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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
21

Estudo comparativo de venenos de serpentes do gênero Crotalus ssp. / Comparative study of the Crotalus ssp. snake venoms

José Pedro Prezotto Neto 06 December 2018 (has links)
As cascavéis são classificadas como grupo monofilético contendo dois gêneros descritos ao grupo: Crotalus ssp. e Sistrurus ssp., os quais surgiram no México a aproximadamente 20 milhões de anos, colonizando então, praticamente todo o continente americano. Fatores como dieta, dimorfismo sexual, ontogenia, mutações e distribuição geográfica podem influenciar na composição dos venenos e consequentemente no envenenamento. O presente trabalho tem como objetivo caracterizar o perfil proteico, bem como as propriedades enzimáticas e imunológicas dos venenos de algumas espécies e subespécies de Crotalus ssp. (C. atrox, C. scutulatus scutulatus, C. viridis viridis, C. vegrandis, C. durissus cascavella, C. d. collilineatus e C. d. terrificus). Os resultados indicaram pouca variabilidade entre os perfis eletroforéticos dos venenos, contudo as diferenças foram na concentração relativa das proteínas. A análises proteômica identificou alguns componentes dos venenos e serinopeptidases, metalopeptidases e fosfolipases A2 foram as mais abundantes. Além disso, por zimografia, observou-se que todos os venenos analisados apresentaram atividade proteolítica e que os venenos norte-americanos em todos os zimogramas foram mais hidrolíticos. Em caseína, a atividade enzimática dos venenos foi menos intensa comparado aos outros substratos. Em relação às gelatinases das amostras estudadas, pôde ser observado inibição da atividade enzimática induzida por alguns componentes utilizando EDTA, principalmente nos venenos de C. atrox e C. vegrandis. Em relação à inibição das serinopeptidases, foi observado que todas as gelatinases dos venenos crotálicos apresentaram inibição total ou parcial da atividade hidrolítica. Houve variabilidade entre as hialuronidases encontradas dos venenos crotálicos, tanto em relação à massa das enzimas e intensidade da degradação, quanto em diferentes pHs. Nos ensaios enzimáticos quantitativos (azocaseinolítico fosfolipásico e peptidásico) os venenos Norte Americanos demonstraram conter mais proteases em relação aos venenos Sul Americanos. Por Western Blotting, as amostras reagiram com os anticorpos presentes nos soros anti-crotálico e anti-botrópico, apresentando reatividade antigênica cruzada entre as amostras homólogas e heterólogas. Além disso, houve imunoreatividade entre o soro anti-jararagina e alguns componentes de todos os venenos crotálicos norte-americanos. / The rattlesnakes are classified as a monophyletic group containing two genera referring to the group: Crotalus ssp. and Sistrurus ssp., which arose in Mexico 20 millions of years ago, colonizing then, practically all the American continent. Some scientific works indicate that factors such as diet, sexual dimorphism, ontogeny, mutations and distribution may influence the composition of the venoms and consequently the poisoning. The present work aims to characterize the enzymatic and immunological properties of the venoms of some species and subspecies of Crotalus ssp. (C. atrox, C. scutulatus scutulatus, C. viridis viridis, C. vegrandis, C. durissus cascavella, C. collilineatus and C. d. terrificus). The results indicated few variability among the electrophoretic profiles of the venoms, however the differences were in the relative concentration of the proteins. The proteomic analysis identified serinopeptidases, metallopeptidases and phospholipases A2, which were the most abundant components of the venoms. In addition, zymography assays indicate that the all the venoms showed proteolytic activity, furthermore, the North American venoms, presented more hydrolysis in all zimograms. The caseinolytic activity was less intense compared with other substrates. Regarding the gelatinolytic activity of the samples, inhibition of the enzymatic activity of some components could be observed using EDTA, mainly in the C. atrox and C. vegrandis venoms. Partial or total inhibition was observed of the serinopeptidases activity of the crotalic gelatinases. Among the hyaluronidases, variations between crotalic venoms, in relation to the enzymes mass and degradation intensity were identified. In addition, when incubated at different pHs, the hyaluronidase profile presented different patterns in the activity. In the quantitative enzymatic assays (azocaseinolytic phospholipasic, peptidasic) the North American venoms displayed higher activity in relation to the South American venoms. In the Western Blotting assays, the samples reacted with antibodies present in the Brazilian anti-crotalic and bothropic sera, indicating cross-reactive antigenicity between the homologous and heterologous samples. Besides that, there was immunoreactivity between the anti-jararrhagin serum and some components of all North American crotalic venoms.
22

