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Dwivedi R, Kaushik M, Tripathi M, Dada R, Tiwari P. Unraveling the genetic basis of epilepsy: Recent advances and implications for diagnosis and treatment. Brain Res 2024; 1843:149120. [PMID: 39032529 DOI: 10.1016/j.brainres.2024.149120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2024] [Revised: 07/05/2024] [Accepted: 07/08/2024] [Indexed: 07/23/2024]
Abstract
Epilepsy, affecting approximately 1% of the global population, manifests as recurring seizures and is heavily influenced by genetic factors. Recent advancements in genetic technologies have revolutionized our understanding of epilepsy's genetic landscape. Key studies, such as the discovery of mutations in ion channels (e.g., SCN1A and SCN2A), neurotransmitter receptors (e.g., GABRA1), and synaptic proteins (e.g., SYNGAP1, KCNQ2), have illuminated critical pathways underlying epilepsy susceptibility and pathogenesis. Genome-wide association studies (GWAS) have identified specific genetic variations linked to epilepsy risk, such as variants near SCN1A and PCDH7, enhancing diagnostic accuracy and enabling personalized treatment strategies. Moreover, epigenetic mechanisms, including DNA methylation (e.g., MBD5), histone modifications (e.g., HDACs), and non-coding RNAs (e.g., miR-134), play pivotal roles in altering gene expression and synaptic plasticity, contributing to epileptogenesis. These discoveries offer promising avenues for therapeutic interventions aimed at improving outcomes for epilepsy patients. Genetic testing has become essential in clinical practice, facilitating precise diagnosis and tailored management approaches based on individual genetic profiles. Furthermore, insights into epigenetic regulation suggest novel therapeutic targets for developing more effective epilepsy treatments. In summary, this review highlights significant progress in understanding the genetic and epigenetic foundations of epilepsy. By integrating findings from key studies and specifying genes involved in epigenetic modifications, we underscore the potential for advanced therapeutic strategies in this complex neurological disorder, emphasizing the importance of personalized medicine approaches in epilepsy management.
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Affiliation(s)
- Rekha Dwivedi
- Department of Neurology, All India Institute of Medical Sciences (AIIMS), New Delhi 110029, India
| | - Meenakshi Kaushik
- Department of Anatomy, All India Institute of Medical Sciences (AIIMS), New Delhi 110029, India
| | - Manjari Tripathi
- Department of Neurology, All India Institute of Medical Sciences (AIIMS), New Delhi 110029, India
| | - Rima Dada
- Department of Anatomy, All India Institute of Medical Sciences (AIIMS), New Delhi 110029, India
| | - Prabhakar Tiwari
- Department of Anatomy, All India Institute of Medical Sciences (AIIMS), New Delhi 110029, India.
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2
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Scheffer IE, Zuberi S, Mefford HC, Guerrini R, McTague A. Developmental and epileptic encephalopathies. Nat Rev Dis Primers 2024; 10:61. [PMID: 39237642 DOI: 10.1038/s41572-024-00546-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 07/29/2024] [Indexed: 09/07/2024]
Abstract
Developmental and epileptic encephalopathies, the most severe group of epilepsies, are characterized by seizures and frequent epileptiform activity associated with developmental slowing or regression. Onset typically occurs in infancy or childhood and includes many well-defined epilepsy syndromes. Patients have wide-ranging comorbidities including intellectual disability, psychiatric features, such as autism spectrum disorder and behavioural problems, movement and musculoskeletal disorders, gastrointestinal and sleep problems, together with an increased mortality rate. Problems change with age and patients require substantial support throughout life, placing a high psychosocial burden on parents, carers and the community. In many patients, the aetiology can be identified, and a genetic cause is found in >50% of patients using next-generation sequencing technologies. More than 900 genes have been identified as monogenic causes of developmental and epileptic encephalopathies and many cell components and processes have been implicated in their pathophysiology, including ion channels and transporters, synaptic proteins, cell signalling and metabolism and epigenetic regulation. Polygenic risk score analyses have shown that common variants also contribute to phenotypic variability. Holistic management, which encompasses antiseizure therapies and care for multimorbidities, is determined both by epilepsy syndrome and aetiology. Identification of the underlying aetiology enables the development of precision medicines to improve the long-term outcome of patients with these devastating diseases.
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Affiliation(s)
- Ingrid E Scheffer
- Epilepsy Research Centre, The University of Melbourne, Austin Health, Heidelberg, Victoria, Australia.
- Florey and Murdoch Children's Research Institutes, Melbourne, Victoria, Australia.
- Department of Paediatrics, The University of Melbourne, Royal Children's Hospital, Parkville, Victoria, Australia.
| | - Sameer Zuberi
- Paediatric Neurosciences Research Group, School of Health & Wellbeing, University of Glasgow, Glasgow, UK
- Paediatric Neurosciences, Royal Hospital for Children, Glasgow, UK
| | - Heather C Mefford
- Center for Paediatric Neurological Disease Research, St. Jude Children's Research Hospital, Memphis, TN, USA
| | - Renzo Guerrini
- Neuroscience Department, Children's Hospital Meyer IRCCS, Florence, Italy
- University of Florence, Florence, Italy
| | - Amy McTague
- Developmental Neurosciences, UCL Great Ormond Street Institute of Child Health, London, UK
- Department of Neurology, Great Ormond Street Hospital, London, UK
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3
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Klein P, Kaminski RM, Koepp M, Löscher W. New epilepsy therapies in development. Nat Rev Drug Discov 2024; 23:682-708. [PMID: 39039153 DOI: 10.1038/s41573-024-00981-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/29/2024] [Indexed: 07/24/2024]
Abstract
Epilepsy is a common brain disorder, characterized by spontaneous recurrent seizures, with associated neuropsychiatric and cognitive comorbidities and increased mortality. Although people at risk can often be identified, interventions to prevent the development of the disorder are not available. Moreover, in at least 30% of patients, epilepsy cannot be controlled by current antiseizure medications (ASMs). As a result of considerable progress in epilepsy genetics and the development of novel disease models, drug screening technologies and innovative therapeutic modalities over the past 10 years, more than 200 novel epilepsy therapies are currently in the preclinical or clinical pipeline, including many treatments that act by new mechanisms. Assisted by diagnostic and predictive biomarkers, the treatment of epilepsy is undergoing paradigm shifts from symptom-only ASMs to disease prevention, and from broad trial-and-error treatments for seizures in general to mechanism-based treatments for specific epilepsy syndromes. In this Review, we assess recent progress in ASM development and outline future directions for the development of new therapies for the treatment and prevention of epilepsy.
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Affiliation(s)
- Pavel Klein
- Mid-Atlantic Epilepsy and Sleep Center, Bethesda, MD, USA.
| | | | - Matthias Koepp
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, University College London, London, UK
| | - Wolfgang Löscher
- Translational Neuropharmacology Lab., NIFE, Department of Experimental Otology of the ENT Clinics, Hannover Medical School, Hannover, Germany.
- Center for Systems Neuroscience, Hannover, Germany.
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Bialer M, Johannessen SI, Koepp MJ, Perucca E, Perucca P, Tomson T, White HS. Progress report on new medications for seizures and epilepsy: A summary of the 17th Eilat Conference on New Antiepileptic Drugs and Devices (EILAT XVII). II. Drugs in more advanced clinical development. Epilepsia 2024. [PMID: 39171993 DOI: 10.1111/epi.18075] [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: 05/16/2024] [Revised: 07/16/2024] [Accepted: 07/17/2024] [Indexed: 08/23/2024]
Abstract
The 17th Eilat Conference on New Antiepileptic Drugs and Devices took place in Madrid, Spain on May 5-8, 2024. As usual, the core part of the conference consisted of presentations on investigational drugs at various stages of development for epilepsy-related indications. Summaries of information on compounds in preclinical or early clinical development are included in an accompanying publication (Part I). In this article, we provide summaries for five compounds in more advanced clinical development, i.e. compounds for which some information on antiseizure activity in individuals with epilepsy is available. These investigational treatments include azetukalner (XEN1101), a potent, KV7.2/7.3-specific potassium channel opener in development for the treatment of focal seizures, generalized tonic-clonic seizures, and major depressive disorder; bexicaserin (LP352), a selective 5-HT2C receptor superagonist in development for the treatment of seizures associated with developmental and epileptic encephalopathies; radiprodil, a selective negative allosteric modulator of NR2B subunit-containing N-methyl-D-aspartate glutamate receptors, in development for the treatment of seizures and behavior manifestations associated with disorders caused by gain-of-function mutations in the GRIN1, -2A, -2B, or -2D genes; soticlestat (TAK-935), a selective inhibitor of cholesterol 24-hydroxylase in development for the treatment of seizures associated with Dravet syndrome and Lennox-Gastaut syndrome; and STK-001, an antisense oligonucleotide designed to upregulate Nav1.1 protein expression and improve outcomes in individuals with Dravet syndrome. The diversity in mechanisms of action of these agents illustrates different approaches being pursued in the discovery of novel treatments for seizures and epilepsy. For two of the compounds discussed in this report (azetukalner and soticlestat), clinical evidence of efficacy has already been obtained in a randomized placebo-controlled adjunctive-therapy trial. For the other compounds, adequately powered placebo-controlled efficacy trials have not been completed to date.
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Affiliation(s)
- Meir Bialer
- Institute for Drug Research, Faculty of Medicine and David R. Bloom Center for Pharmacy, School of Pharmacy, Hebrew University of Jerusalem, Jerusalem, Israel
| | - Svein I Johannessen
- National Center for Epilepsy, Sandvika, Norway
- Oslo University Hospital, member of the European Reference Network EpiCare, Oslo, Norway
- Section for Clinical Pharmacology, Department of Pharmacology, Oslo University Hospital, Oslo, Norway
| | - Matthias J Koepp
- Department of Clinical and Experimental Epilepsy, University College London Queen Square Institute of Neurology, London, UK
| | - Emilio Perucca
- Department of Medicine (Austin Health), University of Melbourne, Melbourne, Victoria, Australia
- Department of Neuroscience, School of Translational Medicine, Monash University, Melbourne, Victoria, Australia
| | - Piero Perucca
- Department of Medicine (Austin Health), University of Melbourne, Melbourne, Victoria, Australia
- Department of Neuroscience, School of Translational Medicine, Monash University, Melbourne, Victoria, Australia
- Bladin-Berkovic Comprehensive Epilepsy Program, Department of Neurology, Austin Health, Melbourne, Victoria, Australia
- Department of Neurology, Royal Melbourne Hospital, Melbourne, Victoria, Australia
- Department of Neurology, Alfred Health, Melbourne, Victoria, Australia
| | - Torbjörn Tomson
- Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - H Steve White
- Department of Pharmacy, Center for Epilepsy Drug Discovery, School of Pharmacy, University of Washington, Seattle, Washington, USA
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Jones DJ, Soundararajan D, Taylor NK, Aimiuwu OV, Mathkar P, Shore A, Teoh JJ, Wang W, Sands TT, Weston MC, Harper SQ, Frankel WN. Effective knockdown-replace gene therapy in a novel mouse model of DNM1 developmental and epileptic encephalopathy. Mol Ther 2024:S1525-0016(24)00531-8. [PMID: 39127888 DOI: 10.1016/j.ymthe.2024.08.009] [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: 05/15/2024] [Revised: 07/12/2024] [Accepted: 08/06/2024] [Indexed: 08/12/2024] Open
Abstract
Effective gene therapy for gain-of-function or dominant-negative disease mutations may require eliminating expression of the mutant copy together with wild-type replacement. We evaluated such a knockdown-replace strategy in a mouse model of DNM1 disease, a debilitating and intractable neurodevelopmental epilepsy. To challenge the approach robustly, we expressed a patient-based variant in GABAergic neurons-which resulted in growth delay and lethal seizures evident by postnatal week three-and delivered to newborn pups an AAV9-based vector encoding a ubiquitously expressed, Dnm1-specific interfering RNA (RNAi) bivalently in tail-to-tail configuration with a neuron-specific, RNAi-resistant, codon-optimized Dnm1 cDNA. Pups receiving RNAi or cDNA alone fared no better than untreated pups, whereas the vast majority of mutants receiving modest doses survived with almost full growth recovery. Synaptic recordings of cortical neurons derived from treated pups revealed that significant alterations in transmission from inhibitory to excitatory neurons were rectified by bivalent vector application. To examine the mutant transcriptome and impact of treatment, we used RNA sequencing and functional annotation clustering. Mutants displayed abnormal expression of more than 1,000 genes in highly significant and relevant functional clusters, clusters that were abrogated by treatment. Together these results suggest knockdown-replace as a potentially effective strategy for treating DNM1 and related genetic neurodevelopmental disease.
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Affiliation(s)
- Devin J Jones
- Department of Genetics and Development and Department of Neurology, Center for Translational Research in Neurodevelopmental Disease, Columbia University Irving Medical Center, New York, NY, USA
| | - Divya Soundararajan
- Department of Genetics and Development and Department of Neurology, Center for Translational Research in Neurodevelopmental Disease, Columbia University Irving Medical Center, New York, NY, USA
| | - Noah K Taylor
- Center for Gene Therapy, The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA
| | - Osasumwen V Aimiuwu
- Department of Genetics and Development and Department of Neurology, Center for Translational Research in Neurodevelopmental Disease, Columbia University Irving Medical Center, New York, NY, USA
| | - Pranav Mathkar
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, USA
| | - Amy Shore
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, USA
| | - Jia Jie Teoh
- Department of Genetics and Development and Department of Neurology, Center for Translational Research in Neurodevelopmental Disease, Columbia University Irving Medical Center, New York, NY, USA
| | - Wanqi Wang
- Department of Genetics and Development and Department of Neurology, Center for Translational Research in Neurodevelopmental Disease, Columbia University Irving Medical Center, New York, NY, USA
| | - Tristan T Sands
- Department of Genetics and Development and Department of Neurology, Center for Translational Research in Neurodevelopmental Disease, Columbia University Irving Medical Center, New York, NY, USA
| | - Matthew C Weston
- Fralin Biomedical Research Institute at Virginia Tech Carilion, Roanoke, VA, USA
| | - Scott Q Harper
- Center for Gene Therapy, The Abigail Wexner Research Institute at Nationwide Children's Hospital, Columbus, OH, USA; Department of Pediatrics, The Ohio State University College of Medicine, Columbus, OH, USA
| | - Wayne N Frankel
- Department of Genetics and Development and Department of Neurology, Center for Translational Research in Neurodevelopmental Disease, Columbia University Irving Medical Center, New York, NY, USA.
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Zhao M, Cheng X, Chen L, Zeng YH, Lin KJ, Li YL, Zheng ZH, Huang XJ, Zuo DD, Guo XX, Guo J, He D, Liu Y, Lin Y, Wang C, Lv WQ, Su HZ, Yao XP, Ye ZL, Chen XH, Lu YQ, Huang CW, Yang G, Zhang YX, Lin MT, Wang N, Xiong ZQ, Chen WJ. Antisense oligonucleotides enhance SLC20A2 expression and suppress brain calcification in a humanized mouse model. Neuron 2024:S0896-6273(24)00535-X. [PMID: 39121859 DOI: 10.1016/j.neuron.2024.07.013] [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: 07/18/2023] [Revised: 05/15/2024] [Accepted: 07/17/2024] [Indexed: 08/12/2024]
Abstract
Primary familial brain calcification (PFBC) is a genetic neurological disease, yet no effective treatment is currently available. Here, we identified five novel intronic variants in SLC20A2 gene from six PFBC families. Three of these variants increased aberrant SLC20A2 pre-mRNA splicing by altering the binding affinity of splicing machineries to newly characterized cryptic exons, ultimately causing premature termination of SLC20A2 translation. Inhibiting the cryptic-exon incorporation with splice-switching ASOs increased the expression levels of functional SLC20A2 in cells carrying SLC20A2 mutations. Moreover, by knocking in a humanized SLC20A2 intron 2 sequence carrying a PFBC-associated intronic variant, the SLC20A2-KI mice exhibited increased inorganic phosphate (Pi) levels in cerebrospinal fluid (CSF) and progressive brain calcification. Intracerebroventricular administration of ASOs to these SLC20A2-KI mice reduced CSF Pi levels and suppressed brain calcification. Together, our findings expand the genetic etiology of PFBC and demonstrate ASO-mediated splice modulation as a potential therapy for PFBC patients with SLC20A2 haploinsufficiency.
