FTIR Spectroscopy as a Tool to Study Age-Related Changes in Cardiac and Skeletal Muscle of Female C57BL/6J Mice.

Studying aging is important to further understand the molecular mechanisms underlying this physiological process and, ideally, to identify a panel of aging biomarkers. Animals, in particular mice, are often used in aging studies, since they mimic important features of human aging, age quickly, and are easy to manipulate. The present work describes the use of Fourier Transform Infrared (FTIR) spectroscopy to identify an age-related spectroscopic profile of the cardiac and skeletal muscle tissues of C57BL/6J female mice. We acquired ATR-FTIR spectra of cardiac and skeletal muscle at four different ages: 6; 12; 17 and 24 months (10 samples at each age) and analyzed the data using multivariate statistical tools (PCA and PLS) and peak intensity analyses. The results suggest deep changes in protein secondary structure in 24-month-old mice compared to both tissues in 6-month-old mice. Oligomeric structures decreased with age in both tissues, while intermolecular ß-sheet structures increased with aging in cardiac muscle but not in skeletal muscle. Despite FTIR spectroscopy being unable to identify the proteins responsible for these conformational changes, this study gives insights into the potential of FTIR to monitor the aging process and identify an age-specific spectroscopic signature.

Stress e estratégias de coping em profissionais de saúde / Stress and coping strategies in health professionals / Estrés y estrategias de afrontamiento para profesionales de la salud

CONTEXTO: As especificidades do trabalho nas organizações de saúde e, em particular, os níveis de stress a que estão sujeitos os profissionais têm reflexos na sua condição de saúde. As medidas de redução do stress profissional inscrevem-se nas estratégias de governação clínica enquanto processo de melhoria da qualidade envolvendo princípios fundamentais da excelência, como a orientação para os resultados, melhoria contínua, responsabilidade social, focalização na saúde e bem-estar das pessoas/colaboradores. OBJETIVO: Avaliar principais fontes de stress e estratégias de coping utilizadas pelos profissionais de saúde no desenvolvimento da sua atividade profissional. MÉTODOS: Trata-se de um estudo descritivo exploratório com amostra por conveniência a diferentes profissionais de saúde. Para a recolha de dados foram utilizados dois instrumentos: Questionário de Stress nos Profissionais de Saúde; e Brief COPE. O questionário foi enviado por e-mail decorrendo a recolha entre os meses de maio e junho de 2018. Os dados foram tratados e analisados com recurso ao SPSS. Todos os procedimentos éticos foram assegurados. RESULTADOS: As dimensões de stress mais críticas referidas pelos profissionais de saúde foram: carreira, remuneração, excesso de trabalho e lidar com os clientes. As estratégias de coping mais referidas foram: coping ativo, planear e reinterpretação positiva. O uso de substâncias foi a menos utilizada. CONCLUSÕES: Os resultados obtidos permitem identificar uma vulnerabilidade particular dos profissionais de saúde a fatores de stress profissional associados à carreira e às condições de exercício profissional. Apurou-se uma resposta relativamente consensual face ao stress: o impacto negativo na saúde, em particular na saúde mental, com as consequências adversas alusivas a todo o processo de governação clínica.

BACKGROUND: The specificities of work in health organizations and, in particular, the levels of stress to which professionals are subjected have consequences for their health condition. Occupational stress reduction measures are part of clinical governance strategies as a quality improvement process involving fundamental principles of excellence, such as results orientation, continuous improvement and social responsibility, and focus on the health and well-being of people / contributors. AIM: To evaluate the main sources of stress and coping strategies used by health professionals in the development of their professional activity. METHODS: This is a descriptive and exploratory study with convenience sample to different health professionals. Two instruments were used to collect data: Stress Questionnaire for Health Professionals; and Brief COPE. The questionnaire was sent by e-mail after the collection between the months of May and June of 2018. The data were treated and analyzed using SPSS. All ethical procedures were ensured during the process. RESULTS: The most critical stress dimensions reported by health professionals were: career, remuneration, overwork and dealing with clients. The most mentioned coping strategies were: active coping, planning and positive reinterpretation. Substance use was the least referred. CONCLUSIONS: The results obtained allow the identification of a particular vulnerability of health professionals to professional stress factors associated with career and working conditions. It was also possible to establish a relatively consensual response to stress in health professionals: the negative impact on health, in particular on mental health, with adverse consequences for the entire clinical governance process.

