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Wong K, Junaid M, Alexander S, Olson HE, Pestana-Knight EM, Rajaraman RR, Downs J, Leonard H. Caregiver Perspective of Benefits and Side Effects of Anti-Seizure Medications in CDKL5 Deficiency Disorder from an International Database. CNS Drugs 2024:10.1007/s40263-024-01105-z. [PMID: 39060900 DOI: 10.1007/s40263-024-01105-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/19/2024] [Indexed: 07/28/2024]
Abstract
BACKGROUND AND OBJECTIVE CDKL5 deficiency disorder presents as a challenging condition with early-onset refractory seizures, severe developmental delays, and a range of other neurological symptoms. Our study aimed to explore the benefits and side effects of anti-seizure medications (ASMs) in managing seizures among individuals with CDKL5 deficiency disorder, drawing on data from the International CDKL5 Disorder Database. METHODS Data for this retrospective cohort study were obtained from the International CDKL5 Disorder Database, which contains responses from a baseline questionnaire administered between 2012 and 2022 and a follow-up questionnaire administered between 2018 and 2019. Families of eligible individuals were asked to provide information on ASMs that were previously and currently taken, the dose prescribed, the age at starting the medications, and the age at discontinuation for past medications. The outcome variables of interest were perceived seizure-related benefits for the current and past use of ASMs and caregiver-reported side effects. Rescue medications and infrequently used ASMs were excluded from the analysis. Descriptive statistics were used to summarise the characteristics of the study population. RESULTS The study included 399 children and adults with CDKL5 deficiency disorder, descriptively analysing the perceived benefits and side effects of 23 unique ASMs based on caregiver reports. The study identified levetiracetam, topiramate, sodium valproate, vigabatrin, phenobarbital and clobazam as the most used ASMs. Notably, cannabidiol showed highly beneficial outcomes with few side effects, whereas levetiracetam and phenobarbital exhibited less favourable benefit-to-side-effect ratios. Dual therapy involving sodium valproate and levetiracetam was only used a small number (n = 5) of times but appeared effective in reducing seizure activity with relatively few side effects. Compared with monotherapy, polytherapy had a relatively higher likelihood of reported side effects than benefits. CONCLUSIONS The study, leveraging a large sample size that exceeds that of previous research, emphasises the complex nature of seizure management in CDKL5 deficiency disorder. Our findings underscore the necessity of ongoing research to optimise treatment strategies, considering both the efficacy of seizure control and the potential for adverse effects. The study also points to the need for future investigations into the therapeutic potential of emerging treatments such as ganaxolone and the unresolved efficacy of cannabis products in seizure management.
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Affiliation(s)
- Kingsley Wong
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, 15 Hospital Avenue, Nedlands, Perth, WA, 6009, Australia
| | - Mohammed Junaid
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, 15 Hospital Avenue, Nedlands, Perth, WA, 6009, Australia
| | - Solomon Alexander
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, 15 Hospital Avenue, Nedlands, Perth, WA, 6009, Australia
| | - Heather E Olson
- Division of Epilepsy and Clinical Neurophysiology and Epilepsy Genetics Program, Department of Neurology, Boston Children's Hospital, Boston, MA, USA
| | | | | | - Jenny Downs
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, 15 Hospital Avenue, Nedlands, Perth, WA, 6009, Australia
| | - Helen Leonard
- Telethon Kids Institute, Centre for Child Health Research, The University of Western Australia, 15 Hospital Avenue, Nedlands, Perth, WA, 6009, Australia.
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2
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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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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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4
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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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5
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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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6
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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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7
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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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8
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Das M, Mao W, Voskobiynyk Y, Necula D, Lew I, Petersen C, Zahn A, Yu GQ, Yu X, Smith N, Sayed FA, Gan L, Paz JT, Mucke L. Alzheimer risk-increasing TREM2 variant causes aberrant cortical synapse density and promotes network hyperexcitability in mouse models. Neurobiol Dis 2023; 186:106263. [PMID: 37591465 PMCID: PMC10681293 DOI: 10.1016/j.nbd.2023.106263] [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: 05/12/2023] [Revised: 07/12/2023] [Accepted: 08/14/2023] [Indexed: 08/19/2023] Open
Abstract
The R47H variant of triggering receptor expressed on myeloid cells 2 (TREM2) increases the risk of Alzheimer's disease (AD). To investigate potential mechanisms, we analyzed knockin mice expressing human TREM2-R47H from one mutant mouse Trem2 allele. TREM2-R47H mice showed increased seizure activity in response to an acute excitotoxin challenge, compared to wildtype controls or knockin mice expressing the common variant of human TREM2. TREM2-R47H also increased spontaneous thalamocortical epileptiform activity in App knockin mice expressing amyloid precursor proteins bearing autosomal dominant AD mutations and a humanized amyloid-β sequence. In mice with or without such App modifications, TREM2-R47H increased the density of putative synapses in cortical regions without amyloid plaques. TREM2-R47H did not affect synaptic density in hippocampal regions with or without plaques. We conclude that TREM2-R47H increases AD-related network hyperexcitability and that it may do so, at least in part, by causing an imbalance in synaptic densities across brain regions.
