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12
result(s) for
"Araujo, Galber"
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A Short Peptide That Mimics the Binding Domain of TGF-β1 Presents Potent Anti-Inflammatory Activity
by
Lima, Carla
,
Silva, Rangel L.
,
Araujo, Galber R.
in
Animals
,
Anti-inflammatory agents
,
Anti-Inflammatory Agents, Non-Steroidal - chemistry
2015
The transforming growth factor beta 1 (TGF-β1) is a pleiotropic cytokine with multiple roles in development, wound healing, and immune regulation. TGF-β1-mediated immune dysfunction may lead to pathological conditions, such as inflammation. Chronic inflammatory process is characterized by a continuous release of pro-inflammatory cytokines, and the inhibition or the blockage of these cytokines signaling pathways are considered a target treatment. In this context, despite the high numbers of TGF-β-targeted pathways, the inducible regulatory T cells (iTreg) to control inflammation seems to be a promising approach. Our aim was to develop novel peptides through phage display (PhD) technology that could mimic TGF-β1 function with higher potency. Specific mimetic peptides were obtained through a PhD subtraction strategy from whole cell binding using TGF-β1 recombinant as a competitor during elution step. We have selected a peptide that seems to play an important role on cellular differentiation and modulation of TNF-α and IL-10 cytokines. The synthetic pm26TGF-β1 peptide tested in PBMC significantly down-modulated TNF-α and up-regulated IL-10 responses, leading to regulatory T cells (Treg) phenotype differentiation. Furthermore, the synthetic peptide was able to decrease leukocytes rolling in BALB/C mice and neutrophils migration during inflammatory process in C57BL/6 mice. These data suggest that this peptide may be useful for the treatment of inflammatory diseases, especially because it displays potent anti-inflammatory properties and do not exhibit neutrophils' chemoattraction.
Journal Article
Leishmania infantum β-Tubulin Identified by Reverse Engineering Technology through Phage Display Applied as Theranostic Marker for Human Visceral Leishmaniasis
2019
Two Leishmania infantum mimotopes (B10 and C01) identified by phage display showed to be antigenic and immunogenic for visceral (VL) and tegumentary (TL) leishmaniasis; however, their biological targets in the parasites have not been identified. The aim of the present study was to investigate the native antigens expressing both mimotopes, and to use them in distinct immunological assays. For this, a subtractive phage display technology was used, where a combinatorial library of single-chain variable fragments (scFv) was employed and the most reactive monoclonal antibodies for each target were captured, being the target antigens identified by mass spectrometry. Results in immunoblotting and immunoprecipitation assays showed that both monoclonal scFvs antibodies identified the β-tubulin protein as the target antigen in L. infantum. To validate these findings, the recombinant protein was cloned, purified and tested for the serodiagnosis of human leishmaniasis, and its immunogenicity was evaluated in PBMC derived from healthy subjects and treated or untreated VL patients. Results showed high diagnostic efficacy, as well as the development of a specific Th1 immune response in the cell cultures, since higher IFN-γ and lower IL-10 production was found.
Journal Article
A Short Peptide That Mimics the Binding Domain of TGF-beta1 Presents Potent Anti-Inflammatory Activity
by
Lima, Carla
,
Goulart, Luiz R
,
Taketomi, Ernesto A
in
Anti-inflammatory agents
,
Chemical properties
,
Drug therapy
2015
The transforming growth factor beta 1 (TGF-[beta]1) is a pleiotropic cytokine with multiple roles in development, wound healing, and immune regulation. TGF-[beta]1-mediated immune dysfunction may lead to pathological conditions, such as inflammation. Chronic inflammatory process is characterized by a continuous release of pro-inflammatory cytokines, and the inhibition or the blockage of these cytokines signaling pathways are considered a target treatment. In this context, despite the high numbers of TGF-[beta]-targeted pathways, the inducible regulatory T cells (iTreg) to control inflammation seems to be a promising approach. Our aim was to develop novel peptides through phage display (PhD) technology that could mimic TGF-[beta]1 function with higher potency. Specific mimetic peptides were obtained through a PhD subtraction strategy from whole cell binding using TGF-[beta]1 recombinant as a competitor during elution step. We have selected a peptide that seems to play an important role on cellular differentiation and modulation of TNF-[alpha] and IL-10 cytokines. The synthetic pm26TGF-[beta]1 peptide tested in PBMC significantly down-modulated TNF-[alpha] and up-regulated IL-10 responses, leading to regulatory T cells (Treg) phenotype differentiation. Furthermore, the synthetic peptide was able to decrease leukocytes rolling in BALB/C mice and neutrophils migration during inflammatory process in C57BL/6 mice. These data suggest that this peptide may be useful for the treatment of inflammatory diseases, especially because it displays potent anti-inflammatory properties and do not exhibit neutrophils' chemoattraction.