CONTEXTO: Las especificidades del trabajo en las organizaciones de salud y, en particular, los niveles de estrés a que están sujetos los profesionales tienen reflejos en su condición de salud. Las medidas de reducción del estrés profesional se inscriben en las estrategias de gobernanza clínica como proceso de mejora de la calidad que involucra principios fundamentales de la excelencia, como la orientación hacia los resultados, la mejora continua y la responsabilidad social y la focalización en la salud y el bienestar de las personas / empleados. OBJETIVO(S): Evaluar las principales fuentes de estrés y estrategias de coping utilizadas por los profesionales de la salud en el desarrollo de su actividad profesional METODOLOGÍA: Se trata de un estudio descriptivo y exploratorio con muestra por conveniencia a diferentes profesionales de la salud. Para la recogida de datos se utilizaron dos instrumentos: i) Cuestionario de estrés en los profesionales de la salud; y ii) Brief COPE. El cuestionario fue enviado por correo electrónico a través de la recogida entre los meses de mayo y junio de 2018.Los datos del fueron tratados y analizados con recurso al SPSS. Todos los procedimientos éticos se garantizaron durante el proceso. RESULTADOS: Las dimensiones de estrés más críticas referidas por los profesionales de salud fueron: carrera, remuneración, exceso de trabajo y lidiar con los clientes. Las estrategias de coping más mencionadas fueron: coping activo, planeamiento y reinterpretación positiva. El uso de sustancias fue la menos utilizada. CONCLUSIONES: Los resultados obtenidos permiten identificar una vulnerabilidad particular de los profesionales de la salud a factores de estrés profesional asociados a la carrera ya las condiciones de ejercicio profesional. También es posible determinar una respuesta relativamente consensuada frente al estrés en los profesionales de la salud: el impacto negativo en la salud mental, con las consecuencias adversas en lo que se refiere a todo el proceso de gobernanza clínica.

Predicting the targeting of tail-anchored proteins to subcellular compartments in mammalian cells.

Tail-anchored (TA) proteins contain a single transmembrane domain (TMD) at the C-terminus that anchors them to the membranes of organelles where they mediate critical cellular processes. Accordingly, mutations in genes encoding TA proteins have been identified in a number of severe inherited disorders. Despite the importance of correctly targeting a TA protein to its appropriate membrane, the mechanisms and signals involved are not fully understood. In this study, we identify additional peroxisomal TA proteins, discover more proteins that are present on multiple organelles, and reveal that a combination of TMD hydrophobicity and tail charge determines targeting to distinct organelle locations in mammals. Specifically, an increase in tail charge can override a hydrophobic TMD signal and re-direct a protein from the ER to peroxisomes or mitochondria and vice versa. We show that subtle changes in those parameters can shift TA proteins between organelles, explaining why peroxisomes and mitochondria have many of the same TA proteins. This enabled us to associate characteristic physicochemical parameters in TA proteins with particular organelle groups. Using this classification allowed successful prediction of the location of uncharacterized TA proteins for the first time.

Hepatitis C virus NS3-4A inhibits the peroxisomal MAVS-dependent antiviral signalling response.

Hepatitis C virus (HCV) is the cause of one of the most prevalent viral infections worldwide. Upon infection, the HCV genome activates the RIG-I-MAVS signalling pathway leading to the production of direct antiviral effectors which prevent important steps in viral propagation. MAVS localizes at peroxisomes and mitochondria and coordinate the activation of an effective antiviral response: peroxisomal MAVS is responsible for a rapid but short-termed antiviral response, while the mitochondrial MAVS is associated with the activation of a stable response with delayed kinetics. The HCV NS3-4A protease was shown to specifically cleave the mitochondrial MAVS, inhibiting the downstream response. In this study, we have analysed whether HCV NS3-4A is also able to cleave the peroxisomal MAVS and whether this would have any effect on the cellular antiviral response. We show that NS3-4A is indeed able to specifically cleave this protein and release it into the cytosol, a mechanism that seems to occur at a similar kinetic rate as the cleavage of the mitochondrial MAVS. Under these conditions, RIG-I-like receptor (RLR) signalling from peroxisomes is blocked and antiviral gene expression is inhibited. Our results also show that NS3-4A is able to localize at peroxisomes in the absence of MAVS. However, mutation studies have shown that this localization pattern is preferred in the presence of a fully cleavable MAVS. These findings present evidence of a viral evasion strategy that disrupts RLR signalling on peroxisomes and provide an excellent example of how a single viral evasion strategy can block innate immune signalling from different organelles.

New insights into the peroxisomal protein inventory: Acyl-CoA oxidases and -dehydrogenases are an ancient feature of peroxisomes.

Peroxisomes are ubiquitous organelles which participate in a variety of essential biochemical pathways. An intimate interrelationship between peroxisomes and mitochondria is emerging in mammals, where both organelles cooperate in fatty acid ß-oxidation and cellular lipid homeostasis. As mitochondrial fatty acid ß-oxidation is lacking in yeast and plants, suitable genetically accessible model systems to study this interrelationship are scarce. Here, we propose the filamentous fungus Ustilago maydis as a suitable model for those studies. We combined molecular cell biology, bioinformatics and phylogenetic analyses and provide the first comprehensive inventory of U. maydis peroxisomal proteins and pathways. Studies with a peroxisome-deficient Δpex3 mutant revealed the existence of parallel and complex, cooperative ß-oxidation pathways in peroxisomes and mitochondria, mimicking the situation in mammals. Furthermore, we provide evidence that acyl-CoA dehydrogenases (ACADs) are bona fide peroxisomal proteins in fungi and mammals and together with acyl-CoA oxidases (ACOX) belong to the basic enzymatic repertoire of peroxisomes. A genome comparison with baker's yeast and human gained new insights into the basic peroxisomal protein inventory shared by humans and fungi and revealed novel peroxisomal proteins and functions in U. maydis. The importance of our findings for the evolution and function of the complex interrelationship between peroxisomes and mitochondria in fatty acid ß-oxidation is discussed.