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Merritt JK, Fang X, Caylor RC, Skinner SA, Friez MJ, Percy AK, Neul JL. Normalized Clinical Severity Scores Reveal a Correlation between X Chromosome Inactivation and Disease Severity in Rett Syndrome. Genes (Basel) 2024; 15:594. [PMID: 38790223 PMCID: PMC11120815 DOI: 10.3390/genes15050594] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2024] [Revised: 05/01/2024] [Accepted: 05/05/2024] [Indexed: 05/26/2024] Open
Abstract
Rett Syndrome (RTT) is a severe neurodevelopmental disorder predominately diagnosed in females and primarily caused by pathogenic variants in the X-linked gene Methyl-CpG Binding Protein 2 (MECP2). Most often, the disease causing the MECP2 allele resides on the paternal X chromosome while a healthy copy is maintained on the maternal X chromosome with inactivation (XCI), resulting in mosaic expression of one allele in each cell. Preferential inactivation of the paternal X chromosome is theorized to result in reduced disease severity; however, establishing such a correlation is complicated by known MECP2 genotype effects and an age-dependent increase in severity. To mitigate these confounding factors, we developed an age- and genotype-normalized measure of RTT severity by modeling longitudinal data collected in the US Rett Syndrome Natural History Study. This model accurately reflected individual increase in severity with age and preserved group-level genotype specific differences in severity, allowing for the creation of a normalized clinical severity score. Applying this normalized score to a RTT XCI dataset revealed that XCI influence on disease severity depends on MECP2 genotype with a correlation between XCI and severity observed only in individuals with MECP2 variants associated with increased clinical severity. This normalized measure of RTT severity provides the opportunity for future discovery of additional factors contributing to disease severity that may be masked by age and genotype effects.
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Affiliation(s)
- Jonathan K. Merritt
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37232, USA;
| | - Xiaolan Fang
- Department of Pathology, Henry Ford Health System, Detroit, MI 48202, USA;
- Greenwood Genetic Center, Greenwood, SC 29646, USA; (R.C.C.); (S.A.S.); (M.J.F.)
| | - Raymond C. Caylor
- Greenwood Genetic Center, Greenwood, SC 29646, USA; (R.C.C.); (S.A.S.); (M.J.F.)
| | - Steven A. Skinner
- Greenwood Genetic Center, Greenwood, SC 29646, USA; (R.C.C.); (S.A.S.); (M.J.F.)
| | - Michael J. Friez
- Greenwood Genetic Center, Greenwood, SC 29646, USA; (R.C.C.); (S.A.S.); (M.J.F.)
| | - Alan K. Percy
- Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL 35294, USA;
| | - Jeffrey L. Neul
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN 37232, USA;
- Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA
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2
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Desnous B, Beretti T, Muller N, Neveu J, Villeneuve N, Lépine A, Daquin G, Milh M. Efficacy and tolerance of cannabidiol in the treatment of epilepsy in patients with Rett syndrome. Epilepsia Open 2024; 9:397-403. [PMID: 37485779 PMCID: PMC10839357 DOI: 10.1002/epi4.12796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 07/20/2023] [Indexed: 07/25/2023] Open
Abstract
We aim to assess the efficacy and tolerance of cannabidiol as adjunctive therapy for Rett syndrome (RTT) patients with epilepsy. We conducted a longitudinal observational study through a monocentric cohort of 46 patients with RTT. Patients were recruited from March 2020 to October 2022 and were treated with Epidyolex® (cannabidiol, CBD, 100 mg/mL oral solution). In our cohort, 26 patients had associated epilepsy (26/46 [56%]), and 10/26 (38%) were treated with CBD, in combination with clobazam in 50% of cases. The median dose at their last follow-up was 15 mg/kg/day. The median treatment duration was 13 months (range: 1-32 months). CBD reduced the incidence of seizures in seven out of 10 patients (70%) with one seizure-free patient, two patients with a reduction of seizures of more than 75%, and four patients with a decrease of more than 50%. No aggravation of symptoms or adverse effects were observed. Only one patient experienced a transitory drooling and somnolence episode at the CBD initiation. Half of the patients showed a reduction in agitation and/or anxiety attacks, and an improvement in spasticity was reported in 4/10 (40%) of patients. CBD appears to have potential therapeutic value for the treatment of drug-resistant epilepsy in Rett syndrome. CBD is well tolerated and, when used in combination with clobazam, may increase the effectiveness of clobazam alone.
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Affiliation(s)
- Béatrice Desnous
- Pediatric Neurology DepartmentTimone Enfant, APHMMarseilleFrance
| | - Thibault Beretti
- Pediatric Neurology DepartmentTimone Enfant, APHMMarseilleFrance
| | - Nathan Muller
- Pediatric Neurology DepartmentTimone Enfant, APHMMarseilleFrance
| | | | | | - Anne Lépine
- Pediatric Neurology DepartmentTimone Enfant, APHMMarseilleFrance
| | - Géraldine Daquin
- Epileptology and Cerebral Rhythmology DepartmentTimone Adulte, APHMMarseilleFrance
| | - Mathieu Milh
- Pediatric Neurology DepartmentTimone Enfant, APHMMarseilleFrance
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3
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Palmieri M, Pozzer D, Landsberger N. Advanced genetic therapies for the treatment of Rett syndrome: state of the art and future perspectives. Front Neurosci 2023; 17:1172805. [PMID: 37304036 PMCID: PMC10248472 DOI: 10.3389/fnins.2023.1172805] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Accepted: 05/02/2023] [Indexed: 06/13/2023] Open
Abstract
Loss and gain of functions mutations in the X-linked MECP2 (methyl-CpG-binding protein 2) gene are responsible for a set of generally severe neurological disorders that can affect both genders. In particular, Mecp2 deficiency is mainly associated with Rett syndrome (RTT) in girls, while duplication of the MECP2 gene leads, mainly in boys, to the MECP2 duplication syndrome (MDS). No cure is currently available for MECP2 related disorders. However, several studies have reported that by re-expressing the wild-type gene is possible to restore defective phenotypes of Mecp2 null animals. This proof of principle endorsed many laboratories to search for novel therapeutic strategies to cure RTT. Besides pharmacological approaches aimed at modulating MeCP2-downstream pathways, genetic targeting of MECP2 or its transcript have been largely proposed. Remarkably, two studies focused on augmentative gene therapy were recently approved for clinical trials. Both use molecular strategies to well-control gene dosage. Notably, the recent development of genome editing technologies has opened an alternative way to specifically target MECP2 without altering its physiological levels. Other attractive approaches exclusively applicable for nonsense mutations are the translational read-through (TR) and t-RNA suppressor therapy. Reactivation of the MECP2 locus on the silent X chromosome represents another valid choice for the disease. In this article, we intend to review the most recent genetic interventions for the treatment of RTT, describing the current state of the art, and the related advantages and concerns. We will also discuss the possible application of other advanced therapies, based on molecular delivery through nanoparticles, already proposed for other neurological disorders but still not tested in RTT.
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Affiliation(s)
- Michela Palmieri
- Rett Research Unit, Division of Neuroscience, San Raffaele Hospital (IRCCS), Milan, Italy
| | - Diego Pozzer
- Rett Research Unit, Division of Neuroscience, San Raffaele Hospital (IRCCS), Milan, Italy
| | - Nicoletta Landsberger
- Rett Research Unit, Division of Neuroscience, San Raffaele Hospital (IRCCS), Milan, Italy
- Department of Medical Biotechnology and Translational Medicine, Faculty of Medicine and Surgery, University of Milan, Milan, Italy
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4
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Hurley EN, Ellaway CJ, Johnson AM, Truong L, Gordon R, Galettis P, Martin JH, Lawson JA. The efficacy and safety of cannabidivarin treatment on epilepsy in girls with Rett syndrome: A phase I clinical trial. Epilepsia 2022; 63:1736-1747. [PMID: 35364618 PMCID: PMC9544893 DOI: 10.1111/epi.17247] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2021] [Revised: 03/30/2022] [Accepted: 03/30/2022] [Indexed: 11/30/2022]
Abstract
Objective Rett syndrome (RTT), commonly caused by methyl‐CpG‐binding protein 2 (MECP2) pathogenic variants, has many comorbidities. Fifty to ninety percent of children with RTT have epilepsy, which is often drug‐resistant. Cannabidivarin (CBDV), a non‐hallucinogenic phytocannabinoid, has shown benefit in MECP2 animal models. This phase 1 trial assessed the safety and tolerability of CBDV in female children with RTT and drug‐resistant epilepsy, as well as the effect on mean monthly seizure frequency (MMSF), the electroencephalogram (EEG), and non‐epilepsy comorbid symptoms. Methods Five female children with drug‐resistant epilepsy and a pathogenic MECP2 variant were enrolled. Baseline clinical and laboratory assessments, including monthly seizure frequency, were recorded. CBDV oral solution (50 mg/ml) was prescribed and titrated to 10 mg/kg/day. Data collected included pharmacokinetics, seizure type and frequency, adverse events, EEG, and responses to the Rett Syndrome Behaviour Questionnaire and Rett Syndrome Symptom Severity Index, and were compared to baseline data. Results All five children reached the maximum CBDV dose of 10 mg/kg/day and had a reduction in MMSF (median = 79% reduction). Three children had MMSF reduction > 75%. This corresponded to an overall reduction in seizure frequency from 32 to 7.2 seizures per month. Ninety‐one percent of adverse events were mild or moderate, and none required drug withdrawal. Sixty‐two percent were judged to be unrelated to CBDV. Thirty‐one percent of adverse events were identified as possibly related, of which nearly all were mild, and the remainder were later assessed as RTT symptoms. Hypersomnolence and drooling were identified as related to CBDV. No serious adverse events reported were related to CBDV. No significant change was noted in EEG or non‐epilepsy‐related symptoms of RTT. Significance A dose of 10 mg/kg/day of CBDV is safe and well tolerated in a pediatric RTT cohort and suggests improved seizure control in children with MECP2‐related RTT.
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Affiliation(s)
- Ellen N Hurley
- Department of Neurology, Sydney Children's Hospital Randwick, NSW, Australia.,School of Women's and Children's Health, UNSW Medicine and Health, University of New South Wales, NSW, Australia
| | - Carolyn J Ellaway
- Genetic Metabolic Disorders Service, Sydney Children's Hospital Network, Sydney, NSW, Australia.,Disciplines of Child and Adolescent Health and Genomic Medicine, University of Sydney, Sydney, NSW, Australia
| | - Alexandra M Johnson
- Department of Neurology, Sydney Children's Hospital Randwick, NSW, Australia.,School of Women's and Children's Health, UNSW Medicine and Health, University of New South Wales, NSW, Australia
| | - Linda Truong
- Department of Neurology, Sydney Children's Hospital Randwick, NSW, Australia.,School of Women's and Children's Health, UNSW Medicine and Health, University of New South Wales, NSW, Australia.,NHMRC Australian Centre for Cannabinoid Clinical and Research Excellence, University of Newcastle, NSW, Australia
| | - Rebecca Gordon
- NHMRC Australian Centre for Cannabinoid Clinical and Research Excellence, University of Newcastle, NSW, Australia.,Centre for Drug Repurposing and Medicines Research, School of Medicine & Public Health, The University of Newcastle, Callaghan, NSW, 2308, Australia.,Hunter Medical Research Institute, New Lambton Heights 2305, Australia
| | - Peter Galettis
- NHMRC Australian Centre for Cannabinoid Clinical and Research Excellence, University of Newcastle, NSW, Australia.,Centre for Drug Repurposing and Medicines Research, School of Medicine & Public Health, The University of Newcastle, Callaghan, NSW, 2308, Australia.,Hunter Medical Research Institute, New Lambton Heights 2305, Australia
| | - Jennifer H Martin
- NHMRC Australian Centre for Cannabinoid Clinical and Research Excellence, University of Newcastle, NSW, Australia.,Centre for Drug Repurposing and Medicines Research, School of Medicine & Public Health, The University of Newcastle, Callaghan, NSW, 2308, Australia.,Hunter Medical Research Institute, New Lambton Heights 2305, Australia
| | - John A Lawson
- Department of Neurology, Sydney Children's Hospital Randwick, NSW, Australia.,School of Women's and Children's Health, UNSW Medicine and Health, University of New South Wales, NSW, Australia.,NHMRC Australian Centre for Cannabinoid Clinical and Research Excellence, University of Newcastle, NSW, Australia
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5
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Akol I, Gather F, Vogel T. Paving Therapeutic Avenues for FOXG1 Syndrome: Untangling Genotypes and Phenotypes from a Molecular Perspective. Int J Mol Sci 2022; 23:ijms23020954. [PMID: 35055139 PMCID: PMC8780739 DOI: 10.3390/ijms23020954] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2021] [Revised: 12/23/2021] [Accepted: 01/13/2022] [Indexed: 02/01/2023] Open
Abstract
Development of the central nervous system (CNS) depends on accurate spatiotemporal control of signaling pathways and transcriptional programs. Forkhead Box G1 (FOXG1) is one of the master regulators that play fundamental roles in forebrain development; from the timing of neurogenesis, to the patterning of the cerebral cortex. Mutations in the FOXG1 gene cause a rare neurodevelopmental disorder called FOXG1 syndrome, also known as congenital form of Rett syndrome. Patients presenting with FOXG1 syndrome manifest a spectrum of phenotypes, ranging from severe cognitive dysfunction and microcephaly to social withdrawal and communication deficits, with varying severities. To develop and improve therapeutic interventions, there has been considerable progress towards unravelling the multi-faceted functions of FOXG1 in the neurodevelopment and pathogenesis of FOXG1 syndrome. Moreover, recent advances in genome editing and stem cell technologies, as well as the increased yield of information from high throughput omics, have opened promising and important new avenues in FOXG1 research. In this review, we provide a summary of the clinical features and emerging molecular mechanisms underlying FOXG1 syndrome, and explore disease-modelling approaches in animals and human-based systems, to highlight the prospects of research and possible clinical interventions.
