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1
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Lin P, Ho C, Lin C, Hou Y, Chan C, Tsai M. Self-limited familial focal epilepsy caused by ANK2 variants: A potentially under-recognized condition. Epilepsia Open 2025; 10:635-642. [PMID: 39962910 PMCID: PMC12014929 DOI: 10.1002/epi4.70003] [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: 04/05/2024] [Accepted: 01/27/2025] [Indexed: 04/24/2025] Open
Abstract
The Ankyrin 2 (ANK2) gene encodes the ankyrin-B protein (ANKB), which is involved in the organization and stability of membrane ion channels, transporters, and receptors in cardiomyocytes and neurons. Variants in ANK2 genes are initially reported in long QT syndrome and autism. Animal models with ANK2 deletion have exhibited seizures and been anecdotally associated with epilepsy in case reports. Hereby, we reported a Taiwanese family with the ANK2 pathogenic variant (chr4:114276707, c.6933del, p.T2312Lfs*2) that affects the giant ankyrin-B isoform. The family members presented with young-onset self-limited focal epilepsy, and achieved seizure-free in adulthood with antiseizure medications. Interestingly, the electrocardiogram revealed no obvious cardiac phenotype. We further reviewed reported ANK2-related epilepsies. Most variants are de novo and loss-of-function variants. Most patients had young epilepsy or neonatal seizures. Notably, most cases of ANK2-related epilepsy are self-limited and pharmaco-responsive, which suggests that it is likely to be underdiagnosed. With the increased availability of whole exome sequencing, the diagnosis of ANK2-related epilepsies may increase. The co-existence of QT prolongation on electrocardiogram, autism, and a positive family history of cardiac arrhythmia or sudden death may provide important clues in the clinical diagnosis of ANK2-related epilepsy. Furthermore, a correct genetic diagnosis of ANK2-related epilepsy will initiate close cardiac surveillance to avoid the potential sudden death risk of this disorder. PLAIN LANGUAGE SUMMARY: ANK2 has long been regarded as an arrhythmic gene. This study reported the first familial ANK2-related epilepsy, highlighting the role of ANK2 in epileptogenesis. Most reported ANK2-related epilepsies are self-limited and pharmaco-responsive, suggesting that they are likely to be underdiagnosed. Literature review of the phenotype and genotype of ANK2 showed that LOF ANK2 variants tend to have CNS phenotypes, whereas missense variants are arrhythmic. Early detection of ANK2 variants in epilepsy patients is worthwhile considering the potential sudden death risk of this disorder.
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Affiliation(s)
- Po‐Hsi Lin
- Department of NeurologyKaohsiung Chang Gung Memorial HospitalKaohsiungTaiwan
| | - Chen‐Jui Ho
- Department of NeurologyKaohsiung Chang Gung Memorial HospitalKaohsiungTaiwan
| | - Chih‐Hsiang Lin
- Department of NeurologyKaohsiung Chang Gung Memorial HospitalKaohsiungTaiwan
| | - Ya‐Yuan Hou
- Department of NeurologyKaohsiung Chang Gung Memorial HospitalKaohsiungTaiwan
| | - Cheng‐Han Chan
- Division of Cardiology, Department of Internal MedicineTaipei Veterans General HospitalTaipeiTaiwan
| | - Meng‐Han Tsai
- Department of NeurologyKaohsiung Chang Gung Memorial HospitalKaohsiungTaiwan
- Department of Medical ResearchKaohsiung Chang Gung Memorial HospitalKaohsiungTaiwan
- School of MedicineChang Gung UniversityTaoyuanTaiwan
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2
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Zhao L, Qiao Z, Jia Y, Fu J, Li T, Jia K, Zhao H, Bao J, Yang X, Pan H, Yang G. A Mutation in the ANK2 Gene Causing ASD and a Review of the Literature. Mol Genet Genomic Med 2025; 13:e70083. [PMID: 40035441 PMCID: PMC11877552 DOI: 10.1002/mgg3.70083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2024] [Revised: 01/17/2025] [Accepted: 02/04/2025] [Indexed: 03/05/2025] Open
Abstract
OBJECTIVE To investigate the clinical and genetic characteristics of patients with ANK2(HGNC:493)-associated autism spectrum disorders (ASDs) and epilepsy (EP). METHODS We identified a novel ANK2 variant in a patient with ASD and EP and summarized the clinical and genetic characteristics of ANK2 gene variants in this patient and those in previous reports. RESULTS A novel nonsense variant, ANK2 (NM_001148.6):c.3007C>T/p.R1003* in exon 27, was identified in one patient. We described the clinical features and molecular genetics of this patient and previously reported patients. This was discovered at a follow-up visit to the pediatric neurology department where genetic testing based on condition identified this rare genetic variant. He mainly presents with language delay, intellectual disability, limited learning, and communication skills, and later develops seizures, combined with common childhood neurological disorders such as hyperactivity, behavioral abnormalities, and even self-injury. The patient cohort included 16 patients with a complex array of neurological disabilities: ASD (9 patients); EP (10 patients); ASD with EP (4 patients); intellectual disability and developmental delay (5 patients); poor language communication (11 patients); language and learning impairment (11 patients); anxiety/agitation mood disorder (6 patients); attention-deficit/hyperactivity disorder (5 patients); cognitive, memory, and adaptability deficits (1 patient); tic disorder (1 patient); electrocardiogram and cardiac damage (1 patient); and abnormal electroencephalography (EEG) (9 patients). CONCLUSION For the first time, we identified a novel variant of the ANK2 gene in China, broadening the genetic spectrum of the ANK2 gene. ANK2 gene mutations can cause ASD, EP, ASD with EP, developmental delay and intellectual disability, poor language communication skills, language and learning disorders, anxiety/agitation mood disorder, and attention-deficit/hyperactivity disorder. Clinical ASD, EP, common EP should consider the ANK2 gene mutation.
