A yeast three-hybrid system that reconstitutes mammalian hypoxia inducible factor regulatory machinery

Background: Several human pathologies, including neoplasia and ischemic cardiovascular diseases, course with an unbalance between oxygen supply and demand ( hypoxia). Cells within hypoxic regions respond with the induction of a specific genetic program, under the control of the Hypoxia Inducible Factor (HIF), that mediates their adaptation to the lack of oxygen. The activity of HIF is mainly regulated by the EGL-nine homolog (EGLN) enzymes that hydroxylate the alpha subunit of this transcription factor in an oxygen-dependent reaction. Hydroxylated HIF is then recognized and ubiquitinilated by the product of the tumor suppressor gene, pVHL, leading to its proteosomal degradation. Under hypoxia, the hydroxylation of HIF by the EGLNs is compromised due to the lack of oxygen, which is a reaction cosubstrate. Thus, HIF escapes degradation and drives the transcription of its target genes. Since the progression of the aforementioned pathologies might be influenced by activation of HIF-target genes, development of small molecules with the ability to interfere with the HIF-regulatory machinery is of great interest.Results: Herein we describe a yeast three-hybrid system that reconstitutes mammalian HIF regulation by the EGLNs and VHL. In this system, yeast growth, under specific nutrient restrictions, is driven by the interaction between the beta domain of VHL and a hydroxyproline-containing HIF alpha peptide. In turn, this interaction is strictly dependent on EGLN activity that hydroxylates the HIFa peptide. Importantly, this system accurately preserves the specificity of the hydroxylation reaction toward specific substrates. We propose that this system, in combination with a matched control, can be used as a simple and inexpensive assay to identify molecules that specifically modulate EGLN activity. As a proof of principle we show that two known EGLN inhibitors, dimethyloxaloylglycine (DMOG) and 6-chlor-3-hydroxychinolin-2-carbonic acid-N-carboxymethylamide (S956711), have a profound and specific effect on the yeast HIF/EGLN/VHL system.Conclusion: The system described in this work accurately reconstitutes HIF regulation while preserving EGLN substrate specificity. Thus, it is a valuable tool to study HIF regulation, and particularly EGLN biochemistry, in a cellular context. In addition, we demonstrate that this system can be used to identify specific inhibitors of the EGLN enzymes

Crystallized and fluid intelligence are predicted by microstructure of specific white-matter tracts

Studies of the neural basis of intelligence have focused on comparing brain imaging variables with global scales instead of the cognitive domains integrating these scales or quotients. Here, the relation between mean tract‐based fractional anisotropy (mTBFA) and intelligence indices was explored. Deterministic tractography was performed using a regions of interest approach for 10 white‐matter fascicles along which the mTBFA was calculated. The study sample included 83 healthy individuals from the second wave of the Cuban Human Brain Mapping Project, whose WAIS‐III intelligence quotients and indices were obtained. Inspired by the “Watershed model” of intelligence, we employed a regularized hierarchical Multiple Indicator, Multiple Causes model (MIMIC), to assess the association of mTBFA with intelligence scores, as mediated by latent variables summarizing the indices. Regularized MIMIC, used due to the limited sample size, selected relevant mTBFA by means of an elastic net penalty and achieved good fits to the data. Two latent variables were necessary to describe the indices: Fluid intelligence (Perceptual Organization and Processing Speed indices) and Crystallized Intelligence (Verbal Comprehension and Working Memory indices). Regularized MIMIC revealed effects of the forceps minor tract on crystallized intelligence and of the superior longitudinal fasciculus on fluid intelligence. The model also detected the significant effect of age on both latent variables

Polarized cortical tension drives zebrafish epiboly movements

The principles underlying the biomechanics of morphogenesis are largely unknown. Epiboly is an essential embryonic event in which three tissues coordinate to direct the expansion of the blastoderm. How and where forces are generated during epiboly, and how these are globally coupled remains elusive. Here we developed a method, hydrodynamic regression (HR), to infer 3D pressure fields, mechanical power, and cortical surface tension profiles. HR is based on velocity measurements retrieved from 2D+T microscopy and their hydrodynamic modeling. We applied HR to identify biomechanically active structures and changes in cortex local tension during epiboly in zebrafish. Based on our results, we propose a novel physical description for epiboly, where tissue movements are directed by a polarized gradient of cortical tension. We found that this gradient relies on local contractile forces at the cortex, differences in elastic properties between cortex components and the passive transmission of forces within the yolk cell. All in all, our work identifies a novel way to physically regulate concerted cellular movements that might be instrumental for the mechanical control of many morphogenetic processes.Peer ReviewedPostprint (author's final draft

