Navegando por Palavras-chave "Paracoccidioides Brasiliensis"
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- ItemAcesso aberto (Open Access)Análise proteômica comparativa de isolados de p. brasiliensis e sua relação com a virulência fúngica(Universidade Federal de São Paulo (UNIFESP), 2018-06-07) Amaral, Cristiane Candida do [UNIFESP]; Camargo, Zoilo Pires de [UNIFESP]; http://lattes.cnpq.br/0632912481397728; http://lattes.cnpq.br/9021981707387327Paracoccidioidomycosis (PCM) is a systemic mycosis commonly found in Latin America that is caused by two distinct species of Paracoccidioides genus, Paracoccidioides brasiliensis complex (S1, PS2, PS3 e PS4) and Paracoccidioides lutzii. Its pathobiology has been recently explored by different approaches to clarify the mechanisms of host-pathogen interactions underpinning PCM. The diversity of clinical forms of this disease has been attributed to both host- and fungus-related factors. For better understanding of the molecular underpinnings of host-fungus interactions, we evaluated in vivo virulence of nine Paracoccidoides brasiliensis isolates and correlated it to protein expression profiles obtained by two-dimensional gel electrophoresis. Based on the recovery of viable fungi from mouse organs, the isolates were classified as those having low, moderate, or high virulence. Highly virulent isolates overexpressed proteins related to adhesion process and stress response, probably indicating important roles of those fungal proteins in regulating the colonization capacity, survival, and ability to escape host immune system reaction. Moreover, highly virulent isolates exhibited enhanced expression of glycolytic pathway enzymes concomitantly with repressed expression of succinyl-CoA ligase beta chain, a protein related to the tricarboxylic acid cycle. Our findings may point to the mechanisms used by highly virulent P. brasiliensis isolates to withstand host immune reactions and to adapt to transient iron availability as strategies to survive and overcome stress conditions inside the host.
- ItemSomente MetadadadosCharacterization of paracoccidioides brasiliensis by ft-ir spectroscopy and nanotechnology(Univ Brasilia, 2016) Ferreira, Isabelle; Ferreira-Strixino, Juliana; Castilho, Maiara L.; Campos, Claudia Barbosa Ladeira de [UNIFESP]; Tellez, Claudio; Raniero, LeandroParacoccidioides brasiliensis, the etiological agent of paracoccidioidomycosis, is a dimorphic fungus existing as mycelia in the environment (or at 25 degrees C in vitro) and as yeast cells in the human host (or at 37 degrees C in vitro). Because mycological examination of lesions in patients frequently is unable to show the presence of the fungus and serological tests can misdiagnose the disease with other mycosis, the development of new approach's for molecular identification of P. brasiliensis spurges is needed. This study describes the use of a gold nanoprobe of a known gene sequence of P. brasiliensis as a molecular tool to identify P. brasiliensis by regular polymerase chain reaction (PCR) associated with a colorimetric methods. This approach is suitable for testing in remote areas because it does not require any further step than gene amplification, being safer and cheaper than electrophoresis methods. The proposed test showed a color change of the PCR reaction mixture from red to blue in negative samples, whereas the solution remains red in positive samples. We also performed a Fourier Transform Infrared (FT-IR) Spectroscopy analysis to characterize and compare the chemical composition between yeast and mycelia forms, which revealed biochemical differences between these two forms. The analysis of the spectra showed that differences were distributed in chemical bonds of proteins, lipids and carbohydrates. The most prominent difference between both forms was vibration modes related to 1,3-beta-glucan usually found in mycelia and 1,3-alpha-glucan found in yeasts and also chitin forms. In this work, we introduce FT-IR as a new method suitable to reveal overall differences that biochemically distinguish each form of P. brasiliensis that could be additionally used to discriminate biochemical differences among a single form under distinct environmental conditions. (C) 2015 Elsevier B.V. All rights reserved.
- ItemSomente MetadadadosEstudo do papel da Histidina quinase reguladora do dimorfismo (DRK1) do fungo patogênico Paracoccidioides brasiliensis(Universidade Federal de São Paulo (UNIFESP), 2021) Navarro, Marina Valente [UNIFESP]; Batista, Wagner Luiz [UNIFESP]; Universidade Federal de São PauloThermal dimorphic fungi of Paracoccidioides genus are the causative agents of paracoccidioidomycosis (PCM), a systemic endemic disease in Latin America with high incidence in Brazil. This pathogen presents as infective mycelium at 25°C in the soil, reverting to its pathogenic form when inhaled by mammalian host (37°C). This ability to switch from mycelium to yeast form is essential to disease development. Among dimorphic fungus species, dimorphism regulating histidine kinase (Drk1) plays an essential role to morphological transition. Histidine kinases (HK) are very important as virulence and cellular survival regulators. These kinases are present in bacteria and fungi, but absent in mammalian cells. This evidence suggests that HKs are interesting pharmacological targets to fungal diseases. Recently, our group characterized P. brasiliensis DRK1 (PbDRK1) expression during mycelium-yeast transition. It was observed that this gene is predominantly expressed in pathogenic yeast phase. In addition, we verified that when Dkr1 pharmacological inhibitor (iDrk1) was incubated with mycelium at 37°C, it alters the dimorphic switch. Hence, the purpose of this study was to investigate the role of PbDrk1 in cell wall modulation of P. brasiliensis. Previous data indicates a correlation between PbDrk1 and MAP kinase Hog1 over osmotic stress condition. In the present work it was observed decreased Hog1 phosphorylation levels after incubation with iDrk1 over osmotic stress but also related with cell wall integrity, confirming the participation of this HK in Hog1 signaling pathway. Additionally, we observed that PbDrk1 participates in fungal resistance to different cell wall disturbing agents, such as Congo Red, Calcofluor White and sodium chloride, by reducing yeasts viability after treatment with iDrk1. In order to verify the role of PbDRK1 in cell wall morphogenesis, we performed RTqPCR analysis. The results indicated that samples previously exposed to iDrk1 presented higher expression levels in several genes related to cell wall modulation. Among the genes analyzed, we highlighted FKS1, a β-glucan synthase which was 3,6-fold increase when compared to no treatment control. Confocal microscopy analysis and flow cytometry showed higher β-glucan exposure in cell surface of P. brasiliensis after 24 h incubation with iDrk1. Accordingly, through phagocytosis assay, it was observed a significant higher phagocytic index in yeasts treated with iDrk1 than control group, evidencing the role of PbDrk1 in cell wall modulation, which becomes a relevant target to be investigated. In parallel, the immune response profile was also assayed, with increased levels of pro-inflammatory cytokines. It is important to highlight that iDrk1 concentration used on this study did not reduce yeast viability. Finally, our data strongly suggests that PbDrk1 modulates cell wall components expression,among which we can point out b-glucan. The comprehension of this signaling pathway may be of great value to identify targets to antifungal molecular activity, since HK are not present in mammals.
- ItemSomente MetadadadosProteômica Aplicada Ao Estudo De Corpúsculos Lipídicos E Sua Relação Com A Atividade Da Fosfatase Calcineurina Do Fungo Paracoccidioides Brasiliensis(Universidade Federal de São Paulo (UNIFESP), 2018-11-05) Lima, Beatriz Pereira De Sousa [UNIFESP]; Campos, Claudia Barbosa Ladeira De [UNIFESP]; Universidade Federal de São Paulo (UNIFESP)Objective: To Investigate The Role Of Calcineurin In Lipid Metabolism, Especially Lipid Droplets In Yeasts Of Paracoccidioides Brasiliensis. Method: Triplicate Samples Of Total Yeast Proteins Grown At 0.2% And 2% Glucose In The Absence And Presence Of Cyclosporin A Were Analyzed By Lc-Ms / Ms Type Mass Spectrometry. The Intensities Of The Proteins Identified By The Mass Spectrometer Were Submitted To The Triplicate Homogeneity Test. Working With Three Biologically Comparable Groups (1) 0.2% Control Versus 0.2% Csa, (2) 0.2% Control Versus 2% Control And (3) 2% Control Versus 2% Csa, Differentially Expressed Proteins Were Determined For Each Sample Combination Considering Pvalor " 0.05 And Log2 (Fold Change)> 1 And <-1. The Exclusive And Differentially Expressed Proteins Of Each Of The Three Comparable Groups Were Analyzed For The Biological Pathways That Are Involved From The Use Of The Keeg Pathway Virtual Tool. Results: Yeasts Grown At 2% Of Glucose With Csa Present A Metabolic Profile That Indicates To Be