, our transcriptomic and proteomic experimental profiling provided a high coverage report of the expressed proteome from a human lymphoma B-cell type with a clear insight into the biological processes that characterized these cells. In this way, we demonstrated the usefulness of combining -omics for a comprehensive characterization of specific biological systems.


Asunto(s)
Mapeo Cromosómico , Linfoma de Células B/metabolismo , Proteómica , Transcriptoma , Línea Celular Tumoral , Cromatografía Liquida , Electroforesis en Gel de Poliacrilamida , Humanos , Linfoma de Células B/genética , Linfoma de Células B/patología , Espectrometría de Masas en Tándem
6.
Mult Scler ; 21(2): 235-45, 2015 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-25257610

RESUMEN

BACKGROUND AND OBJECTIVES: The aim of this paper is to analyse the scientific research on multiple sclerosis using a bibliographic analysis of articles published during the period 2003-2012. METHODS: The items under study were obtained from the Science Citation Index-Expanded (SCI-E) database, which was accessed through the Web of Science (WOS) platform. All records with the term 'multiple sclerosis' in the title, plus all articles published in the journals Multiple Sclerosis and Multiple Sclerosis Journal, were analysed. RESULTS: A total of 9778 articles, with 160,966 citations, were retrieved on multiple sclerosis, and the majority of the articles were published in Multiple Sclerosis Journal (n = 1511). The articles were published in journals belonging to 135 different subject areas, with the greatest number of papers falling under the category of clinical neurology. The countries that published the largest numbers of articles were the United States (US) (n = 2786), Italy (n = 1263), the United Kingdom (n = 1147) and Germany (n = 1018). International collaborations produced 20.4% of the papers. CONCLUSIONS: We emphasise the progressive growth of publications worldwide, the publication of articles in a wide variety of journals covering numerous subject areas, and the research leadership of Western countries, most notably European countries, the US and Canada.


Asunto(s)
Bibliometría , Bases de Datos Bibliográficas/estadística & datos numéricos , Esclerosis Múltiple , Humanos
7.
Materials (Basel) ; 16(17)2023 Sep 02.
Artículo en Inglés | MEDLINE | ID: mdl-37687736

RESUMEN

Bioconsolidation treatment using bacterial carbonatogenesis has been proposed as an environmentally friendly strategy for the efficient preservation of damaged stones, particularly suitable for carbonate stones. The study presented here deals with the evaluation of the performance of this treatment, applied to damaged carbonate stones in two historical buildings in Spain. The methodology applied in this research serves as a reference for future similar studies. Results showed significant improvement in the petrophysical and mechanical properties of the damaged stone following the treatment through the production of calcite and vaterite by the abundant carbonatogenic bacteria inhabiting the stone. These bacteria were able to effectively consolidate weathered areas if an adequate nutritional solution was employed, thereby augmenting the stone's resistance, as evidenced by the Drilling Resistance Measurement System (DRMS). FESEM images showed calcified bacteria and calcified exopolymeric substances (EPS) consolidating stone minerals without blocking their pores. In addition to consolidation, this biotreatment improves the stone's behavior against water absorption and increases the contact angle of water droplets without significant modifications in the pore size or diminishing vapor permeability. No color changes are observed. Overall, these results show that the application of the nutritional solution (M-3P) for in situ consolidation of different types of porous carbonate building stones is a highly effective conservation method, with no modification of the chemical composition of the treated materials.

