Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2015-03-26T13:52:57Z No. of bitstreams: 2 Tese - Delson Jose da Silva - 2014.pdf: 4417980 bytes, checksum: 09ba5f6cc0d7b39ded36ffee59e305f4 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2015-03-26T15:48:14Z (GMT) No. of bitstreams: 2 Tese - Delson Jose da Silva - 2014.pdf: 4417980 bytes, checksum: 09ba5f6cc0d7b39ded36ffee59e305f4 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2015-03-26T15:48:14Z (GMT). No. of bitstreams: 2 Tese - Delson Jose da Silva - 2014.pdf: 4417980 bytes, checksum: 09ba5f6cc0d7b39ded36ffee59e305f4 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2014-08-29 / Fundação de Amparo à Pesquisa do Estado de Goiás - FAPEG / Parkinson’s disease (PD) is as a neurodegenerative disorder caused by neuron loss in the substantia nigra, which produces dopamine. Evidences suggest that several inflammatory cytokines are enhanced in the brain and blood of patients presenting with PD. These cytokines might be induced by Toll-like receptor (TLR) activation. In peripheral blood, monocytes express TLR and may participate in the immunopathogenicity of neurodegenerative diseases. The objectives of this work were: carry out a literature review about neuroinflammation in PD; assess possible alterations in production of inflammatory cytokines in blood cultures of patients presenting with PD activated by TLR agonists; evaluate the percentages of the two main monocyte subpopulations, as well as TLR2 and TLR4 expression in these subpopulations in peripheral blood of patients presenting with PD. Patients presenting with PD (n = 31) and healthy individuals (n = 31), matched by gender and age, were evaluated and the patients were assessed regarding the severity of their neurological and psychiatric symptoms using the Hoen & Yahr scale (H&Y) and the Unified Parkinson’s Disease Rating Scale (UPDRS). Blood cultures were activated with TLR2 agonists (Pam3Cys), TLR4 (LPS), or TLR7/8 (R848). Cytokines (TNF, IL-1β, IL-6, IL-12p70, and IL-10) were Abstract 12 quantified in the serum and supernatant of blood cultures using Cytometer bead array. Monocytes (CD14+CD16– and CD14+CD16+) and TLR2 and TLR4 expression were identified using flow cytometry. Cytokine concentrations in the serum of patients and controls were similar and no significant association was found between cytokine concentrations and UPDRS scores. However, after activation of blood cultures of patients, a significant decreased response to TLR2 (TNF, IL-1β, IL-6, IL-10) and TLR7/8 (IL-6) agonists was observed. No correlation was observed between the concentrations of cytokines induced by TLR2 or TLR7/8 agonists and UPDRS scores. The percentages of monocytes CD14+CD16– and CD14+CD16+ did not significantly differ between patients and controls, and no alterations in TLR2 or TLR4 expressions were detected in these monocyte subpopulations in patients. The results indicate that leukocytes, especially monocytes, of patients presenting with PD show decreased capacity to respond to the activation via TLR2. This decrease may be associated with the previous activation of TLR2 in vivo, making the cells tolerant to new stimuli ex vivo. Assessing the activation of monocytes in peripheral blood, via TLR, may help the evaluation of the neurodegenerative/ neuroinflammatory process in PD, contributing to a better understanding of the pathophysiology of this disease. / A doença de Parkinson (DP) é uma afecção neurodegenerativa que ocorre devido à perda neuronal na substância negra, produtora de dopamina. Evidências sugerem que várias citocinas inflamatórias estão aumentadas no cérebro e no sangue de pacientes com DP. Essas citocinas podem ser induzidas por ativação dos receptores similares a Toll (Toll-like receptors, TLR). No sangue periférico, os monócitos expressam TLR e podem participar na imunopatogenia de doenças neurodegenerativas. Os objetivos deste trabalho foram: realizar uma revisão de literatura sobre neuroinflamação na DP; avaliar possíveis alterações na produção de citocinas inflamatórias em hemoculturas de pacientes com DP ativada por agonistas de TLR; avaliar as porcentagens das duas principais subpopulações de monócitos e a expressão de TLR2 e TLR4 nestas subpopulações no sangue periférico de pacientes com DP. Foram avaliados 31 pacientes com DP e 31 indivíduos sadios, pareados por gênero e idade, sendo os pacientes avaliados quanto à gravidade dos sintomas neurológicos e psiquiátricos utilizando-se as escalas H&Y (Hoen & Yahr scale) e UPDRS (Unified Parkinson’s Disease Rating Scale). As hemoculturas foram ativadas com agonistas de TLR2 (Pam3Cys), TLR4 (LPS) ou TLR7/8 (R848). As citocinas (TNF, IL-1β, IL-6, IL-12p70 e IL-10) foram quantificadas no soro e nos sobrenadantes das culturas utilizando citometria (Cytometer bead array). Os monócitos (CD14+CD16– e CD14+CD16+) e a expressão de TLR2 e TLR4 nestes foram identificados por citometria de fluxo. As concentrações de citocinas nos soros de pacientes e controles foram similares e não houve Resumo 10 associação significativa entre as concentrações das citocinas e os escores da UPDRS. No entanto, após ativação das hemoculturas dos pacientes, foi observada significativa resposta diminuída aos agonistas de TLR2 (TNF, IL- 1β, IL-6, IL-10) e de TLR7/8 (IL-6). Não foi observada correlação entre as concentrações de citocinas induzidas pelos agonistas de TLR2 ou de TLR7/8 e os escores de UPDRS. As porcentagens dos monócitos CD14+CD16– e CD14+CD16+ não diferiram significativamente entre os pacientes e os controles, e não foram detectadas alterações nas expressões de TLR2 ou TLR4 nestas subpopulações de monócitos nos pacientes. Os resultados indicam que os leucócitos, especialmente os monócitos, de pacientes com DP apresentam diminuída capacidade de resposta à ativação via TLR2. Essa diminuição pode estar associada à ativação prévia de TLR2 in vivo, tornando as células tolerantes a novos estímulos ex vivo. Avaliar a ativação de monócitos no sangue periférico, via TLR, pode auxiliar na avaliação do processo neurodegenerativo/neuroinflamatório na DP, contribuindo para a melhor compreensão da patofisiologia desta doença.