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Affiliation(s)
- Ipek Akol
- Department of Molecular Embryology, Institute for Anatomy and Cell Biology, Medical Faculty, University of Freiburg, 79104 Freiburg, Germany; (I.A.); (F.G.)
- Faculty of Biology, University of Freiburg, 79104 Freiburg, Germany
- Center for Basics in NeuroModulation (NeuroModul Basics), Medical Faculty, Albert-Ludwigs-University Freiburg, 79104 Freiburg, Germany
| | - Fabian Gather
- Department of Molecular Embryology, Institute for Anatomy and Cell Biology, Medical Faculty, University of Freiburg, 79104 Freiburg, Germany; (I.A.); (F.G.)
| | - Tanja Vogel
- Department of Molecular Embryology, Institute for Anatomy and Cell Biology, Medical Faculty, University of Freiburg, 79104 Freiburg, Germany; (I.A.); (F.G.)
- Center for Basics in NeuroModulation (NeuroModul Basics), Medical Faculty, Albert-Ludwigs-University Freiburg, 79104 Freiburg, Germany
- Correspondence:
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Samarasinghe RA, Miranda OA, Buth JE, Mitchell S, Ferando I, Watanabe M, Allison TF, Kurdian A, Fotion NN, Gandal MJ, Golshani P, Plath K, Lowry WE, Parent JM, Mody I, Novitch BG. Identification of neural oscillations and epileptiform changes in human brain organoids. Nat Neurosci 2021; 24:1488-1500. [PMID: 34426698 PMCID: PMC9070733 DOI: 10.1038/s41593-021-00906-5] [Citation(s) in RCA: 90] [Impact Index Per Article: 30.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 07/08/2021] [Indexed: 02/06/2023]
Abstract
Brain organoids represent a powerful tool for studying human neurological diseases, particularly those that affect brain growth and structure. However, many diseases manifest with clear evidence of physiological and network abnormality in the absence of anatomical changes, raising the question of whether organoids possess sufficient neural network complexity to model these conditions. Here, we explore the network-level functions of brain organoids using calcium sensor imaging and extracellular recording approaches that together reveal the existence of complex network dynamics reminiscent of intact brain preparations. We demonstrate highly abnormal and epileptiform-like activity in organoids derived from induced pluripotent stem cells from individuals with Rett syndrome, accompanied by transcriptomic differences revealed by single-cell analyses. We also rescue key physiological activities with an unconventional neuroregulatory drug, pifithrin-α. Together, these findings provide an essential foundation for the utilization of brain organoids to study intact and disordered human brain network formation and illustrate their utility in therapeutic discovery.
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Affiliation(s)
- Ranmal A. Samarasinghe
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA,Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA,Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, California, USA,Intellectual Development and Disabilities Research Center, David Geffen School of Medicine at UCLA, Los Angeles, California USA
| | - Osvaldo A. Miranda
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA,Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, California, USA,Intellectual Development and Disabilities Research Center, David Geffen School of Medicine at UCLA, Los Angeles, California USA
| | - Jessie E. Buth
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA,Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, California, USA,Intellectual Development and Disabilities Research Center, David Geffen School of Medicine at UCLA, Los Angeles, California USA
| | - Simon Mitchell
- Institute for Quantitative and Computational Biosciences, Department of Microbiology, Immunology, and Molecular Genetics, University of California, Los Angeles, California, USA,Brighton and Sussex Medical School, Falmer, United Kingdom
| | - Isabella Ferando
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Momoko Watanabe
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA,Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, California, USA,Intellectual Development and Disabilities Research Center, David Geffen School of Medicine at UCLA, Los Angeles, California USA
| | - Thomas F. Allison
- Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, California, USA,Department of Biological Chemistry, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Arinnae Kurdian
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA,Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, California, USA,Intellectual Development and Disabilities Research Center, David Geffen School of Medicine at UCLA, Los Angeles, California USA,California State University, Northridge, Northridge, California USA
| | - Namie N. Fotion
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA,Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, California, USA,Intellectual Development and Disabilities Research Center, David Geffen School of Medicine at UCLA, Los Angeles, California USA
| | - Michael J. Gandal
- Intellectual Development and Disabilities Research Center, David Geffen School of Medicine at UCLA, Los Angeles, California USA,Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Peyman Golshani
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA,Intellectual Development and Disabilities Research Center, David Geffen School of Medicine at UCLA, Los Angeles, California USA,Semel Institute for Neuroscience and Human Behavior, University of California, Los Angeles, Los Angeles, California, USA,West Los Angeles VA Medical Center, Los Angeles, California, USA
| | - Kathrin Plath
- Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, California, USA,Department of Biological Chemistry, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - William E. Lowry
- Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, California, USA,Department of Molecular, Cell, and Developmental Biology, University of California, Los Angeles, Los Angeles, California, USA
| | - Jack M. Parent
- Department of Neurology, University of Michigan Medical School, Ann Arbor, MI, USA,Michigan Neuroscience Institute, University of Michigan, Ann Arbor, MI, USA,Ann Arbor VA Healthcare System, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Istvan Mody
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA,Department of Physiology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA
| | - Bennett G. Novitch
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, California, USA,Eli and Edythe Broad Center for Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, California, USA,Intellectual Development and Disabilities Research Center, David Geffen School of Medicine at UCLA, Los Angeles, California USA,Corresponding author. (B.G.N.)
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7
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MECP2-Related Disorders and Epilepsy Phenotypes. JOURNAL OF PEDIATRIC NEUROLOGY 2021. [DOI: 10.1055/s-0041-1728643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Abstract
MECP2 (methyl-CpG binding protein-2) gene, located on chromosome Xq28, encodes for a protein particularly abundant in the brain that is required for maturation of astrocytes and neurons and is developmentally regulated. A defective homeostasis of MECP2 expression, either by haploinsufficiency or overexpression, leads to a neurodevelopmental phenotype. As MECP2 is located on chromosome X, the clinical presentation varies in males and females ranging from mild learning disabilities to severe encephalopathies and early death. Typical Rett syndrome (RTT), the most frequent phenotype associated with MECP2 mutations, primarily affects girls and it was previously thought to be lethal in males; however, MECP2 duplication syndrome, resulting from a duplication of the Xq28 region including MECP2, leads to a severe neurodevelopmental disorder in males. RTT and MECP2 duplication syndrome share overlapping clinical phenotypes including intellectual disabilities, motor deficits, hypotonia, progressive spasticity, and epilepsy. In this manuscript we reviewed literature on epilepsy related to MECP2 disorders, focusing on clinical presentation, genotype–phenotype correlation, and treatment.
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8
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Lee HM, Kuijer MB, Ruiz Blanes N, Clark EP, Aita M, Galiano Arjona L, Kokot A, Sciaky N, Simon JM, Bhatnagar S, Philpot BD, Cerase A. A small-molecule screen reveals novel modulators of MeCP2 and X-chromosome inactivation maintenance. J Neurodev Disord 2020; 12:29. [PMID: 33172406 PMCID: PMC7657357 DOI: 10.1186/s11689-020-09332-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 10/22/2020] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND Rett syndrome (RTT) is a neurodevelopmental disorder caused by mutations in the X-linked methyl-CpG binding protein 2 (MeCP2) gene. While MeCP2 mutations are lethal in most males, females survive birth but show severe neurological defects. Because X-chromosome inactivation (XCI) is a random process, approximately 50% of the cells silence the wild-type (WT) copy of the MeCP2 gene. Thus, reactivating the silent WT copy of MeCP2 could provide therapeutic intervention for RTT. METHODS Toward this goal, we screened ~ 28,000 small-molecule compounds from several libraries using a MeCP2-luciferase reporter cell line and cortical neurons from a MeCP2-EGFP mouse model. We used gain/increase of luminescence or fluorescence as a readout of MeCP2 reactivation and tested the efficacy of these drugs under different drug regimens, conditions, and cellular contexts. RESULTS We identified inhibitors of the JAK/STAT pathway as XCI-reactivating agents, both by in vitro and ex vivo assays. In particular, we show that AG-490, a Janus Kinase 2 (JAK2) kinase inhibitor, and Jaki, a pan JAK/STAT inhibitor, are capable of reactivating MeCP2 from the inactive X chromosome, in different cellular contexts. CONCLUSIONS Our results suggest that inhibition of the JAK/STAT pathway is a new potential pathway to reinstate MeCP2 gene expression as an efficient RTT treatment.
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Affiliation(s)
- Hyeong-Min Lee
- Department of Cell Biology & Physiology, University of North Carolina School of Medicine, Chapel Hill, NC, USA
- UNC Neuroscience Center, Carolina Institute for Developmental Disabilities, University of North Carolina School of Medicine, Chapel Hill, NC, USA
- Current Address: High-Throughput Bioscience Center, Chemical Biology & Therapeutics, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - M Bram Kuijer
- Department of Cell Biology & Physiology, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | | | - Ellen P Clark
- Department of Cell Biology & Physiology, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Megumi Aita
- Department of Cell Biology & Physiology, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | | | - Agnieszka Kokot
- Department of Biochemistry and Molecular Genetics, Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Noah Sciaky
- Department of Pharmacology, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Jeremy M Simon
- UNC Neuroscience Center, Carolina Institute for Developmental Disabilities, University of North Carolina School of Medicine, Chapel Hill, NC, USA
- Department of Genetics, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Sanchita Bhatnagar
- Department of Biochemistry and Molecular Genetics, Department of Neuroscience, University of Virginia School of Medicine, Charlottesville, VA, USA
| | - Benjamin D Philpot
- Department of Cell Biology & Physiology, University of North Carolina School of Medicine, Chapel Hill, NC, USA
- UNC Neuroscience Center, Carolina Institute for Developmental Disabilities, University of North Carolina School of Medicine, Chapel Hill, NC, USA
| | - Andrea Cerase
- Blizard Institute, Queen Mary University of London, London, UK.
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9
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Gomathi M, Padmapriya S, Balachandar V. Drug Studies on Rett Syndrome: From Bench to Bedside. J Autism Dev Disord 2020; 50:2740-2764. [PMID: 32016693 DOI: 10.1007/s10803-020-04381-y] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Drug studies on Rett syndrome (RTT) have drastically increased over the past few decades. This review aims to provide master data on bench-to-bedside drug studies involving RTT. A comprehensive literature review was performed by searching in PUBMED, MEDLINE and Google Scholar, international, national and regional clinical trial registries and pharmaceutical companies using the keywords "Rett syndrome treatment and/or drug or compound or molecule". Seventy drugs were investigated in non-clinical (N = 65 animal/cell line-based studies; N = 5 iPSC-based study) and clinical trials (N = 34) for ameliorating the symptoms of RTT. Though there is good progress in both clinical and non-clinical studies, none of these drugs entered phase III/IV for being launched as a therapeutic agent for RTT.
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Affiliation(s)
- Mohan Gomathi
- Human Molecular Genetics and Stem Cell Laboratory, Department of Human Genetics and Molecular Biology, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India
| | | | - Vellingiri Balachandar
- Human Molecular Genetics and Stem Cell Laboratory, Department of Human Genetics and Molecular Biology, Bharathiar University, Coimbatore, Tamil Nadu, 641046, India.
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10
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Peron A, Canevini MP, Ghelma F, Arancio R, Savini MN, Vignoli A. Phenotypes in adult patients with Rett syndrome: results of a 13-year experience and insights into healthcare transition. J Med Genet 2020; 59:39-45. [PMID: 33106377 PMCID: PMC8685662 DOI: 10.1136/jmedgenet-2020-107333] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2020] [Revised: 09/21/2020] [Accepted: 09/29/2020] [Indexed: 11/04/2022]
Abstract
BACKGROUND Rett syndrome is a complex genetic disorder with age-specific manifestations and over half of the patients surviving into middle age. However, little information about the phenotype of adult individuals with Rett syndrome is available, and mainly relies on questionnaires completed by caregivers. Here, we assess the clinical manifestations and management of adult patients with Rett syndrome and present our experience in transitioning from the paediatric to the adult clinic. METHODS We analysed the medical records and molecular data of women aged ≥18 years with a diagnosis of classic Rett syndrome and/or pathogenic variants in MECP2, CDKL5 and FOXG1, who were in charge of our clinic. RESULTS Of the 50 women with classic Rett syndrome, 94% had epilepsy (26% drug-resistant), 20% showed extrapyramidal signs, 40% sleep problems and 36% behavioural disorders. Eighty-six % patients exhibited gastrointestinal problems; 70% had scoliosis and 90% low bone density. Breathing irregularities were diagnosed in 60%. None of the patients had cardiac issues. CDKL5 patients experienced fewer breathing abnormalities than women with classic Rett syndrome. CONCLUSION The delineation of an adult phenotype in Rett syndrome demonstrates the importance of a transitional programme and the need of a dedicated multidisciplinary team to optimise the clinical management of these patients.
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Affiliation(s)
- Angela Peron
- Department of Health Sciences, Università degli Studi di Milano, Milano, Lombardia, Italy .,Division of Medical Genetics, Department of Pediatrics, University of Utah, Salt Lake City, Utah, USA.,Child Neuropsychiatry Unit - Epilepsy Center, San Paolo Hospital, Milan, Italy
| | - Maria Paola Canevini
- Department of Health Sciences, Università degli Studi di Milano, Milano, Lombardia, Italy.,Child Neuropsychiatry Unit - Epilepsy Center, San Paolo Hospital, Milan, Italy
| | - Filippo Ghelma
- Department of Health Sciences, Università degli Studi di Milano, Milano, Lombardia, Italy.,Disabled Advanced Medical Assistance (DAMA), San Paolo Hospital, Milan, Italy
| | | | - Miriam Nella Savini
- Child Neuropsychiatry Unit - Epilepsy Center, San Paolo Hospital, Milan, Italy
| | - Aglaia Vignoli
- Department of Health Sciences, Università degli Studi di Milano, Milano, Lombardia, Italy.,Child Neuropsychiatry Unit - Epilepsy Center, San Paolo Hospital, Milan, Italy
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11
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Sandweiss AJ, Brandt VL, Zoghbi HY. Advances in understanding of Rett syndrome and MECP2 duplication syndrome: prospects for future therapies. Lancet Neurol 2020; 19:689-698. [PMID: 32702338 DOI: 10.1016/s1474-4422(20)30217-9] [Citation(s) in RCA: 85] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2019] [Revised: 05/07/2020] [Accepted: 05/12/2020] [Indexed: 01/07/2023]
Abstract
The X-linked gene encoding MECP2 is involved in two severe and complex neurodevelopmental disorders. Loss of function of the MeCP2 protein underlies Rett syndrome, whereas duplications of the MECP2 locus cause MECP2 duplication syndrome. Research on the mechanisms by which MeCP2 exerts effects on gene expression in neurons, studies of animal models bearing different disease-causing mutations, and more in-depth observations of clinical presentations have clarified some issues even as they have raised further questions. Yet there is enough evidence so far to suggest possible approaches to therapy for these two diseases that could go beyond attempting to address specific signs and symptoms (of which there are many) and instead target the pathophysiology underlying MECP2 disorders. Further work could bring antisense oligonucleotides, deep brain stimulation, and gene therapy into the clinic within the next decade or so.
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Affiliation(s)
- Alexander J Sandweiss
- Department of Pediatrics, Section of Neurology and Developmental Neurosciences, Baylor College of Medicine, Houston, TX, USA; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX, USA
| | - Vicky L Brandt
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX, USA
| | - Huda Y Zoghbi
- Department of Pediatrics, Section of Neurology and Developmental Neurosciences, Baylor College of Medicine, Houston, TX, USA; Howard Hughes Medical Institute, and Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX, USA.
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12
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Pari E, Cozzi F, Rodocanachi Roidi ML, Grange F, Toshimori K, Ripamonti E. Parenting girls with Rett syndrome: An investigation on self-perceived levels of stress. JOURNAL OF APPLIED RESEARCH IN INTELLECTUAL DISABILITIES 2020; 33:1348-1356. [PMID: 32573922 DOI: 10.1111/jar.12755] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2019] [Revised: 04/14/2020] [Accepted: 05/06/2020] [Indexed: 11/30/2022]
Abstract
BACKGROUND Although lives of parents of girls with Rett syndrome (RTT) are centred on the process of care, in the current literature their perceived levels of stress have been rarely investigated. METHODS We analysed levels of stress in a sample of 79 fathers and mothers parenting girls with RTT, who were required to compile the Parenting Stress Index (PSI) questionnaire. RESULTS We found clinical levels of stress in about 39% of fathers, as compared with 44% of the mothers. Severity of RTT, but not other factors such as the genetic domain, presence of epilepsy or scoliosis, predicted Total Stress scores in both fathers' subsample and mothers' subsample. A cumulative effect of caring, that is association of higher levels of stress with longer process of care, did also emerge from estimation of smoothing splines. CONCLUSIONS Fathers' resources should be taken more into account, especially in the rehabilitation and socialization process of adults with RTT.
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Affiliation(s)
- Elisa Pari
- IRCCS Fondazione Don Carlo Gnocchi, Milano, Italy
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13
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Kadam SD, Sullivan BJ, Goyal A, Blue ME, Smith-Hicks C. Rett Syndrome and CDKL5 Deficiency Disorder: From Bench to Clinic. Int J Mol Sci 2019; 20:ijms20205098. [PMID: 31618813 PMCID: PMC6834180 DOI: 10.3390/ijms20205098] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2019] [Revised: 10/08/2019] [Accepted: 10/11/2019] [Indexed: 12/18/2022] Open
Abstract
Rett syndrome (RTT) and CDKL5 deficiency disorder (CDD) are two rare X-linked developmental brain disorders with overlapping but distinct phenotypic features. This review examines the impact of loss of methyl-CpG-binding protein 2 (MeCP2) and cyclin-dependent kinase-like 5 (CDKL5) on clinical phenotype, deficits in synaptic- and circuit-homeostatic mechanisms, seizures, and sleep. In particular, we compare the overlapping and contrasting features between RTT and CDD in clinic and in preclinical studies. Finally, we discuss lessons learned from recent clinical trials while reviewing the findings from pre-clinical studies.
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Affiliation(s)
- Shilpa D Kadam
- The Hugo Moser Research Institute at Kennedy Krieger, Baltimore, MD 21205, USA.
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| | - Brennan J Sullivan
- The Hugo Moser Research Institute at Kennedy Krieger, Baltimore, MD 21205, USA.
| | - Archita Goyal
- The Hugo Moser Research Institute at Kennedy Krieger, Baltimore, MD 21205, USA.
| | - Mary E Blue
- The Hugo Moser Research Institute at Kennedy Krieger, Baltimore, MD 21205, USA.
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
| | - Constance Smith-Hicks
- The Hugo Moser Research Institute at Kennedy Krieger, Baltimore, MD 21205, USA.
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
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14
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Rett Syndrome and Other Neurodevelopmental Disorders Share Common Changes in Gut Microbial Community: A Descriptive Review. Int J Mol Sci 2019; 20:ijms20174160. [PMID: 31454888 PMCID: PMC6747313 DOI: 10.3390/ijms20174160] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Revised: 08/23/2019] [Accepted: 08/24/2019] [Indexed: 12/12/2022] Open
Abstract
In this narrative review, we summarize recent pieces of evidence of the role of microbiota alterations in Rett syndrome (RTT). Neurological problems are prominent features of the syndrome, but the pathogenic mechanisms modulating its severity are still poorly understood. Gut microbiota was recently demonstrated to be altered both in animal models and humans with different neurodevelopmental disorders and/or epilepsy. By investigating gut microbiota in RTT cohorts, a less rich microbial community was identified which was associated with alterations of fecal microbial short-chain fatty acids. These changes were positively correlated with severe clinical outcomes. Indeed, microbial metabolites can play a crucial role both locally and systemically, having dynamic effects on host metabolism and gene expression in many organs. Similar alterations were found in patients with autism and down syndrome as well, suggesting a potential common pathway of gut microbiota involvement in neurodevelopmental disorders.
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15
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Sun Y, Gao Y, Tidei JJ, Shen M, Hoang JT, Wagner DF, Zhao X. Loss of MeCP2 in immature neurons leads to impaired network integration. Hum Mol Genet 2019; 28:245-257. [PMID: 30277526 DOI: 10.1093/hmg/ddy338] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2018] [Accepted: 09/18/2018] [Indexed: 12/12/2022] Open
Abstract
Rett syndrome (RTT) is a neurodevelopmental disorder caused by mutations or deletions in Methyl-CpG-binding Protein 2 (MeCP2), a brain-enriched transcriptional regulator. MeCP2 is highly expressed during neuronal maturation and its deficiency results in impaired dendritic morphogenesis and reduced dendritic spine numbers in developing neurons. However, whether MeCP2 deficiency impacts the integration of new neurons has not been directly assessed. In this study, we developed a modified rabies virus-mediated monosynaptic retrograde tracing method to interrogate presynaptic integration of MeCP2-deficient new neurons born in the adult hippocampus, a region with lifelong neurogenesis and plasticity. We found that selective deletion of MeCP2 in adult-born new neurons impaired their long-range connectivity to the cortex, whereas their connectivity within the local hippocampal circuits or with subcortical regions was not significantly affected. We further showed that knockdown of MeCP2 in primary hippocampal neurons also resulted in reduced network integration. Interestingly, (1-3) insulin-like growth factor-1 (IGF-1), a small peptide under clinical trial testing for RTT, rescued neuronal integration deficits of MeCP2-deficient neurons in vitro but not in vivo. In addition, (1-3) IGF-1 treatment corrected aberrant excitability and network synchrony of MeCP2-deficient hippocampal neurons. Our results indicate that MeCP2 is essential for immature neurons to establish appropriate network connectivity.
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Affiliation(s)
- Yi Sun
- National Key Research Laboratory of Natural and Biomimetic Drugs.,Department of Molecular and Cellular Pharmacology, School of Pharmaceutical Sciences, Peking University, Beijing, PR China.,Waisman Center
| | - Yu Gao
- Waisman Center.,Department of Neuroscience
| | | | | | | | | | - Xinyu Zhao
- Waisman Center.,Department of Neuroscience.,Cellular and Molecular Biology Program, University of Wisconsin-Madison, Madison, WI, USA
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16
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Rodocanachi Roidi ML, Grange F, Cozzi F, Pari E, Toshimori K, Ripamonti E. Parents' perception of health care services for girls with Rett syndrome. Child Care Health Dev 2019; 45:417-422. [PMID: 30870585 DOI: 10.1111/cch.12660] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/27/2018] [Revised: 03/09/2019] [Accepted: 03/09/2019] [Indexed: 11/27/2022]
Abstract
BACKGROUND Rett syndrome (RTT) is a severe neurodevelopmental disorder, implying impairment and disability across several domains. METHOD We investigated parents' perception of the caregiving process in a sample of 55 mothers and fathers of girls with RTT using the MPOC-20 questionnaire. The association of parents' satisfaction with clinical variables has also been explored. RESULTS We obtained intermediate levels of satisfaction on the MPOC-20 Coordinated and Comprehensive Care and Respectful and Supportive Care scales. The performance was lower on the scales Providing General Information and Providing Specific Information. Mothers' assessment was not associated with clinical variables such as walking disability, presence of scoliosis, or epilepsy. For children with greater degree of walking impairment, fathers expressed the need of having more information available. CONCLUSIONS Although parents seemed satisfied of the caregiving process, clinicians should put more emphasis on their need of receiving general and specific information on RTT along the entire rehabilitation program.
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Affiliation(s)
| | | | | | - Elisa Pari
- IRCCS Fondazione Don Carlo Gnocchi, Milano, Italy
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17
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Mele M, Costa RO, Duarte CB. Alterations in GABA A-Receptor Trafficking and Synaptic Dysfunction in Brain Disorders. Front Cell Neurosci 2019; 13:77. [PMID: 30899215 PMCID: PMC6416223 DOI: 10.3389/fncel.2019.00077] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Accepted: 02/15/2019] [Indexed: 12/12/2022] Open
Abstract
GABAA receptors (GABAAR) are the major players in fast inhibitory neurotransmission in the central nervous system (CNS). Regulation of GABAAR trafficking and the control of their surface expression play important roles in the modulation of the strength of synaptic inhibition. Different pieces of evidence show that alterations in the surface distribution of GABAAR and dysregulation of their turnover impair the activity of inhibitory synapses. A diminished efficacy of inhibitory neurotransmission affects the excitatory/inhibitory balance and is a common feature of various disorders of the CNS characterized by an increased excitability of neuronal networks. The synaptic pool of GABAAR is mainly controlled through regulation of internalization, recycling and lateral diffusion of the receptors. Under physiological condition these mechanisms are finely coordinated to define the strength of GABAergic synapses. In this review article, we focus on the alteration in GABAAR trafficking with an impact on the function of inhibitory synapses in various disorders of the CNS. In particular we discuss how similar molecular mechanisms affecting the synaptic distribution of GABAAR and consequently the excitatory/inhibitory balance may be associated with a wide diversity of pathologies of the CNS, from psychiatric disorders to acute alterations leading to neuronal death. A better understanding of the cellular and molecular mechanisms that contribute to the impairment of GABAergic neurotransmission in these disorders, in particular the alterations in GABAAR trafficking and surface distribution, may lead to the identification of new pharmacological targets and to the development of novel therapeutic strategies.
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Affiliation(s)
- Miranda Mele
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
| | - Rui O Costa
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Institute for Interdisciplinary Research, University of Coimbra, Coimbra, Portugal
| | - Carlos B Duarte
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.,Department of Life Sciences, University of Coimbra, Coimbra, Portugal
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18
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Persico AM, Ricciardello A, Cucinotta F. The psychopharmacology of autism spectrum disorder and Rett syndrome. HANDBOOK OF CLINICAL NEUROLOGY 2019; 165:391-414. [DOI: 10.1016/b978-0-444-64012-3.00024-1] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
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19
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Ali Rodriguez R, Joya C, Hines RM. Common Ribs of Inhibitory Synaptic Dysfunction in the Umbrella of Neurodevelopmental Disorders. Front Mol Neurosci 2018; 11:132. [PMID: 29740280 PMCID: PMC5928253 DOI: 10.3389/fnmol.2018.00132] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Accepted: 04/03/2018] [Indexed: 01/06/2023] Open
Abstract
The term neurodevelopmental disorder (NDD) is an umbrella term used to group together a heterogeneous class of disorders characterized by disruption in cognition, emotion, and behavior, early in the developmental timescale. These disorders are heterogeneous, yet they share common behavioral symptomatology as well as overlapping genetic contributors, including proteins involved in the formation, specialization, and function of synaptic connections. Advances may arise from bridging the current knowledge on synapse related factors indicated from both human studies in NDD populations, and in animal models. Mounting evidence has shown a link to inhibitory synapse formation, specialization, and function among Autism, Angelman, Rett and Dravet syndromes. Inhibitory signaling is diverse, with numerous subtypes of inhibitory interneurons, phasic and tonic modes of inhibition, and the molecular and subcellular diversity of GABAA receptors. We discuss common ribs of inhibitory synapse dysfunction in the umbrella of NDD, highlighting alterations in the developmental switch to inhibitory GABA, dysregulation of neuronal activity patterns by parvalbumin-positive interneurons, and impaired tonic inhibition. Increasing our basic understanding of inhibitory synapses, and their role in NDDs is likely to produce significant therapeutic advances in behavioral symptom alleviation for interrelated NDDs.
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Affiliation(s)
- Rachel Ali Rodriguez
- Neuroscience Emphasis, Department of Psychology, University of Nevada, Las Vegas, Las Vegas, NV, United States
| | - Christina Joya
- Neuroscience Emphasis, Department of Psychology, University of Nevada, Las Vegas, Las Vegas, NV, United States
| | - Rochelle M Hines
- Neuroscience Emphasis, Department of Psychology, University of Nevada, Las Vegas, Las Vegas, NV, United States
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20
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Ho KS, Markham LM, Twede H, Lortz A, Olson LM, Sheng X, Weng C, Wassman ER, Newcomb T, Wassman ER, Carey JC, Battaglia A. A survey of antiepileptic drug responses identifies drugs with potential efficacy for seizure control in Wolf-Hirschhorn syndrome. Epilepsy Behav 2018; 81:55-61. [PMID: 29477837 DOI: 10.1016/j.yebeh.2017.12.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Revised: 12/11/2017] [Accepted: 12/11/2017] [Indexed: 12/19/2022]
Abstract
Seizures are present in over 90% of infants and children with Wolf-Hirschhorn syndrome (WHS). When present, they significantly affect quality of life. The goal of this study was to use caregiver reports to describe the comparative efficacies of commonly used antiepileptic medications in a large population of individuals with WHS. A web-based, confidential caregiver survey was developed to capture seizure semiology and a chronologic record of seizure treatments as well as responses to each treatment. Adverse events for each drug were also cataloged. We received 141 complete survey responses (47% response rate) describing the seizures of individuals ranging in age from 4months to 61years (90 females: 51 males). Using the Early Childhood Epilepsy Severity Scale (E-Chess), WHS-associated seizures are demonstrably severe regardless of deletion size. The best-performing antiepileptic drugs (AEDs) for controlling seizures in this cohort were broad spectrum drugs clobazam, levetiracetam, and lamotrigine; whereas, the three commonly used carboxamide class drugs: carbamazepine, phenytoin, and oxcarbazepine, were reported to have little effect on, or even exacerbate, seizures. The carboxamide class drugs, along with phenobarbital and topiramate, were also associated with the highest rate of intolerance due to cooccurrence of adverse events. Levetiracetam, clobazam, and clonazepam demonstrated higher tolerability and comparatively less severe adverse events (Wilcoxon rank sum comparison between performance of levetiracetam and carboxamide class drugs gives a p<0.0001 after multiple comparison adjustment). This is the largest survey to date assessing WHS seizures. This study design is susceptible to possible bias, as the data are largely drawn from caregiver report and investigators had limited access to medical records. Despite this, our data suggest that the genetic etiology of seizures, together with an accurate electroclinical delineation, are important components of drug selection, even in contiguous gene syndromes which may have complex seizure etiologies.
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Affiliation(s)
- Karen S Ho
- Lineagen, Inc., 2677 Parleys Way, Salt Lake City, UT 84109, United States; Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT, United States.
| | - Leah M Markham
- Lineagen, Inc., 2677 Parleys Way, Salt Lake City, UT 84109, United States.
| | - Hope Twede
- Lineagen, Inc., 2677 Parleys Way, Salt Lake City, UT 84109, United States.
| | - Amanda Lortz
- 4p- Support Group, 1495 Forest Brooke Way, #262, Delaware, OH 43015, United States.
| | - Lenora M Olson
- Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT, United States.
| | - Xiaoming Sheng
- Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT, United States.
| | - Cindy Weng
- Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT, United States.
| | | | - Tara Newcomb
- Department of Neurology, University of Utah School of Medicine, 175 N Medical Dr, Salt Lake City, UT 84132, United States.
| | - E Robert Wassman
- Lineagen, Inc., 2677 Parleys Way, Salt Lake City, UT 84109, United States.
| | - John C Carey
- Department of Pediatrics, University of Utah School of Medicine, Salt Lake City, UT, United States.
| | - Agatino Battaglia
- Stella Maris Clinical Research Institute for Child and Adolescent Neuropsychiatry, Pisa, Italy.
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21
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Wither RG, Colic S, Bardakjian BL, Snead OC, Zhang L, Eubanks JH. Electrographic and pharmacological characterization of a progressive epilepsy phenotype in female MeCP2-deficient mice. Epilepsy Res 2018; 140:177-183. [PMID: 29414525 DOI: 10.1016/j.eplepsyres.2018.01.015] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 01/05/2018] [Accepted: 01/11/2018] [Indexed: 11/27/2022]
Abstract
Rett Syndrome is a neurodevelopmental disorder caused primarily by mutations in the gene encoding Methyl-CpG-binding protein 2 (MECP2). Spontaneous epileptiform activity is a common co-morbidity present in Rett syndrome, and hyper-excitable neural networks are present in MeCP2-deficient mouse models of Rett syndrome. In this study we conducted a longitudinal assessment of spontaneous cortical electrographic discharges in female MeCP2-deficient mice and defined the pharmacological responsiveness of these discharges to anti-convulsant drugs. Our data show that cortical discharge activity in female MeCP2-deficient mice progressively increases in severity as the mice age, with discharges being more frequent and of longer durations at 19-24 months of age compared to 3 months of age. Semiologically and pharmacologically, this basal discharge activity in female MeCP2-deficient mice displayed electroclinical properties consistent with absence epilepsy. Only rarely were convulsive seizures observed in these mice at any age. Since absence epilepsy is infrequently observed in Rett syndrome patients, these results indicate that the predominant spontaneous electroclinical phenotype of MeCP2-deficient mice we examined does not faithfully recapitulate the most prevalent seizure types observed in affected patients.
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Affiliation(s)
- Robert G Wither
- Division of Genetics and Development, Krembil Research Institute, University Health Network, 399 Bathurst Street, Toronto, Ontario, M5T 2S8, Canada; Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Sinisa Colic
- Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Berj L Bardakjian
- University of Toronto Epilepsy Research Program, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Department of Electrical and Computer Engineering, University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - O Carter Snead
- Department of Medicine (Neurology), University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - Liang Zhang
- Division of Fundamental Neurobiology, Krembil Research Institute, University Health Network, 399 Bathurst Street, Toronto, Ontario, M5T 2S8, Canada; University of Toronto Epilepsy Research Program, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Department of Medicine (Neurology), University of Toronto, Toronto, Ontario M5S 1A8, Canada
| | - James H Eubanks
- Division of Genetics and Development, Krembil Research Institute, University Health Network, 399 Bathurst Street, Toronto, Ontario, M5T 2S8, Canada; University of Toronto Epilepsy Research Program, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Department of Physiology, University of Toronto, Toronto, Ontario M5S 1A8, Canada; Department of Surgery (Neurosurgery), University of Toronto, Toronto, Ontario M5S 1A8, Canada.
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