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1
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MONIQUE ALVARES DA SILVA
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GENETIC DIAGNOSIS AND GENOTYPE/PHENOTYPE CHARACTERIZATION OF VARIANTS OF THE PPARG GENE, PRECURSOR OF FAMILIAR PARTIAL LIPODYSTROPHY TYPE 3 IN PATIENTS FROM NORTHEAST BRAZIL
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Leader : JULLIANE TAMARA ARAUJO DE MELO CAMPOS
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MEMBRES DE LA BANQUE :
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VIRGINIA OLIVEIRA FERNANDES CORTEZ
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DANIEL CARLOS FERREIRA LANZA
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JULLIANE TAMARA ARAUJO DE MELO CAMPOS
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NAISANDRA BEZERRA DA SILVA FARIAS
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Data: 8 févr. 2024
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Afficher le Résumé
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Lipodystrophy type 3 (FPLD3) has been described as molecularly associated with the PPARG gene, with predominantly missense variants on chromosome 3. The syndrome causes loss of adipose tissue in the upper and lower limbs, hips, and face. It is generally associated with metabolic disorders such as type 2 diabetes, insulin resistance, hypertriglyceridemia, and liver dysfunction. Therefore, the objective of this work was to molecularly diagnose and characterize the genotype/phenotype of patients with a clinical diagnosis of LPF3 recruited by the endocrinology clinic of the Hospital Universitário Onofre Lopes.To this end, a clinical evaluation was carried out, oral swabs and blood samples were collected. Biochemical analyses and dosages of the hormones adiponectin and leptin were performed using the ELISA technique to evaluate the metabolic disorders inherent to FPLD3. The next-generation sequencing (NGS) technique was chosen to diagnose the variants through a panel of genes related to lipodystrophies including LMNA and PPARG. To confirm the NGS data, amplification of genetic material was carried out by conventional PCR and Sanger sequencing using primers specifically designed for this work. The tools used for bioinformatic analysis of the variants were Poly-Phen2, TCoffee, and Mutation Taster. It was observed that the patients presented clinical characteristics compatible with the presence of lipodystrophy, such as loss of adipose tissue in the extremities, hypertriglyceridemia, and steatosis, in addition to a reduced adiponectin and leptin dosage within normal limits concerning the reference value for the index of corresponding body mass. Molecularly, new heterozygous variants located at positions c.533T>C promoting the replacement of the amino acid leucine by proline at 178 (p.Leu178Pro) and c.641C>T promoting the replacement of the amino acid proline by leucine at 214 were identified and confirmed in three patients. (p.Pro214Leu). The variants respectively affect the DBD domain of the protein, responsible for binding PPAR to the promoter region of target genes, and the Hinge region, involved in the interaction with coactivators and corepressors. Through bioinformatic analysis of each identified variant and its comparative alignment with the wild type, it was observed that the scores corroborated what was observed clinically, classifying the variants as harmful to their function. This was the first study to molecularly characterize patients with familial partial lipodystrophy type 3 in Brazil and the first to report the c.533T>C and c.641C>T variants in the global literature.
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2
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MARIA EDUARDA CARDOSO DE MELO
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Analysis of pathogenic variants in AGPAT2 and biochemical-molecular evaluation of individuals with congenital generalized lipodystrophy types 1 and 2
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Leader : JULLIANE TAMARA ARAUJO DE MELO CAMPOS
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MEMBRES DE LA BANQUE :
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JULLIANE TAMARA ARAUJO DE MELO CAMPOS
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LEONARDO CAPISTRANO FERREIRA
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VIRGINIA OLIVEIRA FERNANDES CORTEZ
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Data: 28 mars 2024
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Afficher le Résumé
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Congenital Generalized Lipodystrophy (CGL) is a rare disease that causes the loss of adipose tissue (AT) throughout the body from birth. Patients with CGL have low levels of leptin and adiponectin (APN), important adipokines produced by AT. There are four types of CGL, with types 1 and 2 being responsible for more than 80% of the cases described in the literature and with patients already reported in northeastern Brazil. The molecular etiology for LGC 1 and LGC 2 is the presence of pathogenic variants (PVs) in the AGPAT2 and BSCL2 genes, respectively. This study carried out the molecular analysis of the main VPs described for AGPAT2 (c.366-588del, c.589-2A>G, c.646A>T, c.570C>A, c.369-372delGCTC, c.202C>T, c.514G>A, c.144C>A) and an analysis of the effects on their transmembrane and functional domains. The genotype vs phenotype relationship of the first patients described in the literature for the PVs in question demonstrates the relationship between molecular alterations and clinical symptoms, so that patients with PVs that more significantly affect the proteins show a higher rate of clinical symptoms. In addition, we performed the molecular diagnosis of two sisters with VPs in compound heterozygosity for c.299G>A and c.493-1G>C and a new patient described for the c.366-588del variant. Using next-generation sequencing (NGS), a panel of genes associated with adipose tissue-related diseases was analyzed in LGC patients, which showed the presence of different VPs for the BSCL2 gene. The comparative study of leptin and APN dosages between the LGC 1 and LGC 2 groups showed that LGC type 2 patients had lower leptin levels, while no differences were observed between APN dosages in these two groups. At the level of expression of enzymes involved in repairing oxidized DNA damage (APE-1, OGG1 and PPARG), no significant differences were observed between the LGC 1 and LGC 2 groups, although both types had higher levels of expression of these genes when compared to that observed in control individuals. This suggests that the different molecular etiology of the two types of LGC is not a significant parameter for altering redox homeostasis between these two groups. Further studies are needed to better understand the relationship between LGC and oxidative stress, DNA repair and cellular response.
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3
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GEORGGIA FÁTIMA SILVA NALIATO
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Tenebrio molitor as an experimental model for comparing virulence profiles and immune response to pathogenic fungi of the genus Sporothrix
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Leader : RAQUEL CORDEIRO THEODORO
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MEMBRES DE LA BANQUE :
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RAQUEL CORDEIRO THEODORO
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DANIEL CARLOS FERREIRA LANZA
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RAFAEL WESLEY BASTOS
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ÉVERTON KORT KAMP FERNANDES
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Data: 5 avr. 2024
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Afficher le Résumé
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Diseases caused by pathogenic fungi have a substantial impact on both immunocompromised and immunocompetent patients, requiring lengthy treatments that, in some cases, demand hospitalization. In this regard, species and/or genotype-specific diagnosis can enhance disease prognosis, enabling a more targeted treatment depending on the etiological agent. Nevertheless, comparative studies on parasitism relationships involving closely related fungal species, often cryptic within the same genus, are still scarce. Species-specific virulence categorization directly impacts therapeutic direction and clinical prognosis, thereby optimizing case resolution. Consequently, the gold standard model for assessing the virulence of these pathogens is the murine model. However, currently, due to increased concerns about bioethical and financial issues, invertebrate animals have been proposed as attractive alternatives for infection models, given their innate immunity evolutionarily close to mammals, infrastructural ease, and robust data reproducibility. In this study, the virulence of different species of medical importance, from both clinical and environmental clades of the dimorphic fungus genus Sporothrix, as well as aspects of the innate immune response, were assessed in the invertebrate model Tenebrio molitor, in both the mycelial and yeast phases of the fungus. Thus, it was possible to compare virulence profiles and the host-parasite relationship among isolates of species within the genus. Significant differences were observed between the mycelial and yeast phases of pathogenic species from both Sporothrix clades. The species S. chilensis and S. pallida (environmental clade) demonstrated higher virulence in the mycelial morphology, whereas the species S. schenckii and S. brasiliensis (clinical clade) showed higher virulence in the yeast morphology. The expression of antimicrobial peptides (AMPs) from the invertebrate model was quantified, showing a significant difference in expression between groups infected with S. pallida and S. schenckii, indicating alterations in the pattern of the innate immune response concerning the Sporothrix species inoculated into the model.
