Role of FAK signaling in chagasic cardiac hypertrophy

Abstract Cardiac hypertrophy and dysfunction are a significant complication of chronic Chagas disease, with heart failure, stroke, and sudden death related to disease progression. Thus, understanding the signaling pathways involved in the chagasic cardiac hypertrophy may provide potential targets for pharmacological therapy. Herein, we investigated the implication of focal adhesion kinase (FAK) signaling pathway in triggering hypertrophic phenotype during acute and chronic T. cruzi infection. C57BL/6 mice infected with T. cruzi (Brazil strain) were evaluated for electrocardiographic (ECG) changes, plasma levels of endothelin-1 (ET-1) and activation of signaling pathways involved in cardiac hypertrophy, including FAK and ERK1/2, as well as expression of hypertrophy marker and components of the extracellular matrix in the different stages of T. cruzi infection (60-210 dpi). Heart dysfunction, evidenced by prolonged PR interval and decrease in heart rates in ECG tracing, was associated with high plasma ET-1 level, extracellular matrix remodeling and FAK signaling activation. Upregulation of both FAK tyrosine 397 (FAK-Y397) and serine 910 (FAK-S910) residues phosphorylation as well as ERK1/2 activation, lead to an enhancement of atrial natriuretic peptide gene expression in chronic infection. Our findings highlight FAK-ERK1/2 signaling as a regulator of cardiac hypertrophy in Trypanosoma cruzi infection. Both mechanical stress, induced by cardiac extracellular matrix (ECM) augment and cardiac overload, and ET-1 stimuli orchestrated FAK signaling activation with subsequent activation of the fetal cardiac gene program in the chronic phase of infection, highlighting FAK as an attractive target for Chagas disease therapy.

IgE antibodies from schistosomiasis patients to recognize epitopes in potato apyrase

Abstract INTRODUCTION: High percentages of structural identity and cross-immunoreactivity have been reported between potato apyrase and Schistosoma mansoni ATP diphosphohydrolase (SmATPDases) isoforms, showing the existence of particular epitopes shared between these proteins. METHODS: Potato apyrase was employed using ELISA, western blot, and mouse immunization methods to verify IgE reactivity. RESULTS: Most of the schistosomiasis patient's (75%) serum was seropositive for potato apyrase and this protein was recognized using western blotting, suggesting that parasite and plant proteins share IgE-binding epitopes. C57BL/6 mice immunized with potato apyrase showed increased IgE antibody production. CONCLUSIONS: Potato apyrase and SmATPDases have IgE-binding epitopes.

Proteômica: uma introdução aos métodos e aplicações / Introduction to methods and applications in proteomics

As proteínas desempenham a maior parte das funções fisiológicas das células, constituindo também importantes alvos farmacológicos e biomarcadores de doenças. A pesquisa qualitativa, quantitativa e a elucidação estrutural destas moléculas são fundamentais para a compreensão do funcionamento dos sistemas biológicos, bem como na aplicação destas para o desenvolvimento de novos métodos diagnóstico. O estudo do proteoma nos permite identificar as proteínas que estão sendo expressas em um determinado momento, quantificá-las e observar suas modificações pós-transducionais. Dessa maneira, a análise proteômica fornece informações mais abrangentes e que não podem ser inferidas a partir das informações obtidas através da análise genômica. Este tipo de estudo envolve etapas como: extração e tratamento da amostra, separação das proteínas e/ou peptídeos, espectrometria de massas e análise dos dados usando ferramentas de bioinformática. O presente trabalho faz uma revisão narrativa sobre as principais técnicas aplicadas desde o preparo de amostras até a identificação das proteínas.