Abnormal coherence and sleep composition in children with Angelman syndrome: a retrospective EEG study / H. DEN BAKKER in Molecular Autism, 9 (2018)  

Public ISBD [article]  inMolecular Autism > 9 (2018) . - 32p. Titre : Abnormal coherence and sleep composition in children with Angelman syndrome: a retrospective EEG study Type de document : Texte imprimé et/ou numérique Auteurs : H. DEN BAKKER, Auteur ; M. S. SIDOROV, Auteur ; Z. FAN, Auteur ; D. J. LEE, Auteur ; L. M. BIRD, Auteur ; C. J. CHU, Auteur ; B. D. PHILPOT, Auteur Article en page(s) : 32p. Langues : Anglais (eng) Mots-clés : Angelman Syndrome/physiopathology  Case-Control Studies  Child  Delta Rhythm  Female  Gamma Rhythm  Humans  Male  Sleep Stages  Angelman syndrome  Biomarker  Coherence  eeg  Spindles  UBE3A Index. décimale : PER Périodiques Résumé : Background: Angelman syndrome (AS) is a neurodevelopmental disorder characterized by intellectual disability, speech and motor impairments, epilepsy, abnormal sleep, and phenotypic overlap with autism. Individuals with AS display characteristic EEG patterns including high-amplitude rhythmic delta waves. Here, we sought to quantitatively explore EEG architecture in AS beyond known spectral power phenotypes. We were motivated by studies of functional connectivity and sleep spindles in autism to study these EEG readouts in children with AS. Methods: We analyzed retrospective wake and sleep EEGs from children with AS (age 4-11) and age-matched neurotypical controls. We assessed long-range and short-range functional connectivity by measuring coherence across multiple frequencies during wake and sleep. We quantified sleep spindles using automated and manual approaches. Results: During wakefulness, children with AS showed enhanced long-range EEG coherence across a wide range of frequencies. During sleep, children with AS showed increased long-range EEG coherence specifically in the gamma band. EEGs from children with AS contained fewer sleep spindles, and these spindles were shorter in duration than their neurotypical counterparts. Conclusions: We demonstrate two quantitative readouts of dysregulated sleep composition in children with AS-gamma coherence and spindles-and describe how functional connectivity patterns may be disrupted during wakefulness. Quantitative EEG phenotypes have potential as biomarkers and readouts of target engagement for future clinical trials and provide clues into how neural circuits are dysregulated in children with AS. En ligne : https://dx.doi.org/10.1186/s13229-018-0214-8 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=371 [article] Abnormal coherence and sleep composition in children with Angelman syndrome: a retrospective EEG study [Texte imprimé et/ou numérique] / H. DEN BAKKER, Auteur ; M. S. SIDOROV, Auteur ; Z. FAN, Auteur ; D. J. LEE, Auteur ; L. M. BIRD, Auteur ; C. J. CHU, Auteur ; B. D. PHILPOT, Auteur . - 32p. Langues : Anglais (eng) in Molecular Autism > 9 (2018) . - 32p. Mots-clés : Angelman Syndrome/physiopathology  Case-Control Studies  Child  Delta Rhythm  Female  Gamma Rhythm  Humans  Male  Sleep Stages  Angelman syndrome  Biomarker  Coherence  eeg  Spindles  UBE3A Index. décimale : PER Périodiques Résumé : Background: Angelman syndrome (AS) is a neurodevelopmental disorder characterized by intellectual disability, speech and motor impairments, epilepsy, abnormal sleep, and phenotypic overlap with autism. Individuals with AS display characteristic EEG patterns including high-amplitude rhythmic delta waves. Here, we sought to quantitatively explore EEG architecture in AS beyond known spectral power phenotypes. We were motivated by studies of functional connectivity and sleep spindles in autism to study these EEG readouts in children with AS. Methods: We analyzed retrospective wake and sleep EEGs from children with AS (age 4-11) and age-matched neurotypical controls. We assessed long-range and short-range functional connectivity by measuring coherence across multiple frequencies during wake and sleep. We quantified sleep spindles using automated and manual approaches. Results: During wakefulness, children with AS showed enhanced long-range EEG coherence across a wide range of frequencies. During sleep, children with AS showed increased long-range EEG coherence specifically in the gamma band. EEGs from children with AS contained fewer sleep spindles, and these spindles were shorter in duration than their neurotypical counterparts. Conclusions: We demonstrate two quantitative readouts of dysregulated sleep composition in children with AS-gamma coherence and spindles-and describe how functional connectivity patterns may be disrupted during wakefulness. Quantitative EEG phenotypes have potential as biomarkers and readouts of target engagement for future clinical trials and provide clues into how neural circuits are dysregulated in children with AS. En ligne : https://dx.doi.org/10.1186/s13229-018-0214-8 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=371