Model-based Biomarker Detection and Systematic Analysis in Translational Science

Sun, Youting 2012 May 1900 (has links)
This dissertation is concerned with the application of mathematical modeling and statistical signal processing into the rapidly expanding fields of proteomics and genomics. The research is guided by a translational goal which drives the problem formalization and experimental design, and leads to optimization, prediction and control of the underlying system. The dissertation is comprised of three interconnected subjects. In the first part of the dissertation, two Bayesian peptide detection algorithms are proposed to optimize the feature extraction step, which is the most fundamental step in mass spectrometry-based proteomics. The algorithms are designed to tackle data processing challenges that are not satisfactorily addressed by existing methods. In contrast to most existing methods, the proposed algorithms perform deisotoping and deconvolution of mass spectra simultaneously, which enables better identification of weak peptide signals. Unlike greedy template-matching algorithms, the proposed methods have the capability to handle complex spectra where features overlap. The proposed methods achieve better sensitivity and accuracy compared to many popular software packages such as msInspect. In the second part of the dissertation, we consider modeling and assessing the entire mass spectrometry-based proteomic data analysis pipeline. Different modules are identified and analyzed, resulting in a framework that captures key factors in system performance. The effects of various model parameters on protein identification rates and quantification errors, differential expression results, and classification performance are examined. The proposed pipeline model can be used to aid experimental design, pinpoint critical bottlenecks, optimize the work flow, and predict biomarker discovery results. Finally, the same system methodology is extended to analyze the work flow in DNA microarray experiments. A model-based approach is developed to explore the relationship among microarray data properties, missing value imputation, and sample classification in a complicated data analysis pipeline. The situations when it is suitable to apply missing value imputation are identified and recommendations regarding imputation are provided. In addition, a missing value rate-related peaking phenomenon is uncovered.
23

Proteomic analysis of nitrile-induced proteins in Klebsiella oxytoca

Chou, Shu-min 06 September 2006 (has links)
The cyanide-degradation bacteria Klebsiella oxytoca SYSU-110 was isolated from the waste water of a metal-plating plant in southern Taiwan. K. oxytoca can utilize many nitrile compounds [including acetonitrile (100 mM), benzonitrile (1 mM), butyronitrile (100 mM), glutaronitrile (50 mM), methacrylnitrile (100 mM), phenylacetonitrile (1 mM), propionitrile (25 mM), succinonitrile (25 mM) and valeronitrile (50 mM)] as its sole nitrogen source. In this study, we found out that K. oxytoca was capable of degrading acetonitrile and propionitrile. Frome GC analysis, we recognized amide was an intermediate compound, while the carboxylic acid and ammonia were the final end-products. Therefore, we presume that K. oxytoca biodegraded nitrile compounds by two enzymes, the nitrile hydratase and amidase. We also analyzed the total cell proteins by 2-D polyacrylamide gel electrophoresis after the cells were cultured in medium containing 25mM succinonitrile. There were 23 proteins could be induced or overexpressed by nitrile and we had identified 11 by Mascot Peptide mass Fingerprint and Blast. Six proteins that can protect the cells from oxidative damage are: superoxide dismutase, glutathione s-transferase, dyp-type peroxidase, metal binding protein PsaA (that can transport metal ions into the cells), LraI, and FepA (used to transport inorganic ions into the cells). Three enzymes glutamine synthetase, methylenetetrahydrofolate reductase,¡@and dihydroxyacid dehydratase were used to synthesize amino acids. One protein was identified as ribosomal protein L9. The last identified protein is nucleoside triphosphates kinase which can convert nucleoside diphosphates to nucleoside triphosphates non-specifically. From the activity analysis, superoxide dismutase and glutathione S-transferase activities were escalated when the cells were cultured in 25mM succinonitrile, and the concentration of ROS has rise. These results suggested that succinonitrile could cause oxidative damage to the cells and induce some anti-oxidative damage proteins to protect them.
24

Aspects of MEN1 Tumorigenesis in Endocrine Pancreas and Adrenal Glands

Chu, Xia January 2015 (has links)
Multiple endocrine neoplasia syndrome type 1 (MEN1) is an autosomal dominantly inherited disease, which is described as an association of tumors mainly in endocrine organs, including pancreas and adrenal glands. Pancreatic neuroendocrine tumors (PNETs) are the most common cause of death in MEN1 patients. More than one third of the MEN1 patients also develop enlargement of the adrenals. MEN1 is caused by a germline mutation of MEN1 gene, a tumor suppressor gene that is located on the human chromosome 11. As noticed, the MEN1 related tumors often develop prior to inactivation of both wild type alleles, indicating MEN1 haploinsufficiency. In this thesis, I utilized a conventional Men1 mouse model that has the phenotype mimicking the human MEN 1 traits, in order to investigate MEN1 tumorigenesis in endocrine pancreas and adrenal glands.   The microvascular aberrations contributing to development and maintenance of PNETs were characterized. The increased vascular density of PNETs developed in the Men1 mice was paralleled by an early and extensive redistribution of pericytes within endocrine tissue. These morphological alterations were supported by fine-tuned variations in expression of several angiogenic regulators  (VEGF, FGF and PDGF) and were further potentiated by hypoxia. Vascular reactivity and blood perfusion of tumor arterioles were significantly altered in response to glucose and L-nitro-arginine methyl ester. Investigation of adrenals from10-month-old Men1 mice showed 681 proteins in mass spectrometry data sets, in which 52 proteins were commonly found in the Men1+/+ and Men1+/- adrenals, and the differential expression between the genotypes reached significant levels. Prdx3, catalyzing the reduction of oxidative stress to cell survival, is one of the overexpressed proteins. Some proteins belonging to the PPARα pathway, e.g. ACLY were also overexpressed. Subsequent microRNA (miRNA) profiling analysis of adrenals from the same age group revealed 31 miRNAs whose expression was significantly altered in comparison between the genotypes. The tumor suppressor miRNAs, miR-486, miR-330 and miR-214, were significantly downregulated in Men1+/- adrenals. The latter, miR-214, is known to inhibit ACLY expression. This finding was in concordance with the proteomic analysis. The oncogene miRNAs, miR-132 and miR-494, were significantly enhanced in the Men1+/- adrenals. Gene ontology analysis demonstrated overrepresentation of the miRNA-targeted genes that are involved in nucleic acid metabolism, vasculature development, angiogenesis, and transcription. Together, these finding after validation in humans may be exploited to improve MEN1 cancer treatment.
25

Proteomic Characterization of Hemogen in Erythropoiesis

Somasundaram, Brinda 31 October 2012 (has links)
Hemogen (Hemgn) is reported as a tissue specific transcriptional regulator in testis as well as hematopoietic tissues. It is known that Hemgn positively regulates erythroid differentiation; however,the underlying molecular mechanism is not well understood. In the current study, using proteomic approach in combination with other molecular biology tools,we have attempted to decipher the role of Hemgn in differentiating Murine erythroblast leukemia (MEL) cells as a model system. Our study reveals that Hemgn predominantly interacts with transcriptional regulators, chromatin modifiers and histones. Furthermore, using Chromatin Immunoprecipitation and knockdown approach, we have demonstrated that Hemgn is recruited to the b-globin locus, which is known to be activated during erythroid differentiation. Based on the results,we speculate that Hemgn acts as a tissue specific histone chaperone that regulates transcription during erythroid differentiation.
26

Developing Mass Spectrometry-Based Analytical Methodologies for Analyzing Complex Protein and Lipid Samples

