Mémoire numérisé par la Division de la gestion de documents et des archives de l'Université de Montréal

Submitted by Renata Lopes (renatasil82@gmail.com) on 2017-03-29T13:30:24Z No. of bitstreams: 1 carolinadelourdesjuliaovieirarocha.pdf: 438849 bytes, checksum: 0e5f838b152a2294e48909758b185709 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2017-03-30T11:20:43Z (GMT) No. of bitstreams: 1 carolinadelourdesjuliaovieirarocha.pdf: 438849 bytes, checksum: 0e5f838b152a2294e48909758b185709 (MD5) / Made available in DSpace on 2017-03-30T11:20:43Z (GMT). No. of bitstreams: 1 carolinadelourdesjuliaovieirarocha.pdf: 438849 bytes, checksum: 0e5f838b152a2294e48909758b185709 (MD5) Previous issue date: 2010-01-01 / O Diabetes Mellitus é um problema mundial de saúde pública, de incidência elevada, em termos de pessoas afetadas e mortalidade prematura. As ulcerações em membros inferiores são a maior causa de morbidade entre os diabéticos, tendo como conseqüência a amputação. Na presença desta doença, o processo cicatricial é mais dificultado. Diversos estudos estão sendo realizados com a utilização da Terapia Laser de Baixa Intensidade no processo de cicatrização e reparo tecidual. A terapia laser de baixa intensidade tem sido relatada como importante moduladora da cicatrização de feridas cutâneas. No presente estudo, nós avaliamos os efeitos da terapia laser de baixa intensidade sobre a intensidade do infiltrado inflamatório e quantidade de vasos sangüíneos em feridas cutâneas de camundongos diabéticos não obesos (NOD), adicionalmente, analisamos a expressão da enzima ciclooxigenase 2 no sítio do reparo tecidual utilizando o modelo experimental camundongos NOD para estudar a cicatrização de feridas cutâneas. Foram utilizados 30 camundongos NOD. Destes, 14 ficaram diabéticos e foram divididos em dois grupos: grupo I (n = 7), controle, composto por camundongos NOD não submetidos à terapia laser de baixa intensidade e grupo II (n = 7), tratado, composto por camundongos NOD submetidos à terapia laser de baixa intensidade nos seguintes parâmetros: 15 mW de potência, dose de 3,8 J/cm2, e tempo de aplicação de 20 segundos. Após sete dias do ato cirúrgico e após aplicação do laser, os animais foram eutanasiados com sobredose de anestesia e foram colhidas amostras das feridas para posterior análise histopatológica, histomorfométrica e imunohistoquímica. Os resultados em conjunto sugeriram que a terapia laser de baixa intensidade é capaz de modular negativamente a expressão da enzima ciclooxigenase 2 contribuindo para o controle da resposta inflamatória em feridas cutâneas de camundongos NOD. / Diabetes Mellitus is a worldwide problem of public health, the high incidence, in terms of people affected and premature mortality. Ulcers of the lower limbs are the leading cause of morbidity among diabetic patients, which resulted in amputation. In this disease, the healing process is hampered. Several studies are being conducted with the use of low-level laser therapy in the process of healing and tissue repair. The low-level laser therapy has been reported as an important modulator of healing of skin wounds. In this study we evaluated the effects of low-level laser therapy intensity of the inflammatory infiltrate and number of blood vessels in wounds of non-obese diabetic mice (NOD), in addition, we analyzed the expression of cyclooxygenase 2 enzyme at the site of repair tissue using the NOD mice experimental model to study the healing of skin wounds. Were used thirty NOD mice, these fourteen were diabetic and were divided into two groups: group I (n = 7) underwent a surgical procedure of skin wounds and group II (n = 7) underwent a surgical procedure of skin wounds and treated with LLLT. Group II was submitted to LLLT in the following parameters: 15 mW of power, dose of 3.8 J/cm2 and exposure time of 20 seconds. Seven days after surgery and after laser application, animals were euthanized with an overdose of anesthesia and were submitted colleted tissue samples for subsequent histological analysis, histomorphometry and immunohistochemistry. A low-level laser therapy has promoted the inhibition of cyclooxygenase 2 expression in skin wounds in mice diabetic. The results together suggested that low-level laser therapy is able to negatively modulate the expression of cyclooxygenase 2 enzyme contributing to the inflammatory response in cutaneous wounds in NOD mice.

