Proefschrift Universiteit van Amsterdam. / Met samenvatting in het Nederlands.

Charcot-Marie-Tooth disease (CMT) is the commonest inherited neuromuscular disorder, which affects the peripheral nervous system leading to nerve degeneration. CMT is categorised into two forms, ‘axonal’ and ‘demyelinating’, which reflects the main site of pathology as the axon or Schwann cells respectively. Over 90 genes have been identified associated with the disease. Among the genes associated with demyelinating CMT, the focus of my thesis is LITAF, mutations in which lead to an autosomal dominant demyelinating CMT known as CMT type 1C. LITAF is a 17 kDa protein likely to be involved in endocytic degradation and trafficking of specific cargo proteins. It contains an N-terminal proline-rich region mediating protein-protein interactions and a C-terminal LITAF domain consisting of a zinc-ribbon structure with a hydrophobic region incorporated. Most of the CMT1C mutations are clustered in this highly conserved LITAF domain. LITAF was predicted to play roles in recruiting ESCRT components and exosome formation, but the precise function remains unclear. Furthermore, why mutations in LITAF lead to CMT is not known. My work therefore focused on characterising the function of the LITAF protein both in health and disease. In my thesis, I first tried to determine the subcellular localisation of LITAF proteins and also investigated the function of the highly conserved C-terminal LITAF domain in targeting protein to the membrane. With regards to the function of LITAF, potential binding partners were screened using the traditional GST pull-down assay and the in-situ proximity labelling assay, BioID. A number of novel potential binding partners were identified in both assays. Among the list of potential binding partners, BAG3 was captured in both pull-down assays and was chosen for further studies. The interaction with LITAF was characterised and the potential role of this interaction in autophagy was investigated. Integrin, which was also captured in the BioID assay, was another protein chosen for further studies. Internalisation and recycling assay were developed to investigate the function of LITAF in integrin trafficking. The potential of CMT mutations in impairing the internalisation of integrin in A431 cells and the difficulty in performing the assays were discussed. Lastly, with patient fibroblasts available in our lab, disease phenotypes were analysed using two types of imaging technique: transmission electron microscopy (TEM) (in collaboration with J. Edgar) and immunofluorescence microscopy. Swollen vacuoles were observed in the TEM images of the patient fibroblasts only, and various uptake assays were performed to identify these enlarged compartments. In summary, this work offers an insight into the function of LITAF both in health and disease as well as identifying potential intracellular binding partners that might shed light on pathogenesis. Furthermore, the modified trafficking assays described in this thesis can be applied to Schwann cell and patient fibroblasts, providing further tools to probe the underlying membrane trafficking pathways that are dysfunctional in CMT.

A doença de Charcot-Marie-Tooth (CMT) caracteriza-se por comprometimento dos nervos periféricos de predomínio distal, tendo curso clínico variável. Observa-se quadro de evolução lenta de atrofia e fraqueza distal em membros inferiores, seguidos por diminuição da sensibilidade. Os reflexos estão em geral abolidos, mas podem estar exaltados e acompanhados de sinal de Babinski. É frequente o encontro de atrofia do terço distal das pernas, de pes cavos e de deformidades em artelhos. A doença de CMT pode ser classificada, com o auxílio da eletroneuromiografia, em desmielinizante (CMT1) ou axonal (CMT2). A CMT1 possui velocidade de condução motora do nervo mediano < 38 m/s e a CMT2 > 38m/s. A CMT1 é de herança autossômica dominante, e a CMT2 pode ser de herança dominante ou recessiva. A CMT2 é geneticamente heterogênea e conhecem-se até o momento 13 loci associados a essa condição, com nove genes identificados. O objetivo deste estudo é investigar do ponto de vista clínico, neurofisiológico e genético uma família com muitos portadores de CMT2. A família multigeneracional que apresenta CMT2 é procedente de Tobias Barreto, SE. Foi feita avaliação neurológica de 50 indivíduos e eletroneuromiografia em 22 pacientes. Com dados da avaliação clínica e eletroneuromiográfica foi aplicado o escore que avalia a gravidade da doença, o CMTNS. Para o estudo genético, foram coletadas 42 amostras de sangue de indivíduos afetados e de familiares não afetados. Entre os 50 indivíduos avaliados, 30 tinham sinais clínicos de neuropatia sensitivo-motora de predomínio distal. Paresia dos músculos distais foram os sinais clínicos mais precoces. Redução da sensibilidade superficial e profunda foi detectada nos segmentos distais. O sinal de Babinski estava presente em 14 indivíduos. A eletroneuromiografia demonstrou alterações compatíveis com polineuropatia axonal sensitiva e motora. O estudo genético demonstrou que, nesta família, CMT2 não está ligada a nenhum dos loci já conhecidos para esta condição, más o lócus do gene responsável não foi identificado até o momento. Em conclusão, as características clínicas e neurofisiológicas dessa família não diferem significativamente das observadas em outras formas de CMT, exceto pela alta prevalência de sinal de Babinski, e nossos resultados indicam a existência de um novo locus para CMT2 / Charcot-Marie-Tooth (CMT) disease is characterized by predominantly distal peripheral neuropathy with variable clinical course. Initial presentation is of a slowly progressive distal atrophy and weakness in lower limbs, followed by sensory compromise. Reflexes are usually abolished, but might be brisk and accompanied by Babinski sign. It is frequent to find distal atrophy of lower limbs, pes cavus and toe deformities. Electromyography can recognize two patterns of CMT: demyelinating (CMT1), which has a conduction median nerve velocity < 38 m/s and axonal (CMT2), with velocity > 38m/s. CMT1 is inherited as an autosomal dominant trait, and CMT2 might be transmitted as an autosomal dominant or recessive. CMT is genetically heterogeneous, and, up to now, 13 loci have been recognized and nine genes identified. The aim of this study was to conduct an investigation of clinical, genetics and neurophysiological investigation of a multigenerational family with several individuals with CMT2 and to characterize phenotype, neurophysiological pattern and genetic basis of this condition. Fifty individuals were clinically evaluated and nerve conduction velocity studies and distal muscular activity in lower limbs using concentric needle were performed in 22 patients. A blood sample was collect from 42 individuals, in order to perform linkage analysis. Thirty, among the 50 evaluated individuals, had clinical signs of predominantely distal sensory motor neuropathy. Distal muscle paresis was an early clinical sign. Reduction of superficial and deep sensory was detected distally. Babinski sign was present in 14 affected individuals. Neurophysiological study was characteristic of axonal sensory-motor neuropathy. Linkage analysis demonstrated that in this family, CMT2 was not linked to any already known loci for this condition, but the responsible gene locus was not identified so far. In conclusion, clinical and neurophysiological characteristics of this family did not differ substantially from other forms of CMT, except by the high prevalence of Babinski sign. Our study also suggests the presence of a new locus for CMT2

A doença de Charcot-Marie-Tooth (CMT) é desordem hereditária do sistema nervoso periférico, caracterizada por fraqueza dos membros inferiores, atrofia muscular e perda sensitiva. CMTX é doença ligada ao cromossomo X a qual corresponde aproximadamente 10% das famílias com CMT, sendo a segunda causa mais frequente da doença, após a duplicação 17p11.2-p12. Neste estudo analisamos 66 pacientes com CMT, negativos para duplicação 17p, por método de DHPLC, confirmado por sequenciamento direto. Foram identificadas seis mutações, em que quatro destas não foram descritas. Desta maneira confirmou uma frequência de mutações em torno de 9% no gene da Cx32. Portanto, nesta pesquisa do gene da Cx32 com CMT demonstrou que em uma população brasileira teve um comportamento mutacional semelhante ao das demais populações estudadas. / The Charcot-Marie-Tooth (CMT) is inherited disorder of the peripheral nervous system characterized by weakness of the lower limbs, muscular atrophy and sensory loss. CMTX is X-linked disease which accounts for approximately 10% of families with CMT, the second most frequent cause of disease after duplication 17p11.2-p12. This study analyzed 66 patients with CMT, negative for duplication 17p, by method of DHPLC, confirmed by direct sequencing. We identified six mutations, four of which were not described. In this way confirmed a mutation frequency of around 9% in the Cx32 gene. Therefore, this research Cx32 gene with CMT showed that in a Brazilian population had a mutational behavior similar to that of other populations studied.

Thesis (Ph. D.)--West Virginia University, 2003. / Title from document title page. Document formatted into pages; contains xii, 156 p. : ill. (some col.). Includes abstract. Includes bibliographical references.

Submitted by Geandra Rodrigues (geandrar@gmail.com) on 2018-01-11T10:44:55Z No. of bitstreams: 1 ederschmidt.pdf: 1289167 bytes, checksum: 940c0a29647adcf0becbe8b6d86e2e69 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2018-01-23T13:11:52Z (GMT) No. of bitstreams: 1 ederschmidt.pdf: 1289167 bytes, checksum: 940c0a29647adcf0becbe8b6d86e2e69 (MD5) / Made available in DSpace on 2018-01-23T13:11:52Z (GMT). No. of bitstreams: 1 ederschmidt.pdf: 1289167 bytes, checksum: 940c0a29647adcf0becbe8b6d86e2e69 (MD5) Previous issue date: 2017-10-30 / Na literatura especializada sobre a história da histeria, a carreira do neurologista francês Jean-Martin Charcot (1825-1893), chefe do serviço de patologias do sistema nervoso no hospital da Salpêtrière, em Paris, é comumente descrita como uma progressão a partir de importantes equívocos iniciais na compreensão do quadro histérico, até uma tardia antecipação das concepções psicanalíticas. A tese ora apresentada é a de que a leitura de sua obra sobre a histeria não autorizaria tal afirmativa: a noção charcotiana da doença se manteve plenamente inserida no campo da clínica do sistema nervoso. Em outras palavras, não é possível identificar no texto de Charcot nenhuma pretensão de aproximar a histeria da esfera das doenças mentais. Foi realizada uma revisão cronológica de sua obra referente à histeria, empreendendo-se uma análise de sua abordagem do quadro a partir da lógica interna dos conceitos que a fundamentaram. Os escritos do autor se constituíram como a fonte primária e principal para esta pesquisa. Foram também utilizados como fontes, textos de seus principais colaboradores, e de comentadores que se dedicaram à sua biografia e à sua obra. Os anos de 1870 e 1893 demarcaram o recorte temporal do presente estudo, precedido por um exame das teorias anteriores formuladas a respeito da histeria, desde sua compreensão como uma alteração do cérebro e dos nervos, até ser tomada por Charcot como objeto de interesse científico. A conclusão é a de que, na obra de Charcot, os fenômenos histéricos são sistematicamente remetidos à neuroanatomia e à neurofisiologia. Os novos conhecimentos expressos por ele nas teorizações referentes à doença se mantêm consistentemente dentro dos limites da neurologia / In the scholarship on the history of hysteria, the career of the French neurologist Jean-Martin Charcot (1825-1893), director of the section of pathologies of the nervous system at the Salpêtrière Hospital in Paris, is commonly described as the progression from important early misconceptions in the understanding of the hysterical condition to a belated anticipation of psychoanalytic conceptions. This dissertation proposes that a close reading of Charcot’s work on hysteria disavows such interpretation and that his conception of hysteria remained fully inserted in the clinical field of the nervous diseases. In other words, it is not possible to identify in Charcot’s texts any intent to bring hysteria closer to the field of mental pathology. A chronological revision of his work on hysteria was undertaken, and an analysis of his approach to this disease was made based on the internal logic of the underlying concepts. Charcot’s own writings were the primary and main source for this research. Other sources were the works of his main collaborators and the scholarship dedicated to his biography and work. The years between 1870 and 1893 defined the timeframe of this study, preceded by an examination of previous theories formulated about hysteria from the time it began to be related to a change in the brain and nerves until it was taken by Charcot as an object of scientific interest. The conclusion is that, in Charcot’s work, hysterical phenomena are systematically referred to neuroanatomy and neurophysiology. The new knowledge expressed in Charcot’s theories about this disease remains consistently within the limits of neurology

A doença de Charcot-Marie-Tooth (CMT) caracteriza-se por comprometimento dos nervos periféricos de predomínio distal, tendo curso clínico variável. Observa-se quadro de evolução lenta de atrofia e fraqueza distal em membros inferiores, seguidos por diminuição da sensibilidade. Os reflexos estão em geral abolidos, mas podem estar exaltados e acompanhados de sinal de Babinski. É frequente o encontro de atrofia do terço distal das pernas, de pes cavos e de deformidades em artelhos. A doença de CMT pode ser classificada, com o auxílio da eletroneuromiografia, em desmielinizante (CMT1) ou axonal (CMT2). A CMT1 possui velocidade de condução motora do nervo mediano < 38 m/s e a CMT2 > 38m/s. A CMT1 é de herança autossômica dominante, e a CMT2 pode ser de herança dominante ou recessiva. A CMT2 é geneticamente heterogênea e conhecem-se até o momento 13 loci associados a essa condição, com nove genes identificados. O objetivo deste estudo é investigar do ponto de vista clínico, neurofisiológico e genético uma família com muitos portadores de CMT2. A família multigeneracional que apresenta CMT2 é procedente de Tobias Barreto, SE. Foi feita avaliação neurológica de 50 indivíduos e eletroneuromiografia em 22 pacientes. Com dados da avaliação clínica e eletroneuromiográfica foi aplicado o escore que avalia a gravidade da doença, o CMTNS. Para o estudo genético, foram coletadas 42 amostras de sangue de indivíduos afetados e de familiares não afetados. Entre os 50 indivíduos avaliados, 30 tinham sinais clínicos de neuropatia sensitivo-motora de predomínio distal. Paresia dos músculos distais foram os sinais clínicos mais precoces. Redução da sensibilidade superficial e profunda foi detectada nos segmentos distais. O sinal de Babinski estava presente em 14 indivíduos. A eletroneuromiografia demonstrou alterações compatíveis com polineuropatia axonal sensitiva e motora. O estudo genético demonstrou que, nesta família, CMT2 não está ligada a nenhum dos loci já conhecidos para esta condição, más o lócus do gene responsável não foi identificado até o momento. Em conclusão, as características clínicas e neurofisiológicas dessa família não diferem significativamente das observadas em outras formas de CMT, exceto pela alta prevalência de sinal de Babinski, e nossos resultados indicam a existência de um novo locus para CMT2 / Charcot-Marie-Tooth (CMT) disease is characterized by predominantly distal peripheral neuropathy with variable clinical course. Initial presentation is of a slowly progressive distal atrophy and weakness in lower limbs, followed by sensory compromise. Reflexes are usually abolished, but might be brisk and accompanied by Babinski sign. It is frequent to find distal atrophy of lower limbs, pes cavus and toe deformities. Electromyography can recognize two patterns of CMT: demyelinating (CMT1), which has a conduction median nerve velocity < 38 m/s and axonal (CMT2), with velocity > 38m/s. CMT1 is inherited as an autosomal dominant trait, and CMT2 might be transmitted as an autosomal dominant or recessive. CMT is genetically heterogeneous, and, up to now, 13 loci have been recognized and nine genes identified. The aim of this study was to conduct an investigation of clinical, genetics and neurophysiological investigation of a multigenerational family with several individuals with CMT2 and to characterize phenotype, neurophysiological pattern and genetic basis of this condition. Fifty individuals were clinically evaluated and nerve conduction velocity studies and distal muscular activity in lower limbs using concentric needle were performed in 22 patients. A blood sample was collect from 42 individuals, in order to perform linkage analysis. Thirty, among the 50 evaluated individuals, had clinical signs of predominantely distal sensory motor neuropathy. Distal muscle paresis was an early clinical sign. Reduction of superficial and deep sensory was detected distally. Babinski sign was present in 14 affected individuals. Neurophysiological study was characteristic of axonal sensory-motor neuropathy. Linkage analysis demonstrated that in this family, CMT2 was not linked to any already known loci for this condition, but the responsible gene locus was not identified so far. In conclusion, clinical and neurophysiological characteristics of this family did not differ substantially from other forms of CMT, except by the high prevalence of Babinski sign. Our study also suggests the presence of a new locus for CMT2

A doença de Charcot-Marie-Tooth (CMT) é desordem hereditária do sistema nervoso periférico, caracterizada por fraqueza dos membros inferiores, atrofia muscular e perda sensitiva. CMTX é doença ligada ao cromossomo X a qual corresponde aproximadamente 10% das famílias com CMT, sendo a segunda causa mais frequente da doença, após a duplicação 17p11.2-p12. Neste estudo analisamos 66 pacientes com CMT, negativos para duplicação 17p, por método de DHPLC, confirmado por sequenciamento direto. Foram identificadas seis mutações, em que quatro destas não foram descritas. Desta maneira confirmou uma frequência de mutações em torno de 9% no gene da Cx32. Portanto, nesta pesquisa do gene da Cx32 com CMT demonstrou que em uma população brasileira teve um comportamento mutacional semelhante ao das demais populações estudadas. / The Charcot-Marie-Tooth (CMT) is inherited disorder of the peripheral nervous system characterized by weakness of the lower limbs, muscular atrophy and sensory loss. CMTX is X-linked disease which accounts for approximately 10% of families with CMT, the second most frequent cause of disease after duplication 17p11.2-p12. This study analyzed 66 patients with CMT, negative for duplication 17p, by method of DHPLC, confirmed by direct sequencing. We identified six mutations, four of which were not described. In this way confirmed a mutation frequency of around 9% in the Cx32 gene. Therefore, this research Cx32 gene with CMT showed that in a Brazilian population had a mutational behavior similar to that of other populations studied.

La maladie de Charcot-Marie-Tooth (CMT) est une pathologie neurologique affectant le système nerveux périphérique. Bien que décrite à la fin du XIXème siècle, la découverte d’une anomalie génétique n’a été identifiée chez ces patients que dans les années 1990 (duplication du gène PMP22). Depuis, de nombreux gènes ont été incriminés, et leur nombre ne cesse d’augmenter. Ainsi, cette multitude de gènes nous incite à rechercher des corrélations phénotype-génotype qui permettent d’orienter au mieux le diagnostic et la prise en charge de ces patients. Comme nous le montrons au travers de nos travaux, il est possible de s’appuyer sur des données cliniques, biologiques, électrophysiologiques (voire radiologiques) et histo-pathologiques (biopsie de nerf) pour orienter la recherche d’anomalies génétiques. Pour illustrer ceci, nous nous sommes appuyés sur l’exemple des mutations du gène INF2, gène récemment associé à la maladie de Charcot-Marie-Tooth. Dans ce cas précis, l’atteinte rénale, le profil électrophysiologique (forme « intermédiaire » de CMT) et surtout les données histo-pathologiques (la biopsie de nerf permettant de retrouver la présence d’expansions schwanniennes caractéristiques) sont évocatrices de la présence d’une anomalie portée par ce gène. D’autres exemples de corrélations génotype-phénotype sont apportés au travers d’observations. / Charcot-Marie-Tooth disease (CMT) is a neurological disorder of the peripheral nervous system. Even if it was described in the end of the nineteenth century, the first genetic abnormality (PMP22 duplication) was found only in the end of the twentieth century. Several other genes were found to be associated with this disease. This important number of potential genes leads us to find genotype-phenotype correlations in order to better and earlier diagnose these patients. As we can show it in our work, it is possible to use biological, electrophysiological (sometimes radiological) and pathological (nerve biopsy) in order to direct the genetic analysis towards the incriminated gene. To illustrate this, we have particularly study the INF2 gene, a gene recently associated with CMT. In this example, clinical (CMT phenotype and renal failure), electrophysiological (intermediate form of CMT), and pathological (supernumerary extensions of Schwann cells cytoplasm) features call to mind mutations in the INF2 gene. Other examples of genotype-phenotype correlations associated with various genes are reported in this manuscript.

No description available.