Journal Article
Identification and Physicochemical Characterization of a New Allergen from Ascaris lumbricoides
2020
To analyze the impact of Ascaris lumbricoides infection on the pathogenesis and diagnosis of allergic diseases, new allergens should be identified. We report the identification of a new Ascaris lumbricoides allergen, Asc l 5. The aim of this study was to evaluate the physicochemical and immunological features of the Asc l 5 allergen. We constructed an A. lumbricoides cDNA library and Asc l 5 was identified by immunoscreening. After purification, rAsc l 5 was physicochemically characterized. Evaluation of its allergenic activity included determination of Immunoglobulin E (IgE) binding frequency (in two populations: 254 children and 298 all-age subjects), CD203c based-basophil activation tests (BAT) and a passive cutaneous anaphylaxis (PCA) mouse model. We found by amino acid sequence analysis that Asc l 5 belongs to the SXP/RAL-2 protein family of nematodes. rAsc l 5 is a monomeric protein with an alpha-helical folding. IgE sensitization to rAsc l 5 was around 52% in general population; positive BAT rate was 60%. rAsc l 5 induced specific IgE production in mice and a positive PCA reaction. These results show that Asc l 5 has structural and immunological characteristics to be considered as a new allergen from A. lumbricoides.
Journal Article
Association of vitamin D receptor variants with clinical parameters in prostate cancer
by
Araújo, Thaise Gonçalves
,
Nunes, Sarah Braga Rodrigues
,
de Matos Oliveira, Fabrícia
in
Humanities and Social Sciences
,
Immune response
,
Medicine
2016
Purpose
Prostate Cancer (PCa) is one of the most common cancers in men and its early detection can provide a high chance of cure. The detection of Vitamin D Receptor (
VDR
) gene polymorphisms may be useful as a molecular indicator of clinical outcome, once VDR is implicated in a wide variety of biological processes including modulation of the immune response and inhibition of cancer cell growth, angiogenesis and metastasis. In this study we explored the Single Nucleotide Polymorphisms (SNPs)
Fok
I,
Bsm
I,
Apa
I and
Taq
I, to evaluate the susceptibility locus for PCa and verify its correlation with clinical parameters.
Methods
VDR
polymorphisms were detected by PCR followed by Restriction Fragment Length Polymorphism (PCR–RFLP). DNA samples were extracted from peripheral blood of 342 patients: 132 PCa, 41 Benign Prostatic Hyperplasia and 169 young healthy volunteers.
Results
Statistical analysis showed a noteworthy correlation among SNPs and clinical pathological features. CC genotype (
Taq
I) was correlated with the age at diagnosis (>58 years old), and GG (
Bsm
I) was associated to lower Prostate-Specific Antigen (PSA) levels (<10 ng/mL). Moreover, when PCa patients were subgrouped, G allele (
Bsm
I) significantly increased the estimated chance for PSA < 10 ng/mL, and GG/GG genotype (
Bsm
I/
Apa
I) provided a 9.75 fold increased chance of patients with PCa to present lower PSA levels.
Conclusions
The polymorphisms of
VDR
gene showed a genotype-phenotype association and presented new correlations with different parameters as age and PSA levels.
Journal Article
Improved serological detection of rheumatoid arthritis: a highly antigenic mimotope of carbonic anhydrase III selected in a murine model by phage display
by
Fonseca, João Eurico
,
Goulart, Luiz Ricardo
,
Cardozo, Karina Helena Morais
in
Adult
,
Aged
,
Amino Acid Sequence
2015
Introduction
Rheumatoid arthritis (RA) is a chronic inflammatory autoimmune disease that affects around 1 % of the human population worldwide. RA diagnosis can be difficult as there is no definitive test for its detection. Therefore, the aim of this study was to identify biomarkers that could be used for RA diagnosis.