8.
Environ Pollut ; 319: 120994, 2023 Feb 15.
Artículo en Inglés | MEDLINE | ID: mdl-36603757

RESUMEN

Microplastics (MPs) are present across the global ocean and can be encountered by many species, including zooplankton. Although they fall within the size range of zooplankton prey, there are few studies on MPs ingestion carried out in situ. In this study, we analyzed MPs ingestion during two seasons (rainy and dry) of organisms from 5 taxonomic groups of zooplankton from two bays of the Mexican central Pacific: Manzanillo and Navidad. In total, 2643 individuals were analyzed, and of those 23 individuals contained MPs. The ingestion rate by taxonomic group was 1 MP/36 copepods (0.02), 1 MP/30 decapods-mysis (0.03), 1 MP/29 decapods-megalopa (0.03), and 1 MP/200 fish larvae (0.005). No plastics were found in chaetognaths, amphipods, or decapods-zoea. The average length of the ingested particles was 468.1 ± 113.8 µm, with a minimum of 15.6 and a maximum of 647.6 µm. All MPs >300 µm were fibers, with diameters <50 µm. Fragments were the most abundant MPs (54.2%), followed by fibers (34.2%) and spheres (11.4%). Statistical analyses showed no significant differences (p > 0.05) between the bays or seasons. Using RAMAN spectroscopy, it was possible to identify 6 different types of polymers, with poly (ethylene:propylene) being the most abundant (42.8%). This polymer is commonly used to manufacture plastic bags, ropes and fishing nets. The results confirm that certain zooplankton groups are consuming MPs and suggest that omnivorous species are more likely to ingest MPs, possibly due to their capacity for foraging flexibility and opportunistic feeding strategies. However, the ingestion of MPs cannot be attributed to a single factor; it is necessary to consider variables such as the sampling area, feeding strategy, size, and seasonality to understand the dynamics of MPs ingestion by zooplankton groups.


Asunto(s)
Contaminantes Químicos del Agua , Zooplancton , Animales , Microplásticos , Plásticos , Contaminantes Químicos del Agua/análisis , Monitoreo del Ambiente/métodos , Polietileno , Ingestión de Alimentos
9.
Appl Environ Microbiol ; 78(11): 4017-29, 2012 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-22447589

RESUMEN

The influence of mineral substrate composition and structure on bacterial calcium carbonate productivity and polymorph selection was studied. Bacterial calcium carbonate precipitation occurred on calcitic (Iceland spar single crystals, marble, and porous limestone) and silicate (glass coverslips, porous sintered glass, and quartz sandstone) substrates following culturing in liquid medium (M-3P) inoculated with different types of bacteria (Myxococcus xanthus, Brevundimonas diminuta, and a carbonatogenic bacterial community isolated from porous calcarenite stone in a historical building) and direct application of sterile M-3P medium to limestone and sandstone with their own bacterial communities. Field emission scanning electron microscopy (FESEM), atomic force microscopy (AFM), powder X-ray diffraction (XRD), and 2-dimensional XRD (2D-XRD) analyses revealed that abundant highly oriented calcite crystals formed homoepitaxially on the calcitic substrates, irrespective of the bacterial type. Conversely, scattered spheroidal vaterite entombing bacterial cells formed on the silicate substrates. These results show that carbonate phase selection is not strain specific and that under equal culture conditions, the substrate type is the overruling factor for calcium carbonate polymorph selection. Furthermore, carbonate productivity is strongly dependent on the mineralogy of the substrate. Calcitic substrates offer a higher affinity for bacterial attachment than silicate substrates, thereby fostering bacterial growth and metabolic activity, resulting in higher production of calcium carbonate cement. Bacterial calcite grows coherently over the calcitic substrate and is therefore more chemically and mechanically stable than metastable vaterite, which formed incoherently on the silicate substrates. The implications of these results for technological applications of bacterial carbonatogenesis, including building stone conservation, are discussed.


Asunto(s)
Bacterias/metabolismo , Carbonato de Calcio/metabolismo , Materiales de Construcción/microbiología , Minerales/química , Bacterias/crecimiento & desarrollo , Calcio/química , Calcio/metabolismo , Materiales de Construcción/análisis , Microscopía de Fuerza Atómica , Microscopía Electrónica de Rastreo , Minerales/metabolismo , Myxococcus xanthus/crecimiento & desarrollo , Myxococcus xanthus/metabolismo , Silicatos/química , Silicatos/metabolismo , Especificidad por Sustrato , Difracción de Rayos X
10.
Nutrients ; 14(23)2022 Dec 01.
Artículo en Inglés | MEDLINE | ID: mdl-36501132

