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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.
51

Efeitos do inibidor específico para serinoprotease rBmTI-A em modelo experimental de inflamação pulmonar alérgica crônica em camundongos Balb/c / Effects of the specific inhibitor for serine protease rBmTI-A in an experimental model of chronic allergic pulmonary inflammation in Balb/c mice

Ariana Corrêa Florencio 05 April 2018 (has links)
INTRODUÇÃO: A asma ainda acomete um número crescente de indivíduos, podendo ser muito grave e, algumas vezes, fatal. A despeito da melhor eficiência diagnóstica e eficácia terapêutica, a maioria dos asmáticos graves não obtém controle total dos sintomas com as terapias disponíveis. Alguns estudos sugerem a atuação de inibidores de serinoproteases em diversos processos inflamatórios, entre estes inibidores encontra-se o Boophilus microplus trypsin Inhibitor (BmTI-A). OBJETIVO: Avaliar se o recombinante do inibidor de serinoproteases rBmTI-A modula a hiperresponsividade brônquica à metacolina, inflamação e remodelamento das vias aéreas em um modelo experimental de inflamação pulmonar alérgica crônica. MÉTODOS: Camundongos Balb-c foram divididos em 4 grupos: SAL (salina), OVA (sensibilizados com ovoalbumina), SAL+rBmTI-A (controle tratados com rBmTI-A ) e OVA+rBmTI-A (sensibilizados com ovoalbumina e tratados com rBmTI-A). Nos dias 0 e 14 do protocolo, os animais receberam injeção intraperitoneal (i.p) de salina (0,9% NaCl) (SAL e SAL+rBmTI-A) e ovoalbumina (50 ug/mL) (OVA e OVA+rBmTI-A). Nos dias 22, 24, 26 e 28 foram submetidos à inalação com salina (0,9% NaCl) ou ovoalbumina (10 mg/ml) e foram tratados com rBmTI-A (35,54 pmol em 50 uL de NaCl) ou apenas salina, via instilação nasal, nos dias 22 e 28. No dia 29, foram realizadas as seguintes análises: hiper-responsividade à metacolina e respostas máximas de resistência e elastância do sistema respiratório; quantificação do número total de células, macrófagos, linfócitos e polimorfonucleares no fluido do lavado broncoalveolar (FLBA); determinação da concentração das citocinas IL-4, IL-5, IL-10, IL-13, IL-17A e IFN-y no FLBA por citometria de fluxo (Cytometric Bead Array - CBA); avaliação da expressão de IL-4, IL-5, IL-10, IL-13, IL-17, MMP-9 e TIMP-1 nas vias aéreas; análise histopatológica do pulmão para quantificação de eosinófilos, fibras colágenas e elásticas e avaliação da atividade proteolítica de tripsina-like, MMP-1 e MMP9. A significância foi considerada p < 0,05. RESULTADOS: O tratamento com rBmTI-A nos animais sensibilizados reduziu a atividade proteolítica de tripsina no tecido pulmonar; a resposta máxima de Rrs e Ers; o número de polimorfonucleares e a concentração de IL-5, IL-10, IL-13 e IL-17A no FLBA; a expressão de IL-5, IL-13, IL-17, MMP-9 e TIMP-1 nas vias aéreas; o número de eosinófilos e a fração de fibras colágenas e elásticas nas vias aéreas do grupo OVA+rBmTI-A comparado ao grupo OVA (p < 0,05). CONCLUSÃO: O rBmTI-A atenuou a hiper-responsividade brônquica, a