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4
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MARYANA THALYTA FERREIRA CÂMARA DE OLIVEIRA
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MALE FERTILITY: MARKET IN LATIN AMERICA AND DEVELOPMENT OF SYSTEMS FOR DETECTING PATHOGENS IN HUMAN SEMEN
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Leader : DANIEL CARLOS FERREIRA LANZA
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MEMBRES DE LA BANQUE :
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DANIEL CARLOS FERREIRA LANZA
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EDILSON DANTAS DA SILVA JUNIOR
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DANIELLE BARBOSA MORAIS
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JANAINA FERREIRA ADERALDO
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KYVIA BEZERRA MOTA
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Data: 15 avr. 2024
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Afficher le Résumé
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According to the World Health Organization (WHO), infertility is a disease of the reproductive system that results in limited fertility in men and women. On a global scale, more than 186 million individuals face infertility challenges, with the majority of them residing in developing countries. This has driven the growth of the infertility treatment industry, including the male fertility market, since around 15% of men of reproductive age face infertility problems. However, diagnosing infertility in men still faces challenges, with semen infections being one of the potential causes. Recent studies have shown that different microorganisms, such as viruses and bacteria, can impact on semen quality, causing damage to organs and cells through inflammatory mediators. In this context, this dissertation aimed to characterize the main topics related to the fertility and assisted reproduction market in Latin America and Brazil, to emphasize the growth of the male fertility market and the challenges faced in diagnosing infertility in men, as well as to develop systems for detecting the main pathogens that infect semen. Three studies were conducted to achieve these objectives: two literature reviews to describe the markets and the last study developed primers and validated in silico three multiplex PCR panels for the detection of the main seminal pathogens of clinical importance already described. The main conclusions of the studies include: 1) Fertility services could earn up to $31.59 billion by 2029 and the use of assisted reproductive technologies (ART) has become a thriving commercial business within fertility services. It was noted that the fertility market has seen significant growth in both Brazil and Latin America. Specifically in Brazil, there has been growth over the last few years, with approximately 40% of assisted reproduction clinics in Latin America and revenues of around R$1.3 billion. It is estimated that between 2021 and 2025, around 77,588 patients up to the age of 35 will be treated via ART in the country. At the same time, both public policies and private sector initiatives aimed at fertility are increasing, underlining the importance of fertility in people's lives (Chapter I). 2) The male fertility market has also shown significant growth as the fertility and assisted reproduction market expands. According to market reports, global trade related to male fertility is estimated to be worth billions of dollars and is expected to reach more than $6 billion by 2027 (Chapter II). 3) Based on the data collected, three panels were developed in silico that focus on seminal quality, covering HPV-16, HPV18, HBV, HHV-5, HSV-1, HSV-2, HIV-1, HIV-2, ZIKV, HCV, Treponema pallidum, Neisseria gonorrhoeae and Chlamydia trachomatis. The implementation of these panels represents a significant advance in seminal quality control, providing more accurate diagnoses for semen banks and guidance for couples facing infertility. The proposed assay promises to meet the needs of the male fertility market, as well as simplifying workflow, allowing it to be used in routine diagnostic laboratories with basic molecular facilities (Chapter III). Overall, all the information gathered in this dissertation contributes to new areas of research in the areas of the market, improving techniques and diagnosing conditions related to male infertility and global reproductive health.
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5
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RAFAELA ALVES DE LIMA
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Comparative analysis of the effects of microgravity, heat, and hypoxia on the gene expression pattern of plants: a bioinformatic approach
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Leader : KATIA CASTANHO SCORTECCI
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MEMBRES DE LA BANQUE :
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ALESSANDRO DE MELLO VARANI
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KATIA CASTANHO SCORTECCI
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LEONARDO CAPISTRANO FERREIRA
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Data: 24 avr. 2024
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Afficher le Résumé
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Plants are subjected to daily environmental changes and must respond optimally to tolerate these modifications. Alterations in gravity, hypoxia, and heat are examples of environmental changes that can induce abiotic stress, primarily triggering oxidative signaling. Since microgravity is not a condition naturally occurring on Earth, some exposure methods are required to place plants in environments with gravity approaching zero. The use of international space stations and space flights are ways to expose plants to this type of environment. However, there is still no consensus on all the effects that microgravity may trigger. Thus, comparing microgravity studies with other environmental factors can enhance understanding of plant responses to microgravity. In this context, the integration of transcriptomic data from studies available on open-access platforms was performed, investigating the impacts of microgravity, hypoxia, and thermal stress on plants. Since these environmental conditions may share oxidative signaling pathways, the objective of this integration was to enrich the understanding of plant responses to microgravity, heat, and hypoxia in a comparative manner, as well as to explore the differential and correlated effects of microgravity in international space station and space flight settings. Therefore, bioinformatics tools were employed to identify significantly activated central genes, ontologies, and metabolic pathways. For data integration, a selection was made according to inclusion and exclusion criteria. For example, studies should clearly state experimental conditions and compare stressed and non-stressed plants. Consequently, 16 microgravity studies were selected, including 11 from international space stations and 6 from space flights, along with 10 thermal stress studies and 9 hypoxia studies. This integration revealed significant regulation of genes related to chlorophyll biosynthesis. These results suggest that photooxidation may be an important effect under microgravity, hypoxia, and heat conditions. This effect appears to be independent of microgravity exposure type. There was also an overlap in the activation of antioxidant metabolic pathways: glutathione metabolism and phenylpropanoid biosynthesis, demonstrating that plants employ redox homeostasis pathways using different strategies. Primary metabolism, specifically through the production of sugars such as starch and fructose, is significantly affected under hypoxia, heat, and microgravity conditions. These sugars are essential for energy production, carbon metabolism, and gravity signaling. Therefore, oxidative signaling triggered by microgravity, heat, and hypoxia significantly affected chlorophyll production and primary metabolism; however, this impact may be mitigated by intense antioxidant activity. Comparing these responses to those induced by other environmental stresses provides important insights into the adaptive capacity of plants in environments with different gravitational forces. Such understanding is crucial for developing strategies to enhance crop resilience in terrestrial and space agriculture contexts.
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6
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OHANA LETÍCIA TAVARES DA SILVA
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Exploring the pharmacological potential of carrageenan disaccharides as antitumor agents: an in silico approach
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Leader : HUGO ALEXANDRE DE OLIVEIRA ROCHA
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MEMBRES DE LA BANQUE :
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HUGO ALEXANDRE DE OLIVEIRA ROCHA
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LEANDRO SILVA COSTA
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ÉDER GALINARI FERREIRA
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Data: 30 avr. 2024
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Afficher le Résumé
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Carrageenans, sulfated galactans, have antitumor activity that can be enhanced by their depolymerization. This means that their oligosaccharides, including disaccharides, being less structurally complex, may have pharmacological potential in the treatment of various tumors. However, it is still unknown whether these disaccharides/oligosaccharides are pharmacologically viable and by what mechanisms they act to inhibit tumor growth. Therefore, the objective of this study was to utilize bioinformatics tools to investigate the pharmacological properties and potential molecular targets of disaccharides most representative of iota, kappa, and lambda carrageenans. To achieve this, the pharmacokinetic profile and drug-like physicochemical properties of disaccharides were initially predicted. Subsequently, the molecular targets of these disaccharides were predicted, and among them, those that are already targets of oncological drugs were selected. Molecular docking was then conducted to evaluate the binding capacity and affinity between the selected targets and disaccharides. For comparative analysis of binding energies, oncological drugs acting on these targets were also subjected to docking. In general, disaccharides exhibited favorable metabolization, excretion, and toxicity profiles, but they face permeability challenges in biological membranes, affecting their absorption and distribution. Furthermore, they met most of the physicochemical criteria proposed in drug similarity tests, except for polarity and lipophilicity, which were below and above the desirable limits, respectively. In the selection of molecular targets, five common targets were predicted: carbonic anhydrases (CAs) I, II, IX, XII, and XIV, which are already targeted by several oncological drugs. In docking, the binding energies were similar or superior to those of drugs already used for these targets. Regarding the interactions between disaccharides and CAs, those involving the zinc cofactor stood out, as it is the primary mechanism for inhibiting these enzymes. These findings indicate a promising avenue for carrageenan disaccharides as cancer therapeutics.
