On the covalent nature of lysine polyphosphorylation.

Post-translational modifications of proteins (PTMs) introduce an extra layer of complexity to cellular regulation. Although phosphorylation of serine, threonine, and tyrosine residues is well-known as PTMs, lysine is, in fact, the most heavily modified amino acid, with over 30 types of PTMs on lysine having been characterized. One of the most recently discovered PTMs on lysine residues is polyphosphorylation, which sees linear chains of inorganic polyphosphates (polyP) attached to lysine residues. The labile nature of phosphoramidate bonds raises the question of whether this modification is covalent in nature. Here, we used buffers with very high ionic strength, which would disrupt any non-covalent interactions, and confirmed that lysine polyphosphorylation occurs covalently on proteins containing PASK domains (polyacidic, serine-, and lysine-rich), such as the budding yeast protein nuclear signal recognition 1 (Nsr1) and the mammalian protein nucleolin. This Matters Arising Response paper addresses the Neville et al. (2024) Matters Arising paper, published concurrently in Molecular Cell.

Evolutionary perspective on mammalian inorganic polyphosphate (polyP) biology.

Inorganic polyphosphate (polyP), the polymeric form of phosphate, is attracting ever-growing attention due to the many functions it appears to perform within mammalian cells. This essay does not aim to systematically review the copious mammalian polyP literature. Instead, we examined polyP synthesis and functions in various microorganisms and used an evolutionary perspective to theorise key issues of this field and propose solutions. By highlighting the presence of VTC4 in distinct species of very divergent eucaryote clades (Opisthokonta, Viridiplantae, Discoba, and the SAR), we propose that whilst polyP synthesising machinery was present in the ancestral eukaryote, most lineages subsequently lost it during evolution. The analysis of the bacteria-acquired amoeba PPK1 and its unique polyP physiology suggests that eukaryote cells must have developed mechanisms to limit cytosolic polyP accumulation. We reviewed the literature on polyP in the mitochondria from the perspective of its endosymbiotic origin from bacteria, highlighting how mitochondria could possess a polyP physiology reminiscent of their 'bacterial' beginning that is not yet investigated. Finally, we emphasised the similarities that the anionic polyP shares with the better-understood negatively charged polymers DNA and RNA, postulating that the nucleus offers an ideal environment where polyP physiology might thrive.

Psychological stress factors and salivary cortisol in nursing students throughout their training.

OBJECTIVE: to analyze psychological stress factors and salivary cortisol concentration in nursing undergraduates throughout their training. METHOD: a cross-sectional, analytical, and comparative study carried out in an evening course using a sociodemographic questionnaire, an Instrument to Assess Stress in Nursing Students, and salivary cortisol analysis. The study included descriptive and comparative analyses and a multiple linear regression model. RESULTS: 187 participants answered the questionnaires, and 129 had their cortisol quantified. The domains Practical Activities Execution, Professional Communication, and Professional Training represented the stress factors with the highest mean values for 3rd, 4th, and 5th-year students compared to 1st and 2nd year. For the 5th year, it was the domains Professional Communication and Professional Training compared to the 3rd year and Environment compared to the 1st and 3rd year. A significant result was obtained between the times of cortisol collections for males (p < 0.0001), females (p < 0.0001), and for 1st (p = 0.0319) 2nd (p = 0.0245), and 5th (p < 0.0001) years. CONCLUSION: Students in years 3 through 5 had higher exposure to stressors, and there were adjustments in cortisol production rhythmicity for students in years 1, 2, and 5.

The inositol pyrophosphate metabolism of Dictyostelium discoideum does not regulate inorganic polyphosphate (polyP) synthesis.

