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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.
11

Clonagem e sequenciamento de genes que expressam proteínas ósseas reconhecidas por anticorpos monoclonais produzidos a partir de células de osteossarcoma humano (MG-63) / Cloning and sequencing genes that express bone proteins recognized by monoclonal antibodies produced from human osteosarcoma cells (MG63)

Gouveia, Veronica do Carmo Neves de 19 September 2014 (has links)
A partir de células de osteossarcoma humano (MG-63) que tem características de osteoblastos imaturos produzimos anticorpos monoclonais (Mabs) nomeados PSP 4-5, PSP 42-22 e PSP 85-9. Esses anticorpos reconhecem antígenos de 100, 26 e 20 kDa respectivamente. Avaliamos a especificidade dos mesmos, testando suas expressões em cortes congelados de tecidos oriundos da mesma célula mesenquimal, ou seja, osso, cartilagem, músculo cardíaco e tecido adiposo. Os anticorpos marcaram o periósteo, com distintos padrões de expressão, porém o PSP 42-22 foi o mais específico marcando a camada osteogênica do periósteo. Os anticorpos marcaram também células ósseas. Diante desses resultados nosso objetivo, no presente estudo, foi identificar os antígenos reconhecidos por esses anticorpos usando clonagem e sequenciamento dos genes em biblioteca de cDNA com capacidade de expressão proteica. Outro objetivo foi testar os anticorpos, pela técnica de imunohistoquímica (IHQ), em tumores ósseos primários visando estabelecer os padrões de marcação e se diferenciavam os diferentes tipos de tumores. Os antígenos reconhecidos pelos anticorpos PSP 42-22 e PSP 85-9 foram isolados, purificados e sequenciados. Devido ao elevado peso molecular do PSP 4-5 necessitaremos de outras técnicas para isolar o clone que codifica seu antígeno. O sequenciamento do clone isolado pelo PSP 42-22, mostrou uma sequência com 99% de homologia descrita no \"Homo sapiens\" como sendo \"serologically defined colon cancer antigen 3 (SDCCAG3), transcript variant 3\". A proteína SDCCAG3 foi descrita pela primeira vez em 1998 como um antígeno de câncer de cólon reconhecido por anticorpo autólogo. Vale lembrar que antígeno reconhecido pelo nosso anticorpo tem um peso molecular de aproximadamente 26 kDa, inferior ao da proteína SDCCAG3. Essa diferença poderia ocorrer devido a uma diferença no local da tradução do mRNA das células MG-63, produzindo uma proteína menor (isoforma), ou no clone isolado (3B2-3-1), poderia ocorrer uma mutação produzindo uma proteína mais curta que se expressaria na membrana celular ao contrário de uma proteína mais longa. Já o alinhamento das sequências obtidas dos clones isolados utilizando o PSP 85-9, mostrou uma sequência com 100% de concordância descrita com a porção não codante da proteína \"Homo sapiens microtubule associated protein, RP/EB family, member 1 (MAPRE1)\" portanto um falso positivo; já o clone 1A5-1-3, mostrou uma sequência de 99% de homologia com a proteína \"Homo sapiens Yip1 interacting factor homolog B (S. cerevisiae) (YIF1B), transcript variant 8\". Trata-se de uma proteína de membrana, com 6 isoformas diferentes que pode interagir com o receptor de serotonina. O resultado da IHQ nos tumores ósseos testados mostrou que o PSP 4-5 se expressou predominantemente no citoplasma de osteossarcoma, condrossarcoma e leiomiossarcoma e no núcleo de osteoblastoma. O anticorpo PSP 42-22 não reconheceu nenhum antígeno nos tumores avaliados. Quanto ao anticorpo PSP 85-9 nos condrossarcomas e leiomiossarcomas a expressão foi predominante citoplasmática e nos osteossarcomas e osteoblastoma foi nuclear. Em conclusão, identificamos os antígenos de dois dos anticorpos estudados que apresentam potencial diagnóstico diferencial em tumores ósseos primários / From human osteosarcoma cells (MG-63), which have characteristics of immature osteoblasts, we produced monoclonal antibodies (Mabs) named PSP 4-5, PSP 42-22 and PSP 85-9. These antibodies recognize antigens with 100, 26 and 20 kDa, respectively. We evaluated their specificity by testing their expression in frozen tissue sections from the same mesenchymal cells, that is, bone, cartilage, cardiac muscle and adipose tissue. The antibodies stained the periosteum, with distinct patterns of expression, but PSP 42-22 was the most specific, scoring the osteogenic layer of the periosteum. The antibodies also marked bone cells. With these results, our goal in this study was to identify the antigens recognized by these antibodies using cloning and sequencing of the genes in the cDNA library with capacity of protein expression. Another objective was to test the antibodies by immunohistochemistry (IHC) in primary bone tumors to establish standards for marking and whether they set apart different types of tumors. The antigens recognized by the PSP 42-22 and PSP 85-9 antibodies were isolated, purified and sequenced. Due to the high molecular weight of PSP 4-5 we will need other techniques to recognize its antigen. Sequencing of the clone isolated using the PSP 42-22 showed a sequence with 99% homology described in \"Homo sapiens\" as being \"serologically defined colon cancer antigen 3 (SDCCAG3), transcript variant 3\". The SDCCAG3 protein was first described in 1998 as a colon cancer antigen recognized by autologous antibody. It is worth remembering that the antigen recognized by our antibody has a molecular weight of approximately 26 kDa, lower than the SDCCAG3 protein. This difference could be due to a difference in mRNA translation site of MG-63 cells producing a lower protein; or on the isolated clone (3B2-3-1) a mutation could occur producing a shorter protein that expresses in the cell membrane instead of a longer protein. The alignment of the sequences obtained from isolated clones using the PSP 85-9 showed a sequence with 100% of homology described with the non-coding protein portion \"Homo sapiens microtubule associated protein, RP/EB family, member 1 (MAPRE1), mRNA\" therefore, a false positive; 1A5-1-3 clone showed a 99% homology sequence with the protein \"Homo sapiens Yip1 interacting factor homolog B (S. cerevisiae) (YIF1B), transcript variant 8, mRNA\". It is a membrane protein with 6 different isoforms which can interact with the serotonin receptor. The result of IHC in bone tumors tested showed that PSP 4-5 expressed predominantly in the cytoplasm of osteosarcoma, chondrosarcoma, leiomyosarcoma and osteoblastoma in was in nucleus. The PSP 42-22 antibody did not recognize any antigen in the tumors examined. As for the PSP 85-9 antibody in chondrosarcoma and leiomyosarcoma, the expression was predominantly cytoplasmic and the osteoblastoma was nuclear in osteosarcomas. In conclusion, we have identified the antigens of two of the antibodies studied which have potential differential diagnosis in primary bone tumors
12

Clonagem e sequenciamento de genes que expressam proteínas ósseas reconhecidas por anticorpos monoclonais produzidos a partir de células de osteossarcoma humano (MG-63) / Cloning and sequencing genes that express bone proteins recognized by monoclonal antibodies produced from human osteosarcoma cells (MG63)

Veronica do Carmo Neves de Gouveia 19 September 2014 (has links)
A partir de células de osteossarcoma humano (MG-63) que tem características de osteoblastos imaturos produzimos anticorpos monoclonais (Mabs) nomeados PSP 4-5, PSP 42-22 e PSP 85-9. Esses anticorpos reconhecem antígenos de 100, 26 e 20 kDa respectivamente. Avaliamos a especificidade dos mesmos, testando suas expressões em cortes congelados de tecidos oriundos da mesma célula mesenquimal, ou seja, osso, cartilagem, músculo cardíaco e tecido adiposo. Os anticorpos marcaram o periósteo, com distintos padrões de expressão, porém o PSP 42-22 foi o mais específico marcando a camada osteogênica do periósteo. Os anticorpos marcaram também células ósseas. Diante desses resultados nosso objetivo, no presente estudo, foi identificar os antígenos reconhecidos por esses anticorpos usando clonagem e sequenciamento dos genes em biblioteca de cDNA com capacidade de expressão proteica. Outro objetivo foi testar os anticorpos, pela técnica de imunohistoquímica (IHQ), em tumores ósseos primários visando estabelecer os padrões de marcação e se diferenciavam os diferentes tipos de tumores. Os antígenos reconhecidos pelos anticorpos PSP 42-22 e PSP 85-9 foram isolados, purificados e sequenciados. Devido ao elevado peso molecular do PSP 4-5 necessitaremos de outras técnicas para isolar o clone que codifica seu antígeno. O sequenciamento do clone isolado pelo PSP 42-22, mostrou uma sequência com 99% de homologia descrita no \"Homo sapiens\" como sendo \"serologically defined colon cancer antigen 3 (SDCCAG3), transcript variant 3\". A proteína SDCCAG3 foi descrita pela primeira vez em 1998 como um antígeno de câncer de cólon reconhecido por anticorpo autólogo. Vale lembrar que antígeno reconhecido pelo nosso anticorpo tem um peso molecular de aproximadamente 26 kDa, inferior ao da proteína SDCCAG3. Essa diferença poderia ocorrer devido a uma diferença no local da tradução do mRNA das células MG-63, produzindo uma proteína menor (isoforma), ou no clone isolado (3B2-3-1), poderia ocorrer uma mutação produzindo uma proteína mais curta que se expressaria na membrana celular ao contrário de uma proteína mais longa. Já o alinhamento das sequências obtidas dos clones isolados utilizando o PSP 85-9, mostrou uma sequência com 100% de concordância descrita com a porção não codante da proteína \"Homo sapiens microtubule associated protein, RP/EB family, member 1 (MAPRE1)\" portanto um falso positivo; já o clone 1A5-1-3, mostrou uma sequência de 99% de homologia com a proteína \"Homo sapiens Yip1 interacting factor homolog B (S. cerevisiae) (YIF1B), transcript variant 8\". Trata-se de uma proteína de membrana, com 6 isoformas diferentes que pode interagir com o receptor de serotonina. O resultado da IHQ nos tumores ósseos testados mostrou que o PSP 4-5 se expressou predominantemente no citoplasma de osteossarcoma, condrossarcoma e leiomiossarcoma e no núcleo de osteoblastoma. O anticorpo PSP 42-22 não reconheceu nenhum antígeno nos tumores avaliados. Quanto ao anticorpo PSP 85-9 nos condrossarcomas e leiomiossarcomas a expressão foi predominante citoplasmática e nos osteossarcomas e osteoblastoma foi nuclear. Em conclusão, identificamos os antígenos de dois dos anticorpos estudados que apresentam potencial diagnóstico diferencial em tumores ósseos primários / From human osteosarcoma cells (MG-63), which have characteristics of immature osteoblasts, we produced monoclonal antibodies (Mabs) named PSP 4-5, PSP 42-22 and PSP 85-9. These antibodies recognize antigens with 100, 26 and 20 kDa, respectively. We evaluated their specificity by testing their expression in frozen tissue sections from the same mesenchymal cells, that is, bone, cartilage, cardiac muscle and adipose tissue. The antibodies stained the periosteum, with distinct patterns of expression, but PSP 42-22 was the most specific, scoring the osteogenic layer of the periosteum. The antibodies also marked bone cells. With these results, our goal in this study was to identify the antigens recognized by these antibodies using cloning and sequencing of the genes in the cDNA library with capacity of protein expression. Another objective was to test the antibodies by immunohistochemistry (IHC) in primary bone tumors to establish standards for marking and whether they set apart different types of tumors. The antigens recognized by the PSP 42-22 and PSP 85-9 antibodies were isolated, purified and sequenced. Due to the high molecular weight of PSP 4-5 we will need other techniques to recognize its antigen. Sequencing of the clone isolated using the PSP 42-22 showed a sequence with 99% homology described in \"Homo sapiens\" as being \"serologically defined colon cancer antigen 3 (SDCCAG3), transcript variant 3\". The SDCCAG3 protein was first described in 1998 as a colon cancer antigen recognized by autologous antibody. It is worth remembering that the antigen recognized by our antibody has a molecular weight of approximately 26 kDa, lower than the SDCCAG3 protein. This difference could be due to a difference in mRNA translation site of MG-63 cells producing a lower protein; or on the isolated clone (3B2-3-1) a mutation could occur producing a shorter protein that expresses in the cell membrane instead of a longer protein. The alignment of the sequences obtained from isolated clones using the PSP 85-9 showed a sequence with 100% of homology described with the non-coding protein portion \"Homo sapiens microtubule associated protein, RP/EB family, member 1 (MAPRE1), mRNA\" therefore, a false positive; 1A5-1-3 clone showed a 99% homology sequence with the protein \"Homo sapiens Yip1 interacting factor homolog B (S. cerevisiae) (YIF1B), transcript variant 8, mRNA\". It is a membrane protein with 6 different isoforms which can interact with the serotonin receptor. The result of IHC in bone tumors tested showed that PSP 4-5 expressed predominantly in the cytoplasm of osteosarcoma, chondrosarcoma, leiomyosarcoma and osteoblastoma in was in nucleus. The PSP 42-22 antibody did not recognize any antigen in the tumors examined. As for the PSP 85-9 antibody in chondrosarcoma and leiomyosarcoma, the expression was predominantly cytoplasmic and the osteoblastoma was nuclear in osteosarcomas. In conclusion, we have identified the antigens of two of the antibodies studied which have potential differential diagnosis in primary bone tumors
13

Estudo das proteínas ósseas não colágenas no processo de reparação óssea alveolar em ratos idosos / Study of non-collagen bone proteins in the process of alveolar bone repair in aged rats

Ana Claudia da Silva Barbosa 30 August 2013 (has links)
O trabalho teve como objetivo avaliar e quantificar o tecido ósseo neoformado, a distribuição e a importância das proteínas não colágenas (osteocalcina, osteopontina e osteonectina) no processo de reparação tecidual do alvéolo dental de ratos Wistar idosos após exodontia. Para sua realização, foram utilizados 80 Rattus Norvegicus albinus, linhagem Wistar, machos. Os animais foram distribuídos em dois grupos: Grupo Controle, correspondente a animais com 60 dias de vida; e Grupo Experimental correspondente aos animais com 2 anos de vida (700 dias em média). Cada grupo foi dividido em 4 subgrupos de 10 animais em cada grupo. Os animais foram submetidos à exodontia do incisivo superior direito e foram sacrificados com 05, 15, 21 e 28 dias de pós-operatório. Após a dissecção, 5 amostras foram submetidas à análise por microscopia convencional com coloração por Hematoxilina e Eosina e análise da imunohistoquímica e 5 amostras para análise por RT-PCR. Os resultados mostraram que o processo de envelhecimento não alterou a cronologia do reparo ósseo alveolar e não promoveu maior remodelação do alvéolo dental. A osteocalcina não apresentou atuação importante nos períodos pós-operatórios estudados. A osteonectina apresentou-se importante no processo de reparo, não sofrendo alterações no início da reparação óssea, apresentando marcação mais intensa durante a maturação óssea entre 21 e 28 dias de pós-operatório no grupo controle e diminuição da marcação no grupo experimental aos 28 dias de pósoperatório. O envelhecimento proporcionou uma diminuição da imunomarcação da osteonectina e demonstrou marcações positivas principalmente em osteoblastos e matriz mineralizada. A osteopontina apresentou-se importante no processo de reparo ósseo durante todos os períodos pós-operatório, apresentando marcações em osteoblastos, matriz osteóide, osteócitos e matriz mineralizada, apresentando maior marcação dos tipos celulares do no grupo experimental aos 28 de pós-operatório. Apesar desses achados, novos estudos são necessários para o melhor entendimento do processo de reparo ósseo alveolar em ratos adultos e idosos. / The aim of the present study was to evaluate and quantify the newly formed bone tissue, as well as the distribution and the importance of non-collagen proteins (osteocalcin, osteopontin and osteonectin) in the process of dental alveolar repair in Wistar aged rats submitted to tooth extraction. To perform that, about 80 male Rattus Norvegicus albinus, Wistar strain, were randomly distributed into two groups: Control Group corresponding to 60 days old rats; and Experimental Group corresponding to 2 years old animals (about 700 days old). Both groups were later subdivided into 4 subgroups consisting of 10 animals each. All animals were submitted to the upright incisive tooth extraction and were euthanized 05, 15, 21 and 28 days after the tooth extraction surgery. After the dissection, five samples from each subgroup underwent conventional microscopy analysis by hematoxylin-eosin stain as well as immunohistochemistry. Bone tissue from other five samples of each groups were subjected to Real Time RT-PCR analysis of non-collagen proteins expression The results obtained suggest that aging process was not able to change either the chronology of alveolar bone repair or the remodeling of dental alveolus. Osteocalcin did not present any important action in the post-operation periods evaluated. On the other hand, osteonectin showed an important role during the repair process, since its expression was increased in the control group and decreased in comparison to the experimental group at 28 days. Osteopontin was important in the bone repair in all times evaluated, since it was present in osteoblasts, osteiod matrix, osteocytes and mineralized matrix, being even more stained at 21 days after the surgery. Finally, besides the results obtained in the present work, other studies are necessary to better understand the alveolar bone repair in adult and aged rats.
14

Estudo dos genes NDRG1, Par-4, osteonectina e pontina, em tecido mamário hiperplásico através de técnica de imunohistoquímica / Study of NDRG1, Par-4, osteonectin and pontin expression in hyperplastic breast lesions with immunohistochemical technique

Barboza, Regina Felippe 06 May 2011 (has links)
INTRODUÇÃO: O câncer de mama é uma das mais importantes causas de mortalidade feminina no mundo. Acredita-se que as lesões proliferativas do parênquima mamário sejam marcadoras de risco para câncer ou precursoras do carcinoma mamário. Apesar da intensa pesquisa na área do câncer de mama, os eventos moleculares precoces associados à evolução e progressão do câncer mamário ainda são pouco conhecidos. OBJETIVOS: Com a expectativa de melhor compreender os eventos iniciais da carcinogênese mamária examinamos um conjunto de oitenta e quarto lesões proliferativas mamárias quanto à expressão dos genes N-myc down regulated gene (NDRG1), Prostate Apoptosis Response-4 (PAR-4), Osteonectina e Pontina. A expressão destes genes foi documentada, por trabalhos prévios em nosso laboratório ou por estudos de outros autores, como tendo impacto na evolução do câncer de mama. MÉTODOS: Construímos um TMA com lesões proliferativas da mama e testamos este TMA por método imunohistoquímico para Ndrg1, Par-4, Osteonectina e Pontina, bem como para o receptor de estrógeno e citoqueratinas de alto e baixo peso molecular, com o objetivo de caracterizar as lesões presentes no TMA. A avaliação imunohistoquímica foi feita de forma quantitativa, com o aplicativo e sistema de análise quantitativa para TMA ACIS III, da Dako. RESULTADOS: Após excluirmos amostras não informativas, contamos com 68 amostras de lesões proliferativas mamárias para análise. Nestas, observamos uma notável positividade de NDRG1, em lesões com morfologia apócrina. Observamos ainda alta expressão de NDRG1 em lesões proliferativas mamárias, quando comparadas aos outros tipos de lesões presentes no TMA. Pontina exibiu os mais altos valores de expressão nos casos de lesões proliferativas mamárias, com valor de p estatisticamente significativo. A expressão de PAR-4 foi predominantemente nuclear nas lesões mamárias analisadas no TMA. Osteonectina teve expressão diferenciada no epitélio de lesões hiperplásicas da mama, papilomas e papilomas de pequenos ductos, quando comparada às outras lesões presentes no TMA. CONCLUSÕES: Nossos resultados sugerem uma possível associação entre a expressão de NDRG1 e diferenciação apócrina no parênquima mamário. Esta observação está de acordo com os dados publicados a respeito da superexpressão de NDRG1 e a assinatura apócrina molecular de alguns carcinomas de mama. Também demonstramos superexpressão de NDRG1 em condições hiperproliferativas do parênquima mamário, não associadas à diferenciação apócrina. Até o momento não há informações na literatura que possam explicar a translocação nuclear de Par-4 em lesões benignas da mama observada em nosso estudo. Nossos achados fornecem pela primeira vez evidências de que PAR-4 é ativado em lesões proliferativas da mama, indicando a necessidade de estudos futuros dirigidos à investigação das funções de PAR-4 em tecido mamário não neoplásico. O presente trabalho também indicou uma possível ação coordenada entre a expressão de Osteonectina e NDRG1, pelo menos em lesões apócrinas mamárias. A expressão estromal de Osteonectina pareceu ser menos frequente em lesões mamárias com arquitetura papilífera, quando comparadas a lesões mamárias com tendência a recapitular a arquitetura lobular / INTRODUCTION: Breast cancer is a leading cause of death among women all over the Word. Proliferative lesions of the breast are believed to be precursors of or markers of increased risk for breast carcinoma. Although the active research in the field of breast cancer, the early molecular events associated with cancer evolution and progression are still poorly understood. OBJECTIVES: In order to better understand the early events in the breast carcinogenesis, we examined a set of eighty-four proliferative lesions of the breast for the expression of N-myc down regulated gene (NDRG1), Prostate Apoptosis Response-4 (PAR-4), Osteonectin and Pontin, which expression was previously shown by our laboratory to have impact in breast cancer prognosis. METHODS: A tissue microarray were constructed and immunohistochemically tested for Ndrg1, Par-4, Osteonectin and Pontin together with estrogen receptor, low and high weight cytokeratins, aiming to properly characterize the lesions sorted in the tissue microarray. Immunohistochemistry assessment was made quantitative, with the ACIS III Dako quantitative analysis system and TMA application software. RESULTS: After excluding non informative cores, cores with fibroadipose tissue or mammary parenchyma with normal appearing breast epithelium, we ended up with a TMA with 68 breast lesions. Of those, we observed a noticeable positivity of Ndrg1 for lesions with apocrine morphology. Additionally, all cases of florid epithelial hyperplasia showed variable high immunoexpression levels of protein, when compared to the other sorted out lesions in the TMA. Pontin expression level was highest among the breast hyperplasia cases, with statistically significant p value. PAR-4 protein expression was found to be predominantly localized in the nucleous in the non-malignant breast lesions analyzed. Osteonectin exhibited differentiated expression values in the epithelium of hyperplastic breast lesions, papillomas and multiple papillomas when compared to the other types of breast lesions assorted in the TMA. CONCLUSIONS: Our results suggest a possible association of NDRG1 with apocrine differentiation in the breast parenchyma. This observation are consonant with the publish data about the NDRG1 overexpression and the apocrine signature of some mammary cancers. Additionally, we demonstrated that NDRG1 is also overexpressed in some hyperproliferative breast conditions unassociated with apocrine morphology. At present, there is no data available in the in the literature to explain the nuclear translocation of Par-4 in benign breast lesions as observed in our study. However, our findings provide for the first time evidence that PAR-4 is activated in proliferative lesions of the breast indicating that further clinical and experimental studies aiming to investigate PAR-4 function in non neoplastic breast tissue are warranted. Our study also indicated a possible coordinated expression between Osteonectin and NDRG1, at least in apocrine lesions of the breast. Stromal Osteonectin expression seemed to be less intense in breast lesions with papillary architecture, when compared to breast lesions with tendency to recapitulate breast lobular architecture
15

Olfactory ensheathing cell mediated mechanisms of neurite outgrowth and axon regeneration

Witheford Richter, Miranda 11 1900 (has links)
The capacity of the olfactory neuraxis to undergo neuronal replacement and axon targeting following injury, has led to scrutiny concerning the molecular and physical determinants of this growth capacity. This is because injury to the central nervous system, in contrast, leads to permanent disconnection of neurons with targets. Olfactory ensheathing cells (OECs), a specialized glial cell, may contribute to olfactory repair, and have been used to promote recovery from spinal cord injury. However, there mechanisms underlying OEC-induced regeneration are poorly appreciated. To understand these mechanisms, OECs from the lamina propria (LP OECs) or olfactory bulb (OB OECs) were transplanted into a lesion of the dorsolateral funiculus. While both cells demonstrated reparative capacities, LP and OB OECs differentially promoted spinal fibre growth; large-diameter neurofilament-positive, CGRP-positive, and serotonergic fibres sprouted in response to both LP and OB OEC transplantation, whereas substance-P and tyrosine hydroxylase-positive neurons grew more extensively following OB or LP OEC transplantation, respectively. To further understand the growth of spinal cord neurons in response to OECs, a proteomic analysis of OEC secreted factors was performed, identifying secreted protein acidic and rich in cysteines (SPARC) as a mediator of OEC-induced outgrowth in vitro. To test the contributions of SPARC to spinal cord repair after OEC transplantation, cultures of LP OECs from SPARC null and wildtype (WT) mice were transplanted into a crush of the dorsolateral funiculus. Substance P and tyrosine hydroxylase positive axon sprouting was significantly reduced in SPARC null OEC-treated animals, suggesting that individual factors may contribute to OEC-promoted regeneration. To investigate the effect of OECs on corticospinal (CST) neurons, an in vitro assay was developed using postnatal day 8 CST neurons. Coculture of CST neurons with OB OECs produced extensive axon elongation. Application of OB OEC secreted factors increased CST neurite branching, but did not increase axon elongation. In contrast, plating of CST neurons on OB OEC plasma membrane resulted in extensive axon elongation. Furthermore, the OB OEC plasma membrane could overcome CST neurite outgrowth inhibition induced by an outgrowth inhibitor. Together these findings provide insight into OEC mechanisms of neurite outgrowth and axon regeneration.
16

Olfactory ensheathing cell mediated mechanisms of neurite outgrowth and axon regeneration

Witheford Richter, Miranda 11 1900 (has links)
The capacity of the olfactory neuraxis to undergo neuronal replacement and axon targeting following injury, has led to scrutiny concerning the molecular and physical determinants of this growth capacity. This is because injury to the central nervous system, in contrast, leads to permanent disconnection of neurons with targets. Olfactory ensheathing cells (OECs), a specialized glial cell, may contribute to olfactory repair, and have been used to promote recovery from spinal cord injury. However, there mechanisms underlying OEC-induced regeneration are poorly appreciated. To understand these mechanisms, OECs from the lamina propria (LP OECs) or olfactory bulb (OB OECs) were transplanted into a lesion of the dorsolateral funiculus. While both cells demonstrated reparative capacities, LP and OB OECs differentially promoted spinal fibre growth; large-diameter neurofilament-positive, CGRP-positive, and serotonergic fibres sprouted in response to both LP and OB OEC transplantation, whereas substance-P and tyrosine hydroxylase-positive neurons grew more extensively following OB or LP OEC transplantation, respectively. To further understand the growth of spinal cord neurons in response to OECs, a proteomic analysis of OEC secreted factors was performed, identifying secreted protein acidic and rich in cysteines (SPARC) as a mediator of OEC-induced outgrowth in vitro. To test the contributions of SPARC to spinal cord repair after OEC transplantation, cultures of LP OECs from SPARC null and wildtype (WT) mice were transplanted into a crush of the dorsolateral funiculus. Substance P and tyrosine hydroxylase positive axon sprouting was significantly reduced in SPARC null OEC-treated animals, suggesting that individual factors may contribute to OEC-promoted regeneration. To investigate the effect of OECs on corticospinal (CST) neurons, an in vitro assay was developed using postnatal day 8 CST neurons. Coculture of CST neurons with OB OECs produced extensive axon elongation. Application of OB OEC secreted factors increased CST neurite branching, but did not increase axon elongation. In contrast, plating of CST neurons on OB OEC plasma membrane resulted in extensive axon elongation. Furthermore, the OB OEC plasma membrane could overcome CST neurite outgrowth inhibition induced by an outgrowth inhibitor. Together these findings provide insight into OEC mechanisms of neurite outgrowth and axon regeneration.
17

Estudo dos genes NDRG1, Par-4, osteonectina e pontina, em tecido mamário hiperplásico através de técnica de imunohistoquímica / Study of NDRG1, Par-4, osteonectin and pontin expression in hyperplastic breast lesions with immunohistochemical technique

Regina Felippe Barboza 06 May 2011 (has links)
INTRODUÇÃO: O câncer de mama é uma das mais importantes causas de mortalidade feminina no mundo. Acredita-se que as lesões proliferativas do parênquima mamário sejam marcadoras de risco para câncer ou precursoras do carcinoma mamário. Apesar da intensa pesquisa na área do câncer de mama, os eventos moleculares precoces associados à evolução e progressão do câncer mamário ainda são pouco conhecidos. OBJETIVOS: Com a expectativa de melhor compreender os eventos iniciais da carcinogênese mamária examinamos um conjunto de oitenta e quarto lesões proliferativas mamárias quanto à expressão dos genes N-myc down regulated gene (NDRG1), Prostate Apoptosis Response-4 (PAR-4), Osteonectina e Pontina. A expressão destes genes foi documentada, por trabalhos prévios em nosso laboratório ou por estudos de outros autores, como tendo impacto na evolução do câncer de mama. MÉTODOS: Construímos um TMA com lesões proliferativas da mama e testamos este TMA por método imunohistoquímico para Ndrg1, Par-4, Osteonectina e Pontina, bem como para o receptor de estrógeno e citoqueratinas de alto e baixo peso molecular, com o objetivo de caracterizar as lesões presentes no TMA. A avaliação imunohistoquímica foi feita de forma quantitativa, com o aplicativo e sistema de análise quantitativa para TMA ACIS III, da Dako. RESULTADOS: Após excluirmos amostras não informativas, contamos com 68 amostras de lesões proliferativas mamárias para análise. Nestas, observamos uma notável positividade de NDRG1, em lesões com morfologia apócrina. Observamos ainda alta expressão de NDRG1 em lesões proliferativas mamárias, quando comparadas aos outros tipos de lesões presentes no TMA. Pontina exibiu os mais altos valores de expressão nos casos de lesões proliferativas mamárias, com valor de p estatisticamente significativo. A expressão de PAR-4 foi predominantemente nuclear nas lesões mamárias analisadas no TMA. Osteonectina teve expressão diferenciada no epitélio de lesões hiperplásicas da mama, papilomas e papilomas de pequenos ductos, quando comparada às outras lesões presentes no TMA. CONCLUSÕES: Nossos resultados sugerem uma possível associação entre a expressão de NDRG1 e diferenciação apócrina no parênquima mamário. Esta observação está de acordo com os dados publicados a respeito da superexpressão de NDRG1 e a assinatura apócrina molecular de alguns carcinomas de mama. Também demonstramos superexpressão de NDRG1 em condições hiperproliferativas do parênquima mamário, não associadas à diferenciação apócrina. Até o momento não há informações na literatura que possam explicar a translocação nuclear de Par-4 em lesões benignas da mama observada em nosso estudo. Nossos achados fornecem pela primeira vez evidências de que PAR-4 é ativado em lesões proliferativas da mama, indicando a necessidade de estudos futuros dirigidos à investigação das funções de PAR-4 em tecido mamário não neoplásico. O presente trabalho também indicou uma possível ação coordenada entre a expressão de Osteonectina e NDRG1, pelo menos em lesões apócrinas mamárias. A expressão estromal de Osteonectina pareceu ser menos frequente em lesões mamárias com arquitetura papilífera, quando comparadas a lesões mamárias com tendência a recapitular a arquitetura lobular / INTRODUCTION: Breast cancer is a leading cause of death among women all over the Word. Proliferative lesions of the breast are believed to be precursors of or markers of increased risk for breast carcinoma. Although the active research in the field of breast cancer, the early molecular events associated with cancer evolution and progression are still poorly understood. OBJECTIVES: In order to better understand the early events in the breast carcinogenesis, we examined a set of eighty-four proliferative lesions of the breast for the expression of N-myc down regulated gene (NDRG1), Prostate Apoptosis Response-4 (PAR-4), Osteonectin and Pontin, which expression was previously shown by our laboratory to have impact in breast cancer prognosis. METHODS: A tissue microarray were constructed and immunohistochemically tested for Ndrg1, Par-4, Osteonectin and Pontin together with estrogen receptor, low and high weight cytokeratins, aiming to properly characterize the lesions sorted in the tissue microarray. Immunohistochemistry assessment was made quantitative, with the ACIS III Dako quantitative analysis system and TMA application software. RESULTS: After excluding non informative cores, cores with fibroadipose tissue or mammary parenchyma with normal appearing breast epithelium, we ended up with a TMA with 68 breast lesions. Of those, we observed a noticeable positivity of Ndrg1 for lesions with apocrine morphology. Additionally, all cases of florid epithelial hyperplasia showed variable high immunoexpression levels of protein, when compared to the other sorted out lesions in the TMA. Pontin expression level was highest among the breast hyperplasia cases, with statistically significant p value. PAR-4 protein expression was found to be predominantly localized in the nucleous in the non-malignant breast lesions analyzed. Osteonectin exhibited differentiated expression values in the epithelium of hyperplastic breast lesions, papillomas and multiple papillomas when compared to the other types of breast lesions assorted in the TMA. CONCLUSIONS: Our results suggest a possible association of NDRG1 with apocrine differentiation in the breast parenchyma. This observation are consonant with the publish data about the NDRG1 overexpression and the apocrine signature of some mammary cancers. Additionally, we demonstrated that NDRG1 is also overexpressed in some hyperproliferative breast conditions unassociated with apocrine morphology. At present, there is no data available in the in the literature to explain the nuclear translocation of Par-4 in benign breast lesions as observed in our study. However, our findings provide for the first time evidence that PAR-4 is activated in proliferative lesions of the breast indicating that further clinical and experimental studies aiming to investigate PAR-4 function in non neoplastic breast tissue are warranted. Our study also indicated a possible coordinated expression between Osteonectin and NDRG1, at least in apocrine lesions of the breast. Stromal Osteonectin expression seemed to be less intense in breast lesions with papillary architecture, when compared to breast lesions with tendency to recapitulate breast lobular architecture
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Olfactory ensheathing cell mediated mechanisms of neurite outgrowth and axon regeneration

Witheford Richter, Miranda 11 1900 (has links)
The capacity of the olfactory neuraxis to undergo neuronal replacement and axon targeting following injury, has led to scrutiny concerning the molecular and physical determinants of this growth capacity. This is because injury to the central nervous system, in contrast, leads to permanent disconnection of neurons with targets. Olfactory ensheathing cells (OECs), a specialized glial cell, may contribute to olfactory repair, and have been used to promote recovery from spinal cord injury. However, there mechanisms underlying OEC-induced regeneration are poorly appreciated. To understand these mechanisms, OECs from the lamina propria (LP OECs) or olfactory bulb (OB OECs) were transplanted into a lesion of the dorsolateral funiculus. While both cells demonstrated reparative capacities, LP and OB OECs differentially promoted spinal fibre growth; large-diameter neurofilament-positive, CGRP-positive, and serotonergic fibres sprouted in response to both LP and OB OEC transplantation, whereas substance-P and tyrosine hydroxylase-positive neurons grew more extensively following OB or LP OEC transplantation, respectively. To further understand the growth of spinal cord neurons in response to OECs, a proteomic analysis of OEC secreted factors was performed, identifying secreted protein acidic and rich in cysteines (SPARC) as a mediator of OEC-induced outgrowth in vitro. To test the contributions of SPARC to spinal cord repair after OEC transplantation, cultures of LP OECs from SPARC null and wildtype (WT) mice were transplanted into a crush of the dorsolateral funiculus. Substance P and tyrosine hydroxylase positive axon sprouting was significantly reduced in SPARC null OEC-treated animals, suggesting that individual factors may contribute to OEC-promoted regeneration. To investigate the effect of OECs on corticospinal (CST) neurons, an in vitro assay was developed using postnatal day 8 CST neurons. Coculture of CST neurons with OB OECs produced extensive axon elongation. Application of OB OEC secreted factors increased CST neurite branching, but did not increase axon elongation. In contrast, plating of CST neurons on OB OEC plasma membrane resulted in extensive axon elongation. Furthermore, the OB OEC plasma membrane could overcome CST neurite outgrowth inhibition induced by an outgrowth inhibitor. Together these findings provide insight into OEC mechanisms of neurite outgrowth and axon regeneration. / Medicine, Faculty of / Graduate

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