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7
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MELISSA FARIAS ALVES DA SILVA
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PROSPECTION OF ANTIFUNGAL ACTIVITY AND MODULATORY POTENTIAL OF EXTRACTS AND FRACTIONS OF Tephrosia toxicaria (Sw.) Pers in REFERENCE ANTIMICROBIALS
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Leader : ADRIANA FERREIRA UCHOA
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MEMBRES DE LA BANQUE :
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GABRIEL BONAN TAVEIRA
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ADRIANA FERREIRA UCHOA
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KATIA CASTANHO SCORTECCI
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THALES DOMINGOS ARANTES
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Data: 9 mai 2024
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Afficher le Résumé
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Fungal infections represent a major contributor to the increasing global mortality rate associated with infectious diseases. This increase is largely attributed to the indiscriminate use of antibiotics and antifungals agents, whose effectiveness is compromised by the development of resistance in pathogens and the adverse effects observed in non-target organisms. Botanical extracts and their fractions have been highlighted as promising sources for the development of antifungals and therapeutic adjuvants for reference drugs as they are derived from renewable sources and present toxic selectivity. Tephrosia toxicaria (Sw.) Pers, a legume well adapted to the northeastern semi-arid region, has stood out for its biopotential. The present research aimed to investigate the antifungal potential of extracts and protein fractions obtained from T. toxicaria seeds against species of the Candida and Cryptococcus genera and their modulating activity for reference antimicrobials. The extracts and fractions obtained by the Scopes and Osborne methods were partially biochemically characterized and evaluated for their antifungal activity by determining the MICs (Minimum Inhibitory Concentration). Subsequently, the most active fraction and its combinations were also investigated regarding their possible mode of action. The extracts and fractions showed antifungal activity to different degrees for at least one of the yeasts tested, in which the T 50-75 fraction was the most active against Cryptococcus gattii, Cryptococcus neoformans and Candida parapsilosis and the GLB fraction against Candida albicans. The lowest MIC100 values (MIC, capable of inhibiting 100% of growth) found were 32 µg/mL for the T 50-75 fraction against Cryptococcus gattii (R-265), 128 µg/mL for the ST extract and 256 µg/mL for fractions T 50-75 and T 75-100, all against C. gattii (FC1). The ST extract and the fractions T 50-75 and T 75-100, as they presented the lowest MIC100 values, were selected to investigate their modulating potential in combination with Amphotericin B, Fluconazole and 5-Flucytosine, using the association method (checkerboard) by FICI (Fractional Inhibitory Concentration Index) and by mathematical models (Blis, HSA, Loewe and ZIP). All tested combinations were able to reduce the MIC100 for C. gattii and after data harmonization, the combinations between the T 50-75 and T 75-100 fractions with Amphotericin B and Fluconazole were classified as synergistic, however the combinations with the fraction T 50-75 showed greater sensitivity (93%) and degree of synergistic intensity. The combination of the fraction T 50-75 with the drugs caused greater interference in the growth curve, melanization and a significant reduction in capsule size. However, exposure of C. gattii to treatment with only the T 50-75 fraction also caused morphological changes in the cell wall and capsule, indicating that the fraction contributed strongly to the result observed in combination with the drug. Therefore, the T 50-75 fraction presents itself as a promising candidate for the development of adjuvants and/or new drugs for antifungal chemotherapy. Analysis of the results suggests that the fungistatic action of the T 50-75 fraction can contribute to minimizing the emergence of resistance in the pathogen, acting in redundant pathways and reducing the effective concentrations of clinical reference drugs, thus improving treatment and minimizing toxicity generated.
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8
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JOHN WESLLEY LIRA SANTOS
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Effect of simulated microgravity using clinostat 2D in Lemna aequinoctialis Welw.
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Leader : KATIA CASTANHO SCORTECCI
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MEMBRES DE LA BANQUE :
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KATIA CASTANHO SCORTECCI
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RAQUEL CORDEIRO THEODORO
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TERCILIO CALSA JUNIOR
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Data: 21 juin 2024
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Afficher le Résumé
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Understanding the effects of microgravity on plants is still limited, it has been observed that the response changes according to tissue, plant and microgravity conditions. This study evaluated the effects of simulated microgravity on Lemna aequinoctialis, a plant from the subfamily Lemnoideae, important for bioremediation and animal feeding. Using a 2D clinostat machine to simulate microgravity, the plants were exposed to different rotations (15, 30, 45 rpm) for 2 and 4 hours, along with a control (0 rpm). Plant development was monitored at 0, 5, and 10 days after treatment. Biochemical analyses were conducted to measure total antioxidant capacity (CAT), reducing power, phenolic compounds, protein content, and catalase enzyme activity. The results showed that simulated microgravity significantly increased antioxidant markers and protein content. It has been observed that CAT and reducing power increased up to three times, in special after 4 hours of treatment. The 45 rpm rotation for 2 hours resulted it was verified an increase in phenolic compounds on days 5 and 10, while for the 30 rpm rotation for 4 hours treatment is as verified an important increase on day 0. For the catalase activity, it was higher with 30 rpm in both time treatment on day 10. In addition, protein content increased up to seven times with 45 rpm for 2 hours. These results suggest that simulated microgravity can enhance the nutritional profile of L. aequinoctialis, boosting its biotechnological applications in sustainable food production and bioremediation. This study advances the understanding of the mechanisms involved in L. aequinoctialis response to microgravity.
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9
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DYONATAN FONSECA SILVA
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EVALUATION OF THE METALLOPROTEINASE PROFILE IN TISSUE SAMPLES FROM ANIMALS EXPERIMENTALLY INFECTED WITH Trypanosoma cruzi
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Leader : MARCELO DE SOUSA DA SILVA
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MEMBRES DE LA BANQUE :
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MARCELO DE SOUSA DA SILVA
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ALINE RIMOLDI RIBEIRO
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CLÁUDIA JASSICA GONÇALVES MORENO
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TAFFAREL MELO TORRES
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Data: 26 juin 2024
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Afficher le Résumé
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Chagas disease (DCh) is caused by the parasite Trypanosoma cruzi (T. cruzi) and is characterized by two clinical phases: acute and chronic. During the acute phase, the parasite targets specific tissues and dysregulates cytokines and matrix metalloproteinases (MMPs), which are major risk factors for the development of cardiopathies, common complications in both the acute and chronic phases of the disease. This study aimed to optimize gel-based methods, such as SDS-PAGE and zymography, to evaluate whether T. cruzi infection could alter the metalloproteinase profile of key organs during the acute phase of DCh. For this purpose, total protein extract from epimastigote forms of T. cruzi Y strain from axenic culture was obtained, and experimental infection with blood trypomastigote forms was performed in female mice, divided into three groups: uninfected (CN, negative control, n=3) and infected, euthanized at 17 (D17, n=3) and 32 (D32, n=3) days post-infection. Control animals were used as a baseline for comparison with infected animals. Heart, spleen, liver, and blood from all groups were collected to produce total extract and blood plasma. Optimization allowed the determination of the protein profile of T. cruzi, revealing bands with approximate molecular weights of 95, 85, 63, 57, 48-52, 43-45, 40-41, 29, and 18-20 kDa, which were discussed in terms of their possible identification and function in the infection. The results also demonstrated the protein profiles of cardiac, splenic, hepatic tissues, and plasma in the three analyzed groups. The T. cruzi zymogram revealed three activity bands with approximate molecular weights of 66 kDa, 55 kDa, and 35 kDa, along with a faint activity band between 66 and 35 kDa. In the infected animal group, clinical signs of hepatomegaly and splenomegaly characteristic of the acute phase of DCh were observed. Several gelatin-degrading metalloproteinases were detected in the zymogram of tissues and plasma, especially in splenic tissue. Differences in their expression during acute infection were observed only in splenic and cardiac tissues, with the alteration in cardiac tissue related to the increased expression of a 93 kDa protease, likely proMMP-9, and in the spleen, a 146 kDa unknown protease. In summary, the findings provide information on the protein and proteolytic expression patterns for T. cruzi and the analyzed organs plus plasma, revealing abundant proteins as potential immunogenic targets against T. cruzi. These data serve for comparison of the genetic and functional diversity of the parasite along with other studies, besides confirming changes in protease expression during the acute phase of DCh, opening avenues for diagnostics and treatment based on the necessity and feasibility of inhibiting these proteins.
