Dissertations / Theses: 'MMPs'

1

Peres, Juliana Alves. "Avaliação histométrica do reparo de defeito ósseo em calvária de rato após implante de rhMMP-2 ligada à monoleína." Universidade de São Paulo, 2012. http://www.teses.usp.br/teses/disponiveis/58/58137/tde-18092012-154340/.

Full text

Abstract:

As metaloproteinases da matriz (MMPs) são enzimas proteolíticas dependentes de zinco que degradam componentes da matriz extracelular, facilitando a remodelação tecidual e a migração celular. MMPs secretadas por osteoclastos exercem papel central na absorção óssea fisiológica e estão também associadas a processos de degradação patológica do osso. No entanto, o papel essencialmente degradador de osso das MMPs, particularmente da MMP-2, vem sendo questionado em anos recentes por estudos que evidenciam sua importância na diferenciação de células da linhagem osteoblástica e na formação de tecido ósseo em cultura. Neste sentido, é possível que a MMP-2 exerça um papel importante na formação de tecido ósseo em processo de reparação. O objetivo do presente trabalho foi investigar a pretensa ação osteo-estimulatória da rhMMP-2 ligada à monoleína (usada como carreador) implantada em defeito confeccionado na calvária de ratos. Foram confeccionados defeitos ósseos unilaterais de 4 mm de diâmetro na calvária de ratos adultos; nos animais controles o defeito ósseo foi mantido com o preenchimento natural de coágulo sanguíneo e nos animais implantados o defeito foi preenchido com monoleína ou com rhMMP-2 ligada à monoleína. Os animais foram eutanasiados após 2 e 4 semanas e a taxa de neoformação óssea foi estimada em cortes histológicos por um método histométrico de contagem diferencial de pontos. A taxa de neoformação óssea foi semelhante nos animais dos grupos controle e monoleína e significativamente maior nos animais do grupo MMP-2, em ambos os períodos analisados. Os resultados permitem concluir que a monoleína não interferiu com o processo reparacional e pareceu eficaz como carreador da rhMMP-2, e adicionam evidências á hipótese da importância da atividade da MMP-2 para a formação óssea, em um modelo experimental in vivo de reparo ósseo. Matrix metalloproteinases (MMPs) are zinc-dependent proteolytic enzymes that degrade extracellular matrix components, facilitating cell migration and tissue remodeling. MMPs secreted by osteclasts are important in the physiological bone resorption as in pathological bone degradation. However, the essentially bone absorbing hole of MMPs, particularly of the MMP-2, has been questioned in recent years by studies that show its importance in osteoblastic cells differentiation and in vitro bone formation. Therefore, the MMP-2 may have also an important hole in reparational bone formation. The purpose of the present study was to investigate the pretense osteostimulatory effect of the rhMMP-2 linked to monoolein (used as a carrier) implanted into rat calvarial defects. Bone defects of 4mm in diameter were created unilaterally in rats calvaria and filled with natural blood clot (control), monoolein or rhMMP-2 linked to monoolein. The animals were killed 2 and 4 weeks postoperatively and the rate of new bone formation was estimated in histological sections by a histometric differential point-counting method. The rate of reparational bone formation was similar in the animals from control and monoolein groups and was significantly greater in the MMP-2 group, in both periods. From the results it may be concluded that monoolein did not interfere with the reparacional process and seemed effective as a rhMMP-2 carrier. In addition, the results add evidence to the importance of MMP-2 activity for bone formation, in an in vivo bone healing experimental model.

APA, Harvard, Vancouver, ISO, and other styles

2

Ylipalosaari, M. (Merja). "Matrix metalloproteinases (MMPs) in oral carcinomas." Doctoral thesis, University of Oulu, 2005. http://urn.fi/urn:isbn:9514277309.

Full text

Abstract:

Abstract Matrix metalloproteinases, MMPs, are a family of enzymes capable of modulating connective tissue components. The expression of several MMPs is increased in oral squamous cell carcinomas (OSCCs). They are assumed to have an important role in the development and progression of OSCCs. However, the exact role and mechanism of the regulation of MMPs in malignant transformation are still largely unknown. In this study, tumour-associated trypsin-2 (TAT-2) was detected in OSCC tissue sections, and its role in MMP-2 and -9 regulation in carcinoma cells was evaluated. The TAT-2 gene was transfected into two different OSCC cell lines and one immortalized oral epithelial cell line. In TAT-2-transfected cells, MMP-9 activation increased OSCC cell invasion in chicken chorionallantoic membrane assay. Increased intravasation was prevented by tumour-associated trypsin inhibitor or specific gelatinase-inhibiting CTT-peptide. TAT-2 also converted MMP-1, -8, -13 and -3 into smaller molecular weight forms in vitro. However, TAT-2-transfected OSCC cells showed no conversion. TAT-2 was demonstrated to degrade powerfully type I collagen into small fragments in vitro. The cell surface receptor αvβ6 integrin is strongly up-regulated in OSCCs. By using β6-transfected OSCC cells, it was demonstrated that αvβ6 integrin down-regulates MMP-13 expression. However, this integrin did not regulate other collagenases or TIMP-1. β6-transfected cells invaded more efficiently through the basement membrane matrix, but their migration through type I collagen remained unchanged. MMP-8 expression was detected for the first time in head and neck squamous cell carcinoma (HNSCC) cell lines and corresponding cultured dermal and tumour fibroblasts. The localization of MMP-8 in HNSCC was determined by immunohistochemical stainings and in situ hybridization. MMP-8 production levels in carcinoma cells were faint and sporadic in HNSCCs sections. Ninety-two primary mobile tongue SCCs were subjected to MMP-8 immunohistochemical staining, and the staining results were compared to survival rates. MMP-8 was associated with improved disease-free survival in females but not in males.

APA, Harvard, Vancouver, ISO, and other styles

3

Stott, Holly Rosannah. "MMP-12 activity during vascular remodelling." Thesis, University of Edinburgh, 2017. http://hdl.handle.net/1842/23609.

Full text

Abstract:

Matrix metalloproteinases (MMPs) are required for tissue remodelling processes, including angiogenesis. MMP activity is generally proangiogenic but MMP-12 is suggested to be antiangiogenic and its precise role is still unclear. The work in this thesis describes the synthesis of an MMP-12 inhibitor and activity probe to address the hypothesis that MMP-12 inhibits angiogenesis. An inhibitor, synthesised in-house, selectively inhibited MMP-12 in in vitro recombinant enzyme assays. An activity probe, also synthesised in-house, was selective for MMP-12 in in vitro recombinant enzyme assays. The function of MMP-12 during angiogenesis was assessed using murine models of angiogenesis; the in vivo sponge implantation, and the ex vivo aortic ring assays. Angiogenesis and MMP activity were imaged in vivo in sponges in C57Bl6/J mice over 7 − 21 days (D) using commercial probes (MMPSense™ and AngioSense™). MMP-12 protein concentration and activity were higher in sponges during early angiogenesis (D 3 − 7) when gene expression of vascular endothelial growth factor (a proangiogenic marker) was also high. Gene expression for MMP-12 and platelet-derived growth factor receptor (a marker of vascular maturation) were both higher on D 21 as angiogenesis started to stabilise. The MMP-12 activity probe was unsuccessful in selectively detecting MMP-12 activity in sponge lysate mixtures from D 7 − 21. Administration of an MMP-12 inhibitor did not increase angiogenesis in the sponges in vivo. Additionally, sponges implanted in MMP-12-/- mice did not exhibit significant changes in angiogenesis or MMP activity when imaged in vivo using commercial probes (MMPSense™ and AngioSense™) on D 7. Supporting this, histological analysis of the sponges (removed on D 21) showed that deletion of MMP-12 also did not increase angiogenesis within the sponges.

APA, Harvard, Vancouver, ISO, and other styles

4

Bourd-Boittin, Katia. "Rôle des métalloprotéinases matricielles (MMPs) dans l'odontologie." Paris 5, 2005. http://www.theses.fr/2005PA05M001.

Full text

Abstract:

La dégradation protéolytique des constituants de la matrice extracellulaire par les métalloprotéinases matricielles (MMPs) joue un rôle majeur dans l'odontogénèse. Après avoir identifié la présence et le profil d'expression des gélatinases (MMP-2 et MMP-9), de la MMP-20 et des TIMP-1 et -2 dans l'incisive de rat, nous avons cherché à mieux comprendre comment les MMPs et plus particulièrement les gélatinases et la MMP-20 pouvaient agir dans les processus d'organisation et de minéralisation des matrices dentaires. L'inhibition de leur activité par un inhibiteur synthétique des MMPs à large spectre, le Marimastat, dans un modèle des germes embryonnaires de souris en culture, a pertubé les mécanismes de nucléation dans la matrice dentinaire et a provoqué des pertubations sévères de la mise en place et par conséquent de la minéralisation de l'émail. Ces importantes altérations observées au niveau structural sont associées à des modifications au niveau moléculaire. En présence de Marimastat, deux des protéines majoritaires du tissu dentaire, la sialoprotéine dentinaire (DSP) et plus particulièrement l'amélogénine s'accumulent de manière anormale dans la matrice extracellulaire. Ces pertubations se traduisent par une modification de leurs différentes formes moléculaires. Ceci démontre la nécessité de la dégradation progressive de ces constituants matriciels. Le clivage de l'amélogénine par la MMP-20 a déjà été rapporté. En revanche, la dégradation protéolytique de la DSP par des protéases n'a jamais été décrite auparavant, nous avons pu montrer que la DSP mais aussi l'amélogénine sont clivées de manière rapide et totale par la MMP-2 recombinante. Par contre la MMP-9 n'a pas d'effet sur ces deux protéines dans les mêmes conditions expérimentales. La large distribution de la MMP-2 au sein des tissus dentaires, ainsi que sa capacité à dégrader certains constituants spécifiques des matrices dentaires permettent de lui attribuer un rôle majeur en association avec la MMP-20 dans l'établissement et la minéralisation de la dentine et de l'émail The proteolytic degradation of the ECM components by the matrix metalloproteinases (MMPs) is thought to play a crucial role in odontogenesis. The aim of this thesis was to analyse the expression of several MMPs, namely MMP-2, MMP-9 and MMP-20, as well as of their physiological inhibitors, the TIMP-1 and TIMP-2 during tooth development and study their role in the formation and maturation of dental matrices. The two gelatinases (MMP-2 and MMP-9), enamelysin (MMP-20) and TIMP-1 and -2 have shown a developmentally regulated expression and specific localization within the developing tootth. The role of these MMPs in the processing and mineralization of the dental matrix was further studied in an organotypic culture model of developing mouse tooth germ. The inhibition of the MMPs activity in this model by a broad spectrum synthetic inhibitor, Marimastat, altered dental matrix nucleation and caused severe disruptions of enamel organisation and mineralization. These macroscopic effects was associated with significant modifications at the molecular level. MMP inhibition deregulated the molecular processing of two major dental matrix proteins, amelogenin and dental sialoprotein (DSP), coinciding with their accumulation and the loss of their normal distribution. While the cleavage of amelogenin by MMP-20 has been extensively studied, that of DSP has not been previously described. Our experiments provide evidence that MMP-2 is able to efficiently degrade DSP as well as amelogenin, while under the same conditions, MMP-9 had no effect. Based on the intense expression and large distribution of MMP-2 and its importance in the processing of the dental matrix, we suggest a major role for this enzyme, in association with MMP-20, in the maturation and mineramization of dentin and enamel

APA, Harvard, Vancouver, ISO, and other styles

5

David, Arnaud. "Protéomique fonctionnelle des Métalloprotéases Matricielles (MMPs) dédiée à la détection des formes acitves de MMPs dans des protéomes complexes." Phd thesis, Museum national d'histoire naturelle - MNHN PARIS, 2007. http://tel.archives-ouvertes.fr/tel-00555061.

Full text

Abstract:

Les Métalloprotéases matricielles (MMPs) constituent une famille des métalloprotéases à zinc capables conjointement de dégrader l'ensemble des protéines de la matrice extracellulaire. Aujourd'hui, vingt-trois MMPs humaines ont été identifiées et sont caractérisées par leur séquence en aminoacides et leur structure 3D fortement conservées. Ces enzymes sont exprimées de manière constitutive au cours des processus de remodelage tissulaire. Leur surexpression dans un certain nombre de pathologies étroitement liée au phénomène d'inflammation (arthrite, emphysème, cancer) fait des MMPs des cibles thérapeutiques de choix. Cependant, le remodelage entraînant des modifications des contacts cellulaires, les MMPs apparaissent aujourd'hui comme des protéines des voies de signalisation à part entière. Les récentes découvertes de substrats des MMPs ne faisant pas partie des constituants de la matrice extracellulaire renforcent cette vision. Dans le but d'identifier le rôle particulier et le taux d'expression protéique des MMPs dans un contexte pathologique, nous avons développé une technique de protéomique fonctionnelle dédiée à la détection des formes actives des MMPs dans des échantillons tumoraux. Cette technique repose sur le développement d'une nouvelle sonde de photoaffinité, basée sur la structure d'un puissant inhibiteur des MMPs de type phosphinique, permettant de cibler les MMPs sous forme active et de les isoler par marquage par photoaffinité. Le marquage par photoaffinité nous permet ainsi grâce à un élément radioactif incorporé à la sonde de radiomarquer les protéines ciblées. Cette sonde a montré in vitro sa capacité remarquable à modifier de manière covalente la hMMP-12 avec un rendement de 42 %, affichant une sensibilité extrême de détection (2.5 fmoles de hMMP-12). En présence de protéome complexe, la sensibilité de détection de la sonde pour la hMMP-12 est tout à fait comparable (5 fmoles) ; la hMMP-12 représente une fraction de 0.001 % de la quantité totale des protéines. Cette méthode nous a permis également d'identifier de manière indirecte les formes actives des gélatinases en comparant les extraits tumoraux traités par la sonde et les extraits tumoraux analysés en zymographie. Ces études indiquent que les niveaux d'expression des formes actives de MMPs sont très faibles (fmoles) ne permettant pas une caractérisation de celles-ci par spectrométrie de masse, ce qui constitue un véritable défi pouvant être abordé avec de nouvelles sondes incorporant une biotine. Cet exemple de protéines exprimées sous forme active en très faible abondance, implique une orientation des efforts à consentir vers le développement de nouvelles stratégies de capture.

APA, Harvard, Vancouver, ISO, and other styles

6

A, David Arnaud. "Protéomique fonctionnelle des métalloprotéases naturelles (MMPs) dédiée à la détection des formes actives de MMPs dans des protéomes complexes." Phd thesis, Museum national d'histoire naturelle - MNHN PARIS, 2007. http://tel.archives-ouvertes.fr/tel-00327187.

Full text

Abstract:

Les Métalloprotéases matricielles (MMPs) constituent une famille des métalloprotéases à zinc capables conjointement de dégrader l'ensemble des protéines de la matrice extracellulaire. Aujourd'hui, vingt-trois MMPs humaines ont été identifiées et sont caractérisées par leur séquence en aminoacides et leur structure 3D fortement conservées. Ces enzymes sont exprimées de manière constitutive au cours des processus de remodelage tissulaire. Leur surexpression dans un certain nombre de pathologies étroitement liée au phénomène d'inflammation (arthrite, emphysème, cancer) fait des MMPs des cibles thérapeutiques de choix. Cependant, le remodelage entraînant des modifications des contacts cellulaires, les MMPs apparaissent aujourd'hui comme des protéines des voies de signalisation à part entière. Les récentes découvertes de substrats des MMPs ne faisant pas partie des constituants de la matrice extracellulaire renforcent cette vision. Dans le but d'identifier le rôle particulier et le taux d'expression protéique des MMPs dans un contexte pathologique, nous avons développé une technique de protéomique fonctionnelle dédiée à la détection des formes actives des MMPs dans des échantillons tumoraux. Cette technique repose sur le développement d'une nouvelle sonde de photoaffinité, basée sur la structure d'un puissant inhibiteur des MMPs de type phosphinique, permettant de cibler les MMPs sous forme active et de les isoler par marquage par photoaffinité. Le marquage par photoaffinité nous permet ainsi grâce à un élément radioactif incorporé à la sonde de radiomarquer les protéines ciblées. Cette sonde a montré in vitro sa capacité remarquable à modifier de manière covalente la hMMP-12 avec un rendement de 42 %, affichant une sensibilité extrême de détection (2.5 fmoles de hMMP-12). En présence de protéome complexe, la sensibilité de détection de la sonde pour la hMMP-12 est tout à fait comparable (5 fmoles) ; la hMMP-12 représente une fraction de 0.001 % de la quantité totale des protéines. Cette méthode nous a permis également d'identifier de manière indirecte les formes actives des gélatinases en comparant les extraits tumoraux traités par la sonde et les extraits tumoraux analysés en zymographie. Ces études indiquent que les niveaux d'expression des formes actives de MMPs sont très faibles (fmoles) ne permettant pas une caractérisation de celles-ci par spectrométrie de masse, ce qui constitue un véritable défi pouvant être abordé avec de nouvelles sondes incorporant une biotine. Cet exemple de protéines exprimées sous forme active en très faible abondance, implique une orientation des efforts à consentir vers le développement de nouvelles stratégies de capture.

APA, Harvard, Vancouver, ISO, and other styles

7

Candiani, Gabriele. "TNF-a et MMPs dans le remodelage cardiaque." Paris 11, 2006. http://www.theses.fr/2006PA11T016.

Full text

APA, Harvard, Vancouver, ISO, and other styles

8

Lund, Dane. "It's a Jungle Out There| Myoblasts, Matrix, and MMPs." Thesis, University of Missouri - Columbia, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10182609.

Full text

APA, Harvard, Vancouver, ISO, and other styles

9

Le, Dour Gwennaël. "Synthèse de nouveaux inhibiteurs potentiels de métalloprotéinases matricielles (MMPs)." Reims, 2005. http://www.theses.fr/2005REIMP206.

Full text

Abstract:

Les @métalloprotéinases matricielles (MMPs) sont des enzymes protéolytiques calcium et zinc dépendantes dont l'action principale est de dégrader les protéines et particulièrement celles de la matrice extracellulaire. Les MMPs jouent un rôle prépondérant dans divers processus physiologiques tels que le développement embryonnaire, la cicatrisation mais aussi pathologiques comme l'arthrite rhumatoïde et surtout le cancer. Du fait de l'intérêt grandissant pour l'inhibition des métalloprotéinases matricielles dans les thérapies anticancéreuses, le laboratoire s'est donné comme objectif de synthétiser de nouveaux inhibiteurs sélectifs. Nos recherches sont alors dirigées vers la synthèse d'analogues structuraux de l'Ilomastat®, inhibiteur puissant mais non sélectif. Trois familles de composés originaux sont développées tout en conservant leur activité et en tentant de leur conférer de meilleures sélectivité et biodisponibilité. Elles présentent des modifications structurales du squelette pseudopeptidique, pour une meilleure insertion dans les poches enzymatiques S'2, S'3, ainsi que sur le groupement fonctionnel chélatant l'ion zinc du site actif (" Zinc Binding Group "). La synthèse, l'évaluation et la sélectivité de ces différents inhibiteurs potentiels seront présentées @Matrix metalloproteinase (MMPs) are proteolytic calcium and zinc dependent enzymes. Their principal action is to degrade proteins, mainly on the extracellular matrix. MMPs play a determining role in various physiological processes such as the embryonic development, wound healing and also in pathological ones like arthritis and especially cancer. Thus, in this ongoing interest for the inhibition of MMPs in the anti-cancer therapies, the goal of our laboratory is to synthesize new selective inhibitors. Our research is then directed towards the synthesis of structural analogues of Ilomastat®, a potent but a no selective inhibitor. Three families of original compounds are developed preserving their activity and offering a better selectivity and bioavailability. They present structural modifications of backbone pseudopeptide for a best insertion in the enzymatic pocket S'2, S'3 and new ZBG (zinc binding group) functions for higher affinity. The synthesis, the evaluation and the selectivity of these various potential inhibitors will be presented

APA, Harvard, Vancouver, ISO, and other styles

10

Behonick, Danielle J. "A study of MMPs during skeletal development and repair." Diss., Search in ProQuest Dissertations & Theses. UC Only, 2007. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3261265.

Full text

APA, Harvard, Vancouver, ISO, and other styles

11

David, Arnaud. "Protéomique fonctionnelle dédiée aux Métalloprotéases Matricielles (MMPs) : développement d'une méthode extrêmement sensible permettant la détection des formes actives des MMPs dans les protéomes complexes." Paris, Muséum national d'histoire naturelle, 2007. http://www.theses.fr/2007MNHN0011.

Full text

Abstract:

Les Métalloprotéases matricielles (MMPs) constituent une famille des métalloprotéases à zinc capables conjointement de dégrader l’ensemble des protéines de la matrice extracellulaire. Aujourd’hui, vingt-trois MMPs humaines ont été identifiées et sont caractérisées par leur séquence en aminoacides et leur structure 3D fortement conservées. Ces enzymes sont exprimées de manière constitutive au cours des processus de remodelage tissulaire. Leur surexpression dans un certain nombre de pathologies étroitement liée au phénomène d’inflammation (arthrite, emphysème, cancer) fait des MMPs des cibles thérapeutiques de choix. Cependant, le remodelage entraînant des modifications des contacts cellulaires, les MMPs apparaissent aujourd’hui comme des protéines des voies de signalisation à part entière. Les récentes découvertes de substrats des MMPs ne faisant pas partie des constituants de la matrice extracellulaire renforcent cette vision. Dans le but d’identifier le rôle particulier et le taux d’expression protéique des MMPs dans un contexte pathologique, nous avons développé une technique de protéomique fonctionnelle dédiée à la détection des formes actives des MMPs dans des échantillons tumoraux. Cette technique repose sur le développement d’une nouvelle sonde de photoaffinité, basée sur la structure d’un puissant inhibiteur des MMPs de type phosphinique, permettant de cibler les MMPs sous forme active et de les isoler par marquage par photoaffinité. Le marquage par photoaffinité nous permet ainsi grâce à un élément radioactif incorporé à la sonde deradiomarquer les protéines ciblées. Cette sonde a montré in vitro sa capacité remarquable à modifier de manière covalente la hMMP-12 avec un rendement de 42 %, affichant une sensibilité extrême de détection (2. 5 fmoles de hMMP-12). En présence de protéome complexe, la sensibilité de détection de la sonde pour la hMMP-12 est tout à fait comparable (5 fmoles) ; la hMMP-12 représente une fraction de 0. 001 % de la quantité totale des protéines. Cette méthode nous a permis également d’identifier de manière indirecte les formes actives des gélatinases en comparant les extraits tumoraux traités par la sonde et les extraits tumoraux analysés en zymographie. Ces études indiquent que les niveaux d’expression des formes actives de MMPs sont très faibles (fmoles) ne permettant pas une caractérisation de celles-ci par spectrométrie de masse, ce qui constitue un véritable défi pouvant être abordé avec de nouvelles sondes incorporant une biotine. Cet exemple de protéines exprimées sous forme active en très faible abondance,implique une orientation des efforts à consentir vers le développement de nouvelles stratégies de capture The Matrix Metalloproteinases (MMP) represent a family of Zinc dependent extracellular proteinases able to cleave collectively all the proteins constituting the extracellular matrix. Currently, 23 human MMP have been identified and are characterized by their sequence in aminoacids and their highly conserved 3D structure. These enzymes are expressed constitutively during the tissue remodelling process. Their over-expression in various diseases tightly related to inflammatory processes (arthritis, emphysema, cancer) described MMP as choice therapeutic targets. However, as the tissue remodelling implicates modification of cellular contacts, MMP appear currently as proteins involved in signalling pathways. Recent works demonstrating that MMP are able to cleave substrates, which are different than proteins constituting the extracellular matrix, reinforce this vision. In order to identify the individual role and the protein expression level of MMP in pathological context, we developed a new technique of functional proteomics dedicated to the detection of active forms of MMP in tumour samples. This technique relied on the development of a new photoaffinity probe, based on the structure of a potent phosphinic inhibitor of MMP, allowing targeting and isolating active forms of MMP by photoaffinity labelling. Furthermore, asthe new developed probe incorporated a radioactive element, photoaffinity labelling permitted to radiolabel the targeted proteins. This probe demonstrated in vitro its remarkable ability to covalently modify the hMMP-12, with a singular cross-linking yield, determined at 42 %, displaying an extremely sensitive detection (2. 5 fmoles of hMMP-12). When added to complex proteome, the photoaffinity probe presents the same sensibility of detection for the hMMP-12 (5 fmoles); importantly, in this case, hMMP-12 represents only 0. 001 % of the totality of the proteins present in the sample. Moreover, this technique allows us to identify active forms of gelatinases (MMP-2 & -9) in an indirect manner by comparing the results of tumour samples treated with the photoaffinity probe and the results of tumour samples analysed in zymography. These studies indicate that the protein expression levels of active forms of MMP are extremely low (fmoles) and do not permit any characterisation of those forms of MMP by mass spectrometry, constituting a genuine challenge which can be approached by the development of new photoaffinity probes incorporating a biotin-group. The example of this class of proteins expressed in very low abundance under active form implicates to grant efforts to develop new strategies allowing the capture of the targeted proteins

APA, Harvard, Vancouver, ISO, and other styles

12

Haq, Imran. "Genetic variants of MMPs 1, 9 and 12 in COPD." Thesis, University of Nottingham, 2012. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.575071.

Full text

Abstract:

Chronic Obstructive Pulmonary Disease (COPD) is a condition characterised by a progressive, irreversible obstruction of the airways. It is the fourth leading cause of mortality and morbidity worldwide. Although cigarette smoking is the main aetiological factor, not all smokers develop the disease, suggesting a genetic component. The pathogenesis of COPD is poorly understood. However, a widely accepted hypothesis for its aetiology is protease - anti protease imbalance with increased protease activity in the lung resulting in alveolar destruction. This hypothesis arose from the well described association of alpha - 1 - antitrypsin deficiency with COPD; this protein protects the lung from damage caused by uninhibited neutrophil elastase activity. The Matrix Metalloproteinases (MMPs) are a family of proteases, making them promising candidates for genetic studies as they can degrade all components of the extracellular matrix of the lung and play a key role in tissue remodeling. Specifically, MMPs 1, 9 and 12 have been implicated in COPD pathogenesis through both animal and human studies. Investigation of variation within these genes in relation to COPD is limited and provided conflicting results, probably due to small sample size, improper matching of controls and use of different COPD phenotypes. To address these issues, I undertook a case - control genetic association study in the largest sample size reported to date. This study demonstrated that A - A alleles compared to the G - G alleles of a haplotype consisting ofrs2276109 and rs652438 in MMP - 12 (p = 0.0138, OR = 1.32, n = 1929) were associated with severe forms of COPD. SNPs in MMPs 1 and 9 were not associated with COPD or severity. Functional characterisation of rs652438, in MMP - 12 showed that with the A allele there was significantly higher metalloproteinase activity and increased cellular migration compared to the G allele. Human studies showed A/A homozygotes to have increased macrophages in the airways and higher CT emphysema scores. This suggests that increased activity of MMP -12 is important in COPD pathological processes. I also undertook the functional characterisation of the disease implicated SNP rs 17576 in MMP - 9. The G allele of this SNP had higher metalloproteinase activity and increased cell migratory activity compared to the A allele in cellular models. Furthermore, GIG homozygous individuals showed increased activity of active MMP - 9 in plasma samples compared to A/A homozygotes. This is interesting due to the implication of MMP - 9 in arterial stiffness of healthy individuals, it is plausible that it could be involved in arterial stiffness in COPD patients. To conclude, I have provided genetic and functional evidence that implicates MMP - 12 as a locus in COPD pathogenesis. I did not find evidence for genetic variants of MMP 1 and 9's role in COPD susceptibility. I have also demonstrated a disease implicated SNP in MMP - 9 to significantly alter the protein's function.

APA, Harvard, Vancouver, ISO, and other styles

13

Mridha, Auvro Robin. "Role of MMPs and CD147 in non-alcoholic steatohepatitis progression." Thesis, The University of Sydney, 2014. http://hdl.handle.net/2123/13897.

Full text

Abstract:

Obesity and diabetes is increasing exponentially and this is accompanied with prevalence of metabolic diseases like non-alcoholic steatohepatitis (NASH), an inflammatory often fibrotic condition of the liver. Fibrotic NASH is characterised by matrix turnover but the regulation of matrix degrading metalloproteinases (MMPs) remains poorly characterised. The aim of this thesis was to explore the role of MMPs and their regulator CD147 in NASH pathogenesis. Using a novel murine model of diet-induced obesity with added diabetes we showed characteristic temporal changes in MMP activity that increases with severity of NASH. Hepatocyte expression and glycosylation of CD147 also increases. By in-vitro studies we determined CD147 in hepatocytes were up-regulated by saturated free fatty acids and glucose via ERK1/2 and PI3K/Akt pathways. CD147 in cell membranes or when released in microparticles induced MMPs in hepatic cells, an effect abrogated by anti-CD147 antibody. We validated the possible role of microparticles in-vivo where microparticle concentration, particularly those expressing hepatocyte CD147 increased in NASH livers. This thesis establishes that MMPs and CD147 are regulated in NASH progression, and shows MMPs activity is induced by CD147 via cell membrane interaction or via microparticles. Blocking MMP activity or CD147 is therefore a logical therapeutic approach in NASH.

APA, Harvard, Vancouver, ISO, and other styles

14

Sassi, M. L. (Mirja-Liisa). "Carboxyterminal degradation products of type I collagen." Doctoral thesis, University of Oulu, 2001. http://urn.fi/urn:isbn:9514264916.

Full text

Abstract:

Abstract The assay for the carboxyterminal telopeptide of type I collagen, ICTP, has been shown to be a reliable marker in many pathological conditions but insensitive to changes in physiological bone turnover. This has induced uncertainty and confusion regarding the role of ICTP assay in the study of collagen metabolism in bones. Especially, since another assay for the carboxyterminal telopeptide of type I collagen, serum CrossLaps ELISA, sensitively follows the changes in physiological bone turnover. To find out the reasons for the discrepancy we characterized the antigenic determinant of the ICTP assay by comparing human and bovine antigens after trypsin and chymotrypsin treatments. An assay for bovine ICTP was developed contemporarily with the present study. The epitope lies on the phenylalanine rich region of two telopeptide chains. We were able to show that the region is destroyed by cathepsin K, an osteoclastic enzyme responsible for physiological bone turnover, but not by several matrix metalloproteinases (MMPs), which are important collagen degrading enzymes in pathological conditions. Cathepsin K treatment had no effect on the CrossLaps assay. The CrossLaps assay is also able to measure the MMP-derived fragments, but usually their amount is so low in serum that it is masked by the cathepsin K-derived collagen degradation. The results explain the apparent discrepancy regarding the different behaviour of ICTP and CrossLaps assays in various conditions as also verified in our study with rheumatoid arthritis patients. The ICTP assay was also found to measure only trivalently cross-linked forms of the carboxyterminal telopeptide which contains two telopeptide chains, and is therefore unable to react with divalently or histidinohydroxylysinonorleucine (HHL)-cross-linked forms of the carboxyterminal telopeptide. These forms can be measured with the SP4 (synthetic peptide 4) assay. We utilized this property in analyzing the skin samples of 18 breast cancer patients on both the irradiated and unirradiated side. The content of HHL was increased on the irradiated side, as were type I collagen synthesis and degradation. In conclusion, there are two assays for two different degradation products of the trivalently cross-linked carboxyterminal telopeptide of type I collagen, ICTP and CrossLaps, the former measuring the MMP-derived and the latter the cathepsin K-derived collagen degradation.

APA, Harvard, Vancouver, ISO, and other styles

15

Zhao, Puyan [Verfasser]. "Arabidopsis thaliana matrix metalloproteinases (MMPs) in plant defense against pathogens / Puyan Zhao." Gießen : Universitätsbibliothek, 2012. http://d-nb.info/1064838278/34.

Full text

APA, Harvard, Vancouver, ISO, and other styles

16

Qian, Xinxin. "Diversity, structure, reproduction of multicellular magnetotactic prokaryotes (MMPs) in the Mediterranean sea." Thesis, Aix-Marseille, 2019. http://theses.univ-amu.fr.lama.univ-amu.fr/190926_QIAN_101jwhzy259dng72qaf912jk_TH.pdf.

Full text

Abstract:

Les bactéries magnétotactiques (MTB) sont un groupe de bactéries caractérisées par leur capacité à synthétiser des magnétosomes et à nager le long de lignes du champ géomagnétique. Les Procaryotes Multicellulaires Magnétotactiques (MMP) représentent les MTB les plus évoluées. Deux morphotypes de MMP ont été découverts: sphérique (sMMPs) et ellipsoïdal (eMMP). Dans cette thèse, j'ai tout d'abord révélé une diversité inattendue d'eMMP de la mer Méditerranée. Quatre nouvelles espèces ont été détectées, ce qui augmente le nombre total d'eMMP identifiés en Méditerranée d’une espèce appartenant un genre à cinq espèces affiliées à deux genres. J'ai également effectué une analyse approfondie de l'architecture des eMMPs en utilisant plusieurs approches microscopiques. Les eMMP sont composés d'une couche de cellules entourant une lumière centrale. Les cellules sont disposées axisymétriquement le long du grand axe des eMMP et sont radialement symétriques le long du petit axe. Leurs membranes juxtaposées relient étroitement les cellules en une entité multicellulaire. Les eMMP se reproduisent par constriction unilatérale des cellules constituantes, de la périphérie vers le centre et par fission binaire unidirectionnelle des globules ellipsoïdaux. J'ai identifié deux bactéries magnétotactiques Nitrospirae pour la première fois collectées en milieu marin. Elles ont une morphologie sphérique, une motilité similaire. Elles synthétisent des magnétosomes en forme de balle, composés de magnétite et disposés en plusieurs de chaînes. Les deux nouvelles espèces de MTB Nitrospirae élargissent la distribution des MTB Nitrospirae de l’eau douce au milieu marin Magnetotactic bacteria (MTB) are characterized by synthesizing magnetosomes and swimming along geomagnetic field lines. Multicellular Magnetotactic Prokaryotes (MMPs) is the most evolved MTB. Two morphotypes of MMPs have been discovered: spherical (sMMPs) and ellipsoidal (eMMPs). In this thesis, I revealed a high diversity of eMMPs from the Mediterranean Sea. Four new eMMPs species have been detected, extending the total number of identified eMMPs in the Mediterranean Sea from one species of one genus to five species of two genera. I also performed a comprehensive analysis of eMMP architecture. The eMMPs was composed of one layer of cells that surround a central lumen. The constituent cells are arranged axisymmetrically along the long axis of eMMPs and radial symmetric along the short axis. The juxtaposed membranes connect cells into a multicellular entity. The eMMPs reproduce through periphery–core unilateral constriction of constituent cells and unidirectional binary fission of the ellipsoidal MMPs. I have also identified two Nitrospirae MTB collected, for the first time, from marine environment. They have similar morphology, motility but different colors. They synthesized multiple bundles of bullet-shaped magnetite magnetosomes. The two novel Nitrospirae MTB species expand the distribution of Nitrospirae MTB from freshwater to marine

APA, Harvard, Vancouver, ISO, and other styles

17

Maravic, Tatjana <1984&gt. "The role of MMPs inhibitors in the stability of the adhesive interface." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2019. http://amsdottorato.unibo.it/8900/1/Doctoral%20thesis%20Maravic%20FINAL.pdf.

Full text

Abstract:

Aims: This thesis aimed to investigate the influence of several protease inhibitors/inactivators, as separate primers or blended within the adhesive resin, on the longevity of dental restorations and on the dentinal enzymatic activity immediately, or after aging in vitro. Methods: A series of studies was conducted using several different MMPs inhibitors and several adhesive systems. The first three studies investigated the longevity of the hybrid layer by means of microtensile bond strength test, and the enzymatic activity using gelatin and in situ zymography, immediately or after 1 year of aging in the artificial saliva. Study 4 tested samples bonded with or without an inhibitor-containing-primer, that were previously aged for 10 years. The degradation of the hybrid layer was observed using transmission electron microscopy, the enzymatic activity in the hybrid layer using in situ zymography. Raman spectroscopy was used to investigate whether the active substance was still within the hybrid layer after 10 years. Results: The results of the studies showed that the inhibitors/inactivators of endogenous dentinal enzymes were efficient in preserving bond strength after aging in vitro when used as separate primers. In the cases when the inhibitory agent was introduced within the adhesive resin, bond preservation was adhesive system- and/or bonding mode-dependent. The enzymatic activity was lower in all experimental groups, at baseline, as well as after aging (for 1 and 10 years) with a slight influence of the bonding mode. Conclusions: The tested protease inhibitors used as separate aqueous primers in etch-and-rinse adhesives seem to be clinically applicable, since the procedure is not overly time-consuming and seems to preserve the hybrid layer over time. As for the inhibitors blended within adhesives, comprehensive studies on the mechanical properties of the adhesives as well as their influence on the longevity of the hybrid layer should be performed before clinical use.

APA, Harvard, Vancouver, ISO, and other styles

18

Manzetti, Sergio. "Studies of enzymes from two protease families: Tissue Kallikreins, ADAMs and MMPs." Thesis, Queensland University of Technology, 2005. https://eprints.qut.edu.au/16088/1/Sergio_Manzetti_Thesis.pdf.

Full text

Abstract:

The human kallikrein family is a family of proteolytic enzymes, classified as serine proteases, that derive from chromosome 19, locus 13.3-13.4. These enzymes are widespread in pathophysiological processes such as cancer and neurodegenerative diseases; hence studies of catalytic sites and inhibitors are important in relation to the longer term of design of therapeutic drugs. One member of the family, human kallikrein 4 (hK4) which is thought to carry out crucial functions in the prostate, was expressed in this study as a secreted protein in a baculovirus expression system, bearing a His-tag and V5-epitope that were used for purification and detection respectively. Its mass was estimated to be 35kDa, ~2kDa less than the equivalent product expressed in monkey kidney cells. The protein was purified to 50-90% purity with a yield of 0.93mg/L-4.8mg/L based on methods derived from computational prediction of its properties, such as pI. Computational analysis was extended by applying high-performing computing techniques, such as molecular dynamics, and flexible ligand docking, to predict antigenic regions, the likely substrate specificity and putative inhibitors. These results show that hK4 has a loop, between Leu83-Ser94 that shows promise as a specific segment that can be exploited for generation of antibodies. Preferred substrates were also predicted to bear hydrophobic residues at the P'-region of the scissile bond and amphiphilic residues at the P-region. At the S-region, hK4 potentially involves its unique PLYH-motif in recognizing the P4/P5 position from the substrate. Flexible ligand-docking studies indicate that hK4 can be inhibited by inhibitors that carry a modified bulky hydrophobic sidechain with a guanidinium group at the P1-position and its own putative autoactivation region residues at the P2, P1' and P2' position. The computational study was extended to other members of the kallikrein family, predicting distinctions between these that could be used for future studies. These results show that 8 of the fifteen kallikrein members are very homologous in terms of specificity bearing typical trypsinlike activity and specificity, except for hK2, hK3, hK4, hK5, hK7, hK9, hK15 that retain certain distinct signatures in the binding pocket in terms of secondary specificity. The principles of substrate-specificity analysis that were developed were further applied on three metzincins, MMP-3, ADAM-9 and ADAM-10. These three enzymes are metalloproteases, which are involved in tissue remodeling, intracellular signalling and cell-to-cell mediation. The substrate-specificity analysis was carried out on all three metzincins using the structure of a crystallized complex of the MMP-3 enzyme with the TIMP-1 natural inhibitor as template. In this specific enzyme-substrate complex, the challenge was to model and suggest a possible orientation of the P-region, which is not known. The interactions on the P/S-region are therefore unclear and need to be clarified. In order to suggest the arrangement of the enzyme-substrate complex and the undefined S-subsites, four new residues were added in an extended beta-sheet conformation to the P1' residue (derived originally from the TIMP-1 inhibitor) to create a full-length modeled substrate spanning P4'-P4. This new modeled region, in particular, was bound through backbone H-bonds with the enzyme at position 169 (MMP nomenclature) suggesting a new crucial residue for substrate binding, and satisfied steric and chemical restraints in the S'-region of the enzyme. This modeling approach also indicated a putative presence of an S2/S3-pocket on these metzincins which is composed of different residues for MMP-3, ADAM-9 and ADAM-10, and which could prove useful for future drug design projects. Furthermore, the data argue against the involvement of a polarizable water molecule in catalysis, a mechanism that has been postulated by various groups. A new catalytic mechanism is suggested to involve an oxyanion anhydride transition state. This study is a demonstration of the power of combining bioinformatics with wet-lab biochemistry.

APA, Harvard, Vancouver, ISO, and other styles

19

Manzetti, Sergio. "Studies of enzymes from two protease families: Tissue Kallikreins, ADAMs and MMPs." Queensland University of Technology, 2005. http://eprints.qut.edu.au/16088/.

Full text

Abstract:

The human kallikrein family is a family of proteolytic enzymes, classified as serine proteases, that derive from chromosome 19, locus 13.3-13.4. These enzymes are widespread in pathophysiological processes such as cancer and neurodegenerative diseases; hence studies of catalytic sites and inhibitors are important in relation to the longer term of design of therapeutic drugs. One member of the family, human kallikrein 4 (hK4) which is thought to carry out crucial functions in the prostate, was expressed in this study as a secreted protein in a baculovirus expression system, bearing a His-tag and V5-epitope that were used for purification and detection respectively. Its mass was estimated to be 35kDa, ~2kDa less than the equivalent product expressed in monkey kidney cells. The protein was purified to 50-90% purity with a yield of 0.93mg/L-4.8mg/L based on methods derived from computational prediction of its properties, such as pI. Computational analysis was extended by applying high-performing computing techniques, such as molecular dynamics, and flexible ligand docking, to predict antigenic regions, the likely substrate specificity and putative inhibitors. These results show that hK4 has a loop, between Leu83-Ser94 that shows promise as a specific segment that can be exploited for generation of antibodies. Preferred substrates were also predicted to bear hydrophobic residues at the P'-region of the scissile bond and amphiphilic residues at the P-region. At the S-region, hK4 potentially involves its unique PLYH-motif in recognizing the P4/P5 position from the substrate. Flexible ligand-docking studies indicate that hK4 can be inhibited by inhibitors that carry a modified bulky hydrophobic sidechain with a guanidinium group at the P1-position and its own putative autoactivation region residues at the P2, P1' and P2' position. The computational study was extended to other members of the kallikrein family, predicting distinctions between these that could be used for future studies. These results show that 8 of the fifteen kallikrein members are very homologous in terms of specificity bearing typical trypsinlike activity and specificity, except for hK2, hK3, hK4, hK5, hK7, hK9, hK15 that retain certain distinct signatures in the binding pocket in terms of secondary specificity. The principles of substrate-specificity analysis that were developed were further applied on three metzincins, MMP-3, ADAM-9 and ADAM-10. These three enzymes are metalloproteases, which are involved in tissue remodeling, intracellular signalling and cell-to-cell mediation. The substrate-specificity analysis was carried out on all three metzincins using the structure of a crystallized complex of the MMP-3 enzyme with the TIMP-1 natural inhibitor as template. In this specific enzyme-substrate complex, the challenge was to model and suggest a possible orientation of the P-region, which is not known. The interactions on the P/S-region are therefore unclear and need to be clarified. In order to suggest the arrangement of the enzyme-substrate complex and the undefined S-subsites, four new residues were added in an extended beta-sheet conformation to the P1' residue (derived originally from the TIMP-1 inhibitor) to create a full-length modeled substrate spanning P4'-P4. This new modeled region, in particular, was bound through backbone H-bonds with the enzyme at position 169 (MMP nomenclature) suggesting a new crucial residue for substrate binding, and satisfied steric and chemical restraints in the S'-region of the enzyme. This modeling approach also indicated a putative presence of an S2/S3-pocket on these metzincins which is composed of different residues for MMP-3, ADAM-9 and ADAM-10, and which could prove useful for future drug design projects. Furthermore, the data argue against the involvement of a polarizable water molecule in catalysis, a mechanism that has been postulated by various groups. A new catalytic mechanism is suggested to involve an oxyanion anhydride transition state. This study is a demonstration of the power of combining bioinformatics with wet-lab biochemistry.

APA, Harvard, Vancouver, ISO, and other styles

20

Collins, Hilary M. "The role of matrix metalloproteinases, their activators and inhibitors in colorectal tumourigenesis." Thesis, University of Nottingham, 2000. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.342046.

Full text

APA, Harvard, Vancouver, ISO, and other styles

21

Sulkala, M. (Merja). "Matrix metalloproteinases (MMPs) in the dentin-pulp complex of healthy and carious teeth." Doctoral thesis, University of Oulu, 2004. http://urn.fi/urn:isbn:9514274598.

Full text

Abstract:

Abstract The dentin-pulp complex comprises mineralized dentin and the vital soft tissues encased inside dentin, i.e. odontoblasts and pulp tissue. During caries progression, the dentinal minerals are dissolved and eventually the collagenous organic matrix is degraded. However, the exact mechanisms and enzymes responsible for the organic matrix breakdown remain unknown. Matrix metalloproteinases (MMPs), a family of endopeptidases capable of degrading in concert virtually all extracellular matrix components, are expressed during normal dentin-pulp complex formation and maintenance. MMP activity has also been suggested to contribute to the organic matrix degradation during dentin caries progression and to the repair and defense reactions elicited by caries in the dentin-pulp complex cells. The aim of the study was to further elucidate the role of host MMPs in dentin caries progression and the origin of MMPs in carious dentin as well as the possible changes in MMP expression in the cells of the dentin-pulp complex in response to caries. MMP inhibitors decreased the area of dentin caries lesions in vivo, suggesting the involvement of host MMPs in dentin caries pathogenesis. When the overall MMP gene expression was examined by cDNA microarray, pooled pulp samples demonstrated a high level of MMP-13 expression, but failed to show any unequivocal changes in MMP expression due to caries. MMP-13 expression is rare among normal human adult tissues. Real-time quantitative PCR of individual pulp and odontoblast samples demonstrated a rather large variation in relative MMP-13 mRNA expression between samples, especially pulp samples. Protein expression of MMP-13 was detected in pulp and odontoblasts without any major differences between the tissues of sound and carious teeth. This was also the case with the MMP-20 (enamelysin) protein, which was demonstrated in odontoblasts and the pulp tissue of fully developed human teeth. MMP-20, MMP-8, and gelatinases (especially MMP-2) were demonstrated in human dentin, and dentinal MMPs exhibited activity against native and denatured type I collagen when released. The study demonstrates the presence of MMPs in the soft and hard tissue compartments of the dentin-pulp complex. These enzymes may also contribute to dentin caries progression and response reactions to caries.

APA, Harvard, Vancouver, ISO, and other styles

22

Palliyaguru, Tishila Sepali. "The expression and regulation of membranetype matrix metalloproteinases (MT-MMPS) in prostate cancer." Thesis, Queensland University of Technology, 2005. https://eprints.qut.edu.au/16009/1/Tishila_Palliyaguru_Thesis.pdf.

Full text

Abstract:

Prostate cancer (PCa) represents the most frequently diagnosed cancer and the second leading cause of cancer death in males. Initial development and progression of the disease is mainly regulated by androgens. However, the pathology of the disease may progress to a loss of hormone dependence, resulting in rapid growth and a metastatic phenotype. Invasion and metastasis of tumour cells results from the degradation of the basement membrane (BM) and extracellular matrix (ECM). The degradation of the BM and ECM is in part mediated by a family of proteinases called the matrix metalloproteinases (MMPs). Currently more than 20 members of the MMP family have been identified and they are further divided in to sub-classes according to their protein structure. Collectively, MMPs are capable of degrading essentially all ECM components. High expression of some MMPs correlates with a malignant phenotype of various tumours. This study focused on the expression and regulation of a sub-class of MMPs called the membrane-type MMPs (MT-MMPs) in PCa. To date 6 MT-MMPs have been identified and they are characterized by a transmembrane domain, followed by a short cytoplasmic tail (MT1-, MT2-, MT3- and MT5-MMPs) or a glycosylphosphatidylinositol (GPI) moiety (MT4- and MT6-MMPs). MT-MMPs are thought to play a key role in tumour cell invasion by virtue of their ability to activate MMP-2 (a secreted MMP, which is implicated in many metastatic tumours) and their direct degradation activity on ECM components. Elevated MT-MMP expression has been shown in breast, colon, skin, stomach, lung, pancreas and brain cancers. Until very recently there had been no studies conducted on MT-MMPs in PCa. The few studies preceding or occurring in parallel with this one, have mainly reported the mRNA expression of these enzymes in PCa. Most studies have focused on MT1-MMP. Thus, at the commencement of this project there were many unexplored aspects of the expression and regulation of the broader MT-MMP family in PCa. The aims of this study were to examine: 1 a) The expression of MT-MMPs in prostate cancer cell lines using RT-PCR and western blot analysis and b) expression of MT1-MMP and MT5-MMP in BPH (benign prostatic hyperplasia) and PCa clinical tissue sections by immunohistochemistry. 2) The regulation of MT1-MMP, MT3-MMP and MT5-MMP in PCa cell lines by Concanavalin A (Con A), phorbol-12-myristate 13-acetate (PMA), dihydrotestosterone (DHT) and insulin-like growth factors I and II (IGF I and IGF II) using western blot analysis. In this study RWPE1, a transformed but non-tumorigenic prostate cell line was used as a "normal" prostate cell model, ALVA-41 and LNCaP as androgen-dependent PCa cell models and DU-145 and PC-3 as androgen-independent PCa cell models. The mRNA expression for the 6 MT-MMPs was determined by RT-PCR. The results indicate that MT1- and MT3-MMP were detected in all cell lines. This is the first study to report MT1-MMP mRNA expression in LNCaP cells and MT3-MMP mRNA in DU-145 cells. MT2-MMP mRNA was detected in only LNCaP and DU-145 cells, whilst MT5-MMP was detected in PC-3, DU-145 and LNCaP cells. nterestingly, MT2-, MT4-, MT5- or MT6-MMP mRNA expression was not detected in the "normal" cell line RWPE1, perhaps indicating an induction in gene transcription in tumour cells. MT4-MMP mRNA was only detected in the androgen-independent cell lines, indicating a potential role in the invasion and metastasis processes of the aggressive androgen-independent PCa. In this study, very low expression of MT6-MMP was detected only in LNCaP and DU-145 cells. Previously there had been no reports on the expression of MT6-MMP in the normal or cancerous prostate. Due to the mRNA of MT1-, MT3- and MT5-MMPs being the predominant MT-MMPs expressed in the current study, and the availability of suitable antibodies against them, the protein expression of these three MT-MMPs was studied by western blot analysis. MT1-, MT3- and MT5-MMP protein expression was detected in the cell lysates and conditioned medium (CM) of RWPE1, LNCaP and PC-3 cells. For each MT-MMP, various protein species were detected including putative proforms, mature (active) forms, processed or fragmented forms as well as soluble or shed forms. The presence of soluble or shed forms of MT-MMPs in the CM of cultures of "normal" and PCa cells could imply one of the following mechanisms: ectodomain shedding by either extracellular sheddases, the secretion of intracellular processed proteins without the transmembrane domain, the release of membrane vesicles containing membrane-bound enzymes, or the presence of alternatively spliced mRNA, which gives rise to MT-MMPs without a transmembrane domain. Further characterization of these various forms, including their amino acid sequence, is required to fully elucidate their structural composition. Despite the detection of the mRNA, we did not detect the cell-associated proteins of MT1-MMP and MT5-MMP and only very low expression of MT3-MMP in DU-145 cells (CM of DU-145 cells were not screened for soluble forms of the enzymes). This is the first study to report MT5-MMP expression at the protein level in prostate derived cell lines. Immunohistochemistry was carried out on benign prostatic hyperplasia (BPH) and PCa clinical tissues using MT1- and MT5-MMP antibodies to determine their cellular localisation in benign and cancer glands. MT1- and MT5-MMPs were expressed in BPH and moderate and high grade PCa. MT1-MMP expression was highest in moderate grade cancer compared to BPH and high grade cancer. MT1-MMP expression was predominantly observed in the cytoplasm of secretory epithelial cells of both benign and cancer glands, although in cancer glands, some nuclear staining was also observed. Stromal expression of MT1-MMP was only observed in high grade cancer. This study is the first to report the immunolocalization of MT5-MMP outside the brain and in kidneys of diabetic patients. MT5-MMP was predominantly expressed in the cytoplasm of the secretory cells in benign glands. In the cancer glands, staining was heterogeneous with low to intense staining, mainly in the nuclei, plasma membrane and cytoplasm of secretory epithelial cells. Stromal expression of MT5-MMP was only observed in cancer tissues, particularly in high grade cancer. To study the regulation of MT-MMPs in PCa, we treated LNCaP and PC-3 cells, with either Con A, PMA, DHT or IGF-I and -II and studied the protein expression of MT1-, MT3- and MT5-MMPs by western blot analysis. Con A and PMA have been shown to stimulate MMP expression in other cell systems. Con A treatment showed a general increase in the protein expression of MT1-, MT3- and MT5-MMPs. By far the greatest induction by Con A observed was the nearly 4 fold increase in MT5-MMP expression caused by 40μg/mL Con A treatment of PC-3 cells. PMA treatment of LNCaP and PC-3 cells appeared to increase shedding or secretion of all three MT-MMPs in to the CM. This increase in the soluble forms corresponded to a decrease in cell-associated forms in LNCaP cells. Treatment of LNCaP with DHT alone and treatment of LNCaP and PC-3 cells with IGF-I and -II alone failed to detect any change in expression of MT1-MMP. The information gathered in this study on MT-MMPs with respect to cellular localization, expression levels and regulation by growth factors or chemicals that mimic their actions, will aid in our understanding of the role of MT-MMPs in PCa. This study provides strong preliminary data for further research, particularly with respect to functional studies of MT-MMPs in PCa. Understanding the processes which govern the actions of such proteins as these will provide potential insights into development of new management and therapeutic regimens to prevent cancer progression.

APA, Harvard, Vancouver, ISO, and other styles

23

Palliyaguru, Tishila Sepali. "The expression and regulation of membranetype matrix metalloproteinases (MT-MMPS) in prostate cancer." Queensland University of Technology, 2005. http://eprints.qut.edu.au/16009/.

Full text

Abstract:

Prostate cancer (PCa) represents the most frequently diagnosed cancer and the second leading cause of cancer death in males. Initial development and progression of the disease is mainly regulated by androgens. However, the pathology of the disease may progress to a loss of hormone dependence, resulting in rapid growth and a metastatic phenotype. Invasion and metastasis of tumour cells results from the degradation of the basement membrane (BM) and extracellular matrix (ECM). The degradation of the BM and ECM is in part mediated by a family of proteinases called the matrix metalloproteinases (MMPs). Currently more than 20 members of the MMP family have been identified and they are further divided in to sub-classes according to their protein structure. Collectively, MMPs are capable of degrading essentially all ECM components. High expression of some MMPs correlates with a malignant phenotype of various tumours. This study focused on the expression and regulation of a sub-class of MMPs called the membrane-type MMPs (MT-MMPs) in PCa. To date 6 MT-MMPs have been identified and they are characterized by a transmembrane domain, followed by a short cytoplasmic tail (MT1-, MT2-, MT3- and MT5-MMPs) or a glycosylphosphatidylinositol (GPI) moiety (MT4- and MT6-MMPs). MT-MMPs are thought to play a key role in tumour cell invasion by virtue of their ability to activate MMP-2 (a secreted MMP, which is implicated in many metastatic tumours) and their direct degradation activity on ECM components. Elevated MT-MMP expression has been shown in breast, colon, skin, stomach, lung, pancreas and brain cancers. Until very recently there had been no studies conducted on MT-MMPs in PCa. The few studies preceding or occurring in parallel with this one, have mainly reported the mRNA expression of these enzymes in PCa. Most studies have focused on MT1-MMP. Thus, at the commencement of this project there were many unexplored aspects of the expression and regulation of the broader MT-MMP family in PCa. The aims of this study were to examine: 1 a) The expression of MT-MMPs in prostate cancer cell lines using RT-PCR and western blot analysis and b) expression of MT1-MMP and MT5-MMP in BPH (benign prostatic hyperplasia) and PCa clinical tissue sections by immunohistochemistry. 2) The regulation of MT1-MMP, MT3-MMP and MT5-MMP in PCa cell lines by Concanavalin A (Con A), phorbol-12-myristate 13-acetate (PMA), dihydrotestosterone (DHT) and insulin-like growth factors I and II (IGF I and IGF II) using western blot analysis. In this study RWPE1, a transformed but non-tumorigenic prostate cell line was used as a "normal" prostate cell model, ALVA-41 and LNCaP as androgen-dependent PCa cell models and DU-145 and PC-3 as androgen-independent PCa cell models. The mRNA expression for the 6 MT-MMPs was determined by RT-PCR. The results indicate that MT1- and MT3-MMP were detected in all cell lines. This is the first study to report MT1-MMP mRNA expression in LNCaP cells and MT3-MMP mRNA in DU-145 cells. MT2-MMP mRNA was detected in only LNCaP and DU-145 cells, whilst MT5-MMP was detected in PC-3, DU-145 and LNCaP cells. nterestingly, MT2-, MT4-, MT5- or MT6-MMP mRNA expression was not detected in the "normal" cell line RWPE1, perhaps indicating an induction in gene transcription in tumour cells. MT4-MMP mRNA was only detected in the androgen-independent cell lines, indicating a potential role in the invasion and metastasis processes of the aggressive androgen-independent PCa. In this study, very low expression of MT6-MMP was detected only in LNCaP and DU-145 cells. Previously there had been no reports on the expression of MT6-MMP in the normal or cancerous prostate. Due to the mRNA of MT1-, MT3- and MT5-MMPs being the predominant MT-MMPs expressed in the current study, and the availability of suitable antibodies against them, the protein expression of these three MT-MMPs was studied by western blot analysis. MT1-, MT3- and MT5-MMP protein expression was detected in the cell lysates and conditioned medium (CM) of RWPE1, LNCaP and PC-3 cells. For each MT-MMP, various protein species were detected including putative proforms, mature (active) forms, processed or fragmented forms as well as soluble or shed forms. The presence of soluble or shed forms of MT-MMPs in the CM of cultures of "normal" and PCa cells could imply one of the following mechanisms: ectodomain shedding by either extracellular sheddases, the secretion of intracellular processed proteins without the transmembrane domain, the release of membrane vesicles containing membrane-bound enzymes, or the presence of alternatively spliced mRNA, which gives rise to MT-MMPs without a transmembrane domain. Further characterization of these various forms, including their amino acid sequence, is required to fully elucidate their structural composition. Despite the detection of the mRNA, we did not detect the cell-associated proteins of MT1-MMP and MT5-MMP and only very low expression of MT3-MMP in DU-145 cells (CM of DU-145 cells were not screened for soluble forms of the enzymes). This is the first study to report MT5-MMP expression at the protein level in prostate derived cell lines. Immunohistochemistry was carried out on benign prostatic hyperplasia (BPH) and PCa clinical tissues using MT1- and MT5-MMP antibodies to determine their cellular localisation in benign and cancer glands. MT1- and MT5-MMPs were expressed in BPH and moderate and high grade PCa. MT1-MMP expression was highest in moderate grade cancer compared to BPH and high grade cancer. MT1-MMP expression was predominantly observed in the cytoplasm of secretory epithelial cells of both benign and cancer glands, although in cancer glands, some nuclear staining was also observed. Stromal expression of MT1-MMP was only observed in high grade cancer. This study is the first to report the immunolocalization of MT5-MMP outside the brain and in kidneys of diabetic patients. MT5-MMP was predominantly expressed in the cytoplasm of the secretory cells in benign glands. In the cancer glands, staining was heterogeneous with low to intense staining, mainly in the nuclei, plasma membrane and cytoplasm of secretory epithelial cells. Stromal expression of MT5-MMP was only observed in cancer tissues, particularly in high grade cancer. To study the regulation of MT-MMPs in PCa, we treated LNCaP and PC-3 cells, with either Con A, PMA, DHT or IGF-I and -II and studied the protein expression of MT1-, MT3- and MT5-MMPs by western blot analysis. Con A and PMA have been shown to stimulate MMP expression in other cell systems. Con A treatment showed a general increase in the protein expression of MT1-, MT3- and MT5-MMPs. By far the greatest induction by Con A observed was the nearly 4 fold increase in MT5-MMP expression caused by 40μg/mL Con A treatment of PC-3 cells. PMA treatment of LNCaP and PC-3 cells appeared to increase shedding or secretion of all three MT-MMPs in to the CM. This increase in the soluble forms corresponded to a decrease in cell-associated forms in LNCaP cells. Treatment of LNCaP with DHT alone and treatment of LNCaP and PC-3 cells with IGF-I and -II alone failed to detect any change in expression of MT1-MMP. The information gathered in this study on MT-MMPs with respect to cellular localization, expression levels and regulation by growth factors or chemicals that mimic their actions, will aid in our understanding of the role of MT-MMPs in PCa. This study provides strong preliminary data for further research, particularly with respect to functional studies of MT-MMPs in PCa. Understanding the processes which govern the actions of such proteins as these will provide potential insights into development of new management and therapeutic regimens to prevent cancer progression.

APA, Harvard, Vancouver, ISO, and other styles

24

Khaddam, Mayssam. "Role of EMMPRIN and MMPs in tooth development, dental caries and pulp-dentin regeneration." Thesis, Paris 5, 2014. http://www.theses.fr/2014PA05T046/document.

Full text

Abstract:

Le développement dentaire est orchestré par une série de signalisations inductives réciproques entre l'épithélium dentaire et le mésenchyme, qui conduit à la formation de la dentine et de l'émail. EMMPRIN/CD147 est un INducteur des MetalloPRoteinases de la Matrice Extracellulaire (MMPs) qui régule les interactions épithélio-mésenchymateuses dans le cancer et d'autres processus pathologiques et est exprimé lors du développement dentaire. Ainsi, nous avons utilisé des souris KO pour EMMPRIN pour déterminer le rôle d'EMMPRIN dans la formation des tissus dentaires. Nous avons démontré que l’absence d’EMMPRIN conduisait dans le germe dentaire à une diminution de l’expression de MMP-3 et de MMP-20, à un retard de la dégradation de la membrane basale, à un retard de la formation de l’émail bien visible dans l'incisive à croissance continue, à une diminution du volume et de l'épaisseur d'émail, mais à une maturation amélaire normale. Ces résultats indiquent qu'EMMPRIN est impliqué dans le dialogue épithélio-mésenchymateuse pendant le développement dentaire, principalement par la régulation de l'expression de certaines MMPS. Nous avons ensuite essayé d'évaluer le rôle potentiel d'EMMPRIN dans le processus de réparation dentaire en comparant la cicatrisation de blessures pulpaires des souris KO pour EMMPRIN à des souris WT. Enfin, dans un souci de transfert vers la clinique, nous avons évalué la capacité d’extraits de pépin de raisin (connu pour être des inhibiteurs naturels de MMPs) à empêcher la dégradation de la matrice dentinaire humaine déminéralisée et traitée par MMP-3 Tooth development is regulated by a series of reciprocal inductive signalings between the dental epithelium and mesenchyme, which culminates with the formation of dentin and enamel. EMMPRIN/CD147 is an Extracellular Matrix MetalloPRoteinase (MMP) INducer that mediates epithelial-mesenchymal interactions in cancer and other pathological processes and is expressed in developing teeth. Here we used EMMPRIN knockout (KO) mice to determine the functional role of EMMPRIN on dental tissues formation. We demonstrated that EMMPRIN deficiency results in decreased in MMP-3 and MMP-20 expressions, delayed in basement membrane degradation in tooth germ, delayed in enamel formation well distinguishable in incisor, and in decreased enamel volume and thickness but normal maturation. These results indicate that EMMPRIN is involved in the epithelial-mesenchymal cross-talk during tooth development by regulating the expression of MMPs. Then we tried to investigate the potential role of EMMPRIN in the pulp dentin repair process by comparing the healing of injured pulps of EMMPRIN KO and WT mice. Finally, we evaluated the capacity of grape-seed extracts (known to be natural inhibitors of MMPs and used in new daily mouthrinse) to prevent the degradation of human demineralized dentin matrix by MMP-3

APA, Harvard, Vancouver, ISO, and other styles

25

Bonnet, Amandine. "Etudes de trois métalloprotéases matricielles, MT1-MMP, MT5-MMP et MMP-12 dans l'amyloïdogenèse et les atteintes inflammatoires et vasculaires associées à la maladie d'Alzheimer." Thesis, Aix-Marseille, 2017. http://www.theses.fr/2017AIXM0036.

Full text

Abstract:

La maladie d’Alzheimer (MA) est la maladie neurodégénérative la plus commune et reste à ce jour incurable. Elle se caractérise par l’accumulation dans le cerveau du peptide neurotoxique bêta-amyloïde (Aβ), par une neuroinflammation et des atteintes neurovasculaires, qui ensemble induisent la mort des neurones et des déficits cognitifs. En raison de leurs activités multiples, les métalloprotéases matricielles (MMPs) émergent comme des acteurs importants dans la MA. Mes travaux ont permis de mieux comprendre l’implication de 3 de ces MMPs dans la MA et soulignent le caractère spécifique et complémentaire de MT1- et MT5-MMP, directement impliquées dans la production d’Aβ, et le rôle de MMP-12 dans la neuroinflammation et dans la perte d’intégrité de la barrière hémato-encéphalique, un système vasculaire particulier qui protège efficacement le cerveau. Mes travaux ouvrent des perspectives dans le développement de nouvelles stratégies thérapeutiques basées sur la modulation de ces MMPs Alzheimer's disease (AD) is the most common neurodegenerative disease and remains to this day incurable. It is characterized by the accumulation in the brain of the beta-amyloid (Aß) neurotoxic peptide, by neuroinflammation and neurovascular damage, which together induce neuronal death and cognitive deficits. Because of their multiple activities, matrix metalloproteinases (MMPs) are emerging as important players in AD. My work has provided insight into the involvement of 3 of these MMPs in AD and highlight the specific and complementary nature of MT1- and MT5-MMP, directly involved in the production of Aß, and the role of MMP-12 in neuroinflammation and in the loss of integrity of the blood-brain barrier, a particular vascular system, which effectively protects the brain. My work opens perspectives in the development of new therapeutic strategies based on the modulation of these MMPs

APA, Harvard, Vancouver, ISO, and other styles

26

Santos, Lívia Mara. "Diferentes respostas à alternagina-c, uma proteína tipo desintegrina, em fibroblastos, células tumorais de mama e células endoteliais in vitro." Universidade Federal de São Carlos, 2013. https://repositorio.ufscar.br/handle/ufscar/1252.

Full text

Abstract:

Made available in DSpace on 2016-06-02T19:22:10Z (GMT). No. of bitstreams: 1 5684.pdf: 2471155 bytes, checksum: f035dbceafb88325d3cb0d3fb8280603 (MD5) Previous issue date: 2013-12-10 Financiadora de Estudos e Projetos Matrix metalloproteinases (MMPs) are key factors in tumor progression that allow tumor cells to modify the extracellular matrix (ECM) and to release cytokines, growth factors being activated by cell surface molecules such as the integrins. Integrins are major adhesion receptors of cell surface that connect the cells to the external environment enabling its movement. Integrins activate signaling cascades that influence the adhesion, survival and cell proliferation. Important inhibitors of these molecules were found in snake venoms called disintegrins. Alternagin-C (ALT-C) a disintegrin from Rhinocerophis alternatus snake venom has affinity with α2β1 integrin therfore modulating cell adhesion, migration and proliferation. However, the effect of ALT-C on MMP activity has not been described yet. Here, we have found that, ALT-C increased cell migration in MDA-MB-231 at lower concentration (10 nM) and it decreased cell migration at higher concentrations (40, 100 and 1000 nM). ALT-C was able to inhibit MMP-9 activity in human breast cancer (MDA-MB-231) conditioned medium and MMP-2 activity in fibroblastas and human microvascular endothelial cells (HMEC-1) conditioned medium. ALT-C also modulated the expression of angiogenic genes such as VEGF, c-MYC, MMP-2 and MMP-9 and it was able to inhibit transendothelial migration of MDA-MB-231 cells at all concentrations (10, 40, 100 and 1000 nM). In conclusion, ALT-C affects the extracellular matrix remodeling by modulating the activity of MMPs and expression of angiogenic genes essential for tumor growth as well as decreased cell migration. As metaloproteinases de matriz (MMPs) são fatores chave na progressão tumoral, pois participam do remodelamento da matriz extracelular (ECM), liberam citocinas, fatores de crescimento e são reguladas por moléculas da superfície celular (integrinas). As integrinas são os principais receptores de adesão da superfície celular. Elas interagem com proteínas presentes na matriz extracelular conectando as células ao meio no qual estão inseridas possibilitando sua locomoção e a participação em cascatas de sinalização que influenciam a adesão, sobrevivência e a proliferação celular. Importantes inibidores dessas moléculas foram encontrados em venenos de serpentes denominados de desintegrinas. Alternagina-C (ALT-C), uma desintegrina de veneno da serpente Rhinocerophis alternatus, tem afinidade para a integrina α2β1, modula a adesão, migração e a proliferação celular mas não há nenhum estudo publicado sobre sua influência na atividade das MMPs. Nesse estudo, a ALT-C foi capaz de aumentar a migração celular em MDA-MB-231 em baixa concentração (10 nM) e diminuir a migração em concentrações mais elevadas (40, 100 e 1000 nM). ALT-C também inibiu a atividade de MMP-9 em meio condicionado de células de carcinoma de mama (MDAMB- 231) e atividade de MMP-2 em meio condicionado de fibroblastos e células endoteliais microvasculares humanas (HMEC-1). A desintegrina também foi capaz de modular a expressão de genes angiogênicos como VEGF, c-MYC, MMP-2 e MMP-9 e inibir a transmigração das células tumorais através das células endoteliais. Conclui-se que a ALT-C atua no remodelamento da matriz extracelular do microambiente tumoral por modular a atividade de MMPs e a expressão de genes angiogênicos essenciais no crescimento tumoral, bem como diminuindo a migração celular.

APA, Harvard, Vancouver, ISO, and other styles

27

Partridge, Juneth Ann Joaquin. "The role of MMPs in the intravasation of a highly disseminating HT-1080 fibrosarcoma cell variant a protective role for tumor-derived MMP-9 /." Diss., [La Jolla] : University of California, San Diego, 2009. http://wwwlib.umi.com/cr/ucsd/fullcit?p3378523.

Full text

Abstract:

Thesis (Ph. D.)--University of California, San Diego, 2009. Title from first page of PDF file (viewed October 22, 2009). Available via ProQuest Digital Dissertations. Vita. Includes bibliographical references (p. 119-134).

APA, Harvard, Vancouver, ISO, and other styles

28

Lamy, Edouard. "Hyperhomocystéinémie et remodelages matriciels : étude de la balance MMPs/TIMPs dans l'artère en culture." Aix-Marseille 2, 2003. http://www.theses.fr/2003AIX22953.

Full text

APA, Harvard, Vancouver, ISO, and other styles

29

González, García Laura. "Mécanismes moléculaires d'action des MT-MMPs impliqués dans la pathogenèse de la maladie d'Alzheimer." Thesis, Aix-Marseille, 2020. http://www.theses.fr/2020AIXM0025.

Full text

Abstract:

La maladie d'Alzheimer (MA) est la forme de démence la plus courante. Les principales lésions cérébrales comprennent: i) l'agrégation du peptide bêta-amyloïde (Aβ) à l'origine de la formation des plaques amyloïdes et ii) les dégénérescences neurofibrillaires intracellulaires. Aβ et d'autres métabolites toxiques sont produits suite aux clivages de l'APP par β- et γ-secrétase. La découverte récente de nouvelles sécrétases ouvre la voie au développement de nouveaux médicaments contre la MA. Dans ce contexte, j'ai étudié les mécanismes par lesquels une métalloprotéase matricielle (MT5-MMP) pourrait réguler la pathophysiologie de la MA. Nous avons montré que la suppression de MT5-MMP dans un modèle murin de la MA limite le clivage pathologique de l'APP et une diminution des taux d’Aβ et de C99. Nous avons démontré in vitro que MT5-MMP stimule le trafic de l'APP vers les endosomes et favorise la production d’Aβ. De manière intéressante, les propriétés pro-amyloïdogéniques de MT5-MMP semblent être indépendantes de son activité catalytique. Afin d'étudier les fonctions de MT5-MMP dans un contexte humain, nous avons mis en place et utilisé des neurones humains dérivés de cellules iPS provenant de personnes atteintes ou non de MA, ainsi que la technique CRISPR/Cas9 pour générer des cellules déficientes pour MT5-MMP. Pour la première fois, nous avons démontré que le MT5-MMP contribue au métabolisme de l'APP, aux processus neuroinflammatoires. De plus, nous avons découvert un rôle inattendu de MT5-MMP dans la protéolyse d'APOE et de tau. Pour conclure, MT5-MMP pourrait devenir une nouvelle cible thérapeutique pour combattre la MA Alzheimer's disease (AD) is the most common form of dementia. The main brain lesions include: i) the aggregation of the amyloid-beta peptide (Aβ) giving rise to amyloid plaques and ii) tau hyperphosphorylation generating the intracellular neurofibrillary tangles. Aβ and other toxic metabolites are produced following various cleavages of APP by β- and γ-secretase. The recent discovery of new APP secretases paves the way for the development of new drugs against AD. In this context, I studied the mechanisms whereby a matrix metalloprotease (MT5-MMP) could regulate AD pathophysiology. We have shown that MT5-MMP deletion in a mouse model of AD prevents pathological cleavage of APP, resulting in lower levels of Aβ and C99. We demonstrated in vitro that MT5-MMP stimulates APP endosomal trafficking and promotes Aβ production. Most interestingly, pro-amyloidogenic features of MT5-MMP can be independent of its catalytic activity, underlying mechanisms reveal specific control of some MT5-MMP domains on C99 fate. In order to study MT5-MMP functions in a human context we implemented and used human iPSCs-derived neurons from Alzheimer’s and non-demented individuals, as well as CRISPR/Cas9 to generate isogenic MT5-MMP knockout cells. For the first time, we provided evidence that MT5-MMP contributes to APP/Aβ metabolism and neuroinflammation in human neural cells. Moreover, we discovered an unexpected role of MT5-MMP in APOE and tau proteolysis. Overall, we conclude that MT5-MMP could become a new therapeutic target and thereby open new avenues to develop drugs to treat AD pathology

APA, Harvard, Vancouver, ISO, and other styles

30

Bonilla, Claudia María Carpio. "Radioterapia ativa e inibidores de proteases inativam MMPs, na junção amelodentinária de dentes permanentes." Universidade de São Paulo, 2016. http://www.teses.usp.br/teses/disponiveis/58/58135/tde-30052016-134545/.

Full text

Abstract:

O tratamento radioterápico para pacientes com neoplasias de cabeça e pescoço pode trazer consequências secundárias graves como alterações da estrutura dental, com conseguinte prejuízo da função oral, a qual influencia negativamente a qualidade de vida. Recentemente trabalhos de pesquisa tem demonstrado que a radiação induz a expressão e ativação das metaloproteinases da matriz (MMPs), consideradas as principais enzimas responsáveis pela remodelação da matriz orgânica, incluindo os componentes e estruturas da junção amelodentinária (JAD). Questiona-se então se as alterações dentais observadas em pacientes pós-radioterapia poderiam ser causadas também pela ativação das MMPs que se encontram na JAD. O presente estudo apresentou três avaliações: a ativação e expressão das MMPs, a implementação de inibidores de proteases como método de inibição das MMPs e a ativação das MMPs devido a um desafio ácido. Para as medições foram utilizados 178 fragmentos dentais de molares, divididos aleatoriamente em 2 grupos (decíduos e permanentes) / 4 subgrupos experimentais (irradiados e não-irradiados). Os fragmentos foram expostos à radiacao com Co-60, com fracao de dose de 2 Gy, 5 dias consecutivos, ate atingirem a dose total de 60 Gy, com um total de 30 ciclos, durante 6 semanas. Com o objetivo de determinar a expressão e atividade das MMPs, foram realizados os ensaios de imunofluorescência e zimografia in situ, nos fragmentos dentais de 0,6mm, analisando os tecidos duros do esmalte, dentina e JAD. Para avaliar se produtos odontológicos inativam as MMPs, os dentes foram imersos em 0,5ml de digluconato de clorexidina a 0,12%, fluoreto de sódio a 0,05%, polifenol epigalocatequina 3-galato 400μM e água destilada (grupo controle), por 1 hora. Assim também com objetivo de avaliar se em um ambiente ácido, as MMPs apresentariam maior atividade, os dentes foram colocados em contato com 20μl de solucao desmineralizadora com pH de 4,8, por um minuto, e posteriormente lavados com 20μl de água deionizada, por um minuto. De maneira geral pudemos observar que a irradiação ativa as MMPs na JAD e estes efeitos foram mais evidentes nos dentes permanentes que nos decíduos. Com relação à expressão das diferentes MMPs, foi observada uma maior expressão das MMPs-9 e -20 para dentes decíduos, e para dentes permanentes as MMPs-2, -9 e -20 apresentaram expressão semelhante. Tendo em vista que a irradiação foi capaz de ativar as MMPs expressas na JAD de dentes permanentes, e em busca de soluções capazes de inibi-las, observamos que o Digluconato de Clorexidina, o Fluoreto de Sódio e o Polifenol Epigalocatequina 3-galato inibiram a atividade das MMPs na JAD em dentes permanentes. Por último ao investigar o efeito de um desafio ácido, na atividade das MMPs, observamos que a desmineralização não aumentou a atividade das MMPs em dentes não irradiados, porém aumentou a atividade das MMPs em dentes irradiados. Comparando dentes irradiados submetidos ou não à desmineralização, observou-se que a desmineralização incrementou a atividade das MMPs, já induzida pela irradiação. Radiotherapy for patients with head and neck cancer can have serious secondary consequences such as changes in tooth structure, with consequent loss of oral function which negatively influences an individual\'s quality of life. Recently research work has shown that radiation induces the expression and activation of matrix metalloproteinases (MMPs) which are considered the major enzymes responsible for the remodeling of the organic matrix, including the components and structures of the dentinoenamel junction (DEJ). It is questionable if the dental changes observed in post-radiotherapy patients could also be caused by the activation of MMPs that are in the DEJ. The present study has three assessments: the activation and expression of MMPs, the implementation of protease inhibitors such as method of inactivating MMPs and the activation of MMPs due to an acid challenge. The measurements that were used were 178 molar dental fragments randomly divided into 2 groups (deciduous and permanent) / 4 experimental subgroups (irradiated and non-irradiated). The samples were exposed to radiation using Co-60 at a cumulative dose of 2 Gy fraction, 5 consecutive days, until they reached a total dose of 60 Gy, with a total of 30 cycles for 6 weeks. In order to determine the expression and activity of MMPs immunofluorescence assays were performed and in situ zymography, the dental fragments of 0.6mm, analyzing the DEJ in three areas of the tooth (cervical, cuspal and groove of pit). To assess whether MMPs inactivate dental products, the teeth were immersed in 0.5 ml of chlorhexidine digluconate at 0.12%, sodium fluoride 0.05%, polyphenol epigallocatechin-3 gallate 400μM and distilled water (control group) for 1 hour. To evaluate effects in an acidic environment, MMPs have higher activity, the teeth were put in contact with 20μl of demineralizing solution with pH 4.8, for a minute, and then washed with 20μl of deionized water, one minute. In general we observed that the radiation active MMPs in DEJ and these effects were more evident in the permanent teeth than in the primary teeth. Regarding the expression of different MMPs, showed the greatest expression of MMP-9 and -20 for deciduous teeth, and permanent teeth MMPs-2, -9 and -20 showed similar expression. Given that the irradiation was able to activate MMPs expressed in the DEJ permanent teeth, and looking for solutions that inactive them, we observed that the digluconate Chlorhexidine, the Sodium Fluoride and Polyphenol Epigallocatechin-3-gallate inhibited activity of MMPs in the DEJ in permanent teeth. Finally, to investigate the effect of an acid challenge, in the activity of MMPs, we observed that the demineralization did not increase the activity of MMPs in non-irradiated teeth but increased the activity of MMPs in irradiated teeth. Comparing irradiated whether subjected to demineralization teeth or not, it was found that demineralization increased activity of MMPs, induced by the radiation.

APA, Harvard, Vancouver, ISO, and other styles

31

Planello, Aline Cristiane 1980. "Analise de polimorfismos no promotor dos genes MMP1, MMP3 e MMP9 na desordem da articulação temporomandibular." [s.n.], 2010. http://repositorio.unicamp.br/jspui/handle/REPOSIP/288534.

Full text

Abstract:

Orientador: Ana Paula de Souza Pardo Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba Made available in DSpace on 2018-08-15T12:46:18Z (GMT). No. of bitstreams: 1 Planello_AlineCristiane_M.pdf: 940083 bytes, checksum: 36ed3b0b3b0d10c144805116e08917dd (MD5) Previous issue date: 2010 Resumo: Objetivo: As Metaloproteinases da Matriz ( MMPs) são enzimas que degradam a matriz extracelular (MEC) e tem sido associadas às desordens temporomandibulares (DTM). Nós investigamos a freqüência dos -1607 1G/2G MMP1 polimorfismo (rs1799750), -1171 6A/5A MMP3 polimorfismo (rs3025058) e -1562 C/T MMP9 polimorfismo (rs3918242) em indivíduos com sinais de degeneração da ATM, diagnosticados por exame de imagem, a fim de analisar a associação desses polimorfismos e a DTM. Métodos: A população estudada foi composta por 115 indivíduos diagnosticados por exame de imagem (grupo DTM) e 117 controles. Os polimorfismos genéticos foram determinados por PCR/RFLP. Resultados: A freqüência do genótipo 2G/2G no gene MMP1 foi significantemente mais alta no grupo DTM do que no grupo Controle (p = 0.008). O genótipo 2G/2G no grupo DTM mostrou um risco aumentado para a DTM com um OR = 2.25 ( 95% IC = 1.26 - 3.99) quando comparado com os genótipo 1G/2G e 1G/1G. A freqüência dos alelos do gene MMP1 não mostrou diferença significativa entre os grupos (p > 0.05). A distribuição dos genótipos e alelos dos genes MMP3 e MMP9 não mostrou diferença significativa (p > 0.05). Conclusão: Nossos resultados mostram a associação entre o polimorfismo -1607 MMP1 e a suscetibilidade à DTM Abstract: Objective. Matrix metalloproteinases (MMPs) degrade extracellular matrix components and have been implicated to play an important role in temporomandibular joint disorder (TMD). We investigated the frequency of -1607 1G/2G MMP1 polymorphism (rs1799750), -1171 6A/5A MMP3 polymorphism (rs3025058) and -1562 C/T MMP9 polymorphism (rs3918242) in individuals with TMJ degeneration diagnosed by image exam in order to analyze the association of these MMPs polymorphisms and TMD. Methods. The studied population comprised 115 TMD individuals diagnosed by image exam and 117 healthy controls. Genotypes were determined using polymerase chain reaction/Restriction fragment length polymorphism PCR/RFLP. Results. The MMP1 2G/2G genotype was significantly higher in the TMD group than in the Control group (p = 0.008). The genotype 2G/2G in the TMD group showed an increased risk to TMD with an OR = 2.25 (95% CI = 1.26 - 3.99) when compared with 1G/2G and 1G/1G genotypes. Analysis of MMP1 allele frequencies showed no significant difference (p > 0.05). The MMP3 and MMP9 genotypes distribution and alleles frequency did not differ between the groups (p > 0.05). Conclusion. Our results report the association of -1607 MMP1 gene polymorphism and increased risk to TMD Mestrado Histologia e Embriologia Mestre em Biologia Buco-Dental

APA, Harvard, Vancouver, ISO, and other styles

32

Hannas, Angélica Reis. "Determinação da expressão de MMP-2 e MMP-9 na saliva de pacientes portadores de lesões cervicais não cariosas e da influência das MMPs sobre lesões radiculares artificiais através de EDX." Universidade de São Paulo, 2007. http://www.teses.usp.br/teses/disponiveis/25/25131/tde-30032009-155558/.

Full text

Abstract:

As metaloproteinases da matriz (MMPs) foram identificadas na saliva, na placa dental, na dentina e no cemento. Este trabalho teve como objetivos: Estudo I (I) - avaliar a expressão de MMP-2 e MMP-9 presentes na saliva total e parotidiana e no fluido gengival crevicular (FGC) de pacientes portadores e não portadores de lesões cervicais não cariosas (LCNC); Estudo II (II) - investigar se a presença de MMP-8 e -9/TIMPs poderia influenciar a remineralização de lesões artificialmente criadas na superfície radicular, com ou sem desgaste por abrasão. Os métodos utilizados foram: (I) Coleta de amostras de saliva e do FGC de 32 pacientes, com (n=16) e sem LCNC (n=16). A atividade gelatinolítica das MMPs foi avaliada através de análise zimográfica e Western Blot. (II): Espécimes de dentina humana radicular foram obtidos. O grupo controle G1(10) não sofreu nenhum tratamento. Os demais segmentos radiculares foram desmineralizados G2(60). O Grupo A não foi submetido à escovação e o Grupo B foi submetido à abrasão por escovação em uma máquina de escovação simulada. G2(10) foi apenas desmineralizado, G3(10) desmineralizado e remineralizado, e os Grupos G4(10), G5(10), G6(10), G7(10) foram desmineralizados e remineralizados em presença de tampão neutro, TIMP, MMP-8 e -9, MMP-8,-9 e TIMP, respectivamente. Para a análise elemental, as concentrações de Ca+2, P, Mg+2 assim como a relação molar Ca/P e Mg/Ca foram determinadas através de uma sonda eletrônica para microanálise (EPMA). A análise qualitativa por retrodispersão (BSE) foi realizada para demonstrar a distribuição global da densidade mineral. Os resultados (I) mostraram que a principal gelatinase presente, tanto na saliva total quanto no FGC, é a proMMP-9. Na saliva secretada pela glândula parótida, não foram detectadas bandas indicando a presença de gelatinases. Os resultados do estudo (II) indicaram que os espécimes escovados apresentaram maior conteúdo de Ca+2 a 20µm e maior conteúdo de Mg+2 a 30 e 50µm. Em presença de TIMPs, ocorreu uma redução do conteúdo de Ca+2 a 20µm. Para os espécimes não escovados, em todas as profundidades, as amostras incubadas com MMPs apresentaram maiores valores de Ca+2. Portanto, pode-se concluir que (I) a comparação entre pacientes com e sem LCNC mostrou não haver diferença estatisticamente significante quanto à atividade gelatinolítica; (II) quando não inibidas pelos TIMPs, as MMPs degradaram o colágeno completamente desmineralizado na superfície radicular, permitindo melhor recalcificação na superfície subjacente. Esse fenômeno foi também facilitado pela abrasão por escovação. Matrix metalloproteinases (MMPs) have been identified in saliva, plaque, gingival crevicular fluid (GCF), dentin and cementum. Study (I) aimed at evaluating the presence and quantity of gelatinases MMP-2 and MMP-9 in total and parotid saliva and in GCF (GCF) of subjects with and without NCCL. Study (II) aimed at investigating whether the presence of matrix metalloproteinase (MMP)-8 and - 9/TIMPs would influence the remineralization of artificial root lesions with and without mechanical wear. (I) Total stimulated saliva, parotid saliva, and GCF from patients with (n=16) and without NCCL (n=16) were collected and assessed for gelatin zymography and for western immunoblot analysis. (II) Human root segments from Group A (n=35) were not brushed and from Group B (n=35) were subjected to machine-controlled brushing, simulating mechanical wear. Specimens from Group 1 (control, n=10) were left untreated. Group 2 (n=10), was just demineralized; Group 3 (n=10) was demineralized and remineralized. The other samples G4 (n=10), G5 (n=10), G6 (n=10), G7 (n=10) were subjected to remineralization with HEPES buffer, tissue inhibitor of matrix metalloproteinase-2 (TIMP-2), activated MMP-8 and MMP-9 and activated MMP-8, MMP-9 and TIMP-2, respectively. Ca+2, P, Mg+2 concentrations as well as Ca/P and Mg/Ca molar ratios were determined through an Electron Probe Microanalyser (EPMA). (I) Densitometric analysis revealed that the main gelatinase was proMMP-9. No statistically significant difference was observed for MMP-2 and MMP-9 levels, separately. In parotid saliva, gelatinolytic activity was very low or absent. Western immunoblots revealed that, while little immunoreactivity was detected for MMP-2, there was positive immunoreaction for MMP-9, both in total saliva and in GCF. Gelatinases do not seem to originate from parotid gland. (II) The results indicated that the brushed specimens presented higher Ca+2 levels at 20 µm and higher Mg+2 content at 30 and 50 µm. Ca+2 content at 20 µm decreased in the presence of TIMPs. For the non-brushed specimens, in all depths, samples incubated with MMPs showed highest Ca+2 values. It can be concluded that (I) the main gelatinase present in the oral cavity is MMP-9. No significant differences were found in total gelatinolytic activity among NCCL+ and NCCL- patients. (II) When not inhibited by TIMPs, MMPs degraded the completely demineralized collagen in the root surface, allowing for better recalcification in the deeper areas. This phenomenon was also facilitated by the brushing procedure.

APA, Harvard, Vancouver, ISO, and other styles

33

Kelly, Stephen Richard. "The expression of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) in metastatic colorectal carcinoma (CRC)." Thesis, University of Southampton, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.412204.

Full text

APA, Harvard, Vancouver, ISO, and other styles

34

Koloze, Mary T. "The Role of Matrix Metalloproteinases (MMPs) and their Proteolytic Degradation of Chemokines in the Lung." Case Western Reserve University School of Graduate Studies / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=case1269959847.

Full text

APA, Harvard, Vancouver, ISO, and other styles

35

Sbai, Oualid. "Distribution, trafic et sécrétion vésiculaire des MMPs et de leurs inhibiteurs dans les cellules neurales." Aix-Marseille 2, 2009. http://www.theses.fr/2009AIX20733.

Full text

Abstract:

Les métalloprotéinases matricielles (MMPs) et leurs inhibiteurs endogènes les Tissues inhibitors of MMPs (TIMPs) constitue le système MMP/TIMP, un des principaux régulateurs de l’espace péricellulaire. Cette régulation est réalisée via le clivage de nombreuses cibles protéiques, notamment les composants de la matrice extracellulaire, les protéines d’adhérence, les cytokines, les récepteurs et molécules de surface cellulaire. Les MMPs sont subdivisées en deux grands groupes selon qu’elles sont sécrétées ou membranaires (MT-MMPs). Dans le système nerveux central (SNC), l’expression des MMPs et les TIMPs est largement régulée au cours des processus développementaux et pathologiques. Cependant, rien n'est connu concernant la distribution intracellulaire et les voies de sécrétion des MMPs et des TIMPs dans les cellules neurales. En combinant des approches de biologie cellulaire et moléculaire, de biochimie et d’imagerie, nous avons entrepris une étude de la distribution intracellulaire, du transport et de la sécrétion de MMP- 2, MMP-9 et de leurs inhibiteurs TIMP-1 et de TIMP-2 dans les cellules neurales. Cette étude a permis de démontrer notamment une localisation nucléaire de MMP-2 et MMP-9 ainsi qu’une distribution vésiculaire différentielle des MMPs, notamment vis-à-vis des moteurs moléculaires qui participent au transport des vésicules le long des microtubules et des filaments d’actine. Nous montrons aussi que les vésicules MMP-9 sont de nature lysosomale et que les MMPs et les TIMPs sont sécrétées en partie sous forme vésiculaire dans le milieu extracellulaire. Ainsi, nos résultats suggèrent que ces protéinases ainsi que leurs inhibiteurs utilisent différentes voies de transport et de sécrétion associées à différents fonctions cellulaires. Nous avons également étudié le rôle de MT5-MMP, une MMP membranaire presque exclusivement exprimée dans le SNC, dans la plasticité neuronale. Nous avons comparé des souris naïves (WT) et des souris déficientes pour le gène MT5-MMP (KO) qui ont un développement apparemment normal. Cependant, elles présentent des déficits d’apprentissage dans un test olfactif impliquant la mémoire déclarative qui est dépendante de l’hippocampe, alors que leur mémoire procédurale qui elle est indépendante de l’hippocampe n’est pas affectée. Les souris KO présentent également des déficits dans la LTP, dont l’amplitude est diminuée comparé aux WT. Au niveau cellulaire, et à l’aide de protéines de fusion GFP, nous montrons que MT5-MMP a une distribution vésiculaire, elle co-localise avec les éléments du cytosquelette mais son transport semble indépendant des moteurs moléculaires kinésine et myosine V, contrairement à nos observations sur MMP-2 et MMP-9. Finalement, et de manière surprenante, MT5-MMP est également détectée dans le noyau en accord avec la présence de plusieurs sites d’adressage nucléaire dans sa séquence protéique. L’ensemble de ces résultats contribue à mieux comprendre la sécrétion et le trafic des MMPs dans les cellules neurales et renforce l’idée selon laquelle les MMPs et les TIMPs jouent des rôles prépondérants dans la physiopathologie du SNC.

APA, Harvard, Vancouver, ISO, and other styles

36

Sarrazy, Vincent. "Cellules fibrogéniques impliquées dans la réparation tissulaire (comparaison foie / système nerveux central) : rôles des MMPs." Limoges, 2010. https://aurore.unilim.fr/theses/nxfile/default/8106f6b5-5fae-4fc4-938e-7703c794bc7b/blobholder:0/2010LIMO330A.pdf.

Full text

Abstract:

Le développement d’une fibrose est caractérisé par une accumulation de matrice extracellulaire (MEC). Dans la plupart des organes, les cellules fibrogéniques impliquées dans ce dépôt de MEC sont les fibroblastes et les myofibroblastes alors que, dans le système nerveux central (SNC), ce sont les astrocytes. Au cours de ce travail, nous avons réalisé une comparaison entre les cellules fibrogéniques impliquées dans la fibrose hépatique et celles impliquées dans la « fibrose » du SNC appelée cicatrice gliale. Dans la fibrose hépatique, en utilisant un modèle élégant de culture de tranches de foie, nous avons confirmé que les cellules fibrogéniques impliquées dérivent des cellules étoilées du foie et / ou des fibroblastes portaux. Parallèlement, nous avons réalisé une étude protéomique pour caractériser la réaction stromale des cholangiocarcinomes qui implique principalement les fibroblastes portaux. Afin de pouvoir comparer les phénomènes de fibroses hépatiques et la formation de la cicatrice gliale, nous avons développé des cultures d’astrocytes à partir de cortex de rats nouveau-nés que nous avons traités avec du LPS pour mimer l’activation observée in vivo. Nous avons étudié les interactions entre la voie pro-apoptique Fas et le système des MMPs. De plus, nous avons séparé différentes populations astrocytaires grâce à une technique originale de fractionnement par couplage flux/force. Parallèlement, nous avons développé un modèle in vivo de lésion corticale chez le rat pour corréler nos observations in vitro et in vivo, et pour étudier également l’effet de différents facteurs neuroprotecteurs. En fin, nous avons étudié les interactions entres les voies Fas et TLR4 ainsi que le système des MMPs dans les glioblastomes Fibrosis development is characterized by a deposition of extracellular matrix (ECM). In most organs, fibrogenic cells involved in ECM deposition are fibroblasts and myofibroblasts. In the case of the central nervous system (CNS), the secretion of ECM is mostly performed by astrocytes. In this thesis, we conducted a comparison between the cells involved in liver fibrosis and those involved in the CNS "fibrosis" called glial scar. In hepatic fibrosis, using an elegant model of cultured hepatic slices, we confirmed that fibrogenic cells involved derived from hepatic stellate cells and / or portal fibroblasts. In parallel, we performed a proteomic study to characterize the stromal reaction of cholangiocarcinomas which mainly involves portal fibroblasts. To compare the phenomena of liver fibrosis and the formation of the glial scar, we have developed a culture model of astrocytes derived from cortex of newborn rats that we have treated with LPS to mimic in vivo activation. We have studied the interactions between the pro-apoptotic Fas pathway and the MMPs system. In addition, we separated different populations of astrocytes using an original technique of sedimentation field flow fractionation. In parallel, we developed an in vivo model of cortical lesion in the rat to correlate our observations in vitro and in vivo and to study the neuroprotective effects of different factors. Finally, we studied the interactions between Fas and TLR4 pathways and the MMP system in glioblastoma cell lines

APA, Harvard, Vancouver, ISO, and other styles

37

Sanchez, Vidales Maria Del Mar. "Release of Soluble Interleukin-7 α Receptor (CD127) from CD8+ T-Cells and Human Thymocytes". Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/34631.

Full text

Abstract:

ABSTRACT Background Interleukin-7 (IL-7) is a cytokine crucial for T-cell development and homeostasis. IL-7 is thought to be a limited resource, and its interaction with the IL-7 receptor (IL-7R) has effects on increasing cell survival, proliferation and cytolytic function. Considering the roles of IL-7, it is no surprise that the expression of the IL-7 receptor alpha chain (CD127) is tightly regulated. Despite increased levels of soluble CD127 (sCD127) being detected in a number of disease states and being associated with disease activity, the biological function of sCD127 and its clinical relevance remains to be established. In this study, I explore the post-translational mechanisms leading to the release of the soluble form of CD127 receptor through IL-7 and αCD3/αCD28 stimulation. Here I specifically established two different mechanisms by which CD127 is processed; shedding of the receptor ectodomain and clipping. Results In CD8+ T-cells, IL-7 plus TcR stimulation resulted in an increased release of sCD127. Here I found that matrix metalloproteases (MMPs), in particular MMP-9, have a role in the proteolytic clipping of CD127 resulting in the release of sCD127. In addition, I found that IL-7 plus TcR stimulation resulted in an increase in MMP activity and this activity was particularly dampened when MMP-2 and -9 inhibitors were used. I also found that neither MMP-3 nor cysteine and serine proteases seem to be directly involved in the generation of sCD127. Using a biotinylation assay I found that CD127 is being shed from the surface of CD8+ T-cells as well as thymocytes through a MMP-independent mechanism. Conclusion These results demonstrate that MMPs (in particular MMP-9) have a role in the generation of sCD127. Further studies are required to determine the specific sheddase responsible for the ectodomain shedding of CD127, as well as the details behind the regulation of MMP-9 activity both in CD8+ T-cells and thymocytes. A thorough understanding of these mechanisms will aid in the development of alternative and more specific strategies to control IL-7 mediated processes in both normal and disease states.

APA, Harvard, Vancouver, ISO, and other styles

38

Toupance, Simon. "Rôle des peptides de l’élastine dans la progression des carcinomes broncho-pulmonaires." Thesis, Reims, 2011. http://www.theses.fr/2011REIMP205.

Full text

Abstract:

Au cours de l'invasion tumorale, la matrice extracellulaire du tissu broncho-pulmonaire, riche en élastine, subit de nombreux remaniements. La dégradation de cette élastine conduit à la production de peptides bioactifs. Ces peptides d'élastine (PE) possèdent un récepteur spécifique, le complexe récepteur de l'élastine (CRE), et peuvent également interagir avec l'intégrine alphavbeta3 et la galectine-3. Dans cette étude, nous avons étudié le rôle des PE et de leurs récepteurs dans la progression tumorale des carcinomes broncho-pulmonaires.Des cellules épithéliales bronchiques tumorales sont incubées in vitro avec un mélange de PE, la kappa-élastine (kE), ou avec des peptides synthétiques. Le traitement par les peptides entraine une augmentation de la capacité infiltrante des cellules invasives associée à un relargage précoce de MMP 2, MMP 9 et uPA mais n'a pas d'effet sur la prolifération et le phénotype cellulaire. Les niveaux d'ARNm des 3 protéases stimulées ne sont pas modifiés et ni l'actinomycine D, ni le cycloheximide ou la bréfeldine A ne sont capables d'inhiber les effets liés à la kE. Ces effets ne sont pas non plus inhibés par le lactose et les autres antagonistes des trois récepteurs. Enfin, les peptides VGVAPG et GRKRK, présentant les séquences spécifiques reconnues par les récepteurs, ne réussissent pas à reproduire les effets observés avec la kE, alors que des nonapeptides les reproduisent de façon quasi-identique.Ces résultats montrent que les PE régulent la capacité invasive des carcinomes broncho-pulmonaires, via le relargage d'enzymes protéolytiques. Cette modulation mettrait en jeu des mécanismes post-traductionnels et un récepteur lactose-insensible, différent du CRE, de l'intégrine alphavbeta3 et de la galectine-3, et reconnaissant des nonapeptides d'élastine Elastin-rich lung extra-cellular matrix is largely remodeled during tumor invasion. Elastin degradation produces peptides displaying a wide range of biological activities. These elastin derived peptides (EP) interact with the Elastin Receptor Complex (ERC) but also bind to alphaVbeta3 integrin and galectin-3. In this study, we explored the role of EP and their receptors in tumor progression of lung carcinomas.In vitro, lung tumor cells were incubated in presence of kappa-elastin (kE), a mix of EP or with synthetic elastin peptides. EP treatment induced an increase of invasive capacity of invasive cells with quickly increased levels of MMP-2, MMP 9 and uPA but had no effect on cell proliferation and phenotype. Interestingly, protease regulation was not observed at the mRNA level and actinomycin D, cycloheximide and brefeldin A were unable to inhibit kE effects. These effects could not be inhibited either by classical receptor antagonists including lactose or blocking antibodies. Finally, synthetic peptides VGVAPG and GRKRK, displaying receptor-specific sequences, failed to reproduce kE effects whereas nonapeptides partially mimicked them.These results demonstrate that treatment with EP up-regulates invasiveness of lung tumor cells via the release of proteolytic enzymes. This modulation involves post-translational mechanisms and a lactose-insensitive receptor, different from the ERC, alphaVbeta3 integrin and galectin-3 and recognizing nonapeptidic sequences

APA, Harvard, Vancouver, ISO, and other styles

39

Rapti, Magdalini. "Molecular basis of the inhibition of matrix metalloproteinases (MMPs) by the tissue inhibitors of metalloproteinases (TIMPs)." Thesis, University of Kent, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.404554.

Full text

APA, Harvard, Vancouver, ISO, and other styles

40

Hill, Jane Alison. "Immunochemical studies on the cellular expression of MMPs and TIMPs and their interactions with extracellular matrices." Thesis, Open University, 1995. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.262660.

Full text

APA, Harvard, Vancouver, ISO, and other styles

41

Oddsdóttir, Charlotta. "Development of endometrial fibrosis in the mare : factors involved in tissue remodelling and collagen deposition." Thesis, University of Edinburgh, 2008. http://hdl.handle.net/1842/4218.

Full text

Abstract:

Age-related degeneration of the equine endometrium is an established and important cause of fertility problems in thoroughbred mares, causing great loss to the industry. As a part of the age-related endometrial degeneration complex, an excessive deposition of collagen leading to endometrial fibrosis is particularly important due to the limitations it causes to uterine function. The consequences include reduced efficacy of uterine defence mechanisms and a decrease in the uterine capacity for foetal nutrition. Extensive research into the process of fibrosis in other organs has shown that this condition results from the malfunction of physiological tissue repair mechanisms. These mechanisms revolve around tissue fibroblasts that due to continuous stimulation secrete excessive amounts of collagen and inhibit the activation of factors essential to the normal collagen degradation occurring in scar resolution. Among these factors are the MMPs, an enzyme family with the ability to degrade extracellular matrix components such as collagen during the normal repair mechanisms following tissue injury. The malfunction in the regulation of these enzymes is important in the development of fibrosis in the liver and other organs. In this study it was demonstrated that MMPs are involved in the acute uterine inflammatory response and that they were secreted by infiltrating inflammatory cells. The cellular mechanisms observed during endometritis in normal mares were comparable to the normal repair mechanisms known to be altered in the fibrosis of other organs. These enzymes were present in equine foetal fluids, and their regulation may be important in the process of abortion and stillbirth. It was demonstrated that inbreeding may be correlated with increased deposition of endometrial collagen in a study population of the Icelandic horse breed even though this breed appears to exhibit less severe endometrial degeneration than what is known in lighter breeds. It is likely that genetic predisposition leads to the disruption of normally self-limiting inflammatory and repair mechanisms in the endometrium, resulting in constant activation of collagen synthesis by local and infiltrating cells. This thesis has shown that tissue repair mechanisms involving MMPs are likely to be involved in endometrial fibrosis in the mare. An inherent alteration in these mechanisms may play a role in the pathogenesis of this condition, and might arise due to genetic predisposition. Further understanding of the pathways leading to excess collagen amounts in the endometrium may produce preventative measures, and even therapeutic targets.

APA, Harvard, Vancouver, ISO, and other styles

42

Tao, Duy Anh. "Matrix Metalloproteinase (MMP) activity and its regulators in diabetic kidney disease." Thesis, The University of Sydney, 2021. https://hdl.handle.net/2123/27355.

Full text

Abstract:

Matrix metalloproteinases are a large family of proteolytic enzymes which are key players in tissue remodelling and can degrade almost all componets of the extracellular matrix (ECM). The imbalance of matrix synthesis and degradation could be related to the dysregulation of MMPs, potentially contributing to pathogenic features of diabetic kidney disease (DKD). A hallmark feature of DKD is fibrosis, which occurs due to dysregulation of matrix synthesis and degradation. Published findings have suggested measurement of MMPs as potential early makers for the likelihood of development of early kidney changes. However, these studies have focused on measurement in kidney tissue, their gene and protein expression, and little is known regarding their activity. This thesis explored the utility of MMP activity measurement in preclinical diabetic animal models and in clinical studies in people with various levels of DKD. MMP activity was affected by the diabetic environment and MMP activity was shown to be associated with progression of DKD in animals with long duration of diabetes. In cells, high glucose environment showed increased MMP activity and its regulators including TIMP-1 and histone deacetylases (HDACs). In humans, total MMP activity was correlated with diabetes duration and HbA1c. However, in the human cohort, the cross-sectional studies performed were unable to show an association between MMP activity and kidney structural changes such as those seen in DKD. Overall, this suggests that total MMP activity are altered in diabetes in association with markers of diabetic control and in mice with development of kidney changes. However, more detailed longitudinal studies are required to determine the utility of MMPs as a marker of early DKD.

APA, Harvard, Vancouver, ISO, and other styles

43

Jarosz, Camille. "Rôle de l'EMMPRIN, inducteur des MMPs,dans l'activation des fibroblastes : conséquences sur la formation du stroma tumoral." Thesis, Paris Est, 2014. http://www.theses.fr/2014PEST0064.

Full text

Abstract:

Les fibroblastes activés qui composent les stromas tumoraux sont des acteurs majeurs des interactions tumeur-stroma impliquées dans la croissance et la dissémination des cellules tumorales. Ce processus d'activation des fibroblastes est caractérisé par l'expression de marqueurs protéiques spécifiques parmi lesquels figure l'alphaSMA et FAPalpha;. Le TGFbeta;, cytokine secrétée massivement par les cellules tumorales, est un des éléments impliqués dans l'activation des fibroblastes et la formation du stroma tumoral qui en résulte. L'EMMPRIN, glycoprotéine transmembranaire surexprimée dans les cellules tumorales est également un médiateur des interactions tumeur-stroma puisqu'il a la capacité d'induire la synthèse des MMPs par les fibroblastes péri-tumoraux accroissant ainsi la propagation des cellules tumorales à travers l'organisme. Nos travaux identifièrent que le TGFbeta secrété par les cellules tumorales induisait la synthèse du marqueur FAPalpha par les fibroblastes. L'EMMPRIN stromal apparaît comme récepteur de ces signaux tumoraux et est nécessaire à la synthèse du marqueur FAPalpha; par les fibroblastes. L'EMMPRIN participe donc à l'activation TGFbeta; dépendante des fibroblastes. Son inhibition dans ces cellules conduit à un dysfonctionnement de la signalisation médiée par les protéines Smad2/Smad3 aboutissant à une diminution de la synthèse du marqueur alphaSMA ainsi que de certaines protéines matricielles induites par le TGFbeta. L'étude du mécanisme d'action de l'EMMPRIN dans ce processus a permis d'identifier l'EMMPRIN comme nouvelle protéine chaperonne du récepteur de type I au TGFbeta Tumor stroma activated fibroblasts are major actors of tumor stroma interactions taking to tumor growth and spreading. Activated fibroblasts are characterized by the expression of specific markers including alphaSMA and FAPalpha;. The TGFbeta;, a cytokine highly secreted by tumor cells, is one of the key factors involved in fibroblast activation and tumor stroma formation. EMMPRIN, a transmembrane glycoprotein overexpressed in tumor cells, is also a mediator of tumor-stroma interactions by its ability to induce the synthesis of MMPs by peri-tumor fibroblasts enhancing then tumor cells dissemination across the organism.Here, we demonstrate that TGFbeta; secreted by tumor cells is the tumor factor involved in the synthesis of FAPalpha; by fibroblasts. Stromal EMMPRIN appeared to be the receptor of these tumor-stroma interactions and is required for the synthesis of FAPalpha; by fibroblasts. EMMPRIN was also evidenced to take part in TGFbeta;-dependent fibroblast activation. Its inhibition in these cells correlate to a dysfunction in Smad2/Smad3 signaling leading to a decrease in the expression of alphaSMA and matrix proteins induced by TGFbeta;. The study of the mechanism used by EMMPRIN in this process evidenced this protein as a new chaperone for the type I TGFbeta; receptor

APA, Harvard, Vancouver, ISO, and other styles

44

Candido, Saverio. "Neutrophil gelatinase-associated lipocalin (NGAL) and matrix metalloproteinases (MMPs) as biomarkers of bladder cancer development and progression." Doctoral thesis, Università di Catania, 2016. http://hdl.handle.net/10761/3777.

Full text

Abstract:

Neutrophil gelatinase-associated lipocalin (NGAL), also called lipocalin-2, is a secreted protein belonging to the lipocalin family proteins and actively participates into the proliferation, differentiation, and development of human tissues, including tumours. It positively modulates the activity of the matrix metalloproteinases-9 (MMP-9) that are involved in the enzymatic remodelling of the extracellular matrix. MMP-9 regulates the degradation of extracellular matrix in processes such as angiogenesis, tumour growth, and metastasis. By forming the NGAL/MMP-9 complex, NGAL protects MMP-9 from proteolytic degradation, a fundamental mechanism in controlling the activity of the proteins, and enhances its enzymatic activities. As a secreted protein, NGAL is detectable in many biologic fluids, including urine, where several neoplastic cells and other tumor microenvironmental factors can be directly released from the cancer. Our in silico analysis suggested an active role of NGAL in tumour development of several cancer types. Validation of these findings is here described in bladder cancer as a good tumor model in which investigate the role of this protein because urine is in direct contact with the primary tumor. On these bases, the release of NGAL in both urine and serum samples from 89 bladder cancer patients was measured. Further investigations, aimed to emphasize the role of NGAL in cancer, were performed by analysing MMP-9 and NGAL/MMP-9 complex levels in the same subset of bladder cancer patients. Control experiments were performed in 119 cancer-free controls, previously enrolled in a case-control study. Urinary concentrations were standardized on creatinine level. The performance of these proteins as cancer biomarkers was evaluated through the receiver operating characteristic (ROC) analysis. In conclusion, the present study deepens the knowledge of the molecular mechanisms sustaining NGAL expression in tumor cells and its effects on cancer metastatic behaviour. Furthermore, NGAL/MMP-9 pathway is associated with an aggressive phenotype of transitional cell carcinoma of the bladder (TCC). The elevated negative predictive value of MMP-9 and NGAL/MMP-9 complex make them candidate markers of exclusion test for TCC. These findings suggest that these proteins may be integrated in the surveillance of bladder cancer, thus improving patients complaints and diminishing their discomfort.

APA, Harvard, Vancouver, ISO, and other styles

45

Nury, Catherine. "Développement d’une sonde de photoaffinité pour la détection sensible de formes actives de Métalloprotéases Matricielles dans des systèmes biologiques complexes." Thesis, Paris 5, 2012. http://www.theses.fr/2012PA05P629/document.

Full text

Abstract:

Le développement d’une nouvelle sonde dite « activity-based probe » pour réaliser la détection de formes actives de protéases appartenant à la famille des protéases à zinc de la matrice (MMP) a été réalisé dans ce travail, en partant d’un inhibiteur phosphinique puissant des MMP dans lequel a été introduit un groupement photoactivable de type diazérine. Ce composé se révèle un inhibiteur puissant de plusieurs MMP avec des affinités nanomolaires. Ce composé incubé avec différentes MMP est par ailleurs capables de modifier de façon covalente un grand nombre de MMP au niveau de leur site actif, avec des rendements de modification variant de plus de 50% à 11%, selon la nature des MMP. En ayant choisi comme moyen de détection la radioactivité, nous démontrons qu’avec cette nouvelle sonde qu’il est possible de détecter des formes actives de MMP avec des sensibilités de l’ordre de la femtomole dans des systèmes modèles de protéomes complexes. Appliquée à l’analyse de lavages broncho alvéolaires de souris traitées par voie pulmonaire avec des nanoparticules pour induire une réponse inflammatoire, cette nouvelle sonde permet de mettre en évidence la présence de formes actives du domaine catalytique de la MMP-12, une métalloprotéase à zinc exprimée par les macrophages, mais pas dans les animaux contrôles. En revanche l’analyse de carotides humaines de patients souffrant d’athérosclérose ne nous pas conduit avec cette sonde à la détection de formes actives de MMP. Malgré ce résultat, il est à noter que la détection de forme active de MMP dans un fluide pathologique est une première dans ce domaine. Cette sonde étant validée pour sa capacité à détecter des formes actives de MMP, elle permettra dans l’avenir de tester d’autres fluides pathologiques d’origine humaine ou bien des extraits de tissu comme des tumeurs pour lesquels les MMP pourraient être des marqueurs de ces pathologies A new activity-based probe able to covalently modify the active site of proteases belonging to the matrix metalloprotease family (MMPs) has been developed in this thesis project. The probe was shown to behave as potent inhibitor of several MMPs, with nanomolar Ki values. This probe was also able to modify specifically only the free active site of MMPs, with particular high yields of cross-linking varying from 50 % to 11 %, depending of the MMPs tested. Using radioactivity as means of detection, this probe was able to detect active form of MMPs with a threshold of 1 femtomole. Applied to the study of bronchoalvelolar fluids (BAL) from mice exposed to nanoparticles by a lung aspiration protocol, this probe revealed the presence of the catalytic domain of MMP-12 under its active form, but not in control animals. When used to detect active form of MMPs from extracts obtained from human arteries of patient suffering from atherosclerosis, the probe was not able to detect such MMP active forms. Despite this negative result, the detection of active form of MMP in pathological fluid like BAL has never been reported before this work. Having validated this novel MMP activity-based probe, it will be possible to use it now for detecting MMPs from other pathological fluids or tissues extracts in which MMPs can be good markers of the pathology

APA, Harvard, Vancouver, ISO, and other styles

46

Figueira, Rita de Cássia Savio. "Expressão de metaloproteinases de matriz (MMPS) e de seus inibidores (TIMPS e RECK) em modelo de progressão tumoral de Câncer de mama e sua correlação com dados clínicos-patológicos." Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/46/46131/tde-31052016-184027/.

Full text

Abstract:

O câncer de mama é o tipo de câncer mais comumente detectado em mulheres de todo o mundo. Na maioria das pacientes, a causa de morte se deve, principalmente, à doença metastática que pode se desenvolver a partir do tumor primário. O processo metastático envolve uma complexa cascata de eventos, incluindo a quebra organizada dos componentes da matriz extracelular por metaloproteinases de matriz (MMPs). A atividade das MMPs é precisamente regulada por inibidores específicos, os inibidores teciduais das MMPs (TIMPs). Dado seu papel na progressão tumoral, níveis elevados de MMPs têm sido associados com prognóstico desfavorável para pacientes com câncer. Por outro lado, sendo os TIMPs proteínas multifuncionais, níveis elevados de TlMP-1 e de TIMP-2 correlacionam com agressividade do tumor e prognóstico ruim em diferentes tipos de câncer, incluindo o câncer de mama. O gene supressor de metástase RECK codifica uma glicoproteína de membrana capaz de inibir a invasão e a metástase tumoral através da regulação negativa da atividade de MMPs envolvidas em carcinogênese: MMP-2, MMP-9 e MMP-14 (MT1-MMP). A fim de analisar o papel das MMPs e de seus inibidores (TIMPs e RECK) na progressão tumoral do câncer de mama, o perfil de expressão destes genes foi detectado, através de ensaios de Real-Time PCR, em um painel de cinco linhagens celulares de carcinoma de mama humano com diferentes potenciais invasivos e metastáticos e em 72 amostras teciduais de tumores primários de mama e 30 amostras teciduais de borda normal adjacente ao tumor. O perfil de expressão protéica de RECK foi avaliado em 236 amostras de tumores primários de mama através de ensaios de Tissue Microarray. Além disso, a atividade proteolítica das MMPs foi detectada em ensaios de Zimografia. Os resultados obtidos indicam que a progressão do câncer de mama humano está relacionada com um aumento dos níveis de expressão das MMPs e de seus inibidores específicos. O aumento dos níveis de expressão dos TIMPs parece estar relacionado ao seu papel como proteína multifuncional que pode estar funcionando de maneira a promover, mais do que suprimir, a progressão tumoral. Níveis elevados da expressão protéica de RECK estão associados com pior prognóstico. No entanto, para pacientes em estádios clínicos avançados, altos níveis de expressão de RECK podem estar correlacionados com melhor prognóstico, dependendo do balanço MMP/inibidor. Os níveis de expressão das MMPs apresentaram correlação positiva em relação aos níveis de expressão de seus inibidores específicos, sugerindo a existência de fatores e vias de sinalização comuns envolvidas na regulação coordenada destes genes. Além disso, a síntese do inibidor pode estar relacionada a uma resposta celular ao aumento da expressão e atividade de proteases. O balanço transcricional enzima/inibidor favorece a enzima nas amostras tumorais e, de modo contrário, o inibidor específico nas amostras de borda normal, sugerindo o balanço como o principal fator na determinação da degradação da MEC em processos invasivos e metastáticos. Os resultados obtidos podem contribuir para um melhor entendimento da complexidade dos mecanismos envolvidos na metástase do câncer de mama. Breast cancer is among the most common tumors affecting women. Like most solid tumors, metastatic disease rather than the primary tumor itself is responsible for death. The metastatic process involves a complex cascade of events, including the organized breakdown of the extracellular matrix by matrix metalloproteinases (MMPs). The activity of these proteases is tightly regulated by specific inhibitors, known as tissue inhibitors of MMPs (TIMPs). Consistent with their role in tumor progression, high levels of a number of MMPs have been shown to correlate with poor prognosis in human cancers. On the other hand, TIMPs are multifunctional molecules with high levels of TIMP-1 and TIMP-2 having been shown to predict adverse prognosis and correlate with tumor aggressiveness in several different human cancers, including breast cancer. The RECK metastasis suppressor gene encodes a membrane-associated MMP regulator protein that is able to suppress tumor invasion and metastasis by negatively regulating MMPs involved in carcinogenesis, namely: MMP-2, MMP-9 and MMP-14 (MT1-MMP). In order to analyse the role of these genes in breast cancer progression, the expression levels of MMPs and theirs inhibitors were detected by Real Time PCR in a panel of five human breast cancer cell lines displaying different degrees of invasiveness and metastatic potential and in 72 primary breast cancer and 30 adjacent normal tissue specimens. The RECK protein expression profile was also examined in 236 primary breast cancer tissue specimens by Tissue Microarray technology. The proteolytic activity of MMPs was examined by Zymography. The results suggest that high expression levels of MMPs and their inhibitors are correlated with breast cancer progression. High levels of TIMP transcript may be involved in tumor-promoting activity as a result of their multifunctional role. Increased levels of the RECK protein are correlated with poor prognosis for the patient. However, high levels of RECK would be expected to confer a favorable prognosis to patients with advanced disease. The expression levels of MMPs significantly correlated with the levels of TIMPs and may be explained by coordinate correlation of these molecules or, alternatively, the synthesis of an inhibitor may be a cellular reaction to the presence of the protease. The enzyme/inhibitor balance at the transcriptional level favors the enzyme in tumor tissue and the inhibitor in adjacent normal tissue. It is probably the parameter that will determine the matrix degradation at invasion and metastatic process. Our results are likely to contribute for better understanding of the complex mechanisms involved in breast cancer metastasis.

APA, Harvard, Vancouver, ISO, and other styles

47

Gomes, Luciana Rodrigues. "Papel de TGFβ-1 na regulação da expressão de MMPs seus inibidores (TIMPs e Reck) em modelo de carcinoma mamário humano: análise funcional de RECK e sua correlação com dados clínico-patológicos." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/46/46131/tde-04092012-095106/.

Full text

Abstract:

A causa de morte da maioria das pacientes com câncer de mama se deve à doença metastática desenvolvida a partir do tumor primário. A degradação dos componentes da matriz extracelular (MEC), um dos principais eventos do processo metastático, é regulada pelo balanço entre as atividades das metaloproteinases de matriz (MMPs) e dos seus inibidores, tanto os inibidores teciduais (TIMPs) como o inibidor associado à membrana (RECK). Contudo, ainda existe pouca informação sobre os mecanismos moleculares responsáveis pela manutenção deste balanço. No presente trabalho, foi investigado o envolvimento de TGF-β1 (Transforming Growth Factor-β1), uma citocina multifuncional é capaz tanto de inibir o crescimento celular, quanto de promover invasão e metástase, dependendo do estadiamento e do tipo de tumor, na regulação da expressão de MMPs, TIMPs e RECK, em modelo de câncer de mama. Primeiramente, examinou-se os níveis de expressão de mRNA das isoformas e receptores de TGF-β, em um painel de cinco linhagens de carcinoma mamário humano, com diferentes potenciais invasivos e metastáticos, por qRT-PCR. Os resultados obtidos demonstraram uma correlação positiva entre a expressão dessas moléculas, e a progressão do caráter invasivo e metastático celular. Em seguida, a linhagem altamente invasiva, MDA-MB-231, foi tratada com diferentes concentrações de TGF-β1 recombinante. Esta citocina foi capaz de modular a expressão gênica de MMPs (MMP-2 e MMP-9) e de seus inibidores (TIMP- 2 e RECK). Tanto ERK½, quanto p38MAPK mostraram-se envolvidas neste mecanismo. Foi demonstrado que a inibição da atividade de ERK½ alterou a expressão das proteínas MMP-9, TIMP-2 e RECK, enquanto o bloqueio de p38 MAPK afetou os níveis protéicos de MMP-2 e TIMP-2. O aumento do potencial migratório e invasivo da linhagem MDA-MB-231, induzido por TGF-β1, mostrou-se também dependente da atividade de MMPs, ERK½ e p38MAPK. Dada a ausência de informações sobre o papel de RECK em modelo mamário, a função deste inibidor de MMPs também foi investigada. Primeiramente, analisou-se a expressão de RECK ao longo do desenvolvimento da mama e, posteriormente, em 1040 amostras tumorais de mama humana, através da metodologia de Tissue Microarray, tendo sido possível demonstrar que a alta expressão de RECK associa-se a menor tempo de sobrevida global e livre de doença em 10 anos. Os resultados obtidos indicaram que a expressão da proteína RECK, em oposição ao verificado em outros tipos de tumores, está relacionada ao fenótipo mais agressivo de tumores de mama. Entretanto, a análise funcional de RECK, realizada por meio da utilização de vetores shRNA específicos para a inibição desta proteína, demonstrou que RECK também atua como um inibidor de invasão celular e da expressão de MMP-9, na linhagem MDA-MB-231. Em conjunto, os resultados obtidos neste trabalho contribuíram para a elucidação dos mecanismos moleculares de regulação de RECK, por clássicas moléculas associadas ao processo de tumorigênese (TGF-β1 e MAPKs), bem como para o esclarecimento de suas funções em modelo mamário, sugerindo-o como mais um promissor candidato a marcador prognóstico e alvo molecular para a terapia do câncer de mama. The metastatic disease is the main mortality cause of breast cancer patients. The metastatic process involves a complex cascade of events, including the organized breakdown of the extracellular matrix (ECM) compounds. The degradation of ECM is tightly regulated by the balance between the activities of matrix metalloproteinases (MMPs) and their inhibitors, the tissue inhibitors (TIMPs) and the membrane-associated inhibitor (RECK). Among the several molecules released and activated by ECM remodeling, TGF-β1 (Transforming Growth Factor-β1) is a multifunctional cytokine able to regulate both cell growth inhibition and invasion and metastasis promotion, depending on the tumor stage and type. Since the molecular mechanisms involved in the ECM remodeling control are still not completed understood, in this study, we investigated the involvement of TGF-β1 in regulating of MMPs, TIMPs and RECK expression, in the breast cancer model. By qRT-PCR, we first examined the gene expression levels of TGF-β isoforms and receptors, in a panel of five human breast cancer cell lines displaying different degrees of invasiveness and metastatic potential. Our results suggest a positive correlation between the mRNA expression of these molecules and the breast cancer progression. Moreover, the highly invasive breast cancer cell line MDA-MB-231 was treated with different concentrations of recombinant TGF-β1. We described that this cytokine was able to modulate the gene expression of MMPs (MMP-2 and MMP-9) and MMPs inhibitors (TIMP-2 and RECK) at both the mRNA and protein levels, with ERK½ and p38 MAPK being involved in this molecular mechanism. However, while ERK½ activity inhibition altered MMP-9, TIMP-2 and RECK expression, the p38 MAPK blockage affected the protein levels of MMP-2 and TIMP-2. Finally, we reposted that the TGF-β1-enhanced migration and invasion capacities of MDA-MB- 231 cells were blocked by MMPs, ERK½ and p38 MAPK inhibitors. Analysis of the RECK function in the breast model was also an objective of this study. We analyzed RECK expression during mammary gland development. We evaluated the RECK protein profile in 1040 breast tumor tissue samples using Tissue Microarray assays. We demonstrated that high expression levels of RECK were associated with shorter overall and disease-free survival in 10 years. Moreover, we verified that RECK is a biomarker of poor prognosis mainly for patients diagnosed with less aggressive breast tumor. Therefore, in contrast to other tumor types, our results indicate that high protein expression levels of RECK are related to a more aggressive phenotype. In fact, the RECK functional analysis, performed by using of shRNA vectors, showed that RECK function remains as an inhibitor of cellular invasion and MMP-9 expression, in MDA-MB-231 cells. Taken together, our results contribute to better understanding of the molecular mechanisms associated to RECK regulation by TGF-β1 and MAPK as well as to clarify its role in breast model. Thus, we suggests RECK as a new and promising prognostic marker and molecular target candidate for breast cancer therapy.

APA, Harvard, Vancouver, ISO, and other styles

48

Palosaari, H. (Heidi). "Matrix metalloproteinases (MMPs) and their specific tissue inhibitors (TIMPs) in mature human odontoblasts and pulp tissue:the regulation of expressions of fibrillar collagens, MMPs and TIMPs by growth factors, transforming growth factor-β1 (TGF-β1) and bone morphogenetic protein-2 (BMP-2)". Doctoral thesis, University of Oulu, 2003. http://urn.fi/urn:isbn:9514270789.

Full text

Abstract:

Abstract Dentin formation in physiological and pathological conditions has been widely studied, but the events and regulation are still not completely understood. Odontoblasts, terminally differentiated post-mitotic cells located in a single cell layer around pulp tissue, synthesize and mineralize dentin organic matrix. Growth factors, such as TGF-β1 and BMP-2, have been implicated in the regulation of the responses of odontoblasts and pulp tissue to external irritation. Matrix metalloproteinases (MMPs), a family of 28 endopeptidases collectively capable of degrading virtually all extracellular matrix components, and their specific tissue inhibitors (TIMPs) participate in the organo- and morphogenesis, physiological tissue turnover and pathological tissue destruction in many tissues, but very little is known about their presence, function, and regulation in the dentin-pulp complex cells and tissues. The aim of the work presented in this thesis was to analyze the expression and regulation of collagens, MMPs and TIMPs by TGF-β1 and BMP-2 in mature human odontoblasts and pulp tissue. Odontoblasts synthesize and secrete type I and type III collagens, with no clear effect of TGF-β1 on their expression levels. MMP-1, -2, -8, -9, -10, -11, -14, -15, -16, -19 and TIMP-1, -2, -3 and -4 were expressed by both odontoblasts and pulp tissue. MMP-3 and MMP-12 were not expressed in native odontoblasts or pulp tissue, and MMP-7, -24, and -25 were expressed only in odontoblasts. MMP-2, -10, -14, -20 and -23 were expressed more abundantly in odontoblasts, whereas pulp tissue expressed more MMP-13 and MMP-17. Growth factors differentially regulated the expression of different MMPs and TIMPs within and among the cells and tissues studied. In odontoblasts, MMP-1, -8 and -14 were down-regulated, but MMP-7, MMP-9, TIMP-1 and TIMP-3 up-regulated, by either TGF-β1 or BMP-2, alone or in combination. In pulp tissue, growth factors up-regulated the expression of MMP-1, -2, -10, -13, -17 and TIMP-3, but down-regulated TIMP-4. The widespread of expression of MMPs and TIMPs by mature human odontoblasts and pulp tissue suggests that they may participate in dentin matrix organization prior to mineralization, and that growth factors may further control dentin matrix modeling, not by regulating the synthesis of type I or III collagens as previously believed, but rather by differentially regulating each MMPs and TIMPs.

APA, Harvard, Vancouver, ISO, and other styles

49

Ganguly, Sourik S. "MOLECULAR MECHANISMS BY WHICH c-ABL AND ARG MEDIATE MELANOMA INVASION AND METASTASIS." UKnowledge, 2013. http://uknowledge.uky.edu/pharmacol_etds/3.

Full text

Abstract:

Metastasis is one of the main causes of death in cancer patients. Metastatic melanoma is a death sentence, as chemotherapeutic agents have a 5% success rate or do not extend survival beyond 10 months. The lack of effective chemotherapeutic agents for treating metastatic melanoma indicates a dire need to identify new drug targets and develop new therapies. Our lab has previously shown that the kinase activity of Abelson family of non-receptor tyrosine kinases (c-Abl and Arg) is elevated in invasive breast cancer cell lines as compared to non-invasive cell lines. Previous studies from our lab have shown that Abl kinases are convergent point of ErbB2 and Src Kinases in melanoma cells and Abl kinases promote invasion by an undefined mechanism. Although Abl kinases promote invasion, it is not known whether they are important for metastastic potential. For the first time, we report that Abl kinases promote melanoma cell proliferation, survival, matrigel-invasion and single-cell 3D invasion. To investigate the mechanism by which Abl kinases promote invasion, we found out that active c-Abl transcriptionally upregulates MMP-1, and using rescue approaches we show that c-Abl promotes invasion via a STAT3àMMP-1 pathway. In contrast, active Arg drives invasion in a STAT3-independent manner, and upregulates the expression of MMP-3 and MT1-MMP, in addition to MMP-1. We also found that Abl kinases promote invasion via lysosomal degradation of a metastasis suppressor, NM23-H1 by activating lysosomal cathepsins B and L, which directly cleave and degrade NM23-H1. Furthermore, c-Abl and Arg are activated in primary melanomas and cAbl/Arg activity is inversely correlated with NM23-H1 expression both in primary melanoma and human melanoma cells. We also demonstrate, for the first time that active Abl kinases promote metastasis in vivo, as inhibition of c-Abl/Arg with nilotinib, dramatically inhibits lung colonization/metastasis in a mouse model using two different melanoma cell lines. In summary, we identify Abl kinases as critical, novel, drug targets in metastatic melanoma, and our data indicate that nilotinib may be useful in preventing metastasis in a select group of patients, harboring active Abl kinases.

APA, Harvard, Vancouver, ISO, and other styles

50

François, Mathias. "Effets anti-interleukine 1beta in vitro des ligands des récepteurs Activés par les proliférateurs de péroxysomes (PPARs) dans les chondrocytes articulaires : analyse des mécanismes d'action moléculaires." Paris 6, 2004. http://www.theses.fr/2004PA066120.

Full text

APA, Harvard, Vancouver, ISO, and other styles

Dissertations / Theses on the topic 'MMPs'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles