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Simões de Oliveira L, O'Leary HE, Nawaz S, Loureiro R, Davenport EC, Baxter P, Louros SR, Dando O, Perkins E, Peltier J, Trost M, Osterweil EK, Hardingham GE, Cousin MA, Chattarji S, Booker SA, Benke TA, Wyllie DJA, Kind PC. Enhanced hippocampal LTP but normal NMDA receptor and AMPA receptor function in a rat model of CDKL5 deficiency disorder. Mol Autism 2024; 15:28. [PMID: 38877552 PMCID: PMC11177379 DOI: 10.1186/s13229-024-00601-9] [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: 11/03/2023] [Accepted: 05/07/2024] [Indexed: 06/16/2024] Open
Abstract
BACKGROUND Mutations in the X-linked gene cyclin-dependent kinase-like 5 (CDKL5) cause a severe neurological disorder characterised by early-onset epileptic seizures, autism and intellectual disability (ID). Impaired hippocampal function has been implicated in other models of monogenic forms of autism spectrum disorders and ID and is often linked to epilepsy and behavioural abnormalities. Many individuals with CDKL5 deficiency disorder (CDD) have null mutations and complete loss of CDKL5 protein, therefore in the current study we used a Cdkl5-/y rat model to elucidate the impact of CDKL5 loss on cellular excitability and synaptic function of CA1 pyramidal cells (PCs). We hypothesised abnormal pre and/or post synaptic function and plasticity would be observed in the hippocampus of Cdkl5-/y rats. METHODS To allow cross-species comparisons of phenotypes associated with the loss of CDKL5, we generated a loss of function mutation in exon 8 of the rat Cdkl5 gene and assessed the impact of the loss of CDLK5 using a combination of extracellular and whole-cell electrophysiological recordings, biochemistry, and histology. RESULTS Our results indicate that CA1 hippocampal long-term potentiation (LTP) is enhanced in slices prepared from juvenile, but not adult, Cdkl5-/y rats. Enhanced LTP does not result from changes in NMDA receptor function or subunit expression as these remain unaltered throughout development. Furthermore, Ca2+ permeable AMPA receptor mediated currents are unchanged in Cdkl5-/y rats. We observe reduced mEPSC frequency accompanied by increased spine density in basal dendrites of CA1 PCs, however we find no evidence supporting an increase in silent synapses when assessed using a minimal stimulation protocol in slices. Additionally, we found no change in paired-pulse ratio, consistent with normal release probability at Schaffer collateral to CA1 PC synapses. CONCLUSIONS Our data indicate a role for CDKL5 in hippocampal synaptic function and raise the possibility that altered intracellular signalling rather than synaptic deficits contribute to the altered plasticity. LIMITATIONS This study has focussed on the electrophysiological and anatomical properties of hippocampal CA1 PCs across early postnatal development. Studies involving other brain regions, older animals and behavioural phenotypes associated with the loss of CDKL5 are needed to understand the pathophysiology of CDD.
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MESH Headings
- Animals
- Long-Term Potentiation
- Receptors, N-Methyl-D-Aspartate/metabolism
- Receptors, N-Methyl-D-Aspartate/genetics
- Receptors, AMPA/metabolism
- Receptors, AMPA/genetics
- Spasms, Infantile/genetics
- Spasms, Infantile/metabolism
- Disease Models, Animal
- Rats
- Protein Serine-Threonine Kinases/metabolism
- Protein Serine-Threonine Kinases/genetics
- Hippocampus/metabolism
- Pyramidal Cells/metabolism
- Pyramidal Cells/pathology
- Male
- CA1 Region, Hippocampal/metabolism
- CA1 Region, Hippocampal/pathology
- CA1 Region, Hippocampal/physiopathology
- Epileptic Syndromes/genetics
- Epileptic Syndromes/metabolism
- Genetic Diseases, X-Linked/genetics
- Genetic Diseases, X-Linked/metabolism
- Genetic Diseases, X-Linked/physiopathology
- Synapses/metabolism
- Excitatory Postsynaptic Potentials
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Affiliation(s)
- Laura Simões de Oliveira
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, UK
| | - Heather E O'Leary
- School of Medicine, University of Colorado, Denver, CO, USA
- Department of Pharmacology, University of Colorado Denver, 12800 East 19th Ave, Aurora, CO, 80045, USA
| | - Sarfaraz Nawaz
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, UK
- National Centre for Biological Sciences, Tata Institute for Fundamental Research, Bangalore, 560065, India
- Centre for Brain Development and Repair, Instem, Bangalore, India
| | - Rita Loureiro
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, UK
| | | | - Paul Baxter
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
- UK Dementia Research Institute, University of Edinburgh, Edinburgh, UK
| | - Susana R Louros
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, UK
| | - Owen Dando
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, UK
- UK Dementia Research Institute, University of Edinburgh, Edinburgh, UK
| | - Emma Perkins
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, UK
| | - Julien Peltier
- Faculty of Medical Sciences, Newcastle University Biosciences Institute, Newcastle upon Tyne, NE2 4HH, UK
| | - Matthias Trost
- Faculty of Medical Sciences, Newcastle University Biosciences Institute, Newcastle upon Tyne, NE2 4HH, UK
| | - Emily K Osterweil
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, UK
| | - Giles E Hardingham
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, UK
- UK Dementia Research Institute, University of Edinburgh, Edinburgh, UK
| | - Michael A Cousin
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, UK
- Centre for Brain Development and Repair, Instem, Bangalore, India
| | - Sumantra Chattarji
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, UK
- National Centre for Biological Sciences, Tata Institute for Fundamental Research, Bangalore, 560065, India
- Centre for Brain Development and Repair, Instem, Bangalore, India
| | - Sam A Booker
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, UK
| | - Tim A Benke
- School of Medicine, University of Colorado, Denver, CO, USA.
- Department of Pharmacology, University of Colorado Denver, 12800 East 19th Ave, Aurora, CO, 80045, USA.
| | - David J A Wyllie
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, UK.
- Centre for Brain Development and Repair, Instem, Bangalore, India.
- Centre for Discovery Brain Sciences, Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, Edinburgh, EH8 9XD, UK.
| | - Peter C Kind
- Centre for Discovery Brain Sciences, University of Edinburgh, Edinburgh, UK.
- Simons Initiative for the Developing Brain, Patrick Wild Centre, University of Edinburgh, Edinburgh, UK.
- Centre for Brain Development and Repair, Instem, Bangalore, India.
- Centre for Discovery Brain Sciences, Simons Initiative for the Developing Brain, University of Edinburgh, Hugh Robson Building, Edinburgh, EH8 9XD, UK.
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Swanson MA, Jiang H, Busquet N, Carlsen J, Brindley C, Benke TA, Van Hove RA, Friederich MW, MacLean KN, Mesches MH, Van Hove JLK. Deep postnatal phenotyping of a new mouse model of nonketotic hyperglycinemia. J Inherit Metab Dis 2024. [PMID: 38840294 DOI: 10.1002/jimd.12755] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Revised: 04/18/2024] [Accepted: 05/02/2024] [Indexed: 06/07/2024]
Abstract
Nonketotic hyperglycinemia due to deficient glycine cleavage enzyme activity causes a severe neonatal epileptic encephalopathy. Current therapies based on mitigating glycine excess have only limited impact. An animal model with postnatal phenotyping is needed to explore new therapeutic approaches. We developed a Gldc p.Ala394Val mutant model and bred it to congenic status in two colonies on C57Bl/6J (B6) and J129X1/SvJ (J129) backgrounds. Mutant mice had reduced P-protein and enzyme activity indicating a hypomorphic mutant. Glycine levels were increased in blood and brain regions, exacerbated by dietary glycine, with higher levels in female than male J129 mice. Birth defects were more prevalent in mutant B6 than J129 mice, and hydrocephalus was more frequent in B6 (40%) compared to J129 (none). The hydrocephalus rate was increased by postnatal glycine challenge in B6 mice, more so when delivered from the first neonatal week than from the fourth. Mutant mice had reduced weight gain following weaning until the eighth postnatal week, which was exacerbated by glycine loading. The electrographic spike rate was increased in mutant mice following glycine loading, but no seizures were observed. The alpha/delta band intensity ratio was decreased in the left cortex in female J129 mice, which were less active in an open field test and explored less in a Y-maze, suggesting an encephalopathic effect. Mutant mice showed no evidence of memory dysfunction. This partial recapitulation of human symptoms and biochemistry will facilitate the evaluation of new therapeutic approaches with an early postnatal time window likely most effective.
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Affiliation(s)
- Michael A Swanson
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Hua Jiang
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Nicolas Busquet
- NeuroTechnology Center, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
- Department of Neurology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Jessica Carlsen
- NeuroTechnology Center, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Connie Brindley
- NeuroTechnology Center, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Tim A Benke
- Department of Pediatrics, Section of Pediatric Neurology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Roxanne A Van Hove
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Marisa W Friederich
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Kenneth N MacLean
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Michael H Mesches
- NeuroTechnology Center, School of Medicine, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
- Department of Pediatrics, Section of Pediatric Neurology, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Johan L K Van Hove
- Department of Pediatrics, Section of Clinical Genetics and Metabolism, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
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Li X, Yennawar M, Wiest A, O'Brien WT, Babrowicz B, White RS, Talos DM, Jensen FE. Cannabidiol attenuates seizure susceptibility and behavioural deficits in adult CDKL5 R59X knock-in mice. Eur J Neurosci 2024; 59:3337-3352. [PMID: 38654472 DOI: 10.1111/ejn.16350] [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: 09/09/2023] [Revised: 02/15/2024] [Accepted: 03/25/2024] [Indexed: 04/26/2024]
Abstract
Cyclin-dependent kinase-like 5 (CDKL5) deficiency disorder (CDD) is caused by a loss-of-function mutation in CDKL5 gene, encoding a serine-threonine kinase highly expressed in the brain. CDD manifests with early-onset epilepsy, autism, motor impairment and severe intellectual disability. While there are no known treatments for CDD, the use of cannabidiol has recently been introduced into clinical practice for neurodevelopmental disorders. Given the increased clinical utilization of cannabidiol, we examined its efficacy in the CDKL5R59X knock-in (R59X) mice, a CDD model based on a human mutation that exhibits both lifelong seizure susceptibility and behavioural deficits. We found that cannabidiol pre-treatment rescued the increased seizure susceptibility in response to the chemoconvulsant pentylenetetrazol (PTZ), attenuated working memory and long-term memory impairments, and rescued social deficits in adult R59X mice. To elucidate a potential mechanism, we compared the developmental hippocampal and cortical expression of common endocannabinoid (eCB) targets in R59X mice and their wild-type littermates, including cannabinoid type 1 receptor (CB1R), transient receptor potential vanilloid type 1 (TRPV1) and 2 (TRPV2), G-coupled protein receptor 55 (GPR55) and adenosine receptor 1 (A1R). Many of these eCB targets were developmentally regulated in both R59X and wild-type mice. In addition, adult R59X mice demonstrated significantly decreased expression of CB1R and TRPV1 in the hippocampus, and TRPV2 in the cortex, while TRPV1 was increased in the cortex. These findings support the potential for dysregulation of eCB signalling as a plausible mechanism and therapeutic target in CDD, given the efficacy of cannabidiol to attenuate hyperexcitability and behavioural deficits in this disorder.
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Affiliation(s)
- Xiaofan Li
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Madhumita Yennawar
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Alyssa Wiest
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - William T O'Brien
- Neurobehavior Testing Core, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Bergan Babrowicz
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Rachel S White
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Delia M Talos
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Frances E Jensen
- Department of Neurology, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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4
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Swanson MA, Jiang H, Busquet N, Carlsen J, Brindley C, Benke TA, Van Hove RA, Friederich MW, MacLean KN, Mesches MH, Van Hove JLK. Deep postnatal phenotyping of a new mouse model of nonketotic hyperglycinemia. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.26.586818. [PMID: 38586005 PMCID: PMC10996592 DOI: 10.1101/2024.03.26.586818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Nonketotic hyperglycinemia due to deficient glycine cleavage enzyme activity causes a severe neonatal epileptic encephalopathy. Current therapies based on mitigating glycine excess have only limited impact. An animal model with postnatal phenotyping is needed to explore new therapeutic approaches. We developed a Gldc p.Ala394Val mutant model and bred it to congenic status in 2 colonies on C57Bl/6J (B6) and J129X1/SvJ (J129) backgrounds. Mutant mice had reduced P-protein and enzyme activity indicating a hypomorphic mutant. Glycine levels were increased in blood and brain regions, exacerbated by dietary glycine, with higher levels in female than male J129 mice. Birth defects were more prevalent in mutant B6 than J129 mice, and hydrocephalus was more frequent in B6 (40%) compared to J129 (none). The hydrocephalus rate was increased by postnatal glycine challenge in B6 mice, more so when delivered from the first neonatal week than from the fourth. Mutant mice had reduced weight gain following weaning until the eighth postnatal week, which was exacerbated by glycine loading. The electrographic spike rate was increased in mutant mice following glycine loading, but no seizures were observed. The alpha/delta band intensity ratio was decreased in the left cortex in female J129 mice, which were less active in an open field test and explored less in a Y-maze, suggesting an encephalopathic effect. Mutant mice showed no evidence of memory dysfunction. This partial recapitulation of human symptoms and biochemistry will facilitate the evaluation of new therapeutic approaches with an early postnatal time window likely most effective. Take home message A mouse model of nonketotic hyperglycinemia is described that shows postnatal abnormalities in glycine levels, neural tube defects, body weight, electroencephalographic recordings, and in activity in young mice making it amenable for the evaluation of novel treatment interventions. Author contributions Study concept and design: JVH, MHM, NB, KNMAnimal study data: MAS, HJ, NB, MHM, JC, CBBiochemical and genetic studies: MAS, RAVH, MWFStatistical analysis: NB, JVHFirst draft writing: JVH, NB, MHMCritical rewriting: MAS, NB, MHM, TAB, JC, MWF, KNM, JVHFinal responsibility, guarantor, and communicating author: JVH. Competing interest statement The University of Colorado (JVH, MS, KNM, HJ) has the intention to file Intellectual property protection for certain biochemical treatments of NKH. Otherwise, the authors have stated that they had no interests that might be perceived as posing a conflict or bias to this subject matter. Funding support Financial support is acknowledged form the NKH Crusaders, Brodyn's Friends, Nora Jane Almany Foundation, the Dickens Family Foundation, the Lucas John Foundation, Les Petits Bourdons, Joseph's Fund, the Barnett Family, Maud & Vic Foundation, Lucy's BEElievers fund, Hope for NKH, Madi's Mission NKH fund, and from Dr. and Ms. Shaw, and the University of Colorado Foundation NKH research fund. The study was supported by a grant (CNS-X-19-103) from the University of Colorado School of Medicine and the Colorado Clinical Translational Science Institute, which is supported by NIH/NCATS Colorado CTSA Grant Number UL1 TR002535. Contents are the authors' sole responsibility and do not necessarily represent official NIH views. All funding sources had no role in the design or execution of the study, the interpretation of data, or the writing of the study. Ethics approval on Laboratory Animal Studies Mouse studies were carried out with approval from the Institutional Animal Care and Use Committee of the University of Colorado Anschutz Medical Campus (IACUC# 00413). Data sharing statement The data that support the findings of this study are available from the corresponding author upon reasonable request.
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Martinez D, Jiang E, Zhou Z. Overcoming genetic and cellular complexity to study the pathophysiology of X-linked intellectual disabilities. J Neurodev Disord 2024; 16:5. [PMID: 38424476 PMCID: PMC10902969 DOI: 10.1186/s11689-024-09517-0] [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] [Received: 12/17/2023] [Accepted: 02/04/2024] [Indexed: 03/02/2024] Open
Abstract
X-linked genetic causes of intellectual disability (ID) account for a substantial proportion of cases and remain poorly understood, in part due to the heterogeneous expression of X-linked genes in females. This is because most genes on the X chromosome are subject to random X chromosome inactivation (XCI) during early embryonic development, which results in a mosaic pattern of gene expression for a given X-linked mutant allele. This mosaic expression produces substantial complexity, especially when attempting to study the already complicated neural circuits that underly behavior, thus impeding the understanding of disease-related pathophysiology and the development of therapeutics. Here, we review a few selected X-linked forms of ID that predominantly affect heterozygous females and the current obstacles for developing effective therapies for such disorders. We also propose a genetic strategy to overcome the complexity presented by mosaicism in heterozygous females and highlight specific tools for studying synaptic and circuit mechanisms, many of which could be shared across multiple forms of intellectual disability.
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Affiliation(s)
- Dayne Martinez
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19102, USA
- Medical Scientist Training Program, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19102, USA
| | - Evan Jiang
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19102, USA
- Medical Scientist Training Program, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19102, USA
| | - Zhaolan Zhou
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19102, USA.
- Medical Scientist Training Program, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19102, USA.
- Department of Neuroscience, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA, 19102, USA.
- Intellectual and Developmental Disabilities Research Center, Children's Hospital of Philadelphia, Philadelphia, PA, 19104, USA.
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Silvestre M, Dempster K, Mihaylov SR, Claxton S, Ultanir SK. Cell type-specific expression, regulation and compensation of CDKL5 activity in mouse brain. Mol Psychiatry 2024:10.1038/s41380-024-02434-7. [PMID: 38326557 DOI: 10.1038/s41380-024-02434-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2023] [Revised: 01/04/2024] [Accepted: 01/15/2024] [Indexed: 02/09/2024]
Abstract
CDKL5 is a brain-enriched serine/threonine kinase, associated with a profound developmental and epileptic encephalopathy called CDKL5 deficiency disorder (CDD). To design targeted therapies for CDD, it is essential to determine where CDKL5 is expressed and is active in the brain and test if compensatory mechanisms exist at cellular level. We generated conditional Cdkl5 knockout mice in excitatory neurons, inhibitory neurons and astrocytes. To assess CDKL5 activity, we utilized a phosphospecific antibody for phosphorylated EB2, a well-known substrate of CDKL5. We found that CDKL5 and EB2 pS222 were prominent in excitatory and inhibitory neurons but were not detected in astrocytes. We observed that approximately 15-20% of EB2 pS222 remained in Cdkl5 knockout brains and primary neurons. Surprisingly, the remaining phosphorylation was modulated by NMDA and PP1/PP2A in neuronal CDKL5 knockout cultures, indicating the presence of a compensating kinase. Using a screen of candidate kinases with highest homology to the CDKL5 kinase domain, we found that CDKL2 and ICK can phosphorylate EB2 S222 in HEK293T cells and in primary neurons. We then generated Cdkl5/Cdkl2 dual knockout mice to directly test if CDKL2 phosphorylates EB2 in vivo and found that CDKL2 phosphorylates CDKL5 substrates in the brain. This study is the first indication that CDKL2 could potentially replace CDKL5 functions in the brain, alluding to novel therapeutic possibilities.
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Affiliation(s)
- Margaux Silvestre
- Kinases and Brain Development Laboratory, The Francis Crick Institute, London, UK
| | - Kelvin Dempster
- Kinases and Brain Development Laboratory, The Francis Crick Institute, London, UK
| | - Simeon R Mihaylov
- Kinases and Brain Development Laboratory, The Francis Crick Institute, London, UK
| | - Suzanne Claxton
- Kinases and Brain Development Laboratory, The Francis Crick Institute, London, UK
| | - Sila K Ultanir
- Kinases and Brain Development Laboratory, The Francis Crick Institute, London, UK.
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Sampedro-Castañeda M, Baltussen LL, Lopes AT, Qiu Y, Sirvio L, Mihaylov SR, Claxton S, Richardson JC, Lignani G, Ultanir SK. Epilepsy-linked kinase CDKL5 phosphorylates voltage-gated calcium channel Cav2.3, altering inactivation kinetics and neuronal excitability. Nat Commun 2023; 14:7830. [PMID: 38081835 PMCID: PMC10713615 DOI: 10.1038/s41467-023-43475-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Accepted: 11/09/2023] [Indexed: 12/18/2023] Open
Abstract
Developmental and epileptic encephalopathies (DEEs) are a group of rare childhood disorders characterized by severe epilepsy and cognitive deficits. Numerous DEE genes have been discovered thanks to advances in genomic diagnosis, yet putative molecular links between these disorders are unknown. CDKL5 deficiency disorder (CDD, DEE2), one of the most common genetic epilepsies, is caused by loss-of-function mutations in the brain-enriched kinase CDKL5. To elucidate CDKL5 function, we looked for CDKL5 substrates using a SILAC-based phosphoproteomic screen. We identified the voltage-gated Ca2+ channel Cav2.3 (encoded by CACNA1E) as a physiological target of CDKL5 in mice and humans. Recombinant channel electrophysiology and interdisciplinary characterization of Cav2.3 phosphomutant mice revealed that loss of Cav2.3 phosphorylation leads to channel gain-of-function via slower inactivation and enhanced cholinergic stimulation, resulting in increased neuronal excitability. Our results thus show that CDD is partly a channelopathy. The properties of unphosphorylated Cav2.3 closely resemble those described for CACNA1E gain-of-function mutations causing DEE69, a disorder sharing clinical features with CDD. We show that these two single-gene diseases are mechanistically related and could be ameliorated with Cav2.3 inhibitors.
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Affiliation(s)
| | - Lucas L Baltussen
- Kinases and Brain Development Lab, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
- Laboratory for the Research of Neurodegenerative Diseases (VIB-KU Leuven), Department of Neurosciences, ON5 Herestraat 49, 3000, Leuven, Belgium
| | - André T Lopes
- Kinases and Brain Development Lab, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Yichen Qiu
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, Queen Square House, London, WC1N 3BG, UK
| | - Liina Sirvio
- Kinases and Brain Development Lab, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Simeon R Mihaylov
- Kinases and Brain Development Lab, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Suzanne Claxton
- Kinases and Brain Development Lab, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK
| | - Jill C Richardson
- Neuroscience, MSD Research Laboratories, 120 Moorgate, London, EC2M 6UR, UK
| | - Gabriele Lignani
- Department of Clinical and Experimental Epilepsy, UCL Queen Square Institute of Neurology, Queen Square House, London, WC1N 3BG, UK
| | - Sila K Ultanir
- Kinases and Brain Development Lab, The Francis Crick Institute, 1 Midland Road, London, NW1 1AT, UK.
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Liao W, Lee KZ. CDKL5-mediated developmental tuning of neuronal excitability and concomitant regulation of transcriptome. Hum Mol Genet 2023; 32:3276-3298. [PMID: 37688574 DOI: 10.1093/hmg/ddad149] [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: 04/03/2023] [Revised: 08/31/2023] [Accepted: 09/06/2023] [Indexed: 09/11/2023] Open
Abstract
Cyclin-dependent kinase-like 5 (CDKL5) is a serine-threonine kinase enriched in the forebrain to regulate neuronal development and function. Patients with CDKL5 deficiency disorder (CDD), a severe neurodevelopmental condition caused by mutations of CDKL5 gene, present early-onset epilepsy as the most prominent feature. However, spontaneous seizures have not been reported in mouse models of CDD, raising vital questions on the human-mouse differences and the roles of CDKL5 in early postnatal brains. Here, we firstly measured electroencephalographic (EEG) activities via a wireless telemetry system coupled with video-recording in neonatal mice. We found that mice lacking CDKL5 exhibited spontaneous epileptic EEG discharges, accompanied with increased burst activities and ictal behaviors, specifically at postnatal day 12 (P12). Intriguingly, those epileptic spikes disappeared after P14. We next performed an unbiased transcriptome profiling in the dorsal hippocampus and motor cortex of Cdkl5 null mice at different developmental timepoints, uncovering a set of age-dependent and brain region-specific alterations of gene expression in parallel with the transient display of epileptic activities. Finally, we validated multiple differentially expressed genes, such as glycine receptor alpha 2 and cholecystokinin, at the transcript or protein levels, supporting the relevance of these genes to CDKL5-regulated excitability. Our findings reveal early-onset neuronal hyperexcitability in mouse model of CDD, providing new insights into CDD etiology and potential molecular targets to ameliorate intractable neonatal epilepsy.
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Affiliation(s)
- Wenlin Liao
- Institute of Neuroscience, National Cheng-Chi University, Taipei 116, Taiwan
- Research Center for Mind, Brain and Learning, National Cheng-Chi University, Taipei 116, Taiwan
| | - Kun-Ze Lee
- Department of Biological Sciences, National Sun Yat-Sen University, No. 70, Lienhai Road, Kaohsiung 80424, Taiwan
- Department of Biomedical Science and Environmental Biology, Kaohsiung Medical University, 100, Shih-Chuan 1st Road, Kaohsiung 80708, Taiwan
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9
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Zhu ZA, Li YY, Xu J, Xue H, Feng X, Zhu YC, Xiong ZQ. CDKL5 deficiency in adult glutamatergic neurons alters synaptic activity and causes spontaneous seizures via TrkB signaling. Cell Rep 2023; 42:113202. [PMID: 37777961 DOI: 10.1016/j.celrep.2023.113202] [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: 05/04/2023] [Revised: 07/26/2023] [Accepted: 09/16/2023] [Indexed: 10/03/2023] Open
Abstract
CDKL5 deficiency disorder (CDD) is a severe epileptic encephalopathy resulting from pathological mutations in the X-linked cyclin-dependent kinase-like 5 (CDKL5) gene. Despite significant progress in understanding the neuronal function of CDKL5, the molecular mechanisms underlying CDD-associated epileptogenesis are unknown. Here, we report that acute ablation of CDKL5 from adult forebrain glutamatergic neurons leads to elevated neural network activity in the dentate gyrus and the occurrence of early-onset spontaneous seizures via tropomyosin-related kinase B (TrkB) signaling. We observe increased expression of brain-derived neurotrophic factor (BDNF) and enhanced activation of its receptor TrkB in the hippocampus of Cdkl5-deficient mice prior to the onset of behavioral seizures. Moreover, reducing TrkB signaling in these mice rescues the altered synaptic activity and suppresses recurrent seizures. These results suggest that TrkB signaling mediates epileptogenesis in a mouse model of CDD and that targeting this pathway might be effective for treating epilepsy in patients affected by CDKL5 mutations.
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Affiliation(s)
- Zi-Ai Zhu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai 200031, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yi-Yan Li
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai 200031, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Juan Xu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai 200031, China
| | - Hui Xue
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai 200031, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Xue Feng
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai 200031, China
| | - Yong-Chuan Zhu
- Shanghai Key Laboratory of Psychotic Disorders, Shanghai Mental Health Center, Shanghai Jiao Tong University School of Medicine, Shanghai 200030, China.
| | - Zhi-Qi Xiong
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Shanghai 200031, China; University of Chinese Academy of Sciences, Beijing 100049, China; School of Life Science and Technology, ShanghaiTech University, Shanghai 201210, China; Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai 201210, China; School of Future Technology, University of Chinese Academy of Sciences, Beijing 100049, China.
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10
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Awad PN, Zerbi V, Johnson-Venkatesh EM, Damiani F, Pagani M, Markicevic M, Nickles S, Gozzi A, Umemori H, Fagiolini M. CDKL5 sculpts functional callosal connectivity to promote cognitive flexibility. Mol Psychiatry 2023:10.1038/s41380-023-01962-y. [PMID: 36737483 DOI: 10.1038/s41380-023-01962-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/09/2022] [Revised: 01/02/2023] [Accepted: 01/13/2023] [Indexed: 02/05/2023]
Abstract
Functional and structural connectivity alterations in short- and long-range projections have been reported across neurodevelopmental disorders (NDD). Interhemispheric callosal projection neurons (CPN) represent one of the major long-range projections in the brain, which are particularly important for higher-order cognitive function and flexibility. However, whether a causal relationship exists between interhemispheric connectivity alterations and cognitive deficits in NDD remains elusive. Here, we focused on CDKL5 Deficiency Disorder (CDD), a severe neurodevelopmental disorder caused by mutations in the X-linked Cyclin-dependent kinase-like 5 (CDKL5) gene. We found an increase in homotopic interhemispheric connectivity and functional hyperconnectivity across higher cognitive areas in adult male and female CDKL5-deficient mice by resting-state functional MRI (rs-fMRI) analysis. This was accompanied by an increase in the number of callosal synaptic inputs but decrease in local synaptic connectivity in the cingulate cortex of juvenile CDKL5-deficient mice, suggesting an impairment in excitatory synapse development and a differential role of CDKL5 across excitatory neuron subtypes. These deficits were associated with significant cognitive impairments in CDKL5 KO mice. Selective deletion of CDKL5 in the largest subtype of CPN likewise resulted in an increase of functional callosal inputs, without however significantly altering intracortical cingulate networks. Notably, such callosal-specific changes were sufficient to cause cognitive deficits. Finally, when CDKL5 was selectively re-expressed only in this CPN subtype, in otherwise CDKL5-deficient mice, it was sufficient to prevent the cognitive impairments of CDKL5 mutants. Together, these results reveal a novel role of CDKL5 by demonstrating that it is both necessary and sufficient for proper CPN connectivity and cognitive function and flexibility, and further validates a causal relationship between CPN dysfunction and cognitive impairment in a model of NDD.
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Affiliation(s)
- Patricia Nora Awad
- F. M. Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Valerio Zerbi
- Neural Control of Movement Lab, Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland
- Neuro-X Institute, School of Engineering (STI), École Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
- CIBM Center for Biomedical Imaging, Lausanne, Switzerland
| | - Erin M Johnson-Venkatesh
- F. M. Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Francesca Damiani
- F. M. Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Marco Pagani
- Functional Neuroimaging Laboratory, Center for Neuroscience and Cognitive Systems, Istituto Italiano di Tecnologia, Rovereto, Italy
- Autism Center, Child Mind Institute, New York, NY, USA
| | - Marija Markicevic
- Neural Control of Movement Lab, Department of Health Sciences and Technology, ETH Zurich, Zurich, Switzerland
| | - Sarah Nickles
- F. M. Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Alessandro Gozzi
- Functional Neuroimaging Laboratory, Center for Neuroscience and Cognitive Systems, Istituto Italiano di Tecnologia, Rovereto, Italy
| | - Hisashi Umemori
- F. M. Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Michela Fagiolini
- F. M. Kirby Neurobiology Center, Department of Neurology, Boston Children's Hospital, Harvard Medical School, Boston, MA, USA.
- Hock E. Tan and K. Lisa Yang Center for Autism Research at Harvard University, Boston, MA, USA.
- International Research Center for Neurointelligence (IRCN), University of Tokyo Institutes for Advanced Study, Tokyo, Japan.
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11
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Loss of CDKL5 Causes Synaptic GABAergic Defects That Can Be Restored with the Neuroactive Steroid Pregnenolone-Methyl-Ether. Int J Mol Sci 2022; 24:ijms24010068. [PMID: 36613509 PMCID: PMC9820583 DOI: 10.3390/ijms24010068] [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: 11/02/2022] [Revised: 12/09/2022] [Accepted: 12/16/2022] [Indexed: 12/24/2022] Open
Abstract
CDKL5 deficiency disorder (CDD) is an X-linked neurodevelopmental disorder characterised by early-onset drug-resistant epilepsy and impaired cognitive and motor skills. CDD is caused by mutations in cyclin-dependent kinase-like 5 (CDKL5), which plays a well-known role in regulating excitatory neurotransmission, while its effect on neuronal inhibition has been poorly investigated. We explored the potential role of CDKL5 in the inhibitory compartment in Cdkl5-KO male mice and primary hippocampal neurons and found that CDKL5 interacts with gephyrin and collybistin, two crucial organisers of the inhibitory postsynaptic sites. Through molecular and electrophysiological approaches, we demonstrated that CDKL5 loss causes a reduced number of gephyrin puncta and surface exposed γ2 subunit-containing GABAA receptors, impacting the frequency of miniature inhibitory postsynaptic currents, which we ascribe to a postsynaptic function of CDKL5. In line with previous data showing that CDKL5 loss impacts microtubule (MT) dynamics, we showed that treatment with pregnenolone-methyl-ether (PME), which promotes MT dynamics, rescues the above defects. The impact of CDKL5 deficiency on inhibitory neurotransmission might explain the presence of drug-resistant epilepsy and cognitive defects in CDD patients. Moreover, our results may pave the way for drug-based therapies that could bypass the need for CDKL5 and provide effective therapeutic strategies for CDD patients.
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12
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CDKL5 deficiency causes epileptic seizures independent of cellular mosaicism. J Neurol Sci 2022; 443:120498. [PMID: 36417806 DOI: 10.1016/j.jns.2022.120498] [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: 07/20/2022] [Revised: 10/06/2022] [Accepted: 11/12/2022] [Indexed: 11/17/2022]
Abstract
OBJECTIVE In a study using a mouse model of CDKL5 deficiency disorder (CDD), seizures are specific to female mice heterozygous for Cdkl5 mutations and not observed in hemizygous knockout males or homozygous knockout females. The aim of this study was to examine whether the clinical phenotype of patients with CDD can be impacted by the type of genetic variant. METHODS Eleven CDD patients (six females and five males) were included in this study. The molecular diagnosis of hemizygous male patients was performed using digital PCR and their clinical phenotypes were compared with those of patients with mosaic or heterozygous CDKL5 variants. The severity of clinical phenotypes was graded by using CDKL5 Developmental Score and the adapted version of the CDKL5 Clinical Severity Assessment. The effect of cellular mosaicism on the severity of CDD was studied by comparing the clinical characteristics and comorbidities between individuals with hemizygous and mosaic or heterozygous CDKL5 variants. RESULTS One of the five male patients was mosaic for the CDKL5 variant. All patients developed seizures irrespective of their genetic status of the pathogenic variant. However, cellular mosaicism of CDKL5 deficiency was associated with lesser severity of other comorbidities such as feeding, respiratory, and visual functional impairments. SIGNIFICANCE This study provided evidence that cellular mosaicism of CDKL5 deficiency was not necessarily required for developing epilepsy. CDD patients not only exhibited clinical features of epilepsy but also exhibited the developmental consequences arising directly from the effect of the CDKL5 pathogenic variant.
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13
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Neuronal hyperexcitability and ion channel dysfunction in CDKL5-deficiency patient iPSC-derived cortical organoids. Neurobiol Dis 2022; 174:105882. [DOI: 10.1016/j.nbd.2022.105882] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 10/01/2022] [Accepted: 10/02/2022] [Indexed: 11/18/2022] Open
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14
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Goldman AM. Can a Mouse Help Us Unravel the Mysteries of CDKL5-Related Epilepsy? Epilepsy Curr 2022; 22:375-377. [DOI: 10.1177/15357597221125236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
[Box: see text]
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Affiliation(s)
- Alica M. Goldman
- Department of Neurology, Baylor College of Medicine, Houston, TX, USA
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15
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Chakraborty S, Parayil R, Mishra S, Nongthomba U, Clement JP. Epilepsy Characteristics in Neurodevelopmental Disorders: Research from Patient Cohorts and Animal Models Focusing on Autism Spectrum Disorder. Int J Mol Sci 2022; 23:ijms231810807. [PMID: 36142719 PMCID: PMC9501968 DOI: 10.3390/ijms231810807] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Revised: 08/31/2022] [Accepted: 09/05/2022] [Indexed: 11/24/2022] Open
Abstract
Epilepsy, a heterogeneous group of brain-related diseases, has continued to significantly burden society and families. Epilepsy comorbid with neurodevelopmental disorders (NDDs) is believed to occur due to multifaceted pathophysiological mechanisms involving disruptions in the excitation and inhibition (E/I) balance impeding widespread functional neuronal circuitry. Although the field has received much attention from the scientific community recently, the research has not yet translated into actionable therapeutics to completely cure epilepsy, particularly those comorbid with NDDs. In this review, we sought to elucidate the basic causes underlying epilepsy as well as those contributing to the association of epilepsy with NDDs. Comprehensive emphasis is put on some key neurodevelopmental genes implicated in epilepsy, such as MeCP2, SYNGAP1, FMR1, SHANK1-3 and TSC1, along with a few others, and the main electrophysiological and behavioral deficits are highlighted. For these genes, the progress made in developing appropriate and valid rodent models to accelerate basic research is also detailed. Further, we discuss the recent development in the therapeutic management of epilepsy and provide a briefing on the challenges and caveats in identifying and testing species-specific epilepsy models.
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Affiliation(s)
- Sukanya Chakraborty
- Neuroscience Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru 560064, India
| | - Rrejusha Parayil
- Neuroscience Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru 560064, India
| | - Shefali Mishra
- Molecular Reproduction, Development and Genetics (MRDG), Indian Institute of Science, Bengaluru 560012, India
| | - Upendra Nongthomba
- Molecular Reproduction, Development and Genetics (MRDG), Indian Institute of Science, Bengaluru 560012, India
| | - James P. Clement
- Neuroscience Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bengaluru 560064, India
- Correspondence: ; Tel.: +91-08-2208-2613
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16
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CDKL5 deficiency disorder: molecular insights and mechanisms of pathogenicity to fast-track therapeutic development. Biochem Soc Trans 2022; 50:1207-1224. [PMID: 35997111 PMCID: PMC9444073 DOI: 10.1042/bst20220791] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2022] [Revised: 07/28/2022] [Accepted: 07/28/2022] [Indexed: 12/02/2022]
Abstract
CDKL5 deficiency disorder (CDD) is an X-linked brain disorder of young children and is caused by pathogenic variants in the cyclin-dependent kinase-like 5 (CDKL5) gene. Individuals with CDD suffer infantile onset, drug-resistant seizures, severe neurodevelopmental impairment and profound lifelong disability. The CDKL5 protein is a kinase that regulates key phosphorylation events vital to the development of the complex neuronal network of the brain. Pathogenic variants identified in patients may either result in loss of CDKL5 catalytic activity or are hypomorphic leading to partial loss of function. Whilst the progressive nature of CDD provides an excellent opportunity for disease intervention, we cannot develop effective therapeutics without in-depth knowledge of CDKL5 function in human neurons. In this mini review, we summarize new findings on the function of CDKL5. These include CDKL5 phosphorylation targets and the consequence of disruptions on signaling pathways in the human brain. This new knowledge of CDKL5 biology may be leveraged to advance targeted drug discovery and rapid development of treatments for CDD. Continued development of effective humanized models will further propel our understanding of CDD biology and may permit the development and testing of therapies that will significantly alter CDD disease trajectory in young children.
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17
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Leonard H, Downs J, Benke TA, Swanson L, Olson H, Demarest S. CDKL5 deficiency disorder: clinical features, diagnosis, and management. Lancet Neurol 2022; 21:563-576. [PMID: 35483386 PMCID: PMC9788833 DOI: 10.1016/s1474-4422(22)00035-7] [Citation(s) in RCA: 43] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 12/19/2021] [Accepted: 01/18/2022] [Indexed: 12/25/2022]
Abstract
CDKL5 deficiency disorder (CDD) was first identified as a cause of human disease in 2004. Although initially considered a variant of Rett syndrome, CDD is now recognised as an independent disorder and classified as a developmental epileptic encephalopathy. It is characterised by early-onset (generally within the first 2 months of life) seizures that are usually refractory to polypharmacy. Development is severely impaired in patients with CDD, with only a quarter of girls and a smaller proportion of boys achieving independent walking; however, there is clinical variability, which is probably genetically determined. Gastrointestinal, sleep, and musculoskeletal problems are common in CDD, as in other developmental epileptic encephalopathies, but the prevalence of cerebral visual impairment appears higher in CDD. Clinicians diagnosing infants with CDD need to be familiar with the complexities of this disorder to provide appropriate counselling to the patients' families. Despite some benefit from ketogenic diets and vagal nerve stimulation, there has been little evidence that conventional antiseizure medications or their combinations are helpful in CDD, but further treatment trials are finally underway.
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Affiliation(s)
- Helen Leonard
- Telethon Kids Institute, The University of Western Australia, Perth, WA, Australia.
| | - Jenny Downs
- Telethon Kids Institute, The University of Western Australia, Perth, WA, Australia; Curtin School of Allied Health, Curtin University, Perth, WA, Australia
| | - Tim A Benke
- Department of Neurology, Children's Hospital Colorado, Aurora, CO, USA; Department of Pediatrics, University of Colorado at Denver, Aurora, CO, USA; Department of Pharmacology, University of Colorado at Denver, Aurora, CO, USA; Department of Neurology, University of Colorado at Denver, Aurora, CO, USA; Department of Otolaryngology, University of Colorado at Denver, Aurora, CO, USA
| | - Lindsay Swanson
- Department of Neurology, Boston Children's Hospital, Boston, MA, USA
| | - Heather Olson
- Department of Neurology, Boston Children's Hospital, Boston, MA, USA
| | - Scott Demarest
- Department of Neurology, Children's Hospital Colorado, Aurora, CO, USA; Department of Pediatrics, University of Colorado at Denver, Aurora, CO, USA; Department of Neurology, University of Colorado at Denver, Aurora, CO, USA
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18
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CDKL5 Deficiency Disorder-Related Epilepsy: A Review of Current and Emerging Treatment. CNS Drugs 2022; 36:591-604. [PMID: 35633486 PMCID: PMC9876658 DOI: 10.1007/s40263-022-00921-5] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 04/10/2022] [Indexed: 01/27/2023]
Abstract
Cyclin-dependent kinase-like 5 (CDKL5) deficiency disorder (CDD) is a developmental and epileptic encephalopathy with infantile-onset epilepsy. Most individuals with CDD develop refractory epilepsy with multiple seizure types. Management of seizures in CDD remains challenging for clinicians given the highly refractory nature of seizures and the limited number of disease-specific studies that offer a high level of evidence. Epileptic spasms are the most common seizure type in CDD and are more often refractory to standard first-line treatment than are spasms of other etiologies. In other seizure types, the effectiveness of antiseizure medications is limited and wanes over time. Ketogenic diet and palliative surgical treatments have both had mixed results in observational studies. When treating refractory seizures in CDD, we recommend carefully balancing seizure control and treatment-related side effects to optimize each individual's overall quality of life. Clinical trials of medications targeting epilepsy in CDD have been conducted, and additional investigational small molecules, gene therapy, and other disease-modifying therapies are in development for CDD.
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19
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Adhikari A, Buchanan FKB, Fenton TA, Cameron DL, Halmai JANM, Copping NA, Fink KD, Silverman JL. Touchscreen Cognitive Deficits, Hyperexcitability, and Hyperactivity in Males and Females Using Two Models of Cdkl5 Deficiency. Hum Mol Genet 2022; 31:3032-3050. [PMID: 35445702 PMCID: PMC9476626 DOI: 10.1093/hmg/ddac091] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2021] [Revised: 04/06/2022] [Accepted: 04/07/2022] [Indexed: 11/17/2022] Open
Abstract
Many neurodevelopmental disorders (NDDs) are the result of mutations on the X chromosome. One severe NDD resulting from mutations on the X chromosome is CDKL5 deficiency disorder (CDD). CDD is an epigenetic, X-linked NDD characterized by intellectual disability (ID), pervasive seizures and severe sleep disruption, including recurring hospitalizations. CDD occurs at a 4:1 ratio, with a female bias. CDD is driven by the loss of cyclin-dependent kinase-like 5 (CDKL5), a serine/threonine kinase that is essential for typical brain development, synapse formation and signal transmission. Previous studies focused on male subjects from animal models, likely to avoid the complexity of X mosaicism. For the first time, we report translationally relevant behavioral phenotypes in young adult (8–20 weeks) females and males with robust signal size, including impairments in learning and memory, substantial hyperactivity and increased susceptibility to seizures/reduced seizure thresholds, in both sexes, and in two models of CDD preclinical mice, one with a general loss-of-function mutation and one that is a patient-derived mutation.
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Affiliation(s)
- Anna Adhikari
- MIND Institute, University of California Davis School of Medicine, Sacramento, CA.,Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Sacramento, CA
| | - Fiona K B Buchanan
- Department of Neurology, University of California Davis School of Medicine, Sacramento, CA.,Stem Cell Program and Gene Therapy Center, University of California Davis School of Medicine, Sacramento, CA
| | - Timothy A Fenton
- MIND Institute, University of California Davis School of Medicine, Sacramento, CA.,Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Sacramento, CA
| | - David L Cameron
- Department of Neurology, University of California Davis School of Medicine, Sacramento, CA.,Stem Cell Program and Gene Therapy Center, University of California Davis School of Medicine, Sacramento, CA
| | - Julian A N M Halmai
- Department of Neurology, University of California Davis School of Medicine, Sacramento, CA.,Stem Cell Program and Gene Therapy Center, University of California Davis School of Medicine, Sacramento, CA
| | - Nycole A Copping
- MIND Institute, University of California Davis School of Medicine, Sacramento, CA.,Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Sacramento, CA
| | - Kyle D Fink
- MIND Institute, University of California Davis School of Medicine, Sacramento, CA.,Department of Neurology, University of California Davis School of Medicine, Sacramento, CA.,Stem Cell Program and Gene Therapy Center, University of California Davis School of Medicine, Sacramento, CA
| | - Jill L Silverman
- MIND Institute, University of California Davis School of Medicine, Sacramento, CA.,Department of Psychiatry and Behavioral Sciences, University of California Davis School of Medicine, Sacramento, CA
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20
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Barbiero I, Bianchi M, Kilstrup‐Nielsen C. Therapeutic potential of pregnenolone and pregnenolone methyl ether on depressive and CDKL5 deficiency disorders: Focus on microtubule targeting. J Neuroendocrinol 2022; 34:e13033. [PMID: 34495563 PMCID: PMC9286658 DOI: 10.1111/jne.13033] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/06/2021] [Revised: 07/27/2021] [Accepted: 08/08/2021] [Indexed: 12/22/2022]
Abstract
Pregnenolone methyl-ether (PME) is a synthetic derivative of the endogenous neuroactive steroid pregnenolone (PREG), which is an important modulator of several brain functions. In addition to being the precursor of steroids, PREG acts directly on various targets including microtubules (MTs), the functioning of which is fundamental for the development and homeostasis of nervous system. The coordination of MT dynamics is supported by a plethora of MT-associated proteins (MAPs) and by a specific MT code that is defined by the post-translational modifications of tubulin. Defects associated with MAPs or tubulin post-translational modifications are linked to different neurological pathologies including mood and neurodevelopmental disorders. In this review, we describe the beneficial effect of PME in major depressive disorders (MDDs) and in CDKL5 deficiency disorder (CDD), two pathologies that are joint by defective MT dynamics. Growing evidence indeed suggests that PME, as well as PREG, is able to positively affect the MT-binding of MAP2 and the plus-end tracking protein CLIP170 that are both found to be deregulated in the above mentioned pathologies. Furthermore, PME influences the state of MT acetylation, the deregulation of which is often associated with neurological abnormalities including MDDs. By contrast to PREG, PME is not metabolised into other downstream molecules with specific biological properties, an aspect that makes this compound more suitable for therapeutic strategies. Thus, through the analysis of MDDs and CDD, this work focuses attention on the possible use of PME for neuronal pathologies associated with MT defects.
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Affiliation(s)
- Isabella Barbiero
- Department of Biotechnology and Life Sciences, (DBSV)Centre of NeuroScienceUniversity of InsubriaBusto ArsizioItaly
| | - Massimiliano Bianchi
- Ulysses Neuroscience Ltd.Trinity College DublinDublinIreland
- Institute of NeuroscienceTrinity College DublinDublinIreland
| | - Charlotte Kilstrup‐Nielsen
- Department of Biotechnology and Life Sciences, (DBSV)Centre of NeuroScienceUniversity of InsubriaBusto ArsizioItaly
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21
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Saby JN, Mulcahey PJ, Zavez AE, Peters SU, Standridge SM, Swanson LC, Lieberman DN, Olson HE, Key AP, Percy AK, Neul JL, Nelson CA, Roberts TPL, Benke TA, Marsh ED. Electrophysiological biomarkers of brain function in CDKL5 deficiency disorder. Brain Commun 2022; 4:fcac197. [PMID: 35974796 PMCID: PMC9374482 DOI: 10.1093/braincomms/fcac197] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Revised: 05/05/2022] [Accepted: 08/02/2022] [Indexed: 11/14/2022] Open
Abstract
CDKL5 deficiency disorder is a debilitating developmental and epileptic encephalopathy for which no targeted treatment exists. A number of promising therapeutics are under development for CDKL5 deficiency disorder but a lack of validated biomarkers of brain function and clinical severity may limit the ability to objectively assess the efficacy of new treatments as they become available. To address this need, the current study quantified electrophysiological measures in individuals with CDKL5 deficiency disorder and the association between these parameters and clinical severity. Visual and auditory evoked potentials, as well as resting EEG, were acquired across 5 clinical sites from 26 individuals with CDKL5 deficiency disorder. Evoked potential and quantitative EEG features were calculated and compared with typically developing individuals in an age- and sex-matched cohort. Baseline and Year 1 data, when available, were analysed and the repeatability of the results was tested. Two clinician-completed severity scales were used for evaluating the clinical relevance of the electrophysiological parameters. Group-level comparisons revealed reduced visual evoked potential amplitude in CDKL5 deficiency disorder individuals versus typically developing individuals. There were no group differences in the latency of the visual evoked potentials or in the latency or amplitude of the auditory evoked potentials. Within the CDKL5 deficiency disorder group, auditory evoked potential amplitude correlated with disease severity at baseline as well as Year 1. Multiple quantitative EEG features differed between CDKL5 deficiency disorder and typically developing participants, including amplitude standard deviation, 1/f slope and global delta, theta, alpha and beta power. Several quantitative EEG features correlated with clinical severity, including amplitude skewness, theta/delta ratio and alpha/delta ratio. The theta/delta ratio was the overall strongest predictor of severity and also among the most repeatable qEEG measures from baseline to Year 1. Together, the present findings point to the utility of evoked potentials and quantitative EEG parameters as objective measures of brain function and disease severity in future clinical trials for CDKL5 deficiency disorder. The results also underscore the utility of the current methods, which could be similarly applied to the identification and validation of electrophysiological biomarkers of brain function for other developmental encephalopathies.
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Affiliation(s)
| | | | - Alexis E Zavez
- Orphan Disease Center, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sarika U Peters
- Department of Pediatrics, Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Shannon M Standridge
- Cincinnati Children’s Hospital Medical Center, Division of Neurology and University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Lindsay C Swanson
- Department of Neurology, Boston Children’s Hospital, Boston, MA 02115, USA
| | - David N Lieberman
- Department of Neurology, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Heather E Olson
- Department of Neurology, Boston Children’s Hospital, Boston, MA 02115, USA
| | - Alexandra P Key
- Department of Hearing and Speech Sciences, Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Alan K Percy
- Department of Pediatrics, University of Alabama at Birmingham, Birmingham, AL 35233, USA
| | - Jeffrey L Neul
- Department of Pediatrics, Vanderbilt Kennedy Center, Vanderbilt University Medical Center, Nashville, TN 37232, USA
| | - Charles A Nelson
- Laboratories of Cognitive Neuroscience, Boston Children’s Hospital, Boston, MA 02115, USA
- Department of Pediatrics, Harvard Medical School, Cambridge, MA 02115, USA
- Graduate School of Education, Harvard University, Cambridge, MA 02115, USA
| | - Timothy P L Roberts
- Division of Radiology Research, Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Timothy A Benke
- Department of Pediatrics, University of Colorado School of Medicine and Children’s Hospital Colorado, Aurora, CO 80045, USA
- Department of Neurology, University of Colorado School of Medicine and Children’s Hospital Colorado, Aurora, CO 80045, USA
- Department of Pharmacology, University of Colorado School of Medicine and Children’s Hospital Colorado, Aurora, CO 80045, USA
- Department of Otolaryngology, University of Colorado School of Medicine and Children’s Hospital Colorado, Aurora, CO 80045, USA
| | - Eric D Marsh
- Correspondence to: Eric D. Marsh, MD Division of Child Neurology Abramson Research Building, Room 502E 3615 Civic Center Boulevard Philadelphia, PA 19104, USA E-mail:
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22
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Negraes PD, Trujillo CA, Yu NK, Wu W, Yao H, Liang N, Lautz JD, Kwok E, McClatchy D, Diedrich J, de Bartolome SM, Truong J, Szeto R, Tran T, Herai RH, Smith SEP, Haddad GG, Yates JR, Muotri AR. Altered network and rescue of human neurons derived from individuals with early-onset genetic epilepsy. Mol Psychiatry 2021; 26:7047-7068. [PMID: 33888873 PMCID: PMC8531162 DOI: 10.1038/s41380-021-01104-2] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Revised: 03/22/2021] [Accepted: 04/06/2021] [Indexed: 02/02/2023]
Abstract
Early-onset epileptic encephalopathies are severe disorders often associated with specific genetic mutations. In this context, the CDKL5 deficiency disorder (CDD) is a neurodevelopmental condition characterized by early-onset seizures, intellectual delay, and motor dysfunction. Although crucial for proper brain development, the precise targets of CDKL5 and its relation to patients' symptoms are still unknown. Here, induced pluripotent stem cells derived from individuals deficient in CDKL5 protein were used to generate neural cells. Proteomic and phosphoproteomic approaches revealed disruption of several pathways, including microtubule-based processes and cytoskeleton organization. While CDD-derived neural progenitor cells have proliferation defects, neurons showed morphological alterations and compromised glutamatergic synaptogenesis. Moreover, the electrical activity of CDD cortical neurons revealed hyperexcitability during development, leading to an overly synchronized network. Many parameters of this hyperactive network were rescued by lead compounds selected from a human high-throughput drug screening platform. Our results enlighten cellular, molecular, and neural network mechanisms of genetic epilepsy that could ultimately promote novel therapeutic opportunities for patients.
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Affiliation(s)
- Priscilla D Negraes
- Department of Pediatrics, University of California San Diego, La Jolla, CA, USA
| | - Cleber A Trujillo
- Department of Pediatrics, University of California San Diego, La Jolla, CA, USA.
| | - Nam-Kyung Yu
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA, USA
| | - Wei Wu
- Department of Pediatrics, University of California San Diego, La Jolla, CA, USA
| | - Hang Yao
- Department of Pediatrics, University of California San Diego, La Jolla, CA, USA
| | - Nicholas Liang
- Department of Pediatrics, University of California San Diego, La Jolla, CA, USA
| | - Jonathan D Lautz
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, USA
- Graduate Program in Neuroscience, University of Washington, Seattle, WA, USA
| | - Ellius Kwok
- Department of Pediatrics, University of California San Diego, La Jolla, CA, USA
| | - Daniel McClatchy
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA, USA
| | - Jolene Diedrich
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA, USA
| | | | - Justin Truong
- Department of Pediatrics, University of California San Diego, La Jolla, CA, USA
| | - Ryan Szeto
- Department of Pediatrics, University of California San Diego, La Jolla, CA, USA
| | - Timothy Tran
- Department of Pediatrics, University of California San Diego, La Jolla, CA, USA
| | - Roberto H Herai
- Experimental Multiuser Laboratory, Graduate Program in Health Sciences, School of Medicine, Pontifícia Universidade Católica do Paraná, Curitiba, Paraná, Brazil
| | - Stephen E P Smith
- Center for Integrative Brain Research, Seattle Children's Research Institute, Seattle, WA, USA
- Graduate Program in Neuroscience, University of Washington, Seattle, WA, USA
| | - Gabriel G Haddad
- Department of Pediatrics, University of California San Diego, La Jolla, CA, USA
- Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
| | - John R Yates
- Department of Chemical Physiology, The Scripps Research Institute, La Jolla, CA, USA
| | - Alysson R Muotri
- Department of Pediatrics, University of California San Diego, La Jolla, CA, USA.
- Kavli Institute for Brain and Mind, University of California San Diego, La Jolla, CA, USA.
- Center for Academic Research and Training in Anthropogeny (CARTA), La Jolla, CA, USA.
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23
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Terzic B, Davatolhagh MF, Ho Y, Tang S, Liu YT, Xia Z, Cui Y, Fuccillo MV, Zhou Z. Temporal manipulation of Cdkl5 reveals essential postdevelopmental functions and reversible CDKL5 deficiency disorder-related deficits. J Clin Invest 2021; 131:143655. [PMID: 34651584 DOI: 10.1172/jci143655] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2020] [Accepted: 08/05/2021] [Indexed: 12/23/2022] Open
Abstract
CDKL5 deficiency disorder (CDD) is an early onset, neurodevelopmental syndrome associated with pathogenic variants in the X-linked gene encoding cyclin-dependent kinase-like 5 (CDKL5). CDKL5 has been implicated in neuronal synapse maturation, yet its postdevelopmental necessity and the reversibility of CDD-associated impairments remain unknown. We temporally manipulated endogenous Cdkl5 expression in male mice and found that postdevelopmental loss of CDKL5 disrupts numerous behavioral domains, hippocampal circuit communication, and dendritic spine morphology, demonstrating an indispensable role for CDKL5 in the adult brain. Accordingly, restoration of Cdkl5 after the early stages of brain development using a conditional rescue mouse model ameliorated CDD-related behavioral impairments and aberrant NMDA receptor signaling. These findings highlight the requirement of CDKL5 beyond early development, underscore the potential for disease reversal in CDD, and suggest that a broad therapeutic time window exists for potential treatment of CDD-related deficits.
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Affiliation(s)
| | - M Felicia Davatolhagh
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | | | | | | | | | | | - Marc V Fuccillo
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
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24
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Galvani G, Mottolese N, Gennaccaro L, Loi M, Medici G, Tassinari M, Fuchs C, Ciani E, Trazzi S. Inhibition of microglia overactivation restores neuronal survival in a mouse model of CDKL5 deficiency disorder. J Neuroinflammation 2021; 18:155. [PMID: 34238328 PMCID: PMC8265075 DOI: 10.1186/s12974-021-02204-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2021] [Accepted: 06/23/2021] [Indexed: 11/16/2022] Open
Abstract
Background CDKL5 deficiency disorder (CDD), a severe neurodevelopmental disorder characterized by early onset epilepsy, intellectual disability, and autistic features, is caused by mutations in the CDKL5 gene. Evidence in animal models of CDD showed that absence of CDKL5 negatively affects neuronal survival, as well as neuronal maturation and dendritic outgrowth; however, knowledge of the substrates underlying these alterations is still limited. Neuroinflammatory processes are known to contribute to neuronal dysfunction and death. Recent evidence shows a subclinical chronic inflammatory status in plasma from CDD patients. However, to date, it is unknown whether a similar inflammatory status is present in the brain of CDD patients and, if so, whether this plays a causative or exacerbating role in the pathophysiology of CDD. Methods We evaluated microglia activation using AIF-1 immunofluorescence, proinflammatory cytokine expression, and signaling in the brain of a mouse model of CDD, the Cdkl5 KO mouse, which is characterized by an impaired survival of hippocampal neurons that worsens with age. Hippocampal neuron survival was determined by DCX, NeuN, and cleaved caspase-3 immunostaining in Cdkl5 KO mice treated with luteolin (10 mg/kg), a natural anti-inflammatory flavonoid. Since hippocampal neurons of Cdkl5 KO mice exhibit increased susceptibility to excitotoxic stress, we evaluated neuronal survival in Cdkl5 KO mice injected with NMDA (60 mg/kg) after a 7-day treatment with luteolin. Results We found increased microglial activation in the brain of the Cdkl5 KO mouse. We found alterations in microglial cell morphology and number, increased levels of AIF-1 and proinflammatory cytokines, and activation of STAT3 signaling. Remarkably, treatment with luteolin recovers microglia alterations as well as neuronal survival and maturation in Cdkl5 KO mice, and prevents the increase in NMDA-induced cell death in the hippocampus. Conclusions Our results suggest that neuroinflammatory processes contribute to the pathogenesis of CDD and imply the potential usefulness of luteolin as a treatment option in CDD patients. Supplementary Information The online version contains supplementary material available at 10.1186/s12974-021-02204-0.
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Affiliation(s)
- Giuseppe Galvani
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Piazza di Porta San Donato 2, 40126, Bologna, Italy
| | - Nicola Mottolese
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Piazza di Porta San Donato 2, 40126, Bologna, Italy
| | - Laura Gennaccaro
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Piazza di Porta San Donato 2, 40126, Bologna, Italy
| | - Manuela Loi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Piazza di Porta San Donato 2, 40126, Bologna, Italy
| | - Giorgio Medici
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Piazza di Porta San Donato 2, 40126, Bologna, Italy
| | - Marianna Tassinari
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Piazza di Porta San Donato 2, 40126, Bologna, Italy
| | - Claudia Fuchs
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Piazza di Porta San Donato 2, 40126, Bologna, Italy
| | - Elisabetta Ciani
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Piazza di Porta San Donato 2, 40126, Bologna, Italy.
| | - Stefania Trazzi
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Piazza di Porta San Donato 2, 40126, Bologna, Italy.
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25
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Marshall GF, Gonzalez-Sulser A, Abbott CM. Modelling epilepsy in the mouse: challenges and solutions. Dis Model Mech 2021; 14:dmm.047449. [PMID: 33619078 PMCID: PMC7938804 DOI: 10.1242/dmm.047449] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
In most mouse models of disease, the outward manifestation of a disorder can be measured easily, can be assessed with a trivial test such as hind limb clasping, or can even be observed simply by comparing the gross morphological characteristics of mutant and wild-type littermates. But what if we are trying to model a disorder with a phenotype that appears only sporadically and briefly, like epileptic seizures? The purpose of this Review is to highlight the challenges of modelling epilepsy, in which the most obvious manifestation of the disorder, seizures, occurs only intermittently, possibly very rarely and often at times when the mice are not under direct observation. Over time, researchers have developed a number of ways in which to overcome these challenges, each with their own advantages and disadvantages. In this Review, we describe the genetics of epilepsy and the ways in which genetically altered mouse models have been used. We also discuss the use of induced models in which seizures are brought about by artificial stimulation to the brain of wild-type animals, and conclude with the ways these different approaches could be used to develop a wider range of anti-seizure medications that could benefit larger patient populations. Summary: This Review discusses the challenges of modelling epilepsy in mice, a condition in which the outward manifestation of the disorder appears only sporadically, and reviews possible solutions encompassing both genetic and induced models.
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Affiliation(s)
- Grant F Marshall
- Centre for Genomic and Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK.,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Alfredo Gonzalez-Sulser
- Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, UK.,Centre for Discovery Brain Sciences, 1 George Square, University of Edinburgh, Edinburgh EH8 9XD, UK
| | - Catherine M Abbott
- Centre for Genomic and Experimental Medicine, MRC Institute of Genetics and Molecular Medicine, University of Edinburgh, Western General Hospital, Crewe Road, Edinburgh EH4 2XU, UK .,Simons Initiative for the Developing Brain, University of Edinburgh, Edinburgh EH8 9XD, UK
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26
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Carli S, Chaabane L, Butti C, De Palma C, Aimar P, Salio C, Vignoli A, Giustetto M, Landsberger N, Frasca A. In vivo magnetic resonance spectroscopy in the brain of Cdkl5 null mice reveals a metabolic profile indicative of mitochondrial dysfunctions. J Neurochem 2021; 157:1253-1269. [PMID: 33448385 DOI: 10.1111/jnc.15300] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 10/24/2020] [Accepted: 01/07/2021] [Indexed: 12/12/2022]
Abstract
Mutations in the X-linked CDKL5 gene cause CDKL5 deficiency disorder (CDD), a severe neurodevelopmental condition mainly characterized by infantile epileptic encephalopathy, intellectual disability, and autistic features. The molecular mechanisms underlying the clinical symptoms remain largely unknown and the identification of reliable biomarkers in animal models will certainly contribute to increase our comprehension of CDD as well as to assess the efficacy of therapeutic strategies. Here, we used different Magnetic Resonance (MR) methods to disclose structural, functional, or metabolic signatures of Cdkl5 deficiency in the brain of adult mice. We found that loss of Cdkl5 does not cause cerebral atrophy but affects distinct brain areas, particularly the hippocampus. By in vivo proton-MR spectroscopy (MRS), we revealed in the Cdkl5 null brain a metabolic dysregulation indicative of mitochondrial dysfunctions. Accordingly, we unveiled a significant reduction in ATP levels and a decrease in the expression of complex IV of mitochondrial electron transport chain. Conversely, the number of mitochondria appeared preserved. Importantly, we reported a significant defect in the activation of one of the major regulators of cellular energy balance, the adenosine monophosphate-activated protein kinase (AMPK), that might contribute to the observed metabolic impairment and become an interesting therapeutic target for future preclinical trials. In conclusion, MRS revealed in the Cdkl5 null brain the presence of a metabolic dysregulation suggestive of a mitochondrial dysfunction that permitted to foster our comprehension of Cdkl5 deficiency and brought our interest towards targeting mitochondria as therapeutic strategy for CDD.
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Affiliation(s)
- Sara Carli
- Neuroscience Division, IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Linda Chaabane
- Institute of Experimental Neurology (INSPE) and Experimental Imaging Center (CIS), IRCCS San Raffaele Scientific Institute, Milan, Italy
| | - Clarissa Butti
- Neuroscience Division, IRCCS San Raffaele Scientific Institute, Milan, Italy.,Molecular Nociception Group, Wolfson Institute for Biomedical Research (WIBR), University College London, London, UK
| | - Clara De Palma
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Segrate (Milan), Italy
| | - Patrizia Aimar
- Department of Veterinary Sciences, University of Turin, Grugliasco, Italy
| | - Chiara Salio
- Department of Veterinary Sciences, University of Turin, Grugliasco, Italy
| | - Aglaia Vignoli
- Epilepsy Center-Child Neuropsychiatric Unit, ASST Santi Paolo e Carlo, Department of Health Sciences, University of Milan, Milan, Italy
| | - Maurizio Giustetto
- Department of Neuroscience, University of Turin, Turin, Italy.,National Institute of Neuroscience-Italy, Turin, Italy
| | - Nicoletta Landsberger
- Neuroscience Division, IRCCS San Raffaele Scientific Institute, Milan, Italy.,Department of Medical Biotechnology and Translational Medicine, University of Milan, Segrate (Milan), Italy
| | - Angelisa Frasca
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Segrate (Milan), Italy
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27
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Wang W, Frankel WN. Overlaps, gaps, and complexities of mouse models of Developmental and Epileptic Encephalopathy. Neurobiol Dis 2021; 148:105220. [PMID: 33301879 PMCID: PMC8547712 DOI: 10.1016/j.nbd.2020.105220] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2020] [Revised: 11/17/2020] [Accepted: 12/04/2020] [Indexed: 11/28/2022] Open
Abstract
Mouse models have made innumerable contributions to understanding the genetic basis of neurological disease and pathogenic mechanisms and to therapy development. Here we consider the current state of mouse genetic models of Developmental and Epileptic Encephalopathy (DEE), representing a set of rare but devastating and largely intractable childhood epilepsies. By examining the range of mouse lines available in this rapidly moving field and by detailing both expected and unusual features in representative examples, we highlight lessons learned in an effort to maximize the full potential of this powerful resource for preclinical studies.
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Affiliation(s)
- Wanqi Wang
- Department of Genetics & Development, Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY, United States of America.
| | - Wayne N Frankel
- Department of Genetics & Development, Institute for Genomic Medicine, Columbia University Irving Medical Center, New York, NY, United States of America.
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28
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Terzic B, Cui Y, Edmondson AC, Tang S, Sarmiento N, Zaitseva D, Marsh ED, Coulter DA, Zhou Z. X-linked cellular mosaicism underlies age-dependent occurrence of seizure-like events in mouse models of CDKL5 deficiency disorder. Neurobiol Dis 2021; 148:105176. [PMID: 33197557 PMCID: PMC7856307 DOI: 10.1016/j.nbd.2020.105176] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2020] [Accepted: 11/08/2020] [Indexed: 11/29/2022] Open
Abstract
CDKL5 deficiency disorder (CDD) is an infantile, epileptic encephalopathy presenting with early-onset seizures, intellectual disability, motor impairment, and autistic features. The disorder has been linked to mutations in the X-linked CDKL5, and mouse models of the disease recapitulate several aspects of CDD symptomology, including learning and memory impairments, motor deficits, and autistic-like features. Although early-onset epilepsy is one of the hallmark features of CDD, evidence of spontaneous seizure activity has only recently been described in Cdkl5-deficient heterozygous female mice, but the etiology, prevalence, and sex-specificity of this phenotype remain unknown. Here, we report the first observation of disturbance-associated seizure-like events in heterozygous female mice across two independent mouse models of CDD: Cdkl5 knockout mice and CDKL5 R59X knock-in mice. We find that both the prevalence and severity of this phenotype increase with aging, with a median onset around 28 weeks of age. Similar seizure-like events are not observed in hemizygous knockout male or homozygous knockout female littermates, suggesting that X-linked cellular mosaicism is a driving factor underlying these seizure-like events. Together, these findings not only contribute to our understanding of the effects of CDKL5 loss on seizure susceptibility, but also document a novel, pre-clinical phenotype for future therapeutic investigation.
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Affiliation(s)
- Barbara Terzic
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Yue Cui
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Andrew C Edmondson
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Division of Human Genetics, Department of Pediatrics, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Sheng Tang
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Division of Child Neurology and CHOP Research Institute, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Nicolas Sarmiento
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Daria Zaitseva
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA
| | - Eric D Marsh
- Departments of Neuroscience, Neurology, and Pediatrics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Division of Child Neurology and CHOP Research Institute, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Douglas A Coulter
- Departments of Neuroscience, Neurology, and Pediatrics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA; Division of Child Neurology and CHOP Research Institute, Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Zhaolan Zhou
- Department of Genetics, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA 19104, USA.
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