Angelman syndrome: advancing the research frontier of neurodevelopmental disorders / B. D. PHILPOT in Journal of Neurodevelopmental Disorders, 3-1 (March 2011)  

Public ISBD [article]  inJournal of Neurodevelopmental Disorders > 3-1 (March 2011) . - p.50-6 Titre : Angelman syndrome: advancing the research frontier of neurodevelopmental disorders Type de document : Texte imprimé et/ou numérique Auteurs : B. D. PHILPOT, Auteur ; Charlotte E. THOMPSON, Auteur ; L. FRANCO, Auteur ; C. A. WILLIAMS, Auteur Article en page(s) : p.50-6 Langues : Anglais (eng) Index. décimale : PER Périodiques Résumé : This report is a meeting summary of the 2010 Angelman Syndrome Foundation's scientific symposium on the neuroscience of UBE3A. Angelman syndrome is characterized by loss of speech, severe developmental delay, seizures, and ataxia. These core symptoms are caused by maternal allele disruptions of a single gene-UBE3A. UBE3A encodes an E3 ubiquitin ligase that targets certain proteins for proteasomal degradation. This biology has led to the expectation that the identification of Ube3a protein targets will lead to therapies for Angelman syndrome. The recent discovery of Ube3a substrates such as Arc (activity-regulated cytoskeletal protein) provides new insight into the mechanisms underlying the synaptic function and plasticity deficits caused by the loss of Ube3a. In addition to identifying Ube3a substrates, there have also been recent advances in understanding UBE3A's integrated role in the neuronal repertoire of genes and protein interactions. A developmental picture is now emerging whereby UBE3A gene dosage on chromosome 15 alters synaptic function, with deficiencies leading to Angelman syndrome and overexpression associated with classic autism symptomatology. En ligne : http://dx.doi.org/10.1007/s11689-010-9066-z Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=343 [article] Angelman syndrome: advancing the research frontier of neurodevelopmental disorders [Texte imprimé et/ou numérique] / B. D. PHILPOT, Auteur ; Charlotte E. THOMPSON, Auteur ; L. FRANCO, Auteur ; C. A. WILLIAMS, Auteur . - p.50-6. Langues : Anglais (eng) in Journal of Neurodevelopmental Disorders > 3-1 (March 2011) . - p.50-6 Index. décimale : PER Périodiques Résumé : This report is a meeting summary of the 2010 Angelman Syndrome Foundation's scientific symposium on the neuroscience of UBE3A. Angelman syndrome is characterized by loss of speech, severe developmental delay, seizures, and ataxia. These core symptoms are caused by maternal allele disruptions of a single gene-UBE3A. UBE3A encodes an E3 ubiquitin ligase that targets certain proteins for proteasomal degradation. This biology has led to the expectation that the identification of Ube3a protein targets will lead to therapies for Angelman syndrome. The recent discovery of Ube3a substrates such as Arc (activity-regulated cytoskeletal protein) provides new insight into the mechanisms underlying the synaptic function and plasticity deficits caused by the loss of Ube3a. In addition to identifying Ube3a substrates, there have also been recent advances in understanding UBE3A's integrated role in the neuronal repertoire of genes and protein interactions. A developmental picture is now emerging whereby UBE3A gene dosage on chromosome 15 alters synaptic function, with deficiencies leading to Angelman syndrome and overexpression associated with classic autism symptomatology. En ligne : http://dx.doi.org/10.1007/s11689-010-9066-z Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=343

Characterization and structure-activity relationships of indenoisoquinoline-derived topoisomerase I inhibitors in unsilencing the dormant Ube3a gene associated with Angelman syndrome / H. M. LEE in Molecular Autism, 9 (2018)  

Public ISBD [article]  inMolecular Autism > 9 (2018) . - 45p. Titre : Characterization and structure-activity relationships of indenoisoquinoline-derived topoisomerase I inhibitors in unsilencing the dormant Ube3a gene associated with Angelman syndrome Type de document : Texte imprimé et/ou numérique Auteurs : H. M. LEE, Auteur ; E. P. CLARK, Auteur ; M. B. KUIJER, Auteur ; M. CUSHMAN, Auteur ; Y. POMMIER, Auteur ; B. D. PHILPOT, Auteur Article en page(s) : 45p. Langues : Anglais (eng) Mots-clés : Angelman syndrome  Indenoisoquinoline  Indotecan  Topoisomerase I  Topoisomerase inhibitor  Topotecan  UBE3A Index. décimale : PER Périodiques Résumé : Background: Angelman syndrome (AS) is a severe neurodevelopmental disorder lacking effective therapies. AS is caused by mutations in ubiquitin protein ligase E3A (UBE3A), which is genomically imprinted such that only the maternally inherited copy is expressed in neurons. We previously demonstrated that topoisomerase I (Top1) inhibitors could successfully reactivate the dormant paternal allele of Ube3a in neurons of a mouse model of AS. We also previously showed that one such Top1 inhibitor, topotecan, could unsilence paternal UBE3A in induced pluripotent stem cell-derived neurons from individuals with AS. Although topotecan has been well-studied and is FDA-approved for cancer therapy, its limited CNS bioavailability will likely restrict the therapeutic use of topotecan in AS. The goal of this study was to identify additional Top1 inhibitors with similar efficacy as topotecan, with the expectation that these could be tested in the future for safety and CNS bioavailability to assess their potential as AS therapeutics. Methods: We tested 13 indenoisoquinoline-derived Top1 inhibitors to identify compounds that unsilence the paternal allele of Ube3a in mouse neurons. Primary cortical neurons were isolated from embryonic day 14.5 (E14.5) mice with a Ube3a-YFP fluorescent tag on the paternal allele (Ube3a(m+/pYFP) mice) or mice that lack the maternal Ube3a allele and hence model AS (Ube3a(m-/p+) mice). Neurons were cultured for 7 days, treated with drug for 72 h, and examined for paternal UBE3A protein expression by Western blot or fluorescence immunostaining. Dose responses of the compounds were determined across a log range of drug treatments, and cytotoxicity was tested using a luciferase-based assay. Results: All 13 indenoisoquinoline-derived Top1 inhibitors unsilenced paternal Ube3a. Several compounds exhibited favorable paternal Ube3a unsilencing properties, similar to topotecan, and of these, indotecan (LMP400) was the most effective based on estimated Emax (maximum response of unsilencing paternal Ube3a) and EC50 (half maximal effective concentration). Conclusions: We provide pharmacological profiles of indenoisoquinoline-derived Top1 inhibitors as paternal Ube3a unsilencers. All 13 tested compounds were effective at unsilencing paternal Ube3a, although with variable efficacy and potency. Indotecan (LMP400) demonstrated a better pharmacological profile of Ube3a unsilencing compared to our previous lead compound, topotecan. Taken together, indotecan and its structural analogues are potential AS therapeutics whose translational potential in AS treatment should be further assessed. En ligne : https://dx.doi.org/10.1186/s13229-018-0228-2 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=371 [article] Characterization and structure-activity relationships of indenoisoquinoline-derived topoisomerase I inhibitors in unsilencing the dormant Ube3a gene associated with Angelman syndrome [Texte imprimé et/ou numérique] / H. M. LEE, Auteur ; E. P. CLARK, Auteur ; M. B. KUIJER, Auteur ; M. CUSHMAN, Auteur ; Y. POMMIER, Auteur ; B. D. PHILPOT, Auteur . - 45p. Langues : Anglais (eng) in Molecular Autism > 9 (2018) . - 45p. Mots-clés : Angelman syndrome  Indenoisoquinoline  Indotecan  Topoisomerase I  Topoisomerase inhibitor  Topotecan  UBE3A Index. décimale : PER Périodiques Résumé : Background: Angelman syndrome (AS) is a severe neurodevelopmental disorder lacking effective therapies. AS is caused by mutations in ubiquitin protein ligase E3A (UBE3A), which is genomically imprinted such that only the maternally inherited copy is expressed in neurons. We previously demonstrated that topoisomerase I (Top1) inhibitors could successfully reactivate the dormant paternal allele of Ube3a in neurons of a mouse model of AS. We also previously showed that one such Top1 inhibitor, topotecan, could unsilence paternal UBE3A in induced pluripotent stem cell-derived neurons from individuals with AS. Although topotecan has been well-studied and is FDA-approved for cancer therapy, its limited CNS bioavailability will likely restrict the therapeutic use of topotecan in AS. The goal of this study was to identify additional Top1 inhibitors with similar efficacy as topotecan, with the expectation that these could be tested in the future for safety and CNS bioavailability to assess their potential as AS therapeutics. Methods: We tested 13 indenoisoquinoline-derived Top1 inhibitors to identify compounds that unsilence the paternal allele of Ube3a in mouse neurons. Primary cortical neurons were isolated from embryonic day 14.5 (E14.5) mice with a Ube3a-YFP fluorescent tag on the paternal allele (Ube3a(m+/pYFP) mice) or mice that lack the maternal Ube3a allele and hence model AS (Ube3a(m-/p+) mice). Neurons were cultured for 7 days, treated with drug for 72 h, and examined for paternal UBE3A protein expression by Western blot or fluorescence immunostaining. Dose responses of the compounds were determined across a log range of drug treatments, and cytotoxicity was tested using a luciferase-based assay. Results: All 13 indenoisoquinoline-derived Top1 inhibitors unsilenced paternal Ube3a. Several compounds exhibited favorable paternal Ube3a unsilencing properties, similar to topotecan, and of these, indotecan (LMP400) was the most effective based on estimated Emax (maximum response of unsilencing paternal Ube3a) and EC50 (half maximal effective concentration). Conclusions: We provide pharmacological profiles of indenoisoquinoline-derived Top1 inhibitors as paternal Ube3a unsilencers. All 13 tested compounds were effective at unsilencing paternal Ube3a, although with variable efficacy and potency. Indotecan (LMP400) demonstrated a better pharmacological profile of Ube3a unsilencing compared to our previous lead compound, topotecan. Taken together, indotecan and its structural analogues are potential AS therapeutics whose translational potential in AS treatment should be further assessed. En ligne : https://dx.doi.org/10.1186/s13229-018-0228-2 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=371

