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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Mutações da glicocerebrosidade em pacientes com doença de Parkinson / Glucocerebrosidase mutations in Parkinson\'s disease patients

Spitz, Mariana 15 December 2006 (has links)
Introdução: A doença de Parkinson é uma enfermidade neurodegenerativa decorrente da perda de neurônios dopaminérgicos na substância negra, principalmente, e em outras regiões cerebrais. Caracteriza-se clinicamente por tremor, rigidez, bradicinesia e instabilidade postural. O tratamento é sintomático e consiste essencialmente na reposição da dopamina deficiente. A etiologia da doença de Parkinson ainda não é conhecida, mas os recentes avanços da Neurologia trouxeram novos conhecimentos acerca dos mecanismos fisiopatológicos envolvidos. Disfunção mitocondrial, estresse oxidativo e degradação de proteínas são alguns dos processos celulares que foram relacionados à degeneração dos neurônios dopaminérgicos. O campo da genética da doença de Parkinson tem recebido atenção especial na última década, graças à descoberta de vários genes associados ao desenvolvimento da doença. Um fator de risco genético recentemente descrito é a presença de mutações no gene da glicocerebrosidase, uma enzima lisossomal cuja deficiência resulta na doença de Gaucher. Apesar de a maioria dos estudos já publicados terem confirmado esta associação, um trabalho mais recente da Noruega não encontrou significância estatística ao analisar a presença destas mutações em pacientes com doença de Parkinson, tornando o assunto ainda controverso. Objetivo: Pesquisar a presença de mutações da glicocerebrosidase em pacientes com diagnóstico de doença de Parkinson no Brasil, acompanhados no ambulatório de Distúrbios do Movimento do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo e correlacionar tais achados com estudos recém-publicados que analisaram esta associação em outras populações em âmbito mundial, além de descrever possíveis características dos pacientes portadores de mutações que os diferenciem de não portadores. Métodos: Foram incluídos no estudo 65 pacientes com o diagnóstico de doença de Parkinson e idade de início da doença inferior ou igual a 55 anos e 267 controles sem a doença, emparelhados para sexo e idade. Foi realizada análise genética de material obtido a partir de raspagem da mucosa oral destes indivíduos, tendo sido pesquisadas as três mutações da glicocerebrosidase mais comuns na população brasileira: N370S, L444P e G377S. Resultados: Em dois dos 65 pacientes e em nenhum dos 267 controles foram identificadas mutações no gene da glicocerebrosidase. Os dois pacientes carreadores de mutações (L444P em um e L444P + E326K em outro) apresentavam quadro clínico indistinguível dos demais pacientes com doença de Parkinson não portadores das mutações. Conclusões: Foi observada uma associação estatisticamente significativa (P=0,0379, teste exato de Fisher) entre doença de Parkinson e mutações da glicocerebrosidase na nossa população. A prevalência de mutações da glicocerebrosidase neste grupo de pacientes foi maior do que a esperada para a população geral, porém menor do que a encontrada em estudos internacionais previamente publicados. Espera-se que a identificação desta nova associação permita uma maior compreensão dos mecanismos subjacentes à doença de Parkinson e que em um futuro próximo possa propiciar o desenvolvimento de novas estratégias terapêuticas. / Introduction: Parkinson\'s disease is a neurodegenerative disorder due to the loss of dopaminergic neurons in the substantia nigra, primarily, and in other brain regions. It is clinically characterized by tremor, rigidity, bradykinesia and postural instability. Treatment is symptomatic and consists essentially in replacing the deficient dopamine. The etiology of Parkinson\'s disease remains unknown, but recent advances in Neurology have provided data concerning the pathophysiological mechanisms involved. Mithocondrial dysfunction, oxidative stress and protein degradation are some of the cellular processes that have been linked to dopaminergic neurons degeneration. The field of genetics in Parkinson\'s disease has gained special attention in the past decade, thanks to the discovery of several genes associated with the development of the disease. A recently described genetic risk factor for Parkinson\'s disease is the presence of glucocerebrosidase gene mutations. Glucocerebrosidase is a lysosomal enzyme which is deficient in Gaucher disease. Although most studies published to date have confirmed such association, a recent article from Norway could not find statistical significance when Parkinson\'s disease patients were analyzed for glucocerebrosidase mutations, generating controversy. Objective: To search for glucocerebrosidase mutations in Parkinson\'s disease patients in Brazil, followed at the Movement Disorders Division at Hospital das Clínicas, University of São Paulo Medical School, and correlate these findings with recently published studies which evaluated this association in other populations worldwide, besides describing possible features of patients carrying the mutations that may help differentiating them from non-carriers. Methods: Sixty five patients diagnosed with Parkinson’s disease, with disease onset before age 55, and 267 age and sex-matched controls were included in the study. DNA analysis of the three most common glucocerebrosidase mutations in the Brazilian population, N370S, L444P and G377S, was performed utilizing samples obtained from mouth mucus. Results: Glucocerebrosidase gene mutations were identified in two of the 65 Parkinson\'s disease patients and in none of the 267 controls. The two patients who were carriers of mutations (one of them had L444P and the other L444P+E326K) had a clinical picture indistinguishable from the other Parkinson\'s disease non-carriers patients. Conclusion: A statistically significant association (P=0,0379, Fisher\'s exact test) between Parkinson\'s disease and glucocerebrosidase mutations was observed in our population. The prevalence of glucocerebrosidase mutations was higher than expected for the general population, though lower than reported in previous international studies. It is expected that the finding of this association will allow a better understanding of Parkinson\'s disease mechanisms and that in a near future it may help providing the development of new therapeutic strategies.