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10
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PABLO FELIPE FERREIRA FARIAS
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SULFATED POLYSACCHARIDES FROM THE SEAWEED CAULERPA CUPRESSOIDES VAR. FLABELLATA WITH ANTIOXIDANT ACTIVITY: EVALUATION OF BIOSAFETY IN NEURO-2A CELLS AND ZEBRAFISH MODELS
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Leader : SUSANA MARGARIDA GOMES MOREIRA
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MEMBRES DE LA BANQUE :
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SUSANA MARGARIDA GOMES MOREIRA
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KATIA CASTANHO SCORTECCI
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RAFAEL BARROS GOMES DA CAMARA
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DOUGLAS DOURADO OLIVEIRA
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Data: 25 sept. 2024
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Afficher le Résumé
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Neurodegenerative diseases (NDs), such as Alzheimer's and Parkinson's, are global health issues affecting millions of people. Oxidative stress is believed to be a key factor in the cause and/or progression of NDs, damaging neuronal cells and leading to symptoms such as memory loss and motor problems. Therefore, searching for new antioxidant agents to mitigate those damages is crucial. Among the potential antioxidant agents, sulfated polysaccharides (SPs) obtained from seaweeds stand out. Beyond their antioxidant properties, SPs also exhibit various bioactivity properties, including anticoagulant, antiproliferative, and anti-inflammatory effects. Thus, this study evaluated the antioxidant potential of SP-rich fractions of the green seaweed Caulerpa cupressoides var. flabellata against H2O2 in murine neuroblastoma cells (Neuro-2A). Four SP-rich samples (CCB-F0.3, CCB-F0.5, CCB-F1.0, and CCB-F2.0) were obtained from polysaccharide-crude extract of Caulerpa cupressoides (PCE). The cytotoxicity and protective effect of the samples against H2O2 in Neuro-2A cells were evaluated, using the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) reduction method. No cytotoxic effects were observed, except for the PCE and CCB-F0.5 samples at higher concentrations. The CCB-F2.0 sample presented antioxidant potential and protective effects against H2O2 under the tested conditions. Additionally, the CCB-F2.0 sample reduced the reactive oxygen species (ROS), evaluated by the 2,7-dichlorofluorescein diacetate (DCFH-DA) fluorescent probe. This sample did not exhibit genotoxicity or mutagenicity, as determined by single-cell gel electrophoresis assays (comet assay) and the Salmonella microsuspension reversion assay (Kado test), respectively. Furthermore, embryotoxicity and optomotor response were evaluated using the zebrafish model. Thus, CCB-F2.0 sample showed no embryotoxic or neurotoxic effects in the zebrafish embryos at different concentrations, since no changes in mortality, malformations, and optomotor response were observed in the larvae. Therefore, it is expected that the results of this study may contribute to the development of an alternative treatment for NDs.
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11
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GABRIEL CHRISTIAN DE FARIAS MORAIS
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ADMET and Quantum Biochemistry Predictions of Bioactives with Antimicrobial or Neuroactive Potential
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Leader : JONAS IVAN NOBRE OLIVEIRA
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MEMBRES DE LA BANQUE :
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JONAS IVAN NOBRE OLIVEIRA
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EDILSON DANTAS DA SILVA JUNIOR
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JÉSSICA DE FÁTIMA VIANNA
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Data: 26 nov. 2024
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Afficher le Résumé
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The increasing demand for novel neuroactive and antimicrobial drugs motivated this study to conduct ADMET (Absorption, Distribution, Metabolism, Excretion, and Toxicity) predictions and quantum biochemical analyses of bioactive compounds with eugeroic (modafinil), noradrenergic (atomoxetine), antiviral (tecovirimat), and antiparasitic (BZTS) activities. Advanced computational tools such as ADMETlab 2.0, admetSAR, FAFDrugs4, MolInspiration, SwissADME, ADMET-AI, pkCSM, and PRED-HERG were utilized to evaluate the pharmacokinetic and toxicological profiles of Modafinil, Atomoxetine, and Tecovirimat, identifying risks such as hepatotoxicity, cardiotoxicity, and mutagenic potential. The focus then shifted to Chagas disease, selecting six compounds with antichagasic potential, with BZTS emerging as a standout due to its favorable ADMET profile and low toxicity risk, meeting all medicinal chemistry guidelines. Molecular modeling studies and Density Functional Theory (DFT) calculations revealed robust and specific interactions between BZTS and cruzain, a key Trypanosoma cruzi enzyme, indicating stability and high affinity within the ligand-receptor complex through interactions with amino acids GLU208 (-10.2 kcal/mol), MET68 (-4.75 kcal/mol), LEU67 (-4.08 kcal/mol), ASN69 (-3.68 kcal/mol), LEU160 (-3.38 kcal/mol), ALA138 (-1.98 kcal/mol), GLU117 (-1.97 kcal/mol), and ASP161 (-1.68 kcal/mol). Additionally, frontier orbital analyses (HOMO -5.85 eV, LUMO -3.37 eV) and quantum chemical descriptors—ionization potential (5.85 eV), electron affinity (3.37 eV), chemical hardness (1.24 eV), softness (0.81 eV), chemical potential (-4.61 eV), electronegativity (4.61 eV), and electrophilicity (13.19 eV)—confirmed the BZTS compound’s potential for effective biological target interactions, reinforcing its therapeutic potential. This study underscores the effectiveness of in silico methodologies in identifying and characterizing promising bioactive compounds, with BZTS emerging as a promising candidate for Chagas disease treatment. Integrating computational predictions in drug development proves crucial for accelerating the discovery and optimization of safer, more effective drugs, significantly contributing to advances in pharmacology and public health.
