Les dommages au nerf optique (neuropathie optique) peuvent entraîner la perte permanente de la vision ou la cécité causée par la mort des cellules ganglionnaires de la rétine (CGR). Nous avons identifié qu’une surproduction de l'anion superoxyde constitue un événement moléculaire critique précédant la mort cellulaire induite par des lésions. Récemment, Suarez-Moreira et al (JACS 131:15078, 2009) ont démontré que la vitamine B12 peut capter l’anion superoxyde aussi efficacement que l’enzyme superoxyde dismutase. La carence en vitamine B12 peut conduire à une neuropathie optique causée par des mécanismes inconnus. Nous avons étudié la relation entre la captation de superoxyde par la cyanocobalamine (forme de vitamine B12 la plus abondante) et ses propriétés neuroprotectrices dans les cellules neuronales. La cyanocobalamine aux concentrations de 10 μM et 100 μM a réduit le taux de production de superoxyde respectivement par 34% et 79% dans les essais sans-cellule. Dans les cellules RGC-5 traités avec la ménadione, les concentrations de cyanocobalamine supérieures à 10 nM ont diminué l’anion superoxyde à des valeurs similaires à celles traitées par PEG-SOD. La cyanocobalamine aux concentrations de 100 μM et 1 μM a réduit la mort des cellules RGC-5 exposées à la ménadione par 20% et 32%, respectivement. Chez les rats avec section du nerf optique unilatérale, une dose intravitréenne de 667 μM de cyanocobalamine a réduit le nombre de CGRs exposées au superoxyde. Cette dose a également augmenté le taux de survie des CGRs comparativement aux rats injectés avec la solution témoin. Ces données suggèrent que la vitamine B12 peut être un neuroprotecteur important, et sa carence nutritionnelle pourrait causer la mort de CGRs. La vitamine B12 pourrait aussi potentiellement être utilisée comme une thérapie pour ralentir la progression de la mort CGR chez les patients avec les neuropathies optiques caractérisés par une surproduction de superoxyde. / Damage to the optic nerve (optic neuropathy) can result in permanent loss of vision or blindness through retinal ganglion cell (RGC) death. Our prior work identified a burst of superoxide anion as a critical molecular event in RGCs prior to injury-induced cell death. Recently, Suarez-Moreira et al (JACS 131:15078, 2009) demonstrated that vitamin B12 scavenges superoxide as effectively as superoxide dismutase. Vitamin B12 deficiency can lead to optic neuropathy through unknown mechanisms. We investigated the relationship between superoxide scavenging by cyanocobalamin, the most abundant vitamin B12¬¬ vitamer, and its neuroprotective properties in neuronal cells. Cyanocobalamin at concentrations of 10 μM and 100 μM reduced the rate of superoxide generation by 34% and 79% in cell free assays, respectively. In menadione-treated RGC-5 cells, cyanocobalamin concentrations above 10 nM scavenged superoxide anion similar to those treated with pegylated-SOD. Cyanocobalamin at concentrations of 100 μM and 1 mM reduced RGC-5 cell death from menadione by 20% and 32%, respectively. In rats with unilateral optic nerve transection, a single intravitreal dose of 667 μM cyanocobalamin significantly reduced the number of RGCs with superoxide. This dose also increased RGC survival rate compared to rats injected with saline control. These data suggest that vitamin B¬¬12 may be an important neuroprotectant, which could cause death of RGCs when depleted in nutritional deficiency. Vitamin B12 could also potentially be used as a therapy to slow progression of RGC death in patients with optic neuropathies characterized by overproduction of superoxide.

Depuis déjà plusieurs décennies, nous sommes en mesure d'identifier les mutations responsable de diverses maladies mendéliennes. La découverte des gènes responsables de ces maladies permet non seulement un meilleur diagnostic clinique pour ces familles, mais aussi de mieux comprendre les mécanismes physiopathologiques de ces maladies ainsi que mieux définir la fonction normale des gènes causales. Ultimement, ces découvertes mènent à l'identification de cibles thérapeutiques pour le traitement de ces maladies. Les progrès technologiques sont depuis toujours un facteur très important dans la découverte de ces gènes mutés. De l'approche traditionnelle de clonage positionnel en passant par la première séquence du génome humain et maintenant les technologies de séquençage à grande échelle, de plus en plus de maladies ont maintenant une entité génétique. Dans le cadre de ce projet de doctorat, nous avons utilisé tant les approches traditionnelles (leucodystrophies) que les nouvelles technologies de séquençage (polyneuropathie douloureuse) qui ont mené à l'identification du gène causal pour plusieurs de nos familles. L'efficacité de ces deux approches n'est plus à démontrer, chacune d'entre elles possèdent des avantages et des inconvénients. Dans le cadre de ces projets, nous avons utilisé la population canadienne-française connue pour ces effets fondateurs et la présence, encore aujourd'hui, de grandes familles. Les différents projets ont permis d'établir certains avantages et inconvénients quant à l'utilisation de ces techniques et de la population canadienne-française. Dans le cadre d'un phénotype assez homogène et bien défini comme celui du projet leucodystrophie, l'approche traditionnel par gène candidat nous a permis d'identifier le gène causal, POLR3B, sans trop de difficulté. Par contre, pour les autres projets où nous sommes en présence d'une hétérogénéité clinique et génétique une approche non-biaisée utilisant le séquençage exomique a obtenu un plus grand succès. La présence de grandes familles est un grand avantage dans les deux approches. Dans le projet polyneuropathie douloureuse, une grande famille originaire du Saguenay-Lac-St-Jean nous a permis d'identifier le gène NAGLU comme responsable suite à l'exclusion des autres variants candidats par analyse de ségrégation. Comme NAGLU était déjà associé à un phénotype qui diffère sur plusieurs points à celui de notre famille, une approche traditionnelle n'aurait pas été en mesure d'identifier NAGLU comme le gène causal. Dans l'analyse de nos données de séquençage exomique, nous avons observé que plusieurs variants rares, absents des bases de données, étaient partagés entre les différents individus Canadiens français. Ceci est probablement dû à la démographie génétique particulière observée chez les Canadiens français. En conclusion, les technologies de séquençage à grande échelle sont avantageuses dans l'étude de maladies hétérogènes au niveau clinique et génétique. Ces technologies sont en voie de modifier l'approche d'identification de gènes en permettant une analyse de génétique inversée, c'est-à-dire de la génétique vers la clinique. / Since many decades we are able to identify mutations responsible for Mendelian diseases. The identification of the causative gene not only allows a better diagnostic to these families, but also allows a better understanding of the pathophysiological mechanisms of these disorders and of the normal function of a gene. Ultimately, those discoveries lead to the identification of therapeutic targets that will enable clinicians to treat these diseases. Technological progress has forever driven gene identification. Starting with traditional approaches like positional cloning passing through the first sequence of the human genome and finally the recent high-throughput sequencing technologies, more and more diseases are now linked to a genetic cause. During my PhD, I had the opportunity to use traditional approaches (leukodystrophy) as well as new sequencing technologies (painful sensory polyneuropathy) which both led to gene identification for some of our families. The efficiency of these approaches is well known, each of them has advantages and disadvantages. In these projects, we used the french-canadian population well known for its founder effect and the presence, still today, of large families. Working on these projects allowed us to establish advantages and disadvantages concerning the use of those technologies and the french-canadian population. In the presence of a homogenous and well defined phenotype, like the leukodystrophy project, the traditional approach enables us to rapidly identify the causative gene (POLR3B). On the other hand, the unbiased exome sequencing approach has had more success for diseases characterized with clinical and genetic heterogeneity. Large families are a great advantage for both methods. In the painful sensory polyneuropathy project, a large family originated from the Saguenay-Lac-St-Jean region allowed us to identify the NAGLU gene as responsible for the disease after exclusion of the candidate variants by segregation analysis. NAGLU has already been associated with a phenotype that differs in many points with the clinical features observed in our family. In this case a traditional approach would have failed to identify NAGLU as the causative gene. In the analysis of our exome sequencing results, we observed many rare variants absent from databases but shared between french-canadian individuals. This enrichment in rare variants is probably due to the particular genetic demography of Quebec. In conclusion, high-throughput sequencing technologies are advantageous in the study of clinically and genetically heterogeneous diseases. These technologies are changing the gene identification approach towards reverse genetics, meaning genetics towards clinic.

Les neuropathies à anticorps anti-MAG sont secondaires à une gammapathie monoclonale IgM dirigée contre la MAG des gaines de myéline des nerfs périphériques. Le traitement est celui de l’hémopathie sous‐jacente. Même si les thérapeutiques sont de plus en plus efficaces, les hémopathies restent le plus souvent incurables. Le rituximab est couramment utilisé dans le traitement des neuropathies à anticorps anti‐MAG, mais son efficacité n’a pas pu être clairement démontrée dans deux études contrôlées. Le FTY720 ou fingolimod est un sphingolipide, analogue de la sphingosine, qui inhibe les récepteurs de la sphingosine-1-phosphate (S1P). Il est utilisé comme immunosuppresseur dans la Sclérose en Plaques. Des études ont également rapporté un effet cytotoxique du FTY720 dans des hémopathies sans toutefois clairement expliquer son mécanisme d’action. L’objectif de ce travail est d’élucider les mécanismes moléculaires de l’effet cytotoxique du FTY720 dans un modèle d’hémopathie B, la leucémie lymphoïde chronique (LLC). Des cellules leucémiques primaires de LLC et une lignée cellulaire MEC1 ont été utilisées comme modèle expérimental in vitro. Le FTY720, comme la sphingosine, entraîne une cytotoxicité dose‐dépendante dans la LLC. Cet effet, médié par la forme non phosphorylée de FTY720, est indépendant des récepteurs au S1P. Le FTY720 induit l’expression de marqueurs d’apoptose: exposition de la phosphaJdylsérine, clivage de PARP et de caspase 3. Cependant sa toxicité apparaît indépendante des caspases. La lipidation accrue de LC3 et la formation d’autophagolysosomes indiquent que le FTY720 augmente également le flux autophagique. Cependant, des inhibiteurs de l’autophagie ne permettent pas de bloquer la mort cellulaire induite par le FTY720, suggérant que l’autophagie a ici un