Browsing by Author "Paula, Fabiana Martins de"

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    Immunoreactivity of proteins within 30-40 kDa range during the acute and the recovery phases in rats experimentally infected with Strongyloides venezuelensis.
    (2020) Fonseca, Priscilla Duarte Marques; Corral, Marcelo Andreetta; Meisel, Dirce Mary Correia Lima; Levi, Debora; Nascimento, Rafael Correa; Borges, William de Castro; Gryschek, Ronaldo Cesar Borges; Cruz, Julia Maria Costa; Paula, Fabiana Martins de
    In experimental infection with Strongyloides venezuelensis, the acute and recovery phases can be distinguished, unlike human infections caused by Strongyloides stercoralis. The objective of this study was to evaluate the production of anti-Strongyloides IgG antibodies and the recognition of immunogenic protein bands during the acute and the recovery phases in rats experimentally infected with S. venezuelensis. Rats were infected subcutaneously with 400 or 4,000 S. venezuelensis infective larvae. The acute phase was characterized by elimination of a large number of eggs in the faeces on days 6-14 post infection; the recovery phase was characterized by the resolution of the infection between days 30 and 35 post infection. Differences in IgG levels were observed in the acute and the recovery phases. Different antigenic fractions were recognized in both phases of infection. It is concluded that proteins within the 30-40 kDa range are immunoreactive markers for both the acute and the recovery phases in rats experimentally infected with S. venezuelensis, particularly using membrane antigen.
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    Investigation on the 19S ATPase proteasome subunits (Rpt1 6) conservation and their differential gene expression in Schistosoma mansoni.
    (2013) Pereira Junior, Olavo dos Santos; Pereira, Roberta Verciano; Silva, Camila Siqueira; Borges, William de Castro; Cota, Renata Guerra de Sá; Cabral, Fernanda Janku; Silva, Sérgio Henrique da; Soares, Cláudia Sossai; Morais, Enyara Rezende; Moreira, Érika Bueno de Carvalho; Magalhães, Lizandra Guidi; Paula, Fabiana Martins de; Rodrigues, Vanderlei
    The ubiquitin-proteasome system is responsible for degradation of the majority of intracellular proteins in eukaryotic cells. The 26S proteasome proteolytic complex is composed of a 20S core particle responsible for protein degradation and the 19S lid which plays a role in the recognition of polyubiquitinated substrates. The 19S regulatory particle (Rps) is composed of ATPase (Rpt) and non-ATPase (Rpn) subunits. In this study, we analyzed the expression profile of 19S Rpt subunits in the larvae and adult stage of the Schistosoma mansoni life cycle. Conventional reverse transcriptase polymerase chain reaction (RT-PCR) revealed that the majority of the 19S Rpt subunits amplified at the expected molecular masses for various investigated stages. In addition, SmRpt1, SmRpt2, and SmRpt6 transcript levels were increased in 3 h-cultured schistosomula and reasonably maintained until 5 h in culture, as revealed by qRT-PCR. Phylogenetic analysis of 19S Rpt subunits showed high structural conservation in comparison to other Rpt orthologues. The mRNA expression profile of 19S Rpt subunits did not correlate with 26S proteasome proteolytic activity as judged by a 14C-casein-degrading assay, in the early cultured schistosomula. Taken together, these results revealed a differential expression profile for 19S Rpt subunits whose transcript levels could not be directly associated to 26S proteasome activity.
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    Shotgun proteomics of Strongyloides venezuelensis infective third stage larvae : insights into host-parasite interaction and novel targets for diagnostics.
    (2020) Fonseca, Priscilla Duarte Marques; Corral, Marcelo Andreetta; Cosenza Contreras, Miguel de Jesus; Meisel, Dirce Mary Correia Lima; Melo, Gessica Baptista de; Antunes, Milena Monteiro de Souza; Santo, Maria C. E.; Gryschek, Ronaldo Cesar Borges; Cruz, Julia Maria Costa; Borges, William de Castro; Paula, Fabiana Martins de
    Strongyloides venezuelensis is an important alternative source of antigen for the serologic diagnosis of human strongyloidiasis. Proteomics techniques applied to the analysis of the protein content of infective third stage larvae (iL3) of S. venezuelensis provide a powerful tool for the discovery of new candidates for immunodiagnosis. This study presents an overview of the protein iL3 S. venezuelensis focusing on the diagnosis of strongyloidiasis. A total of 877 proteins were identified by shotgun proteomics. Many of these proteins are involved in different cellular processes, metabolic as well as structural maintenance. Our results point to a catalog of possible diagnostic targets for human strongyloidiasis and highlight the need for evaluation of uncharacterized proteins, especially the proteins within the CAP domain, transthyretin, and BTPI inhibitor domains, as a repertoire as yet unexplored in the context of strongyloidiasis diagnostic markers. We believe that the protein profile presented in this shotgun analysis extends our understanding of the protein composition within the Strongyloides genus, opening up new perspectives for research on biomarkers that may help with the diagnosis of human strongyloidiasis. Data are available via ProteomeXchange with identifier PXD013703.
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    The ubiquitin proteasome system in Strongyloididae. Biochemical evidence for developmentally regulated proteolysis in Strongyloides venezuelensis.
    (2009) Paula, Fabiana Martins de; Borges, William de Castro; Pereira Junior, Olavo dos Santos; Gomes, Matheus de Souza; Ueta, Marlene Tiduko; Rodrigues, Vanderlei
    Nematode parasites from the genus Strongyloides spp. are important pathogens of the intestinal mucosa of animals and humans. Their complex life cycles involve alternating developmental adaptations between larvae stages and the adult parthenogenetic female. Here, we report, primarily through homology-based searching, the existence of the major components of the ubiquitin– proteasome system in this genus, using the available EST data from S. ratti, S. stercoralis, and Parastrongyloides trichosuri. In this study, S. venezuelensis was used as our model organism for detection of proteasome activity and ubiquitinated substrates in cytosolic preparations from the L3 larvae and the adult female. Marked differences in proteasome capabilities were found when these two stages were compared. A preference for degradation of chymotryptic synthetic peptides was found in both stages with the adult exhibiting a higher rate of hydrolysis compared to the larvae. Due to the high evolutionary conservation of proteasome alpha subunits, an anti-human proteasome antibody was able to recognize proteasome subunits in these preparations by Western blotting, supporting the proposal that the activity of the ubiqutin–proteasome system is developmentally regulated in this nematode.