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1
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LÍDIA LEONIZE RODRIGUES MATIAS
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New alternatives for treatment against bacterial infections: evaluation of the potential of Trypsin Inhibitor isolated from Tamarind seed (TTI) as an anti-infective agent
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Leader : ANA HELONEIDA DE ARAUJO MORAIS
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MEMBRES DE LA BANQUE :
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ANA HELONEIDA DE ARAUJO MORAIS
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FRANCISCO CANINDE DE SOUSA JUNIOR
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KARLA SUZANNE FLORENTINO DA SILVA CHAVES DAMASCENO
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MAYARA SANTA ROSA LIMA
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PATRICIA SANTOS LOPES
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RICHELE JANAINA ARAUJO MACHADO
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Data: 23 févr. 2024
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Afficher le Résumé
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Infections have become a worrying threat to public health, especially when caused by bacteria resistant to currently available antimicrobials. This thesis aimed to study new alternatives for treatments against bacterial infections. For this purpose, a narrative review and an in vitro and in vivo study were performed. Thus, the first chapter of this thesis presents a narrative review of new biomedical alternatives in antibacterial treatments. As a result, it was found that some areas of research aiming to control bacterial infections have been highlighted, namely bioinformatics, nanotechnology, and genomics, in addition to studies developed with natural molecules such as antimicrobial peptides. Furthermore, the articles in this narrative review presented promising research in developing antimicrobial agents, and their mechanisms of action and strategies to minimize the consequences of bacterial resistance. The review will present current alternatives may contribute to future studies in the area. In the second chapter, the effect of trypsin inhibitor isolated from tamarind seeds (TTI) on the survival of Caenorhabditis elegans (C. elegans) (wild strain) under conditions of bacterial infection was investigated. The TTI was isolated in Trypsin-Sepharose CNBr-4B affinity chromatography. Its protein quantification was performed using the Bradford method, and an antitryptic assay monitored its specific activity. The animals were maintained in Nematode Growth Medium (NGM) and Escherichia coli bacteria (OP50) as a food source at 20 ⸰C and, for the analysescarried out, they were previously exposed to different concentrations of TTI, from stage L1 to L4, in addition to a group control without treatment. Besides, the toxicity test was performed by evaluatingoviposition, progeny, locomotion, and body size. Subsequently, the bacterial infection test was carried out with Staphylococcus aureus in C. elegans previously subjected to concentrations of 0.1 and 1.0 mg/mL of TTI. Nematodes were exposed to the stressor tert-butyl hydroperoxide (TBOOH) in an oxidative stress test. Then, bacterial growth curve and antioxidant and antibacterial activity tests were carried out in vitro. In the toxicity test, no statistical difference was found between the control group and the other concentrations tested (p> 0.05). Regarding body size, the tested TTI concentrations showed a statistical difference (p<0.05) and presented higher length than the untreated group. Regarding bacterial infection analyses, animals subjected to 0.1 mg/mL and 1.0 mg/mL of TTI showed survival of 16.10% and 30.32%, respectively, higher than the group infected without treatment (8.08%). To understand the role of TTI on animal survival, in the oxidative stress test, at all tested TTI concentrations, greater survival was observed about the control at 12h and 18h (p< 0.05). In in vitro studies about the bacterial growth curve, no inhibitory activity of TTI was observed about Escherichia coli (OP50) (p>0.05) at the concentrations tested, nor was antibacterial and antioxidant activity observed. Given the results, a greater survival of C. elegans was found when previously exposed to TTI; however, in a different antioxidant and antibacterial pathway. In this way, the study contributed to consolidating theoretical and scientific understanding through narrative review and ITT tests, respectively, on new alternatives for controlling bacterial infection.
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MARYELLE DE CÁSSIA ALBINO
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Effects of sucrose and ethanol withdrawal on behaviors related toanxiety and depression: investigation of the role of the KynureninePathway
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Leader : VANESSA DE PAULA SOARES RACHETTI
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MEMBRES DE LA BANQUE :
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VANESSA DE PAULA SOARES RACHETTI
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EDILSON DANTAS DA SILVA JUNIOR
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ELAINE CRISTINA GAVIOLI
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ISABELLA MARIA DE OLIVEIRA PONTES FERNANDES
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JANAINA MENEZES ZANOVELI
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Data: 27 févr. 2024
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Afficher le Résumé
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In disorders related to substance use/abuse, the withdrawal phase favors negative reinforcement and continued consumption despite physical and mental harm. Women constitute a risk group for these disorders and few studies investigate changes in neural substrates in females. The enzyme indoleamine 2,3-dioxygenase (IDO), responsible for the metabolism of tryptophan into kynurenines, was seen hyperactivated in males undergoing alcohol withdrawal and associated with emotional disorders. Thus, the present work investigated the effects of sucrose and ethanol withdrawal on behaviors related to anxiety and depression and on IDO activity in brain areas that participate in the modulation of these emotions in Wistar rats. In experiment 1, the rats were subjected to a liquid sucrose diet for 16 days and to behavioral tests on days 3, 5, 22 and 24 after sucrose withdrawal. In experiment 2, females were subjected to an exclusive liquid ethanol diet in increasing concentrations (2, 4 and 6%) for 21 days and to a battery of behavioral tests on days 22, 23, 24, 25 and 26 after withdrawal of ethanol. The rats that received ethanol were treated with inulin (10 or 30 mg/kg orally, gavage) or mineral water. After the behavioral assessment, the animals were euthanized and had blood and frontal cortex, striatum and hippocampus samples collected. In rats exposed to sucrose there was a reduction in immobility time in the forced swimming test and an increase in plasma triglyceride concentration. No biochemical and behavioral changes were seen in animals on sucrose withdrawal. Rats withdrawing from ethanol exhibited less exploration of open arms in the elevated plus maze, greater grooming in the sucrose spray test, greater burying of glass balls in the marble burying test and greater immobility time in the forced swimming test. There was a trend towards an increase in kynurenine concentration in the cortex. Inulin at doses of 10 and 30 mg/Kg attenuated this increase, and the dose of 30 mg/Kg mitigated the behavioral effects on animals in the elevated plus maze, sucrose spray, marble burying and forced swimming tests. In conclusion, females were not sensitive to sucrose withdrawal. Prolonged consumption of sucrose has demonstrated an antidepressant effect. Ethanol withdrawal promoted anxious and depressive-like behaviors and increased the activity of the kynurenine pathway in females, such changes were reversed by treatment with inulin. The prebiotic demonstrated a potential candidate for the treatment of alcohol use disorder.
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MYCHELLE KYTCHIA RODRIGUES NUNES DUARTE
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NUTRIGENETIC TESTS: POSSIBLE APPLICATIONS IN THE PREVENTION AND TRE- ATMENT OF OBESITY
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Leader : LUCYMARA FASSARELLA AGNEZ LIMA
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MEMBRES DE LA BANQUE :
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LUCYMARA FASSARELLA AGNEZ LIMA
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HUGO ALEXANDRE DE OLIVEIRA ROCHA
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VIVIANE SOUZA DO AMARAL
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ANNETE BRESSAN RENTE FERREIRA MARUM
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TATIANE MIEKO DE MENESES FUJII
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Data: 26 juin 2024
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Afficher le Résumé
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Obesity is a complex disease and mostly polygenic disease. In this context, several trea- tments are listed to mitigate it and nutritional genomics has been gaining prominence with possible tools to assist in the prevention and/or treatment of obesity with nutrigenetic testing (NT) . Therefore, this thesis is divided into two chapters, aiming to evaluate whether NT can be used to prevent and/or treat obesity. In the first chapter, a narrative review was carried out to understand the current panorama of obesity and NT, covering the themes of precision nutrition, exposome, genetic testing sold directly to the consumer. The benefits and nega- tive aspects of using NT as a tool to help prevent or treat overweight and obesity were analyzed. Some entities, such as the Brazilian Association for the Study of Obesity and Metabolic Syndrome (ABESO) are against the use of NT for obesity. The Academy of Nu- trition and Dietetics recommends its use, however not in isolation, but within a context of well-conducted anamnesis. Therefore, NT should not be used alone in the treatment of obesity, but always associated with a good anamnesis for the individualized treatment of obesity or at a public health level. In the second chapter, a retrospective study was carried out, evaluating the relationship of 29 candidate gene SNP related to obesity. Thus, 112 individuals were divided into two groups: 64 eutrophic (BMI< 25 kg/m²) and 48 overweight and obese (BMI≥ 25 g/m²). It was verified that the population was in Hardy-Weinberg equi- librium and a multivariate logistic analysis was performed to verify whether the SNP were associated with overweight and obesity. In this analysis, it was found that of the 29 SNP found in NT marketed in Brazil, only ADIPOQ rs17300539, PPARG rs1801282 were asso- ciated with overweight and obesity, while SOD rs4880 was related to protection against overweight and obesity. Thus, it was shown that more studies are needed to validate which SNP are related to overweight and obesity in the Brazilian population. Furthermore, lifestyle analysis must be added, as these factors can epigenetically alter gene expression and im- pact the phenotype.