Initial studies on the inositol phosphates metabolism were enabled by the social amoeba Dictyostelium discoideum. The abundant amount of inositol hexakisphosphate (IP6 also known as Phytic acid) present in the amoeba allowed the discovery of the more polar inositol pyrophosphates, IP7 and IP8, possessing one or two high energy phosphoanhydride bonds, respectively. Considering the contemporary growing interest in inositol pyrophosphates, it is surprising that in recent years D. discoideum, has contributed little to our understanding of their metabolism and function. This work fulfils this lacuna, by analysing the ip6k, ppip5k and ip6k-ppip5K amoeba null strains using PAGE, 13C-NMR and CE-MS analysis. Our study reveals an inositol pyrophosphate metabolism more complex than previously thought. The amoeba Ip6k synthesizes the 4/6-IP7 in contrast to the 5-IP7 isomer synthesized by the mammalian homologue. The amoeba Ppip5k synthesizes the same 1/3-IP7 as the mammalian enzyme. In D. discoideum, the ip6k strain possesses residual amounts of IP7. The residual IP7 is also present in the ip6k-ppip5K strain, while the ppip5k single mutant shows a decrease in both IP7 and IP8 levels. This phenotype is in contrast to the increase in IP7 observable in the yeast vip1Δ strain. The presence of IP8 in ppip5k and the presence of IP7 in ip6k-ppip5K indicate the existence of an additional inositol pyrophosphate synthesizing enzyme. Additionally, we investigated the existence of a metabolic relationship between inositol pyrophosphate synthesis and inorganic polyphosphate (polyP) metabolism as observed in yeast. These studies reveal that contrary to the yeast, Ip6k and Ppip5k do not control polyP cellular level in amoeba.

Psychological stress factors and salivary cortisol in nursing students throughout their training / Factores de estrés psicológico y cortisol salivar en alumnos de enfermería a lo largo de la formación / Fatores de estresse psicológico e cortisol salivar em alunos de enfermagem ao longo da formação

ABSTRACT Objective: to analyze psychological stress factors and salivary cortisol concentration in nursing undergraduates throughout their training. Method: a cross-sectional, analytical, and comparative study carried out in an evening course using a sociodemographic questionnaire, an Instrument to Assess Stress in Nursing Students, and salivary cortisol analysis. The study included descriptive and comparative analyses and a multiple linear regression model. Results: 187 participants answered the questionnaires, and 129 had their cortisol quantified. The domains Practical Activities Execution, Professional Communication, and Professional Training represented the stress factors with the highest mean values for 3rd, 4th, and 5th-year students compared to 1st and 2nd year. For the 5th year, it was the domains Professional Communication and Professional Training compared to the 3rd year and Environment compared to the 1st and 3rd year. A significant result was obtained between the times of cortisol collections for males (p < 0.0001), females (p < 0.0001), and for 1st (p = 0.0319) 2nd (p = 0.0245), and 5th (p < 0.0001) years. Conclusion: Students in years 3 through 5 had higher exposure to stressors, and there were adjustments in cortisol production rhythmicity for students in years 1, 2, and 5.

RESUMEN Objetivo: analizar los factores de estrés psicológico y la concentración de cortisol salivar de estudiantes de enfermería a lo largo de su formación. Método: es un estudio transversal, analítico y comparativo realizado en un curso nocturno mediante cuestionario sociodemográfico, Instrumento para Evaluación del Estrés en Estudiantes de Enfermería y análisis del cortisol salivar. Se llevaron a cabo diversos análisis descriptivos, comparativos y modelo de regresión linear múltiple. Resultados: 187 respondieron a los cuestionarios y a 129 se les cuantificó el cortisol. Los dominios Realización de Actividades Prácticas, Comunicación Profesional y Formación Profesional representaron los factores de estrés con los valores medios más altos en los estudiantes de 3er, 4º y 5º año en comparación con los de 1er y 2º año. Para el 5º año fueron los dominios Comunicación Profesional y Formación Profesional en comparación con el 3er año y Medio Ambiente en comparación con el 1er y 3er año. Se obtuvo un resultado significativo entre los momentos de las recogidas de cortisol de los hombres (p < 0,0001), de las mujeres (p < 0,0001), y del 1er (p = 0,0319), 2º (p = 0,0245) y 5º (p < 0,0001) año. Conclusión: los alumnos de 3er a 5º año tuvieron una mayor exposición a los estresores y hubo ajustes en la ritmicidad de la producción de cortisol en los alumnos de 1er, 2º y 5º año.

