Doctor of Philosophy / Abstract Neurodegenerative disorders are a diverse group of disorders that affect specific subsets of neurons. Motor neuron diseases, neurodegenerative disorders of motor neurons, are seen commonly as sporadic cases and less frequently as familial disease forms. The familial forms show genetic and phenotypic heterogeneity. Clinically motor neuron diseases may be seen as rapidly progressive disorders like amyotrophic lateral sclerosis, ALS or slowly progressive disorders like hereditary motor neuropathies, HMN. The only proven causes for motor neuron diseases are gene mutations that lead to motor neuron degeneration in familial disease forms. Only some of these genes have been identified and have contributed greatly to our understanding of the neurobiology of familial and sporadic disease forms. Identification of additional disease causing genes would help enhance our knowledge of the pathophysiological mechanisms underlying all forms of motor neuron disorders, which would lead to early diagnoses, effective prophylaxis and efficient therapies for these disorders. This study aimed to find gene mutations that cause rapid and slowly progressive familial motor neuron disorders in Australian families and to determine their relevance to sporadic forms of motor neuron disease. The familial forms of ALS show reduced disease penetrance, that is, not all gene mutation carriers manifest the disease. This study examines ALS penetrance in a group of Australian families. The most frequently observed mutations in ALS families are cytosolic superoxide dismutase/SOD1 gene mutations. In a collection of ALS families in our centre, families without the common SOD1 gene mutations were genotyped for other ALS genes and loci and studied using genetic linkage and haplotype analyses. Studies in a large Australian ALS family further confirmed genetic heterogeneity in non-SOD familial ALS, all known autosomal dominant ALS genes and chromosomal loci were excluded as cause of disease in this family. Such families can be studied further to identify additional disease genes and loci mapped in other ALS families. These families represent powerful resources for identification of additional ALS genes. Identifying the pathogenic genes in families with reduced disease penetrance may be more relevant to sporadic forms of disease. dHMN is a chronic neurodegenerative disorder predominantly affecting motor neurons. In a large Australian dHMN family, all the known dHMN genes and chromosomal loci were excluded as cause of disease. A genome wide microsatellite screen was performed in this family and genetic linkage was established to a novel 12.98 Mb locus on chromosome 7q34.2-q36. Candidate genes in this large interval will be screened based on their function and expression profile. Identification of a new dHMN locus provides the basis for future identification of a novel gene involved in motor neuron degeneration. Genes in dHMN have been shown to be pathogenic in ALS and Charcot Marie Tooth syndromes. The new locus for dHMN mapped in this project would lead to identification of a novel dHMN gene, which may elucidate the pathogenesis underlying a wide range of neurodegenerative disorders.

Diss. (sammanfattning) Umeå : Umeå universitet, 2005. / Härtill 6 uppsatser.

La sclérose Latérale Amyotrophique (SLA) est une maladie neurodégénérative des motoneurones impliquant des facteurs environnementaux et génétiques. Notre étude porte sur l’étude des relations entre la voie de la SUMOylation post-Traductionnelle des protéines et les effets du stress oxydant et de mutants SOD1. Nous montrons tout d’abord que 2 nouveaux mutants, SOD1V31A et SOD1E121G identifiés chez des patients SLA à évolution lente, entraîne la formation d’agrégats cellulaires Ub/SUMO dans la formation des agrégats était suggérée. Nous montrons 1) que les NSC-34 exposées à un stress oxydant et exprimant SOD1 mutée présentent une modification d’expression de plusieurs gènes des voies de l’Ub/SUMO ; 2) que l’expression de SOD1 mutée réduit le pool de protéine SUMO-1 libre dans les cellules motoneuronales, possible conséquence d’une séquestration dans les agrégats ; 3) qu’inhiber la SUMOylation de SOD1 mutée réduit la quantité de cellules avec agrégats. Nos résultats indiquent qu’une meilleure connaissance de la voie de SUMO pourrait conduire à de nouvelles cibles thérapeutiques intéressantes dans la SLA. / Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disease of motor neurones involving a combination of environmental and genetics factors. Ours work focuses on the relathionship between the SUMOylation pathway and the effects of oxidative stress and SOD1 mutants. We first show that 2 new mutants, SOD1V31A and SOD1E121G identified in ALS patients with a slowly progressive disease, induce the formation of Ub/SUMO positive aggregates in motor neuronal cells NSC-34. The implication of the Ub/SUMO pathways has been proposed in the formation of aggregates in ALS. We show 1) modification of expression of several genes of the Ub/SUMO pathways in NSC-34 exposed to oxidative stress and expressing various mutated SOD1 proteins; 2) that the expression of mutants SOD1 reduces free-SUMO1 concentration in motor neuronal cell, perhaps by a sequestration in aggregates; 3) that the inhibition of SUMIylation of various mutants SOD1 reduces the amount of cells with aggregates. Our results support further studies on the SUMO pathway that may lead to new therapeutics targets in ALS.

Chronic Traumatic Encephalopathy (CTE) is a neurodegenerative disease caused by repetitive head trauma and mild traumatic brain injuries (mTBIs) and has been associated with contact sports such as football, boxing, and ice hockey. CTE is a slowly progressing neurological disease that is often clinically associated with symptoms of memory loss, decline in cognitive function, behavioral changes such as increased impulsivity and aggression, and/or suicidal thoughts. Advanced stages of the disease present with more severe neurological changes such as dementia, speech and gait abnormalities, and parkinsonism. Amyotrophic Lateral Sclerosis (ALS, also known as Lou Gehrig Disease) is a progressive and fatal neurodegenerative disease characterized by motor neuron loss and corticospinal tract degeneration. While 90-95% of ALS cases are sporadic in nature, many genetic mutations have been identified that contribute to familial forms of the disease. The etiology of sporadic ALS is unknown but it is likely caused by a complex interaction of various genetic and environmental risk factors. Epidemiological evidence suggests that one such risk factor is brain trauma, the main risk factor associated with the development of CTE. In this study the spinal cord tissue of twelve athletes diagnosed with CTE who also developed a progressive motor neuron disease and showed symptoms of profound muscle weakness, atrophy, spasticity, and fasciculations several years before death was examined. The spinal cord tissue from these 12 CTE cases with motor neuron disease (CTE+MND) was compared to the spinal cord tissue of 10 sporadic ALS control cases. Results showed a difference in frequency of tau pathology between the two disease cohorts, as one-third of CTE+MND cases and none of the ALS cases showed tau immunoreactivity. In addition, TDP-43 immunoreactivity was present in every CTE+MND case but one and was present in all ALS cases. Motor neuron inclusions were positive for both FUS and p62 in both cohorts, and no distinct differences were observed cystatin C pathology. Overall, this suggests that the spinal cord inclusions in CTE+MND have a similar composition to sporadic ALS. However, there is an increased frequency of tau pathology in CTE+MND though this result did not reach statistical significance in this study.

Bakgrund: Amyotrofisk lateralskleros är en fortskridande motorneuronsjukdom som drabbar de nervceller som styr skelettmuskulaturen. Sjukdomen leder till en successivt ökande muskelförsvagning och till sist döden, oftast inom 3-5 år från det att diagnos satts. Sjukdomen orsakar ett stort lidande för patienten och dennes närstående då den kan vara snabbt fortskridande och oförutsägbar. Syfte: Syftet var att beskriva upplevelsen av att leva med ALS. Metod: Studien genomfördes som en kvalitativ litteraturstudie med induktiv ansats och är baserad på 10 kvalitativa originalartiklar. Artiklarna analyserades med hjälp av en manifest innehållsanalys och resulterade i 4 huvudkategorier och 12 underkategorier. Resultat: Resultatet visade att upplevelsen av att leva med ALS är individuell men vissa fynd stack ut mer än andra. Dessa var de ständiga förlusterna sjukdomen medförde, upplevelsen av att vara en börda för andra, sjukdomen gav patienten en ny synvinkel på livet samt att kunna finna mening trots sjukdomen. Slutsats: Upplevelsen av ALS är mångdimensionell och individuell. Sjukdomen innebär svåra prövningar för den drabbade individen men med rätt stöd från anhöriga och sjuksköterskan kan lidandet lindras och meningen i livet bibehållas.