Le diabète de type 1 (T1D) est une maladie auto-immune caractérisée par la destruction des cellules β du pancréas par les lymphocytes T auto-réactifs. Durant ma thèse, nous nous sommes intéressés au rôle des cellules de l’immunité innée dans le T1D à l’aide d’un modèle murin de la maladie : la souris NOD. Au contraire des cellules du système adaptatif (lymphocytes T et B), les cellules de l’immunité innée constituent la première ligne de défense de l’organisme lors d’une infection. Cette population est constituée entre autre de neutrophiles, cellules dendritiques plasmacytoïdes (pDC), macrophages, mais aussi de lymphocytes T et B non conventionnels tel que les cellules iNKT et B-1a. Précédemment, notre laboratoire a mis en lumière le rôle des lymphocytes iNKT dans le développement du T1D. Durant la première partie de ma thèse, nous avons démontré que les lymphocytes iNKT17, une sous-population des lymphocytes iNKT, ont un rôle délétère dans le T1D chez la souris NOD. Ces cellules infiltrent le pancréas et y produisent de l’IL-17, une cytokine pro-inflammatoire. Grâce à des expériences de transferts, nous avons mis en évidence que les lymphocytes iNKT17 exacerbent la maladie via la production d’IL-17. Dans la deuxième partie de ma thèse, nous nous sommes intéressés aux mécanismes qui induisent l’activation des lymphocytes T auto-réactifs. Nous avons observé chez la souris NOD, que la mort physiologique des cellules β conduit à l’activation de cellules de l’immunité innée : les neutrophiles, les lymphocytes B-1a et les pDC. La coopération entre ces cellules conduit à l’activation des pDC qui produisent de l’IFNα. Cette cytokine active les lymphocytes T auto-réactifs qui vont détruire les cellules β du pancréas. Nos résultats montrent que l’immunité innée est un acteur important dans la physiopathologie du diabète sucré. / The type 1 diabetes ( T1D ) is an autoimmune disease characterized by the destruction of β cells in the pancreas by autoreactive T lymphocytes. During my thesis, we are interested in the role of cells of innate immunity in T1D using a mouse model of the disease: NOD mice. In contrast to cells of the adaptive system (T and B lymphocytes ) cells of innate immunity is the first line of defense of the body during infection . This population consists of neutrophils , among other , plasmacytoid dendritic cells ( pDC ) , macrophages , T lymphocytes but not conventional B as iNKT cells and B -1a.Previously, our laboratory has highlighted the role of iNKT cells in the development of T1D . During the first part of my thesis , we demonstrated that iNKT17 cells, a subpopulation of iNKT cells, have a deleterious role in T1D in NOD mice . These cells infiltrate the pancreas and there produce IL -17 , a proinflammatory cytokine. Through transfer experiments , we demonstrated that lymphocytes iNKT17 exacerbate disease through the production of IL-17 . In the second part of my thesis , we investigated the mechanisms that induce the activation of autoreactive T lymphocytes. We observed in NOD mice , the physiological death of β cells leads to activation of innate immunity cells : neutrophils, lymphocytes B- 1a and pDCs . The cooperation between these cells leads to activation of pDC that produce IFNa . This cytokine activates autoreactive T cells which will destroy the β cells of the pancreas. Our results show that innate immunity is an important player in the pathogenesis of diabetes mellitus.

No description available.

The aim of the study was to examine the immune response and different immunoprotective strategies in experimental type 1 diabetes mellitus. The autoimmune destruction of the insulin-producing pancreatic β-cells that leads to type 1 diabetes is complex and incompletely understood. Activated immune cells infiltrate the pancreatic islets at an early stage of the disease, and they produce and release cytokines, which may contribute to β-cell dysfunction and death. Several immunomodulatory agents with different mechanisms have recently been developed in order to suppress cytokine function such as MDL 201, 449A, a novel transcriptional inhibitor of TNF-α. At least in rodent β-cells, many of the toxic actions of cytokines depend on the synthesis of nitric oxide (NO). Aminoguanidine (AG), an inhibitor of NO formation, might therefore be an interesting compound for prevention of type 1 diabetes. Another substance that could influence the course of events leading to this disease is the pituitary hormone prolactin (PRL), since it has the ability to activate different immune cells. We have studied the effects of AG, PRL and MDL 201, 449A on the development of hyperglycaemia and pancreatic insulitis in multiple low dose streptozotocin induced autoimmune diabetes in mice. The natural course after syngeneic islet transplantation of pancreatic islets in NOD mice, a model of type 1 diabetes mellitus was also investigated. AG and PRL were also studied in vitro on cultured isolated rodent pancreatic islets. We suggest that the insulin-producing cells are specifically targeted by the inflammatory response after syngeneic islet transplantation in type 1 diabetic mice. Our data do not exclude a role for NO in type 1 diabetes, but it raises concerns about the use of AG as a therapeutic agent since an increased mortality and no decline in diabetes frequency was observed. AG did not seem to be directly harmful to β-cell function, but it could affect pancreatic and islet blood flows. PRL and MDL 201, 449A could both counteract hyperglycaemia and insulitis in the early phase of autoimmune diabetes.

Orientador: Ricardo de Lima Zollner / Tese (doutorado) - Universidade Estadual de Campinas, Faculdade de Ciencias Medicas / Made available in DSpace on 2018-08-11T22:15:47Z (GMT). No. of bitstreams: 1 Domingos_PriscilaPerez_D.pdf: 2379926 bytes, checksum: df7f068098f3454b58caf0a13e61f196 (MD5) Previous issue date: 2008 / Resumo: O camundongo não obeso diabético (NOD) é caracterizado por desenvolver naturalmente diabetes mellitus tipo 1 (DM-1) com similaridade ao diabetes mellitus tipo 1 em humanos. A manifestação espontânea do diabetes neste modelo animal é caracterizado por infiltração progressiva das ilhotas de Langerhans por células mononucleares linfócitos T (CD4+ e CD8+) e destruição das células ß pancreáticas produtoras de insulina. O fator de crescimento neural (NGF) e algumas citocinas estão associados a regeneração neural, além de atuarem sobre células do sistema imune. Em adição a estes efeitos, NGF age na liberação de insulina pelas células betas das ilhotas pancreáticas, tornando-se foco de interesse com relação as suas propriedades moduladoras no processo inflamatório na ilhota pancreática. O gangliosídeo GM1 liga-se ao receptor de alta afinidade (TrkA) do NGF-ß, mimetizando seus efeitos. No presente trabalho, avaliamos a ação modulatória de GM1 e NGF em cultura de ilhotas pancreáticas, provenientes de camundongos NOD. Foram avaliados por meio de RT-PCR a expressão gênica de NGF-ß, TrkA e insulina e, por ensaio imunoenzimático, a concentração de citocinas IL-1ß, IL-12, TNF-a, INF-y e insulina. Nossos resultados sugerem ação moduladora similar entre GM1 e NGF sobre as ilhotas de NOD não diabéticos e pré-diabéticos. NGF e GM1 aumentam a expressão gênica de NGF e TrkA e diminuem a expressão gênica de insulina em NOD não diabéticos e pré-diabéticos. Além disso, aumentam a liberação de insulina e diminui a de citocinas inflamatórias IL-1ß, IL-12, TNF-a, IFN-y que caracterizam a resposta Th1. / Abstract: The non-obese diabetic mice (NOD) lineage is characterized by developing type 1 diabetes mellitus (DM-1) naturally, bearing a similarity to DM-1 in human beings. The spontaneous manifestation of diabetes is characterized by gradual infiltration in pancreatic islets by mononuclear cells lymphocytes T (CD4+ and CD8+) and destruction of the ß-cells producers of insulin. One consequence of this effect, is the release of neurotrophins trying modulate the insulin release by the ß cells of pancreatic islets. Thus, the neurotrophins have been the focus of interest in the modulation of the inflammatory process in the pancreatic islets. The ganglioside GM1 binds to the high affinity receptor (TrkA) of the NGF-ß, enhancing its effect. In the present work, we evaluate the immune modulation properties of GM1 and NGF in culture of pancreatic islets from NOD mice. The gene expression of NGF-ß, TrkA and insulin for immune enzymatic assay, the concentration of cytokines IL 1ß, IL-12, TNF-a, IFN-y and insulin were evaluated by RT-PCR and ELISA. Our results suggest similar modulation action between GM1 and NGF on islets of NOD non-diabetic and pre-diabetic. GM1 and NGF action increases the gene expression of NGF and TrkA and the decrease of insulin in mice NOD non-diabetic and pre-diabetic. Moreover, GM1 and NGF increase the insulin release and decrease inflammatory cytokines that characterize the Th1 reply. / Doutorado / Ciencias Basicas / Doutor em Clínica Médica