Les récepteurs Toll-like 7 et 8 jouent un rôle important dans l’activation de la réponse immunitaire innée et adaptative. Leur stimulation conduit à la production des cytokines pro-inflammatoires et d’interférons de type I. L’imiquimod et son dérivé le résiquimod sont les premières molécules de faible poids moléculaire décrites comme agonistes du TLR7 et TLR8. Ces deux molécules ont montré des activités anticancéreuses et adjuvantes très importantes. Récemment, les TLR 7 et 8 ont fait l’objet de plusieurs publications visant à développer de nouveaux agonistes TLR7 et/ou TLR8 dans la perspective d’être utilisés comme adjuvants vaccinaux. Malgré les rôles essentiels de TLR7 et TLR8 dans la stimulation du système immunitaire, une activation immunitaire chronique peut être responsable de plusieurs maladies infectieuses et auto-immunes. D’où l’importance de développer également des antagonistes TLR7 et/ou TLR8.Ce travail de thèse est consacré à la synthèse et le développement de nouvelles molécules hétérocycliques, analogues de l’imiquimod et de résiquimod, dans le but d’identifier de nouveaux ligands TLR7 et/ou TLR8. Des voies de synthèse innovantes, permettant une modulation chimique importante grâce à des couplages croisés pallado-catalysés, ont été mises au point et ont permis d’obtenir une cinquantaine de molécules appartenant à trois séries chimiques différentes de type imidazo[1,2-a]pyrazine, imidazo[1,5-a]quinoxaline et pyrazolo[1,5-a]quinoxaline. De nombreux essais d’alkylation ont été tentés sur ces trois séries chimiques afin d’introduire une large variété de substituants sur le cycle à cinq sommets. L’application du couplage croisé de Sonogashira nous a permis d’établir une liaison C-C et introduire diverses chaines alkyles. Ces composés ont été testés pour leur activité agoniste et antagoniste TLR7 et 8. Aucun des composés cibles n'a présenté d’activité agoniste TLR7 et TLR8, dans l'intervalle des concentrations testées. Par contre, tous les composés ont montré une activité antagoniste sélective du TLR7. Les composés les plus actifs, 5.35a et 5.35b, membres de la série pyrazolo[1,5-a]quinoxaline ont montré des IC50 de l’ordre de 10 μM. Ces résultats prometteurs nous ont permis la découverte d’une activité antagoniste TLR7 importante pour la série pyrazolo[1,5-a]quinoxaline, une série très peu développée dans la littérature. La modulation chimique des molécules actives nous permet de donner naissance à de nouveaux leaders, qui peuvent jouer un rôle important dans la thérapie de plusieurs maladies infectieuses et auto-immunes. / Toll-like receptors 7 and 8 play an important role in immune system activation. Their stimulation leads to the production of pro-inflammatory cytokines and type I interferons. Both receptors recognize viral ssRNA, as well as synthetic tricyclic imidazoquinoline derivatives such as imiquimod (TLR7 agonist) and resiquimod (TLR7/8 agonist). These two molecules showed significative anti-cancer and adjuvant activities. Many reports in the literature have been focused on the development of new TLR7/8 agonists belonging to different chemical series. These agonists strongly induce the production of T helper 1-polarizing cytokines and may therefore serve as promising candidate vaccine adjuvants. Despite the essential roles of TLR7 and TLR8 in the immune system stimulation, chronic immune activation may be responsible for several infectious and autoimmune diseases. Consequently, the development of TLR7 inhibitors may play an important role in the therapy of these diseases.In this study, we are interested in the synthesis and development of new heterocyclic molecules, analogs of imiquimod and resiquimod, in order to identify new TLR7 and/or TLR8 ligands. Different synthetic pathways have been developed, using cross coupling reactions, in order to obtain a wide variety of molecules belonging to three chemical series: imidazo[1,2-a]pyrazine, imidazo[1,5-a]quinoxaline et pyrazolo[1,5-a]quinoxaline. Various alkylation reactions were attempted on these three chemical series in order to introduce a wide variety of substituents on the five-membered ring. The application of Sonogashira's cross-coupling allowed us to establish a C-C bond and introduce various alkyl chains. All compounds have been tested for their TLR7/8 agonistic and antagonistic activity using HEK-Blue™-hTLR7/8 cells. The synthesized compounds are completely inactive as TLR7/8 agonists and are selective TLR7 antagonists. Two compounds of the pyrazolo[1,5-a]quinoxaline series, compound 5.35a and 5.35b, bearing butyl and isobutyl chain respectively, are potent and selective TLR7 antagonists with low micromolar IC50. Results allowed us to discover significative activity for the pyrazolo[1,5-a]quinoxaline series as selective TLR7 antagonists, which may therefore play an important role in the therapy of several infectious or autoimmune diseases.