Hou, Weimin 18 September 2013 (has links)
Mass spectrometry has increasingly become the method of choice for the analysis of complex biological samples, including proteins and lipids. This thesis describes the development of MS-based analytical methodologies for the analysis of complex proteomic and lipidomic samples. Chapter 3 describes the development of microfluidic proteomic reactors, in the formats of SCX reactor, SCX 96-well plate reactor, and SAX reactor, for the enzymatic digestion of complex proteomic samples for subsequent LC-MS/MS analysis. These microfluidic proteomic reactors greatly simplified the enzymatic digestion of complex proteomic samples by combining multiple processing steps, such as rapid extraction and enrichment of proteins. Furthermore, chemical and enzymatic treatments of proteins were all performed in a few nanoliters effective volume, resulting in an increased protein digestion efficacy. After the protein digestion process, the resulting peptides were eluted in buffers that were compatible with HPLC-MS/MS analysis. In chapter 4, a methodology based on nano-HPLC-ESI-MS/MS for the analysis of PAF and LPC lipid species is described. In this method, lipid extracts from biological samples were separated by nano-flow HPLC prior to being introduced into a Q-TRAP 2000 mass spectrometer, where the lipid species of interest were detected using a precursor ion scan at m/z 184. Absolute quantitation of PAF family lipid species were performed with standard addition method, where 5 standard solutions containing 0.2-1 ng each of C16:0, C18:0 PAF and C16:0, C18:0 lyso-PAF were used in the experiment. Further, the spiking of identical amount of non-endogenous C13:0 LPC at time of extraction allow the relative comparisons of other LPC lipid species of interest between different samples. The developed methods were employed to analyze the changes of PAF and LPC lipid species in NGFdifferentiated PC12 cells, in the posterior/entorhinal cortex of AD patients and TgCRND8 transgenic mice, and over the course of 24 hour exposure of human hNT neurons to Aβ42 treatment, respectively, in comparison to controls. iii Chapter 5 describes the development of a novel shotgun lipidomic methodology for the determination of stereospecificity of diacyl glycerophospholipids including glycerophosphatidic acids (PA), glycerophosphoserines (PS), glycerophosphoglycerols (PG), glycerophosphoinositols(PI), and glycerophosphoethanolamines (PE), which can be conventionally ionized under negative ion mode. The stereospecificity of diacyl glycerophospholipids was determined based on the relative abundance of the lyso-form fragment ions, attributed to the neutral loss of fatty acyl moieties. The fragmentation patterns of a variety of diacyl glycerophospholipid standards were first fully examined over a wide range of collision energy. We observed that lyso-form fragment ions corresponding to the neutral loss of fatty acyl moieties attached to the sn2 position as free fatty acids ([M-Sn2]-) and as ketenes ([M-(Sn2-H2O)]-) exhibited consistently higher intensity than their counter part ions due to the neutral loss of fatty acyl moieties attached to the sn1 position ([M-Sn1]- and [M-(Sn1-H2O)]-). We then examined the product ion spectra of diacyl glycerophospholipids recorded from lipid extracts of rat hepatoma cells, where the stereospecific information of these lipids was conclusively determined.
27

Caracterização química e avaliação da atividade biológica da própolis vermelha em células tumorais e não tumorais

