1
|
Wu Y, Zhang D, Liu J, Jiang J, Xie K, Wu L, Leng Y, Liang P, Zhu T, Zhou C. Activity of the Sodium Leak Channel Maintains the Excitability of Paraventricular Thalamus Glutamatergic Neurons to Resist Anesthetic Effects of Sevoflurane in Mice. Anesthesiology 2024; 141:56-74. [PMID: 38625708 DOI: 10.1097/aln.0000000000005015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
BACKGROUND Stimulation of the paraventricular thalamus has been found to enhance anesthesia recovery; however, the underlying molecular mechanism by which general anesthetics modulate paraventricular thalamus is unclear. This study aimed to test the hypothesis that the sodium leak channel (NALCN) maintains neuronal activity in the paraventricular thalamus to resist anesthetic effects of sevoflurane in mice. METHODS Chemogenetic and optogenetic manipulations, in vivo multiple-channel recordings, and electroencephalogram recordings were used to investigate the role of paraventricular thalamus neuronal activity in sevoflurane anesthesia. Virus-mediated knockdown and/or overexpression was applied to determine how NALCN influenced excitability of paraventricular thalamus glutamatergic neurons under sevoflurane. Viral tracers and local field potentials were used to explore the downstream pathway. RESULTS Single neuronal spikes in the paraventricular thalamus were suppressed by sevoflurane anesthesia and recovered during emergence. Optogenetic activation of paraventricular thalamus glutamatergic neurons shortened the emergence period from sevoflurane anesthesia, while chemogenetic inhibition had the opposite effect. Knockdown of the NALCN in the paraventricular thalamus delayed the emergence from sevoflurane anesthesia (recovery time: from 24 ± 14 to 64 ± 19 s, P < 0.001; concentration for recovery of the righting reflex: from 1.13% ± 0.10% to 0.97% ± 0.13%, P < 0.01). As expected, the overexpression of the NALCN in the paraventricular thalamus produced the opposite effects. At the circuit level, knockdown of the NALCN in the paraventricular thalamus decreased the neuronal activity of the nucleus accumbens, as indicated by the local field potential and decreased single neuronal spikes in the nucleus accumbens. Additionally, the effects of NALCN knockdown in the paraventricular thalamus on sevoflurane actions were reversed by optical stimulation of the nucleus accumbens. CONCLUSIONS Activity of the NALCN maintains the excitability of paraventricular thalamus glutamatergic neurons to resist the anesthetic effects of sevoflurane in mice. EDITOR’S PERSPECTIVE
Collapse
Affiliation(s)
- Yujie Wu
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China; Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - Donghang Zhang
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China; Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - Jin Liu
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China; Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - Jingyao Jiang
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China; Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - Keyu Xie
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China; Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - Lin Wu
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China; Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - Yu Leng
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China; Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - Peng Liang
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - Tao Zhu
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| | - Cheng Zhou
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu, China
| |
Collapse
|
2
|
Follmer ML, Isner T, Ozekin YH, Levitt C, Bates EA. Depolarization induces calcium-dependent BMP4 release from mouse embryonic palate mesenchyme. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.06.11.598333. [PMID: 38915514 PMCID: PMC11195066 DOI: 10.1101/2024.06.11.598333] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Ion channels are essential for proper morphogenesis of the craniofacial skeleton. However, the molecular mechanisms underlying this phenomenon are unknown. Loss of the Kcnj2 potassium channel disrupts Bone Morphogenetic Protein (BMP) signaling within the developing palate. BMP signaling is essential for the correct development of several skeletal structures, including the palate, though little is known about the mechanisms that govern BMP secretion. We introduce a tool to image the release of bone morphogenetic protein 4 (BMP4) from mammalian cells. Using this tool, we show that depolarization induces BMP4 release from mouse embryonic palate mesenchyme cells in a calcium-dependent manner. We show native transient changes in intracellular calcium occur in cranial neural crest cells, the cells from which embryonic palate mesenchyme derives. Waves of transient changes in intracellular calcium suggest that these cells are electrically coupled and may temporally coordinate BMP release. These transient changes in intracellular calcium persist in palate mesenchyme cells from embryonic day (E) 9.5 to 13.5 mice. Disruption of Kcnj2 significantly decreases the amplitude of calcium transients and the ability of cells to secrete BMP. Together, these data suggest that temporal control of developmental cues is regulated by ion channels, depolarization, and changes in intracellular calcium for mammalian craniofacial morphogenesis. SUMMARY We show that embryonic palate mesenchyme cells undergo transient changes in intracellular calcium. Depolarization of these cells induces BMP4 release suggesting that ion channels are a node in BMP4 signaling.
Collapse
|
3
|
Chen Y, Xia X, Zhang Y, Gao L, He C, Cao J. Case Report: New presentation of CLIFAHDD syndrome with a novel variant in the NALCN gene and a literature review. Front Pediatr 2024; 12:1370790. [PMID: 38873579 PMCID: PMC11169720 DOI: 10.3389/fped.2024.1370790] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2024] [Accepted: 05/08/2024] [Indexed: 06/15/2024] Open
Abstract
Background Congenital contractures of the limbs and face, hypotonia, and developmental delay (CLIFAHDD) syndrome (OMIM #616266) is an autosomal dominant hereditary disease that can lead to the congenital contracture of the limbs and face, hypotonia, and developmental delay. In addition, it may result in growth retardation and present various clinical symptoms, such as brain atrophy, a small pituitary gland, musculoskeletal abnormalities, abnormal breathing, abdominal hernia, and abnormal facial features. Herein, we describe a novel de novo missense genetic variant in the sodium leak channel, non-selective (NALCN) gene that is associated with CLIFAHDD syndrome. Case description This study describes a patient with varus deformities in both feet, deviation of the ulnar side of the fingers, and severe hypotonia. This patient was subsequently confirmed to have CLIFAHDD syndrome through genetic testing, which also revealed a novel missense de novo genetic variant in the NALCN gene (c.3553G > A, p.Ala1185Thr). Conclusions Our findings further enrich the known variant spectrum of the NALCN gene and may expand the range of clinical options for treating NALCN-related disorders.
Collapse
Affiliation(s)
| | | | | | | | | | - Jianguo Cao
- Department of Rehabilitation Medicine, Shenzhen Children’s Hospital, Shenzhen, China
| |
Collapse
|
4
|
Schott K, Usher SG, Serra O, Carnevale V, Pless SA, Chua HC. Unplugging lateral fenestrations of NALCN reveals a hidden drug binding site within the pore region. Proc Natl Acad Sci U S A 2024; 121:e2401591121. [PMID: 38787877 PMCID: PMC11145269 DOI: 10.1073/pnas.2401591121] [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: 01/23/2024] [Accepted: 04/09/2024] [Indexed: 05/26/2024] Open
Abstract
The sodium (Na+) leak channel (NALCN) is a member of the four-domain voltage-gated cation channel family that includes the prototypical voltage-gated sodium and calcium channels (NaVs and CaVs, respectively). Unlike NaVs and CaVs, which have four lateral fenestrations that serve as routes for lipophilic compounds to enter the central cavity to modulate channel function, NALCN has bulky residues (W311, L588, M1145, and Y1436) that block these openings. Structural data suggest that occluded fenestrations underlie the pharmacological resistance of NALCN, but functional evidence is lacking. To test this hypothesis, we unplugged the fenestrations of NALCN by substituting the four aforementioned residues with alanine (AAAA) and compared the effects of NaV, CaV, and NALCN blockers on both wild-type (WT) and AAAA channels. Most compounds behaved in a similar manner on both channels, but phenytoin and 2-aminoethoxydiphenyl borate (2-APB) elicited additional, distinct responses on AAAA channels. Further experiments using single alanine mutants revealed that phenytoin and 2-APB enter the inner cavity through distinct fenestrations, implying structural specificity to their modes of access. Using a combination of computational and functional approaches, we identified amino acid residues critical for 2-APB activity, supporting the existence of drug binding site(s) within the pore region. Intrigued by the activity of 2-APB and its analogues, we tested compounds containing the diphenylmethane/amine moiety on WT channels. We identified clinically used drugs that exhibited diverse activity, thus expanding the pharmacological toolbox for NALCN. While the low potencies of active compounds reiterate the pharmacological resistance of NALCN, our findings lay the foundation for rational drug design to develop NALCN modulators with refined properties.