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JOELTON IGOR OLIVEIRA DA CRUZ
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ANTIBACTERIAL, ANTIBIOTIC MODULATING AND ANTIPROTEASIC ACTIONS OF PROTEIN FRACTIONS FROM CATINGUEIRA SEEDS (Poincianella pyramidalis Tul.)
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Leader : ELIZEU ANTUNES DOS SANTOS
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MEMBRES DE LA BANQUE :
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ELIZEU ANTUNES DOS SANTOS
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RAFAEL BARROS GOMES DA CAMARA
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BRUNO OLIVEIRA DE VERAS
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MARIA TATIANA ALVES OLIVEIRA
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PAULA IVANI MEDEIROS DOS SANTOS
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Data: 30 août 2024
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Afficher le Résumé
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Bacterial resistance, as well as inflammatory disorders, are significant public health problems that take thousands of people to hospitals every year, often requiring several days of hospitalization for treatment, generating excessive costs and, sometimes, without solving the problem. Considering the importance of discovering new substances that mitigate these problems, this study aimed to evaluate the crude extract and protein fractions of the seed of Poincianella pyramidalis (Tul.) for antibacterial, antibiotic-modulating, and protease-inhibiting activities. The protein extracts were obtained from extraction with 0.05M Tris-HCL buffer pH 7.5 and subsequent fractionation with ammonium sulfate in different saturation ranges 0-30%, 30-60% and 60-90% of sodium sulfate ammonium. The electrophoretic profile revealed several protein bands between 12 KDa and 225 KDa. The inhibitor-enriched fraction (FE) was obtained using only a Trypsin-Sepharose affinity chromatography after extraction. The antimicrobial activity test was performed through the microdilution assay and the modulating action of the antibiotics ampicillin, norfloxacin and gentamicin, using a subinhibitory concentration MIC/8. Although the samples did not show direct antimicrobial action against the ATCC strains Escherichia coli, Staphylococcus aureus and methicillin-resistant S. aureus (MRSA), it was observed that, at a concentration of 128 µg/mL, the samples associated with the different antibiotics (aminoglycoside, β-lactam and fluoroquinolone) had a synergistic action against the multiresistant strains of E. coli, S. aureus and Pseudomonas aeruginosa. While the other samples inhibited the action of the serine proteases tested in percentages above 80%, FE reduced 50% of the activities of the enzymes trypsin, human neutrophil elastase (HNE) and chymotrypsin, at concentrations of 0.017, 0.023 and 0.156 µg/µL, respectively, and its antitrypsin activity was maintained at high temperatures (80 ºC) and a wide pH range (2 to 12). No hemolytic activity was observed at concentrations up to 10x higher than the IC50, thus enabling its use in possible pharmacological preparations. In this way, we were able to separate, in a relatively simple way, products derived from P. pyramidalis seeds with relevant activities in the clinical context, considering their potential application in combating infections caused by resistant bacteria, as well as in inflammatory protease disorders, and with reduced treatment costs.
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DANIEL MELO DE OLIVEIRA CAMPOS
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Development of Multi-Epitope Vaccine and Potential Inhibitors of Sars-Cov-2 Mpro Protease: Reverse Vaccinology and Computational Chemistry Approaches
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Leader : JONAS IVAN NOBRE OLIVEIRA
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MEMBRES DE LA BANQUE :
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JONAS IVAN NOBRE OLIVEIRA
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UMBERTO LAINO FULCO
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JOAO FIRMINO RODRIGUES NETO
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JÉSSICA DE FÁTIMA VIANNA
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KATYANNA SALES BEZERRA
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Data: 9 sept. 2024
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Afficher le Résumé
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Infections caused by SARS-CoV-2 have posed a significant threat to global public health and continue to be a relevant and complex issue. This thesis aimed to explore new approaches to combating the virus, focusing on the development of a multi-epitope vaccine and the identification of potential Mpro protease inhibitors. Two in silico studies were conducted: one dedicated to the design of a multi-epitope vaccine using reverse vaccinology, and the other focused on developing non-covalent inhibitors through computational chemistry. Additionally, the thesis includes a critical review of emerging antiviral strategies. The first chapter of this thesis presents a critical commentary on promising targets and pharmacological strategies adopted during the pandemic. Among the main targets were Mpro, the S glycoprotein, and TMPRSS2. It concludes that, despite advancements, definitive evidence on the efficacy of these treatments was still necessary. Meanwhile, repurposing existing drugs and using convalescent plasma remained the best alternatives until an effective vaccine was developed. In the second chapter, we conducted an in silico study to develop a new multi-epitope vaccine against SARS-CoV-2, including the Alpha, Beta, Gamma, Delta, and Omicron variants. We used an immunoinformatics approach to identify the best immunogenic epitopes from the four structural proteins of the virus (S, M, N, and E) from 475 genomes sequenced from regions with high disease incidence. The vaccine was modeled, refined, validated, and its molecular docking with the TLR3 receptor was evaluated. The results suggest that the candidate vaccine increases antibody response and should be tested in clinical trials. In the third chapter, we evaluated and compared two potential non-covalent inhibitors of SARS-CoV-2 Mpro, WU-04 and ML188, using computational chemistry approaches, including quantum calculations and ADMET analysis. Our results revealed that residues Met165, Asn142, Glu166, His41, and Leu141 are critical as they interact with high affinity with both inhibitors, suggesting that these residues are essential for complex stabilization. The total energy calculated for the Mpro-WU-04 complex was -52.21 kcal/mol, while for Mpro-ML188, it was -40.47 kcal/mol, indicating that the WU-04 inhibitor has greater energetic affinity.
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CYNTHIA HAYNARA FERREIRA DA SILVA
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Development of Blends Containing Fucoidan and Evaluation of Antioxidant Activity In Vitro and In Vivo in Caenorhabditis elegans and Zebrafish (Danio rerio) Models
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Leader : HUGO ALEXANDRE DE OLIVEIRA ROCHA
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MEMBRES DE LA BANQUE :
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DAYANNE LOPES GOMES
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HUGO ALEXANDRE DE OLIVEIRA ROCHA
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LEANDRO SILVA COSTA
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MARÍLIA MEDEIROS FERNANDES DE NEGREIROS
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ÉDER GALINARI FERREIRA
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Data: 30 sept. 2024
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Afficher le Résumé
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Oxidative stress is a crucial physiological process involved in regulating and maintaining several fundamental processes in organisms, as well as in diseases such as cardiovascular diseases, neurodegenerative diseases, and cancer. There is growing interest in identifying new molecules, particularly from natural sources, that possess antioxidant properties. Marine macroalgae have emerged as functional foods and sources of active molecules with various properties, including sulfated polysaccharides (PS). One example is PS fucoidan A (FucA), extracted from the algae Spatoglossum schroederi, which has been studied for its antithrombotic, anti-inflammatory, and non-genotoxic potential. However, FucA does not exhibit significant antioxidant activity. The presence of antioxidant properties could enhance the effects of the biological activities already identified. One strategy to enhance the effects of a molecule is through chemical modification by adding functional groups and developing blends that combine the properties of two components. To improve the antioxidant activity of FucA, factorial design and response surface plots were employed to develop blends containing FucA and dextran modified with gallic acid (Dex-Gal). Chemical and structural analyses confirmed that Dex-Gal was modified with the addition of 3% GA and exhibited a total antioxidant capacity (TAC) 3.2 times higher than that of unmodified Dex. Dex-Gal and FucA were subjected to factorial design to create different proportions and develop five blends (BLD1, BLD2, BLD3, BLD4, and BLD5). Two blends, BLD1 and BLD5, demonstrated low activity in the antioxidant tests performed. In the TAC test, three blends stood out: BLD4 (22 Eq. AA), BLD3 (17 Eq. AA), and BLD2 (13 Eq. AA). In the reducing power test, BLD4 showed a reduction of 28%, compared to 17% for BLD2 and 15% for BLD3. Notably, BLD4 also excelled in the hydroxyl radical scavenging test, demonstrating approximately 100% activity. Analysis of the surface graphs confirmed that the ideal proportion of the FucA and Dex-Gal blend is that formulated in BLD4, with a 1:1 ratio of each component. BLD4 was selected for antioxidant tests in the 3T3 cell line, as well as in biological models of Caenorhabditis elegans and zebrafish (Danio rerio). BLD4 did not exhibit cytotoxicity in 3T3 cells and provided protective effects against oxidative stress induced by H2O2; it enhanced the survival of C. elegans larvae under oxidative stress with T-BOOH and reduced intracellular ROS by 30%; it also protected zebrafish embryos from oxidative stress caused by H2O2. In both cellular and C. elegans models, BLD4 performed better compared to its isolated components.
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ELLYNES AMANCIO CORREIA NUNES
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PURIFICATION, CHARACTERIZATION AND BACTERIOSTATIC ACTIVITY OF A MANGANESE-DEPENDENT LECTIN FROM THE VENOM OF Bothrops moojeni
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Leader : LUDOVICO MIGLIOLO
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MEMBRES DE LA BANQUE :
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LUDOVICO MIGLIOLO
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ADRIANA FERREIRA UCHOA
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ELIZEU ANTUNES DOS SANTOS
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JULIANA PAVAN ZULIANI
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OCTÁVIO LUIZ FRANCO
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Data: 15 oct. 2024
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Afficher le Résumé
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Bioactive molecules isolated from venomous animals constitute a variety of components with biological activities that can be directed to the treatment of different diseases. Snake venoms are composed of approximately 90% proteins and peptides. These toxins perform different biochemical mechanisms and are therefore responsible for the clinical response observed in snakebites. Knowledge of snake proteins allows the study of heterologous activities related to these toxins, such as antibacterial and antitumor activity. In this context, the objective of this study was to conduct a bibliographic review on the protein group of lectins isolated from snake venoms and to isolate, characterize and understand the biological activities of a lectin from the venom of the snake Bothrops moojeni. A literature review was conducted on lectins isolated and characterized from snake venoms, focusing on their main characteristics and classification, with an emphasis on studies from the last decade. It was found that, to date, snake venom lectins are predominantly classified as C-type lectins and C-type lectin-like proteins, exhibiting diverse biological activities. These include potential applications in the treatment of neoplastic and hematologic diseases, as well as demonstrated antibacterial properties. In addition, the identification of a protein with lectin activity was performed using Size Exclusion Chromatography (SEM) and Reverse-Phase High Performance Liquid Chromatography (RP-HPLC). The following procedures included analysis by Polyacrylamide Gel (SDS-PAGE), as well as hemagglutination assays, inhibition of hemagglutinating activity, and evaluation of ion, pH and temperature dependence. Additionally, hemolytic activity, antibacterial activity against the bacterial strains Acinetobacter baumannii and Staphylococcus aureus, and antibiofilm activity was evaluated. Molecular exclusion generated a chromatographic profile with 6 peaks that were analyzed by polyacrylamide gel electrophoresis and subjected to hemagglutination assays. Hemagglutinating activity was observed in fractions 5 and 6, with the best result for fraction 5, which was named BmoojL. It was also confirmed that BmoojL is manganese-dependent. Furthermore, BmoojL was inhibited in the presence of the carbohydrate’s glucose, fructose, mannose, fucose and N-acetylgalactosamine, and was active at temperatures up to 80 °C and in pH ranges from 5 to 9. The hemolytic assay showed that the molecule did not promote hemagglutination at the concentrations tested (31.25 - 500 µg. mL-1), with a hemolysis percentage below 10%. The antibacterial assays showed that despite not reaching the minimum inhibitory concentration, BmoojL reduced the bacterial growth of A. baumannii from the concentration of 64 µg. mL-1. The antibiofilm assay showed that for S. aureus, BmoojL was effective, considerably reducing biofilm growth at all concentrations tested (16 - 512 µg. mL-1) by approximately 50%. It was also shown that the ion, in isolation and associated with another protein, did not perform significant activity, as observed with BmoojL. Furthermore, it was found that BmoojL inhibited bacterial growth, indicating that the molecule acts bacteriostatically. Thus, the study allowed the isolation of a molecule with manganese-dependent lectin activity with the potential to exert antibacterial and antibiofilm activity, contributing to the research of bioactive molecules derived from venomous snakes. Although the literature recommends some studies involving such molecules and their heterologous activity, when compared to other molecular groups, the study involving lectins from venomous animals remain an underexplored area of research. These findings show what there is still to know about these molecules and to direct and propose new activities that may add to biotechnological research involving these animal groups.
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GEOVANNA MARIA DE MEDEIROS MOURA
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Unveiling the Antibiotic Modulating and Antioxidant Properties of the Wild Mushroom Langermannia bicolor
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Leader : ELIZEU ANTUNES DOS SANTOS
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MEMBRES DE LA BANQUE :
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ELIZEU ANTUNES DOS SANTOS
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BRUNO OLIVEIRA DE VERAS
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MARIA TATIANA ALVES OLIVEIRA
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PAULA IVANI MEDEIROS DOS SANTOS
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WESLLEY DE SOUZA PAIVA
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Data: 4 déc. 2024
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Afficher le Résumé
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The emergence of multidrug-resistant bacteria has driven the search for new therapeutic agents and adjuvants. In this study, we investigated the properties of an extract from the mushroom Langermannia bicolor as a modulator of antibiotics (gentamicin, norfloxacin, and ampicillin) against multidrug-resistant strains of Staphylococcus aureus, Escherichia coli, and Pseudomonas aeruginosa, as well as its antioxidant activity and toxicity. The crude aqueous extract of L. bicolor was fractionated using increasing volumes of acetone, resulting in three fractions (F0.5, F1, and F2), which exhibited different biochemical profiles. Tests with human erythrocytes revealed that the extract and its fractions did not exhibit hemolytic activity, while MTT reduction assays in fibroblast cells (NHI/3T3) showed that the crude extract reduced viability by 50%. In vivo tests with zebrafish embryos, up to young larvae (Danio rerio), confirmed the absence of toxicity of the fractions through embryotoxic analyses, heart rate measurements, and behavioral tests. Although none of the fractions demonstrated direct antibacterial activity, all exhibited significant modulatory effects when combined with conventional antibiotics against the tested multidrug-resistant bacteria. Notably, fraction F2, rich in proteins with higher proteolytic and hemagglutinating activities, reduced the Minimum Inhibitory Concentration (MIC) of gentamicin across all tested strains. The fractions also displayed potent antioxidant properties both in vitro and in vivo. Fraction F0.5, enriched with phenolic compounds and flavonoids, exhibited the broadest spectrum of antioxidant activities, including metal chelation (Fe²⁺ and Cu²⁺), free radical scavenging (•OH and O₂⁻•), and both concurrent and preventive cellular protection against hydrogen peroxide (H₂O₂) induced oxidative stress in 3T3 cells. Meanwhile, fraction F1, which was carbohydrate-rich, was able to repair oxidative damage following H₂O₂ stress. In vivo, all fractions protected zebrafish embryos exposed to H₂O₂. When quantifying reactive oxygen species (ROS) using a fluorescent probe (DFCH), zebrafish larvae treated with F0.5 followed by H₂O₂ significantly reduced ROS production in their cells, yielding values even lower than those of larvae not exposed to the oxidizing agent. To a lesser extent, F1 and F2 also protected zebrafish cells by reducing ROS production. By pioneering the therapeutic potential of L. bicolor, our study paves the way for future investigations into the bioactive composition of this mushroom and its respective molecular mechanisms involved in the observed properties: antibiotic potentiation and protection against oxidative stress.
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ALESSANDRA MARINHO MIRANDA LUCENA
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ANTIOXIDANT ACTION AND NEUROPROTECTIVE EFFECT OF SULFATED POLYSACCHARIDES
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Leader : RAFAEL BARROS GOMES DA CAMARA
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MEMBRES DE LA BANQUE :
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RAFAEL BARROS GOMES DA CAMARA
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HUGO ALEXANDRE DE OLIVEIRA ROCHA
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KATIA CASTANHO SCORTECCI
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FAUSTO PIERDONA GUZEN
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PABLO DE CASTRO SANTOS
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ÉDER GALINARI FERREIRA
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Data: 4 déc. 2024
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Afficher le Résumé
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Neurodegenerative diseases are the result of multifactorial biological mechanisms, involving both exogenous and endogenous causes. Due to the increase in life expectancy and the predicted growth of dementia conditions, there is a growing concern in the search for more effective prevention and treatment for neurodegeneration. Oxidative stress has been shown to be an important factor in the development and progression of these diseases, due to intrinsic characteristics of nervous tissue (e.g., low regenerative capacity and high energy demand). Seaweeds are sources of various bioactive molecules, especially sulfated polysaccharides (SP). These compounds are important for the maintenance and survival of sea weeds and have significant biological activities, such as antioxidant and anti-inflammatory. These properties can be useful in the treatment of neurodegenerative diseases. Seaweeds SP have shown promise as an alternative for neuroprotection. Nine species of seaweed have been identified whose SPs exhibit antioxidant action under different conditions. Forty-four sulfated polysaccharides rich fractions (PRF) were obtained. These PRF were evaluated for their cytotoxicity in Neuro-2A cells at different concentrations (0.1, 0.25, 0.5, or 1 mg/mL). From each PRF, two concentrations were selected, one higher and one lower, which showed MTT reduction values equal to or greater than 80%. They were analyzed for their ability to protect against oxidative damage caused by hydrogen peroxide. To select the PRF that would be evaluated for the possible protection mechanisms employed, the results of yield parameters, cytotoxic effect, and neuroprotective potential in cell culture were considered to construct a Score. The possible mechanisms involved were analyzed by determining the hydrogen peroxide scavenging potential and the effect on the expression of genes in the antioxidant pathway (Keap1, Nrf2, Sod1, Cat, Gpx, Hmox1, Gclc, Gclm) and the subunits of the NFκB transcription factor (Nfkb1 and Rela). Additionally, the antioxidant protection capacity was evaluated in an in vivo model (Zebrafish). Forty-two PRF did not show cytotoxic effects against Neuro-2A cells at at least one of the evaluated concentrations. All evaluated seaweeds had PRF that protected Neuro-2A cells from oxidative damage induced by hydrogen peroxide. Furthermore, through the Score, it was possible to observe that brown seaweed had the best results. Based on these data, four PRF (DJ 1.2, SF 0.5, SS 1.3, and DM 1.0) were selected for the evaluation of the possible mechanisms involved. The data obtained here demonstrate that the mechanisms used by these samples range from direct action on oxidant molecules to the modulation of endogenous antioxidant mechanisms, promoting an increase in the expression of genes related to the translation of antioxidant enzymes and a reduction in the expression of genes related to a pro-inflammatory and pro-oxidant response. Additionally, these polysaccharides were able to promote protection against oxidative stress in an in vivo model. These data are important for the development of future evaluations of these molecules, as they provided knowledge about their potential neuroprotective effect and antioxidant behavior in more complex organisms, thus guiding the possible mechanisms employed.
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ISAIANE MEDEIROS
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STUDY OF THE EFFECT OF NATURAL BIOACTIVE PROTEINS AND PEPTIDES IN THE TREATMENT OF DIABETES MELLITUS
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Leader : ANA HELONEIDA DE ARAUJO MORAIS
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MEMBRES DE LA BANQUE :
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ADRIANA AUGUSTO DE REZENDE
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ANA HELONEIDA DE ARAUJO MORAIS
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ANA LUISA PIRES MOREIRA
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AUGUSTO MONTEIRO DE SOUZA
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EDUARDO BORGES DE MELO
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Data: 27 déc. 2024
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Afficher le Résumé
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Diabetes mellitus (DM) is a public health problem characterized by hyperglycemia. The aim of this study was to evaluate the effect of natural bioactive proteins and peptides in the treatment of DM. Thus, this thesis is divided into three chapters. The first chapter describes the protocol for the systematic review (SR), which was registered in the International Register of Prospective Systematic Reviews (PROSPERO, number: CRD42022355540) and guided the construction of the SR presented in the second chapter. In the second chapter, the SR was conducted with the objective of answering the starting question: which peptides or proteins have been studied in silico for the treatment of diabetes mellitus? The articles were selected based on PECOs (Population, Exposure, and Context) from the databases PubMed, ScienceDirect, Scopus, Web of Science, Virtual Health Library, and EMBASE. Based on eligibility criteria, five articles were included, and the risk of bias was assessed using the adapted Strengthening the Reporting of Empirical Simulation Studies (STRESS) tool. The results showed that proteins and/or peptides extracted from natural sources interacted in silico with therapeutic targets involved in DM management, such as α-amylase, dipeptidyl peptidase IV (DPP-IV), α-glucosidase, insulin receptor (IR), glucose transporter type 2 (GLUT-2), and sodium-glucose co-transporter protein (SGLT1). When re-evaluated in vivo, these interactions promoted a reduction in fasting blood glucose, improvement in pancreatic morphology, positive regulation of insulin secretion and expression, reduction or maintenance of plasma insulin levels, a decrease in HOMA-IR, an increase in HOMA-β, and maintenance of GLP-1. This demonstrated that in silico studies provided crucial insights into therapeutic strategies for DM. In the third chapter, a preclinical study was conducted to evaluate the effect of trypsin inhibitor isolated from tamarind seed (ITT) in zebra fish with increased fasting blood glucose developed by overfeeding with Artemia sp., aiming to determine the mechanism of action of this inhibitor through glycation or insulin-like pathways. Biochemical parameters, relative expression of the IR gene, and morphological changes in organs and tissues relevant to type 2 diabetes (T2DM) and protein glycation (in vitro and in vivo) were evaluated. The diagnosis of T2DM was made using Accu-Chek® for fasting blood glucose measurement before treatment began. The animals (n = 140), of both sexes, were divided into four groups (n = 35): 1) healthy, untreated, and normo-fed animals, 2) T2DM animals without treatment and overfed, 3) T2DM animals treated with 25 mg of ITT/L and overfed, and 4) T2DM animals treated with 25 mg of ITT/L and normo-fed for 10 days. Fasting blood glucose was 62.33 mg/dL (2.52) for normo-fed animals and 104.70 mg/dL (4.16) for overfed animals pre-treatment (p = 0.008). After treatment, a significant reduction (p < 0.01) in fasting blood glucose, HOMA-IR, and QUICKI index, and a significant increase (p < 0.01) in HOMA-β were observed in the animals treated with ITT and overfeeding compared to the untreated T2DM group. However, these values showed no significant difference (p > 0.05) compared to the healthy animals, except for the QUICKI index. A significant increase (p < 0.01) in insulin was observed in all groups compared to the healthy control. No significant change (p > 0.05) in in vitro glycation of bovine serum albumin was observed for ITT concentrations of 1.4 and 5 mg/mL, while the concentration of 25 mg/mL of ITT significantly increased (p < 0.01). This finding did not persist when checking the formation of advanced glycation end products (AGEs) in vivo (p > 0.05) among the groups treated with 25 mg of ITT/L. Additionally, ITT promoted negative regulation of relative IR expression in adipose tissue and skeletal muscle. Histopathological findings showed reduced visceral adiposity, pancreatic and hepatic steatosis, and renal degeneration in animals treated with ITT and overfeeding. However, further studies are still needed to elucidate the mechanisms of fasting blood glucose reduction.
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