Dans les pays industrialisés, les pathologies oculaires à composante vasculaires, que ce soit la rétinopathie du prématuré (ROP), la rétinopathie du diabétique ou la dégénérescence lié à l’âge, représentent la première cause de cécité respectivement chez l’enfant, l’adulte et la personne âgée. Plusieurs études sur l’homme ou sur des modèles animaux ont souligné le rôle crucial joué des acides gras polyinsaturés (AGPI) au cours de ces rétinopathies et notamment l’action préventive des acides gras polyinsaturés oméga 3 (AGPI n-3) sur l’angiogenèse pathologique. Ces AGPI sont estérifiés dans les glycérophospholipides constituant les membranes cellulaires. On les retrouve également dans une classe particulière de glycérophospholipides, les plasmalogènes. La particularité des plasmalogènes réside dans leur liaison vinyl-éther en position sn-1 au lieu d’une liaison ester dans les autres glycérophospholipides. Les AGPI sont libérés des plasmalogènes par une phospholipase indépendante au calcium, la iPLA2, pour devenir des métabolites actifs. Les plasmalogènes via la libération des AGPI joueraient un rôle dans la mise en place et la maturation du réseau vasculaire rétinien et ce, notamment grâce à la bonne mise en place du réseau astrocytaire. Les astrocytes et les cellules de Müller sont les cellules macrogliales qui servent de soutien physique et métabolique à la rétine. De plus, les cellules de Müller participent au métabolisme des lipides. L’objectif de ce travail de thèse a été d’évaluer l’implication des plasmalogènes dans le métabolisme des cellules de Müller et des astrocytes mais aussi dans la communication entre ces cellules macrogliales. Nous avons également étudié le profil lipidique d’enfants prématurés pour mettre en évidence de potentielles altérations du métabolisme des plasmalogènes chez des nouveau-nés développant une rétinopathie à composante vasculaire, la rétinopathie du prématuré (ROP). Pour ce faire nous avons étudié les effets d’une diminution en plasmalogènes et/ou en iPLA2 sur des cellules de Müller en culture primaire après avoir préalablement vérifié l’expression de l’enzyme clef de la biosynthèse des plasmalogènes. Nous avons ensuite étudié les effets d’une diminution des teneurs en plasmalogènes sur la communication calcique entre les cellules de Müller et les astrocytes. Nos résultats ont montré que les cellules de Müller expriment l’enzyme-clé de synthèse des plasmalogènes et que ces cellules sont plus riches en plasmalogènes que la rétine entière. Les plasmalogènes seraient impliqués dans le contrôle de la migration des cellules de Müller par l’action de la voie ERK1/2 MAPK. Ces effets ne semblent pas passer par la libération des AGPI. De plus nos résultats suggèrent une dégradation de la communication entre les astrocytes et les cellules de Müller en cas de diminution des teneurs en plasmalogènes dans les cellules de Müller. Enfin chez l’homme nous avons mis en évidence une accumulation des AGPI n-6 au détriment des AGPI n-3 dans les érythrocytes des enfants développant une rétinopathie du prématuré et inversement dans le groupe d’enfants prématuré contrôle. L’ensemble de ces travaux confirme l’importance du métabolisme lipidique, et plus particulièrement celui des plasmalogènes, sur le fonctionnement de la rétine. / Retinal vascular disorders such as retinopathy of prematurity (ROP), diabetic retinopathy or age-related macular degeneration represent the first cause of vision loss at all ages in industrialized countries. Many epidemiological or animal studies have shown the involvement of polyunsaturated fatty acids (PUFA) in the regulation of vascular development and more specifically the beneficial properties of omega 3 PUFA (n-3 PUFA) against pathological vascularization. Those PUFA are esterified on glycerophospholipids (GP). GP are the primary constituents of the lipid bilayer of cell membranes. PUFA can be also esterified on a specific class of GP, called plasmalogens. Plasmalogens are characterized by the presence of a vinyl ether linkage at the sn-1 position of glycerol instead of an ester linkage as seen in other GP. PUFA are released from plasmalogens by a calcium-independent phospholipase (iPLA2). Free PUFA can be converted into biologically active metabolites. Plasmalogens may have an impact on the development and the maturation of retinal vascular network through the PUFA they release through the control of astrocyte template formation prior to vessel formation. Astrocytes and Müller cells are macroglials cells providing physical and metabolic supports to the retina. Müller cells are key actors of the retinal lipid metabolism. The aim of this work was to evaluate the involvement of plasmalogens in