Le programme des modèles minimaux (MMP) est l'une des grandes théories développée en géométrie algébrique en vue de classifier les variétés algébriques complexes. Pour certaines familles d'exemples, le MMP est très bien connu. Notamment, pour les variétés toriques et horosphériques, la théorie se résume à une étude assez simple de familles de polytopes, dits polytopes moments, et elle s'étend même à des variétés plus singulières que dans le cas général. Le but de cette thèse est d'étendre ces résultats à des compactifications sphériques d'un groupe. On décrit dans un premier temps ces variétés, et on classifie tous les polytopes moments attachés à de telles compactifications. Puis on démontre que le MMP appliqué sur ces compactifications sphériques se traduit en termes de polytopes moments. Enfin on donne un programme codé en SageMath qui permet de donner les polytopes apparaissant dans le MMP d'une compactification sphérique d'un groupe simple. / The Minimal Model Program (MMP) is one of the greatest theories in Algebraic Geometry developped to classify algebraic varieties. For some families of algebraic varieties, the MMP has been studied in depth. In particular, for toric and horospherical varieties, it comes down to a quite easy study of families of polytopes, called moment polytopes, and it could be adapted to weaker hypothesis of singularities. The goal of this thesis is to show that this reduction can be extended to spherical compactifications of a group. First of all we describe these varieties and classify all moment polytopes of such compactifications. Then we prove that the MMP applied on this spherical compactifications reduces to a study of a families of this moment polytopes. Finaly we give a computer program, coded in SageMath, which gives all polytopes appearing in the MMP of a simple group's spherical compactification.

RECK stands for ¡¥reversion-inducing cysteine-rich protein with Kazal motifs¡¦. This gene was initially discovered by screening a human fibroblast cDNA library for genes giving rise to reversion-inducing clones when transfected into v-Ki-ras transformed NIH3T3 cells. The key action of RECK is to inhibit matrix metalloproteinases (MMPs), and it has a significant effect on limiting tumor invasion. Located within the middle part of RECK protein are three serine protease inhibitor-like (SPI) domains (635-654,716-735 and 754-772 amino acids, respectively) which are similar to Kazal motif. Kazal motif is a peptidase inhibitor motif containing disulfide bonds with small alpha and beta folds. The first of these SPI is identical to the Kazal motif (named as K1) and the other two SPIs are highly similar to the Kazal motif (named as K2 & K3). Given RECK is a MMP inhibitor, these SPI-like domains are likely to have a significant role in MMP inhibition. Our previous data indicated that K23 motifs of RECK protein can inhibit MMP-9 secretion and activity and attenuate metastasis of lung cancer cells. To go a step further, we constructed secretory mammalian expression vectors which could produce K1, K2 and K3 to investigate their effect on MMP activity and cell invasion. We found that K2 also exhibited inhibitory activity on MMP activity and cell invasion. Thus, these finding indicate that the K2 domain of RECK function may be developed as a peptide inhibitor of tumor invasion.

A osteoporose é uma doença osteometabólica que atinge milhares de pessoas; e as doenças cardiovasculares são as principais causas de mortes no mundo. Estudos demonstram que pacientes com baixa densidade mineral óssea apresentam maior risco de desenvolverem doenças cardiovasculares. No entanto, os mecanismos patológicos, fisiológicos e moleculares que correlacionam a osteoporose e a aterosclerose ainda são desconhecidos. O objetivo deste estudo in vivo foi realizar avaliação histológica e imuno-histoquímica do osso fêmur de camundongos ovariectomizados e ateroscleróticos após tratamento com três drogas: doxiciclina, atorvastatina e vitamina D. Foram utilizados 36 camundongos fêmeas, como controle (linhagem C57BL/6), divididos aleatoriamente em seis grupos: Grupo I: Água; Grupo II: Etanol; Grupo III: Azeite; Grupo IV: Doxiciclina; Grupo V: Atorvastatina e Grupo VI: Vitamina D; e 36 camundongos fêmeas knockout para Apolipoproteína E (ApoE-/-) divididos aleatoriamente em seis grupos: Grupo VII: Água OVX; Grupo VIII: Etanol OVX; Grupo IX: Azeite OVX; Grupo X: Doxiciclina OVX; Grupo XI: Atorvastatina OVX e Grupo XII: Vitamina D OVX. Após indução dos quadros de osteoporose e aterosclerose foi realizado o tratamento conforme cada grupo. Decorrido o tempo experimental, os animais foram eutanasiados e o material coletado submetido ao processamento histotécnico para análise histológica, em cortes corados com Tricrômio de Masson e avaliação da expressão por imunohistoquímica de TRAP, IL-1β, TNF-α, RANKL e MMP-9. Os resultados obtidos foram submetidos à análise estatística por meio dos testes One-Way ANOVA, seguido pelo pósteste de Bonferroni (histologia e colesterol); Kruskal Wallis e Student-Newman-Keuls (imuno-histoquímica). O nível de significância adotado foi de 5%. Os resultados obtidos evidenciaram diferença significativa entre o número de células imunorreativas para MMP-9, TRAP, IL-1β, TNF-α e RANKL nos grupos VII e X; VIII e XI; demonstrando a ação da Doxiciclina e Atorvastatina sob tais moléculas. Os resultados histológicos evidenciaram a eficácia da vitamina D no tratamento da osteoporose, uma vez que promoveu aumento da área óssea / Osteoporosis is an osteometabolic disease that affects thousands of people; and cardiovascular diseases are the leading causes of death in the world. Studies have shown that patients with low bone density are at a higher risk of developing cardiovascular disease. However, the pathological, physiological and molecular mechanisms that are correlated to osteoporosis and atherosclerosis are still unknown. The present work in vivo was to perform a histological and immunohistochemical evaluation of the femoral bone of ovariectomized and atherosclerotic mice after treatment with three drugs: doxycycline, atorvastatin and vitamin D. Thirty-six female mice were used as controls (C57BL/6 strain) randomly divided into six groups: Group I: Water; Group II: Ethanol; Group III: Olive oil; Group IV: Doxycycline; Group V: Atorvastatin and Group VI: Vitamin D; and the 36 knockout mice for Apolipoprotein E (ApoE-/-) randomly divided into six groups: Group VII: Water OVX; Group VIII: Ethanol OVX; Group IX: OVX olive oil; Group X: Doxycycline OVX; Group XI: Atorvastatin OVX and Group XII: Vitamin D OVX. After induction of osteoporosis and atherosclerosis, treatment was performed according to each group. After the experimental time, the animals were euthanized and the collected material submitted to histotechnical processing for histological analysis in stained sections with Masson\'s Trichrome and evaluation of the expression by immunohistochemistry of TRAP, IL-1β, TNF-α, RANKL and MMP-9. The results were submitted to statistical analysis using One-Way ANOVA, followed by Bonferroni post-test (histology and cholesterol); Kruskal Wallis and Student-Newman-Keuls (immunohistochemistry). The level of significance was 5%. The results obtained showed a significant difference between the number of immunoreactive cells for MMP-9, TRAP, IL-1β, TNF-α and RANKL in groups VII and X; VIII and XI; demonstrating the action of Doxycycline and Atorvastatin on such molecules. The histological results evidenced the efficacy of vitamin D in the treatment of osteoporosis, since it promoted increased bone area

