Philosophiae Doctor - PhD / Ovarian cancer is called the “Silent Killer” as it is often diagnosed in advanced stages of the disease or misdiagnosed which ends with a poor prognostic outcome for the patient. A high rate of disease relapse, a high incidence-to-mortality ratio as well as acquired multidrug resistance makes it necessary to find alternative diagnostic- and therapeutic tools for ovarian cancer. Nanotechnology describes molecular devices with at least one dimension in the sub- 1μm scale and has been suggested as a possible solution for overcoming challenges in cancer multidrug resistance as well as early diagnosis of the disease. One-pot synthesized gold nanoparticles were used to demonstrate in vitro drug delivery of doxorubicin in a manner which overcame the cytoprotective mechanisms of a multidrug resistant ovarian carcinoma cell line (A2780cis) by inducing apoptosis mediated by caspase-3 within 3h of treatment. The gold nanoparticles were further functionalized with nitrilotriacetic acid and displayed specific interaction with a 6xHis-tagged cancer targeting peptide, chlorotoxin. Proprietary indium based quantum dots were functionalized with the same surface chemistry used for gold nanoparticles and bioconjugated with chlorotoxin. Wide field fluorescence studies showed the peptide-quantum dot construct specifically targeted enhanced green fluorescent tagged matrix metalloproteinase-2 transfected A2780cis cells in a specific manner. The cytoprotective multidrug resistant mechanisms of the ovarian carcinoma was overcome successfully with a single dose of doxorubicin loaded gold nanoparticles and tumour specific targeting was demonstrated using quantum dots with a similar surface chemistry used for the gold nanoparticles.

The disruption of the blood-brain barrier (BBB) occurs after ischemic and hemorrhagic stroke and contributes to secondary brain damage. Matrix metalloproteinase-9 (MMP9) has been identified to be the main mediator of post-stroke BBB disruption. It is unknown whether deposition of heme/iron in the brain following stroke would affect MMP9 expression. In this study, I have demonstrated that heme/iron up-regulated MMP9 expression in rat astrocytes and that this upregulation was most likely due to reactive oxygen species (ROS) generated by heme/iron deposition on cells. ROS can activate AP-1 and NFκB signaling pathways which were responsible for increased MMP9 expression. Inhibiting AP-1 and NFκB decreased MMP9 expression. Heme/iron deposition also activated Nrf-2 and increased the expression of neuroprotective heme oxygenase-1. My study suggests that heme and iron deposition generates ROS and increases MMP9 expression through AP-1 and NFκB signaling pathways and that targeting these pathways or clearance of heme and iron may modulate MMP9 expression for reduced damage.

Pulmonary vascular disease (PVD) and lung hypoplasia (LH) are the two main causes of mortality and morbidity in patients with congenital diaphragmatic hernia (CDH). Previous studies have shown that remodeling of the extracellular matrix (ECM) by elastase and matrix metalloproteinase (MMP) enzymes, concomitant with smooth muscle cell (SMC) proliferation and deposition of ECM proteins and growth factors, leads to primary pulmonary hypertension (PH) and that blockade of this pathway results in disease reversal. The aim of our study is to determine whether a similar pathway is induced in the PVD associated with CDH and to verify whether its inhibition will lead to reversal of PVD. Firstly, we confirmed various aspects of PVD in the nitrofen induced CDH rat model. These included: left lung hypoplasia, right ventricular hypertrophy, and increased arterial smooth muscle wall thickness alongside decreases in arterial lumen area and total number of distal pulmonary vessels. We also showed increases in elastase and matrix metalloproteinase (MMP) enzyme activities within distal pulmonary arteries (PAs), which, we were able to inhibit using serine elastase (sivelestat, elafin, and serpina1) and MMP (GM6001) inhibitors. Furthermore, we confirmed increased SMC proliferation and deposition of osteopontin (OPN) and epidermal growth factor (EGF) within the diseased vasculatures. We are now working on using sivelestat and GM6001 pharmaceuticals as well as endothelial progenitor cells (EPCs) and mesenchymal stem cells (MSCs) modified to express elafin and serpina1 to determine their abilities to reverse the PVD associated with CDH. This project is part of our translational research program with the ultimate goal of developing a novel strategy of targeting PVD in infants with CDH to improve patient survival and long-term outcome.

