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Percy AK, Ananth A, Neul JL. Rett Syndrome: The Emerging Landscape of Treatment Strategies. CNS Drugs 2024:10.1007/s40263-024-01106-y. [PMID: 39251501 DOI: 10.1007/s40263-024-01106-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/27/2024] [Indexed: 09/11/2024]
Abstract
Rett syndrome (RTT) has enjoyed remarkable progress in achieving specific therapies. RTT, a unique neurodevelopmental disorder first described in 1966, progressed slowly until the landmark paper of Hagberg and colleagues in 1983. Thereafter, rapid advances were achieved including the development of specific diagnostic criteria and the active search for a genetic etiology, resulting 16 years later in identification of variants in the methyl-CpG-binding protein (MECP2) gene located at Xq28. Shortly thereafter, the NIH Office of Rare Diseases funded the RTT Natural History Study (NHS) in 2003, initiating the acquisition of natural history data on clinical features from a large population of individuals with RTT. This information was essential for advancement of clinical trials to provide specific therapies for this disorder. In the process, the International Rett Syndrome Association (IRSA) was formed (now the International Rett Syndrome Foundation-IRSF), which participated directly in encouraging and expanding enrollment in the NHS and, subsequently, in developing the SCOUT program to facilitate testing of potential therapeutic agents in a mouse model of RTT. The overall objective was to review clinical characteristics developed from the NHS and to discuss the status of specific therapies for this progressive neurodevelopmental disorder. The NHS study provided critical information on RTT: growth, anthropometrics, longevity, key comorbidities including epilepsy, breath abnormalities, gastroesophageal dysfunction, scoliosis and other orthopedic issues, puberty, behavior and anxiety, and progressive motor deterioration including the appearance of parkinsonian features. Phenotype-genotype correlations were noted including the role of X chromosome inactivation. Development of clinical severity and quality of life measures also proved critical for subsequent clinical trials. Further, development of biochemical and neurophysiologic biomarkers offered further endpoints for clinical trials. Initial clinical trials prior to the NHS were ineffective, but advances resulting from the NHS and other studies worldwide promoted significant interest from pharmaceutical firms resulting in several clinical trials. While some of these have been unrewarding such as sarizotan, others have been quite promising including the approval of trofinetide by the FDA in 2023 as the first agent available for specific treatment of RTT. Blarcamesine has been trialed in phase 3 trials, 14 agents have been studied in phase 2 trials, and 7 agents are being evaluated in preclinical/translational studies. A landmark study in 2007 by Guy et al. demonstrated that activation of a normal MECP2 gene in a null mouse model resulted in significant improvement. Gene replacement therapy has advanced through translational studies to two current phase 1/2 clinical trials (Taysha102 and Neurogene-401). Additional genetic therapies are also under study including gene editing, RNA editing, and X-chromosome reactivation. Taken together, progress in understanding and treating RTT over the past 40 years has been remarkable. This suggests that further advances can be expected.
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Affiliation(s)
- Alan K Percy
- University of Alabama at Birmingham, Lowder Bldg 416, Birmingham, AL, 35233, USA.
| | - Amitha Ananth
- University of Alabama at Birmingham, Lowder Bldg 416, Birmingham, AL, 35233, USA
| | - Jeffrey L Neul
- Vanderbilt University Medical Center, Nashville, TN, USA
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2
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Saldaris JM, Ayalde J, Kankanange S, Keeley J, Leonard H, Jacoby P, Marsh ED, Benke TA, Demarest ST, Downs J. Parent-reported outcome measures evaluating communication in individuals with rare neurodevelopmental disorders: A systematic review. INTERNATIONAL JOURNAL OF LANGUAGE & COMMUNICATION DISORDERS 2024. [PMID: 39141588 DOI: 10.1111/1460-6984.13100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/07/2024] [Accepted: 07/25/2024] [Indexed: 08/16/2024]
Abstract
BACKGROUND Communication impairments are a leading concern for parent caregivers of individuals with rare neurodevelopmental disorders (RNDDs). Clinical trials of disease modifying therapies require valid and responsive outcome measures that are relevant to individuals with RNDDs. Identifying and evaluating current psychometric properties for communication measures is a critical step towards the selection and use of appropriate instruments. AIMS This systematic review offers (1) a description of parent-reported communication measures and (2) evidence for their psychometric properties, in RNDDs. METHODS The systematic review protocol was registered in the International Prospective Register of Systematic Reviews (PROSPERO; CRD42022334649). MEDLINE (Ovid), Embase, PsychINFO, Web of Science, CINAHL Plus, Cochrane Library, ClinicalTrials.gov, the Australian New Zealand Clinical Trials Registry were searched from inception to August 2023. Methodological assessment of quality was completed using the COnsensus-based Standards for the selection of health status Measurement INstruments (COSMIN) checklist. Parent-reported measures used in observational studies and clinical trials were identified. Data on utility, reliability and validity for RNDDs were extracted. MAIN CONTRIBUTION Sixteen parent-reported communication measures were used in RNDD research, the Vineland Adaptive Behavior Scales being most commonly used. Validation data in RNDDs were identified for six of these measures. Limitations related to sample size or the scope of psychometric testing. CONCLUSIONS Many communication measures have been used for RNDDs but there are few data validating their use. Valid and reliable methods of measuring communication in persons with RNDDs is a priority for future high-quality clinical trials. WHAT THIS PAPER ADDS What is already known on the subject Communication is a critical domain for families with a child with a rare neurodevelopmental disorder (RNDD). Validated outcome measures are essential for accurate evaluation and interpretation of responses to treatments in clinical trials. What this paper adds to existing knowledge We identified 16 parent-reported communication measures that have been used with RNDDs, but only six measures had validation data for at least one RNDD. High quality evidence is accumulating, with all validation studies in this review published between 2020 to 2023. Modifications of existing measures may be required to assess communication for RNDDs. What are the clinical implications of this work? This systematic review catalogues the available psychometric data for communication measures and indicates an ongoing need for new validation studies to ensure they are fit-for-purpose for upcoming clinical trials in RNDDs. This review will inform the selection of communication measures for clinical trials and research studies.
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Affiliation(s)
- Jacinta M Saldaris
- Telethon Kids Institute, Nedlands, Western Australia, Australia
- The University of Western Australia, Centre for Child Health Research, Crawley, Western Australia, Australia
| | - Jeremiah Ayalde
- Telethon Kids Institute, Nedlands, Western Australia, Australia
| | | | - Jessica Keeley
- Telethon Kids Institute, Nedlands, Western Australia, Australia
| | - Helen Leonard
- Telethon Kids Institute, Nedlands, Western Australia, Australia
- The University of Western Australia, Centre for Child Health Research, Crawley, Western Australia, Australia
| | - Peter Jacoby
- Telethon Kids Institute, Nedlands, Western Australia, Australia
| | - Eric D Marsh
- Children's Hospital of Philadelphia, Division of Child Neurology, Philadelphia, Pennsylvania, USA
- Departments of Neurology and Pediatrics, University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania, USA
| | - Tim A Benke
- Children's Hospital Colorado, Neurology and Pharmacology, Aurora, Colorado, USA
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Scott T Demarest
- Children's Hospital Colorado, Neurology and Pharmacology, Aurora, Colorado, USA
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, Colorado, USA
| | - Jenny Downs
- Telethon Kids Institute, Nedlands, Western Australia, Australia
- The University of Western Australia, Centre for Child Health Research, Crawley, Western Australia, Australia
- Curtin University, School of Allied Health, Bentley, Western Australia, Australia
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Fuchs C, ‘t Hoen PAC, Müller AR, Ehrhart F, Van Karnebeek CDM. Drug repurposing in Rett and Rett-like syndromes: a promising yet underrated opportunity? Front Med (Lausanne) 2024; 11:1425038. [PMID: 39135718 PMCID: PMC11317438 DOI: 10.3389/fmed.2024.1425038] [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: 04/29/2024] [Accepted: 07/12/2024] [Indexed: 08/15/2024] Open
Abstract
Rett syndrome (RTT) and Rett-like syndromes [i.e., CDKL5 deficiency disorder (CDD) and FOXG1-syndrome] represent rare yet profoundly impactful neurodevelopmental disorders (NDDs). The severity and complexity of symptoms associated with these disorders, including cognitive impairment, motor dysfunction, seizures and other neurological features significantly affect the quality of life of patients and families. Despite ongoing research efforts to identify potential therapeutic targets and develop novel treatments, current therapeutic options remain limited. Here the potential of drug repurposing (DR) as a promising avenue for addressing the unmet medical needs of individuals with RTT and related disorders is explored. Leveraging existing drugs for new therapeutic purposes, DR presents an attractive strategy, particularly suited for neurological disorders given the complexities of the central nervous system (CNS) and the challenges in blood-brain barrier penetration. The current landscape of DR efforts in these syndromes is thoroughly examined, with partiuclar focus on shared molecular pathways and potential common drug targets across these conditions.
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Affiliation(s)
| | - Peter A. C. ‘t Hoen
- Center for Molecular and Biomolecular Informatics, Radboud Institute for Molecular Life Sciences, Radboud University Medical Center, Nijmegen, Netherlands
| | - Annelieke R. Müller
- Department of Pediatrics, Emma Children’s Hospital, Amsterdam Gastroenterology Endocrinology Metabolism, Amsterdam UMC Location University of Amsterdam, Amsterdam, Netherlands
- Amsterdam UMC, Emma Center for Personalized Medicine, Amsterdam, Netherlands
- Department of Human Genetics, Amsterdam Reproduction and Development, Amsterdam UMC Location University of Amsterdam, Amsterdam, Netherlands
| | - Friederike Ehrhart
- Department of Bioinformatics – BiGCaT, Research Institute of Nutrition and Translational Research in Metabolism (NUTRIM), Maastricht University, Maastricht, Netherlands
| | - Clara D. M. Van Karnebeek
- Department of Pediatrics, Emma Children’s Hospital, Amsterdam Gastroenterology Endocrinology Metabolism, Amsterdam UMC Location University of Amsterdam, Amsterdam, Netherlands
- Amsterdam UMC, Emma Center for Personalized Medicine, Amsterdam, Netherlands
- Department of Human Genetics, Amsterdam Reproduction and Development, Amsterdam UMC Location University of Amsterdam, Amsterdam, Netherlands
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Summers J, Baribeau D, Perlman P, Hoang N, Cui S, Krakowski A, Ambrozewicz P, Ho A, Selvanayagam T, Sándor-Bajusz KA, Palad K, Patel N, McGaughey S, Gallagher L, Scherer SW, Szatmari P, Vorstman J. An integrated clinical approach to children at genetic risk for neurodevelopmental and psychiatric conditions: interdisciplinary collaboration and research infrastructure. J Neurodev Disord 2024; 16:37. [PMID: 38970057 PMCID: PMC11229023 DOI: 10.1186/s11689-024-09552-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/28/2023] [Accepted: 06/04/2024] [Indexed: 07/07/2024] Open
Abstract
BACKGROUND A sizeable proportion of pathogenic genetic variants identified in young children tested for congenital differences are associated with neurodevelopmental psychiatric disorders (NPD). In this growing group, a genetic diagnosis often precedes the emergence of diagnosable developmental concerns. Here, we describe DAGSY (Developmental Assessment of Genetically Susceptible Youth), a novel interdisciplinary 'genetic-diagnosis-first' clinic integrating psychiatric, psychological and genetic expertise, and report our first observations and feedback from families and referring clinicians. METHODS We retrieved data on referral sources and indications, genetic and NPD diagnoses and recommendations for children seen at DAGSY between 2018 and 2022. Through a survey, we obtained feedback from twenty families and eleven referring clinicians. RESULTS 159 children (mean age 10.2 years, 57.2% males) completed an interdisciplinary (psychiatry, psychology, genetic counselling) DAGSY assessment during this period. Of these, 69.8% had a pathogenic microdeletion or microduplication, 21.5% a sequence-level variant, 4.4% a chromosomal disorder, and 4.4% a variant of unknown significance with emerging evidence of pathogenicity. One in four children did not have a prior NPD diagnosis, and referral to DAGSY was motivated by their genetic vulnerability alone. Following assessment, 76.7% received at least one new NPD diagnosis, most frequently intellectual disability (24.5%), anxiety (20.7%), autism spectrum (18.9%) and specific learning (16.4%) disorder. Both families and clinicians responding to our survey expressed satisfaction, but also highlighted some areas for potential improvement. CONCLUSIONS DAGSY addresses an unmet clinical need for children identified with genetic variants that confer increased vulnerability for NPD and provides a crucial platform for research in this area. DAGSY can serve as a model for interdisciplinary clinics integrating child psychiatry, psychology and genetics, addressing both clinical and research needs for this emerging population.
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Affiliation(s)
- Jane Summers
- Department of Psychiatry, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Psychiatry, The Hospital for Sick Children, Toronto, ON, Canada
- Autism Research Unit, The Hospital for Sick Children, Toronto, ON, Canada
| | - Danielle Baribeau
- Department of Psychiatry, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Department of Psychiatry, The Hospital for Sick Children, Toronto, ON, Canada
- Holland Bloorview Kids Rehabilitation Hospital, Toronto, ON, Canada
- Autism Research Unit, The Hospital for Sick Children, Toronto, ON, Canada
| | - Polina Perlman
- Department of Psychiatry, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Department of Psychiatry, The Hospital for Sick Children, Toronto, ON, Canada
- Centre for Addiction and Mental Health, Toronto, ON, Canada
- Autism Research Unit, The Hospital for Sick Children, Toronto, ON, Canada
| | - Ny Hoang
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Genetic Counselling, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
- Autism Research Unit, The Hospital for Sick Children, Toronto, ON, Canada
| | - Sunny Cui
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
- Autism Research Unit, The Hospital for Sick Children, Toronto, ON, Canada
| | - Aneta Krakowski
- Department of Psychiatry, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Department of Psychiatry, The Hospital for Sick Children, Toronto, ON, Canada
- Autism Research Unit, The Hospital for Sick Children, Toronto, ON, Canada
| | - Patricia Ambrozewicz
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
- Autism Research Unit, The Hospital for Sick Children, Toronto, ON, Canada
| | - Ariel Ho
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
- Autism Research Unit, The Hospital for Sick Children, Toronto, ON, Canada
| | - Thanuja Selvanayagam
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Genetic Counselling, The Hospital for Sick Children, Toronto, ON, Canada
- The Centre for Applied Genomics, The Hospital for Sick Children, Toronto, ON, Canada
- Autism Research Unit, The Hospital for Sick Children, Toronto, ON, Canada
| | - Kinga A Sándor-Bajusz
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
- Autism Research Unit, The Hospital for Sick Children, Toronto, ON, Canada
| | - Katrina Palad
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
- Autism Research Unit, The Hospital for Sick Children, Toronto, ON, Canada
| | - Nishi Patel
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
- Autism Research Unit, The Hospital for Sick Children, Toronto, ON, Canada
| | - Sarah McGaughey
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
- Autism Research Unit, The Hospital for Sick Children, Toronto, ON, Canada
| | - Louise Gallagher
- Department of Psychiatry, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada
- Department of Psychiatry, The Hospital for Sick Children, Toronto, ON, Canada
- Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Stephen W Scherer
- The Centre for Applied Genomics, The Hospital for Sick Children, Toronto, ON, Canada
- McLaughlin Centre and Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
- Department of Molecular Genetics, University of Toronto, Toronto, ON, Canada
| | - Peter Szatmari
- Department of Psychiatry, The Hospital for Sick Children, Toronto, ON, Canada
- Centre for Addiction and Mental Health, Toronto, ON, Canada
| | - Jacob Vorstman
- Department of Psychiatry, Temerty Faculty of Medicine, University of Toronto, Toronto, ON, Canada.
- Program in Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON, Canada.
- Department of Psychiatry, The Hospital for Sick Children, Toronto, ON, Canada.
- The Centre for Applied Genomics, The Hospital for Sick Children, Toronto, ON, Canada.
- Autism Research Unit, The Hospital for Sick Children, Toronto, ON, Canada.
- Hospital for Sick Children, Peter Gilgan Centre for Research and Learning, 686 Bay Street Room 12.9702, Toronto, ON, M5G 0A4, Canada.
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5
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Saldaris J, Leonard H, Wong K, Jacoby P, Spence M, Marsh ED, Benke TA, Demarest S, Downs J. Validating the Communication and Symbolic Behavior Scales-Developmental Profile Infant-Toddler Checklist (CSBS-DP ITC) Beyond Infancy in the CDKL5 Deficiency Disorder. J Autism Dev Disord 2024; 54:2526-2535. [PMID: 37184758 PMCID: PMC10699574 DOI: 10.1007/s10803-023-06002-w] [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] [Accepted: 04/20/2023] [Indexed: 05/16/2023]
Abstract
CDKL5 deficiency disorder (CDD) results in early-onset epilepsy and lifelong cognitive and motor impairments. With no validated measure for communication in CDD, this study evaluated the psychometric properties of the Communication and Symbolic Behavior Scales-Developmental Profile Infant Toddler Checklist (CSBS-DP ITC). Caregivers (n = 150; affected individuals aged 1-29 years) completed the CSBS-DP ITC. Distribution of scores indicated a floor effect. There was poor divergent validity for the three-factor model but goodness of fit and convergent validity data were satisfactory for the one-factor model. Individuals with poorer overall functional abilities scored lower on the CSBS-DP ITC. Test-retest reliability was excellent. The floor effect could explain the very high reliability, suggesting problems as a sensitive outcome measure in clinical trials for CDD.
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Affiliation(s)
- Jacinta Saldaris
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, PO Box 855, West Perth, WA, 6872, Australia
| | - Helen Leonard
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, PO Box 855, West Perth, WA, 6872, Australia
| | - Kingsley Wong
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, PO Box 855, West Perth, WA, 6872, Australia
| | - Peter Jacoby
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, PO Box 855, West Perth, WA, 6872, Australia
| | - Mary Spence
- Children's Hospital Colorado Therapy Care, Highlands Ranch, CO, USA
| | - Eric D Marsh
- Division of Neurology, Children's Hospital of Philadelphia, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA, USA
| | - Tim A Benke
- Children's Hospital Colorado, Paediatric Neurology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Scott Demarest
- Children's Hospital Colorado, Paediatric Neurology, University of Colorado School of Medicine, Aurora, CO, USA
| | - Jenny Downs
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, PO Box 855, West Perth, WA, 6872, Australia.
- School of Physiotherapy and Exercise Science, Curtin University, Perth, WA, Australia.
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Abbas A, Fayoud AM, El Din Moawad MH, Hamad AA, Hamouda H, Fouad EA. Safety and efficacy of trofinetide in Rett syndrome: a systematic review and meta-analysis of randomized controlled trials. BMC Pediatr 2024; 24:206. [PMID: 38521908 PMCID: PMC10960414 DOI: 10.1186/s12887-024-04526-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/23/2023] [Accepted: 01/01/2024] [Indexed: 03/25/2024] Open
Abstract
INTRODUCTION Rett syndrome is a rare genetic neurodevelopmental disorder that predominantly impacts females. It presents with loss of acquired skills, impaired communication, and stereotypic hand movements. Given the limited treatment options for Rett syndrome, there is a dire need for effective interventions. OBJECTIVE To evaluate the safety and efficacy of trofinetide in Randomized Controlled Trials (RCTs) that report on Rett syndrome patients. METHODS We identified 109 articles from four databases (Scopus, PubMed, Web of Science, and Cochrane CENTRAL). After removing the duplicates, we narrowed them down to 59 articles for further assessment. We included RCTs that evaluated the efficacy and safety of trofinetide in patients with Rett syndrome. Three studies were eligible for inclusion. Two independent reviewers evaluated the identified studies' titles, abstracts, and full texts, extracting pertinent data. We assessed the quality of the studies using the Cochrane Risk of Bias (RoB) 2.0 tool. We then conducted a meta-analysis using the fixed effects model in the case of insignificant heterogeneity; otherwise, we used the random effects model. Based on the nature of the outcome, we analyzed the mean difference or the odds ratio. Analysis was conducted using RevMan version 5.3. RESULTS Among the analyzed outcomes in 181 patients in the trofinetide group and 134 patients in the placebo group, significant improvement in Rett Syndrome Behavior Questionnaire (RSBQ) scores was observed at 200 mg dosage (overall mean difference: -3.53, p = 0.001). Clinical Global Impression-Improvement (CGI-I) scores improved considerably at 200 mg dosage (overall mean difference: -0.34, p < 0.0001). No substantial changes were observed in Motor Behavioral Assessment (MBA) or Top 3 Caregiver Concerns. We evaluated Treatment Emergent Adverse Events (TEAEs) across the various dosages and noted significant associations with diarrhea (200 mg), vomiting (200 mg), and irritability (200 mg). However, we did not find a significant association between any of the dosages and the incidence of decreased appetite. CONCLUSION Trofinetide demonstrated potential in improving RSBQ and CGI-I scores at 200 mg dosage. Although no substantial changes were found in MBA and top 3 caregiver concerns. Adverse events were linked to specific dosages.
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Affiliation(s)
- Abdallah Abbas
- Faculty of Medicine, Al-Azhar University, Damietta, Egypt.
| | - Aya M Fayoud
- Faculty of Pharmacy, Kafr El sheik university, Kafr El Sheik, Egypt
| | - Mostafa Hossam El Din Moawad
- Faculty of Pharmacy Clinical Department, Alexandria University, Alexandria, Egypt
- Faculty of Medicine, Suez Canal University, Ismailia, Egypt
| | | | - Heba Hamouda
- Faculty of Medicine, Menoufia University, Menoufia, Egypt
| | - Eman A Fouad
- Department of Pediatrics, Ubbo-Emmius-Klinik, Aurich, Germany
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Mykins M, Bridges B, Jo A, Krishnan K. Multidimensional Analysis of a Social Behavior Identifies Regression and Phenotypic Heterogeneity in a Female Mouse Model for Rett Syndrome. J Neurosci 2024; 44:e1078232023. [PMID: 38199865 PMCID: PMC10957218 DOI: 10.1523/jneurosci.1078-23.2023] [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: 06/09/2023] [Revised: 11/01/2023] [Accepted: 11/17/2023] [Indexed: 01/12/2024] Open
Abstract
Regression is a key feature of neurodevelopmental disorders such as autism spectrum disorder, Fragile X syndrome, and Rett syndrome (RTT). RTT is caused by mutations in the X-linked gene methyl-CpG-binding protein 2 (MECP2). It is characterized by an early period of typical development with subsequent regression of previously acquired motor and speech skills in girls. The syndromic phenotypes are individualistic and dynamic over time. Thus far, it has been difficult to capture these dynamics and syndromic heterogeneity in the preclinical Mecp2-heterozygous female mouse model (Het). The emergence of computational neuroethology tools allows for robust analysis of complex and dynamic behaviors to model endophenotypes in preclinical models. Toward this first step, we utilized DeepLabCut, a marker-less pose estimation software to quantify trajectory kinematics and multidimensional analysis to characterize behavioral heterogeneity in Het in the previously benchmarked, ethologically relevant social cognition task of pup retrieval. We report the identification of two distinct phenotypes of adult Het: Het that display a delay in efficiency in early days and then improve over days like wild-type mice and Het that regress and perform worse in later days. Furthermore, regression is dependent on age and behavioral context and can be detected in the initial days of retrieval. Together, the novel identification of two populations of Het suggests differential effects on neural circuitry, opens new avenues to investigate the underlying molecular and cellular mechanisms of heterogeneity, and designs better studies for stratifying therapeutics.
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Affiliation(s)
- Michael Mykins
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee
| | - Benjamin Bridges
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee
| | - Angela Jo
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee
| | - Keerthi Krishnan
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee
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Neul JL, Percy AK, Benke TA, Berry-Kravis EM, Glaze DG, Peters SU, Marsh ED, An D, Bishop KM, Youakim JM. Trofinetide Treatment Demonstrates a Benefit Over Placebo for the Ability to Communicate in Rett Syndrome. Pediatr Neurol 2024; 152:63-72. [PMID: 38232652 DOI: 10.1016/j.pediatrneurol.2023.11.005] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Revised: 10/27/2023] [Accepted: 11/18/2023] [Indexed: 01/19/2024]
Abstract
BACKGROUND Trofinetide was approved by the US Food and Drug Administration for the treatment of Rett syndrome (RTT) in March 2023. Benefiting the ability to communicate in RTT is often identified as the most important caregiver goal for new therapies. This analysis reports the communication-related end points from the phase 3 LAVENDER study of trofinetide in RTT. METHODS Females with RTT, aged five to 20 years, were randomized 1:1 to trofinetide or placebo for 12 weeks. Secondary efficacy end points related to communication were based on change from baseline to week 12 and included the caregiver-rated Communication and Symbolic Behavior Scales Developmental Profile™ Infant-Toddler Checklist (CSBS-DP-IT) Social Composite score (key secondary end point; scores ranged from 0 to 26 [higher scores indicated better communication]) and novel clinician rating scales (0 [normal] to 7 [severe impairment]) measuring the ability to communicate choices nonverbally (RTT-COMC) and verbally (RTT-VCOM). RESULTS Trofinetide demonstrated a statistically significant difference versus placebo for the CSBS-DP-IT Social Composite score (least squares mean [LSM] difference = 1.0; 95% confidence interval [CI], 0.3 to 1.7; P = 0.0064; Cohen's d effect size = 0.43) and a nominally significant difference for the RTT-COMC (LSM difference: -0.3; 95% CI, -0.6 to -0.0; P = 0.0257; Cohen's d effect size = 0.36). As expected, there was no difference for the RTT-VCOM. CONCLUSIONS Significant treatment benefit for trofinetide versus placebo was observed in scales measuring the ability to communicate. These scales may be appropriate for future clinical studies in RTT and other neurodevelopmental disorders.
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Affiliation(s)
- Jeffrey L Neul
- Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Alan K Percy
- University of Alabama at Birmingham, Birmingham, Alabama
| | - Timothy A Benke
- Children's Hospital of Colorado, University of Colorado School of Medicine, Aurora, Colorado
| | | | - Daniel G Glaze
- Texas Children's Hospital, Baylor College of Medicine, Houston, Texas
| | - Sarika U Peters
- Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, Tennessee
| | - Eric D Marsh
- Children's Hospital of Philadelphia, Philadelphia, Pennsylvania; University of Pennsylvania Perelman School of Medicine, Philadelphia, Pennsylvania
| | - Di An
- Acadia Pharmaceuticals Inc, San Diego, California
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9
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Percy AK, Neul JL, Benke TA, Marsh ED, Glaze DG. A review of the Rett Syndrome Behaviour Questionnaire and its utilization in the assessment of symptoms associated with Rett syndrome. Front Pediatr 2023; 11:1229553. [PMID: 37635789 PMCID: PMC10450502 DOI: 10.3389/fped.2023.1229553] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/26/2023] [Accepted: 07/03/2023] [Indexed: 08/29/2023] Open
Abstract
The Rett Syndrome Behaviour Questionnaire (RSBQ), which is completed by the caregiver, is one of the most widely used efficacy measures in clinical studies of Rett syndrome (RTT) due to its specificity to the core features of RTT. As healthcare providers participate in routine healthcare assessments of individuals with RTT in clinical practice, there is a need for these providers to understand the psychometric properties of the RSBQ and how it relates to the core clinical features of RTT. Here, we describe the characteristics of the RSBQ, review the literature on its validity and reliability as well as its performance in a phase 2 study and the recent phase 3 LAVENDER study. The RSBQ was first shown to discriminate RTT from other intellectual disorders with good inter-rater and test-retest reliability scores. It was subsequently validated as an appropriate instrument for measuring behavior in females with RTT and adopted as a clinical trial outcome. In LAVENDER, the FDA-approved drug trofinetide significantly improved the RSBQ total score over placebo in girls and women with RTT and change from baseline for all RSBQ subscores were directionally in favor of trofinetide. The change in RSBQ was aligned with the Clinical Global Impression-Improvement scale, suggesting that improvement in behavioral components may be related to overall clinical status. Given its validity and ubiquity in RTT clinical studies, it is important that the interplay of the domains and the psychometric profile of the RSBQ are understood.
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Affiliation(s)
- Alan K. Percy
- Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL, United States
| | - Jeffrey L. Neul
- Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Timothy A. Benke
- Children’s Hospital of Colorado/University of Colorado School of Medicine, Aurora, CO, United States
| | - Eric D. Marsh
- Department of Neurology, Children’s Hospital of Philadelphia, Philadelphia, PA, United States
| | - Daniel G. Glaze
- Texas Children’s Hospital/Baylor College of Medicine, Houston, TX, United States
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10
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Lotan M, Downs J, Stahlhut M, Romano A. Evaluation Tools Developed for Rett Syndrome. Diagnostics (Basel) 2023; 13:1708. [PMID: 37238191 PMCID: PMC10217473 DOI: 10.3390/diagnostics13101708] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Revised: 05/08/2023] [Accepted: 05/08/2023] [Indexed: 05/28/2023] Open
Abstract
Rett syndrome (RTT) is a complex neurodevelopmental X-linked disorder associated with severe functional impairments and multiple comorbidities. There is wide variation in the clinical presentation, and because of its unique characteristics, several evaluation tools of clinical severity, behavior, and functional motor abilities have been proposed specifically for it. This opinion paper aims to present up-to date evaluation tools which have specifically been adapted for individuals with RTT often used by the authors in their clinical and research practice and to provide the reader with essential considerations and suggestions regarding their use. Due to the rarity of Rett syndrome, we found it important to present these scales in order to improve and professionalize their clinical work. The current article will review the following evaluation tools: (a) the Rett Assessment Rating Scale; (b) the Rett Syndrome Gross Motor Scale; (c) the Rett Syndrome Functional Scale; (d) the Functional Mobility Scale-Rett Syndrome; (e) the Two-Minute Walking Test modified for Rett syndrome; (f) the Rett Syndrome Hand Function Scale; (g) the StepWatch Activity Monitor; (h) the activPALTM; (i) the Modified Bouchard Activity Record; (j) the Rett Syndrome Behavioral Questionnaire; and (k) the Rett Syndrome Fear of Movement Scale. The authors recommend that service providers consider evaluation tools validated for RTT for evaluation and monitoring to guide their clinical recommendations and management. In this article, the authors suggest factors that should be considered when using these evaluation tools to assist in interpreting scores.
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Affiliation(s)
- Meir Lotan
- Department of Physiotherapy, Ariel University, Ariel 4070000, Israel
- Israeli Rett Syndrome National Evaluation Team, Ramat Gan 5211401, Israel
| | - Jenny Downs
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, Nedlands, WA 6009, Australia
- School of Allied Health, Curtin University, Perth, WA 6102, Australia
| | - Michelle Stahlhut
- Department of Paediatrics and Adolescent Medicine, Center for Rett Syndrome, Rigshospitalet, 2100 Copenhagen, Denmark
| | - Alberto Romano
- Department of Health System Management, Ariel University, Ariel 4070000, Israel
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11
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Goodspeed K, Armstrong D, Dolce A, Evans P, Said R, Tsai P, Sirsi D. Electroencephalographic (EEG) Biomarkers in Genetic Neurodevelopmental Disorders. J Child Neurol 2023; 38:466-477. [PMID: 37264615 PMCID: PMC10644693 DOI: 10.1177/08830738231177386] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 10/17/2022] [Accepted: 04/28/2023] [Indexed: 06/03/2023]
Abstract
Collectively, neurodevelopmental disorders are highly prevalent, but more than a third of neurodevelopmental disorders have an identifiable genetic etiology, each of which is individually rare. The genes associated with neurodevelopmental disorders are often involved in early brain development, neuronal signaling, or synaptic plasticity. Novel treatments for many genetic neurodevelopmental disorders are being developed, but disease-relevant clinical outcome assessments and biomarkers are limited. Electroencephalography (EEG) is a promising noninvasive potential biomarker of brain function. It has been used extensively in epileptic disorders, but its application in neurodevelopmental disorders needs further investigation. In this review, we explore the use of EEG in 3 of the most prevalent genetic neurodevelopmental disorders-Angelman syndrome, Rett syndrome, and fragile X syndrome. Quantitative analyses of EEGs, such as power spectral analysis or measures of connectivity, can quantify EEG signatures seen on qualitative review and potentially correlate with phenotypes. In both Angelman syndrome and Rett syndrome, increased delta power on spectral analysis has correlated with clinical markers of disease severity including developmental disability and seizure burden, whereas spectral power analysis on EEG in fragile X syndrome tends to demonstrate abnormalities in gamma power. Further studies are needed to establish reliable relationships between quantitative EEG biomarkers and clinical phenotypes in rare genetic neurodevelopmental disorders.
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Affiliation(s)
- Kimberly Goodspeed
- Department of Pediatrics, Division of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Dallas Armstrong
- Department of Pediatrics, Division of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Alison Dolce
- Department of Pediatrics, Division of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Patricia Evans
- Department of Pediatrics, Division of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Rana Said
- Department of Pediatrics, Division of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Peter Tsai
- Department of Pediatrics, Division of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Psychiatry, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Neuroscience, University of Texas Southwestern Medical Center, Dallas, TX, USA
| | - Deepa Sirsi
- Department of Pediatrics, Division of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
- Department of Neurology, University of Texas Southwestern Medical Center, Dallas, TX, USA
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12
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Oberman LM, Leonard H, Downs J, Cianfaglione R, Stahlhut M, Larsen JL, Madden KV, Kaufmann WE. Rett Syndrome Behaviour Questionnaire in Children and Adults With Rett Syndrome: Psychometric Characterization and Revised Factor Structure. AMERICAN JOURNAL ON INTELLECTUAL AND DEVELOPMENTAL DISABILITIES 2023; 128:237-253. [PMID: 37104862 DOI: 10.1352/1944-7558-128.3.237] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2021] [Accepted: 10/18/2022] [Indexed: 05/25/2023]
Abstract
Rett syndrome (RTT) is a severe neurodevelopmental disorder associated with multiple neurobehavioral abnormalities. The Rett Syndrome Behaviour Questionnaire (RSBQ) was developed for pediatric RTT observational studies. Because its application has expanded to adult and interventional studies, we evaluated the RSBQ's psychometric properties in six pediatric (n = 323) and five adult (n = 309) datasets. Total and General Mood subscale scores had good reliability. Clinical severity had no influence on RSBQ scores. Exploratory and confirmatory factor analyses yielded 6 pediatric and 7 adult clinically relevant and psychometrically strong factors including the original Breathing Problems and Fear/Anxiety subscales and the novel Emotional and Disruptive Behavior subscale composed of items from the original General Mood and Nighttime Behaviours subscales. The present findings support additional evaluations and improvements of an important RTT behavioral measure.
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Affiliation(s)
- Lindsay M Oberman
- Lindsay M. Oberman, Center for Neuroscience and Regenerative Medicine, Henry M. Jackson Foundation for the Advancement of Military Medicine, USA
| | - Helen Leonard
- Helen Leonard, Telethon Kids Institute, The University of Western Australia, Perth, Western Australia, Australia
| | - Jenny Downs
- Jenny Downs, Telethon Kids Institute, The University of Western Australia and School of Physiotherapy and Exercise Science, Curtin University, Perth, Western Australia, Australia
| | | | - Michelle Stahlhut
- Michelle Stahlhut, Center for Rett Syndrome, Rigshospitalet, Copenhagen, Denmark
| | - Jane L Larsen
- Jane L. Larsen, Center for Rett Syndrome, Rigshospitalet, Copenhagen, Denmark
| | | | - Walter E Kaufmann
- Walter E. Kaufmann, Anavex Life Sciences Corp. and Emory University School of Medicine, USA
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13
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Transition from Animal-Based to Human Induced Pluripotent Stem Cells (iPSCs)-Based Models of Neurodevelopmental Disorders: Opportunities and Challenges. Cells 2023; 12:cells12040538. [PMID: 36831205 PMCID: PMC9954744 DOI: 10.3390/cells12040538] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2022] [Revised: 01/25/2023] [Accepted: 02/02/2023] [Indexed: 02/11/2023] Open
Abstract
Neurodevelopmental disorders (NDDs) arise from the disruption of highly coordinated mechanisms underlying brain development, which results in impaired sensory, motor and/or cognitive functions. Although rodent models have offered very relevant insights to the field, the translation of findings to clinics, particularly regarding therapeutic approaches for these diseases, remains challenging. Part of the explanation for this failure may be the genetic differences-some targets not being conserved between species-and, most importantly, the differences in regulation of gene expression. This prompts the use of human-derived models to study NDDS. The generation of human induced pluripotent stem cells (hIPSCs) added a new suitable alternative to overcome species limitations, allowing for the study of human neuronal development while maintaining the genetic background of the donor patient. Several hIPSC models of NDDs already proved their worth by mimicking several pathological phenotypes found in humans. In this review, we highlight the utility of hIPSCs to pave new paths for NDD research and development of new therapeutic tools, summarize the challenges and advances of hIPSC-culture and neuronal differentiation protocols and discuss the best way to take advantage of these models, illustrating this with examples of success for some NDDs.
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14
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Dang LT. More Hormones, Less Spasms: IGF-1 as a Potential Therapy for Infantile Spasms. Epilepsy Curr 2023; 23:130-132. [PMID: 37122414 PMCID: PMC10131574 DOI: 10.1177/15357597221149265] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
[Box: see text]
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15
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Megagiannis P, Suresh R, Rouleau GA, Zhou Y. Reversibility and therapeutic development for neurodevelopmental disorders, insights from genetic animal models. Adv Drug Deliv Rev 2022; 191:114562. [PMID: 36183904 DOI: 10.1016/j.addr.2022.114562] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Revised: 08/30/2022] [Accepted: 09/24/2022] [Indexed: 01/24/2023]
Abstract
Neurodevelopmental Disorders (NDDs) encompass a broad spectrum of conditions resulting from atypical brain development. Over the past decades, we have had the fortune to witness enormous progress in diagnosis, etiology discovery, modeling, and mechanistic understanding of NDDs from both fundamental and clinical research. Here, we review recent neurobiological advances from experimental models of NDDs. We introduce several examples and highlight breakthroughs in reversal studies of phenotypes using genetically engineered models of NDDs. The in-depth understanding of brain pathophysiology underlying NDDs and evaluations of reversibility in animal models paves the foundation for discovering novel treatment options. We discuss how the expanding property of cutting-edge technologies, such as gene editing and AAV-mediated gene delivery, are leveraged in animal models for the therapeutic development of NDDs. We envision opportunities and challenges toward faithful modeling and fruitful clinical translation.
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Affiliation(s)
- Platon Megagiannis
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital; Faculty of Medicine and Health Sciences, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Rahul Suresh
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital; Faculty of Medicine and Health Sciences, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Guy A Rouleau
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital; Faculty of Medicine and Health Sciences, McGill University, Montreal, Quebec H3A 2B4, Canada
| | - Yang Zhou
- Department of Neurology and Neurosurgery, Montreal Neurological Institute-Hospital; Faculty of Medicine and Health Sciences, McGill University, Montreal, Quebec H3A 2B4, Canada.
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16
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Zlatic SA, Duong D, Gadalla KK, Murage B, Ping L, Shah R, Fink JJ, Khwaja O, Swanson LC, Sahin M, Rayaprolu S, Kumar P, Rangaraju S, Bird A, Tarquinio D, Carpenter R, Cobb S, Faundez V. Convergent cerebrospinal fluid proteomes and metabolic ontologies in humans and animal models of Rett syndrome. iScience 2022; 25:104966. [PMID: 36060065 PMCID: PMC9437849 DOI: 10.1016/j.isci.2022.104966] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Revised: 07/30/2022] [Accepted: 08/12/2022] [Indexed: 11/22/2022] Open
Abstract
MECP2 loss-of-function mutations cause Rett syndrome, a neurodevelopmental disorder resulting from a disrupted brain transcriptome. How these transcriptional defects are decoded into a disease proteome remains unknown. We studied the proteome of Rett cerebrospinal fluid (CSF) to identify consensus Rett proteome and ontologies shared across three species. Rett CSF proteomes enriched proteins annotated to HDL lipoproteins, complement, mitochondria, citrate/pyruvate metabolism, synapse compartments, and the neurosecretory protein VGF. We used shared Rett ontologies to select analytes for orthogonal quantification and functional validation. VGF and ontologically selected CSF proteins had genotypic discriminatory capacity as determined by receiver operating characteristic analysis in Mecp2 -/y and Mecp2 -/+ . Differentially expressed CSF proteins distinguished Rett from a related neurodevelopmental disorder, CDKL5 deficiency disorder. We propose that Mecp2 mutant CSF proteomes and ontologies inform putative mechanisms and biomarkers of disease. We suggest that Rett syndrome results from synapse and metabolism dysfunction.
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Affiliation(s)
| | - Duc Duong
- Departments of Biochemistry, Emory University, Atlanta, GA 30322, USA
| | - Kamal K.E. Gadalla
- Simons Initiative for the Developing Brain, Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Brenda Murage
- Simons Initiative for the Developing Brain, Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Lingyan Ping
- Departments of Biochemistry, Emory University, Atlanta, GA 30322, USA
| | - Ruth Shah
- The Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, King’s Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | | | - Omar Khwaja
- Department of Neurology, Rosamund Stone Zander Translational Neuroscience Center, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Lindsay C. Swanson
- Department of Neurology, Rosamund Stone Zander Translational Neuroscience Center, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Mustafa Sahin
- Department of Neurology, Rosamund Stone Zander Translational Neuroscience Center, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Sruti Rayaprolu
- Departments of Neurology, Emory University, Atlanta, GA 30322, USA
| | - Prateek Kumar
- Departments of Neurology, Emory University, Atlanta, GA 30322, USA
| | | | - Adrian Bird
- The Wellcome Centre for Cell Biology, University of Edinburgh, Michael Swann Building, King’s Buildings, Max Born Crescent, Edinburgh EH9 3BF, UK
| | | | | | - Stuart Cobb
- Simons Initiative for the Developing Brain, Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Victor Faundez
- Departments of Cell Biology, Emory University, Atlanta, GA 30322, USA
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17
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Improving clinical trial readiness to accelerate development of new therapeutics for Rett syndrome. Orphanet J Rare Dis 2022; 17:108. [PMID: 35246185 PMCID: PMC8894842 DOI: 10.1186/s13023-022-02240-w] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2021] [Accepted: 02/06/2022] [Indexed: 12/16/2022] Open
Abstract
Rett syndrome is associated with severe functional impairments and many comorbidities, each in urgent need of treatments. Mutations in the MECP2 gene were identified as causing Rett syndrome in 1999. Over the past 20 years there has been an abundance of preclinical research with some studies leading to human clinical trials. Despite this, few viable therapeutic options have emerged from this investment of effort. Reasons for this lack of success as they relate both to preclinical research and the clinical trial landscape are discussed. Considering what needs to be done to promote further success in the field, we take a positive and constructive approach and introduce the concept of clinical trial readiness and its necessary ingredients for Rett syndrome. These include: listening to the needs of families; support from advocacy groups; optimising use of existing clinic infrastructures and available natural history data; and, finally, the validation of existing outcome measures and/or the development and validation of new measures. We conclude by reiterating the need for a collaborative and coordinated approach amongst the many different stakeholder groups and the need to engage in new types of trial design which could be much more efficient, less costly and much less burdensome on families.
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Abstract
PURPOSE OF REVIEW There are currently no approved medications for the core symptoms of autism spectrum disorder (ASD), and only limited data on the management of co-occurring mental health and behavioural symptoms. The purpose of this review is to synthesize recent trials on novel treatments in ASD, with a focus on research trends in the past 2 years. RECENT FINDINGS No new pharmacologic agents received regulatory approval for use in ASD. Several large randomized controlled trials (RCTs) had negative or ambiguous results (e.g. fluoxetine, oxytocin). A cross-over RCT of an oral cannabinoid suggested possible benefits for disruptive behaviours. Two large-scale multicentre trials of bumetanide were terminated early for lack of efficacy. Multicenter trials using repetitive transcranial magnetic stimulation are underway. Recent meta-analyses indicate that specific behavioural and psychological interventions can support social communication and treat anxiety. Numerous novel treatment targets informed by biological mechanisms are under investigation. SUMMARY Recent data support the use of behavioural and psychological interventions for social communication and anxiety in ASD; data are more limited regarding pharmacotherapy for core and associated symptoms. Next steps include replication of early findings, trials of new molecular targets, and the identification of novel biomarkers, including genetic predictors, of treatment response.
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Affiliation(s)
- Danielle Baribeau
- University of Toronto
- The Hospital for Sick Children, Toronto, Ontario, Canada
- Holland Bloorview Kids Rehabilitation Hospital, Toronto, Ontario, Canada
| | - Jacob Vorstman
- University of Toronto
- The Hospital for Sick Children, Toronto, Ontario, Canada
| | - Evdokia Anagnostou
- University of Toronto
- The Hospital for Sick Children, Toronto, Ontario, Canada
- Holland Bloorview Kids Rehabilitation Hospital, Toronto, Ontario, Canada
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19
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Li W. Excitation and Inhibition Imbalance in Rett Syndrome. Front Neurosci 2022; 16:825063. [PMID: 35250460 PMCID: PMC8894599 DOI: 10.3389/fnins.2022.825063] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Accepted: 01/31/2022] [Indexed: 12/12/2022] Open
Abstract
A loss of the excitation/inhibition (E/I) balance in the neural circuit has emerged as a common neuropathological feature in many neurodevelopmental disorders. Rett syndrome (RTT), a prevalent neurodevelopmental disorder that affects 1:10,000-15,000 women globally, is caused by loss-of-function mutations in the Methyl-CpG-binding Protein-2 (Mecp2) gene. E/I imbalance is recognized as the leading cellular and synaptic hallmark that is fundamental to diverse RTT neurological symptoms, including stereotypic hand movements, impaired motor coordination, breathing irregularities, seizures, and learning/memory dysfunctions. E/I balance in RTT is not homogeneously altered but demonstrates brain region and cell type specificity instead. In this review, I elaborate on the current understanding of the loss of E/I balance in a range of brain areas at molecular and cellular levels. I further describe how the underlying cellular mechanisms contribute to the disturbance of the proper E/I ratio. Last, I discuss current pharmacologic innervations for RTT and their role in modifying the E/I balance.
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Affiliation(s)
- Wei Li
- Department of Neurobiology, University of Alabama at Birmingham, Birmingham, AL, United States
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20
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Design and outcome measures of LAVENDER, a phase 3 study of trofinetide for Rett syndrome. Contemp Clin Trials 2022; 114:106704. [PMID: 35149233 DOI: 10.1016/j.cct.2022.106704] [Citation(s) in RCA: 31] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 02/01/2022] [Accepted: 02/02/2022] [Indexed: 11/23/2022]
Abstract
INTRODUCTION Rett syndrome (RTT) is a debilitating neurodevelopmental disorder with no approved treatments. Trofinetide is a synthetic analog of glycine-proline-glutamate, the N-terminal tripeptide of insulin-like growth factor 1. In a phase 2, placebo-controlled trial in 82 females with RTT aged 5-15 years, a significant (p ≤ 0.042) improvement over placebo was observed with the highest trofinetide dose (200 mg/kg twice daily [BID]) on three measures: Rett Syndrome Behavior Questionnaire (RSBQ), Clinical Global Impression-Improvement (CGI-I), and RTT-Clinician Domain Specific Concerns-Visual Analog Scale (RTT-DSC-VAS). Trofinetide was well tolerated at all doses (50, 100, and 200 mg/kg BID). A phase 3 trial utilizing disease-specific and novel scales was designed to investigate the efficacy and safety of trofinetide in girls and women with RTT. METHODS This 12-week, double-blind, randomized, placebo-controlled study (LAVENDER; NCT04181723) will evaluate trofinetide in 187 females, aged 5-20 years, with RTT. Co-primary endpoints are the RSBQ and CGI-I scales. Clinical domains of the CGI-I include communication, ambulation, hand use, seizures, attentiveness, and social (eye contact) and autonomic (breathing) aspects. Secondary endpoints will leverage four novel RTT-specific clinician ratings (derived from the RTT-DSC-VAS) of hand function, ambulation, ability to communicate, and verbal communication, and existing scales, to evaluate other core symptoms of RTT, quality of life and caregiver burden. A 40-week, open-label extension study will follow. DISCUSSION This study was designed using disease-specific scales optimized to demonstrate changes in core symptoms of RTT and may provide the first phase 3 data demonstrating drug efficacy in individuals with RTT. TRIAL REGISTRATION Clinicaltrials.govNCT04181723.
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21
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Shovlin S, Delepine C, Swanson L, Bach S, Sahin M, Sur M, Kaufmann WE, Tropea D. Molecular Signatures of Response to Mecasermin in Children With Rett Syndrome. Front Neurosci 2022; 16:868008. [PMID: 35712450 PMCID: PMC9197456 DOI: 10.3389/fnins.2022.868008] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Accepted: 04/26/2022] [Indexed: 11/21/2022] Open
Abstract
Rett syndrome (RTT) is a devastating neurodevelopmental disorder without effective treatments. Attempts at developing targetted therapies have been relatively unsuccessful, at least in part, because the genotypical and phenotypical variability of the disorder. Therefore, identification of biomarkers of response and patients' stratification are high priorities. Administration of Insulin-like Growth Factor 1 (IGF-1) and related compounds leads to significant reversal of RTT-like symptoms in preclinical mouse models. However, improvements in corresponding clinical trials have not been consistent. A 20-weeks phase I open label trial of mecasermin (recombinant human IGF-1) in children with RTT demonstrated significant improvements in breathing phenotypes. However, a subsequent randomised controlled phase II trial did not show significant improvements in primary outcomes although two secondary clinical endpoints showed positive changes. To identify molecular biomarkers of response and surrogate endpoints, we used RNA sequencing to measure differential gene expression in whole blood samples of participants in the abovementioned phase I mecasermin trial. When all participants (n = 9) were analysed, gene expression was unchanged during the study (baseline vs. end of treatment, T0-T3). However, when participants were subclassified in terms of breathing phenotype improvement, specifically by their plethysmography-based apnoea index, individuals with moderate-severe apnoea and breathing improvement (Responder group) displayed significantly different transcript profiles compared to the other participants in the study (Mecasermin Study Reference group, MSR). Many of the differentially expressed genes are involved in the regulation of cell cycle processes and immune responses, as well as in IGF-1 signalling and breathing regulation. While the Responder group showed limited gene expression changes in response to mecasermin, the MSR group displayed marked differences in the expression of genes associated with inflammatory processes (e.g., neutrophil activation, complement activation) throughout the trial. Our analyses revealed gene expression profiles associated with severe breathing phenotype and its improvement after mecasermin administration in RTT, and suggest that inflammatory/immune pathways and IGF-1 signalling contribute to treatment response. Overall, these data support the notion that transcript profiles have potential as biomarkers of response to IGF-1 and related compounds.
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Affiliation(s)
- Stephen Shovlin
- Neuropsychiatric Genetics, Trinity Center for Health Sciences, Trinity Translational Medicine Institute, St James Hospital, Dublin, Ireland
| | - Chloe Delepine
- Department of Brain and Cognitive Sciences, Simons Center for the Social Brain, Picower Institute for Learning and Memory, MIT, Cambridge, MA, United States
| | - Lindsay Swanson
- Department of Neurology, Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital and Harvard Medical School, Boston, MA, United States
| | - Snow Bach
- Neuropsychiatric Genetics, Trinity Center for Health Sciences, Trinity Translational Medicine Institute, St James Hospital, Dublin, Ireland
| | - Mustafa Sahin
- Department of Neurology, Rosamund Stone Zander Translational Neuroscience Center, Boston Children's Hospital and Harvard Medical School, Boston, MA, United States
| | - Mriganka Sur
- Department of Brain and Cognitive Sciences, Simons Center for the Social Brain, Picower Institute for Learning and Memory, MIT, Cambridge, MA, United States
| | - Walter E Kaufmann
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, United States.,Department of Neurology, Boston Children's Hospital, Boston, MA, United States
| | - Daniela Tropea
- Neuropsychiatric Genetics, Trinity Center for Health Sciences, Trinity Translational Medicine Institute, St James Hospital, Dublin, Ireland.,Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland.,FutureNeuro, The SFI Research Centre for Chronic and Rare Neurological Diseases, Dublin, Ireland
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22
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Chiola S, Edgar NU, Shcheglovitov A. iPSC toolbox for understanding and repairing disrupted brain circuits in autism. Mol Psychiatry 2022; 27:249-258. [PMID: 34497379 PMCID: PMC8901782 DOI: 10.1038/s41380-021-01288-7] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Revised: 08/16/2021] [Accepted: 08/26/2021] [Indexed: 02/08/2023]
Abstract
Over the past decade, tremendous progress has been made in defining autism spectrum disorder (ASD) as a disorder of brain connectivity. Indeed, whole-brain imaging studies revealed altered connectivity in the brains of individuals with ASD, and genetic studies identified rare ASD-associated mutations in genes that regulate synaptic development and function. However, it remains unclear how specific mutations alter the development of neuronal connections in different brain regions and whether altered connections can be restored therapeutically. The main challenge is the lack of preclinical models that recapitulate important aspects of human development for studying connectivity. Through recent technological innovations, it is now possible to generate patient- or mutation-specific human neurons or organoids from induced pluripotent stem cells (iPSCs) and to study altered connectivity in vitro or in vivo upon xenotransplantation into an intact rodent brain. Here, we discuss how deficits in neurodevelopmental processes may lead to abnormal brain connectivity and how iPSC-based models can be used to identify abnormal connections and to gain insights into underlying cellular and molecular mechanisms to develop novel therapeutics.
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Affiliation(s)
- Simone Chiola
- Department of Neurobiology, University of Utah, Salt Lake City, UT, USA
| | - Nicolas U Edgar
- Department of Neurobiology, University of Utah, Salt Lake City, UT, USA
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23
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Bach S, Shovlin S, Moriarty M, Bardoni B, Tropea D. Rett Syndrome and Fragile X Syndrome: Different Etiology With Common Molecular Dysfunctions. Front Cell Neurosci 2021; 15:764761. [PMID: 34867203 PMCID: PMC8640214 DOI: 10.3389/fncel.2021.764761] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 10/27/2021] [Indexed: 01/04/2023] Open
Abstract
Rett syndrome (RTT) and Fragile X syndrome (FXS) are two monogenetic neurodevelopmental disorders with complex clinical presentations. RTT is caused by mutations in the Methyl-CpG binding protein 2 gene (MECP2) altering the function of its protein product MeCP2. MeCP2 modulates gene expression by binding methylated CpG dinucleotides, and by interacting with transcription factors. FXS is caused by the silencing of the FMR1 gene encoding the Fragile X Mental Retardation Protein (FMRP), a RNA binding protein involved in multiple steps of RNA metabolism, and modulating the translation of thousands of proteins including a large set of synaptic proteins. Despite differences in genetic etiology, there are overlapping features in RTT and FXS, possibly due to interactions between MeCP2 and FMRP, and to the regulation of pathways resulting in dysregulation of common molecular signaling. Furthermore, basic physiological mechanisms are regulated by these proteins and might concur to the pathophysiology of both syndromes. Considering that RTT and FXS are disorders affecting brain development, and that most of the common targets of MeCP2 and FMRP are involved in brain activity, we discuss the mechanisms of synaptic function and plasticity altered in RTT and FXS, and we consider the similarities and the differences between these two disorders.
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Affiliation(s)
- Snow Bach
- School of Mathematical Sciences, Dublin City University, Dublin, Ireland.,Neuropsychiatric Genetics, Department of Psychiatry, School of Medicine, Trinity College Dublin, Trinity Translational Medicine Institute, St James's Hospital, Dublin, Ireland
| | - Stephen Shovlin
- Neuropsychiatric Genetics, Department of Psychiatry, School of Medicine, Trinity College Dublin, Trinity Translational Medicine Institute, St James's Hospital, Dublin, Ireland
| | | | - Barbara Bardoni
- Inserm, CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology, Université Côte d'Azur, Valbonne, France
| | - Daniela Tropea
- Neuropsychiatric Genetics, Department of Psychiatry, School of Medicine, Trinity College Dublin, Trinity Translational Medicine Institute, St James's Hospital, Dublin, Ireland.,Trinity College Institute of Neuroscience, Trinity College Dublin, Dublin, Ireland.,FutureNeuro, The SFI Research Centre for Chronic and Rare Neurological Diseases, Dublin, Ireland
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24
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Gigliucci V, Teutsch J, Woodbury-Smith M, Luoni M, Busnelli M, Chini B, Banerjee A. Region-Specific KCC2 Rescue by rhIGF-1 and Oxytocin in a Mouse Model of Rett Syndrome. Cereb Cortex 2021; 32:2885-2894. [PMID: 34791112 DOI: 10.1093/cercor/bhab388] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/31/2020] [Revised: 09/13/2021] [Accepted: 09/14/2021] [Indexed: 01/17/2023] Open
Abstract
Rett syndrome (RTT) is characterized by dysfunction in neuronal excitation/inhibition (E/I) balance, potentially impacting seizure susceptibility via deficits in K+/Cl- cotransporter 2 (KCC2) function. Mice lacking the Methyl-CpG binding protein 2 (MeCP2) recapitulate many symptoms of RTT, and recombinant human insulin-like growth factor-1 (rhIGF-1) restores KCC2 expression and E/I balance in MeCP2 KO mice. However, clinical trial outcomes of rhIGF-1 in RTT have been variable, and increasing its therapeutic efficacy is highly desirable. To this end, the neuropeptide oxytocin (OXT) is promising, as it also critically modulates KCC2 function during early postnatal development. We measured basal KCC2 expression levels in MeCP2 KO mice and identified 3 key frontal brain regions showing KCC2 alterations in young adult mice, but not in postnatal P10 animals. We hypothesized that deficits in an IGF-1/OXT signaling crosstalk modulating KCC2 may occur in RTT during postnatal development. Consistently, we detected alterations of IGF-1 receptor and OXT receptor levels in those brain areas. rhIGF-1 and OXT treatments in KO mice rescued KCC2 expression in a region-specific and complementary manner. These results suggest that region-selective combinatorial pharmacotherapeutic strategies could be most effective at normalizing E/I balance in key brain regions subtending the RTT pathophysiology.
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Affiliation(s)
| | - Jasper Teutsch
- Neuroscience Theme, Biosciences Institute, Newcastle University, United Kingdom.,Brain Research Institute, University of Zurich, Zurich, Switzerland
| | - Marc Woodbury-Smith
- Neuroscience Theme, Biosciences Institute, Newcastle University, United Kingdom
| | - Mirko Luoni
- Stem Cells and Neurogenesis Unit, San Raffaele Scientific Institute, Milan, Italy
| | - Marta Busnelli
- Institute of Neuroscience, CNR, Milan, Italy.,NeuroMi Milan Center for Neuroscience, Milan, Italy
| | - Bice Chini
- Institute of Neuroscience, CNR, Milan, Italy.,NeuroMi Milan Center for Neuroscience, Milan, Italy
| | - Abhishek Banerjee
- Neuroscience Theme, Biosciences Institute, Newcastle University, United Kingdom.,Brain Research Institute, University of Zurich, Zurich, Switzerland
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25
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Berg EL, Petkova SP, Born HA, Adhikari A, Anderson AE, Silverman JL. Insulin-like growth factor-2 does not improve behavioral deficits in mouse and rat models of Angelman Syndrome. Mol Autism 2021; 12:59. [PMID: 34526125 PMCID: PMC8444390 DOI: 10.1186/s13229-021-00467-1] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2021] [Accepted: 09/02/2021] [Indexed: 02/08/2023] Open
Abstract
BACKGROUND Angelman Syndrome (AS) is a rare neurodevelopmental disorder for which there is currently no cure or effective therapeutic. Since the genetic cause of AS is known to be dysfunctional expression of the maternal allele of ubiquitin protein ligase E3A (UBE3A), several genetic animal models of AS have been developed. Both the Ube3a maternal deletion mouse and rat models of AS reliably demonstrate behavioral phenotypes of relevance to AS and therefore offer suitable in vivo systems in which to test potential therapeutics. One promising candidate treatment is insulin-like growth factor-2 (IGF-2), which has recently been shown to ameliorate behavioral deficits in the mouse model of AS and improve cognitive abilities across model systems. METHODS We used both the Ube3a maternal deletion mouse and rat models of AS to evaluate the ability of IGF-2 to improve electrophysiological and behavioral outcomes. RESULTS Acute systemic administration of IGF-2 had an effect on electrophysiological activity in the brain and on a metric of motor ability; however the effects were not enduring or extensive. Additional metrics of motor behavior, learning, ambulation, and coordination were unaffected and IGF-2 did not improve social communication, seizure threshold, or cognition. LIMITATIONS The generalizability of these results to humans is difficult to predict and it remains possible that dosing schemes (i.e., chronic or subchronic dosing), routes, and/or post-treatment intervals other than that used herein may show more efficacy. CONCLUSIONS Despite a few observed effects of IGF-2, our results taken together indicate that IGF-2 treatment does not profoundly improve behavioral deficits in mouse or rat models of AS. These findings shed cautionary light on the potential utility of acute systemic IGF-2 administration in the treatment of AS.
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Affiliation(s)
- Elizabeth L. Berg
- MIND Institute and Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Sacramento, CA USA
| | - Stela P. Petkova
- MIND Institute and Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Sacramento, CA USA
| | - Heather A. Born
- Department of Pediatrics and Neurology, Baylor College of Medicine, Houston, TX USA
- Gene Therapy Program, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA USA
| | - Anna Adhikari
- MIND Institute and Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Sacramento, CA USA
| | - Anne E. Anderson
- Department of Pediatrics and Neurology, Baylor College of Medicine, Houston, TX USA
| | - Jill L. Silverman
- MIND Institute and Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Sacramento, CA USA
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26
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Bicker F, Nardi L, Maier J, Vasic V, Schmeisser MJ. Criss-crossing autism spectrum disorder and adult neurogenesis. J Neurochem 2021; 159:452-478. [PMID: 34478569 DOI: 10.1111/jnc.15501] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2021] [Revised: 08/05/2021] [Accepted: 08/28/2021] [Indexed: 12/19/2022]
Abstract
Autism spectrum disorder (ASD) comprises a group of multifactorial neurodevelopmental disorders primarily characterized by deficits in social interaction and repetitive behavior. Although the onset is typically in early childhood, ASD poses a lifelong challenge for both patients and caretakers. Adult neurogenesis (AN) is the process by which new functional neurons are created from neural stem cells existing in the post-natal brain. The entire event is based on a sequence of cellular processes, such as proliferation, specification of cell fate, maturation, and ultimately, synaptic integration into the existing neural circuits. Hence, AN is implicated in structural and functional brain plasticity throughout life. Accumulating evidence shows that impaired AN may underlie some of the abnormal behavioral phenotypes seen in ASD. In this review, we approach the interconnections between the molecular pathways related to AN and ASD. We also discuss existing therapeutic approaches targeting such pathways both in preclinical and clinical studies. A deeper understanding of how ASD and AN reciprocally affect one another could reveal important converging pathways leading to the emergence of psychiatric disorders.
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Affiliation(s)
- Frank Bicker
- Institute for Microscopic Anatomy and Neurobiology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
| | - Leonardo Nardi
- Institute for Microscopic Anatomy and Neurobiology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
| | - Jannik Maier
- Institute for Microscopic Anatomy and Neurobiology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
| | - Verica Vasic
- Institute for Microscopic Anatomy and Neurobiology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
| | - Michael J Schmeisser
- Institute for Microscopic Anatomy and Neurobiology, University Medical Center of the Johannes Gutenberg-University, Mainz, Germany.,Focus Program Translational Neurosciences (FTN), University Medical Center of the Johannes Gutenberg-University, Mainz, Germany
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27
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Marballi K, MacDonald JL. Proteomic and transcriptional changes associated with MeCP2 dysfunction reveal nodes for therapeutic intervention in Rett syndrome. Neurochem Int 2021; 148:105076. [PMID: 34048843 PMCID: PMC8286335 DOI: 10.1016/j.neuint.2021.105076] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 04/13/2021] [Accepted: 05/17/2021] [Indexed: 12/28/2022]
Abstract
Mutations in the methyl-CpG binding protein 2 (MECP2) gene cause Rett syndrome (RTT), an X-linked neurodevelopmental disorder predominantly impacting females. MECP2 is an epigenetic transcriptional regulator acting mainly to repress gene expression, though it plays multiple gene regulatory roles and has distinct molecular targets across different cell types and specific developmental stages. In this review, we summarize MECP2 loss-of-function associated transcriptome and proteome disruptions, delving deeper into the latter which have been comparatively severely understudied. These disruptions converge on multiple biochemical and cellular pathways, including those involved in synaptic function and neurodevelopment, NF-κB signaling and inflammation, and the vitamin D pathway. RTT is a complex neurological disorder characterized by myriad physiological disruptions, in both the central nervous system and peripheral systems. Thus, treating RTT will likely require a combinatorial approach, targeting multiple nodes within the interactomes of these cellular pathways. To this end, we discuss the use of dietary supplements and factors, namely, vitamin D and polyunsaturated fatty acids (PUFAs), as possible partial therapeutic agents given their demonstrated benefit in RTT and their ability to restore homeostasis to multiple disrupted cellular pathways simultaneously. Further unravelling the complex molecular alterations induced by MECP2 loss-of-function, and contextualizing them at the level of proteome homeostasis, will identify new therapeutic avenues for this complex disorder.
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Affiliation(s)
- Ketan Marballi
- Department of Biology, Program in Neuroscience, Syracuse University, Syracuse, NY, USA
| | - Jessica L MacDonald
- Department of Biology, Program in Neuroscience, Syracuse University, Syracuse, NY, USA.
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28
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Morrow EM. Early Human Postnatal Brain Development Through the Lens of Rare Genetic Disorders. Biol Psychiatry 2021; 90:281-282. [PMID: 34384527 PMCID: PMC8767462 DOI: 10.1016/j.biopsych.2021.07.001] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/30/2021] [Accepted: 07/01/2021] [Indexed: 10/20/2022]
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29
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Brock DC, Demarest S, Benke TA. Clinical Trial Design for Disease-Modifying Therapies for Genetic Epilepsies. Neurotherapeutics 2021; 18:1445-1457. [PMID: 34595733 PMCID: PMC8609073 DOI: 10.1007/s13311-021-01123-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/07/2021] [Indexed: 02/04/2023] Open
Abstract
Although trials with anti-seizure medications (ASMs) have not shown clear anti-epileptogenic or disease-modifying activity in humans to date, rapid advancements in genomic technology and emerging gene-mediated and gene replacement options offer hope for the successful development of disease-modifying therapies (DMTs) for genetic epilepsies. In fact, more than 26 potential DMTs are in various stages of preclinical and/or clinical development for genetic syndromes associated with epilepsy. The scope of disease-modification includes but is not limited to effects on the underlying pathophysiology, the condition's natural history, epilepsy severity, developmental achievement, function, behavior, sleep, and quality of life. While conventional regulatory clinical trials for epilepsy therapeutics have historically focused on seizure reduction, similarly designed trials may prove ill-equipped to identify these broader disease-modifying benefits. As we look forward to this pipeline of DMTs, focused consideration should be given to the challenges they pose to conventional clinical trial designs for epilepsy therapeutics. Just as DMTs promise to fundamentally alter how we approach the care of patients with genetic epilepsy syndromes, DMTs likewise challenge how we traditionally construct and measure the success of clinical trials. In the following, we briefly review the historical and preclinical frameworks for DMT development for genetic epilepsies and explore the many novel challenges posed for such trials, including the choice of suitable outcome measures, trial structure, timing and duration of treatment, feasible follow-up period, varying safety profile, and ethical concerns.
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Affiliation(s)
- Dylan C Brock
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, 80045, USA.
- Children's Hospital Colorado, Aurora, CO, 80045, USA.
| | - Scott Demarest
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, 80045, USA
- Children's Hospital Colorado, Aurora, CO, 80045, USA
| | - Tim A Benke
- Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO, 80045, USA
- Departments of Neurology, Pharmacology, and Otolaryngology, University of Colorado School of Medicine, CO, 80045, Aurora, USA
- Children's Hospital Colorado, Aurora, CO, 80045, USA
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30
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Armstrong C, Marsh ED. Electrophysiological Biomarkers in Genetic Epilepsies. Neurotherapeutics 2021; 18:1458-1467. [PMID: 34642905 PMCID: PMC8609056 DOI: 10.1007/s13311-021-01132-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/27/2021] [Indexed: 02/04/2023] Open
Abstract
Precision treatments for epilepsy targeting the underlying genetic diagnoses are becoming a reality. Historically, the goal of epilepsy treatments was to reduce seizure frequency. In the era of precision medicine, however, outcomes such as prevention of epilepsy progression or even improvements in cognitive functions are both aspirational targets for any intervention. Developing methods, both in clinical trial design and in novel endpoints, will be necessary for measuring, not only seizures, but also the other neurodevelopmental outcomes that are predicted to be targeted by precision treatments. Biomarkers that quantitatively measure disease progression or network level changes are needed to allow for unbiased measurements of the effects of any gene-level treatments. Here, we discuss some of the promising electrophysiological biomarkers that may be of use in clinical trials of precision therapies, as well as the difficulties in implementing them.
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Affiliation(s)
- Caren Armstrong
- Division of Neurology and Pediatric Epilepsy Program, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA
| | - Eric D Marsh
- Division of Neurology and Pediatric Epilepsy Program, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA.
- Department of Pediatrics and Neurology, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19104, USA.
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31
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Novel treatments for autism spectrum disorder based on genomics and systems biology. Pharmacol Ther 2021; 230:107939. [PMID: 34174273 DOI: 10.1016/j.pharmthera.2021.107939] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2021] [Accepted: 06/03/2021] [Indexed: 12/14/2022]
Abstract
BACKGROUND Autism spectrum disorder (ASD) is a highly heterogeneous neurodevelopmental disorder with a complex underlying genetic architecture. There are currently no known pharmacologic treatments for the core ASD symptoms of social deficits and restricted/ repetitive behavior. However, there are dozens of clinical trials currently underway that are testing the impact of novel and existing agents on core and associated symptoms in ASD. METHODS We present a narrative synthesis of the historical and contemporary challenges to drug discovery in ASD. We then provide an overview of novel treatments currently under investigation from a genomics and systems biology perspective. RESULTS Data driven network and cluster analyses suggest alterations in transcriptional regulation, chromatin remodelling, synaptic transmission, neuropeptide signalling, and/or immunological mechanisms may contribute to or underlie the development of ASD. Agents and upcoming trials targeting each of the above listed systems are reviewed. CONCLUSION Identifying effective pharmacologic treatments for the core and associated symptom domains in ASD will require further collaboration and innovation in the areas of outcome measurement, biomarker research, and genomics, as well as systematic efforts to identify and treat subgroups of individuals with ASD who may be differentially responsive to specific treatments.
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32
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Reviewing Evidence for the Relationship of EEG Abnormalities and RTT Phenotype Paralleled by Insights from Animal Studies. Int J Mol Sci 2021; 22:ijms22105308. [PMID: 34069993 PMCID: PMC8157853 DOI: 10.3390/ijms22105308] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Revised: 05/09/2021] [Accepted: 05/12/2021] [Indexed: 12/29/2022] Open
Abstract
Rett syndrome (RTT) is a rare neurodevelopmental disorder that is usually caused by mutations of the MECP2 gene. Patients with RTT suffer from severe deficits in motor, perceptual and cognitive domains. Electroencephalogram (EEG) has provided useful information to clinicians and scientists, from the very first descriptions of RTT, and yet no reliable neurophysiological biomarkers related to the pathophysiology of the disorder or symptom severity have been identified to date. To identify consistently observed and potentially informative EEG characteristics of RTT pathophysiology, and ascertain areas most worthy of further systematic investigation, here we review the literature for EEG abnormalities reported in patients with RTT and in its disease models. While pointing to some promising potential EEG biomarkers of RTT, our review identify areas of need to realize the potential of EEG including (1) quantitative investigation of promising clinical-EEG observations in RTT, e.g., shift of mu rhythm frequency and EEG during sleep; (2) closer alignment of approaches between patients with RTT and its animal models to strengthen the translational significance of the work (e.g., EEG measurements and behavioral states); (3) establishment of large-scale consortium research, to provide adequate Ns to investigate age and genotype effects.
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33
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The role of GABAergic signalling in neurodevelopmental disorders. Nat Rev Neurosci 2021; 22:290-307. [PMID: 33772226 PMCID: PMC9001156 DOI: 10.1038/s41583-021-00443-x] [Citation(s) in RCA: 72] [Impact Index Per Article: 24.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 02/12/2021] [Indexed: 02/08/2023]
Abstract
GABAergic inhibition shapes the connectivity, activity and plasticity of the brain. A series of exciting new discoveries provides compelling evidence that disruptions in a number of key facets of GABAergic inhibition have critical roles in the aetiology of neurodevelopmental disorders (NDDs). These facets include the generation, migration and survival of GABAergic neurons, the formation of GABAergic synapses and circuit connectivity, and the dynamic regulation of the efficacy of GABAergic signalling through neuronal chloride transporters. In this Review, we discuss recent work that elucidates the functions and dysfunctions of GABAergic signalling in health and disease, that uncovers the contribution of GABAergic neural circuit dysfunction to NDD aetiology and that leverages such mechanistic insights to advance precision medicine for the treatment of NDDs.
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34
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Gomes AR, Fernandes TG, Cabral JM, Diogo MM. Modeling Rett Syndrome with Human Pluripotent Stem Cells: Mechanistic Outcomes and Future Clinical Perspectives. Int J Mol Sci 2021; 22:3751. [PMID: 33916879 PMCID: PMC8038474 DOI: 10.3390/ijms22073751] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2021] [Revised: 03/23/2021] [Accepted: 04/02/2021] [Indexed: 12/19/2022] Open
Abstract
Rett syndrome (RTT) is a neurodevelopmental disorder caused by mutations in the gene encoding the methyl-CpG-binding protein 2 (MeCP2). Among many different roles, MeCP2 has a high phenotypic impact during the different stages of brain development. Thus, it is essential to intensively investigate the function of MeCP2, and its regulated targets, to better understand the mechanisms of the disease and inspire the development of possible therapeutic strategies. Several animal models have greatly contributed to these studies, but more recently human pluripotent stem cells (hPSCs) have been providing a promising alternative for the study of RTT. The rapid evolution in the field of hPSC culture allowed first the development of 2D-based neuronal differentiation protocols, and more recently the generation of 3D human brain organoid models, a more complex approach that better recapitulates human neurodevelopment in vitro. Modeling RTT using these culture platforms, either with patient-specific human induced pluripotent stem cells (hiPSCs) or genetically-modified hPSCs, has certainly contributed to a better understanding of the onset of RTT and the disease phenotype, ultimately allowing the development of high throughput drugs screening tests for potential clinical translation. In this review, we first provide a brief summary of the main neurological features of RTT and the impact of MeCP2 mutations in the neuropathophysiology of this disease. Then, we provide a thorough revision of the more recent advances and future prospects of RTT modeling with human neural cells derived from hPSCs, obtained using both 2D and organoids culture systems, and its contribution for the current and future clinical trials for RTT.
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Affiliation(s)
- Ana Rita Gomes
- Department of Bioengineering and IBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal; (A.R.G.); (T.G.F.); (J.M.S.C.)
- Associate Laboratory i4HB-Institute for Health and Bioeconomy, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
- Instituto de Medicina Molecular-João Lobo Antunes, Faculdade de Medicina da Universidade de Lisboa, 1649-028 Lisboa, Portugal
| | - Tiago G. Fernandes
- Department of Bioengineering and IBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal; (A.R.G.); (T.G.F.); (J.M.S.C.)
- Associate Laboratory i4HB-Institute for Health and Bioeconomy, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| | - Joaquim M.S. Cabral
- Department of Bioengineering and IBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal; (A.R.G.); (T.G.F.); (J.M.S.C.)
- Associate Laboratory i4HB-Institute for Health and Bioeconomy, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
| | - Maria Margarida Diogo
- Department of Bioengineering and IBB-Institute for Bioengineering and Biosciences, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal; (A.R.G.); (T.G.F.); (J.M.S.C.)
- Associate Laboratory i4HB-Institute for Health and Bioeconomy, Instituto Superior Técnico, Universidade de Lisboa, Av. Rovisco Pais, 1049-001 Lisboa, Portugal
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35
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Trujillo CA, Adams JW, Negraes PD, Carromeu C, Tejwani L, Acab A, Tsuda B, Thomas CA, Sodhi N, Fichter KM, Romero S, Zanella F, Sejnowski TJ, Ulrich H, Muotri AR. Pharmacological reversal of synaptic and network pathology in human MECP2-KO neurons and cortical organoids. EMBO Mol Med 2021; 13:e12523. [PMID: 33501759 PMCID: PMC7799367 DOI: 10.15252/emmm.202012523] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2020] [Revised: 10/26/2020] [Accepted: 10/28/2020] [Indexed: 12/19/2022] Open
Abstract
Duplication or deficiency of the X-linked MECP2 gene reliably produces profound neurodevelopmental impairment. MECP2 mutations are almost universally responsible for Rett syndrome (RTT), and particular mutations and cellular mosaicism of MECP2 may underlie the spectrum of RTT symptomatic severity. No clinically approved treatments for RTT are currently available, but human pluripotent stem cell technology offers a platform to identify neuropathology and test candidate therapeutics. Using a strategic series of increasingly complex human stem cell-derived technologies, including human neurons, MECP2-mosaic neurospheres to model RTT female brain mosaicism, and cortical organoids, we identified synaptic dysregulation downstream from knockout of MECP2 and screened select pharmacological compounds for their ability to treat this dysfunction. Two lead compounds, Nefiracetam and PHA 543613, specifically reversed MECP2-knockout cytologic neuropathology. The capacity of these compounds to reverse neuropathologic phenotypes and networks in human models supports clinical studies for neurodevelopmental disorders in which MeCP2 deficiency is the predominant etiology.
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Affiliation(s)
- Cleber A Trujillo
- Department of Pediatrics/Rady Children's HospitalDepartment of Cellular & Molecular MedicineSchool of MedicineUniversity of California San DiegoLa JollaCAUSA
| | - Jason W Adams
- Department of Pediatrics/Rady Children's HospitalDepartment of Cellular & Molecular MedicineSchool of MedicineUniversity of California San DiegoLa JollaCAUSA
- Department of NeurosciencesSchool of MedicineUniversity of California San DiegoLa JollaCAUSA
- Center for Academic Research and Training in AnthropogenyUniversity of California San DiegoLa JollaCAUSA
| | - Priscilla D Negraes
- Department of Pediatrics/Rady Children's HospitalDepartment of Cellular & Molecular MedicineSchool of MedicineUniversity of California San DiegoLa JollaCAUSA
- StemoniX IncMaple GroveMNUSA
| | - Cassiano Carromeu
- Department of Pediatrics/Rady Children's HospitalDepartment of Cellular & Molecular MedicineSchool of MedicineUniversity of California San DiegoLa JollaCAUSA
- StemoniX IncMaple GroveMNUSA
| | - Leon Tejwani
- Department of Pediatrics/Rady Children's HospitalDepartment of Cellular & Molecular MedicineSchool of MedicineUniversity of California San DiegoLa JollaCAUSA
- Present address:
Interdepartmental Neuroscience ProgramYale School of MedicineNew HavenCTUSA
| | - Allan Acab
- Department of Pediatrics/Rady Children's HospitalDepartment of Cellular & Molecular MedicineSchool of MedicineUniversity of California San DiegoLa JollaCAUSA
| | - Ben Tsuda
- Department of NeurosciencesSchool of MedicineUniversity of California San DiegoLa JollaCAUSA
- Computational Neurobiology LaboratorySalk Institute for Biological StudiesLa JollaCAUSA
| | - Charles A Thomas
- Department of Pediatrics/Rady Children's HospitalDepartment of Cellular & Molecular MedicineSchool of MedicineUniversity of California San DiegoLa JollaCAUSA
| | | | | | | | | | - Terrence J Sejnowski
- Computational Neurobiology LaboratorySalk Institute for Biological StudiesLa JollaCAUSA
- Institute for Neural ComputationUniversity of California San DiegoLa JollaCAUSA
- Division of Biological SciencesUniversity of California San DiegoLa JollaCAUSA
| | - Henning Ulrich
- Departamento de BioquímicaInstituto de QuímicaUniversidade de São PauloSão PauloBrazil
| | - Alysson R Muotri
- Department of Pediatrics/Rady Children's HospitalDepartment of Cellular & Molecular MedicineSchool of MedicineUniversity of California San DiegoLa JollaCAUSA
- Center for Academic Research and Training in AnthropogenyUniversity of California San DiegoLa JollaCAUSA
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36
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Huang ZX, Chen Y, Guo HR, Chen GF. Systematic Review and Bioinformatic Analysis of microRNA Expression in Autism Spectrum Disorder Identifies Pathways Associated With Cancer, Metabolism, Cell Signaling, and Cell Adhesion. Front Psychiatry 2021; 12:630876. [PMID: 34744804 PMCID: PMC8566729 DOI: 10.3389/fpsyt.2021.630876] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/18/2020] [Accepted: 08/31/2021] [Indexed: 12/13/2022] Open
Abstract
Background: Previous studies have identified differentially expressed microRNAs in autism spectrum disorder (ASD), however, results are discrepant. We aimed to systematically review this topic and perform bioinformatic analysis to identify genes and pathways associated with ASD miRNAs. Methods: Following the Preferred Reporting Items for Systematic reviews and Meta-Analyses, we searched the Web of Science, PubMed, Embase, Scopus, and OVID databases to identify all studies comparing microRNA expressions between ASD persons and non-ASD controls on May 11, 2020. We obtained ASD miRNA targets validated by experimental assays from miRTarBase and performed pathway enrichment analysis using Metascape and DIANA-miRPath v3. 0. Results: Thirty-four studies were included in the systematic review. Among 285 altered miRNAs reported in these studies, 15 were consistently upregulated, 14 were consistently downregulated, and 39 were inconsistently dysregulated. The most frequently altered miRNAs including miR-23a-3p, miR-106b-5p, miR-146a-5p, miR-7-5p, miR-27a-3p, miR-181b-5p, miR-486-3p, and miR-451a. Subgroup analysis of tissues showed that miR-146a-5p, miR-155-5p, miR-1277-3p, miR-21-3p, miR-106b-5p, and miR-451a were consistently upregulated in brain tissues, while miR-4742-3p was consistently downregulated; miR-23b-3p, miR-483-5p, and miR-23a-3p were consistently upregulated in blood samples, while miR-15a-5p, miR-193a-5p, miR-20a-5p, miR-574-3p, miR-92a-3p, miR-3135a, and miR-103a-3p were consistently downregulated; miR-7-5p was consistently upregulated in saliva, miR-23a-3p and miR-32-5p were consistently downregulated. The altered ASD miRNAs identified in at least two independent studies were validated to target many autism risk genes. TNRC6B, PTEN, AGO1, SKI, and SMAD4 were the most frequent targets, and miR-92a-3p had the most target autism risk genes. Pathway enrichment analysis showed that ASD miRNAs are significantly involved in pathways associated with cancer, metabolism (notably Steroid biosynthesis, Fatty acid metabolism, Fatty acid biosynthesis, Lysine degradation, Biotin metabolism), cell cycle, cell signaling (especially Hippo, FoxO, TGF-beta, p53, Thyroid hormone, and Estrogen signaling pathway), adherens junction, extracellular matrix-receptor interaction, and Prion diseases. Conclusions: Altered miRNAs in ASD target autism risk genes and are involved in various ASD-related pathways, some of which are understudied and require further investigation.
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Affiliation(s)
- Zhi-Xiong Huang
- Department of Pediatrics, Fujian Medical University Union Hospital, Fuzhou, China
| | - Yanhui Chen
- Department of Pediatrics, Fujian Medical University Union Hospital, Fuzhou, China
| | - Hong-Ru Guo
- Department of Pediatrics, Fujian Medical University Union Hospital, Fuzhou, China
| | - Guo-Feng Chen
- Department of Pediatrics, Fujian Medical University Union Hospital, Fuzhou, China
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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: 27] [Impact Index Per Article: 6.8] [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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38
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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: 97] [Impact Index Per Article: 24.3] [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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39
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Javed S, Selliah T, Lee YJ, Huang WH. Dosage-sensitive genes in autism spectrum disorders: From neurobiology to therapy. Neurosci Biobehav Rev 2020; 118:538-567. [PMID: 32858083 DOI: 10.1016/j.neubiorev.2020.08.009] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2020] [Revised: 07/26/2020] [Accepted: 08/17/2020] [Indexed: 12/24/2022]
Abstract
Autism spectrum disorders (ASDs) are a group of heterogenous neurodevelopmental disorders affecting 1 in 59 children. Syndromic ASDs are commonly associated with chromosomal rearrangements or dosage imbalance involving a single gene. Many of these genes are dosage-sensitive and regulate transcription, protein homeostasis, and synaptic function in the brain. Despite vastly different molecular perturbations, syndromic ASDs share core symptoms including social dysfunction and repetitive behavior. However, each ASD subtype has a unique pathogenic mechanism and combination of comorbidities that require individual attention. We have learned a great deal about how these dosage-sensitive genes control brain development and behaviors from genetically-engineered mice. Here we describe the clinical features of eight monogenic neurodevelopmental disorders caused by dosage imbalance of four genes, as well as recent advances in using genetic mouse models to understand their pathogenic mechanisms and develop intervention strategies. We propose that applying newly developed quantitative molecular and neuroscience technologies will advance our understanding of the unique neurobiology of each disorder and enable the development of personalized therapy.
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Affiliation(s)
- Sehrish Javed
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
| | - Tharushan Selliah
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
| | - Yu-Ju Lee
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada
| | - Wei-Hsiang Huang
- Centre for Research in Neuroscience, Department of Neurology and Neurosurgery, The Research Institute of the McGill University Health Centre, Montréal, Québec, Canada.
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40
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Functional Network Mapping Reveals State-Dependent Response to IGF1 Treatment in Rett Syndrome. Brain Sci 2020; 10:brainsci10080515. [PMID: 32756423 PMCID: PMC7465931 DOI: 10.3390/brainsci10080515] [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: 06/14/2020] [Revised: 07/22/2020] [Accepted: 07/24/2020] [Indexed: 01/20/2023] Open
Abstract
Rett Syndrome (RTT) is a neurodevelopmental disorder associated with mutations in the gene MeCP2, which is involved in the development and function of cortical networks. The clinical presentation of RTT is generally severe and includes developmental regression and marked neurologic impairment. Insulin-Like growth factor 1 (IGF1) ameliorates RTT-relevant phenotypes in animal models and improves some clinical manifestations in early human trials. However, it remains unclear whether IGF1 treatment has an impact on cortical electrophysiology in line with MeCP2’s role in network formation, and whether these electrophysiological changes are related to clinical response. We performed clinical assessments and resting-state electroencephalogram (EEG) recordings in eighteen patients with classic RTT, nine of whom were treated with IGF1. Among the treated patients, we distinguished those who showed improvements after treatment (responders) from those who did not show any changes (nonresponders). Clinical assessments were carried out for all individuals with RTT at baseline and 12 months after treatment. Network measures were derived using statistical modelling techniques based on interelectrode coherence measures. We found significant interaction between treatment groups and timepoints, indicating an effect of IGF1 on network measures. We also found a significant effect of responder status and timepoint, indicating that these changes in network measures are associated with clinical response to treatment. Further, we found baseline variability in network characteristics, and a machine learning model using these measures applied to pretreatment data predicted treatment response with 100% accuracy (100% sensitivity and 100% specificity) in this small patient group. These results highlight the importance of network pathology in RTT, as well as providing preliminary evidence for the potential of network measures as tools for the characterisation of disease subtypes and as biomarkers for clinical trials.
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41
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Saby JN, Peters SU, Roberts TPL, Nelson CA, Marsh ED. Evoked Potentials and EEG Analysis in Rett Syndrome and Related Developmental Encephalopathies: Towards a Biomarker for Translational Research. Front Integr Neurosci 2020; 14:30. [PMID: 32547374 PMCID: PMC7271894 DOI: 10.3389/fnint.2020.00030] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2019] [Accepted: 05/04/2020] [Indexed: 12/17/2022] Open
Abstract
Rett syndrome is a debilitating neurodevelopmental disorder for which no disease-modifying treatment is available. Fortunately, advances in our understanding of the genetics and pathophysiology of Rett syndrome has led to the development of promising new therapeutics for the condition. Several of these therapeutics are currently being tested in clinical trials with others likely to progress to clinical trials in the coming years. The failure of recent clinical trials for Rett syndrome and other neurodevelopmental disorders has highlighted the need for electrophysiological or other objective biological markers of treatment response to support the success of clinical trials moving forward. The purpose of this review is to describe the existing studies of electroencephalography (EEG) and evoked potentials (EPs) in Rett syndrome and discuss the open questions that must be addressed before the field can adopt these measures as surrogate endpoints in clinical trials. In addition to summarizing the human work on Rett syndrome, we also describe relevant studies with animal models and the limited research that has been carried out on Rett-related disorders, particularly methyl-CpG binding protein 2 (MECP2) duplication syndrome, CDKL5 deficiency disorder, and FOXG1 disorder.
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Affiliation(s)
- Joni N. Saby
- Lurie Family Foundations MEG Imaging Center, Department of Radiology, The Children’s Hospital of Philadelphia, Philadelphia, PA, United States
| | - Sarika U. Peters
- Department of Pediatrics, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Timothy P. L. Roberts
- Lurie Family Foundations MEG Imaging Center, Department of Radiology, The Children’s Hospital of Philadelphia, Philadelphia, PA, United States,Department of Radiology, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, United States
| | - Charles A. Nelson
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Boston Children’s Hospital, Harvard Medical School, Boston, MA, United States
| | - Eric D. Marsh
- Division of Neurology and Pediatrics, Children’s Hospital of Philadelphia, Philadelphia, PA, United States,Departments of Neurology and Pediatrics, Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, United States,*Correspondence: Eric D. Marsh
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42
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Fagiolini M, Patrizi A, LeBlanc J, Jin LW, Maezawa I, Sinnett S, Gray SJ, Molholm S, Foxe JJ, Johnston MV, Naidu S, Blue M, Hossain A, Kadam S, Zhao X, Chang Q, Zhou Z, Zoghbi H. Intellectual and Developmental Disabilities Research Centers: A Multidisciplinary Approach to Understand the Pathogenesis of Methyl-CpG Binding Protein 2-related Disorders. Neuroscience 2020; 445:190-206. [PMID: 32360592 DOI: 10.1016/j.neuroscience.2020.04.037] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2020] [Revised: 04/20/2020] [Accepted: 04/21/2020] [Indexed: 12/20/2022]
Abstract
Disruptions in the gene encoding methyl-CpG binding protein 2 (MECP2) underlie complex neurodevelopmental disorders including Rett Syndrome (RTT), MECP2 duplication disorder, intellectual disabilities, and autism. Significant progress has been made on the molecular and cellular basis of MECP2-related disorders providing a new framework for understanding how altered epigenetic landscape can derail the formation and refinement of neuronal circuits in early postnatal life and proper neurological function. This review will summarize selected major findings from the past years and particularly highlight the integrated and multidisciplinary work done at eight NIH-funded Intellectual and Developmental Disabilities Research Centers (IDDRC) across the US. Finally, we will outline a path forward with identification of reliable biomarkers and outcome measures, longitudinal preclinical and clinical studies, reproducibility of results across centers as a synergistic effort to decode and treat the pathogenesis of the complex MeCP2 disorders.
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Affiliation(s)
- Michela Fagiolini
- Children's Hospital Intellectual and Developmental Disabilities Research Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
| | - Annarita Patrizi
- Children's Hospital Intellectual and Developmental Disabilities Research Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Jocelyn LeBlanc
- Children's Hospital Intellectual and Developmental Disabilities Research Center, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Lee-Way Jin
- UC Davis MIND Institute, University of California, Sacramento, CA, USA
| | - Izumi Maezawa
- UC Davis MIND Institute, University of California, Sacramento, CA, USA
| | - Sarah Sinnett
- UNC Intellectual and Developmental Disabilities Research Center, University of North Carolina, Gene Therapy Center and Dept. of Ophthalmology, Chapel Hill, NC, USA; Department of Pediatrics, UT Southwestern Medical Center, Dallas, TX, USA
| | - Steven J Gray
- UNC Intellectual and Developmental Disabilities Research Center, University of North Carolina, Gene Therapy Center and Dept. of Ophthalmology, Chapel Hill, NC, USA; Department of Pediatrics, UT Southwestern Medical Center, Dallas, TX, USA
| | - Sophie Molholm
- The Cognitive Neurophysiology Laboratory, Departments of Pediatrics, Neuroscience, and Psychiatry and Behavioral Sciences, Albert Einstein College of Medicine, Bronx, NY, USA
| | - John J Foxe
- The Cognitive Neurophysiology Laboratory, Ernest J. Del Monte Institute for Neuroscience, Department of Neuroscience, University of Rochester School of Medicine and Dentistry, Rochester, NY, USA
| | - Michael V Johnston
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Sakkubai Naidu
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Mary Blue
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Ahamed Hossain
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Shilpa Kadam
- Kennedy Krieger Institute Intellectual and Developmental Disabilities Research Center/Hugo Moser Research Institute at Kennedy Krieger and Johns Hopkins School of Medicine, USA
| | - Xinyu Zhao
- Waisman Center, University of Wisconsin-Madison, Madison, WI, USA
| | - Quiang Chang
- Waisman Center, University of Wisconsin-Madison, Madison, WI, USA
| | - Zhaolan Zhou
- Department of Genetic, Epigenetic Institute, University of Pennsylvania Perelman School of Medicine, Intellectual and Developmental Disabilities Research Center, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Huda Zoghbi
- Jan and Dan Duncan Neurological Research Institute at Texas Children's Hospital, Houston, TX, USA; Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA; Program in Developmental Biology, Baylor College of Medicine, Houston, TX, USA; Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA; Department of Neuroscience, Baylor College of Medicine, Houston, TX, USA; Howard Hughes Medical Institute, Baylor College of Medicine, Houston, TX, USA
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43
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Bernardo P, Cobb S, Coppola A, Tomasevic L, Di Lazzaro V, Bravaccio C, Manganelli F, Dubbioso R. Neurophysiological Signatures of Motor Impairment in Patients with Rett Syndrome. Ann Neurol 2020; 87:763-773. [PMID: 32129908 DOI: 10.1002/ana.25712] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2019] [Revised: 03/02/2020] [Accepted: 03/02/2020] [Indexed: 12/15/2022]
Abstract
OBJECTIVE Rett syndrome (RTT) is an X-linked dominant neurodevelopmental disorder due to pathogenic mutations in the MECP2 gene. Motor impairment constitutes the core diagnostic feature of RTT. Preclinical studies have consistently demonstrated alteration of excitation/inhibition (E/I) balance and aberrant synaptic plasticity at the cortical level. We aimed to understand neurobiological mechanisms underlying motor deficit by assessing in vivo synaptic plasticity and E/I balance in the primary motor cortex (M1). METHODS In 14 patients with typical RTT, 9 epilepsy control patients, and 11 healthy controls, we applied paired-pulse transcranial magnetic stimulation (TMS) protocols to evaluate the excitation index, a biomarker reflecting the contribution of inhibitory and facilitatory circuits in M1. Intermittent TMS-theta burst stimulation was used to probe long-term potentiation (LTP)-like plasticity in M1. Motor impairment, assessed by ad hoc clinical scales, was correlated with neurophysiological metrics. RESULTS RTT patients displayed a significant increase of the excitation index (p = 0.003), as demonstrated by the reduction of short-interval intracortical inhibition and increase of intracortical facilitation, suggesting a shift toward cortical excitation likely due to GABAergic dysfunction. Impairment of inhibitory circuits was also confirmed by the reduction of long-interval intracortical inhibition (p = 0.002). LTP-like plasticity in M1 was abolished (p = 0.008) and scaled with motor disability (all p = 0.003). INTERPRETATION TMS is a method that can be used to assess cortical motor function in RTT patients. Our findings support the introduction of TMS measures in clinical and research settings to monitor the progression of motor deficit and response to treatment. ANN NEUROL 2020;87:763-773.
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Affiliation(s)
- Pia Bernardo
- Department of Neuroscience, Child Neuropsychiatry Unit, Santobono-Pausilipon Children's Hospital, Naples, Italy.,Department of Translational Medical Sciences, Child Neuropsychiatry Unit, University of Naples Federico II, Naples, Italy
| | - Stuart Cobb
- Institute of Neuroscience and Psychology, College of Medical, Veterinary, and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Antonietta Coppola
- Department of Neurosciences, Reproductive Sciences and Odontostomatology, University of Naples Federico II, Naples, Italy
| | - Leo Tomasevic
- Danish Research Center for Magnetic Resonance, Copenhagen University Hospital Hvidovre, Hvidovre, Denmark
| | - Vincenzo Di Lazzaro
- Unit of Neurology, Neurophysiology, Neurobiology, Department of Medicine, Campus Bio-Medico University of Rome, Rome, Italy
| | - Carmela Bravaccio
- Department of Translational Medical Sciences, Child Neuropsychiatry Unit, University of Naples Federico II, Naples, Italy
| | - Fiore Manganelli
- Department of Neurosciences, Reproductive Sciences and Odontostomatology, University of Naples Federico II, Naples, Italy
| | - Raffaele Dubbioso
- Department of Neurosciences, Reproductive Sciences and Odontostomatology, University of Naples Federico II, Naples, Italy
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44
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Cioana M, Michalski B, Fahnestock M. Insulin‐Like Growth Factor and Insulin‐Like Growth Factor Receptor Expression in Human Idiopathic Autism Fusiform Gyrus Tissue. Autism Res 2020; 13:897-907. [DOI: 10.1002/aur.2291] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 02/04/2020] [Accepted: 02/26/2020] [Indexed: 12/17/2022]
Affiliation(s)
- Milena Cioana
- Department of Psychiatry and Behavioural Neurosciences McMaster University Hamilton Ontario L8S 4K1 Canada
| | - Bernadeta Michalski
- Department of Psychiatry and Behavioural Neurosciences McMaster University Hamilton Ontario L8S 4K1 Canada
| | - Margaret Fahnestock
- Department of Psychiatry and Behavioural Neurosciences McMaster University Hamilton Ontario L8S 4K1 Canada
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45
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Ribeiro MC, MacDonald JL. Sex differences in Mecp2-mutant Rett syndrome model mice and the impact of cellular mosaicism in phenotype development. Brain Res 2020; 1729:146644. [PMID: 31904347 DOI: 10.1016/j.brainres.2019.146644] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2019] [Revised: 12/08/2019] [Accepted: 12/31/2019] [Indexed: 12/29/2022]
Abstract
There is currently no effective treatment for Rett syndrome (RTT), a severe X-linked progressive neurodevelopmental disorder caused by mutations in the transcriptional regulator MECP2. Because MECP2 is subjected to X-inactivation, most affected individuals are female heterozygotes who display cellular mosaicism for normal and mutant MECP2. Males who are hemizygous for mutant MECP2 are more severely affected than heterozygous females and rarely survive. Mecp2 loss-of-function is less severe in mice, however, and male hemizygous null mice not only survive until adulthood, they have been the most commonly studied model system. Although heterozygous female mice better recapitulate human RTT, they have not been as thoroughly characterized. This is likely because of the added experimental challenges that they present, including delayed and more variable phenotypic progression and cellular mosaicism due to X-inactivation. In this review, we compare phenotypes of Mecp2 heterozygous female mice and male hemizygous null mouse models. Further, we discuss the complexities that arise from the many cell-type and tissue-type specific roles of MeCP2, as well as the combination of cell-autonomous and non-cell-autonomous disruptions that result from Mecp2 loss-of-function. This is of particular importance in the context of the female heterozygous brain, composed of a mixture of MeCP2+ and MeCP2- cells, the ratio of which can alter RTT phenotypes in the case of skewed X-inactivation. The goal of this review is to provide a clearer understanding of the pathophysiological differences between the mouse models, which is an essential consideration in the design of future pre-clinical studies.
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Affiliation(s)
- Mayara C Ribeiro
- Department of Biology, Program in Neuroscience, Syracuse University, Syracuse, NY, United States
| | - Jessica L MacDonald
- Department of Biology, Program in Neuroscience, Syracuse University, Syracuse, NY, United States.
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46
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Kaufmann WE, Sprouse J, Rebowe N, Hanania T, Klamer D, Missling CU. ANAVEX®2-73 (blarcamesine), a Sigma-1 receptor agonist, ameliorates neurologic impairments in a mouse model of Rett syndrome. Pharmacol Biochem Behav 2019; 187:172796. [PMID: 31704481 DOI: 10.1016/j.pbb.2019.172796] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/23/2019] [Revised: 09/26/2019] [Accepted: 10/04/2019] [Indexed: 11/23/2022]
Abstract
Rett syndrome (RTT) is a severe neurodevelopmental disorder that is associated in most cases with mutations in the transcriptional regulator MECP2. At present, there are no effective treatments for the disorder. Despite recent advances in RTT genetics and neurobiology, most drug development programs have focused on compounds targeting the IGF-1 pathway and no pivotal trial has been completed as yet. Thus, testing novel drugs that can ameliorate RTT's clinical manifestations is a high priority. ANAVEX2-73 (blarcamesine) is a Sigma-1 receptor agonist and muscarinic receptor modulator with a strong safety record and preliminary evidence of efficacy in patients with Alzheimer's disease. Its role in calcium homeostasis and mitochondrial function, cellular functions that underlie pathological processes and compensatory mechanisms in RTT, makes blarcamesine an intriguing drug candidate for this disorder. Mice deficient in MeCP2 have a range of physiological and neurological abnormalities that mimic the human syndrome. We tested blarcamesine in female heterozygous mice carrying one null allele of Mecp2 (HET) using a two-tier approach, with age-appropriate tests. Administration of the drug to younger and older adult mice resulted in improvement in multiple motor, sensory, and autonomic phenotypes of relevance to RTT. The latter included motor coordination and balance, acoustic and visual responses, hindlimb clasping, and apnea in expiration. In line with previous animal and human studies, blarcamesine also showed a good safety profile in this mouse model of RTT. Clinical studies in RTT with blarcamesine are ongoing.
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Affiliation(s)
- Walter E Kaufmann
- Anavex Life Sciences Corp., 51 West 52nd Street, 7th floor, New York, NY 10019, USA; Department of Human Genetics, Emory University School of Medicine, 615 Michael Street, Atlanta, GA 30322.
| | - Jeffrey Sprouse
- Anavex Life Sciences Corp., 51 West 52nd Street, 7th floor, New York, NY 10019, USA
| | - Nell Rebowe
- Anavex Life Sciences Corp., 51 West 52nd Street, 7th floor, New York, NY 10019, USA
| | - Taleen Hanania
- PsychoGenics Inc., 215 College Road, Paramus, NJ 07652, USA
| | - Daniel Klamer
- Anavex Life Sciences Corp., 51 West 52nd Street, 7th floor, New York, NY 10019, USA
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47
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Sanders SJ, Sahin M, Hostyk J, Thurm A, Jacquemont S, Avillach P, Douard E, Martin CL, Modi ME, Moreno-De-Luca A, Raznahan A, Anticevic A, Dolmetsch R, Feng G, Geschwind DH, Glahn DC, Goldstein DB, Ledbetter DH, Mulle JG, Pasca SP, Samaco R, Sebat J, Pariser A, Lehner T, Gur RE, Bearden CE. A framework for the investigation of rare genetic disorders in neuropsychiatry. Nat Med 2019; 25:1477-1487. [PMID: 31548702 PMCID: PMC8656349 DOI: 10.1038/s41591-019-0581-5] [Citation(s) in RCA: 64] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2018] [Accepted: 07/31/2019] [Indexed: 02/07/2023]
Abstract
De novo and inherited rare genetic disorders (RGDs) are a major cause of human morbidity, frequently involving neuropsychiatric symptoms. Recent advances in genomic technologies and data sharing have revolutionized the identification and diagnosis of RGDs, presenting an opportunity to elucidate the mechanisms underlying neuropsychiatric disorders by investigating the pathophysiology of high-penetrance genetic risk factors. Here we seek out the best path forward for achieving these goals. We think future research will require consistent approaches across multiple RGDs and developmental stages, involving both the characterization of shared neuropsychiatric dimensions in humans and the identification of neurobiological commonalities in model systems. A coordinated and concerted effort across patients, families, researchers, clinicians and institutions, including rapid and broad sharing of data, is now needed to translate these discoveries into urgently needed therapies.
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Affiliation(s)
- Stephan J Sanders
- Department of Psychiatry, UCSF Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA
| | - Mustafa Sahin
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | - Joseph Hostyk
- Institute for Genomic Medicine, Columbia University Medical Center, Hammer Health Sciences, New York, NY, USA
| | - Audrey Thurm
- National Institute of Mental Health, Bethesda, MD, USA
| | - Sebastien Jacquemont
- CHU Sainte-Justine Research Centre, University of Montreal, Montreal, Quebec, Canada
| | - Paul Avillach
- Department of Biomedical Informatics, Harvard Medical School, Boston, MA, USA
| | - Elise Douard
- CHU Sainte-Justine Research Centre, University of Montreal, Montreal, Quebec, Canada
| | - Christa L Martin
- Geisinger Autism & Developmental Medicine Institute, Danville, PA, USA
| | - Meera E Modi
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA, USA
| | | | | | - Alan Anticevic
- Tommy Fuss Center for Neuropsychiatric Disease Research, Boston Children's Hospital, Boston, MA, USA
- Department of Psychiatry, Harvard Medical School, Boston, MA, USA
| | - Ricardo Dolmetsch
- Department of Neuroscience, Novartis Institutes for BioMedical Research, Cambridge, MA, USA
| | - Guoping Feng
- McGovern Institute for Brain Research and Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
- Stanley Center for Psychiatric Research, Broad Institute of MIT and Harvard, Cambridge, MA, USA
| | - Daniel H Geschwind
- Center for Autism Research and Treatment, Semel Institute for Neuroscience and Human Behavior and Departments of Neurology and Human Genetics, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - David C Glahn
- Tommy Fuss Center for Neuropsychiatric Disease Research, Boston Children's Hospital, Boston, MA, USA
| | - David B Goldstein
- Institute for Genomic Medicine, Columbia University Medical Center, Hammer Health Sciences, New York, NY, USA
| | - David H Ledbetter
- Geisinger Autism & Developmental Medicine Institute, Danville, PA, USA
| | - Jennifer G Mulle
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA
| | - Sergiu P Pasca
- Department of Psychiatry and Behavioral Sciences, Stanford University, Palo Alto, CA, USA
| | - Rodney Samaco
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Jonathan Sebat
- Beyster Center for Genomics of Psychiatric Diseases, University of California, San Diego, La Jolla, CA, USA
| | - Anne Pariser
- National Center for Advancing Translational Sciences, Bethesda, MD, USA
| | - Thomas Lehner
- National Institute of Mental Health, Bethesda, MD, USA
| | - Raquel E Gur
- Department of Psychiatry, Neuropsychiatry Section, and the Lifespan Brain Institute, Perelman School of Medicine and Children's Hospital of Philadelphia, University of Pennsylvania, Philadelphia, PA, USA.
| | - Carrie E Bearden
- Semel Institute for Neuroscience and Human Behavior, Departments of Psychiatry and Biobehavioral Sciences and Psychology, University of California, Los Angeles, Los Angeles, CA, USA.
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48
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Banerjee A, Miller MT, Li K, Sur M, Kaufmann WE. Towards a better diagnosis and treatment of Rett syndrome: a model synaptic disorder. Brain 2019; 142:239-248. [PMID: 30649225 DOI: 10.1093/brain/awy323] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2018] [Accepted: 10/31/2018] [Indexed: 12/21/2022] Open
Abstract
With the recent 50th anniversary of the first publication on Rett syndrome, and the almost 20 years since the first report on the link between Rett syndrome and MECP2 mutations, it is important to reflect on the tremendous advances in our understanding and their implications for the diagnosis and treatment of this neurodevelopmental disorder. Rett syndrome features an interesting challenge for biologists and clinicians, as the disorder lies at the intersection of molecular mechanisms of epigenetic regulation and neurophysiological alterations in synapses and circuits that together contribute to severe pathophysiological endophenotypes. Genetic, clinical, and neurobiological evidences support the notion that Rett syndrome is primarily a synaptic disorder, and a disease model for both intellectual disability and autism spectrum disorder. This review examines major developments in both recent neurobiological and preclinical findings of Rett syndrome, and to what extent they are beginning to impact our understanding and management of the disorder. It also discusses potential applications of knowledge on synaptic plasticity abnormalities in Rett syndrome to its diagnosis and treatment.
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Affiliation(s)
- Abhishek Banerjee
- Laboratory of Neural Circuit Dynamics, Brain Research Institute, University of Zürich, Zürich, Switzerland
| | - Meghan T Miller
- Roche Pharma Research and Early Development, Roche Innovation Center, F. Hoffman-La Roche, Basel, Switzerland
| | - Keji Li
- Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge MA, USA
| | - Mriganka Sur
- Department of Brain and Cognitive Sciences, Picower Institute for Learning and Memory, Massachusetts Institute of Technology, Cambridge MA, USA
| | - Walter E Kaufmann
- Department of Human Genetics, Emory University School of Medicine, Atlanta GA, USA
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49
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Vidal S, Xiol C, Pascual-Alonso A, O'Callaghan M, Pineda M, Armstrong J. Genetic Landscape of Rett Syndrome Spectrum: Improvements and Challenges. Int J Mol Sci 2019; 20:ijms20163925. [PMID: 31409060 PMCID: PMC6719047 DOI: 10.3390/ijms20163925] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2019] [Revised: 08/08/2019] [Accepted: 08/10/2019] [Indexed: 02/06/2023] Open
Abstract
Rett syndrome (RTT) is an early-onset neurodevelopmental disorder that primarily affects females, resulting in severe cognitive and physical disabilities, and is one of the most prevalent causes of intellectual disability in females. More than fifty years after the first publication on Rett syndrome, and almost two decades since the first report linking RTT to the MECP2 gene, the research community's effort is focused on obtaining a better understanding of the genetics and the complex biology of RTT and Rett-like phenotypes without MECP2 mutations. Herein, we review the current molecular genetic studies, which investigate the genetic causes of RTT or Rett-like phenotypes which overlap with other genetic disorders and document the swift evolution of the techniques and methodologies employed. This review also underlines the clinical and genetic heterogeneity of the Rett syndrome spectrum and provides an overview of the RTT-related genes described to date, many of which are involved in epigenetic gene regulation, neurotransmitter action or RNA transcription/translation. Finally, it discusses the importance of including both phenotypic and genetic diagnosis to provide proper genetic counselling from a patient's perspective and the appropriate treatment.
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Affiliation(s)
- Silvia Vidal
- Sant Joan de Déu Research Foundation, 08950 Barcelona, Spain
- Institut de Recerca Pediàtrica Hospital Sant Joan de Déu, 08950 Barcelona, Spain
| | - Clara Xiol
- Sant Joan de Déu Research Foundation, 08950 Barcelona, Spain
- Institut de Recerca Pediàtrica Hospital Sant Joan de Déu, 08950 Barcelona, Spain
| | - Ainhoa Pascual-Alonso
- Sant Joan de Déu Research Foundation, 08950 Barcelona, Spain
- Institut de Recerca Pediàtrica Hospital Sant Joan de Déu, 08950 Barcelona, Spain
| | - M O'Callaghan
- Institut de Recerca Pediàtrica Hospital Sant Joan de Déu, 08950 Barcelona, Spain
- Neurology Service, Hospital Sant Joan de Déu, 08950 Barcelona, Spain
- CIBER-ER (Biomedical Network Research Center for Rare Diseases), Institute of Health Carlos III (ISCIII), 28029 Madrid, Spain
| | - Mercè Pineda
- Sant Joan de Déu Research Foundation, 08950 Barcelona, Spain
| | - Judith Armstrong
- Institut de Recerca Pediàtrica Hospital Sant Joan de Déu, 08950 Barcelona, Spain.
- CIBER-ER (Biomedical Network Research Center for Rare Diseases), Institute of Health Carlos III (ISCIII), 28029 Madrid, Spain.
- Molecular and Genetics Medicine Section, Hospital Sant Joan de Déu, 08950 Barcelona, Spain.
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50
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Roche KJ, LeBlanc JJ, Levin AR, O'Leary HM, Baczewski LM, Nelson CA. Electroencephalographic spectral power as a marker of cortical function and disease severity in girls with Rett syndrome. J Neurodev Disord 2019; 11:15. [PMID: 31362710 PMCID: PMC6668116 DOI: 10.1186/s11689-019-9275-z] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Accepted: 07/10/2019] [Indexed: 11/17/2022] Open
Abstract
Background Rett syndrome is a neurodevelopmental disorder caused by a mutation in the X-linked MECP2 gene. Individuals with Rett syndrome typically develop normally until around 18 months of age before undergoing a developmental regression, and the disorder can lead to cognitive, motor, sensory, and autonomic dysfunction. Understanding the mechanism of developmental regression represents a unique challenge when viewed through a neuroscience lens. Are circuits that were previously established erased, and are new ones built to supplant old ones? One way to examine circuit-level changes is with the use of electroencephalography (EEG). Previous studies of the EEG in individuals with Rett syndrome have focused on morphological characteristics, but few have explored spectral power, including power as an index of brain function or disease severity. This study sought to determine if EEG power differs in girls with Rett syndrome and typically developing girls and among girls with Rett syndrome based on various clinical characteristics in order to better understand neural connectivity and cortical organization in individuals with this disorder. Methods Resting state EEG data were acquired from girls with Rett syndrome (n = 57) and typically developing children without Rett syndrome (n = 37). Clinical data were also collected for girls with Rett syndrome. EEG power across several brain regions in numerous frequency bands was then compared between girls with Rett syndrome and typically developing children and power in girls with Rett syndrome was compared based on these clinical measures. 1/ƒ slope was also compared between groups. Results Girls with Rett syndrome demonstrate significantly lower power in the middle frequency bands across multiple brain regions. Additionally, girls with Rett syndrome that are postregression demonstrate significantly higher power in the lower frequency delta and theta bands and a significantly more negative slope of the power spectrum. Increased power in these bands, as well as a more negative 1/ƒ slope, trended with lower cognitive assessment scores. Conclusions Increased power in lower frequency bands is consistent with previous studies demonstrating a “slowing” of the background EEG in Rett syndrome. This increase, particularly in the delta band, could represent abnormal cortical inhibition due to dysfunctional GABAergic signaling and could potentially be used as a marker of severity due to associations with more severe Rett syndrome phenotypes.
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Affiliation(s)
- Katherine J Roche
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Boston Children's Hospital, Harvard Medical School, 1 Autumn Street, Boston, MA, 02215, USA.,Harvard-MIT Division of Health Sciences and Technology, Cambridge, MA, USA
| | - Jocelyn J LeBlanc
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Boston Children's Hospital, Harvard Medical School, 1 Autumn Street, Boston, MA, 02215, USA.,F.M. Kirby Neurobiology Center, Neurology Department, Harvard Medical School, Boston, MA, USA
| | - April R Levin
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Boston Children's Hospital, Harvard Medical School, 1 Autumn Street, Boston, MA, 02215, USA.,Department of Neurology, Boston Children's Hospital, Boston, MA, USA
| | - Heather M O'Leary
- Department of Neurology, Boston Children's Hospital, Boston, MA, USA
| | - Lauren M Baczewski
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Boston Children's Hospital, Harvard Medical School, 1 Autumn Street, Boston, MA, 02215, USA
| | - Charles A Nelson
- Laboratories of Cognitive Neuroscience, Division of Developmental Medicine, Boston Children's Hospital, Harvard Medical School, 1 Autumn Street, Boston, MA, 02215, USA. .,Graduate School of Education, Harvard University, Cambridge, MA, USA.
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