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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
141

Collagen XVII and TIMP-1 in epithelial cell migration

Parikka, M. (Mataleena) 28 November 2003 (has links)
Abstract Collagen XVII (BP180) is a transmembrane component of hemidesmosomes, which connect basal keratinocytes to the basement membrane. The extracellular domain of collagen XVII is proteolytically shed from the cell surface and released to the extracellular matrix. Apart from its function in epithelial cell adhesion, collagen XVII has been suggested to participate in keratinocyte motility. The collagen XVII expression pattern was studied in wounds of oral mucosa and in epithelial tumors. During re-epithelialization, collagen XVII was expressed in the keratinocytes distal to the wound edge, but not in the leading cells of the epithelial tip. Collagen XVII upregulation was observed in moderate/severe dysplasias of oral mucosa. In follicular ameloblastomas and basal cell carcinomas, collagen XVII expression was reduced in peripheral cells, whereas cytoplasmic staining was detected in central tumor cells. Tongue squamous cell carcinomas showed increased collagen XVII expression in grade II/III tumors, particularly in areas of invasive growth. The results suggest a correlation between overexpression of collagen XVII and the invasive potential of the tumor. For the first time, the role of collagen XVII in the regulation of malignant migration was explored. The presence of COL15, the cell adhesion domain of collagen XVII, induced migration of tongue squamous cell carcinoma cells in transmigration assays. Experiments with specific function-blocking integrin antibodies revealed that the promigratory function of COL15 is mediated by αv and α5 integrins. The role of the matrix metalloproteinase (MMP) family of proteolytic enzymes in wound re-epithelialization was studied in a transgenic mouse model. In these mice, a specific inhibitor of MMPs, TIMP-1, was overexpressed in cells that normally produce MMP-9. The healing of cutaneous wounds was found to be significantly delayed, but not prevented, due to the impaired ability of keratinocytes to migrate to the wound area. These results suggest that collagen XVII may participate in epithelial tumor progression and invasion by promoting migration of tumor cells. Based on the present study, epithelial cell-derived MMPs play a significant role in the migration of wound keratinocytes during re-epithelialization.
142

Estudo imunohistoquímico da expressão de inibidores de metaloproteínas da matriz TIMP-2 e RECK nas lesões e câncer cervical