Collapse
Affiliation(s)
- Katharina Schott
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen2100, Denmark
| | - Samuel George Usher
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen2100, Denmark
| | - Oscar Serra
- Department of Biology, Temple University, Philadelphia, PA19122
- Institute for Genomics and Evolutionary Medicine, Temple University, Philadelphia, PA19122
- Institute of Computational Molecular Science, Temple University, Philadelphia, PA19122
| | - Vincenzo Carnevale
- Department of Biology, Temple University, Philadelphia, PA19122
- Institute for Genomics and Evolutionary Medicine, Temple University, Philadelphia, PA19122
- Institute of Computational Molecular Science, Temple University, Philadelphia, PA19122
| | - Stephan Alexander Pless
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen2100, Denmark
| | - Han Chow Chua
- Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen2100, Denmark
| |
Collapse
|
5
|
Schott K, Usher SG, Serra O, Carnevale V, Pless SA, Chua HC. Unplugging lateral fenestrations of NALCN reveals a hidden drug binding site within the pore module. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.04.12.536537. [PMID: 38328210 PMCID: PMC10849497 DOI: 10.1101/2023.04.12.536537] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/09/2024]
Abstract
The sodium (Na + ) leak channel (NALCN) is a member of the four-domain voltage-gated cation channel family that includes the prototypical voltage-gated sodium and calcium channels (Na V s and Ca V s, respectively). Unlike Na V s and Ca V s, which have four lateral fenestrations that serve as routes for lipophilic compounds to enter the central cavity to modulate channel function, NALCN has bulky residues (W311, L588, M1145 and Y1436) that block these openings. Structural data suggest that oc-cluded lateral fenestrations underlie the pharmacological resistance of NALCN to lipophilic compounds, but functional evidence is lacking. To test this hypothesis, we unplugged the fenestrations of NALCN by substituting the four aforementioned resi-dues with alanine (AAAA) and compared the effects of Na V , Ca V and NALCN block-ers on both wild-type (WT) and AAAA channels. Most compounds behaved in a simi-lar manner on both channels, but phenytoin and 2-aminoethoxydiphenyl borate (2-APB) elicited additional, distinct responses on AAAA channels. Further experiments using single alanine mutants revealed that phenytoin and 2-APB enter the inner cav-ity through distinct fenestrations, implying structural specificity to their modes of ac-cess. Using a combination of computational and functional approaches, we identified amino acid residues critical for 2-APB activity, supporting the existence of drug bind-ing site(s) within the pore region. Intrigued by the activity of 2-APB and its ana-logues, we tested additional compounds containing the diphenylmethane/amine moiety on WT channels. We identified compounds from existing clinically used drugs that exhibited diverse activity, thus expanding the pharmacological toolbox for NALCN. While the low potencies of active compounds reiterate the resistance of NALCN to pharmacological targeting, our findings lay the foundation for rational drug design to develop NALCN modulators with refined properties. Significance statement The sodium leak channel (NALCN) is essential for survival: mutations cause life-threatening developmental disorders in humans. However, no treatment is currently available due to the resistance of NALCN to pharmacological targeting. One likely reason is that the lateral fenestrations, a common route for clinically used drugs to enter and block related ion channels, are occluded in NALCN. Using a combination of computational and functional approaches, we unplugged the fenestrations of NALCN which led us to the first molecularly defined drug binding site within the pore region. Besides that, we also identified additional NALCN modulators from existing clinically used therapeutics, thus expanding the pharmacological toolbox for this leak channel.
Collapse
|
6
|
Ngodup T, Irie T, Elkins SP, Trussell LO. The Na + leak channel NALCN controls spontaneous activity and mediates synaptic modulation by α2-adrenergic receptors in auditory neurons. eLife 2024; 12:RP89520. [PMID: 38197879 PMCID: PMC10945507 DOI: 10.7554/elife.89520] [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] [Indexed: 01/11/2024] Open
Abstract
Cartwheel interneurons of the dorsal cochlear nucleus (DCN) potently suppress multisensory signals that converge with primary auditory afferent input, and thus regulate auditory processing. Noradrenergic fibers from locus coeruleus project to the DCN, and α2-adrenergic receptors inhibit spontaneous spike activity but simultaneously enhance synaptic strength in cartwheel cells, a dual effect leading to enhanced signal-to-noise for inhibition. However, the ionic mechanism of this striking modulation is unknown. We generated a glycinergic neuron-specific knockout of the Na+ leak channel NALCN in mice and found that its presence was required for spontaneous firing in cartwheel cells. Activation of α2-adrenergic receptors inhibited both NALCN and spike generation, and this modulation was absent in the NALCN knockout. Moreover, α2-dependent enhancement of synaptic strength was also absent in the knockout. GABAB receptors mediated inhibition through NALCN as well, acting on the same population of channels as α2 receptors, suggesting close apposition of both receptor subtypes with NALCN. Thus, multiple neuromodulatory systems determine the impact of synaptic inhibition by suppressing the excitatory leak channel, NALCN.
Collapse
Affiliation(s)
- Tenzin Ngodup
- Oregon Hearing Research Center and Vollum Institute, Oregon Health & Science UniversityPortlandUnited States
| | - Tomohiko Irie
- Department of Physiology, Kitasato University School of MedicineSagamiharaJapan
| | - Seán P Elkins
- Oregon Hearing Research Center and Vollum Institute, Oregon Health & Science UniversityPortlandUnited States
| | - Laurence O Trussell
- Oregon Hearing Research Center and Vollum Institute, Oregon Health & Science UniversityPortlandUnited States
| |
Collapse
|
7
|
Monteil A, Guérineau NC, Gil-Nagel A, Parra-Diaz P, Lory P, Senatore A. New insights into the physiology and pathophysiology of the atypical sodium leak channel NALCN. Physiol Rev 2024; 104:399-472. [PMID: 37615954 DOI: 10.1152/physrev.00014.2022] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Revised: 07/13/2023] [Accepted: 08/15/2023] [Indexed: 08/25/2023] Open
Abstract
Cell excitability and its modulation by hormones and neurotransmitters involve the concerted action of a large repertoire of membrane proteins, especially ion channels. Unique complements of coexpressed ion channels are exquisitely balanced against each other in different excitable cell types, establishing distinct electrical properties that are tailored for diverse physiological contributions, and dysfunction of any component may induce a disease state. A crucial parameter controlling cell excitability is the resting membrane potential (RMP) set by extra- and intracellular concentrations of ions, mainly Na+, K+, and Cl-, and their passive permeation across the cell membrane through leak ion channels. Indeed, dysregulation of RMP causes significant effects on cellular excitability. This review describes the molecular and physiological properties of the Na+ leak channel NALCN, which associates with its accessory subunits UNC-79, UNC-80, and NLF-1/FAM155 to conduct depolarizing background Na+ currents in various excitable cell types, especially neurons. Studies of animal models clearly demonstrate that NALCN contributes to fundamental physiological processes in the nervous system including the control of respiratory rhythm, circadian rhythm, sleep, and locomotor behavior. Furthermore, dysfunction of NALCN and its subunits is associated with severe pathological states in humans. The critical involvement of NALCN in physiology is now well established, but its study has been hampered by the lack of specific drugs that can block or agonize NALCN currents in vitro and in vivo. Molecular tools and animal models are now available to accelerate our understanding of how NALCN contributes to key physiological functions and the development of novel therapies for NALCN channelopathies.
Collapse
Affiliation(s)
- Arnaud Monteil
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
- LabEx "Ion Channel Science and Therapeutics," Montpellier, France
- Department of Physiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, Thailand
| | - Nathalie C Guérineau
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
- LabEx "Ion Channel Science and Therapeutics," Montpellier, France
| | - Antonio Gil-Nagel
- Department of Neurology, Epilepsy Program, Hospital Ruber Internacional, Madrid, Spain
| | - Paloma Parra-Diaz
- Department of Neurology, Epilepsy Program, Hospital Ruber Internacional, Madrid, Spain
| | - Philippe Lory
- Institut de Génomique Fonctionnelle, Université de Montpellier, CNRS, INSERM, Montpellier, France
- LabEx "Ion Channel Science and Therapeutics," Montpellier, France
| | - Adriano Senatore
- Department of Biology, University of Toronto Mississauga, Mississauga, Ontario, Canada
| |
Collapse
|
8
|
Tehrani Fateh S, Bagheri S, Sadeghi H, Salehpour S, Fazeli Bavandpour F, Sadeghi B, Jamshidi S, Tonekaboni SH, Mirfakhraie R, Miryounesi M, Ghasemi MR. Extending and outlining the genotypic and phenotypic spectrum of novel mutations of NALCN gene in IHPRF1 syndrome: identifying recurrent urinary tract infection. Neurol Sci 2023; 44:4491-4498. [PMID: 37452996 DOI: 10.1007/s10072-023-06960-0] [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: 06/29/2023] [Accepted: 07/10/2023] [Indexed: 07/18/2023]
Abstract
Infantile hypotonia with psychomotor retardation and characteristic facies 1 (IHPRF1) is caused by biallelic mutations in the NALCN gene, the major ion channel responsible for the background Na + conduction in neurons. Through whole-exome sequencing (WES), we report three novel homozygous variants in three families, including c.1434 + 1G > A, c.3269G > A, and c.2648G > T, which are confirmed and segregated by Sanger sequencing. Consequently, intron 12's highly conserved splice donor location is disrupted by the pathogenic c.1434 + 1G > A variation, most likely causing the protein to degrade through nonsense-mediated decay (NMD). Subsequently, a premature stop codon is thus generated at amino acid 1090 of the protein as a result of the pathogenic c.3269G > A; p.W1090* variation, resulting in NMD or truncated protein production. Lastly, the missense mutation c.2648G > T; p.G883V can play a critical role in the interplay of functional domains. This study introduces recurrent urinary tract infections for the first time, broadening the phenotypic range of IHPRF1 syndrome in addition to the genotypic spectrum. This trait may result from insufficient bladder emptying, which may be related to the NALCN channelosome's function in background Na + conduction. This work advances knowledge about the molecular genetic underpinnings of IHPRF1 and introduces a novel phenotype through the widespread use of whole exome sequencing.
Collapse
Affiliation(s)
- Sahand Tehrani Fateh
- School of Medicine, Tehran University of Medical Sciences (TUMS), Tehran, Iran
- Center for Comprehensive Genetic Services, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Saman Bagheri
- Center for Comprehensive Genetic Services, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Hossein Sadeghi
- Genomic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Shadab Salehpour
- Department of Pediatrics, Clinical Research Development Unit, Loghman Hakim Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | | | - Behnia Sadeghi
- Center for Comprehensive Genetic Services, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Sanaz Jamshidi
- Center for Comprehensive Genetic Services, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Seyed Hassan Tonekaboni
- Department of Pediatric Neurology, School of Medicine, Pediatric Neurology Research Center, Mofid Children's Hospital, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Reza Mirfakhraie
- Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Miryounesi
- Center for Comprehensive Genetic Services, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
- Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| | - Mohammad-Reza Ghasemi
- Center for Comprehensive Genetic Services, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
- Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| |
Collapse
|
9
|
George LF, Follmer ML, Fontenoy E, Moran HR, Brown JR, Ozekin YH, Bates EA. Endoplasmic Reticulum Calcium Mediates Drosophila Wing Development. Bioelectricity 2023; 5:290-306. [PMID: 38143873 PMCID: PMC10733776 DOI: 10.1089/bioe.2022.0036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2023] Open
Abstract
Background The temporal dynamics of morphogen presentation impacts transcriptional responses and tissue patterning. However, the mechanisms controlling morphogen release are far from clear. We found that inwardly rectifying potassium (Irk) channels regulate endogenous transient increases in intracellular calcium and bone morphogenetic protein (BMP/Dpp) release for Drosophila wing development. Inhibition of Irk channels reduces BMP/Dpp signaling, and ultimately disrupts wing morphology. Ion channels impact development of several tissues and organisms in which BMP signaling is essential. In neurons and pancreatic beta cells, Irk channels modulate membrane potential to affect intracellular Ca++ to control secretion of neurotransmitters and insulin. Based on Irk activity in neurons, we hypothesized that electrical activity controls endoplasmic reticulum (ER) Ca++ release into the cytoplasm to regulate the release of BMP. Materials and Methods To test this hypothesis, we reduced expression of four proteins that control ER calcium, Stromal interaction molecule 1 (Stim), Calcium release-activated calcium channel protein 1 (Orai), SarcoEndoplasmic Reticulum Calcium ATPase (SERCA), small conductance calcium-activated potassium channel (SK), and Bestrophin 2 (Best2) using RNAi and documented wing phenotypes. We use live imaging to study calcium and Dpp release within pupal wings and larval wing discs. Additionally, we employed immunohistochemistry to characterize Small Mothers Against Decapentaplegic (SMAD) phosphorylation downstream of the BMP/Dpp pathway following RNAi knockdown. Results We found that reduced Stim and SERCA function decreases amplitude and frequency of endogenous calcium transients in the wing disc and reduced BMP/Dpp release. Conclusion Our results suggest control of ER calcium homeostasis is required for BMP/Dpp release, and Drosophila wing development.
Collapse
Affiliation(s)
- Laura Faith George
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Mikaela Lynn Follmer
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Emily Fontenoy
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Hannah Rose Moran
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Jeremy Ryan Brown
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Yunus H. Ozekin
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| | - Emily Anne Bates
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, Colorado, USA
| |
Collapse
|
10
|
Ngodup T, Irie T, Elkins S, Trussell LO. The Na + leak channel NALCN controls spontaneous activity and mediates synaptic modulation by α2-adrenergic receptors in auditory neurons. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.06.23.546323. [PMID: 37987013 PMCID: PMC10659375 DOI: 10.1101/2023.06.23.546323] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/22/2023]
Abstract
Cartwheel interneurons of the dorsal cochlear nucleus (DCN) potently suppress multisensory signals that converge with primary auditory afferent input, and thus regulate auditory processing. Noradrenergic fibers from locus coeruleus project to the DCN, and α2-adrenergic receptors inhibit spontaneous spike activity but simultaneously enhance synaptic strength in cartwheel cells, a dual effect leading to enhanced signal-to-noise for inhibition. However, the ionic mechanism of this striking modulation is unknown. We generated a glycinergic neuron-specific knockout of the Na+ leak channel NALCN, and found that its presence was required for spontaneous firing in cartwheel cells. Activation of α2-adrenergic receptors inhibited both NALCN and spike generation, and this modulation was absent in the NALCN knockout. Moreover, α2-dependent enhancement of synaptic strength was also absent in the knockout. GABAB receptors mediated inhibition through NALCN as well, acting on the same population of channels as α2 receptors, suggesting close apposition of both receptor subtypes with NALCN. Thus, multiple neuromodulatory systems determine the impact of synaptic inhibition by suppressing the excitatory leak channel, NALCN.
Collapse
Affiliation(s)
- Tenzin Ngodup
- Oregon Hearing Research Center and Vollum Institute, Oregon Health & Science University, Portland OR USA
| | - Tomohiko Irie
- Department of Physiology, Kitasato University School of Medicine, Sagamihara, Japan
| | - Sean Elkins
- Oregon Hearing Research Center and Vollum Institute, Oregon Health & Science University, Portland OR USA
| | - Laurence O Trussell
- Oregon Hearing Research Center and Vollum Institute, Oregon Health & Science University, Portland OR USA
| |
Collapse
|
11
|
Bayat A, Liu Z, Luo S, Fenger CD, Højte AF, Isidor B, Cogne B, Larson A, Zanus C, Faletra F, Keren B, Musante L, Gourfinkel-An I, Perrine C, Demily C, Lesca G, Liao W, Ren D. A new neurodevelopmental disorder linked to heterozygous variants in UNC79. Genet Med 2023; 25:100894. [PMID: 37183800 DOI: 10.1016/j.gim.2023.100894] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2022] [Revised: 05/05/2023] [Accepted: 05/07/2023] [Indexed: 05/16/2023] Open
Abstract
PURPOSE The "NALCN channelosome" is an ion channel complex that consists of multiple proteins, including NALCN, UNC79, UNC80, and FAM155A. Only a small number of individuals with a neurodevelopmental syndrome have been reported with disease causing variants in NALCN and UNC80. However, no pathogenic UNC79 variants have been reported, and in vivo function of UNC79 in humans is largely unknown. METHODS We used international gene-matching efforts to identify patients harboring ultrarare heterozygous loss-of-function UNC79 variants and no other putative responsible genes. We used genetic manipulations in Drosophila and mice to test potential causal relationships between UNC79 variants and the pathology. RESULTS We found 6 unrelated and affected patients with UNC79 variants. Five patients presented with overlapping neurodevelopmental features, including mild to moderate intellectual disability and a mild developmental delay, whereas a single patient reportedly had normal cognitive and motor development but was diagnosed with epilepsy and autistic features. All displayed behavioral issues and 4 patients had epilepsy. Drosophila with UNC79 knocked down displayed induced seizure-like phenotype. Mice with a heterozygous loss-of-function variant have a developmental delay in body weight compared with wild type. In addition, they have impaired ability in learning and memory. CONCLUSION Our results demonstrate that heterozygous loss-of-function UNC79 variants are associated with neurologic pathologies.
Collapse
Affiliation(s)
- Allan Bayat
- Department of Regional Health Research, University of Southern Denmark, Odense, Denmark; Department of Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Centre, Dianalund, Denmark; Department of Drug Design and Pharmacology, University of Copenhagen, Copenhagen, Denmark.
| | - Zhenjiang Liu
- Department of Biology, University of Pennsylvania, Philadelphia, PA; National Engineering Laboratory for AIDS Vaccine, School of Life Sciences, Jilin University, Changchun, China
| | - Sheng Luo
- Department of Neurology, Institute of Neuroscience, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China
| | - Christina D Fenger
- Department of Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Centre, Dianalund, Denmark; Amplexa Genetics A/S, Odense, Denmark
| | - Anne F Højte
- Department of Epilepsy Genetics and Personalized Medicine, Danish Epilepsy Centre, Dianalund, Denmark
| | - Bertrand Isidor
- Department of Genetics, CHU Nantes, Nantes, France; University of Nantes, CNRS, INSERM, l'institut du thorax, Nantes, France
| | - Benjamin Cogne
- Department of Genetics, CHU Nantes, Nantes, France; University of Nantes, CNRS, INSERM, l'institut du thorax, Nantes, France
| | - Austin Larson
- University of Colorado School of Medicine and Children's Hospital Colorado, Aurora, CO
| | - Caterina Zanus
- Institute for Maternal and Child Health, IRCCS "Burlo Garofolo," Trieste, Italy
| | - Flavio Faletra
- Institute for Maternal and Child Health, IRCCS "Burlo Garofolo," Trieste, Italy
| | - Boris Keren
- Department of Neurology, Epileptology Unit, Reference Center for Rare Epilepsies, Sorbonne University, La Pitié-Salpêtrière Hospital, AP-HP, Paris, France
| | - Luciana Musante
- Institute for Maternal and Child Health, IRCCS "Burlo Garofolo," Trieste, Italy
| | - Isabelle Gourfinkel-An
- Department of Neurology, Epileptology Unit, Reference Center for Rare Epilepsies, Sorbonne University, La Pitié-Salpêtrière Hospital, AP-HP, Paris, France
| | - Charles Perrine
- Department of Medical Genetics, Pitié-Salpêtrière Hospital, AP-HP, University of Sorbonne, Paris, France
| | - Caroline Demily
- GénoPsy, Reference Center for Diagnosis and Management of Genetic Psychiatric Disorders, Vinatier Hospital Center and EDR-Psy Team (National Center for Scientific Research and Lyon 1 Claude Bernard University), Lyon, France; iMIND Excellence Center for Autism and Neurodevelopmental Disorders, Lyon, France
| | - Gaeton Lesca
- Department of Medical Genetics, University Hospital of Lyon, Lyon, France
| | - Weiping Liao
- Department of Neurology, Institute of Neuroscience, Key Laboratory of Neurogenetics and Channelopathies of Guangdong Province and the Ministry of Education of China, the Second Affiliated Hospital, Guangzhou Medical University, Guangzhou, China.
| | - Dejian Ren
- Department of Biology, University of Pennsylvania, Philadelphia, PA
| |
Collapse
|
12
|
Al-Mazidi S, Al-Ayadhi L, Alqahtany F, Abualnaja A, Alzarroug A, Alharbi T, Farhat K, AlMnaizel A, El-Ansary A. The possible role of sodium leakage channel localization factor-1 in the pathophysiology and severity of autism spectrum disorders. Sci Rep 2023; 13:9747. [PMID: 37328585 PMCID: PMC10275888 DOI: 10.1038/s41598-023-36953-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2022] [Accepted: 06/13/2023] [Indexed: 06/18/2023] Open
Abstract
Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by social, stereotypical, and repetitive behaviors. Neural dysregulation was proposed as an etiological factor in ASD. The sodium leakage channel (NCA), regulated by NLF-1 (NCA localization factor-1), has a major role in maintaining the physiological excitatory function of neurons. We aimed to examine the level of NLF-1 in ASD children and correlate it with the severity of the disease. We examined the plasma levels of NLF-1 in 80 ASD and neurotypical children using ELISA. The diagnosis and severity of ASD were based on the Diagnostic and Statistical Manual of Mental Disorders, Fourth Edition (DSM-IV), Childhood Autism Rating Score, Social Responsiveness Scale, and Short Sensory Profile. Then, we compared the levels of NLF-1 with the severity of the disease and behavioral and sensory symptoms. Our results showed a significant decrease in the plasma levels of NLF-1 in ASD children compared to neurotypical children (p < 0.001). Additionally, NLF-1 was significantly correlated with the severity of the behavioral symptoms of ASD (p < 0.05). The low levels of NLF-1 in ASD children potentially affect the severity of their behavioral symptoms by reducing neuron excitability through NCA. These novel findings open a new venue for pharmacological and possible genetic research involving NCA in ASD children.