Müller cells and astrocytes metabolism as well as in the ability of these cells to communicate. On one hand, we have studied the effects of a decrease in plasmalogen biosynthesis and/or in iPLA2 activity on Müller cell physiology. Müller cells express a biosynthesis key enzyme of plasmalogen and reducing the biosynthesis of plasmalogens affects Müller cell ability to migrate through the ERK1/2 MAPK signalling. In a second series of studies, we studied the repercussions of such modifications on Müller cell physiology on their ability to communicate with retinal astrocytes through calcium signalling. Our results suggest that affecting plasmalogen metabolism in Müller cells alters the communication between astrocytes and Müller cells. Finally, and in order to investigate whether plasmalogen metabolism may be modified in a human disease displaying abnormal retinal vascular development, we performed a lipidomic study of circulating lipids in infants affected by retinopathy of prematurity. ROP was characterized by the accumulation of n-6 PUFA at the expense of n-3 PUFA, these changes being associated to plasmalogens. All these experiments confirm the importance of lipid metabolism, and especially plasmalogens, on the retina functioning.

O envelhecimento é uma falha progressiva nos processos fisiológicos celulares, produzindo alterações morfológicas nas células e nos tecidos. No sistema nervoso, produz uma redução no número de neurônios, nas fibras nervosas, principalmente nas arborizações dendríticas e nas espinhas sinápticas, e nas células da glia que, de acordo com sua localização e tipo celular, podem diminuir, permanecer constantes ou mesmo aumentar numericamente. Na presente pesquisa, avaliou-se os efeitos do envelhecimento sobre o gânglio trigeminal (GT) de ratos Wistar em animais jovens (2 meses de vida), adultos (12 meses de vida) e idosos (24 meses de vida). Os GT foram submetidos às técnicas histológicas da hematoxilina e eosina e Picro-sírius, onde avaliou-se, respectivamente, a densidade das células satélites glias (CGS) e o componente colágeno ganglionar. Através da técnica histoquímica da NADH-d, avaliou-se a área do perfil do GT, a área do perfil dos corpos celulares dos neurônios ganglionares e a densidade neuronal. Uma avaliação qualitativa foi também realizada relativamente à imunorreatividade dos neurônios ganglionares à substância P (SP) e ao peptídeo intestinal vasoativo (VIP). A densidade das CGS foi maior nos animais jovens do que nos animais adultos e idosos. Verificou-se, qualitativamente, que à medida que o animal envelhece há uma diminuição das fibras colágenas do tipo III, passando a predominar, nos animais idosos, as fibras do tipo I. A área do perfil celular dos corpos neuronais foi maior nos animais adultos sendo que em todos os grupos predominaram neurônios de tamanho médio, com a área do perfil celular entre 490 e 1100 μm2. A densidade neuronal apresentou-se maior nos animais jovens, e sem variações estatísticas entre os animais adultos e idosos. Em todos os grupos estudados, os neurônios pequenos foram os que apresentaram maior imunorreatividade à SP e ao VIP. / Aging is a progressive failure in cellular physiological processes. It determines morphological changes in cells of different tissues. In the nervous system, a reduction in neuron number and in neuron fibers, mainly in dendritic tree and synaptic, are described. With aging the glial cells may increase or decrease in number or also remain constant. In the present work the effects of aging were evaluated on the trigeminal ganglion (TG) comparing young (2 months age), adult (12 months age) and old rats (24 months age). Histological sections of TG were stained with hematoxilin-eosin technique to determine the density of satellite glial cells and Picro-sirius under polarized light to evaluate the Types I and III of collagen fibers. The NADH-diaphorase technique allowed determining the perycarion area. The immunoreactivity of ganglionar neurons to Substance P (SP) and vasoactive intestinal peptide (VIP) were also qualitatively evaluated. The glial cells density was higher in young and adult animals than in old animals. The type I collagen fibers predominates in ganglia of old animals whereas in the young animals is characteristic the presence of the type III collagen fibers. Although the perycarion area was higher in adult animals the medium-sized neurons predominated in all groups. Their areas ranged from 490 to 1100 μm2. It was also observed that the neuron density was higher in young animals. In the adult and old animals the neuron density was similar. In all groups the immunoreactivity both to SP an VIP was detected mainly in neurons of small perycarion.