Frozza, Caroline Olivieri da Silva 07 December 2012 (has links)
A própolis vermelha brasileira tem atraído interesses científicos e econômicos devido às suas variadas atividades biológicas. Este produto natural possui composição química diferente de acordo com a região na qual é encontrado, sendo necessária uma completa caracterização química para cada tipo de própolis, a fim de se elucidar os compostos presentes e possivelmente responsáveis por estas atividades. Dentre as atividades biológicas mais investigadas, destacam-se as atividades antioxidante e antitumoral. Neste trabalho, buscou-se caracterizar quimicamente o extrato hidroalcoólico da própolis vermelha brasileira, avaliar as atividades antioxidantes e antitumorais, além de investigar o padrão proteico de células tumorais de laringe tratadas e não tratadas com extratos da própolis vermelha através da análise proteômica comparativa. A caracterização química realizada através de espectrometria de massas com ionização por electrospray mostrou que a própolis apresenta moléculas complexas, principalmente isoflavonoides, compostos com importantes atividades biológicas. Os extratos hidroalcoólicos obtidos a partir da própolis vermelha revelaram um significante conteúdo de polifenóis associados a uma habilidade de sequestrar radicais livres DPPH·. Os extratos também apresentaram atividades superóxido-dismutase-/ike e catalase-/ike, indicando que podem exercer um papel fundamental na manutenção fisiológica do equilíbrio redox quando em um organismo. A atividade citotóxica dos extratos da própolis foi avaliada nas linhagens tumorais Hep-2, HeLa e não tumoral Hek-293, sendo que os valores de IC50 foram menores para a linhagens tumorais em relação a não tumoral. Desta forma, sugere-se uma seletividade da própolis vermelha quanto às linhagens tumorais. A análise proteômica, usando eletroforese bidimensional associada à cromatografia líquida de alta eficiência acoplada a espectrômetro de massa, permitiu a comparação dos mapas proteicos da linhagem Hep-2, na ausência ou presença de extratos da própolis vermelha, nas concentrações 6 f.1g/mL (não citotóxica) e 120 f.lg/mL (IC50). A excisão manual de 325 spots foi efetuada nos géis 2D- SDS-PAGE, em que 177 proteínas foram identificadas. Estas proteínas foram relacionadas com diversos processos metabólicos e estruturais como produção e conversão de energia, transporte e metabolismo de carboidratos, modificação pós-traducional, reciclagem de proteínas e chaperonas, proteínas do citoesqueleto, proteínas de reparo, entre outros. Das proteínas identificadas com expressão diferencial, cinco apresentaram expressão reduzida na presença do extrato da própolis, este em sua maior concentração (120 f.lg/mL). Apenas duas proteínas identificadas neste estudo mostraram expressão aumentada na concentração não citotóxica (6 f.lg/mL) do extrato da própolis vermelha. Os resultados da proteômica comparativa mostram que a própolis interfere em um conjunto de eventos intracelulares e, assim, passa a ser uma candidata promissora para inibir o crescimento celular e contribuir para os diferentes passos relacionados com o processo de carcinogênese. Embora os mecanismos moleculares pelos quais a própolis vermelha interaja com o metabolismo das células permaneçam ainda desconhecidos, estudos adicionais servirão para melhor elucidar as atividades antioxidantes e antitumorais aqui observadas. / Submitted by Marcelo Teixeira (mvteixeira@ucs.br) on 2014-06-11T12:18:58Z No. of bitstreams: 1 Dissertacao Caroline Olivieri da Silva Frozza.pdf: 43747 bytes, checksum: ca596fd367a149df47e208c279da85cb (MD5) / Made available in DSpace on 2014-06-11T12:18:58Z (GMT). No. of bitstreams: 1 Dissertacao Caroline Olivieri da Silva Frozza.pdf: 43747 bytes, checksum: ca596fd367a149df47e208c279da85cb (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Brazilian red propolis has attracted scientific and economic interests because of its varied biological activities. This natural product has different chemical compositions according to the region in which it is found, requiring a robust chemical characterization to elucidate the compounds responsible for the activities in each type of propolis investigated. So far antioxidant and antitumor properties are amongst the most studied biological activities. This study aimed to characterize chemically the hydroalcoholic extract of Brazilian propolis from the state of Sergipe, evaluate the antitumor and antioxidant activities, and to investigate the pattern o f proteins in tumor cells o f the larynx treated o r not with extracts of propolis through comparative proteomic analysis. The chemical characterization by mass spectrometry with electrospray ionization showed that propolis presents complex molecules, especially isoflavones, which has important biological and antioxidant capacity. The hydroalcoholic extracts obtained from propolis revealed a significant content of polyphenols associated with the ability to scavenge DPPH. radicais. The extracts also showed significant activities for superoxide dismutase-like and catalase-like, indicating an important role in maintaining physiological redox equilibrium, decreasing oxidative stress. Cytotoxic activity was assessed for tumor cell !ines Hep-2, HeLa and non-tumor cell line Hek-293, showing IC50 values greater for Hek-293 compared to Hep-2 and HeLa cells, which suggests a selectivity of propolis for the tumor !ines. The proteomic analysis using two-dimensional electrophoresis associated with high performance liquid chromatography coupled with mass spectrometer allowed the comparison of the protein maps of Hep-2 cell line in the absence or presence of propolis extracts in concentrations of 6 f.lg/mL (not cytotoxic) and 120 f.lg/mL (IC50). 325 spots were manually excised from the gels 2D SDS-PAGE and 177 proteins were identified. These proteins have been linked to various structural and metabolic processes, such as production and energy conversion, transport and carbohydrate metabolism, post-translational modification, protein tumover and chaperones, cytoskeletal proteins, repair proteins, among others. From the identified proteins that showed differential expression five were downregulated in the presence of propolis extract in the highest concentration (120 J.lg/mL). Only . two proteins identified in this study showed increased expression in the no cytotoxic concentration (6 J.tg/mL) ofthe red propolis extract. The results of comparative proteomic showed that the propolis interacts with a series of intracellular events and hence becomes a promising candidate to inhibit cellular growth and contribute to the different steps related to the process of carcinogenesis. Although the molecular mechanisms by which propolis interacts with the metabolism of the cells remain unknown, additional studies will better elucidate the antitumor and antioxidant activities here observed.
28