rôle protecteur vis à vis de la toxicité du FTY720. Plusieurs éléments permettent de conclure que le FTY720 est responsable d’une nécrose cellulaire : aspect morphologique de nécrose en microscopie électronique, perméabilisation membranaire précoce avec relocalisation cytoplasmique de HMGB1, libération extracellulaire de LDH, perméabilisation de la membrane lysosomale associée à une activation des cathepsines. Au niveau moléculaire, l’action du FTY720 n’est pas bloquée par la nécrostatine 1, indiquant que la nécrose induite par le FTY720 est indépendante de RIPK1 (receptor interacJng protein 1), une kinase clef des voies extrinsèques de nécrose cellulaire programmée. Par contre, nos travaux ont établi l’implication de DRP1 (dynamin related protein), une enzyme régulatrice de la fission mitochondriale, dans le processus de nécrose induite par le FTY720. En plus d’une relocalisation précoce de DRP1 à la mitochondrie accompagnée d’une augmentation de sa phosphorylation sur des sites régulateurs de son activité, nos expériences montrent que la suppression de son expression par interférence à ARN dans les cellules leucémiques réduit fortement la mort cellulaire induite par le FTY720. Le FTY720 est donc responsable dans la LLC d’une nécrose cellulaire programmée dépendante de DRP1. Nos résultats illustrent l’implication des sphingolipides dans la régulation de la survie cellulaire et dans les voies de nécrose programmée. Le FTY720 a un mode d’action original différent de l’apoptose induite par les chimiothérapies classiques. Le FTY720 pourrait donc être une alternative thérapeutique dans les néoplasies B résistantes aux chimiothérapies usuelles et dans certaines manifestations auto‐immunes des hémopathies comme les neuropathies à anticorps anti‐MAG. / Fingolimod (FTY720) is an immunosuppressive drug that was recently approved for the treatment of multiple sclerosis and is currently under pre-clinical investigation as a therapy for a number of haematological malignancies. Previous studies have indicated a role for FTY720 in inducing autophagy and caspase-independent cell death in cancer cells through incompletely characterized molecular mechanisms. Our study thus aims at a beeer understanding of the way of action of FTY720. In chronic lymphocytic leukaemia (CLL) cells, FTY720 induced cell death with typical features of apoptosis, including phosphatidylserine exposure and caspase-3 activation, and features of autophagy, including LC3 conversion, autophagolysosome formation and lysosomal cathepsins activation. However, neither caspase nor autophagy blockade prevented the cytotoxic effect of FTY720, suggesting another mechanism of cell death. Using electron and fluorescence microscopy, flow cytometry and biochemical analyses, we found that FTY720 treatment increased a fraction of annexin V-/7-AAD+ cells both in primary and transformed leukemic cells and induced morphological changes representative of necrosis, including oncosis, mitochondrial and plasma membrane alteration. FTY720 treatment resulted in increased plasma membrane permeability as shown by the extracellular translocation of the nuclear high mobility group box 1 (HMGB1) protein and by the release into the culture medium of the cytosolic enzyme lactate dehydrogenase (LDH). Interestingly, cell death induced by FTY720 was not prevented by pharmacological inhibition of RIPK1 and PP2A. In contrast, FTY720--‐induced necrosis was accompanied by an early relocation to the mitochondria of Dynamin Related Protein 1, DRP1. Importantly, FTY720 stimulation led to ma tior changes in the phosphorylation of serine residues associated with the mitochondrial fission activity of DRP1. Finally, siRNA--‐mediated knockdown of DRP1 significantly reduced necrotic cell death induced by FTY720. In this study, we thus demonstrate that in leukemic cells the cytotoxic effect of the immunosuppressive drug Fingolimod involves a DRP1--‐dependent regulated necrosis. These observations are important in line of the future development of Fingolimod as a new therapeutic agent in haematological malignancies.

No description available.

La douleur est une expérience désagréable qui fait partie de notre vie. Quand elle ne dure pas longtemps, elle est un signal d’alarme pour notre organisme. Cependant malheureusement, dans certaines conditions pathologiques, elle se prolonge dans le temps, elle devient alors chronique, intolérable, et nécessite un traitement qui ne suffit pas toujours à soulager le patient, un traitement qui dispose une efficacité limitée avec des effets secondaires indésirables non négligeables. Il est crucial alors d’améliorer nos connaissances sur les mécanismes enclenchés dans la transmission douloureuse pour développer des nouveaux outils thérapeutiques. Dans ce contexte, des études menées ces dernières années dans notre laboratoire ont indiqué que les neurones de la corne dorsale de la moelle épinière présentent des propriétés intrinsèques d’amplification des messages afférents douloureux qui reposent notamment sur des courants calciques via les canaux calciques de type L. Pour cela, le rôle de ces canaux L et plus particulièrement le rôle exact de chaque canal : Cav1.2 et Cav1.3, les deux seuls iso-formes des canaux L exprimés dans la corne dorsale de la moelle épinière, dans la sensibilisation douloureuse a été étudié dans la première partie de ce présent travail. Nous avons étudié chez le rat, in vivo, et en utilisant une approche computationnelle pour simuler l’activité neuronale, l’impact de ces courants Cav1.2 et Cav1.3, à la fois sur le phénomène de Wind-up, une forme de sensibilisation à court terme, et