90 research outputs found

    Anatomical damage caused by Bacillus thuringiensis variety israelensis in yellow fever mosquito Aedes aegypti (L.) larvae revealed by micro‑computed tomography

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    With micro-computed tomography techniques, using the single-distance phase-retrieval algorithm phase contrast, we reconstructed enhanced rendered images of soft tissues of Aedes aeqypti fourth instar larvae after Bti treatment. In contrast to previous publications based on conventional microscopy, either optical or electron microscopy, which were limited to partial studies, mostly in the form of histological sections, here we show for the first time the effects of Bti on the complete internal anatomy of an insect. Using 3D rendered images it was possible to study the effect of the bacterium in tissues and organs, not only in sections but also as a whole. We compared the anatomy of healthy larvae with the changes undergone in larvae after being exposed to Bti (for 30 min, 1 h and 6 h) and observed the progressive damage that Bti produce. Damage to the midgut epithelia was confirmed, with progressive swelling of the enterocytes, thickening epithelia, increase of the vacuolar spaces and finally cell lysis, producing openings in the midgut walls. Simultaneously, the larvae altered their motility, making it difficult for them to rise to the surface and position the respiratory siphon properly to break surface tension and breathe. Internally, osmotic shock phenomena were observed, resulting in a deformation of the cross-section shape, producing the appearance of a wide internal space between the cuticle and the internal structures and a progressive collapse of the tracheal trunks. Taken together, these results indicate the death of the larvae, not by starvation as a consequence of the destruction of the epithelia of the digestive tract as previously stated, but due to a synergic catastrophic multifactor process in addition to asphyxia due to a lack of adequate gas exchange.Consejería de Universidad, Investigación e Innovación of Junta de Andalucia (Spain)FEDER Programe through the research projects: “Caracterización de variantes de toxinas Cry activas frente a la Mosca de la Fruta del Mediterráneo (Ceratitis capitata) obtenidas mediante la tecnología del despliegue de proteínas en fagos” (B-BIO-081-UGR18)Búsqueda de nuevas toxinas Cry con actividad frente al ectoparásito de la abeja Varroa destructor mediante la evolución in vitro de proteínas y la técnica del despliegue de proteínas en fago” (A-BIO-424-UGR20

    Trypanosoma cruzi pathogenicity involves virulence factor expression and upregulation of bioenergetic and biosynthetic pathways

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    The molecular repertoire of Trypanosoma cruzi effects its virulence and impacts the clinical course of the resulting Chagas disease. This study aimed to determine the mechanism underlying the pathogenicity of T. cruzi. Two T. cruzi cell lines (C8C3hvir and C8C3lvir), obtained from the clone H510 C8C3 and exhibiting different virulence phenotypes, were used to evaluate the parasite’s infectivity in mice. The organ parasite load was analysed by qPCR. The proteomes of both T. cruzi cell lines were compared using nLC-MS/MS. Cruzipain (Czp), complement regulatory protein (CRP), trans-sialidase (TS), Tc-85, and sialylated epitope expression levels were evaluated by immunoblotting. High-virulence C8C3hvir was highly infectious in mice and demonstrated three to five times higher infectivity in mouse myocardial cells than low-virulence C8C3lvir. qPCR revealed higher parasite loads in organs of acute as well as chronically C8C3hvir-infected mice than in those of C8C3lvir-infected mice. Comparative quantitative proteomics revealed that 390 of 1547 identified proteins were differentially regulated in C8C3hvir with respect to C8C3lvir. Amongst these, 174 proteins were upregulated in C8C3hvir and 216 were downregulated in C8C3lvir. The upregulated proteins in C8C3hvir were associated with the tricarboxylic acid cycle, ribosomal proteins, and redoxins. Higher levels of Czp, CRP, TS, Tc-85, and sialylated epitopes were expressed in C8C3hvir than in C8C3lvir. Thus, T. cruzi virulence may be related to virulence factor expression as well as upregulation of bioenergetic and biosynthetic pathways proteins.Antofagasta University FellowshipAgencia Nacional de Investigacion y Desarrollo (ANID)Millennium Science Initiative Program: MillenniumInstitute on Immunology and Immunotherapy ICN09_016Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP) 2018/18257-1 2018/15549-1 2020/04923-0 2021/00140-3Bridge Fund for Research of Excellence, University of Antofagasta SEM-17-0

    Polyamide fabric coated with a DHA-loaded chitosan hydrogel for a cosmeto-textile application

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    Cosmeto-textiles, which allow the administration of molecules when in contact with the skin, are increasingly being developed by cosmetic industries. We have designed an innovative approach for cosmeto-textile products, based on the impregnation of textile fibers with chitosan hydrogels, which have been cross-linked with genipin and loaded with dihydroxyacetone, which is an active component that induces sunless tanning. Dihydroxyacetone-loaded chitosan hydrogels have been prepared and characterized by means of cryogenic scanning electron microscopy (cryo-SEM). The images showed that genipin cross-linking decreases the mesh distance of hydrogels. The release of dihydroxyacetone from these cross-linked genipin chitosan hydrogels has been studied by a dialysis membrane method. These dihydroxyacetone-loaded chitosan hydrogels have been incorporated to polyamide textiles by a simple padding technique. The presence of dihydroxyacetone on these textiles has been detected by hyperspectral imaging on a dark field high resolution optical microscope. Finally, the performance of fabrics as cosmeto-textiles, with a tanning effect, has been evaluated by skin-colorimetry measured with an evaluation panel of 10 people. The results have demonstrated that dihydroxyacetone-loaded textiles produce a tanning effect on skin, and incorporation of dihydroxyacetone-loaded chitosan hydrogels into polyamide fabrics represents a friendly and appropriate strategy to obtain a cosmeto-textile with tanning effect

    Searching for selective scaffolds against Plasmodium falciparum glucose-6-phosphate dehydrogenase 6-phosphogluconolactonase

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    Malaria is a parasitic disease caused by Plasmodium spp., being one of the major causes of death worldwide with two-hundred million new infections and hundreds of thousands of deaths in 2015. Despite the important advances in its prevention and treatment, its resistance to current drug therapies is still a serious risk in its eradication. There is urgency in finding novel targets and drugs operating by novel mechanisms, avoiding cross-resistance to classical antimalarials. In this context, the bifunctional enzyme Glucose-6- phosphate dehydrogenase 6-phosphogluconolactonase appears to be a promising therapeutic target due to its crucial role in regulating the PPP pathway (pentose phosphate pathway), which is the major source of redox potential in Plasmodium falciparum. In the last few years, our group detected a specific mutation between the human and the Plasmodium falciparum form in the binding site of Glucose-6-phosphate (G6P), the endogenous ligand of Glucose-6-phosphate dehydrogenase (G6PD). This mutation involves the substitution of an Arginine (human) by an Aspartate (parasite), which allowed us to create a validated in-house homology model of PfG6PD. Based on this result, the group has focused their efforts, through different molecular modelling techniques, in the discovery of selective scaffolds against PfG6PD. Current efforts address the development of a complete structural model of the bifunctional enzyme, which may offer novel opportunities to develop molecules capable of inhibiting this relevant enzyme

    Characterisation of night-time outdoor lighting in urban centres using cluster analysis of remotely sensed light emissions

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    Evidence of the negative impact of light pollution on ecosystems is increasing every year. Its monitoring and study requires the identification, characterisation and control of the emitting sources. This is the case of urban centres with outdoor lighting that spills light outside the place it is intended to illuminate. The quantity and nature of the pollutant (artificial light at night) depends on the lamps used and how they are positioned. This is important because a greater proportion of blue light means a greater scattering effect. In this study, we analysed the emissions of 100 urban centres in the north of Granada province (Spain), using International Space Station (ISS) images from 2012 and 2021, in order to compare the results with public lighting inventories and verify the validity of these data for characterising night-time lighting emissions. Using inference and cluster analysis techniques, we confirmed an overall increase in emissions and a shift in their colour towards blue, consistent with the results of the lighting inventory analysis. We concluded that it is possible to use ISS imagery to characterise artificial light emissions and the lighting that causes them, none the less there are a number of inherent problems with the data and the way it was collected that require the results to be interpreted with caution

    Adaptable photochromic switches with self-aggregating heterocyclic azo dyes

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    It is well-known that the thermal isomerization kinetics of photochromic azo dyes can be modulated by subtle changes in their chemical architecture. However, the availability of an orthogonal input to control the thermal relaxation of azo dyes is essential to enable access to multifunctional and adaptive photochromic switches based on these particular organic chromophores. In this work, we have designed and synthesized a new family of green-light-activated heterocyclic azo derivatives that modify their switching capabilities as a function of concentration. In this line, we have investigated their self-assembly and the nature of the supramolecular aggregates formed by means of dynamic light scattering, polarized optical microscopy, and X-ray diffraction. Indeed, imparting control over the self-assembly of these organic dyes allows to fine-tune their thermal relaxation time and produce adaptable photochromic switches. Specifically, swapping the azo dye concentration between values located above and below the corresponding critical aggregation concentration modifies significantly the relaxation time up to 250 times, i.e., from the millisecond to the microsecond timescale. Moreover, the optical density of the system can be switched back and forth hundreds of times, for both diluted and concentrated solutions, without any sign of fatigue.Financial support for this research was obtained from the Ministerio de Economia y Competitividad (Spain, PGC2018-095477-B-I00, CTQ2016-78454-C2-1-R, and CTQ2017-84998-P MINECO/FEDER). Thanks are also due to Fundacao para a Ciencia e Tecnologia (Portugal) for financial support to the Portuguese NMR network (PTNMR, Bruker Avance III 400-Univ. Minho), FCT, and FEDER (European Fund for Regional Development)-COMPETEQREN-EU for financial support to the research centre CQ/UM [ref UID/QUI/00686/2013 and UID/QUI/0686/2016], and a PhD grant to M.C.R.C. (SFRH/BD/78037/2011)

    Characterization and functional analysis of the proteins Prohibitin 1 and 2 in Trypanosoma cruzi

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    Background Chagas disease is the third most important neglected tropical disease. There is no vaccine available, and only two drugs are generally prescribed for the treatment, both of which with a wide range of side effects. Our study of T. cruzi PHBs revealed a pleiotropic function in different stages of the parasite, participating actively in the transformation of the non-infective replicative epimastigote form into metacyclic trypomastigotes and also in the multiplication of intracellular amastigotes. Methodology/principal findings To obtain and confirm our results, we applied several tools and techniques such as electron microscopy, immuno-electron microscopy, bioinformatics analysis and molecular biology. We transfected T. cruzi clones with the PHB genes, in order to overexpress the proteins and performed a CRISPR/Cas9 disruption to obtain partially silenced PHB1 parasites or completely silenced PHB2 parasites. The function of these proteins was also studied in the biology of the parasite, specifically in the transformation rate from non-infective forms to the metacyclic infective forms, and in their capacity of intracellular multiplication. Conclusion/significance This research expands our understanding of the functions of PHBs in the life cycle of the parasite. It also highlights the protective role of prohibitins against ROS and reveals that the absence of PHB2 has a lethal effect on the parasite, a fact that could support the consideration of this protein as a possible target for therapeutic action

    Searching for Selective Scaffolds against Plasmodium falciparum Glucose-6-Phosphate Dehydrogenase 6-Phosphogluconolactonase

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    Malaria is a parasitic disease caused by Plasmodium spp., being one of the major causes of death worldwide with two-hundred million new infections and hundreds of thousands of deaths in 2015. [...

    Impact of polymorphisms in transporter and metabolizing enzyme genes on olanzapine pharmacokinetics and safety in healthy volunteers

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    Olanzapine is an atypical antipsychotic widely used for the treatment of schizophrenia, which often causes serious adverse drug reactions. Currently, there are no clinical guidelines implementing pharmacogenetic information on olanzapine. Moreover, the Dutch Pharmacogenomics Working Group (DPWG) states that CYP2D6 phenotype is not related to olanzapine response or side effects. Thus, the objective of this candidate-gene study was to investigate the effect of 72 polymorphisms in 21 genes on olanzapine pharmacokinetics and safety, including transporters (e.g. ABCB1, ABCC2, SLC22A1), receptors (e.g. DRD2, HTR2C), and enzymes (e.g. UGT, CYP and COMT), in a cohort of healthy volunteers. Polymorphisms in CYP2C9, SLC22A1, ABCB1, ABCC2, and APOC3 were related to olanzapine pharmacokinetic variability. The incidence of adverse reactions was related to several genes: palpitations to ABCB1 and SLC22A1, asthenia to ABCB1, somnolence to DRD2 and ABCB1, and dizziness to CYP2C9. However, further studies in patients are warranted to confirm the influence of these genetic polymorphisms on olanzapine pharmacokinetics and tolerability.D. Koller is financed by the H2020 Marie Sklodowska-Curie Innovative Training Network721236 grant. Marcos Navares-G´omez is cofinaneced by the European Social Fund and the Youth European Initiative, grant number PEJ-2018-TL/MD-1108

    The mutation of Transportin 3 gene that causes limb girdle muscular dystrophy 1F induces protection against HIV-1 infection

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    The causative mutation responsible for limb girdle muscular dystrophy 1F (LGMD1F) is one heterozygous single nucleotide deletion in the stop codon of the nuclear import factor Transportin 3 gene (TNPO3). This mutation causes a carboxy-terminal extension of 15 amino acids, producing a protein of unknown function (TNPO3_mut) that is co-expressed with wild-type TNPO3 (TNPO3_wt). TNPO3 has been involved in the nuclear transport of serine/arginine-rich proteins such as splicing factors and also in HIV-1 infection through interaction with the viral integrase and capsid. We analyzed the effect of TNPO3_mut on HIV-1 infection using PBMCs from patients with LGMD1F infected ex vivo. HIV-1 infection was drastically impaired in these cells and viral integration was reduced 16-fold. No significant effects on viral reverse transcription and episomal 2-LTR circles were observed suggesting that the integration of HIV-1 genome was restricted. This is the second genetic defect described after CCR5Δ32 that shows strong resistance against HIV-1 infection.This work was supported by crowfunding site PRECIPITA from FECYT, the MERCKSALUD Foundation, the Spanish Ministry of Science (FIS PI12/00969; PI16CIII/00034; SAF2016-78480-R); the Spanish AIDS Research Network RD16CIII/0002/0001 that is included in Acción Estratégica en Salud, Plan Nacional de Investigación Científica, Desarrollo e Innovación Tecnológica 2016-2020, Instituto de Salud Carlos III, European Region Development Fund (FEDER); CIBERer-ISCIII (FIS PI16/00316) co-financed by the European Regional Development Founds (FEDER), IIS La Fe (2016-0388; 2018-0200), and Fundación Isabel Gemio (http://www.fundacionisabelgemio.com). The work of Dra. Sara Rodríguez-Mora is supported by the Asociación Conquistando Escalones, funded by Spanish LGMD1F patients and Sara Borrell grant from Instituto de Salud Carlos III. The work of Dra. María Rosa López-Huertas is financed by ISCIII-Subdirección General de Evaluación and European Funding for Regional Development (FEDER) and by Spanish Ministry of Economy and Competitiveness (PIE13/00040). The work of Elena Mateos is supported by the Spanish Ministry of Economy and Competitiveness SAF2016-78480-R. The work of Lorena Vigón is supported by a pre-doctoral grant from Instituto de Salud Carlos III. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.S
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