Extracellular Kir2.1C122Y Mutant Upsets Kir2.1-PIP2 Bonds and Is Arrhythmogenic in Andersen-Tawil Syndrome.

BACKGROUND: Andersen-Tawil syndrome type 1 is a rare heritable disease caused by mutations in the gene coding the strong inwardly rectifying K+ channel Kir2.1. The extracellular Cys (cysteine)122-to-Cys154 disulfide bond in the channel structure is crucial for proper folding but has not been associated with correct channel function at the membrane. We evaluated whether a human mutation at the Cys122-to-Cys154 disulfide bridge leads to Kir2.1 channel dysfunction and arrhythmias by reorganizing the overall Kir2.1 channel structure and destabilizing its open state. METHODS: We identified a Kir2.1 loss-of-function mutation (c.366 A>T; p.Cys122Tyr) in an ATS1 family. To investigate its pathophysiological implications, we generated an AAV9-mediated cardiac-specific mouse model expressing the Kir2.1C122Y variant. We employed a multidisciplinary approach, integrating patch clamping and intracardiac stimulation, molecular biology techniques, molecular dynamics, and bioluminescence resonance energy transfer experiments. RESULTS: Kir2.1C122Y mice recapitulated the ECG features of ATS1 independently of sex, including corrected QT prolongation, conduction defects, and increased arrhythmia susceptibility. Isolated Kir2.1C122Y cardiomyocytes showed significantly reduced inwardly rectifier K+ (IK1) and inward Na+ (INa) current densities independently of normal trafficking. Molecular dynamics predicted that the C122Y mutation provoked a conformational change over the 2000-ns simulation, characterized by a greater loss of hydrogen bonds between Kir2.1 and phosphatidylinositol 4,5-bisphosphate than wild type (WT). Therefore, the phosphatidylinositol 4,5-bisphosphate-binding pocket was destabilized, resulting in a lower conductance state compared with WT. Accordingly, on inside-out patch clamping, the C122Y mutation significantly blunted Kir2.1 sensitivity to increasing phosphatidylinositol 4,5-bisphosphate concentrations. In addition, the Kir2.1C122Y mutation resulted in channelosome degradation, demonstrating temporal instability of both Kir2.1 and NaV1.5 proteins. CONCLUSIONS: The extracellular Cys122-to-Cys154 disulfide bond in the tridimensional Kir2.1 channel structure is essential for the channel function. We demonstrate that breaking disulfide bonds in the extracellular domain disrupts phosphatidylinositol 4,5-bisphosphate-dependent regulation, leading to channel dysfunction and defects in Kir2.1 energetic stability. The mutation also alters functional expression of the NaV1.5 channel and ultimately leads to conduction disturbances and life-threatening arrhythmia characteristic of Andersen-Tawil syndrome type 1.

The Kir2.1E299V mutation increases atrial fibrillation vulnerability while protecting the ventricles against arrhythmias in a mouse model of short QT syndrome type 3.

AIMS: Short QT syndrome type 3 (SQTS3) is a rare arrhythmogenic disease caused by gain-of-function mutations in KCNJ2, the gene coding the inward rectifier potassium channel Kir2.1. We used a multidisciplinary approach and investigated arrhythmogenic mechanisms in an in-vivo model of de-novo mutation Kir2.1E299V identified in a patient presenting an extremely abbreviated QT interval and paroxysmal atrial fibrillation. METHODS AND RESULTS: We used intravenous adeno-associated virus-mediated gene transfer to generate mouse models, and confirmed cardiac-specific expression of Kir2.1WT or Kir2.1E299V. On ECG, the Kir2.1E299V mouse recapitulated the QT interval shortening and the atrial-specific arrhythmia of the patient. The PR interval was also significantly shorter in Kir2.1E299V mice. Patch-clamping showed extremely abbreviated action potentials in both atrial and ventricular Kir2.1E299V cardiomyocytes due to a lack of inward-going rectification and increased IK1 at voltages positive to -80 mV. Relative to Kir2.1WT, atrial Kir2.1E299V cardiomyocytes had a significantly reduced slope conductance at voltages negative to -80 mV. After confirming a higher proportion of heterotetrameric Kir2.x channels containing Kir2.2 subunits in the atria, in-silico 3D simulations predicted an atrial-specific impairment of polyamine block and reduced pore diameter in the Kir2.1E299V-Kir2.2WT channel. In ventricular cardiomyocytes, the mutation increased excitability by shifting INa activation and inactivation in the hyperpolarizing direction, which protected the ventricle against arrhythmia. Moreover, Purkinje myocytes from Kir2.1E299V mice manifested substantially higher INa density than Kir2.1WT, explaining the abbreviation in the PR interval. CONCLUSION: The first in-vivo mouse model of cardiac-specific SQTS3 recapitulates the electrophysiological phenotype of a patient with the Kir2.1E299V mutation. Kir2.1E299V eliminates rectification in both cardiac chambers but protects against ventricular arrhythmias by increasing excitability in both Purkinje-fiber network and ventricles. Consequently, the predominant arrhythmias are supraventricular likely due to the lack of inward rectification and atrial-specific reduced pore diameter of the Kir2.1E299V-Kir2.2WT heterotetramer.

Exploring the Impact of Nanoparticle Stealth Coatings in Cancer Models: From PEGylation to Cell Membrane-Coating Nanotechnology.

Nanotechnological platforms offer advantages over conventional therapeutic and diagnostic modalities. However, the efficient biointerfacing of nanomaterials for biomedical applications remains challenging. In recent years, nanoparticles (NPs) with different coatings have been developed to reduce nonspecific interactions, prolong circulation time, and improve therapeutic outcomes. This study aims to compare various NP coatings to enhance surface engineering for more effective nanomedicines. We prepared and characterized polystyrene NPs with different coatings of poly(ethylene glycol), bovine serum albumin, chitosan, and cell membranes from a human breast cancer cell line. The coating was found to affect the colloidal stability, adhesion, and elastic modulus of NPs. Protein corona formation and cellular uptake of NPs were also investigated, and a 3D tumor model was employed to provide a more realistic representation of the tumor microenvironment. The prepared NPs were found to reduce protein adsorption, and cell-membrane-coated NPs showed significantly higher cellular uptake. The secretion of proinflammatory cytokines in human monocytes after incubation with the prepared NPs was evaluated. Overall, the study demonstrates the importance of coatings in affecting the behavior and interaction of nanosystems with biological entities. The findings provide insight into bionano interactions and are important for the effective implementation of stealth surface engineering designs.

Intermediate Molecular Phenotypes to Identify Genetic Markers of Anthracycline-Induced Cardiotoxicity Risk.

Cardiotoxicity due to anthracyclines (CDA) affects cancer patients, but we cannot predict who may suffer from this complication. CDA is a complex trait with a polygenic component that is mainly unidentified. We propose that levels of intermediate molecular phenotypes (IMPs) in the myocardium associated with histopathological damage could explain CDA susceptibility, so variants of genes encoding these IMPs could identify patients susceptible to this complication. Thus, a genetically heterogeneous cohort of mice (n = 165) generated by backcrossing were treated with doxorubicin and docetaxel. We quantified heart fibrosis using an Ariol slide scanner and intramyocardial levels of IMPs using multiplex bead arrays and QPCR. We identified quantitative trait loci linked to IMPs (ipQTLs) and cdaQTLs via linkage analysis. In three cancer patient cohorts, CDA was quantified using echocardiography or Cardiac Magnetic Resonance. CDA behaves as a complex trait in the mouse cohort. IMP levels in the myocardium were associated with CDA. ipQTLs integrated into genetic models with cdaQTLs account for more CDA phenotypic variation than that explained by cda-QTLs alone. Allelic forms of genes encoding IMPs associated with CDA in mice, including AKT1, MAPK14, MAPK8, STAT3, CAS3, and TP53, are genetic determinants of CDA in patients. Two genetic risk scores for pediatric patients (n = 71) and women with breast cancer (n = 420) were generated using machine-learning Least Absolute Shrinkage and Selection Operator (LASSO) regression. Thus, IMPs associated with heart damage identify genetic markers of CDA risk, thereby allowing more personalized patient management.

Extracellular cysteine disulfide bond break at Cys122 disrupts PIP2-dependent Kir2.1 channel function and leads to arrhythmias in Andersen-Tawil Syndrome.

Background: Andersen-Tawil Syndrome Type 1 (ATS1) is a rare heritable disease caused by mutations in the strong inwardly rectifying K+ channel Kir2.1. The extracellular Cys122-to-Cys154 disulfide bond in the Kir2.1 channel structure is crucial for proper folding, but has not been associated with correct channel function at the membrane. We tested whether a human mutation at the Cys122-to-Cys154 disulfide bridge leads to Kir2.1 channel dysfunction and arrhythmias by reorganizing the overall Kir2.1 channel structure and destabilizing the open state of the channel. Methods and Results: We identified a Kir2.1 loss-of-function mutation in Cys122 (c.366 A>T; p.Cys122Tyr) in a family with ATS1. To study the consequences of this mutation on Kir2.1 function we generated a cardiac specific mouse model expressing the Kir2.1C122Y mutation. Kir2.1C122Y animals recapitulated the abnormal ECG features of ATS1, like QT prolongation, conduction defects, and increased arrhythmia susceptibility. Kir2.1C122Y mouse cardiomyocytes showed significantly reduced inward rectifier K+ (IK1) and inward Na+ (INa) current densities independently of normal trafficking ability and localization at the sarcolemma and the sarcoplasmic reticulum. Kir2.1C122Y formed heterotetramers with wildtype (WT) subunits. However, molecular dynamic modeling predicted that the Cys122-to-Cys154 disulfide-bond break induced by the C122Y mutation provoked a conformational change over the 2000 ns simulation, characterized by larger loss of the hydrogen bonds between Kir2.1 and phosphatidylinositol-4,5-bisphosphate (PIP2) than WT. Therefore, consistent with the inability of Kir2.1C122Y channels to bind directly to PIP2 in bioluminescence resonance energy transfer experiments, the PIP2 binding pocket was destabilized, resulting in a lower conductance state compared with WT. Accordingly, on inside-out patch-clamping the C122Y mutation significantly blunted Kir2.1 sensitivity to increasing PIP2 concentrations. Conclusion: The extracellular Cys122-to-Cys154 disulfide bond in the tridimensional Kir2.1 channel structure is essential to channel function. We demonstrated that ATS1 mutations that break disulfide bonds in the extracellular domain disrupt PIP2-dependent regulation, leading to channel dysfunction and life-threatening arrhythmias.

