Perfringolysin O-induced plasma membrane pores trigger actomyosin remodeling and endoplasmic reticulum redistribution

Clostridium perfringens produces an arsenal of toxins that act together to cause severe infections in humans and livestock animals. Perfringolysin O (PFO) is a cholesterol-dependent pore-forming toxin encoded in the chromosome of virtually all C. perfringens strains and acts in synergy with other toxins to determine the outcome of the infection. However, its individual contribution to the disease is poorly understood. Here, we intoxicated human epithelial and endothelial cells with purified PFO to evaluate the host cytoskeletal responses to PFO-induced damage. We found that, at sub-lytic concentrations, PFO induces a profound reorganization of the actomyosin cytoskeleton culminating into the assembly of well-defined cortical actomyosin structures at sites of plasma membrane (PM) remodeling. The assembly of such structures occurs concomitantly with the loss of the PM integrity and requires pore-formation, calcium influx, and myosin II activity. The recovery from the PM damage occurs simultaneously with the disassembly of cortical structures. PFO also targets the endoplasmic reticulum (ER) by inducing its disruption and vacuolation. ER-enriched vacuoles were detected at the cell cortex within the PFO-induced actomyosin structures. These cellular events suggest the targeting of the endothelium integrity at early stages of C. perfringens infection, in which secreted PFO is at sub-lytic concentrations.This work was financed by FEDER—Fundo Europeu de Desenvolvimento Regional funds through the COMPETE 2020—Operacional Programme for Competitiveness and Internationalisation (POCI), Portugal 2020, and by Portuguese funds through FCT - Fundação para a Ciência e a Tecnologia/Ministério da Ciência, Tecnologia e Ensino Superior in the framework of the project POCI-01-0145-FEDER-030863 (PTDC/BIA-CEL/30863/2017) and Norte-01-0145-FEDER-000012—Structured program on bioengineered therapies for infectious diseases and tissue regeneration, supported by Norte Portugal Regional Operational Programme (NORTE 2020), under the PORTUGAL 2020 Partnership Agreement, through the European Regional Development Fund (FEDER). Publication Fees were supported by ICBAS, University of Porto. CB and FSM were supported by FCT fellowships (SFRH/BD/112217/2015, SFRH/BPD/94458/2013, respectively). CB was a Fulbright and FLAD fellow. SS received support from FCT Investigator program (COMPETE, POPH, and FCT)

Old war, new battle, new fighters!

This work was supported by the Fundo Europeu de Desenvolvimento Regional – Programa Operacional Factores de Competitividade (FEDER-COMPETE) and Fundação para a Ciência e a Tecnologia (FCT) (PTDC/BIA-BCM/111215/2009FCOMP-01-0124- FEDER-014178, PTDC/SAU-MIC/111581/2009 FCOMP-01-0124-FEDER-0158449, and InfectERA PROANTILIS/0001/2013 to D. C.), the European Molecular Biology Organization (EMBO) (to F. S. M.), and European Society of Clinical Microbiology and Infectious Diseases (ESCMID) (to S. S.)

PHYSICAL QUALITY OF A YELLOW LATOSSOL UNDER INTEGRATED CROP-LIVESTOCK SYSTEM

Soil physical quality is essential to global sustainability of agroecosystems, once it is related to processes that are essential to agricultural crop development. This study aimed to evaluate physical attributes of a Yellow Latossol under different management systems in the savanna area in the state of Piaui. This study was developed in Urucui southwest of the state of Piaui. Three systems of soil management were studied: an area under conventional tillage (CT) with disk plowi and heavy harrow and soybean crop; an area under no-tillage with soybean-maize rotation and millet as cover crop (NT + M); two areas under Integrated Crop. Livestock System, with five-month pasture grazing and soybean cultivation and then continuous pasture grazing (ICL + S and ICL + P, respectively). Also, an area under Native Forest (NF) was studied. The soil depths studied were 0.00-0.05, 0.05-0.10 and 0.10-0.20 m. Soil bulk density, as well as porosity and stability of soil aggregates were analyzed as physical attributes. Anthropic action has changed the soil physical attributes, in depth, in most systems studied, in comparison to NF. In the 0.00 to 0.05 m depth, ICL + P showed higher soil bulk density value. As to macroporosity, there was no difference between the management systems studied and NF. The management systems studied changed the soil structure, having, as a result, a small proportion of soil in great aggregate classes (MWD). Converting native forest into agricultural production systems changes the soil physical quality. The Integrated Crop-Livestock System did not promote the improvement in soil physical quality.34371772

Pulse wave velocity and coronary risk stratification.