sur un modèle de neuropathie périphérie (SNL) caractérisé par une forme de sensibilisation à long terme. Nous avons pu montrer que la présence de Cav1.3 (mais pas de Cav1.2) est crucial pour l’expression du Wind-up quel que soit le contexte physiopathologique (contrôle/neuropathie), alors que la suppression de Cav1.2 (mais pas de Cav1.3) diminue significativement l’expression du comportement douloureux dans le contexte de neuropathie. D’autre part, il a été montré également dans notre laboratoire que les récepteurs métabotropiques de groupe I (mGluRs I), récepteurs du Glutamate, principal neurotransmetteur excitateur dans la transmission nociceptive, interagissent avec ces canaux L en modulant leur activité. Dans des conditions pathologiques telles que les conditions des douleurs inflammatoires le rôle de ces canaux L est controversé, et si l’interaction entre les mGluRs I et les canaux L est toujours présente dans ces conditions inflammatoires est mal connue. Nous avons décidé alors d’étudier dans la deuxième partie de ce travail le rôle de ces canaux L, et leur interaction avec les mGluRs I dans les conditions des douleurs inflammatoires. En utilisant des approches : l’électrophysiologie extracellulaire in vivo, pharmacologie, comportement, les injections intrathécales, et biologie moléculaire, nous avons montré que l’activation pharmacologique des mGluRs I augmente la transmission nociceptive et que cet effet nécessite l’activation des canaux calciques de type L dans les conditions contrôles. D'une façon inattendue, dans le contexte d’inflammation, nos résultats ont montré que l’activation des mGluRs I induit un effet totalement opposé anti-nociceptif et que cet effet est indépendant des canaux L. En plus, nous confirmons que le blocage des canaux L est sans effet dans le cas d’inflammation. D’autre part, nous avons montré que l’effet contradictoire dû à l’activation des mGluRs I passe par un renforcement de la transmission inhibitrice. En conclusion, nos résultats montrent l’intérêt de cibler les canaux calciques de type L et plus précisément le canal Cav1.2 dans le cadre des douleurs chroniques neuropathiques. De plus, nous montrons aussi que les mGluRs I pourraient être des bons candidats thérapeutiques dans le contexte inflammatoire. / Pain is an unpleasant experience which is part of our lives. When it does not last long time, it is often a warning sign for our organism. However unfortunately, in some pathological cases, it can last a long time, and become chronic, intolerable, and requires a treatment that is not always enough to relieve the patient, a treatment that has limited efficacy with significant undesirable side effects. It is important now to ameliorate our knowledge about the mechanisms implicated in pain transmission to develop new therapeutic tools. In this context, many studies conducted in recent years in our laboratory have indicated that the neurons in the dorsal horn of the spinal cord express intrinsic amplification properties of afferents input rely on calcium currents via the L type calcium channels. For that, the role of L type calcium channels and especially the role exact of each canal: Cav1.2 and Cav1.3, the two only iso-forms of L channels expressed in the dorsal horn of the spinal cord, in the painful sensitization has been studied in the first part of this present work. We studied in rat, in vivo, and by using a computational approach to simulate neuronal activity, the impact of these currents Cav1.2 and Cav1.3, both on the phenomenon of Wind-up, a form of short term sensitization, and in the model of a peripheral neuropathy model (SNL) characterized by a form of long-term sensitization. We showed that the presence of Cav1.3 (but not the Cav1.2) is important for Wind-up’s expression regardless of the physio-pathological context (control / neuropathy), whereas the removal of Cav1.2 (but not Cav1.3) decreases significantly the expression of the pain behavior in the context of neuropathy. In another side, it has been shown in our laboratory that group I metabotropic glutamatergic receptors (mGluRs I), receptors of Glutamate, the main excitatory neurotransmitter in nociceptive transmission, interact with L channels by modulating their activity. In pathological condition such in the condition of inflammatory pain the role of these channels L is controversial, and if the interaction between mGluRs I and L channels is always present in these inflammatory conditions is poorly known. We decided then to study in the second part of this work the role of these channels, and their interaction with mGluRs I in the condition of inflammatory pain. By using electrophysiological extracellular recording, pharmacology, behavior, intrathecal injections, and molecular biology, we showed that pharmacological activation of mGluRs I increase the nociceptive transmission and that this effect requires the activation of L type calcium channels in control conditions. Unexpectedly, in the context of the inflammation, our results show that activation of mGluRs I induce an anti-nociceptive effect and this effect is independent of L channels. Moreover, we confirmed that the blockade of L calcium channels is without effect in case of the inflammation. Furthermore, we showed that the contradictory effect due to the activation of mGluRs I pass through a strengthening of inhibitory transmission. In conclusion, our results show the interest to target L type calcium channels and more specifically the Cav1.2 channel in case of neuropathic chronic pain. We also show that mGluRs I could be good therapeutic candidates in the inflammatory context.