RESUMEN

The consumption of energy drinks (EDs) is increasing globally while the evidence and concern about the potential health risks are also growing. Caffeine (generally 32 mg/100 mL) together with a wide variety of other active components such as taurine (usually 4000 mg/L) and D-glucuronolactone (generally 2400 mg/L) are the main ingredients of EDs. This study aims to assess the exposures to caffeine, taurine and D-glucuronolactone from EDs in various consumption scenarios and consumer profiles and to characterize the risks by evaluating caffeine and taurine intakes with their reference values and by calculating the margin of safety (MOS) for D-glucuronolactone. While the exposure assessment results showed that caffeine intakes from EDs ranged from 80 to 160 mg (1.14-4 mg/kg b.w.) for the considered scenarios, the risk characterization estimated some risks that could be managed with consumption recommendations such as limiting EDs in 40, 60 and 80 kg b.w. consumers to 175, 262.5 and 350 mL, respectively, to prevent sleep disturbances and to 375, 562.5 and 750 mL to prevent general caffeine adverse health risks, respectively. Dietary exposure to D-glucuronolactone from EDs ranged from 600 to 1200 mg (7.5-30 mg/kg b.w.). As D-glucuronolactone MOS ≥ 100 is only observed when EDs consumption is limited to 250 mL, for individuals weighing above 60 kg, some risks were observed in some of the studied scenarios. A taurine exposure from EDs varied from 1000 to 2000 mg (12.5-50 mg/kg b.w.) and consumptions over 500 mL were estimated to generate intakes above the reference value. In conclusion, the management of these risks requires a European legal framework for EDs with maximum limits for the active components, volume size limitations and labeling improvements along with the development of education and awareness programs and risk communication actions in collaboration with the industry and society.


Asunto(s)
Bebidas Energéticas , Humanos , Bebidas Energéticas/efectos adversos , Cafeína/efectos adversos , Taurina/efectos adversos , Medición de Riesgo
11.
Br J Nutr ; 106(10): 1476-86, 2011 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-21736796

RESUMEN

Some seaweeds exert antioxidant and hypocholesterolaemic properties. The effects of diets including restructured meats (RM) containing Wakame (W) or Nori (N) algae on arylesterase (AE) activity and lipoprotein concentration and composition were tested. In the present study, six groups of ten male growing Wistar rats each were fed a mix of 85 % AIN-93M diet and 15 % freeze-dried RM for 35 d. The control group (C) consumed control RM, the W and N groups consumed RM with 5 % W and 5 % N, respectively. The cholesterol-enriched C (CC), W (CW) and N (CN) groups consumed their corresponding basal diets with supplementary cholesterol (2·43 %) and cholic acid (0·49 %). Cholesterol in the diet induced lower (P < 0·001) growth ratios. Both W and N diets significantly increased AE activity. VLDL-cholesterol values were lower in N rats than in W rats. AE activity increased (P < 0·001) in CC and CW rats but not in CN rats compared with their corresponding counterparts. AE was lower (P < 0·05) in the CN group than in the CC and CW groups. The CN diet partially blocked (P < 0·001) the hypercholesterolaemic induction observed in CC and CW diets and reduced TAG levels (at least P < 0·05) with respect to those of CC rats. Although dietary cholesterol supplementation increased total cholesterol, VLDL-cholesterol and (intermediate-density lipoprotein+LDL)-cholesterol (all P < 0·001) in all rats, the CN diet moderately improved the lipoprotein profile of hypercholesterolaemic rats. Changes in AE activity and plasma cholesterol in CN rats but not in CW rats suggest a possible relationship between the two parameters. It is concluded that inclusion of RM enriched with N may be used in hypercholesterolaemic diets to improve lipoprotein metabolism.


Asunto(s)
Hidrolasas de Éster Carboxílico/metabolismo , Colesterol en la Dieta/administración & dosificación , Hiperlipidemias/sangre , Lipoproteínas/sangre , Carne , Animales , Masculino , Ratas , Ratas Wistar
12.
Adv Nutr ; 12(4): 1514-1539, 2021 07 30.
Artículo en Inglés | MEDLINE | ID: mdl-33578416