Delayed loss of UBE3A reduces the expression of Angelman syndrome-associated phenotypes / M. SONZOGNI in Molecular Autism, 10 (2019)  

Public ISBD [article]  inMolecular Autism > 10 (2019) . - 23p. Titre : Delayed loss of UBE3A reduces the expression of Angelman syndrome-associated phenotypes Type de document : Texte imprimé et/ou numérique Auteurs : M. SONZOGNI, Auteur ; J. HAKONEN, Auteur ; M. BERNABE KLEIJN, Auteur ; S. SILVA-SANTOS, Auteur ; M. C. JUDSON, Auteur ; B. D. PHILPOT, Auteur ; G. M. VAN WOERDEN, Auteur ; Y. ELGERSMA, Auteur Article en page(s) : 23p. Langues : Anglais (eng) Mots-clés : Angelman syndrome  Autism spectrum disorder  Mouse model  Phenotype  Seizure  Ube3a Index. décimale : PER Périodiques Résumé : Background: Angelman syndrome (AS) is a severe neurodevelopmental disorder caused by mutations affecting UBE3A gene expression. Previous studies in mice revealed distinct critical periods during neurodevelopment in which reactivation of Ube3a gene expression can prevent the onset of behavioral deficits. Whether UBE3A is required for brain function throughout life is unknown. Here, we address the importance of maintaining UBE3A expression after normal brain development. Findings: Using a conditional mouse, we deleted the Ube3a gene at three ages spanning brain maturation. We assessed the consequences of Ube3a gene deletion by testing the mice in behavioral tasks previously shown to produce robust phenotypes in AS model mice. Early embryonic deletion of Ube3a recapitulated all behavioral deficits of AS mice. In contrast, Ube3a gene deletion at 3 or 12 weeks of age did not have a significant effect on most behavioral tasks and did not increase seizure sensitivity. Conclusions: Taken together, these results emphasize that UBE3A critically impacts early brain development, but plays a more limited role in adulthood. Our findings provide important considerations for upcoming clinical trials in which UBE3A gene expression is reactivated and suggest that even transient UBE3A reinstatement during a critical window of early development is likely to prevent most adverse Angelman syndrome phenotypes. However, sustained UBE3A expression into adulthood is probably needed for optimal clinical benefit. En ligne : http://dx.doi.org/10.1186/s13229-019-0277-1 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=402 [article] Delayed loss of UBE3A reduces the expression of Angelman syndrome-associated phenotypes [Texte imprimé et/ou numérique] / M. SONZOGNI, Auteur ; J. HAKONEN, Auteur ; M. BERNABE KLEIJN, Auteur ; S. SILVA-SANTOS, Auteur ; M. C. JUDSON, Auteur ; B. D. PHILPOT, Auteur ; G. M. VAN WOERDEN, Auteur ; Y. ELGERSMA, Auteur . - 23p. Langues : Anglais (eng) in Molecular Autism > 10 (2019) . - 23p. Mots-clés : Angelman syndrome  Autism spectrum disorder  Mouse model  Phenotype  Seizure  Ube3a Index. décimale : PER Périodiques Résumé : Background: Angelman syndrome (AS) is a severe neurodevelopmental disorder caused by mutations affecting UBE3A gene expression. Previous studies in mice revealed distinct critical periods during neurodevelopment in which reactivation of Ube3a gene expression can prevent the onset of behavioral deficits. Whether UBE3A is required for brain function throughout life is unknown. Here, we address the importance of maintaining UBE3A expression after normal brain development. Findings: Using a conditional mouse, we deleted the Ube3a gene at three ages spanning brain maturation. We assessed the consequences of Ube3a gene deletion by testing the mice in behavioral tasks previously shown to produce robust phenotypes in AS model mice. Early embryonic deletion of Ube3a recapitulated all behavioral deficits of AS mice. In contrast, Ube3a gene deletion at 3 or 12 weeks of age did not have a significant effect on most behavioral tasks and did not increase seizure sensitivity. Conclusions: Taken together, these results emphasize that UBE3A critically impacts early brain development, but plays a more limited role in adulthood. Our findings provide important considerations for upcoming clinical trials in which UBE3A gene expression is reactivated and suggest that even transient UBE3A reinstatement during a critical window of early development is likely to prevent most adverse Angelman syndrome phenotypes. However, sustained UBE3A expression into adulthood is probably needed for optimal clinical benefit. En ligne : http://dx.doi.org/10.1186/s13229-019-0277-1 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=402

Delta rhythmicity is a reliable EEG biomarker in Angelman syndrome: a parallel mouse and human analysis / M. S. SIDOROV in Journal of Neurodevelopmental Disorders, 9-1 (December 2017)  

Public ISBD [article]  inJournal of Neurodevelopmental Disorders > 9-1 (December 2017) . - p.17 Titre : Delta rhythmicity is a reliable EEG biomarker in Angelman syndrome: a parallel mouse and human analysis Type de document : Texte imprimé et/ou numérique Auteurs : M. S. SIDOROV, Auteur ; G. M. DECK, Auteur ; M. DOLATSHAHI, Auteur ; R. L. THIBERT, Auteur ; L. M. BIRD, Auteur ; C. J. CHU, Auteur ; B. D. PHILPOT, Auteur Article en page(s) : p.17 Langues : Anglais (eng) Mots-clés : Angelman syndrome  Biomarker  Delta  Eeg  Mouse model  Outcome measure  Ube3a Index. décimale : PER Périodiques Résumé : BACKGROUND: Clinicians have qualitatively described rhythmic delta activity as a prominent EEG abnormality in individuals with Angelman syndrome, but this phenotype has yet to be rigorously quantified in the clinical population or validated in a preclinical model. Here, we sought to quantitatively measure delta rhythmicity and evaluate its fidelity as a biomarker. METHODS: We quantified delta oscillations in mouse and human using parallel spectral analysis methods and measured regional, state-specific, and developmental changes in delta rhythms in a patient population. RESULTS: Delta power was broadly increased and more dynamic in both the Angelman syndrome mouse model, relative to wild-type littermates, and in children with Angelman syndrome, relative to age-matched neurotypical controls. Enhanced delta oscillations in children with Angelman syndrome were present during wakefulness and sleep, were generalized across the neocortex, and were more pronounced at earlier ages. CONCLUSIONS: Delta rhythmicity phenotypes can serve as reliable biomarkers for Angelman syndrome in both preclinical and clinical settings. En ligne : http://dx.doi.org/10.1186/s11689-017-9195-8 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=350 [article] Delta rhythmicity is a reliable EEG biomarker in Angelman syndrome: a parallel mouse and human analysis [Texte imprimé et/ou numérique] / M. S. SIDOROV, Auteur ; G. M. DECK, Auteur ; M. DOLATSHAHI, Auteur ; R. L. THIBERT, Auteur ; L. M. BIRD, Auteur ; C. J. CHU, Auteur ; B. D. PHILPOT, Auteur . - p.17. Langues : Anglais (eng) in Journal of Neurodevelopmental Disorders > 9-1 (December 2017) . - p.17 Mots-clés : Angelman syndrome  Biomarker  Delta  Eeg  Mouse model  Outcome measure  Ube3a Index. décimale : PER Périodiques Résumé : BACKGROUND: Clinicians have qualitatively described rhythmic delta activity as a prominent EEG abnormality in individuals with Angelman syndrome, but this phenotype has yet to be rigorously quantified in the clinical population or validated in a preclinical model. Here, we sought to quantitatively measure delta rhythmicity and evaluate its fidelity as a biomarker. METHODS: We quantified delta oscillations in mouse and human using parallel spectral analysis methods and measured regional, state-specific, and developmental changes in delta rhythms in a patient population. RESULTS: Delta power was broadly increased and more dynamic in both the Angelman syndrome mouse model, relative to wild-type littermates, and in children with Angelman syndrome, relative to age-matched neurotypical controls. Enhanced delta oscillations in children with Angelman syndrome were present during wakefulness and sleep, were generalized across the neocortex, and were more pronounced at earlier ages. CONCLUSIONS: Delta rhythmicity phenotypes can serve as reliable biomarkers for Angelman syndrome in both preclinical and clinical settings. En ligne : http://dx.doi.org/10.1186/s11689-017-9195-8 Permalink : https://www.cra-rhone-alpes.org/cid/opac_css/index.php?lvl=notice_display&id=350

Erratum to: Delta rhythmicity is a reliable EEG biomarker in Angelman syndrome: a parallel mouse and human analysis / M. S. SIDOROV in Journal of Neurodevelopmental Disorders, 9-1 (December 2017)  

Permalink

Subcellular organization of UBE3A in human cerebral cortex / A. C. BURETTE in Molecular Autism, 9 (2018)  

Permalink

---

1 (1 - 7 / 7)