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Monoamines appear to play an important modulatory role on pain descending pathways and are involved in the antinociceptive mechanism of several drugs commonly used for the management of pain. In this study, we assessed the involvement of monoamine oxidase B (MAO-B), a key enzyme implicated in monoamine metabolism, on models of postsurgical and neuropathic pain in mice. For this purpose, we evaluated the effects of the selective and irreversible MAO-B inhibitor selegiline on mechanical sensitivity and ex vivo MAO-B activity in different central nervous system regions in mice submitted to incisional and partial sciatic nerve ligation (PSNL) pain models. Mice subjected to plantar incision showed a significant decrease in mechanical threshold when compared with sham-operated mice, characterizing the development of mechanical allodynia. Selegiline, at a dose sufficient to inhibit selectively the MAO-B activity (10 mg/kg), showed an anti-allodynic effect from 0.5 until 6 h after incision. The MAO-B activity was not altered in incision submitted mice when compared with sham-operated animals in any analyzed structure. Likewise, PSNL submitted mice also developed mechanical allodynia, which was reversed by selegiline (10 mg/kg) from 2 until 6 h after treatment. In addition, a significant increase on striatal MAO-B activity was observed in mice subjected to PSNL when compared with sham-operated animals, which was reversed by selegiline treatment. Taken together, our results showed that selegiline presented an antinociceptive effect on mice models of both acute and chronic pain, suggesting a potential involvement of MAO-B on pain mechanisms. / As monoaminas possuem uma função modulatória importante nas vias descendentes do controle da dor e estão envolvidas no mecanismo antinociceptivo de diversos fármacos comumente utilizados no tratamento de síndromes dolorosas. Nesse estudo, nós avaliamos a participação da monoamina oxidase B (MAO-B), uma enzima chave envolvida no metabolismo das monoaminas, em modelos de dor pós-operatória e neuropática em camundongos. Para esse propósito, foram avaliados os efeitos da selegilina, um inibidor seletivo e irreversível da MAO-B, na sensibilidade mecânica e na atividade ex vivo da MAO-B em diferentes regiões do sistema nervoso central (córtex cerebral, estriado e medula espinhal) de camundongos submetidos à incisão plantar ou à ligação parcial do nervo ciático (PSNL). Os camundongos que foram submetidos à incisão plantar apresentaram uma diminuição significativa no limiar mecânico quando comparados aos animais falso-operados, caracterizando o desenvolvimento de alodínia mecânica. Tanto o pré quanto o pós-tratamento com selegilina, em uma dose capaz de inibir seletivamente a atividade da MAO-B (10 mg/kg, p.o.), apresentaram efeito anti-alodínico a partir de 0,5 até 6 h após o tratamento. A atividade da MAO-B, medida 4 h após o procedimento cirúrgico, não foi alterada nos camundongos submetidos à incisão quando comparada com a atividade dos animais falso-operados em nenhuma das estruturas analisadas. Os camundongos submetidos à PSNL também desenvolveram alodínia mecânica, a qual foi revertida pela selegilina (10 mg/kg, p.o.) de 2 até 6 h após o tratamento. Além disso, os camundongos submetidos à PSNL apresentaram um aumento significativo na atividade da MAO-B no estriado 4 h após o tratamento, o qual foi revertido pela selegilina. Foi observado também que a selegilina, em uma dose sem efeito antinociceptivo (1 mg/kg, p.o.) em ambos os modelos de dor utilizados, não foi capaz de inibir a atividade da MAO-B. Nossos resultados mostram que a selegilina apresentou um efeito antinociceptivo tanto em um modelo de dor aguda quanto em um modelo de dor crônica, sugerindo um possível envolvimento da MAO-B nos mecanismos da dor.

A Neuropatia autonômica cardiovascular (NAC), apesar de ter sido apontada como fator de risco independente para doença cardiovascular (DCV) em pacientes com diabetes tipo 1 (DM1), permanece subdiagnosticada. Os objetivos do trababalho foram determinar a prevalência de NAC e seus indicadores clínicos e laboratoriais em pacientes com DM1 e a associação com outras complicações crônicas do diabetes, além de avaliar a concordância entre os critérios diagnósticos da NAC determinados pelos parâmetros da análise espectral e pelos testes reflexos cardiovasculares. Pacientes com DM1, duração da doença ≥ 5 anos e com idade ≥ 13 anos foram submetidos a um questionário clínico-epidemiológico, a coleta de sangue e de urina para determinação da concentração urinária de albumina, ao mapeamento de retina, e exame clínico para pesquisa de neuropatia diabética sensitivo motora além da realização de testes reflexos cardiovasculares. Cento e cinquenta e um pacientes com DM1, 53.6 % do sexo feminino, 45.7% brancos, com média de idade de 33.4 13 anos, idade ao diagnóstico de 17.2 9.8 anos, duração de DM1 de 16.3 9.5 anos, índice de massa corporal (IMC) de 23.4 (13.7-37.9) Kg/m2 e níveis de hemoglobina glicada de 9.1 2% foram avaliados. Após realização dos testes para rastreamento das complicações microvasculares, encontramos neuropatia diabética sensitivo motora, retinopatia diabética, nefropatia diabética e NAC em 44 (29.1%), 54 (38%), 35 (24.1%) e 46 (30.5%) dos pacientes avaliados, respectivamente. A presença de NAC foi associada com idade (p=0.01), duração do DM (p=0.036), HAS (p=0.001), frequência cardíaca em repouso (p=0.000), HbA1c (p=0.048), uréia (p=0.000), creatinina (p=0.008), taxa de filtração glomerular (p=0.000), concentração urinária de albumina (p=0.000), níveis séricos de LDL-colesterol (p=0.048), T4 livre (p=0.023) e hemoglobina (p=0.01) e a presença de retinopatia (p=0.000), nefropatia (p=0.000) e neuropatia diabética sensitivo motora (p=0.000), além dos seguintes sintomas; lipotimia (p=0.000), náuseas pós alimentares (p=0.042), saciedade precoce (p=0.031), disfunção sexual (p=0.049) e sudorese gustatória (p=0.018). No modelo de regressão logística binária, avaliando o diagnóstico de NAC como variável dependente, foi observado que apenas a FC em repouso, presença de neuropatia diabética sensitivo motora e retinopatia diabética foram consideradas variáveis independentes significativamente. A NAC é uma complicação crônica comum do DM1, atingindo cerca de 30% dos pacientes estudados e encontra-se associada à presença de outras complicações da doença. Indicadores da presença de NAC nos pacientes avaliados incluíram a idade, duração do diabetes, presença