Cerebrospinal fluid (CSF) analysis is a standard part of a diagnostic evaluation. Commonly evaluated components include the cell count, protein concentration, glucose, and cytology. CSF analysis can be diagnostic in some diseases such as fungal infections and CNS lymphoma. Often, CSF analysis is not specific, but more information can be obtained. Matrix Metalloproteinases (MMPs) are enzymes that have been found in human CSF. They are calcium and zinc dependent endoproteinases with overlapping substrates. They hydrolyze at least one component of tissue extracellular matrix (ECM), such as collagen or elastin. They are important in normal physiologic processes such as angiogenesis, reproduction and wound healing. One class of MMPs, the gelatinases, degrade gelatins and type IV collagen include MMP 2 and MMP 9. MMPs are important in many pathological processes that involve unregulated matrix destruction such as arthritis, neoplasia and CNS diseases. MMP2 is known to be constituitively produced in CSF while MMP 9 is present only in certain pathologic conditions such as multiple sclerosis, neoplasia and inflammatory diseases. We hypothesize that MMP2 is present in normal canine CSF while MMP 9 is absent. Cerebrospinal fluid samples were taken from 23 normal dogs that were being used for other research purposes. Each CSF sample was evaluated immediately for red blood cells (RBCs), white blood cells (WBCs), protein, and glucose, and then stored at -70°C. Cytological examination was also performed. CSF samples were considered normal if the protein was less than 25 mg/dl, WBCs were less than 6 µl, and RBCs were less than 25 µl. Each dog was euthanized and the brains processed for routine histopathology. MMP analysis was done using gelatin zymography and an enzyme linked immunosorbent assay (ELISA). Bands of enzyme activity were visible following staining due to enzyme degradation of the gelatin. A commercially available polyclonal sandwich ELISA was used to identify the pro form of MMP2. The mean WBC count for the CSF samples was 0.96 WBC/ml with a range of 0-3 WBC/ml. The mean protein was 12 mg/dl, with a range of 8-17 mg/dl. The mean RBC count was 3.65 RBC/ml with a range of 0-21 RBC/ml. All normal samples of CSF contained a band of clearing that corresponded to the human commercial standard of proMMP2. No other major bands of clearing were noted on normal samples. The commercial human standards also contained ProMMP2. Other bands were present, but were faint and variable. Using a polyclonal antibody based sandwich ELISA, with samples run in triplicate, the mean pro MMP 2 levels were determined to be 5.61 ng/ml with a range of 3.36 - 10.83 ng/ml. We conclude that normal CSF values are narrower than what has been previously reported for protein concentration and WBC count. Also, the pro form of MMP 2 is present in normal canine CSF based on results of gelatin zymography and ELISA. / Master of Science

Bien que les taux de survie soient des plus élevés depuis 1950 au Canada, le cancer du sein peut réapparaître jusqu'à 15 ans après traitements par radiations. Les radiations produisent des radicaux libres reconnus pour activer les métalloprotéinases de matrice (MMP). Ces MMPs sont relâchées par les cellules cancéreuses sous forme inactive (proMMP) et peuvent être activées par des radicaux libres. Les MMPs activées, dont la MMP-2 et -9, dégradent la matrice extracellulaire (MEC) qui a pour rôle d'empêcher le passage des cellules cancéreuses de la tumeur primaire vers la circulation sanguine et lymphatique. Une fois cet obstacle contrecarré, les cellules cancéreuses forment alors des métastases. Le métabolisme de l'estradiol est altéré chez presque sinon toutes les cellules cancéreuses du sein. Ce qui résulte en une accumulation de ces métabolites. Ces derniers génèrent des radicaux libres qui comme cela a été prouvé par plusieurs équipes causent des mutations cellulaires. Mais, une autre conséquence de la présence de ces métabolites a attiré notre attention. La stimulation de l'expression de MMPs clés de l'invasion et l'augmentation de leur activation. Ce projet de recherche s'articule suivant trois axes. L'objectif premier consistait à déterminer si les radiations pourraient effectivement augmenter la capacité d'invasion des cellules cancéreuses du sein. Le second, était d'examiner l'implication des métabolites de l'estradiol, en l'occurrence la 4-OHE[indice inférieur 2], dans ce phénomène d'invasion. En dernier lieu, il s'avérait important de vérifier l'existence d'un effet synergique des précédents phénomènes observés. En utilisant des chambres d'invasion, l'irradiation (5 à 20 Gy) de la matrice basale (MB) artificielle augmentait de 2,5 fois la capacité d'invasion des cellules cancéreuses du sein MDA-MB-231. Lorsque ces mêmes cellules ont été traitées avec la 4-OHE[indice inférieur 2], une augmentation de l'invasion de plus de 3 fois a également été observée. À la suite de ces expériences, les niveaux d'ARNm des MMPs clés de l'invasion ont augmenté. Inversement chez les MCF-7, des cellules faiblement métastasiques, aucune augmentation n'a été observée.Bien que très utiles pour les traitements, les radiations pourraient contribuer à la migration des cellules cancéreuses, favorisant ainsi la formation des métastases et la récurrence du cancer du sein. La 4-OHE[indice inférieur 2] produite par les cellules cancéreuses influence aussi la capacité d'invasion de ces cellules. Pour contrer ces effets, il serait donc intéressant d'utiliser lors des traitements des inhibiteurs de MMPs. C'est une voie potentielle d'avenir pour empêcher toute récurrence du cancer du sein.