Background: There is still a paucity of information on maternal biological mechanisms specific to adverse birth outcomes despite maternal environmental exposure and health status being known to influence neonatal morbidity and mortality. The purpose of this study was to explore maternal biomarkers pertinent to infant development in utero, specifically matrix metalloproteinases (MMPs), and determine their relationships to environmental heavy metals such as arsenic, cadmium, lead, mercury, and manganese as well as their relationships to outcomes such as preterm birth, low birth weight and small for gestational age infant outcomes. Methods: A secondary data analysis on 1533 mother-infant pairs from the Maternal and Infant Research on Environmental Chemicals (MIREC) cohort was conducted to statistically test relationships between metals and biomarkers, as well as biomarkers and outcome. A systematic literature review and meta-analysis was also conducted to identify the interdependencies between maternal blood biomarkers relating to adverse pregnancy outcomes. Results: Multivariate regression models were used to estimate odds ratios (OR) for the association between metal concentrations in quartiles and both high (90%) and low (10%) maternal MMP levels. Significant metal-related effects were observed with different MMP responses. A total of 54 studies (35 for meta-analysis), including 43,702 women and evaluating 50 biomarkers, met the inclusion criteria and all subgroups of biomarkers showed significant associations with birth outcomes with no apparent publication bias. Conclusions: Maternal plasma markers may serve as potentially valuable tools in the investigation of maternal molecular mechanisms, especially select toxicity pathways underlying metal-mediated adverse infant outcomes. Further research is still needed to evaluate biomarkers such as proteomic and genetic profiles in other various maternal biological samples.