RESUMO Objetivo: analisar os fatores de estresse psicológico e a concentração de cortisol salivar de graduandos de Enfermagem ao longo da formação. Método: estudo transversal, analítico e comparativo realizado em curso noturno por meio de questionário sociodemográfico, Instrumento para Avaliação de Estresse em Estudantes de Enfermagem e análise do cortisol salivar. Foram feitas análises descritivas, comparativas e modelo de regressão linear múltipla. Resultados: um total de 187 responderam aos questionários, e 129 tiveram o cortisol quantificado. Os domínios Realização das Atividades Práticas, Comunicação Profissional e Formação Profissional representaram os fatores de estresse com os maiores valores médios para alunos do 3º, 4º e 5º anos em comparação ao 1º e 2º anos. Para o 5º ano, foram os domínios Comunicação Profissional e Formação Profissional em relação ao 3º ano e Ambiente em comparação ao 1º e 3º anos. Obteve-se resultado significativo entre os horários das coletas de cortisol para homens (p < 0,0001), mulheres (p < 0,0001) e para o 1º (p = 0,0319) 2º (p = 0,0245) e 5º (p < 0,0001) anos. Conclusão alunos do 3º ao 5º ano tiveram maior exposição aos fatores de estresse, e houve ajustes na ritmicidade de produção do cortisol para alunos do 1º, 2º e 5º anos.

The impact of confinement in the psychosocial behaviour due COVID-19 among members of a Brazilian university.

BACKGROUND: The current situation due COVID-19 may cause an eminent impact on mental health because the confinement restrictions. AIMS: The aim of this study was to analyze and compare perceived stress, resilience, depression symptoms and coping strategies on the members of University of Campinas, in Brazil, before and during the outbreak of the COVID-19. METHODS: Volunteers over 18 years of both sexes, members of the University of Campinas (Unicamp) in Brazil answered instruments related to perceived stress, depression, resilience and coping strategies during final exams at the end of semester during 2018 to 2020. RESULTS: We obtained 1,135 responses (893 before COVID-19 and 242 during COVID-19). The volunteers did not show significant differences for perceived stress, depressive signs and resilience before and during the pandemic. In both periods, men exhibited lower scores for perceived stress and depression and higher scores for resilience when compared to women. Undergraduate and graduate students exhibited higher perceived stress scores, more pronounced depressive signs and lower resilience, and employees and professors presented lower scores for perceived stress, depressive signs and greater resilience. CONCLUSIONS: These first months of confinement did not directly affect the scores of perceived stress, depression and resilience, however, each subgroup adapted to the new routine by changing the coping strategy used. This study suggests the importance of monitoring the mental health of member in the university, especially in times of epidemic, in the search for policies that aim to improve the resilience of the population and seek positive and effective coping strategies within the university environment.

The influence of angiotensin II and RAAS blockers on lipolytic and glycolytic activity in isolated adipocytes from Wistar, Wistar-Kyoto and Spontaneously Hypertensive Rats.

The renin-angiotensin-aldosterone system (RAAS) is related to dysfunctional adipose tissue, but the actions of angiotensin II (AII) in adipocytes remains unclear. This study aimed to investigate the effects of RAAS blockers and AII in lipolysis and glycolysis from isolated adipocytes in Wistar (WIS), Wistar-Kyoto (WKY) and Spontaneously Hypertensive Rats (SHR). Adipocytes from 15-weeks-old WIS, WKY and SHR were incubated with AII (10-17 M to 10-6 M) and noradrenaline (NOR - 10-10 M to 10-4 M) in presence or not of antagonists (Losartan Potassium 10-4 M, PD 123319 5.6 nM or co-incubation). Glycerol and lactate production in WIS and WKY were not affected by the RAAS blockade. SHR glycerol was attenuated by the blockers but lactate was not affected. NOR induced increase in glycerol from 10-7 M for all strains. Normotensive rats are not affected by blockers but decreased lipolytic activity ins SHR. The SHR hypolipodistrophy cannot be related to any disturbance in lipolytic or glycolytic upstream pathways.