Made available in DSpace on 2014-06-11T19:31:08Z (GMT). No. of bitstreams: 0 Previous issue date: 2010-07-02Bitstream added on 2014-06-13T19:01:27Z : No. of bitstreams: 1 lachat_d_dr_jabo.pdf: 9336468 bytes, checksum: f5dea24e18ee6a7cb21848540c6d48af (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Diversos estudos mostraram que a ingestão de dieta com níveis inadequados de ferro pode causar, no sistema nervoso central (SNC) de ratos, alterações morfológicas, bioquímicas e comportamentais no animal. Esses estudos têm ainda indicado que animais deficientes em ferro apresentam redução no número de lamelas de mielina e prejuízos na aprendizagem. A deficiência de ferro é uma das mais comuns desordens nutricionais em pacientes pediátricos e adultos e atinge cerca de 2,5 a 5 bilhões de pessoas em todo mundo. A consequência mais explícita da deficiência de ferro é a anemia. O ferro está relacionado ao desenvolvimento de fibras nervosas mielínicas, as quais constituem mais de 80% do nervo óptico. Objetivou-se, na presente investigação, avaliar com o auxílio de microscopia eletrônica de transmissão, os possíveis efeitos da anemia ferropriva na estrutura do nervo óptico de ratos Wistar durante os períodos de lactação e pós-lactação. Os animais foram divididos em 2 grupos: Controle e Anêmico. Os anêmicos receberam uma dieta com 4 mg de ferro/Kg, e os controle, uma dieta com 35 mg de ferro/Kg. Avaliações do peso corpóreo, hemoglobina e hematócrito foram feitas para checar os efeitos da deficiência de ferro. Os animais foram anestesiados com cloridrato de quetamina IM (22 mg/Kg) e então sacrificados por perfusão transcardíaca com PBS 0,05M, pH 7,4, seguido da mistura fixadora paraformaldeído 2% e glutaraldeído 1% diluída em tampão fosfato. Um segmento do nervo óptico foi retirado e pós-fixado em solução de tetróxido de ósmio a 1% por duas horas a 4ºC, desidratado em acetona e incluído em araldite. Cortes ultra-finos com 60 nanômetros de espessura foram montados em grades de cobre, contrastados com acetato de uranila e citrato de chumbo, observados e fotografados ao microscópio eletrônico de transmissão para detalhada análise ultraestrutural... / Several studies showed that ingestion of diets with inadequate iron levels can cause morphological, biochemical and behavioral changes in the central nervous system (CNS) of rats. These studies have also shown that iron-deficient animals have reduced number of myelin lamellae and prejudice on learning. Iron deficiency is one of the most common nutritional disorders in pediatric patients and adults and affects about 2.5-5 billion people around the world. The most explicit result of iron deficiency is anemia. The iron is related to the development of myelinated nerve fibers, which constitute more than 80% of the optic nerve. The aim of this research is to evaluate, with transmission electronic microscopy, the possible effects of iron deficiency anemia in Wistar rats optic nerve structure during lactation and pos-lactation period. The animals were divided into 2 groups: Control and Anemic. The anemic group received 4 mg iron/Kg, the control group received 35 mg iron/Kg. Evaluation of body weight, hemoglobin and hematocrit were made to check the iron deficiency effects. The animals were anesthetized with ketamine 22 mg/Kg and then sacrificed by transcardiac perfusion with PBS 0.05 M, pH 7.4, followed by paraformaldehyde fixative mixture 2% and 1% glutaraldehyde. An optic nerve segment was removed and post-fixed in a solution of osmium tetroxide for two hours at 4°C, dehydrated in acetone and embedded in Araldite. Ultrathin sections with 60 nanometers thick were mounted on copper grids, contrasted with uranyl acetate and lead citrate, observed and photographed by transmission electronic microscope for detailed ultrastructural analysis of nerve fibers, blood vessels and glial cells. Both hematological and body weight were smaller in the anemic group. The ultrastructural analysis showed damaged myelinated and unmyelinated fibers, and glial cells of the anemic animals when compared with... (Complete abstract click electronic access below)

A técnica de mobilização neural (NM) clinicamente é eficaz, porém ainda é pouco fundamentada. Neste trabalho, submetemos ratos Wistar no 14º dia após a lesão constritiva crônica (CCI) do nervo isquiático ao tratamento com NM, em 10 sessões, e avaliamos o comportamento doloroso utilizando testes comportamentais para hiperalgesia e alodinia. Ainda, observamos através de ensaios de Western blotting o envolvimento das células gliais e do fator neurotrófico derivado do cérebro (BDNF). No estudo comportamental, os animais com CCI mostraram diminuição no limiar nociceptivo, tratados com a NM apresentaram melhora no comportamento doloroso. Os ensaios de Western blotting mostraram que após a CCI houve aumento de OX-42, GFAP e BDNF, na medula, tálamo e mesencéfalo, também observado em analise de imuno-histoquímica e após a NM observamos diminuição desses mediadores através da primeira técnica mencionada. Sendo assim, sugerimos que a técnica de NM é eficaz como terapia analgésica, sendo possível observar o envolvimento das células gliais e do BDNF neste modelo experimental. / The technique of neural mobilization (NM) is clinically effective, although it is still poorly reasoned. In this study, Wistar rats on day 14th after chronic constrictive injury (CCI) of the sciatic nerve were submitted to treatment with NM in 10 sessions, and it was evaluated the painful behavior using tests for hyperalgesia and allodynia. Also, we observed through Western blotting assays the involvementof glial cells and brain-derived neurotrophic factor (BDNF). In the behavioral study, animals with CCI showed a decrease in nociceptive threshold, and those treated with NM showed an improvement in pain behavior. Western blotting assays showed an increase after CCI of OX-42, GFAP and BDNF levels in the spinal cord, thalamus and midbrain, also observed in immunohistochemical analysis, and after the NM we observed a decrease of these mediators through the first technique mentioned. Therefore, we suggest that the NM technique is an effective analgesic therapy, and it is possible to observe the involvement of glial cells and BDNF in this experimental model.

O envelhecimento é uma falha progressiva nos processos fisiológicos celulares, produzindo alterações morfológicas nas células e nos tecidos. No sistema nervoso, produz uma redução no número de neurônios, nas fibras nervosas, principalmente nas arborizações dendríticas e nas espinhas sinápticas, e nas células da glia que, de acordo com sua localização e tipo celular, podem diminuir, permanecer constantes ou mesmo aumentar numericamente. Na presente pesquisa, avaliou-se os efeitos do envelhecimento sobre o gânglio trigeminal (GT) de ratos Wistar em animais jovens (2 meses de vida), adultos (12 meses de vida) e idosos (24 meses de vida). Os GT foram submetidos às técnicas histológicas da hematoxilina e eosina e Picro-sírius, onde avaliou-se, respectivamente, a densidade das células satélites glias (CGS) e o componente colágeno ganglionar. Através da técnica histoquímica da NADH-d, avaliou-se a área do perfil do GT, a área do perfil dos corpos celulares dos neurônios ganglionares e a densidade neuronal. Uma avaliação qualitativa foi também realizada relativamente à imunorreatividade dos neurônios ganglionares à substância P (SP) e ao peptídeo intestinal vasoativo (VIP). A densidade das CGS foi maior nos animais jovens do que nos animais adultos e idosos. Verificou-se, qualitativamente, que à medida que o animal envelhece há uma diminuição das fibras colágenas do tipo III, passando a predominar, nos animais idosos, as fibras do tipo I. A área do perfil celular dos corpos neuronais foi maior nos animais adultos sendo que em todos os grupos predominaram neurônios de tamanho médio, com a área do perfil celular entre 490 e 1100 μm2. A densidade neuronal apresentou-se maior nos animais jovens, e sem variações estatísticas entre os animais adultos e idosos. Em todos os grupos estudados, os neurônios pequenos foram os que apresentaram maior imunorreatividade à SP e ao VIP. / Aging is a progressive failure in cellular physiological processes. It determines morphological changes in cells of different tissues. In the nervous system, a reduction in neuron number and in neuron fibers, mainly in dendritic tree and synaptic, are described. With aging the glial cells may increase or decrease in number or also remain constant. In the present work the effects of aging were evaluated on the trigeminal ganglion (TG) comparing young (2 months age), adult (12 months age) and old rats (24 months age). Histological sections of TG were stained with hematoxilin-eosin technique to determine the density of satellite glial cells and Picro-sirius under polarized light to evaluate the Types I and III of collagen fibers. The NADH-diaphorase technique allowed determining the perycarion area. The immunoreactivity of ganglionar neurons to Substance P (SP) and vasoactive intestinal peptide (VIP) were also qualitatively evaluated. The glial cells density was higher in young and adult animals than in old animals. The type I collagen fibers predominates in ganglia of old animals whereas in the young animals is characteristic the presence of the type III collagen fibers. Although the perycarion area was higher in adult animals the medium-sized neurons predominated in all groups. Their areas ranged from 490 to 1100 μm2. It was also observed that the neuron density was higher in young animals. In the adult and old animals the neuron density was similar. In all groups the immunoreactivity both to SP an VIP was detected mainly in neurons of small perycarion.

Notre approche biomimétique permet de régénérer une dent entière. Un protocole en deux étapes à partir de réassociations de cellules dentaires embryonnaires permet le développement de la couronne in vitro et, après implantation, la différenciation fonctionnelle des cellules, l’initiation du développement radiculaire et la vascularisation dentaire. Cependant, l’absence d’innervation a nécessité des expériences complémentaires :- La co-implantation de réassociations cellulaires avec un ganglion trigéminal permet la croissance d’axones autour de la dent formée, mais pas dans le mésenchyme dentaire.- Pour tenter de résoudre ce problème, la régénération axonale a été testée dans un contexte immunodéprimé en utilisant la cyclosporine A (CsA). Dans ces conditions, des fibres nerveuses entrent dans la pulpe dentaire, jusqu’aux odontoblastes. Cependant, la CsA a aussi un effet direct sur la croissance axonale.- Des co-implantations chez des souris immunodéprimées (Nude) montrent que l’immunomodulation seule suffit pour l’innervation de la dent.- Dans la dent, les axones assurent différentes fonctions en interagissant avec les cellules voisines. Les relations entre axones et autres cellules (odontoblastes, cellules endothéliales, péricytes et cellules gliales) ont été analysées dans les mésenchymes dentaire et péri-dentaire de réassociations implantées et comparées à ce que l’on observe pour une molaire physiologique à un stade similaire.Ce travail décrit les conditions permettant l’innervation des dents régénérées. Des expériences préliminaires encourageantes ont été réalisées avec des cellules souches pour remplacer la CsA. / Our biomimetic approach allowed the regeneration of a whole tooth. Using embryonic dental cells, a two-steps protocol allowed crown formation in vitro and, after implantation, functional cells differentiation, initiation of root formation and tooth vascularization. However, the teeth were not innervated, which led to complementary experiments:- The co-implantation of cell re-associations with a trigeminal ganglion allowed axonal growth around the forming teeth, but not in the dental mesenchyme. - To try to solve this point, axonal regeneration was tested in immunodepressed conditions, using cyclosporin A (CsA). In these conditions, nerve fibers entered the dental pulp and reached odontoblasts. However, CsA shows multiple effects, including direct ones on nerve growth. - Co-implantations were performed in immunocompromised Nude mice allowed axons to reach the odontoblast layer, thus showing that immunomodulation is sufficient.- Axons in the dental mesenchyme interfere with several functions by interacting with neighbor cells. Relationships between axons and other cells (odontoblasts, endothelial cells, pericytes and glial cells) were analyzed in the peridental and dental mesenchymes of implanted reassociations and compared to the physiological situation in developing molars at similar stage. This work describes conditions allowing the innervation of engineered teeth. Preliminary encouraging attempts have been made to replace CsA by using stem cells.