inflamação e o remodelamento nesse modelo experimental de inflamação pulmonar alérgica crônica. Embora mais estudos precisem ser realizados, este inibidor pode contribuir como potencial ferramenta terapêutica para o tratamento de asma / INTRODUCTION: Asthma still affects an increasing number of individuals and can be very serious and sometimes fatal. Despite the improved diagnostic efficiency and therapeutic efficacy, most severe asthmatics do not have complete symptom control with available therapies. Some studies suggest the role of serine protease inhibitors in various inflammatory processes, such as Boophilus microplus trypsin inhibitor (BmTIA). AIMS: To evaluate whether rBmTI-A serine protease inhibitor recombinant modulates bronchial hyperresponsiveness to methacholine, airway inflammation and remodeling in an experimental model of chronic allergic lung inflammation. METHODS: Balb/c mice were divided in four groups: SAL (saline), OVA (sensitized with ovalbumin), SAL+rBmTI-A (control treated with rBmTI-A) and OVA+rBmTI-A (sensitized with ovalbumin and treated with rBmTI-A). On days 0 and 14 of the protocol the animals received intraperitoneal injection (i.p) of saline (0.9% NaCl) (SAL and SAL+rBmTI-A) and ovalbumin (50 ug/mL) (OVA and OVA+rBmTI-A). On days 22, 24, 26 and 28 the groups were submitted to inhalations with saline (0.9% NaCl) or ovalbumin (10 mg/ml) and were treated with a rBmTI-A (35.54 pmol in 50 uL of saline or just saline) by nasal instillation, on the days 22 and 28. On day 29, the following analysis were performed: hyperresponsiveness to methacholine and the maximal resistance and elastance responses of the respiratory system were obtained; quantification of the total number of cells, macrophages, lymphocytes and polymorphonuclear in bronchoalveolar lavage fluid (FLBA); determination of the cytokines IL-4, IL-5, IL-10, IL-13, IL-17A and IFN-y concentration in FLBA by Cytometric Bead Array (CBA); IL4, IL-5, IL-10, IL-13, IL-17, MMP-9 and TIMP-1 expression in the airways; histopathological analysis of the lung for quantification of eosinophils, collagen and elastic fibers and evaluation of trypsin-like, MMP-1 and MMP9 proteolytic activity. Significance was considered when p < 0.05. RESULTS: The treatment with rBmTI-A in sensitized animals reduced: the proteolytic activity of trypsinlike in lung tissue, the maximum response of Rrs and Ers, the number of polymorphonuclear cells and the concentration of IL-5, IL-10, IL-13 and IL-17A in FLBA, the expression of IL-5, IL-13, IL-17, MMP-9 and TIMP-1 in the airways, the number of eosinophils and the fraction of collagen and elastic fibers in the airways of the OVA + rBmTI-A group compared to the OVA group (p < 0.05). CONCLUSION: rBmTI-A attenuated bronchial hyperresponsiveness, inflammation and remodeling in this experimental model of chronic allergic pulmonary inflammation. Although more studies need to be performed, this inhibitor may contribute as a potential therapeutic tool for the asthma treatment
52

