Introdução: A maioria das doenças lisossômicas são herdadas como traços recessivos, mas a mucopolissacaridose tipo II (MPS II) é de herança ligada ao cromossomo X. As doenças ligadas ao cromossomo X possuem um importante impacto para as famílias devido ao risco que as heterozigotas apresentam em ter um filho afetado. A maioria das heterozigotas para as doenças ligadas ao cromossomo X são clinicamente assintomáticas. Em relação à MPS II somente dez mulheres afetadas foram relatadas na literatura. Entretanto, nenhum estudo foi realizado para a avaliação da presença de sinais sutis da doença nessas heterozigotas. Objetivo: o objetivo principal desse estudo foi a identificação de sinais clínicos sutis e bioquímicos relacionados à MPS II nas heterozigotas para essa doença e adicionalmente estabelecer a associação desses achados com o padrão de inativação do cromossomo X. Métodos: esse foi um estudo observacional e transversal. Essas mulheres foram classificadas como heterozigotas e não heterozigotas baseadas na análise molecular do gene da iduronato sulfatase (IDS). Ambos grupos foram comparados com relação às seguintes variáveis: dados clínicos, achados do exame físico, cariótipo, padrão de inativação do cromossomo X (ensaio HUMARA), atividades da IDS em leucócitos e plasma, níveis de glicosaminoglicanos na urina, tomografia computadorizada de abdomen e coluna e ressonância magnetica de crânio. Resultados: Quarenta mulheres pertencentes a 24 famílias foram avaliadas. De acordo com a análise do DNA 22 foram classificadas em heterozigotas e 18 em não heterozigotas. Não foi encontrada nenhuma anormalidade no exame físico (n=40), cariótipo (n=31/40) ou na TC de coluna (n=31/40). A incidência de abortamento também não apresentou diferenças entre essas mulheres. Entretanto, a atividade da IDS em plasma (p<0,001) e em leucócitos (p<0,001) apresentaram níveis inferiores nas heterozigotas. A correção de Bonferroni foi aplicada e não foi encontrada nenhuma diferença entre os grupos dentre as variáveis analisadas. Também em relação ao padrão de inativação do cromossomo X não foi observada diferença esntre as heterozigotas e não heterozigotas. Conclusões: Esse é o primeiro estudo sistemático realizado em heterozigotas para MPS II. Não foi encontrada nenhuma evidência de manifestações clínicas sutis ou sinais radiológicos da doença MPS II nessas mulheres. Nossos achados sugerem que não existe relação entre a ausência dos sinais clínicos nessas mulheres e a ocorrência de um padrão favorável de desvio da inativação do cromossomo X. Esses dados sugerem que a MPS II apresenta uma baixa penetrância nas heterozigotas. / Introduction: Most lysosomal diseases are inherited as recessive traits, but muchopolysaccharidosis type II (MPS II) presents X-linked inheritance. The X-linked disorders have an important impact for families because the risk heterozygous present of having an affected child. Most heterozygotes for X-linked disorders are clinically asymptomatic. Regarding MPS II only ten affected females have been reported in the literature. However, none study has been taken in order to evaluate subtle signs of the disease in heterozygotes. Objective: The main objective of this study was to identify subtle clinical and biochemical signs of MPS II in heterozygotes for this disease, and to correlate the findings with the pattern of X chromosome inactivation presented by these women. Methods: This was an observational, transversal and controlled study. The women were classified as heterozygote or non-heterozygote based on molecular analysis of the iduronate sulfatase (IDS) gene. Both groups were compared between regarding clinical data, physical exam findings, karyotype, pattern of X inactivation (HUMARA assay), IDS activity in leukocytes and plasma, glycosaminoglicans levels in urine, computadorized tomography scans of abdomen and spine, and brain magnetic resonance imaging. Results: Forty women from 24 families were evaluated. According to DNA analysis, 22 women were classified as heterozygote and 18 as non-heterozygotes. We did not found any abnormality in physical examination (n=40), karyotype (n=31/40) or spine CT scans (n=31/40). The incidence of miscarriage also did not differ between these females. However, IDS activities in plasma (p<0.001) and in leukocyte (p<0.001) were lower in heterozygotes. Applying the Bonferroni’s correction, we did not find any difference between the groups regarding the variables analyzed. Also the pattern of X chromosome inactivation was not different between heterozygotes and non-heterozygotes. Conclusion: This is the first systematic study performed in heterozygotes for MPS II. We did not find any evidence of subtle clinical manifestations or radiological signs of MPS II disease in these females. Our findings suggest that there is no relation between the absence of clinical signs in these women and the occurrence of a favorable skewing pattern of X chromosome inactivation. This data suggests that MPS II is a disease which shows low penetrance in heterozygotes.

Os fagócitos contêm uma nicotinamida adenina dinucleotídeo fosfato (NADPH) oxidase associada à membrana, que gera superóxido e outros reativos intermediários do oxigênio. Defeitos nesta oxidase em seres humanos resultam na doença granulomatosa crônica (DGC). Mutações próximas aos sítios de splicing que interferem com o processamento do RNA mensageiro, acarretando deleção de um ou mais exons, são cada vez mais freqüentes na literatura científica, nesses casos, os mecanismos moleculares que levam a DGC nem sempre são totalmente esclarecidos, assim como o efeito do IFN-g, seja sobre o processamento da mensagem ou estabilidade dos transcritos. Com base nessas informações o objetivo geral deste trabalho é investigar o efeito do IFN-g sobre a regulação do sistema NADPH oxidase fagocítico humano. Através dos resultados obtidos, não se pode constatar melhora na produção de ânions superóxido após o tratamento com IFN-g em pacientes com defeito de splicing, no entanto detectou-se aumento da expressão do gene CYBB através de PCR convencional e através de real-time PCR além de um aumento na marcação de proteínas do spliceossoma através do FAN. / Phagocytes have a nicotinamide adenine dinucleotide phosphate-oxidase (NADPH) associated to plasmatic membrane that generates superoxide and other oxygen reactive intermediates. Defects on this oxidase in humans result in a disorder called Chronic Granulomatous Disease (CGD). Mutations next to splicing sites that interfere with the mRNA processing leading to deletion of one or more exons, are even more frequent on scientific literature, in these cases, the molecular mechanisms causing CGD are not always completetly clear, as well as the effect of IFN-g on the mRNA processing or on the stability of transcripts. Based on this information our aim is to investigate the effect of IFN-g on the regulation of the human NADPH oxidase phagocyte system.. With the obtained results it wasnt possible to see an increase in anion superoxide production after the IFN-g treatment in patients with splicing defects, however it was detected an increase on the expression of CYBB gene by conventional and real-time PCR besides an increase in the marking of spliceossomal proteins by FAN.

O sistema NADPH oxidase humano é responsável pela geração de reativos intermediários do oxigênio e defeitos neste sistema resultam na Doença Granulomatosa Crônica (DGC). Nesta tese de doutorado, investigamos o efeito do IFN-g sobre eventos pós-transcricionais em pacientes com DGC ligada ao X, ocasionada por defeitos de splicing. Os dados obtidos sugerem que o uso do IFN-g in vitro interfere no processamento da mensagem causando aumento da expressão de transcritos do gene CYBB e NCF1 em células B-EBV de indivíduos sadios e pacientes DGC analisados. Observamos também que o IFN-g dimunui a expressão dos genes THOC4 NONO, SF3A1, SRRM1 e UPF3A e promove aumento de expressão de SRSF10, SNRPA1 e C2 em células B-EBV de paciente X-DGC secundária a defeitos de splicing. Identificamos que o IFN-g e o TNF-&alpha; aumentam a expressão das proteínas envolvidas no processo do splicing. Concluímos que o IFN-g aumenta a expressão de genes importantes para uma resposta eficiente do sistema imunológico, incluindo os do sistema NADPH oxidase, além de promover aumento da expressão de genes e de proteínas relacionados ao processo de splicing, que podem estar relacionados aos efeitos benéficos observados no uso do IFN-g em pacientes com DGC ligada ao X, ocasionada por defeitos de splicing. / The human phagocyte NADPH oxidase is responsible for the generation of reactive oxygen intermediates and defects in this system result in Chronic Granulomatous Disease (CGD). In this PhD Thesis, we investigated the effect of IFN-g on post-transcriptional events in normal individuals and patients with X-linked CGD, caused by splicing defects. The obtained data suggests that the use of IFN-g in vitro interferes in the message processing causing an increase of expression of CYBB and NCF1 gene transcripts in B-EBV cells of healthy individuals and analyzed CGD patients. We also observed that IFN-g decreases the expression of THOC4, NONO, SF3A1, SRRM1 and UPF3A, and increases the expression of SRSF10, SNRPA1 and C2 genes in cells from X-CGD patients, due to splicing defects. We identified that IFN-g and TNF-&alpha; induce expression of proteins involved in the splicing process. We conclude that IFN-g increases the expression of important genes for an effective immune response, including the NADPH oxidase system genes, and promotes augment of gene and protein expression related to the splicing process, which may be related to the beneficial effects related to the use of IFN-g in CGD patient caused by splicing defects.

Thèse réalisée en cotutelle avec l'Université Pierre et Marie Curie, Paris VI, France / Le contrôle de la transcription constitue le principal niveau de la régulation de l’expression des gènes dans les cellules eucaryotes. Dans le génome de ces derniers, les éléments régulateurs peuvent être localisés à de très grandes distances du gène qu’ils régulent. Le laboratoire a identifié 6 familles indépendantes avec un diabète insipide néphrogénique (DIN) lié à l’X portant de grandes délétions en amont du gène de l’AVPR2. Dans chacune de ces familles, les gènes AVPR2 et AQP2 ont été retrouvés intacts et les hommes sont atteints de DIN lié à l’X dans sa forme rénale « classique ». Le séquençage et l’analyse de 30 et 31 kilobases en amont et en aval de l’AVPR2 ont permis l’identification de 6 zones délétées chez 6 familles indépendantes, dont 5 zones de taille supérieure à 7 kilo bases, et une zone, de 102 paires de bases, commune à l’ensemble des délétions. Chez le patient porteur de cette délétion, l’osmolalité urinaire ne répond pas au dDAVP. Contrairement à ce qui est observé chez les patients atteints de DIN avec mutations de l’AVPR2, celui-ci présente des réponses hémodynamiques et de coagulation, normales. Ceci indique que les récepteurs V2 ne sont pas exprimés dans le tubule collecteur mais le sont au niveau des cellules endothéliales. Le but de notre travail est donc de tenter de comprendre les mécanismes régulateurs du locus de l’AVPR2, et plus précisément d’étudier l’expression « tissu spécifique » de ce gène. Les études réalisées in vivo, dans le système Hprt, confirment le rôle activateur de la séquence de 102 pb : coloration intense des tubules collecteurs avec la construction comportant la zone délétée et absence avec la construction ne la contenant pas. Cependant, les expériences menées in vitro semblent indiquer que cet effet dépende du contexte extracellulaire, isotonique ou hypertonique, de la nature des cellules, du tubule proximal ou collecteur, ainsi que du promoteur de l’AVPR2. L’identification des protéines liant potentiellement l’une des extrémités de la délétion a révélé la présence, soit de protéines régulatrices, soit de séquences inconnues, toutes exprimées dans le rein. À terme, ces études, ainsi que celles en découlant, permettront de positioner l’AVPR2 comme une cible de choix dans le traitement des diabètes insipides, centraux et néphrogéniques, par thérapie génique. / Transcriptional control is the primary means of regulating genes expression in eukaryotes cells. In the genome of the latter, regulatory elements can be localised with very long distance from the gene which they control. The laboratory identified six independent families with X-linked nephrogenic diabete insipidus (NDI) bearing large deletions upstream of the AVPR2 gene leaving intact AVPR2 and AQP2 coding sequences. Males bearing these deletions have classical renal X-linked NDI. The sequencing and analysis of 30 and 31 kilo bases upstream and downstream, respectively, encompassing the AVPR2 gene had led to identify 6 deletions in 6 ancestrally independent families including, 5 larger than 7 kilo bases and one of 102 base paires shared by the other deletions. In male patient bearing the 102 bp upstream deletion, urinary osmolality was unresponsive to dDAVP but, unlike patients with mutations in the coding sequence, their coagulation and hemodynamic responses to dDAVP were normal. This suggests that V2 receptors are not expressed in renal collecting duct cells but normally expressed in endothelial cells. Our goal is thus to understand the regulatory mechanism controlling the AVPR2 locus and more precisely the tissu specific expression of this gene.. The studies carried out in vivo, in the Hprt system, confirm the enhancer role of the sequence of 102 bp: intense coloration of the collecting tubules with construction comprising the deleted zone and abscence with construction not containing it. However, in vitro undertaken experiments seem to indicate that this effect depends on the extracellular context, isotonic or hypertonic, of the nature of the cells, of the tubule proximal or collecting duct, as well as promoter of the AVPR2. The identification of proteins potentially binding one of the ends of the deletion revealed the presence, either of regulating proteins, or of unknown sequences, all expressed in the kidney. In the long term, these studies, like those while rising, will make it possible to position the AVPR2 gene like a target of choice in the treatment of the diabetes insipidus, central and nephrogenic, by genic therapy.

In comparison to men, the number of X-linked genes is doubled in women as they have two chromosomes X while men are hemizygotes for X-linked genes. This imbalance is compensated by X inactivation (XCI) process, also known as primary X-inactivation, occurring in the early stage of embryogenesis. X inactivation is a random process and females are mosaics of two cell populations. The ratio of expressed alleles in women can be random (50:50) or skewed (≥80:20). The skewed X inactivation may occur due to selection when one of the alleles is preferentially inactivated (secondary X inactivation). In this study XCI status in heterozygous females with various severity of phenotypic symptoms and traits in selected X linked inherited metabolic diseases is analysed, with the focus being Fabry disease - the deficiency of the enzyme alpha-galactosidase A encoded by GLA gene. Moreover, XCI in one family with X linked agammaglobulinemia is examined. Mutant alleles and XCI status based on various loci, different methodical approaches and different tissues is subjected to examination. For the first time, the direct analysis of GLA gene transcript to detect the allele ratio was used alongside with the single-nucleotide polymorphisms in the IDS and LAMP genes for allele-specific expression (ASE) and the AR, RP2 and...

Entre as neuropatias periféricas hereditárias, a Doença de Charcot Marie Tooth (CMT) é a mais prevalente, sendo o Charcot Marie Tooth Lidado ao X tipo 1 (CMTX1) o segundo subtipo mais comum, causado por mutações no gene GJB1 e de herança ligada ao X. A sintomatologia de fraqueza, atrofia e alteração de sensibilidade progressiva, de padrão simétrico e distal é característica da CMT e, no CMTX1, o acometimento do sistema nervoso central pode estar associado ao quadro típico. Com relação à eletroneurofisiologia, há redução dos parâmetros de velocidade de condução nervosa, com prolongamento da latência de onda F. Não há terapias modificadoras do curso da doença, sendo importante acompanhamento multidiciplinar a fim de assistir as possíveis deformidades, dando mais conforto e otimização das atividades de vida diária dos pacientes. O objetivo do presente estudo é relatar casos diagnosticados como CMTX1 atendidos pelo ambulatório de Neurogenética do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo (HCFMRP-USP) e comparar aos dados da literatura pertinente. Os critérios de inclusão foram idade no atendimento abaixo de 17 anos e 11 meses e confirmação do CMTX1 por exame genético molecular, com mutação em GJB1. Assim, foram encontradas quatro crianças, três do sexo feminino e uma do masculino, com idade variando de 3 a 17 anos, sendo que em dois deles foi observado atraso na marcha independente. Os sinais clínicos e eletroneuromiográficos observados foram concordantes com a literatura, exceto por não apresentarem sinais de acometimento do sistema norvoso central (SNC) associados. A presença de atraso na marcha e surgimento de casos precoces suscita a necessidade de protocolo adequado para crianças no primeiro e segundo anos de vida; 1. Anotar época de aparecimento e duração do movimento de levantar-se e postura ereta ou não do tronco ao se manter sentado. 2. Tipo do engatinhar. 3. Idade em meses no início de sentar e andar com e sem apoio. 4. Análise da funcionalidade manual, motricidade fina com auxílio de testes da especialidade em terapia ocupacional, desde os primeiros meses. 5. Tipo de marcha e época de início da marcha. 6. Reflexos fásicos - evolução - com atenção especial aos aquilianos, que são os mais precocemente acometidos. 7. Verificação de clônus de tornozelo, no sentido de detecção de sinais de espasticidade. Para crianças maiores de 3 anos de idade: 1. Início do uso de chinelo (capacidade de reter o chinelo nos pés - desenvolvimento da propriocepção). 2. Verificação do equilíbrio estático e dinâmico de acordo com Lefèvre (1972), nas faixas etárias de 3 a 7 anos. / Among the hereditary peripheral neuropathies, Charcot-Marie-Tooth disease (CMT) is the most prevalent, being the second most common the subtype CMTX1, caused by mutations in the GJB1 gene and producing a X-linked inheritance. The symptoms of symmetrical and distal weakness, atrophy and progressive sensory changes, are characteristics of the CMT and in the CMTX1 central nervous system involvement is often associated with the typical picture. With respect to eletroneurophysiology, there is reduction of nerve conduction velocity parameters, with extension of F wave latency. There is no modifier therapies of the course of the disease, being important, multidisciplinary monitoring to assist the possible deformities, giving more comfort and optimization of daily life activities of patients. The main objective of this study is to report cases diagnosed as CMTX1 by Neurogenetics Clinic of the Hospital of Clinics of the School of Medicine at Ribeirão Preto, São Paulo University (HCFMRPUSP) and to compare the data from the relevant literature. Inclusion criteria were age in attendance below 17 years and 11 months and CMTX1 confirmation by genetic testing, mutation GJB1. Four children were included, three female and a male, with age ranging from 3 to 17 years. Two of them presented late onset of independent walking. Clinical and eletroneuromiographics finds resulted similar to that observed in the literature, except for the absence of clinical signs of CNS involvement. The presence of delay for independent walking raises the need for proper protocol for children in the first and second years of life: 1. Time of onset (age) and duration of motion to lift from a horizontal position and upright posture of trunk to keep sitting. 2. Type of crawl. 3. Age in months earlier to sit and walk with and without support. 4. Analysis of manual functionality, fine motricity with specialty tests in occupational therapy, since the first few months age. 5. Type of gear when he or she begins to walk with support, and then, without support, the use of the heels. 6. Stretch Reflex - evolution - with special attention to the aquileus, that are the most affected early. 7. Ankle clonus checking, aimed to detecting signs of spasticity. For children after 3 years of age: 1. Initiation of the use of slippers (ability to retain the slippers on the feet - proprioception development). 2. Verification of static and dynamic balance according to Lefèvre (1972), in the age groups from 3 to 7 years.

Entre as neuropatias periféricas hereditárias, a Doença de Charcot Marie Tooth (CMT) é a mais prevalente, sendo o Charcot Marie Tooth Lidado ao X tipo 1 (CMTX1) o segundo subtipo mais comum, causado por mutações no gene GJB1 e de herança ligada ao X. A sintomatologia de fraqueza, atrofia e alteração de sensibilidade progressiva, de padrão simétrico e distal é característica da CMT e, no CMTX1, o acometimento do sistema nervoso central pode estar associado ao quadro típico. Com relação à eletroneurofisiologia, há redução dos parâmetros de velocidade de condução nervosa, com prolongamento da latência de onda F. Não há terapias modificadoras do curso da doença, sendo importante acompanhamento multidiciplinar a fim de assistir as possíveis deformidades, dando mais conforto e otimização das atividades de vida diária dos pacientes. O objetivo do presente estudo é relatar casos diagnosticados como CMTX1 atendidos pelo ambulatório de Neurogenética do Hospital das Clínicas da Faculdade de Medicina de Ribeirão Preto da Universidade de São Paulo (HCFMRP-USP) e comparar aos dados da literatura pertinente. Os critérios de inclusão foram idade no atendimento abaixo de 17 anos e 11 meses e confirmação do CMTX1 por exame genético molecular, com mutação em GJB1. Assim, foram encontradas quatro crianças, três do sexo feminino e uma do masculino, com idade variando de 3 a 17 anos, sendo que em dois deles foi observado atraso na marcha independente. Os sinais clínicos e eletroneuromiográficos observados foram concordantes com a literatura, exceto por não apresentarem sinais de acometimento do sistema norvoso central (SNC) associados. A presença de atraso na marcha e surgimento de casos precoces suscita a necessidade de protocolo adequado para crianças no primeiro e segundo anos de vida; 1. Anotar época de aparecimento e duração do movimento de levantar-se e postura ereta ou não do tronco ao se manter sentado. 2. Tipo do engatinhar. 3. Idade em meses no início de sentar e andar com e sem apoio. 4. Análise da funcionalidade manual, motricidade fina com auxílio de testes da especialidade em terapia ocupacional, desde os primeiros meses. 5. Tipo de marcha e época de início da marcha. 6. Reflexos fásicos - evolução - com atenção especial aos aquilianos, que são os mais precocemente acometidos. 7. Verificação de clônus de tornozelo, no sentido de detecção de sinais de espasticidade. Para crianças maiores de 3 anos de idade: 1. Início do uso de chinelo (capacidade de reter o chinelo nos pés - desenvolvimento da propriocepção). 2. Verificação do equilíbrio estático e dinâmico de acordo com Lefèvre (1972), nas faixas etárias de 3 a 7 anos. / Among the hereditary peripheral neuropathies, Charcot-Marie-Tooth disease (CMT) is the most prevalent, being the second most common the subtype CMTX1, caused by mutations in the GJB1 gene and producing a X-linked inheritance. The symptoms of symmetrical and distal weakness, atrophy and progressive sensory changes, are characteristics of the CMT and in the CMTX1 central nervous system involvement is often associated with the typical picture. With respect to eletroneurophysiology, there is reduction of nerve conduction velocity parameters, with extension of F wave latency. There is no modifier therapies of the course of the disease, being important, multidisciplinary monitoring to assist the possible deformities, giving more comfort and optimization of daily life activities of patients. The main objective of this study is to report cases diagnosed as CMTX1 by Neurogenetics Clinic of the Hospital of Clinics of the School of Medicine at Ribeirão Preto, São Paulo University (HCFMRPUSP) and to compare the data from the relevant literature. Inclusion criteria were age in attendance below 17 years and 11 months and CMTX1 confirmation by genetic testing, mutation GJB1. Four children were included, three female and a male, with age ranging from 3 to 17 years. Two of them presented late onset of independent walking. Clinical and eletroneuromiographics finds resulted similar to that observed in the literature, except for the absence of clinical signs of CNS involvement. The presence of delay for independent walking raises the need for proper protocol for children in the first and second years of life: 1. Time of onset (age) and duration of motion to lift from a horizontal position and upright posture of trunk to keep sitting. 2. Type of crawl. 3. Age in months earlier to sit and walk with and without support. 4. Analysis of manual functionality, fine motricity with specialty tests in occupational therapy, since the first few months age. 5. Type of gear when he or she begins to walk with support, and then, without support, the use of the heels. 6. Stretch Reflex - evolution - with special attention to the aquileus, that are the most affected early. 7. Ankle clonus checking, aimed to detecting signs of spasticity. For children after 3 years of age: 1. Initiation of the use of slippers (ability to retain the slippers on the feet - proprioception development). 2. Verification of static and dynamic balance according to Lefèvre (1972), in the age groups from 3 to 7 years.

Le contrôle de la transcription constitue le principal niveau de la régulation de l’expression des gènes dans les cellules eucaryotes. Dans le génome de ces derniers, les éléments régulateurs peuvent être localisés à de très grandes distances du gène qu’ils régulent. Le laboratoire a identifié 6 familles indépendantes avec un diabète insipide néphrogénique (DIN) lié à l’X portant de grandes délétions en amont du gène de l’AVPR2. Dans chacune de ces familles, les gènes AVPR2 et AQP2 ont été retrouvés intacts et les hommes sont atteints de DIN lié à l’X dans sa forme rénale « classique ». Le séquençage et l’analyse de 30 et 31 kilobases en amont et en aval de l’AVPR2 ont permis l’identification de 6 zones délétées chez 6 familles indépendantes, dont 5 zones de taille supérieure à 7 kilo bases, et une zone, de 102 paires de bases, commune à l’ensemble des délétions. Chez le patient porteur de cette délétion, l’osmolalité urinaire ne répond pas au dDAVP. Contrairement à ce qui est observé chez les patients atteints de DIN avec mutations de l’AVPR2, celui-ci présente des réponses hémodynamiques et de coagulation, normales. Ceci indique que les récepteurs V2 ne sont pas exprimés dans le tubule collecteur mais le sont au niveau des cellules endothéliales. Le but de notre travail est donc de tenter de comprendre les mécanismes régulateurs du locus de l’AVPR2, et plus précisément d’étudier l’expression « tissu spécifique » de ce gène. Les études réalisées in vivo, dans le système Hprt, confirment le rôle activateur de la séquence de 102 pb : coloration intense des tubules collecteurs avec la construction comportant la zone délétée et absence avec la construction ne la contenant pas. Cependant, les expériences menées in vitro semblent indiquer que cet effet dépende du contexte extracellulaire, isotonique ou hypertonique, de la nature des cellules, du tubule proximal ou collecteur, ainsi que du promoteur de l’AVPR2. L’identification des protéines liant potentiellement l’une des extrémités de la délétion a révélé la présence, soit de protéines régulatrices, soit de séquences inconnues, toutes exprimées dans le rein. À terme, ces études, ainsi que celles en découlant, permettront de positioner l’AVPR2 comme une cible de choix dans le traitement des diabètes insipides, centraux et néphrogéniques, par thérapie génique. / Transcriptional control is the primary means of regulating genes expression in eukaryotes cells. In the genome of the latter, regulatory elements can be localised with very long distance from the gene which they control. The laboratory identified six independent families with X-linked nephrogenic diabete insipidus (NDI) bearing large deletions upstream of the AVPR2 gene leaving intact AVPR2 and AQP2 coding sequences. Males bearing these deletions have classical renal X-linked NDI. The sequencing and analysis of 30 and 31 kilo bases upstream and downstream, respectively, encompassing the AVPR2 gene had led to identify 6 deletions in 6 ancestrally independent families including, 5 larger than 7 kilo bases and one of 102 base paires shared by the other deletions. In male patient bearing the 102 bp upstream deletion, urinary osmolality was unresponsive to dDAVP but, unlike patients with mutations in the coding sequence, their coagulation and hemodynamic responses to dDAVP were normal. This suggests that V2 receptors are not expressed in renal collecting duct cells but normally expressed in endothelial cells. Our goal is thus to understand the regulatory mechanism controlling the AVPR2 locus and more precisely the tissu specific expression of this gene.. The studies carried out in vivo, in the Hprt system, confirm the enhancer role of the sequence of 102 bp: intense coloration of the collecting tubules with construction comprising the deleted zone and abscence with construction not containing it. However, in vitro undertaken experiments seem to indicate that this effect depends on the extracellular context, isotonic or hypertonic, of the nature of the cells, of the tubule proximal or collecting duct, as well as promoter of the AVPR2. The identification of proteins potentially binding one of the ends of the deletion revealed the presence, either of regulating proteins, or of unknown sequences, all expressed in the kidney. In the long term, these studies, like those while rising, will make it possible to position the AVPR2 gene like a target of choice in the treatment of the diabetes insipidus, central and nephrogenic, by genic therapy. / Thèse réalisée en cotutelle avec l'Université Pierre et Marie Curie, Paris VI, France

X–linked adrenoleukodystrophy (X–ALD) is the most common peroxisomal enzyme deficiency disorder, characterized by inborn mutations in the ABCD1 gene, an ATP–binding cassette (ABC) half–transporter. The ABCD1 gene encodes the adrenoleukodystrophy protein (ALDP), the transporter for the very–long–chain fatty acids (VLCFA; C > 22:0) from the cytosol into the peroxisomes to enter the peroxisomal B–oxidation pathway. The diagnostic disease marker is the elevated levels of VLCFAs which accumulate in different tissues and body fluids, leading to inflammatory demyelination, neuro–deterioration and adrenocortical insufficiency. At present, there is no satisfactory therapy for X–ALD available. However, another peroxisomal ABC half–transporter, ALDRP can compensate for the functional loss of ALDP and is encoded by the ABCD2 gene. This prompted a new approach to treatment strategies. Phenylbutyric acid (PBA) over–expresses the ABCD2 gene, leading to an increased expression of ALDRP and PBA decreases VLCFA levels by increasing peroxisomal B–oxidation. This study had a dual aim: to determine the antioxidant capacity of PBA and to verify known and identify new metabolites of PBA. In vitro, HeLa cells were cultivated and treated with 0.5 mM, 1 mM, 2 mM and 5 mM PBA for 48 hours. The ROS, lipid peroxidation, apoptosis and cell viability were determined using fluorescein–based flow cytometry. Images were taken to visualize the peroxisome proliferation. In vivo, a vervet monkey was given a single dose of 130 mg/kg PBA. Blood was collected before treatment and 15 minutes, 30 minutes, 1, 2 and 3 hours after treatment. ROS, apoptosis and lipid peroxidation were determined by fluorescein–based flow cytometry. Urine was collected before treatment and 15 minutes, 30 minutes, 1, 2, 3, 7 and 24 hours after PBA treatment. A standardised method, employing gas chromatography–mass spectrometry (GC/MS), was used to analyse the organic acids in the urine and fatty acids in the blood. In vitro results showed decreased levels of ROS and lipid peroxidation with increased concentrations of PBA. PBA showed a protective effect towards the HeLa cells with reduced apoptosis and a high number of viable cells. In vivo levels of ROS en lipid peroxidation decreased over time of treatment with PBA. The fluorescence microscope images confirmed an increased number of peroxisomes after PBA treatment. The short term effect of PBA showed an initial, but small decrease in the levels of the fatty acids, suggesting induction over a longer period rather than activation of peroxisomal B–oxidation. New metabolites of phenylbutyrate were identified in the urine of a vervet monkey. These new metabolites originated from monooxygenase, N–phenylacetyl–glutamine synthases and B–oxidation byproducts. Recently discovered metabolites in humans and rats were also verified and confirmed in the vervet monkey. We therefore propose that treatment with PBA, on account of its beneficial effects of restoring VLCFA levels and reducing oxidative stress, could be considered a novel approach for the treatment of X–ALD. / Thesis (M.Sc. (Pharmaceutical Chemistry))--North-West University, Potchefstroom Campus, 2011.

X–linked adrenoleukodystrophy (X–ALD) is the most common peroxisomal enzyme deficiency disorder, characterized by inborn mutations in the ABCD1 gene, an ATP–binding cassette (ABC) half–transporter. The ABCD1 gene encodes the adrenoleukodystrophy protein (ALDP), the transporter for the very–long–chain fatty acids (VLCFA; C > 22:0) from the cytosol into the peroxisomes to enter the peroxisomal B–oxidation pathway. The diagnostic disease marker is the elevated levels of VLCFAs which accumulate in different tissues and body fluids, leading to inflammatory demyelination, neuro–deterioration and adrenocortical insufficiency. At present, there is no satisfactory therapy for X–ALD available. However, another peroxisomal ABC half–transporter, ALDRP can compensate for the functional loss of ALDP and is encoded by the ABCD2 gene. This prompted a new approach to treatment strategies. Phenylbutyric acid (PBA) over–expresses the ABCD2 gene, leading to an increased expression of ALDRP and PBA decreases VLCFA levels by increasing peroxisomal B–oxidation. This study had a dual aim: to determine the antioxidant capacity of PBA and to verify known and identify new metabolites of PBA. In vitro, HeLa cells were cultivated and treated with 0.5 mM, 1 mM, 2 mM and 5 mM PBA for 48 hours. The ROS, lipid peroxidation, apoptosis and cell viability were determined using fluorescein–based flow cytometry. Images were taken to visualize the peroxisome proliferation. In vivo, a vervet monkey was given a single dose of 130 mg/kg PBA. Blood was collected before treatment and 15 minutes, 30 minutes, 1, 2 and 3 hours after treatment. ROS, apoptosis and lipid peroxidation were determined by fluorescein–based flow cytometry. Urine was collected before treatment and 15 minutes, 30 minutes, 1, 2, 3, 7 and 24 hours after PBA treatment. A standardised method, employing gas chromatography–mass spectrometry (GC/MS), was used to analyse the organic acids in the urine and fatty acids in the blood. In vitro results showed decreased levels of ROS and lipid peroxidation with increased concentrations of PBA. PBA showed a protective effect towards the HeLa cells with reduced apoptosis and a high number of viable cells. In vivo levels of ROS en lipid peroxidation decreased over time of treatment with PBA. The fluorescence microscope images confirmed an increased number of peroxisomes after PBA treatment. The short term effect of PBA showed an initial, but small decrease in the levels of the fatty acids, suggesting induction over a longer period rather than activation of peroxisomal B–oxidation. New metabolites of phenylbutyrate were identified in the urine of a vervet monkey. These new metabolites originated from monooxygenase, N–phenylacetyl–glutamine synthases and B–oxidation byproducts. Recently discovered metabolites in humans and rats were also verified and confirmed in the vervet monkey. We therefore propose that treatment with PBA, on account of its beneficial effects of restoring VLCFA levels and reducing oxidative stress, could be considered a novel approach for the treatment of X–ALD. / Thesis (M.Sc. (Pharmaceutical Chemistry))--North-West University, Potchefstroom Campus, 2011.