Cardiomyopathies are often initiated by diastolic dysfunction, and treatment of diastolic dysfunction remains empirical with an emphasis on prevention. This dissertation focuses on the mechanism of cardiomyopathy and diastolic dysfunction during aging and immune dysfunction. The governing hypothesis is that altered cytokine release such as that seen during aging and immune dysfunction can lead to diastolic dysfunction and myocardial fibrosis. Our first study examined the role of aging and immunosenescence on the cardiac extracellular matrix (ECM) and left ventricular stiffness. We demonstrated age-related immune dysfunction, myocardial fibrosis, and diastolic dysfunction. We also found that exogenous dehydroepiandrosterone (DHEA), an adrenal steroid hormone popular due to its anti-aging effects, partially reversed these pathologies in aged mice. In this model, fibrosis and its reversal were associated with altered regulation of matrix metalloproteinases (MMP) and collagen cross-linking. We propose two mechanisms for the protective effects of DHEA: (1) a direct effect on cardiac fibroblasts, or (2) downstream effects of immune modulation. In the subsequent study, we found that DHEA is capable of directly altering cardiac fibroblasts, suggesting a mechanism for the effects of DHEA on cardiac function. Due to pleiotropic effects of DHEA, we decided to specifically target the immune system using T-cell receptor peptides during murine AIDS(mAIDS). Mice with mAIDS suffer from cardiomyopathy in the absence of myocarditis and opportunistic pathogens. We demonstrated that reversal of immune dysfunction in mAIDS was associated with reversal of myocardial fibrosis and ventricular stiffness. In conclusion, we have demonstrated age- and immune-related diastolic dysfunction that can be reversed by modulation of the T-cells of the immune system. Immune modulation should be further investigated as a therapeutic target to treat diastolic dysfunction during immune dysfunction. We also found that MMPs and collagen cross-linking are highly involved in extracellular matrix regulation in the models used in this dissertation.

Made available in DSpace on 2018-08-01T23:25:58Z (GMT). No. of bitstreams: 1 tese_10204_Artigo Mestradro Nathália - Defesa 01.08 (1) (1).pdf: 7254929 bytes, checksum: 36eb94c32d1fc4c52933a3189e3caba0 (MD5) Previous issue date: 2016-08-19 / À medida que o processo de odontogênese avança, dando início à deposição de tecidos mineralizados da coroa, ocorre de forma paralela o processo de erupção dentária, que permite ao dente atravessar as barreiras teciduais que o circundam até que ele possa emergir na cavidade oral. Esse processo envolve a degradação da lâmina própria e a reabsorção da parte superior da cripta óssea que envolve o dente por ação de metaloproteinases (MMPs).O objetivo desta pesquisa foi identificar a expressão de MMP-2 em germes dentários de molares de ratos e nos tecidos circunjacentes ao longo do processo eruptivo. A detecção de MMP-2 foi realizada por imuno-histoquímica em 24 amostras de animais com idades entre 04 a 16 dias. A expressão de MMP-2 foi bservada no tecido ósseo basal e apical e em regiões do germe dentário: papila dentária, ameloblastos, odontoblastos, retículo estrelado efolículo dentário. Os esultados desta pesquisa indicam que a forte expressão de MMP-2 em ameloblastos e odontoblastos pode indicar um papel dessa enzima nos processos de síntese, mineralização e maturação dos tecidos mineralizados do dente. Por outro lado, a expressão de MMP-2 no folículo dentário e osso ao redor do germe podem indicar a participação de MMP-2 nos processos de remodelação óssea necessários para o prosseguimento do processo de erupção dentária.

Epithelial wound healing is a common occurrence in many organisms. In spite of a long history of study in this field, we do not have a complete understanding of the molecular and cellular mechanisms of wound healing, which is a key element to appreciate in order to modulate this process for better clinical outcomes. Optimal outcomes are especially critical in the cornea as a failure to regenerate can result in blindness and a huge decline in quality of life. Matrix Metalloproteinases (MMPs) are a family of zinc dependent proteases that have been shown to be both regulators and effectors of the corneal wound healing process. Strict regulation of MMP-9, the most extensively studied member of the MMP family, has been shown to be critical for efficient wound regeneration. While we now know that MMP-9 is important, and we even have evidence defining some of the roles it plays in the corneal wound healing process, the mechanism by which MMP-9 is regulated is still under debate. Possible extracellular regulatory mechanisms range from cell-cell interactions to cell-matrix interactions to secreted factors. However, the detailed mechanism of events that takes place on the extracellular surface and the downstream signals that mediate MMP-9 are unknown. Therefore, one of the objectives of the presented work is to define the external mechanisms which mediate MMP-9 expression in resurfacing epithelial cells and to link these external signals to internal signaling pathways in vitro. Furthermore, while MMP-9 acts to slow the resurfacing phase of wound healing, other MMPs seem to cause opposing effects. The second objective of the presented work is to provide the first global spatial and temporal MMP expression profile for an in vivo epithelial wound healing scenario and to define possible macroscopic roles of these heretofore unknown MMPs. Finally, this thesis will look at the expression of many MMP family members in a penetrating model which is an increasingly more common wound scenario due to the increase in corrective surgery. The final objective is to examine human post-LASIK corneas and correlate MMP expression with age, post-operative time, or histopathological abnormalities. The knowledge obtained from all aspects of these studies will contribute to the current understanding and knowledge about the roles and regulatory mechanisms of MMPs in the corneal wound healing process.

RECK(reversion-inducing cysteine-rich protein with Kazal motifs) encodes a membrane-anchored glycoprotein of about 110 kDa with multiple epidermal growth factor-like repeat, four N-glycosylation sites and three Kazal-like domains. RECK functions as a tumor suppressor gene which may inhibit the release and activation of MMP-2 and MMP-9. Previous studies indicated that RECK-mediated suppression of tumor cell invasion is regulated by glycosylation of RECK in human tumor cell lines. However, the anti-cancer action of other functional domains of RECK have not been studied. In the study, We investigated the effects of different functional domains of RECK protein on the invasion of tumor cell lines and on the activation of matrix metalloproteinase. We constructed bacterial expression vector and secretory mammalian expression vector which could produce full-length, Kazal-like motifs 1~3, Kazal-like motifs 2~3 and CKM5 polypeptides. Recombinant proteins were purified and used for treatment of human lung cancer cell lines. We found that treatment of K23 and RECK recombinant proteins resulted in suppression of invasive ability and MMP activity. Moreover,K23 and RECK proteins were found to inhibit the secretion of matrix metallo- protease-9 (MMP-9). K23 also formed a complex with MMP-9 and inhibited its proteolytic activity noncompetitively. Experimental metastasis assay revealed that there were fewer tumor nodule formation in the lungs injected with A549 cells stably expressing K23 than control vector. Thus, these findings indicate that the K23 domain of RECK functions as an inhibitor of tumor invasion and metastasis.

Injection of gases into a reservoir for enhanced oil recovery results in complex fluid phase behavior that cannot be modeled by black oil simulators. This interaction of flow and phase behavior is best captured by fully compositional simulators. A drawback of fully compositional simulators is that they require accurate reservoir fluid characterizations by equations of state (EOS) to capture the phase interactions in miscible gas floods. Another disadvantage is that EOS are computationally intensive. An EOS is typically tuned to standard PVT data, which may include multicontact experiments and swelling tests. The standard method of tuning, however, does not incorporate important displacement parameters such as the minimum miscibility pressure or enrichment (MMP or MME) or the likely compositions that result in a reservoir from condensing-vaporizing displacements. / text