Efeitos do inibidor específico para serinoprotease rBmTI-A em modelo experimental de inflamação pulmonar alérgica crônica em camundongos Balb/c / Effects of the specific inhibitor for serine protease rBmTI-A in an experimental model of chronic allergic pulmonary inflammation in Balb/c mice

Florencio, Ariana Corrêa 05 April 2018 (has links)
INTRODUÇÃO: A asma ainda acomete um número crescente de indivíduos, podendo ser muito grave e, algumas vezes, fatal. A despeito da melhor eficiência diagnóstica e eficácia terapêutica, a maioria dos asmáticos graves não obtém controle total dos sintomas com as terapias disponíveis. Alguns estudos sugerem a atuação de inibidores de serinoproteases em diversos processos inflamatórios, entre estes inibidores encontra-se o Boophilus microplus trypsin Inhibitor (BmTI-A). OBJETIVO: Avaliar se o recombinante do inibidor de serinoproteases rBmTI-A modula a hiperresponsividade brônquica à metacolina, inflamação e remodelamento das vias aéreas em um modelo experimental de inflamação pulmonar alérgica crônica. MÉTODOS: Camundongos Balb-c foram divididos em 4 grupos: SAL (salina), OVA (sensibilizados com ovoalbumina), SAL+rBmTI-A (controle tratados com rBmTI-A ) e OVA+rBmTI-A (sensibilizados com ovoalbumina e tratados com rBmTI-A). Nos dias 0 e 14 do protocolo, os animais receberam injeção intraperitoneal (i.p) de salina (0,9% NaCl) (SAL e SAL+rBmTI-A) e ovoalbumina (50 ug/mL) (OVA e OVA+rBmTI-A). Nos dias 22, 24, 26 e 28 foram submetidos à inalação com salina (0,9% NaCl) ou ovoalbumina (10 mg/ml) e foram tratados com rBmTI-A (35,54 pmol em 50 uL de NaCl) ou apenas salina, via instilação nasal, nos dias 22 e 28. No dia 29, foram realizadas as seguintes análises: hiper-responsividade à metacolina e respostas máximas de resistência e elastância do sistema respiratório; quantificação do número total de células, macrófagos, linfócitos e polimorfonucleares no fluido do lavado broncoalveolar (FLBA); determinação da concentração das citocinas IL-4, IL-5, IL-10, IL-13, IL-17A e IFN-y no FLBA por citometria de fluxo (Cytometric Bead Array - CBA); avaliação da expressão de IL-4, IL-5, IL-10, IL-13, IL-17, MMP-9 e TIMP-1 nas vias aéreas; análise histopatológica do pulmão para quantificação de eosinófilos, fibras colágenas e elásticas e avaliação da atividade proteolítica de tripsina-like, MMP-1 e MMP9. A significância foi considerada p < 0,05. RESULTADOS: O tratamento com rBmTI-A nos animais sensibilizados reduziu a atividade proteolítica de tripsina no tecido pulmonar; a resposta máxima de Rrs e Ers; o número de polimorfonucleares e a concentração de IL-5, IL-10, IL-13 e IL-17A no FLBA; a expressão de IL-5, IL-13, IL-17, MMP-9 e TIMP-1 nas vias aéreas; o número de eosinófilos e a fração de fibras colágenas e elásticas nas vias aéreas do grupo OVA+rBmTI-A comparado ao grupo OVA (p < 0,05). CONCLUSÃO: O rBmTI-A atenuou a hiper-responsividade brônquica, a inflamação e o remodelamento nesse modelo experimental de inflamação pulmonar alérgica crônica. Embora mais estudos precisem ser realizados, este inibidor pode contribuir como potencial ferramenta terapêutica para o tratamento de asma / INTRODUCTION: Asthma still affects an increasing number of individuals and can be very serious and sometimes fatal. Despite the improved diagnostic efficiency and therapeutic efficacy, most severe asthmatics do not have complete symptom control with available therapies. Some studies suggest the role of serine protease inhibitors in various inflammatory processes, such as Boophilus microplus trypsin inhibitor (BmTIA). AIMS: To evaluate whether rBmTI-A serine protease inhibitor recombinant modulates bronchial hyperresponsiveness to methacholine, airway inflammation and remodeling in an experimental model of chronic allergic lung inflammation. METHODS: Balb/c mice were divided in four groups: SAL (saline), OVA (sensitized with ovalbumin), SAL+rBmTI-A (control treated with rBmTI-A) and OVA+rBmTI-A (sensitized with ovalbumin and treated with rBmTI-A). On days 0 and 14 of the protocol the animals received intraperitoneal injection (i.p) of saline (0.9% NaCl) (SAL and SAL+rBmTI-A) and ovalbumin (50 ug/mL) (OVA and OVA+rBmTI-A). On days 22, 24, 26 and 28 the groups were submitted to inhalations with saline (0.9% NaCl) or ovalbumin (10 mg/ml) and were treated with a rBmTI-A (35.54 pmol in 50 uL of saline or just saline) by nasal instillation, on the days 22 and 28. On day 29, the following analysis were performed: hyperresponsiveness to methacholine and the maximal resistance and elastance responses of the respiratory system were obtained; quantification of the total number of cells, macrophages, lymphocytes and polymorphonuclear in bronchoalveolar lavage fluid (FLBA); determination of the cytokines IL-4, IL-5, IL-10, IL-13, IL-17A and IFN-y concentration in FLBA by Cytometric Bead Array (CBA); IL4, IL-5, IL-10, IL-13, IL-17, MMP-9 and TIMP-1 expression in the airways; histopathological analysis of the lung for quantification of eosinophils, collagen and elastic fibers and evaluation of trypsin-like, MMP-1 and MMP9 proteolytic activity. Significance was considered when p < 0.05. RESULTS: The treatment with rBmTI-A in sensitized animals reduced: the proteolytic activity of trypsinlike in lung tissue, the maximum response of Rrs and Ers, the number of polymorphonuclear cells and the concentration of IL-5, IL-10, IL-13 and IL-17A in FLBA, the expression of IL-5, IL-13, IL-17, MMP-9 and TIMP-1 in the airways, the number of eosinophils and the fraction of collagen and elastic fibers in the airways of the OVA + rBmTI-A group compared to the OVA group (p < 0.05). CONCLUSION: rBmTI-A attenuated bronchial hyperresponsiveness, inflammation and remodeling in this experimental model of chronic allergic pulmonary inflammation. Although more studies need to be performed, this inhibitor may contribute as a potential therapeutic tool for the asthma treatment
53