Characterization and Evaluation of Layered Bi2WO6 Nanosheets as a New Antibacterial Agent

Background: Pathogenic microorganisms are causing increasing cases of mortality and morbidity, along with alarming rates of ineffectiveness as a result of acquired antimicrobial resistance. Bi2WO6 showed good potential to be used as an antibacterial substance when exposed to visible light. This study demonstrates for the first time the dimension-dependent antibacterial activity of layered Bi2WO6 nanosheets. Materials and methods: The synthesized layered Bi2WO6 nanosheets were prepared by the hydrothermal method and characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM), and Raman and Fourier transform infrared spectroscopy (FTIR). Antibacterial and antibiotic-modulation activities were performed in triplicate by the microdilution method associated with visible light irradiation (LEDs). Results: Bi2WO6 nanosheets were effective against all types of bacteria tested, with MIC values of 256 µg/mL against Escherichia coli standard and resistant strains, and 256 µg/mL and 32 µg/mL against Staphylococcus aureus standard and resistant strains, respectively. Two-dimensional (2D) Bi2WO6 nanosheets showed antibacterial efficiency against both strains studied without the presence of light. Conclusions: Layered Bi2WO6 nanosheets revealed dimension-dependent antibacterial activity of the Bi2WO6 system.The authors thank Conselho Nacional de Desenvolvimento Científico e Tecnológico— CNPq, Coordenação de Aperfeiçoamento de Pessoal de Nível Superior—CAPES, and Fundação Cearense de Apoio ao Desenvolvimento Científico e Tecnológico—FUNCAP (Proc. BP4-00172-00232.01.00/20 and Proc. PR2-0101-00006.01.00/15) for the financial support. The authors would also like to thank the educational institutions UFCA, URCA, and UNILEÃO for their support during the experiments

A

In Argentina, the SARS-CoV2 pandemic led the Government to take preventive social distancing measures on March 20, 2021. During this period, the population was forced to stay in their households, experiencing changes in their routines and social meetings. This had an emotional impact on people\u27s lifestyle, affecting their eating behavior and physical activity. Analyze the influence of the lockdown on eating habits, physical exercise and its impact on the Body Mass Index (BMI) of the Health Insurance company DASPU population between May-November 2020. Quantitative, cross-sectional, observational, descriptive study. Variable: BMI, Frequency of food intake, Frequency and Intensity of Physical Activity Instrument: Self-administered questionnaire, short  IPAQ questionnaire The sample consisted of 336 people, over 18 years old, that are covered by DASPU health insurance, who were asked to take a survey with prior informed consent, on habits before and during the lockdown. Univariate and multivariate descriptive analysis were performed before and during the quarantine, constructing a variable that indicated whether people changed their weight, relating it to consumption patterns and physical activity. Significant differences (p <0.001) were found between BMI before and during quarantine. Regarding the differences in weight, 60% of the population increased on average 4.2 Kg, during the social distancing measures. There were significant differences in the frequency of moderate physical activity (p <0.05 generalized linear model), showing a decrease in the weekly frequency. Weight gain cases were related to those who did not exercise or only did it once per week, during the social distancing measures. According to the multivariate analysis, a weight gain was observed in those who ate little or no fruit (1-2 days per week) and more refined grains (from 2-3 days per week to every day) and those who consumed vegetables daily decreased, during the social distancing measures. We can conclude that the lockdown had a negative impact on the level of physical activity and food consumption patterns of the population, causing weight gain in the majority of cases. Recognizing this association enables us to think of strategies from the health sector to address and prevent the negative impact that lockdown has had on our population, with special emphasis on physical activity.En Argentina, la pandemia por SARS-CoV2 llevó al Gobierno a tomar medidas de aislamiento social preventivo y obligatorio el 20 de marzo de 20201. Durante el mismo, las personas debieron realizar desplazamientos mínimos y permanecer en sus domicilios, vivenciando cambios en sus rutinas y encuentros sociales. Esto tuvo impacto emocional y en el estilo de vida de las personas, repercutiendo en las conductas alimenticias y actividad física Analizar la influencia del confinamiento en los hábitos alimentarios, ejercicio físico y su impacto en el Indice de Masa Coporal (IMC) de la población Obra Social DASPU entre mayo-noviembre 2020. Estudio cuantitativo, transversal, observacional, descriptivo. Variable: IMC, Frecuencia de consumo alimentario, Frecuencia e Intensidad de Actividad Fisica Instrumento: Cuestionario autoadministrado, Cuenstionario corto IPAQ La muestra fue de 336 personas,  mayores de 18 años afiliadas a  DASPU, realizándose una encuesta previo consentimiento informado, sobre hábitos antes y durante el confinamiento. Se realizaron análisis descriptivos uni y multivariados antes y durante la cuarentena, construyéndose una variable que indicó si las personas modificaron su peso, relacionándola con patrones de consumo y actividad física. Se encontraron diferencias significativas (p<0.001) entre el IMC antes y durante la cuarentena. En cuanto a las diferencias de peso el 60% aumentó en promedio 4,2 Kg, durante el ASPO Hubo diferencias significativas en la frecuencia de actividad física moderada (p<0.05 modelo lineal generalizado), mostrandose disminución en la frecuencia semanal y relacionándose aumento de peso con quienes no realizaron actividad o sólo lo hicieron 1/semana, durante el ASPO De acuerdo al análisis multivariado, se observó un aumento de peso en quienes ingieren poca o ninguna fruta(1-2 días/semana) y más harinas refinadas (de 2-3 días/semana a todos los días) y descendieron quienes consumen  verduras diariamente, durante el ASPO. Podemos concluir que el confinamiento impactó negativamente en el nivel de actividad física y los patrones de consumo alimentarios de las personas, provocando un aumento de peso en la mayoría. Reconocer esta asociación, nos habilita a pensar en estrategias desde el sector salud para abordar y prevenir el impacto negativo que ha tenido el confinamiento en nuestra población, haciendo especial hincapie en la actividad fisica