Orientador: Marcela Rocha de Oliveira Carrilho, Mario Fernando de Góes / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-22T04:19:13Z (GMT). No. of bitstreams: 1 Scaffa_PollianaMendesCandia_D.pdf: 3692601 bytes, checksum: 6b5331b03a6d5fcfc0192039b767ea01 (MD5) Previous issue date: 2012 / Resumo: Para o entendimento do processo de adesão à dentina é fundamental conhecer a estrutura bioquímica e biomecânica deste substrato em condições normais ou quando submetido às diferentes etapas do procedimento restaurador adesivo. Evidências indicam que a reportada degradação da camada híbrida pode ocorrer pela ação de enzimas proteolíticas, pertencentes à família das metaloproteinases da matriz (MMPs) e das cisteíno-catepsinas (CTs). No entanto, é ainda necessário elucidar as funções biológicas dessas enzimas nesse processo, bem como, definir uma estratégia para prolongar a durabilidade das restaurações adesivas. O presente estudo teve como objetivo caracterizar o perfil proteolítico da dentina humana frente a sua exposição a diferentes concentrações de digluconato de clorexidina (CHX), um potente inibidor da atividade de MMPs. O efeito da CHX sobre a atividade proteolítica intrínseca da dentina foi avaliado a partir da análise do comportamento mecânico e bioquímico da matriz dentinária e da durabilidade de restaurações adesivas. No primeiro estudo, foi analisada a capacidade da CHX em inibir a atividade das CTs (B, K e L) por hidrólise de substratos fluorogênicos específicos, verificando a afinidade de ligação entre a CHX e as enzimas. No segundo estudo, o tratamento da matriz de dentina com diferentes concentrações de CHX foi avaliado pela análise do módulo de elasticidade e do grau de hidrólise do colágeno (liberação de hidroxiprolina) após armazenagem das amostras em solução fisiológica por 1 dia, 7 ou 30 dias. Finalmente, a função terapêutica da CHX como agente inibitório da atividade proteolítica da dentina foi investigada a partir de sua capacidade em preservar a integridade mecânica (resistência de união) e morfológica de interfaces adesivas tratadas com diferentes concentrações de CHX (0,2; 2,2 e 22 mM) e armazenadas por 6 a 18 meses. No terceiro estudo, a presença das CT-B e CT-K na dentina humana foram avaliadas por imunomarcação em MEV e MET. A atividade enzimática das MMPs e CTs na dentina e uma possível interação entre as duas famílias de enzimas foram verificadas por zimografia in situ e por espectrofluorimetria. Os resultados mostraram, de forma até então inédita, que a CHX é um potente inibidor das CTs presentes no complexo dentino-pulpar. No entanto, a CHX não foi capaz de preservar integralmente o módulo de elasticidade (E) da matriz dentinária após o período mais longo de armazenagem. De modo similar, maior grau de hidrólise do colágeno ocorreu após 30 dias de armazenamento para as amostras que não foram tratadas com CHX ou que foram tratadas com baixa concentração da mesma (0,2 mM) (p<0,05). Notavelmente, o grau de hidrólise do colágeno foi mínimo ou insignificante quando a matriz dentinária foi tratada com concentração mais elevada de CHX (22 mM) (p>0,05). A CHX não afetou a resistência de união imediata da interface adesiva e preservou a resistência da união dentina/resina mesmo após 6 ou 18 meses de armazenamento. Similarmente, menor grau de nanoinfiltração com prata, significando maior integridade morfológica, foi observado para os espécimes tratados com CHX e envelhecidos por 6 ou 18 meses em comparação com as amostras do grupo controle. As imagens de imuno-histoquímica mostraram que as proteases CT-B e CT-K estão presentes na dentina humana, e não apenas na região de pré-dentina e interior dos túbulos dentinários como anteriormente antecipado. A zimografia in situ sugere que a atividade gelatinolítica das MMPs na dentina parece ser preponderante em relação à atividade das CTs, embora a espectrofluorimetria sugira que a atividade proteolítica de ambas as famílias de enzimas esteja presente no tecido dentinário. Dessa forma, concluiu-se que MMPs e CTs podem atuar sinergicamente na degradação da matriz orgânica dentinária, mas que parte dessa atividade proteolítica pode ser controlada pela presença de CHX, sobretudo, se essa estiver confinada no interior da camada híbrida / Abstract: To better understand the process of adhesion to dentin is essential to understand the biochemical and biomechanical structures of this substrate under normal conditions or when subjected to the different steps of the adhesive restorative procedure. Evidences indicate that the hybrid layer degradation can result from the activity of proteolytic enzymes, belonging to the family of matrix metalloproteinases (MMPs) and cysteine-cathepsins (CTs). However, it is still necessary to comprehend the role of these enzymes in this degrading process as well as to determine the best way to extend the durability of adhesive restorations. The general purpose of the present study was to characterize the human dentin proteolytic profile when exposed to different concentration of chlorhexidine digluconate (CHX), a potent inhibitor of MMPs activity. The effect of CHX on the dentin endogenous proteolytic activity was evaluated by the analysis of dentin matrix mechanical and biochemical properties and adhesive restorations durability. The first study evaluated the CHX ability to inhibit CTs (B, K and L) activity by the hydrolysis of fluorogenic substrates, verifying the binding affinity between CHX and enzymes. The dentin matrix treatment with different CHX concentrations was evaluated in the second study by the elastic modulus (E) and degree of collagen hydrolysis (hydroxyproline release) after storage for 1, 7 or 30 days in saline solution. Finally, the CHX therapeutic action as an inhibitor of dentin proteolytic activity was investigated by its ability to maintain the mechanical (bond strength) and morphological (nanoleakage) properties of adhesive interfaces treated with different CHX concentrations (0.2, 2.2 and 22 mM) after aging for 6 to 18 months. The third study evaluated the presence of CT-B and CT-K in human dentin using immunolabeling in SEM and TEM. MMPs and CTs proteolytic activities and a possible interaction between these two families were verified by in situ zymography and by spectrofluorimetry. Results showed, for the first time, that the CHX is a potent inhibitor of CTs in the pulp-dentin complex. However, CHX was not able to preserve the integrity of the dentin matrix E after the longest storage period. Likewise, higher collagen hydrolysis occurred after 30 days of storage when the samples were not treated or treated with low CHX concentration (0.2 mM) (p<0.05). It was noticeable that the collagen hydrolysis was minimum or insignificant when the dentin matrix was treated with the highest CHX concentration (22 mM) (p>0.05). CHX did not affect the immediate bond strength of adhesive interfaces and preserved the resin/dentin bond strength even after 6 or 18 months of storage. Similarly, less nanoleakage with silver particles, which means better morphological integrity, was observed for specimens treated with CHX and aged for 6 or 18 months in comparison with control samples. Immunohistochemistry images showed that the proteases CT-B and CT-K are present in human dentin matrix, not only in pre-dentin region and inside the dentin tubules as previous suggested. In situ zymography suggests that the MMPs gelatinolytic activity in dentin seems to be predominant when compared to CTs activities, although the spectrofluorimetry suggests that the proteolytic activity of both families of enzymes are present in dentin. In this way, it was concluded that MMPs and CTs may synergistically act in the dentin organic matrix degradation, but part of this proteolytic activity can be controlled by the presence of CHX, especially when it is restrained inside the hybrid layer / Doutorado / Materiais Dentarios / Doutora em Materiais Dentários

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

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第19573号 / 医博第4080号 / 新制||医||1013(附属図書館) / 32609 / 京都大学大学院医学研究科医学専攻 / (主査)教授 伊達 洋至, 教授 小池 薫, 教授 瀬原 淳子 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

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京都大学 / 新制・課程博士 / 博士(医学) / 甲第25005号 / 医博第5039号 / 新制||医||1070(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 羽賀 博典, 教授 竹内 理, 教授 小林 恭 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM