104 research outputs found

    Temporal development of muscle atrophy in murine model of arthritis is related to disease severity

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    Results The clinical parameters of arthritis progressively increased in CIA in all experimental times, demonstrating the greatest difference from other groups at 45 days after induction (clinical score: CO, 00±00; SA, 1.00±0.14; CIA, 3.28±0.41 p>0.05). The CIA animals had lower weights during all the experimentation periods with a difference of 6 % from CO at 45 days (p>0.05). CIA animals also demonstrated progressive decrease in distance walked, with a reduction of 54 % in 35 and 74 % at 45 days. Cytokine analysis identified significant increase in IL-6 serum levels in CIA than CO and SA in all experimental times. CSA of the myofiber of GA and TAwas decreased 26 and 31 % (p> 0.05) in CIA in 45 days after the induction of disease, respectively. There was significant and inverse correlation between the disease clinical score and myofiber CSA in 45 days (GA: r=−0.71; p=0.021). Conclusion Our results point to a progressive development of muscle wasting, with premature onset arthritis. These observations are relevant to understand the development of muscle loss, as well as for the design of future studies trying to understand the mechanisms involved in muscle wasting. As far as we are concerned, this is the first study to evaluate the relation between disease score and muscle atrophy in a model of arthritis

    Desenvolvimento de artrite induzida por colĂĄgeno em camundongos DBA/1J entre os gĂȘneros

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    Introdução: A artrite reumatoide (AR) Ă© uma doença autoimune inflamatĂłria sistĂȘmica de etiologia desconhecida. Modelos animais de artrite sĂŁo extremamente Ășteis para o estudo da fisiopatologia da doença e de novas terapias.Objetivo: Considerando a predominĂąncia da AR em mulheres e escassez de estudos sobre influĂȘncia do sexo no desenvolvimento da artrite experimental, o objetivo deste trabalho foi avaliar o impacto do sexo no desenvolvimento clĂ­nico da artrite experimental induzida por colĂĄgeno do tipo II (CIA).MĂ©todos: Camundongos DBA1J foram divididos em machos e fĂȘmeas, ambos n=6. CIA foi induzida por duas injeçÔes intradĂ©rmicas com colĂĄgeno no dia zero e 18. Escore clĂ­nico da artrite e do edema articular foram avaliados diariamente por 10 dias apĂłs o desenvolvimento da doença.Resultados: A evolução do escore clĂ­nico nĂŁo demonstrou diferença entre os machos e fĂȘmeas. O escore clĂ­nico avaliado separadamente - patas dianteiras e traseiras, apresentou diferença significativa (p <0,001) – patas traseiras dia 5 (machos 5,8±1,1; fĂȘmeas 3,1±1,8 - p <0,05). Entretanto, o edema articular foi significativamente maior nos machos (p <0,001) no dia 5 (machos 4,5±0,4; fĂȘmeas 3,8±0,5 - p <0,05).ConclusĂ”es: Apesar de nĂŁo serem claras as diferenças entre machos e fĂȘmeas na CIA em camundongos, a maioria dos pesquisadores da ĂĄrea optam por trabalhar com machos. Como em humanos, acredita-se na influĂȘncia da genĂ©tica e dos hormĂŽnios no desenvolvimento da CIA. Portanto, estudos como este sĂŁo de relevĂąncia Ă s pesquisas nesta ĂĄrea, para um melhor aproveitamento da criação dos animais de laboratĂłrio

    Collagen-induced arthritis as an animal model of rheumatoid cachexia

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    Background Rheumatoid arthritis is characterized by chronic polyarticular synovitis and presents systemic changes that impact quality of life, such as impaired muscle function, seen in up to 66% of the patients. This can progress to severely debilitating state known as rheumatoid cachexia—without loss of fat mass and body weight—for which there is little consensus in terms of diagnosis or treatment. This study aims to evaluate whether the collagen-induced arthritis (CIA) animal model also develops clinical and functional features characteristic of rheumatoid cachexia. Methods Male DBA1/J mice were randomly divided into 2 groups: healthy animals (CO, n = 11) and CIA animals (n = 13). The clinical score and edema size, animal weight and food intake, free exploratory locomotion, grip strength, and endurance exercise performance were tested 0, 18, 35, 45, 55, and 65 days after disease induction. After euthanasia, several organs, visceral and brown fat, and muscles were dissected and weighed. Muscles were used to assess myofiber diameter. Ankle joint was used to assess arthritis severity by histological score. Statistical analysis were performed using one-way and two-way analyses of variance followed by Tukey’s and Bonferroni’s test or t-test of Pearson and statistical difference were assumed for a P value under 0.05. Background Rheumatoid arthritis is characterized by chronic polyarticular synovitis and presents systemic changes that impact quality of life, such as impaired muscle function, seen in up to 66% of the patients. This can progress to severely debilitating state known as rheumatoid cachexia—without loss of fat mass and body weight—for which there is little consensus in terms of diagnosis or treatment. This study aims to evaluate whether the collagen-induced arthritis (CIA) animal model also develops clinical and functional features characteristic of rheumatoid cachexia. Methods Male DBA1/J mice were randomly divided into 2 groups: healthy animals (CO, n = 11) and CIA animals (n = 13). The clinical score and edema size, animal weight and food intake, free exploratory locomotion, grip strength, and endurance exercise performance were tested 0, 18, 35, 45, 55, and 65 days after disease induction. After euthanasia, several organs, visceral and brown fat, and muscles were dissected and weighed. Muscles were used to assess myofiber diameter. Ankle joint was used to assess arthritis severity by histological score. Statistical analysis were performed using one-way and two-way analyses of variance followed by Tukey’s and Bonferroni’s test or t-test of Pearson and statistical difference were assumed for a P value under 0.0

    Metabolomic biomarker candidates for skeletal muscle loss in the collagen-induced arthritis (CIA) model

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    There is no consensus for diagnosis or treatment of RA muscle loss. We aimed to investigate metabolites in arthritic mice urine as biomarkers of muscle loss. DBA1/J mice comprised collagen-induced arthritis (CIA) and control (CO) groups. Urine samples were collected at 0, 18, 35, 45, 55, and 65 days of disease and subjected to nuclear magnetic resonance spectroscopy. Metabolites were identified using Chenomx and Birmingham Metabolite libraries. The statistical model used principal component analysis, partial least-squares discriminant analysis, and partial least-squares regression analysis. Linear regression and Fisher’s exact test via the MetaboAnalyst website were performed (VIP-score). Nearly 100 identified metabolites had CIA vs. CO and disease time-dependent differences (p < 0.05). Twenty-eight metabolites were muscle-associated: carnosine (VIPs 2.8 × 102) and succinyl acetone (VIPs 1.0 × 10) showed high importance in CIA vs. CO models at day 65; CIA pair analysis showed histidine (VIPs 1.2 × 102) days 55 vs. 65, histamine (VIPs 1.1 × 102) days 55 vs. 65, and L-methionine (VIPs 1.1 × 102) days 0 vs. 18. Carnosine was fatigue- (0.039) related, creatine was food intake- (−0.177) and body weight- (−0.039) related, and both metabolites were clinical score- (0.093; 0.050) and paw edema- (0.125; 0.026) related. Therefore, muscle metabolic alterations were detected in arthritic mice urine, enabling further validation in RA patient’s urine, targeting prognosis, diagnosis, and monitoring of RA-mediated muscle loss

    Abordagem sobre bullying, drogas e violĂȘncia com adolescentes na escola / Approach on bullying, drugs and violence with adolescents in school

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    A prevalĂȘncia de violĂȘncia, bullying e uso de drogas entre os adolescentes vem aumentando em todo o mundo, sendo necessĂĄria intervençÔes para sensibilizĂĄ-los sobre os assuntos, tendo na escola um ambiente ideal. O objetivo principal foi relacionar a incidĂȘncia de bullying, uso de drogas e violĂȘncia e as relaçÔes entre elas nas turmas do oitavo e nono ano de uma escola estadual e promover açÔes de prevenção. Nesse contexto, o presente trabalho realizou questionĂĄrios sobre esses temas com alunos de 13 a 15 anos, e realizou palestras educativas, aplicando novamente os questionĂĄrios para avaliar a validade da intervenção. Coletamos dados relevantes, 37% dos entrevistados relataram ter usado alguma droga, e 16% jĂĄ foram agredidos, o que demonstram a estreita relação entre o uso de drogas e a violĂȘncia, pontuada como bullying, entre os escolares, alĂ©m de mensurar o consumo de substĂąncias entre eles e quais sĂŁo elas. AlĂ©m disso, foi promovida a saĂșde no ambiente escolar, com engajamento de alunos e professores.

    Protein Aggregation Is an Early Manifestation of Phospholamban p.(Arg14del)-Related Cardiomyopathy:Development of PLN-R14del-Related Cardiomyopathy

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    BACKGROUND: The p.(Arg14del) pathogenic variant (R14del) of the PLN (phospholamban) gene is a prevalent cause of cardiomyopathy with heart failure. The exact underlying pathophysiology is unknown, and a suitable therapy is unavailable. We aim to identify molecular perturbations underlying this cardiomyopathy in a clinically relevant PLN-R14del mouse model. METHODS: We investigated the progression of cardiomyopathy in PLN-R14Δ/Δ mice using echocardiography, ECG, and histological tissue analysis. RNA sequencing and mass spectrometry were performed on cardiac tissues at 3 (before the onset of disease), 5 (mild cardiomyopathy), and 8 (end stage) weeks of age. Data were compared with cardiac expression levels of mice that underwent myocardial ischemia-reperfusion or myocardial infarction surgery, in an effort to identify alterations that are specific to PLN-R14del-related cardiomyopathy. RESULTS: At 3 weeks of age, PLN-R14Δ/Δ mice had normal cardiac function, but from the age of 4 weeks, we observed increased myocardial fibrosis and impaired global longitudinal strain. From 5 weeks onward, ventricular dilatation, decreased contractility, and diminished ECG voltages were observed. PLN protein aggregation was present before onset of functional deficits. Transcriptomics and proteomics revealed differential regulation of processes involved in remodeling, inflammation, and metabolic dysfunction, in part, similar to ischemic heart disease. Altered protein homeostasis pathways were identified exclusively in PLN-R14Δ/Δ mice, even before disease onset, in concert with aggregate formation. CONCLUSIONS: We mapped the development of PLN-R14del-related cardiomyopathy and identified alterations in proteostasis and PLN protein aggregation among the first manifestations of this disease, which could possibly be a novel target for therapy
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