Dystroglycan is a ubiquitous protein that links the extracellular matrix to the cytoskeleton and is the central unit of the dystrophin glycoprotein complex (DGC), a membrane complex that connects the cytoskeleton to the extracellular matrix (ECM). Dystroglycan is composed of two subunits that are tightly but non-covalently linked. alpha Dystroglycan (alpha DG) is located extracellularly and it is the only component of the DGC linked to the ECM, while beta Dystroglycan (beta DG) spans the plasma membrane and has both an extracellular and a cytoplasmic domain. The DGC is involved in skeletal muscle maintenance and viability, and in the organization and stabilization of the neuromuscular junction, but its function in brain is poorly understood. DGC components are target of several protein kinases, indicating that they are involved in cell signalling pathways. The finding of new dystroglycan interacting proteins could help to obtain some insights in its function in brain tissues. Previous immunoprecipitation and pull down experiments have been used to identify proteins interacting with the cytoplasmic tail of beta DG in brain tissues. Here, we attempt to extend the use of these techniques by using pull down experiments performed with the Glutathione-S-transferase (GST) fusion expression system as a tool for the proteomic analysis of Dystroglycan interacting proteins in the brain.

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Orientador: Valeria Helena Alves Cagnon Quitete / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-13T16:32:13Z (GMT). No. of bitstreams: 1 Pinto_LeslieCristina_M.pdf: 6161359 bytes, checksum: e53c13123d8d830910aa70a9f89b179c (MD5) Previous issue date: 2009 / Resumo: A distroglicana (DG) é uma importante proteína estrutural a qual está envolvida no desenvolvimento celular epitelial, formação de membrana basal e manutenção da integridade de diferentes tecidos. Estudos indicaram que a alteração na expressão da DG é um evento freqüente nas malignecências humanas e sugerem que esta molécula tem um papel importante no desenvolvimento de tumor. No câncer de próstata, verificou-se expressiva redução das distroglicanas, especialmente da _-DG, acarretando em progressão tumoral e ocorrência de metástases. Desta maneira, alterações na expressão das distroglicanas podem ser relevantes na patogênese das doenças prostáticas. Além disto, estas moléculas fazem parte de um complexo glicoproteíco e estão relacionadas a uma série de proteínas tais como, agrinas, lamininas e a distrofina. Devido à deficiência de distrofina, este complexo está desestruturado na distrofia muscular de Duchenne e, no camundongo mdx. Este trabalho teve como objetivos caracterizar a estrutura epitelial e estromal do lobo ventral da próstata do camundongo mdx, identificar a ocorrência de receptores para distroglicanas _ e _, IGF-1, laminina _-3, estabelecer correlações entre os processos de proliferação e morte celular e analisar a viabilidade do camundongo mdx como modelo experimental no estudo de patologias prostáticas. Um total de 30 animais (15 C57BL10 e 15 mdx) foi dividido em 2 grupos experimentais: controle e mdx. Amostras do lobo ventral da próstata foram coletadas para análises macroscópicas, imunohistoquímicas, microscopias de luz e eletrônica de transmissão e análises morfométricas. Dosagens sorológicas de estradiol e testosterona foram realizadas. Os resultados mostraram que os níveis séricos de testosterona foram significativamente diminuídos nos camundongos mdx em relação aos controles. Em contraste, os níveis séricos de estradiol do grupo mdx mostraram-se significativamente aumentados em relação ao controle. Acentuada atrofia celular, ocorrência de neoplasia intraepitelial prostática, hipertrofia estromal, presença de células inflamatórias e hipertrofia estromal foram evidenciadas nos animais mdx. A intensidade da reação de imunolocalização da distroglicana foi de fraca expressão em relação ao controle, assim como a da laminina. Já a imunolocalização do IGF foi intensa em relação ao controle. Conclui-se que os animais mdx apresentaram alterações significativas na integridade estrutural e molecular prostática, com sinais de aumento do processo proliferativo, comprometendo a homeostase glandular e o processo reprodutivo destes animais. / Abstract: The prostate is a fundamental accessory sex gland for the male reproductive process and the stroma-epithelium interaction has an important role in prostate structural maintenance and function. The basal membrane is an interaction link, offering mechanical and physiological support. Nowadays, different studies suggest that dystroglycan (DG), which is an adhesion protein, plays a role in different types of cancer development and progression, including that of the prostate. Thus, the aims of this work were to characterize structural, ultrastructural and proliferative features of the prostatic stroma and epithelium of mdx mice; to verify the immunolocalization of the _ and ß dystroglycan, IGF-I and laminin _3 receptors; and to relate those structural and molecular events to prostate pathogenesis as well as to verify the viability of this experimental model in prostate disease studies. Thirty male mice (mdx and C57BL10/Uni) were divided into two groups: control and mdx. Samples from the ventral prostate were collected for immunological, Western Blotting, transmission electron and light microscopies and morphometrical analyses. Estradiol and testosterone measurements were verified. The results showed diminished testosterone and increased estradiol levels in the mdx group. Atrophied cells, stromal hypertrophy and prostatic intraepithelial were verified in the mdx mice. Weak _ and ß dystroglycan and laminin _3 immunolocalization was verified in the mdx group. However, intense IGF-I receptor localization was identified in the mdx animals. Thus, it was concluded that mdx animals presented changes in the molecular and structural integrity and proliferation signals, leading to glandular pathogenesis, compromising prostate homeostasis and the reproductive process. Apart from this, the destructuring of the dystroglycandystrophin complex can be considered a trigger factor for prostate pathogenesis. It can also point towards that the steroid-hormone and IGF relationship can be an alternative towards new therapies to treat prostatic diseases. / Mestrado / Anatomia / Mestre em Biologia Celular e Estrutural

No / Dystroglycan is a ubiquitously expressed cell adhesion molecule frequently found to be altered or reduced in adenocarcinomas, however the mechanisms or consequences of dystroglycan loss have not been studied extensively. We examined the consequence of overexpression or RNAi depletion of dystroglycan on properties of in vitro growth migration and invasion of LNCaP, PC3, and DU145 prostate cancer cell lines. RESULTS: Using LNCaP cells we observed cell density-dependent changes in beta-dystroglycan with the appearance of several lower molecular weight species ranging in size from 43 to 26 kDa. The bands of 31 and 26 kDa were attributed to proteolysis, whereas bands between 43 and 38 kDa were a consequence of mis-glycosylation. The localization of beta-dystroglycan in LNCaP colonies in culture also varied, cells with a mesenchymal appearance at the periphery of the colony had more pronounced membrane localization of dystroglycan. Whereas some cells demonstrated nuclear dystroglycan. Increased dystroglycan levels were inhibitory to growth in soft agar but promoted Matrigel invasion, whereas reduced dystroglycan levels promoted growth in soft agar but inhibited invasion. Similar results were also obtained for PC3 and DU145 cells. This study suggests that changes in beta-dystroglycan distribution within the cell and/or the loss of dystroglycan during tumorigenesis, through a combination of proteolysis and altered glycosylation, leads to an increased ability to grow in an anchorage independent manner, however dystroglycan may need to be re-expressed for cell invasion and metastasis to occur.

Orientador: Valéria Helena Alves Cagnon Quitete / Dissertação (mestrado) - Universidade Estadual de Campinas, Instituto de Biologia / Made available in DSpace on 2018-08-18T10:44:47Z (GMT). No. of bitstreams: 1 Montico_Fabio_M.pdf: 7570263 bytes, checksum: a775095a6141dbe3b18c6ec768585813 (MD5) Previous issue date: 2011 / Resumo: A reposição androgênica representa uma alternativa para minimizar os efeitos prejudiciais do desequilíbrio hormonal em homens senis, embora seus efeitos sobre o desenvolvimento de doenças prostáticas ainda seja assunto controvertido. Assim, o objetivo deste estudo foi caracterizar aspectos estruturais e moleculares do lobo ventral da próstata de ratos senis frente à reposição de hormônios esteróides, relacionando as alterações decorrentes da terapia hormonal a possíveis condições de lesões prostáticas. Ratos machos (Sprague- Dawley) foram divididos em um grupo Jovem (JOV) (4 meses), que recebeu óleo de amendoim (5 mL/Kg, s.c.), e grupos senis (10 meses), submetidos aos tratamentos: grupo Senil (SEN): óleo de amendoim (5 mL/Kg, s.c.); grupo Testosterona (TEST): cipionato de testosterona (5 mg/Kg, s.c.); grupo Estrógeno (EST): 17?-estradiol (25 ?g/Kg, s.c.); grupo Castrado (CAS): castração cirúrgica; grupo Castrado-Testosterona (CT): castração e após 30 dias tratamento similar ao grupo TEST; grupo Castrado-Estrógeno (CE): castração e após 30 dias tratamento similar ao grupo EST. Após 30 dias de tratamento, foram coletadas amostras de sangue, para dosagens hormonais séricas, e do lobo ventral, para análises em microscopias de luz e eletrônica de transmissão, morfométricas, imunohistoquímicas e Western Blotting. As moléculas investigadas foram: distroglicanas ? e ? (?-DG e ?-DG), receptor do fator de crescimento homólogo à insulina tipo I (IGFR-1), metaloproteinase-9 de matriz (MMP-9), fator de crescimento do endotélio vascular (VEGF) e endostatina. Redução dos níveis séricos de testosterona foi verificada na senescência, com aumento destes após a reposição hormonal no grupo TEST. O estroma do grupo SEN apresentou hipertrofia e células inflamatórias. Após a reposição hormonal na senescência ou frente à castração, verificou-se atrofia no epitélio, células epiteliais com halo citoplasmático claro ao redor do núcleo, microácinos e manutenção do estroma hipertrófico com células inflamatórias. Diminuição dos níveis das DGs foi verificada na senescência, sendo que após a terapia hormonal ocorreu aumento dos níveis protéicos dessas moléculas, especialmente nos grupos que receberam estradiol. Aumento do IGFR-1 e da MMP-9, bem como distribuição diferencial dessas moléculas no compartimento epitelial, foram observados nos grupos submetidos à reposição hormonal e no grupo CAS. O grupo SEN caracterizou acréscimo dos níveis de VEGF, sendo o inverso observado para a endostatina. A terapia hormonal e a castração levaram à elevação dos níveis de VEGF, sobretudo nos grupos EST, CAS e CE. Em oposição, a endostatina demonstrou-se aumentada especialmente nos grupos submetidos à reposição de testosterona. Os presentes resultados sugeriram que o desequilíbrio entre andrógenos e estrógenos verificado na senescência foi acentuado após a terapia hormonal e a castração, potencializando as alterações estruturais associadas a esse período e rompendo o equilíbrio das sinalizações parácrinas prostáticas, com aumento simultâneo de IGFR-1 e MMP-9 e geração de fatores pró e anti-angiogênicos em resposta ao tratamento com estrógenos e andrógenos, respectivamente. Assim, concluiu-se que a terapia hormonal, apesar de seus efeitos positivos sobre as DGs, gerou microambiente prostático reativo, caracterizado por aumento de um fator mitogênico e da remodelação tecidual bem como por desequilíbrio da angiogênese, o que possivelmente comprometeu a função do órgão e o predispôs a desordens glandulares / Abstract: Androgen replacement is an alternative to minimize the harmful effects of hormonal imbalance in elderly men, even though its influence on the development of prostatic diseases is unclear. Thus, the aim herewith was to characterize structural and molecular features of the ventral prostate of senile rats submitted to steroid hormone replacement, relating the alterations resulting from hormonal therapy to possible prostatic lesions. Male rats (Sprague-Dawley) were divided into Young group (YNG) (4 months old rats), which received peanut oil (5 mL/Kg, s.c.), and senile groups (10 months old rats), submitted to the treatments: Senile group (SEN): peanut oil (5 mL/Kg, s.c.); Testosterone group (TEST): testosterone cipionate (5 mg/Kg, s.c.); Estrogen group (EST): 17?-estradiol (25 ?g/Kg, s.c.); Castrated group (CAS): surgical castration; Castrated-Testosterone group (CT): castration and after 30 days treatment similar to TEST group; Castrated-Estrogen group (CE): castration and after 30 days treatment similar to EST group. After 30 days treatment, blood samples were collected for hormonal analysis and ventral prostate samples were processed for light and transmission electronic microscopies, morphometric, immunohistochemical and Western Blotting analysis. The investigated molecules were alfa and beta dystroglycans (?DG and ?DG), insulin-like growth factor receptor-1 (IGFR-1), matrix metalloproteinase-9 (MMP-9), vascular endothelial growth factor (VEGF) and endostatin. Decreased serum testosterone levels were verified in senescence, with an increase after hormonal replacement in the TEST group. Hypertrophied stroma with inflammatory cells was seen in the SEN group. After hormonal therapy in the senescence or following castration, atrophic and pale cytoplasmatic epithelial cells, microacini and hypertrophied stroma were observed. Decreased DG levels were verified in senescence, but there was an increase of these levels following hormonal therapy, especially in the groups treated with estradiol. Increased IGFR- 1 and MMP-9 protein levels and differential distribution of these molecules were observed in epithelial compartment in those groups which received hormone replacement and in the CAS group. SEN group showed increased VEGF levels in contrast to decreased endostatin levels. Hormonal therapy and castration led to raised VEGF levels, mainly in EST, CAS and CE groups. On the other hand, endostatin was increased especially in those groups submitted to testosterone replacement. The present results suggested that the imbalance between androgens and estrogens in senescence was enhanced after hormone replacement and castration, intensifying structural changes associated with this period. Also, there was a disruption of prostatic paracrine signaling balance, with simultaneous increase of IGFR-1 and MMP-9 and generation of pro and anti-angiogenic factors in response to treatment with estrogens and androgens, respectively. Thus, it could be concluded that despite its positive effects on DGs levels, hormonal therapy created a reactive prostatic microenvironment, characterized by increase of a mitogenic factor and tissue remodelling as well as prostatic angiogenesis imbalance, which could compromise glandular functions and lead to the emergence of prostatic lesions / Mestrado / Anatomia / Mestre em Biologia Celular e Estrutural

Dystroglycan is frequently lost in adenocarcinoma, but the mechanisms and consequences are poorly understood. We report an analysis of beta-dystroglycan in prostate cancer in human tissue samples and in LNCaP cells in vitro. There is progressive loss of beta-dystroglycan immunoreactivity from basal and lateral surfaces of prostate epithelia which correlates significantly with increasing Gleason grade. In about half of matched bone metastases there is significant dystroglycan re-expression. In tumour tissue and in LNCaP cells there is also a tyrosine phosphorylation-dependent translocation of beta-dystroglycan to the nucleus. Analysis of gene expression data by microarray, reveals that nuclear targeting of beta-dystroglycan in LNCaP cells alters the transcription of relatively few genes, the most unregulated being the transcription factor ETV1. These data suggest that proteolysis, tyrosine phosphorylation and translocation of dystroglycan to the nucleus resulting in altered gene transcription could be important mechanisms in the progression of prostate cancer.