LIMA, Mirella Cristina Pereira de 11 September 2015 (has links)
Submitted by Fabio Sobreira Campos da Costa (fabio.sobreira@ufpe.br) on 2016-04-15T12:35:53Z No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Trabalho e Artigo. BIBLIOTECA.pdf: 1144641 bytes, checksum: 49381fb9cd2af1b7f9dccd4c30011139 (MD5) / Made available in DSpace on 2016-04-15T12:35:53Z (GMT). No. of bitstreams: 2 license_rdf: 1232 bytes, checksum: 66e71c371cc565284e70f40736c94386 (MD5) Trabalho e Artigo. BIBLIOTECA.pdf: 1144641 bytes, checksum: 49381fb9cd2af1b7f9dccd4c30011139 (MD5) Previous issue date: 2015-09-11 / CAPEs / O câncer de colo uterino é o terceiro câncer mais comum em mulheres. A infecção e persistência do papilomavirus humano (HPV) tem papel fundamental no surgimento e evolução das lesões cervicais, promovendo alterações no ciclo celular e proliferação celular descontrolada através das oncoproteínas E6 e E7. Entretanto, fazem-se necessários diversos outros fatores para o desenvolvimento de neoplasias. Entre estes, encontram-se as metaloproteinases de matriz (MMP), endopeptidases capazes de digerir matriz extracelular, membrana basal e induzir fatores de crescimento, que participam dos processos de invasão, metástase, angiogênese e recidiva tumorais. Em lesões neoplásicas, a síntese de MMPs encontra-se aumentada. Sua atividade normalmente é contrarregulada por inibidores endógenos, sendo muito comum que haja desequilíbrio nesta relação em lesões tumorais. A despeito de muito estudo sobre sua relação com o câncer cervical, sabe-se pouco sobre o papel das MMPs e seus inibidores na progressão de lesões cervicais causadas por HPV. Este estudo procura correlacionar a expressão de TIMP2 e RECK às lesões cervicais causadas por HPV. Foram utilizadas 115 amostras teciduais, obtidas por conização de lesões cervicais uterinas entre 2011 e 2015 no Hospital das Clínicas de Recife, nas quais foi realizado estudo histopatológico e imunohistoquímico. Foi observada reatividade fraca no citoplasma de células do tecido escamoso de 28,5% dos controles, sem nenhuma lâmina demonstrar reatividade moderada ou forte. Quanto ao núcleo, a quase totalidade das amostras não apresentou TIMP-2, enquanto 28,5% dos controles o fez. No epitélio glandular nenhuma amostra do Grupo Controle, NIC I ou NIC II foi positiva para TIMP2 no citoplasma e núcleo. Das amostras de NIC III, 6% demonstraram positividade no citoplasma. Os resultados de RECK no citoplasma do epitélio escamoso mostraram que a expressão de RECK no citoplasma de células epiteliais escamosas é significativamente maior quanto maior o grau de lesão do tecido, exceto no CC, onde a expressão é menor que a das lesões NIC III (p = 0,019). Os resultados demonstraram que a expressão nuclear de RECK em células epiteliais escamosas é significativamente menor nos tecidos displásicos (p < 0,001). Nas análises de citoplasma do epitélio glandular , nenhuma amostra do Grupo Controle, NIC I e NIC II foi positiva, havendo 3,6% de positividade nas lesões de NIC III, todas com reatividade fraca ou moderada, e 10% de positividade moderada nas amostras de CC. Nenhuma das amostras apresentou positividade nuclear. Os resultados obtidos demonstram menor expressão nuclear de TIMP2 e RECK na presença de displasia e maior expressão citoplasmática de RECK nas células escamosas. Esta foi maior quanto mais alto o grau de displasia, mas foi menor nas amostras de carcinoma do que nas de NIC III. Conclui-se que os inibidores de MMPs podem ter utilidade como marcadores imunohistológicos nas lesões cervicais, sendo necessários mais estudos para sua validação prática. / Cervical cancer is the third most common cancer in women. The infection and persistence of human papillomavirus (HPV) plays a key role in the emergence and evolution of cervical lesions, promoting changes in the cell cycle and uncontrolled cell proliferation through the oncoproteins E6 and E7. However, make up several other factors required for the development of malignancies. Among these are the matrix metalloproteinases (MMPs), endopeptidases capable of digesting the extracellular matrix, basement membrane and induce growth factors, that participate in the processes of invasion, metastasis, angiogenesis and tumor recurrence. In neoplastic lesions, MMPs synthesis is increased. Its activity is usually contrarregulada by endogenous inhibitors, being very common there is imbalance in this relationship in tumor lesions. Despite much study on its relationship with cervical cancer, little is known about the role of MMPs and their inhibitors in the progression of cervical lesions caused by HPV. This study tries to correlate the expression of RECK and TIMP2 the cervical lesions caused by HPV. 115 tissue samples were used, obtained by conization to uterine cervical lesions between 2011 and 2015 at the Hospital das Clinicas of Recife, in which was conducted histopathological and immunohistochemical study. Weak reactivity was observed in the cytoplasm of the squamous tissue cells of 28.5% of controls, with no slide show moderate or strong reactivity. As for the core, almost all of the samples showed no TIMP-2, while 28.5% of controls did. Glandular epithelium in any sample of the control group, CIN I or CIN II was positive for TIMP2 in the cytoplasm and nucleus. Samples of CIN III, 6% showed positivity in the cytoplasm. The results of RECK in the cytoplasm of squamous epithelium showed that RECK expression in the cytoplasm of squamous epithelial cells is significantly higher the higher the degree of tissue injury, except DC, where expression is lower than that of CIN III lesions (p = 0.019). The results showed that nuclear RECK expression in squamous epithelial cells is significantly lower in dysplastic tissues (p <0.001). In the cytoplasm analysis of glandular epithelium, no sample of the control group, CIN I and CIN II was positive, with 3.6% of positivity in CIN III lesions, all with low or moderate reactivity, and 10% moderate positivity in the samples DC. None of the samples showed nuclear positivity. The results showed lower nuclear expression TIMP2 and RECK in the presence of dysplasia and increased cytoplasmic expression of RECK in squamous cells. This was greater the higher the degree of dysplasia, but was lower in carcinoma samples than in CIN III. We conclude that MMP inhibitors may have utility as immunohistological markers in cervical lesions, more research is needed to validate your practice.
143

Influência do estrógeno, progesterona e testosterona nos níveis de expressão e na distribuição de ADAMTS-1 (uma desintegrina e metaloproteinase com domínios trombospondinas 1) em células mamárias humanas normais e tumorais. / Influence of estrogen, progesterone and testosterone on ADAMTS-1 (a disintegrin and metalloproteinase with thrombospondin motifs 1) levels and distribution in normal and tumoral breast cells.