Caractérisation de IrSPI, un inhibiteur de sérine protéase impliqué dans la prise du repas sanguin et l’infection bactérienne des tiques Ixodes ricinus. / Characterization of IrSPI, a serine protease inhibitor implicated both in tick feeding and tick bacterial infection of Ixodes ricinus.

Blisnick, Adrien 21 February 2019 (has links)
Ixodes ricinus est l’espèce de tique la plus abondante et ayant la plus vaste répartition géographique en Europe. Elle est le vecteur de nombreux agents pathogènes d’importance en santé publique et vétérinaire. Le remplacement des acaricides générant pollution environnementale et apparition croissante de résistances requiert le développement urgent de nouvelles stratégies de lutte efficaces contre les tiques et les agents pathogènes qu’elles transmettent. La découverte de telles stratégies passe nécessairement par une meilleure connaissance des interactions entre les tiques, leurs hôtes et les agents pathogènes transmis. La salive de tique, à l’interface de ces interactions, est un fluide essentiel pour ces arthropodes et possède notamment des propriétés protéolytiques, anticoagulantes, immunomodulatrices, analgésique, et anti-inflammatoires qui permettent à la tique de réaliser ses repas sanguins extrêmement longs. Afin de comprendre les mécanismes moléculaires impliqués dans la transmission des agents pathogènes et pour identifier de possibles candidats vaccinaux contre I. ricinus, une étude transcriptomique comparative entre des glandes salivaires infectées et non infectées par la bactérie Bartonella henselae a été antérieurement réalisée. Le transcrit le plus surexprimé suite à cette infection était IrSPI, un inhibiteur de sérine protéase de la famille des Kunitz. Les analyses fonctionnelles par ARN interférence ont montré l’implication de ce gène dans le gorgement et de l’infection des glandes salivaires par B. henselae. Ainsi, les travaux de thèse présentés ici ont concerné l’analyse structurelle, biochimique et fonctionnelle de IrSPI en tant que molécule impliquée dans les interactions tick-hôte-pathogène. Le premier objectif était de définir la structure et la séquence du gène IrSPI mais, malheureusement, bien que nos résultats aient permit des avancés sur cette question, nous n'avons pu obtenir la totalité de sa séquence. Dans un second temps, la dynamique d’expression d’IrSPI a été évaluée au cours du gorgement et de l’infection des tiques par différents agents pathogènes, montrant que son expression est induite par le repas sanguin, par des agents transmis par la tique mais pas par Escherichia coli, bactérie non transmise. De plus, nos résultats ont montré l’expression de IrSPI dans plusieurs organes de la tique, suggérant son implication dans diverses fonctions au sein de ce vecteur. Parmi elles, la mise en évidence d'une injection, par la salive, de la protéine à l'hôte vertébré nous a permis d'envisager un rôle sur les réponses de l'hôte à la piqûre de tique. Nos résultats n’ont montré aucune implication dans la voie extrinsèque de la coagulation ni dans la fibrinolyse, ni dans l’angiogenèse. En revanche, ils ont démontré que IrSPI inhibe la prolifération des lymphocytes TCD4+ sous stimulation monogénique quand chez des lymphocytes B non stimulés IRSPI, il induit une hausse de la prolifération. De plus IrSPI a montré une action négative significative sur la production de la majorité des cytokines et chimiokines pro-inflammatoires produites par les macrophages et les splénocytes. Ainsi, IrSPI, correspond à un des composants salivaires d’I. ricinus lui permettant de moduler la réponse immune de l’hôte pour lui permettre de prélever son repas sanguin tout en favorisant la transmission des agents pathogènes. Enfin, des résultats préliminaires dans l'identification des interactants de IrSPI à la fois chez la tique et l’hôte vertébré ouvre de nombreuses voies de recherche quant à la compréhension de ses fonctions. / Ixodes ricinus tick species, the most abundant and widespread tick in Europe, is an important vector of pathogens affecting both animal and human health. To replace the use of acaricides that generate environmental contamination and resistances, new environmentally sustainable approaches providing broad protection against ticks and tick-borne pathogens (TBP) are urgently needed. Such development requires improved understanding of the biology of ticks and more particularly of their interactions with vertebrate hosts and TBP. Tick saliva is an essential biofluid for ticks, as its proteolytic, anticoagulant, immunomodulatory, analgesic and anti-inflammatory activities allow ticks to acquire their blood meal under optimal conditions. Moreover, injection of saliva during blood feeding represents the principal route by which TBP are transmitted to the host. To understand the molecular mechanisms involved in TBP transmission, as well as to identify putative vaccine candidates against I. ricinus, salivary glands from bacteria infected and uninfected ticks were previously compared by high throughput transcriptomics. The most up-regulated transcript following infection was IrSPI, which belongs to the Kunitz/BPTI inhibitor family. Functional analyses via RNAi knockdown experiments revealed that IrSPI enhances both blood feeding and bacterial burden in the salivary glands. This present PhD work concerns then the structural, biochemical and functional characterization of IrSPI as a molecule involved in tick-host-pathogen interactions. Our aim was first to define the structure of IrSPI gene but, unfortunately, while our results have led to progress on this issue, we have not been able to get the full sequence. Then, the dynamic of IrSPI expression was evaluated during both tick feeding and colonization of ticks by pathogens, showing that its expression is induced by blood feeding and TBP but not by Escherichia coli that is not transmitted by I. ricinus. In addition, our results shown the expression of IrSPI in several tick organs, suggesting its implication in several functions in tick physiology. Among them, the discovery of the injection of IrSPI, through the saliva, to the vertebrate host allowed us to consider a role in host responses to tick bite. Evaluation of IrSPI effect on host showed no impact on coagulation through extrinsic pathway, as determined by analysis of thrombin generation time and by fibrinolysis, or in angiogenesis. However, it inhibited the proliferation of mitogen-stimulated CD4+ lymphocytes and increased unstimulated-B cell proliferation. In addition, IrSPI also modulated cytokine production from macrophages and splenocytes, repressing significantly most of proinflammatory cytokines and chemokines. Thus, we demonstrated that IrSPI plays a role in modulating the host immune response during blood feeding. Finally, preliminary results in the identification of the protein’s interactants open many research perspectives for understanding how IrSPI acts in tick physiology and counteracts host responses to tick injury and pathogen transmission.
54