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Affiliation(s)
- Miao Zhao
- Department of Neurology, the First Affiliated Hospital, Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou 350005, China; Department of Neurology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350212, China
| | - Xuewen Cheng
- Center for Excellence in Brain Science and Intelligence Technology, Institute of Neuroscience and State Key Laboratory of Neuroscience, Chinese Academy of Sciences, Shanghai 200031, China; Lin Gang Laboratory, Shanghai 201602, China.
| | - Lei Chen
- Center for Excellence in Brain Science and Intelligence Technology, Institute of Neuroscience and State Key Laboratory of Neuroscience, Chinese Academy of Sciences, Shanghai 200031, China; School of Future Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yi-Heng Zeng
- Department of Neurology, the First Affiliated Hospital, Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou 350005, China
| | - Kai-Jun Lin
- Department of Neurology, the First Affiliated Hospital, Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou 350005, China
| | - Yun-Lu Li
- Department of Neurology, the First Affiliated Hospital, Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou 350005, China
| | - Ze-Hong Zheng
- Department of Neurology, the First Affiliated Hospital, Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou 350005, China
| | - Xue-Jing Huang
- Department of Neurology, the First Affiliated Hospital, Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou 350005, China
| | - Dan-Dan Zuo
- Department of Neurology, the First Affiliated Hospital, Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou 350005, China
| | - Xin-Xin Guo
- Department of Neurology, the First Affiliated Hospital, Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou 350005, China
| | - Jun Guo
- Department of Neurology, Tangdu Hospital, Air Force Medical University, Xi'an 710038, China
| | - Dian He
- Department of Neurology, Affiliated Hospital of Guizhou Medical University, Guiyang 550001, China
| | - Ying Liu
- Department of Neurology, Affiliated Hospital of Guizhou Medical University, Guiyang 550001, China
| | - Yu Lin
- Department of Neurology, the First Affiliated Hospital, Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou 350005, China
| | - Chong Wang
- Department of Neurology, the First Affiliated Hospital, Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou 350005, China
| | - Wen-Qi Lv
- Department of Neurology, the First Affiliated Hospital, Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou 350005, China
| | - Hui-Zhen Su
- Department of Neurology, the First Affiliated Hospital, Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou 350005, China; Department of Neurology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350212, China
| | - Xiang-Ping Yao
- Department of Neurology, the First Affiliated Hospital, Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou 350005, China; Department of Neurology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350212, China
| | - Zi-Ling Ye
- Department of Neurology, the First Affiliated Hospital, Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou 350005, China
| | - Xiao-Hong Chen
- Department of Neurology, the First Affiliated Hospital, Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou 350005, China
| | - Ying-Qian Lu
- Department of Neurology, the First Affiliated Hospital, Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou 350005, China
| | - Chen-Wei Huang
- Center for Excellence in Brain Science and Intelligence Technology, Institute of Neuroscience and State Key Laboratory of Neuroscience, Chinese Academy of Sciences, Shanghai 200031, China; School of Future Technology, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Guang Yang
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
| | - Yu-Xian Zhang
- Center for Excellence in Brain Science and Intelligence Technology, Institute of Neuroscience and State Key Laboratory of Neuroscience, Chinese Academy of Sciences, Shanghai 200031, China
| | - Min-Ting Lin
- Department of Neurology, the First Affiliated Hospital, Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou 350005, China; Department of Neurology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350212, China
| | - Ning Wang
- Department of Neurology, the First Affiliated Hospital, Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou 350005, China; Department of Neurology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350212, China
| | - Zhi-Qi Xiong
- Center for Excellence in Brain Science and Intelligence Technology, Institute of Neuroscience and State Key Laboratory of Neuroscience, Chinese Academy of Sciences, Shanghai 200031, China; School of Future Technology, University of Chinese Academy of Sciences, Beijing 100049, China; Shanghai Center for Brain Science and Brain-inspired Technology, Shanghai 201602, China.
| | - Wan-Jin Chen
- Department of Neurology, the First Affiliated Hospital, Institute of Neuroscience, Fujian Key Laboratory of Molecular Neurology, Fujian Medical University, Fuzhou 350005, China; Department of Neurology, National Regional Medical Center, Binhai Campus of the First Affiliated Hospital, Fujian Medical University, Fuzhou, Fujian 350212, China.
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Barker-Haliski M, Hawkins NA. Innovative drug discovery strategies in epilepsy: integrating next-generation syndrome-specific mouse models to address pharmacoresistance and epileptogenesis. Expert Opin Drug Discov 2024:1-15. [PMID: 39075876 DOI: 10.1080/17460441.2024.2384455] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2024] [Accepted: 07/22/2024] [Indexed: 07/31/2024]
Abstract
INTRODUCTION Although there are numerous treatment options already available for epilepsy, over 30% of patients remain resistant to these antiseizure medications (ASMs). Historically, ASM discovery has relied on the demonstration of efficacy through the use of 'traditional' acute in vivo seizure models (e.g. maximal electroshock, subcutaneous pentylenetetrazol, and kindling). However, advances in genetic sequencing technologies and remaining medical needs for people with treatment-resistant epilepsy or special patient populations have encouraged recent efforts to identify novel compounds in syndrome-specific models of epilepsy. Syndrome-specific models, including Scn1a variant models of Dravet syndrome and APP/PS1 mice associated with familial early-onset Alzheimer's disease, have already led to the discovery of two mechanistically novel treatments for developmental and epileptic encephalopathies (DEEs), namely cannabidiol and soticlestat, respectively. AREAS COVERED In this review, the authors discuss how it is likely that next-generation drug discovery efforts for epilepsy will more comprehensively integrate syndrome-specific epilepsy models into early drug discovery providing the reader with their expert perspectives. EXPERT OPINION The percentage of patients with pharmacoresistant epilepsy has remained unchanged despite over 30 marketed ASMs. Consequently, there is a high unmet need to reinvent and revise discovery strategies to more effectively address the remaining needs of patients with specific epilepsy syndromes, including drug-resistant epilepsy and DEEs.
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Affiliation(s)
| | - Nicole A Hawkins
- Feinberg School of Medicine Chicago, Northwestern University, Chicago, IL, USA
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Zhang X. Splice-switching antisense oligonucleotides for pediatric neurological disorders. Front Mol Neurosci 2024; 17:1412964. [PMID: 39119251 PMCID: PMC11306167 DOI: 10.3389/fnmol.2024.1412964] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2024] [Accepted: 07/12/2024] [Indexed: 08/10/2024] Open
Abstract
Pediatric neurological disorders are frequently devastating and present unmet needs for effective medicine. The successful treatment of spinal muscular atrophy with splice-switching antisense oligonucleotides (SSO) indicates a feasible path to targeting neurological disorders by redirecting pre-mRNA splicing. One direct outcome is the development of SSOs to treat haploinsufficient disorders by targeting naturally occurring non-productive splice isoforms. The development of personalized SSO treatment further inspired the therapeutic exploration of rare diseases. This review will discuss the recent advances that utilize SSOs to treat pediatric neurological disorders.
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Affiliation(s)
- Xiaochang Zhang
- Department of Human Genetics, The Neuroscience Institute, University of Chicago, Chicago, IL, United States
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Bao N, Wang Z, Fu J, Dong H, Jin Y. RNA structure in alternative splicing regulation: from mechanism to therapy. Acta Biochim Biophys Sin (Shanghai) 2024. [PMID: 39034824 DOI: 10.3724/abbs.2024119] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 07/23/2024] Open
Abstract
Alternative splicing is a highly intricate process that plays a crucial role in post-transcriptional regulation and significantly expands the functional proteome of a limited number of coding genes in eukaryotes. Its regulation is multifactorial, with RNA structure exerting a significant impact. Aberrant RNA conformations lead to dysregulation of splicing patterns, which directly affects the manifestation of disease symptoms. In this review, the molecular mechanisms of RNA secondary structure-mediated splicing regulation are summarized, with a focus on the complex interplay between aberrant RNA conformations and disease phenotypes resulted from splicing defects. This study also explores additional factors that reshape structural conformations, enriching our understanding of the mechanistic network underlying structure-mediated splicing regulation. In addition, an emphasis has been placed on the clinical role of targeting aberrant splicing corrections in human diseases. The principal mechanisms of action behind this phenomenon are described, followed by a discussion of prospective development strategies and pertinent challenges.
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Zielińska A, Skarżyńska U, Górka-Skoczylas P, Mazurczak T, Kuźniar-Pałka A, Kanabus K, Hoffman-Zacharska D, Stawicka E. How Has the Treatment of Polish Children with Dravet Syndrome Changed? Future Perspectives. Biomedicines 2024; 12:1249. [PMID: 38927456 PMCID: PMC11200592 DOI: 10.3390/biomedicines12061249] [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: 03/31/2024] [Revised: 05/09/2024] [Accepted: 05/31/2024] [Indexed: 06/28/2024] Open
Abstract
BACKGROUND This report focuses on the treatment histories of 21 patients diagnosed with Dravet syndrome (DRVT) under the care of the Mother and Child Institute in Warsaw. This paper aims to present typical treatment schemes for patients with drug-resistant epilepsy, as well as to highlight the influence of genetic diagnosis on pharmacotherapeutic management and to present an economic analysis of hospitalization costs. This paper will also summarize the effectiveness of the latest drugs used in DRVT. METHODS Clinical data were collected retrospectively from available medical records. The effectiveness of anticonvulsant treatment was assessed based on epileptic seizure diaries and observations by caregivers and pediatric neurologists. RESULTS The study group (n = 21) consisted of patients aged 3-26 years. Orphan drugs dedicated to Dravet syndrome were introduced in all patients due to the genetic diagnosis, which significantly improved the patients' clinical conditions. The breakthrough drugs were stiripentol (in 16/21) and fenfluramine (in 3/21). CONCLUSIONS In recent years, molecular genetics has rapidly developed in Poland, along with a steady increase in knowledge of Dravet syndrome among the medical profession. Early and precise diagnosis provides the opportunity to target treatment with drugs dedicated to Dravet syndrome with high efficacy.
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Affiliation(s)
- Anita Zielińska
- Clinic of Paediatric Neurology, Institute of Mother and Child, Kasprzaka 17A, 01-211 Warsaw, Poland; (A.Z.); (T.M.); (A.K.-P.)
| | - Urszula Skarżyńska
- Department of Organization and Accounts, Institute of Mother and Child, Kasprzaka 17A, 01-211 Warsaw, Poland;
| | - Paulina Górka-Skoczylas
- Department of Medical Genetics, Institute of Mother and Child, Kasprzaka 17A, 01-211 Warsaw, Poland; (P.G.-S.); (K.K.); (D.H.-Z.)
| | - Tomasz Mazurczak
- Clinic of Paediatric Neurology, Institute of Mother and Child, Kasprzaka 17A, 01-211 Warsaw, Poland; (A.Z.); (T.M.); (A.K.-P.)
| | - Aleksandra Kuźniar-Pałka
- Clinic of Paediatric Neurology, Institute of Mother and Child, Kasprzaka 17A, 01-211 Warsaw, Poland; (A.Z.); (T.M.); (A.K.-P.)
| | - Karolina Kanabus
- Department of Medical Genetics, Institute of Mother and Child, Kasprzaka 17A, 01-211 Warsaw, Poland; (P.G.-S.); (K.K.); (D.H.-Z.)
| | - Dorota Hoffman-Zacharska
- Department of Medical Genetics, Institute of Mother and Child, Kasprzaka 17A, 01-211 Warsaw, Poland; (P.G.-S.); (K.K.); (D.H.-Z.)
| | - Elżbieta Stawicka
- Clinic of Paediatric Neurology, Institute of Mother and Child, Kasprzaka 17A, 01-211 Warsaw, Poland; (A.Z.); (T.M.); (A.K.-P.)
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11
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van der Smagt JJ, Lampri AP, de Lange I, Alders M, Houben ML, Koudijs MJ, van Jaarsveld RH. Identification of a pathogenic deep intronic variant in ATRX ends a diagnostic odyssey. Eur J Med Genet 2024; 69:104949. [PMID: 38797245 DOI: 10.1016/j.ejmg.2024.104949] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2024] [Revised: 05/16/2024] [Accepted: 05/23/2024] [Indexed: 05/29/2024]
Abstract
Variation in the non-coding genome is being increasingly recognized to be involved in monogenic disease etiology. However, the interpretation of non-coding variation is complicated by a lack of understanding of how non-coding genetic elements function. Additional lines of evidence are therefore needed to recognize non-coding variants as pathogenic. We here present a case where a collective body of evidence resulted in the identification and conclusive classification of a pathogenic deep intronic variant in ATRX. This report demonstrates the utility of a multi-platform approach in aiding the identification of pathogenic variants outside coding regions. Furthermore, it marks the first reported instance of a deep intronic pathogenic variant in ATRX.
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Affiliation(s)
| | - Angeliki P Lampri
- Department of Genetics, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Iris de Lange
- Department of Genetics, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Mariëlle Alders
- Amsterdam UMC, Department of Human Genetics, Genome Diagnostics Laboratory, Amsterdam Reproduction & Development, University of Amsterdam, Amsterdam, the Netherlands
| | - Michiel L Houben
- Department of Pediatrics, Wilhelmina Children's Hospital, University Medical Center Utrecht, Utrecht, the Netherlands
| | - Marco J Koudijs
- Department of Genetics, University Medical Center Utrecht, Utrecht, the Netherlands
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12
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Ng ACH, Chahine M, Scantlebury MH, Appendino JP. Channelopathies in epilepsy: an overview of clinical presentations, pathogenic mechanisms, and therapeutic insights. J Neurol 2024; 271:3063-3094. [PMID: 38607431 DOI: 10.1007/s00415-024-12352-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2024] [Revised: 03/24/2024] [Accepted: 03/25/2024] [Indexed: 04/13/2024]
Abstract
Pathogenic variants in genes encoding ion channels are causal for various pediatric and adult neurological conditions. In particular, several epilepsy syndromes have been identified to be caused by specific channelopathies. These encompass a spectrum from self-limited epilepsies to developmental and epileptic encephalopathies spanning genetic and acquired causes. Several of these channelopathies have exquisite responses to specific antiseizure medications (ASMs), while others ASMs may prove ineffective or even worsen seizures. Some channelopathies demonstrate phenotypic pleiotropy and can cause other neurological conditions outside of epilepsy. This review aims to provide a comprehensive exploration of the pathophysiology of seizure generation, ion channels implicated in epilepsy, and several genetic epilepsies due to ion channel dysfunction. We outline the clinical presentation, pathogenesis, and the current state of basic science and clinical research for these channelopathies. In addition, we briefly look at potential precision therapy approaches emerging for these disorders.
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Affiliation(s)
- Andy Cheuk-Him Ng
- Clinical Neuroscience and Pediatric Neurology, Department of Pediatrics, Cumming School of Medicine, Alberta Children's Hospital, University of Calgary, 28 Oki Drive NW, Calgary, AB, T3B 6A8, Canada
- Division of Neurology, Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta and Stollery Children's Hospital, Edmonton, AB, Canada
| | - Mohamed Chahine
- Department of Medicine, Faculty of Medicine, Université Laval, Quebec City, QC, Canada
- CERVO, Brain Research Centre, Quebec City, Canada
| | - Morris H Scantlebury
- Clinical Neuroscience and Pediatric Neurology, Department of Pediatrics, Cumming School of Medicine, Alberta Children's Hospital, University of Calgary, 28 Oki Drive NW, Calgary, AB, T3B 6A8, Canada
- Hotchkiss Brain Institute and Alberta Children's Hospital Research Institute, Calgary, Canada
| | - Juan P Appendino
- Clinical Neuroscience and Pediatric Neurology, Department of Pediatrics, Cumming School of Medicine, Alberta Children's Hospital, University of Calgary, 28 Oki Drive NW, Calgary, AB, T3B 6A8, Canada.
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13
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Fronk AD, Manzanares MA, Zheng P, Geier A, Anderson K, Stanton S, Zumrut H, Gera S, Munch R, Frederick V, Dhingra P, Arun G, Akerman M. Development and validation of AI/ML derived splice-switching oligonucleotides. Mol Syst Biol 2024; 20:676-701. [PMID: 38664594 PMCID: PMC11148135 DOI: 10.1038/s44320-024-00034-9] [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: 09/15/2023] [Revised: 04/03/2024] [Accepted: 04/09/2024] [Indexed: 06/05/2024] Open
Abstract
Splice-switching oligonucleotides (SSOs) are antisense compounds that act directly on pre-mRNA to modulate alternative splicing (AS). This study demonstrates the value that artificial intelligence/machine learning (AI/ML) provides for the identification of functional, verifiable, and therapeutic SSOs. We trained XGboost tree models using splicing factor (SF) pre-mRNA binding profiles and spliceosome assembly information to identify modulatory SSO binding sites on pre-mRNA. Using Shapley and out-of-bag analyses we also predicted the identity of specific SFs whose binding to pre-mRNA is blocked by SSOs. This step adds considerable transparency to AI/ML-driven drug discovery and informs biological insights useful in further validation steps. We applied this approach to previously established functional SSOs to retrospectively identify the SFs likely to regulate those events. We then took a prospective validation approach using a novel target in triple negative breast cancer (TNBC), NEDD4L exon 13 (NEDD4Le13). Targeting NEDD4Le13 with an AI/ML-designed SSO decreased the proliferative and migratory behavior of TNBC cells via downregulation of the TGFβ pathway. Overall, this study illustrates the ability of AI/ML to extract actionable insights from RNA-seq data.
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Affiliation(s)
| | | | - Paulina Zheng
- Envisagenics, Inc., Long Island City, NY, 11101, USA
| | - Adam Geier
- Envisagenics, Inc., Long Island City, NY, 11101, USA
| | | | | | - Hasan Zumrut
- Envisagenics, Inc., Long Island City, NY, 11101, USA
| | - Sakshi Gera
- Envisagenics, Inc., Long Island City, NY, 11101, USA
| | - Robin Munch
- Envisagenics, Inc., Long Island City, NY, 11101, USA
| | | | | | - Gayatri Arun
- Envisagenics, Inc., Long Island City, NY, 11101, USA
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14
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Recinos Y, Ustianenko D, Yeh YT, Wang X, Jacko M, Yesantharao LV, Wu Q, Zhang C. CRISPR-dCas13d-based deep screening of proximal and distal splicing-regulatory elements. Nat Commun 2024; 15:3839. [PMID: 38714659 PMCID: PMC11076525 DOI: 10.1038/s41467-024-47140-8] [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: 06/21/2023] [Accepted: 03/16/2024] [Indexed: 05/10/2024] Open
Abstract
Pre-mRNA splicing, a key process in gene expression, can be therapeutically modulated using various drug modalities, including antisense oligonucleotides (ASOs). However, determining promising targets is hampered by the challenge of systematically mapping splicing-regulatory elements (SREs) in their native sequence context. Here, we use the catalytically inactive CRISPR-RfxCas13d RNA-targeting system (dCas13d/gRNA) as a programmable platform to bind SREs and modulate splicing by competing against endogenous splicing factors. SpliceRUSH, a high-throughput screening method, was developed to map SREs in any gene of interest using a lentivirus gRNA library that tiles the genetic region, including distal intronic sequences. When applied to SMN2, a therapeutic target for spinal muscular atrophy, SpliceRUSH robustly identifies not only known SREs but also a previously unknown distal intronic SRE, which can be targeted to alter exon 7 splicing using either dCas13d/gRNA or ASOs. This technology enables a deeper understanding of splicing regulation with applications for RNA-based drug discovery.
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Affiliation(s)
- Yocelyn Recinos
- Department of Systems Biology, Columbia University, New York, NY, 10032, USA
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, 10032, USA
| | - Dmytro Ustianenko
- Department of Systems Biology, Columbia University, New York, NY, 10032, USA
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, 10032, USA
- Flagship Pioneering, Cambridge, MA, 02142, USA
| | - Yow-Tyng Yeh
- Department of Systems Biology, Columbia University, New York, NY, 10032, USA
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, 10032, USA
| | - Xiaojian Wang
- Department of Systems Biology, Columbia University, New York, NY, 10032, USA
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, 10032, USA
| | - Martin Jacko
- Department of Systems Biology, Columbia University, New York, NY, 10032, USA
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, 10032, USA
- Aperture Therapeutics, Inc., San Carlos, CA, 94070, USA
| | - Lekha V Yesantharao
- Department of Systems Biology, Columbia University, New York, NY, 10032, USA
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, 10032, USA
- Johns Hopkins University School of Medicine, Baltimore, MD, 21205, USA
| | - Qiyang Wu
- Department of Systems Biology, Columbia University, New York, NY, 10032, USA
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, 10032, USA
| | - Chaolin Zhang
- Department of Systems Biology, Columbia University, New York, NY, 10032, USA.
- Department of Biochemistry and Molecular Biophysics, Columbia University, New York, NY, 10032, USA.
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15
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Lee HHC, Latzer IT, Bertoldi M, Gao G, Pearl PL, Sahin M, Rotenberg A. Gene replacement therapies for inherited disorders of neurotransmission: Current progress in succinic semialdehyde dehydrogenase deficiency. J Inherit Metab Dis 2024; 47:476-493. [PMID: 38581234 PMCID: PMC11096052 DOI: 10.1002/jimd.12735] [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: 07/30/2023] [Revised: 03/06/2024] [Accepted: 03/20/2024] [Indexed: 04/08/2024]
Abstract
Neurodevelopment is a highly organized and complex process involving lasting and often irreversible changes in the central nervous system. Inherited disorders of neurotransmission (IDNT) are a group of genetic disorders where neurotransmission is primarily affected, resulting in abnormal brain development from early life, manifest as neurodevelopmental disorders and other chronic conditions. In principle, IDNT (particularly those of monogenic causes) are amenable to gene replacement therapy via precise genetic correction. However, practical challenges for gene replacement therapy remain major hurdles for its translation from bench to bedside. We discuss key considerations for the development of gene replacement therapies for IDNT. As an example, we describe our ongoing work on gene replacement therapy for succinic semialdehyde dehydrogenase deficiency, a GABA catabolic disorder.
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Affiliation(s)
- Henry HC Lee
- F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Boston, MA 02115, USA
- Rosamund Stone Zander Translational Neuroscience Center, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Itay Tokatly Latzer
- Division of Epilepsy & Clinical Neurophysiology, Department of Neurology, Boston Children’s Hospital, Boston, MA 02115, USA
- Tel-Aviv University Faculty of Medicine, Tel-Aviv, Israel
| | - Mariarita Bertoldi
- Dept. of Neuroscience, Biomedicine and Movement Sciences, University of Verona, Verona, Italy
| | - Guangping Gao
- The Horae Gene Therapy Center, UMass Medical School, MA 01605, USA
| | - Phillip L Pearl
- Division of Epilepsy & Clinical Neurophysiology, Department of Neurology, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Mustafa Sahin
- F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Boston, MA 02115, USA
- Rosamund Stone Zander Translational Neuroscience Center, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Alexander Rotenberg
- F.M. Kirby Neurobiology Center, Boston Children’s Hospital, Boston, MA 02115, USA
- Division of Epilepsy & Clinical Neurophysiology, Department of Neurology, Boston Children’s Hospital, Boston, MA 02115, USA
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16
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Di Berardino C, Mainardi M, Brusco S, Benvenuto E, Broccoli V, Colasante G. Temporal manipulation of the Scn1a gene reveals its essential role in adult brain function. Brain 2024; 147:1216-1230. [PMID: 37812819 PMCID: PMC10994529 DOI: 10.1093/brain/awad350] [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: 05/23/2023] [Revised: 09/23/2023] [Accepted: 09/30/2023] [Indexed: 10/11/2023] Open
Abstract
Dravet syndrome is a severe epileptic encephalopathy, characterized by drug-resistant epilepsy, severe cognitive and behavioural deficits, with increased risk of sudden unexpected death (SUDEP). It is caused by haploinsufficiency of SCN1A gene encoding for the α-subunit of the voltage-gated sodium channel Nav1.1. Therapeutic approaches aiming to upregulate the healthy copy of SCN1A gene to restore its normal expression levels are being developed. However, whether Scn1a gene function is required only during a specific developmental time-window or, alternatively, if its physiological expression is necessary in adulthood is untested up to now. We induced Scn1a gene haploinsufficiency at two ages spanning postnatal brain development (P30 and P60) and compared the phenotypes of those mice to Scn1a perinatally induced mice (P2), recapitulating all deficits of Dravet mice. Induction of heterozygous Nav1.1 mutation at P30 and P60 elicited susceptibility to the development of both spontaneous and hyperthermia-induced seizures and SUDEP rates comparable to P2-induced mice, with symptom onset accompanied by the characteristic GABAergic interneuron dysfunction. Finally, delayed Scn1a haploinsufficiency induction provoked hyperactivity, anxiety and social attitude impairment at levels comparable to age matched P2-induced mice, while it was associated with a better cognitive performance, with P60-induced mice behaving like the control group. Our data show that maintenance of physiological levels of Nav1.1 during brain development is not sufficient to prevent Dravet symptoms and that long-lasting restoration of Scn1a gene expression would be required to grant optimal clinical benefit in patients with Dravet syndrome.
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Affiliation(s)
- Claudia Di Berardino
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Martina Mainardi
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
| | - Simone Brusco
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
- National Research Council (CNR), Institute of Neuroscience, 20129 Milan, Italy
| | - Elena Benvenuto
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
- Gene and Cell Therapy PhD Program, Vita- Salute San Raffaele University, 20132 Milan, Italy
| | - Vania Broccoli
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
- National Research Council (CNR), Institute of Neuroscience, 20129 Milan, Italy
| | - Gaia Colasante
- Stem Cell and Neurogenesis Unit, Division of Neuroscience, IRCCS San Raffaele Scientific Institute, 20132 Milan, Italy
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17
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Yuan Y, Lopez-Santiago L, Denomme N, Chen C, O'Malley HA, Hodges SL, Ji S, Han Z, Christiansen A, Isom LL. Antisense oligonucleotides restore excitability, GABA signalling and sodium current density in a Dravet syndrome model. Brain 2024; 147:1231-1246. [PMID: 37812817 PMCID: PMC10994531 DOI: 10.1093/brain/awad349] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2023] [Revised: 09/13/2023] [Accepted: 09/27/2023] [Indexed: 10/11/2023] Open
Abstract
Dravet syndrome is an intractable developmental and epileptic encephalopathy caused by de novo variants in SCN1A resulting in haploinsufficiency of the voltage-gated sodium channel Nav1.1. We showed previously that administration of the antisense oligonucleotide STK-001, also called ASO-22, generated using targeted augmentation of nuclear gene output technology to prevent inclusion of the nonsense-mediated decay, or poison, exon 20N in human SCN1A, increased productive Scn1a transcript and Nav1.1 expression and reduced the incidence of electrographic seizures and sudden unexpected death in epilepsy in a mouse model of Dravet syndrome. Here, we investigated the mechanism of action of ASO-84, a surrogate for ASO-22 that also targets splicing of SCN1A exon 20N, in Scn1a+/- Dravet syndrome mouse brain. Scn1a +/- Dravet syndrome and wild-type mice received a single intracerebroventricular injection of antisense oligonucleotide or vehicle at postnatal Day 2. We examined the electrophysiological properties of cortical pyramidal neurons and parvalbumin-positive fast-spiking interneurons in brain slices at postnatal Days 21-25 and measured sodium currents in parvalbumin-positive interneurons acutely dissociated from postnatal Day 21-25 brain slices. We show that, in untreated Dravet syndrome mice, intrinsic cortical pyramidal neuron excitability was unchanged while cortical parvalbumin-positive interneurons showed biphasic excitability with initial hyperexcitability followed by hypoexcitability and depolarization block. Dravet syndrome parvalbumin-positive interneuron sodium current density was decreased compared to wild-type. GABAergic signalling to cortical pyramidal neurons was reduced in Dravet syndrome mice, suggesting decreased GABA release from interneurons. ASO-84 treatment restored action potential firing, sodium current density and GABAergic signalling in Dravet syndrome parvalbumin-positive interneurons. Our work suggests that interneuron excitability is selectively affected by ASO-84. This new work provides critical insights into the mechanism of action of this antisense oligonucleotide and supports the potential of antisense oligonucleotide-mediated upregulation of Nav1.1 as a successful strategy to treat Dravet syndrome.
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Affiliation(s)
- Yukun Yuan
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Luis Lopez-Santiago
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Nicholas Denomme
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Chunling Chen
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Heather A O'Malley
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Samantha L Hodges
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
| | - Sophina Ji
- Stoke Therapeutics, Inc., Bedford, MA 01730, USA
| | - Zhou Han
- Stoke Therapeutics, Inc., Bedford, MA 01730, USA
| | | | - Lori L Isom
- Department of Pharmacology, University of Michigan, Ann Arbor, MI 48109, USA
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18
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Nelson AD, Catalfio AM, Gupta JP, Min L, Caballero-Florán RN, Dean KP, Elvira CC, Derderian KD, Kyoung H, Sahagun A, Sanders SJ, Bender KJ, Jenkins PM. Physical and functional convergence of the autism risk genes Scn2a and Ank2 in neocortical pyramidal cell dendrites. Neuron 2024; 112:1133-1149.e6. [PMID: 38290518 PMCID: PMC11097922 DOI: 10.1016/j.neuron.2024.01.003] [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: 06/08/2022] [Revised: 04/26/2023] [Accepted: 01/03/2024] [Indexed: 02/01/2024]
Abstract
Dysfunction in sodium channels and their ankyrin scaffolding partners have both been implicated in neurodevelopmental disorders, including autism spectrum disorder (ASD). In particular, the genes SCN2A, which encodes the sodium channel NaV1.2, and ANK2, which encodes ankyrin-B, have strong ASD association. Recent studies indicate that ASD-associated haploinsufficiency in Scn2a impairs dendritic excitability and synaptic function in neocortical pyramidal cells, but how NaV1.2 is anchored within dendritic regions is unknown. Here, we show that ankyrin-B is essential for scaffolding NaV1.2 to the dendritic membrane of mouse neocortical neurons and that haploinsufficiency of Ank2 phenocopies intrinsic dendritic excitability and synaptic deficits observed in Scn2a+/- conditions. These results establish a direct, convergent link between two major ASD risk genes and reinforce an emerging framework suggesting that neocortical pyramidal cell dendritic dysfunction can contribute to neurodevelopmental disorder pathophysiology.
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Affiliation(s)
- Andrew D Nelson
- Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA, USA
| | - Amanda M Catalfio
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Julie P Gupta
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Lia Min
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, USA
| | | | - Kendall P Dean
- Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Carina C Elvira
- Cellular and Molecular Biology Program, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Kimberly D Derderian
- Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA, USA
| | - Henry Kyoung
- Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA, USA
| | - Atehsa Sahagun
- Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA, USA
| | - Stephan J Sanders
- Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA; Department of Psychiatry, University of California, San Francisco, San Francisco, CA, USA
| | - Kevin J Bender
- Weill Institute for Neurosciences, University of California, San Francisco, San Francisco, CA, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA, USA.
| | - Paul M Jenkins
- Department of Pharmacology, University of Michigan Medical School, Ann Arbor, MI, USA; Department of Psychiatry, University of Michigan Medical School, Ann Arbor, MI, USA.
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19
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Spangsberg Petersen US, Dembic M, Martínez-Pizarro A, Richard E, Holm LL, Havelund JF, Doktor TK, Larsen MR, Færgeman NJ, Desviat LR, Andresen BS. Regulating PCCA gene expression by modulation of pseudoexon splicing patterns to rescue enzyme activity in propionic acidemia. MOLECULAR THERAPY. NUCLEIC ACIDS 2024; 35:102101. [PMID: 38204914 PMCID: PMC10776996 DOI: 10.1016/j.omtn.2023.102101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/10/2023] [Accepted: 12/08/2023] [Indexed: 01/12/2024]
Abstract
Pseudoexons are nonfunctional intronic sequences that can be activated by deep-intronic sequence variation. Activation increases pseudoexon inclusion in mRNA and interferes with normal gene expression. The PCCA c.1285-1416A>G variation activates a pseudoexon and causes the severe metabolic disorder propionic acidemia by deficiency of the propionyl-CoA carboxylase enzyme encoded by PCCA and PCCB. We characterized this pathogenic pseudoexon activation event in detail and identified hnRNP A1 to be important for normal repression. The PCCA c.1285-1416A>G variation disrupts an hnRNP A1-binding splicing silencer and simultaneously creates a splicing enhancer. We demonstrate that blocking this region of regulation with splice-switching antisense oligonucleotides restores normal splicing and rescues enzyme activity in patient fibroblasts and in a cellular model created by CRISPR gene editing. Interestingly, the PCCA pseudoexon offers an unexploited potential to upregulate gene expression because healthy tissues show relatively high inclusion levels. By blocking inclusion of the nonactivated wild-type pseudoexon, we can increase both PCCA and PCCB protein levels, which increases the activity of the heterododecameric enzyme. Surprisingly, we can increase enzyme activity from residual levels in not only patient fibroblasts harboring PCCA missense variants but also those harboring PCCB missense variants. This is a potential treatment strategy for propionic acidemia.
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Affiliation(s)
- Ulrika Simone Spangsberg Petersen
- Department of Biochemistry and Molecular Biology and the Villum Center for Bioanalytical Sciences, University of Southern Denmark, 5230 Odense M, Denmark
| | - Maja Dembic
- Department of Biochemistry and Molecular Biology and the Villum Center for Bioanalytical Sciences, University of Southern Denmark, 5230 Odense M, Denmark
- Department of Clinical Genetics, Odense University Hospital, 5000 Odense C, Denmark
- Department of Mathematics and Computer Science, University of Southern Denmark, 5230 Odense M, Denmark
| | - Ainhoa Martínez-Pizarro
- Centro de Biología Molecular Severo Ochoa, UAM-CSIC, CEDEM, CIBERER, IdiPaz, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Eva Richard
- Centro de Biología Molecular Severo Ochoa, UAM-CSIC, CEDEM, CIBERER, IdiPaz, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Lise Lolle Holm
- Department of Biochemistry and Molecular Biology and the Villum Center for Bioanalytical Sciences, University of Southern Denmark, 5230 Odense M, Denmark
| | - Jesper Foged Havelund
- Department of Biochemistry and Molecular Biology and the Villum Center for Bioanalytical Sciences, University of Southern Denmark, 5230 Odense M, Denmark
| | - Thomas Koed Doktor
- Department of Biochemistry and Molecular Biology and the Villum Center for Bioanalytical Sciences, University of Southern Denmark, 5230 Odense M, Denmark
| | - Martin Røssel Larsen
- Department of Biochemistry and Molecular Biology and the Villum Center for Bioanalytical Sciences, University of Southern Denmark, 5230 Odense M, Denmark
| | - Nils J. Færgeman
- Department of Biochemistry and Molecular Biology and the Villum Center for Bioanalytical Sciences, University of Southern Denmark, 5230 Odense M, Denmark
| | - Lourdes Ruiz Desviat
- Centro de Biología Molecular Severo Ochoa, UAM-CSIC, CEDEM, CIBERER, IdiPaz, Universidad Autónoma de Madrid, 28049 Madrid, Spain
| | - Brage Storstein Andresen
- Department of Biochemistry and Molecular Biology and the Villum Center for Bioanalytical Sciences, University of Southern Denmark, 5230 Odense M, Denmark
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20
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Miralles RM, Boscia AR, Kittur S, Vundela SR, Wengert ER, Patel MK. Parvalbumin Interneuron Impairment Leads to Synaptic Transmission Deficits and Seizures in SCN8A Epileptic Encephalopathy. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.02.09.579511. [PMID: 38464208 PMCID: PMC10925130 DOI: 10.1101/2024.02.09.579511] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
SCN8A epileptic encephalopathy (EE) is a severe epilepsy syndrome resulting from de novo mutations in the voltage-gated sodium channel Na v 1.6, encoded by the gene SCN8A . Na v 1.6 is expressed in both excitatory and inhibitory neurons, yet previous studies have primarily focused on the impact SCN8A mutations have on excitatory neuron function, with limited studies on the importance of inhibitory interneurons to seizure onset and progression. Inhibitory interneurons are critical in balancing network excitability and are known to contribute to the pathophysiology of other epilepsies. Parvalbumin (PV) interneurons are the most prominent inhibitory neuron subtype in the brain, making up about 40% of inhibitory interneurons. Notably, PV interneurons express high levels of Na v 1.6. To assess the role of PV interneurons within SCN8A EE, we used two mouse models harboring patient-derived SCN8A gain-of-function mutations, Scn8a D/+ , where the SCN8A mutation N1768D is expressed globally, and Scn8a W/+ -PV, where the SCN8A mutation R1872W is selectively expressed in PV interneurons. Expression of the R1872W SCN8A mutation selectively in PV interneurons led to the development of spontaneous seizures in Scn8a W/+ -PV mice and seizure-induced death, decreasing survival compared to wild-type. Electrophysiology studies showed that PV interneurons in Scn8a D/+ and Scn8a W/+ -PV mice were susceptible to depolarization block, a state of action potential failure. Scn8a D/+ and Scn8a W/+ -PV interneurons also exhibited increased persistent sodium current, a hallmark of SCN8A gain-of-function mutations that contributes to depolarization block. Evaluation of synaptic connections between PV interneurons and pyramidal cells showed an increase in synaptic transmission failure at high frequencies (80-120Hz) as well as an increase in synaptic latency in Scn8a D/+ and Scn8a W/+ -PV interneurons. These data indicate a distinct impairment of synaptic transmission in SCN8A EE, potentially decreasing overall cortical network inhibition. Together, our novel findings indicate that failure of PV interneuron spiking via depolarization block along with frequency-dependent inhibitory synaptic impairment likely elicits an overall reduction in the inhibitory drive in SCN8A EE, leading to unchecked excitation and ultimately resulting in seizures and seizure-induced death.
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The role of copy number variants in the genetic architecture of common familial epilepsies. Epilepsia 2024; 65:792-804. [PMID: 38101940 PMCID: PMC10948303 DOI: 10.1111/epi.17860] [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: 08/03/2023] [Revised: 12/08/2023] [Accepted: 12/11/2023] [Indexed: 12/17/2023]
Abstract
OBJECTIVE Copy number variants (CNVs) contribute to genetic risk and genetic etiology of both rare and common epilepsies. Whereas many studies have explored the role of CNVs in sporadic or severe cases, fewer have been done in familial generalized and focal epilepsies. METHODS We analyzed exome sequence data from 267 multiplex families and 859 first-degree relative pairs with a diagnosis of genetic generalized epilepsies or nonacquired focal epilepsies to predict CNVs. Validation and segregation studies were performed using an orthogonal method when possible. RESULTS We identified CNVs likely to contribute to epilepsy risk or etiology in the probands of 43 of 1116 (3.9%) families, including known recurrent CNVs (16p13.11 deletion, 15q13.3 deletion, 15q11.2 deletion, 16p11.2 duplication, 1q21.1 duplication, and 5-Mb duplication of 15q11q13). We also identified CNVs affecting monogenic epilepsy genes, including four families with CNVs disrupting the DEPDC5 gene, and a de novo deletion of HNRNPU in one affected individual from a multiplex family. Several large CNVs (>500 kb) of uncertain clinical significance were identified, including a deletion in 18q, a large duplication encompassing the SCN1A gene, and a 15q13.3 duplication (BP4-BP5). SIGNIFICANCE The overall CNV landscape in common familial epilepsies is similar to that of sporadic epilepsies, with large recurrent deletions at 15q11, 15q13, and 16p13 contributing in 2.5%-3% of families. CNVs that interrupt known epilepsy genes and rare, large CNVs were also identified. Multiple etiologies were found in a subset of families, emphasizing the importance of genetic testing for multiple affected family members. Rare CNVs found in a single proband remain difficult to interpret and require larger cohorts to confirm their potential role in disease. Overall, our work indicates that CNVs contribute to the complex genetic architecture of familial generalized and focal epilepsies, supporting the role for clinical testing in affected individuals.
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Nieto-Estevez V, Varma P, Mirsadeghi S, Caballero J, Gamero-Alameda S, Hosseini A, Goswami S, Silvosa MJ, Thodeson DM, Lybrand ZR, Giugliano M, Navara C, Hsieh J. Dual effects of ARX poly-alanine mutations in human cortical and interneuron development. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.01.25.577271. [PMID: 38328230 PMCID: PMC10849640 DOI: 10.1101/2024.01.25.577271] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
Mutations in ARX , an X-linked gene, are implicated in a wide spectrum of neurological disorders including patients who have intellectual disability and epilepsy. Mouse models have shown that Arx is critical for cortical development and interneuron migration, however they do not recapitulate the full phenotype observed in patients. Moreover, the epilepsy in many patients with poly-alanine tract expansion (PAE) mutations in ARX show pharmacoresistance, emphasizing the need to develop new treatments. Here, we used human neural organoid models to study the consequences of PAE mutations, one of the most prevalent mutations in ARX . We found that PAE mutations result in an early increase in radial glia cells and intermediate progenitor cells, and premature differentiation leading to a loss of cortical neurons at later timepoints. Moreover, ARX expression is upregulated in CO derived from patient at 30 DIV which alters the expression of CDKN1C , SFRP1 , DLK1 and FABP7 , among others. We also found a cell autonomously enhanced interneuron migration, which can be rescued by CXCR4 inhibition. Furthermore, ARX PAE assembloids had hyper-activity and synchrony evident from the early stages. These data provide novel insights to the pathogenesis of these and likely related human neurological disorders and identifies a critical window for therapeutic interventions.
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Feng T, Makiello P, Dunwoody B, Steckler F, Symonds JD, Zuberi SM, Dorris L, Brunklaus A. Long-term predictors of developmental outcome and disease burden in SCN1A-positive Dravet syndrome. Brain Commun 2024; 6:fcae004. [PMID: 38229878 PMCID: PMC10789590 DOI: 10.1093/braincomms/fcae004] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2023] [Revised: 11/25/2023] [Accepted: 01/05/2024] [Indexed: 01/18/2024] Open
Abstract
Dravet syndrome is a severe infantile onset developmental and epileptic encephalopathy associated with mutations in the sodium channel alpha 1 subunit gene SCN1A. Prospective data on long-term developmental and clinical outcomes are limited; this study seeks to evaluate the clinical course of Dravet syndrome over a 10-year period and identify predictors of developmental outcome. SCN1A mutation-positive Dravet syndrome patients were prospectively followed up in the UK from 2010 to 2020. Caregivers completed structured questionnaires on clinical features and disease burden; the Epilepsy & Learning Disability Quality of Life Questionnaire, the Adaptive Behavioural Assessment System-3 and the Sleep Disturbance Scale for Children. Sixty-eight of 113 caregivers (60%) returned posted questionnaires. Developmental outcome worsened at follow-up (4.45 [SD 0.65], profound cognitive impairment) compared to baseline (2.9 [SD 1.1], moderate cognitive impairment, P < 0.001), whereas epilepsy severity appeared less severe at 10-year follow-up (P = 0.042). Comorbidities were more apparent at 10-year outcome including an increase in autistic features (77% [48/62] versus 30% [17/57], χ2 = 19.9, P < 0.001), behavioural problems (81% [46/57] versus 38% [23/60], χ2 = 14.1, P < 0.001) and motor/mobility problems (80% [51/64] versus 41% [24/59], χ2 = 16.9, P < 0.001). Subgroup analysis demonstrated a more significant rise in comorbidities in younger compared to older patients. Predictors of worse long-term developmental outcome included poorer baseline language ability (P < 0.001), more severe baseline epilepsy severity (P = 0.003) and a worse SCN1A genetic score (P = 0.027). Sudden unexpected death in epilepsy had not been discussed with a medical professional in 35% (24/68) of participants. Over 90% of caregivers reported a negative impact on their own health and career opportunities. Our study identifies important predictors and potential biomarkers of developmental outcome in Dravet syndrome and emphasizes the significant caregiver burden of illness. The negative impact of epilepsy severity at baseline on long-term developmental outcomes highlights the importance of implementing early and focused therapies whilst the potential impact of newer anti-seizure medications requires further study.
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Affiliation(s)
- Tony Feng
- School of Health and Wellbeing, University of Glasgow, Clarice Pears Building, 90 Byres Road, Glasgow G12 8TB, UK
- The Paediatric Neurosciences Research Group, Royal Hospital for Children, Office Block, Level 0, Zone 1, 1345 Govan Road, Glasgow G51 4TF, UK
| | - Phoebe Makiello
- The Paediatric Neurosciences Research Group, Royal Hospital for Children, Office Block, Level 0, Zone 1, 1345 Govan Road, Glasgow G51 4TF, UK
| | - Benjamin Dunwoody
- The Paediatric Neurosciences Research Group, Royal Hospital for Children, Office Block, Level 0, Zone 1, 1345 Govan Road, Glasgow G51 4TF, UK
| | - Felix Steckler
- School of Health and Wellbeing, University of Glasgow, Clarice Pears Building, 90 Byres Road, Glasgow G12 8TB, UK
- The Paediatric Neurosciences Research Group, Royal Hospital for Children, Office Block, Level 0, Zone 1, 1345 Govan Road, Glasgow G51 4TF, UK
| | - Joseph D Symonds
- School of Health and Wellbeing, University of Glasgow, Clarice Pears Building, 90 Byres Road, Glasgow G12 8TB, UK
- The Paediatric Neurosciences Research Group, Royal Hospital for Children, Office Block, Level 0, Zone 1, 1345 Govan Road, Glasgow G51 4TF, UK
| | - Sameer M Zuberi
- School of Health and Wellbeing, University of Glasgow, Clarice Pears Building, 90 Byres Road, Glasgow G12 8TB, UK
- The Paediatric Neurosciences Research Group, Royal Hospital for Children, Office Block, Level 0, Zone 1, 1345 Govan Road, Glasgow G51 4TF, UK
| | - Liam Dorris
- School of Health and Wellbeing, University of Glasgow, Clarice Pears Building, 90 Byres Road, Glasgow G12 8TB, UK
- The Paediatric Neurosciences Research Group, Royal Hospital for Children, Office Block, Level 0, Zone 1, 1345 Govan Road, Glasgow G51 4TF, UK
| | - Andreas Brunklaus
- School of Health and Wellbeing, University of Glasgow, Clarice Pears Building, 90 Byres Road, Glasgow G12 8TB, UK
- The Paediatric Neurosciences Research Group, Royal Hospital for Children, Office Block, Level 0, Zone 1, 1345 Govan Road, Glasgow G51 4TF, UK
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Lauffer MC, van Roon-Mom W, Aartsma-Rus A. Possibilities and limitations of antisense oligonucleotide therapies for the treatment of monogenic disorders. COMMUNICATIONS MEDICINE 2024; 4:6. [PMID: 38182878 PMCID: PMC10770028 DOI: 10.1038/s43856-023-00419-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2023] [Accepted: 11/27/2023] [Indexed: 01/07/2024] Open
Abstract
Antisense oligonucleotides (ASOs) are incredibly versatile molecules that can be designed to specifically target and modify RNA transcripts to slow down or halt rare genetic disease progression. They offer the potential to target groups of patients or can be tailored for individual cases. Nonetheless, not all genetic variants and disorders are amenable to ASO-based treatments, and hence, it is important to consider several factors before embarking on the drug development journey. Here, we discuss which genetic disorders have the potential to benefit from a specific type of ASO approach, based on the pathophysiology of the disease and pathogenic variant type, as well as those disorders that might not be suitable for ASO therapies. We further explore additional aspects, such as the target tissues, intervention time points, and potential clinical benefits, which need to be considered before developing a compound. Overall, we provide an overview of the current potentials and limitations of ASO-based therapeutics for the treatment of monogenic disorders.
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Affiliation(s)
- Marlen C Lauffer
- Dutch Center for RNA Therapeutics, Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Willeke van Roon-Mom
- Dutch Center for RNA Therapeutics, Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands
| | - Annemieke Aartsma-Rus
- Dutch Center for RNA Therapeutics, Department of Human Genetics, Leiden University Medical Center, Leiden, The Netherlands.
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Khan R, Chaturvedi P, Sahu P, Ludhiadch A, Singh P, Singh G, Munshi A. Role of Potassium Ion Channels in Epilepsy: Focus on Current Therapeutic Strategies. CNS & NEUROLOGICAL DISORDERS DRUG TARGETS 2024; 23:67-87. [PMID: 36578258 DOI: 10.2174/1871527322666221227112621] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Revised: 11/10/2022] [Accepted: 11/12/2022] [Indexed: 12/30/2022]
Abstract
BACKGROUND Epilepsy is one of the prevalent neurological disorders characterized by disrupted synchronization between inhibitory and excitatory neurons. Disturbed membrane potential due to abnormal regulation of neurotransmitters and ion transport across the neural cell membrane significantly contributes to the pathophysiology of epilepsy. Potassium ion channels (KCN) regulate the resting membrane potential and are involved in neuronal excitability. Genetic alterations in the potassium ion channels (KCN) have been reported to result in the enhancement of the release of neurotransmitters, the excitability of neurons, and abnormal rapid firing rate, which lead to epileptic phenotypes, making these ion channels a potential therapeutic target for epilepsy. The aim of this study is to explore the variations reported in different classes of potassium ion channels (KCN) in epilepsy patients, their functional evaluation, and therapeutic strategies to treat epilepsy targeting KCN. METHODOLOGY A review of all the relevant literature was carried out to compile this article. RESULTS A large number of variations have been reported in different genes encoding various classes of KCN. These genetic alterations in KCN have been shown to be responsible for disrupted firing properties of neurons. Antiepileptic drugs (AEDs) are the main therapeutic strategy to treat epilepsy. Some patients do not respond favorably to the AEDs treatment, resulting in pharmacoresistant epilepsy. CONCLUSION Further to address the challenges faced in treating epilepsy, recent approaches like optogenetics, chemogenetics, and genome editing, such as clustered regularly interspaced short palindromic repeats (CRISPR), are emerging as target-specific therapeutic strategies.
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Affiliation(s)
- Rahul Khan
- Department of Human Genetics and Molecular Medicine Central University of Punjab, Bathinda 151401, India
| | - Pragya Chaturvedi
- Department of Human Genetics and Molecular Medicine Central University of Punjab, Bathinda 151401, India
| | - Prachi Sahu
- Department of Human Genetics and Molecular Medicine Central University of Punjab, Bathinda 151401, India
| | - Abhilash Ludhiadch
- Department of Human Genetics and Molecular Medicine Central University of Punjab, Bathinda 151401, India
| | - Paramdeep Singh
- Department of Radiology, All India Institute of Medical Sciences, Bathinda, Punjab, 151001 India
| | - Gagandeep Singh
- Department of Neurology, Dayanand Medical College and Hospital, Ludhiana, Punjab, India
| | - Anjana Munshi
- Department of Human Genetics and Molecular Medicine Central University of Punjab, Bathinda 151401, India
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26
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Schneider MF, Vogt M, Scheuermann J, Müller V, Fischer-Hentrich AHL, Kremer T, Lugert S, Metzger F, Kudernatsch M, Kluger G, Hartlieb T, Noachtar S, Vollmar C, Kunz M, Tonn JC, Coras R, Blümcke I, Pace C, Heinen F, Klein C, Potschka H, Borggraefe I. Brain expression profiles of two SCN1A antisense RNAs in children and adolescents with epilepsy. Transl Neurosci 2024; 15:20220330. [PMID: 38283997 PMCID: PMC10811528 DOI: 10.1515/tnsci-2022-0330] [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: 09/29/2023] [Revised: 12/11/2023] [Accepted: 12/12/2023] [Indexed: 01/30/2024] Open
Abstract
Objective Heterozygous mutations within the voltage-gated sodium channel α subunit (SCN1A) are responsible for the majority of cases of Dravet syndrome (DS), a severe developmental and epileptic encephalopathy. Development of novel therapeutic approaches is mandatory in order to directly target the molecular consequences of the genetic defect. The aim of the present study was to investigate whether cis-acting long non-coding RNAs (lncRNAs) of SCN1A are expressed in brain specimens of children and adolescent with epilepsy as these molecules comprise possible targets for precision-based therapy approaches. Methods We investigated SCN1A mRNA expression and expression of two SCN1A related antisense RNAs in brain tissues in different age groups of pediatric non-Dravet patients who underwent surgery for drug resistant epilepsy. The effect of different antisense oligonucleotides (ASOs) directed against SCN1A specific antisense RNAs on SCN1A expression was tested. Results The SCN1A related antisense RNAs SCN1A-dsAS (downstream antisense, RefSeq identifier: NR_110598) and SCN1A-usAS (upstream AS, SCN1A-AS, RefSeq identifier: NR_110260) were widely expressed in the brain of pediatric patients. Expression patterns revealed a negative correlation of SCN1A-dsAS and a positive correlation of lncRNA SCN1A-usAS with SCN1A mRNA expression. Transfection of SK-N-AS cells with an ASO targeted against SCN1A-dsAS was associated with a significant enhancement of SCN1A mRNA expression and reduction in SCN1A-dsAS transcripts. Conclusion These findings support the role of SCN1A-dsAS in the suppression of SCN1A mRNA generation. Considering the haploinsufficiency in genetic SCN1A related DS, SCN1A-dsAS is an interesting target candidate for the development of ASOs (AntagoNATs) based precision medicine therapeutic approaches aiming to enhance SCN1A expression in DS.
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Affiliation(s)
- Marius Frederik Schneider
- Division of Molecular Biology, Biomedical Center Munich, Ludwig Maximilians University, Munich, Germany
- International Max Planck Research School (IMPRS) for Molecular Life Sciences, Planegg-Martinsried, Germany
| | | | - Johanna Scheuermann
- Division of Molecular Biology, Biomedical Center Munich, Ludwig Maximilians University, Munich, Germany
| | - Veronika Müller
- Division of Molecular Biology, Biomedical Center Munich, Ludwig Maximilians University, Munich, Germany
| | | | - Thomas Kremer
- Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, F Hoffmann-La Roche Ltd, Basel, Switzerland
| | - Sebastian Lugert
- Roche Pharmaceutical Research and Early Development, Roche Innovation Center Basel, F Hoffmann-La Roche Ltd, Basel, Switzerland
| | | | - Manfred Kudernatsch
- Clinic for Neurosurgery, Schoen-Klinik Vogtareuth, Germany
- Paracelsus Medical University, Salzburg, Austria
| | - Gerhard Kluger
- Paracelsus Medical University, Salzburg, Austria
- Neuropediatric Clinic and Clinic for Neurorehabilitation, Epilepsy Center for Children and Adolescents, Schoen-Klinik Vogtareuth, Germany
| | - Till Hartlieb
- Paracelsus Medical University, Salzburg, Austria
- Neuropediatric Clinic and Clinic for Neurorehabilitation, Epilepsy Center for Children and Adolescents, Schoen-Klinik Vogtareuth, Germany
| | - Soheyl Noachtar
- Department of Neurology, Comprehensive Epilepsy Center, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
| | - Christian Vollmar
- Department of Neurology, Comprehensive Epilepsy Center, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
- Comprehensive Epilepsy Center, Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, Department of Pediatrics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
| | - Mathias Kunz
- Department of Neurosurgery, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
| | - Jörg Christian Tonn
- Department of Neurosurgery, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
| | - Roland Coras
- Department of Neuropathology, University Hospital Erlangen, Erlangen, Germany
| | - Ingmar Blümcke
- Department of Neuropathology, University Hospital Erlangen, Erlangen, Germany
| | - Claudia Pace
- Institute of Pharmacology, Toxicology, and Pharmacy, Ludwig Maximilians University, Munich, Germany
| | - Florian Heinen
- Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, Department of Pediatrics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
| | - Christoph Klein
- Department of Pediatrics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
| | - Heidrun Potschka
- Institute of Pharmacology, Toxicology, and Pharmacy, Ludwig Maximilians University, Munich, Germany
| | - Ingo Borggraefe
- Comprehensive Epilepsy Center, Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, Department of Pediatrics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
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Sharma R. Innovative Genoceuticals in Human Gene Therapy Solutions: Challenges and Safe Clinical Trials of Orphan Gene Therapy Products. Curr Gene Ther 2024; 24:46-72. [PMID: 37702177 DOI: 10.2174/1566523223666230911120922] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2022] [Revised: 04/14/2023] [Accepted: 04/20/2023] [Indexed: 09/14/2023]
Abstract
The success of gene therapy attempts is controversial and inconclusive. Currently, it is popular among the public, the scientific community, and manufacturers of Gene Therapy Medical Products. In the absence of any remedy or treatment options available for untreatable inborn metabolic orphan or genetic diseases, cancer, or brain diseases, gene therapy treatment by genoceuticals and T-cells for gene editing and recovery remains the preferred choice as the last hope. A new concept of "Genoceutical Gene Therapy" by using orphan 'nucleic acid-based therapy' aims to introduce scientific principles of treating acquired tissue damage and rare diseases. These Orphan Genoceuticals provide new scope for the 'genodrug' development and evaluation of genoceuticals and gene products for ideal 'gene therapy' use in humans with marketing authorization application (MAA). This perspective study focuses on the quality control, safety, and efficacy requirements of using 'nucleic acid-based and human cell-based new gene therapy' genoceutical products to set scientific advice on genoceutical-based 'orphan genodrug' design for clinical trials as per Western and European guidelines. The ethical Western FDA and European EMA guidelines suggest stringent legal and technical requirements on genoceutical medical products or orphan genodrug use for other countries to frame their own guidelines. The introduction section proposes lessknown 'orphan drug-like' properties of modified RNA/DNA, human cell origin gene therapy medical products, and their transgene products. The clinical trial section explores the genoceutical sources, FDA/EMA approvals for genoceutical efficacy criteria with challenges, and ethical guidelines relating to gene therapy of specific rare metabolic, cancer and neurological diseases. The safety evaluation of approved genoceuticals or orphan drugs is highlighted with basic principles and 'genovigilance' requirements (to observe any adverse effects, side effects, developed signs/symptoms) to establish their therapeutic use. Current European Union and Food and Drug Administration guidelines continuously administer fast-track regulatory legal framework from time to time, and they monitor the success of gene therapy medical product efficacy and safety. Moreover, new ethical guidelines on 'orphan drug-like genoceuticals' are updated for biodistribution of the vector, genokinetics studies of the transgene product, requirements for efficacy studies in industries for market authorization, and clinical safety endpoints with their specific concerns in clinical trials or public use.
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Affiliation(s)
- Rakesh Sharma
- Surgery NMR Lab, Plastic Surgery Research, Massachusetts General Hospital, Boston, MA 02114, USA
- CCSU, Government Medical College, Saharanpur, 247232 India
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Hullett PW, Lowenstein DH. Major advances in epilepsy research in 2023. Lancet Neurol 2024; 23:19-20. [PMID: 38101887 DOI: 10.1016/s1474-4422(23)00457-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2023] [Accepted: 11/20/2023] [Indexed: 12/17/2023]
Affiliation(s)
- Patrick W Hullett
- Department of Neurology, University of California, San Francisco, CA 94143, USA.
| | - Daniel H Lowenstein
- Department of Neurology, University of California, San Francisco, CA 94143, USA
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De Wachter M, Schoonjans AS, Weckhuysen S, Van Schil K, Löfgren A, Meuwissen M, Jansen A, Ceulemans B. From diagnosis to treatment in genetic epilepsies: Implementation of precision medicine in real-world clinical practice. Eur J Paediatr Neurol 2024; 48:46-60. [PMID: 38039826 DOI: 10.1016/j.ejpn.2023.11.003] [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: 09/30/2022] [Revised: 07/20/2023] [Accepted: 11/11/2023] [Indexed: 12/03/2023]
Abstract
The implementation of whole exome sequencing (WES) has had a major impact on the diagnostic yield of genetic testing in individuals with epilepsy. The identification of a genetic etiology paves the way to precision medicine: an individualized treatment approach, based on the disease pathophysiology. The aim of this retrospective cohort study was to: (1) determine the diagnostic yield of WES in a heterogeneous cohort of individuals with epilepsy referred for genetic testing in a real-world clinical setting, (2) investigate the influence of epilepsy characteristics on the diagnostic yield, (3) determine the theoretical yield of treatment changes based on genetic diagnosis and (4) explore the barriers to implementation of precision medicine. WES was performed in 247 individuals with epilepsy, aged between 7 months and 68 years. In 34/247 (14 %) a (likely) pathogenic variant was identified. In 7/34 (21 %) of these individuals the variant was found using a HPO-based filtering. Diagnostic yield was highest for individuals with an early onset of epilepsy (39 %) or in those with a developmental and epileptic encephalopathy (34 %). Precision medicine was a theoretical possibility in 20/34 (59 %) of the individuals with a (likely) pathogenic variant but implemented in only 11/34 (32 %). The major barrier to implementation of precision treatment was the limited availability or reimbursement of a given drug. These results confirm the potential impact of genetic analysis on treatment choices, but also highlight the hurdles to the implementation of precision medicine. To optimize precision medicine in real-world practice, additional endeavors are needed: unifying definitions of precision medicine, establishment of publicly accessible databases that include data on the functional effect of gene variants, increasing availability and reimbursement of precision therapeutics, and broadening access to innovative clinical trials.
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Affiliation(s)
- Matthias De Wachter
- Department of Pediatric Neurology, Antwerp University Hospital, University of Antwerp, Drie eikenstraat 655, 2650, Edegem, Belgium.
| | - An-Sofie Schoonjans
- Department of Pediatric Neurology, Antwerp University Hospital, University of Antwerp, Drie eikenstraat 655, 2650, Edegem, Belgium
| | - Sarah Weckhuysen
- Department of Neurology, Antwerp University Hospital, University of Antwerp, Drie eikenstraat 655, 2650, Edegem, Belgium; Applied&Translational Neurogenomics Group, VIB-CMN, VIB, UAntwerpen, Universiteitsplein 1, 2610, Wilrijk, Belgium; Translational Neurosciences, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium
| | - Kristof Van Schil
- Department of Medical Genetics, Antwerp University Hospital, University of Antwerp, Drie eikenstraat 655, 2650, Edegem, Belgium
| | - Ann Löfgren
- Department of Medical Genetics, Antwerp University Hospital, University of Antwerp, Drie eikenstraat 655, 2650, Edegem, Belgium
| | - Marije Meuwissen
- Department of Medical Genetics, Antwerp University Hospital, University of Antwerp, Drie eikenstraat 655, 2650, Edegem, Belgium
| | - Anna Jansen
- Department of Pediatric Neurology, Antwerp University Hospital, University of Antwerp, Drie eikenstraat 655, 2650, Edegem, Belgium; Translational Neurosciences, University of Antwerp, Universiteitsplein 1, 2610, Wilrijk, Belgium
| | - Berten Ceulemans
- Department of Pediatric Neurology, Antwerp University Hospital, University of Antwerp, Drie eikenstraat 655, 2650, Edegem, Belgium
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Fan HC, Yang MT, Lin LC, Chiang KL, Chen CM. Clinical and Genetic Features of Dravet Syndrome: A Prime Example of the Role of Precision Medicine in Genetic Epilepsy. Int J Mol Sci 2023; 25:31. [PMID: 38203200 PMCID: PMC10779156 DOI: 10.3390/ijms25010031] [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: 11/23/2023] [Revised: 12/14/2023] [Accepted: 12/17/2023] [Indexed: 01/12/2024] Open
Abstract
Dravet syndrome (DS), also known as severe myoclonic epilepsy of infancy, is a rare and drug-resistant form of developmental and epileptic encephalopathies, which is both debilitating and challenging to manage, typically arising during the first year of life, with seizures often triggered by fever, infections, or vaccinations. It is characterized by frequent and prolonged seizures, developmental delays, and various other neurological and behavioral impairments. Most cases result from pathogenic mutations in the sodium voltage-gated channel alpha subunit 1 (SCN1A) gene, which encodes a critical voltage-gated sodium channel subunit involved in neuronal excitability. Precision medicine offers significant potential for improving DS diagnosis and treatment. Early genetic testing enables timely and accurate diagnosis. Advances in our understanding of DS's underlying genetic mechanisms and neurobiology have enabled the development of targeted therapies, such as gene therapy, offering more effective and less invasive treatment options for patients with DS. Targeted and gene therapies provide hope for more effective and personalized treatments. However, research into novel approaches remains in its early stages, and their clinical application remains to be seen. This review addresses the current understanding of clinical DS features, genetic involvement in DS development, and outcomes of novel DS therapies.
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Affiliation(s)
- Hueng-Chuen Fan
- Department of Pediatrics, Tungs’ Taichung Metroharbor Hospital, Wuchi, Taichung 435, Taiwan;
- Department of Rehabilitation, Jen-Teh Junior College of Medicine, Nursing and Management, Miaoli 356, Taiwan
- Department of Life Sciences, Agricultural Biotechnology Center, National Chung Hsing University, Taichung 402, Taiwan
| | - Ming-Tao Yang
- Department of Pediatrics, Far Eastern Memorial Hospital, New Taipei City 220, Taiwan;
- Department of Chemical Engineering and Materials Science, Yuan Ze University, Taoyuan 320, Taiwan
| | - Lung-Chang Lin
- Department of Pediatrics, School of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung 807, Taiwan;
- Department of Pediatrics, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung 807, Taiwan
| | - Kuo-Liang Chiang
- Department of Pediatric Neurology, Kuang-Tien General Hospital, Taichung 433, Taiwan;
- Department of Nutrition, Hungkuang University, Taichung 433, Taiwan
| | - Chuan-Mu Chen
- Department of Life Sciences, Agricultural Biotechnology Center, National Chung Hsing University, Taichung 402, Taiwan
- The iEGG and Animal Biotechnology Center, and Rong Hsing Research Center for Translational Medicine, National Chung Hsing University, Taichung 402, Taiwan
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Mich JK, Ryu J, Wei AD, Gore BB, Guo R, Bard AM, Martinez RA, Bishaw Y, Luber E, Oliveira Santos LM, Miranda N, Ramirez JM, Ting JT, Lein ES, Levi BP, Kalume FK. AAV-mediated interneuron-specific gene replacement for Dravet syndrome. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.15.571820. [PMID: 38168178 PMCID: PMC10760176 DOI: 10.1101/2023.12.15.571820] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/05/2024]
Abstract
Dravet syndrome (DS) is a devastating developmental epileptic encephalopathy marked by treatment-resistant seizures, developmental delay, intellectual disability, motor deficits, and a 10-20% rate of premature death. Most DS patients harbor loss-of-function mutations in one copy of SCN1A , which has been associated with inhibitory neuron dysfunction. Here we developed an interneuron-targeting AAV human SCN1A gene replacement therapy using cell class-specific enhancers. We generated a split-intein fusion form of SCN1A to circumvent AAV packaging limitations and deliver SCN1A via a dual vector approach using cell class-specific enhancers. These constructs produced full-length Na V 1.1 protein and functional sodium channels in HEK293 cells and in brain cells in vivo . After packaging these vectors into enhancer-AAVs and administering to mice, immunohistochemical analyses showed telencephalic GABAergic interneuron-specific and dose-dependent transgene biodistribution. These vectors conferred strong dose-dependent protection against postnatal mortality and seizures in two DS mouse models carrying independent loss-of-function alleles of Scn1a, at two independent research sites, supporting the robustness of this approach. No mortality or toxicity was observed in wild-type mice injected with single vectors expressing either the N-terminal or C-terminal halves of SCN1A , or the dual vector system targeting interneurons. In contrast, nonselective neuronal targeting of SCN1A conferred less rescue against mortality and presented substantial preweaning lethality. These findings demonstrate proof-of-concept that interneuron-specific AAV-mediated SCN1A gene replacement is sufficient for significant rescue in DS mouse models and suggest it could be an effective therapeutic approach for patients with DS.
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Ricobaraza A, Bunuales M, Gonzalez-Aparicio M, Fadila S, Rubinstein M, Vides-Urrestarazu I, Banderas J, Sola-Sevilla N, Sanchez-Carpintero R, Lanciego JL, Roda E, Honrubia A, Arnaiz P, Hernandez-Alcoceba R. Preferential expression of SCN1A in GABAergic neurons improves survival and epileptic phenotype in a mouse model of Dravet syndrome. J Mol Med (Berl) 2023; 101:1587-1601. [PMID: 37819378 PMCID: PMC10697872 DOI: 10.1007/s00109-023-02383-8] [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: 05/05/2023] [Revised: 09/15/2023] [Accepted: 09/25/2023] [Indexed: 10/13/2023]
Abstract
The SCN1A gene encodes the alpha subunit of a voltage-gated sodium channel (Nav1.1), which is essential for the function of inhibitory neurons in the brain. Mutations in this gene cause severe encephalopathies such as Dravet syndrome (DS). Upregulation of SCN1A expression by different approaches has demonstrated promising therapeutic effects in preclinical models of DS. Limiting the effect to inhibitory neurons may contribute to the restoration of brain homeostasis, increasing the safety and efficacy of the treatment. In this work, we have evaluated different approaches to obtain preferential expression of the full SCN1A cDNA (6 Kb) in GABAergic neurons, using high-capacity adenoviral vectors (HC-AdV). In order to favour infection of these cells, we considered ErbB4 as a surface target. Incorporation of the EGF-like domain from neuregulin 1 alpha (NRG1α) in the fiber of adenovirus capsid allowed preferential infection in cells lines expressing ErbB4. However, it had no impact on the infectivity of the vector in primary cultures or in vivo. For transcriptional control of transgene expression, we developed a regulatory sequence (DP3V) based on the Distal-less homolog enhancer (Dlx), the vesicular GABA transporter (VGAT) promoter, and a portion of the SCN1A gene. The hybrid DP3V promoter allowed preferential expression of transgenes in GABAergic neurons both in vitro and in vivo. A new HC-AdV expressing SCN1A under the control of this promoter showed improved survival and amelioration of the epileptic phenotype in a DS mouse model. These results increase the repertoire of gene therapy vectors for the treatment of DS and indicate a new avenue for the refinement of gene supplementation in this disease. KEY MESSAGES: Adenoviral vectors can deliver the SCN1A cDNA and are amenable for targeting. An adenoviral vector displaying an ErbB4 ligand in the capsid does not target GABAergic neurons. A hybrid promoter allows preferential expression of transgenes in GABAergic neurons. Preferential expression of SCN1A in GABAergic cells is therapeutic in a Dravet syndrome model.
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Affiliation(s)
- Ana Ricobaraza
- Gene Therapy and Regulation of Gene Expression Program, CIMA, University of Navarra, CIMA, Av. Pio XII 55, E-31008, Pamplona, Spain
| | - Maria Bunuales
- Gene Therapy and Regulation of Gene Expression Program, CIMA, University of Navarra, CIMA, Av. Pio XII 55, E-31008, Pamplona, Spain
| | - Manuela Gonzalez-Aparicio
- Gene Therapy and Regulation of Gene Expression Program, CIMA, University of Navarra, CIMA, Av. Pio XII 55, E-31008, Pamplona, Spain
| | - Saja Fadila
- Sackler Faculty of Medicine, Goldschleger Eye Research Institute, Tel Aviv University, Tel Aviv, Israel
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
| | - Moran Rubinstein
- Sackler Faculty of Medicine, Goldschleger Eye Research Institute, Tel Aviv University, Tel Aviv, Israel
- Department of Human Molecular Genetics and Biochemistry, Sackler Faculty of Medicine, Tel Aviv University, Tel Aviv, Israel
- Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, Israel
| | - Irene Vides-Urrestarazu
- Gene Therapy and Regulation of Gene Expression Program, CIMA, University of Navarra, CIMA, Av. Pio XII 55, E-31008, Pamplona, Spain
| | - Julliana Banderas
- Gene Therapy and Regulation of Gene Expression Program, CIMA, University of Navarra, CIMA, Av. Pio XII 55, E-31008, Pamplona, Spain
| | - Noemi Sola-Sevilla
- Gene Therapy and Regulation of Gene Expression Program, CIMA, University of Navarra, CIMA, Av. Pio XII 55, E-31008, Pamplona, Spain
| | - Rocio Sanchez-Carpintero
- University Clinic of Navarra, Dravet Syndrome Unit, Pediatric Neurology Unit, IdiSNA, Navarra Institute for Health Research, Pamplona, Spain
| | - Jose Luis Lanciego
- Department of Neuroscience, CIMA, University of Navarra, Pamplona, Spain
- Instituto de Investigación Sanitaria de Navarra (IdiSNA), Pamplona, Spain
- Centro de Investigación Biomédica en Red de Enfermedades Neurodegenerativas (CiberNed), Madrid, Spain
| | - Elvira Roda
- Department of Neuroscience, CIMA, University of Navarra, Pamplona, Spain
| | - Adriana Honrubia
- Department of Neuroscience, CIMA, University of Navarra, Pamplona, Spain
| | - Patricia Arnaiz
- Department of Neuroscience, CIMA, University of Navarra, Pamplona, Spain
| | - Ruben Hernandez-Alcoceba
- Gene Therapy and Regulation of Gene Expression Program, CIMA, University of Navarra, CIMA, Av. Pio XII 55, E-31008, Pamplona, Spain.
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Hansen SN, Holm A, Kauppinen S, Klitgaard H. RNA therapeutics for epilepsy: An emerging modality for drug discovery. Epilepsia 2023; 64:3113-3129. [PMID: 37703096 DOI: 10.1111/epi.17772] [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: 06/14/2023] [Revised: 09/04/2023] [Accepted: 09/11/2023] [Indexed: 09/14/2023]
Abstract
Drug discovery in epilepsy began with the finding of potassium bromide by Sir Charles Locock in 1857. The following century witnessed the introduction of phenotypic screening tests for discovering antiseizure medications (ASMs). Despite the high success rate of developing ASMs, they have so far failed in eliminating drug resistance and in delivering disease-modifying treatments. This emphasizes the need for new drug discovery strategies in epilepsy. RNA-based drugs have recently shown promise as a new modality with the potential of providing disease modification and counteracting drug resistance in epilepsy. RNA therapeutics can be directed either toward noncoding RNAs, such as microRNAs, long noncoding RNAs (ncRNAs), and circular RNAs, or toward messenger RNAs. The former show promise in sporadic, nongenetic epilepsies, as interference with ncRNAs allows for modulation of entire disease pathways, whereas the latter seem more promising in monogenic childhood epilepsies. Here, we describe therapeutic strategies for modulating disease-associated RNA molecules and highlight the potential of RNA therapeutics for the treatment of different patient populations such as sporadic, drug-resistant epilepsy, and childhood monogenic epilepsies.
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Affiliation(s)
| | - Anja Holm
- Department of Clinical Medicine, Center for RNA Medicine, Aalborg University, Copenhagen, Denmark
| | - Sakari Kauppinen
- Department of Clinical Medicine, Center for RNA Medicine, Aalborg University, Copenhagen, Denmark
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Lersch R, Jannadi R, Grosse L, Wagner M, Schneider MF, von Stülpnagel C, Heinen F, Potschka H, Borggraefe I. Targeted Molecular Strategies for Genetic Neurodevelopmental Disorders: Emerging Lessons from Dravet Syndrome. Neuroscientist 2023; 29:732-750. [PMID: 35414300 PMCID: PMC10623613 DOI: 10.1177/10738584221088244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Dravet syndrome is a severe developmental and epileptic encephalopathy mostly caused by heterozygous mutation of the SCN1A gene encoding the voltage-gated sodium channel α subunit Nav1.1. Multiple seizure types, cognitive deterioration, behavioral disturbances, ataxia, and sudden unexpected death associated with epilepsy are a hallmark of the disease. Recently approved antiseizure medications such as fenfluramine and cannabidiol have been shown to reduce seizure burden. However, patients with Dravet syndrome are still medically refractory in the majority of cases, and there is a high demand for new therapies aiming to improve behavioral and cognitive outcome. Drug-repurposing approaches for SCN1A-related Dravet syndrome are currently under investigation (i.e., lorcaserin, clemizole, and ataluren). New therapeutic concepts also arise from the field of precision medicine by upregulating functional SCN1A or by activating Nav1.1. These include antisense nucleotides directed against the nonproductive transcript of SCN1A with the poison exon 20N and against an inhibitory noncoding antisense RNA of SCN1A. Gene therapy approaches such as adeno-associated virus-based upregulation of SCN1A using a transcriptional activator (ETX101) or CRISPR/dCas technologies show promising results in preclinical studies. Although these new treatment concepts still need further clinical research, they offer great potential for precise and disease modifying treatment of Dravet syndrome.
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Affiliation(s)
- Robert Lersch
- Department of Pediatrics, Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
| | - Rawan Jannadi
- Department of Pediatrics, Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
- Institute of Human Genetics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
| | - Leonie Grosse
- Department of Pediatrics, Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
| | - Matias Wagner
- Department of Pediatrics, Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
- Institute of Human Genetics, Technical University of Munich, Munich, Germany
- Institute for Neurogenomics, Helmholtz Centre Munich, German Research Center for Health and Environment (GmbH), Munich, Germany
| | - Marius Frederik Schneider
- Metabolic Biochemistry, Biomedical Center Munich, Medical Faculty, Ludwig Maximilians University, Munich, Germany
- International Max Planck Research School (IMPRS) for Molecular Life Sciences, Planegg-Martinsried, Germany
| | - Celina von Stülpnagel
- Department of Pediatrics, Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
- Research Institute for Rehabilitation, Transition and Palliation, Paracelsus Medical Private University (PMU), Salzburg, Austria
| | - Florian Heinen
- Department of Pediatrics, Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
| | - Heidrun Potschka
- Institute of Pharmacology, Toxicology, and Pharmacy, Ludwig Maximilians University, Munich, Germany
| | - Ingo Borggraefe
- Department of Pediatrics, Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
- Comprehensive Epilepsy Center, University Hospital of Munich, Ludwig Maximilians University, Munich, Germany
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Ünalp A, Güzin Y, Ünay B, Tosun A, Çavuşoğlu D, Tekin HG, Kurul SH, Arhan E, Edizer S, Öztürk G, Yiş U, Yılmaz Ü. Retracted: Clinical and genetic evaluations of rare childhood epilepsies in Turkey's national cohort. Epileptic Disord 2023; 25:924. [PMID: 37584621 DOI: 10.1002/epd2.20150] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/25/2023] [Revised: 12/25/2022] [Accepted: 08/10/2023] [Indexed: 08/17/2023]
Abstract
Aycan Ünalp, Yiğithan Güzin, Bülent Ünay, Ayşe Tosun, Dilek Çavuşoğlu, Hande Gazeteci Tekin, Semra Hız Kurul, Ebru Arhan, Selvinaz Edizer, Gülten Öztürk, Uluç Yiş, Ünsal Yılmaz, Turkish Rare Epilepsies Study Group, Clinical and genetic evaluations of rare childhood epilepsies in Turkey's national cohort, Epileptic Disorders, 2023, (https://doi.org/10.1002/epd2.20150) The above article, published online on 16 August 2023 on Wiley Online Library (www.onlinelibrary.wiley.com), has been retracted by agreement between the authors, the Editor-in-Chief, Sándor Beniczky, and John Wiley & Sons Ltd. The authors asked for a retraction based on an experimental error which would alter the results of the study if corrected.
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Yang Y, Yang R, Kang B, Qian S, He X, Zhang X. Single-cell long-read sequencing in human cerebral organoids uncovers cell-type-specific and autism-associated exons. Cell Rep 2023; 42:113335. [PMID: 37889749 PMCID: PMC10842930 DOI: 10.1016/j.celrep.2023.113335] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 09/12/2023] [Accepted: 10/09/2023] [Indexed: 10/29/2023] Open
Abstract
Dysregulation of alternative splicing has been repeatedly associated with neurodevelopmental disorders, but the extent of cell-type-specific splicing in human neural development remains largely uncharted. Here, single-cell long-read sequencing in induced pluripotent stem cell (iPSC)-derived cerebral organoids identifies over 31,000 uncatalogued isoforms and 4,531 cell-type-specific splicing events. Long reads uncover coordinated splicing and cell-type-specific intron retention events, which are challenging to study with short reads. Retained neuronal introns are enriched in RNA splicing regulators, showing shorter lengths, higher GC contents, and weaker 5' splice sites. We use this dataset to explore the biological processes underlying neurological disorders, focusing on autism. In comparison with prior transcriptomic data, we find that the splicing program in autistic brains is closer to the progenitor state than differentiated neurons. Furthermore, cell-type-specific exons harbor significantly more de novo mutations in autism probands than in siblings. Overall, these results highlight the importance of cell-type-specific splicing in autism and neuronal gene regulation.
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Affiliation(s)
- Yalan Yang
- Department of Human Genetics, Neuroscience Institute, The University of Chicago, Chicago, IL 60637, USA
| | - Runwei Yang
- Department of Human Genetics, Neuroscience Institute, The University of Chicago, Chicago, IL 60637, USA
| | - Bowei Kang
- Department of Human Genetics, Neuroscience Institute, The University of Chicago, Chicago, IL 60637, USA
| | - Sheng Qian
- Department of Human Genetics, Neuroscience Institute, The University of Chicago, Chicago, IL 60637, USA
| | - Xin He
- Department of Human Genetics, Neuroscience Institute, The University of Chicago, Chicago, IL 60637, USA.
| | - Xiaochang Zhang
- Department of Human Genetics, Neuroscience Institute, The University of Chicago, Chicago, IL 60637, USA.
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Whyte-Fagundes P, Vance A, Carroll A, Figueroa F, Manukyan C, Baraban SC. Testing of putative antiseizure drugs in a preclinical Dravet syndrome zebrafish model. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.11.11.566723. [PMID: 38014342 PMCID: PMC10680609 DOI: 10.1101/2023.11.11.566723] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
Dravet syndrome (DS) is a severe genetic epilepsy primarily caused by de novo mutations in a voltage-activated sodium channel gene (SCN1A). Patients face life-threatening seizures that are largely resistant to available anti-seizure medications (ASM). Preclinical DS animal models are a valuable tool to identify candidate ASMs for these patients. Among these, scn1lab mutant zebrafish exhibiting spontaneous seizure-like activity are particularly amenable to large-scale drug screening. Prior screening in a scn1lab mutant zebrafish line generated using N-ethyl-Nnitrosourea (ENU) identified valproate, stiripentol, and fenfluramine e.g., Federal Drug Administration (FDA) approved drugs with clinical application in the DS population. Successful phenotypic screening in scn1lab mutant zebrafish consists of two stages: (i) a locomotion-based assay measuring high-velocity convulsive swim behavior and (ii) an electrophysiology-based assay, using in vivo local field potential (LFP) recordings, to quantify electrographic seizure-like events. Using this strategy more than 3000 drug candidates have been screened in scn1lab zebrafish mutants. Here, we curated a list of nine additional anti-seizure drug candidates recently identified in preclinical models: 1-EBIO, AA43279, chlorzoxazone, donepezil, lisuride, mifepristone, pargyline, soticlestat and vorinostat. First-stage locomotion-based assays in scn1lab mutant zebrafish identified only 1-EBIO, chlorzoxazone and lisuride. However, second-stage LFP recording assays did not show significant suppression of spontaneous electrographic seizure activity for any of the nine anti-seizure drug candidates. Surprisingly, soticlestat induced frank electrographic seizure-like discharges in wild-type control zebrafish. Taken together, our results failed to replicate clear anti-seizure efficacy for these drug candidates highlighting a necessity for strict scientific standards in preclinical identification of ASMs.
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Affiliation(s)
- P Whyte-Fagundes
- Epilepsy Research Laboratory and Weill Institute for Neuroscience, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
| | - A Vance
- Epilepsy Research Laboratory and Weill Institute for Neuroscience, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
| | - A Carroll
- Behavioral Neurosciences, Northeastern University, Boston, MA, USA
| | - F Figueroa
- Epilepsy Research Laboratory and Weill Institute for Neuroscience, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
| | - C Manukyan
- Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA
| | - S C Baraban
- Epilepsy Research Laboratory and Weill Institute for Neuroscience, Department of Neurological Surgery, University of California San Francisco, San Francisco, CA, USA
- Helen Wills Neuroscience Institute, University of California, Berkeley, CA, USA
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Buchanan GF. Revoking the Seize Order: Preventing Spontaneous Seizures With AAV in a CLN2 Mouse Model. Epilepsy Curr 2023; 23:386-388. [PMID: 38269343 PMCID: PMC10805085 DOI: 10.1177/15357597231200702] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/26/2024] Open
Abstract
Gene Therapy Ameliorates Spontaneous Seizures Associated With Cortical Neuron Loss in a Cln2R207X Mouse Model Takahashi K, Eultgen EM, Wang S, Rensing NR, Nelvagal HR, Dearborn JT, Danos O, Buss N, Sands MS, Wong M, Cooper JD. 2023. J Clin Invest. 133(12):e165908. doi:10.1172/JCI165908 Although a disease-modifying therapy for classic late infantile neuronal ceroid lipofuscinosis (CLN2 disease) exists, poor understanding of cellular pathophysiology has hampered the development of more effective and persistent therapies. Here, we investigated the nature and progression of neurological and underlying neuropathological changes in Cln2R207X mice, which carry one of the most common pathogenic mutations in human patients but are yet to be fully characterized. Long-term electroencephalography recordings revealed progressive epileptiform abnormalities, including spontaneous seizures, providing a robust, quantifiable, and clinically relevant phenotype. These seizures were accompanied by the loss of multiple cortical neuron populations, including those stained for interneuron markers. Further histological analysis revealed early localized microglial activation months before neuron loss started in the thalamocortical system and spinal cord, which was accompanied by astrogliosis. This pathology was more pronounced and occurred in the cortex before the thalamus or spinal cord and differed markedly from the staging seen in mouse models of other forms of neuronal ceroid lipofuscinosis. Neonatal administration of adeno-associated virus serotype 9–mediated gene therapy ameliorated the seizure and gait phenotypes and prolonged the life span of Cln2R207X mice, attenuating most pathological changes. Our findings highlight the importance of clinically relevant outcome measures for judging preclinical efficacy of therapeutic interventions for CLN2 disease.
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Affiliation(s)
- Gordon F Buchanan
- Department of Neurology and Iowa Neuroscience Institute, Carver College of Medicine, University of Iowa
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Auvin S, Galanopoulou AS, Moshé SL, Potschka H, Rocha L, Walker MC. Revisiting the concept of drug-resistant epilepsy: A TASK1 report of the ILAE/AES Joint Translational Task Force. Epilepsia 2023; 64:2891-2908. [PMID: 37676719 PMCID: PMC10836613 DOI: 10.1111/epi.17751] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2023] [Revised: 08/08/2023] [Accepted: 08/16/2023] [Indexed: 09/08/2023]
Abstract
Despite progress in the development of anti-seizure medications (ASMs), one third of people with epilepsy have drug-resistant epilepsy (DRE). The working definition of DRE, proposed by the International League Against Epilepsy (ILAE) in 2010, helped identify individuals who might benefit from presurgical evaluation early on. As the incidence of DRE remains high, the TASK1 workgroup on DRE of the ILAE/American Epilepsy Society (AES) Joint Translational Task Force discussed the heterogeneity and complexity of its presentation and mechanisms, the confounders in drawing mechanistic insights when testing treatment responses, and barriers in modeling DRE across the lifespan and translating across species. We propose that it is necessary to revisit the current definition of DRE, in order to transform the preclinical and clinical research of mechanisms and biomarkers, to identify novel, effective, precise, pharmacologic treatments, allowing for earlier recognition of drug resistance and individualized therapies.
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Affiliation(s)
- Stéphane Auvin
- Institut Universitaire de France, Paris, France
- Paediatric Neurology, Assistance Publique - Hôpitaux de Paris, EpiCARE ERN Member, Robert-Debré Hospital, Paris, France
- University Paris-Cité, Paris, France
| | - Aristea S Galanopoulou
- Saul R. Korey Department of Neurology, Isabelle Rapin Division of Child Neurology, Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, and Montefiore/Einstein Epilepsy Center, Bronx, New York, USA
| | - Solomon L Moshé
- Saul R. Korey Department of Neurology, Isabelle Rapin Division of Child Neurology, Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, and Montefiore/Einstein Epilepsy Center, Bronx, New York, USA
- Department of Pediatrics, Albert Einstein College of Medicine, Bronx, New York, USA
| | - Heidrun Potschka
- Institute of Pharmacology, Toxicology, and Pharmacy, Ludwig-Maximilians-University (LMU), Munich, Germany
| | - Luisa Rocha
- Pharmacobiology Department, Center for Research and Advanced Studies (CINVESTAV), Mexico City, Mexico
| | - Matthew C Walker
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, London, UK
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Brunklaus A, George AL, Lal D, Heinzen EL, Goldman AM. Prophecy or empiricism? Clinical value of predicting versus determining genetic variant functions. Epilepsia 2023; 64:2909-2913. [PMID: 37562820 DOI: 10.1111/epi.17743] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 08/08/2023] [Accepted: 08/09/2023] [Indexed: 08/12/2023]
Abstract
The recent explosion of epilepsy genetic testing has created challenges for interpretation of gene variants. Assessments of the functional consequences of genetic variants either by predictive or experimental strategies can contribute to estimating pathogenicity, but there is no consensus on which approach is best. The Special Interest Group on Epilepsy Genetics hosted a session during the Annual American Epilepsy Society Meeting in December 2022 to discuss this topic. The session featured a debate of the relative advantages and limitations of predicting (prophecy) versus experimentally determining (empiricism) variant function using ion channel gene variants as examples. This commentary summarizes these discussions.
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Affiliation(s)
- Andreas Brunklaus
- Royal Hospital for Children, Glasgow, UK
- Institute of Health and Wellbeing, University of Glasgow, Glasgow, UK
| | - Alfred L George
- Department of Pharmacology, Feinberg School of Medicine, Northwestern University, Chicago, Illinois, USA
| | - Dennis Lal
- Genomic Medicine Institute, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA
| | - Erin L Heinzen
- Division of Pharmacotherapy and Experimental Therapeutics, Eshelman School of Pharmacy, University of North Carolina, Chapel Hill, North Carolina, USA
- Department of Genetics, School of Medicine, University of North Carolina, Chapel Hill, North Carolina, USA
| | - Alica M Goldman
- Department of Neurology, Peter Kellaway Neurophysiology Section, Baylor College of Medicine, Houston, Texas, USA
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41
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Cao Y, Liu H, Lu SS, Jones KA, Govind AP, Jeyifous O, Simmons CQ, Tabatabaei N, Green WN, Holder JL, Tahmasebi S, George AL, Dickinson BC. RNA-based translation activators for targeted gene upregulation. Nat Commun 2023; 14:6827. [PMID: 37884512 PMCID: PMC10603104 DOI: 10.1038/s41467-023-42252-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Accepted: 10/04/2023] [Indexed: 10/28/2023] Open
Abstract
Technologies capable of programmable translation activation offer strategies to develop therapeutics for diseases caused by insufficient gene expression. Here, we present "translation-activating RNAs" (taRNAs), a bifunctional RNA-based molecular technology that binds to a specific mRNA of interest and directly upregulates its translation. taRNAs are constructed from a variety of viral or mammalian RNA internal ribosome entry sites (IRESs) and upregulate translation for a suite of target mRNAs. We minimize the taRNA scaffold to 94 nucleotides, identify two translation initiation factor proteins responsible for taRNA activity, and validate the technology by amplifying SYNGAP1 expression, a haploinsufficiency disease target, in patient-derived cells. Finally, taRNAs are suitable for delivery as RNA molecules by lipid nanoparticles (LNPs) to cell lines, primary neurons, and mouse liver in vivo. taRNAs provide a general and compact nucleic acid-based technology to upregulate protein production from endogenous mRNAs, and may open up possibilities for therapeutic RNA research.
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Affiliation(s)
- Yang Cao
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
| | - Huachun Liu
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
| | - Shannon S Lu
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
| | - Krysten A Jones
- Department of Chemistry, The University of Chicago, Chicago, IL, USA
| | - Anitha P Govind
- Department of Neurobiology, The University of Chicago, Chicago, IL, USA
| | - Okunola Jeyifous
- Department of Neurobiology, The University of Chicago, Chicago, IL, USA
| | - Christine Q Simmons
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Negar Tabatabaei
- Department of Pharmacology and Regenerative Medicine, University of Illinois College of Medicine, Chicago, IL, USA
| | - William N Green
- Department of Neurobiology, The University of Chicago, Chicago, IL, USA
| | - Jimmy L Holder
- Department of Pediatrics, Baylor College of Medicine, Houston, TX, USA
- Jan and Dan Duncan Neurological Research Institute, Texas Children's Hospital, Houston, TX, USA
| | - Soroush Tahmasebi
- Department of Pharmacology and Regenerative Medicine, University of Illinois College of Medicine, Chicago, IL, USA
| | - Alfred L George
- Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL, USA
| | - Bryan C Dickinson
- Department of Chemistry, The University of Chicago, Chicago, IL, USA.
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Won Lee J, Kyu Shim M, Kim H, Jang H, Lee Y, Hwa Kim S. RNAi therapies: Expanding applications for extrahepatic diseases and overcoming delivery challenges. Adv Drug Deliv Rev 2023; 201:115073. [PMID: 37657644 DOI: 10.1016/j.addr.2023.115073] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2023] [Revised: 07/31/2023] [Accepted: 08/20/2023] [Indexed: 09/03/2023]
Abstract
The era of RNA medicine has become a reality with the success of messenger RNA (mRNA) vaccines against COVID-19 and the approval of several RNA interference (RNAi) agents in recent years. Particularly, therapeutics based on RNAi offer the promise of targeting intractable and previously undruggable disease genes. Recent advances have focused in developing delivery systems to enhance the poor cellular uptake and insufficient pharmacokinetic properties of RNAi therapeutics and thereby improve its efficacy and safety. However, such approach has been mainly achieved via lipid nanoparticles (LNPs) or chemical conjugation with N-Acetylgalactosamine (GalNAc), thus current RNAi therapy has been limited to liver diseases, most likely to encounter liver-targeting limitations. Hence, there is a huge unmet medical need for intense evolution of RNAi therapeutics delivery systems to target extrahepatic tissues and ultimately extend their indications for treating various intractable diseases. In this review, challenges of delivering RNAi therapeutics to tumors and major organs are discussed, as well as their transition to clinical trials. This review also highlights innovative and promising preclinical RNAi-based delivery platforms for the treatment of extrahepatic diseases.
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Affiliation(s)
- Jong Won Lee
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul 02841, Republic of Korea; Medicinal Materials Research Center, Biomedical Research Division, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
| | - Man Kyu Shim
- Medicinal Materials Research Center, Biomedical Research Division, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
| | - Hyosuk Kim
- Medicinal Materials Research Center, Biomedical Research Division, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea
| | - Hochung Jang
- Medicinal Materials Research Center, Biomedical Research Division, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea; Division of Bio-Medical Science and Technology, KIST School, Korea University of Science and Technology, Seoul 02792, Republic of Korea
| | - Yuhan Lee
- Department of Anesthesiology, Perioperative, and Pain Medicine, Center for Accelerated Medical Innovation & Center for Nanomedicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA.
| | - Sun Hwa Kim
- KU-KIST Graduate School of Converging Science and Technology, Korea University, Seoul 02841, Republic of Korea; Medicinal Materials Research Center, Biomedical Research Division, Korea Institute of Science and Technology (KIST), Seoul 02792, Republic of Korea.
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43
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Borggraefe I, Wagner M. Precision Therapy in KCNQ2-Related Epilepsy. Neuropediatrics 2023; 54:295-296. [PMID: 37722392 DOI: 10.1055/s-0043-1772667] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 09/20/2023]
Affiliation(s)
- Ingo Borggraefe
- Department of Pediatrics, Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, Dr. von Hauner Children's Hospital, University Hospital, Ludwig Maximilian University Munich, Munich, Germany
- Comprehensive Epilepsy Center for Children and Adolescents, University Hospital, Ludwig Maximilians University Munich, Munich, Germany
| | - Matias Wagner
- Department of Pediatrics, Division of Pediatric Neurology, Developmental Medicine and Social Pediatrics, Dr. von Hauner Children's Hospital, University Hospital, Ludwig Maximilian University Munich, Munich, Germany
- Institute of Neurogenomics, Helmholtz Centrum, Munich, Germany
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44
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Kioutchoukova IP, Foster DT, Thakkar RN, Foreman MA, Burgess BJ, Toms RM, Molina Valero EE, Lucke-Wold B. Neurologic orphan diseases: Emerging innovations and role for genetic treatments. World J Exp Med 2023; 13:59-74. [PMID: 37767543 PMCID: PMC10520757 DOI: 10.5493/wjem.v13.i4.59] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/17/2023] [Revised: 07/16/2023] [Accepted: 08/11/2023] [Indexed: 09/15/2023] Open
Abstract
Orphan diseases are rare diseases that affect less than 200000 individuals within the United States. Most orphan diseases are of neurologic and genetic origin. With the current advances in technology, more funding has been devoted to developing therapeutic agents for patients with these conditions. In our review, we highlight emerging options for patients with neurologic orphan diseases, specifically including diseases resulting in muscular deterioration, epilepsy, seizures, neurodegenerative movement disorders, inhibited cognitive development, neuron deterioration, and tumors. After extensive literature review, gene therapy offers a promising route for the treatment of neurologic orphan diseases. The use of clustered regularly interspaced palindromic repeats/Cas9 has demonstrated positive results in experiments investigating its role in several diseases. Additionally, the use of adeno-associated viral vectors has shown improvement in survival, motor function, and developmental milestones, while also demonstrating reversal of sensory ataxia and cardiomyopathy in Friedreich ataxia patients. Antisense oligonucleotides have also been used in some neurologic orphan diseases with positive outcomes. Mammalian target of rapamycin inhibitors are currently being investigated and have reduced abnormal cell growth, proliferation, and angiogenesis. Emerging innovations and the role of genetic treatments open a new window of opportunity for the treatment of neurologic orphan diseases.
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Affiliation(s)
| | - Devon T Foster
- Florida International University Herbert Wertheim College of Medicine, Florida International University Herbert Wertheim College of Medicine, Miami, FL 33199, United States
| | - Rajvi N Thakkar
- College of Medicine, University of Florida, Gainesville, FL 32611, United States
| | - Marco A Foreman
- College of Medicine, University of Florida, Gainesville, FL 32611, United States
| | - Brandon J Burgess
- College of Medicine, University of Florida, Gainesville, FL 32611, United States
| | - Rebecca M Toms
- College of Medicine, University of Florida, Gainesville, FL 32611, United States
| | | | - Brandon Lucke-Wold
- Department of Neurosurgery, University of Florida, Gainesville, FL 32611, United States
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45
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Martins Custodio H, Clayton LM, Bellampalli R, Pagni S, Silvennoinen K, Caswell R, Brunklaus A, Guerrini R, Koeleman BPC, Lemke JR, Møller RS, Scheffer IE, Weckhuysen S, Zara F, Zuberi S, Kuchenbaecker K, Balestrini S, Mills JD, Sisodiya SM. Widespread genomic influences on phenotype in Dravet syndrome, a 'monogenic' condition. Brain 2023; 146:3885-3897. [PMID: 37006128 PMCID: PMC10473570 DOI: 10.1093/brain/awad111] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2022] [Revised: 02/01/2023] [Accepted: 03/12/2023] [Indexed: 04/04/2023] Open
Abstract
Dravet syndrome is an archetypal rare severe epilepsy, considered 'monogenic', typically caused by loss-of-function SCN1A variants. Despite a recognizable core phenotype, its marked phenotypic heterogeneity is incompletely explained by differences in the causal SCN1A variant or clinical factors. In 34 adults with SCN1A-related Dravet syndrome, we show additional genomic variation beyond SCN1A contributes to phenotype and its diversity, with an excess of rare variants in epilepsy-related genes as a set and examples of blended phenotypes, including one individual with an ultra-rare DEPDC5 variant and focal cortical dysplasia. The polygenic risk score for intelligence was lower, and for longevity, higher, in Dravet syndrome than in epilepsy controls. The causal, major-effect, SCN1A variant may need to act against a broadly compromised genomic background to generate the full Dravet syndrome phenotype, whilst genomic resilience may help to ameliorate the risk of premature mortality in adult Dravet syndrome survivors.
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Affiliation(s)
- Helena Martins Custodio
- University College London Queen Square Institute of Neurology, Department of Clinical and Experimental Epilepsy, London, WC1N 3BG, UK
- Chalfont Centre for Epilepsy, Chalfont St Peter SL9 0RJ, UK
| | - Lisa M Clayton
- University College London Queen Square Institute of Neurology, Department of Clinical and Experimental Epilepsy, London, WC1N 3BG, UK
- Chalfont Centre for Epilepsy, Chalfont St Peter SL9 0RJ, UK
| | - Ravishankara Bellampalli
- University College London Queen Square Institute of Neurology, Department of Clinical and Experimental Epilepsy, London, WC1N 3BG, UK
- Chalfont Centre for Epilepsy, Chalfont St Peter SL9 0RJ, UK
| | - Susanna Pagni
- University College London Queen Square Institute of Neurology, Department of Clinical and Experimental Epilepsy, London, WC1N 3BG, UK
- Chalfont Centre for Epilepsy, Chalfont St Peter SL9 0RJ, UK
| | - Katri Silvennoinen
- University College London Queen Square Institute of Neurology, Department of Clinical and Experimental Epilepsy, London, WC1N 3BG, UK
- Chalfont Centre for Epilepsy, Chalfont St Peter SL9 0RJ, UK
- Kuopio Epilepsy Center, Neurocenter, Kuopio University Hospital, Kuopio 70210, Finland
| | - Richard Caswell
- Exeter Genomics Laboratory, Royal Devon University Healthcare NHS Foundation Trust, Exeter EX2 5DW, UK
| | - Andreas Brunklaus
- Paediatric Neuroscience Research Group, Royal Hospital for Children, Glasgow G51 4TF, UK
- Institute of Health and Wellbeing, University of Glasgow, Glasgow G12 8TB, UK
| | - Renzo Guerrini
- Neuroscience Department, Meyer Children’s Hospital IRCSS, University of Florence, 50139 Florence, Italy
| | - Bobby P C Koeleman
- Department of Genetics, University Medical Centre Utrecht, 3584CX Utrecht, The Netherlands
| | - Johannes R Lemke
- Institute of Human Genetics, University of Leipzig Medical Center, Leipzig 04103, Germany
- Center for Rare Diseases, University of Leipzig Medical Center, Leipzig 04103, Germany
| | - Rikke S Møller
- Department of Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Centre, DK-4293 Dianalund, Denmark
- Department of Regional Health Research, University of Southern Denmark, DK-5230 Odense, Denmark
| | - Ingrid E Scheffer
- Epilepsy Research Centre, Florey Institute, University of Melbourne, Austin Health and Royal Children's Hospital, Melbourne, VIC 3084, Australia
- Murdoch Children's Research Institute, Parkville, VIC 3052, Australia
| | - Sarah Weckhuysen
- Applied and Translational Neurogenomics Group, VIB Centre for Molecular Neurology, VIB, Antwerp 2610, Belgium
- Translational Neurosciences, Faculty of Medicine and Health Science, University of Antwerp, Antwerp 2650, Belgium
- Department of Neurology, University Hospital Antwerp, Antwerp 2650, Belgium
- µNEURO Research Centre of Excellence, University of Antwerp, Antwerp 2610, Belgium
| | - Federico Zara
- Unit of Medical Genetics, IRCCS Istituto Giannina Gaslini, 16147 Genoa, Italy
- Department of Neurosciences Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, 16132 Genoa, Italy
| | - Sameer Zuberi
- Paediatric Neuroscience Research Group, Royal Hospital for Children, Glasgow G51 4TF, UK
- Institute of Health and Wellbeing, University of Glasgow, Glasgow G12 8TB, UK
| | | | - Simona Balestrini
- University College London Queen Square Institute of Neurology, Department of Clinical and Experimental Epilepsy, London, WC1N 3BG, UK
- Chalfont Centre for Epilepsy, Chalfont St Peter SL9 0RJ, UK
- Neuroscience Department, Meyer Children’s Hospital IRCSS, University of Florence, 50139 Florence, Italy
| | - James D Mills
- University College London Queen Square Institute of Neurology, Department of Clinical and Experimental Epilepsy, London, WC1N 3BG, UK
- Chalfont Centre for Epilepsy, Chalfont St Peter SL9 0RJ, UK
- Amsterdam UMC, University of Amsterdam, Department of (Neuro)Pathology, Amsterdam Neuroscience, 1105 AZ Amsterdam, The Netherlands
| | - Sanjay M Sisodiya
- University College London Queen Square Institute of Neurology, Department of Clinical and Experimental Epilepsy, London, WC1N 3BG, UK
- Chalfont Centre for Epilepsy, Chalfont St Peter SL9 0RJ, UK
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46
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Lopez L, De Waard S, Meudal H, Caumes C, Khakh K, Peigneur S, Oliveira-Mendes B, Lin S, De Waele J, Montnach J, Cestèle S, Tessier A, Johnson JP, Mantegazza M, Tytgat J, Cohen C, Béroud R, Bosmans F, Landon C, De Waard M. Structure-function relationship of new peptides activating human Na v1.1. Biomed Pharmacother 2023; 165:115173. [PMID: 37453200 DOI: 10.1016/j.biopha.2023.115173] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 07/11/2023] [Accepted: 07/12/2023] [Indexed: 07/18/2023] Open
Abstract
Nav1.1 is an important pharmacological target as this voltage-gated sodium channel is involved in neurological and cardiac syndromes. Channel activators are actively sought to try to compensate for haploinsufficiency in several of these pathologies. Herein we used a natural source of new peptide compounds active on ion channels and screened for drugs capable to inhibit channel inactivation as a way to compensate for decreased channel function. We discovered that JzTx-34 is highly active on Nav1.1 and subsequently performed a full structure-activity relationship investigation to identify its pharmacophore. These experiments will help interpret the mechanism of action of this and formerly identified peptides as well as the future identification of new peptides. We also reveal structural determinants that make natural ICK peptides active against Nav1.1 challenging to synthesize. Altogether, the knowledge gained by this study will help facilitate the discovery and development of new compounds active on this critical ion channel target.
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Affiliation(s)
- Ludivine Lopez
- Nantes Université, CNRS, INSERM, l'institut du thorax, F-44000 Nantes, France; Smartox Biotechnology, Saint-Egrève, France
| | - Stephan De Waard
- Nantes Université, CNRS, INSERM, l'institut du thorax, F-44000 Nantes, France; LabEx "Ion Channels, Science and Therapeutics", Valbonne, France
| | - Hervé Meudal
- Center for Molecular Biophysics, CNRS, rue Charles Sadron, CS 80054, Orléans 45071, France
| | | | - Kuldip Khakh
- Xenon Pharmaceuticals, Burnaby, British Columbia, Canada
| | | | | | - Sophia Lin
- Xenon Pharmaceuticals, Burnaby, British Columbia, Canada
| | - Jolien De Waele
- Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
| | - Jérôme Montnach
- Nantes Université, CNRS, INSERM, l'institut du thorax, F-44000 Nantes, France
| | - Sandrine Cestèle
- Université Cote d'Azur, CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology, Valbonne-Sophia Antipolis, France
| | - Agnès Tessier
- Nantes Université, CNRS, INSERM, l'institut du thorax, F-44000 Nantes, France
| | - J P Johnson
- Xenon Pharmaceuticals, Burnaby, British Columbia, Canada
| | - Massimo Mantegazza
- Université Cote d'Azur, CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology, Valbonne-Sophia Antipolis, France
| | - Jan Tytgat
- University of Leuven, 3000 Leuven, Belgium
| | - Charles Cohen
- Xenon Pharmaceuticals, Burnaby, British Columbia, Canada
| | | | - Frank Bosmans
- Department of Basic and Applied Medical Sciences, Ghent University, Ghent, Belgium
| | - Céline Landon
- Center for Molecular Biophysics, CNRS, rue Charles Sadron, CS 80054, Orléans 45071, France
| | - Michel De Waard
- Nantes Université, CNRS, INSERM, l'institut du thorax, F-44000 Nantes, France; Smartox Biotechnology, Saint-Egrève, France; LabEx "Ion Channels, Science and Therapeutics", Valbonne, France.
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47
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Perucca E, White HS, Bialer M. New GABA-Targeting Therapies for the Treatment of Seizures and Epilepsy: II. Treatments in Clinical Development. CNS Drugs 2023; 37:781-795. [PMID: 37603261 PMCID: PMC10501930 DOI: 10.1007/s40263-023-01025-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/29/2023] [Indexed: 08/22/2023]
Abstract
The inhibitory neurotransmitter γ-aminobutyric acid (GABA) plays an important role in the modulation of neuronal excitability, and a disruption of GABAergic transmission contributes to the pathogenesis of some seizure disorders. Although many currently available antiseizure medications do act at least in part by potentiating GABAergic transmission, there is an opportunity for further research aimed at developing more innovative GABA-targeting therapies. The present article summarises available evidence on a number of such treatments in clinical development. These can be broadly divided into three groups. The first group consists of positive allosteric modulators of GABAA receptors and includes Staccato® alprazolam (an already marketed benzodiazepine being repurposed in epilepsy as a potential rescue inhalation treatment for prolonged and repetitive seizures), the α2/3/5 subtype-selective agents darigabat and ENX-101, and the orally active neurosteroids ETX155 and LPCN 2101. A second group comprises two drugs already marketed for non-neurological indications, which could be repurposed as treatments for seizure disorders. These include bumetanide, a diuretic agent that has undergone clinical trials in phenobarbital-resistant neonatal seizures and for which the rationale for further development in this indication is under debate, and ivermectin, an antiparasitic drug currently investigated in a randomised double-blind trial in focal epilepsy. The last group comprises a series of highly innovative therapies, namely GABAergic interneurons (NRTX-001) delivered via stereotactic cerebral implantation as a treatment for mesial temporal lobe epilepsy, an antisense oligonucleotide (STK-001) aimed at upregulating NaV1.1 currents and restoring the function of GABAergic interneurons, currently tested in a trial in patients with Dravet syndrome, and an adenoviral vector-based gene therapy (ETX-101) scheduled for investigation in Dravet syndrome. Another agent, a subcutaneously administered neuroactive peptide (NRP2945) that reportedly upregulates the expression of GABAA receptor α and β subunits is being investigated, with Lennox-Gastaut syndrome and other epilepsies as proposed indications. The diversity of the current pipeline underscores a strong interest in the GABA system as a target for new treatment development in epilepsy. To date, limited clinical data are available for these investigational treatments and further studies are required to assess their potential value in addressing unmet needs in epilepsy management.
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Affiliation(s)
- Emilio Perucca
- Department of Medicine (Austin Health), Melbourne Brain Centre, The University of Melbourne, 245 Burgundy Street, Melbourne, VIC, 3084, Australia.
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia.
| | - H Steve White
- Department of Pharmacy, School of Pharmacy, University of Washington, Seattle, WA, USA
| | - Meir Bialer
- Faculty of Medicine, Institute of Drug Research, School of Pharmacy, The Hebrew University of Jerusalem, Jerusalem, Israel
- David R. Bloom Center for Pharmacy, The Hebrew University of Jerusalem, Jerusalem, Israel
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48
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Rusina E, Simonti M, Duprat F, Cestèle S, Mantegazza M. Voltage-gated sodium channels in genetic epilepsy: up and down of excitability. J Neurochem 2023. [PMID: 37654020 DOI: 10.1111/jnc.15947] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2023] [Revised: 08/11/2023] [Accepted: 08/13/2023] [Indexed: 09/02/2023]
Abstract
The past two decades have witnessed a wide range of studies investigating genetic variants of voltage-gated sodium (NaV ) channels, which are involved in a broad spectrum of diseases, including several types of epilepsy. We have reviewed here phenotypes and pathological mechanisms of genetic epilepsies caused by variants in NaV α and β subunits, as well as of some relevant interacting proteins (FGF12/FHF1, PRRT2, and Ankyrin-G). Notably, variants of all these genes can induce either gain- or loss-of-function of NaV leading to either neuronal hyperexcitability or hypoexcitability. We present the results of functional studies obtained with different experimental models, highlighting that they should be interpreted considering the features of the experimental system used. These systems are models, but they have allowed us to better understand pathophysiological issues, ameliorate diagnostics, orientate genetic counseling, and select/develop therapies within a precision medicine framework. These studies have also allowed us to gain insights into the physiological roles of different NaV channels and of the cells that express them. Overall, our review shows the progress that has been made, but also the need for further studies on aspects that have not yet been clarified. Finally, we conclude by highlighting some significant themes of general interest that can be gleaned from the results of the work of the last two decades.
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Affiliation(s)
- Evgeniia Rusina
- University Cote d'Azur, Valbonne-Sophia Antipolis, France
- CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology (IPMC), Valbonne-Sophia Antipolis, France
| | - Martina Simonti
- University Cote d'Azur, Valbonne-Sophia Antipolis, France
- CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology (IPMC), Valbonne-Sophia Antipolis, France
| | - Fabrice Duprat
- University Cote d'Azur, Valbonne-Sophia Antipolis, France
- CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology (IPMC), Valbonne-Sophia Antipolis, France
- Inserm, Valbonne-Sophia Antipolis, France
| | - Sandrine Cestèle
- University Cote d'Azur, Valbonne-Sophia Antipolis, France
- CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology (IPMC), Valbonne-Sophia Antipolis, France
| | - Massimo Mantegazza
- University Cote d'Azur, Valbonne-Sophia Antipolis, France
- CNRS UMR 7275, Institute of Molecular and Cellular Pharmacology (IPMC), Valbonne-Sophia Antipolis, France
- Inserm, Valbonne-Sophia Antipolis, France
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49
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Recinos Y, Ustianenko D, Yeh YT, Wang X, Jacko M, Yesantharao LV, Wu Q, Zhang C. Deep screening of proximal and distal splicing-regulatory elements in a native sequence context. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.21.554109. [PMID: 37662340 PMCID: PMC10473672 DOI: 10.1101/2023.08.21.554109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/05/2023]
Abstract
Pre-mRNA splicing, a key process in gene expression, can be therapeutically modulated using various drug modalities, including antisense oligonucleotides (ASOs). However, determining promising targets is impeded by the challenge of systematically mapping splicing-regulatory elements (SREs) in their native sequence context. Here, we use the catalytically dead CRISPR-RfxCas13d RNA-targeting system (dCas13d/gRNA) as a programmable platform to bind SREs and modulate splicing by competing against endogenous splicing factors. SpliceRUSH, a high-throughput screening method, was developed to map SREs in any gene of interest using a lentivirus gRNA library that tiles the genetic region, including distal intronic sequences. When applied to SMN2, a therapeutic target for spinal muscular atrophy, SpliceRUSH robustly identified not only known SREs, but also a novel distal intronic splicing enhancer, which can be targeted to alter exon 7 splicing using either dCas13d/gRNA or ASOs. This technology enables a deeper understanding of splicing regulation with applications for RNA-based drug discovery.
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Affiliation(s)
- Yocelyn Recinos
- Department of Systems Biology, Department of Biochemistry and Molecular Biophysics, Center for Motor Neuron Biology and Disease, Columbia University, New York, NY 10032, USA
| | - Dmytro Ustianenko
- Department of Systems Biology, Department of Biochemistry and Molecular Biophysics, Center for Motor Neuron Biology and Disease, Columbia University, New York, NY 10032, USA
- Present address: Flagship Pioneering, Cambridge, MA 02142, USA
| | - Yow-Tyng Yeh
- Department of Systems Biology, Department of Biochemistry and Molecular Biophysics, Center for Motor Neuron Biology and Disease, Columbia University, New York, NY 10032, USA
| | - Xiaojian Wang
- Department of Systems Biology, Department of Biochemistry and Molecular Biophysics, Center for Motor Neuron Biology and Disease, Columbia University, New York, NY 10032, USA
| | - Martin Jacko
- Department of Systems Biology, Department of Biochemistry and Molecular Biophysics, Center for Motor Neuron Biology and Disease, Columbia University, New York, NY 10032, USA
- Present address: Aperture Therapeutics, Inc., San Carlos, CA 94070, USA
| | - Lekha V. Yesantharao
- Department of Systems Biology, Department of Biochemistry and Molecular Biophysics, Center for Motor Neuron Biology and Disease, Columbia University, New York, NY 10032, USA
- Present address: Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA
| | - Qiyang Wu
- Department of Systems Biology, Department of Biochemistry and Molecular Biophysics, Center for Motor Neuron Biology and Disease, Columbia University, New York, NY 10032, USA
| | - Chaolin Zhang
- Department of Systems Biology, Department of Biochemistry and Molecular Biophysics, Center for Motor Neuron Biology and Disease, Columbia University, New York, NY 10032, USA
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Felker SA, Lawlor JMJ, Hiatt SM, Thompson ML, Latner DR, Finnila CR, Bowling KM, Bonnstetter ZT, Bonini KE, Kelly NR, Kelley WV, Hurst ACE, Rashid S, Kelly MA, Nakouzi G, Hendon LG, Bebin EM, Kenny EE, Cooper GM. Poison exon annotations improve the yield of clinically relevant variants in genomic diagnostic testing. Genet Med 2023; 25:100884. [PMID: 37161864 PMCID: PMC10524927 DOI: 10.1016/j.gim.2023.100884] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Revised: 05/01/2023] [Accepted: 05/03/2023] [Indexed: 05/11/2023] Open
Abstract
PURPOSE Neurodevelopmental disorders (NDDs) often result from rare genetic variation, but genomic testing yield for NDDs remains below 50%, suggesting that clinically relevant variants may be missed by standard analyses. Here, we analyze "poison exons" (PEs), which are evolutionarily conserved alternative exons often absent from standard gene annotations. Variants that alter PE inclusion can lead to loss of function and may be highly penetrant contributors to disease. METHODS We curated published RNA sequencing data from developing mouse cortex to define 1937 conserved PE regions potentially relevant to NDDs, and we analyzed variants found by genome sequencing in multiple NDD cohorts. RESULTS Across 2999 probands, we found 6 novel clinically relevant variants in PE regions. Five of these variants are in genes that are part of the sodium voltage-gated channel alpha subunit family (SCN1A, SCN2A, and SCN8A), which is associated with epilepsies. One variant is in SNRPB, associated with cerebrocostomandibular syndrome. These variants have moderate to high computational impact assessments, are absent from population variant databases, and in genes with gene-phenotype associations consistent with each probands reported features. CONCLUSION With a very minimal increase in variant analysis burden (average of 0.77 variants per proband), annotation of PEs can improve diagnostic yield for NDDs and likely other congenital conditions.
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Affiliation(s)
| | | | - Susan M Hiatt
- HudsonAlpha Institute for Biotechnology, Huntsville, AL
| | | | | | | | | | | | - Katherine E Bonini
- Institute for Genomic Health, Icahn School of Medicine at Mount Sinai, New York, NY
| | - Nicole R Kelly
- Division of Pediatric Genetic Medicine, Department of Pediatrics, Children's Hospital at Montefiore/Montefiore Medical Center/Albert Einstein College of Medicine, Bronx, NY
| | | | | | | | | | | | | | - E Martina Bebin
- Department of Neurology, University of Alabama at Birmingham, Birmingham, AL
| | - Eimear E Kenny
- Institute for Genomic Health, Icahn School of Medicine at Mount Sinai, New York, NY; Department of Genetics and Genomic Sciences, Icahn School of Medicine at Mount Sinai, New York, NY; Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, NY
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