Introdução: A compliance arterial ou distensibilidade é uma determinante fundamental nas doenças cardiovasculares, apresentando grande interesse a sua medição não invasiva. A velocidade da onda de pulso (VOP) é usada, actualmente, como um índice de distensibilidade arterial. Objectivos: Avaliar se a VOP constitui um factor de risco, independente, para doença das artérias coronárias (DAC). Investigar se a determinação da mesma pode constituir uma ferramenta útil, na estratificação do risco cardiovascular, tanto nos indivíduos assintomáticos, como nos doentes com DAC População e Métodos: 811 indivíduos, 301 consecutivos com DAC, confirmada por coronário-angiografia, média de idade 53,7±10,0 anos e 510 assintomáticos, seleccionados das listas eleitorais, média de idade 46,1±10,0 anos. Os indivíduos assíntomáticos formavam o grupo A e eram subdivididos em A1 (grupo sem HTA, dislipidémia e ou diabetes) e A2 (grupo com HTA, dislipidémia, e ou diabetes). Os doentes coronários constituiam o grupo B, também sub dividido em B1 sem HTA, dislipidémia e ou diabetes e B2 com HTA, dislipidemia e ou diabetes. Os dados foram expressos em média ± desvio padrão (DP). O teste t de Student foi usado para comparar as variáveis contínuas e o c2 para comparar as variáveis categóricas. A força da correlação independente entre as variáveis contínuas foi avaliada segundo Pearson. Finalmente, foi efectuado um modelo de regressão logística (step by step) para avaliar quais as variáveis que se relacionavam de forma significativa e independente com a DAC. A análise estatística foi efectuada através do software SPSS for Windows, sendo o valor de p <0,05 considerado significativo. Resultados: Comparando os dois grupos, A1 e A2, no primeiro, a média da VOP foi significantemente mais baixa em relação ao A2. Comparando o grupo B1 e B2, também no grupo B1 a média da VOP é mais baixa. No grupo A1 a VOP correlacionou-se, segundo Pearson, com a idade, pressão arterial sistólica (PAS), diastólica e média, IMC, glicémia, colesterol total, LDL, relação CT/HDL, ApoB, triglicerídeos, ingestão de álcool, relação cintura/anca (C/A), e proteína C reactiva(as). A correlação foi inversa com o colesterol HDL. No grupo A2 a correlação da VOP foi positiva com a idade, PAS, PAM, PAD, glicémia, CT/ HDL e pressão do pulso (PP). No grupo B1 a correlação foi positiva e significante com a idade, PAS, PAM, PAD e PP. Foi inversa com a fracção de ejecção do VE. No grupo B2, foi positiva e significante com a idade, PAS, PAM, relação C/A, PP e homocisteína. Conclusão: A VOP foi sempre, quer nos indivíduos assintomáticos quer nos doentes coronários, mais elevada nos grupos com maior número de factores de risco. Esta constatação sugere influência cumulativa dos factores de risco, no processo de rigidez arterial. Correlacionou-se de forma positiva e significativa, com alguns dos factores de risco clássicos e alguns dos novos marcadores bioquímicos de risco. Após análise de regressão logística, manteve-se na equação de forma significativa, mostrando ser um factor de risco independente para DAC. Assim, a avaliação da distensibilidade arterial, através da medição da VOP, poderá representar um método simples, rápido e não invasivo, capaz de estratificar o risco de DAC, tanto nos indivíduos assintomáticos com nos doentes coronários.BACKGROUND: Arterial compliance or stiffness is an important determinant of cardiovascular disease and there is considerable interest in its noninvasive measurement. Pulse wave velocity (PWV) is widely used as an index of arterial stiffness. AIM: To determine whether PWV is useful for risk stratification in both healthy individuals and coronary patients. METHODS: Control subjects, n=510, aged 46.1 +/- 11 years, with no history of coronary disease, were selected from electoral rolls, and coronary patients, n=301, aged 53.7 +/- 10 years, were selected from hospital patients with a history of coronary artery disease (CAD) confirmed by coronary angiogram (at least 75% obstruction of one of the main coronary vessels). The asymptomatic subjects without CAD formed Group A, and were subdivided into A1 (without hypertension, dyslipidemia and/or diabetes) and A2 (with hypertension, dyslipidemia and/or diabetes). The coronary patients formed Group B, who were also subdivided into B1, without these classic risk factors, and B2 with hypertension, dyslipidemia and/or diabetes. We used the Student's t test to compare continuous variables and the chi-square test to compare categorical data. The strength of correlation between continuous variables was tested by Pearson's linear correlation. Independent variables predictive of CAD were determined by backward logistic regression analysis. The statistical analysis was performed using SPSS for Windows version 11.0 and data were expressed as means +/- SD; a p value of 0.05 was considered significant. RESULTS: Comparing the two groups A1 and A2, mean PWV was significantly lower in group A1. Comparing B1 and B2, mean PWV was also significantly lower in group B1. In group A1, PWV was significantly and positively correlated with age, body mass index, waist-to-hip ratio, alcohol consumption, total/HDL cholesterol ratio, systolic, diastolic and mean blood pressure (BP), blood glucose, apo B, triglycerides, and high-sensitivity C-reactive protein, unlike HDL which was inversely correlated (Pearson's coefficient). In group A2, PWV was significantly and positively correlated with age, alcohol consumption, total/HDL cholesterol ratio, systolic, diastolic and mean BP, blood glucose and pulse pressure (PP), but not HDL, which was inversely correlated with PWV. In group B1, PWV was only significantly and positively correlated with age, systolic, mean, and diastolic BP and PP, and presented a significant inverse correlation with ejection fraction. However, in the high-risk coronary population (group B2), there was a positive correlation with age, waist-to-hip ratio, systolic and mean BP, PP and homocysteine. After stepwise logistic regression, PWV remained in the model and proved to be a significant and independent risk factor for CAD. CONCLUSION: The results of our study show that PWV is higher in high-risk groups and significantly correlated with many classic and new CAD risk markers, suggesting that there is a cumulative influence of risk factors in the development of arterial stiffness. We believe that PWV is a useful index of vascular status and hence cardiovascular risk and that it may be useful for risk stratification in both asymptomatic and coronary patients.info:eu-repo/semantics/publishedVersio

The ρ(1S,2S)\rho(1S,2S), ψ(1S,2S)\psi(1S,2S), Υ(1S,2S)\Upsilon(1S,2S) and ψt(1S,2S)\psi_t(1S,2S) mesons in a double pole QCD Sum Rule

We use the method of double pole QCD sum rule which is basically a fit with two exponentials of the correlation function, where we can extract the masses and decay constants of mesons as a function of the Borel mass. We apply this method to study the mesons: $\rho(1S,2S)$, $\psi(1S,2S)$, $\Upsilon(1S,2S)$ and $\psi_t(1S,2S)$. We also present predictions for the toponiuns masses $\psi_t(1S,2S)$ of m(1S)=357 GeV and m(2S)=374 GeV.Comment: 14 pages, 11 figures in Braz J Phys (2016

Src-dependent tyrosine phosphorylation of non-muscle myosin heavy chain-IIA restricts Listeria monocytogenes cellular infection.

Bacterial pathogens often interfere with host tyrosine phosphorylation cascades to control host responses and cause infection. Given the role of tyrosine phosphorylation events in different human infections and our previous results showing the activation of the tyrosine kinase Src upon incubation of cells with Listeria monocytogenes, we searched for novel host proteins undergoing tyrosine phosphorylation upon L. monocytogenes infection. We identify the heavy chain of the non-muscle myosin IIA (NMHC-IIA) as being phosphorylated in a specific tyrosine residue in response to L. monocytogenes infection. We characterize this novel post-translational modification event and show that, upon L. monocytogenes infection, Src phosphorylates NMHC-IIA in a previously uncharacterized tyrosine residue (Tyr-158) located in its motor domain near the ATP-binding site. In addition, we found that other intracellular and extracellular bacterial pathogens trigger NMHC-IIA tyrosine phosphorylation. We demonstrate that NMHC-IIA limits intracellular levels of L. monocytogenes, and this is dependent on the phosphorylation of Tyr-158. Our data suggest a novel mechanism of regulation of NMHC-IIA activity relying on the phosphorylation of Tyr-158 by Src.This work was supported by the Fundo Europeu de Desenvolvimento Regional (FEDER) through the Operational Competitiveness Programme (COMPETE), by National Funds through Fundação para a Ciência e Tecnologia (FCT) under Project PTDC/BIA-BCM/100088/2008FCOMP-01-0124- FEDER-008860 and ERANet-Pathogenomics LISTRESS ERA-PTG/0003/ 2010, Project NORTE-07-0124-FEDER-000002-Host-Pathogen Interactions, co-funded by Programa Operacional Regional do Norte (ON.2-O Novo Norte), under the Quadro de Referência Estratégico Nacional, through FEDER, by FCT, and by a Research Grant 2014 by the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) (to S. S.). M. T. A. received a Travel Grant from Boehringer Ingelheim Fonds. Recipients of Fundação para a Ciência e Tecnologia Doctoral Fellowships BD/43352/2008 and BD/90607/2012. Recipient of EMBO Long Term Post-doctoral Fellowship EMBO ALTF 864-2012. Supported by Ciência 2008 and FCT Investigator Programs COMPETE, POPH, and FCT