Pulmonary arterial hypertension (PAH) is a rare, devastating disease with no cure. Current treatment consists of a cocktail of vasodilators which relieve symptoms of PAH but do not treat the cause. Thus, there is a need for novel drugs that target the underlying pathological causes of PAH. PAH is a multi-factorial, but one key contributor is the pro-inflammatory cytokine IL-6 which stimulates pro-inflammatory and pro-angiogenic signalling mediated by the JAK/STAT pathway. One way in which IL-6 signalling via JAK/STAT is inhibited is via SOCS3 in a type of negative feedback loop whereby IL-6 induces transcription of SOCS3, which then attenuates further JAK/STAT signalling. SOCS3 can also be induced by cAMP. This is interesting as prostanoids, a type of drug used in the treatment of PAH due to its vasodilator effects and the only type to show any efficacy improving the life expectancy of PAH patients, acts by mobilising cAMP. Thus, prostanoid stimulation of cAMP could potentially limit IL-6 signalling via the induction of SOCS3. This is a novel mechanism of prostanoids which has not previously been considered. This study investigated the capability of prostanoids to limit the pro-inflammatory/pro-angiogenic effects of IL-6 that enable PAH to develop. Initial experiments confirmed that vascular endothelial cells responded to prostanoids which increased SOCS3 and limited IL-6 signalling activity. Further experiments utilising SOCS3 KO endothelial cell models demonstrated prostanoid inhibition of IL-6 signalling was due in part to SOCS3. In conclusion, this project has confirmed that prostanoids do limit the pro-inflammatory effects induced by IL-6 and that this is in part due to SOCS3. Although the exact mechanism is yet to be discovered, it will be beneficial in the treatment of PAH as it provides currently unexploited drug targets which can be considered for future PAH therapies. / British Heart Foundation

A periodontite está relacionada à genética do hospedeiro, constituição do biofilme dental e fatores ambientais como o hábito de fumar. A metilação do DNA é um mecanismo de expressão genética que pode inibir ou silenciar a expressão do gene. Desta forma, vários pesquisadores têm se dedicado a estudar a influência genética sobre a suscetibilidade e/ou risco aumentado à doença periodontal. Estudos têm relatado associação entre vários biomarcadores epigenéticos com a inflamação periodontal. Considerando a hipótese de que existe associação do tabagismo com a metilação em genes relacionados à doença periodontal, o objetivo deste estudo foi verificar o padrão de metilação do DNA em células do epitélio oral de pacientes com periodontite crônica (CP) no promotor de um gene específico envolvido no controle da inflamação, como supressor da sinalização de citocinas (SOCS-1) em pacientes fumantes e não fumantes. O gene SOCS-1 é localizado no cromossomo 16p13.3, compostos por uma região amino-terminal, um domínio SH2 central e uma caixa SOCS. É um regulador negativo da via JAK / STAT. Inibe os efeitos biológicos de várias citocinas, incluindo IL-2, IL-3, IL-4, IL-6, interferão (INF) - γ e INF- α / β. Este foi um estudo caso-controle, comparando dois grupos, um grupo (teste) com consumo de 10 cigarros mínimos por dia, com diagnóstico de periodontite crônica e outro grupo controle que foram pacientes não fumantes com periodontite crônica. Para tal, DNA genômico foi purificado de células epiteliais bucais obtidas por meio de enxágue com sacarose 3%, por tempo único de coleta. O DNA foi modificado pelo bissulfito de Sódio e os padrões de metilação do DNA foram analisados com a técnica MS-PCR (Polymerase chain reaction). A análise estatística foi realizada pela plataforma estatística R version 3.3.2 Core Team (2016). Foi realizado Teste t de Student para amostras independentes e teste não paramétrico de Wilcoxon & Mann-Whitney para variáveis qualitativas; teste qui-quadrado e para a variável metilação, foi feito um teste exato de Fisher para testar a associação entre os grupos e a metilação. Os resultados indicaram que, para células epiteliais da mucosa bucal, a frequência de desmetilação no gene SOCS-1 é maior no grupo sem o hábito do fumo, em comparação ao grupo fumante. Foram detectadas diferenças no padrão de metilação entre os dois grupos. Ao estabelecer uma estimativa de risco relativo entre os grupos e a variável metilação, foi observado que pacientes fumantes têm 7,08 vezes (risco relativo) com um intervalo (1,95-51.46) de apresentar doença periodontal crônica, com um padrão de metilação no gene SOCS-1 / Periodontitis is related to host genetics, constitution of the dental biofilm and environmental factors such as smoking. DNA methylation is a mechanism of genetic expression that can inhibit or silence gene expression. In this way several researchers have been dedicated to study the genetic influence on the susceptibility and / or increased risk to periodontal disease. Studies have reported association between several epigenetic biomarkers with periodontal inflammation. Considering the hypothesis that there is an association between smoking and methylation in genes related to periodontal disease, the objective of this study was to verify the DNA methylation pattern in oral epithelial cells of patients with chronic periodontitis (ChP) in the promoter of a specific gene involved in the control of inflammation, as suppressor of cytokine signaling (SOCS-1) in smokers and nonsmokers patients. The SOCS-1 gene is located on chromosome 16p13.3 composed of an amino-terminal region, a central SH2 domain and a SOCS box. It is a negative regulator of the JAK / STAT path. It inhibits the biological effects of various cytokines, including IL-2, IL-3, IL-4, IL-6, interferon (INF) -γ and INF-α / β . This was an case-control type study, comparing two groups, a group with consumption of 10 minimum cigarettes per day, with a diagnosis of chronic periodontitis and another control group were non-smokers with chronic periodontitis. For this, genomic DNA was purified from oral epithelial cells obtained by rinsing with 3% sucrose, for a single time of collection. The DNA was modified by Sodium bisulfite and the methylation patterns of the DNA were analyzed with the MS-PCR technique (Polymerase chain reaction). Statistical analysis was performed by the statistical platform R version 3.3.2 Core Team (2016), Student\'s t-test was performed for independent samples and Wilcoxon\'s & Mann-Whitney non-parametric test for qualitative variables; chi-square test. For the methylation variable, an exact Fisher\'s test was performed to test the association between the groups and the methylation. The results indicated that, for oral mucosal epithelial cells, the frequency of demethylation in the SOCS-1 gene is higher in the non-smoking group as compared to the smoker group. statistically significant differences were detected in the methylation pattern between the two groups. When establishing an relative risk between the groups and the methylation variable, it was observed that smokers are 7.08 times (relative risk) of having chronic periodontal disease with a methylation pattern in the SOCS-1 gene

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

Made available in DSpace on 2014-06-11T19:28:02Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-03-30Bitstream added on 2014-06-13T19:26:31Z : No. of bitstreams: 1 souza_jac_me_arafo.pdf: 631355 bytes, checksum: 9371a4a7027469c6d4a66de2870a71ed (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / 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... / 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)

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Poon, Fan Fong. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2009. / Includes bibliographical references (leaves 109-124). / Abstract also in Chinese. / Abstract --- p.i / Acknowledgements --- p.v / Table of Content --- p.vi / List of Figures --- p.xi / List of Tables --- p.xiii / List of Abbreviations --- p.xiv / List of papers published during the study --- p.xvi / Chapter Chapter 1 --- Introduction and Aim of Study --- p.1 / Chapter 1.1 --- General Introduction --- p.1 / Chapter 1.2 --- Project objective and potential significances --- p.6 / Chapter Chapter 2 --- Literature Reviews --- p.8 / Chapter 2.1 --- Cancer genetics --- p.8 / Chapter 2.1.1 --- Oncogenes and TSGs --- p.8 / Chapter 2.1.2 --- Kundsońةs two-hit event of cancer gene --- p.9 / Chapter 2.2 --- Cancer Epigenetics --- p.9 / Chapter 2.2.1 --- Types of Epigenetic regulation --- p.10 / Chapter 2.2.2 --- DNA methylation in TSGs --- p.10 / Chapter 2.2.2.1 --- Promoter CpG island in DNA methylation --- p.10 / Chapter 2.2.2.2 --- Protection system in DNA methylation --- p.11 / Chapter 2.2.2.3 --- Transcriptional silencing by DNA methylation --- p.11 / Chapter 2.2.2.4 --- DNA methylation of TSG silencing in cancers --- p.13 / Chapter 2.2.3 --- Hypomethylation of the cancer genome --- p.14 / Chapter 2.2.4 --- Clinical relevance of cancer epigenetic --- p.14 / Chapter 2.3 --- EGFR/STAT/SOCS pathway --- p.15 / Chapter 2.3.1 --- General Introduction of the EGFR pathway --- p.15 / Chapter 2.3.2 --- EGFR survival signaling pathways --- p.16 / Chapter 2.3.3 --- EGFR/STAT/SOCS signaling --- p.17 / Chapter 2.3.4 --- EGFR/STAT/SOCS signaling and cancers --- p.18 / Chapter 2.3.4.1 --- EGF and cancers --- p.18 / Chapter 2.3.4.2 --- EGFR/STAT/SOCS pathway and cancers --- p.18 / Chapter 2.3.4.3 --- EGF survival signaling as a target for cancer therapy --- p.19 / Chapter 2.4 --- TSGs in the EGFR/STAT/SOCS pathway --- p.20 / Chapter 2.4.1 --- Suppressors of cytokine signaling (SOCS) family --- p.20 / Chapter 2.4.2 --- Signal transducers and activators of transcription (STATs) family --- p.22 / Chapter 2.4.3 --- Sprouty (SPRY) family --- p.23 / Chapter 2.4.4 --- Protein Inhibitor of Activated STAT (PIASs) family --- p.25 / Chapter 2.4.5 --- Ras and Rab Interactor (RIN) family --- p.26 / Chapter 2.4.6 --- Ras-association domain family (RASSF) --- p.26 / Chapter 2.4.7 --- Glycine N-methyltransferase (GNMT) --- p.28 / Chapter 2.5 --- Nasopharyngeal carcinoma (NPC) --- p.30 / Chapter 2.5.1 --- Epidemiology of NPC --- p.30 / Chapter 2.5.2 --- Histopathology of NPC --- p.30 / Chapter 2.5.3 --- Genetic and epigenetic alteration in NPC --- p.31 / Chapter 2.5.4 --- EGFR signaling in NPC --- p.32 / Chapter 2.6 --- Esophageal squamous cell carcinoma (ESCC) --- p.33 / Chapter 2.6.1 --- Epidemiology of ESCC --- p.34 / Chapter 2.6.2 --- Histopathology of ESCC --- p.34 / Chapter 2.6.3 --- Genetic and epigenetic alteration in ESCC --- p.35 / Chapter 2.6.4 --- EGFR signaling in ESCC --- p.36 / Chapter Chapter 3 --- Materials and Methods --- p.38 / Chapter 3.1 --- General Materials --- p.38 / Chapter 3.1.1 --- "Cell lines, tumor and normal tissue samples" --- p.38 / Chapter 3.1.2 --- Maintenance of cell lines --- p.38 / Chapter 3.1.3 --- Drugs treatment of cell lines --- p.39 / Chapter 3.1.4 --- Total RNA extraction --- p.39 / Chapter 3.1.5 --- Genomic DNA extraction --- p.40 / Chapter 3.2 --- General techniques --- p.40 / Chapter 3.2.1 --- Agarose gel electrophoresis of DNA --- p.40 / Chapter 3.2.2 --- TA cloning and blunt end cloning of PCR product --- p.40 / Chapter 3.2.3 --- Transformation of cloning products to E. coli competent cells --- p.41 / Chapter 3.2.4 --- Preparation of plasmid DNA --- p.41 / Chapter 3.2.4.1 --- Mini-prep plasmid DNA extraction --- p.41 / Chapter 3.2.4.2 --- Midi-prep of plasmid DNA --- p.42 / Chapter 3.2.5 --- Measurement of DNA or RNA concentrations --- p.42 / Chapter 3.2.6 --- DNA sequencing of plasmid DNA and PCR products --- p.42 / Chapter 3.3 --- Preparation of reagents and medium --- p.43 / Chapter 3.4 --- Semi-quatitative Reverse-Transcription (RT) PCR expression analysis --- p.44 / Chapter 3.4.1 --- Reverse transcriptin reaction --- p.44 / Chapter 3.4.2 --- Semi-quantitative RT-PCR --- p.44 / Chapter 3.4.2.1 --- Primers design --- p.44 / Chapter 3.4.2.2 --- PCR reaction --- p.46 / Chapter 3.5 --- Methylation analysis of candidate genes --- p.47 / Chapter 3.5.1 --- Bisulfite treatment of genomic DNA --- p.47 / Chapter 3.5.2 --- Methylation-specific PCR (MSP) --- p.48 / Chapter 3.5.2.1 --- Bioinformatics prediction of CpG island --- p.48 / Chapter 3.5.2.2 --- Primers design --- p.48 / Chapter 3.5.2.3 --- PCR reaction --- p.49 / Chapter 3.5.3 --- Bisulfite Genomic Sequencing (BGS) --- p.50 / Chapter 3.6 --- Construction of expression vectors of candidate genes --- p.51 / Chapter 3.6.1 --- Sub-cloning of expression vector of candidate genes --- p.51 / Chapter 3.6.1.1 --- Mouse Socsl expression vector --- p.51 / Chapter 3.6.1.2 --- SPRY1 expression vector --- p.51 / Chapter 3.6.1.3 --- GNMT expression vector --- p.52 / Chapter 3.6.2 --- Restriction digestion of cloning vectors and expression --- p.52 / Chapter 3.6.3 --- Ligation of cloning fragments --- p.53 / Chapter 3.6.4 --- Colony formation assay on monolayer culture --- p.53 / Chapter 3.6.5 --- Statistical analysis --- p.54 / Chapter Chapter 4 --- Screening of candidate TSGs in EGFR pathway --- p.55 / Chapter 5.3.3 --- Restoration of GNMT expression by pharmacological demethylation --- p.89 / Chapter 5.3.4 --- Confirmation of the methylation status of GNMT promoter by BGS --- p.90 / Chapter 5.3.5 --- Methylation status of GNMT in ESCC and NPC primary tumors --- p.90 / Chapter 5.3.6 --- GNMT inhibited the growth of tumor cells in-vitro --- p.90 / Chapter 5.3.7 --- Discussion --- p.95 / Chapter Chapter 6 --- General Discussion --- p.100 / Chapter Chapter 7 --- Summary --- p.105 / Chapter Chapter 8 --- Future Study --- p.107 / Reference --- p.109

CIS/SOCS (cytokine-inducible SH2 protein/suppressor of cytokine signaling) are a family of proteins that are thought to act as negative regulators of signaling by erythropoetin, interleukin-6 and other cytokines whose receptors are related to the growth hormone receptor (GHR), and like growth hormone (GH), signal through the JAK/STAT pathway. We examined the possibility that CIS/SOCS proteins may also be involved in GH signaling, in particular, in termination of the transient insulin-like effects of GH. mRNAs for CIS, SOCS3, and to a lesser extent SOCS1 were detectable by Northern blot analysis of rat adipocyte total RNA, and the expression of CIS and SOCS3 was markedly increased 30 min after incubation with 500 ng/ml hGH. Both CIS and SOCS3 were detected in adipocyte extracts by immunoprecipitation and immunoblotting with their corresponding antisera. GH stimulated the tyrosine phosphorylation of a 120 kDa protein (p120) that was co-precipitated from adipocyte extracts along with αCIS and detected in Western blots with phospho-tyrosine antibodies. However, no tyrosine phosphorylated proteins in these cell extracts were immunoprecipitated with antibodies to CIS3/SOCS3. p120 was later identified as the GHR based on the observations that two GHR antibodies recognized p120 in scale-up experiments and that p120 and the GHR share several characteristics, including their molecular weights, tyrosine phosphorylation upon GH stimulation, interaction with CIS, similar extent of glycosylation as judged by electrophoretic mobility shift after Endo F digestion, comparable mobility shifts upon thrombin digestion, and N-terminal histidine-tagging. The findings, however, do not rule out the possibility that there might be other tyrosine phosphorylated 120 kDa protein(s) that interact with CIS and contribute to the p120 signal, as well as the GHR. Further studies of the association of CIS with the GHR revealed that CIS might selectively interact with multiply tyrosine phosphorylated forms of the GHR, and these tyrosines are likely located near the carboxyl end of the GHR. Overexpression of CIS partially inhibited GH-induced STAT5 phosphorylation in CHO cells. Studies in freshly isolated and GH-deprived (sensitive) adipocytes revealed that the abundance of CIS does not correlate with the termination of the insulin-like effects of GH or the emergence of refractoriness. Neither the association of CIS with the GHR nor the tyrosine phosphorylation status of the GHR, JAK2 and STAT5 appear responsible for refractoriness in adipocytes. These data imply that some negative regulators other than CIS might contribute to the termination of GH-induced insulin-like effects in adipocytes.