Understanding the genetic control of gametogenesis is a central goal of developmental biology and is important for treating infertility in humans. An approach to identifying critical genes in mammals is to search for and study homologues of genes known to play key roles in other organisms. In the fly, Drosophila melanogaster, GUS protein is a component of nuage, an electron-dense aggregation in early germ cells, and is required for oocyte development. GUS physically interacts with VASA, an RNA helicase thought to regulate mRNA metabolism. I identified two murine genes, SSB-1 and SSB-4, that are similar to and likely homologues of gus. SSB-1, SSB-4 and GUS each contain two conserved regions, termed the SPRY domain and the SOCS box, respectively. SSB-1 and SSB-4 share about 75% sequence identity and about 70% identity with GUS. Both SSB-1 and SSB-4 RNA and protein were found to be express in mouse ovarian granulosa cells of all stages of folliculogenesis. These cells support oocyte development and also produce steroids. Unexpectedly, SSB-1 and SSB-4 were only weakly or not detectable in oocytes, that contrasts with the expression of GUS in Drosophila oocytes. However, SSB-1 mRNA and protein were expressed in male germ cells; specifically in spermatocytes and spermatids. SSB-1 in spermatids was localized in a specialized structure known as the chromatoid body. Although the function of this structure is not quite clear, it has been compared to nuage, and one of its components is MVH, the murine homologue of VASA. Finally, using RNAi technology, SSB-1 was transiently depleted SSB-1 from a granulosa cell line. These cells showed a transient decrease in expression of the gene encoding P450scc, the rate-limiting enzyme in steroid synthesis. Preliminary results also indicated a decrease in progesterone synthesis. Taken together, these results establish the expression pattern of murine homologues of Drosophila GUS in mouse ovary and testis, reveal it might play function in translation regulation in male spermatogenesis, and identify a potential role in steroidogenesis by ovarian granulosa cells.

Thesis (Ph.D.)--University of Alabama at Birmingham, 2010. / Title from PDF title page (viewed on June 25, 2010). Includes bibliographical references.

No description available.

Thesis (Ph.D.)--University of Alabama at Birmingham, 2009. / Title from PDF title page (viewed on Feb. 2, 2010). Includes bibliographical references.

Thesis (Ph. D.)--Cornell University, January, 2007. / Vita. Includes bibliographical references (leaves 92-106).

Orientador: Ana Paula de Souza Pardo / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Odontologia de Piracicaba / Made available in DSpace on 2018-08-22T12:44:41Z (GMT). No. of bitstreams: 1 Guedes_RogerAntoniaci_M.pdf: 960151 bytes, checksum: c0a68bdbdf663d427c182550b1d9fa14 (MD5) Previous issue date: 2013 / Resumo: A periodontite é caracterizada pela inflamação do periodonto, o tecido de suporte dos dentes. Este processo inflamatório pode evoluir da fase aguda para a fase crônica, acarretando severa destruição dos tecidos periodontais como também grave perda de inserção dos dentes ao osso alveolar. É evidente que o acúmulo de patógenos periodontais sobre a superfície dos dentes desencadeia a doença, porém seu agravamento e severidade também são dependentes de fatores ambientais, socioeconômicos, tabagismo, condição de saúde sistêmica e carga genética dos indivíduos. Desta forma, vários pesquisadores têm se dedicado a estudar a influência dos polimorfismos genéticos sobre a suscetibilidade e/ou risco aumentado à doença periodontal, uma vez que estes podem exercer efeito sobre o prognóstico da periodontite crônica. Estudos têm relatado associação entre vários polimorfismos genéticos com a inflamação periodontal. Há ainda estudos em larga escala onde grande parte do genoma (GWA) foi investigado, relatando efeito da genética do hospedeiro sobre a resposta à doença. Desde modo, considerando a hipótese de associação entre periodontite e polimorfismos no gene SOCS1 que expressa uma proteína chave no controle da via intracelular JAK/STAT ativada por diversas citocinas pró-inflamatórias presentes na inflamação periodontal, nosso objetivo neste estudo foi estudar a frequência dos genótipos, alelos e haplótipos dos polimorfismos SOCS1-1478 (rs33989964) e SOCS1-820 (rs33977706) em grupo de indivíduos com saúde periodontal e indivíduos com periodontite crônica, na tentativa de observar associação entre variações no gene SOCS1 com a doença periodontal crônica. Para tal, DNA genômico foi purificado de células epiteliais bucais obtidas por meio de enxágue com dextrose a 3%. Após, os genótipos foram identificados com a utilização das técnicas de PCR/ RFLP/ eletroforese. Análises estatísticas possibilitaram a observação da associação do polimorfismo SOCS1 -820 (rs33977706) com os casos de periodontite crônica mais severa / Abstract: The periodontitis is characterized by the periodontium inflammation, the supporting tissue of the teeth. This inflammatory disorder might evolve from the acute to the chronic phase, causing severe periodontal tissue destruction as well as teeth insertion loss in the alveolar bones. It is evident that the accumulation of periodontal pathogens on the teeth surface origins the disease, yet its aggravation and severity also depend on socioeconomic and environmental factors, smoking, systemic health condition and the genetic background of the subjects. Thus, several researchers have focused their studies on the influence of the genetic polymorphisms in the susceptibility and/or increased risk to the periodontal disease, once they might play a role on the chronic periodontitis prognosis. Studies have shown association between several genetic polymorphisms and periodontal inflammation. Still, there are large-scale studies in which the majority of the genome (GWA) has been investigated, reporting genetic host roles as responses to the disease. Thus, considering the hypothesis of association between periodontitis and polymorphisms in the SOCS1 gene which expresses a key protein in the control of the intracellular JAK/STAT via activated by varied pro-inflammatory cytokines found in the periodontal inflammation, we aimed to study the frequency of genotypes, alleles and haplotypes of the polymorphisms SOCS1-1478 (rs33989964) and SOCS1-820 (rs33977706) in a healthy periodontal subjects group and in a chronic periodontal subjects group, attempting to observe association between variations in the SOCS1 gene and the chronic periodontal disease. To do so, genomic DNA was purified from mouth epithelial cells collected through 3% dextrose rinse. Afterwards, the genotypes were identified by the use of PCR/RFLP electrophoresis techniques. Statistical analysis allowed us to observe association of SOCS1-820 polymorphism (rs33977706) with more severe chronic periodontitis cases / Mestrado / Histologia e Embriologia / Mestre em Biologia Buco-Dental

No description available.

Heme-based gas sensor proteins have the ability to sense diatomic molecules such as O2 (FixL, EcDos or HemAT), CO (CooA, a CO-sensing protein of Rhodospirillum rubrum) and NO (guanylate cyclase) molecules and subsequently regulate numerous important biological processes in prokaryotic and eukaryotic organisms. The sensing function of these proteins is initiated by the binding of an effector (i.e., O2, CO, etc5) to the heme iron which then leads to a cascade of conformational events which gives rise to changes in kinase activity, DNA-binding activity, etc... In order to better understand the mechanism heme-based signaling, time resolved photothermal methods as well as transient optical techniques were utilized to obtain thermodynamic profiles for ligand binding/release in heme based signaling proteins including HemAT from Bacillus subtilis (aerotactic transducer), FixL from Sinorhizobium meliloti (regulation of the nitrogen fixation) and CooA from Rhodospirillum rubrum (transcriptional activator). In addition, a number of model systems were examined to understand the underlying thermodynamic processes involved in heme ligation. The variation of volume and enthalpy changes associated with spin state change of the iron from high-spin to low-spin where examined using the spin crossover Fe(III)(salten)(mepepy) complex. In addition, the experimental determination of the volume change due to electrostriction events were using Ru(II)(L)3 and the Debye-Hückel equation. Finally, different model heme proteins were studied to understand how a signal is conformationaly transmitted within a heme protein matrix. Sandbar shark hemoglobin was examined as an example of a non-signaling an allosteric protein. Two different peroxidases (horseradish and soybean) which have a direct channel between the heme pocket and the solvent involving no barrier energetic for the photodissociated ligand leaving the heme pocket were examined as example of non-signaling, non-allosteric proteins. The results show that each protein has a unique thermodynamic profile to conformationaly transmit signals subsequent to photodissociation of CO, even within the same class of protein (i.e. PAS domains, globins, etc...).

Submitted by Ana Maria Fiscina Sampaio (fiscina@bahia.fiocruz.br) on 2014-09-18T13:07:03Z No. of bitstreams: 1 Gabriela da Silva Cruz. Avaliação... 2014.pdf: 1237079 bytes, checksum: 7beefa52e21bd18ac4325a1c493249ba (MD5) / Made available in DSpace on 2014-09-18T13:07:04Z (GMT). No. of bitstreams: 1 Gabriela da Silva Cruz. Avaliação... 2014.pdf: 1237079 bytes, checksum: 7beefa52e21bd18ac4325a1c493249ba (MD5) Previous issue date: 2014 / Fundação Oswaldo Cruz. Centro de Pesquisa Gonçalo Moniz. Salvador, BA, Brasil / O Trypanosoma cruzi é um parasita intracelular e agente causador da doença de Chagas, que afeta milhões de pessoas em todo o mundo. Sabe-se que durante os processos de inflamação, regeneração e fibrose desencadeados pelo T. cruzi no hospedeiro há a participação de diversos mediadores e fatores. O objetivo deste trabalho foi avaliar a associação entre polimorfismos de nucleotídeos únicos com as formas clínicas e o grau de fibrose em pacientes com doença de Chagas. Os polimorfismos foram analisados por PCR em tempo real. Foram incluídos no estudo 55 pacientes com diagnóstico de doença de Chagas e classificados de acordo com a forma clínica da doença, sendo que 17 apresentavam a forma indeterminada, 15 a forma cardíaca sem disfunção ventricular e 23 a forma cardíaca com disfunção ventricular. Os genótipos CA dos polimorfismos do gene LGALS3 (rs4644 e rs4652); AG e GG do SOCS3 (rs4969170); CT e TT do IL-28B (rs12979860 e 8099917, respectivamente); AG, AG, CC, AG e AG do CLDN-1 (rs10212165, rs3909582, rs9865082, rs9880018 e rs9848283, respectivamente); e CC do CCL5 (rs2280789) foram estatisticamente mais frequentes em pacientes com a forma cardíaca do que com a forma indeterminada da doença. Com relação ao grau de fibrose, os genótipos CC dos polimorfismos do gene LGALS3 (rs4644 e rs4652); AA do SOCS3 (rs4969170); CC do rs12979860 e TT do rs8099917 do IL-28B; AA do rs10212165, AA, AG e GG do rs3909582, CC e CT do rs9865082, AG e GG do rs9880018 e AA do rs9848283 do gene CLDN1; e CC do CCL5 (rs2280789) foram estatisticamente mais frequentes em indivíduos com fibrose cardíaca <15% quando comparados com o grupo com fibrose ≥15%. Diante do exposto concluimos que os polimorfismos analisados podem ser úteis como futuros biomarcadores para estadiamento e conduta terapêutica em pacientes com doença de Chagas. / Trypanosoma cruzi is an intracellular parasite and the agent that causes Chagas disease, which affects millions of people worldwide. Several factors and mediators are known to actively participate in the inflammation, fibrosis and tissue regeneration, which is triggered by T. cruzi within the host. The aim of this study was to evaluate the association of single nucleotide polymorphisms with clinical forms and rate of fibrosis in Chagas disease patients. The polymorphisms were analyzed by real-time PCR. The study consisted of 55 Chagas disease patients that were classified according to the clinical form of the disease, including 17 patients presenting the indeterminate form, 15 patients presenting the cardiac form without ventricular dysfunction and 23 patients presenting the cardiac form with ventricular dysfunction. The genotypes of CA of LGALS3 gene polymorphisms (rs4644 and rs4652); AG and GG of SOCS3 (rs4969170); CT and TT of IL-28B (rs12979860 and 8099917, respectively); AG, AG, CC, AG and AG of CLDN-1 (rs10212165, rs3909582, rs9865082, rs9880018 and rs9848283, respectively); and CC of CCL5 (rs2280789) were significantly more frequent in patients presenting the cardiac form compared to patients presenting the indeterminate form. Regarding the degree of fibrosis, the CC genotype of polymorphisms of the genes LGALS3 (rs4644 and rs4652); AA of SOCS3 (rs4969170); CC of rs12979860 and TT of rs8099917 of the IL-28B; AA of rs10212165 and AA, AG and GG of rs3909582, CC and CT of rs9865082, AG and GG of rs9880018 and AA of rs9848283 of the gene CLDN1; and CC of CCL5 (rs2280789) were statistically more frequent in patients presenting <15% cardiac fibrosis when compared to patients presenting fibrosis ≥15%. Taken together, our results suggest that the polymorphisms analyzed may be useful biomarkers for therapeutic management of patients with Chagas disease.

Resumo: A expressão de citocinas inflamatórias é um processo estritamente regulado por mecanismos variados, incluindo o controle da sinalização intracelular e da atividade transcricional por inibidores endógenos, os quais são pouco estudados e compreendidos. Três grupos de proteínas: SHP, PIAS e SOCS inibem de maneira distinta e específica a transdução de sinais pela via JAK/STAT, bem como a atividade dos fatores de transcrição, eventos que modulam a expressão de diversas citocinas. As doenças periodontais estão associadas à inflamação persistente, com elevados níveis de citocinas proinflamatórias, no entanto praticamente não existem informações sobre a participação destes mecanismos de regulação nas diferentes condições clínicas periodontais. Os objetivos deste projeto incluíram avaliar a cinética de expressão das proteínas SOCS1 e SOCS3 e suas proteínas-alvo, STAT1 e STAT3, respectivamente, durante a evolução da doença periodontal. Foram utilizados 36 ratos Wistar divididos em 2 grupos: DP - doença periodontal induzida por 2 métodos: ligaduras ao redor dos 1os molares inferiores e injeções de 60 μg de LPS de E. coli no tecido gengival palatino dos molares superiores, 3x/semana; Grupo controle negativo - recebeu apenas injeções de PBS (veículo). Os ratos foram sacrificados 7, 15 e 30 dias após a indução da doença periodontal para avaliação histológica e análise macroscópica da perda óssea alveolar. A expressão de SOCS1 e SOCS3 e a ativação de STAT1 e STAT3 foram avaliadas nas biópsias gengivais por PCR em tempo real e Western blot. Ambos os modelos apresentaram significante e progressiva perda óssea dos 7 aos 30 dias. A inflamação foi evidente já no período de 7 dias em ambos os modelos, porém enquanto manteve-se similar nos demais períodos no modelo de indução por LPS, apresentou uma diminuição na severidade da inflamação... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: Inflammatory cytokine gene expression is a process strictly regulated by various mechanisms, including the negative regulation of signaling of cytokine receptors and of the activity of transcription factors such as STATs. These mechanisms involve endogenous proteins and are largely unknown, especially in periodontal diseases. Three groups of proteins, SHP, PIAS and SOCS modulate in a fairly specific manner JAK/STAT signaling and/or STAT activity. Periodontal diseases are infectious-inflammatory conditions of the supporting tissues of the teeth associated with increased levels of proinflammatory cytokines, but there are no information regarding the role of these endogenous mediators of JAK/STAT during its course. The aims of this study included the evaluation of the expression kinetics of inducible negative regulators and their target proteins during the course of experimentally induced periodontal disease. 36 Wistar rats were divided into two groups: PD - experimental periodontal disease induced by two methods: ligature placement around the first mandibular molars and E. coli lipopolysaccharide (LPS) injections into the palatal gingival tissues of the maxillary molars, 3x/week, and Negative Control group. Rats were sacrificed 07, 15 and 30 days after disease induction for histological evaluation of periodontal inflammation and macroscopic analysis of alveolar bone loss. SOCS expression and the activation status of STAT1 and STAT3 were evaluated in gingival biopsies by real time PCR and Western Blot. Both disease models presented significant progressive bone loss from 7 to 30 days. Inflammation was evident and similar for all the periods in LPS injected sites; however, a decrease on severity at the end of the experimental period was observed in the ligature model. There was a significant (p<0.05) increase on SOCS1 and SOCS3 gene expression in PD compared to control... (Complete abstract click electronic access below) / Orientador: Joni Augusto Cirelli / Coorientador: Carlos Rossa Junior / Banca: Carlos Ferreira dos Santos / Banca: Paulo Sergio Cerri / Mestre