Intermediate molecular phenotypes to identify genetic markers of anthracycline-induced cardiotoxicity risk.

Cardiotoxicity due to anthracyclines (CDA) affects cancer patients, but we cannot predict who may suffer from this complication. CDA is a complex disease whose polygenic component is mainly unidentified. We propose that levels of intermediate molecular phenotypes in the myocardium associated with histopathological damage could explain CDA susceptibility; so that variants of genes encoding these intermediate molecular phenotypes could identify patients susceptible to this complication. A genetically heterogeneous cohort of mice generated by backcrossing (N = 165) was treated with doxorubicin and docetaxel. Cardiac histopathological damage was measured by fibrosis and cardiomyocyte size by an Ariol slide scanner. We determine intramyocardial levels of intermediate molecular phenotypes of CDA associated with histopathological damage and quantitative trait loci (ipQTLs) linked to them. These ipQTLs seem to contribute to the missing heritability of CDA because they improve the heritability explained by QTL directly linked to CDA (cda-QTLs) through genetic models. Genes encoding these molecular subphenotypes were evaluated as genetic markers of CDA in three cancer patient cohorts (N = 517) whose cardiac damage was quantified by echocardiography or Cardiac Magnetic Resonance. Many SNPs associated with CDA were found using genetic models. LASSO multivariate regression identified two risk score models, one for pediatric cancer patients and the other for women with breast cancer. Molecular intermediate phenotypes associated with heart damage can identify genetic markers of CDA risk, thereby allowing a more personalized patient management. A similar strategy could be applied to identify genetic markers of other complex trait diseases.

Rapid antigen test as a tool for the identification of SARS-CoV-2 infection and its potential as a self-testing device

ABSTRACT Background: SARS-CoV-2 virus originated in Wuhan (China) in December (2019) and quickly spread worldwide. Antigen tests are rapid diagnostic tests (RDT) that produce results in 15-30 min and are an important tool for the scale-up of COVID-19 testing. COVID-19 diagnostic tests are authorized for self-testing at home in some countries, including Brazil. Widespread COVID-19 diagnostic testing is required to guide public health policies and control the speed of transmission and economic recovery. Methods: Patients with suspected COVID-19 were recruited at the Hospital da Baleia (Belo Horizonte, Brazil). The SARS-CoV-2 antigen-detecting rapid diagnostic tests were evaluated from June 2020 to June 2021 using saliva, nasal, and nasopharyngeal swab samples from 609 patients. Patient samples were simultaneously tested using a molecular assay (RT-qPCR). Sensitivity, specificity, accuracy, and positive and negative predictive values were determined using the statistical program, MedCalc, and GraphPad Prism 8.0. Results: The antigen-detecting rapid diagnostic tests displayed 98% specificity, 60% sensitivity, 96% positive predictive value, and moderate concordance with RT-qPCR. Substantial agreement was found between the two methods for patients tested < 7 days of symptom onset. Conclusions: Our findings support the use of Ag-RDT as a valuable and safe diagnostic method. Ag-RDT was also demonstrated to be an important triage tool for suspected COVID-19 patients in emergencies. Overall, Ag-RDT is an effective strategy for reducing the spread of SARS-CoV-2 and contributing to COVID-19 control.

Autobiographical Narrative as a Methodological Instrument of the Network of Meanings / A Narrativa Autobiográfica como Instrumento Metodológico da Rede de Significações / La Narrativa Autobiográfica como Instrumento Metodológico de la Red de Significados

Abstract This article briefly presents the theoretical-methodological perspective of the Network of Meanings and its methodological implications. The aim is to question the use of autobiographical narratives as a possible methodological tool to approach the study of development, with the specificity of understanding processes of constitutive transformations in human ontogenesis, from an interactional perspective, as is the case of the Network of Meanings. We revisit a study based on autobiographical narratives with five adult drag queens, aged between 20 and 39 years old, exploring personal and artistic experiences. Their narratives were analyzed microgenetically and some central concepts of the Network of Meanings were raised - dialogic interactive fields, socio-historical matrix, and temporalities. The autobiographical narrative of the participants constitutes a fruitful field of qualitative analysis, allowing us to approach the processes of change and transformation throughout life. As a result, a dialogue between Developmental Psychology and Social and Cultural Psychology is promoted.

Resumo O estudo apresenta brevemente a perspectiva teórico-metodológica da Rede de Significações (RedSig) e suas implicações metodológicas. O presente estudo teve como objetivo problematizar a narrativa autobiográfica como ferramenta metodológica possível para abordar o estudo do desenvolvimento com a especificidade de compreender processos de transformações constitutivos da ontogênese humana, em uma perspectiva interacional como é o caso da RedSig. Retoma-se um estudo realizado a partir de narrativas autobiográficas com cinco drag queens adultas, com idade entre 20 e 39 anos, explorando experiências pessoais e artísticas. Suas narrativas foram analisadas microgeneticamente e são alçados alguns conceitos centrais da Rede de Significações − campos interativos dialógicos, matriz sócio-histórica e temporalidades. A narrativa autobiográfica das participantes se constitui como um campo profícuo de análise qualitativa, permitindo abordar os processos de mudança e transformação ao longo da vida. Em decorrência, promove-se um diálogo entre a Psicologia do Desenvolvimento e a Psicologia Social e Cultural.

Resumen El artículo presenta brevemente la perspectiva teórico-metodológica de la Red de Sentidos y sus implicaciones metodológicas. El objetivo es problematizar el uso de la narrativa autobiográfica como posible herramienta metodológica para abordar el estudio del desarrollo, con la especificidad de comprender procesos de transformaciones constitutivas de la ontogénesis humana. Retomamos un estudio realizado con cinco drag queens adultas, con edades entre 20 y 39 años, a partir de narrativas autobiográficas, explorando experiencias personales y artísticas. Sus narrativas fueron analizadas microgenéticamente y se plantean algunos conceptos centrales de la Red de Sentidos: campos interactivos dialógicos, matriz sociohistórica y temporalidades. La narrativa autobiográfica de los participantes constituye un campo fecundo de análisis cualitativo, que permite abordar los procesos de cambio y transformación a lo largo de la vida. Como resultado, se promueve un diálogo entre la Psicología del Desarrollo y la Psicología Social y Cultural.

Microglial angiotensin type 2 receptors mediate sex-specific expression of inflammatory cytokines independently of circulating estrogen.

There are sex differences in microglia, which can maintain sex-related gene expression and functional differences in the absence of circulating sex steroids. The angiotensin type 2 (AT2) receptors mediate anti-inflammatory actions in different tissues, including brain. In mice, we performed RT-PCR analysis of microglia isolated from adult brains and RNA scope in situ hybridization from males, females, ovariectomized females, orchiectomized males and brain masculinized females. We also compared wild type and AT2 knockout mice. The expression of AT2 receptors in microglial cells showed sex differences with much higher AT2 mRNA expression in females than in males, and this was not dependent on circulating gonadal hormones, as observed using ovariectomized females, brain masculinized females and orchiectomized males. These results suggest genomic reasons, possibly related to sex chromosome complement, for sex differences in AT2 expression in microglia, as the AT2 receptor gene is located in the X chromosome. Furthermore, sex differences in expression of AT2 receptors were associated to sex differences in microglial expression of key anti-inflammatory cytokines such as interleukin-10 and pro-inflammatory cytokines such as interleukin-1ß and interleukin-6. In conclusion, sex differences in microglial AT2 receptor expression appear as a major factor contributing to sex differences in the neuroinflammatory responses beyond the effects of circulating steroids.

Angiotensin type-1 receptor and ACE2 autoantibodies in Parkinson´s disease.

The role of autoimmunity in neurodegeneration has been increasingly suggested. The renin-angiotensin system (RAS) autoantibodies play a major role in several peripheral inflammatory processes. Dysregulation of brain RAS has been involved in neuroinflammation and neurodegeneration. We aimed to know whether angiotensin type-1 receptor (AT1) autoantibodies (AT1 agonists) and angiotensin-converting enzyme 2 (ACE2) autoantibodies (ACE2 antagonists) may be involved in Parkinson's disease (PD) progression and constitute a new therapeutical target. Both AT1 and ACE2 serum autoantibodies were higher in a group of 117 PD patients than in a group of 106 controls. Serum AT1 autoantibodies correlated with several cytokines, particularly Tumor Necrosis Factor Ligand Superfamily Member 14 (TNFSF14, LIGHT), and 27-hydroxycholesterol levels. Serum ACE2 autoantibodies correlated with AT1 autoantibodies. Both autoantibodies were found in cerebrospinal fluid (CSF) of four PD patients with CSF samples. Consistent with the observations in patients, experimental dopaminergic degeneration, induced by 6-hydroxydopamine, increased levels of autoantibodies in serum and CSF in rats, as well as LIGHT levels and transglutaminase activity in rat substantia nigra. In cultures, administration of AT1 autoantibodies enhanced dopaminergic neuron degeneration and increased levels of neuroinflammation markers, which was inhibited by the AT1 antagonist candesartan. The results suggest dysregulation of RAS autoantibodies as a new mechanism that can contribute to PD progression. Therapeutical strategies blocking the production, or the effects of these autoantibodies may be useful for PD treatment, and the results further support repurposing AT1 blockers (ARBs) as treatment against PD progression.

Interactions between curcumin and cell membrane models by Langmuir monolayers.

Studying interactions between potential anticancer drugs and cell membrane models is of great interest to explore the capability of novel drugs in the development of anticancer treatments. Lipid membrane models are useful to understand cellular interactions and to discern drug mechanism action. Here, the interactions of curcumin, as a bioactive natural compound with anti-cancer properties, with both healthy and cancerous or tumor cell membrane models, based on Langmuir monolayers, have been studied. The healthy-cell membrane model is composed of cholesterol 67%, and saturated lipid dipalmitoylphosphatidylcholine 33%. The cancerous-cell-membrane-model is composed of a lower proportion of cholesterol, 25%, and unsaturated lipid sphingomyelin 75%. To compare their interaction with curcumin we report the compression isotherms registered for both lipid membrane models and curcumin in different proportions, their compression moduli and the thermodynamic interaction parameters. From this analysis, we evidence a destabilizing interaction between curcumin and the cancerous cell membrane model in comparison with the healthy one. This interaction is further visualized by micro-Brewster Angle and Atomic Force Microscopies. Our experiments show that the drug enhances cohesion in the healthy membrane model whereas it fluidifies the cancerous cell membrane model causing thermodynamic destabilization. These are useful results to improve the selectivity of the drug avoiding adverse side effects of most current anticancer therapies.

House dust mite fauna characterization in the city of Rio de Janeiro and its importance in allergy diagnosis / Caracterização da fauna dos ácaros de poeira na cidade do Rio de Janeiro e sua importância em diagnósticos de alergias

Introduction: The home environment is one of the most favorable spaces for the development of mites because of its low light, humidity, and temperature. Thus, it contributes to the growing cases of allergies among atopic individuals. Objective: To investigate the faunal profile of house dust mites in the city of Rio de Janeiro and the allergenic potential in this region. Methods: Thirty dust samples were collected from homes in the city of Rio de Janeiro, and the species found were classified according to their morphology, family, and genus by classification key. For the collection region, the total protein level was assessed by the Lowry method and electrophoresis under denaturing conditions (SDSPAGE). Results: There was a predominance of Pyroglyphidae mites, accounting for 84.9% of samples; Tyrophagus putrescentiae accounted for 8%, Blomia tropicalis for 6%, Cheyletus malaccensis for 1%, and Acarus siro for 0.1%. The allergen protein content of the samples was the following: group 1 ­ 25 kDa (Der 1, Der p 1, and Blo t 1), group 2 ­ 15 kDa (Der f 2, Der 2, Tyr p 2, and Blo t 2), and group 3 ­ 29-30 kDa (Der f 3 and Blo t 3), which indicates that people in this region are susceptible to sensitization to these mites. Conclusion: Knowledge of the mite fauna in the region under study allows the guidance of health care professionals to perform skin tests for specific mites and conduct treatment according to the pool of mite extracts containing antigens, making immunotherapy more effective.

Introdução: O ambiente domiciliar é um dos espaços favoráveis para o desenvolvimento de ácaros, tendo em vista a baixa luminosidade, umidade e temperatura, o que contribui para os crescentes casos de alergias em indivíduos atópicos. Objetivo: Investigar o perfil faunístico dos ácaros na cidade do Rio de Janeiro e o potencial alergêncio para essa região. Métodos: Foram coletadas 30 amostras de poeira em residências na cidade do Rio de Janeiro, e as espécies encontradas foram classificadas quanto à morfologia, família e o gênero por chave de classificação. Para as regiões das coletas, a carga total de proteínas contendo os alérgenos foi determinada pelo método de Lowry e eletroforese em condições desnaturantes (SDS-PAGE). Resultados: Os resultados mostram a predominância de 84,9% de ácaros da família Pyroglyphidae; para os demais ácaros o percentual corresponde a 8% Tyrophagus putrescentiae, 6% Blomia tropicalis, 1% Cheyletus malaccensis, e 0,1% de Acarus siro. O conteúdo proteico alergêncio constituinte das amostras foram, grupo 1: 25 kDa (Der 1, Der p 1 e Blo t 1); grupo 2: 15 kDa (Der f 2, Der 2, Tyr p 2 e Blo t 2); e para o grupo 3: 29-30 kDa (Der f 3 e Blo t 3), o que indica uma região passível à sensibilização de indivíduos por estes ácaros. Conclusão: O conhecimento da acarofauna nas regiões em estudo permite orientar a comunidade médica quanto à realização de testes cutâneos, além da terapêutica a partir do pool de extratos de ácaros contendo os antígenos, a fim de tornar a imunoterapia mais eficaz.

Aprendizagem Cultural por Crianças de Dois Anos em seu Grupo de Brinquedo / Cultural Learning by Two-Year-Old Children in Play Group / Aprendizaje Cultural de Niños de Dos Años en el Grupo de Juego

Neste trabalho, discute-se a aprendizagem cultural de crianças de dois anos do seu entorno social, examinando, a partir de uma perspectiva sociointeracionista, o modo como participam de brincadeiras que se efetivam no grupo de brinquedo. 20 crianças foram observadas duas vezes por semana, durante 45 dias, perfazendo um total de 11 sessões videogravadas com duração média de 24 minutos. Elas brincavam livremente em espaços de um Centro Municipal de Educação Infantil, em Recife. Foram identificados e transcritos 56 episódios de brincadeiras. A análise qualitativa evidencia que as crianças trazem para a situação de interação com seus pares (microcultura) conhecimentos produzidos em diferentes ambientes sociais (macrocultura). Conhecimentos da cultura popular foram inferidos a partir dos comportamentos observados em uma encenação de maracatu e em um jogo de capoeira. O protagonismo das crianças indica que convenções e regras são respeitadas e compartilhadas, o que garante a negociação de significados e transmissão da cultura, mesmo em crianças bem novas. Imitação, ações complementares e cooperativas parecem contribuir na manutenção e reconstrução de conhecimentos com os parceiros. Sublinha-se a importância de se propiciar um contexto coletivo de desenvolvimento para instigar a participação das crianças na assimilação e construção da microcultura do grupo. (AU)

This paper discusses the cultural learning of two-year-old children of their social environment, examining, from a socio-interactionist perspective, the way they participate in play activities that take place in the peer group. Twenty children were observed twice a week, for forty-five days, totaling 11 video-recorded sessions, each one lasting 24 minutes on average. They played freely in spaces of a Municipal Center for Early Childhood Education, in Recife. Fifty-six episodes of play activity were identified and transcribed. Qualitative analysis shows that children bring knowledge produced in different social environments (macroculture) to the situation of interaction with their peers (microculture). Knowledge of popular culture was inferred from behaviors observed by featuring maracatu and a capoeira performance. The protagonism of children indicates that conventions and rules are respected and shared, which guarantees the negotiation of meanings and the transmission of culture, even among children at their earlier ages. Imitation, complementary, and cooperative actions seem to contribute to the maintenance and reconstruction of knowledge with peers. The importance of providing a collective context of development is underlined to encourage the participation of children in the assimilation and construction of the group's microculture. (AU)

En este trabajo se discute el aprendizaje cultural de niños de dos años en su entorno social, examinando, desde una perspectiva sociointeraccionista, la forma en que participan de juegos y se desarrollan en el grupo de juguetes. Veinte niños fueron observados dos veces por semana en cuarenta y cinco días, un total de 11 sesiones grabadas en video con una duración promedio de 24 minutos. Jugaron libremente en un Centro Municipal de Educación Infantil, en Recife. Se identificaron y transcribieron 56 episodios de juegos. El análisis cualitativo muestra conocimientos de los niños producidos en distintos entornos sociales (macrocultura) y interacción con sus pares (microcultura). El conocimiento de cultura popular se infirió a partir de conductas observadas en una puesta en escena de maracatu y juego de capoeira. El protagonismo de los niños indica que han respetado y compartido las convenciones y reglas, lo que garantiza negociación de significados y la transmisión de cultura, incluso en niños muy pequeños. Las acciones de imitación, complementarias y cooperativas parecen apoyar el mantenimiento y reconstrucción del conocimiento con los parceros. Se destaca la importancia de brindar un contexto colectivo de desarrollo para instigar la participación de niños en la asimilación y construcción de microcultura de grupo. (AU)

Autoantibodies against ACE2 and angiotensin type-1 receptors increase severity of COVID-19.

The renin-angiotensin system (RAS) plays a major role in COVID-19. Severity of several inflammation-related diseases has been associated with autoantibodies against RAS, particularly agonistic autoantibodies for angiotensin type-1 receptors (AA-AT1) and autoantibodies against ACE2 (AA-ACE2). Disease severity of COVID-19 patients was defined as mild, moderate or severe following the WHO Clinical Progression Scale and determined at medical discharge. Serum AA-AT1 and AA-ACE2 were measured in COVID-19 patients (n = 119) and non-infected controls (n = 23) using specific solid-phase, sandwich enzyme-linked immunosorbent assays. Serum LIGHT (TNFSF14; tumor necrosis factor ligand superfamily member 14) levels were measured with the corresponding assay kit. At diagnosis, AA-AT1 and AA-ACE2 levels were significantly higher in the COVID-19 group relative to controls, and we observed significant association between disease outcome and serum AA-AT1 and AA-ACE2 levels. Mild disease patients had significantly lower levels of AA-AT1 (p < 0.01) and AA-ACE2 (p < 0.001) than moderate and severe patients. No significant differences were detected between males and females. The increase in autoantibodies was not related to comorbidities potentially affecting COVID-19 severity. There was significant positive correlation between serum levels of AA-AT1 and LIGHT (TNFSF14; rPearson = 0.70, p < 0.001). Both AA-AT1 (by agonistic stimulation of AT1 receptors) and AA-ACE2 (by reducing conversion of Angiotensin II into Angiotensin 1-7) may lead to increase in AT1 receptor activity, enhance proinflammatory responses and severity of COVID-19 outcome. Patients with high levels of autoantibodies require more cautious control after diagnosis. Additionally, the results encourage further studies on the possible protective treatment with AT1 receptor blockers in COVID-19.

Experimental data using candesartan and captopril indicate no double-edged sword effect in COVID-19.

The key link between renin-angiotensin system (RAS) and COVID-19 is ACE2 (angiotensin-converting enzyme 2), which acts as a double-edged sword, because ACE2 increases the tissue anti-inflammatory response but it is also the entry receptor for the virus. There is an important controversy on several drugs that regulate RAS activity and possibly ACE2, and are widely used, particularly by patients most vulnerable to severe COVID-19. In the lung of healthy rats, we observed that candesartan (an angiotensin type-1, AT1, receptor blocker; ARB) and captopril (an ACE inhibitor; ACEI) up-regulated expression of tissue ACE2 and RAS anti-inflammatory axis receptors (AT2 and Mas receptors). This effect was particularly pronounced in rats with metabolic syndrome (obesity, increased blood pressure and hyperglycemia) and aged rats. Treatment of cultures of human type-II pneumocytes with candesartan or captopril induced up-regulation of ACE2 expression in cells. Treatment with viral spike protein induced a decrease in full-length (i.e. transmembrane) ACE2, an increase in levels of a short intracellular ACE2 polypeptide and an increase in ADAM17 activity in cells, together with an increase in levels of soluble ACE2 and major proinflammatory cytokines in the culture medium. Spike protein-induced changes and levels of spike protein internalization in cells were inhibited by pretreatment with the above-mentioned drugs. The results suggest that these drugs increase ACE2 levels and promote the anti-inflammatory RAS axis in the lung. Furthermore, possible up-regulation of viral entry by the drug-induced increase in expression of transmembrane ACE2 is counteracted by additional mechanisms, particularly by drug-induced inhibition of ADAM17 activity.

The Meanings of Pregnancy in Adolescence for Young People without a History of Pregnancies / Os Significados da Gravidez na Adolescência para Jovens sem Histórico de Gestação / Los Significados del Embarazo en la Adolescencia para Jóvenes sin Antecedentes de Gestación

Abstract In the academic literature there is lack of studies on teenage pregnancy in young people who have not experienced pregnancy. This article aimed to investigate and analyze the meanings of teenage pregnancy for adolescents without a gestation history. The participants were 37 adolescents with no pregnancy history (22 males and 15 females), aged between 12 and 18 years old. The thematic design-story procedure was used as instrument, in which the young individuals were asked to draw "a pregnant adolescent in their Community". To systematize the data, Bardin's content analysis was used. Thirteen themes were observed, the most frequent being related to families, relationships and/or friends and very early pregnancies, showing the relevance of these themes for adolescents. It is concluded that teenage pregnancy, in its majority, was seen as disadvantageous, but also as desired by some young individuals, pointing to the ambiguity of the phenomenon.

Resumo Na literatura acadêmica, são escassos os estudos sobre gravidez na adolescência em jovens que não vivenciaram a gestação. Este artigo teve como objetivo investigar e analisar os significados da gravidez na adolescência para adolescentes sem histórico de gestação. Participaram 37 adolescentes sem histórico de gravidez (22 homens e 15 mulheres) entre 12 e 18 anos. Foi utilizado como instrumento o procedimento desenho-estória temático, tendo sido solicitado que os jovens desenhassem "uma adolescente grávida na sua comunidade". Para sistematização dos dados, utilizou-se a análise de conteúdo de Bardin. Observaram-se 13 temas, sendo os mais frequentes relacionados às famílias, às relações amorosas e/ou amizades e à gravidez muito cedo, demonstrando a relevância desses temas para os adolescentes. Conclui-se que a gravidez na adolescência, em sua maioria, foi vista como desvantajosa, mas também como desejada por alguns jovens, apontando para a ambiguidade do fenômeno.

Resumen En la literatura académica faltan estudios sobre el embarazo adolescente en jóvenes que todavía no lo han experimentado. Este artículo tuvo como objetivo investigar y analizar los significados del embarazo en la adolescencia para adolescentes sin antecedentes de gestación. Participaron 37 adolescentes sin antecedentes de embarazo (22 hombres y 15 mujeres) de entre 12 y 18 años de edad. Se utilizó como instrumento el procedimiento dibujo-historia temático, habiéndose solicitado que los jóvenes dibujaran "una adolescente embarazada en su comunidad". Para sistematizar los datos se utilizó el análisis de contenido de Bardin. Se observaron 13 temas, siendo los más frecuentes los relacionados con las familias, relaciones amorosas y/o amistades y embarazo muy temprano, lo que demuestra la relevancia de estos temas para las adolescentes. Se concluye que el embarazo adolescente, en su mayoría, fue visto como desventajoso, pero también como deseado por algunos jóvenes, lo que apunta a la ambigüedad del fenómeno.

Effects of açai on oxidative stress, ER stress, and inflammation-related parameters in mice with high fat diet-fed induced NAFLD.

Non-alcoholic fatty liver disease (NAFLD), the most predominant liver disease worldwide, is a progressive condition that encompasses a spectrum of disorders ranging from steatosis to steatohepatitis, and, ultimately, cirrhosis and hepatocellular carcinoma. Although the underlying mechanism is complex and multifactorial, several intracellular events leading to its progression have been identified, including oxidative stress, inflammation, mitochondrial dysfunction, apoptosis, and altered endoplasmic reticulum (ER) homeostasis. Phenolic compounds, such as those present in açai (Euterpe oleracea Mart.), are considered promising therapeutic agents due to their possible beneficial effects on the prevention and treatment of NAFLD. We tested in vitro effects of aqueous açai extract (AAE) in HepG2 cells and its influence on oxidative stress, endoplasmic reticulum stress, and inflammation in a murine model of high fat diet-induced NAFLD. In vitro AAE exhibited high antioxidant capacity, high potential to inhibit reactive oxygen species production, and no cytotoxicity. In vivo, AAE administration (3 g/kg) for six weeks attenuated liver damage (alanine aminotransferase levels), inflammatory process (number of inflammatory cells and serum TNFα), and oxidative stress, through the reduction of lipid peroxidation and carbonylation of proteins determined by OxyBlot and modulation of the antioxidant enzymes: glutathione reductase, SOD and catalase. No change was observed in collagen content indicating an absence of fibrosis, stress-related genes in RE, and protein expression of caspase-3, a marker of apoptosis. With these results, we provide evidence that açai exhibits hepatoprotective effects and may prevent the progression of liver damage related to NAFLD by targeting pathways involved in its progression.

Non-anthocyanin phenolics in cherry (Prunus avium L.) modulate IL-6, liver lipids and expression of PPARδ and LXRs in obese diabetic (db/db) mice.

Anthocyanin-rich cherries are known for preventing/decreasing risk factors associated with obesity; however, the specific benefits exerted by cherry non-anthocyanin phenolics are not clear. Obese diabetic (db/db) mice fed a diet supplemented with anthocyanin-depleted cherry powder (cherry) were compared to db/db (obese) or lean counterparts (lean) fed a control isocaloric diet for 12 weeks. The reduced plasma interleukin (IL)-6 and improved liver health may be mediated by cherry fibre and non-anthocyanin phenolics. Benefits for liver health included reduction of lipids and protein carbonyls, and modulation of peroxisome proliferator-activated receptor (PPAR)δ mRNA to resemble levels in lean. Lack of plasma antilipidemic, improvement of antioxidant defenses, and PPARα/γ mRNA modulation in liver suggest cherry anthocyanins specific benefits. This is the first study to elucidate in vivo the potential benefits of cherry non-anthocyanin phenolics for diabetes-induced liver disorders and the importance of choosing processing technologies that preserve anthocyanins and health benefits of whole cherries.

Physical exercise improves body weight gain and liver function in malnourished rats without disturbing the redox balance / O exercício físico melhora o ganho de peso corporal e a função hepática em ratos desnutridos sem perturbar o balanço de redox

ABSTRACT Objective To study the relationship between exercise and malnourishment because recent evidence suggests that exercise can cause the beneficial adaptation of antioxidant systems, whereas malnourishment can cause harmful adaptation of these systems. Methods Thirty-two female Fischer rats were equally divided into Sedentary Control, Trained Control, Sedentary Malnourished and Trained Malnourished groups. The training protocol consisted of swimming for 30 minutes continuously for 5 days/week for 8 weeks. Results It was demonstrated that aspartate aminotransferase and alanine aminotransferase activities increased in malnourished rats, but physical training reversed these effects by lowering the raised levels. The glutathione level was diminished by malnourishment whereas physical training increased the levels of liver carbonyl protein and increased the levels of thiobarbituric acid reactive substances that were diminished by malnourishment. In addition, Trained Malnourished rats had a higher average body weight than Sedentary Malnourished ones (62.77g vs. 55.08g, respectively). Conclusion The data show that exercise was able to reverse or reduce damage caused by malnourishment, such as weight loss and liver dysfunction by a pathway independent of the participation of enzymes involved in antioxidant defense and that there is no interaction between exercise and malnutrition.

RESUMO Objetivo Estudar a relação entre exercício e desnutrição, pois evidências recentes sugerem que o exercício físico pode causar a adaptação benéfica de sistemas antioxidantes, enquanto a desnutrição pode causar adaptação prejudicial a esses sistemas. Métodos Trinta e duas ratas Fischer foram igualmente divididas nos grupos Controle Sedentário, Controle Treinado, Desnutrido Sedentário e Desnutrido Treinado. O protocolo de treinamento consistiu em nadar por 30 minutos continuamente por 5 dias/semana por 8 semanas. Resultados Demonstramos que as atividades de aspartato aminotransferase e alanina aminotransferase aumentaram em ratos desnutridos, mas o treinamento físico reverteu esses efeitos. O nível de glutationa foi diminuído pela desnutrição, enquanto o treinamento físico aumentou os níveis de proteína carbonilada do fígado e aumentou os níveis de substâncias reativas ao ácido tiobarbitúrico que foram diminuídas pela desnutrição. Além disso, os ratos desnutridos treinados tiveram um peso corporal médio maior que os desnutridos sedentários (62,77g vs 55,08g, respectivamente). Conclusão Os dados mostram que o exercício foi capaz de reverter ou reduzir os danos causados pela desnutrição, como perda de peso e a disfunção hepática por uma via independente da participação de enzimas envolvidas na defesa antioxidante e que não há interação entre exercício e desnutrição.