Suély Vieira da Silva 28 November 2014 (has links)
O câncer de mama é no Brasil o segundo maior causador de morte entre mulheres. Os hormônios sexuais estão dentre os vários fatores indutores ou promotores da carcinogênese. ADAMTS (uma desintegrina e metaloproteinase com domínios trombospondina) é uma enzima Zn2+/Ca2+dependente. Avaliamos a influência dos hormônios na expressão e localização da ADAMTS-1 em 3 linhagens de mama. qPCR demonstrou que a progesterona estimulou o aumento de mRNA de ADAMTS-1 na MCF-10A e na MDA-MB-231, o tratamento com estrógeno e progesterona estimulou a diminuição. No Western blot observamos nas linhagens MCF-10A e MCF-7 que os hormônios tendem a aumentar os níveis de ADAMTS-1, e o estrógeno estimulou uma acentuada secreção em MCF-7. Na linhagem MDA-MB-231, os tratamentos demonstraram uma tendência a diminuir os níveis de ADAMTS-1 intracelular. Na imunofluorescência e Western blot observamos a predominância de ADAMTS-1 nuclear. Os resultados sugerem que os hormônios regulam a expressão de ADAMTS-1 nas células normais e tumorais, e que está predominantemente presente no núcleo celular. / Breast cancer is the second largest cause of death among women in Brazil. Sex hormones are one of the several inducers factors or cancer promoters. ADAMTS (a disintegrin and metaloproteinase with thrombospondin motifs) are dependent on Zn2+/Ca2+ enzymes. We evaluated influence of hormones on ADAMTS-1 levels and localization in three different breast cell lines. qPCR showed that progesterone stimulated an increase of ADAMTS-1 mRNA in MCF-10A, however, in MDA-MB-231, the treatment by estrogen and progesterone decreased levels. Western blot analysis showed a tendency to increased ADAMTS-1 levels in MCF-10A and MCF-7 due to the hormone treatment. Treatment by estrogen led to a marked secretion in MCF-7. In MDA-MB-231 the treatment showed a tendency to decreased intracellular ADAMTS-1 protein levels. Immunofluorescence and Western Blot we observed ADAMTS-1 predominant in the nucleus. Results suggest that sex hormones regulate the ADAMTS-1 expression in normal and tumoral breast cells, ADAMTS-1 is predominant in the cellular nucleus.
144

Convergent Biochemical and Biomechanical Pathways in Tissue Remodeling: The Role of α₂β₁ Integrin and MMP Activity: A Dissertation

Phillips, Jonathan Adam 06 August 2004 (has links)
The extracellular matrix is a multi-functional environment that cells inhabit to form living tissue. To maintain the tissue, cells require constant telemetry with the matrix and respond to a variety of cues by remodeling matrix architecture. In this study the physical and biochemical manipulation of the matrix by resident cells is explored to better understand how these are used to remodel tissue. Cell-populated collagen hydrogels are used as a controllable in vitro tissue model. To directly measure mechanical forces involved with gel contraction, a culture force monitor was designed and built. Measuring dimensional changes together with contractile forces presents a method of separating mechanisms that influence tissue remodeling. Together, these techniques revealed a correlation between contractile force and gel deformation, suggesting a novel method for examining the material properties of the matrix. Limiting matrix metalloproteinase (MMP) activity altered the correlation as predicted, indicating a stiffer matrix. Contractile force was found to be regulated independent of MMP activity. In contrast, contractile force was found to be dependent on α2β1 integrin function. Collagen gel contraction correlated with both α2β1 function and MMP activity, and was significantly enhanced when combined. The results of this study indicate cells have the capacity to use multiple mechanisms for remodeling the extracellular matrix and may alternately use them together or independently to vary the rate of matrix contraction.
145

High Throughput 3D Hydrogel Cell and Tissue Encapsulation Assay to Measure Matrix Metalloproteinase and Metabolic Activity

Fakhouri, Abdulaziz Saud W. 04 September 2019 (has links)
No description available.
146

Proteomic Profiling of Pro and Active Matrix Metalloproteinases using Tandem Mass Spectrometry. Optimization of Affinity Chromatography and nHPLC-MALDI-MS/MS for Proteomic discrimination of Matrix Metalloproteinases in pre-clinical Cancer Model.

Saleem, Saira January 2012 (has links)
Matrix metalloproteinases (MMPs) network with other biological molecules to maintain the extracellular matrix (ECM) in normal physiology and perform different roles. Understanding and assigning specific role to each of 24 members of these endoproteinases is impeded because of lack of specific and efficient detection methods in biological samples. Moreover, MMP-based anti-cancer drug development has also been challenged because, currently, there is no robust methodology to distinguish the inactive pro-enzymes, active enzymes or those complexed with endogenous inhibitors in biological specimens. The objective of this project is to develop a chemical proteomics strategy based on Matrix assisted laser desorption ionization tandem mass spectrometry (MALDI-MS/MS) to help identify and discriminate the various MMP forms. Firstly, a triazine dye-based ligand immobilized on chromatography beads was utilized to assess whether it binds to recombinant human MMPs (rhMMPs). The results highlighted that the ligand interacts with latent forms of MMPs in agreement with the literature. Secondly, the potential of the ligand was assessed using MALDI-MS/MS based methodology in in vitro cancer models. Cell line culture supernatants were used in amounts to emulate the availability of tumour biopsies in clinical settings. The MS/MS spectral peaks specific to MMPs (MMP-2 and MMP- 14), and two endogenous inhibitors TIMP-1 and TIMP-2 were found in affinity chromatography eluates of cell culture supernatants with higher Mascot scores for the latter. While western blot detected MMP-2 in cell extracts, MALDI-MS/MS did not detect MMPs because of amounts below the limit of detection (LOD) of the instrument. Although the ligand was found to be interacting with MMPs and detergent-free salt elution buffers improved MALDI analysis, recovery of MMPs from biological samples was sub-optimal. The dye ligand was observed to bind other enzymes and despite various strategies to reduce non-specific binding of proteins or enable selective elution did not improve MMP enrichment. Further work using methodology described in this study is required after scaling up the MMP amounts in biological specimen and to resolve the issue of non-specific binding of proteins to the ligand by understanding its structure. / Shaukat Khanam Memorial Cancer Hospital and Research Centre, Pakistan and University of Bradford
147

Detection of Inflammatory and Homeostasis Biomarkers after Selective Removal of Carious Dentin—An In Vivo Feasibility Study

Schmidt, Jana, Hübler, Clemens, Krohn, Sandra, Schmalz, Gerhard, Schneider, Hartmut, Berg, Thomas, Haak, Rainer, Ziebolz, Dirk 04 May 2023 (has links)
Deep carious dentin lesions induce an immune reaction within the pulp-dentin complex, leading to the release of cytokines, which might be suitable biomarkers in pulp diagnostics. This in vivo feasibility study determines the concentration of different cytokines after selective removal of carious infected dentin (SCR). In our methodology, paired samples are obtained from 21 patients—each of them with two deep carious lesions at posterior teeth without clinical symptoms. After SCR, lesions are randomly assigned to treatment strategy: Group 1 (11 patients): Carious dentin is covered either with BiodentineTM (n = 11) or gutta-percha (n = 11) before using the adhesive OptibondTM FL. Group 2 (10 patients): The adhesives ClearfilTM SE Protect Bond (n = 10) or ClearfilTM SE Bond 2 (n = 10) are directly applied. Prepared cavities are rinsed with phosphate buffered saline containing 0.05% Tween 20 (10X) for five minutes immediately after SCR (visit 1) and eight weeks later (visit 2). Rinsing liquid is regained. Concentrations of IL-1β, IL-6, IL-10, C-reactive protein (CRP), TNF-α, IFN-γ, TIMP-1, -2, and MMP-7, -8, -9 are assessed by customized multiplex assays, evaluated with fluorescence analyzer. Non-parametric statistical analysis (Wilcoxon, Mann–Whitney U Test, p < 0.05) is performed (SPSS 25). Our results show that concentrations of CRP, IL-1β, IL-6, TIMP-1, -2, and MMPs were detectable. Median concentrations of CRP, IL-1β und IL-6 were significantly higher in visit 1 (304.9, 107.4, 3.8 pg/mL), compared to visit 2 (67.8, 2.3, 0.0 pg/mL; pi < 0.001). The study revealed that the non-invasive determination of cytokines from prepared dental cavities is possible.
148

Conception, élaboration et caractérisation photophysiques et biochimiques de molécules photoactivables pour la thérapie photodynamique / Selective antitumor effect in PhotoDynamic Therapy mediated by photo-activable molecules, activated by endopeptidases

Verhille, Marc 25 October 2012 (has links)
L'angiogenèse est une étape clef dans le processus de progression tumorale. Elle est caractérisée par une surexpresssion d'un grand nombre de métalloprotéinases matricielles (MMP). Parmis ces MMP, les gélatinases (MMP-2 et MMP-9) sont connues pour jouer un rôle important dans l'angiogenèse tumorale et la croissance de nombreux cancers. Les "Photodynamic Molecular Beacon" (PMB) sont des constructions moléculaires qui peuvent être utilisées dans le traitement de cancers en associant un photosensibilisateur (PS) de type chlorine et un inhibiteur d'états excités, aussi appelé "Quencher", liés par un peptide substrat des gélatinases afin d'inhiber la toxicité du PS dans les cellules non ciblées, et de restaurer sa toxicité uniquement à proximité des gélatinases. Nous avons donc cherché à déterminer le couple PS/quencher permettant la meilleure inhibition de la production d'oxygène singulet, principale source de la toxicité du PS, puis avons synthétisé une famille de PMB ciblant les gélatinases. Différents peptides et bras espaceurs ont été utilisés pour évaluer l'influence de la distance entre le PS et le quencher sur les propriétés photophysiques et l'activation enzymatique du PMB / Angiogenesis is a key step in the tumoral progression process. It is characterized by an over-expression of a number of matrix metalloproteinases (MMP). Among these MMPs, gelatinases (MMP-2 and MMP-9) are known to play a critical role in tumor angiogenesis and the growth of many cancers. Photodynamic Molecular Beacons (PMB) can be designed for cancer treatment by associating a chlorin-like photosensitizer and a black hole quencher linked by a gelatinase substrate peptide with the aim of silencing photosensitizer toxicity in non-targeted cells and restore its toxicity only in surrounding gelatinases. We investigated the PS/quencher pair allowing the best singlet oxygen production inhibition, and then we synthesized a novel family of PMB triggering gélatinases MMP-2 and MMP-9. Different lengths of peptide and spacers were used in order to determinate the influence of the distance between PS and quencher on the PMB photophysical properties and enzymatic activation.
149

Aplicação de modelagem molecular e de formalismo do CAMD (Computer-Aided Molecular Design) na elucidação do mecanismo de ação de inibidores de metalopropteinases de matriz / Molecular modeling methods and computer-aided molecular design (CAMD) formalisms for elucidating the mechanism of action of matrix metalloproteinases inhibitors

