Introdução: O Carcinoma Urotelial de Bexiga (CUB) é o segundo tumor urológico mais prevalente no Brasil. Devido ao elevado custo médico no processo que envolve seu diagnóstico, tratamento e seguimento, o CUB é um dos tipos de tumores mais caros para os sistemas de saúde. Embora existam fatores prognósticos definidos, como o estadiamento patológico, a diferenciação histológica e a presença de invasão angiolinfática (IAL), os mesmos demonstram-se insuficientes para uma acurada definição de comportamento da doença. Com a evolução da pesquisa molecular um grande número de potenciais novos marcadores de agressividade tem surgido. As Metaloproteinases da matriz (MMP) sao proteínas teciduais, pertencentes à família das endoproteinases, que degradam vários componentes da matriz extracelular. A expressão de diversas MMPs, especialmente MMP-2 e MMP-9 (gelatinases), bem como seus ativadores e inibidores, tem sido estudada como potencial marcador de comportamento tumoral em várias neoplasias. Objetivos: Avaliarmos os níveis de expressão dos genes das gelatinases MMP-2 e MMP-9 no CUB, assim como proteínas envolvidas em suas vias de ativação e inibição (MMP-14, IL-8, TIMP-1, TIMP-2, RECK e TGF-! ). Material e Método: Estudamos pela técnica de qRT-PCR a expressão dos 8 genes em amostras de CUB de 40 pacientes submetidos a RTUb, tendo como grupo controle amostras de urotélio sem câncer de 6 pacientes submetidos a prostatectomia aberta por HPB, bem como sua relação com marcadores prognósticos clássicos (estádio, grau e IAL). Resultados: Houve uma superexpressão de MMP-9 na maioria das amostras de CUB, bem como subexpressão de MMP-2, TIMP-1, TIMP-2, MMP-14, IL-8, TGF-! e RECK. Comparando os níveis de expressão dos genes com o estádio patológico, houve uma superexpressão de MMP-9 nos tumores pT1-2, quando comparados com pTa (p=0,026), bem como maior expressão de IL-8 nos tumores pT1 e pT2 (p=0,015 e p=0,048, respectivamente). Embora estatisticamente nao significativa, houve uma superexpressão de MMP-14 nos tumores pT2, quando comparados aos demais (p=0,087). Com relação ao grau histológico, também identificamos superexpressão de MMP-9 nos tumores de alto grau, quando comparados aos de baixo grau (p=0,012), assim como maior expressão de IL-8 nos tumores de alto grau (p=0,003). Conclusão: Houve uma superexpressão de MMP-9 e uma subexpressão de MMP-2, TIMP-1, TIMP-2, MMP-14, RECK, IL-8 e TGF-! no CUB, quando comparado com o grupo controle. Também identificamos uma superexpressão de MMP-9 e IL-8 em tumores pT1-2 quando comparados com pTa e de alto grau quando comparados com baixo grau. A subexpressão dos principais inibidores da MMP-9 (TIMP-1 e RECK) pode explicar sua superexpressão no CUB, assim como a superexpressão de IL-8 nos tumores invasivos e de alto grau pode agir como fator ativador da MMP-9 nestes mesmos tumores / Introduction: Bladder cancer (BC) is the second most common urological tumor in Brazil. Because its high cost on diagnosis, treatment and follow-up, BC is one of the most expensive malignancies for health care providers. Although we have well-known prognostic factors, like pathological stage, histologic grade and lymphovascular invasion, they are insufficient to figure more accurate tumor aggressiveness. Recent molecular biology helped us to discover a huge amount of potential markers. Matrix metalloproteinases (MMP) are tissue endopeptidases that degrade components of extracellular matrix. Expression of several MMP, specially MMP-2 and MMP-9 (gelatinases), and their activators and inhibitors, are investigated as potential behavior markers in many neoplasms. Objectives: The aim of this study was to evaluate expression levels of gelatinases MMP-2 and MMP-9 genes by quantitative real-time polymerase chain reaction (qRT-PCR) in BC, as well as other proteins evolved in the activation and inhibition pathways (MMP-14, IL-8, TIMP-1, TIMP-2, RECK e TGF-b). Material and Method: Present study analyzed tissue expression of 8 genes in BC samples of transutethral resection of 40 patients by qRT-PCR, as well as their relation with current prognostic factors (stage, grade and LVI). The control group was composed of utothelial tissue from 6 patients with benign prostatic hyperplasia (BPH) treated surgically with retropubic prostatectomy. Results: In the tumor samples, MMP-9 presented an overexpression and MMP-2, TIMP-1, TIMP-2, MMP-14, RECK, IL-8, and TGF-b were underexpressed in BC tissue compared to control. Comparing gene level expression to pathologic stage, there was MMP-9 overexpression in pT1-2 tumors compared to pTa (p=0.026), as wall as IL-8 overexpression in pT1 and pT2 tumors (p=0.015 e p=0.048, respectively). Although not statiscally significant, there was MMP-14 overexpression in pT2 tumors in comparison to pTa-1 (p=0.087). About grade, there was MMP-9 overexpression in high-grade tumors compared to low-grade (p=0.012), as well as IL-8 overexpression in high-grade tumors (p=0.003). There was not relation of any gene expression to LVI. Conclusions: We found overexpression of MMP-9 and underexpression of MMP-2, TIMP-1, TIMP-2, MMP-14, RECK, TGF-b and IL-8 in BC compared with the control group. According to the prognostic factors we found increased levels of MMP-9 and IL-8 gene expression in pT1-2 compared to pTa tumors and high-grade compared to low-grade tumors. Underexpression of major MMP-9 inhibitors (TIMP-1 and RECK) could explain MMP-9 overexpression in BC, as well as IL-8 overexpression in high-grade and stage tumors could act as activation factor of MMP-9 in these tumors

Orientador: José Eduardo Tanus dos Santos / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-21T14:39:20Z (GMT). No. of bitstreams: 1 Goncalves_FlaviaMagazoni_D.pdf: 13094273 bytes, checksum: b37b538d1e8c37ba2a2ec5c8c99a5a30 (MD5) Previous issue date: 2012 / Resumo: A migrânea é uma cefaleia primária comum e altamente incapacitante que atinge cerca de 10% da população mundial, especialmente as mulheres. Apesar dos esforços, a fisiopatologia da migrânea não está completamente elucidada. No entanto, acredita-se que as metaloproteinases da matriz (MMPs) estejam envolvidas no rompimento da barreira-hematoencefálica durante uma crise de migrânea. O objetivo do presente trabalho é avaliar se polimorfismos funcionais nos genes da MMP-2 (C-1306T e C-735T) e da MMP-9 (C-1562T, -90(CA)n e R(279)Q) e haplótipos estão associados com a migrânea e se eles podem modificar os níveis circulantes de MMPs na migrânea. Para avaliar o efeito de polimorfismos da MMP-9, foram estudadas 102 mulheres sem migrânea (grupo controle) e 187 mulheres com migrânea (141 com migrânea sem aura; MSA e 46 com migrânea com aura; MA). As genotipagens para os polimorfismos C-1562T, -90(CA)n e R(279)Q da MMP-9 foram realizadas por PCR-RFLP, PCR convencional seguida de eletroforese em gel de poliacrilamida e PCR em Tempo Real, utilizando-se o sistema Taqman® para discriminação de alelo, respectivamente. As concentrações plasmáticas de MMP-9 e TIMP-1 foram determinadas por ELISA. Os genótipos para os polimorfismos da MMP-2 foram determinados por PCR em Tempo Real, utilizando-se o sistema Taqman® para discriminação de alelo em 148 mulheres sem migrânea e em 204 mulheres com migrânea (153 MSA e 51 MA). As concentrações plasmáticas da MMP-2 e do TIMP-2 foram avaliadas, respectivamente, por zimografia e por ELISA. Os haplótipos foram inferidos utilizando o programa PHASE. Este estudo é o primeiro a mostrar que polimorfismos funcionais e haplótipos nos genes da MMP-2 e da MMP-9 podem afetar os níveis circulantes das MMPs em pacientes com migrânea. Enquanto o haplótipo H6 (CLQ) da MMP-9 foi associado aos maiores níveis plasmáticos de MMP-9 nas pacientes com migrânea (359,8±69,53ng/ml versus 195,8±9,70ng/ml para o CLR; 201,5±18,67ng/ml para o CHR e 200,2±17,02ng/ml para o CHQ), as maiores concentrações de MMP-2 foram encontradas nas pacientes com migrânea com aura com o genótipo CC para o polimorfismo C-735T (1,29±0,07U.A. versus 0,96±0,06U.A. para os genótipos CT ou TT) e com o haplótipo H1 (CC) (1,24±0,05U.A. versus 0,94±0,05U.A. para o haplótipo CT) no gene da MMP-2. Apesar de não investigarmos os mecanismos moleculares que explicam esses resultados, podemos sugerir que o aumento dos níveis das MMPs associados a genótipos e haplótipos específicos podem predispor essas pacientes a um aumento da permeabilidade vascular da barreira hematoencefálica, promovendo assim o desenvolvimento de um ambiente neuroinflamatório no sistema nervoso central, contribuindo para uma crise de migrânea / Abstract: Migraine is a common primary headache and highly disabling, affecting approximately 10% of the population worldwide, especially women. Despite the efforts, the pathophysiology of migraine is not completely understood. However, it is believed that the matrix metalloproteinases (MMPs) are involved in the disruption of blood-brain barrier (BBB) during migraine attacks. The aim of this study was to evaluate whether functional polymorphisms in MMP-2 (C-1306T and C-735T) and MMP-9 (C-1562T, -90(CA)n and R(279)Q) genes and haplotypes are associated with migraine and whether they modify circulating MMPs levels in migraine. To evaluate the effect of MMP-9 polymorphisms, we studied 102 healthy women (controls) and 187 women with migraine (141 migraine without aura; MWA, and 46 migraine with aura; MA). Genotypes for C-1562T, -90(CA)n e R(279)Q MMP-9 polymorphisms were determined by PCR-RFLP, by conventional PCR followed by electrophoresis in polyacrylamide gels and by real time-PCR using Taqman® allele discrimination assays, respectively. The plasma MMP-9 and TIMP-1 concentrations were measured by ELISA. Genotypes for MMP-2 polymorphisms were determined by real time-PCR using Taqman® allele discrimination assays in 148 healthy women without history of migraine and in 204 women with migraine (153 MWA and 51 MA). The plasma concentrations of MMP-2 and TIMP-2 were evaluated by gelatin zymography and ELISA, respectively. Haplotypes were inferred using the PHASE program. This is the first study to show that functional MMP-2 and MMP-9 polymorphisms and haplotypes can affect the circulating MMPs levels in patients with migraine. While the MMP-9 H6 (CLQ) haplotyple is associated with high MMP-9 concentrations in patients with migraine (359,8±69,53ng/ml versus 195,8±9,70ng/ml for CLR; 201,5±18,67ng/ml for CHR and 200,2±17,02ng/ml for CHQ) , the highest concentrations of MMP-2 were found in patients with migraine with aura carrying the CC genotype for C-735T polymorphism (1,29±0,07A.U. versus 0,96±0,06A.U. for CT or TT genotypes) and the H1 (CC) haplotype (1,24±0,05A.U. versus 0,94±0,05A.U. for CT haplotype) in the MMP-2 gene. Although we have not investigated the molecular mechanisms explaining these results, we can suggest that an increase of the MMPs levels associated with these genotypes and haplotypes may predispose these patients to increased vascular BBB permeability, thus promoting the development of an inflammatory environment in their central nervous systems, which contributes to migraine attacks / Doutorado / Farmacologia / Doutora em Farmacologia

Introdução: O Carcinoma Urotelial de Bexiga (CUB) é o segundo tumor urológico mais prevalente no Brasil. Devido ao elevado custo médico no processo que envolve seu diagnóstico, tratamento e seguimento, o CUB é um dos tipos de tumores mais caros para os sistemas de saúde. Embora existam fatores prognósticos definidos, como o estadiamento patológico, a diferenciação histológica e a presença de invasão angiolinfática (IAL), os mesmos demonstram-se insuficientes para uma acurada definição de comportamento da doença. Com a evolução da pesquisa molecular um grande número de potenciais novos marcadores de agressividade tem surgido. As Metaloproteinases da matriz (MMP) sao proteínas teciduais, pertencentes à família das endoproteinases, que degradam vários componentes da matriz extracelular. A expressão de diversas MMPs, especialmente MMP-2 e MMP-9 (gelatinases), bem como seus ativadores e inibidores, tem sido estudada como potencial marcador de comportamento tumoral em várias neoplasias. Objetivos: Avaliarmos os níveis de expressão dos genes das gelatinases MMP-2 e MMP-9 no CUB, assim como proteínas envolvidas em suas vias de ativação e inibição (MMP-14, IL-8, TIMP-1, TIMP-2, RECK e TGF-! ). Material e Método: Estudamos pela técnica de qRT-PCR a expressão dos 8 genes em amostras de CUB de 40 pacientes submetidos a RTUb, tendo como grupo controle amostras de urotélio sem câncer de 6 pacientes submetidos a prostatectomia aberta por HPB, bem como sua relação com marcadores prognósticos clássicos (estádio, grau e IAL). Resultados: Houve uma superexpressão de MMP-9 na maioria das amostras de CUB, bem como subexpressão de MMP-2, TIMP-1, TIMP-2, MMP-14, IL-8, TGF-! e RECK. Comparando os níveis de expressão dos genes com o estádio patológico, houve uma superexpressão de MMP-9 nos tumores pT1-2, quando comparados com pTa (p=0,026), bem como maior expressão de IL-8 nos tumores pT1 e pT2 (p=0,015 e p=0,048, respectivamente). Embora estatisticamente nao significativa, houve uma superexpressão de MMP-14 nos tumores pT2, quando comparados aos demais (p=0,087). Com relação ao grau histológico, também identificamos superexpressão de MMP-9 nos tumores de alto grau, quando comparados aos de baixo grau (p=0,012), assim como maior expressão de IL-8 nos tumores de alto grau (p=0,003). Conclusão: Houve uma superexpressão de MMP-9 e uma subexpressão de MMP-2, TIMP-1, TIMP-2, MMP-14, RECK, IL-8 e TGF-! no CUB, quando comparado com o grupo controle. Também identificamos uma superexpressão de MMP-9 e IL-8 em tumores pT1-2 quando comparados com pTa e de alto grau quando comparados com baixo grau. A subexpressão dos principais inibidores da MMP-9 (TIMP-1 e RECK) pode explicar sua superexpressão no CUB, assim como a superexpressão de IL-8 nos tumores invasivos e de alto grau pode agir como fator ativador da MMP-9 nestes mesmos tumores / Introduction: Bladder cancer (BC) is the second most common urological tumor in Brazil. Because its high cost on diagnosis, treatment and follow-up, BC is one of the most expensive malignancies for health care providers. Although we have well-known prognostic factors, like pathological stage, histologic grade and lymphovascular invasion, they are insufficient to figure more accurate tumor aggressiveness. Recent molecular biology helped us to discover a huge amount of potential markers. Matrix metalloproteinases (MMP) are tissue endopeptidases that degrade components of extracellular matrix. Expression of several MMP, specially MMP-2 and MMP-9 (gelatinases), and their activators and inhibitors, are investigated as potential behavior markers in many neoplasms. Objectives: The aim of this study was to evaluate expression levels of gelatinases MMP-2 and MMP-9 genes by quantitative real-time polymerase chain reaction (qRT-PCR) in BC, as well as other proteins evolved in the activation and inhibition pathways (MMP-14, IL-8, TIMP-1, TIMP-2, RECK e TGF-b). Material and Method: Present study analyzed tissue expression of 8 genes in BC samples of transutethral resection of 40 patients by qRT-PCR, as well as their relation with current prognostic factors (stage, grade and LVI). The control group was composed of utothelial tissue from 6 patients with benign prostatic hyperplasia (BPH) treated surgically with retropubic prostatectomy. Results: In the tumor samples, MMP-9 presented an overexpression and MMP-2, TIMP-1, TIMP-2, MMP-14, RECK, IL-8, and TGF-b were underexpressed in BC tissue compared to control. Comparing gene level expression to pathologic stage, there was MMP-9 overexpression in pT1-2 tumors compared to pTa (p=0.026), as wall as IL-8 overexpression in pT1 and pT2 tumors (p=0.015 e p=0.048, respectively). Although not statiscally significant, there was MMP-14 overexpression in pT2 tumors in comparison to pTa-1 (p=0.087). About grade, there was MMP-9 overexpression in high-grade tumors compared to low-grade (p=0.012), as well as IL-8 overexpression in high-grade tumors (p=0.003). There was not relation of any gene expression to LVI. Conclusions: We found overexpression of MMP-9 and underexpression of MMP-2, TIMP-1, TIMP-2, MMP-14, RECK, TGF-b and IL-8 in BC compared with the control group. According to the prognostic factors we found increased levels of MMP-9 and IL-8 gene expression in pT1-2 compared to pTa tumors and high-grade compared to low-grade tumors. Underexpression of major MMP-9 inhibitors (TIMP-1 and RECK) could explain MMP-9 overexpression in BC, as well as IL-8 overexpression in high-grade and stage tumors could act as activation factor of MMP-9 in these tumors

Mammals cannot re-form heavily damaged bones as in large fracture gaps, whereas zebrafish efficiently regenerate bones even after amputation of appendages. However, the source of osteoblasts that mediate appendage regeneration is controversial. Several studies in zebrafish have shown that osteoblasts are generated by dedifferentiation of existing osteoblasts at injured sites, but other observations suggest that de novo production of osteoblasts also occurs. In this study, we found from cell-lineage tracing and ablation experiments that a group of cells reserved in niches serves as osteoblast progenitor cells (OPCs) and has a significant role in fin ray regeneration. Besides regeneration, OPCs also supply osteoblasts for normal bone maintenance. We further showed that OPCs are derived from embryonic somites, as is the case with embryonic osteoblasts, and are replenished from mesenchymal precursors in adult zebrafish. Our findings reveal that reserved progenitors are a significant and complementary source of osteoblasts for zebrafish bone regeneration.

Das ADAMTS16-Gen kodiert für eine Metalloproteinase, deren Funktion und Regulation bislang nicht beschrieben sind. Die ADAMTSs werden von Zellen verschiedener Organsysteme sezerniert und sind für den Abbau extrazellulärer Matrixbestandteile und die Prozessierung von Oberflächenrezeptoren, Signalmolekülen oder Wachstumsfaktoren verantwortlich. In der vorliegenden Arbeit wurden die gewebespezifische Lokalisation von Adamts16 und die möglichen Funktionen der Metalloproteinase im Urogenitalsystem untersucht. Weiterhin konnte die Regulation der Adamts16-Expression durch das Wilms-Tumor Protein beschrieben werden. In verschiedenen Zelllinien des Urogenitalsystems konnte eine Wt1-abhängige Adamts16-Expression festgestellt werden. Zudem erfolgte im Urogenitalsystem eine Koexpression von Adamts16 und Wt1 in embryonalen und adulten Podozyten, somatische Zellen der XX-Gonadenanlage und Granulosazellen und Epithelzellen des adulten Ovars. Im Testis war Adamts16 ohne signifikante Wt1-Koexpression in Spermatozyten und elongierten Spermatiden lokalisiert. Außerhalb des Urogenitalsystems waren Adamts16 und Wt1 im Epikard koexprimiert. Ein Wt1-Knockdown in Epikardzellen und embryonalen Nieren zeigte jeweils einen Rückgang des Adamts16-Expressionsniveaus. Ein Adamts16-Knockdown in embryonalen Nieren resultierte in verminderten Ureterverästelungen, was eine funktionelle Rolle von Adamts16 in der murinen Nierenentwicklung ex vivo andeutet. Der Wt1-Knockdown in Gonadenkulturen zeigte, dass Wt1 die Adamts16-Expression in XY-Gonaden hemmt, in XX-Gonaden hingegen aktiviert. Innerhalb des Adamts16-Gens konnten drei Wt1-Konsensusmotive identifiziert werden. Mit Hilfe von EMSAs und ChIPs konnte die Bindung der Wt1(-KTS)-Isoform an diese Konsensusmotive belegt werden. Ein Reportergenassay zeigte die Aktivierung des Adamts16-Promotors durch Wt1(-KTS) in Granulosazellen, wobei eine Verkürzung der Adamts16-Promotorsequenz zu einer Reduktion der Promotoraktivität führte. / The Adamts16 gene encodes for a metalloproteinase, whose function and regulation is hardly explored. ADAMTSs are secreted by different cells of various organs and are responsible for breaking down extracellular matrix compounds and processing signaling molecules, growth factors and surface receptors. In this work the tissue specific localization of Adamts16 and its possible function and regulation within the genito-urinary system were analyzed. Furthermore the regulation of Adamts16 through the wilms tumor transcription factor Wt1 is described. Different cell lines derived from the genito-urinary system showed a Wt1-dependent mRNA expression of Adamts16. In addition both proteins were co-expressed in embryonic and adult podocytes, somatic cells of the embryonic XX-gonad and granulosa and epithelial cells of the adult ovary. The testes showed a Wt1-independent Adamts16 expression in spermatocytes and elongated spermatids. Outside the genito-urinary system Adamts16 and Wt1 were co-expressed in the epicardium. Knockdown of Wt1 in both epicardial cells and embryonic kidney explants showed a decrease in the Adamts16 mRNA expression level. In turn the Knockdown of Adamts16 led to an inhibited branching morphogenesis in embryonic kidney explants. This indicates a functional role of Adamts16 in the ex vivo kidney development. Knockdown of Wt1 in cultured embryonic gonads revealed that Wt1 inhibits the expression of Adamts16 in XY-gonads but activates it in XX-gonads. Three Wt1 consensus motives were identified within the Adamts16 gene. Using EMSA and ChIP the binding of the Wt1(-KTS)-isoform to all three consensus motives was verified. The ability of Wt1 to activate the Adamts16 promoter was confirmed through reporter gene assays in granulosa cells.

Patients with cystic fibrosis who are infected with the pathogen Pseudomonas aeruginosa have shown favorable responses to the drug azithromycin (AZM). This drug works in an anti-inflammatory capacity, improving clinical outcomes and improving quality of life in this population. The drug has also been shown to affect macrophage polarization by shifting these cells away from an inflammatory phenotype toward an alternatively activated anti-inflammatory phenotype. The full impact of this phenotypic change is not well understood in the context of the response to P. aeruginosa infection, or the overall immune response in cystic fibrosis. To understand how the AZM-polarized macrophage affects other types of cells, we utilized a co-culture in vitro system, with macrophages and fibroblasts incubating together. In this system, we determined that AZM causes upregulation of the pro-fibrotic mediator transforming growth factor-β as well as the extracellular matrix (ECM) protein fibronectin. The mediator of ECM turnover, matrix metalloproteinase (MMP)-9 was upregulated in this system as well. In an in vivo model of P. aeruginosa infection, MMP- 9 and fibronectin were increased in the bronchoalveolar lavage 7 days post-infection in mice that were treated with AZM. This was accompanied by a decrease in damage to the lung tissue, determine by histological examination. To determine if these changes would continue in human subjects with cystic fibrosis, a clinical study was done in this population. Subjects with AZM treatment had decreased TGF-β levels, but no differences in MMP-9 or fibronectin. Interestingly, correlations between certain fibrotic mediators and inflammatory cytokines, specifically interleukin -1β, were different in subjects with AZM treatment compared to subjects without AZM therapy. Together, these data indicate that AZM alters the fibrotic response from the macrophages, as well as the interaction of the inflammatory response and fibrosis development.

Periodontal diseases may increase risk of vascular calcification in cardiovascular diseases but the potential mechanisms are not defined. Fetuin, a naturally-occurring serum glycoprotein in humans, protects against ectopic arterial calcification. We considered that patients with periodontitis could be at increased risk of developing calcifying atheromas because periodontal-disease associated enzymes may enter the circulation and subsequently degrade fetuin, thereby disrupting its ability to inhibit calcification. By in silico investigation, MMP -3 and -7 were predicted to cleave fetuin but only MMP-7 actually degraded human fetuin in vitro. MMP-7 degradation of fetuin was time- and concentration- dependent and was inhibited by an MMP Inhibitor. By mass spectrometry the presence of novel, MMP-7-mediated cleavage sites in fetuin were found. Fetuin bound tightly to MMP-7 (kd =2.96 x 10-9 M). The degradation of fetuin by MMP-7 could explain, at least in part, the apparent association between periodontal diseases and calcifying atheromas.

Periodontal diseases may increase risk of vascular calcification in cardiovascular diseases but the potential mechanisms are not defined. Fetuin, a naturally-occurring serum glycoprotein in humans, protects against ectopic arterial calcification. We considered that patients with periodontitis could be at increased risk of developing calcifying atheromas because periodontal-disease associated enzymes may enter the circulation and subsequently degrade fetuin, thereby disrupting its ability to inhibit calcification. By in silico investigation, MMP -3 and -7 were predicted to cleave fetuin but only MMP-7 actually degraded human fetuin in vitro. MMP-7 degradation of fetuin was time- and concentration- dependent and was inhibited by an MMP Inhibitor. By mass spectrometry the presence of novel, MMP-7-mediated cleavage sites in fetuin were found. Fetuin bound tightly to MMP-7 (kd =2.96 x 10-9 M). The degradation of fetuin by MMP-7 could explain, at least in part, the apparent association between periodontal diseases and calcifying atheromas.

Systemic hypoxia frequently occurs in patients with cardiopulmonary diseases. Maintenance of vascular reactivity and endothelial viability is essential to preserving oxygen delivery in these patients. The role of matrix metalloproteinase-2 (MMP-2) and heme oxygenase-2 (HO-2) in the vascular response to hypoxia were investigated. In the first part of the thesis, the role of MMP-2 in regulating systemic arterial contraction after prolonged hypoxia was investigated. MMP-2 inhibition with cyclic peptide CTTHWGFTLC (CTT) reduced phenylephrine (PE)-induced contraction in aortae and mesenteric arteries harvested from rats exposed to hypoxia for 7 d. Responses to PE were reduced in MMP-2-/- mice exposed to hypoxia for 7 d compared to wild-type controls. CTT reduced contraction induced by big endothelin-1 (big ET-1) in aortae harvested from rats exposed to hypoxia. Increased contraction to big ET-1 after hypoxia was observed in wild-type controls, but not MMP-2-/- mice. Rat aortic MMP-2 and MT1-MMP protein levels and MMP activity were increased after 7 d of hypoxia. Rat aortic MMP-2 and MT1-MMP mRNA levels were increased in the deep medial vascular smooth muscle. These results suggest that hypoxic induction of MMP-2 activity potentiates contraction in systemic conduit and resistance arteries through proteolytic activation of big ET-1. The second part of the thesis investigated oxygen regulation of HO-2 protein and whether it plays a role in preserving endothelial cell viability during hypoxia. HO-2, but not HO-1, protein level was maintained during hypoxia in human endothelial cells through enhanced translation of HO-2 transcripts. Inhibition of HO-2 expression increased the production of reactive oxygen species, decreased mitochondrial membrane potential, and enhanced apoptotic cell death and activated caspases during hypoxia, but not during normoxia. These data indicate that HO-2 is translationally regulated and important in maintaining endothelial viability and function during hypoxia. In summary, the thesis demonstrates the importance of MMP-2 and HO-2 in preserving vascular function during prolonged systemic hypoxia. These enzymatic pathways may, therefore, represent novel therapeutic targets that may be exploited to ameliorate the effects of hypoxia in patients with cardiopulmonary disease.

Fragment based drug discovery (FBDD) has been applied to two protease drug targets, MMP-12 and HIV-1 protease. The primary screening and characterization of hit fragments were performed with surface plasmon resonance -technology. Further evaluation of the interaction was done by inhibition studies and in one case with X-ray crystallography. The focus of the two projects was different. Many MMP inhibitors contain a strong zinc chelating group, hydroxamate, interacting with the catalytic zinc atom. This strategy may be the cause for the low specificity of MMP inhibitors. Using FBDD we found a fragment with an unusual strong affinity for MMP-12. An inhibition assay confirmed that it was an inhibitor but indicated a stoichiometry of 2:1. Crystallography data revealed that an adduct of the fragment was bound in the active site, with interactions both with the catalytic zinc and the S1’ pocket. This may present a new scaffold for MMP-12 inhibitors. For HIV-1 protease the focus was on identifying inhibitors not sensitive to current resistance mutations. A fragment library for screening with SPR-technology was designed and used for screening against wild type enzyme and three variants with resistance mutations. Many of the hits were promiscuous but a number of fragments with possible allosteric inhibition mechanism were identified. The temperature dependency of the dissociation rate and reported resistance mutations was studied with thermodynamics. A good, but not perfect correlation was found between resistance and both the dissociation data and the free energy for dissociation compared to data from wild type enzyme. However, the type of mutation also influenced the results. The flap mutation G48V displayed thermodynamic profiles not completely correlating with resistance. It was found that dissociation rate and thermodynamics may complement each other when studying resistance, but only one of them may not be enough.