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Mount, Rebecca Helen. "An exploration of pro-social behaviour in genetic syndromes, with a focus on Angelman and Williams syndromes." Thesis, University of Birmingham, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.423365.
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Handley, Louise. "Movement disorders and catatonia-like presentations in rare genetic syndromes." Thesis, University of Manchester, 2016. https://www.research.manchester.ac.uk/portal/en/theses/movement-disorders-and-catatonialike-presentations-in-rare-genetic-syndromes(581c9b5a-0681-4a14-8b49-35fecded2f55).html.
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The prevalence of Autism Spectrum Disorder (ASD) and its defining features has been increasingly investigated in genetic syndromes associated with intellectual disability, with syndrome specific profiles reported. The experience of catatonia and other movement disorders in people with ASD has been increasing highlighted within both research and diagnostic guidelines. However, these issues have not typically been investigated alongside other features of ASD within research into genetic syndromes. The first paper in this thesis provides a review of the literature on movement disorders in genetic syndromes associated with ASD, which focuses on the prevalence of reported movement disorders, the methods of assessment used, and the quality of research to date. An empirical study is reported in Paper 2. Within a cohort of individuals with Cornelia de Lange and Fragile X syndromes the prevalence of attenuated behaviour [autistic catatonia] is examined, based on parent/carer report, and the extent to which features of ASD predict later attenuated behaviour is investigated. Paper 3 provides a critical reflection on the first two papers as well as some wider considerations on undertaking research in this area. The results of both the literature review and the empirical study indicated that across a number of genetic syndromes (Angelman syndrome, Cornelia de Lange syndrome, Fragile X syndrome and Rett syndrome) attenuated behaviour [autistic catatonia] and/or movement disorders affect a substantial proportion of individuals. Furthermore, repetitive behaviours, one of the characteristic features of ASD, appear to predict later attenuated behaviour in Cornelia de Lange and Fragile X syndromesThe results presented in this thesis have important implications for the way services support individuals with specific genetic syndromes. Paper 1 confirms the high prevalence of movement problems in Angelman and Rett syndromes, and Paper 2 provides a new insight into movement problems in Cornelia de Lange and Fragile X syndromes. Movement disorders are reported to impact negatively on wellbeing and quality of life in people with ASD, and are likely to have a similar impact on the lives of people with genetic syndromes. Greater awareness and recognition of movement problems in CdLS and FXS is required, and although specialist services may already be aware of some of the above issues, there should be an increased emphasis on ensuring that community services are aware of the needs of individuals with genetic syndromes, including the implications of movement problems for support needs and quality of life.
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Kokkonen, H. (Hannaleena). "Genetic changes of chromosome region 15q11-q13 in Prader-Willi and Angelman syndromes in Finland." Doctoral thesis, University of Oulu, 2003. http://urn.fi/urn:isbn:9514270274.
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Abstract
The Prader-Willi (PWS) and Angelman (AS) syndromes are clinically distinct developmental disorders which are caused by genetic defects in the imprinted domain at chromosome 15q11-q13, resulting in the loss of paternal (PWS) or maternal (AS) gene function. In this study, the genetic changes of 15q11-q13 and their possible inheritance in Finnish PWS (n=76) and AS (n=47) patients are described. The diagnosis could be confirmed by laboratory methods in all PWS and in 43 (91%) AS patients.
A deletion of 15q11-q13 accounted for 76% of the PWS and 67% of the AS patients in whom a specific genetic defect had been established. The origin of deletion was always paternal in PWS and maternal in AS. In PWS, deletions of four different sizes were detected, while in AS only type I or II deletions were found. The smallest overlap of deletions/critical region detected was from locus D15S13 to locus D15S10 in PWS and from locus D15S128 to locus D15S12 in AS. A rare recurrence of del(15)(q11q13) due to maternal germ line mosaicism is described.
Maternal uniparental disomy of chromosome 15 accounted for 21% of PWS patients and paternal UPD for 2% of AS patients. In PWS, most UPD cases were due to errors in maternal meiosis (87%), most commonly leading to maternal heterodisomy (MI error). In AS, a rare error in the second segregation of paternal meiosis was found. UPD was associated with advanced maternal age, the mean being 34.6 years.
Imprinting defects were found in 3% of PWS (two non-IC-deletions) and 11% of AS (IC deletion in one sib pair and three non-IC-deletions) patients. In the case with IC deletion, the mutation was seen in several generations. The non-deletion cases were thought to be due to a de novo prezygotic or postzygotic error. In the non-deletion PWS cases, the maternally imprinted paternal chromosome region was shown to have been inherited from the paternal grandmother, while in AS the paternally imprinted maternal chromosome region had been inherited from either the maternal grandfather or the maternal grandmother. The region of IC involved in AS was defined to be 1.15 kb.
Five (11%) AS patients with normal DNA methylation test results had a UBE3A mutation. One of the two novel missense mutations (902A→C) had been inherited from the mosaic mother, while the mutation 975T→C was a new one. De novo deletions 1930delAG and 3093delAAGA have also been described previously, suggesting that these sites may be mutation hotspots in UBE3A.
Identification of different genetic aetiologies with different recurrence risks is essential for genetic counselling, and close co-operation between clinicians and the laboratory is required both for diagnosis and for the detection of possible inheritance.
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Tunnicliffe, Penelope Louisa. "Self-injurious and aggressive behaviour in Angelman, Cri du Chat and Cornelia de Lange syndromes." Thesis, University of Birmingham, 2010. http://etheses.bham.ac.uk//id/eprint/768/.
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In a series of studies, the role of operant reinforcement of phenotypic problem behaviours in Angelman, Cri du Chat and Cornelia de Lange syndromes was explored. Firstly, a systematic review of the literature highlighted papers with robust experimental functional analytic designs; providing appropriate methodology for the subsequent studies. The review also showed a trend towards an increase in the number of published papers that linked facets of the behavioural phenotype to challenging behaviour (gene-environment interactions). Next, the phenomenology and correlates of self-injurious and aggressive behaviour in the syndromes were explored at a given level of behavioural specificity. Results showed that self-injury was more common in Cornelia de Lange syndrome and specific forms of aggressive behaviour were common in Angelman syndrome. Experimental functional analysis and structured descriptive assessments were utilised to examine gene-environment interactions in the syndromes and broadly, challenging behaviour in the Cornelia de Lange syndrome group evidenced a stronger association with pain, whereas challenging behaviour in the Angelman syndrome group evidenced a stronger association with positive social reinforcement. Overall, the studies provide evidence that challenging behaviour in genetic syndromes can be influenced by environmental factors. Implications for practice and for informing a comprehensive model of challenging behaviour are discussed.
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Peery, Edwin G. "Using mouse models to study the mechanism of imprinting involved in prader-willi and angelman syndromes." [Gainesville, Fla.] : University of Florida, 2004. http://purl.fcla.edu/fcla/etd/UFE0008392.
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Thesis (Ph.D.)--University of Florida, 2004.Typescript. Title from title page of source document. Document formatted into pages; contains 141 pages. Includes Vita. Includes bibliographical references.
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Olivera, Curotti Graciela Renée. "Evaluation diagnostique et pronostique des syndromes microdeletionnels en genetique post et prenatale : cytogenetique classique et genetique moleculaire des microdeletions ; recherche de disomie uniparentale (dup) dans la region critique des syndromes de prader-willi et d'angelman (15q11-q13) (doctorat : biologie et sciences de la sante)." Rennes 1, 1999. http://www.theses.fr/1999REN1B040.
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Villatoro, Gómez Sergio. "Estudio de variantes estructurales del genoma humano asociadas a trastornos del neurodesarrollo." Doctoral thesis, Universitat Autònoma de Barcelona, 2016. http://hdl.handle.net/10803/400662.
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El síndrome de Angelman (SA) y el de Prader Wili (SPW) son trastornos del neurodesarrollo cuya principal etiología molecular es la deleción de la región 15q11.2-q13. Esta deleción está promovida por la Recombinación Homóloga No Alélica (NAHR) y mediada por secuencias altamente repetitivas de bajo número de copias (LCRs) que la flanquean. La orientación de estas LCRs predispone al reordenamiento final que se obtendrá por NAHR. Las LCRs en orientación directa generan deleciones y duplicaciones mientras las que presentan orientación invertida originan inversiones. Estas inversiones pueden facilitar una recombinación inadecuada entre las LCRs que flanquean la región 15q11.2-q13 dando lugar a la deleción en la descendencia. En este trabajo se presenta un nuevo análisis de la frecuencia de la inversión 15q11.2-q13 en 23 controles de población general, 21 progenitores de pacientes con SA y 32 con descendencia por SPW. Se han analizado un total de 9540 cromosomas informativos mediante FISH de sondas de BACs, encontrando la inversión en el 4,61% de los cromosomas estudiados en la población control. También se ha analizado la frecuencia de la inversión en progenitores de pacientes con SA y SPW observando un incremento significativo de inversiones en las madres de hijos con SA por deleción y en los padres de SPW por deleción frente a la población control (p=8x10-7 y p=0.007, respectivamente). Nuestros resultados indican que la inversión 15q11.2-q13 es un polimorfismo presente en población general. Así mismo, el incremento de la frecuencia de la inversión en madres de SA y padres de SPW con deleción sugiere que la inversión podría ser una estructura que promueve el mal alineamiento de los LCRs y facilita la generación de deleciones en 15q11.2-q13. El SA es diagnosticado molecularmente en el 90% de los pacientes, sin embargo, en el 10% restante, aún presentando unas características clínicas bien definidas, su etiología molecular es todavía una incógnita (SA-like). Se han analizado 20 pacientes SA-like mediante a-CGH previo cribado de variaciones en número de copias (CNVs) en regiones sindrómicas y subteloméricas. Las regiones variables en número de copia con una frecuencia poblacional inferior al 5% o que no se encuentran estudiadas según la Database of Genomic Variants se han seleccionado para ser confirmadas mediante Multiplex Ligation-depenent Probe Amplificatio (MLPA). Se han evaluado las CNVs en 20 pacientes SA-like y sus progenitores y se ha ampliado el estudio para cribar pacientes con
discapacidad intelectual (n=296), trastornos del espectro autista (n=164) y controles de población general española (n=453). Se ha identificado una deleción de novo (1q44), dos duplicaciones heredadas de la madre (Xp11.23 y Xq28) y 20 regiones heredadas con CNVs en los pacientes SA-like pero que no se observan en la población control. En tres pacientes la concomitancia de una deleción y un SNP puede estar originando una discapacidad intelectual de herencia recesiva, sugiriendo que el gen MYH13 y los ARNs no codificantes largos podrían estar involucrados en el fenotipo SA-like. En lo referente a los pacientes con discapacidad intelectual y trastornos del espectro autista se han identificado alteraciones de gran tamaño implicadas en la etiología: del(1)(p36), del(1)(q44), dup(10)(q21.1), dup(X)(q11.23q28) y dup(X)(q28) en tres casos. También se han detectado 29 regiones con CNVs heredadas que no son variables en población general, 12 de las cuales son compartidas con los pacientes SA-like. Nuestros resultados respaldan la idea de que regiones con CNVs pueden ser, probablemente, responsables de un alto porcentaje de trastornos del neurodesarrollo. Las CNVs identificadas en pacientes, pero no detectadas en población control, aún siendo heredadas, podrían estar asociadas a algunas características clínicas de la enfermedad desenmascarando, en genes específicos, mutaciones de carácter recesivo relacionados con los fenotipos.Angelman syndrome (AS) and Prader Willi syndrome (PWS) are neurodevelomental disorders in which main molecular etiology is the 15q11.2-q13 deletion. This deletion is leaded by Non Allelic Homologous Recombination (NAHR) mediated by flanking high repetitive sequences named Low Copy Repeats (LCRs). The orientation of these LCRs leads the final product of NAHR. LCRs in direct orientation are solved in deletions or duplications while LCRs in inverted orientation lead inversions. These inversions could facilitate abnormal recombination between flanking LCRs and could mediate interstitial deletion of chromosome 15q11.2-q13 in the offspring. Herein we report a new analysis of the frequency of inversion 15q11.2-q13 in 23 controls from general population, 21 AS parents and 32 PWS parents. Molecular cytogenetic analysis was performed using FISH with BACs probes by examining a total of 9540 informative chromosomes. First, the 15q11.2-q13 inversion was detected on average in 4.61% of chromosomes of Spanish control population. Then we analyzed the frequency of the 15q11.2-q13 inversion in parents of AS and PWS and a significant increase in AS mothers and PWS fathers with offspring affected by deletion was observed in front of control group (p= 8x10-7and p=0,007, respectively). Our results indicate that 15q11.2-q13 inversion is a polymorphism presents in general population. Moreover, the high inversion frequency observed in AS mothers and PWS fathers of offspring affected by deletion suggest that the inversion could be a structure that promotes misalignment between the LCRs and facilitates the occurrence of 15q11.2-q13 deletions. AS has a recognizable molecular cause in about 90% of cases, nevertheless in 10% with well-defined clinical features the molecular etiology is still unknown (AS-like). We have analysed 20 AS-like patients by a-CGH after screening the patients for syndromic and subtelomeric copy number alterations (CNVs). Regions that contained rare CNVs or not reported in the Database of Genomic Variants were selected for validation using custom Multiplex Ligation-dependent Probe Amplification (MLPA) assays. We assessed the CNV status in the 20 AS-like cases and in their parents, and also expanded the study to larger sets of samples of individuals suffering idiopathic intellectual disability (n=296), autism spectrum disorders (n=164) as well as to a control cohort of normal individuals (n=453). We have identified one de novo deletion (1q44), two maternally inherited duplications (Xp11.23 and Xq28) and 20 inherited altered regions present in AS-like cases that have not been present in control population. In three patients a concomitance of a deletion and SNPs is leading a possible recessive intellectual disability disease suggesting that MYH13 and long non-coding RNAs could be involved in AS-like. Concerning intellectual disability and autism spectrum disorders big alterations: del(1)(p36), del(1)(q44), dup(10)(q21.1), dup(X)(q11.23q28) and dup(X)(q28) in three patients, have been associated with the etiology. We also have identified 29 inherited genomic variants that were not present in the general population, 12 out of them shared with AS-like patients. Our results support the point of view that a considerable proportion of genomic regions showing variability in copy number could be responsible for neurodevelopment disorders. The inherited CNVs identified in cases, but not detected in controls, suggesting that even if they are inherited, they could be responsible for some of the clinical features perhaps unmasking, in specific genes, recessive mutations involved in the phenotypes.
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Locke, Devin Paul. "SEGMENTAL DUPLICATIONS PROMOTE GENOMIC INSTABILITY IN HUMAN CHROMOSOME 15q11-q13." Case Western Reserve University School of Graduate Studies / OhioLINK, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=case1088114861.
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Adams, Dawn M. "Laughing and smiling in angelman syndrome." Thesis, University of Southampton, 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.505819.
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MALZAC, PERRINE. "Le syndrome d'angelman : etude clinique, cytogenetique et moleculaire." Aix-Marseille 2, 1992. http://www.theses.fr/1992AIX20909.
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Heald, Mary Elizabeth. "Refining the behavioural phenotype of Angelman syndrome." Thesis, University of Birmingham, 2014. http://etheses.bham.ac.uk//id/eprint/5130/.
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Angelman syndrome is associated with distinctive behavioural characteristics including frequent laughing and smiling, heightened motivation for adult attention, sensory seeking, aggression and impaired learning. The main aim of this thesis was to refine and extend description of the behavioural characteristics of Angelman syndrome, including sensory processing and sociability, in order to establish the principles of intervention to increase the speed of acquisition and lower levels of ‘challenging behaviours’, with a focus on excessive social approach. A longitudinal study highlighted limited change in behaviours characteristic of Angelman syndrome over an eight year period, both in children and adults. Further examination of specific behavioural characteristics refined the behavioural phenotype of Angelman syndrome, highlighting elevated levels of seeking sensory stimuli, and differences in social behaviour across genetic subtypes of Angelman syndrome. Direct observations demonstrated the successful use of these preferred sensory and social experiences as rewards that increased the rate of acquisition of target behaviours. Direct observations identified a subset of children for whom social interaction was extremely rewarding. A proof of principle intervention for children displaying heightened sociability successfully reduced the frequency of ‘excessive’ social approaches in the presence of a discriminative stimulus. The results from the thesis refine the knowledge of the behavioural phenotype of Angelman syndrome, and have important implications for future behavioural interventions within this population.
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Robinett, Sheldon J. (Sheldon Jay). "Genomic imprinting: support for the concept from a study of Prader-Willi Syndrome patients." Thesis, University of North Texas, 1994. https://digital.library.unt.edu/ark:/67531/metadc332745/.
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In this study, nineteen cases of suspected or clinically diagnosed Prader-Willi Syndrome (PWS) were tested for molecular deletions by in situ hybridization with two DNA probes, IR4-3R and GABRB3. Both probes are specific for sequences within the chromosome region 15q11-13, with IR4-3R located within the putative PWS region and GABRB3 in the distal area associated with Angelman Syndrome.
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Mandel-Brehm, Caleigh. "A Behavioral and Molecular Approach for Understanding Angelman Syndrome." Thesis, Harvard University, 2016. http://nrs.harvard.edu/urn-3:HUL.InstRepos:26718736.
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Autism Spectrum Disorder (ASD) is a set of human developmental disorders that affects ~1 in 68 children. The clinical features of ASD include deficits in social behavior and frequent co-morbidity of motor, emotional and sensory impairment. Currently, there are no effective treatments. A major obstacle for treating ASD is the limited knowledge of the neuronal circuits that drive these complex behaviors.
Several monogenic, or single-gene, disorders that possess similar features to ASD have been identified, implicating a role for molecular pathways in the development of these behavioral circuits. This dissertation focuses on Angelman Syndrome (AS), a neurodevelopmental disorder characterized by social communication deficits, movement disorder and hyper-excitable behavioral traits. The phenotype of AS arises from mutation of the UBE3A gene, encoding an E3 ubiquitin ligase. The overarching goal of this study is to understand how deregulation of UBE3A-dependent pathways contribute to the behavioral phenotype of AS.
Neuronal substrates of UBE3A have been identified and their expression has been shown to be up-regulated in AS neurons. I now test the hypothesis that this deregulation contributes to specific pathology of AS. First, I described clinically relevant behavioral phenotypes in an AS mouse model. Next, I genetically reduced the expression level of two UBE3A substrates, ARC (Activity-Regulated Cytoskeleton-Associated Protein) and EPHEXIN5 (Rho Guanine Nucleotide Exchange Factor 15) in the AS mouse and assayed for reversal of behavioral abnormalities.
I find that the AS mouse model has impaired communication and motor behavior during early postnatal development, enhanced seizure-like activity and an abnormal cortical electroencephalogram (EEG). Reducing the levels of ARC reversed the enhanced seizure-like activity and EEG, but not the communication or motor deficits. The specific rescue of seizure-like activity by reducing ARC, but not EPHEXIN5, reveals a role for molecular diversity in the development of behavioral circuits. Further, these findings suggest that therapeutic interventions that reduce the level of ARC expression have the potential to reverse the seizures associated with AS. Lastly, the identification of aberrant behaviors in AS mice provides clues regarding the neural circuit defects that occur in AS and ultimately allow new approaches for treating this disorder, and broader ASDs.Medical Sciences
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CHARVET, FRANCOIS. "Contribution a l'etude du syndrome d'angelman : a propos d'une observation." Aix-Marseille 2, 1989. http://www.theses.fr/1989AIX20025.
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Daily, Jennifer L. "Efficacy of Increased Ube3a Protein Levels in the Brain in Rescuing the Phenotype of an Angelman Syndrome Mouse." Scholar Commons, 2012. http://scholarcommons.usf.edu/etd/4305.
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Angelman syndrome (AS), a genetic disorder occurring in approximately one in every 15,000 births, is characterized by severe mental retardation, seizures, difficulty speaking and ataxia. The gene responsible for AS was discovered to be UBE3A and encodes an E6-AP ubiquitin ligase. A unique feature of this gene is that it undergoes maternal imprinting in a neuron-specific manner. In the majority of AS cases, there is a mutation or deletion in the maternally inherited UBE3A gene, although other cases are the result of uniparental disomy or mismethylation of the maternal gene. While most human disorders characterized by severe mental retardation involve abnormalities in brain structure, no gross anatomical changes are associated with AS. Although it was previously believed that UBE3A was imprinted in a brain region-specific manner, primarily in the hippocampus and cortex, recent evidence indicates that there is a widespread knockdown of Ube3a protein throughout the AS mouse brain. As a result, it became necessary to evaluate AS human brain samples to verify the relevance and accuracy of the AS mouse model. It was determined that Ube3a is deficient throughout all major brain regions in humans with AS. The remainder of this dissertation work was focused on determining if increased UBE3A expression in the AS mouse brain would be sufficient to rescue the AS phenotype. The results show that adeno-associated virus-mediated UBE3A delivery is not effective in the AS neonatal brain. In the adult AS mouse brain, however, it increased Ube3a in the hippocampus to near wild-type levels. This was sufficient to rescue the associative fear conditioning learning deficit in the AS mouse and improve learning and memory in the Morris water maze. These studies are the first to demonstrate that increased protein production in the adult AS mouse is sufficient to improve the AS phenotype, indicating that the symptoms of AS are not necessarily embryonic developmental.
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Filonova, Irina. "Ube3a Role in Synaptic Plasticity and Neurodevelopmental Disorders.The Lessons from Angelman Syndrome." Scholar Commons, 2014. https://scholarcommons.usf.edu/etd/5015.
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Angelman Syndrome (AS) is a severe neurodevelopmental disorder that affects 1:12000 newborns. It is characterized by mental retardation, delayed major motor and cognitive milestones, seizures, absence of speech and excessive laughter. The majority of AS cases arise from deletions or mutations of UBE3A gene located on the chromosome 15q11-13. UBE3A codes for E3-ubiquitin ligase that target specific proteins for degradation. To date, a wide variety of Ube3a substrates has been identified. The accumulation of Ube3a-dependent proteins and their effect on the multitude of signal transduction pathways are` considered the main cause of the AS pathology. While the majority of research has been directed towards target identifications, the overall role of Ube3a in activity-dependent synaptic plasticity has been greatly overlooked. The present work is designed to fill some of these knowledge gaps.
Chapter 2 is focused on the activity-dependent aspect of Ube3a expression following neuronal stimulation in vivo and in vitro. We examined total Ube3a expression followed by KCl depolarization in neuronal primary culture. By utilizing a subcellular fractionation technique, we were able to determine which cellular pools are responsive to the depolarization. Next, a fear conditioning paradigm (FC) was used to activate neurons in the paternal Ube3a-YFP reporter mouse brain. This mouse model allowed us to resolve spatial and temporal alterations of the maternal and the paternal Ube3a in hippocampus and cortex followed by FC. In accordance to KCl depolarization results, we observed alterations in Ube3a protein but at later time points. Furthermore, we investigated if the absence of activity-dependent Ube3a changes has any effect on learning and memory kinase activation. We utilized KCl and FC to determine synaptic activity-induced ERK 1/2 phosphorylation in acute hippocampal slices and in CA1 area of hippocampus of wild type (Ube3a m+/p+) and Ube3a deficient mice (Ube3a m-/p+). We demonstrated that Ube3a loss leads to impaired activity-dependent ERK 1/2 phosphorylation.
It has been established that Ube3a m-/p+ mice have a profound deficit in LTP, implying the importance of this ligase in excitatory synaptic transmission. The abnormal LTP could be partially explained by an aberrant CaMKII function, decreased activity-dependent ERK 1/2 phosphorylation and reduced phosphatase activity. These proteins have also been implicated in another form of synaptic plasticity such as long-term depression (LTD). Chapter 3, we investigated the contribution of Ube3a to NMDAR - dependent and - independent LTD. Our data showed that Ube3a m-/p+ P21-30 animals exhibit the impairments in both forms of LTD. Next, we focused on elucidating molecular mechanism underlying the reduced mGluR1/5-LTD. We discovered that mGluR1/5 kinase activation such as ERK, mTOR and p38 is not affected by Ube3a loss. In concordance with previous work, we detected increased Arc expression together with abnormal AMPAR distribution in the Ube3a m-/p+ hippocampus. Surprisingly, the mGluR1/5 induced GluR2 trafficking was normal. Our findings infer that elevated Arc levels together with the increased internalization of AMPAR may result in compromised basal state of the synapses leading to a more depression-like state in Ube3a m-/p+ mice.
Evidence points that loss of Ube3a produces alterations in a variety of activity-dependent signal transduction cascades that may ultimately result in impaired synaptic plasticity and cognition. Similar to AS, abnormal molecular and behavioral phenotypes have already been observed in other mouse models of human mental retardation such as Fragile X Mental Retardation Syndrome (FXS). Chapter 4 is set to explore if any correlation can be found in between these neurodevelopmental disorders. Analysis of crude synaptoneurosomes of adult Fmr1 KO mice revealed a significant reduction in Ube3a protein. Additionally, a blunted translation of Ube3a in response to mGluR1/5 stimulation was observed. However, we didn't find any evidence of direct interaction between Ube3a mRNA and Fragile X Mental Retardation Protein (FMRP). To examine if some of the pathology seen in Fmr1 KO mice is due to Ube3a downregulation, we performed a rescue experiment by increasing overall levels of Ube3a in hippocampus of FRMP deficient mice. An exhaustive battery of behavioral testing indicated that alterations of Ube3a expression impacted only associative fear conditioning.
In summary, the present work has attempted to answer some of the fundamental questions about Ube3a and its role in synaptic plasticity. We have demonstrated that Ube3a expression is modulated by synaptic activation and its activity-dependent alterations are essential for normal brain functioning. Additionally, our data suggest that Ube3a is not only significant for the synaptic excitation but also crucial for the synaptic depression. Finally, our findings indicate that the alteration of Ube3a expression may contribute to the cognitive phenotypes in other neurodevelopmental disorders such as FXS suggesting an advantage of exploring Ube3a function outside the AS research.
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Rodriguez-Jato, Sara. "Identification and characterization of cis-acting elements in the regulation of imprinted gene expression." [Gainesville, Fla.] : University of Florida, 2004. http://wwwlib.umi.com/cr/ufl/fullcit?p3138595.
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Thesis (Ph.D.)--University of Florida, 2004.Typescript. Title from title page of source document. Document formatted into pages; contains 148 pages. Includes Vita. Includes bibliographical references.
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Salogiannis, John. "Regulation of excitatory synapse development by the RhoGEF Ephexin5." Thesis, Harvard University, 2013. http://dissertations.umi.com/gsas.harvard:11082.
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The neuronal synapse is a specialized cell-cell junction that mediates communication between neurons. The formation of a synapse requires the coordinated activity of signaling molecules that can either promote or restrict synapse number and function. Tight regulation of these signaling molecules are critical to ensure that synapses form in the correct number, time and place during brain development. A number of molecular mechanisms that promote synapse formation have been elucidated, but specific mechanisms that restrict synapse formation are less well understood. The findings presented within this dissertation focus on how a specific Rho guanine nucleotide exchange factor (GEF) Ephexin5 functions to restrict early synaptic development and how perturbations in Ephexin5 signaling may lead to human neurodevelopmental disease.
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Burrow, Caroline Elizabeth. "An investigation of sleep disturbance experienced by children with Angelman syndrome and Prader-Willi syndrome and their parents." Thesis, University of Birmingham, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.486629.
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Background: Sleep disturbance is documented as part of the behavioural phenotype ofAngelman syndrome (AS) and its 'sister' syndrome, Prader-Willi syndrome (PWS). Method: The sleeping patterns of22 children (AS 12, PWS 10), aged 5-13 years, and their parents were investigated using parental reports and actigraphy. Findings: Both groups of children have less sleep than would be expected for children oftheir age, and both groups experience night and early morning wakings. Both groups of children may take some time to fall asleep but children with AS appear to have more severe settling difficulties and require parental intervention, unlike children with PWS. Data suggest that parents' sleep is disturbed by children's sleeping patterns in both groups, although parents ofchildren with PWS may be less aware of the severity oftheir child's sleep disturbance. Conclusions: There are a number offactors which limit the conclusions of this study, primarily the small number ofparticipants. In terms ofclinical practice the findings ofthis study suggest that children diagnosed with the two syndromes should be screened for sleep disturbance. Treatment may include medical intervention for causes such as sleep related breathing disorders or epilepsy, and/or psychological intervention for behavioural factors.
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Hatt, Allyson Lesly. "Angelman's syndrome case study and appropriate educational curriculum." Lynchburg, Va. : Liberty University, 1988. http://digitalcommons.liberty.edu.
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Stoppel, David Christopher. "Social Behavior and Gene Expression Disturbances in Mouse Models of Angelman Syndrome and Idic15 Autism." Thesis, Harvard University, 2014. http://dissertations.umi.com/gsas.harvard:11314.
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Reciprocal changes in UBE3A gene dosage cause two neurodevelopmental disorders. Maternally inherited deletions of UBE3A cause Angelman syndrome, characterized by intellectual disability, motor defects, seizures, and a pathognomonic increased social motivation. Whereas maternally inherited triplications of UBE3A as in Idic15 Autism underlie decreased sociability and increased repetitive restrictive behaviors of this disorder. Identifying the cellular compartments and neuronal subtypes where excess and loss of Ube3a impair behavior is essential to understanding and potentially treating the disorders. In Chapter 2, we show that mouse models of maternal loss of UBE3A (Ube3a-mKO, Angelman syndrome) and triplication of UBE3A (Ube3a-2x, Idic15) have opposite effects on social behavioral and cortical gene expression. Social preference and social vocalizations are reduced in Ube3a-2x and increased in Ube3a-mKO mimicking the human phenotypes. Using a nuclear localizing signal tagged Ube3a transgenic mouse (Ube3a-NLS), we show that Ube3a acts in the nucleus to impair social behavior and cortical gene expression. Many of the genes reciprocally regulated by nuclear Ube3a are part of an Autism protein-interaction network. In Chapter 3, we demonstrate Ube3a-2x mice have increased aggression, an important Autism comorbidity. In contrast, maternal loss of Ube3a reduces aggression, consistent with the gregarious, amiable nature of individuals with Angelman syndrome. We then mapped the loci where increased Ube3a increases aggression. Increased aggression was observed when Ube3a was targeted to glutamatergic and vasopressinergic but not to GABAergic or oxytocinergic neurons. In Chapter 4, we show that in mice, social behavior is downregulated by social experience via Ube3a. In wild-type mice, altering their social environment strongly regulates their social behavior: individual housing causes hypersocial whereas group housing causes hyposocial behavior. In Ube3a-2x animals, group housing caused an excessive downregulation of social behavior whereas single housing fully rescued their social behavior deficits. By contrast, in Ube3a-mKO animals, the suppressive effects of group housing on social experience was largely blocked, suggesting Ube3a is required for this process. In summary, this thesis characterizes the role of UBE3A gene dosage in regulating social and aggression behaviors and identifies the subcellular compartment and neuronal subtypes where changes in Ube3a gene dosage disturb the homeostasis of these behaviors.
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Grieco, Joseph Christopher. "Minocycline Treatment and the Necessity to Develop a Novel Outcome Measure for Children with Angelman Syndrome." Scholar Commons, 2015. http://scholarcommons.usf.edu/etd/5693.
Full textAbstract:
Angelman syndrome (AS) is a rare genetic disorder affecting 1/10,000 to 1/20,000 births. This disorder arises through the genetic disruption of the maternal UBE3A allele, which when coupled with epigenetic silencing of the paternal allele UBE3A allele, gives rise to an absence of UBE3A protein in the central nervous system. Clinical manifestations of the syndrome vary in severity and include poor motor function, deficits in language and severe intellectual impairments. Previous research in the Angelman syndrome mouse model revealed abnormalities in dendritic spine density and morphology of hippocampal pyramidal cells. As seen in humans with AS, mice show abnormal behavioral characteristics that include deficits in motor coordination and ability as well as hippocampal dependent associative fear conditioning. Physiologically, these animals exhibit severe deficits in long-term potentiation (LTP) when compared to wildtype littermates.
In an attempt to reduce the time from laboratory study to human translation, we began to search a small molecule library for established compounds with the ability to improve the behavioral and physiological defects normally associated with the AS mouse. One compound, minocycline, was found to normalize the density of dendritic spines in the hippocampus as well as recover the associative memory of AS mice. Moreover, a significant increase in LTP after theta-burst stimulation was also observed in area CA1 hippocampal pyramidal neurons of AS mice treated with minocycline when compared to saline vehicle control mice. These results suggest treatment with minocycline improves synaptic function and learning and memory of AS mice and may provide similar improvements to patients with Angelman syndrome.
Twenty-five participants ages 4-12 were enrolled in a clinical trial examining the safety and tolerability of minocycline in children with Angelman syndrome. Patients were evaluated at 3 time points, baseline (T1), after 8 weeks of treatment (T2) and again 8 weeks after the drug was discontinued (T3). Each evaluation was identical and included laboratory testing, EEG recording and neuropsychological examination. Results of the study showed minocycline was safe and well tolerated with only minor adverse effects reported. While no change was observed in EEG recordings, significant increases in the mean clinical global impressions severity scale score were observed after treatment with minocycline. Moreover, participants showed significant improvement in the raw scores of the communication and self-care domains of the Bayley Scale of Infant and Toddler Development, 3rd Edition. These results show for the first time, a therapeutic with the ability to improve the characteristic behaviors of Angelman syndrome.
Unfortunately, currently available neuropsychological measures were found to be insensitive to the behavioral phenotype of AS. The primary outcome measure, the Bayley Scale of Infant and Toddler Development, 3rd Edition relies on verbal communication and for the examinee to perform specific tasks on command. These testing methods are not compatible with this patient population and resulted in raw scores outside of 2 standard deviations from the mean. The inability of the participants to perform on these exams led us to develop a novel outcome measure; one that relies on observation rather than verbal communication. 9 children with AS and 7 healthy children were enrolled in an observational study in which 30 minutes of free play activity was video recorded. Using behavioral coding software, 3 independent raters quantified stereotypical AS behaviors as well as communication methods. Speech attempts were categorized into five difference types of vocalizations and revealed children with AS used less advance forms of vocalization consisting mostly of phonation control. Phonetic inventories show mostly front or back vowel usage suggesting little tongue movement occurs during speech production. These results suggest deficits in verbal ability may be related to a childhood apraxia of speech.
Impairments in balance and motor coordination have been associated with AS. In an attempt to measure gross motor function, spatiotemporal gait parameters were collected using an electronic walkway and gait analysis software. Results show the gait of children with AS most resembles that of patients with ataxia but without cognitive impairment. In an attempt to develop a single quantitative measure able to describe the severity of gait-related disability, statistical methods were used to create a gait index for patients with AS. The results of this study provides AS researchers with the tools necessary to accurately measure changes in behavior and gait during the clinical evaluation of potential therapeutics
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Neureiter, Anika [Verfasser], and Peter A. [Akademischer Betreuer] Horn. "Modelling Angelman syndrome with patient specific induced pluripotent stem cells / Anika Neureiter ; Betreuer: Peter Horn." Duisburg, 2019. http://d-nb.info/1225308224/34.
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Wu, Katie Jennifer. "The influence of UBE3A, NEDD4L, and ARFGEF2 on the progression of Angelman syndrome and sickle cell anemia." Thesis, Boston University, 2012. https://hdl.handle.net/2144/12683.
Full textAbstract:
Thesis (M.A.)--Boston University
PLEASE NOTE: Boston University Libraries did not receive an Authorization To Manage form for this thesis or dissertation. It is therefore not openly accessible, though it may be available by request. If you are the author or principal advisor of this work and would like to request open access for it, please contact us at open-help@bu.edu. Thank you.This project investigates the impact of UBE3A, NEDD4L, and ARFGEF2 on disorder and disease in humans. UBE3A is a member of the homologous to E6AP COOH-terminus (HECT) E3 ubiquitin ligase family and is parentally imprinted in certain cell types. Mutation of the gene causes Angelman syndrome (AS), which is characterized by developmental delays, mental retardation, motor ataxia, and seizures. Patients frequently display excitable behavior, laughing, and a happy appearance. I found a previously unreported UBE3A candidate mutation, F606S, in twin boys diagnosed with AS.To test the change's clinical significance, I looked at its presence throughout the probands' family by sequencing, its influence on expression levels by qRT-PCR, and structure change predictions. The S606 is located in the functional domain of the enzyme, and its inheritance pattern correlates with disorder expression. The expression data is inconclusive, however, which highlights problems of using human experimental subjects. Nevertheless, there are indications that the F606S missense change could be responsible for AS. Another HECT E3 ligase, NEDD4L influences hypertension severity. Hypertension and inflammation are a complication of sickle cell anemia (SCA) and can affect patient outcome. Mutations in the gene increase epithelial Na+ channel surface expression and thus raise sodium uptake in epithelial cells. It is possible NEDD4L is a component of hypertension in a system instrumental to SCA development, endothelial cells. I conducted a pilot study to determine the effectiveness of NEDD4L knockdown by siRNA as a model for gene dysfunction and found that expression levels were significantly reduced in human pulmonary artery endothelial cells (HPAEC). I also did a preliminary study of the knockdown's influence on other genes that showed no change in ACTB, ARFGEF2, NOS3, or TNFRSFJA expression. Inflammation is a key component in hypertension. ARFGEF2 is a gene that could modulate endothelial inflammation response in sickle cell anemia. It is a GDP-GTP exchange factor involved in the downregulation of the TNF-α receptor, TNFRSF IA, a significant part of the inflammatory signaling pathway. Data from a gene chip expression assay yielded genes with four-fold expression change after ARFGEF2 knockdown. There is a strong inflammatory trend in the functional connections between these genes. It is a promising indication that ARFGEF2 has a role in inflammation, especially in immune response and intercellular signaling.
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Ciarlone, Stephanie Lynn. "The Effects of Synthetic and Dietary Therapeutics on Learning, Memory, Motor Coordination, and Seizure in an Angelman Syndrome Mouse Model." Scholar Commons, 2016. http://scholarcommons.usf.edu/etd/6482.
Full textAbstract:
Angelman syndrome (AS) is a rare genetic and neurological disorder presenting with severe developmental delay, ataxia, epilepsy, and lack of speech. AS is associated with a neuron-specific loss of function of the maternal UBE3A allele, a gene encoding an E3 ubiquitin ligase. Currently, no cure exists for this disorder; however, recent research using an AS mouse model suggests that pharmacological intervention is plausible, and can alleviate some of the detrimental phenotypes reported in AS patients.
Although there is no curative treatment for AS, seizure medication and behavioral therapies are most commonly prescribed in order to minimize symptoms. However, these options only moderately improve quality of life and can cause adverse side effects, such as alterations in mood and cognition following seizure treatment. Unfortunately, epilepsy is a common cause of death in AS and affects greater than 80% of AS patients, with 77% of those patients remaining refractory. The severity of seizures and lack of consistently effective anti-epileptic medications for AS patients demonstrates a considerable need for other therapeutic options. The goal of this work was to evaluate the effects of seizure therapies that have proven beneficial for treating refractory epilepsy in seizure-related disorders. These studies focused specifically on advances in both a pharmacological and dietary therapy evaluated in the AS mouse model.
Previous work in our lab has demonstrated the importance of interneurons and GABAergic tone in hippocampal network regulation and cognition. GABA is an important modulator of synaptic plasticity, and learning increases both inhibitory synaptogenesis and GABA release from hippocampal inhibitory neurons. A neuronal excitatory/inhibitory imbalance, coupled with decreased GABAergic tone, altered synaptic plasticity, and impaired cognition have been reported in the AS mouse model. Therefore, we proposed to examine two therapeutic strategies used in seizure treatment – a ketone ester (KE) supplement, which is thought to increase the [GABA]/[glutamate] ratio via alterations in brain metabolism, and ganaxolone, a positive allosteric modulator of GABAA receptors. We evaluated the effects of each therapeutic on learning and cognitive enhancement, alterations in synaptic function, and anticonvulsant activity. We hypothesized that both the KE and ganaxolone would demonstrate anticonvulsant efficacy in both behavioral and chemiconvulsant seizure models. Additionally, as chronic epilepsy has been linked to progressive cognitive and memory impairment which may be related to GABA deficiencies, we hypothesized that both therapeutics would improve cognition and modulate synaptic plasticity (i.e., synaptic function).
KE administration produced sustained ketosis and improved motor coordination, learning and memory, and synaptic plasticity in AS mice. The KE was also anticonvulsant and altered brain amino acid metabolism in AS treated animals. Ganaxolone was anxiolytic, anticonvulsant, and improved motor deficits in AS mice. Four weeks of treatment also led to recovery of spatial working memory and hippocampal synaptic plasticity deficits. This study demonstrates that the KE and ganaxolone ameliorate many of the behavioral abnormalities in the adult AS mouse, possibly through modulations of GABAergic tone. These results support clinical investigation of both the KE and ganaxolone in AS, which may lead to the development of a novel treatment for AS patients.
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Cruvinel, Estela Mitie. "Estudo de expressão do gene UBE3A em neurônios derivados de células-tronco da polpa dentária de pacientes com a síndrome de Angelman." Universidade de São Paulo, 2011. http://www.teses.usp.br/teses/disponiveis/41/41131/tde-22092011-135856/.
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Síndrome de Angelman (AS - MIM 105830) é causada pela ausência de função do gene UBE3A que codifica uma proteína ubiquitina - ligase (E6-AP). Esse gene é expresso bialelicamente em vários tecidos exceto no cérebro, onde a expressão é preferencialmente materna. O RNA anti-senso de UBE3A é considerado o regulador dessa expressão diferencial entre os alelos, e faz parte de um transcrito grande que só o alelo paterno é expresso devido ao imprinting genômico; no cérebro, esse transcrito se entende até a região anti-senso de UBE3A, mas nos demais tecidos o transcrito é menor e não engloba a região anti-senso. Este trabalho visa obter um modelo para estudo da AS. Células-tronco da polpa do dente (SHEDs) de pacientes com deleção do segmento 15q11-q13 ou mutação no gene UBE3A foram caracterizadas e submetidas à diferenciação neuronal. A diferenciação foi analisada através do estudo de RNA e proteínas para marcadores neuronais e, também, por testes funcionais. As SHEDs são células-tronco mesenquimais e constituem uma população heterogênea. Essas células ou algumas dessas células já expressam algumas proteínas neuronais ou de células excitáveis como nestina, β-tubulina III, MAP2 e proteína de canais dependentes de voltagem de sódio e potássio. Um ponto interessante é que as SHEDs apresentam baixa expressão do UBE3A anti-senso e a expressão do UBE3A nas células de pacientes é menor que 50% da expressão encontrada nas células de controles, que pode indicar a ocorrência de expressão preferencial materna desse gene em outros tipos celulares além de neurônios maduros. Quando induzidas à diferenciação neurogênica, a maioria das linhagens controles apresentou aumento da expressão de MAP2 e, principalmente, β-tubulina III; e a maioria das linhagens de pacientes com AS não apresentou aumento notável na expressão dessas proteínas, exceto uma linhagem de paciente que aumentou a expressão de β-tubulina III. As células induzidas à diferenciação apresentaram aumento estatisticamente significativo da condutância de sódio através de canais de sódio dependentes de voltagem. Com a análise de expressão de UBE3A e do UBE3A anti-senso é possível afirmar que a expressão deles não alterou com a diferenciação neuronal. Assim, é possível concluir que as células-tronco da polpa do dente, com o protocolo de diferenciação neurogênica, progrediram na via de diferenciação, mas a maioria das células não atingiu o estágio de maturação necessário para que ocorresse o imprinting do UBE3A ou a via de diferenciação não ia em direção a neurônios que apresentam imprinting do UBE3A.Angelman syndrome (AS - MIN 105830) is caused by the loss of function of the maternal UBE3A gene, which encodes an ubiquitin protein ligase (E6-AP). UBE3A displays biallelic expression in most of tissues, but maternal predominant expression is observed in the brain. A RNA antisense that is paternally expressed in some regions in the brain is considered to be responsible for this tissue-specific imprinting; UBE3A antisense is part of a large transcript that starts at SNURF-SNRPN gene and is paternally expressed, and in the brain this transcript includes UBE3A antisense region however in other tissues this region is not included. The aim of the present study is to develop a new model for studying AS. Dental pulp stem cells (SHEDs) were characterized and differentiated by an already described protocol. SHEDs intrinsically express some neuronal proteins as nestin, β-tubulin III, MAP2 and voltage-gated sodium channels and potassium channels. Interestingly, SHEDs also present a low expression of UBE3A antisense, and UBE3A expression in cells from patients with AS is lower than 50% of the cells from normal control, so it is possible that preferential maternal expression of this gene might occur in some cells beyond mature neurons. After the neuronal differentiation, most control lineages and one lineage of AS patients had an increase of MAP2 and β-tubulin III expression. Two control lineages and most lineages from AS patients did not have a notable increase of expression of these proteins. Neuronal differentiated cells displayed an increase in conductance through voltage-gated sodium channels. Analysis of UBE3A and UBE3A antisense expression in SHEDs and cells induced to differentiate into neurons indicated no changes in their expression. Thus, after neuronal differentiation induction, dental pulp stem cells progressed through neuronal differentiation pathway. However, most cells did not reach the stage which UBE3A imprinting occurs or the neuronal differentiation is resulting in a cell that do not present UBE3A imprinting.
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Stanurova, Jana [Verfasser], and Bernhard [Akademischer Betreuer] Horsthemke. "Induction of site-specific methylation in induced pluripotent stem cells of a patient with Angelman syndrome / Jana Stanurova ; Betreuer: Bernhard Horsthemke." Duisburg, 2017. http://d-nb.info/1144856655/34.
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Netto, Marcia Mirian Ferreira Corrêa. "A Comunicação Alternativa favorecendo a aprendizagem de crianças com autismo, Asperger e Angelman: formação continuada de profissionais de Educação e Saúde." Universidade do Estado do Rio de Janeiro, 2012. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=5505.
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A formação continuada de profissionais de Educação e Saúde se constitui como objeto desta dissertação. Na presente pesquisa pretendi planejar, implementar e avaliar os efeitos de um programa de formação continuada de profissionais de Educação e Saúde, oferecendo instruções e orientações de uso dos recursos da Comunicação Alternativa e Ampliada (CAA), para favorecer a comunicação e aprendizagem de crianças com autismo, Asperger e Angelman. Os estudos foram realizados em uma escola regular e em uma instituição especializada, com abordagem clínica-terapêutica-educacional. O universo da pesquisa abrangeu oito profissionais: duas professoras de classes regulares de ensino, uma professora especialista (Atendimento Educacional Especializado), duas estagiárias (estudantes de Pedagogia), exercendo a função de mediadora do aluno com autismo incluído, uma professora da instituição especializada, um auxiliar da professora e uma psicóloga. Também nove crianças fizeram parte desse universo: uma criança com autismo, incluída em classe regular e oito crianças que frequentavam a instituição especializada, sendo duas com Asperger, quatro com autismo e duas com Angelman. Para responder à pergunta principal do estudo: A Comunicação Alternativa e Ampliada pode favorecer a comunicação e a aprendizagem de crianças com autismo, Asperger e Angelman?, foi necessário conhecer os profissionais, as instituições e as respectivas gestoras, bem como o corpo docente, a equipe técnica e as crianças assistidas pelos profissionais, para verificar as suas necessidades, potencialidades, interesses e limitações. Outro elemento fundamental na proposta de formação dos profissionais foram os procedimentos do ensino e da consultoria colaborativa. A pesquisa foi desenvolvida em três estudos, durante o período de julho de 2010 a abril de 2012. Foi utilizado o delineamento intrasujeitos do tipo A-B (estudo I) e A-B-C (estudos II e III) e análise qualitativa dos resultados. Os procedimentos iniciais adotados foram: aplicação de questionários para os profissionais e os responsáveis pelas crianças, entrevistas semiestruturadas com as gestoras das instituições, observações in loco, filmagens das atividades pedagógicas e anotações de campo. Com base nos questionários, entrevistas, observações e anotações foram levantadas as principais dificuldades e necessidades dos profissionais e das crianças e construídos protocolos de observação dos comportamentos destes sujeitos. Durante o desenvolvimento dos estudos foram realizadas filmagens das atividades pedagógicas e anotações de campo, bem como reuniões com os profissionais, para orientações e planejamento das atividades pedagógicas adaptadas a serem desenvolvidas com as crianças, bem como materiais e recursos da CAA. Os resultados apontaram à presença de algumas modificações nos comportamentos dos profissionais e nos comportamentos das crianças. Revelaram ainda, que este trabalho proporcionou aos profissionais a oportunidade de reverem as suas atuações e as suas crenças, com relação à inclusão de crianças com autismo, Asperger e Angelman em ambientes não protegidos. Foi possível verificar as contribuições dos procedimentos e dos recursos da CAA, para favorecer a comunicação, a autorregulação e a aprendizagem dessas crianças e o quanto os procedimentos do ensino e da consultoria colaborativa se apresentam como promissores para o desenvolvimento dos profissionais.A formação continuada de profissionais de Educação e Saúde se constitui como objeto desta dissertação. Na presente pesquisa pretendi planejar, implementar e avaliar os efeitos de um programa de formação continuada de profissionais de Educação e Saúde, oferecendo instruções e orientações de uso dos recursos da Comunicação Alternativa e Ampliada (CAA), para favorecer a comunicação e aprendizagem de crianças com autismo, Asperger e Angelman. Os estudos foram realizados em uma escola regular e em uma instituição especializada, com abordagem clínica-terapêutica-educacional. O universo da pesquisa abrangeu oito profissionais: duas professoras de classes regulares de ensino, uma professora especialista (Atendimento Educacional Especializado), duas estagiárias (estudantes de Pedagogia), exercendo a função de mediadora do aluno com autismo incluído, uma professora da instituição especializada, um auxiliar da professora e uma psicóloga. Também nove crianças fizeram parte desse universo: uma criança com autismo, incluída em classe regular e oito crianças que frequentavam a instituição especializada, sendo duas com Asperger, quatro com autismo e duas com Angelman. Para responder à pergunta principal do estudo: A Comunicação Alternativa e Ampliada pode favorecer a comunicação e a aprendizagem de crianças com autismo, Asperger e Angelman?, foi necessário conhecer os profissionais, as instituições e as respectivas gestoras, bem como o corpo docente, a equipe técnica e as crianças assistidas pelos profissionais, para verificar as suas necessidades, potencialidades, interesses e limitações. Outro elemento fundamental na proposta de formação dos profissionais foram os procedimentos do ensino e da consultoria colaborativa. A pesquisa foi desenvolvida em três estudos, durante o período de julho de 2010 a abril de 2012. Foi utilizado o delineamento intrasujeitos do tipo A-B (estudo I) e A-B-C (estudos II e III) e análise qualitativa dos resultados. Os procedimentos iniciais adotados foram: aplicação de questionários para os profissionais e os responsáveis pelas crianças, entrevistas semiestruturadas com as gestoras das instituições, observações in loco, filmagens das atividades pedagógicas e anotações de campo. Com base nos questionários, entrevistas, observações e anotações foram levantadas as principais dificuldades e necessidades dos profissionais e das crianças e construídos protocolos de observação dos comportamentos destes sujeitos. Durante o desenvolvimento dos estudos foram realizadas filmagens das atividades pedagógicas e anotações de campo, bem como reuniões com os profissionais, para orientações e planejamento das atividades pedagógicas adaptadas a serem desenvolvidas com as crianças, bem como materiais e recursos da CAA. Os resultados apontaram à presença de algumas modificações nos comportamentos dos profissionais e nos comportamentos das crianças. Revelaram ainda, que este trabalho proporcionou aos profissionais a oportunidade de reverem as suas atuações e as suas crenças, com relação à inclusão de crianças com autismo, Asperger e Angelman em ambientes não protegidos. Foi possível verificar as contribuições dos procedimentos e dos recursos da CAA, para favorecer a comunicação, a autorregulação e a aprendizagem dessas crianças e o quanto os procedimentos do ensino e da consultoria colaborativa se apresentam como promissores para o desenvolvimento dos profissionais.
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Runte, Maren. "Identifizierung und Expressionsanalyse der SNURF-SNRPN-Sense -UBE3A-Antisense- Transkriptionseinheit in der Prader-Willi-/Angelman-Syndrom-Region auf Chromosom 15." [S.l.] : [s.n.], 2003. http://deposit.ddb.de/cgi-bin/dokserv?idn=971368589.
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Neubert, Gerda [Verfasser]. "Hereditäre Mikrozephalien: Charakterisierung des Pathomechanismus der Autosomal-rezessiven primären Mikrozephalie Typ 3 und klinisch-genetischer Aspekt bei Angelman-Syndrom / Gerda Neubert." Berlin : Medizinische Fakultät Charité - Universitätsmedizin Berlin, 2016. http://d-nb.info/1082237736/34.
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Cruvinel, Estela Mitie. "Estudo da expressão diferencial de genes localizados no segmento cromossômico 15q11-q13 em pacientes com as síndromes de Angelman e Prader-Willi." Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/41/41131/tde-24092015-133351/.
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A síndrome de Prader Willi (PWS) é uma doença de neurodesenvolvimento; a principal hipótese de causa de PWS é a ausência da expressão de SNORD116. O SNORD116 fica na região 15q11-q13 que apresenta vários genes com imprinting genômico e é conhecida por ser controlada pela região de controle de imprinting PWS (PWS-IC) que se localiza sobreposta à região promotora e ao exon 1 do gene SNRPN. Em camundongos, uma proteína zinc finger (Zfp57) foi descrita como importante para o estabelecimento e manutenção do imprinting no Snrpn. Através de análise do ENCODE do Genome Browser, verificamos que outra proteína zinc finger (ZNF274) se liga ao SNORD116. ZNF274 é conhecida por formar um complexo com TRIM28 e SETDB1 que inibe a expressão através da trimetilação da lisina 9 na histona 3 (H3K9me3). No atual estudo mostramos que ZNF274 se liga ao SNORD116 preferencialmente ao alelo materno nas células-tronco pluripotente induzidas (iPSCs). Adicionalmente, as proteínas TRIM28 e SETDB1, que formam um complexo com a ZNF274, estão presentes na região do SNORD116, e a modificação H3K9me3 ocorre preferencialmente no alelo materno nas iPSCs. Na análise funcional, mostramos que o knockdown de SETDB1 isoladamente ou combinado com o knockdown de ZNF274 causa aumento na expressão de SNRPN e SNORD116 nas iPSCs. Além disso, ocorre redução do H3K9me3 e aumento da modificação relacionada à ativação da transcrição, H3K4me2 (dimetilação da lisina 4 na histona 3), na PWS-IC. Os knockdowns também afetam a metilação de DNA, ocasionando o aumento de 5-hidroximetliação de citosinas na PWS-IC. Em outros tipos celulares estudados, neurônios derivados de iPSCs e SHEDs, ZNF274 e a modificação H3K9me3 ocorrem em ambos os alelos dentro do SNORD116. É possível que, nas iPSCs, este complexo proteja a região imprintada da desmetilação do DNA de proteína(s) que atue(m) nessa região somente em células pluripotentes. Nossos achados possibilitam melhor compreensão dos mecanismos envolvidos no imprinting da região 15q11-q13, principalmente do SNORD116, e, consequentemente, disponibiliza novas ferramentas para o desenvolvimento de futuras terapias para PWS.Prader-Willi syndrome (PWS) is a neurodevelopmental disorder. Loss of paternal copies of the cluster of SNORD116 C/D box snoRNAs and their host transcript, 116HG, on human chromosome 15q11-q13 imprinted region is considered to be the major responsible for PWS. PWS-imprinting center (PWS-IC) regulates 15q11-q13 imprinting. PWS-IC is located upstream and in the exon 1 of SNURF-SNRPN gene. In mice, Zfp57 plays an important role in establishment and maintenance of Snrpn imprinting. In human, ENCODE database indicates that ZNF274 binds to SNORD116. Moreover, ZNF274 are C2H2/KRAB zinc finger proteins as Zfp57. We have investigated the mechanism of repression of the maternal SNORD116. Here, we report that the ZNF274, in association with the histone H3 lysine 9 (H3K9) methyltransferase SETDB1, is part of a complex that binds to the silent maternal but not to the active paternal alleles in induced pluripotent stem cells (iPSCs). Knockdown of SETDB1 in PWS-specific iPSCs causes a decrease in the accumulation of H3K9 trimethylation (H3K9me3) at SNORD116. We also show that upon knockdown of SETDB1 in PWS-specific iPSCs, expression of maternally silenced 116HG RNA is partially restored. SETDB1 knockdown in PWS iPSCs also disrupts DNA methylation at the PWS-IC where a decrease in 5-methylcytosine is observed in association with a concomitant increase in 5-hydroxymethylcytosine. In iPSCs-derived neurons and stem cells from human exfoliated teeth (SHEDs) ZNF274/SETDB1 complex binding and H3K9me3 modification occur in both alleles. These observations suggest that the ZNF274/SETDB1 complex bound to the SNORD116 cluster may protect the PWS-IC from DNA demethylation during early development, as indicated by iPSCs. Our findings reveal novel epigenetic mechanisms that function to repress the maternal 15q11-q13 region. The better understanding of epigenetic mechanisms provides new tools for future therapy research.
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Allmaras, Sibylle [Verfasser], and Angela [Akademischer Betreuer] Abicht. "Phänotypen, Mutationsdetektionsrate und Mutationsspektrum in einem Kollektiv von Patienten mit kongenitalen myasthenen Syndromen (CMS) / Sibylle Allmaras. Betreuer: Angela Abicht." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2014. http://d-nb.info/1065610599/34.
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Aguilera, Román Cinthia. "Identificació de nous gens responsables de la síndrome d’Angelman-like." Doctoral thesis, Universitat Autònoma de Barcelona, 2020. http://hdl.handle.net/10803/670321.
Full textAbstract:
La síndrome d’Angelman (SA) és un trastorn neurogenètic caracteritzat per discapacitat intel·lectual greu amb absència de parla, característiques craniofacials dismòrfiques distintives, problemes neurològics com l’atàxia i/o tremolor en les extremitats i epilèpsia amb un patró específic d’electroencefalograma (EEG). El fenotip conductual es caracteritza per una aparença feliç, hiperactivitat, dèficit d’atenció i problemes de la son. La seva prevalença és d’aproximadament 1/15.000 naixements.
La causa de la SA és la pèrdua d’expressió en neurones de la proteïna ubiquitina lligasa E6-AP codificada per l’al·lel matern del gen UBE3A, que es troba en la regió cromosòmica 15q11-q13. En el 10% dels individus que presenten el fenotip característic de la SA es desconeix la causa a nivell molecular i es classifiquen com a SA-like. En alguns casos, aquests pacients presenten síndromes amb fenotips que es solapen amb la SA, produïts per variants en gens amb funcions similars o solapants amb UBE3A o canvis en número de còpies (CNVs). Es creu que hi ha nous gens responsables de la SA que encara no han estat identificats.
En els últims anys, l’anàlisi de l’exoma gràcies a la utilització de les noves tècniques de seqüenciació massiva (NGS) ha permès de forma exitosa identificar nous gens causants de malalties amb una herència mendeliana. L’objectiu principal d’aquesta tesi doctoral ha estat la identificació de nous gens responsables del fenotip SA-like a través de la seqüenciació de l’exoma complet (WES). En una cohort de 17 pacients amb fenotip SA i en els que s’ha descartat les causes genètiques de la SA, l’aplicació de WES en trios pacient-progenitors ha permès la identificació de 11 variants de novo i una variant lligada al cromosoma X patogèniques/probablement patogèniques en 11 gens implicats en trastorns del neurodesenvolupament (KIF1A, VAMP2, SYNGAP1, SATB2, ASXL3, KCNQ3, TBL1XR1, SMARCE1, SPTAN1, SLC6A1 i LAS1L). La taxa diagnòstica de la nostra cohort ha estat del 70,5% (12/17). A més, s’han identificat dues variants deletèries de novo en dos nous gens candidats (HSF2 i CHMP7) a la SA-like, que no han estat associades prèviament a malaltia. Els gens identificats en la nostra cohort no interaccionen directament amb el gen UBE3A, però si intervenen en les mateixes vies moleculars (sinapsi, remodelació de la cromatina i regulació de la transcripció). Els resultats mostren que existeix una gran heterogeneïtat genètica en els pacients SA-like, només dos dels pacients presenten variants en el mateix gen (TBL1XR1). En tots els casos, les característiques clíniques associades als gens identificats es solapen amb les de la SA.
En la nostra cohort, el 50% de les variants identificades són missense, essent difícil de predir l’impacte d’aquest tipus de variants sobre la funció de la proteïna. Malgrat que els programes de predicció in silico poden ajudar a classificar aquestes variants, es necessiten portar a terme estudis funcionals que demostrin la seva patogenicitat. En aquest projecte, s’ha realitzat l’anàlisi funcional de la variant missense p.Arg169Thr en el gen KIF1A, demostrant que afecta a l’activitat ATPasa del domini motor probablement per un defecte en la unió dels microtúbuls, afectant de manera indirecta a la motilitat de la proteïna i al transport de vesícules.
En conjunt, els resultats obtinguts en aquesta tesi mostren que el 70,5% dels pacients SA-like presenten variants en altres gens que no són UBE3A. A més, s’ha demostrat que el WES és una eina útil pel diagnòstic de pacients amb un fenotip SA-like. Es proposa que el WES s’inclogui en l’algoritme diagnòstic de la SA, fet que permetrà augmentar la taxa de diagnòstic, permetent un millor seguiment dels pacients, realitzar un correcte assessorament genètic a la família i identificar noves dianes terapèutiques.El síndrome de Angelman (SA) es un trastorno neurogenético caracterizado por discapacidad intelectual grave con ausencia de lenguaje, características craneofaciales dismórficas distintivas, problemas neurológicos como la ataxia y/o el temblor en las extremidades y epilepsia con un patrón específico en electroencefalograma (EEG). El fenotipo conductual se caracteriza por una apariencia feliz, hiperactividad, déficit de atención y problemas del sueño. La prevalencia es de aproximadamente 1/15.000 nacimientos. La causa del SA es la perdida de expresión en neuronas de la proteína ubiquitina ligasa E6-AP codificada por el alelo materno del gen UBE3A, que se encuentra en la región cromosómica 15q11-q13. En el 10% de los individuos que presentan el fenotipo característico del SA se desconoce la causa a nivel molecular y se clasifican como SA-like. En algunos casos, estos pacientes presentan síndromes cuyos fenotipos se solapan con el SA, producidos por variantes en genes que desempeñan funciones similares o solapantes con las de UBE3A o bien por cambios en número de copias (CNVs). Se cree que hay nuevos genes responsables del SA que todavía no han sido identificados. En los últimos años, el análisis del exoma gracias a la utilización de las nuevas técnicas de secuenciación masiva (NGS), ha permitido de forma exitosa identificar nuevos genes causantes de enfermedades con una herencia mendeliana. El objetivo principal de esta tesis doctoral ha sido identificar nuevos genes responsables del fenotipo SA-like a través de la secuenciación del exoma completo (WES). En una cohorte de 17 pacientes con fenotipo SA y en los que se han descartado las causas genéticas de la SA, la aplicación de WES en tríos paciente-progenitores ha permitido la identificación de 11 variantes de novo y una variante ligada al cromosoma X patogénicas/probablemente patogénicas en 11 genes implicados en trastornos del neurodesarrollo (KIF1A, VAMP2, SYNGAP1, SATB2, ASXL3, KCNQ3, TBL1XR1, SMARCE1, SPTAN1, SLC6A1 y LAS1L). La tasa diagnostica en nuestra cohorte ha sido del 70,5% (12/17). Además, se han identificado dos variantes deletéreas de novo en dos nuevos genes candidatos (HSF2 i CHMP7) a la SA-like, que no han sido asociados previamente a enfermedad. Los genes identificados en nuestra cohorte no interaccionan directamente con el gen UBE3A, pero sí que intervienen en las mismas vías moleculares (sinapsis, remodelación de la cromatina y regulación de la transcripción). Los resultados muestran que existe una gran heterogeneidad genética en los pacientes SA-like, sólo dos pacientes presentan variantes en el mismo gen (TBL1XR1). En todos los casos, las características clínicas asociadas a los genes identificados se solapan con las del SA. En nuestra cohorte, el 50% de las variantes identificadas son missense, siendo difícil de predecir el impacto de estas variantes sobre la función de la proteína. Pese a que los programas de predicción in silico pueden ayudar a clasificar estas variantes, se necesitan llevar a cabo estudios funcionales que demuestren su patogenicidad. En este proyecto, el análisis funcional de la variante missense p.Arg169T en el gen KIF1A ha demostrado que afecta a la actividad ATPasa del dominio motor, probablemente por un defecto en la unión a los microtúbulos, afectando de manera indirecta a la motilidad de la proteína y al transporte de vesículas. En conjunto, los resultados obtenidos en esta tesis doctoral muestran que el 70,5% de los pacientes SA-like presentan variantes en otros genes que no son UBE3A. Además, se ha demostrado que el WES es una herramienta útil para el diagnóstico de los pacientes SA-like. Se propone que el WES se incluya en el algoritmo diagnóstico del SA, lo que permitirá aumentar la tasa de diagnóstico, ofrecer un correcto asesoramiento genético a la familia y la identificación de nuevas dianas terapéuticas.
Angelman syndrome (AS) is a neurogenetic disorder characterized by severe intellectual disability with absent speech, dysmorphic craniofacial features, neurological problems such as ataxia and/or tremor of the limbs and seizures with a specific pattern in the electroencephalogram (EEG). The behavioral phenotype is characterized by apparent happy demeanor, hyperactivity, attention deficit and sleep disorder. The prevalence is about 1/15.000 of newborns. AS is caused by the loss of expression in neurons of the ubiquitin ligase protein E6-AP encoded by the maternal allele of the UBE3A gene, that is located in the chromosomal region 15q11-q13. The genetic cause remains unknown in around 10% of individuals with the characteristic clinical features of AS (AS-like). In some cases, these patients present syndromes whose clinical features overlap with AS and that are caused by variants in other genes with similar or overlapping functions with that of UBE3A or copy number variants (CNVs). It is believed that there are new genes responsible for AS that have not been discovered yet. Next generation sequencing (NGS) has been broadly used in the recent years to analyze the exome, leading to the identification of new genes responsible for Mendelian disorders. The main goal of this thesis is the identification of new genes responsible for AS by using whole exome sequencing (WES). In a cohort of 17 patients presenting an AS phenotype and in which the genetic causes of AS have been ruled out, the implementation of WES in trios lead to the identification of 11 de novo and one X-linked pathogenic/likely pathogenic variants in 11 neurodevelopmental genes (SYNGAP1, VAMP2, TBL1XR1, ASXL3, SATB2, SMARCE1, SPTAN1, KIF1A, KCNQ3, SLC6A1 and LAS1L). The global yield diagnostic in this study is 70,5%. In addition, two deleterious de novo variants have been identified in two candidate genes for AS-like (HSF2 and CHMP7), not previously associated with disease. The new identified AS-like genes do not interact directly with UBE3A gene product but are involved in the same molecular pathways (synapsis, chromatin remodeling and regulation of transcription). The results obtained show that there is a wide genetic heterogeneity in AS-like patients, only two patients carry variants in the same gene (TBL1XR1). In all cases, the clinical features associated with the genes identified overlap with the ones of AS. In our cohort, missense variants account for 50% of all the pathogenic/likely pathogenic variants identified being difficult to predict their impact on the protein. Even though, in silico tools can help to classify them, functional studies are needed to prove their pathogenicity. In this project, the functional analysis of the missense variant p.Arg169Thr in the KIF1A gene was performed, showing that it affects the ATPase activity of the motor domain, probably, due to defects in microtubule binding and therefore the motility of the protein and the capability of vesicle transport. Altogether, the results obtained in this thesis show that the 70,5% of AS-like patients carry variants in other genes that are not UBE3A. Furthermore, it has been shown that WES is a useful tool for the diagnosis of AS-like patients. We propose that WES should be included in the diagnostic algorithm of AS, which will increase the diagnostic rate, allowing a better patient follow-up, the appropriate genetic counseling to the family and to identify novel therapeutic targets.
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Gallenmüller, Constanze [Verfasser], and Angela [Akademischer Betreuer] Abicht. "Molekulargenetische Analyse bei Patienten mit kongenitalen myasthenen Syndromen : Untersuchung von seltenen Krankheitsgenen und von Kandidatengenen des Hexosaminstoffwechselweges / Constanze Gallenmüller. Betreuer: Angela Abicht." München : Universitätsbibliothek der Ludwig-Maximilians-Universität, 2014. http://d-nb.info/106620649X/34.
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Assmann, Angela [Verfasser], Oliver [Akademischer Betreuer] Gross, Max [Akademischer Betreuer] Lakomek, and Margarete [Akademischer Betreuer] Schön. "Prognose von Patienten mit Alport-Syndrom unter Berücksichtigung einer medikamentösen Intervention und verschiedener Nierenersatzverfahren / Angela Assmann. Gutachter: Max Lakomek ; Margarete Schön. Betreuer: Oliver Gross." Göttingen : Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2015. http://d-nb.info/1065881983/34.
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Dill, Veronika [Verfasser], Philipp J. [Akademischer Betreuer] Jost, Philipp J. [Gutachter] Jost, Angela [Gutachter] Krackhardt, and Florian [Gutachter] Bassermann. "Aufhebung erworbener Apoptoseresistenz als therapeutischer Ansatz für Patienten mit Myelodysplastischen Syndromen (MDS) und Patienten mit sekundärer akuter myeloischer Leukämie (sAML) / Veronika Dill ; Gutachter: Philipp J. Jost, Angela Krackhardt, Florian Bassermann ; Betreuer: Philipp J. Jost." München : Universitätsbibliothek der TU München, 2019. http://d-nb.info/1200098412/34.
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Doubková, Světla. "Vývojová specifika jedinců s Angelmanovým syndromem a syndromem Prader - Willi jako východiska pro práci speciálního pedagoga." Master's thesis, 2014. http://www.nusl.cz/ntk/nusl-335018.
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Developmental specifics of individuals with Angelman and Prader - Willi syndrome as the basis for special educator's work The thesis deals in a complex way with the issue of two rare syndromes - Angelman and Prader- Willi syndrome. It describes the manifestations and genetic background, outlines the options for special education and rehabilitation interventions as well as selected medical and regime measures. The thesis informs about the category of rare diseases and also mentions the strategies for approach to these diseases used in the Czech Republic. It also comprises a list of organizations in the Czech Republic that deal with the Angelman and Prader - Willi syndrome and which associate parents and others interested in this topic. The end, the thesis comprises casuistry of two individuals, characteristic syndrome bearers, and conclusions of a questionnaire survey among parents. Surveys through questionnaires illustrate the specific characteristics of inidividuals that have been used to define areas of support. The goal of the thesis was to describe the possibilities for pedagogic and other interdisciplinary interventions, map the situation in the Czech Republic, and to provide more information about this issue to anyone interested.
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Wu, Yaning 1974. "Establishing a Drosophila model for Angelman syndrome." Thesis, 2007. http://hdl.handle.net/2152/3357.
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Drosophila models for human diseases have helped in advancing our knowledge on human diseases and the discovery of potential treatments. Angelman syndrome is a rare neurological disorder that results in severe mental retardation and loss of motor coordination. The disease is caused by loss-of-function mutations in the UBE3A gene encoding a HECT domain ubiquitin protein ligase. Drosophila dube3a is the fly homolog of human UBE3A and their protein products share ~55% similarity in amino acid sequence along the entire length of the proteins. My goal was to develop a Drosophila AS model that will allow us to identify the AS-associated substrate(s) of the Drosophila UBE3A homolog and ultimately, to determine why the lack of UBE3A protein causes Angelman syndrome in humans. Dube3a is present in the embryonic, larval and adult central nervous system, including the adult mushroom bodies, which is the center for learning and memory. I have generated dube3a knock-out flies and they appear normal externally, but display abnormal locomotor behaviors. Flies that overexpress wild-type dube3a in the nervous system also display locomotion defects, and these overexpression phenotypes are dependent on the presence of a conserved cysteine residue essential for HECT domain E3 enzymatic activity. Targeted overexpression of dube3a in the eye, the wing, or ubiquitously causes rough eyes, curly wings and lethality, respectively. These morphological abnormalities in the eye or wing depend on the critical catalytic cysteine of Dube3a. Overexpression of mutant dube3a carrying AS-associated point mutations does not elicit such defects, suggesting they act as loss-of-function mutants. Taken together, dube3a mutants are a candidate fly model for Angelman syndrome, and the flies that overexpress dube3a in the eye or wing are useful for genetic screens to identify the elusive UBE3A substrates relevant to Angelman syndrome.
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Sá, Ana Teresa Capitão Moreira de. "Targeting adenosine A2A receptors to manage Angelman syndrome symptoms." Master's thesis, 2019. http://hdl.handle.net/10316/87879.
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Dissertação de Mestrado em Biologia Celular e Molecular apresentada à Faculdade de Ciências e TecnologiaA síndrome de Angelman (SA) é um distúrbio neuro-genético raro caracterizado por atrasos no desenvolvimento cognitivo, défices motores (ataxia e movimentos desconexos), crises epiléticas e um comportamento peculiar, com os pacientes a manifestar um sorriso fácil e frequente. Esta patologia está associada a uma variedade de mecanismos genéticos e epigenéticos que envolvem a região cromossómica 15q11.2-q13, os quais resultam na perda de função da proteína Ube3A nos neurónios – codificada pelo gene UBE3A, que possui um padrão de imprinting materno. Atualmente, não existe cura para a síndrome de Angelman e as opções terapêuticas com vista ao alívio de sintomas são limitadas. De facto, infelizmente, os traços típicos da patologia tendem a persistir ao longo da vida do doente.Vários estudos científicos relatam que o bloqueio farmacológico dos recetores A2A para a adenosina (A2AR) é capaz de exercer um papel neuroprotector em modelos animais de outras doenças neurológicas com traços fenotípicos semelhantes (Parkinson, Huntington, Alzheimer ou Machado-Joseph, por exemplo), contribuindo para o alívio tanto dos défices motores como cognitivos. Do mesmo modo, diversos artigos apontam para um papel proeminente dos A2AR na modulação da plasticidade sináptica. Assim, este conhecimento prévio levou-nos a especular que o reposicionamento deste tipo de estratégia poderia também ser útil na atenuação dos problemas de desenvolvimento intelectual e motor, bem como nos défices sinápticos, descritos no modelo de murganho de SA. Caso a nossa hipótese se venha a mostrar válida, poderá ter futuras implicações clínicas para o controlo e gerenciamento dos sintomas.Os objetivos deste estudo foram os seguintes: (i) avaliar se o antagonista seletivo dos A2AR, o SCH58261, é capaz de recuperar os défices motores e de coordenação bem como as perturbações de memória a longo prazo encontradas no modelo de murganho de SA; (ii) examinar o impacto de uma administração aguda e crónica de SCH58261 nos processos de plasticidade sináptica no hipocampo de animais SA; (iii) aferir possíveis alterações nos níveis de densidade de proteínas sinápticas relevantes para o entendimento da patologia. Assim, com vista a concretizá-los, realizamos experiências em murganhos controlo e Ube3Am-/p+ num background C57BL/6. Os animais foram injetados diariamente via intraperitoneal com o antagonista SCH58261 por um período de 21 dias; posteriormente, foram sujeitos a uma avaliação comportamental minuciosa a fim de perceber se o bloqueio dos A2AR é realmente capaz de reverter o fenótipo saliente dos animais. Adicionalmente, também avaliamos a transmissão sináptica basal e os processos de plasticidade a longo prazo (nomeadamente, potenciação e depressão de longa duração) em fatias de hipocampo de animais controlo e SA, bem como o efeito do tratamento com SCH58261 nos registos eletrofisiológicos. Por último, procuramos ainda por quaisquer sinais de alterações sinápticas nos murganhos Ube3Am-/p+, através de uma análise por Western Blot de frações enriquecidas em sinaptosomas de diversas regiões cerebrais. Os resultados obtidos demonstraram que o bloqueio dos A2AR consegue melhorar a aprendizagem motora nos murganhos Ube3Am-/p+ no protocolo de rotarod, bem como resgatar défices na força de preensão no teste do grasping. Além do mais, as perturbações de memória a longo prazo identificadas no protocolo de Morris water maze também parecem ser atenuadas após o tratamento. O mesmo efeito benéfico foi observado nos registos eletrofisiológicos efetuados na região CA1 do hipocampo dos animais Ube3Am-/p+, com o antagonista a contribuir para a recuperação da magnitude da depressão de longa duração, que se encontra diminuída neste modelo. De facto, os nossos resultados revelam que tanto uma incubação aguda com SCH58261 na fatia como uma administração crónica nos animais via injeção intraperitoneal, parecem ser vantajosas na prevenção dos danos nos processos de plasticidade sináptica encontrados no circuito hipocampal dos murganhos SA. Relativamente aos estudos neuroquímicos, os animais SA revelaram um desequilíbrio notório quer nos marcadores de sistemas de transmissão excitatórios quer inibitórios no cerebelo e no estriado, bem como no sistema dopaminérgico no estriado e nos marcadores sinápticos gerais no córtex pré-frontal. Assim, é possível que estes défices sinápticos estejam, de alguma forma, a contribuir para as perturbações motoras identificadas neste modelo. Em suma, o nosso trabalho apresenta fortes evidências que uma estratégia terapêutica baseada no bloqueio dos A2AR pode ser potencialmente benéfica na modulação dos traços fenotípicos distintos do modelo de murganho Ube3Am-/p+, que se assemelham aos sintomas do quadro clínico da síndrome. Além do mais, os resultados obtidos também contribuem para um maior conhecimento acerca dos mecanismos sinápticos que podem estar por detrás da sintomatologia associada à patologia.
Angelman syndrome (AS) is a rare neurogenetic disorder whose main features comprise marked intellectual delay, motor impairments such as ataxia and wide-based gait, epileptiform EEG abnormalities and a very singular behavioural profile. This condition is associated with a handful of genetic and epigenetic mechanisms involving the chromosome region 15q11.2-q13, that ultimately result in a loss of function of the neuronal Ube3A protein, which is maternally imprinted in the brain by the UBE3A gene. Until date, AS therapeutics has met with limited success, with the clinical traits that deeply impair the life-quality of the children persisting throughout adulthood.Several lines of evidence state that pharmacological blockade of adenosine A2A receptors (A2AR) can afford a neuroprotective role in mouse models of other brain diseases with similar phenotypical traits (e.g., Parkinson, Huntington, Alzheimer or Machado-Joseph disease), being helpful in counteracting both locomotor deficits as well as memory impairments. Moreover, there are also diverse reports which claim that A2AR-mediated signalling has a prominent role in modulating synaptic plasticity processes. Thus, we hypothesized that the use of this type of strategy could also ameliorate the cognitive and motor disablements as well as synaptic plasticity impairments found in the AS mouse model, with prospective future implications for the clinical management of the disease.Hence, we had the following aims: (i) evaluate whether the A2AR antagonist SCH58261 is able to recover the motor and coordination as well as the spatial and associative memory deficits found in the AS mouse model; (ii) check the impact of SCH58261 acute and chronic administration on hippocampal synaptic plasticity processes; (iii) appraise for changes in synaptic protein density levels which may bring to light the underlying causes of the pathology. To fulfil our goals, experiments were conducted in both wild-type and Ube3Am-/p+ animals with a C57BL/6 background. Mice were administered daily with the selective antagonist SCH58261 for a 21-days period and subjected to a thorough behavioural characterization in order to evaluate whether A2AR blockade is indeed able to revert the pronounced behavioural phenotype. Moreover, we also appraised basal synaptic transmission as well as long-lasting synaptic plasticity processes (namely long-term potentiation and long-term depression) in hippocampal slices of both wild-type and AS mice and check the impact of both an acute and chronic administration of SCH58261 through electrophysiological recordings. Finally, we assessed if there were any signs of synaptic alterations in the Ube3Am-/p+ mouse model by Western Blot analysis of synaptosomal fractions from several brain regions.Obtained results show that A2AR blockade is able to ameliorate the motor learning phenotype of Ube3Am-/p+ mice in the rotarod task as well as rescue their grip strength impairment in a grasping protocol. Furthermore, our chronic treatment also seems to slightly improve the reported long-term memory disturbances in a Morris water maze protocol. In addition, SCH58261 also seems to be helpful in recovering the diminished long-term depression magnitude in hippocampal slices from Ube3Am-/p+ mice, as shown by the electrophysiological recordings we carried in the Schaffer Collaterals – CA1 pathway. Indeed, our data shows that both an acute – through direct application in the slice – and chronic – via intraperitoneal injection – SCH58261 treatment seem to be helpful in counteracting the marked plasticity impairments found in the hippocampal circuitry of AS mice. In what concerns our neurochemical results, AS mice present a noticeable unbalance of markers for both excitatory and inhibitory neurotransmission in both the cerebellum and striatum as well as for dopaminergic systems in the striatum and general synaptic markers in the prefrontal cortex. Ergo, it is possible that the aforementioned synaptic deficits somehow afford the motor impairments spotted in animals. Altogether, our findings seem to support the idea that an A2AR-signalling based therapeutic strategy might be useful and of potential value to manage the distinctive behavioural traits found in the Ube3A-maternal deficient mouse model, which closely mimic some of the hallmarks of AS. Additionally, the data obtained from this experimental work also contributes to a greater knowledge of the underlying neuronal and synaptic mechanisms which may account for AS symptomology.
Outro - POCI-01-0145-FEDER-007440; POCI-01-0145-FEDER-031274
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Joaquim, Mariana Isabel Lopes. "Exploring cell reprogramming techniques for Angelman Syndrome disease modelling." Master's thesis, 2017. http://hdl.handle.net/10362/42365.
Full textAbstract:
Angelman Syndrome (AS) is an imprinted neurodevelopmental disease with no cure caused by the lack of UBE3A expression, which, in neurons, is exclusively maternally expressed. The paternal UBE3A allele is silenced by the UBE3A antisense transcript (UBE3A-ATS), which is only expressed from the paternal chromosome. In AS mouse model, inhibition of the UBE3A-ATS transcription can reactivate paternal UBE3A. To translate such an approach to humans, the development of a cellular model for this disease is necessary.
Here we sought to develop cellular model systems of AS from patient-derived fibroblasts and evaluate their imprinting status using RNA FISH-based single-cell approaches.
First, a neural direct conversion protocol based on expression of two neuronal transcription factors - ASCL1, NGN2 – and SMAD pathway inhibitors was tried in order to convert fibroblasts into neurons. Despite high infection efficiency and detection of transgenic ASCL1 expression, the generated “iNs” did not show signs of neuronal identity based on RT-qPCR and IF analysis. This failure might have been caused by lack of lentiviruses concentration by ultracentrifugation, antibiotic selection skipping and/or dislodging of the cells under conversion. Second, we tried to generate NPCs from iPSCs using a commercially available differentiation protocol. Based on RT-qPCR and IF analysis, the generated “NPCs” failed to express the correct genetic markers. This failure might be explained by inappropriate accelerated division rate of the cells during induction or lack of pluripotency of the newly-generated iPSCs used.
Despite unsuccessful generation of neuronal cells, we were able to optimize nascent-transcript RNA FISH, combining UBE3A and paternally expressed SNORD116, which is a crucial tool to confirm the imprinting status of the Angelman locus in newly-generated cells.
With future efforts, the establishment of AS cellular model systems will serve as drug screening platform to test paternal UBE3A reactivation as a therapeutic target for AS.
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Freitas, Paula Cristina Fernandes de. "O impacto da hipoterapia em crianças com Síndrome de Angelman : estudo de caso." Master's thesis, 2014. http://hdl.handle.net/10400.14/18483.
Full textAbstract:
A generalização do direito à educação institui uma das mais expressivas
conquistas resultantes da modernização das sociedades, conferindo liberdade de
aprender a todas as crianças com ou sem deficiência, assim como, o direito à sua
construção pessoal e social, ou seja à sua real inclusão.
O presente estudo, focaliza-se na Síndrome de Angelman, uma doença rara de
base genética que se revela num distúrbio neurológico que causa atraso mental grave,
alterações do comportamento, demora no desenvolvimento psicomotor, ausência de fala
e deficit de atenção.
Quisemos verificar a influência da intervenção terapêutica – hipoterapia
– na recuperação ao nível psicomotor, tendo em conta o vínculo afetivo entre criançacavalo.
Nesta técnica, hipoterapia, utiliza-se o passo do cavalo, movimento
tridimensional, com fins terapêuticos de forma a que os estímulos produzidos em todo o
corpo do cavaleiro proporcionem melhorias em termos neuro-musculares e sensoriais.
O participante deste estudo é uma criança de 8 anos de idade, do sexo
masculino, que apresenta diagnóstico de Síndrome de Angelman. Participaram também
a mãe da criança, a psicóloga e fisioterapeuta da Associação Equiterapêutica do Porto e
Matosinhos.
Através da exploração do paradigma metodológico qualitativo, foi feita
previamente uma análise documental (e.g., PEI, ficha de grupo e ficha individual) e
configuradas entrevistas direcionadas à mãe da criança, à psicóloga e fisioterapeuta.
Foram ainda realizadas seis sessões de observação direta não-participante, relativas às
sessões de hipoterapia.
Os resultados obtidos neste estudo são indicadores probabilísticos da
importância da hipoterapia, contribuindo de forma satisfatória para um melhor
desenvolvimento psicomotor (i.e. equilíbrio e ajuste corporal, auto-estima e estabilidade
emocional). Ponderamos equitativamente, a hipótese da relação que se estabelece entre
criança-cavalo, o vínculo afetivo, estar fortemente associada a esta evolução
desenvolvimental. Reiteramos a importância do investimento nesta terapia e na articulação entre os diferentes agentes educativos para uma intervenção mais eficaz e
frutífera.The generalization of the right to education establishing one of the most significant achievements resulting from the modernization of societies, giving children , with or without disabilities, freedom to learn, as well as the right to personal and social construction, promoting its actual inclusion. The present study focuses on Angelman Syndrome, a rare genetic base disease that reveals a neurological disorder that causes severe mental retardation, behavioural disturbances, delayed psychomotor development, lack of speech and attention deficit. The hippo therapy technique uses the horse step, a three-dimensional movement, with therapeutic purposes, so that the stimulus produced around the body of the rider provide improvements in neuro-muscular and sensory terms. The goal of this study was to verify the effect of therapeutic intervention - hippo therapy - its recovery in the psychomotor level, taking into account the affective link between child and horse. The participant of this study is an 8-year-old male child, presenting diagnosis of Angelman Syndrome. The child's mother, the psychologist and physiotherapist of Associação Equiterapêutica do Porto e Matosinhos also participated in the study. The analysis and treatment of data were made using several documents (e.g., PEI, group and individual record sheet) and set directed to the mother of the child, psychologist and physiotherapist interviews. There were also six sessions of direct nonparticipant observation concerning the hippo therapy sessions. The results obtained in this study are probabilistic indicators of the importance of hippo therapy, contributing satisfactorily to a better psychomotor development (e.g. body balance and adjustment, self-esteem and emotional stability, due to the threedimensional movement of the horse). However, these results are only possible due to the affective bound between the child and horse. We reiterate the importance of investment in this therapy and the relationship between the various educational agents in order to achieve a more effective and fruitful intervention.
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Condon, Kathryn Helen. "Alteration of Golgi Apparatus Ion Homeostasis in Cellular and Mouse Models of Angelman Syndrome." Diss., 2009. http://hdl.handle.net/10161/1297.
Full textAbstract:
Ube3a is a HECT domain E3 ubiquitin ligase originally recognized for its role in degrading p53 in the presence of the human papilloma virus protein E6. Loss of maternal Ube3a expression causes Angelman syndrome, a severe neurodevelopmental disorder characterized by mental retardation, ataxia, epilepsy, lack of speech, and a unique behavioral phenotype that includes a happy demeanor and frequent laughing. However, characterization of the endogenous properties and cellular role for Ube3a has been limited. Over the last few years, an interesting cohort of Ube3a interacting partners and putative substrates were named, though the consequences of these interactions were not thoroughly investigated. These include two Golgi localized proteins - PIST and Golgin-160 - as well as several proteins that can regulate trafficking of proteins at the Golgi apparatus: Src family kinases, ubiquilin, and tuberin. Therefore, we decided to focus on whether Ube3a could regulate Golgi structure or function.
In this dissertation, I will describe a new role for Ube3a at the Golgi apparatus in the regulation of intralumenal ion homeostasis. First, I characterized the expression pattern of endogenous Ube3a and overexpressed Ube3a isoforms by immunostaining and fractionation and demonstrated that although Ube3a has diffuse nuclear/cytoplasmic localization, it also associates with membrane fractions. I also confirmed that Ube3a interacts endogenously with both PIST and Golgin-160. Next, I demonstrated that Golgi morphology is perturbed in a cell line with stable knockdown of Ube3a. I found that the Golgi apparatus in Ube3a knockdown cells is under-acidifed, and that this is the primary defect underlying the disrupted Golgi morphology. Finally, I extended these findings in vivo and examined the morphology of the Golgi apparatus in the brains of Angelman syndrome model mice. The Golgi structures in the visual cortex of these mice appeared disorganized by immunohistochemistry and individual cisternae were significantly distended by electron microscopy, consistent with a defect in ion homeostasis at the Golgi apparatus. These findings define new cellular role for Ube3a at the Golgi apparatus and provide insight into the pathogenesis of Angelman syndrome.
Dissertation
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Sivá, Monika. "Hledání biologické role rodiny proteinů podobných Ddi1." Doctoral thesis, 2019. http://www.nusl.cz/ntk/nusl-396154.
Full textAbstract:
Ddi1-like protein family has been recently raised into the spotlight by the scientific community due to its important roles in cellular homeostasis maintenance. It represents a specific group among shuttling proteins of the ubiquitin-proteasome system. When compared to other shuttles, Ddi1-like protein family members harbor a unique retroviral-protease like domain besides the conventional ubiquitin-like (UBL) domain and domains interacting with ubiquitin. In addition, a helical domain of Ddi (HDD) has been recently found in most of the orthologs. In this thesis, I focus on characterization of several members of Ddi1-like protein family, both on molecular level using NMR and in model mouse strains via a variety of biological methods. Solution structure of the UBL domain of Ddi1p of S. cerevisiae was solved and its characteristics were compared to those of the UBL domain of its human ortholog. Furthermore, we show that human DDI2 specifically binds to ubiquitin with its terminal domains, both the UBL and the UIM; however, with very low affinity in contrast to binding properties of its yeast counterpart. Our study also show that hDDI2 does not form a head-to-tail homodimer. Based on our structural studies, we hypothesize that human DDI2 might have evolved a different function compared to its yeast...
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"Disrupted Synaptic Transmission and Abnormal Short-term Synaptic Plasticity in an Angelman Syndrome Mouse Model." Doctoral diss., 2017. http://hdl.handle.net/2286/R.I.44228.
Full textAbstract:
abstract: Angelman syndrome (AS) is a neurodevelopmental disorder characterized by developmental delays, intellectual disabilities, impaired language and speech, and movement defects. Most AS cases are caused by dysfunction of a maternally-expressed E3 ubiquitin ligase (UBE3A, also known as E6 associated protein, E6-AP) in neurons. Currently, the mechanism on how loss-of-function of the enzyme influences the nervous system development remains unknown. We hypothesize that impaired metabolism of proteins, most likely those related to E6-AP substrates, may alter the developmental trajectory of neuronal structures including dendrites, spines and synaptic proteins, which leads to disrupted activity/experience-dependent synaptic plasticity and maturation. To test this hypothesis, we conducted a detailed investigation on neuronal morphology and electrophysiological properties in the prefrontal cortex (PFC) layer 5 (L5) corticostriatal pyramidal neurons (target neurons). We found smaller soma size in the maternal Ube3a deficient mice (m-/p+; 'AS' mice) at postnatal 17-19 (P17-19), P28-35 and older than 70 days (>P70), and decreased basal dendritic processes at P28-35. Surprisingly, both excitatory and inhibitory miniature postsynaptic currents (mEPSCs and mIPSCs) decreased on these neurons. These neurons also exhibited abnormalities in the local neural circuits, short-term synaptic plasticity and AMPA/NMDA ratio: the excitatory inputs from L2/3 and L5A, and inhibitory inputs from L5 significantly reduced in AS mice from P17-19; Both the release probability (Pr) and readily-releasable vesicle (RRV) pool replenishment of presynaptic neurons of the target neurons were disrupted at P17-19 and P28-35, and the change of RRV pool replenishment maintained through adulthood (>P70). The AMPA/NMDA ratio showed abnormality in the L5 corticostriatal neurons of PFC in AS mice older than P28-35, during which it decreased significantly compared to that of age-matched WT littermates. Western Blot analysis revealed that the expression level of a key regulator of the cytoskeleton system, Rho family small GTPase cell division control protein 42 homolog (cdc42), reduced significantly in the PFC of AS mice at P28-35.These impairments of synaptic transmission and short-term synaptic plasticity may account for the impaired neuronal morphology and synaptic deficits observed in the PFC target neurons, and contribute to the phenotypes in AS model mice. The present work reveals for the first time that the E6-AP deficiency influences brain function in both brain region-specific and age-dependent ways, demonstrates the functional impairment at the neural circuit level, and reveals that the presynaptic mechanisms are disrupted in AS model. These novel findings shed light on our understanding of the AS pathogenesis and inform potential novel therapeutic explorations.Dissertation/Thesis
Doctoral Dissertation Neuroscience 2017
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Brandão, Duarte Pólvora. "Generation and characterization of Angelman Syndrome iPSCs for disease modelling and drug screening." Dissertação, 2016. https://repositorio-aberto.up.pt/handle/10216/90966.
Full text
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Brandão, Duarte Pólvora. "Generation and characterization of Angelman Syndrome iPSCs for disease modelling and drug screening." Master's thesis, 2016. https://repositorio-aberto.up.pt/handle/10216/90966.
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Vieira, Adriana Andrade. "In vitro Modeling of Angelman Syndrome using the Neural Commitment of Patient-Specific iPSCs." Master's thesis, 2020. http://hdl.handle.net/10451/47760.
Full textAbstract:
Tese de mestrado, Biologia Molecular e Genética, Universidade de Lisboa, Faculdade de Ciências, 2020Angelman syndrome (AS) is a rare neurodevelopmental disorder with no cure, characterized by a severe developmental delay, speech impairment, motor dysfunction, and a characteristic happy behavior. AS is caused by the loss of functional UBE3A protein, an E3 ubiquitin ligase that targets proteins for degradation by the ubiquitin-proteasome system. Disruption of UBE3A activity in neurons impairs ubiquitination leading to accumulation of UBE3A-specific targets which results in neuronal dysfunction. The UBE3A gene undergoes tissue-specific genomic imprinting, an epigenetic phenomenon that leads to parent-of-origin-specific monoallelic expression. Thus, UBE3A is exclusively expressed from the maternally inherited allele in mature neurons, since the paternal allele is silenced upon neuronal differentiation due to transcriptional interference of an antisense RNA called UBE3A-ATS. Loss of maternal UBE3A allele results in complete absence of UBE3A protein ultimately leading to AS. Most of what we know about AS has been studied in animal models, however, this pre-clinical model has several limitations for direct translation to the human disease. Recently, somatic cell reprogramming technology and neuronal differentiation protocols have contributed to overcome such difficulty and establish in vitro models using patient-derived induced pluripotent stem cells (iPSCs). These models enable the generation of disease-relevant cells in limitless amounts while faithfully recapitulating neuronal developmental hallmarks, which allows the detailed elucidation of the disease mechanisms responsible for the clinical features observed in patients. In this project, we submitted healthy control and AS-derived iPSCs to a neuronal differentiation protocol for 80 days to obtain fully mature neurons. Our data suggest AS-derived neuronal cultures display increased neuronal apoptosis, enhanced gliogenesis and persistence or progenitor-like neural rosettes at the final stages of differentiation. We hypothesize that loss of UBE3A function impairs neuronal viability and consequently prompts neural progenitors to continue proliferating and differentiating, causing a precocious neuro-to-glia switch. Our results show the suitability of patient-derived iPSCs to be used as a disease modelling approach to study Angelman syndrome and future works will use this system to tackle the pathophysiological mechanisms at the molecular level that causes AS.
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Wawrzik, Michaela [Verfasser]. "Expressionsanalysen geprägter Gene in der Prader-Willi-Angelman-Syndrom-Region / vorgelegt von Michaela Wawrzik." 2009. http://d-nb.info/1000834867/34.
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Nazlican, Hülya [Verfasser]. "Somatische Mosaike und atypische Deletionen bei Patienten mit Prader-Willi- und Angelman-Syndrom / vorgelegt von Hülya Nazlican." 2006. http://d-nb.info/979031389/34.
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Klapos, Angela [Verfasser]. "Langzeitergebnisse nach operativer Dekompression des Sulcus-ulnaris-Syndroms : eine katamnestische Studie / Angela Klapos." 2002. http://d-nb.info/96548159X/34.
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