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Affiliation(s)
- Melanie Das
- Gladstone Institute of Neurological Disease, Gladstone Institutes, San Francisco, CA 94158, USA
| | - Wenjie Mao
- Gladstone Institute of Neurological Disease, Gladstone Institutes, San Francisco, CA 94158, USA
| | - Yuliya Voskobiynyk
- Gladstone Institute of Neurological Disease, Gladstone Institutes, San Francisco, CA 94158, USA
| | - Deanna Necula
- Gladstone Institute of Neurological Disease, Gladstone Institutes, San Francisco, CA 94158, USA; Neuroscience Graduate Program, University of California, San Francisco, CA 94158, USA
| | - Irene Lew
- Gladstone Institute of Neurological Disease, Gladstone Institutes, San Francisco, CA 94158, USA
| | - Cathrine Petersen
- Gladstone Institute of Neurological Disease, Gladstone Institutes, San Francisco, CA 94158, USA; Neuroscience Graduate Program, University of California, San Francisco, CA 94158, USA
| | - Allie Zahn
- Gladstone Institute of Neurological Disease, Gladstone Institutes, San Francisco, CA 94158, USA
| | - Gui-Qiu Yu
- Gladstone Institute of Neurological Disease, Gladstone Institutes, San Francisco, CA 94158, USA
| | - Xinxing Yu
- Gladstone Institute of Neurological Disease, Gladstone Institutes, San Francisco, CA 94158, USA
| | - Nicholas Smith
- Gladstone Institute of Neurological Disease, Gladstone Institutes, San Francisco, CA 94158, USA
| | - Faten A Sayed
- Gladstone Institute of Neurological Disease, Gladstone Institutes, San Francisco, CA 94158, USA
| | - Li Gan
- Helen and Robert Appel Alzheimer's Disease Research Institute, Weill Cornell Medicine, New York City, NY 10065, USA
| | - Jeanne T Paz
- Gladstone Institute of Neurological Disease, Gladstone Institutes, San Francisco, CA 94158, USA; Neuroscience Graduate Program, University of California, San Francisco, CA 94158, USA; Department of Neurology and Weill Institute for Neurosciences, University of California, San Francisco, CA 94158, USA
| | - Lennart Mucke
- Gladstone Institute of Neurological Disease, Gladstone Institutes, San Francisco, CA 94158, USA; Neuroscience Graduate Program, University of California, San Francisco, CA 94158, USA; Department of Neurology and Weill Institute for Neurosciences, University of California, San Francisco, CA 94158, USA.
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9
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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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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: 3] [Impact Index Per Article: 1.5] [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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11
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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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12
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Faubel RJ, Santos Canellas VS, Gaesser J, Beluk NH, Feinstein TN, Wang Y, Yankova M, Karunakaran KB, King SM, Ganapathiraju MK, Lo CW. Flow blockage disrupts cilia-driven fluid transport in the epileptic brain. Acta Neuropathol 2022; 144:691-706. [PMID: 35980457 DOI: 10.1007/s00401-022-02463-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 06/27/2022] [Accepted: 06/28/2022] [Indexed: 01/28/2023]
Abstract
A carpet of ependymal motile cilia lines the brain ventricular system, forming a network of flow channels and barriers that pattern cerebrospinal fluid (CSF) flow at the surface. This CSF transport system is evolutionary conserved, but its physiological function remains unknown. Here we investigated its potential role in epilepsy with studies focused on CDKL5 deficiency disorder (CDD), a neurodevelopmental disorder with early-onset epilepsy refractory to seizure medications and the most common cause of infant epilepsy. CDKL5 is a highly conserved X-linked gene suggesting its function in regulating cilia length and motion in the green alga Chlamydomonas might have implication in the etiology of CDD. Examination of the structure and function of airway motile cilia revealed both the CDD patients and the Cdkl5 knockout mice exhibit cilia lengthening and abnormal cilia motion. Similar defects were observed for brain ventricular cilia in the Cdkl5 knockout mice. Mapping ependymal cilia generated flow in the ventral third ventricle (v3V), a brain region with important physiological functions showed altered patterning of flow. Tracing of cilia-mediated inflow into v3V with fluorescent dye revealed the appearance of a flow barrier at the inlet of v3V in Cdkl5 knockout mice. Analysis of mice with a mutation in another epilepsy-associated kinase, Yes1, showed the same disturbance of cilia motion and flow patterning. The flow barrier was also observed in the Foxj1± and FOXJ1CreERT:Cdkl5y/fl mice, confirming the contribution of ventricular cilia to the flow disturbances. Importantly, mice exhibiting altered cilia-driven flow also showed increased susceptibility to anesthesia-induced seizure-like activity. The cilia-driven flow disturbance arises from altered cilia beating orientation with the disrupted polarity of the cilia anchoring rootlet meshwork. Together these findings indicate motile cilia disturbances have an essential role in CDD-associated seizures and beyond, suggesting cilia regulating kinases may be a therapeutic target for medication-resistant epilepsy.
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Affiliation(s)
- Regina J Faubel
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15201, USA
| | - Veronica S Santos Canellas
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15201, USA
| | - Jenna Gaesser
- Division of Child Neurology, Department of Pediatrics, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15201, USA
| | - Nancy H Beluk
- Division of Radiology, University of Pittsburgh, Pittsburgh, PA, 15260, USA
| | - Tim N Feinstein
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15201, USA
| | - Yong Wang
- Laboratory for Fluid Physics, Pattern Formation and Biocomplexity, Max Planck Institute for Dynamics and Self-Organization, Am Faßberg 17, 37077, Göttingen, Germany
| | - Maya Yankova
- Department of Molecular Biology and Biophysics, And Electron Microscopy Facility, University of Connecticut Health Center, Farmington, CT, 06030-3305, USA
| | - Kalyani B Karunakaran
- Supercomputer Education and Research Centre, Indian Institute of Science, Bangalore, 560012, India
| | - Stephen M King
- Department of Molecular Biology and Biophysics, And Electron Microscopy Facility, University of Connecticut Health Center, Farmington, CT, 06030-3305, USA
| | - Madhavi K Ganapathiraju
- Department of Biomedical Informatics, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15201, USA
| | - Cecilia W Lo
- Department of Developmental Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, 15201, USA.
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13
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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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14
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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: 12] [Impact Index Per Article: 6.0] [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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15
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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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16
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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: 10] [Impact Index Per Article: 5.0] [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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17
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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: 29] [Impact Index Per Article: 9.7] [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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18
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Koh HY, Jang J, Ju SH, Kim R, Cho GB, Kim DS, Sohn JW, Paik SB, Lee JH. Non-Cell Autonomous Epileptogenesis in Focal Cortical Dysplasia. Ann Neurol 2021; 90:285-299. [PMID: 34180075 DOI: 10.1002/ana.26149] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2021] [Revised: 06/24/2021] [Accepted: 06/25/2021] [Indexed: 01/01/2023]
Abstract
OBJECTIVE Low-level somatic mosaicism in the brain has been shown to be a major genetic cause of intractable focal epilepsy. However, how a relatively few mutation-carrying neurons are able to induce epileptogenesis at the local network level remains poorly understood. METHODS To probe the origin of epileptogenesis, we measured the excitability of neurons with MTOR mutation and nearby nonmutated neurons recorded by whole-cell patch-clamp and array-based electrodes comparing the topographic distribution of mutation. Computational simulation is used to understand neural network-level changes based on electrophysiological properties. To examine the underlying mechanism, we measured inhibitory and excitatory synaptic inputs in mutated neurons and nearby neurons by electrophysiological and histological methods using the mouse model and postoperative human brain tissue for cortical dysplasia. To explain non-cell-autonomous hyperexcitability, an inhibitor of adenosine kinase was injected into mice to enhance adenosine signaling and to mitigate hyperactivity of nearby nonmutated neurons. RESULTS We generated mice with a low-level somatic mutation in MTOR presenting spontaneous seizures. The seizure-triggering hyperexcitability originated from nonmutated neurons near mutation-carrying neurons, which proved to be less excitable than nonmutated neurons. Interestingly, the net balance between excitatory and inhibitory synaptic inputs onto mutated neurons remained unchanged. Additionally, we found that inhibition of adenosine kinase, which affects adenosine metabolism and neuronal excitability, reduced the hyperexcitability of nonmutated neurons. INTERPRETATION This study shows that neurons carrying somatic mutations in MTOR lead to focal epileptogenesis via non-cell-autonomous hyperexcitability of nearby nonmutated neurons. ANN NEUROL 2021;90:285-299.
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Affiliation(s)
- Hyun Yong Koh
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - Jaeson Jang
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - Sang Hyeon Ju
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - Ryunhee Kim
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - Gyu-Bon Cho
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - Dong Seok Kim
- Department of Neurosurgery, Pediatric Epilepsy Clinics, Brain Korea 21 Project for Medical Science, Severance Children's Hospital, Yonsei University College of Medicine, Seoul, Republic of Korea
| | - Jong-Woo Sohn
- Department of Biological Sciences, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - Se-Bum Paik
- Department of Bio and Brain Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea.,Program of Brain and Cognitive Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea
| | - Jeong Ho Lee
- Graduate School of Medical Science and Engineering, Korea Advanced Institute of Science and Technology, Daejeon, Republic of Korea.,SoVarGen, Daejeon, Republic of Korea
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19
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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: 21] [Impact Index Per Article: 7.0] [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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20
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Haigh JL, Adhikari A, Copping NA, Stradleigh T, Wade AA, Catta-Preta R, Su-Feher L, Zdilar I, Morse S, Fenton TA, Nguyen A, Quintero D, Agezew S, Sramek M, Kreun EJ, Carter J, Gompers A, Lambert JT, Canales CP, Pennacchio LA, Visel A, Dickel DE, Silverman JL, Nord AS. Deletion of a non-canonical regulatory sequence causes loss of Scn1a expression and epileptic phenotypes in mice. Genome Med 2021; 13:69. [PMID: 33910599 PMCID: PMC8080386 DOI: 10.1186/s13073-021-00884-0] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 04/06/2021] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Genes with multiple co-active promoters appear common in brain, yet little is known about functional requirements for these potentially redundant genomic regulatory elements. SCN1A, which encodes the NaV1.1 sodium channel alpha subunit, is one such gene with two co-active promoters. Mutations in SCN1A are associated with epilepsy, including Dravet syndrome (DS). The majority of DS patients harbor coding mutations causing SCN1A haploinsufficiency; however, putative causal non-coding promoter mutations have been identified. METHODS To determine the functional role of one of these potentially redundant Scn1a promoters, we focused on the non-coding Scn1a 1b regulatory region, previously described as a non-canonical alternative transcriptional start site. We generated a transgenic mouse line with deletion of the extended evolutionarily conserved 1b non-coding interval and characterized changes in gene and protein expression, and assessed seizure activity and alterations in behavior. RESULTS Mice harboring a deletion of the 1b non-coding interval exhibited surprisingly severe reductions of Scn1a and NaV1.1 expression throughout the brain. This was accompanied by electroencephalographic and thermal-evoked seizures, and behavioral deficits. CONCLUSIONS This work contributes to functional dissection of the regulatory wiring of a major epilepsy risk gene, SCN1A. We identified the 1b region as a critical disease-relevant regulatory element and provide evidence that non-canonical and seemingly redundant promoters can have essential function.
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Affiliation(s)
- Jessica L Haigh
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA
| | - Anna Adhikari
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- MIND Institute and Department of Psychiatry and Behavioral Sciences, UC Davis School of Medicine, Sacramento, CA, USA
| | - Nycole A Copping
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- MIND Institute and Department of Psychiatry and Behavioral Sciences, UC Davis School of Medicine, Sacramento, CA, USA
| | - Tyler Stradleigh
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA
| | - A Ayanna Wade
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA
| | - Rinaldo Catta-Preta
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA
| | - Linda Su-Feher
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA
| | - Iva Zdilar
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA
| | - Sarah Morse
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA
| | - Timothy A Fenton
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- MIND Institute and Department of Psychiatry and Behavioral Sciences, UC Davis School of Medicine, Sacramento, CA, USA
| | - Anh Nguyen
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA
| | - Diana Quintero
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA
| | - Samrawit Agezew
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA
| | - Michael Sramek
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA
| | - Ellie J Kreun
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA
| | - Jasmine Carter
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA
| | - Andrea Gompers
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA
| | - Jason T Lambert
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA
| | - Cesar P Canales
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA
| | - Len A Pennacchio
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, CA, USA
- Comparative Biochemistry Program, University of California, Berkeley, Berkeley, CA, USA
| | - Axel Visel
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, CA, USA
- Comparative Biochemistry Program, University of California, Berkeley, Berkeley, CA, USA
- School of Natural Sciences, University of California, Merced, CA, USA
| | - Diane E Dickel
- Environmental Genomics and Systems Biology Division, Lawrence Berkeley National Laboratory, Berkeley, CA, USA
- U.S. Department of Energy Joint Genome Institute, Walnut Creek, CA, USA
- Comparative Biochemistry Program, University of California, Berkeley, Berkeley, CA, USA
| | - Jill L Silverman
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA.
- MIND Institute and Department of Psychiatry and Behavioral Sciences, UC Davis School of Medicine, Sacramento, CA, USA.
| | - Alex S Nord
- Department of Psychiatry and Behavioral Sciences, University of California, Davis, Davis, CA, USA.
- Department of Neurobiology, Physiology and Behavior, University of California, Davis, Davis, CA, USA.
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