Turra, Kely Medeiros 27 March 2015 (has links)
As metaloproteinases de matriz (MMP) são enzimas superexpressas em quase todos os tumores humanos, sendo que os subtipos MMP-2 e MMP-9 têm sido associados ao potencial metastático e prognóstico desfavorável em neoplasias malignas como, por exemplo, melanoma metastático e glioma. Compostos capazes de inibir a atividade destas enzimas podem representar potenciais agentes terapêuticos. O composto 4-nerolidilcatecol (4-NC), isolado de plantas do gênero Pothomorphe, apresentou resultados promissores para o tratamento do melanoma e glioma e foi capaz de atuar em várias etapas bioquímicas importantes envolvidas na progressão dessas patologias, inclusive inibindo MMP-2 e MMP-9. No entanto, o mecanismo de ação do 4-NC não está completamente elucidado. O presente estudo envolveu a aplicação de métodos de modelagem molecular e de formalismos do planejamento de novas moléculas auxiliado por computador, CAMD (Computer-Aided Molecular Design) a fim de explorar a interação entre esta molécula e as enzimas MMP-2 e MMP-9, além de planejar novos inibidores para estes alvos. Análise exploratória de dados, que compreende a análise de agrupamentos hierárquicos e de componentes principais. foi desenvolvida para um conjunto de hidroxamatos (N=64) descritos como inibidores de MMP-2 e MMP-9, a fim de identificar as propriedades moleculares que mais influenciavam o processo de discriminação dos compostos. As propriedades termodinâmicas, eletrônicas e estéricas foram importantes para descrever os compostos mais ativos no conjunto de dados da MMP-2. Para a MMP-9, o coeficiente de distribuição (ClogD) em pH 1,5 foi relevante no processo de discriminação do conjunto. A presença de substituintes volumosos na porção R3 parece ser crucial para o conjunto de inibidores investigados. Esta região está envolvida em interações moleculares com a cavidade S1 de ambas as enzimas, mas há um limite de volume a ser considerado para estes substituintes. O formalismo QSAR-4D independente do receptor (IR) foi aplicado ao mesmo conjunto de dados e permitiu estabelecer o mapeamento do farmacóforo, além de explorar diferentes alinhamentos para a obtenção da hipótese de conformação bioativa prevista pelo melhor modelo de QSAR. OS modelos QSAR apresentaram boa capacidade de previsão, auxiliaram na proposição de novos inibidores e estimaram a atividade do 4-NC. Com o melhor modelo QSAR para MMP-9 (N=64), a atividade prevista para o 4-NC foi classificada na faixa dos inibidores com atividade moderada. Entretanto, o melhor modelo QSAR obtido para MMP-2 (N=38) não foi capaz de prever, de forma adequada, a atividade de compostos com arcabouço químico diferente daqueles utilizados na construção dos modelos. Estudos de ancoramento molecular foram desenvolvidos para investigar a orientação do 4-NC no sitio catalítico das duas enzimas e as interações que poderiam ser estabelecidas nestes complexos. Duas conformações favoráveis foram encontradas. Simulações computacionais de dinâmica molecular foram desenvolvidas com os complexos mais promissores selecionados nos estudos de ancoramento, a fim de obter informações mais detalhadas e de maior confiabilidade. sobre suas interações intermoleculares. O 4-NC tende a se orientar no sítio de forma a acomodar sua cadeia lateral no bolso S1 adjacente ao sítio catalítico em ambas as enzimas. Ensaios de zimografia também foram realizados com o objetivo de elucidar possíveis contribuições da cadeia lateral e do núcleo catecólico do 4-NC na atividade inibitória frente às enzimas em estudo. O núcleo catecólico parece ser o responsável por sua atividade, pois o composto 1,2dimetoxibenzeno, que possui as hidroxilas bloqueadas por grupos metil, não foi capaz de exercer atividade inibitória significante frente à MMP-2 e MMP-9. Estudos de voltametria reforçaram a hipótese de que o 4-NC tem a capacidade de quelar os íons zinco presentes no tampão de incubação. / Matrix metalloproteinases (MMP) enzymes are overexpressed in almost all human tumors, and MMP-2 and MMP-9 subtypes have been associated with metastatic potential and poor prognosis in malignant tumors, such as metastatic melanoma and glioma. Compounds capable of inhibiting the activity of theses enzymes would be considered as potential therapeutic agents. The 4-nerolidylcatechol compound (4-NC), isolated from plants of genus Pothomorphe, has showed promising results in the treatment of melanoma and glioma, and was able to act in several important biochemical steps involved in the progression of these diseases, as well as inhibiting MMP-2 and MMP-9. However, the 4-NC mechanism of action is not completely understood. This study has involved the application of molecular modeling methods and formalisms of computer-aided molecular design (CAMD) in order to explore the interaction between 4-NC and MMP-2/MMP-9, and to design new inhibitors for these targets. Exploratory data analysis, which comprises hierarchical cluster analysis and principal components analysis, was performed to a set of hydroxamates (N=64). previously reported as MMP-2 and MMP-9 inhibitors, in order lo identify the molecular properties that is most critical for the discrimination process regarding the investigated compounds. The thermodynamic, electronic, and steric properties were: quite important to describe the highly active compounds in the data set of MMP-2, whereas the apparent partition coefficient (ClogD) at pH 1.5 was the property more relevant for MMP-9 data set. The presence of bulky substituents on the R3 moiety seems to be crucial for this set of inhibitors due to the molecular interaction with the S1 subsite of both enzymes. However, there is a limit regarding the substituents volume in this region. Receptor independent (RI) 4D-QSAR analysis was applied lo the same data set and it was possible to establish the pharmacophore mapping, besides to explore different alignments in order to generate the hypothesized bioactive conformation through the best QSAR model. The QSAR models have presented good predictability, assisted in proposing new inhibitors, and estimated the activity of 4-NC. Regarding the best QSAR model for MMP-9 (N=64), the 4-NC predicted activity was classified in the range of the moderate active inhibitors. The best QSAR model obtained for MMP-2 (N=38), however was not able to properly predict the activity for compounds with different chemical scaffold from those used to build up the QSAR model. Molecular docking studies have been developed to investigate the 4-NC binding mode into the catalytic site of the two enzymes and the interactions that could be established in those complexes. The results have shown two favorable conformers regarding the MMP inhibition. Molecular dynamics computational simulation were combined to molecular docking studies in order to obtain more detailed and reliable information regarding the intermolecular interactions of each complex. The 4-NC molecule tends to accommodate the side chain in the S1 pocket adjacent to the catalytic site in both enzymes. Experimental zymography assays were also performed to elucidate the possible contribution of the side chain and the catechol core in the 4-NC inhibitory activity against the MMP-2 and MMP-9 enzymes. The catechol core seems to be responsible for its activity, since the 1,2 dimethoxybenzene compound, which has the hydroxyl blocked by a methyl group, was not able to exert any significant inhibition on enzymes. Voltametric assays confirmed the hypothesis that 4-NC chelates zinc ions present in the incubation buffer.
150

Análise da expressão de metaloproteinases da matriz em células satélites gliais do gânglio trigeminal de ratos portadores de inflamação da articulação temporomandibular persistente submetidos a laserterapia de baixa intensidade / Analysis of matrix metalloproteinase expression in glial cells satellites of the trigeminal ganglia of rats with persistent inflammation of the temporomandibular joint subjected to low intensity laser therapy

Desiderá, Amanda de Carvalho 14 April 2016 (has links)
A dor é uma das principais sintomatologias capazes de levar indivíduos a buscar tratamento médico-odontológico. Na odontologia estima-se que cerca de 40 a 75% da população seja portadora de dor de origem orofacial e tenha pelo menos um sinal ou sintoma de disfunção temporomandibular (DTM). A DTM corresponde a um quadro patológico de caráter multifatorial que acomete a articulação temporomandibular (ATM) e os músculos mastigatórios, ocasionando dores na região orofacial bom como alterações na realização de movimentos bucais. O principal sinal desta enfermidade é a inflamação articular, a qual gera dor nas estruturas relacionadas. A inflamação, por sua vez, leva a liberação de mediadores tais como, substância P, peptídeo relacionada ao gene da calcitonina (CGRP), além de fator de necrose tumoral a (TNF-&alpha;) e interleucina 1&beta; (IL-1&beta;). Estes mediadores sensibilizam as terminações nervosas livres e a informação nociceptiva caminha para a primeira estação sináptica, o gânglio trigeminal. A inflamação quando persistente promove a expressão de metaloproteinases da matriz (MMP), cuja ação modifica a matriz extracelular podendo, então, modular vias neuronais de percepção. Células satélites gliais (CSGs) são células envolvidas no suporte microambiente neuronal e, possivelmente, células que atuariam na modulação de vias de percepção nociceptiva. Conhecendo mais profundamente os mecanismos de modulação da dor, são buscadas terapêuticas não invasivas eficientes para atenuar a sintomatologia dolorosa advinda da DTM. A laserterapia de baixa intensidade (LLLT) mostra-se como um tratamento eficiente, porém seu efeito dose-dependente gera resultados ambíguos. Nesse contexto o presente trabalho teve como objetivos verificar os biomarcadores inflamatórios presentes no fluído sinovial em ratos portadores de inflamação persistente da ATM, tratados ou não com LLLT. Foram utilizados ratos Wistar (200-240g, n=440 - CEUA 2013.1.1111.58.7), os quais receberam administração de CFA (Adjuvante Completo de Freund) ou salina 0,9% (SAL) intraarticular e que foram submetidos (LLLT) ou não a aplicação de laser na região temporomandibular no primeiro dia, 1 hora após a indução da inflamação,, e nos dias 3, 5, 7 e 10 após indução da inflamação. Resultados obtidos neste trabalho mostram que a LLLT reduz as células polimorfonucleares presentes na cápsula articular das ATM, e, também, de espécies reativas de oxigênio (redução da atividade de mieloperoxidase - MPO). Ainda, verificou-se a redução da expressão de MMP-2 e MMP-9 no líquido sinovial de ratos com inflamação persistente induzida pela administração de CFA intraarticular. Citocinas pró-inflamatórias (por exemplo: IL-1&alpha;, IL-1&beta;, IL-6, IL-12p70, IFN-&upsih;, GM-CSF e TNF-&alpha;.) analisadas do líquido sinovial mostraram aumento significativo em sua expressão quando da presença de inflamação, a LLLT reduziu a expressão de dessas citocinas. No entanto, a fotoestimulação em alguns momentos na ausência de inflamação estimulou a expressão das citocinas IL-2, IL-5, IL-12p70, GM-CSF. Além disso, a terapia fotodinâmica aumentou expressão das citocinas anti-inflamatórias IL-4, IL-10 e IL-13 na presença de inflamação. A análise da imunofluorescência para marcação de MMP-2 e MMP-9 co-localizadas para células suporte mostrou que a expressão mais significativa ocorreu em neurônios, e resultados apontam que a LLLT na dose de 60J/cm&sup2; não reduziu a expressão dessas gelatinases no gânglio trigeminal. / Pain is one of the main symptomatology able to lead individuals to seek medical and dental treatment. In dentistry it is estimated that about 40-75% of the population is a carrier of orofacial pain source and has at least one sign or symptom of temporomandibular disorders (TMD). The TMD corresponds to a pathological condition of multifactorial affecting the temporomandibular joint (TMJ) and masticatory muscles, causing pain in the orofacial region well as changes in the performance of mouth movements. The main sign of this disease is joint inflammation, which generates pain related structures. The inflammation leads to release of mediators such as substance P, calcitonin-related peptide gene (CGRP), and tumor necrosis factor (TNF-&alpha;) and interleukin-1&beta; (IL-1&beta;). These mediators sensitize terminal fiber nerves and nociceptive information goes to the first synaptic station, the trigeminal ganglion. The persistent inflammation when promotes the expression of metalloproteinase (MMP), whose operation modifies the extracellular matrix may therefore modulate neuronal pathways perception. Satellite glial cells (CSGs) are involved in neuronal microenvironment support, and possibly cells that act in the modulation of nociceptive pathways perception. Knowing deeper into the mechanisms of pain modulation, are sought noninvasive therapeutic effective to alleviate the painful symptoms arising from the DTM. The low level laser therapy (LLLT) is shown as an effective treatment, but their dose-dependent effect produces ambiguous results. In this context, this study aimed to verify the inflammatory biomarkers present in the synovial fluid in rats with persistent inflammation of the ATM, or not treated with LLLT. Wistar rats (200-240g, n = 440 - CEUA 2013.1.1111.58.7), which received CFA administration (Complete Freund\'s Adjuvant) or 0.9% saline (SAL) intraarticular and underwent (LLLT) or not applying laser temporomandibular region on the first day, 1 hour after inflammation induction, and after days 3, 5, 7 and 10. Our results showed that LLLT reduces polymorphonuclear cells present in the joint capsule of the TMJ, and also of reactive oxygen species (reduction in myeloperoxidase activity - MPO). Still, there was a reduction in expression of MMP-2 and MMP-9 in the synovial fluid of rats with persistent inflammation induced by the intraarticular administration of CFA. Pro-inflammatory cytokines (IL-1&alpha;, IL-1&beta;, IL-6, IL-12p70, IFN-&upsih;, GM-CSF and TNF-&alpha;) analyzed synovial fluid showed a significant increase in its expression induced by TMJ 20 inflammation, and LLLT reduced expression of these cytokines. However, the photostimulation in the absence of inflammation stimulated the expression of cytokines IL-2, IL-5, IL-12p70, GM-CSF. Furthermore, photodynamic therapy increased expression of anti-inflammatory cytokines IL-4, IL-10 and IL-13 in rats with TMJ inflammation. Analysis of immunofluorescence for MMP-2 and MMP-9 co-located to support cells showed that the most significant expression was located in neurons, and results indicate that LLLT at a dose of 60 J/cm&sup2; did not reduce the expression of these gelatinases in the ganglion trigeminal.

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