Molecular aspects of temperature regulation of sunflower seed dormancy / Mécanismes moléculaires de la régulation de la dormance des graines de tournesol par la température

Xia, Qiong 29 September 2016 (has links)
La graine est le produit de la reproduction sexuée chez les Angiospermes. Elle assure la survie et la dispersion de l'espèce. La germination des graines est la première étape de la croissance des plantes. La transition entre l'état de dormance des graines et leur germination est une étape clef dans le cycle de vie des plantes qui a des conséquences écologique et commerciale. Depuis plusieurs décennies, de nombreux facteurs de l'environnement ont été étudiés pour leurs implications et leurs conséquences dans le processus de dormance et de germination des graines. Les études sur la réponse des semences aux changements de température en liens avec le réchauffement climatique ont un intérêt primordial. Le but de ce travail a été d'étudier la régulation de la dormance et de la germination des graines de tournesol par la température. Une analyse protéomique et un profilage enzymatique ont été réalisés afin de mieux comprendre la régulation du métabolisme pendant la levée de dormance par la température. L'utilisation d'approches moléculaires et cytologiques, nous ont permis d'appréhender l'interaction entre la température et les phytohormones impliquées dans ce processus. Nos résultats ont révélé le rôle joué par la température comme facteur externe affectant la dormance et la germination des graines en agissant d'une part sur le métabolisme et d'autre part sur la quantité et la localisation cellulaire des principales hormones endogènes. / A seed is the product of sexual reproduction and the means by which the new individual is dispersed by angiosperms. Seed germination being the first step of plant establishment, the ultimate role of the transition between seed dormancy and germination during plant lifecycle is an important ecological and commercial trait. Last several decades, several environment factors have been reviewed to strongly effect the process of seed dormancy and germination. However, studies about seed response to temperature change are acute with the global warming. The aim of this work was to investigate temperature regulation of dormancy and germination in sunflower seeds. Proteomic analysis and enzyme profiling have been used to study metabolism regulation during seed dormancy release by temperature. Moreover, using molecular and cytological approaches, we investigate the interaction between temperature and phytohormones involved in this process. Our results revealed that temperature as an external factor to effect seed dormancy and germination by affecting, in one hand, the metabolism, and in the other hand the level and localization of major endogenous hormones.
29

Caracterização química e avaliação da atividade biológica da própolis vermelha em células tumorais e não tumorais

Frozza, Caroline Olivieri da Silva 07 December 2012 (has links)
A própolis vermelha brasileira tem atraído interesses científicos e econômicos devido às suas variadas atividades biológicas. Este produto natural possui composição química diferente de acordo com a região na qual é encontrado, sendo necessária uma completa caracterização química para cada tipo de própolis, a fim de se elucidar os compostos presentes e possivelmente responsáveis por estas atividades. Dentre as atividades biológicas mais investigadas, destacam-se as atividades antioxidante e antitumoral. Neste trabalho, buscou-se caracterizar quimicamente o extrato hidroalcoólico da própolis vermelha brasileira, avaliar as atividades antioxidantes e antitumorais, além de investigar o padrão proteico de células tumorais de laringe tratadas e não tratadas com extratos da própolis vermelha através da análise proteômica comparativa. A caracterização química realizada através de espectrometria de massas com ionização por electrospray mostrou que a própolis apresenta moléculas complexas, principalmente isoflavonoides, compostos com importantes atividades biológicas. Os extratos hidroalcoólicos obtidos a partir da própolis vermelha revelaram um significante conteúdo de polifenóis associados a uma habilidade de sequestrar radicais livres DPPH·. Os extratos também apresentaram atividades superóxido-dismutase-/ike e catalase-/ike, indicando que podem exercer um papel fundamental na manutenção fisiológica do equilíbrio redox quando em um organismo. A atividade citotóxica dos extratos da própolis foi avaliada nas linhagens tumorais Hep-2, HeLa e não tumoral Hek-293, sendo que os valores de IC50 foram menores para a linhagens tumorais em relação a não tumoral. Desta forma, sugere-se uma seletividade da própolis vermelha quanto às linhagens tumorais. A análise proteômica, usando eletroforese bidimensional associada à cromatografia líquida de alta eficiência acoplada a espectrômetro de massa, permitiu a comparação dos mapas proteicos da linhagem Hep-2, na ausência ou presença de extratos da própolis vermelha, nas concentrações 6 f.1g/mL (não citotóxica) e 120 f.lg/mL (IC50). A excisão manual de 325 spots foi efetuada nos géis 2D- SDS-PAGE, em que 177 proteínas foram identificadas. Estas proteínas foram relacionadas com diversos processos metabólicos e estruturais como produção e conversão de energia, transporte e metabolismo de carboidratos, modificação pós-traducional, reciclagem de proteínas e chaperonas, proteínas do citoesqueleto, proteínas de reparo, entre outros. Das proteínas identificadas com expressão diferencial, cinco apresentaram expressão reduzida na presença do extrato da própolis, este em sua maior concentração (120 f.lg/mL). Apenas duas proteínas identificadas neste estudo mostraram expressão aumentada na concentração não citotóxica (6 f.lg/mL) do extrato da própolis vermelha. Os resultados da proteômica comparativa mostram que a própolis interfere em um conjunto de eventos intracelulares e, assim, passa a ser uma candidata promissora para inibir o crescimento celular e contribuir para os diferentes passos relacionados com o processo de carcinogênese. Embora os mecanismos moleculares pelos quais a própolis vermelha interaja com o metabolismo das células permaneçam ainda desconhecidos, estudos adicionais servirão para melhor elucidar as atividades antioxidantes e antitumorais aqui observadas. / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Brazilian red propolis has attracted scientific and economic interests because of its varied biological activities. This natural product has different chemical compositions according to the region in which it is found, requiring a robust chemical characterization to elucidate the compounds responsible for the activities in each type of propolis investigated. So far antioxidant and antitumor properties are amongst the most studied biological activities. This study aimed to characterize chemically the hydroalcoholic extract of Brazilian propolis from the state of Sergipe, evaluate the antitumor and antioxidant activities, and to investigate the pattern o f proteins in tumor cells o f the larynx treated o r not with extracts of propolis through comparative proteomic analysis. The chemical characterization by mass spectrometry with electrospray ionization showed that propolis presents complex molecules, especially isoflavones, which has important biological and antioxidant capacity. The hydroalcoholic extracts obtained from propolis revealed a significant content of polyphenols associated with the ability to scavenge DPPH. radicais. The extracts also showed significant activities for superoxide dismutase-like and catalase-like, indicating an important role in maintaining physiological redox equilibrium, decreasing oxidative stress. Cytotoxic activity was assessed for tumor cell !ines Hep-2, HeLa and non-tumor cell line Hek-293, showing IC50 values greater for Hek-293 compared to Hep-2 and HeLa cells, which suggests a selectivity of propolis for the tumor !ines. The proteomic analysis using two-dimensional electrophoresis associated with high performance liquid chromatography coupled with mass spectrometer allowed the comparison of the protein maps of Hep-2 cell line in the absence or presence of propolis extracts in concentrations of 6 f.lg/mL (not cytotoxic) and 120 f.lg/mL (IC50). 325 spots were manually excised from the gels 2D SDS-PAGE and 177 proteins were identified. These proteins have been linked to various structural and metabolic processes, such as production and energy conversion, transport and carbohydrate metabolism, post-translational modification, protein tumover and chaperones, cytoskeletal proteins, repair proteins, among others. From the identified proteins that showed differential expression five were downregulated in the presence of propolis extract in the highest concentration (120 J.lg/mL). Only . two proteins identified in this study showed increased expression in the no cytotoxic concentration (6 J.tg/mL) ofthe red propolis extract. The results of comparative proteomic showed that the propolis interacts with a series of intracellular events and hence becomes a promising candidate to inhibit cellular growth and contribute to the different steps related to the process of carcinogenesis. Although the molecular mechanisms by which propolis interacts with the metabolism of the cells remain unknown, additional studies will better elucidate the antitumor and antioxidant activities here observed.
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Análise proteômica comparativa do processo de diferenciação celular do fungo patogênico Paracoccidioides brasiliensis / Comparative proteomic analysis of the cell differentiation process in Paracoccidioides sp