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Affiliation(s)
- Lu Zhao
- Department of PediatricsThe Affiliated Hospital of Inner Mongolia Medical UniversityHohhotInner MongoliaChina
| | - Zhi‐Dong Qiao
- Department of PediatricsThe Affiliated Hospital of Inner Mongolia Medical UniversityHohhotInner MongoliaChina
| | - Yue‐Xin Jia
- Department of PediatricsThe Affiliated Hospital of Inner Mongolia Medical UniversityHohhotInner MongoliaChina
| | - Jun‐Xian Fu
- Department of PediatricsThe Affiliated Hospital of Inner Mongolia Medical UniversityHohhotInner MongoliaChina
| | - Tian‐Xia Li
- Department of PediatricsThe Affiliated Hospital of Inner Mongolia Medical UniversityHohhotInner MongoliaChina
| | - Kai‐Ru Jia
- Department of PediatricsThe Affiliated Hospital of Inner Mongolia Medical UniversityHohhotInner MongoliaChina
| | - Hong Zhao
- Department of PediatricsThe Affiliated Hospital of Inner Mongolia Medical UniversityHohhotInner MongoliaChina
| | - Jin‐Ping Bao
- Department of PediatricsThe Affiliated Hospital of Inner Mongolia Medical UniversityHohhotInner MongoliaChina
| | - Xiao‐Fan Yang
- Department of PediatricsThe Affiliated Hospital of Inner Mongolia Medical UniversityHohhotInner MongoliaChina
| | - Hao Pan
- Department of PediatricsThe Affiliated Hospital of Inner Mongolia Medical UniversityHohhotInner MongoliaChina
| | - Guang‐Lu Yang
- Department of PediatricsThe Affiliated Hospital of Inner Mongolia Medical UniversityHohhotInner MongoliaChina
- Inner Mongolia Science and Technology DepartmentInner Mongolia Autonomous Region Nervous System Disease Clinical Medical Research CenterHohhotChina
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Yoon S, Penzes P. Roles of ANK2/ankyrin-B in neurodevelopmental disorders: Isoform functions and implications for autism spectrum disorder and epilepsy. Curr Opin Neurobiol 2025; 90:102938. [PMID: 39631164 PMCID: PMC11839328 DOI: 10.1016/j.conb.2024.102938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2024] [Revised: 11/12/2024] [Accepted: 11/13/2024] [Indexed: 12/07/2024]
Abstract
The ANK2 gene, encoding ankyrin-B, is a high-confidence risk factor for neurodevelopmental disorders (NDDs). Evidence from exome sequencing studies have repeatedly implicated rare variants in ANK2 in autism spectrum disorder. Recently, the functions of ankyrin-B isoforms on neuronal phenotypes have been investigated using a number of techniques including electrophysiology, proteomic screens and behavioral analysis using animal models with loss of distinct Ank2 isoforms or with targeted loss of Ank2 in different cell types and time points during brain development. ANK2 variants and their pathophysiology could provide valuable insights into the molecular mechanisms underlying NDDs. In this review, we focus on recently reported studies to help understand the pathological mechanisms of ANK2 loss and how it may facilitate the development of treatments for NDDs in the future.
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Affiliation(s)
- Sehyoun Yoon
- Department of Neuroscience, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA.
| | - Peter Penzes
- Department of Neuroscience, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA; Department of Psychiatry and Behavioral Sciences, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA; Department of Pharmacology, Northwestern University Feinberg School of Medicine, Chicago, IL 60611, USA; Northwestern University, Center for Autism and Neurodevelopment, Chicago, IL, 60611, USA
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4
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Li Y, Zhao Y, He Y, Liu F, Xia L, Liu K, Zhang M, Chen K. New targets and designed inhibitors of ASAP Arf-GAPs derived from structural characterization of the ASAP1/440-kD ankyrin-B interaction. J Biol Chem 2024; 300:107762. [PMID: 39265663 PMCID: PMC11490884 DOI: 10.1016/j.jbc.2024.107762] [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: 05/09/2024] [Revised: 08/15/2024] [Accepted: 08/27/2024] [Indexed: 09/14/2024] Open
Abstract
ASAP1 and its paralog ASAP2 belong to a PI4,5P2-dependent Arf GTPase-activating protein (Arf-GAP) family capable of modulating membrane and cytoskeletal dynamics. ASAPs regulate cell adhesive structures such as invadosomes and focal adhesions during cell attachment and migration. Malfunctioning of ASAP1 has been implicated in the malignant phenotypes of various cancers. Here, we discovered that the SH3 domain of ASAP1 or ASAP2 specifically binds to a 12-residue, positively charged peptide fragment from the 440 kDa giant ankyrin-B, a neuronal axon specific scaffold protein. The high-resolution structure of the ASAP1-SH3 domain in complex with the gAnkB peptide revealed a noncanonical SH3-ligand binding mode with high affinity and specificity. Structural analysis of the complex readily uncovered a consensus ASAP1-SH3 binding motif, which allowed the discovery of a number of previously unknown binding partners of ASAP1-SH3 including Clasp1/Clasp2, ALS2, β-Pix, DAPK3, PHIP, and Limk1. Fittingly, these newly identified ASAP1 binding partners are primarily key modulators of the cytoskeletons. Finally, we designed a cell-penetrating, highly potent ASAP1 SH3 domain binding peptide with a Kd ∼7 nM as a tool for studying the roles of ASAPs in different cellular processes.
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Affiliation(s)
- Yubing Li
- Greater Bay Biomedical Innocenter, Shenzhen Bay Laboratory, Shenzhen, China; Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Yipeng Zhao
- Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China; School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Yaojun He
- Greater Bay Biomedical Innocenter, Shenzhen Bay Laboratory, Shenzhen, China
| | - Fang Liu
- Greater Bay Biomedical Innocenter, Shenzhen Bay Laboratory, Shenzhen, China
| | - Lu Xia
- Greater Bay Biomedical Innocenter, Shenzhen Bay Laboratory, Shenzhen, China
| | - Kai Liu
- Division of Life Science, Hong Kong University of Science and Technology, Clear Water Bay, Kowloon, Hong Kong, China
| | - Mingjie Zhang
- Greater Bay Biomedical Innocenter, Shenzhen Bay Laboratory, Shenzhen, China; School of Life Sciences, Southern University of Science and Technology, Shenzhen, China
| | - Keyu Chen
- Greater Bay Biomedical Innocenter, Shenzhen Bay Laboratory, Shenzhen, China.
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5
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Gallo G. The Axonal Actin Filament Cytoskeleton: Structure, Function, and Relevance to Injury and Degeneration. Mol Neurobiol 2024; 61:5646-5664. [PMID: 38216856 DOI: 10.1007/s12035-023-03879-7] [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: 10/26/2023] [Accepted: 12/13/2023] [Indexed: 01/14/2024]
Abstract
Early investigations of the neuronal actin filament cytoskeleton gave rise to the notion that, although growth cones exhibit high levels of actin filaments, the axon shaft exhibits low levels of actin filaments. With the development of new tools and imaging techniques, the axonal actin filament cytoskeleton has undergone a renaissance and is now an active field of research. This article reviews the current state of knowledge about the actin cytoskeleton of the axon shaft. The best understood forms of actin filament organization along axons are axonal actin patches and a submembranous system of rings that endow the axon with protrusive competency and structural integrity, respectively. Additional forms of actin filament organization along the axon have also been described and their roles are being elucidated. Extracellular signals regulate the axonal actin filament cytoskeleton and our understanding of the signaling mechanisms involved is being elaborated. Finally, recent years have seen advances in our perspective on how the axonal actin cytoskeleton is impacted by, and contributes to, axon injury and degeneration. The work to date has opened new venues and future research will undoubtedly continue to provide a richer understanding of the axonal actin filament cytoskeleton.
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Affiliation(s)
- Gianluca Gallo
- Department of Neural Sciences, Shriners Pediatric Research Center, Lewis Katz School of Medicine at Temple University, 3500 North Broad St, Philadelphia, PA, 19140, USA.
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6
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Silverman JB, Vega PN, Tyska MJ, Lau KS. Intestinal Tuft Cells: Morphology, Function, and Implications for Human Health. Annu Rev Physiol 2024; 86:479-504. [PMID: 37863104 PMCID: PMC11193883 DOI: 10.1146/annurev-physiol-042022-030310] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2023]
Abstract
Tuft cells are a rare and morphologically distinct chemosensory cell type found throughout many organs, including the gastrointestinal tract. These cells were identified by their unique morphologies distinguished by large apical protrusions. Ultrastructural data have begun to describe the molecular underpinnings of their cytoskeletal features, and tuft cell-enriched cytoskeletal proteins have been identified, although the connection of tuft cell morphology to tuft cell functionality has not yet been established. Furthermore, tuft cells display variations in function and identity between and within tissues, leading to the delineation of distinct tuft cell populations. As a chemosensory cell type, they display receptors that are responsive to ligands specific for their environment. While many studies have demonstrated the tuft cell response to protists and helminths in the intestine, recent research has highlighted other roles of tuft cells as well as implicated tuft cells in other disease processes including inflammation, cancer, and viral infections. Here, we review the literature on the cytoskeletal structure of tuft cells. Additionally, we focus on new research discussing tuft cell lineage, ligand-receptor interactions, tuft cell tropism, and the role of tuft cells in intestinal disease. Finally, we discuss the implication of tuft cell-targeted therapies in human health and how the morphology of tuft cells may contribute to their functionality.
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Affiliation(s)
- Jennifer B Silverman
- Epithelial Biology Center and Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA; ,
| | - Paige N Vega
- Epithelial Biology Center and Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA; ,
| | - Matthew J Tyska
- Epithelial Biology Center and Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA; ,
| | - Ken S Lau
- Epithelial Biology Center and Department of Cell and Developmental Biology, Vanderbilt University School of Medicine, Nashville, Tennessee, USA; ,
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7
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Murphy KE, Duncan B, Sperringer JE, Zhang E, Haberman V, Wyatt EV, Maness P. Ankyrin B promotes developmental spine regulation in the mouse prefrontal cortex. Cereb Cortex 2023; 33:10634-10648. [PMID: 37642601 PMCID: PMC10560577 DOI: 10.1093/cercor/bhad311] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 08/08/2023] [Accepted: 08/09/2023] [Indexed: 08/31/2023] Open
Abstract
Postnatal regulation of dendritic spine formation and refinement in cortical pyramidal neurons is critical for excitatory/inhibitory balance in neocortical networks. Recent studies have identified a selective spine pruning mechanism in the mouse prefrontal cortex mediated by class 3 Semaphorins and the L1 cell adhesion molecules, neuron-glia related cell adhesion molecule, Close Homolog of L1, and L1. L1 cell adhesion molecules bind Ankyrin B, an actin-spectrin adaptor encoded by Ankyrin2, a high-confidence gene for autism spectrum disorder. In a new inducible mouse model (Nex1Cre-ERT2: Ank2flox: RCE), Ankyrin2 deletion in early postnatal pyramidal neurons increased spine density on apical dendrites in prefrontal cortex layer 2/3 of homozygous and heterozygous Ankyrin2-deficient mice. In contrast, Ankyrin2 deletion in adulthood had no effect on spine density. Sema3F-induced spine pruning was impaired in cortical neuron cultures from Ankyrin B-null mice and was rescued by re-expression of the 220 kDa Ankyrin B isoform but not 440 kDa Ankyrin B. Ankyrin B bound to neuron-glia related CAM at a cytoplasmic domain motif (FIGQY1231), and mutation to FIGQH inhibited binding, impairing Sema3F-induced spine pruning in neuronal cultures. Identification of a novel function for Ankyrin B in dendritic spine regulation provides insight into cortical circuit development, as well as potential molecular deficiencies in autism spectrum disorder.
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Affiliation(s)
- Kelsey E Murphy
- Department of Biochemistry and Biophysics, University of North Carolina School of Medicine at Chapel Hill, Campus Box 7260, Chapel Hill, NC, 27599, United States
| | - Bryce Duncan
- Department of Biochemistry and Biophysics, University of North Carolina School of Medicine at Chapel Hill, Campus Box 7260, Chapel Hill, NC, 27599, United States
| | - Justin E Sperringer
- Department of Biochemistry and Biophysics, University of North Carolina School of Medicine at Chapel Hill, Campus Box 7260, Chapel Hill, NC, 27599, United States
| | - Erin Zhang
- Department of Biochemistry and Biophysics, University of North Carolina School of Medicine at Chapel Hill, Campus Box 7260, Chapel Hill, NC, 27599, United States
| | - Victoria Haberman
- Department of Biochemistry and Biophysics, University of North Carolina School of Medicine at Chapel Hill, Campus Box 7260, Chapel Hill, NC, 27599, United States
| | - Elliott V Wyatt
- Department of Biochemistry and Biophysics, University of North Carolina School of Medicine at Chapel Hill, Campus Box 7260, Chapel Hill, NC, 27599, United States
| | - Patricia Maness
- Department of Biochemistry and Biophysics, University of North Carolina School of Medicine at Chapel Hill, Campus Box 7260, Chapel Hill, NC, 27599, United States
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8
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Murphy KE, Duncan BW, Sperringer JE, Zhang EY, Haberman VA, Wyatt EV, Maness PF. Ankyrin B Promotes Developmental Spine Regulation in the Mouse Prefrontal Cortex. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.07.11.548527. [PMID: 37503187 PMCID: PMC10369899 DOI: 10.1101/2023.07.11.548527] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/29/2023]
Abstract
Postnatal regulation of dendritic spine formation and refinement in cortical pyramidal neurons is critical for excitatory/inhibitory balance in neocortical networks. Recent studies have identified a selective spine pruning mechanism in the mouse prefrontal cortex (PFC) mediated by class 3 Semaphorins and the L1-CAM cell adhesion molecules Neuron-glia related CAM (NrCAM), Close Homolog of L1 (CHL1), and L1. L1-CAMs bind Ankyrin B (AnkB), an actin-spectrin adaptor encoded by Ankyrin2 ( ANK2 ), a high confidence gene for autism spectrum disorder (ASD). In a new inducible mouse model (Nex1Cre-ERT2: Ank2 flox : RCE), Ank2 deletion in early postnatal pyramidal neurons increased spine density on apical dendrites in PFC layer 2/3 of homozygous and heterozygous Ank2 -deficient mice. In contrast, Ank2 deletion in adulthood had no effect on spine density. Sema3F-induced spine pruning was impaired in cortical neuron cultures from AnkB-null mice and was rescued by re-expression of the 220 kDa AnkB isoform but not 440 kDa AnkB. AnkB bound to NrCAM at a cytoplasmic domain motif (FIGQY 1231 ), and mutation to FIGQH inhibited binding, impairing Sema3F-induced spine pruning in neuronal cultures. Identification of a novel function for AnkB in dendritic spine regulation provides insight into cortical circuit development, as well as potential molecular deficiencies in ASD.
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Teunissen MWA, Lewerissa E, van Hugte EJH, Wang S, Ockeloen CW, Koolen DA, Pfundt R, Marcelis CLM, Brilstra E, Howe JL, Scherer SW, Le Guillou X, Bilan F, Primiano M, Roohi J, Piton A, de Saint Martin A, Baer S, Seiffert S, Platzer K, Jamra RA, Syrbe S, Doering JH, Lakhani S, Nangia S, Gilissen C, Vermeulen RJ, Rouhl RPW, Brunner HG, Willemsen MH, Nadif Kasri N. ANK2 loss-of-function variants are associated with epilepsy, and lead to impaired axon initial segment plasticity and hyperactive network activity in hiPSC-derived neuronal networks. Hum Mol Genet 2023; 32:2373-2385. [PMID: 37195288 PMCID: PMC10321384 DOI: 10.1093/hmg/ddad081] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2022] [Revised: 04/21/2023] [Accepted: 05/09/2023] [Indexed: 05/18/2023] Open
Abstract
PURPOSE To characterize a novel neurodevelopmental syndrome due to loss-of-function (LoF) variants in Ankyrin 2 (ANK2), and to explore the effects on neuronal network dynamics and homeostatic plasticity in human-induced pluripotent stem cell-derived neurons. METHODS We collected clinical and molecular data of 12 individuals with heterozygous de novo LoF variants in ANK2. We generated a heterozygous LoF allele of ANK2 using CRISPR/Cas9 in human-induced pluripotent stem cells (hiPSCs). HiPSCs were differentiated into excitatory neurons, and we measured their spontaneous electrophysiological responses using micro-electrode arrays (MEAs). We also characterized their somatodendritic morphology and axon initial segment (AIS) structure and plasticity. RESULTS We found a broad neurodevelopmental disorder (NDD), comprising intellectual disability, autism spectrum disorders and early onset epilepsy. Using MEAs, we found that hiPSC-derived neurons with heterozygous LoF of ANK2 show a hyperactive and desynchronized neuronal network. ANK2-deficient neurons also showed increased somatodendritic structures and altered AIS structure of which its plasticity is impaired upon activity-dependent modulation. CONCLUSIONS Phenotypic characterization of patients with de novo ANK2 LoF variants defines a novel NDD with early onset epilepsy. Our functional in vitro data of ANK2-deficient human neurons show a specific neuronal phenotype in which reduced ANKB expression leads to hyperactive and desynchronized neuronal network activity, increased somatodendritic complexity and AIS structure and impaired activity-dependent plasticity of the AIS.
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Affiliation(s)
- Maria W A Teunissen
- Department of Neurology, Maastricht University Medical Center, Maastricht, HX 6229, The Netherlands
- Academic Center for Epileptology Kempenhaeghe/Maastricht University Medical Center, Heeze 5591 VE, The Netherlands
| | - Elly Lewerissa
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behaviour, Nijmegen, HB 6500, the Netherlands
| | - Eline J H van Hugte
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behaviour, Nijmegen, HB 6500, the Netherlands
| | - Shan Wang
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behaviour, Nijmegen, HB 6500, the Netherlands
| | - Charlotte W Ockeloen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, GA 6525, the Netherlands
| | - David A Koolen
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behaviour, Nijmegen, HB 6500, the Netherlands
| | - Rolph Pfundt
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, GA 6525, the Netherlands
| | - Carlo L M Marcelis
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, GA 6525, the Netherlands
| | - Eva Brilstra
- Department of Human Genetics, University Medical Center Utrecht, Utrecht, CX 3584, The Netherlands
| | - Jennifer L Howe
- The Centre for Applied Genomics and Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
| | - Stephen W Scherer
- The Centre for Applied Genomics and Genetics and Genome Biology, The Hospital for Sick Children, Toronto, ON M5G 1X8, Canada
- McLaughlin Centre and Department of Molecular Genetics, University of Toronto, Toronto, ON M5S 3H7, Canada
| | - Xavier Le Guillou
- Department of Medical Genetics, Centre Hospitalier Universitaire de Poitiers, Poitiers 86000, France
| | - Frédéric Bilan
- Department of Medical Genetics, Centre Hospitalier Universitaire de Poitiers, Poitiers 86000, France
- Laboratory of Experimental and Clinical Neurosciences University of Poitiers, INSERM U1084, Poitiers 86000, France
| | - Michelle Primiano
- Department of Clinical Genetics, Morgan Stanley Children’s Hospital of New York-Presbytarian, New York, NY, 10032, USA
| | - Jasmin Roohi
- Department of Clinical Genetics, Morgan Stanley Children’s Hospital of New York-Presbytarian, New York, NY, 10032, USA
- Clinical Genetics, Kaiser Permanente Mid-Atlantic Permanente Medical Group, Rockville, MD 20852, USA
| | - Amelie Piton
- Laboratoire de Diagnostic Génétique, Institut de Génétique Médicale d’Alsace (IGMA), Hôspitaux Universitaire de Strasbourg, Strasbourg, BP 426 67091, France
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch 67400, France
| | - Anne de Saint Martin
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch 67400, France
- Department of Pediatric Neurology, Strasbourg University Hospital, Hôspital de Hautepierre, Strasbourg, BP 426 67091, France
| | - Sarah Baer
- Institut de Génétique et de Biologie Moléculaire et Cellulaire, Illkirch 67400, France
- Department of Pediatric Neurology, Strasbourg University Hospital, Hôspital de Hautepierre, Strasbourg, BP 426 67091, France
| | - Simone Seiffert
- Department of Neurology and Epileptology, Hertie Institute for Clinical Brain Research, Tuebingen, 72076, Germany
| | - Konrad Platzer
- Institute of Human Genetics, University Medical Center Leipzig, Leipzig 04103, Germany
| | - Rami Abou Jamra
- Institute of Human Genetics, University Medical Center Leipzig, Leipzig 04103, Germany
| | - Steffen Syrbe
- Division of Paediatric Epileptology, Centre for Paediatric and Adolescent Medicine, University Hospital Heidelberg, Heidelberg 69120, Germany
| | - Jan H Doering
- Division of Paediatric Epileptology, Centre for Paediatric and Adolescent Medicine, University Hospital Heidelberg, Heidelberg 69120, Germany
| | - Shenela Lakhani
- Department of neurogenetics, Weill Cornell Medicine, Brain and Mind Research Institute, New York, NY, 10065, USA
| | - Srishti Nangia
- Department of Pediatrics, Division of Child Neurology, New York Presbyterian Hospital-Weill Cornell Medical Center, New York, NY, 10032, USA
| | - Christian Gilissen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, GA 6525, the Netherlands
| | - R Jeroen Vermeulen
- Department of Neurology, Maastricht University Medical Center, Maastricht, HX 6229, The Netherlands
| | - Rob P W Rouhl
- Department of Neurology, Maastricht University Medical Center, Maastricht, HX 6229, The Netherlands
- Academic Center for Epileptology Kempenhaeghe/Maastricht University Medical Center, Heeze 5591 VE, The Netherlands
- School for Mental Health and Neuroscience, Maastricht University, Maastricht, MD 6200, the Netherlands
| | - Han G Brunner
- Academic Center for Epileptology Kempenhaeghe/Maastricht University Medical Center, Heeze 5591 VE, The Netherlands
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behaviour, Nijmegen, HB 6500, the Netherlands
- School for Mental Health and Neuroscience, Maastricht University, Maastricht, MD 6200, the Netherlands
- Department of Clinical Genetics and GROW School for Oncology and Developmental Biology, Maastricht University Medical Centre+, Maastricht, MD 6299, the Netherlands
| | - Marjolein H Willemsen
- Department of Human Genetics, Radboud University Medical Center, Nijmegen, GA 6525, the Netherlands
| | - Nael Nadif Kasri
- Department of Human Genetics, Radboudumc, Donders Institute for Brain, Cognition, and Behaviour, Nijmegen, HB 6500, the Netherlands
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10
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York NS, Sanchez-Arias JC, McAdam ACH, Rivera JE, Arbour LT, Swayne LA. Mechanisms underlying the role of ankyrin-B in cardiac and neurological health and disease. Front Cardiovasc Med 2022; 9:964675. [PMID: 35990955 PMCID: PMC9386378 DOI: 10.3389/fcvm.2022.964675] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Accepted: 07/11/2022] [Indexed: 11/13/2022] Open
Abstract
The ANK2 gene encodes for ankyrin-B (ANKB), one of 3 members of the ankyrin family of proteins, whose name is derived from the Greek word for anchor. ANKB was originally identified in the brain (B denotes “brain”) but has become most widely known for its role in cardiomyocytes as a scaffolding protein for ion channels and transporters, as well as an interacting protein for structural and signaling proteins. Certain loss-of-function ANK2 variants are associated with a primarily cardiac-presenting autosomal-dominant condition with incomplete penetrance and variable expressivity characterized by a predisposition to supraventricular and ventricular arrhythmias, arrhythmogenic cardiomyopathy, congenital and adult-onset structural heart disease, and sudden death. Another independent group of ANK2 variants are associated with increased risk for distinct neurological phenotypes, including epilepsy and autism spectrum disorders. The mechanisms underlying ANKB's roles in cells in health and disease are not fully understood; however, several clues from a range of molecular and cell biological studies have emerged. Notably, ANKB exhibits several isoforms that have different cell-type–, tissue–, and developmental stage– expression profiles. Given the conservation within ankyrins across evolution, model organism studies have enabled the discovery of several ankyrin roles that could shed important light on ANKB protein-protein interactions in heart and brain cells related to the regulation of cellular polarity, organization, calcium homeostasis, and glucose and fat metabolism. Along with this accumulation of evidence suggesting a diversity of important ANKB cellular functions, there is an on-going debate on the role of ANKB in disease. We currently have limited understanding of how these cellular functions link to disease risk. To this end, this review will examine evidence for the cellular roles of ANKB and the potential contribution of ANKB functional variants to disease risk and presentation. This contribution will highlight the impact of ANKB dysfunction on cardiac and neuronal cells and the significance of understanding the role of ANKB variants in disease.
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Affiliation(s)
- Nicole S. York
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | | | - Alexa C. H. McAdam
- Department of Medical Genetics, University of British Columbia, Victoria, BC, Canada
| | - Joel E. Rivera
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
| | - Laura T. Arbour
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Department of Medical Genetics, University of British Columbia, Victoria, BC, Canada
- *Correspondence: Laura T. Arbour
| | - Leigh Anne Swayne
- Division of Medical Sciences, University of Victoria, Victoria, BC, Canada
- Department of Cellular and Physiological Sciences and Djavad Mowafaghian Centre for Brain Health, University of British Columbia, Vancouver, BC, Canada
- Leigh Anne Swayne
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11
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Kawano S, Baba M, Fukushima H, Miura D, Hashimoto H, Nakazawa T. Autism-associated ANK2 regulates embryonic neurodevelopment. Biochem Biophys Res Commun 2022; 605:45-50. [DOI: 10.1016/j.bbrc.2022.03.058] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2022] [Accepted: 03/11/2022] [Indexed: 11/02/2022]
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12
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Creighton BA, Afriyie S, Ajit D, Casingal CR, Voos KM, Reger J, Burch AM, Dyne E, Bay J, Huang JK, Anton ES, Fu MM, Lorenzo DN. Giant ankyrin-B mediates transduction of axon guidance and collateral branch pruning factor sema 3A. eLife 2021; 10:69815. [PMID: 34812142 PMCID: PMC8610419 DOI: 10.7554/elife.69815] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 11/04/2021] [Indexed: 01/19/2023] Open
Abstract
Variants in the high confident autism spectrum disorder (ASD) gene ANK2 target both ubiquitously expressed 220 kDa ankyrin-B and neurospecific 440 kDa ankyrin-B (AnkB440) isoforms. Previous work showed that knock-in mice expressing an ASD-linked Ank2 variant yielding a truncated AnkB440 product exhibit ectopic brain connectivity and behavioral abnormalities. Expression of this variant or loss of AnkB440 caused axonal hyperbranching in vitro, which implicated AnkB440 microtubule bundling activity in suppressing collateral branch formation. Leveraging multiple mouse models, cellular assays, and live microscopy, we show that AnkB440 also modulates axon collateral branching stochastically by reducing the number of F-actin-rich branch initiation points. Additionally, we show that AnkB440 enables growth cone (GC) collapse in response to chemorepellent factor semaphorin 3 A (Sema 3 A) by stabilizing its receptor complex L1 cell adhesion molecule/neuropilin-1. ASD-linked ANK2 variants failed to rescue Sema 3A-induced GC collapse. We propose that impaired response to repellent cues due to AnkB440 deficits leads to axonal targeting and branch pruning defects and may contribute to the pathogenicity of ANK2 variants.
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Affiliation(s)
- Blake A Creighton
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, United States
| | - Simone Afriyie
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, United States
| | - Deepa Ajit
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, United States
| | - Cristine R Casingal
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, United States.,Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, United States
| | - Kayleigh M Voos
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, United States
| | - Joan Reger
- National Institute of Neurological Disorders and Stroke (NINDS), Bethesda, United States.,Department of Biology and Center for Cell Reprogramming, Georgetown University, Washington, United States
| | - April M Burch
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, United States
| | - Eric Dyne
- National Institute of Neurological Disorders and Stroke (NINDS), Bethesda, United States
| | - Julia Bay
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, United States
| | - Jeffrey K Huang
- Department of Biology and Center for Cell Reprogramming, Georgetown University, Washington, United States
| | - E S Anton
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, United States.,Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, United States
| | - Meng-Meng Fu
- National Institute of Neurological Disorders and Stroke (NINDS), Bethesda, United States
| | - Damaris N Lorenzo
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, United States.,Neuroscience Center, University of North Carolina at Chapel Hill, Chapel Hill, United States.,Carolina Institute for Developmental Disabilities, Chapel Hill, United States
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13
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Pan X, Zhou Y, Hotulainen P, Meunier FA, Wang T. The axonal radial contractility: Structural basis underlying a new form of neural plasticity. Bioessays 2021; 43:e2100033. [PMID: 34145916 DOI: 10.1002/bies.202100033] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2021] [Revised: 05/27/2021] [Accepted: 06/02/2021] [Indexed: 12/25/2022]
Abstract
Axons are the longest cellular structure reaching over a meter in the case of human motor axons. They have a relatively small diameter and contain several cytoskeletal elements that mediate both material and information exchange within neurons. Recently, a novel type of axonal plasticity, termed axonal radial contractility, has been unveiled. It is represented by dynamic and transient diameter changes of the axon shaft to accommodate the passages of large organelles. Mechanisms underpinning this plasticity are not fully understood. Here, we first summarised recent evidence of the functional relevance for axon radial contractility, then discussed the underlying structural basis, reviewing nanoscopic evidence of the subtle changes. Two models are proposed to explain how actomyosin rings are organised. Possible roles of non-muscle myosin II (NM-II) in axon degeneration are discussed. Finally, we discuss the concept of periodic functional nanodomains, which could sense extracellular cues and coordinate the axonal responses. Also see the video abstract here: https://youtu.be/ojCnrJ8RCRc.
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Affiliation(s)
- Xiaorong Pan
- Center for Brain Science, School of Life Science and Technology, Shanghaitech University, Shanghai, China
| | - Yimin Zhou
- Center for Brain Science, School of Life Science and Technology, Shanghaitech University, Shanghai, China
| | - Pirta Hotulainen
- Minerva Foundation Institute for Medical Research, Helsinki, Finland
| | - Frédéric A Meunier
- Clem Jones Centre for Ageing Dementia Research, Queensland Brain Institute, The University of Queensland, Brisbane, Australia
| | - Tong Wang
- Center for Brain Science, School of Life Science and Technology, Shanghaitech University, Shanghai, China
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14
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Duncan BW, Murphy KE, Maness PF. Molecular Mechanisms of L1 and NCAM Adhesion Molecules in Synaptic Pruning, Plasticity, and Stabilization. Front Cell Dev Biol 2021; 9:625340. [PMID: 33585481 PMCID: PMC7876315 DOI: 10.3389/fcell.2021.625340] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2020] [Accepted: 01/04/2021] [Indexed: 11/13/2022] Open
Abstract
Mammalian brain circuits are wired by dynamic formation and remodeling during development to produce a balance of excitatory and inhibitory synapses. Synaptic regulation is mediated by a complex network of proteins including immunoglobulin (Ig)- class cell adhesion molecules (CAMs), structural and signal-transducing components at the pre- and post-synaptic membranes, and the extracellular protein matrix. This review explores the current understanding of developmental synapse regulation mediated by L1 and NCAM family CAMs. Excitatory and inhibitory synapses undergo formation and remodeling through neuronal CAMs and receptor-ligand interactions. These responses result in pruning inactive dendritic spines and perisomatic contacts, or synaptic strengthening during critical periods of plasticity. Ankyrins engage neural adhesion molecules of the L1 family (L1-CAMs) to promote synaptic stability. Chondroitin sulfates, hyaluronic acid, tenascin-R, and linker proteins comprising the perineuronal net interact with L1-CAMs and NCAM, stabilizing synaptic contacts and limiting plasticity as critical periods close. Understanding neuronal adhesion signaling and synaptic targeting provides insight into normal development as well as synaptic connectivity disorders including autism, schizophrenia, and intellectual disability.
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Affiliation(s)
- Bryce W Duncan
- Department of Biochemistry and Biophysics, Neuroscience Research Center, Carolina Institute for Developmental Disabilities, University of North Carolina School of Medicine, Chapel Hill, NC, United States
| | - Kelsey E Murphy
- Department of Biochemistry and Biophysics, Neuroscience Research Center, Carolina Institute for Developmental Disabilities, University of North Carolina School of Medicine, Chapel Hill, NC, United States
| | - Patricia F Maness
- Department of Biochemistry and Biophysics, Neuroscience Research Center, Carolina Institute for Developmental Disabilities, University of North Carolina School of Medicine, Chapel Hill, NC, United States
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15
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Fujishima K, Kurisu J, Yamada M, Kengaku M. βIII spectrin controls the planarity of Purkinje cell dendrites by modulating perpendicular axon-dendrite interactions. Development 2020; 147:226102. [PMID: 33234719 DOI: 10.1242/dev.194530] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2020] [Accepted: 11/04/2020] [Indexed: 01/14/2023]
Abstract
The mechanism underlying the geometrical patterning of axon and dendrite wiring remains elusive, despite its crucial importance in the formation of functional neural circuits. The cerebellar Purkinje cell (PC) arborizes a typical planar dendrite, which forms an orthogonal network with granule cell (GC) axons. By using electrospun nanofiber substrates, we reproduce the perpendicular contacts between PC dendrites and GC axons in culture. In the model system, PC dendrites show a preference to grow perpendicularly to aligned GC axons, which presumably contribute to the planar dendrite arborization in vivo We show that βIII spectrin, a causal protein for spinocerebellar ataxia type 5, is required for the biased growth of dendrites. βIII spectrin deficiency causes actin mislocalization and excessive microtubule invasion in dendritic protrusions, resulting in abnormally oriented branch formation. Furthermore, disease-associated mutations affect the ability of βIII spectrin to control dendrite orientation. These data indicate that βIII spectrin organizes the mouse dendritic cytoskeleton and thereby regulates the oriented growth of dendrites with respect to the afferent axons.
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Affiliation(s)
- Kazuto Fujishima
- Institute for Integrated Cell-Material Sciences (KUIAS-iCeMS), Kyoto University, Kyoto 606-8501, Japan
| | - Junko Kurisu
- Institute for Integrated Cell-Material Sciences (KUIAS-iCeMS), Kyoto University, Kyoto 606-8501, Japan
| | - Midori Yamada
- Institute for Integrated Cell-Material Sciences (KUIAS-iCeMS), Kyoto University, Kyoto 606-8501, Japan.,Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan
| | - Mineko Kengaku
- Institute for Integrated Cell-Material Sciences (KUIAS-iCeMS), Kyoto University, Kyoto 606-8501, Japan.,Graduate School of Biostudies, Kyoto University, Kyoto 606-8501, Japan
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