New Methods for the Synthesis of 3-Substituted 1-Indanones : A Palladium-Catalyzed Approach

Arefalk, Anna January 2005 (has links)
<p>In medicinal chemistry, there is a constant need for new preparative methods, both to make the synthesis process more effective, and to increase the accessibility to a wide variety of compounds. A number of different approaches can be used to attain these goals. Transition metal catalysis is generally performed under mild conditions, providing both regio- and chemoselective reactions. Thus, it offers an attractive means of preparation of complex drug candidates. Two additional methodologies used to increase the preparative efficiency are one-pot protocols and controlled microwave heating. One-pot and multi-component reactions are less time consuming than step-by-step reactions, and microwave heating has been used to considerably shorten the reaction times. </p><p>This thesis describes a new palladium-catalyzed, one-pot reaction producing racemic acetal-protected 3-hydroxy-1-indanones from ethylene glycol vinyl ether and triflates of salicylic aldehydes. The triflates were prepared using controlled microwave heating. The reaction sequence starts with a regioselective internal Heck coupling, followed by an annulation cascade. By including secondary amines in the reaction mixture, the reaction was further developed into a three-component reaction delivering racemic acetal-protected 3-amino-1-indanones. This new method was utilized for the synthesis of primary, secondary and tertiary aminoindanones. Finally, by using enantiopure t-butyl sulfinyl imines, derived from salicylic aldehyde triflates and ethylene glycol vinyl ether as starting materials in a closely related type of palladium coupling–annulation sequence, a stereoselective protocol providing enantiomerically pure 3-amino-1-indanones was developed. To demonstrate an application in medicinal chemistry, the enantiopure 3-amino-1-indanones were incorporated as P2 and/or P2´ substituents into active HIV-1 protease inhibitors.</p>
55

Les complexes métallo-organiques au cuivre (II), une nouvelle famille d'inhibiteurs de la protéase du virus de l'immunodéficience humaine de type 1/Metallo-organic copper (II) complexes as a new family of HIV-1 protease inhibitors

Ledecq, Marie 16 December 2004 (has links)
La protéase du VIH-1 est une cible de choix dans le traitement du SIDA, car l’inhibition de son activité protéolytique contrecarre la réplication virale. Dans ce contexte, une approche de conception de novo d’inhibiteurs non peptidiques de cet enzyme, réalisée au sein de notre laboratoire, avait permis d’épingler une famille originale de complexes métallo-organiques au cuivre (II). Au cours de cette thèse, nous avons entrepris la caractérisation physico-chimique et structurale de ces composés afin d’élucider leur mode d’interaction avec la protéase, en nous appuyant sur diverses techniques expérimentales (DRX, RPE, ESI-MS) et théoriques(mécanique moléculaire, SIBFA). En particulier, nous avons montré que la stabilité thermodynamique de ces complexes en solution était indispensable à toute activité biologique. L’adaptation de la méthode SIBFA aux complexes au cuivre (II) nous a permis d’étudier les phénomènes énergétiques intervenant dans leur stabilité. Enfin, nous avons réuni les critères structuraux responsables de l’activité anti-protéolytique de ces complexes au sein d’un modèle pharmacophorique optimalisé./HIV-1 protease is a main target for the AIDS treatment, because its inhibition blocks the viral replication. De novo drug design, previously conducted in our laboratory, had pointed out several copper (II) chelates as a new family of non peptidic protease inhibitors. In order to provide a better understanding of their structure-activity relationships, we performed the physico-chemical characterization of these compounds using experimental (XRD, EPR, ESIMS)and theoretical (molecular mechanics, SIBFA method) techniques. We demonstrated that the thermodynamic stability of the complexes is an essential property to provide inhibitory activity. The SIBFA procedure adapted to copper (II) complexes helped us to study the energetics involved in the stability process. From our results, we derived a pharmacophore model describing the structural properties needed to achieve a good inhibition of the enzyme.
56

New Methods for the Synthesis of 3-Substituted 1-Indanones : A Palladium-Catalyzed Approach

Arefalk, Anna January 2005 (has links)
In medicinal chemistry, there is a constant need for new preparative methods, both to make the synthesis process more effective, and to increase the accessibility to a wide variety of compounds. A number of different approaches can be used to attain these goals. Transition metal catalysis is generally performed under mild conditions, providing both regio- and chemoselective reactions. Thus, it offers an attractive means of preparation of complex drug candidates. Two additional methodologies used to increase the preparative efficiency are one-pot protocols and controlled microwave heating. One-pot and multi-component reactions are less time consuming than step-by-step reactions, and microwave heating has been used to considerably shorten the reaction times. This thesis describes a new palladium-catalyzed, one-pot reaction producing racemic acetal-protected 3-hydroxy-1-indanones from ethylene glycol vinyl ether and triflates of salicylic aldehydes. The triflates were prepared using controlled microwave heating. The reaction sequence starts with a regioselective internal Heck coupling, followed by an annulation cascade. By including secondary amines in the reaction mixture, the reaction was further developed into a three-component reaction delivering racemic acetal-protected 3-amino-1-indanones. This new method was utilized for the synthesis of primary, secondary and tertiary aminoindanones. Finally, by using enantiopure t-butyl sulfinyl imines, derived from salicylic aldehyde triflates and ethylene glycol vinyl ether as starting materials in a closely related type of palladium coupling–annulation sequence, a stereoselective protocol providing enantiomerically pure 3-amino-1-indanones was developed. To demonstrate an application in medicinal chemistry, the enantiopure 3-amino-1-indanones were incorporated as P2 and/or P2´ substituents into active HIV-1 protease inhibitors.
57

Design and Synthesis of Aspartic and Serine Protease Inhibitors : Targeting the BACE-1 and the HCV NS3 Protease

Wångsell, Fredrik January 2009 (has links)
This thesis describes work done to design and synthesize protease inhibitors, with the intention of developing therapeutic agents for Alzheimer’s disease (AD) and the chronic liver condition caused by infection of the hepatitis C virus (HCV). AD is the most common form of dementia, and HCV infection is the primary reason for liver transplantation in industrialized countries. Today, these two illnesses affect 24 and 170 million people, respectively. It has been shown that the human aspartic protease BACE-1 plays an important role in the development of AD, and thus inhibition of BACE-1 may offer a way to improve the quality of life of individuals afflicted with the disease. Furthermore, it is known that the serine protease NS3 is a vital component in the replication of HCV. Several novel potent BACE-1 inhibitors encompassing different transition state mimics were prepared. First, a hydroxyethylene moiety encompassing a secondary hydroxyl group was evaluated as a transition state analogue, producing inhibitors in the low nanomolar range. Various tertiary hydroxyl isosteres were also investigated as the central core, with the aim of shielding the pivotal hydroxyl group. These transition state isosteres consisted of tertiary hydroxyl analogues of previously used secondary hydroxyl containing norstatine, statine, and hydroxyethylamine isosteres. Several tertiary hydroxyl-containing inhibitors were found to be active in the low micromolar range. In addition, two inhibitors were co-crystallized with the BACE-1 enzyme to provide X-ray crystal structures, which furnished valuable binding information for further design of improved BACE-1 inhibitors. The goal in the HCV NS3 protease inhibitor project was to design, synthesize and evaluate a novel hydroxycyclopentene bioisostere to the previously used acyl-hydroxyproline moiety. The investigation revealed that it was possible to synthesize inhibitors containing this new bioisostere that were potent in the low nanomolar range. Further optimization by rigidification of the most active inhibitor resulted in equipotent macrocyclic compounds.
58

Efeitos de inibidor de protease sobre os epitélios de revestimento e glandular do rato / Effects of protease inhibitors on epithelial tissues and salivar glands of rats

Fabiano Misael Cavenaghi 26 November 2009 (has links)
O tratamento anti-HIV conhecido como HAART (Highly Active Antiretroviral Therapy) se tornou comum por volta de 1996, e utiliza 3 ou 4 diferentes medicamentos em combinação - geralmente dois inibidores de transcriptase reversa + 1 ou 2 inibidores de protease. A introdução desse tipo de tratamento trouxe um grande impacto na morbidade e mortalidade de indivíduos infectados pelo HIV. Os inibidores de protease (PIs) são uma boa alternativa às falhas terapêuticas observadas com o uso dos inibidores de transcriptase reversa, no entanto também são associados a vários efeitos tóxicos, como desconforto abdominal, vômito, diarréia, dor de cabeça, tontura, lipodistrofia, hipercolesterolemia, hipertrigliceridemia e hiperglicemia. Em função da existência de efeitos adversos e da condição do ritonavir como protótipo desse tipo de medicação, nosso objetivo é avaliar o efeito desse medicamento sobre os epitélios de revestimento e glandular relacionados à cavidade bucal, de forma a identificar a possibilidade da existência de complicações bucais relacionadas ao uso de inibidores de protease. Ratos albinos (Wistar) foram tratados com Ritonavir (10mg/Kg) por períodos de 4 e 8 semanas. Foram avaliadas as taxas séricas de triglicérides e colesterol (total, HDL, LDL, VLDL). Ao final dos períodos de tratamentos propostos, os animais foram sacrificados, e as peças utilizadas no estudo foram colhidas, (sangue, pele, língua, palatos e glândulas salivares). O sangue coletado foi imediatamente centrifugado sendo o plasma foi utilizado para avaliação das lipoproteínas. Os tecidos colhidos foram fixados, descalcificados quando necessário, processados para inclusão em parafina, cortados com 6&micro;m de espessura, montados em slides e corados com hematoxilina e eosina, para avaliação histopatológica, morfométrica e estereológica. Os dados colhidos foram apresentados em valores médios, e as diferenças analisadas por testes estatísticos adequados para a comparação entre as amostras. Nossos resultados mostram pequenas variações nas características morfológicas de epitélios de revestimento e glandulares, variações essas que poderiam deixar esses tecidos mais propensos a sofrer alterações significativas com traumas ou injúrias, comuns nos tecidos bucais. Embora observadas com pequeno grau de expressão, essas variações, parecem ser progressivas, ou seja, mais expressivas com o uso continuado do medicamento. Mais estudos devem ser realizados, principalmente voltados para avaliações histoquímicas, bioquímicas e moleculares, no entanto nosso estudo é um alerta inicial para a avaliação dos tecidos bucais de pacientes que utilizam inibidores de protease. / HAART had a dramatic impact on the HIV infection, however, protease inhibitor exhibit significant drug-drug interactions, and side effects. There are only few data on effects of protease inhibitors on oral tissues. We propose to observe experimental effects of ritonavir on oral epithelial tissues, covering and glandular. Wistar rats received Ritonavir twice a week for 4-8 weeks. Controls received no treatment. At the time for sacrifice, plasma were collected for evaluation of triglycerides, total cholesterol, HDL, LDL and VLDL. Were also collected skin, tongue, palate and glandular tissues Lipoproteins were evaluated and histological examination of skin, mucosal epithelium on tongue, palate and salivar submandibular glandula were made under light microscope. Morphometric methods (cariometry and stereology) were used. Data were statistically analysed by Kruskal Wallis test for multiple samples, since our data were considered not-normal. P[U] 0.05 were considered statistically significant. Our results show that protease inhibitor may be associated with small alterations in epithelial tissues, significant mostly when on longer times using the medication. The complete significance of this data has to be better understood, and other studies has to be done to define these points.
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Transformace lilku bramboru genem kódujícím proteázový inhibitor SPI-2 / Transformation of potato with protease inhibitor gene SPI-2

Říhová, Barbora January 2013 (has links)
The subject of my thesis was to genetically modify a potato for increased resistance against its pathogens and pests. In developing a resistant plant, it is quite common to use the same type of molecules that plants use themselves in their defense reactions. In this work I used the gene SPI-2 originating from a honeycomb moth (Galleria mellonella). The protein SPI-2 is a member of serine protease inhibitors. Since the previous attempts of the team to detect the protein in transformed plants haven't been successful, the basic form of the gene was modified by adding a Kozak sequence near the start codon, which should have increased the translation initiation and hence increase the level of the protein. Two constructs were prepared for the transformation: SPI-2-T a SPI-2-Y. They differ by one amino acid, which slightly changes their inhibitory activity. First, the construct SPI-2-T was used for a transient transformation of tobacco Nicotiana benthamiana by agroinfiltration of its leaves. Then both constructs were used for a stable transformation of Solanum tuberosum cv. Desireé. The detection of the protein has not been successful, although the inserted gene was transcribed and his sequence was verified by sequencing. It is therefore most likely that the protein has a low stability in the cytoplasm....
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Basic Residues of β-Sheet A Contribute to Heparin Binding and Activation of Vaspin (Serpin A12)

Ulbricht, David, Oertwig, Kathrin, Arnsburg, Kristin, Saalbach, Anja, Pippel, Jan, Sträter, Norbert, Heiker, John T. 06 March 2019 (has links)
Many members of the serine protease inhibitor (serpin) family are activated by glycosaminoglycans (GAGs). Visceral adipose tissue-derived serpin (vaspin), serpin A12 of the serpin family, and its target protease kallikrein 7 (KLK7) are heparin-binding proteins, and inhibition of KLK7 by vaspin is accelerated by heparin. However, the nature of GAG binding to vaspin is not known. Here, we measured vaspin binding of various glycosaminoglycans and low molecular weight heparins by microscale thermophoresis and analyzed acceleration of protease inhibition by these molecules. In addition, basic residues contributing to heparin binding and heparin activation were identified by a selective labeling approach. Together, these data show that vaspin binds heparin with high affinity (KD = 21 ± 2 nm) and that binding takes place at a basic patch on top of β-sheet A and is different from other heparin-binding serpins. Mutation of basic residues decreased heparin binding and activation of vaspin. Similarly, reactive center loop insertion into sheet A decreased heparin binding because it disturbs the basic cluster. Finally, using vaspin-overexpressing keratinocyte cells, we show that a significant part of secreted vaspin is bound in the extracellular matrix on the cell surface. Together, basic residues of central β-sheet A contribute to heparin binding and activation of vaspin. Thus, binding to GAGs in the extracellular matrix can direct and regulate vaspin interaction with target proteases or other proteins and may play an important role in the various beneficial functions of vaspin in different tissues.

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