Electrocardiographic Abnormalities in Hypertension Models

Abstract Background: Hypertensive condition can lead to abnormalities in heart structure and electrical activity. The electrocardiogram (ECG) is a recording of the electrical activity of the heart and widely used to diagnose and detect heart problem. Objective: We conducted a comparative ECG analysis between two hypertension models (L-NAME and SHR) and their controls (Wistar and Wistar-Kyoto) at six and 15 th week of age. Methods: Blood pressure was measured at the end of the 15 th week, and electrocardiography was performed at six and 15 weeks of age in anaesthetized rats. Data normality was confirmed by Kolmogorov-Smirnov test followed by unpaired Student's t-test and the Mann-Whitney for parametric and non-parametric data, respectively. Results are expressed as mean ± SD. The accepted level of significance was set at p < 0.05. Results: L-NAME exhibited prolongation of JT and QT intervals and SHR showed a decrease in heart rate when compared to Wistar-Kyoto and L-NAME. Wistar-Kyoto exhibited short PR interval with increased QRS complex, and only QT prolongation at 15 weeks compared to Wistar. Conclusions: All the hypertension models used in this study featured an increase in blood pressure. However, while SHR showed cardiac dysfunction, L-NAME exhibited changes in ventricular performance. These results may guide future studies on different types and models of hypertension.

The influence of hypertensive environment on adipose tissue remodeling measured by fluorescence lifetime imaging in spontaneously hypertensive rats.

There is a lack of information correlating low adiposity with hypertension experienced by Spontaneous Hypertensive Rats (SHR) or overweight and normotension in Wistar-Kyoto (WKY). We aimed to investigate this lipodystrophy phenomenon by measuring fluorescence lifetime (FLIM), optical redox ratio (ORR), serum levels of hypothalamic-pituitary-adrenal (HPA) and/or hypothalamic-pituitary-thyroid (HPT) hormones axes between Wistar, WKY and SHR before and after establishment of hypertension. Under high blood pressure, we evaluated serum adipokines. Brown adipose tissue was characterized as lower ORR and shorter FLIM compared to white adipose tissue. HPT axis showed a crucial role in the SHR adipose tissue configuration by attenuating whitening. The increased adiposity in WKY may act as a preventive agent for hypertension, since SHR, with low adiposity, establishes the disease. The hypertensive environment can highlight key adipokines that may result in new therapeutic approaches to the treatment of adiposity dysfunctions and hypertension.

A new perspective of lactatogenesis by isolated adipocytes.

Increased adipose tissue mass exhibited greater capacity of glucose transformation in lactate, highlighting lactatogenesis as a crucial factor in body size. Classically, lactate produced by isolated adipocytes are expressed per million of cells and were never correlated with their size. Spontaneously hypertensive rats (SHR) have a lower body weight and smaller adipocytes when compared to Wistar-Kyoto. We evaluated basal lactate by epididymal 15-weeks-old isolated adipocytes of SHR, Wistar-Kyoto and Wistar. Basal lactate was similar when expressed by one million cells. However, SHR adipocytes were smaller, so we adjusted the results by cell volume and SHR showed higher basal lactate production which was directly endorsed by hyperlactatemia in the presented conditions. Thereby, we suggest a new perspective on lactatogenesis analysis by adipocytes, which could be linked to the receptors density and associate enzymes. Moreover, we showed that the thin and hypertensive rats can be hyperlactemic in fasting conditions.

Efeito agudo da drenagem linfática manual sobre a natriurese e lipólise de mulheres jovens / Acute effect of manual lymphatic drainage on natriuresis and lipolysis in young women

Fundamentos: A importância da validação científica de técnicas coadjuvantes a diversos tratamentos de saúde é inquestionável. Desta forma, a influência da drenagem linfática manual (DLM) na natriurese e na lipólise sob interação de anticoncepcional oral precisa ser investigada. Objetivos: Avaliar o efeito agudo da DLM sobre a natriurese e lipólise de mulheres jovens usuárias ou não de anticoncepcional oral. Método: Participaram 29 mulheres não usuárias de anticoncepcional oral e 29 usuárias, autodeclaradas saudáveis, sedentárias e eutróficas. As análises foram realizadas em dois dias distintos, Controle (C), sem intervenção terapêutica e DLM. Nos dias C e DLM coletamos 4 amostras de urina com intervalos de 60 min. Seguimos o método de Leduc, abdomem e membros inferiores, durante 45 min. Analisamos o fluxo urinário e excreção urinária e sódio, glicerol e peptideo natriurético atrial. A normalidade dos dados foi analisada pelo teste Shapiro-Wilk. Os dados que não obedeceram à normalidade foram apresentados em mediana e intervalo interquartil (25%-75%), enquanto os que obedeceram foram apresentados em média ± erro padrão. O teste de Mann-Whitney foi usado para dados não pareados e Wilcoxon para dados pareados. Dados com normalidade foram avaliados pelo teste t-Student não pareado. O nível de significância estatística adotado foi de 5%. Resultados: O efeito agudo de uma sessão de DLM promove aumento da natriurese em mulheres não usuárias de anticoncepcional oral, por outro lado, em usuárias induz aumento na liberação de glicerol e de ANP

Background: The importance of scientific validation of supporting techniques to various treatments is unquestionable. In this context, the influence of manual lymphatic drainage (MLD) on natriuresis and lipolysis and its interaction with oral contraceptives still need to be investigated. Objectives: To evaluate the acute effect of MLD on natriuresis and lipolysis in young women using or not oral contraceptives. Methods: Twenty-nine non-users of oral contraceptives and 29 oral contraceptive users, self-reported healthy, sedentary, normal weight women were enrolled. Analyses were conducted on two different days ­ control (C), without therapeutic intervention and MLD day. Four urine samples were collected at 60-minute intervals. MLD was performed in lower limbs and abdomen for 45 min following the Leduc method. Urinary flow rat e and urinary sodium, glycerol and atrial natriuretic peptide excretion were analyzed. Data normality was tested by the Shapiro-Wilk test. Data without normal distribution were expressed as median and interquartile range (25%-75%), while normally distributed data were expressed as mean ± standard error. Mann-Whitney test was used for unpaired data and Wilcoxon test for paired data. Data with normal distribution were evaluated by the unpaired t-Student test. Statistical significance was set at 5%. Results: One MLD session had an acute effect on both groups, increasing natriuresis in non-users of oral contraceptives and glycerol and atrial natriuretic peptide excretion in oral contraceptive users. Conclusion: Oral contraceptives influence the effect of MLD on natriuresis

Massage therapy in cortisol circadian rhythm, pain intensity, perceived stress index and quality of life of fibromyalgia syndrome patients.

We investigate the effects of a massage therapy program (MTP) in cortisol concentration (CC), intensity of pain, quality of life and perceived stress index of fibromyalgia patients. Volunteers (n = 24, aged 26-55 years) were treated with MT, twice a week for three months. They answered the Fibromyalgia Impact Questionnaire (FIQ), Perceived Stress Questionnaire (PSQ) and McGill Pain Questionnaire (MPQ-Br), and collected saliva to evaluate CC before and after the end of each month. The MT had improvement in quality of life, according to the FIQ results, and promoted reduction in PSQ values after the second (PSQ2-0.62 ± 0.04vsPSQ0-0.71 ± 0.04) and third month (PSQ3-0.64 ± 0.04vsPSQ0-0.71 ± 0.04). The MTP also promoted reduction in pain after the third month (MQP-Br1-44.50 ± 2.15vsMQP-Br4-35.38 ± 3.71). Despite PSQ reduction, the CC were not affected by the program. This pilot suggests that this treatment improved quality of life, reduced perceived stress index and pain in these volunteers.

History of vascular reactivity models and their involvement in hypertension pathogenesis.

Hypertension is a silent and multifactorial disease. Over two centuries ago, the first device to record blood pressure was developed, making it possible to determine normotension and to establish criteria for hypertension. Since then, several studies have contributed to advance knowledge in this area, promoting significant advances in pharmacological treatments and, as a result, increasing survival of hypertensive people. The main models developed for the study of hypertension and the main findings in the vascular area are included in this review. We considered aspects related to vascular reactivity, changes in the population, and action of beta adrenergic receptors in the pathogenesis of hypertension.

Alterações Cardiometabólicas em Ratos Wistar Alimentados com Dieta Hiperlipídica e Hipercolesterolêmica por Seis Semanas / Cardiometabolic Alterations in Wistar Rats on a Six-Week Hyperlipidic, Hypercholesterolemic Diet

Fundamento: Alta ingestão de lipídeos e colesterol compõe a dieta da sociedade moderna e está envolvida com o desenvolvimento de doenças cardiometabólicas. Entretanto, há lacunas na literatura quanto à existência de modelos de dislipidemias em ratos Wistar. Objetivos: Analisar o perfil cardiometabólico de ratos Wistar alimentados com dieta hiperlipídica e hipercolesterolêmica por seis semanas. Métodos: Ratos Wistar jovens foram alimentados com dieta hiperlipídica e hipercolesterolêmica por seis semanas para induzir a hiperlipidemia. Os ratos foram submetidos à cateterização da artéria carótida para determinar a pressão arterial. Após jejum, amostras de sangue foram coletadas por meio do cateter, e as concentrações de colesterol total, colesterol HDL, triglicerídeos e glicose foram determinadas. Amostras do tecido cardíaco foram removidas para análise histológica, a fim de se verificar a hipertrofia ventricular. Resultados: A ingestão da dieta por seis semanas foi eficaz em induzir alterações cardiometabólicas. O perfil dislipidêmico apresentado pelos ratos Wistar foi acompanhado de hiperinsulinemia, hipertensão moderada e hipertrofia ventricular do coração. Não houve alterações na glicemia. Conclusões: A administração de dieta hiperlipídica e hipercolesterolêmica em ratos Wistar jovens por seis semanas induziram alterações cardiometabólicas tornando-se um modelo eficaz para distúrbios dessa natureza

Background: The diet of modern society is composed by large intakes of lipids and cholesterol, involved in the development of cardiometabolic diseases. However, there are gaps in the literature regarding the existence of dyslipidemia models in Wistar rats. Objectives: To analyze the cardiometabolic profile of Wistar rats on a six-week hyperlipidic, hypercholesterolemic diet. Methods: Young Wistar rats were kept on a hyperlipidic, hypercholesterolemic diet for six weeks to induce hyperlipidemia. The rats underwent catheterization of the carotid artery to determine blood pressure. After fasting, blood samples were drawn through the catheter, and concentrations of total cholesterol, HDL cholesterol, triglycerides and glucose were determined. Cardiac tissue samples were taken for a histological analysis to check for ventricular hypertrophy. Results: The six-week diet was effective in inducing cardiometabolic alterations. The dyslipidemic profile presented by the Wistar rats was accompanied by hyperinsulinemia, moderate hypertension and cardiac ventricular hypertrophy. There were no alterations in glycemia. Conclusion: The six-week hyperlipidic, hypercholesterolemic diet in young Wistar rats induced cardiometabolic alterations, becoming an effective model for disorders of this nature