Tesis sobre el tema "Myotonic Dystrophy type 1 (DM1)"
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Minier, Lisa. "Evaluation de la personnalité, du coping et de la régulation émotionnelle de patients atteints de Dystrophie Myotonique de type 1 (DM1)". Thesis, Paris 10, 2019. http://faraway.parisnanterre.fr/login?URL=http://bdr.parisnanterre.fr/theses/intranet/2019/2019PA100112/2019PA100112.pdf.
Texto completoMyotonic Dystrophy type 1 (DM1) is a neuromuscular disease with multiple impairments leading to blunted affect, apathy, hypersomnia, fatigue, social cognition deficit and theory of mind deficit. In this research, personality traits, coping, and emotion regulation of 60 DM1 patients were assessed. All this information will help us design DM1 adapted psychological care.Regarding personality, our main result is that patients show similar N scores to the healthy control group despite our expectations (high scores in relation with the severity of the disease and its complications). In the light of our coping results, it seems that DM1 patients are using a large variety of coping strategies. However, apathy and reduced motivation constitute obstacles for coping strategies. Finally, apathy and fatigue do not influence emotion regulation in our sample DM1. Furthermore, Cognitive reevaluation strategy seems preserved from the disease’s consequences. This strategy might be an important advantage in the preservation of quality of life in DM1, despite the disease progression. A DM1 specific Cognitive Behavioral Therapy showed promising results. Other psychotherapeutic approaches could be explored, namely Acceptance and Commitment Therapy
De, Dea Diniz Damily. "The study of the consequences of serca1’s missplicing on muscle function in myotonic dystrophy type 1". Electronic Thesis or Diss., Sorbonne université, 2018. http://www.theses.fr/2018SORUS569.
Texto completoMyotonic Dystrophy Type 1 (DM1) is a neuromuscular disease that affects mainly the skeletal muscle with the presence of myotonia and progressive atrophy and is caused by abnormal CTG expansion in the 3'UTR of the DMPK gene. The expression of the mutated RNA induces the loss of function of the MBNL1 splicing factor and leads to the re-expression of fetal isoforms of certain transcripts in the adult tissues of DM1 patients. In order to identify new mechanisms involved in muscle dysfunction, I developed a model of muscle cells conditionally expressing 960 interrupted CTG repeats. Following the targeted expression of RNA-960CUG in myotubes, transcriptome analysis shows that despite the presence of functions/biological processes typical of DM1, the induction of non-DM1 associated pathways and the absence of phenotype suggest that this model is not appropriate for this study of molecular mechanisms. I also did a study of the impact of the ATP2A1 (SERCA1) misplicing, present in DM1 patients, on the muscular function. I used an antisense approach to promote the exclusion of exon 22 from Atp2a1 in the muscle of two animal models, leading to the reexpression of the Serca1b fetal isoform. The re-expression of Serca1b in the muscle of adult wild-type mice leads to a slowing contraction and a loss of muscle mass. In zebrafish, this modification on Atp2a1 splicing causes an alteration on the locomotion. All of these results indicate that reexpression of Serca1b affects muscle function and may contribute to muscle symptoms in DM1
Lallemant, Louison. "Pathologie neuronale et gliale en lien avec les atteintes neurologiques de la dystrophie myotonique de type 1 (DM1)". Electronic Thesis or Diss., Sorbonne université, 2023. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2023SORUS404.pdf.
Texto completoMyotonic dystrophy type 1 (DM1) is a severe neuromuscular disease affecting many tissues and organs. The debilitating neurological manifestations vary from executive dysfunction in adults, to attention deficits and low processing speed in pediatric patients, to severe intellectual disability in congenital cases. DM1 neurological manifestations have a profound impact on the daily life of patients and their families, and there is currently no treatment for this disease. DM1 is caused by the abnormal expansion of a CTG repeat in DMPK gene. Expanded DMPK transcripts are toxic because they accumulate in the cell nucleus, disrupting the activity of important RNA-binding proteins. As a consequence, DM1 cells show abnormal RNA metabolism and processing of many downstream transcripts. Despite progress in the understanding of the muscle pathophysiology, the disease mechanisms remain unclear in the CNS. We still do not know which cell types and molecular pathways are primarily affected in the brain and how they contribute to DM1 neurological symptoms. In order to investigate this problem, our laboratory has developed a transgenic mouse model of DM1: DMSXL mice express expanded human DMPK transcripts in multiple tissues, notably in the brain, and display relevant behavioral, electrophysiological and neurochemical phenotypes. Using this mouse model, the objective of my thesis was to better understand the cellular and molecular mechanisms involved in the neuronal and non-neuronal impairment linked to the neurological damages of DM1. I first focused on the characterization of the different cell types in the DMSXL brain. A multi-omics study was carried out on DMSXL neurons, astrocytes and oligodendrocytes. Our results, which show that glial cells are more impacted by CTG repeats, have allowed us to better understand the cellular and molecular mechanisms of DM1 in the CNS, but above all to emphasize the importance of studying not only the neurons, but also astrocytes and oligodendrocytes in the pathological context of DM1. I then got involved in the study of astrocyte pathology in DM1. We thus demonstrated that DMSXL astrocytes exhibited reduced ramification and impaired cell adhesion, and had a strong negative impact on neuritogenesis. In the same time, I also participated in the study of oligodendroglia impairment in DM1. We found that the toxic CUG RNA disrupts the molecular program of oligodendrocyte (OL) differentiation, impairing the transcriptome changes occurring during the oligodendrocyte precursor cells (OPC)-OL transition and leading to transient hypomyelination in mice. I also studied the neuronal pathology in DMSXL mice. Our results demonstrated that the accumulation of toxic RNA foci in neurons perturbs mainly protein phosphorylation, which seems to lead to neuronal morphological defects associated with vesicle dynamics impairment and axonal transport defects. The three main cell types of the brain therefore present significant damage in the context of DM1, which could have an impact on crucial processes of cerebral functioning. Indeed, we have demonstrated an alteration in neurotransmission and synaptic plasticity in DMSXL mice. All together my work has provided novel insight into the cell-specific mechanisms operating in DM1, demonstrating the implication of astrocyte, oligodendrocyte and neuron defects in a DM1mouse model, and contributing towards an integrative understanding of brain pathology
Vergnol, Amélie. "Les isoformes CaVβ1 : rôle dans la formation de la jonction neuromusculaire et implication dans la physiopathologie de la Dystrophie Myotonique de type 1". Electronic Thesis or Diss., Sorbonne université, 2024. http://www.theses.fr/2024SORUS305.
Texto completoFour CaVβ proteins (CaVβ1 to CaVβ4) are described as regulatory subunit of Voltage-gated Ca2+ channel (VGCC), each exhibiting specific expression pattern in excitable cells based on their function. While primarily recognized for their role in VGCC regulation, CaVβ proteins also function independently of channels, acting as regulators of gene expression. Among these, CaVβ1 is expressed in skeletal muscle as different isoforms. The adult constitutive isoform, CaVβ1D, is located at the sarcolemma and more specifically at the triad, where it plays a crucial role in regulating CaV1 to control Excitation-Contraction Coupling (ECC) mechanism, essential for muscle contraction.In this thesis, we further explored the less studied CaVβ1 isoforms, with a particular focus on embryonic/perinatal variants, including the previously described CaVβ1E. We investigated their roles in the neuromuscular and muscular systems. Indeed, CaVβ1 proteins have been showed as essential for NeuroMuscular Junction (NMJ) development, though the involvement of specific isoform remains unclear. Our investigation assessed the role of CaVβ1 isoforms at different stages of NMJ formation and maturation/maintenance. Additionally, given the deregulation of CaVβ1 in Myotonic Dystrophy Type 1 (DM1), we explored its functional role in this muscular pathological context.First, we identified CaVβ1A as another isoform expressed during embryogenesis and perinatal stages. Our findings revealed that CaVβ1 isoforms expressions are regulated by the differential activation of promoters during development: a promoter1 in exon 1 drives CaVβ1A/E expressions, while a promoter2 in exon 2B controls CaVβ1D expression. Interestingly, nerve damage in adult muscle triggers a shift toward the promoter1 activation and leading to the re-expression of CaVβ1A/E transcripts. Furthermore, we found that CaVβ1 embryonic/perinatal isoforms are critical for proper in vitro pre-patterning of myotubes and that their postnatal expressions influences NMJ maturation/maintenance. In the pathological context of DM1, we observed the increased expression of CaVβ1A/E, which appears to mitigate myotonia symptoms. In addition, we found that the modulation of their expression is linked with MBNL proteins, which are central in the pathophysiology of DM1. In conclusion, this thesis work has clarified knowledge of the various CaVβ1 isoforms in skeletal muscle and provides new insights into their role in two independent contexts of NMJ development and DM1 pathophysiology. Understanding CaVβ1 protein regulation in skeletal muscle is essential to decipher muscle homeostasis mechanisms and potentially identify new therapeutic targets to face muscular disorders
Ney, Michel. "Rôle de l'inclusion de l'exon 7 de BIN1 dans la faiblesse musculaire des patients atteints de dystrophie myotonique". Thesis, Strasbourg, 2016. http://www.theses.fr/2016STRAJ077/document.