Methods
Sera from a collagen-induced arthritis mouse model were used to select potential biomarkers for RA diagnosis by phage display technology. In silico and in vitro analyses were performed to characterize and validate the selected peptides. Samples were classified into three groups: RA; two other immune-mediated rheumatic diseases (systemic lupus erythematosus (SLE) and ankylosing spondylitis (AS)); and healthy controls (HC). Enzyme-linked immunosorbent assay (ELISA) was carried out to determine antibody levels, and diagnostic parameters were determined by constructing receiver operating characteristic curves. Mass spectrometry and Western blot were performed to identify the putative autoantigen that was mimicked by a highly reactive mimotope.
Results
After three rounds of selection, 14 clones were obtained and tested for immunoreactivity analysis against sera from RA and HC groups. The phage-fused peptide with the highest immunoreactivity (M12) was synthesized, and was able to efficiently discriminate RA patients from SLE, AS and HCs (
p
< 0.0001) by ELISA. The specificity and sensitivity of anti-M12 antibodies for RA diagnosis were 91 % and 84.3 %, respectively. The M12 peptide was identified as one that mimics a predicted antigenic site of the carbonic anhydrase III (CAIII) protein, a ubiquitous biomarker that has been identified in patients with other diseases.
Conclusion
M12 is the first peptide associated with the CAIII protein that may be used as an antigen for antibody detection to aid in RA diagnosis with high sensitivity and specificity.
Journal Article
Nutritional, Physicochemical and Structural Parameters of Mauritia flexuosa Fruits and By-Products for Biotechnological Exploration of Sustainable Goods
by
Ferreira, Paulo Michel Pinheiro
,
Frota, Karoline de Macêdo Gonçalves
,
Moura, Arkellau Kenned Silva
in
Acidity
,
Bioactive compounds
,
Biotechnology
2022
Research background. Commercialization of Mauritia flexuosa (buriti) fruits in Brazil is at an early stage. Herein, we evaluate the nutritional value of pulp, peel and endocarp samples from buriti fruits, perform macroscopic and microscopic evaluations and analyze their physicochemical properties. Experimental approach. Size and mass, pH, sugar and protein contents, soluble/insoluble fiber, total titratable acidity and energy value of the samples were analyzed. Mineral profiling was performed by energy dispersive X-ray fluorescence spectrometry, and fatty acids and phytosterols were determined by gas chromatography-mass spectrometry. Samples were also submitted to differential scanning calorimetry coupled to a thermal analyzer, and microstructure, morphology, surface and viscosity were evaluated by scanning electron microscopy (SEM) and X-ray diffraction (XRD) with copper radiation. Rheological behavior was also studied. Results and conclusions. Lyophilized pulp had higher nutritional content of minerals, proteins, carbohydrates and energy than in natura pulp. Lyophilized pulp and its by-products showed suitable yields (>17.31 %) and low aw, and potassium, manganese and monounsaturated fatty acid contents. Peels showed elevated amounts of saturated and polyunsaturated fatty acids and phytosterols (β-sitosterol and stigmasterol), and endothermic behavior. The reductions of calcium, magnesium and manganese ranging from 18.5 to 22.7 % were observed following the lyophilization. Drying processes generated semi-crystalline powders. Both peels and endocarp contained higher amounts of insoluble fiber and lower contents of sugars. Similar results were obtained by microscopic morphological analysis, differential scanning calorimetry and XRD analysis. Pulp and endocarp exhibited pseudoplastic non-Newtonian behavior, and flow behavior index values were lower than 1, while peels presented dilatant behavior. Thus, physicochemical and nutritional characterization of pulp and by-products, such as peels and endocarp, are essential to support scientific research and exploration of new sustainable products. Novelty and scientific contribution. Processing and conservation techniques, like lyophilization, maintain the good quality of nutritional contents and bioactive compounds of buriti whole fruits, and can be used to extend their shelf life, preserve alimentary characteristics and provide wider purposes and availability. Such parameters may generate income and food security for local and regional communities.