Vaz, Alessandro Fernandes 31 July 2014 (has links)
Submitted by Erika Demachki (erikademachki@gmail.com) on 2015-05-18T17:10:51Z No. of bitstreams: 2 Dissertação - Alessandro Fernandes Vaz - 2014.pdf: 2674595 bytes, checksum: 4be2a3df9927e868ec83389dd6ab3365 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Erika Demachki (erikademachki@gmail.com) on 2015-05-18T17:13:28Z (GMT) No. of bitstreams: 2 Dissertação - Alessandro Fernandes Vaz - 2014.pdf: 2674595 bytes, checksum: 4be2a3df9927e868ec83389dd6ab3365 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-05-18T17:13:28Z (GMT). No. of bitstreams: 2 Dissertação - Alessandro Fernandes Vaz - 2014.pdf: 2674595 bytes, checksum: 4be2a3df9927e868ec83389dd6ab3365 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-07-31 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Paracoccidioides spp. is the etiological agent of paracoccidioidomycosis, the most important endemic systemic mycosis in Latin America. Paracoccidioides spp. is a dimorphic fungus; mycelia is found in soil at temperatures below 25ºC, while in host tissues, and temperature around 36-37ºC the fungus takes the yeast form. Infection begins with the inhalation of conidia or mycelia propagules that upon reaching the host lungs differentiate into yeast, establishing disease. The morphological transition from mycelia-to-yeast is involved in the virulence of this pathogen and this aspect of morphogenesis deserves special attention due to its relevance to the fungal virulence. In the present study, we employed proteomic strategies using liquid chromatography coupled to mass spectrometry to evaluate the differential proteomic profile of cells ongoing transition from mycelia-to-yeast after 22 h of temperature shift from 22ºC to 36ºC (P. brasiliensis Pb-18 phylogenetic lineage S1). Nine hundred and ninety-one proteins were identified (350 in the mycelia, 288 in the transition and 353 in the yeast), and 251 were differentially regulated. The analysis of the functional categories to which those proteins belong provided us a comprehension on the metabolic reprogramming that occurs during the cell differentiation process, providing putative virulence factors. / Paracoccidioides spp. é o agente etiológico da paracoccidioidomicose, a mais importante micose sistêmica endêmica da América Latina. Paracoccidioides spp. é um fungo dimórfico, que apresenta alteração morfológica de acordo com a temperatura do ambiente. A forma miceliana é encontrada no solo a temperaturas inferiores a 25 ºC, enquanto que em tecidos do hospedeiro e sob temperaturas de 36-37 ºC o fungo assume forma leveduriforme. A infecção se inicia com a inalação de conídios presentes na forma filamentosa do fungo, os quais ao atingirem os pulmões se diferenciam na forma leveduriforme, estabelecendo a paracoccidioidomicose. A transição de micélio para levedura está envolvida na virulência desse patógeno e esse aspecto da morfogênese do fungo não está totalmente compreendido. No presente estudo, foi utilizada a cromatografia líquida acoplada à espectrometria de massas (nanoUPLC-MSE) para avaliar o perfil proteômico durante a transição de micélio para levedura após 22 h da mudança da temperatura de 22ºC para 36ºC (P. brasiliensis – isolado Pb18). Um total de 991 proteínas foram identificadas (350 em micélio, 288 na transição e 353 em levedrua) e 251 foram diferencialmente expressas durante o processo de diferenciação celular. Entre as proteínas que foram abundantes em micélio estão as subunidades da ATPase que participa na cadeia transportadora de elétrons e enzimas envolvidas na fermentação alcoólica. Proteínas relacionadas à via glicolítica e alguns potenciais fatores de virulência começam sua acumulação após 22 h do início da transição morfológica. Em levedura enzimas relacionadas com a glicólise e a beta-oxidação tiveram alta expressão. As análises das categorias funcionais a que essas proteínas pertencem, forneceram uma melhor compreensão da reorganização metabólica que ocorre durante a transição morfológica de micélio para levedura, incluindo possíveis fatores de virulência.

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