Texto completoMyotonic dystrophy of type 1 (DM1), is an inherited genetic disease affecting around 1 in 8000 person. Patients suffering from DM1 develop essentially muscle disorders such as muscle weakness, muscle loss and atrophy. The cause of DM1 is explained by the mutation of a gene called “DMPK“.During my thesis, I discovered that the alternative splicing of BIN1 mRNA was altered in the muscle of DM1 patients. Indeed, the BIN1 exon 7, which is normally absent in healthy muscle, is aberrantly expressed in DM1 muscle. By using a mouse model, I found that the forced expression of BIN1 exon 7 was responsible of the alteration of both muscle structure and function. Notably, we found a decrease in muscle fibers area (atrophy) and an increase of muscle weakness, compared to wild-type mice. Therefore, this work will help in the understanding of the disease mechanism and could explain the causes of muscle weakness and atrophy, which have never been elucidated to this date
Winblad, Stefan. "Myotonic dystrophy type 1 : cognition, personality and emotion /". Göteborg : Göteborg University, Dept. of Psychology, 2006. http://bvbr.bib-bvb.de:8991/F?func=service&doc_library=BVB01&doc_number=015464022&line_number=0001&func_code=DB_RECORDS&service_type=MEDIA.
Texto completoHaworth, Christine. "Understanding the pathogenesis of myotonic dystrophy type 1". Thesis, University of Glasgow, 2008. http://theses.gla.ac.uk/478/.
Texto completoOsborne, Robert J. "Caenorhabditis elegans models of myotonic dystrophy type 1". Thesis, University of Nottingham, 2004. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.408632.
Texto completoLanglois, Marc-André. "RNA-based gene therapies for myotonic dystrophy type 1". Thesis, Université Laval, 2003. http://www.theses.ulaval.ca/2003/21404/21404.pdf.
Texto completoMyotonic dystrophy type 1 (DM1) is a severe neuromuscular disease that ultimately causes loss of mobility and premature death. DM1 is the most common muscular dystrophy in adults with a world wide incidence of 1 affected individual in every 15 000. This disease is of special relevance in the Saguenay and Charlevoix regions in Quebec, where 1 in every 500 individuals is a carrier of the mutation. DM1 is caused by the expansion of an unstable CTG trinucleotide repeat located in 3’UTR of the DMPK (DM protein kinase) gene. However, it has been shown that most DM1 symptoms are related to the nuclear retention of mutant DMPK mRNA. These mutant transcripts bind to nuclear proteins and form foci in DM1 cell nuclei. This is though to be the leading cause of metabolical disruptions and defective alternative splicing of several mRNAs observed in DM1 cells. Our main project objective was to evaluate whether destruction of mutant DMPK mRNA could restore normal phenotype features in DM1 human skeletal myoblasts. The use of three RNA-based approaches: antisense RNAs, ribozymes and shRNAs, all displayed significant reductions in mutant DMPK mRNA. Antisense RNAs and ribozymes, as opposed to shRNAs, allowed specific targeting and destruction of mutant DMPK mRNAs in the nucleus of DM1 myoblasts. This feature thus allows a basal level of DMPK protein expression which is of particular relevance in the advent of developing a gene therapy for DM1. Ribozymes were effective in reducing the number and intensity of foci present in the nucleus of the myoblasts, thus allowing the release of certain CUG-binding proteins. This resulted in restoration of the defective splicing of the insulin receptor mRNA. Antisense RNAs to the DMPK mRNA expressed by an oncoretrovirus restored myoblast fusion, glucose uptake and lowered nuclear levels of CUGBP, an alternative splicing factor. Over expression of hnRNP-H, an alternative splicing factor that we showed could bind to CUG repeats, also reduces expression of CUGBP and restores defective splicing of the insulin receptor. These results reveal for the first time the intricate link between mutant DMPK mRNA nuclear retention, depletion of a CUG-binding protein that is also a splicing factor and exacerbation of related DM1 features. In conclusion, our work has allowed to better define the mechanisms involved in DM1 pathogenesis and has validated the relevance of developing a gene therapy that specifically targets mutant DMPK mRNAs.
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Nasser, Khalidah K. "Genetic and symptomatic variations in Myotonic Dystrophy Type 1". Thesis, University of Glasgow, 2016. http://theses.gla.ac.uk/7874/.
Texto completoHarrison, Eleanor G. "Redesign of trans-splicing molecules for the correction of dystrophia myotonica type 1 toxic RNA transcripts". Digital Commons @ East Tennessee State University, 2014. https://dc.etsu.edu/honors/248.
Texto completoColdefy, Maurin Anne-Sophie. "Implication des voies de signalisation des MAPK, ERK1/2 et p38, dans la dystrophie myotonique de type 1 (DM1)". Nice, 2006. http://www.theses.fr/2006NICE4059.
Texto completoThe aim of this work was to characterize a putative role of ERK1/2 and p38 MAPK in the myotonic dystrophy 1, called DM1. DM1, the most frequent dystrophy in adults, is a multi-systemic disorder which mainly affects skeletal muscles (myotonia, progressive wasting and weakness, delay in muscular differentiation). DM1 is an autosomal dominant inherited disease. The genetic mutation is an expansion of CTG trinucleotide repeats tract in the DMPK 3’ untranslated region. DMPK encodes a serine/threonine kinase but its function is still unknown. ERK1/2 and p38 MAPK signalling pathways play central and essential roles in cells physiology and are implicated in various cellular processes including muscular differentiation. We show that ERK1/2 and p38 activation is significantly diminished in muscular biopsies from DM1 patients. This diminished activation is not correlated with a diminution of DMPK expression in DM1, as we observed in transgenic mice, Dmpk knock-out or DMPK over-expressing mice. However, in C2C12 cells expressing CUG repeats in 3’ UTR of GFP, ERK1/2 and p38 activation is altered. In DM1, the diminution of ERK1/2 and p38 activation could be due to the expression of CUG repeats tract rather than to the decrease of DMPK expression. Our results and our recently developed molecular tools will enable us to further understand the implication of ERK1/2 and p38 MAPK in DM1 as well as Dmpk function in muscular differentiation
Jimenez, Moreno Aura Cecilia. "Exploring outcome measures for adults with myotonic dystrophy type 1". Thesis, University of Newcastle upon Tyne, 2017. http://hdl.handle.net/10443/3933.
Texto completoMontero, Fernando Alberto Morales. "Somatic mosaicism and genotype-phenotype correlations in myotonic dystrophy type 1". Thesis, University of Glasgow, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.433224.
Texto completoAzimi, Mehrdad. "Analysis and Modulation of PACT, DICER and MBNL1 in the Context of Myotonic Dystrophy Type I". Thesis, Université d'Ottawa / University of Ottawa, 2016. http://hdl.handle.net/10393/35310.
Texto completoLoro, Emanuele Loro. "Normal myogenesis and increased apoptosis in myotonic dystrophy type-1 muscle cells". Doctoral thesis, Università degli studi di Padova, 2010. http://hdl.handle.net/11577/3423200.
Texto completoLa distrofia miotonica di tipo 1 (DM1) è causata dall'espansione (CTG)n nella regione trascritta ma non tradotta al 3' del gene DMPK. I trascritti mutati sono trattenuti in foci nucleari, i quali sequestrano diverse proteine leganti RNA spesso alterandone le funzioni (i.e. regolazione dello splicing). A livello del muscolo, i meccanismi patogenetici che portano a miotonia, debolezza e perdita di massa dei muscoli distali, non sono ad oggi chiari. Otto linee di mioblasti primari umani, ottenuti da biopsie di pazienti affetti da DM1 nelle forme adulta e congenita (range di espansione tra 90 e 1800 CTG), sono state differenziate ed innervate con successo, ottenendo miotubi in grado i contrarre. L'analisi morfologica e la quantificazione di diversi marker di miogenesi mediante RT-PCR e Western blotting, hanno indicato che il diferenziamento in vitro dei mioblasti primari DM1 è indistinguibile da quello ottenuto con mioblasti di controllo. In ciascuna linea DM1 è stata confermata l'espansione (CTG)n mediante long-PCR ed ibridizzazione in situ. Inoltre, nei miotubi DM1 è stato rilevata l'alterazione dello splicing del recettore per l'insulina e di MBNL1, caratteristica del fenotipo DM1. A 15 giorni di differenziamento, una considerevole perdita di miotubi DM1 ha suggerito l'attivazione di pathways catabolici, come confermato dalla presenza di marker di apoptosi (taglio proteolitico della caspasi 3, rilascio di citocromo c dai mitocondri, frammentazione della cromatina) e di autofagia (aumento dei livelli di LC3 lipidato e di P62). Il trattamento con l'inibitore delle caspasi Z-VAD si è dimostrato efficace nell'attenuare la riduzione del numero di mionuclei e del calibro medio dei miotubi a 15 giorni di differenziamento. Proponiamo quindi che la compromissione muscolare tipica della DM1 sia dovuta, più che ad un'alterata miogenesi, a problemi nei meccanismi di mantenimento/rigenerazione, che si esplicano attraverso la prematura attivazione di apoptosi e/o autofagia
Mérola, Claudia Braida. "Molecular analysis of myotonic dystrophy type 1 patients with an unusual molecular diagnosis". Thesis, University of Glasgow, 2008. http://theses.gla.ac.uk/359/.
Texto completoBraida, Claudia. "Molecular analysis of myotonic dystrophy type 1 patients with an unusual molecular diagnosis". Thesis restricted. Connect to e-thesis to view abstract, 2008. http://theses.gla.ac.uk/359/.
Texto completoPh.D. thesis submitted to the Division of Molecular Genetics, Institute of Biomedical and Life Sciences, University of Glasgow, 2008. Includes bibliographical references. Print version also available.
Ueki, Junko. "Myotonic dystrophy type 1 patient-derived iPSCs for the investigation of CTG repeat instability". Kyoto University, 2018. http://hdl.handle.net/2433/230991.
Texto completoO'Reilly, Sean W. P. "RNAi Screening of the Kinome Identifies PACT as a Novel Genetic Modifier of Foci Integrity in Myotonic Dystrophy type 1". Thèse, Université d'Ottawa / University of Ottawa, 2014. http://hdl.handle.net/10393/30639.
Texto completoBallester, López Alfonsina. "Myotonic Dystrophy Type 1: the heterogeneity of a complex disease in a global research approach". Doctoral thesis, Universitat de Barcelona, 2020. http://hdl.handle.net/10803/671860.
Texto completoFortune, Maria Teresa. "Developmental timing and the role of cis and trans acting modifiers on CTG repeat instability in murine models". Thesis, University of Glasgow, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.341709.
Texto completoWei, Christina. "The Role of GSK3ß-CUGBP1 Pathway in the Correction of Myotonic Dystrophy Type 1 Muscle Pathology". University of Cincinnati / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1490350842490709.
Texto completoMalik, Naveed Altaf. "Development and analysis of CTG repeat expansion cell lines to understand molecular events in myotonic dystrophy type 1". Thesis, University of Nottingham, 2018. http://eprints.nottingham.ac.uk/53025/.
Texto completoHigham, Catherine F. "Dynamic DNA and human disease : mathematical modelling and statistical inference for myotonic dystrophy type 1 and Huntington disease". Thesis, University of Glasgow, 2013. http://theses.gla.ac.uk/4228/.
Texto completoDincã, Diana Mihaela. "Mechanisms of brain dysfunction in myotonic dystrophy type 1 : impact of the CTG expansion on neuronal and astroglial physiology". Thesis, Sorbonne Paris Cité, 2017. http://www.theses.fr/2017USPCB054/document.
Texto completoMyotonic dystrophy type 1 (DM1) is a severe disorder that affects many tissues, including the central nervous system (CNS). The degree of brain impairment ranges from executive dysfunction, attention deficits, low processing speed, behavioural changes and hypersomnia in the adult form, to pronounced intellectual disability in the congenital cases. The neurological manifestations have a tremendous impact on the academic, professional, social and emotional aspects of daily life. Today there is no cure for this devastating condition. DM1 is caused by the abnormal expansion of a CTG trinucleotide repeat in the 3’UTR of the DMPK gene. Expanded DMPK transcripts accumulate in RNA aggregates (or foci) in the nucleus of DM1 cells, disrupting the activity of important RNA-binding proteins, like the MBNL and CELF families, and leading to abnormalities in alternative splicing, gene expression, RNA polyadenylation, localisation and translation. In spite of recent progress, fundamental gaps in our understanding of the molecular and cellular mechanisms behind the neurological manifestations still exist: we do not know the contribution of each cell type of the CNS to brain dysfunction, or the molecular pathways specifically deregulated in response to the CTG expansion. The aim of my PhD project has been to gain insight into these two important questions using a relevant transgenic mouse model of DM1 and cell cultures derived thereof. In my studies I used the DMSXL mice, previously generated in my host laboratory. The DMSXL mice express expanded DMPK mRNA with more than 1,000 CTG repeats. They recreate relevant DM1 features, such as RNA foci and missplicing in multiple tissues. The functional impact of expanded DMPK transcripts in the CNS of DMSXL mice translates into behavioural and cognitive abnormalities and defective synaptic plasticity. To identify the molecular mechanisms behind these abnormalities, a global proteomics analysis revealed changes in both neuron-specific and glial-specific proteins in DMSXL brain. We also investigated RNA foci in DMSXL and human DM1 brains and found non-homogenous distribution between cell types, with a higher foci content in astrocytes relative to neurons. Together these results suggest that both neuronal and glial defects contribute to DM1 neuropathogenesis. The global proteomics analysis of DMSXL brains also identified abnormalities in neuronal synaptic proteins that we have validated in human brain samples. SYN1 is hyperphosphorilated in a CELF-dependent manner while RAB3A is upregulated in association with MBNL1 depletion. CELF and MBNL proteins regulate the alternative splicing of a subset of transcripts throughout development, and their deregulation in DM1 leads to abnormal expression of fetal splicing isoforms in adult DM1 brains. In this context, I have studied if RAB3A and SYN1 deregulations observed in adult brains are associated with splicing abnormalities or if they recreated embryonic expression and phosphorylation events. My results indicate that the synaptic proteins abnormalities observed in adult DMSXL brains are not caused by defective alternative splicing and do not recreate embryonic events. Thus, DM1 neuropathogenesis goes beyond missplicing and other molecular pathways must be explored in DM1 brains. To better understand the cellular sub-populations susceptible of accumulating toxic RNA foci we have studied foci distribution in different brain regions. We identified pronounced accumulation of toxic RNAs in Bergman astrocytes of DMSXL mice cerebellum and DM1 patients, associated with neuronal hyperactivity of Purkinje cells. A quantitative proteomics analysis revealed a significant downregulation of GLT1 – a glial glutamate transporter expressed by the Bergmann cell in the cerebellum. I have confirmed the GLT1 downregulation in other brain regions of mouse and human brain. (...)
Ramon, Duaso Carla 1987. "Neurobiological correlates of behavioural alterations in mouse models of MBNL2 deficiency and pharmacological interventions : relevance for myotonic dystrophy type 1". Doctoral thesis, Universitat Pompeu Fabra, 2019. http://hdl.handle.net/10803/668245.
Texto completoLa distrofia miotónica tipo 1 (DM1) es una enfermedad rara caracterizada por defectos musculares, así como por alteraciones cognitivas y afectivas. Aunque estas alteraciones neurofisiológicas son muy debilitantes, faltan datos sobre los mecanismos neurobiológicos involucrados, y no hay un tratamiento específico disponible. Aquí, investigamos los correlatos neurobiológicos subyacentes a la pérdida de función de MBNL2 utilizando dos líneas de ratones transgénicos: (i) ratones knockout (KO) constitutivos del gen Mbnl2 y (ii) ratones KO condicionales con una deleción específia del gen Mbnl2 en las neuronas glutamatérgicas del cerebro anterior. Los resultados demostraron que ambos modelos exhiben déficits de reconocimiento de memoria a largo plazo y un estado depresivo, asociado con un aumento de la microglia y niveles neuroquímicos alterados. Además, los tratamientos crónicos con el psicoestimulante metilfenidato y el antidepresivo atípico mirtazapina, atenuaron estas alteraciones del comportamiento mediante una reducción de la sobreexpresión microglial proinflamatoria y el restablecimiento de los niveles de varios neurotransmisores y sus receptores. Juntos, estos datos aportan nuevos conocimientos sobre la neurobiología de DM1 y proporcionan evidencia de que el metilfenidato y la mirtazapina podrían ser nuevos candidatos potenciales para aliviar los síntomas debilitantes relacionados con el sistema nervioso central en pacientes con DM1.
Tran-Ladam, Hélène. "Mécanismes moléculaires associés aux changements d'épissage de Tau dans une Tauopathie, la dystrophie myotonique de type 1". Thesis, Lille 2, 2010. http://www.theses.fr/2010LIL2S037/document.
Texto completoTau pathology is a brain lesion common to more than twenty neurodegenerative disorders. It consists of the abnormal aggregation of the microtubule-associated protein Tau into neurofibrillary tangles. Mechanisms underlying Tau aggregation are not fully understood yet. However, among the different etiological hypothesises, the one of a relationship between Tau mis-splicing and Tau aggregates particularly interests us. Here, we proposed a disease model, being myotonic dystrophy type I (DMI), in which Tau mis-splicing and Tau aggregate occur. DM1 is the most common adult form of muscular dystrophy. It is an inherited autosomal disorder characterised by a dynamic instable CTG repeats (over 50) in the 3’UTR of DMPK gene. DM1 pathogenesis is suggested to result from a RNA toxic gain of function whereby mutant transcripts modify the splicing machinery activity leading thus to a mis-splicing of several pre-mRNA targets including Tau. In this context, our objectives were to 1) characterize Tau mis-splicing in several DM1 brain patients 2) Model it and identify the trans-regulating splicing factors likely involved and 3) Propose a therapeutic approach to reverse it. Tau mis-splicing was always observed for both exons 2 and 3 in human adult DM1 brain and consisted of a reduced inclusion. Tau exon 10 splicing was seldom mis-regulated and associated with an increase of the CELF proteins family. CELF proteins are splicing factors previously described to regulate alternative splicing of Tau exons 2, 3 and 10. In addition to the CELF proteins, we also investigated the potential role of the splicing factor MBNL1, which was shown to play an essential role in DM1 physiopathology through its sequestration by the CUG repeats. MBNL1’s brain expression was ill-defined. Here, we report that MBNL1’s expression level was not altered but its splicing modified in adult DM1 brain. In addition, we provide evidences by a relationship study between the structure and the function of MBNL1 that this mis-splicing event favored its sequestration to the foci by modifying its cell-localization, splicing activity and oligomerization properties. MBNL1 mis-splicing does not influence Tau mis-splicing. However its loss of expression reproduced the mis-splicing of Tau exons 2/3 as observed in DM1 brain. Interestingly, the overexpression of MBNL1 in the presence of the CTG repeats partially restored a normal splicing of Tau as well as several other mis-regulated pre-mRNA targets. Further experiments performed with different molecular constructs lead us to hypothezied that the reversal of the abnormal splicing events observed in DM1 was mediated by a saturation of the CUG binding sites that lead to the release of a free pool of MBNL1, recovering thus its splicing function. This work leads us to design a new molecular tool that might be of interest to reverse the pathological events observed in DM1
Coleman, Stewart M. "Changes in localisation and dynamics of splicing and alternative splicing factors in human lens epithelial cells of myotonic dystrophy type 1 patients". Thesis, University of St Andrews, 2013. http://hdl.handle.net/10023/3647.
Texto completoLaurent, François-Xavier. "Une nouvelle fonction pour la DEAD-box ARN hélicase p68/DDX5 dans la Dystrophie Myotonique de type 1". Phd thesis, Université Paris Sud - Paris XI, 2011. http://tel.archives-ouvertes.fr/tel-00662593.
Texto completoMerien, Antoine. "Étude de la fonction des protéines MBNL au cours du développement à l’aide de cellules souches humaines induites à la pluripotence". Thesis, université Paris-Saclay, 2021. https://www.biblio.univ-evry.fr/theses/2021/interne/2021UPASQ015.pdf.
Texto completoAlternative splicing has emerged as a fundamental mechanism not only for the diversification of protein isoforms but also for the spatiotemporal control of development. Therefore, a better understanding of how this mechanism is regulated has the potential not only to elucidate fundamental biological principles, but also to decipher pathological mechanisms involved in diseases where normal splicing networks are mis-regulated. As part of this thesis, we took advantage of human pluripotent stem cells to decipher during human myogenesis the role of MBNL proteins, a family of tissue-specific splicing regulators whose loss of function is associated with Myotonic Dystrophy type 1 (DM1), an inherited neuromuscular disease. Thanks to the CRISPR/Cas9 technology, we generated human-induced pluripotent stem cells (hiPSCs) depleted in MBNL proteins and evaluated the molecular and functional consequences of this loss on the generation of skeletal muscle cells. Our results indicated that MBNL proteins are specifically required for the late myogenic maturation but not for early myogenic commitment. By a transcriptomic analysis, we were able to highlight the molecular pathways regulated by these proteins during myogenesis, as well as the compensatory effects between MBNL paralogs. This study also allowed us to identify a new alternative splicing defect in DM1, regulated by MBNL proteins, which leads to structural abnormalities of the muscular post-synaptic compartment. Together, our results reveal the temporal requirement of MBNL proteins in human myogenesis and allow the identification of new molecular pathways regulated by these proteins that could be involved in the development of DM1. In the longer term, the tools developed in this study should also facilitate the identification of new therapeutic strategies capable to cope with the loss of function of these proteins
Maury, Yves. "Utilisation de cellules souches pluripotentes humaines pour le développement de criblages phénotypiques dans le cadre de la dystrophie myotonique de type 1 et l'amyotrophie spinale infantile". Thesis, Evry-Val d'Essonne, 2013. http://www.theses.fr/2013EVRY0019/document.
Texto completoFor only few years, Human pluripotent stem cells (PSC) have become wide spread models in order to study and decipher cellular or molecular mechanims involved in monogenic diseases, but also for the development of large scale screening strategies allowing the identification of new therapeutics among thousands of chemicals. Mythesis research aimed at the development of such strategies, miniaturizing and automating PSC biology within the framework of two monogenic diseases, namely spinal muscular atrophy (SMA) and myotonic dystrophy type 1 (DM1).Basically, PSC based screening programs are generally built around three main steps which are the access to a stem cell model, the identification of a relevant cell type and lastly the screening campaign. There is actually two main ways to generate human PSC. Firstly, human embryonic stem cells (hES) can be derived from the inner cell mass of blastocyte through a pre-implantation diagnosis and secondly, induced pluripotent stem cells (iPS) can be generated after somatic cell reprogramming in vitro. A part of my work has consisted in the generation of hiPS cellular models for SMA by reprogramming fibroplasts that carried SMN1 gene deletion, followed bay the characterization of several dozen of independant clones with high throughput. Then an optimization process of the protocol for the generation of Motoneuron from PSC has been done multiplying experimental conditions. This finally allowed the description of a fast and efficient protocol to generate the most affected cell type in SMA. Finally, DM1 mutated hES were uded for the screening of 12.000 compounds among which a chemical family has been identified to rescue DM1 typical splicing and myogenesis defects
Légaré, Cecilia. "Déterminants génétiques et épigénétiques de la variabilité phénotypique de la dystrophie myotonique de type 1". Mémoire, Université de Sherbrooke, 2017. http://hdl.handle.net/11143/11602.
Texto completoAbstract : Myotonic dystrophy type 1 (DM1) is an autosomal dominant disorder caused by a CTG repeat extension in the 3’ untranslated region of the dystrophia myotonica protein kinase (DMPK) gene. Worldwide, the prevalence of DM1 is 8.26 affected persons per 100 000 persons, but it goes up to 158 affected persons per 100 000 in the Saguenay-Lac-St-Jean region of the province of Quebec (Canada) due to a founder effect. Clinical presentation includes muscular weakness, myotonia, cataracts, respiratory insufficiency, cardiac arrhythmia, hypersomnolence and endocrine and cognitive problems. There is a large variability in the presence and severity of these symptoms that is only partially explained by the CTG repeat length. Many mechanisms such as splicing defects, impaired regulation of transcription factors, repeat-associated non-ATG translation and epigenetic modifications, including DNA methylation, may explain this variability. The objective of this study was to assess the impacts of DNA methylation measured at the DMPK gene locus on phenotypic variability in DM1. We report that DNA methylation upstream of the repeat was negatively correlated with CTG repeat length whereas downstream DNA methylation was positively correlated. The presence of a variant repeat within the CTG repeat was associated with a higher level of DNA methylation. Linear multiple regression models support that DNA methylation contributes significantly and independently of the CTG repeat length to the variability of the ankle dorsiflexor, grip and pinch strengths, as well as forced vital capacity, peak expiratory flow and maximal inspiratory and expiratory pressures. DNA methylation could thus explain part of the phenotypic variability in DM1 and, together with CTG repeat length, could help improve the prediction of the progression of the disease.
Picchio, Lucie. "Mise en place, caractérisation phénotypique et transcriptomique d'un modèle de Drosophilie de la Dystrophie Myotonique de type 1". Thesis, Clermont-Ferrand 1, 2013. http://www.theses.fr/2013CLF1MM15/document.
Texto completoMyotonic Dystrophy Type 1 (DM1) or Steinert's disease is the most common genetic neuromuscular disorder affecting 1 out of 8000 people worldwide. This multisystemic disease affects particularly the skeletal muscles (myotonia, muscle weakness and wasting) and the heart, which can exhibit various symptoms like conduction disturbances and arrhythmia (auricular fibrillation and flutter). DM1 is caused by an unstable CTG repeat expansion in the 3' non-translated region of the DMPK gene. In healthy individuals, the number of CTG repeats ranges from 5 to 37 whereas DM1 patients carry from 50 to thousands repeats. It is well established that when expanded non-coding repeats aggregate into foci within muscle nuclei and sequester the MBNL1 splicing factor. However, the involvement of the stabilization and accumulation of CUGBP1 following PKC hyper-phosphorylation in the disease is a controversial matter in the DM1 community. Lately, in addition to the disruption of the balance between MBNL1/CUGBP1, several mechanisms were identified as part of the DM1 pathogenesis. Among them, transcription factors perturbations, altered maturation of miRNA, kinases activation… each of them leading eventually to transcriptomic alterations. In order to investigate the effect of toxic repeat expression on phenotypic and transcriptomic alterations, we generated three inducible site-specific Drosophila lines expressing 240, 600 and 960 triplet repeats. We worked in parallel on a mbl (MBNL1 orthologue) knocked-down line and two bru-3 (CUGBP1 orthologue) gain of function lines. When expressed in somatic muscles, CTG repeats lead to altered motility, fiber splitting, reduced fiber size and affected myoblast fusion process in a Mbl and Bru-3 dependent manner. In addition, toxic repeats cause fiber hyper-contraction in a Mbldependentmanner due to dSERCA mis-splicing. Comparative transcriptional profiling performed on larval muscles of different conditions show that mbl attenuation reproduces 70-82% of DM1 transcriptomic deregulations whereas bru-3 gain of function represents 32-53% of transcritomic alterations. Thus Mbl appears as a key factor of transcripts deregulations observed in DM1 muscles. On the contrary, physiologic analyses performed on adult hearts suggest that Bru-3 is a key factor for cardiac phenotypes. Indeed, on one hand, mbl attenuated flies display dilated cardiomyopathy, a symptom barely diagnosed in patients. On the other hand, bru-3 gain of function line and DM1 lines display fibrillation, which evolves withage or repeat size into a phenotype reminiscent of heart insufficiency in patients
Pontual, Laure de. "Identification de nouveaux facteurs chimiques capables de moduler l'instabilité des répétitions CTG dans la dystrophie myotonique de type 1". Electronic Thesis or Diss., Sorbonne université, 2024. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2024SORUS198.pdf.
Texto completoMyotonic dystrophy type 1 (DM1) is the most common dystrophy in adults, with an estimated prevalence of 1:8000 individuals. It is a multisystemic disease characterized by muscle, cardiac, cognitive, and digestive impairments, which contribute to a reduction in both life expectancy and quality of life for patients. DM1 is caused by an abnormal expansion of CTG repeats in the 3'UTR of the DMPK gene. In the general population, the number of repeats is under 35 CTG, whereas in patients, it exceeds 50 CTG and can reach several thousand repeats. As in other diseases caused by repeat expansions, the CTG expansion in DM1 is unstable. The repeat size increases across generations (intergenerational instability) and within tissues during a patient's lifetime (somatic instability). The number of inherited repeats and the level of somatic instability correlate with the age of onset and severity of symptoms. Thus, targeting the mutation itself to stabilize or reduce CTG repeat length is the most promising therapeutic strategy, as it would address all the pathophysiological mechanisms resulting from the mutation.Initially, my thesis work focused on identifying repositioned chemical molecules capable of modulating repeat instability. Screening the 1280 molecules from the Prestwick Chemical Library allowed me to identify 39 candidate molecules that alter the expression of a reporter gene, suggesting they could modulate repeat instability. After directly studying their effect on instability, I excluded four of these molecules that do not modulate repeat expression. I demonstrated that a fifth molecule, clomipramine, can modulate repeat instability in the screening cell model but not in murine and human DM1 fibroblasts.Concurrently, I showed that RGFP966, a selective HDAC3 inhibitor, induced contractions of CTG repeats in murine DM1 fibroblasts with approximately 650 repeats. This effect appears to depend on the dose of RGFP966 or the size of the CTG repeat, as it was not replicated in human DM1 fibroblasts with 350 CTG repeats. An RNA-seq approach in murine cells treated with RGFP966 identified several candidate genes involved in DNA replication as possible modifiers of instability. I also showed a decrease in bidirectional DMPK transcription associated with a probable hypermethylation downstream of the repeats in murine DM1 cells. In conclusion, my data suggest that RGFP966 modulates CTG repeat instability in DM1 through multiple mechanisms, potentially including chromatin structure modification at the DM1 locus and alterations in DNA replication.Overall, my thesis project contributed to the understanding of repeat instability mechanisms and the identification of chemical compounds that modulate instability dynamics. My work also highlighted the limitations of each model used and the complexity of identifying small molecules that alter CTG triplet dynamics in reporter cell models. Additionally, I participated in developing long-read sequencing (with and without amplification) for DM1, providing a rapid and highly informative new tool for the analysis of somatic mosaicism
Rodrigues, Luiza Paulsen. "Identificação e avaliação da distribuição alélica de repetições do trinucleotídeo CTG no gene DMPK em indivíduos saudáveis e em pacientes com distrofia miotônica tipo 1". reponame:Biblioteca Digital de Teses e Dissertações da UFRGS, 2016. http://hdl.handle.net/10183/158225.
Texto completoThe human DMPK (Dystrophia Myotonica-Protein Kinase) gene is located at 19q13.3 locus, being organized into 15 exons, with a polymorphic tract of CTG repeats in its 3' untranslated region. Normal individuals have 5-34 CTG repeats. Individuals carrying alleles with more than 50 CTG repeats have myotonic dystrophy type 1 (DM1), a multisystemic disease of autosomal dominant inheritance. Symptoms include myotonia, progressive muscle weakness, hypogonadism, among others. Disease prevalence is variable among populations and may be related to the frequency of large normal alleles (those with more than 18 CTG repeats). Here we determined here the distribution of alleles of DMPK gene in healthy and DM1 patients in Brazilian and Peruvian populations, through conventional PCR using fluorescent primers and repeat-primed PCR. This protocol confirmed 93 unrelated cases of DM1 (76 Brazilians and 17 Peruvians) following the analysis of 224 samples with clinical suspicion. Distribution and frequencies of normal alleles were also established in both populations and the most frequent alleles were 5 (frequency of 0.326) and 13 (frequency of 0.545) CTG repeats in Brazilians and Peruvians, respectively. Frequency of large normal alleles (those with more than 45 CTG repeats) was established to be 9% and 4% in Brazilians and Peruvians, respectively. This report describes molecular analysis of DM1 in the largest Brazilian cohort so far, and is the first to report any data in the Peruvian population. Distribution and frequency of normal alleles were also established and mutable alleles were detected among controls.
Arandel, Ludovic. "Développement d'une thérapie génique pour la Dystrophie Myotonique de type 1". Electronic Thesis or Diss., Sorbonne université, 2023. http://www.theses.fr/2023SORUS229.
Texto completoMyotonie dystrophy types 1(DM1) and 2 (DM2) are autosomal dominant multisystem diseases with a strong neuromuscular component. They are characterized by progressive myotonia, muscle weakness, cognitive impairment, and cardiac conduction defects. These diseases are caused by abnormal amplification of C(C)TG repeat sequences located in the 3'UTR region of the DMPK gene and in the intron of the CNBP gene, respectively. These expansion-containing sequences are transcribed and retained in the nucleus as riboprotein aggregates. The presence of these toxic C(C)UG RNAs induces sequestration of the MBNL family of RNA-binding proteins, leading to their loss of function and deregulation of alternative splicing events, many ofv/hich are associated with clinical symptoms in patients. There is currently no1reatment for DM. In this thesis, I have developed a gene therapy tool based on a modification of the MBNL1 protein. This C- terminal truncated MBNL derivative (MBNLΔ) acts as a decoy to release endogenous MBNL proteins sequestered by mutant RNAs. Our approach was validated in muscle cells from DM1 patients and in a mouse model of the disease after AAV virus injection. Treatment with MBNLΔ allows the delocalisation of endogenous MBNL proteins from the foci, modifies the foci dynamics, corrects the transcriptome and myotonia, which is maintained 1 year after injection
Petitclerc, Émilie. "Association entre le profil de force musculaire et les capacités fonctionnelles aux membres inférieurs chez les personnes atteintes des phénotypes adulte classique et adulte tardif de dystrophie myotonique de type 1". Mémoire, Université de Sherbrooke, 2015. http://hdl.handle.net/11143/8031.
Texto completoAbstract: Purpose: The purposes of this study were 1) to describe lower limbs muscle strength and mobility capacities, and 2) to explore the respective contribution of lower limb muscle weaknesses on mobility in the adult and late-onset phenotypes of myotonic dystrophy type 1 (DM1). Methods: This study is a secondary analysis of part of the results of a larger study, whose purpose was to identify social participation and quality-of-life determinants in 200 DM1 patients (158 adult and 42 late-onset). The strength of four lower limb muscle groups was assessed using manual muscle testing (MMT) and handheld dynamometry quantitative muscle testing (QMT). Mobility capacities were assessed using standardized tests (Berg balance scale, 10 Meter Walk Test and Timed Up & Go). Results: Although the late-onset phenotype showed less weaknesses and mobility limitations than the adult phenotype (p <0.001-0.020), and although MMT showed no weakness in the late-onset phenotype, quantitative strength losses of 12-20% were measured in this phenotype, with the exception of the knee flexors. These weaknesses led to mobility limitations in 22-48% of participants with the late-onset phenotype. In the adult phenotype, muscle strength impairment was slightly more important distally than proximally (2-2.5/10 and 5.8-8.2% for MMT and QMT, respectively) (p <0.001-0.002). According to those results, the adult and late-onset phenotypes show different profiles of lower limb impairment, and should not be pooled for data analysis. A general progression of quantitative muscle weakness and of mobility scores was observed according to the Muscular Impairment Rating Scale (MIRS) classification. Quantitative weaknesses, with the exception of the knee flexors, and mobility limitations were observed from the first MIRS grades. QMT is therefore definitely a more effective tool for measuring weakness in DM1. Finally, ankle dorsiflexors and knee extensors seem to be good indicators of lower limb function in DM1. Conclusion: This study allowed a better characterization of lower limb weaknesses and mobility limitations in the adult and late-onset phenotypes of DM1, and explored the contribution of lower limb weaknesses on mobility capacities in this population. These results will be useful for developing more specific rehabilitation programs and for optimizing the evaluation of these impairments in the context of the upcoming therapeutic trials. Keywords: Myotonic dystrophy type 1, phenotypes, muscle strength, mobility capacities, lower limbs, explanatory variables, physiotherapy.
Antonio, Marie de. "Statistiques et modèles de survie pour améliorer la connaissance d’une maladie rare, la dystrophie myotonique The DM-Scope registry: a rare disease innovative framework bridging the gap between research and medical care Unraveling the myotonic dystrophy type 1 clinical spectrum: a systematic registry-based study - Implications for disease classification". Thesis, Sorbonne université, 2020. http://www.theses.fr/2020SORUS096.
Texto completoMyotonic dystrophy (DM) is considered one of the most complex neuromuscular diseases. Although research work over the past 30 years has permitted a better understanding of its underlying molecular mechanisms, the unusual nature of its genetic anomalies, its multisystemic expression and its broad clinical spectrum do not allow, at the moment, optimal patient management. The purpose of my work was to deepen our knowledge of this rare disease and to clarify its natural history. The first part of my manuscript is dedicated to the presentation of the DM-Scope Registry, on which all my thesis work is based. After the description of the concept, the functioning and the data collection platform, the manuscript features the characteristics of the DM1 cohort, from which our analyses were conducted : the clinical spectrum covered, multisystemic impairment, genotype/phenotype correlations, interrelations between symptoms and comparison to myotonic dystrophy type II (DM2). In the second part, we focus on the major progress achieved through the existence of DM-Scope and the analyses conducted during my thesis: (i) detailing the natural history of the disease, in particular proposing a new classification; (ii) highlighting the phenotype’s determining factors such as gender, mutation size, interrelations between symptoms. This work has led to recommendations for care, in particular for the transition from child to adult, but also the validation of important inclusion criteria for clinical trials such as gender. DM-Scope provides access to available biological samples for basic research studies and validates new therapeutic approaches. DM-Scope is now a worldwide leader and an essential tool in translational research in DM. The DM-Scope concept can be transferred to any other population and can be used for care management in other rare diseases. Finally, we present the development of a survival model built from the DM-Scope cohort. This model has three specificities: (i) it is applicable to high dimensional data, in such cases as DM-Scope, where there is a large number of measurements; (ii) it takes into account competitive risks, when patients are simultaneously exposed to several events. In our registry, the study of respiratory-related deaths is biased if competing events such as heart disease deaths are not taken into account ; (iii) it models the heterogeneity between patient groups probably due to divergent care, called \og centres effects \fg{}. DM-Scope data analysis requires such specificity of frailty models due to its multicentric coverage (55 centres). This model can be transferred and applied to other data, considering the following : more and more large-scaled registries are being used ; a majority of survival analyses includes censorship caused by the occurrence of the event of interest ; multicentre studies have become increasingly common
Poggi, Lucie. "Gene editing approaches of microsatellite disorders : shortening expanded repeats". Electronic Thesis or Diss., Sorbonne université, 2020. http://www.theses.fr/2020SORUS412.
Texto completoMicrosatellite disorders are a specific class of human diseases that are due to the expansion of repeated sequences above pathological thresholds. These disorders have varying symptoms and pathogenic mechanisms, caused by the expanded repeat. No cure exists for any of these dramatic conditions. This thesis is investigating new gene editing approaches to remove pathological expansions in the human genome. In a first part, a yeast-based screen was constructed to identify potent CRISPR-associated nucleases that can cut these microsatellites. The second part focuses on myotonic dystrophy type 1 (DM1), which is due to and expanded CTG repeat tract located at the 3’UTR of the DMKP gene. A nuclease, TALENCTG was designed to induce a double strand break into the CTG repeats. It was previously shown to be active in yeast cells, inducing contractions of CTG repeats from a DM1 patient integrated into the yeast genome. The TALEN was tested in DM1 patient cells. The nuclease was found to trigger some contraction events in patient cells. In vivo experiments were carried out in a mouse model of myotonic dystrophy type 1 containing a human genomic fragment from a patient and 1000 CTG. Intramuscular injections of recombinant AAV encoding the TALENCTG revealed that the nuclease is toxic and/or immunogenic in muscle cells in the tested experimental conditions. Finally, the reporter assay integrated in yeast to screen nucleases was transposed in HEK293FS cell line. The integrated cassette contains a CTG expansion from a myotonic dystrophy type 1 patient flanked by two halves of GFP genes. This system would enable to find nucleases active in human cells
Nguyen, Xuan-Tam. "Approches globales afin d’élucider les mécanismes pathogéniques de la dystrophie myotonique de type 1". Thèse, 2016. http://hdl.handle.net/1866/18667.
Texto completoMyotonic dystrophy of type 1 (DM1) is a degenerative disorder implicating symptoms of muscular atrophy and myotony. In a molecular level, it is caused by the aberrant expansion of CUG repeats in the 3’-UTR region of the DMPK mRNA (Dystrophia Myotonica protein kinase). Excessive CUG repeats then form toxic aggregates (foci) enriched within the nucleus of DM1 patient cells. These RNA foci cause the abnormal sequestration of RNA Binding Proteins (RBP), in particular members of the Muscleblind-like protein 1 (MBNL), that normally bind the CUG motif of other target RNAs, and will hence alter their normal functions. In addition to their role in alternative splicing, MBNL1 has recently been implicated in the intracellular localisation of its RNA targets. It remains elusive whether the pathogenesis of DM1 could result from the deregulating effect of CUG repeats on the localisation of specific RNAs and RBP proteins. In this thesis, a fluorescent imaging-based screening of 322 RBPs in DM1 patient’s myoblasts has been conducted and this had led to the identification of new factors that may colocalize with pathogenic CUG expansions. Moreover, these DM1 myoblasts have been fractionated and subsequent RNA-sequencing has permitted the identification of transcripts that are delocalised between subcellular compartments. From the two large datasets generated from the RBP imaging-based screening and fractionation/RNA-sequencing, new avenues of research can be initiated to further understand not only DM1, but perhaps also other disorders that implicate microsatellite expansions.
Cleary, John. "DNA Replication and Trinucleotide Repeat Instability in Myotonic Dystrophy Type 1". Thesis, 2010. http://hdl.handle.net/1807/24723.
Texto completoBasílio, Ana Cláudia Miquelino. "Characterization of the nuclear envelope alterations in Myotonic Dystrophy Type 1". Master's thesis, 2019. http://hdl.handle.net/10773/28409.
Texto completoA distrofia miotónica tipo 1 (DM1) é uma disfunção genética multissistémica associada principalmente à degeneração do músculo esquelético e causada por uma expansão repetida de trinucleótidos CTG na região 3' não traduzida do gene DMPK, acumulando-se na forma de inclusões nucleares e comprometendo a função nuclear. Nos últimos anos, alguns estudos associaram algumas proteínas do envelope nuclear (NE) como sendo componentes importantes na resposta das células ao stress mecânico, ajudando a manter a integridade das células musculares, o que demonstra uma associação com a DM1. De facto, já foi demonstrado que os fibroblastos de pacientes com DM1 apresentavam uma estrutura nuclear comprometida e uma localização alterada de algumas proteínas do NE. No entanto, a contribuição que o envelope nuclear possa ter para a DM1 ainda não foi totalmente elucidada. Neste trabalho, realizámos um estudo espectroscópico ATR-FTIR usando fibroblastos humanos de controlos e de pacientes com DM1 de forma a identificar diferenças espectrais. Os fibroblastos dos pacientes incluídos neste estudo têm 1000 repetições de CTG e 2000 repetições de CTG, representando os tipos DM1 adulto e congénito, respectivamente desta doença. Os modelos de DM1 usados neste estudo apresentaram diferenças a nível molecular, principalmente nas estruturas das proteínas e dos lipídos: os modelos de DM1 podem ser diferenciados dos controlos através de cadeias lipídicas maiores, cadeias lipídicas mais saturadas e presença de agregados proteicos. Estas diferenças podem ser explicadas por um metabolismo lipídico alterado e pela acumulação de agregados tóxicos sob a forma de RNA e de proteínas de poliglutaminas expandidas. Além disso, foi avaliado o perfil nuclear em fibroblastos humanos de controlos e de pacientes com DM1, de forma a caracterizar algumas características nucleares específicas, nomeadamente: área nuclear, circularidade, deformações (blebs e núcleos irregulares) e presença de micronúcleos. Os nossos resultados evidenciaram uma tendência para a área nuclear, o número de células com micronúcleos e os núcleos deformados aumentarem nos modelos de DM1, em comparação aos controlos. Além disso, para observar a localização de algumas proteínas do envelope nuclear, nomeadamente, lamina A/C, emerina, SUN1 e LAP1, foi realizada uma análise imunocitoquímica nos fibroblastos humanos de controlos e de pacientes com DM1. Em relação à lamina A/C, emerina e LAP1, estas proteínas apresentaram uma localização alterada no envelope nuclear em ambos os modelos de DM1 (DM1 1000 e DM1 2000). Além disso, a lamina A/C e a emerina mostraram estar acumuladas nas inclusões nucleares marcadas por estas proteínas, enquanto que a SUN1 e a LAP1 mostraram estar acumuladas nas invaginações nucleares marcadas por estas proteínas. Para concluir, foram identificadas diferenças espectrais entre os controlos e os modelos de DM1. Além disso, a arquitetura nuclear e as proteínas do envelope nuclear mostraram estar alteradas nos modelos de DM1. Portanto, mais estudos devem ser realizados para elucidar a contribuição que as proteínas do envelope nuclear possam ter para esta doença.
Mestrado em Biomedicina Molecular
Viegas, Diana Ferreira. "Nuclear envelope dysfunctions observed in patients with myotonic dystrophy type 1". Master's thesis, 2021. http://hdl.handle.net/10773/30799.
Texto completoAs distrofias musculares são um grupo muito heterogêneo de doenças hereditárias que se caracterizam por fraqueza muscular, perda de massa muscular e, em alguns casos, alterações do sistema nervoso. Até o momento, são conhecidas mais de 30 formas diferentes de distrofias musculares, incluindo distrofia miotónica (DM). A distrofia miotónica possui duas variantes distintas, distrofia miotónica tipo 1 (DM1) e distrofia miotónica tipo 2 (DM2), que resultam de uma expansão anormal do trinucleótido CTG e do tetranucleótido CCTG, respetivamente. O DM1 resulta de uma expansão anormal de CTG na região 3 'não traduzida do gene DMPK. O mRNA DMPK mutante acumula-se no núcleo como focos ribonucleares comprometendo a função nuclear normal. Nos últimos anos, as proteínas do envelope nuclear (NE) têm sido associadas às distrofias musculares e, especificamente, á DM1, sendo um componente essencial na resposta das células a stresses mecânicos externos e na manutenção da integridade das células musculares. Até ao momento, poucos estudos demonstraram que fibroblastos e mioblastos / miotubos de pacientes com DM1 têm estrutura nuclear comprometida, juntamente com localização e níveis intracelulares alterados de algumas proteínas NE. Apesar disso, o papel das proteínas NE no DM1 ainda não está claro e mais estudos são necessários. Portanto, no presente trabalho, analisamos fibroblastos de um controle aparentemente saudável e de pacientes com DM1 com aproximadamente 1000 e 2000 repetições de CTG (representando os fenótipos adulto e congénito, respetivamente) usando as técnicas de western blotting e imunocitoquímica para avaliar os níveis de proteína NE e localização subcelular, respetivamente. Em relação aos níveis intracelulares das proteínas NE, observamos aumento nos níveis intracelulares de LAP1, SUN1, lamina A / C e lamina B1, em pacientes com DM1 quando comparados aos controles. No caso da nesprina-1, foi observada uma diminuição dos níveis intracelulares da proteína. Os níveis intracelulares de nesprina-2 diminuíram apenas em fibroblastos de DM1_2000 quando comparados aos controles. Finalmente, os níveis da proteína emerina foram semelhantes entre os fibroblastos derivados de DM1 e controles. No estudo da imunocitoquímica, constatamos que os núcleos dos fibroblastos derivados do DM1, quando marcados apenas com DAPI, apresentavam aumento de núcleos deformados, acompanhado de aumento significativo da área nuclear (em DM1_2000). Além disso, descobrimos que os núcleos de fibroblastos derivados de DM1 são positivos para proteínas da lâmina A/C. emerina, LAP1 e nesprina-1 também apresentaram aumento no número de núcleos deformados e inclusões nucleares. No caso da lâmina A/C, emerin e LAP1, também houve aumento da imunomarcação do NE e do nucleoplasma. Em resumo, demonstramos que pacientes com DM1 tendem a apresentar alterações nos níveis intracelulares das proteínas NE e que estas são acompanhadas por alterações na arquitetura nuclear. Assim, mais estudos são necessários para elucidar a contribuição dessa estrutura para os mecanismos patológicos do DM1.
Mestrado em Biomedicina Molecular
Wang, Pei-Ying y 汪佩瑩. "Investigation of Pathogenesis of Myotonic Dystrophy Type 1 in Central Nervous System". Thesis, 2018. http://ndltd.ncl.edu.tw/handle/82g8ad.
Texto completo國立陽明大學
分子醫學博士學位學程
106
Myotonic dystrophy (DM) is the most common cause of adult onset muscular dystrophy. Brain involvement in DM type 1 (DM1) includes mental retardation, psychiatric disorders and neurodegeneration. Cognitive impairment associated with structural change in the brain is prevalent in DM1. The occurrence of cognitive impairment in individuals with DM1 is high, however, the mechanism of causing the deficits remains unknown. The genetic basis of DM1 is caused by an expansion of CTG repeats in the 3’ untranslated region (UTR) of the Dystrophia Myotonica Protein Kinase (DMPK) gene. DMPK mRNA containing expanded CUG repeats accumulates in nuclear foci and affect nuclear and cytoplasmic activities of RNA binding protein muscleblind like (MBNL) family. Dysfunction of MBNL has been implicated in DM1 neural pathogenesis. How expanded CUG RNA and MBNL dysfunction affect cognitive function and brain structure remains elusive. To study the neural pathogenesis of DM1, we established a brain-specific DM1 mouse model, EpA960/ CaMKII-Cre, expressing the expanded CUG RNA in the postnatal brain. The EpA960/ CaMKII-Cre model recapitulates several features of DM1 brain including nuclear RNA and MBNL foci formation, misregulated alternative splicing, learning disability and neuro-degeneration. The pathological abnormality characterized by a time-course study showed that hippocampus-related learning and synaptic potentiation were impaired before structural changes, followed by progressive reduction of axon and dendrite integrity and aberrant MBNL2-regulated alternative splicing. In addition, cytoplasmic MBNL1 on dendrites decreased before dendrite degeneration suggesting reduced cytoplasmic MBNL1 as an early event response to the pathogenic RNA. We further investigated the causal mechanism of cytoplasmic MBNL1 reduction and the function of cytoplasmic MBNL1. We found that neurons expressing expanded CUG RNA and MBNL1-depleted neurons exhibited similar morphological impairment. MBNL1 cytoplasmic, but not nuclear, isoform promoted neurite outgrowth and reversed the morphological defects caused by expanded CUG RNA. The reduced cytoplasmic MBNL1 caused by expanded CUG RNA was due to MBNL1 cytoplasm-to-nucleus translocation. The cytoplasmic localization of MBNL1 was regulated by lysine 63 (K63)-linked polyubiquitination. Reduced cytoplasmic MBNL1 in the EpA960/CaMKII-Cre brain was consistent with the reduced extent of K63 ubiquitination. Expanded CUG RNA induced the deubiqutination of cytoplasmic MBNL1, which resulted in nuclear translocation andmorphological defects that could be ameliorated by inhibiting K63-linked polyubiquitin chain degradation. These results suggest that K63-linked ubiquitination of MBNL1 is required for its cytoplasmic localization and that deubiquitination of cytoplasmic MBNL1 is pathogenic in DM1 brain.
Mateus, Tiago Duarte Cordeiro. "Study of the metabolome and muscle strength measures for the characterization of patients with myotonic dystrophy type 1". Master's thesis, 2021. http://hdl.handle.net/10773/30819.
Texto completoA distrofia miotônica tipo 1 (DM1) é uma doença hereditária autossómica dominante causada por uma alteração que leva a uma expansão anormal de repetições instáveis de CTG na região 3' não traduzida do gene da proteína quinase da distrofia miotônica (DMPK). DM1 é caracterizado por miotonia, fraqueza muscular distal progressiva e por envolvimento multissistémica, nomeadamente cataratas, dores musculares, disfunções cardíacas e respiratórias, disfunções endócrinas (resistência à insulina, síndrome metabólica, dislipidemia), cancro e alterações no sistema nervoso central (SNC). Doentes com DM1 apresentam frequência de síndrome metabólica maior do que na população geral. Assim, o estudo do metaboloma é de grande importância, pois pode fornecer novos ideias sobre as vias moleculares afetadas nas doenças DM1, bem como discriminar entre os diferentes graus de gravidade em doentes com DM1 e também pode levar ao desenvolvimento de novas terapêuticas metabólicas. Dadas as alterações metabólicas previamente descritas e observadas em doentes com DM1, consideramos que a avaliação do perfil metabólico destes doentes é de grande importância. Portanto, elaborou-se uma revisão da literatura para resumir as alterações metabólicas previamente descritas em doentes com DM1 e a relação da Lipina com as alterações metabólicas na DM1 (Capítulo I). Essencialmente, os estudos anteriores mostraram uma clara alteração metabólica entre os doentes com DM1 e os grupos controlo, nomeadamente o aumento dos níveis de colesterol total, lipoproteína de baixa densidade, triacilglicerol, insulina e resistência HOMA-insulina, o aumento dos níveis de glicose, assim como a diminuição dos níveis de lipoproteína de alta densidade. Esta revisão também demonstrou uma potencial relação entre a Lipina e a sua associação com as anormalidades metabólicas encontradas em doentes com DM1, nomeadamente os papéis metabólicos no tecido adiposo, músculo esquelético, fígado e a sua associação com a dislipidemia e a resistência à insulina, que é uma das características em doentes com DM1. O perfil metabólico dos doentes com DM1 foi então avaliado pela técnica de espectroscopia ATR FTIR, em conjunto com a análise multivariada, sendo que é adequada para fornecer um perfil (bio) químico dos doentes com DM1 e controlos. Essencialmente, fibroblastos derivados de DM1 e controlos foram utilizados, e os resultados demonstraram uma clara discriminação dentro de fibroblastos derivados de DM1 com diferentes repetições de CTG e idades de início da doença, o que significa que estes podem ter um perfil metabólico distinto. Esta discriminação pode ser atribuída principalmente ao metabolismo lipídico alterado na região 1800-1500 cm-1 . Também foi possível discriminar entre os grupos controlo e fibroblastos derivados de DM1 do Instituto Coriell e Centro Hospitalar do Tâmega e Sousa na região de 3000-2800 cm-1 (Capítulo II). Além disso, foi feita uma revisão sistemática para reunir informações de todos os resultados e medidas utilizadas para avaliar a força muscular em doentes adultos com DM1 (Capítulo IV). Foi avaliada a força muscular cardíaca, esquelética e respiratória. Resumidamente, a revisão sistemática demonstrou uma utilização consistente da ecocardiografia, teste muscular quantitativo, teste muscular manual e manometria para avaliar a força muscular cardíaca, esquelética e respiratória. As medidas escolhidas para avaliar a força muscular foram: (1) fração de ejeção para a força do musculo cardíaco; (2) torque isométrico muscular, força de preensão e conselho de pesquisa médica (0-5 pontos e 0-60 pontos) para a força do músculo esquelético; (3) pressão inspiratória máxima e pressão expiratória máxima para a força dos músculos respiratórios. Em conclusão, os resultados sugerem que há uma necessidade de estudos adicionais relativamente ao metabolismo lipídico em doentes com DM1, não apenas para caracterizar melhor estes doentes, como também para compreender o mecanismo subjacente das anormalidades lipídicas e ter novas noções sobre a Lipina na DM1. A espectroscopia FTIR é uma ferramenta valiosa para caracterizar doentes com diferentes severidades da DM1, o que é crucial para um diagnóstico adequado e para estudos futuros. Reunimos com sucesso as medidas mais consensuais e importantes para avaliar a força muscular. Os resultados obtidos foram importantes e úteis, pois serão valiosos para avaliação da força muscular em futuros ensaios clínicos e estudos observacionais, principalm
Mestrado em Biologia Molecular e Celular
Costa, Adriana Emília Amaral. "Establishment of skin-derived fibroblast cell lines for the study of protein phosphorylation in Myotonic Dystrophy type 1". Master's thesis, 2021. http://hdl.handle.net/10773/31035.
Texto completoAs distrofias musculares são um grupo de patologias clínica e geneticamente heterogéneas, caracterizadas por fraqueza e degeneração muscular progressivas. Dentro deste grupo, a distrofia muscular mais comum em adultos é a distrofia miotónica tipo 1 (DM1), uma doença hereditária autossómica dominante causada por uma expansão das repetições de tripletos (CTG)n na região 3' não traduzida do gene DMPK. Os pacientes com DM1 apresentam não só sintomas musculares, como miotonia e perda de massa muscular, mas também extramusculares, como cataratas, problemas na condução cardíaca e resistência à insulina. Na DM1, o aumento das expansões CTG levam ao acúmulo de mRNA (CUG)n, que forma estruturas em hairpin no núcleo, levando a um "ganho de função" tóxico que desregula proteínas de ligação ao RNA, como a MBNL1 e CUGBP1. Isso, consequentemente, afeta o splicing alternativo de diferentes mRNAs, o que prejudica a função normal de diferentes vias de sinalização reguladas por fosforilação, um importante mecanismo regulatório. Para perceber as diferentes vias de sinalização de fosforilação afetadas na DM1, executamos uma revisão sistemática sobre a fosforilação de proteínas em DM1. Os resultados forneceram uma compilação das vias de sinalização alteradas e que regulam eventos celulares chave. Alguns dos principais resultados são a reduzida ativação das vias da AKT/mTOR e da AMPK quando estimuladas com insulina ou com condições de privação de nutrientes, respetivamente. Adicionalmente, a miogénese estava também alterada devido ao aumento de vias estimuladoras de proliferação celular (e.g. MEK/ERK, PKR/PERK) e uma diminuição de proteínas importantes para o desenvolvimento muscular, como a DMPK. Para poder estudar os mecanismos subjacentes às vias de sinalização prejudicadas descritas na revisão sistemática, é necessário estabelecer modelos de células DM1. Por esse motivo, os fibroblastos têm sido amplamente utilizados para o estudo dessa doença devido à sua versatilidade e fácil manipulação. Em seguida, estabelecemos com sucesso linhas de células de fibroblastos humanos derivadas da pele de pacientes com DM1 através de um explante de biópsia cutânea. Essas linhas celulares foram posteriormente caracterizadas por imunocitoquímica indireta usando um marcador específico para fibroblastos TE-7. Os níveis intracelulares e a localização de DMPK também foram avaliados. Foi possível detetar diferenças, embora não estatisticamente significativas, de uma expressão reduzida de DMPK em fibroblastos derivados de DM1 com fenótipos de início tardio e juvenil comparando com controlos. Concluindo, esses fibroblastos podem ser um importante modelo celular para o estudo das vias de fosforilação e outros mecanismos, como alterações do envelope nuclear, sendo uma importante ferramenta de pesquisa para DM1. Como perspetivas futuras, estas linhas celulares podem ser usadas para estudar as fosfatases, como a PP1 e PP2, uma vez que não há evidências suficientes de como estas se alteram no DM1 e podem contribuir fortemente para desvendar novos mecanismos moleculares.
Mestrado em Biomedicina Molecular
Burgoci, Vasile. "Étude du rôle des ARN non codants du cluster Dlk1-Dio3 dans la dystrophie myotonique de type 1". Thèse, 2019. http://hdl.handle.net/1866/22793.
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