2

Mutações da glicocerebrosidade em pacientes com doença de Parkinson / Glucocerebrosidase mutations in Parkinson\'s disease patients

Mariana Spitz 15 December 2006 (has links)
Introdução: A doença de Parkinson é uma enfermidade neurodegenerativa decorrente da perda de neurônios dopaminérgicos na substância negra, principalmente, e em outras regiões cerebrais. Caracteriza-se clinicamente por tremor, rigidez, bradicinesia e instabilidade postural. O tratamento é sintomático e consiste essencialmente na reposição da dopamina deficiente. A etiologia da doença de Parkinson ainda não é conhecida, mas os recentes avanços da Neurologia trouxeram novos conhecimentos acerca dos mecanismos fisiopatológicos envolvidos. Disfunção mitocondrial, estresse oxidativo e degradação de proteínas são alguns dos processos celulares que foram relacionados à degeneração dos neurônios dopaminérgicos. O campo da genética da doença de Parkinson tem recebido atenção especial na última década, graças à descoberta de vários genes associados ao desenvolvimento da doença. Um fator de risco genético recentemente descrito é a presença de mutações no gene da glicocerebrosidase, uma enzima lisossomal cuja deficiência resulta na doença de Gaucher. Apesar de a maioria dos estudos já publicados terem confirmado esta associação, um trabalho mais recente da Noruega não encontrou significância estatística ao analisar a presença destas mutações em pacientes com doença de Parkinson, tornando o assunto ainda controverso. Objetivo: Pesquisar a presença de mutações da glicocerebrosidase em pacientes com diagnóstico de doença de Parkinson no Brasil, acompanhados no ambulatório de Distúrbios do Movimento do Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo e correlacionar tais achados com estudos recém-publicados que analisaram esta associação em outras populações em âmbito mundial, além de descrever possíveis características dos pacientes portadores de mutações que os diferenciem de não portadores. Métodos: Foram incluídos no estudo 65 pacientes com o diagnóstico de doença de Parkinson e idade de início da doença inferior ou igual a 55 anos e 267 controles sem a doença, emparelhados para sexo e idade. Foi realizada análise genética de material obtido a partir de raspagem da mucosa oral destes indivíduos, tendo sido pesquisadas as três mutações da glicocerebrosidase mais comuns na população brasileira: N370S, L444P e G377S. Resultados: Em dois dos 65 pacientes e em nenhum dos 267 controles foram identificadas mutações no gene da glicocerebrosidase. Os dois pacientes carreadores de mutações (L444P em um e L444P + E326K em outro) apresentavam quadro clínico indistinguível dos demais pacientes com doença de Parkinson não portadores das mutações. Conclusões: Foi observada uma associação estatisticamente significativa (P=0,0379, teste exato de Fisher) entre doença de Parkinson e mutações da glicocerebrosidase na nossa população. A prevalência de mutações da glicocerebrosidase neste grupo de pacientes foi maior do que a esperada para a população geral, porém menor do que a encontrada em estudos internacionais previamente publicados. Espera-se que a identificação desta nova associação permita uma maior compreensão dos mecanismos subjacentes à doença de Parkinson e que em um futuro próximo possa propiciar o desenvolvimento de novas estratégias terapêuticas. / Introduction: Parkinson\'s disease is a neurodegenerative disorder due to the loss of dopaminergic neurons in the substantia nigra, primarily, and in other brain regions. It is clinically characterized by tremor, rigidity, bradykinesia and postural instability. Treatment is symptomatic and consists essentially in replacing the deficient dopamine. The etiology of Parkinson\'s disease remains unknown, but recent advances in Neurology have provided data concerning the pathophysiological mechanisms involved. Mithocondrial dysfunction, oxidative stress and protein degradation are some of the cellular processes that have been linked to dopaminergic neurons degeneration. The field of genetics in Parkinson\'s disease has gained special attention in the past decade, thanks to the discovery of several genes associated with the development of the disease. A recently described genetic risk factor for Parkinson\'s disease is the presence of glucocerebrosidase gene mutations. Glucocerebrosidase is a lysosomal enzyme which is deficient in Gaucher disease. Although most studies published to date have confirmed such association, a recent article from Norway could not find statistical significance when Parkinson\'s disease patients were analyzed for glucocerebrosidase mutations, generating controversy. Objective: To search for glucocerebrosidase mutations in Parkinson\'s disease patients in Brazil, followed at the Movement Disorders Division at Hospital das Clínicas, University of São Paulo Medical School, and correlate these findings with recently published studies which evaluated this association in other populations worldwide, besides describing possible features of patients carrying the mutations that may help differentiating them from non-carriers. Methods: Sixty five patients diagnosed with Parkinson’s disease, with disease onset before age 55, and 267 age and sex-matched controls were included in the study. DNA analysis of the three most common glucocerebrosidase mutations in the Brazilian population, N370S, L444P and G377S, was performed utilizing samples obtained from mouth mucus. Results: Glucocerebrosidase gene mutations were identified in two of the 65 Parkinson\'s disease patients and in none of the 267 controls. The two patients who were carriers of mutations (one of them had L444P and the other L444P+E326K) had a clinical picture indistinguishable from the other Parkinson\'s disease non-carriers patients. Conclusion: A statistically significant association (P=0,0379, Fisher\'s exact test) between Parkinson\'s disease and glucocerebrosidase mutations was observed in our population. The prevalence of glucocerebrosidase mutations was higher than expected for the general population, though lower than reported in previous international studies. It is expected that the finding of this association will allow a better understanding of Parkinson\'s disease mechanisms and that in a near future it may help providing the development of new therapeutic strategies.
3

Μελέτη της γονιδιακής μεταφοράς του γονιδίου της γλυκοκερεβροσιδάσης με ιικά οχήματα σε προγονικά αιμοποιητικά κύτταρα του ανθρώπου / Study of the glucocerebrosidase gene transfer with viral vectors into human hematopoietic progenitor cells

Πολυβίου, Σταύρος 04 December 2012 (has links)
Η ποσοτική ή ποιοτική ανεπάρκεια του λυσοσωματικού ενζύμου γλυκοκερεβροσιδάση οδηγεί στην παθολογία της νόσου Gaucher με κεντρικό το ρόλο της συσσώρευσης του υποστρώματός της, του γλυκοκερεβροσιδίου, στα μακροφάγα. Για περισσότερες από δύο δεκαετίες χρησιμοποιούνται γ-ρετροϊικά οχήματα στην ερευνητική προσέγγιση της διόρθωσης του ελλείμματος μέσω γονιδιακής μεταφοράς του γονιδίου της γλυκοκερεβροσιδάσης. Όπως έχει αναδειχθεί και σε κλινικό επίπεδο, είναι επιτακτική η ανάγκη για το σχεδιασμό γ ρετροϊικών οχημάτων, τα οποία θα είναι όχι μόνο αποτελεσματικά αλλά και ασφαλή, με κύριο στόχο τον περιορισμό της πιθανότητας εξαλλαγής του κυττάρου από τις συνέπειες της ενσωμάτωσης («μεταλλαξιγένεση κατά την ενσωμάτωση»). Η παρούσα μελέτη έχει ως στόχο τον έλεγχο της αποτελεσματικότητας νέων και θεωρητικά ασφαλέστερων σε σχέση με προηγουμένως χρησιμοποιηθέντα σε προκλινικό και κλινικό επίπεδο γ-ρετροϊικών οχημάτων για τη γονιδιακή μεταφορά του γονιδίου της γλυκοκερεβροσιδάσης σε προγονικά αιμοποιητικά κύτταρα του ανθρώπου. Στο πρώτο μέρος παρουσιάζεται η μελέτη έξι νέων και θεωρητικά ασφαλέστερων γ ρετροϊικών οχημάτων με το γονίδιο της γλυκοκερεβροσιδάσης, τα οποία είναι Self Inactivating (SIN) οχήματα και φέρουν αλληλουχίες για τη βελτίωση της ολοκλήρωσης της μεταγραφής, είτε από τον ιό WHV (WPRE, Woodchuck hepatitis virus Post-transcriptional Regulatory Element) είτε από τον ιό SV40 (2xSV40 USE, Simian Virus 40 Upstream Sequence Element σε δύο διαδοχικά αντίγραφα). Καταδεικνύεται ότι αυτά τα νέα SIN γ ρετροϊικά οχήματα είναι ικανά να μεταφέρουν ένα ενεργό φυσιολογικό γονίδιο γλυκοκερεβροσιδάσης σε CD34+ ανθρώπινο πρωτογενή προγονικό αιμοποιητικό κυτταρικό πληθυσμό. Τα οχήματα αυτά εμφάνισαν διαφορές στην αύξηση της ενζυμικής δραστικότητας, που προέκυψε από τη διαγονιδιακή έκφραση, οι οποίες οφείλονταν εν μέρει σε διαφορές στην αποδοτικότητα της διαμόλυνσης. Το δεύτερο μέρος της μελέτης περιλαμβάνει τέσσερα νέα SIN γ-ρετροϊικά οχήματα με το γονίδιο της γλυκοκερεβροσιδάσης με αντίστοιχο αριθμό οχημάτων-μαρτύρων, τα οποία είναι σχεδιασμένα με στόχο την κυτταροειδική έκφραση στα μονοκύτταρα / μακροφάγα, ώστε να περιοριστούν οι κυτταρικοί πληθυσμοί που εκτίθενται στην πιθανότητα ενεργοποίησης πρωτογκογονιδίων από τη δραστικότητα ενός εσωτερικού υποκινητή. Τα οχήματα φέρουν τους υποκινητές των ανθρώπινων γονιδίων CD11b και CD68 σε αλληλουχίες που είχαν επιδείξει στο παρελθόν μυελοειδοειδική έκφραση σε πειράματα γονιδιακής μεταφοράς. Τα νέα αυτά οχήματα ελέγχθηκαν ως προς την ικανότητά τους να παρουσιάζουν ισχυρότερη έκφραση του διαγονιδίου μετά από μονοκυτταρική / μακροφαγική διαφοροποίηση διαμολυσμένου CD34+ ανθρώπινου πρωτογενή προγονικού αιμοποιητικού κυτταρικού πληθυσμού σε σχέση με την έκφραση σε ένα λιγότερο διαφοροποιημένο διαμολυσμένο κυτταρικό πληθυσμό. Τα αποτελέσματα του δεύτερου μέρος της μελέτης σε συνδυασμό με τα ήδη υπάρχοντα βιβλιογραφικά δεδομένα ενθαρρύνουν την περαιτέρω διερεύνηση του υποκινητή του CD68 στο πλαίσιο των προσπαθειών για μυελοειδοειδική γονιδιακή μεταφορά του γονιδίου της γλυκοκερεβροσιδάσης, χωρίς να ενθαρρύνουν την περαιτέρω διερεύνηση του υποκινητή του CD11b. / Quantitative or qualitative deficiency of the lysosomal enzyme glucocerebrosidase results in the accumulation of its substrate, glucocerebroside, in macrophages, leading to the pathology of Gaucher disease. For more than two decades of research, gammaretroviral vectors have been used for gene transfer of the glucocerebrosidase gene for the correction of the enzyme’s deficit. It has been shown, even on clinical level, that the design of efficient as well as safe gammaretroviral vectors, aiming mainly at eliminating “insertional mutagenesis”, is an imperative need. The present study aims at the determination of the efficiency of new and theoretically safer, gammaretroviral vectors, compared to previously used ones on preclinical and clinical level, for the gene transfer of the glucocerebrosidase gene into human hematopoietic progenitor cells. In the first part of the study, six new and theoretically safer gammaretroviral vectors of the glucocerebrosidase gene have been evaluated. All six vectors are Self-Inactivating (SIN) and bear sequences for the improvement of transcriptional termination. These are either the WPRE (“Woodchuck hepatitis virus Post-transcriptional Regulatory Element”) from the virus WHV or the 2xSV40 USE (two copies of “Simian Virus 40 Upstream Sequence Element” in tandem repeat) from the virus SV40. It is shown that these new gammaretroviral vectors are efficient in transferring an active wild type glucocerebrosidase gene copy into a CD34+ human primary hematopoietic progenitor cell population. All six vectors showed increased enzyme activity, as compared to the untransduced cells, albeit with differences amongst them, partly due to differences in the transduction efficiency. The second part of the study focuses on the analysis of four new SIN gammaretroviral vectors of the glucocerebrosidase gene and the corresponding number of control vectors, designed for cell-specific expression in monocytes / macrophages. The aim is to thus limit the range of cell populations to be exposed to possible proto-oncogene activation from the internal promoter activity. In these vectors the expression of a glucocerebrosidase gene is driven by one of the promoters of the human genes for CD11b and CD68, which have exhibited myeloid specific expression in gene transfer experiments in the past. These new vectors were studied for their effectiveness in leading to stronger transgene expression after monocytic / macrophagic differentiation of a transduced CD34+ human primary hematopoietic progenitor cell population, compared to a less differentiated transduced cell population. The results of this study, taken together with the current bibliographical data, are encouraging for further study mainly of the CD68 promoter in the context of the research approach to myeloid specific gene transfer of the glucocerebrosidase gene.

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