Common genetic variation associated with increased susceptibility to prostate cancer does not increase risk of radiotherapy toxicity.

BACKGROUND: Numerous germline single-nucleotide polymorphisms increase susceptibility to prostate cancer, some lying near genes involved in cellular radiation response. This study investigated whether prostate cancer patients with a high genetic risk have increased toxicity following radiotherapy. METHODS: The study included 1560 prostate cancer patients from four radiotherapy cohorts: RAPPER (n=533), RADIOGEN (n=597), GenePARE (n=290) and CCI (n=150). Data from genome-wide association studies were imputed with the 1000 Genomes reference panel. Individuals were genetically similar with a European ancestry based on principal component analysis. Genetic risks were quantified using polygenic risk scores. Regression models tested associations between risk scores and 2-year toxicity (overall, urinary frequency, decreased stream, rectal bleeding). Results were combined across studies using standard inverse-variance fixed effects meta-analysis methods. RESULTS: A total of 75 variants were genotyped/imputed successfully. Neither non-weighted nor weighted polygenic risk scores were associated with late radiation toxicity in individual studies (P>0.11) or after meta-analysis (P>0.24). No individual variant was associated with 2-year toxicity. CONCLUSION: Patients with a high polygenic susceptibility for prostate cancer have no increased risk for developing late radiotherapy toxicity. These findings suggest that patients with a genetic predisposition for prostate cancer, inferred by common variants, can be safely treated using current standard radiotherapy regimens.This work was supported by Cancer Research UK (C1094/A11728 to CMLW and NGB for the RAPPER study, C26900/A8740 to GCB, C5047A17528 to RE), the Royal College of Radiologists (GCB), Prostate Cancer UK (P2012148 to RE), The ELLIPSE Consortium on behalf of the GAME-ON Network, The National Institute for Health Research (GCB), Addenbrooke’s Charitable Trust (GCB), NIHR support to the Biomedical Research Centre at The Institute of Cancer Research and Royal Marsden NHS Foundation Trust, The National Institute for Health Research Cambridge Biomedical Research Centre (NGB), UK Medical Research Council (LD), the Experimental Cancer Medicine Centre (CMLW), the Royal Marsden NHS Foundation Trust (DPD), the United States National Institutes of Health (1R01CA134444 to BSR), the American Cancer Society (RSGT-05-200-01-CCE to BSR), the United States Department of Defense (PC074201 to BSR), Mount Sinai Tisch Cancer Institute Developmental Fund Award (BSR), the Instituto de Salud Carlos III (FIS PI10/00164 and PI13/02030 to AV), Fondo Europeo de Desarrollo Regional (FEDER 2007-2013 to AV), Xunta de Galicia and the European Social Fund (POS-A/2013/034 to LF), and the Alberta Cancer Board Research Initiative Program (103.0393.71760001404 to MP). Laboratory infrastructure for the RAPPER study was funded by Cancer Research UK [C8197/A10123]. DD acknowledges support from the National Institute for Health Research RM/ICR Biomedical Research Centre and all the researchers at the Royal Marsden Hospital and the Institute of Cancer Research. The RAPPER cohort comprises patients and data recruited into the RT01 and CHHiP UK radiotherapy trials. The RT01 trial was supported by the UK Medical Research Council. The CHHiP trial (CRUK/06/016) was supported by the Department of Health and Cancer Research UK (C8262/A7253); trial recruitment was facilitated within centers by the National Institute for Health Research Cancer Research Network.This is the author accepted manuscript. It is currently under an indefinite embargo pending publication by Nature Publishing Group

A cross-sectional study on attitudes toward gender equality, sexual behavior, positive sexual experiences, and communication about sex among sexually active and non-sexually active adolescents in Bolivia and Ecuador

Background: It is widely agreed upon that gender is a key aspect of sexuality however, questions remain on how gender exactly influences adolescents’ sexual health. Objective: The aim of this research was to study correlations between gender equality attitudes and sexual behavior, sexual experiences and communication about sex among sexually active and non-sexually active adolescents in 2 Latin American countries. Design: In 2011, a cross-sectional study was carried out among 5,913 adolescents aged 14–18 in 20 secondary schools in Cochabamba (Bolivia) and 6 secondary schools in Cuenca (Ecuador). Models were built using logistic regressions to assess the predictive value of attitudes toward gender equality on adolescents’ sexual behavior, on experiences and on communication. Results: The analysis shows that sexually active adolescents who consider gender equality as important report higher current use of contraceptives within the couple. They are more likely to describe their last sexual intercourse as a positive experience and consider it easier to talk with their partner about sexuality than sexually experienced adolescents who are less positively inclined toward gender equality. These correlations remained consistent whether the respondent was a boy or a girl. Non-sexually active adolescents, who consider gender equality to be important, are more likely to think that sexual intercourse is a positive experience. They consider it less necessary to have sexual intercourse to maintain a relationship and find it easier to communicate with their girlfriend or boyfriend than sexually non-active adolescents who consider gender equality to be less important. Comparable results were found for boys and girls. Conclusions: Our results suggest that gender equality attitudes have a positive impact on adolescents’ sexual and reproductive health (SRH) and wellbeing. Further research is necessary to better understand the relationship between gender attitudes and specific SRH outcomes such as unwanted teenage pregnancies and sexual pleasure among adolescents worldwide

Geographical ecology of dry forest tree communities in the West Indies

© 2018 The Authors. Journal of Biogeography Published by John Wiley & Sons Ltd Aim: Seasonally dry tropical forest (SDTF) of the Caribbean Islands (primarily West Indies) is floristically distinct from Neotropical SDTF in Central and South America. We evaluate whether tree species composition was associated with climatic gradients or geographical distance. Turnover (dissimilarity) in species composition of different islands or among more distant sites would suggest communities structured by speciation and dispersal limitations. A nested pattern would be consistent with a steep resource gradient. Correlation of species composition with climatic variation would suggest communities structured by broad-scale environmental filtering. Location: The West Indies (The Bahamas, Cuba, Hispaniola, Jamaica, Puerto Rico, US Virgin Islands, Guadeloupe, Martinique, St. Lucia), Providencia (Colombia), south Florida (USA) and Florida Keys (USA). Taxon: Seed plants—woody taxa (primarily trees). Methods: We compiled 572 plots from 23 surveys conducted between 1969 and 2016. Hierarchical clustering of species in plots, and indicator species analysis for the resulting groups of sites, identified geographical patterns of turnover in species composition. Nonparametric analysis of variance, applied to principal components of bioclimatic variables, determined the degree of covariation in climate with location. Nestedness versus turnover in species composition was evaluated using beta diversity partitioning. Generalized dissimilarity modelling partitioned the effect of climate versus geographical distance on species composition. Results: Despite a set of commonly occurring species, SDTF tree community composition was distinct among islands and was characterized by spatial turnover on climatic gradients that covaried with geographical gradients. Greater Antillean islands were characterized by endemic indicator species. Northern subtropical areas supported distinct, rather than nested, SDTF communities in spite of low levels of endemism. Main conclusions: The SDTF species composition was correlated with climatic variation. SDTF on large Greater Antillean islands (Hispaniola, Jamaica and Cuba) was characterized by endemic species, consistent with their geological history and the biogeography of plant lineages. These results suggest that both environmental filtering and speciation shape Caribbean SDTF tree communities

Cell walls of the dimorphic fungal pathogens Sporothrix schenckii and Sporothrix brasiliensis exhibit bilaminate structures and sloughing of extensive and intact layers

This work was supported by the Fundação Carlos Chagas de Amparo à Pesquisa do Estado do Rio de Janeiro (FAPERJ), grants E-26/202.974/2015 and Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq), grants 229755/2013-5, Brazil. LMLB is a senior research fellow of CNPq and Faperj. NG acknowledged support from the Wellcome Trust (Trust (097377, 101873, 200208) and MRC Centre for Medical Mycology (MR/N006364/1). The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.Peer reviewedPublisher PD