Dans la rétine, la protéine dystrophine Dp71 est principalement exprimée dans les cellules gliales de Müller (CGM), qui contribuent à la stabilisation de la barrière hémato-rétinienne (BHR). Les CGM sont aussi les principales sources de facteurs inflammatoires. Ainsi, nous avons étudié les effets de l’absence de Dp71 sur l’homéostasie potassique et aqueuse, ainsi que sur l’expression de médiateurs de l’inflammation et la perméabilité vasculaire rétinienne.L'absence de Dp71 diminue l'expression de la protéine AQP4 et induit la redistribution de Kir4.1 tout le long des CGM. Par ailleurs, nous avons également constaté que le décollement expérimental de la rétine chez les souris WT induit une diminution de Dp71 associée à une délocalisation de Kir4.1, une régulation à la baisse de la protéine AQP4 dans les CGM.Nos données montrent clairement que l'absence de la Dp71 entraîne une augmentation de l'expression du VEGF, d’ICAM-1, une augmentation du nombre de leucocytes adhérents rétiniens, une dégénérescence accrue des capillaires associée à une forte perméabilité vasculaire chez les souris Dp71-null.L’ensemble de nos résultats a mis en évidence le rôle de la Dp71 dans les mécanismes visant à réguler l'homéostasie rétinienne et à assurer la stabilisation de la BHR. Nous apportons la preuve que la perte de Dp71 favorise l'inflammation vasculaire rétinienne et la dégénérescence des capillaires associée à une perméabilité vasculaire. Ensemble, ces observations suggèrent que la souris Dp71-null serait un modèle approprié pour étudier les pathologies vasculaires rétiniennes telles que la rétinopathie diabétique, l’uvéite rétinienne et l’occlusion veineuse rétinienne. / In the retina, the Dp71 dystrophin protein is mainly expressed in Müller glial cells (MGC), which contribute to the stabilization of the blood-retinal barrier (BRB). MGC are also the main sources of inflammatory factors. Thus, in our thesis project we studied the effects of the absence of the Dp71 protein on potassium and water homeostasis, as well as the expression of inflammatory mediators and retinal vascular permeability.The absence of the Dp71 protein decreased the expression of AQP4 protein and induces the redistribution of Kir4.1, initially restricted to the end-feet of MGC and around vessels, all along the cell membrane. Moreover, we have also shown that the experimental retinal detachment in WT mice induces a reduction of Dp71 which is associated with Kir4.1 mislocation, a down regulation of AQP4 protein in MGC.Our data clearly demonstrate that the absence of the Dp71 leads to increased retinal VEGF and ICAM-1 expression in Dp71-null mouse compared to WT mouse strain. There is also an increase of the number of retinal adherent leukocytes, capillary degeneration associated with high BRB permeability observed in Dp71-null mice.Our findings highlight Dp71 as an important component in the mechanisms leading to the regulation of retinal homeostasis; and to the maintaining of the BRB stabilization. We provide evidence that deficiency of Dp71 promotes retinal vascular inflammation and significantly exacerbated degeneration of capillaries and BRB breakdown. Together these results suggest that the Dp71-null mouse could be a good model to study retinal vascular diseases such as diabetic retinopathy, retinal uveitis and retinal vein occlusion.

Nos últimos anos, os estudos de nosso grupo foram focados na área de dor, avaliando diferentes modelos experimentais de dor aguda, neuropática e muscular. A busca por mecanismos moduladores destes tipos de dores são alvo de grande estudo, uma vez que o fenômeno da dor é peculiar e torna-se de difícil tratamento em muitos casos. Distúrbios (VER) musculoesqueléticos são as principais causas de incapacidade nas pessoas durante seus anos de trabalho. Diversos estudos tem sido realizados lesionando o músculo gastrocnêmio como modelo experimental em diferentes animais para melhor entendimento deste tipo de dor. O nosso objetivo foi observar possíveis alterações histológicas no tecido muscular, avaliar a alteração na sensibilidade nociceptiva e a atividade locomotora dos animais após a indução de dor muscular crônica, bem como observar o envolvimento das células gliais na medula espinal destes animais. Em adição, avaliamos a participação de determinadas citocinas com o intuito de obter um perfil inflamatório em nosso modelo experimental. Nossos resultados demonstraram um quadro de inflamação instalada no tecido muscular de animais com miosite crônica através das analises histológicas realizadas. Os testes comportamentais tanto para hiperalgesia mecânica como térmica e alodinia confirmaram a instalação do quadro álgico uma vez que os animais com miosite apresentaram uma queda em seus limiares nociceptivos em relação aos grupos controle. A atividade locomotora dos animais também se demonstrou comprometida após a indução de miosite. Em relação à participação das células gliais neste modelo, demonstramos que houve um aumento na expressão de GFAP e OX-42, correspondentes à marcação astrócitos e células da microglia na porção lombar da medula espinal dos animais com miosite, quando comparados ao grupo controle. Quanto à participação dos mediadores sistêmicos, observamos um aumento nos níveis de IL-1β e fractalquina (FKN) no sangue dos animais, enquanto o nível de IL-10 permaneceu baixo em relação ao grupo controle. Com nossos achados esperamos colaborar com o aprimoramento de estratégias terapêuticas para tratamento de dores musculares. / In the last years, the studies of our group were focused on the area of pain, evaluating different experimental models of acute, neuropathic and muscular pain. The search for mechanisms modulating types of pain are the subject of great study, since the phenomenon of pain is peculiar and becomes difficult in many cases. Musculoskeletal (VER) disorders are the leading causes of disability in people during their working years. Several studies have been carried out with the model of experimental model in different animals to better understand this type of pain. Our objective was to observe the non-muscular histological changes, to evaluate the nociceptive sensitivity and a locomotor activity of the animals after an induction of chronic muscular pain, as well as to observe the involvement of the glial cells in the spinal cord of the animals. In addition, we evaluated the participation of certain cytokines in order to obtain an inflammatory profile in our experimental model. Our results demonstrated a picture of inflammation installed without muscle tissue of animals with chronic myositis through histological analysis. Behavioral tests for both mechanical and thermal hyperalgesia and allodynia confirmed the onset of pain since animals with myositis showed a decrease in their nociceptive thresholds in relation to the control groups. The locomotor activity of the animals was also shown to be impaired after an induction of myositis. Regarding the participation of glial cells in this model, we demonstrated that there was an increase in the expression of GFAP and OX-42, corresponding to marking astrocytes and microglia cells in the portion of the spinal cord of animals with myositis, when compared to the control group. Regarding the participation of systemic mediators, we observed an increase in the levels of IL-1β and fractalkin (FKN) in the blood of the animals, while the level of IL-10 remained low in relation to the control group. With the findings we hope to collaborate with the improvement of therapeutic strategies for the treatment of muscular pain.

A resposta do sistema nervoso para diversas lesões acarreta a ativação das células gliais entéricas. Este trabalho tem como objetivo analisar o efeito da isquemia e reperfusão intestinal (I/R-i) sobre as células gliais entéricas, neurônios e receptores P2X2 e P2X7. Foram analisados o íleo de ratos Controle, Sham e I/R-i com 0 hora, 24 horas e 14 dias de reperfusão. Foram realizadas dupla marcação dos receptores P2X2 e P2X7 com Hu e S100, densidade, área do perfil e marcação de proliferação celular. Os resultados mostraram dupla marcação de células gliais entéricas e neurônios com os receptores P2X2 e P2X7; a densidade apresentou um aumento de células gliais e diminuição de neurônios imunorreativos ao Hu. A área do perfil de células gliais entericas S100-IR apresentaram diminuição nos grupos I/R-i e foi detectada proliferação de células gliais entéricas nos grupos I/R-i 0 hora e 24 horas. Conclui-se que a isquemia levou a alterações diferenciadas nos receptores P2X2 e P2X7, células gliais entéricas e neurônios, que podem causar disfunções gastrointestinais. / The nervous system response to various injuries involves the activation of enteric glial cells. The aim of the work was to analyze the effect of ischemia and reperfusion (I/R-i) on enteric glial cells, neurons and receptors P2X2 and P2X7. We analyzed the ileum of Control, Sham and I/R-i with 0 hour, 24 hours and 14 days of reperfusion. Double staining were performed P2X2 and P2X7 receptors with Hu and S100, density, area profile and marking of cellular proliferation. The results show double staining of neurons and enteric glial cell with the P2X2 and P2X7; density increased by glial cells and decrease of neurons immunoreactive to Hu. The area profile of enteric glial cell S100-IR showed decreased in Groups I/R-I and enteric glial cell proliferation was observed in groups I/R-i 0 hours and 24 hours. It is concluded that ischemia has led to changes in differential P2X2 and P2X7 receptors, neurons and enteric glial cells, which can cause gastrointestinal dysfunction.

La différenciation cellulaire implique des facteurs clés. Chez la drosophile, le facteur de transcription Glide/Gcm est impliqué dans la différenciation de deux types de cellules immunitaires : les macrophages circulants, qui ont une origine hématopoïétique, et les cellules gliales, macrophages résidents du système nerveux central, qui sont issues des précurseurs neuraux. J'ai d'abord entrepris la caractérisation du potentiel hématopoïétique de Gcm et l'identification de ses cibles dans les hémocytes. Ensuite, pour comprendre comment plusieurs types cellulaires peuvent être spécifiés par un même facteur de transcription, j'ai étudié comment s'effectue le choix entre le destin glial et le destin hémocytaire de la cellule. J'ai en particulier misen évidence le rôle clé des gènes agissant en aval de Gcm, ceux impliqués dans la consolidation et le maintien de l'identité cellulaire. Finalement, j'ai participé à la caractérisation du territoire d'expression de Gcm au niveau protéique et découvert un nouveau rôle de Gcm dans la différenciation de cellules neurosécrétrices, cellules indispensable pour initier le signal hormonal déclenchant le phénomène de mue chez les insectes. / Cell fate determination involves key transcription factors. ln Drosophila, the transcription factor Glide/Gcm is required for the differentiation of two immune cell types: circulating macrophages,which arise from hematopoietic precursors, and glial cells, resident macrophages of the central nervous system, which differentiate from neural precursors. ln first, 1 characterized Gcm hematopoietic potential and identified its target genes in hemocytes. Then, to get an insight intomolecular mechanisms underlying the acquisition of several identities with a single fate determinant, 1 investigated how the choice between the hemocyte and the glial fates is regulated.Being necessary to consolidate and to maintain a specific fate, 1 highlight the key role of genes acting downstream of a fate determinant. Finally, 1 contribute to characterize Gcm expression profile at the protein level and highlight a new role of Gcm in the differentiation of neurosecretory cells, cells absolutely required to initiate the hormonal signal triggering the molting process in insects.