A Esclerose Lateral Amiotrófica (ELA) é uma doença progressiva caracterizada pela perda de neurônios motores levando rapidamente os pacientes à morte. Os mecanismos da morte neuronal são desconhecidos e estudos recentes indicam que a microglia pode participar deste processo. Para investigar o papel da microglia na ELA, camundongos transgênicos SOD1G93A foram utilizados na avaliação da morte e do trofismo neuronal em sistemas de co-culturas neurônio/microglia e do efeito do meio condicionado microglial sob os neurônios motores. Ambas as células foram extraídas da medula espinal de camundongos transgênicos (TG) e wild type (WT). A microglia foi obtida dos animais neonatos e adultos na fase pré-clínica da doença. Os neurônios extraídos de neonatos foram marcados com reagente específico para morte neuronal e seus prolongamentos foram quantificados em contraste de fase por métodos estereológicos específicos. A expressão gênica de moléculas candidatas à participação do processo neurodegenerativo relacionadas com a microglia foi quantificada pelo PCR em tempo real, assim como a quantidade de moléculas secretadas no meio condicionado das culturas microgliais dosada pelo ELISA sanduíche. O meio condicionado da microglia TG neonatal não foi capaz de acentuar a morte neuronal, entretanto a neurodegeneração foi potenciada nas análises das co-culturas. Interessantemente, o meio condicionado das microglias WT provenientes de animais adultos foram capazes de aumentar os prolongamentos neuronais feito não observado em relação às microglias TG. Quantidades aumentadas do fator de necrose tumoral ?, interleucina-6 e fator de crescimento derivado do nervo foram quantificadas no meio condicionado das microglias TG. A microglia TG neonatal apresentou dimuição na expressão gênica de AKAP13, HIPK3, UBE2I E NTF5. Esses achados precoces sugerem perda de migração microglial, perda de resistência à apoptose, desbalanço entre proliferação e morte celular e diminuição do suporte trófico neuronal. Em conjunto, os resultados evidenciam a participação da microglia nos mecanismos da ELA / Amyotrophic Lateral Sclerosis (ALS) is a progressive degenerative disorder affecting motoneurons and leading the patient to death.The cause of motor neurons degeneration in ALS is uncertain and there is any treatment able to prolong the patient life. Recent studies show that microglia could participate of the process of ALS degeneration. Its activation is linked to the disbalance of neuroprotective and neurotoxic action. To investigate the microglia role in ALS, SOD1G93A transgenic mice that develop symptoms similar to the clinical disease were used. We evaluated the neuronal death and trophism in microglia/neuron co-cultures system and in microglial conditioned medium effect under the neurons. Neurons and microglia were extracted from transgenicor wild type mice spinal cord. Microglia was obtained from 1 day pos natal pups and adult onset of disease mice. Cells were stained with a specific marker to neuronal death. Neuronal extensions area and neuronal death was quantified by stereological method. The genic expression of candidate molecules related to degeneration in ALS was quantified by real time PCR and the release of some molecules were quantified by ELISA sandwich. Results showed that maybe transgenic neonatal microglia is not able to increase the neuronal death through releasing molecules in its conditionated medium, on the other hand when transgenic microglia was co-cultured with any kind of neuron, neuronal death was observed. Microglia from adult transgenic mice was not able to promote a neuroprotection compared to wild type in co-culture and conditionated medium experiments. In addition to this, was observed increased tumor necrosis factor alpha, interleukin 6 and nerve growth factor secretion by transgenic microglia. Neonatal transgenic microglia also exhibited reduced genic expression of AKAP13, HIPK3, UBE2I and NTF5. These findings at an early stage suggest a lost of migration potential, lost of apoptosis resistance, disbalance of proliferation and cell death and reduction of neuronal trophic support. So together, these data indicate the involvement of microglia in ALS mechanisms

A Esclerose Lateral Amiotrófica (ELA) é uma doença neurodegenerativa de caráter progressivo caracterizada pela morte seletiva de neurônios motores que leva rapidamente os pacientes à morte. O camundongo transgênico que expressa a superóxido dismutase 1 humana mutante é o modelo experimental mais aceito para o estudo da doença. Os mecanismos que levam a perda neuronal ainda são pouco conhecidos e não existe tratamento eficaz para prolongar a vida do indivíduo. Estudos recentes indicam que as células gliais aceleram o processo neurodegenerativo, entretanto os mecanismos moleculares ainda não estão estabelecidos. Os astrócitos merecem uma atenção particular, pois apresentam íntima interação com os neurônios, fornecendo suporte estrutural, metabólico e trófico. Além disso, participam ativamente da modulação excitatória neuronal e da neurotransmissão, controlando os níveis extracelulares de íons e neurotransmissores. O presente estudo propôs investigar in vitro os possíveis dos astrócitos extraídos da medula espinal do camundongo de idade neonatal (P1) e adulta pré-sintomática (P60) sobre a morte de neurônios motores na ELA. Para isso, o trofismo e sobrevida do neurônio motor espinal foram avaliados nas culturas de neurônios motores tratados com meio condicionado de astrócitos e também em sistemas de co-culturas neurônios motores/astrócitos, de origem SOD1G93A (transgênica) e selvagem (wild type) em diferentes combinações. Investigou-se ainda, a expressão gênica de genes nos astrócitos nas culturas P1 e P60 realizadas através do PCR quantitativo (qPCR) e a quantificação de moléculas secretadas pelos astrócitos por ELISA Sanduíche. Para o estudo do trofismo e degeneração neuronal, as células foram marcadas com marcadores específicos de morte neuronal e o trofismo dos neurônios também foi quantificado por contraste de fase. As células foram quantificadas por métodos estereológicos específicos e as análises mostraram que o tratamento com meio condicionado de astrócitos transgênicos P1 e P60 causaram respectivamente retrações nos prolongamentos e morte dos neurônios transgênicos. As análises da morte neuronal dos meios condicionados e co-cultura mostraram que os astrócitos transgênicos de ambas as idades causaram a morte de neurônios wild type e apenas os astrócitos transgênicos P60 levaram os maiores perfis de morte nos neurônios transgênicos, demonstrando a toxidade dessas células. Quanto à análise da expressão gênica, os genes NKRF, UBE2I e TGFA mostraram-se diferencialmente expressos nos astrócitos transgênicos P1 e os genes HIPK3, TGFA e NTF5 diferencialmente expressos nos astrócitos transgênicos P60. Nas análises das moléculas secretadas nos meios condicionados maior quantidade de NGF foi encontrada no meio dos astrócitos transgênicos P60 comparando-se aos astrócitos wild type. A quantidade de IGF-I diminuiu no meio condicionado da cultura de astrócitos transgênicos P60 comparando-se aos astrócitos wild type E ainda, há a diminuição autócrina de TNF-? e IL-6 nos astrócitos transgênicos P60. Os astrócitos transgênicos parecem promover a toxicidade ao neurônio motor na ELA e moléculas liberadas pelos astrócitos parecem estar envolvidas no processo de desenvolvimento da ELA / Amyotrophic Lateral Sclerosis (ALS) is a neurodegenerative disease characterized by selective motor neurons death that readly leads patients to death. Transgenic mice expressing human mutant superoxide dismutase 1 (hSOD1) is the most accepted experimental model for the disease studying. The mechanisms that lead to neuronal loss are still poorly understood and there is no effective treatment able to prolong the pacient\'s life. Recent studies indicate that glial cells accelerate the neurodegenerative process, but the molecular mechanisms are not yet established. Astrocytes deserve particular attention, since they have close interaction with neurons, providing structural, metabolic and trophic support. In addition, they also participate actively in the neuronal excitatory modulation and in neuronal transmission, controlling ions and neurotransmitters at extracellular levels. The present study aimed to investigate the possible in vitro effects in astrocytes on the motor neurons death in ALS from newborn (P1) and adult pre symptomatic (P60) spinal cord mice. Thus, we evaluated spinal motor neuron survival and trophism in cultures treated with astrocytes conditioned medium and also in co-culture neuron/astrocyte systems of SOD1G93A (transgenic) and wild type in different cells combinations. Still, we investigated genes expression related to P1 and P60 astrocytes cultures performed by quantitative PCR (qPCR) and the molecules secreted by astrocytes were quantified by Sandwich ELISA. For the neuronal degeneration and trophism study, cells were immunostained with specific markers and neurouns were also visualized by phase contrast. These cells were quantified by stereological method and their analysis showed that treatment with transgenic P1 and P60 astrocytes conditioned medium cause length retractions and death on transgenic motor neuron. But, the neuronal death on conditioned medium and co-cultures experiments showed that transgenic P1 and P60 astrocytes caused wild type neuronal death and only transgenic P60 astrocytes led transgenic neurons death, demonstrating major toxicity of transgenic astrocytes. For the gene expression analysis NKRF, UBE2I and TGFa genes showed differentially expressed in transgenic P1 astrocytes and HIPK3, TGFa and NTF5 genes showed differentially expressed in transgenic P60 astrocytes. The analizes of molecules secreted by conditioned media a larger amount of NGF was found in transgenic P60 astrocytes comparing to wild type astrocytes. The amount of IGF-I in the conditioned medium was reduced in astrocytes transgenic P60 cultures compared to the wild type astrocytes Also, there is a reduction autocrine of TNF-? and IL-6 on transgenic astrocytes P60. The transgenic astrocytes seem to promote motor neuron toxicity in ALS and molecules released by astrocytes appear to be involved in the ALS development

Orientador: Lúcia Figueiredo Mourão / Dissertação (mestrado profissional) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-19T03:46:04Z (GMT). No. of bitstreams: 1 Franceschini_AndressadaCosta_M.pdf: 8732521 bytes, checksum: a9d303e9da9fcd34c31872821d899f4b (MD5) Previous issue date: 2011 / Resumo: Esclerose Lateral Amiotrófica (ELA) é definida como uma doença neurodegenerativa, caracterizada por paralisia muscular progressiva dos membros, orofaringe e musculatura respiratória, com consequente disfagia, disartria e insuficiência respiratória devido a degeneração dos neurônios motores no córtex motor primário, no tronco cerebral e na medula espinhal. As mudanças nos aspectos físicos e funcionais da fonoarticulação e da deglutição na ELA podem trazer consequências em termos sociais e psicossociais, acarretando em impacto a qualidade de vida. Apesar da existência de diversos estudos que caracterizam a qualidade de vida de pacientes com ELA, pouca informação está disponível acerca do impacto especificamente da disfagia na qualidade de vida desses indivíduos. O objetivo geral deste estudo foi analisar a qualidade de vida relacionada às alterações de deglutição em pacientes com ELA de inicio espinhal. Os objetivos específicos foram: verificar se o tempo da doença e do diagnóstico interferem na percepção da qualidade de vida; comparar a qualidade de vida relacionada a deglutição com as queixas de deglutição, com a gravidade da disfagia e com a funcionalidade da deglutição; comparar a gravidade da disartria com a gravidade da disfagia e a funcionalidade da deglutição e verificar o impacto da gravidade da disartria na qualidade de vida. Dezessete pacientes com diagnóstico clínico de ELA com início espinhal os sintomas foram avaliados no Ambulatório de Disfagia/ORL do Hospital das Clinicas a UNICAMP através da aplicação do Questionário de Qualidade de Vida em Deglutição SWAL-QOL; da anamnese, que incluiu a coleta das queixas relacionadas a deglutição; da avaliação fonoaudiológica de rotina, que incluiu a avaliação dos aspectos fonoarticulatórios e da avaliação videoendoscópica da deglutição. A disfagia foi graduada par três escalas: Escala de Gravidade da Disfagia (ALSSS), a Escala da Gravidade da Disfagia, e a Escala de Funcionalidade da Ingestão por Via Oral (FOIS). A disartria foi graduada pela Escala de Gravidade da Disartria (ALSSS). Mais de 70% da amostra apresentou disfagia e disartria e houve predomínio de queixas na fase faríngea da deglutição. Foi observado que as alterações e deglutição apresentaram impacto leve a moderado na qualidade de vida, sendo os domínios mais afetados a Duração da alimentação e a Função social. O tempo da doença e do diagnóstico da ELA não interferiu com significância na percepção da qualidade de vida relacionada à deglutição, exceto para o domínio Sono. A piora da qualidade de vida relacionada à deglutição para os pacientes com ELA esteve diretamente relacionada com o aumento do número de queixas de deglutição, com a gravidade da disfagia e com a funcionalidade da deglutição. A gravidade da disartria apresentou impacto na qualidade de vida relacionada à deglutição, e esta correlacionou-se com a disfagia em pacientes com ELA de inicio espinhal / Abstract: Amyotrophic Lateral Sclerosis (ALS) can be defined as a neurodegenerative disorder characterized by progressive muscular paralysis of members, oropharyngeal and respiratory muscles, with consequent dysphagia, dysarthria and respiratory insufficiency, due to degeneration of motor neurons in the primary motor cortex, brainstem and spinal cord. Changes in physical and functional aspects of speech articulation and swallowing in ALS may have social and psychosocial consequences, decreasing the quality of life. Despite many studies that characterize the quality of life in ALS patients, little information is available about the specific impact of dysphagia on quality of life to these individuals. The aim of this study was to analyse the quality of life related to swallowing problems in patients with spinal onset of ALS; verify if the disease duration and the time of diagnosis change the quality of life perception; to compare the swallow-specific quality of life questionnaire (SWAL-QOL) with dysphagia complaints, dysphagia severity and functional oral intake; to compare the severities of dysarthria and dysphagia and the functional oral intake and verify the impact of severity of dysarthria o quality of life. Seventeen patients diagnosed with ALS with spinal onset were evaluated at the Dysphagia Outpatient Clinic at UNICAMP hospital. All the subjects filled out self-report assessment of the Swallowing Quality of Life (SWAL-QOL), underwent to anamnesis that included swallowing-related complaints; to routine speech. evaluation, including a perceptual analysis of the speech, and to Fiberoptic Endoscopic Evaluation of Swallowing (FEES). The dysphagia severity was graded using the Swallowing Subscale of ALS Severity Scale, the Dysphagia Severity Scale and the Functional Oral Intake Scale (FOIS). The dysarthria severity was graded using the Speech Subscale of ALS Severity Scale. Over 70% of the sample had dysphagia and dysarthria, and predominated complaints in the pharyngeal phase of swallowing. Swallowing problems presented mild to moderate impact on quality of protocol, and the domains of eating duration and social function had the worse scores. Disease duration and time of diagnosis did not impact on SWAL-QOL scores, except for the Sleep domain. The worsening swallowing quality of life for patients with ALS was directly related to the increased number of swallowing complaints, with severity of dysphagia and functinality of swallowing. The severity of dysarthria presented impact on quality of life related to swallowing, and this occurred concomitantly with dysphagia in spinal onset of ALS patients / Mestrado / Interdisciplinaridade e Reabilitação / Mestre em Saúde, Interdisciplinaridade e Reabilitação

Lower motor neuron diseases and peripheral neuropathies are two groups of diseases that include multiple rare disorders where many causes are unknown and definitive treatments are unavailable. Understanding the molecular etiology of these genetic diseases provides an opportunity for rapid diagnosis, preconception genetic counseling and, in a subset, direction for the development of future treatment options. The recent introduction of whole exome sequencing (WES) marks a new era in Mendelian genetic disease research as the majority of the coding region of the genome can be sequenced in a timely and cost-effective manner. In this study, WES was used to investigate the molecular etiology of a cohort of 37 patients presenting with lower motor neuron disease or peripheral neuropathy. A molecular diagnosis was determined for seven patients informing the diagnostic utility of WES. Novel phenotypes were found for three genes originally associated with a different disorder. Finally, the foundation has been laid, through the use of functional studies and large scale data-sharing, to identify novel disease-causing genes for lower motor neuron disease and peripheral neuropathy.

L'Atrophie Musculaire spinale (SMA) est une maladie neurodégénérative causée par des mutations du gène SMN1 et caractérisée par la dégénérescence sélective des motoneurones alpha de la moelle épinière. les mécanismes moléculaires de la SMA ne sont aps clairs. cependant, deux hypothèses ont été retenues:D'une part, que la déficience en SMN entraine une perturbation de la biogenèse des snRNPs spliceosomales individuelles et par conséquent des défauts d'épissage. pendant ma thèse, nous avons montré que la déficience en SMN provoquait une diminution des particules tri-snRNPs majeures amis surtout mineures et que cela avait des conséquences sur l'épissage d'un sous-groupe de pré-ARNm contenant des introns mineurs.D'autre part, que la déficience en SMN entraine des altérations de transport d'ARN dans les axones, essentiels pour la survie des motoneurones. A part l'ARNm de la beta-actine et l'ARNm de cpg15 récemment identifié, ceux qui pourraient être transportés par SMN n'ont pas été décrits. nous avons donc identifié les ARN interagissant avec les isoformes a-SMN et SMN-fl dans des cellules neuronales, et montré que certains de ces ARN cibles colocalisent avec SMN dans les axones, suggérant qu'elle est impliquée dans leur transport. / Spinal Muscular Atrophy is a neurodegenerative disease caused by mutations in SMN1 gene. SMA is characterized by the loss of alpha-motoneurons of the spinal cord. However, the precise molecular mechanisms underlying the disease are still unkown. two hypotheses have been retained to explain SMA pathigenesis:In one hand, the fact that SMN deficiency leads to a perturbation of individual snRNPs biogenesis and consequently splicing defects. During my PhD, we have shown that SMN deficiency alters the levels of major, but mostly, minor tri-snRNPs. And that leads to splicing defects of a subset of pre-mRNA containing minor introns.In the other hand, that SMN deficiency causes alteration of axonal transport of RNAs crucial to motoneurons survival. Except beta-actin mRNA and the recently identified cpg mRNA, the RNA targets of SMN have not been described. We succeed to identify RNA targets of both a-SMN and SMN-fl isoformes in a neuronal cell line and colocalisation data of some of these targets suggested that SMN could be implicated in the transport of these RNAs.