de HAS, frequência cardíaca de repouso e presença de sintomas sugestivos de neuropatia autonômica. O presente estudo ratifica a importância do rastreamento sistemático e precoce desta complicação. / The cardiovascular autonomic neuropathy (CAN), although considered as an independent risk factor for cardiovascular disease (CVD) in both patients with type 1 diabetes (T1D), remains underdiagnosed. The objective were to determine the prevalence, clinical and laboratorial indicators of CAN in patients with T1D and its association with other chronic complications of diabetes and evaluate the concordance between the diagnostic criteria for CAN diagnosis determined by the parameters of spectral analysis and the cardiovascular reflex tests. Patients with T1D aged ≥ 13 years and diabetes duration ≥ 5 years underwent a clinical-epidemiological survey, had blood samples collected, urinary samples for the determination of urinary albumin concentration, ophtalmoscopic exam, clinical neurological examination for diabetic neuropathy screeening and cardiovascular reflex tests. One hundred and fifty one patients with T1D, 53.6 % female, 45.7% Caucasian, mean age of 33.4 13 years, age at diagnosis of 17.2 9.8 years, diabetes duration of 16.3 9.5 years, body mass index (BMI) of 23.4 (13.7-37.9) kg/m2, glycated hemoglonin levels of 9.1 2% were evaluated. After performing the tests for screening for microvascular complications, we found diabetic sensory motor neuropathy, diabetic retinopathy, diabetic nephropathy and CAN in 44 (29.1%), 54 (38%), 35 (24.1%) and 46 (30.5%) of the patients, respectively. CAN was associated with age (p=0.01), diabetes duration (p=0.036), hypertension (p=0.001), resting heart rate (p=0.000), HbA1c (p=0.048), urea (p=0.000), creatinine (p=0.008), glomerular filtration rate (p=0.000), urinary albumin concentration (p=0.000), LDL-cholesterol (p=0.048), free T4 (p=0.023), hemoglobin (p=0.01) and presence of retinopathy (p=0.000), nephropathy (p=0.000) and diabetic neuropathy (p=0.000), the following symptons syncope (p=0.000), post prandial nausea (p=0.042), early saciety (p=0.031), sexual dysfunction (p=0.049) and gustatory sweating (p=0.018). In binary logistic regression model evaluating the diagnosis of CAN as a dependent variable, it was observed that only resting heart rate, presence of diabetic neuropathy and retinopathy were considered independent variables significantly. CAN is a common chronic complication of T1D affecting about 30% of the studied population and is associated with the presence of other chronic complications of T1D. Indicators of the presence of CAN included age, duration of diabetes, presence of hypertension, resting heart rate and symptoms suggestive of autonomic neuropathy. This study confirms the importance of systematic and early screening for this complication.

Les relations entre douleur, dysautonomie et atteinte des petites fibres nerveuses sont complexes. Notre travail a porté sur les relations entre le phénotypage clinique de la douleur d’une part, et sur la caractérisation neurophysiologique des atteintes autonomes d’autre part, dans le contexte d’atteinte des petites fibres nerveuses. Ceci a fait l’objet de 5 études. La première étude a montré que plusieurs variables cliniques permettaient de caractériser la douleur de façon différentielle entre des patients atteints de neuropathie des petites fibres idiopathique ou secondaire à un syndrome de Sjögren. La deuxième étude a montré que la lésion ou la perte de fonction des petites fibres entraînait plutôt une majoration de la sensibilisation centrale et des anomalies liées aux grosses fibres sensitives chez des patients ayant un syndrome de Sjögren douloureux associé à une neuropathie des petites fibres. La troisième étude a montré que, dans le syndrome du canal carpien, les troubles sensitifs, en dehors des sensations de brûlure, étaient aussi liés de façon prédominante aux grosses fibres, avec cependant une sensibilité diagnostique particulière de l’étude des fibres autonomes vasomotrices par le test à l'EMLA. La quatrième étude a porté sur l’intérêt de la mesure des conductances cutanées par Sudoscan ® dans le suivi des neuropathies amyloïdes et de leur traitement. Enfin, la cinquième étude a permis d’analyser la sensibilité diagnostique respective de deux tests sudoromoteurs (Sudoscan® et Neuropad®) dans le cadre de la détection précoce de la neuropathie amyloïde et aussi pour le suivi des patients, au moins en ce qui concerne le Sudoscan®. Avec tous ces aspects, ce travail a permis de mieux comprendre les relations entre troubles sensitifs et atteinte des petites fibres sensitives et autonomes dans des contextes neuropathiques cliniques, comme le syndrome de Sjögren, le syndrome du canal carpien et la neuropathie amyloïde. / The relationships between pain, autonomic dysfunction and involvement of small nerve fibers are complex. Our work focused on the relationships between clinical phenotyping of pain on the one hand, and the neurophysiological characterization of autonomic disorders on the other hand, in the context of small nerve fiber involvement. This has been the subject of 5 studies. The first study showed that several clinical variables differentially characterize pain between patients with idiopathic small fiber neuropathy or secondary to Sjögren's syndrome. The second study showed that the lesion or loss of function of small fibers led to an increase in central sensitization and abnormalities related to large sensory fibers in patients with painful Sjögren's syndrome associated with small fiber neuropathy. The third study showed that, in carpal tunnel syndrome, sensory disturbances, apart from burning sensations, were also predominantly related to large fibers, with however a particular diagnostic sensitivity of the study of autonomic vasomotor fibers by the EMLA test. The fourth study focused on the interest of measuring electrochemical skin conductance with Sudoscan ® in the monitoring of amyloid neuropathies and their treatment. Finally, the fifth study analyzed the respective diagnostic sensitivity of two sudoromotor tests (Sudoscan® and Neuropad®) in the context of early detection of amyloid neuropathy and also for patient follow-up, at least with Sudoscan®. With all these aspects, this work has led to a better understanding of the relationships between sensory disturbances and small sensory and autonomic fibre disorders in clinical neuropathic contexts, such as Sjögren's syndrome, carpal tunnel syndrome and amyloid neuropathy.

Submitted by Marlene Santos (marlene.bc.ufg@gmail.com) on 2018-07-11T17:48:42Z No. of bitstreams: 2 Tese - Luciano de Sousa Pereira - 2017.pdf: 2889362 bytes, checksum: cfbc7fe755a68223cf99e2cd3795be90 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2018-07-12T11:26:01Z (GMT) No. of bitstreams: 2 Tese - Luciano de Sousa Pereira - 2017.pdf: 2889362 bytes, checksum: cfbc7fe755a68223cf99e2cd3795be90 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) / Made available in DSpace on 2018-07-12T11:26:01Z (GMT). No. of bitstreams: 2 Tese - Luciano de Sousa Pereira - 2017.pdf: 2889362 bytes, checksum: cfbc7fe755a68223cf99e2cd3795be90 (MD5) license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Previous issue date: 2017-03-14 / Non-arteritic anterior ischemic optic neuropathy (NAION) is the most common acute optic neuropathy in patients over fifty years of age. Management centers around prevention of second eye involvement, without uniformly accepted therapeutic intervention for the involved eye. Several researchers have assessed the benefit of steroids with conflicting results. Animal models based on selective photothrombosis of the microcirculation within the optic nerve head have contributed both to a better understanding of pathophysiological mechanisms associated to NAION; also, it has enabled the testing of potential therapeutic approaches. This study was deisigned to evaluate the efficacy of a single intravitreal triamcinolone acetonide injection (IVTA) in preserving retinal ganglion cells (RGCs) in a rodent model of anterior ischemic optic neuropathy (rNAION). Rodent NAION (rNAION) was induced in female Wistar rats. Animals were randomized into three groups: 1) untreated, 2) treated with 56 μg IVTA, and 3) treated with placebo (intravitreal saline). Procedures were performed in the left eye, with the right eye serving as an internal control. After 30 days, animals were sacrificed and eyes were assessed histologically for RGC number. The average number of RGCs was significantly higher in the control group when compared to rNAION subgroups (p < 0.001). No significant difference was seen between rNAION eyes treated with IVTA, placebo, and untreated eyes (P > 0.05%). In this rodent model for NAION, no therapeutic benefit of intravitreal steroid injection was identified. / A neuropatia óptica isquêmica anterior não-arterítica (NOIA-NA) é a neuropatia óptica aguda mais frequente após os 50 anos de idade. Atualmente, a conduta é centrada na prevenção do acometimento do segundo olho, não havendo, ainda, consenso referente à intervenção terapêutica para o olho acometido. Muitos pesquisadores avaliaram o benefício dos corticosteroides na NOIA-NA, com resultados controversos. Modelos animais baseados na fototrombose seletiva da microcirculação da cabeça do nervo óptico têm contribuído tanto para um maior conhecimento dos mecanismos fisiopatológicos associados a NOIA-NA, quanto para a identificação de potenciais abordagens terapêuticas. O objetivo desse estudo foi avaliar a eficácia da triancinolona intravítrea (TAIV) na preservação das células ganglionares da retina (CGRs) em um modelo animal de NOIA-NA em ratos (rNOIA). A rNOIA foi induzida em 30 ratas da linhagem Wistar. Os animais foram aleatoriamente selecionados em 3 grupos: 1) rNOIA não tratado, 2) rNOIA tratado com 5,6 μg de TAIV, 3) rNOIA tratado com placebo (solução salina intravítrea). Os procedimentos foram realizados no olho esquerdo de cada animal; o olho direito serviu como controle interno. Os tratamentos foram realizados dentro dos primeiros 15 minutos após a indução da rNOIA. Trinta dias após o experimento, os animais foram sacrificados e os olhos foram avaliados histologicamente para contagem e comparação do número de CGRs. A média do número de CGRs foi significamente menor nos subgrupos de rNOIA quando comparados ao grupo controle (p < 0,001). Não foi encontrada diferença estatística entre olhos com rNOIA tratados com TAIV, placebo e não tratados (p > 0,05). Neste modelo animal, a triancinolona intravítrea não se mostrou eficaz na preservação do número de células ganglionares da retina.

The Charcot-Marie-Tooth disease (CMT) is peripheral neuropathy genetically inherited most common worldwide. The most cases of CMT can be classified into two major categories of the nature of the primary nerve injury: CMT type 1 and type 2. The main clinical symptoms are muscle weakness and decreased sensation in the legs and feet, changes in gait and balance. The objectives of this study were to conduct a systematic review of the balance and functionality of individuals with the disease of Charcot-Marie-Tooth (CMT), as well as assess the muscle strength, balance and functionality of individuals with the disease of Charcot-Marie-Tooth type 2 ( CMT2). Methods: A comprehensive literature search was performed using as a database MEDLINE, PubMed, Web of Science, Scopus (1980- 2015). Furthermore, an observational and cross-sectional study was conducted through interviews and clinical evaluation of individuals with CMT2 disease in the city Tobias Barreto. The sample consisted of a group of 15 patients with CMT2 (GCMT2) and a control group (CG), with healthy subjects matched for age and gender with CMT2 group. Individuals with CMT were classified by Neuropathic scale of Charcot-Marie-Tooth disease (Neuropathy Scale Charcot-Marie-Tooth - CMTNS) that assesses the degree of severity of the disease. The muscle strength of the lower limbs was evaluated by a hand dynamometer. The balance was measured through footwork stabilometer and Berg Balance Scale. Functional assessment was measured by the Timed Up Go test (TUG). Results: In the systematic review were selected 18 articles, most of the cross-sectional and performed in Europe. The types of study were prevailed on assessment of balance and functionality, rehabilitation treatment and natural evolution of CMT disease. The number of participants per study ranged 6-211 affected individuals. In the second article, there was a statistically significant difference between the GCMT2 and GC for muscle strength of all assessed muscles (ankle extensor: p = <0.0001, plantarflexors: p = <0.0001, inverters: p = <0.0001, eversors: p = 0.0016).For the VCoPAP and DCopAP parameters stabilometry for open and closed eyes, respectively (p = 0.0123, p = 0.0183, p = 0.0132, p = 0.0129) for the Berg balance scale (p = 0.0066) and the TUG (p = 0.0003) test. The most evident correlations were between all variables and CMTNS. In addition, individuals with CMT2 have loss of balance in the anteroposterior direction and with increasing severity of the disease these individuals need more vision for maintaining balance. Conclusion: Most studies of the systematic review evaluating balance and /or functionality also included in their assessments to measure muscle strength and sensitivity. Furthermore, studies have shown that the distal muscle weakness, especially ankle extensor plantar flexors and is associated with loss of balance and dynamic activities in the stop position, respectively. Clinical evaluations, conducted in CMT2 group and control group, showed that patients with Charcot-Marie-Tooth have less balance and loss of functional activity as compared to healthy subjects. / A doença de Charcot-Marie-Tooth (CMT) é a neuropatia periférica geneticamente herdada mais frequente em todo mundo. A maioria dos casos de CMT pode ser classificada em duas grandes categorias quanto à natureza da lesão primária do nervo: CMT tipo 1 e tipo 2. As principais manifestações clínicas são fraqueza muscular e diminuição da sensibilidade nas pernas e pés, alterações na marcha e equilíbrio. Os objetivos deste estudo foram realizar uma revisão sistemática sobre o equilíbrio e funcionalidade de indivíduos com a doença de Charcot-Marie-Tooth (CMT), assim como avaliar a força muscular, o equilíbrio e funcionalidade de indivíduos com a doença de Charcot-Marie-Tooth tipo 2 (CMT2). Métodos: Uma pesquisa abrangente na literatura foi realizada utilizando como base de dados a MEDLINE-PubMed, Web of Science, Scopus (1980- 2015). Além disso, foi realizado um estudo observacional e transversal, por meio de entrevista e avaliação clínica de indivíduos com a doença de CMT2 no município de Tobias Barreto. A amostra foi composta por um grupo com 15 pacientes com CMT2(GCMT2) e um grupo controle (GC), com indivíduos saudáveis pareados por idades e gêneros com o grupo CMT2. Os indivíduos com CMT foram classificados pela escala neuropática de Charcot-Marie-Tooth (Charcot-Marie-Totth Neuropathy Score - CMTNS) que avalia o grau de severidade da doença. A força muscular foi avaliada através de um dinamômetro manual. O equilíbrio foi mensurado através do baropodômetro footwork e da escala de equilíbrio de Berg. A avaliação funcional foi mensurada pelo teste Timed Up Go (TUG). Resultados: Na revisão sistemática foram selecionados 18 artigos. Os tipos de estudo que prevaleceram foram sobre avaliação do equilibrio e funcionalidade, tratamento de reabilitação e evolução natural da doença de CMT. A maioria dos estudos encontrou que a fraqueza muscular e alterações da sensibilidade estavam relacionadas à perda de equilíbrio e menor desempenho das atividades funcionais. No segundo artigo, houve diferença estatisticamente significativa entre o GCMT2 e GC para força muscular de todos os músculos avaliados (dorsiflexores: p= < 0.0001, flexores plantares: p= < 0.0001, inversores: p= < 0.0001, eversores: p= 0.0016), para os parâmetros VCoPAP e DCopAP da estabilometria para olhos abertos e fechados respectivamente (p= 0,0123; p= 0,0183, p= 0,0132, p=0,0129), para a escala de equilíbrio de Berg (p=0,0066) e para o teste TUG ( p = 0.0003). As correlações mais evidentes foram entre todas as variáveis analisadas e o CMTNS. Além disso, indivíduos com CMT2 apresentam perda de equilíbrio no sentido ântero-posterior e com o aumento da severidade da doença esses indivíduos necessitam mais da visão para manutenção do equilíbrio. Conclusão: A maioria dos estudos da revisão sistemática que avaliaram equilibrio e/ou funcionalidade também incluiram em suas avaliações a mensuração da força muscular e sensibilidade. Além disso, os estudos mostraram que a fraqueza muscular distal, especialmente de dorsiflexores e flexores plantares, está associada à perda de equilíbrio em atividades dinâmicas e a posição estática, respectivamente. As avaliações clínicas, realizadas no grupo CMT2 e grupo controle, revelaram que pacientes com Charcot-Marie-Tooth têm menor equilíbrio e prejuízo das atividades funcionais quando comparados aos indivíduos saudáveis.