RESUMEN

High meat consumption has been associated with increased oxidative stress mainly due to the generation of oxidized compounds in the body, such as malondialdehyde, 4-hydroxy-nonenal, oxysterols, or protein carbonyls, which can induce oxidative damage. Meat products are excellent matrices for introducing different bioactive compounds, to obtain functional meat products aimed at minimizing the pro-oxidant effects associated with high meat consumption. Therefore, this review aims to summarize the concept and preparation of healthy and functional meat, which could benefit antioxidant status. Likewise, the key strategies regarding meat production and storage as well as ingredients used (e.g., minerals, polyphenols, fatty acids, walnuts) for developing these functional meats are detailed. Although most effort has been made to reduce the oxidation status of meat, newly emerging approaches also aim to improve the oxidation status of consumers of meat products. Thus, we will delve into the relation between functional meats and their health effects on consumers. In this review, animal trials and intervention studies are discussed, ascertaining the extent of functional meat products' properties (e.g., neutralizing reactive oxygen species formation and increasing the antioxidant response). The effects of functional meat products in the frame of diet-gene interactions are analyzed to 1) discover target subjects that would benefit from their consumption, and 2) understand the molecular mechanisms that ensure precision in the prevention and treatment of diseases, where high oxidative stress takes place. Long-term intervention-controlled studies, testing different types and amounts of functional meat, are also necessary to ascertain their positive impact on degenerative diseases.


Asunto(s)
Productos de la Carne , Animales , Antioxidantes/farmacología , Humanos , Malondialdehído , Carne/análisis , Estrés Oxidativo
13.
Microb Ecol ; 60(1): 15-28, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20393845

RESUMEN

In this study, we investigated under laboratory conditions the bacterial communities inhabiting quarry and decayed ornamental carbonate stones before and after the application of a Myxococcus xanthus-inoculated culture medium used for consolidation of the stones. The dynamics of the community structure and the prevalence of the inoculated bacterium, M. xanthus, were monitored during the time course of the consolidation treatment (30 days). For this purpose, we selected a molecular strategy combining fingerprinting by denaturing gradient gel electrophoresis (DGGE) with the screening of eubacterial 16S rDNA clone libraries by DGGE and sequencing. Quantification of the inoculated strain was performed by quantitative real-time PCR (qPCR) using M. xanthus-specific primers designed in this work. Results derived from DGGE and sequencing analysis showed that, irrespective of the origin of the stone,the same carbonatogenic microorganisms were activated by the application of a M. xanthus culture. Those microorganisms were Pseudomonas sp., Bacillus sp., and Brevibacillus sp. The monitoring of M. xanthus in the culture media of treated stones during the time course experiment showed disparate results depending on the applied technique. By culture-dependent methods, the detection of this bacterium was only possible in the first day of the treatment, showing the limitation of these conventional techniques. By PCR-DGGE analysis, M. xanthus was detected during the first 3-6 days of the experiment. At this time, the population of this bacterium in the culture media varied between 108-106 cells ml-1, as showed by qPCR analyses. Thereafter, DGGE analyses showed to be not suitable for the detection of M. xanthus in a mixed culture. Nevertheless, qPCR analysis using specific primers for M. xanthus showed to bea more sensitive technique for the detection of thisbacterium, revealing a population of 104 cells ml-1 in the culture media of both treated stones at the end of the consolidation treatment. The molecular strategy used in this study is proposed as an effective monitoring system to evaluate the impact of the application of a bacterially induced carbonate mineralization as restoration/conservation treatment for ornamental stones.


Asunto(s)
Carbonato de Calcio , Microbiología Ambiental , Myxococcus xanthus/aislamiento & purificación , Medios de Cultivo , ADN Bacteriano/genética , Metagenoma/genética , Myxococcus xanthus/genética , Myxococcus xanthus/crecimiento & desarrollo , ARN Ribosómico 16S/genética , Análisis de Secuencia de ADN
14.
Microb Ecol ; 60(1): 39-54, 2010 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-20386895

RESUMEN

The deterioration of the stone built and sculptural heritage has prompted the search and development of novel consolidation/protection treatments that can overcome the limitations of traditional ones. Attention has been drawn to bioconservation, particularly bacterial carbonatogenesis (i.e. bacterially induced calcium carbonate precipitation), as a new environmentally friendly effective conservation strategy, especially suitable for carbonate stones. Here, we study the effects of an in situ bacterial bioconsolidation treatment applied on porous limestone (calcarenite) in the sixteenth century San Jeronimo Monastery in Granada, Spain. The treatment consisted in the application of a nutritional solution (with and without Myxococcus xanthus inoculation) on decayed calcarenite stone blocks. The treatment promoted the development of heterotrophic bacteria able to induce carbonatogenesis. Both the consolidation effect of the treatment and the response of the culturable bacterial community present in the decayed stone were evaluated. A significant surface strengthening (consolidation) of the stone, without altering its surface appearance or inducing any detrimental side effect, was achieved upon application of the nutritional solution. The treatment efficacy was independent of the presence of M. xanthus (which is known as an effective carbonatogenic bacterium). The genetic diversity of 116 bacterial strains isolated from the stone, of which 113 strains showed carbonatogenic activity, was analysed by repetitive extragenic palindromic-polymerase chain reaction (REP-PCR) and 16S rRNA gene sequencing. The strains were distributed into 31 groups on the basis of their REP-PCR patterns, and a representative strain of each group was subjected to 16S rRNA gene sequencing. Analysis of these sequences showed that isolates belong to a wide variety of phylogenetic groups being closely related to species of 15 genera within the Proteobacteria, Firmicutes and the Actinobacteria. This study shows that the abundant carbonatogenic bacteria present in the decayed stone are able to effectively consolidate the degraded stone by producing new calcite (and vaterite) cement if an adequate nutritional solution is used. The implications of these results for the conservation of cultural heritage are discussed.


Asunto(s)
Bacterias/aislamiento & purificación , Carbonato de Calcio/análisis , Materiales de Construcción/microbiología , Bacterias/genética , Bacterias/crecimiento & desarrollo , ADN Bacteriano/genética , Microbiología Ambiental , Myxococcus xanthus/metabolismo , Filogenia , ARN Ribosómico 16S/genética , España
15.
Heliyon ; 6(5): e03922, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-32420488

RESUMEN

The growth factor receptor bound protein 7 (Grb7) is a Ca2+-dependent calmodulin (CaM)-binding adaptor protein implicated, among other functions, in cell proliferation, migration and tumor-associated angiogenesis. The goal of this study was to determine whether a peptide based on the CaM binding site of Grb7 disrupts cellular processes, relevant for the malignancy of tumor cells, in which this adaptor protein is implicated. We designed synthetic myristoylated and non-myristoylated peptides corresponding to the CaM-binding domain of human Grb7 with the sequence 243RKLWKRFFCFLRRS256 and a variant peptide with the mutated sequence RKLERFFCFLRRE (W246E-ΔK247-S256E). The two non-myristoylated peptides bind dansyl-CaM with higher efficiency in the presence than in the absence of Ca2+ and they enter into the cell, as tested with 5(6)-carboxytetramethylrhodamine (TAMRA)-labeled peptides. The myristoylated and non-myristoylated peptides inhibit the proliferation, migration and invasiveness of A431 tumor cells while they enhance their adhesion to the substrate. The myristoylated peptides have stronger inhibitory effect than the non-myristoylated counterparts, in agreement with their expected higher cell-permeant capacity. The myristoylated and non-myristoylated W246E-ΔK247-S256E mutant peptide has a lesser inhibitory effect on cell proliferation as compared to the wild-type peptide. We also demonstrated that the myristoylated peptides were more efficient than the CaM antagonist N-(6-aminohexyl)-5-chloro-1-naphthalenesulfonamide (W-7) inhibiting cell migration and equally efficient inhibiting cell proliferation.

16.
Sci Total Environ ; 712: 135660, 2020 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-31791772

RESUMEN

The role of microbial processes in bioaccumulation of major and trace elements has been broadly demonstrated. However, microbial communities from marine sediments have been poorly investigated to this regard. In marine environments, particularly under high anthropogenic pressure, heavy metal accumulation increases constantly, which may lead to significant environmental issues. A better knowledge of bacterial diversity and its capability to bioaccumulate metals is essential to face environmental quality assessment. The oligotrophic westernmost Mediterranean, which is highly sensitive to environmental changes and subjected to increasing anthropogenic pressure, was selected for this study. A sediment core spanning the last two millennia was sampled at two intervals, with ages corresponding to 140 (S1) and 1400 (S2) yr BP. High-throughput sequencing showed an abundance of Bacillus, Micrococcus, unclassified members of Planococcaceae, Anaerolineaceae, Planctomycetaceae, Microlunatus, and Microbacterium in both intervals, with slight differences in their abundance, along with newly detected ones in S2, i.e., Propionibacterium, Fictibacillus, Thalassobacillus, and Bacteroides. Canonical correspondence analysis (CCA) and co-occurrence patterns confirmed strong correlations among the taxa and the environmental parameters, suggesting either shared and preferred environmental conditions, or the performance of functions similar to or complementary to each other. These results were further confirmed using culture-dependent methods. The diversity of the culturable bacterial community revealed a predominance of Bacillus, and Micrococcus or Kocuria. The interaction of these bacterial communities with selected heavy metals (Cu, Cr, Zn and Pb) was also investigated, and their capacity of bioaccumulating metals within the cells and/or in the extracellular polymeric substances (EPS) is demonstrated. Interestingly, biomineralization of Pb resulted in the precipitation of Pb phosphates (pyromorphite). Our study supports that remnants of marine bacterial communities can survive in deep-sea sediments over thousands of years. This is extremely important in terms of bioremediation, in particular when considering possible environmentally friendly strategies to bioremediate inorganic contaminants.


Asunto(s)
Metales Pesados/análisis , Monitoreo del Ambiente , Sedimentos Geológicos , Mar Mediterráneo , Contaminantes Químicos del Agua
17.
Front Microbiol ; 11: 599144, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-33240254

RESUMEN

To overcome the limitations of traditional conservation treatments used for protection and consolidation of stone and lime mortars and plasters, mostly based on polymers or alkoxysilanes, a novel treatment based on the activation of indigenous carbonatogenic bacteria has been recently proposed and applied both in the laboratory and in situ. Despite very positive results, little is known regarding its effect on the evolution of the indigenous bacterial communities, specially under hot and humid tropical conditions where proliferation of microorganisms is favored, as it is the case of the Maya area. Here, we studied changes in bacterial diversity of severely degraded tuff stone and lime plaster at the archeological Maya site of Copan (Honduras) after treatment with the patented sterile M-3P nutritional solution. High-throughput sequencing by Illumina MiSeq technology shows significant changes in the bacterial population of the treated stones, enhancing the development of Arthrobacter, Micrococcaceae, Nocardioides, Fictibacillus, and Streptomyces, and, in one case, Rubrobacter (carved stone blocks at Structure 18). In the lime plaster, Arthrobacter, Fictibacillus, Bacillus, Agrococcus, and Microbacterium dominated after treatment. Most of these detected genera have been shown to promote calcium carbonate biomineralization, thus implying that the novel bio-conservation treatment would be effective. Remarkably, the treatment induced the reduction or complete disappearance of deleterious acid-producing bacteria such as Marmoricola or the phylum Acidobacteria. The outcome of this study demonstrates that such a bio-conservation treatment can safely and effectively be applied on temples, sculptures and stuccos of the Maya area and, likely, in other hot and humid environments.

18.
Foods ; 9(1)2020 Jan 09.
Artículo en Inglés | MEDLINE | ID: mdl-31936523

RESUMEN

The autohydrolysis of Lentinus edodes was proposed for the extraction of components with antioxidant properties. Operation under non-isothermal conditions was evaluated and compared with isothermal heating. The influence of process severity was assessed in the range of 0.18 to 4.89 (temperature between 50 and 250 °C), up to 80% (d.b.) The influence of process severity during the autohydrolysis of Lentinus edodes was assessed in the range -0.3 to 4.89 (temperature between 50 and 250 °C). Up to 80% (d.b.) of the initial raw material could be solubilized at 210 °C. The different behavior of the saccharide and phenolic fractions was observed with the treatment temperature. Whereas the highest concentration of the saccharide components (mainly glucooligosaccharides) was found at 210 °C, the maximum phenolic yield was identified at 250 °C. The phenolic content and the antiradical properties of the extract showed a continuous increase with the temperature range studied, and at 250 °C, showed antiradical properties comparable to synthetic antioxidants. Autohydrolysis liquid fractions were used as solvents in the formulation of bioactive starch-based hydrogels, identifying a positive correlation between the gel softening and the extracts' bioactivity features.

19.
J Trace Elem Med Biol ; 57: 60-67, 2020 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-31563817

RESUMEN

BACKGROUND: The main exposure route to methylmercury (MeHg) is from eating fish and shellfish containing this compound. Since 2004, women of childbearing age in Spain have been urged not to eat some species (eg, tuna, shark, and swordfish), instead choosing low-MeHg seafood as part of a healthy diet. OBJECTIVE: To describe maternal total blood mercury (THg) and serum selenium (Se) in a cohort of pregnant women living in Spain as it relates to fish intake during the three trimesters and to assess whether or not Spanish women of childbearing age follow the recommendations listed in fish advisories and choose fish species with lower mercury levels. METHODS: We studied 141 female volunteers of childbearing age (16-45 years), interviewing all participants about their overall eating habits and seafood intake. Hg and Se levels were tested using cold-vapor atomic absorption spectrometry (CVAAS) and electrothermal atomic absorption spectrometry (ETAAS), respectively. RESULTS: Average THg levels in pregnant women were 2.89 µg/L (standard deviation [SD], 2.75 µg/L, geometric mean [GM], 2.19 µg/L), and THg GM was positively associated with fish intake. Mean Se levels in pregnant women were 73.06 µg/L (SD, 13.38 µg/L), and Se levels were found to increase with tuna intake. In 16 (12%) pregnant women, THg was higher than the level recommended by the U.S. Environmental Protection Agency (EPA) (6.4 µg/L). A positive association was also found between THg and serum Se. CONCLUSION: Women of childbearing age in Spain had higher THg levels than women in other Western studies. Our study observed that 12% of women had THg levels above the safety limit set by the EPA (6.4 µg/L), and 31% had levels above the relevant benchmark level of 3.5 µg/L suggested by various researchers.


Asunto(s)
Mercurio/sangre , Selenio/sangre , Adolescente , Adulto , Femenino , Humanos , Compuestos de Metilmercurio/sangre , Persona de Mediana Edad , Embarazo , España , Adulto Joven
20.
Food Chem ; 277: 353-361, 2019 Mar 30.
Artículo en Inglés | MEDLINE | ID: mdl-30502157

RESUMEN

The non-isothermal autohydrolysis temperature impact of edible brown seaweed Laminaria ochroleuca was studied to recover high valuable compounds. Extraction yield was determined, above 80% was obtained at 220 °C. The maximal fucose content (17% d.b.) was attained at 180 °C, whereas the maximal sulphate was achieved at 160 °C, and phenolic and protein content at 220 °C. The maximum sulphated fucoidan content (41.38 g fucoidan/100 g extract) was obtained at 160 °C, whereas the maximum fucose oligosaccharides was obtained at 180 °C. The antioxidant capacity was equivalent to 32 mg Trolox/g dry extract produced at 220 °C. The milder processing condition was selected to study the potentiality of the precipitated alginate in terms of viscoelastic properties determined by rheology. Alginate extraction (14.94 g/100 g extract) was determined at 160 °C. The crude fucoidan fractions were tested at 25-500 µg/mL, showed up to 50% cell growth inhibition in four selected tumoral cell lines.


Asunto(s)
Geles/química , Laminaria/química , Algas Marinas/química , Células A549 , Alginatos/análisis , Alginatos/farmacología , Antineoplásicos Fitogénicos/análisis , Antineoplásicos Fitogénicos/farmacología , Antioxidantes/análisis , Antioxidantes/farmacología , Línea Celular Tumoral , Fenómenos Químicos , Cromanos/análisis , Cromanos/farmacología , Inhibidores de Crecimiento/análisis , Inhibidores de Crecimiento/farmacología , Células HCT116 , Calor , Humanos , Hidrólisis , Peso Molecular , Polisacáridos/farmacología , Reología , Espectrometría de Masa por Láser de Matriz Asistida de Ionización Desorción , Espectroscopía Infrarroja por Transformada de Fourier
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA