25 research outputs found

    Ovarian vein thrombosis

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    Ovarian vein thrombosis (OVT) is a rare cause of abdominal pain that may mimic a surgical abdomen. It is most often diagnosed during the postpartum period. In this report, we present four cases of postoperative ovarian vein thrombosis .The complications of OVT can be significant, and the diagnosis relies on a careful examination of the radiographic findings. It can occur with lower quadrant abdominal pain, especially in the setting of recent pregnancy, abdominal surgery, pelvic inflammatory disease, or malignancy. Diagnosis can be made with confidence using ultrasound, computed tomography or magnetic resonance imaging. Treatment of ovarian vein thrombosis is particularly important in the postpartum patients, with anticoagulation therapy being the current recommendation.Key words: Ovarian vein thrombosis, postpartum, pregnanc

    Investigating the Impact of Delivery Routes for Exon Skipping Therapies in the CNS of DMD Mouse Models

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    Nucleic acid-based therapies have demonstrated great potential for the treatment of monogenetic diseases, including neurologic disorders. To date, regulatory approval has been received for a dozen antisense oligonucleotides (ASOs); however, these chemistries cannot readily cross the blood–brain barrier when administered systemically. Therefore, an investigation of their potential effects within the central nervous system (CNS) requires local delivery. Here, we studied the brain distribution and exon-skipping efficacy of two ASO chemistries, PMO and tcDNA, when delivered to the cerebrospinal fluid (CSF) of mice carrying a deletion in exon 52 of the dystrophin gene, a model of Duchenne muscular dystrophy (DMD). Following intracerebroventricular (ICV) delivery (unilateral, bilateral, bolus vs. slow rate, repeated via cannula or very slow via osmotic pumps), ASO levels were quantified across brain regions and exon 51 skipping was evaluated, revealing that tcDNA treatment invariably generates comparable or more skipping relative to that with PMO, even when the PMO was administered at higher doses. We also performed intra-cisterna magna (ICM) delivery as an alternative route for CSF delivery and found a biased distribution of the ASOs towards posterior brain regions, including the cerebellum, hindbrain, and the cervical part of the spinal cord. Finally, we combined both ICV and ICM injection methods to assess the potential of an additive effect of this methodology in inducing efficient exon skipping across different brain regions. Our results provide useful insights into the local delivery and associated efficacy of ASOs in the CNS in mouse models of DMD. These findings pave the way for further ASO-based therapy application to the CNS for neurological disease

    Partial restoration of brain dystrophin by tricyclo-DNA antisense oligonucleotides alleviates emotional deficits in mdx52 mice

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    The mdx52 mouse model recapitulates a frequent mutation profile associated with brain involvement in Duchenne muscular dystrophy. Deletion of exon 52 impedes expression of two dystrophins (Dp427, Dp140) expressed in brain, and is eligible for therapeutic exon-skipping strategies. We previously showed that mdx52 mice display enhanced anxiety and fearfulness, and impaired associative fear learning. In this study, we examined the reversibility of these phenotypes using exon 51 skipping to restore exclusively Dp427 expression in the brain of mdx52 mice. We first show that a single intracerebroventricular administration of tricyclo-DNA antisense oligonucleotides targeting exon 51 restores 5%-15% of dystrophin protein expression in the hippocampus, cerebellum, and cortex, at stable levels between 7 and 11 week after injection. Anxiety and unconditioned fear were significantly reduced in treated mdx52 mice and acquisition of fear conditioning appeared fully rescued, while fear memory tested 24 h later was only partially improved. Additional restoration of Dp427 in skeletal and cardiac muscles by systemic treatment did not further improve the unconditioned fear response, confirming the central origin of this phenotype. These findings indicate that some emotional and cognitive deficits associated with dystrophin deficiency may be reversible or at least improved by partial postnatal dystrophin rescue

    Neurobiologie des atteintes centrales et saut d'exon thérapeutique dans un modÚle murin de dystrophie musculaire de Duchenne

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    La dystrophie musculaire de Duchenne (DMD) est un syndrome neuromusculaire associĂ© Ă  des troubles comportementaux et cognitifs pouvant entraĂźner une dĂ©ficience intellectuelle et des troubles neuropsychiatriques (TSA, TDAH, TOC). La nature et la gravitĂ© des dysfonctionnements cognitifs et des altĂ©rations centrales dĂ©pendent de la position des mutations au sein du gĂšne DMD. En effet, cela peut affecter diffĂ©remment l'expression de plusieurs dystrophines cĂ©rĂ©brales codĂ©es Ă  partir de promoteurs internes, qui ont des fonctions diverses dans divers types de cellules au cours du dĂ©veloppement et dans le cerveau adulte.Ce travail de recherche multidisciplinaire et collaboratif fait partie du projet financĂ© par l'Europe BIND (Behavioural Involvement In Dystrophinopathies). La premiĂšre partie visait Ă  clarifier les relations gĂ©notype-phĂ©notype des anomalies centrales dans cette maladie ainsi que leurs bases molĂ©culaires et neuroanatomiques. La deuxiĂšme partie visait Ă  dĂ©velopper des approches thĂ©rapeutiques prĂ©cliniques de saut d'exon pour corriger le gĂšne dmd et restaurer l'expression des dystrophines cĂ©rĂ©brales fonctionnelles dans un modĂšle murin de DMD.Mon projet de thĂšse a portĂ© sur l'Ă©tude d'une souris transgĂ©nique (mdx52) porteuse d'une mutation dans une rĂ©gion "hot spot" du gĂšne prĂ©sentant frĂ©quemment des dĂ©lĂ©tions chez les patients DMD (63%). Des mutations dans cette rĂ©gion entraĂźnent la perte de plusieurs dystrophines centrales (Dp427, Dp260 et Dp140) et sont associĂ©es Ă  des troubles neurologiques sĂ©vĂšres. En utilisant de multiples paradigmes comportementaux, nous avons montrĂ© de sĂ©vĂšres altĂ©rations des rĂ©ponses Ă©motionnelles et de la peur conditionnĂ©e, ainsi que des dĂ©ficits sensoriels et de mĂ©moire de reconnaissance plus modĂ©rĂ©s. Ceci consolide nos connaissances des relations gĂ©notype-phĂ©notype et valide la souris mdx52 en tant que modĂšle fiable pour les Ă©tudes prĂ©cliniques.De plus, la rĂ©gion "hot spot" du gĂšne DMD est Ă©ligible aux approches correctives de saut d'exon. Notre Ă©quipe a dĂ©veloppĂ© des outils molĂ©culaires de pointe (oligonuclĂ©otides antisens ‘tcDNA' et vecteurs viraux ‘AAV-U7') pour Ă©tudier le saut d'exon thĂ©rapeutique dans le modĂšle murin mdx52. Les approches de saut d'exon ont dĂ©jĂ  dĂ©montrĂ© leur efficacitĂ© pour le traitement de la dystrophie musculaire. Dans la deuxiĂšme partie de ce travail, nous avons abordĂ© l'applicabilitĂ© de ces outils au systĂšme nerveux central (SNC) et dĂ©terminĂ© les conditions thĂ©rapeutiques adĂ©quates via des injections locales dans le SNC. Nous avons ensuite dĂ©montrĂ© que ce saut d'exon induit une rĂ©expression partielle de Dp427 qui attĂ©nue les troubles Ă©motionnels et amĂ©liore les performances de peur conditionnĂ©e chez cette souris. Ces rĂ©sultats prometteurs ouvrent la voie Ă  de futures Ă©tudes visant Ă  mieux comprendre les troubles centraux dans la DMD et Ă  amĂ©liorer leur prise en charge thĂ©rapeutiques.Duchenne muscular dystrophy (DMD) is a neuromuscular disease associated with behavioral and cognitive disturbances that can lead to intellectual disability and neuropsychiatric disorders (ASD, ADHD, OCDs). The nature and severity of cognitive dysfunctions and central alterations depend on the position of the mutations within the DMD gene. Indeed, this may differentially affect the expression of several brain dystrophins encoded from internal promoters, which have diverse functions in various cell types during development and in the adult brain.This multidisciplinary and collaborative research work is part of the European funded project BIND (Behavioural Involvement In Dystrophinopathies). The first part aimed to clarify the genotype-phenotype relationships of central defects in this disease as well as their molecular and neuroanatomical bases. The second part aimed to develop preclinical therapeutic exon skipping approaches to correct the dmd gene and restore the expression of functional brain dystrophins in a mouse model of DMD.My thesis project focused on the study of a transgenic mouse (mdx52) carrying a mutation in a "hot spot" region of the gene frequently presenting deletions in DMD patients (63%). Mutations in this region lead to the loss of several central dystrophins (Dp427, Dp260 and Dp140) and are associated with severe brain disorders. Using multiple behavioral paradigms, we showed severe defects in emotional behavior and fear learning, as well as moderate sensory and recognition memory deficits in this model. This strengthens our knowledge of the genotype-phenotype relationships and validates mdx52 as a reliable model for preclinical studies.Moreover, the "hot spot" region of the DMD gene is eligible for corrective exon skipping approaches. Our team developed state-of-the-art molecular tools (“tcDNA” antisense oligonucleotides and “AAV-U7” viral vectors) to study therapeutic exon skipping in the mdx52 mouse model. Exon skipping approaches are already effective in treating the muscular dystrophy. In the second part of this work, we addressed the applicability of these tools to central nervous system (CNS) and determined the adequate therapeutic conditions using local injections to the CNS. We then demonstrated that the exon skipping induces partial Dp427 re-expression and alleviates emotional and fear learning deficits in this mouse.These promising results pave the way for future studies aimed at better understanding the central disorders in DMD and improving their therapeutic management

    Neurobiologie des atteintes centrales et saut d'exon thérapeutique dans un modÚle murin de dystrophie musculaire de Duchenne

    No full text
    Duchenne muscular dystrophy (DMD) is a neuromuscular disease associated with behavioral and cognitive disturbances that can lead to intellectual disability and neuropsychiatric disorders (ASD, ADHD, OCDs). The nature and severity of cognitive dysfunctions and central alterations depend on the position of the mutations within the DMD gene. Indeed, this may differentially affect the expression of several brain dystrophins encoded from internal promoters, which have diverse functions in various cell types during development and in the adult brain.This multidisciplinary and collaborative research work is part of the European funded project BIND (Behavioural Involvement In Dystrophinopathies). The first part aimed to clarify the genotype-phenotype relationships of central defects in this disease as well as their molecular and neuroanatomical bases. The second part aimed to develop preclinical therapeutic exon skipping approaches to correct the dmd gene and restore the expression of functional brain dystrophins in a mouse model of DMD.My thesis project focused on the study of a transgenic mouse (mdx52) carrying a mutation in a "hot spot" region of the gene frequently presenting deletions in DMD patients (63%). Mutations in this region lead to the loss of several central dystrophins (Dp427, Dp260 and Dp140) and are associated with severe brain disorders. Using multiple behavioral paradigms, we showed severe defects in emotional behavior and fear learning, as well as moderate sensory and recognition memory deficits in this model. This strengthens our knowledge of the genotype-phenotype relationships and validates mdx52 as a reliable model for preclinical studies.Moreover, the "hot spot" region of the DMD gene is eligible for corrective exon skipping approaches. Our team developed state-of-the-art molecular tools (“tcDNA” antisense oligonucleotides and “AAV-U7” viral vectors) to study therapeutic exon skipping in the mdx52 mouse model. Exon skipping approaches are already effective in treating the muscular dystrophy. In the second part of this work, we addressed the applicability of these tools to central nervous system (CNS) and determined the adequate therapeutic conditions using local injections to the CNS. We then demonstrated that the exon skipping induces partial Dp427 re-expression and alleviates emotional and fear learning deficits in this mouse.These promising results pave the way for future studies aimed at better understanding the central disorders in DMD and improving their therapeutic management.La dystrophie musculaire de Duchenne (DMD) est un syndrome neuromusculaire associĂ© Ă  des troubles comportementaux et cognitifs pouvant entraĂźner une dĂ©ficience intellectuelle et des troubles neuropsychiatriques (TSA, TDAH, TOC). La nature et la gravitĂ© des dysfonctionnements cognitifs et des altĂ©rations centrales dĂ©pendent de la position des mutations au sein du gĂšne DMD. En effet, cela peut affecter diffĂ©remment l'expression de plusieurs dystrophines cĂ©rĂ©brales codĂ©es Ă  partir de promoteurs internes, qui ont des fonctions diverses dans divers types de cellules au cours du dĂ©veloppement et dans le cerveau adulte.Ce travail de recherche multidisciplinaire et collaboratif fait partie du projet financĂ© par l'Europe BIND (Behavioural Involvement In Dystrophinopathies). La premiĂšre partie visait Ă  clarifier les relations gĂ©notype-phĂ©notype des anomalies centrales dans cette maladie ainsi que leurs bases molĂ©culaires et neuroanatomiques. La deuxiĂšme partie visait Ă  dĂ©velopper des approches thĂ©rapeutiques prĂ©cliniques de saut d'exon pour corriger le gĂšne dmd et restaurer l'expression des dystrophines cĂ©rĂ©brales fonctionnelles dans un modĂšle murin de DMD.Mon projet de thĂšse a portĂ© sur l'Ă©tude d'une souris transgĂ©nique (mdx52) porteuse d'une mutation dans une rĂ©gion "hot spot" du gĂšne prĂ©sentant frĂ©quemment des dĂ©lĂ©tions chez les patients DMD (63%). Des mutations dans cette rĂ©gion entraĂźnent la perte de plusieurs dystrophines centrales (Dp427, Dp260 et Dp140) et sont associĂ©es Ă  des troubles neurologiques sĂ©vĂšres. En utilisant de multiples paradigmes comportementaux, nous avons montrĂ© de sĂ©vĂšres altĂ©rations des rĂ©ponses Ă©motionnelles et de la peur conditionnĂ©e, ainsi que des dĂ©ficits sensoriels et de mĂ©moire de reconnaissance plus modĂ©rĂ©s. Ceci consolide nos connaissances des relations gĂ©notype-phĂ©notype et valide la souris mdx52 en tant que modĂšle fiable pour les Ă©tudes prĂ©cliniques.De plus, la rĂ©gion "hot spot" du gĂšne DMD est Ă©ligible aux approches correctives de saut d'exon. Notre Ă©quipe a dĂ©veloppĂ© des outils molĂ©culaires de pointe (oligonuclĂ©otides antisens ‘tcDNA' et vecteurs viraux ‘AAV-U7') pour Ă©tudier le saut d'exon thĂ©rapeutique dans le modĂšle murin mdx52. Les approches de saut d'exon ont dĂ©jĂ  dĂ©montrĂ© leur efficacitĂ© pour le traitement de la dystrophie musculaire. Dans la deuxiĂšme partie de ce travail, nous avons abordĂ© l'applicabilitĂ© de ces outils au systĂšme nerveux central (SNC) et dĂ©terminĂ© les conditions thĂ©rapeutiques adĂ©quates via des injections locales dans le SNC. Nous avons ensuite dĂ©montrĂ© que ce saut d'exon induit une rĂ©expression partielle de Dp427 qui attĂ©nue les troubles Ă©motionnels et amĂ©liore les performances de peur conditionnĂ©e chez cette souris. Ces rĂ©sultats prometteurs ouvrent la voie Ă  de futures Ă©tudes visant Ă  mieux comprendre les troubles centraux dans la DMD et Ă  amĂ©liorer leur prise en charge thĂ©rapeutiques

    Les approches thĂ©rapeutiques de modulation de l’épissage: AvancĂ©es et perspectives

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    International audienceAdvances in genetic and genomic research continue to increase our knowledge of hereditary diseases, and an increasing number of them are being attributed to aberrant splicing, thus representing ideal targets for RNA modulation therapies. New strategies to skip or re-include exons during the splicing process have emerged and are now widely evaluated in the clinic. Several drugs have recently been approved in particular for the treatment of Duchenne muscular dystrophy and spinal muscular atrophy. Among these molecules, antisense oligonucleotides, or ASOs, have gained increasing interest and have constantly been improved over the years through chemical modifications and design. However, their limited biodistribution following systemic administration still represents a major hurdle and the development of more potent alternative chemistries or new delivery systems has become a very active line of research in the past few years. In parallel, the use of small molecules with excellent biodistribution properties or of viral vectors to convey antisense sequences is also being investigated. In this review, we summarize the recent advances in splicing therapies through two examples of neuromuscular diseases and we discuss their main benefits and current limitations.Les avancĂ©es en recherches gĂ©nĂ©tique et gĂ©nomique ne cessent d’accroĂźtre nos connaissances des maladies hĂ©rĂ©ditaires. Un nombre croissant de ces maladies relĂšve d’épissages aberrants qui reprĂ©sentent des cibles idĂ©ales pour les approches correctives centrĂ©es sur l’ARN. De nouvelles stratĂ©gies, en particulier mĂ©dicamenteuses, visant Ă  exclure ou Ă  rĂ©-inclure des exons lors du processus d’épissage, ont ainsi Ă©mergĂ© et plusieurs molĂ©cules ont rĂ©cemment obtenu des autorisations de mise sur le marchĂ©, notamment pour le traitement de la dystrophie musculaire de Duchenne et de l’amyotrophie spinale, suscitant de plus en plus d’intĂ©rĂȘt et d’espoir. Parmi ces molĂ©cules, les oligonuclĂ©otides antisens, ou ASO, ont connu un rĂ©el essor et font l’objet de progrĂšs constants en matiĂšre de modifications chimiques et de conception. Toutefois, leur biodistribution aprĂšs administration par voie gĂ©nĂ©rale demeure souvent limitĂ©e, et le dĂ©veloppement de chimies alternatives plus performantes et de nouveaux systĂšmes d’adressage est devenu un axe de recherche trĂšs actif. En parallĂšle, l’utilisation de petites molĂ©cules prĂ©sentant une excellente biodistribution, ou de vecteurs viraux pour vĂ©hiculer les sĂ©quences antisens, est Ă©galement explorĂ©e. Dans cette SynthĂšse, nous prĂ©sentons les derniĂšres avancĂ©es de ces approches de modulation d’épissage Ă  travers deux exemples de maladies neuromusculaires. Nous discutons de leurs avantages et des principales limitations actuelles
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