34 research outputs found

    On the origin of the selectivity of plasmidic H-NS towards horizontally acquired DNA: Linking H-NS oligomerization and cooperative DNA binding

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    The nucleoid-associated protein H-NS is a global modulator of the expression of genes associated with adaptation to environmental changes. A variant of H-NS expressed in the R27 plasmid was previously shown to selectively modulate the expression of horizontally acquired genes, with minimal effects on core genes that are repressed by the chromosomal form of H-NS. Both H-NS proteins are formed by an oligomerization domain and a DNA-binding domain, which are connected by a linker that is highly flexible in the absence of DNA. We studied DNA binding by means of oligomer-forming chimeric proteins in which domains of the chromosomal and plasmidic variants are exchanged, as well as in monomeric truncated forms containing the DNA-binding domain and variable portions of the linker. Point mutations in the linker were also examined in full-length and truncated H-NS constructs. These experiments show that the linker region contributes to DNA binding affinity and that it is a main component of the distinct DNA binding properties of chromosomal and plasmidic H-NS. We propose that interactions between the linker and DNA limit the flexibility of the connection between H- NS oligomerization and DNA binding and provide an allosteric indirect readout mechanism to detect long- range distortions of DNA, thus enabling discrimination between core and horizontally acquired DNA

    Essential residues in the H-NS binding site of Hha, a co-regulator of horizontally acquired genes in Enterobacteria

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    Proteins of the Hha/YmoA family co-regulate with H-NS the expression of horizontally acquired genes in Enterobacteria. Systematic mutations of conserved acidic residues in Hha have allowed the identification of D48 as an essential residue for H-NS binding and the involvement of E25. Mutations of these residues resulted in deregulation of sensitive genes in vivo. D48 is only partially solvent accessible, yet it defines the functional binding interface between Hha and H-NS confirming that Hha has to undergo a conformational change to bind H-NS. Exposed acidic residues, such as E25, may electrostatically facilitate and direct the approach of Hha to the positively charged region of H-NS enabling the formation of the final complex when D48 becomes accessible by a conformational change of Hha

    Improved adhesion and tribological properties of altin-tisin coatings deposited by dcms and hipims on nitrided tool steels

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    Hard coatings, such as AlTiN-TiSiN, deposited by Physical Vapor Deposition (PVD) techniques are widely used in industrial applications to protect and increase the lifetime of industrial components, such as cutting tools, dies, and forming tools. Despite their great properties, such as high hardness and wear and oxidation resistance, they are limited in cases of severe conditions due to the poor adhesion between the coating and the substrate. Duplex treatments have commonly been used to improve the adhesive properties of PVD coatings, especially those of the cathodic arc evaporation type. The purpose of this study is to achieve coatings with the good properties of the Magnetron Sputtering processes but with higher adhesion than that achieved with these techniques, thus achieving coatings that can be used under the most severe conditions. In this work, an AlTiN-TiSiN coating was deposited by a combination of DC Magnetron Sputtering (DCMS) and High-Power Impulse Magnetron Sputtering (HiPIMS) after a gas nitriding pretreatment on 1.2379 and Vanadis 4 tool steels. Mechanical (ultra-microhardness and scratch tests) and tribological tests were carried out to study the improvement in the properties of the coating. Duplex-treated samples showed improved adhesion between the coating and the substrate, with second critical load (Lc2) values greater than 100 N. Furthermore, they showed great toughness and wear resistance. These results show that this type of coating technique could be used in the most extreme applications and that they can compete with other techniques and coatings that to date they have not been able to compete with.This research was funded in part by the Spanish Ministry of Science, Innovation and Universities through grants PGC2018-096855-B-C43 and PGC2018-096855-A-C44

    Ecomobilitat a Sitges : anàlisi de la situació actual i propostes de millora

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    La mobilitat urbana és una de les temàtiques més importants a les ciutats ja que convergeixen diversos aspectes a nivell social i ambiental. El present article es centra en el sistema de mobilitat de la ciutat de Sitges tot avaluant l'estat de la xarxa viària, el parc de vehicles, els sistemes de transport i els serveis bàsics actuals. En l'anàlisi socioambiental de les variables d'aquest àmbit, s'han detectat una sèrie de problemes com ara una distribució no equitativa dels serveis bàsics, desigualtat en la distribució de carrers vianalitzats i carrils bici i manca d'homogeneïtat en la distribució de pàrquings. Els resultats obtinguts permeten proposar una sèrie de millores en busca d'una mobilitat més sostenible. Millorar les parades de bus que no tenen sistema de marquesina per a protegir-les del fred i el sol, augmentar potencialment el carril bici desplegant-lo per carrers que no en tenen, desenvolupar campanyes per a fomentar l'ús de la bici i augmentar la presència de carrers d'exclusiu ús per a vianants.La movilidad urbana es una de las temáticas más importantes en las ciudades ya que convergen varios aspectos a nivel social y ambiental. El presente artículo se centra en el sistema de movilidad de la ciudad de Sitges evaluando el estado de la red viaria, el parque de vehículos, los sistemas de transporte y los servicios básicos actuales. En el análisis socioambiental de las variables de este ámbito, se han detectado una serie de problemas como una distribución no equitativa de los servicios básicos, desigualdad en la distribución de calles peatonales y carriles bici y falta de homogeneidad en la distribución de parkings. Los resultados obtenidos permiten proponer una serie de mejoras en busca de una movilidad más sostenible. Mejorar las paradas de bus que no tienen sistema de marquesina para protegerlas del frío y el Sol, aumentar potencialmente el carril bici desplegándose el por calles que no tienen, desarrollar campañas para fomentar el uso de la bici y aumentar la presencia de calles de exclusivo uso peatonal.Urban mobility is one of the most important issues in cities and converge at various aspects of social and environmental. This article focuses on the mobility system of the city of Sitges assessing the status of the road network, vehicle fleet, transportation systems and basic services today. In the socio-environmental analysis in this field variables, we have detected a number of problems such as inequitable distribution of basic services, inequality in the distribution of pedestrian streets and cycle paths and lack of homogeneity in the distribution of parking. The results obtained suggest a number of improvements in search of a more sustainable mobility. Improve bus stops with no marquee system to protect them from cold and the sun, potentially increasing the unfolding cycle lanes on streets that have not, develop campaigns to promote the use of the bike and increase the presence of street use only crosswalk

    Metabolic and mitochondria alterations induced by SARS-CoV-2 accessory proteins ORF3a, ORF9b, ORF9c and ORF10

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    1 p.Antiviral signaling, immune response and cell metabolism in human body are dysregulated by SARS-CoV-2, the causative agent of COVID-19. However, the impacts of individual accessory proteins on host cell metabolic pathways are unknown.Here, SARS-CoV-2 accessory proteins ORF3a, ORF9b, ORF9c and ORF10 were individually transduced into A549 lung carcinoma cells. Furthermore, by combining transcriptomic analysis with functional and metabolic data in accessory protein-specific GSMMs, several alterations were identified that may point to a putative target for investigating novel therapies. In this study, we showed that these accessory proteins induced a significant mitochondrial and metabolic reprogramming in A549 lung epithelial cells. ORF9b, ORF9c and ORF10 induced largely overlapping transcriptomes. In contrast, ORF3a induced a distinct transcriptome, including the downregulation of numerous genes with critical role in mitochondria function and morphology. On the other hand, while all four ORFs altered mitochondrial dynamics and function, only ORF3a and ORF9c induced a marked structural alteration in mitochondrial cristae. Genome-Scale Metabolic Models identified both metabolic flux reprogramming features shared across all accessory proteins and specific ones for each accessory protein. Notably, a downregulated amino acid metabolism was observed in ORF9b, ORF9c and ORF10, while an upregulated lipid metabolism was distinctly induced by ORF3a. Next, qMTA identified gene knock downs (KDs) that would have the potential to revert the metabolic reprogramming induced by each individual accessory protein, especially in ORF3a and ORF10. These findings reveal metabolic dependencies and vulnerabilities prompted by SARS-CoV-2 accessory proteins that may be exploited to identify new targets for intervention.Peer reviewe

    Metabolic and mitochondria alterations induced by SARS-CoV-2 accessory proteins ORF3a, ORF9b, ORF9c and ORF10

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    Antiviral signaling, immune response and cell metabolism in human body are dysregulated by SARS-CoV-2, the causative agent of the COVID-19. Here, we show that SARS-CoV-2 accessory proteins ORF3a, ORF9b, ORF9c and ORF10 induce a significant mitochondrial and metabolic reprogramming in A549 lung epithelial cells. While all four ORFs caused mitochondrial fragmentation and altered mitochondrial function, only ORF3a and ORF9c induced a marked structural alteration in mitochondrial cristae. ORF9b, ORF9c and ORF10 induced largely overlapping transcriptomes. In contrast, ORF3a induced a distinct transcriptome, including the downregulation of numerous genes for proteins with critical mitochondrial functions and morphology. Genome-Scale Metabolic Models predicted common and private metabolic flux reprogramming, notably a depressed amino acid metabolism, and an enhanced metabolism of specific lipids distinctly induced by ORF3a. These findings reveal metabolic dependencies and vulnerabilities prompted by SARS-CoV-2 accessory proteins that may be exploited to identify new targets for intervention.This research work was funded by the European Commission – NextGenerationEU (Regulation EU 2020/2094), through CSIC's Global Health Platform (PTI+ Salud Global) (COVID-19-117 and SGL2103015), Junta de Andalucía (CV20-20089), Spanish Ministry of Science project (PID2021-123399OB-I00), the Agency for Management of University and Research Grants from Generalitat de Catalunya-AGAUR (2020PANDE00048 and 2021SGR00350) and ICREA foundation (ICREA-Academia-2021 to MC) of Generalitat de Catalunya, and an AESi grant of the Instituto de Salud Carlos III (PI20CIII-00014). TGG is recipient of a Ramón y Cajal contract funded by MCIN/AEU/10.13039/501100011033 and NextGeneration EU/PRTR.N

    The Different Microbial Etiology of Prosthetic Joint Infections According to Route of Acquisition and Time After Prosthesis Implantation, Including the Role of Multidrug-Resistant Organisms

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    The aim of our study was to characterize the etiology of prosthetic joint infections (PJIs)-including multidrug-resistant organisms (MDRO)-by category of infection. A multicenter study of 2544 patients with PJIs was performed. We analyzed the causative microorganisms according to the Tsukayama's scheme (early postoperative, late chronic, and acute hematogenous infections (EPI, LCI, AHI) and "positive intraoperative cultures" (PIC)). Non-hematogenous PJIs were also evaluated according to time since surgery: 12 months. AHIs were mostly caused by Staphylococcus aureus (39.2%) and streptococci (30.2%). EPIs were characterized by a preponderance of virulent microorganisms (S. aureus, Gram-negative bacilli (GNB), enterococci), MDROs (24%) and polymicrobial infections (27.4%). Conversely, coagulase-negative staphylococci (CoNS) and Cutibacterium species were predominant in LCIs (54.5% and 6.1%, respectively) and PICs (57.1% and 15.1%). The percentage of MDROs isolated in EPIs was more than three times the percentage isolated in LCIs (7.8%) and more than twice the proportion found in AHI (10.9%). There was a significant decreasing linear trend over the four time intervals post-surgery for virulent microorganisms, MDROs, and polymicrobial infections, and a rising trend for CoNS, streptococci and Cutibacterium spp. The observed differences have important implications for the empirical antimicrobial treatment of PJIs.Acknowledgments: This work was supported by the Instituto de Salud Carlos III, Spanish Ministry of Economy and Competitiveness (grant number PI15/1026) (Co-funded by European Regional Development Fund/European Social Fund "Investing in your future"). REIPI (Spanish Network for Research in Infectious Disease) is supported by the Instituto de Salud Carlos III, Spanish Ministry of Economy and Competitiveness, and by the European Development Regional Fund “A way to achieve Europe”

    Usefulness of bone turnover markers as predictors of mortality risk, disease progression and skeletal-related events appearance in patients with prostate cancer with bone metastases following treatment with zoledronic acid: TUGAMO study

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    Owing to the limited validity of clinical data on the treatment of prostate cancer (PCa) and bone metastases, biochemical markers are a promising tool for predicting survival, disease progression and skeletal-related events (SREs) in these patients. The aim of this study was to evaluate the predictive capacity of biochemical markers of bone turnover for mortality risk, disease progression and SREs in patients with PCa and bone metastases undergoing treatment with zoledronic acid (ZA). Methods: This was an observational, prospective and multicenter study in which ninety-eight patients were included. Patients were treated with ZA (4mg every 4 weeks for 18 months). Data were collected at baseline and 3, 6, 9, 12, 15 and 18 months after the beginning of treatment. Serum levels of bone alkaline phosphtase (BALP), aminoterminal propeptide of procollagen type I (P1NP) and beta-isomer of carboxiterminal telopeptide of collagen I (b-CTX) were analysed at all points in the study. Data on disease progression, SREs development and survival were recorded. Results: Cox regression models with clinical data and bone markers showed that the levels of the three markers studied were predictive of survival time, with b-CTX being especially powerful, in which a lack of normalisation in visit 1 (3 months after the beginning of treatment) showed a 6.3-times more risk for death than in normalised patients. Levels of these markers were also predictive for SREs, although in this case BALP and P1NP proved to be better predictors. We did not find any relationship between bone markers and disease progression. Conclusion: In patients with PCa and bone metastases treated with ZA, b-CTX and P1NP can be considered suitable predictors for mortality risk, while BALP and P1NP are appropriate for SREs. The levels of these biomarkers 3 months after the beginning of treatment are especially importantThis study was supported by Novartis Oncology Spai

    Genetically predicted telomere length and Alzheimer’s disease endophenotypes: a Mendelian randomization study

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    Telomere length (TL) is associated with biological aging, consequently influencing the risk of age-related diseases such as Alzheimer's disease (AD). We aimed to evaluate the potential causal role of TL in AD endophenotypes (i.e., cognitive performance, N = 2233; brain age and AD-related signatures, N = 1134; and cerebrospinal fluid biomarkers (CSF) of AD and neurodegeneration, N = 304) through a Mendelian randomization (MR) analysis. Our analysis was conducted in the context of the ALFA (ALzheimer and FAmilies) study, a population of cognitively healthy individuals at risk of AD. A total of 20 single nucleotide polymorphisms associated with TL were used to determine the effect of TL on AD endophenotypes. Analyses were adjusted by age, sex, and years of education. Stratified analyses by APOE-epsilon 4 status and polygenic risk score of AD were conducted. MR analysis revealed significant associations between genetically predicted longer TL and lower levels of CSF A beta and higher levels of CSF NfL only in APOE-epsilon 4 non-carriers. Moreover, inheriting longer TL was associated with greater cortical thickness in age and AD-related brain signatures and lower levels of CSF p-tau among individuals at a high genetic predisposition to AD. Further observational analyses are warranted to better understand these associations

    Dinosaur bonebed amber from an original swamp forest soil

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    [EN] Dinosaur bonebeds with amber content, yet scarce, offer a superior wealth and quality of data on ancient terrestrial ecosystems. However, the preserved palaeodiversity and/or taphonomic characteristics of these exceptional localities had hitherto limited their palaeobiological potential. Here, we describe the amber from the Lower Cretaceous dinosaur bonebed of Ariño (Teruel, Spain) using a multidisciplinary approach. Amber is found in both a root layer with amber strictly in situ and a litter layer mainly composed of aerial pieces unusually rich in bioinclusions, encompassing 11 insect orders, arachnids, and a few plant and vertebrate remains, including a feather. Additional palaeontological data-charophytes, palynomorphs, ostracods- are provided. Ariño arguably represents the most prolific and palaeobiologically diverse locality in which fossiliferous amber and a dinosaur bonebed have been found in association, and the only one known where the vast majority of the palaeontological assemblage suffered no or low-grade pre-burial transport. This has unlocked unprecedentedly complete and reliable palaeoecological data out of two complementary windows of preservation-the bonebed and the amber-from the same site.Funding Ministerio de Ciencia, Innovación y Universidades: CGL2017-84419 (Eduardo Barrón, Xavier Delclòs); Ministerio de Ciencia, Innovación y Universidades: PGC2018-094034-B-C22 (Luis Alcalá) ; Ministerio de Economía y Competitividad: CGL2015-69805-P (Carles Martín-Closas) ; Generalitat de Catalunya: 2017SGR-824 (Carles Martín-Closas, Xavier Delclòs) ; Generalitat de Catalunya: 2020FI_B1 00002 (Sergio Álvarez-Parra) ; Oxford University Museum: Research Fellowship (Ricardo Pérez-de la Fuente) ; Ministerio de Ciencia, Innovación y Universidades: BES-2016-076469 (Jordi Pérez-Cano) ; Austrian Academy of Sciences: Project 661 (Khaled Trabelsi) ; Université de Tunis: LR18 ES07 (Khaled Trabelsi) ; Generalitat Valenciana: APOSTD2019 (Alba Sánchez-García) ; European Regional Development Fund: IGME13-4E-1518 (Rafael P Lozano)Peer reviewe
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