<p>Pancreatic cancer is the fourth most lethal cancer and ranks as the eighth most commonly diagnosed cancer worldwide. This is due to its rapid proliferation, strong metastatic potential and its delayed detection. One major risk factor for developing pancreatic cancer is the aggressive inflammatory disease chronic pancreatitis. Chronic inflammation frequently precedes the development of certain pancreatic cancers.</p><p>Inflammation is a protective and necessary process by which the body can alert the immune system of the existence of a wound or infection and mount an immune response to remove the harmful stimuli and start wound healing. The cross-talking of cells of the immune system and infected cells happens through cytokines, soluble proteins that activate and recruit other immune cells to increase the system’s response to the pathogen. Failure to resolve the injury can result in persistent cytokine production that in turn allows a cell that is damaged or altered to survive when in normal conditions it would be killed. Inflammation is thought to create a microenvironment that facilitates the initiation and/or growth of pancreatic cancer cells.</p><p>Cytokines use two important kinases for their signaling: Janus Kinases (JAKs) and Signal Transducers and Activators of Transcription (STATs). The JAKs are activated upon the binding of cytokines to their corresponding receptors. When activated, the JAKs activate STATs through tyrosine phosphorylation. The STATs transduce signals to the nucleus of the cells to induce expression of critical genes essential in normal physiological cellular events such as differentiation, proliferation, cell survival, apoptosis and angiogenesis. STAT3 (a member of the STAT family) is constitutively activated in some pancreatic cancers, promoting cell cycle progression, cellular transformations and preventing apoptosis. Therefore, STAT3 is a promising target for cancer treatment. Novel therapies that inhibit STAT3 activity in cancers are urgently needed. Natural products are a very good resource for the discovery of new drugs against pancreatic cancer.</p><p>Covering more than 70% of the Earths surface, The Ocean is an excellent source of bioactive natural products. Harbor Branch Oceanographic Institute’s Center for Marine Biomedical and Biotechnology Research (HBOI-CMBBR) situated in Florida, aims to find new marine natural products useful in disease prevention and drug therapy. Their current focus is to look for novel treatments for preventing both the formation of new pancreatic tumors and the metastasis of existing tumors.</p><p>The hypothesis of this degree project was that novel inhibitors of STAT3 useful in the treatment of pancreatitis and/or pancreatic cancer could be found from marine-natural products. The first specific aim of this degree project was to set up an assay to identify bioactive marine natural products as inhibitors of inflammation. Furthermore the assay was validated using a commercially available inhibitor of inflammation (Cucurbitacin I). The last aim was to further validate the assay by screening pure compounds and peak library material from the HBOI marine specimen collection.</p><p>At the end of the experimentation time, the assay still was not set-up as there were difficulties in proper cell culture techniques and the cell line did not respond as advertised. While the results were not as expected, the work performed resulted in familiarization with research laboratory practices and increased laboratory skills. Moreover, the results from the assays point to future directions to accomplish this project.</p> / Development of a screening assay for inhibitors of inflammation useful against pancreatic cancer

Helicobacter pylori (H. pylori) is a human-specific gastric pathogen which is responsible for a spectrum of diseases ranging from superficial gastritis to gastric and duodenal ulceration, and which is also highly associated with gastric cancer. The pathogenesis of severe gastric disorders caused by H. pylori is multifactorial and involves complex interactions between the microbe and the gastric mucosa. H. pylori expresses several adhesion proteins. These molecules have important roles in the establishment of persistent infection and chronic inflammation, which cause tissue damage. The aim of this thesis was to study the attachment of this bacterium to human gastric epithelium, mediated by blood group antigens in both health and disease. One of the bestcharacterized H. pylori adhesins is the histo-blood group antigen binding adhesin (BabA), which binds specifically to the Lewis b antigen (Leb) in the gastric mucosa. A protective mucus layer lines the stomach. The mucosal glycosylation patterns (GPs) vary between different cell lineages, different locations along the gastrointestinal (GI) tract and different developmental stages. In addition, GPs undergo changes during malignant transformation. MUC5AC is a mucin molecule produced by the surface epithelium. Three distinctly different types of human gastrointestinal tissue were studied by bacterial adherence analysis in situ. MUC5AC is the most important carrier of Leb and the new results demonstrate that it forms major receptors for H. pylori adherence. By analysing an H. pylori babA-deletion mutant, a novel adhesin-receptor binding mode was found. Surprisingly, the mutant bound efficiently to both human gastric mucosa and to gastric mucosa of Leb transgenic mice. The sialylated and fucosylated blood group antigen, sialyl-dimeric-Lewis x (sdiLex), was structurally identified as the new receptor. A positive correlation was found between adherence of H. pylori to sialyl-Lewis x (sLex) and elevated levels of inflammation response in the human gastric mucosa. These results were supported by detailed analysis of sialylated and fucosylated blood group antigen glycosylation patterns and, in addition, in situ bacterial adherence to gastric mucosa of experimentally challenged Rhesus monkey. The cognate sialic acid-binding adhesin (SabA) was purified by the retagging technique, and the corresponding sabA-gene was identified. H. pylori lipopolysaccharide (LPS) contains various Lewis blood group antigens such as Lewis x (Lex) and Lewis y (Ley). Additional bacterial adherence modes, which are independent of the BabA and/or SabA adhesins, could possibly be mediated by Lex interactions. Adherence of a clinical isolate and its corresponding Lex mutant to human gastric mucosa with various gastric pathologies was studied in situ. The results suggest that H. pylori LPS plays a distinct but minor role in promotion of bacterial adhesion. Taken together, the results suggest mechanisms for continuous selection of H. pylori strains, involving capacity to adapt to changes in the local environment such as shifts in cell differentiation and associated glycosylation patterns. Adherence of H. pylori is dependent on both the BabA and the SabA adhesin. Multi-step dependent attachment mechanisms may direct the microbes to distinct ecological niches during persistent infections, driving the chronic inflammation processes further toward the development of peptic ulcer disease and/or malignant transformation. Key words: H. pylori, BabA, adhesin, Lewis b, MUC5AC, sialyl-dimeric-Lewis x, chronic inflammation, SabA, Lewis x, LPS.

Evidências sugerem o envolvimento de um estado de inflamação crônica de baixo grau na fisiopatologia do transtorno bipolar (TB). Os estudos apresentados nesta tese tiveram como objetivo explorar o papel da inflamação crônica nos mecanismos fisiopatológicos do TB através da avaliação dos níveis séricos de proteína C-reativa (PCR). A PCR é um marcador de inflamação sistêmica comumente utilizado na prática clínica, sendo considerado fator de risco para várias patologias, incluindo câncer e doença cardiovascular. O primeiro artigo, através de um estudo de meta-análise, teve como objetivo avaliar o tamanho de efeito da associação entre níveis de PCR em pacientes bipolares nas diferentes fases de humor (n=730) comparado a indivíduos controles (n=888). Pacientes bipolares apresentaram níveis de PCR significativamente elevados em comparação ao grupo controle, com moderado tamanho de efeito (effect size, ES = 0.39; 95% IC, 0.24 – 0.55; P < 0.0001). Níveis de PCR foram significativamente maiores em pacientes maníacos (ES = 0.73; 95% IC, 0.44 – 1.02; P < 0.001) e em eutímicos (ES = 0.26; 95% IC, 0.01 – 0.51; P = 0.04). O segundo artigo se propôs a revisar dados da literatura relacionados a biomarcadores periféricos potencialmente implicados na progressão do TB. Pacientes em diferentes estágios do TB apresentaram níveis alterados de marcadores de estresse oxidativo, neurotrofinas e de inflamação, incluindo a PCR, o que reforça a hipótese da inflamação crônica exercer um papel importante na fisiopatologia do TB. Em seguida, considerando a abordagem multidimensional no TB, o terceiro artigo avaliou a reatividade emocional como uma dimensão relevante para caracterizar pacientes bipolares apresentando sintomas subclínicos de humor durante a fase de remissão (N=613). Apesar de todos pacientes estarem em remissão, a maioria deles (68%) apresentou reatividade emocional anormal (hipo ou hiper-reatividade emocional). Esse estudo avaliou, também, o funcionamento psicossocial nesses pacientes e os níveis de PCR ultra-sensível como um possível marcador objetivo de hiper-reatividade emocional no TB. Os pacientes com hiper-reatividade emocional, em comparação aos pacientes com hipo- ou normal reatividade emocional, apresentaram prejuízo cognitivo e níveis de PCR significativamente mais elevados (P < 0.001). Esses resultados provêm de um estudo transversal e, portanto, conclusões sobre causalidade dessas associações não podem ser inferidas, já que outros fatores, além dos níveis de PCR, podem também contribuir para o estado inflamatório crônico observado nesses pacientes. Em suma, os resultados desta tese sugerem que a inflamação crônica de baixo grau, evidenciada pelas alterações nos níveis de PCR, parece estar implicada na fisiopatologia e na progressão do TB. Novas intervenções terapêuticas com alvo em mecanismos inflamatórios e na modulação dos níveis de PCR devem ser priorizados em estudos futuros. / Evidence suggests that chronic low-grade inflammation appears to be involved in the pathophysiology of bipolar disorder (BD). The studies presented in this thesis aimed at exploring the role of chronic inflammation in the BD pathophysiological mechanisms by assessing serum levels of C-reactive protein (CRP). CRP is a marker of low-grade inflammation widely used in clinical practice, and a risk factor for cardiovascular and malignant diseases. The first article, a meta-analysis, aimed at evaluating the effect size of the association between CRP levels in bipolar patients (n=730) compared to healthy subjects (n=888). Overall, CRP levels were significantly elevated in patients with BD versus controls (effect size, ES = 0.39; 95% CI, 0.24 to 0.55; P < .0001). CRP levels were significantly higher in manic (ES = 0.73; 95% CI, 0.44 to 1.02; P < 0.001) and euthymic (ES = 0.26; 95% CI, 0.01 to 0.51; P = 0.04). The second paper aimed at reviewing the scientific literature regarding peripheral biomarkers potentially implicated in the progression of BD. Bipolar patients within different disease’s stages presented altered levels of oxidative stress, neurotrophins and inflammatory markers, including PCR. These findings reinforce the hypothesis of the potential role of the chronic inflammation in BD pathophysiology. Regarding the multidimensional approach in BD, the third article assessed emotional reactivity as a major dimension for better characterizing remitted bipolar patients with subthreshold mood symptoms (N=613). Although all patients were in remission, most of them (68%) showed abnormal emotional reactivity (hipo- or hyper-reactivity). In addition, this study assessed the psychosocial functioning in these patients as well as the levels of high-sensitivty PCR (hsCRP) as an objective marker of emotional hyper-reactivity in BD. Patients with emotional hyper-reactivity had higher levels of PCR and cognitive impairment compared to patients with emotional hypo or normal emotional reactivity (P < 0.001). This was a crosssectional study of emotional reactivity, hsCRP levels and functional status in remitted bipolar patients, and no conclusions regarding the causality of these associations can be substantiated. Others factors could also be contributing to the chronic inflammatory state in these patients. In conclusion, the results of this thesis suggest that low-grade chronic inflammation, as evidenced by alteration in CRP levels, may be implicated in the pathophysiology as well as in the BD progression. Novel therapeutic interventions targeting inflammatory mechanisms and the modulation of CRP levels should be prioritized in future studies.

Introdução: Artrite reumatoide é uma doença inflamatória crônica associada a alterações no metabolismo proteico e energético. Objetivos: Investigar a preferência alimentar durante o desenvolvimento da inflamação crônica em ratas com artrite induzida por colágeno. Métodos: Ratas Wistar fêmeas foram alocadas em dois grupos: controle (CO, n=10) e artrite induzida por colágeno (CIA; n=11) e expostas simultaneamente a quatro diferentes dietas (padrão, hipercalórica, hiperlipidica e hiperproteica). Durante o período experimental foi observado dados clínicos da doença, consumo alimentar, peso corporal e parâmetros bioquímicos, bem como, peso muscular esquelético ao final do experimento. Os testes estatísticos realizados foram ANOVA de duas vias e test-t e nível de significância estabelecido para estes testes foi de 95%. Resultados: Os animais com artrite induzida demostram redução voluntária da ingestão total de alimento, redução do peso corporal e redução da relação sarcossomática quando comparados aos animais controles. Ainda, o grupo artrite aumentou o relativo consumo de dieta hiperproteíca, diminuiu as concentrações séricas de creatinina, triglicerídeos e glicose. Conclusão: Condições inflamatórias crônicas como a artrite reumatoide causam alterações no metabolismo energético e proteíco e estas alterações fisiológicas podem induzir a uma mudança na escolha alimentar. / Background: Rheumatoid arthritis is a chronic inflammatory disease associated with changes in energy and protein metabolism. Objective: To investigate food preferences during the development of chronic inflammation in rats with collagen-induced arthritis (CIA). Methods: Female Wistar rats were separated into two groups, control (CO, n=10) and CIA (n=11), and were simultaneously exposed to four different diets (standard, hypercaloric, hyperlipidic and hyperproteic). During the experimental period was observed clinical evidence of disease, food intake, body weight and biochemical parameters, as well as skeletal muscle weight at the end of the experiment. Statistical tests were two-away ANOVA and t-test and significance level for these tests was 95%. Results: CIA animals demonstrate voluntary reduction in total food intake, reduced body weight and reduced relative muscle weight compared to CO animals. In addition, CIA animals increased relative comsuption of high protein diet, decreased serum concentrations creatinine, triglycerides and glucose. Conclusion: Chronic inflammatory conditions such as rheumatoid arthritis cause changes in protein and energy metabolism, and these physiological alterations may induce a change in food choice.

Evidências sugerem o envolvimento de um estado de inflamação crônica de baixo grau na fisiopatologia do transtorno bipolar (TB). Os estudos apresentados nesta tese tiveram como objetivo explorar o papel da inflamação crônica nos mecanismos fisiopatológicos do TB através da avaliação dos níveis séricos de proteína C-reativa (PCR). A PCR é um marcador de inflamação sistêmica comumente utilizado na prática clínica, sendo considerado fator de risco para várias patologias, incluindo câncer e doença cardiovascular. O primeiro artigo, através de um estudo de meta-análise, teve como objetivo avaliar o tamanho de efeito da associação entre níveis de PCR em pacientes bipolares nas diferentes fases de humor (n=730) comparado a indivíduos controles (n=888). Pacientes bipolares apresentaram níveis de PCR significativamente elevados em comparação ao grupo controle, com moderado tamanho de efeito (effect size, ES = 0.39; 95% IC, 0.24 – 0.55; P < 0.0001). Níveis de PCR foram significativamente maiores em pacientes maníacos (ES = 0.73; 95% IC, 0.44 – 1.02; P < 0.001) e em eutímicos (ES = 0.26; 95% IC, 0.01 – 0.51; P = 0.04). O segundo artigo se propôs a revisar dados da literatura relacionados a biomarcadores periféricos potencialmente implicados na progressão do TB. Pacientes em diferentes estágios do TB apresentaram níveis alterados de marcadores de estresse oxidativo, neurotrofinas e de inflamação, incluindo a PCR, o que reforça a hipótese da inflamação crônica exercer um papel importante na fisiopatologia do TB. Em seguida, considerando a abordagem multidimensional no TB, o terceiro artigo avaliou a reatividade emocional como uma dimensão relevante para caracterizar pacientes bipolares apresentando sintomas subclínicos de humor durante a fase de remissão (N=613). Apesar de todos pacientes estarem em remissão, a maioria deles (68%) apresentou reatividade emocional anormal (hipo ou hiper-reatividade emocional). Esse estudo avaliou, também, o funcionamento psicossocial nesses pacientes e os níveis de PCR ultra-sensível como um possível marcador objetivo de hiper-reatividade emocional no TB. Os pacientes com hiper-reatividade emocional, em comparação aos pacientes com hipo- ou normal reatividade emocional, apresentaram prejuízo cognitivo e níveis de PCR significativamente mais elevados (P < 0.001). Esses resultados provêm de um estudo transversal e, portanto, conclusões sobre causalidade dessas associações não podem ser inferidas, já que outros fatores, além dos níveis de PCR, podem também contribuir para o estado inflamatório crônico observado nesses pacientes. Em suma, os resultados desta tese sugerem que a inflamação crônica de baixo grau, evidenciada pelas alterações nos níveis de PCR, parece estar implicada na fisiopatologia e na progressão do TB. Novas intervenções terapêuticas com alvo em mecanismos inflamatórios e na modulação dos níveis de PCR devem ser priorizados em estudos futuros. / Evidence suggests that chronic low-grade inflammation appears to be involved in the pathophysiology of bipolar disorder (BD). The studies presented in this thesis aimed at exploring the role of chronic inflammation in the BD pathophysiological mechanisms by assessing serum levels of C-reactive protein (CRP). CRP is a marker of low-grade inflammation widely used in clinical practice, and a risk factor for cardiovascular and malignant diseases. The first article, a meta-analysis, aimed at evaluating the effect size of the association between CRP levels in bipolar patients (n=730) compared to healthy subjects (n=888). Overall, CRP levels were significantly elevated in patients with BD versus controls (effect size, ES = 0.39; 95% CI, 0.24 to 0.55; P < .0001). CRP levels were significantly higher in manic (ES = 0.73; 95% CI, 0.44 to 1.02; P < 0.001) and euthymic (ES = 0.26; 95% CI, 0.01 to 0.51; P = 0.04). The second paper aimed at reviewing the scientific literature regarding peripheral biomarkers potentially implicated in the progression of BD. Bipolar patients within different disease’s stages presented altered levels of oxidative stress, neurotrophins and inflammatory markers, including PCR. These findings reinforce the hypothesis of the potential role of the chronic inflammation in BD pathophysiology. Regarding the multidimensional approach in BD, the third article assessed emotional reactivity as a major dimension for better characterizing remitted bipolar patients with subthreshold mood symptoms (N=613). Although all patients were in remission, most of them (68%) showed abnormal emotional reactivity (hipo- or hyper-reactivity). In addition, this study assessed the psychosocial functioning in these patients as well as the levels of high-sensitivty PCR (hsCRP) as an objective marker of emotional hyper-reactivity in BD. Patients with emotional hyper-reactivity had higher levels of PCR and cognitive impairment compared to patients with emotional hypo or normal emotional reactivity (P < 0.001). This was a crosssectional study of emotional reactivity, hsCRP levels and functional status in remitted bipolar patients, and no conclusions regarding the causality of these associations can be substantiated. Others factors could also be contributing to the chronic inflammatory state in these patients. In conclusion, the results of this thesis suggest that low-grade chronic inflammation, as evidenced by alteration in CRP levels, may be implicated in the pathophysiology as well as in the BD progression. Novel therapeutic interventions targeting inflammatory mechanisms and the modulation of CRP levels should be prioritized in future studies.

Conselho Nacional de Pesquisa e Desenvolvimento Científico e Tecnológico - CNPq / Neuropsychiatric diseases, as bipolar disorder (BD), have a very complex pathophysiology. Several times the diagnostic and to choose a correct treatment are difficult. Currently, have been developed studies related to mechanisms that can be associated with specific biomarkers present on mental illness. Some studies are describing an association between neuropsychiatric diseases and mitochondrial dysfunction and consequent cellular modifications. Additionally, some psychiatric illnesses are been associated with chronic inflammatory activation via pro-inflammatory cytokines production. In this sense, the search for drug development to treat psychiatric illness is very necessary. Euterpe oleracea, known as açaí, is an Amazonian fruit and a potential candidate for neuropharmacological study due to chemical matrix, including a variety of bioactive compounds with biological effects. There are molecules that could act at mitochondrial function and neurophysiology. Objective: to perform a literature review about the mitochondrial dysfunction impact at bipolar disorder and chemically analyse and evaluate the neupharmacological in vitro effect of açaí extract through mitochondrial function modulation and oxidative and inflammatory metabolisms. Methodology: initially we produced a review about the association between BD and cellular mitochondrial metabolism based on scientific articles published at last 20 years in different journals found at PUBMED-MEDLINE of American library. This review helped to create the ecperimental in vitro design of this study. After, we performed an in vitro experimental research using a cell line SH-SY5Y exposed to rotenone. SH-SY5Y cells were obtained from American Type Culture Collection (ATCC®), and treated with freeze-dried hydroalcoholic açaí extract which was analyzed by high performance liquid chromatography. Initially the açaí effect at cell viability was measured through different concentration-effect curves. We also induced mitochondrial complex I dysfunction using rotenone at 5, 15 and 30 nM. Before and after rotenone exposition 5 μg/mL of açaí extract was added to evaluate the potential effect of açaí to prevent and reverse rotenone damages. After all treatments were performed experimental assays to evaluate the mitochondrial transport chain, the mitochondrial complex I enzyme activity, the protein and gene expression of NDUFS7, S8, V1 and V2 of complex I, the total levels of reactive oxygen species and lipid peroxidation. For the third study we used RAW 264.7 macrophages from ATCC. Cells were activated with PHA and exposed to different concentrations of açaí extract during 72h. Using the most anti-inflammatory effective concentration of açaí extract, we developed all another experimental assays to evaluate oxidative metabolism parameters, cell cycle and protein expression of cytokines and NLRP3-inflammasome. The statistical analysis was performed by one way anova followed by Tukey or Dunnett post hoc. Results: the obtained results were organized in three scientific articles. The review paper was published at Canadian Journal of Psychiatry and indicated the relevance of studies that dentify plants with potential properties to modulate mitochondrial complex I. The obtained results of second study were published at Oxidative and Cellular Longevity journal where we observed that hydroalcoholic açaí extract presented high levels of orientin (8,05±0,03mg/g), p-cumaric acid (3,52±0,01mg/g) and apigenin (3,49±0,01mg/g). In vitro results related to mitochondrial dysfunction and oxidative stress showed that the most effective concentration of açaí extract was 5μg/mL after 48h of incubation. We observed that açaí extract at both experimental models presented protective effects under mitochondrial complex I and this effect was due to an increased protein and gene expression mainly for NDUFS7 and S8 subunits that form the active region of this complex. Despite, was observed a decreased rate of reactive oxygen species and of lipid peroxidation under açaí exposition. Results of third study were organized in a manuscript that will be submitted for publication at Inflammation Research journal. It was observed the anti-inflammatory activity of açaí in macrophage PHA-induced, where the effective concentration able to reduce 50% of cellular proliferation (EC50) 1 μg/mL. Complementary assays showed that this specific concentration is capable to decrease inflammatory markers as proliferation rate, cell cycle, ROS levels and nitric oxide. Açaí also reduced pro-inflammatory cytokines levels (IL-1β, IL-6, TNFα. INFγ), and the inflammasome NLRP3, increasing IL-10 levels. Conclusion: the results obtained until this moment are suggesting that açaí has neuropharmacological activity and is a potential candidate for drug development or food supplement for psychiatric diseases treatment, especially BD which is related to mitochondrial complex I dysfunction and chronic inflammatory activation. / As doenças neuropsiquiátricas, como o transtorno bipolar, possuem fisiopatologia bastante complexa. Muitas vezes o diagnóstico e a escolha de um tratamento eficaz são de difícil realização. Atualmente vêm sendo desenvolvidos estudos relacionados aos mecanismos causais e que podem ser direcionados a descoberta de novos biomarcadores característicos de doenças mentais. Alguns estudos descrevem a existência de uma forte associação entre doenças neuropsiquiátricas e disfunção mitocondrial e consequentes alterações celulares. Adicionalmente, algumas doenças psiquiátricas estão também associadas à inflamação crônica, via produção de citocinas pró-inflamatórias. Dessa forma, a busca pelo desenvolvimento de novos fármacos para o tratamento de doenças psiquiátricas é de grande necessidade. A Euterpe oleracea, espécie conhecida popularmente como açaí, é uma fruta amazônica potencial candidata a estudos neurofarmacológicos devido a sua constituição química que inclui uma variedade de moléculas bioativas que poderiam atuar tanto melhorando a função mitocondrial e a resposta inflamatória. Objetivo: realizar revisão da literatura sobre o impacto da disfunção mitocondrial no transtorno bipolar, caracterizar quimicamente e avaliar o potencial efeito neurofarmacológico in vitro do extrato de açaí na modulação da função mitocondrial, do metabolismo oxidativo e inflamatório. Metodologia: inicialmente foi produzido um estudo de revisão teórico-literário sobre a associação entre o transtorno bipolar e o metabolismo mitocondrial celular baseado em artigos científicos publicados nos últimos 20 anos em revistas indexadas no PUBMED-MEDLINE da Biblioteca dos Estados Unidos da América. Esta revisão auxiliou na concepção do delineamento da parte experimental do trabalho. A pesquisa experimental in vitro foi feita utilizando-se a linhagem comercial SH-SY5Y expostas a rotenona. As células SH-SY5Y foram obtidas da American Type Culture Collection (ATCC®) e foram tratadas com um extrato hidroalcólico de açaí liofilizado, no qual as principais substâncias bioativas foram quantificadas por Cromatografia Líquida de Alta Eficiência (CLAE). O efeito do açaí sobre a viabilidade celular foi avaliado através de diferentes curvas concentração-efeito. Foi induzida disfunção no complexo I mitocondrial através do uso da rotenona nas concentrações de 5, 15 e 30 nM. Antes ou após o tratamento com rotenona, foi adicionado o extrato de açaí (5 μg/mL) a fim de avaliar a capacidade de prevenção e/ou reversão dos efeitos da rotenona. Após os tratamentos, foram desenvolvidos ensaios experimentais de avaliação da cadeia de transporte de elétrons, da atividade enzimática do complexo I mitocondrial, da expressão proteica e gênica das subunidades NDUFS7, S8, V1 e V2, da taxa total de espécies reativas de oxigênio e da lipoperoxidação. Já para o terceiro estudo, foi utilizada linhagem celular de macrófagos RAW 264.7, também obtidos da ATCC. Tais células foram ativadas com fitohemaglutinina (PHA) e expostas a diferentes concentrações de extrato de açaí durante 72h. Com base na concentração mais efetiva do extrato (1 μg/mL) frente à inflamação, foram realizadas as avaliações de parâmetros do metabolismo oxidativo, do ciclo celular e da expressão de citocinas inflamatórias e do inflamassoma NLRP3, via diferentes métodos experimentais. Os resultados foram estatisticamente comparados por análise de variância de uma via seguida de teste post hoc de Tukey ou Dunnet. Resultados: os resultados obtidos foram organizados sob a forma de três artigos científicos. A revisão de literatura foi publicada no Canadian Journal of Psychiatry e indicou a relevância de estudos que identifiquem plantas com potencial propriedade de modular o complexo I mitocondrial. Os resultados obtidos no segundo estudo foram publicados na revista Oxidative Medicine and Cellular Longevity onde se observou que o extrato hidroalcoólico de açaí apresentou níveis elevados das seguintes moléculas: orientina (8,05±0,03 mg/g), ácido p-cumárico (3,52±0,01 mg/g) e apigenina (3,49±0,01 mg/g). Os resultados in vitro relacionados à disfunção mitocondrial e estresse oxidativo mostraram que a concentração mais efetiva do extrato hidroalcoólico de açaí que aumentou a viabilidade celular foi a de 5 μg/mL após 48h de incubação. Foi observado que o extrato de açaí em ambos os modelos experimentais apresentou efeito protetor sobre o complexo I mitocondrial e este efeito deveu-se ao aumento da expressão proteica e gênica principalmente das subunidades NDUFS7 e S8 que constituem a região de atividade deste complexo. Além disso, foi evidenciada redução da taxa total de espécies reativas de oxigênio (EROs) e diminuição dos níveis de peroxidação lipídica. Os resultados do terceiro estudo foram organizados sob a forma de um manuscrito a ser submetido à revista Inflammation Research. Nele foi observada atividade anti-inflamatória do açaí em macrófagos RAW PHA-ativados, sendo a concentração estimada para diminuir em 50% a resposta inflamatória (EC50) de 1 μg/mL. Testes complementares mostraram que esta concentração foi capaz diminuir marcadores inflamatórios como taxa de proliferação celular, ciclo celular, níveis de EROs e de óxido nítrico. O açaí também reduziu os níveis de citocinas pró-inflamatórias (IL-1β, IL-6, TNFα. INFγ) e relacionadas ao inflamassoma NLRP3, e também aumentou os níveis da citoticina anti-inflamatória IL-10. Conclusão: os resultados obtidos sugerem que o açaí possui atividade neurofarmacológica e que é um potencial candidato no desenvolvimento de novos fármacos ou suplementos alimentares direcionados ao tratamento de doenças psiquiátricas, em especial o transtorno bipolar que está relacionado à disfunção do complexo I mitocondrial e à ativação inflamatória crônica.

Introdução: Artrite reumatoide é uma doença inflamatória crônica associada a alterações no metabolismo proteico e energético. Objetivos: Investigar a preferência alimentar durante o desenvolvimento da inflamação crônica em ratas com artrite induzida por colágeno. Métodos: Ratas Wistar fêmeas foram alocadas em dois grupos: controle (CO, n=10) e artrite induzida por colágeno (CIA; n=11) e expostas simultaneamente a quatro diferentes dietas (padrão, hipercalórica, hiperlipidica e hiperproteica). Durante o período experimental foi observado dados clínicos da doença, consumo alimentar, peso corporal e parâmetros bioquímicos, bem como, peso muscular esquelético ao final do experimento. Os testes estatísticos realizados foram ANOVA de duas vias e test-t e nível de significância estabelecido para estes testes foi de 95%. Resultados: Os animais com artrite induzida demostram redução voluntária da ingestão total de alimento, redução do peso corporal e redução da relação sarcossomática quando comparados aos animais controles. Ainda, o grupo artrite aumentou o relativo consumo de dieta hiperproteíca, diminuiu as concentrações séricas de creatinina, triglicerídeos e glicose. Conclusão: Condições inflamatórias crônicas como a artrite reumatoide causam alterações no metabolismo energético e proteíco e estas alterações fisiológicas podem induzir a uma mudança na escolha alimentar. / Background: Rheumatoid arthritis is a chronic inflammatory disease associated with changes in energy and protein metabolism. Objective: To investigate food preferences during the development of chronic inflammation in rats with collagen-induced arthritis (CIA). Methods: Female Wistar rats were separated into two groups, control (CO, n=10) and CIA (n=11), and were simultaneously exposed to four different diets (standard, hypercaloric, hyperlipidic and hyperproteic). During the experimental period was observed clinical evidence of disease, food intake, body weight and biochemical parameters, as well as skeletal muscle weight at the end of the experiment. Statistical tests were two-away ANOVA and t-test and significance level for these tests was 95%. Results: CIA animals demonstrate voluntary reduction in total food intake, reduced body weight and reduced relative muscle weight compared to CO animals. In addition, CIA animals increased relative comsuption of high protein diet, decreased serum concentrations creatinine, triglycerides and glucose. Conclusion: Chronic inflammatory conditions such as rheumatoid arthritis cause changes in protein and energy metabolism, and these physiological alterations may induce a change in food choice.

Introdução: Artrite reumatoide é uma doença inflamatória crônica associada a alterações no metabolismo proteico e energético. Objetivos: Investigar a preferência alimentar durante o desenvolvimento da inflamação crônica em ratas com artrite induzida por colágeno. Métodos: Ratas Wistar fêmeas foram alocadas em dois grupos: controle (CO, n=10) e artrite induzida por colágeno (CIA; n=11) e expostas simultaneamente a quatro diferentes dietas (padrão, hipercalórica, hiperlipidica e hiperproteica). Durante o período experimental foi observado dados clínicos da doença, consumo alimentar, peso corporal e parâmetros bioquímicos, bem como, peso muscular esquelético ao final do experimento. Os testes estatísticos realizados foram ANOVA de duas vias e test-t e nível de significância estabelecido para estes testes foi de 95%. Resultados: Os animais com artrite induzida demostram redução voluntária da ingestão total de alimento, redução do peso corporal e redução da relação sarcossomática quando comparados aos animais controles. Ainda, o grupo artrite aumentou o relativo consumo de dieta hiperproteíca, diminuiu as concentrações séricas de creatinina, triglicerídeos e glicose. Conclusão: Condições inflamatórias crônicas como a artrite reumatoide causam alterações no metabolismo energético e proteíco e estas alterações fisiológicas podem induzir a uma mudança na escolha alimentar. / Background: Rheumatoid arthritis is a chronic inflammatory disease associated with changes in energy and protein metabolism. Objective: To investigate food preferences during the development of chronic inflammation in rats with collagen-induced arthritis (CIA). Methods: Female Wistar rats were separated into two groups, control (CO, n=10) and CIA (n=11), and were simultaneously exposed to four different diets (standard, hypercaloric, hyperlipidic and hyperproteic). During the experimental period was observed clinical evidence of disease, food intake, body weight and biochemical parameters, as well as skeletal muscle weight at the end of the experiment. Statistical tests were two-away ANOVA and t-test and significance level for these tests was 95%. Results: CIA animals demonstrate voluntary reduction in total food intake, reduced body weight and reduced relative muscle weight compared to CO animals. In addition, CIA animals increased relative comsuption of high protein diet, decreased serum concentrations creatinine, triglycerides and glucose. Conclusion: Chronic inflammatory conditions such as rheumatoid arthritis cause changes in protein and energy metabolism, and these physiological alterations may induce a change in food choice.

La schizophrénie est une pathologie caractérisée par des symptômes positifs (idées délirantes et hallucinations), des symptômes négatifs (émoussement affectif, alogie, apragmatisme, retrait social) et des symptômes de désorganisation (cognitifs et affectifs). Cette pathologie est également associée à des altérations cognitives, perceptuelles et de la qualité de vie. La physiopathologie de la schizophrénie reste mal connue. Récemment, des travaux ont mis en avant le rôle central des processus inflammatoires chroniques dans la physiopathologie de ce trouble psychiatrique. En particulier, il a été montré que la CRP (Protéine C-Réactive), marqueur inflammatoire chronique aspécifique et facile à doser dans une prise de sang, est augmentée dans la schizophrénie. La CRP est reliée à la symptomatologie clinique et aux altérations cognitives des patients souffrant de schizophrénie. Mais le lien entre altérations perceptuelles et de la qualité de vie et CRP reste à explorer. / Schizophrenia is an illness characterized by positive symptoms (delusions and hallucinations), negative symptoms (reduced emotional expression, alogia, apragmatism, reduced social engagement) and disorganized symptoms (cognitive and affective). This pathology is also associated to cognitive and perceptual alterations and to quality of life alterations. The physiopathology of schizophrenia is still unclear. Recently, papers put forward the central role of chronic inflammatory process in pathophysiology of this psychiatric disorder. In particular, CRP (C-Reactive Protein), a nonspecific marker of chronic inflammation and easy to measure with blood sample, was shown to be increased in schizophrenia. CRP is connected to clinical symptomatology and to cognitive alterations in patients with schizophrenia. However the connection between alterations of perception, quality of life and CRP remains to be explored.

La chromatine est connue pour son rôle dans le maintien de l'identité cellulaire. Des perturbations dans la dynamique de la chromatine sont des événements courants dans les cancers. La structure de la chromatine et sa dynamique sont fortement dépendante des protéines HP1, connues pour être impliquées dans l’extinction de l’hétérochromatine, mais également dans la régulation de l'expression des gènes, la réplication et la réparation des dommages de l'ADN. Afin de mieux caractériser les fonctions d’HP1 chez les mammifères, nous avons étudié les conséquences de l'inactivation de leurs gènes chez la souris. De façon inattendue, nous démontrons que l'inactivation d’HP1a ou d’HP1g conduit à une prédisposition élevée des souris à développer des tumeurs spécifiquement dans le foie. Par conséquent, nous avons établi des modèles murins permettant l'inactivation simultanée d’HP1a/HP1b et HP1a/HP1g spécifiquement dans les hépatocytes. Ces modèles ont montré une augmentation significative de l'incidence du développement des tumeurs dans le foie, ce qui montre que les protéines HP1 sont des suppresseurs spécifiques de tumeurs hépatiques. L'analyse histologique de foies HP1abliverKO a montré des défauts qui ressemblent à ceux observés dans une pathologie connue du foie humain, la stéatohépatite non alcoolique. Afin de caractériser les mécanismes moléculaires sous-jacents ces fonctions des HP1, nous avons analysé le transcriptome de foies de souris âgées de 5 semaines. Ces analyses ont révélé que les gènes sur-exprimés en réponse à l’absence d’HP1ag ou HP1ab sont fortement enrichis en gènes codant pour des membres de la famille de répresseurs de transcription KRAB-ZFP. Ce résultat est intéressant car il est connu que ces répresseurs sont régulés par le corépresseur TRIM28 qui a besoin d’interagir avec HP1 pour remplir ses fonctions. Cela suggère donc une boucle d'autorégulation entre HP1, TRIM28 et KRAB-ZFP. En utilisant des souris exprimant une protéine TRIM28 qui est incapable d'interagir avec HP1 spécifiquement dans les hépatocytes, nous avons démontré que la perturbation de l'interaction entre TRIM28 et HP1 conduit au développement spontané de tumeurs dans le foie et conduit également à une surexpression des mêmes KRAB-ZFP que ceux dérégulée chez les souris HP1abliverKO et HP1agliverKO. L’immunoprécipitation de la chromatine (ChIP) a mis en évidence que TRIM28 et HP1 sont recrutés de façon interdépendante dans les régions 5 'et/ou 3' des gènes de KRAB-ZFP afin de réguler leur expression. Nous avons également observé la dérégulation de certains gènes liés au cancer, comme Tert, Nox4, AR, GPC3 et Arid1a. Ces modifications sont dépendantes de l’isotope d’HP1 inactivé, ce qui reflète les différents mécanismes moléculaires de l’oncogenèse. Afin d'élucider l'impact possible d’HP1 sur l'organisation générale du noyau, j'ai effectué une analyse par immunofluorescence sur cryosections du foie. Nos données suggèrent que les caractéristiques hétérochromatiques constitutives (H3K9me3) sont remplacées par des caractéristiques hétérochromatiques facultatives (H3K27me3) en l'absence de HP1ag et que les foyers péricentriques hétérochromatiques ont une légère tendance à être délocalisés. Enfin, pour mieux comprendre les profils chromosomiques dans la tumeur du foie HP1-dépendante, nous avons effectué une hybridation génomique comparative dans les foies tumoraux. Comme prévu, plusieurs événements de gain et de perte dans les variations du nombre de copies (CNV) dans certaines régions subchromosomales ont été observés, en particulier pour les chromosomes 4, où certains membres de KRAB-ZFP sont touchés. En résumé, nos résultats montrent que les protéines HP1 sont des suppresseurs de tumeur spécifique du foie. Ces données suggèrent également que la fonction principale d’HP1 au sein du foie est de réguler l'activité de TRIM28 et ainsi réguler l'expression et l'activité de répression des KRAB-ZFP et, finalement, l'homéostasie du foie. / Chromatin is known for its essential role in establishment and maintenance of cellular identity. Accordingly, disturbances in chromatin’s dynamics are common events in cancers. Chromatin structure and dynamics is highly dependent upon HP1, small non-histone chromosomal proteins that are known to be involved in heterochromatin silencing but also in gene expression regulation, DNA replication and DNA damage repair. To better characterize HP1 functions in mammals, we have studied the consequences of the inactivation of the corresponding genes in mice. Unexpectedly, we demonstrated that inactivation of either HP1a or HP1g lead to a high predisposition of mice to develop tumors specifically within liver. Hence, we established mice models allowing simultaneous inactivation of HP1a/HP1b and HP1a/HP1g specifically within hepatocytes. These models (HP1abliverKO and HP1agliverKO) displayed a significant increased incidence of tumor development within liver, demonstrating that HP1 are liver specific tumor suppressors. Histological analysis of HP1abliverKO livers showed defects that resembled those observed in a human liver pathology known as nonalcoholic steatohepatitis (NASH) characterized by an increase of steatosis, followed by an increased inflammation and the development of fibrosis that finally leads to tumors in old animals. In the case of HP1agliverKO mice, even though inflammation and tumor development were observed, this was not linked with steatosis, strongly suggesting that the underlying mechanisms are specific of each HP1 isoform. In order to reveal molecular mechanisms, we did expression analysis in the liver of 5 weeks old mice, which revealed a strong enrichment of genes encoding for members of the KRAB-ZFP of transcriptional repressors family within genes regulated by HP1ag or HP1ab. This result is of particular interest since it is known that these repressors are regulated by the corepressor TRIM28 which has been shown to require its interaction with HP1 to fulfill its functions suggesting a loop of auto-regulation between HP1, TRIM28 and KRAB-ZFP. Using mice expressing a TRIM28 protein unable to interact with HP1 specifically within hepatocytes, we demonstrated here that the disruption of the interaction between TRIM28 and HP1 lead to spontaneous development of tumors within liver and to over-expression of the same KRAB-ZFP as those deregulated in HP1abliverKO and HP1agliverKO mice. Chromatin immunoprecipitation (ChIP) pinpointed that TRIM28 and HP1 are inter-dependently recruited to the 5’ and/or 3’ ends of KRAB-ZFP genes to regulate their expression. We also observed deregulation of some cancer related genes, such as Tert (Telomerase reverse transcriptase), Nox4 (NADPH oxidase 4), AR (Androgen receptor), GPC3 (Glypican3), Arid1a (AT-Rich Interaction Domain 1A), and interestingly these alterations are depended upon the inactivated HP1 isotype, reflecting distinct molecular oncogenesis. In order to elucidate the possible impact of HP1 on global organization of the nucleus, I performed immunofluorescence analysis in the liver cryosections of 5 weeks old mice. Our data suggest that constitutive heterochromatic features (H3K9me3) are replaced by facultative heterochromatic features (H3K27me3) in absence of HP1ag and that heterochromatic pericentric foci tend to slightly be delocalized. Finally, to better understand the chromosomal rearrangements profile in HP1-dependent liver tumor, we performed Comparative genomic hybridization (CGH) in old tumoral liver. As anticipated, multiple events of gain and loss in copy number variations (CNV) in subchromosomal regions were observed, especially for chromosomes 4, where some KRAB-ZFP members are affected. Altogether, our data demonstrated that HP1 are liver-specific tumor suppressor. They also suggest that HP1 main function within liver is to regulate TRIM28 activity and thereby regulate the expression and repression activity of KRAB-ZFP and ultimately liver homeostasis.