Journal Article
Influence of Reduction with NaBH4 and HCl in Obtaining Amino Derivatives of Cashew Gum and Cytotoxic Profile
by
Santos Machado, Fabrício dos
,
Marinho Filho, José Delano Barreto
,
Silva, Durcilene A.
in
Antimicrobial agents
,
Chemical reactions
,
Ethanol
2023
Tree-exuded gums are natural polymers that represent an abundant raw material in the food and pharmaceutical industries. The cashew gum can be obtained by exudation of trees of the genus Anacardium, a native species of the Brazilian northeast; its polymer consists of monosaccharide units propitious to the action of chemical reactions that tend to improve their intrinsic characteristics among them, as the degree of hydro-solubility. The objective of this work was to modify the exudate gum of Anacardium occidentale (cashew gum (CG)) through an amine reaction. The modification was confirmed by Nuclear Magnetic Resonance (1H NMR), infrared spectroscopy (FTIR), gel permeation chromatography (GPC), zeta potential, and thermogravimetric analysis (TG). In addition, the chemical modification altered the molar mass and surface charge of the CG, and the amino group binding to the CG polymers was confirmed by FTIR spectra. In addition, cytotoxicity tests were performed where cell viability was estimated by an MTT assay on RAW 264.7 macrophages. Through these tests, it was found that the amine caused an increase in the thermal stability of the amino compounds and did not present cytotoxic potential at concentrations below 50.0 mg/L.
Journal Article
Ação cicatrizante da nanopartícula de prata com norbixina em queimaduras
by
Rodrigues, Augusto César Evelin
,
Maia Filho, Antônio Luiz Martins
,
Silva, Juscelino Lopes da
in
Nanoparticles
2017
Introduo: A queimadura uma injria que altera a integridade da pele, decorrente de traumas trmicos. Dentre os compostos no convencionais utilizados na cicatrizao de feridas esto a norbixina e as preparaes com prata. Objetivo: avaliar a ao cicatrizante da nanopartcula de prata associada norbixina em queimaduras de Mus musculus. Mtodos: Inicialmente, preparou-se uma soluo nanoprata/norbixina e a partir desta soluo obteve-se o gel teste. Posteriormente dividiu-se os animais em 3 grupos, sendo negativo (sem tratamento), positivo (sulfadiazina de prata) e teste (gel teste). Nestes animais houve a induo das queimaduras. No 7 e 14 dia realizou-se a eutansia e os tecidos lesionados foram coletados para anlise microscpica. Resultado: Verificou-se potencial vantagem do grupo teste em relao ao negativo e igualdade comparada ao positivo. Concluso: A nanopartcula de prata associada norbixina representa uma fonte alternativa para a cicatrizao de queimaduras.
Journal Article
Influence of Reduction with NaBHsub.4 and HCl in Obtaining Amino Derivatives of Cashew Gum and Cytotoxic Profile
by
Silva, Durcilene A
,
Santos Machado, Fabrício dos
,
Marinho Filho, José Delano Barreto
in
Amines
,
Biopolymers
,
Infrared spectroscopy
2023
Tree-exuded gums are natural polymers that represent an abundant raw material in the food and pharmaceutical industries. The cashew gum can be obtained by exudation of trees of the genus Anacardium, a native species of the Brazilian northeast; its polymer consists of monosaccharide units propitious to the action of chemical reactions that tend to improve their intrinsic characteristics among them, as the degree of hydro-solubility. The objective of this work was to modify the exudate gum of Anacardium occidentale (cashew gum (CG)) through an amine reaction. The modification was confirmed by Nuclear Magnetic Resonance ([sup.1]H NMR), infrared spectroscopy (FTIR), gel permeation chromatography (GPC), zeta potential, and thermogravimetric analysis (TG). In addition, the chemical modification altered the molar mass and surface charge of the CG, and the amino group binding to the CG polymers was confirmed by FTIR spectra. In addition, cytotoxicity tests were performed where cell viability was estimated by an MTT assay on RAW 264.7 macrophages. Through these tests, it was found that the amine caused an increase in the thermal stability of the amino compounds and did not present cytotoxic potential at concentrations below 50.0 mg/L.
Journal Article