Collapse
Affiliation(s)
- Sarah Al-Mazidi
- Physiology Department, College of Medicine, Imam Mohammad Ibn Saud Islamic University, P.O.Box: 5701, Riyadh, 11432, Saudi Arabia.
| | - Laila Al-Ayadhi
- Physiology, King Saud University College of Medicine, Riyadh, Saudi Arabia
- Autism Research and Treatment Center, King Saud University College of Medicine, Riyadh, Saudi Arabia
| | - Fatmah Alqahtany
- Hematopathology Unit, Department of Pathology, College of Medicine, King Saud University, King Saud University Medical City, Riyadh, Saudi Arabia
| | - Amani Abualnaja
- College of Medicine, Imam Muhammad bin Saud Islamic University, Riyadh, Saudi Arabia
| | - Abdullah Alzarroug
- College of Medicine, Imam Muhammad bin Saud Islamic University, Riyadh, Saudi Arabia
| | - Turki Alharbi
- College of Medicine, Imam Muhammad bin Saud Islamic University, Riyadh, Saudi Arabia
| | - Karim Farhat
- Cancer Research Chair, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Ahmad AlMnaizel
- Research office, John Hopkins Aramco Healthcare, Dahran, Saudi Arabia
| | - Afaf El-Ansary
- Autism Research and Treatment Center, King Saud University College of Medicine, Riyadh, Saudi Arabia
| |
Collapse
|
13
|
Kanduc D. Exposure to SARS-CoV-2 and Infantile Diseases. Glob Med Genet 2023; 10:72-78. [PMID: 37144240 PMCID: PMC10154082 DOI: 10.1055/s-0043-1768699] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/06/2023] Open
Abstract
Background and Aim Immune response against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) in newborns and children after prophylactic immunization is currently a relevant research topic. The present study analyzes the issue by examining the possibility that the anti-SARS-CoV-2 immune responses are not uniquely directed against the virus but can-via molecular mimicry and the consequent cross-reactivity-also hit human proteins involved in infantile diseases. Methods Human proteins that-if altered-associate with infantile disorders were searched for minimal immune pentapeptide determinants shared with SARS-CoV-2 spike glycoprotein (gp). Then, the shared pentapeptides were analyzed for immunologic potential and immunologic imprinting phenomena. Results Comparative sequence analysis shows that: (1) numerous pentapeptides (namely, 54) are common to SARS-CoV-2 spike gp and human proteins that, when altered, are linked to infantile diseases; (2) all the shared peptides have an immunologic potential since they are present in experimentally validated SARS-CoV-2 spike gp-derived epitopes; and (3) many of the shared peptides are also hosted in infectious pathogens to which children can have already been exposed, thus making immunologic imprint phenomena feasible. Conclusion Molecular mimicry and the consequent cross-reactivity can represent the mechanism that connects exposure to SARS-CoV-2 and various pediatric diseases, with a fundamental role of the immunologic memory and the history of the child's infections in determining and specifying the immune response and the pathologic autoimmune sequela.
Collapse
Affiliation(s)
- Darja Kanduc
- Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari, Bari, Italy
- Address for correspondence Darja Kanduc, PhD Department of Biosciences, Biotechnologies and Biopharmaceutics, University of Bari70126 BariItaly
| |
Collapse
|
14
|
Wang J, Yang Y, Liu J, Qiu J, Zhang D, Ou M, Kang Y, Zhu T, Zhou C. Loss of sodium leak channel (NALCN) in the ventral dentate gyrus impairs neuronal activity of the glutamatergic neurons for inflammation-induced depression in male mice. Brain Behav Immun 2023; 110:13-29. [PMID: 36796706 DOI: 10.1016/j.bbi.2023.02.013] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2022] [Revised: 02/08/2023] [Accepted: 02/11/2023] [Indexed: 02/16/2023] Open
Abstract
BACKGROUND The dentate gyrus (DG) has been implicated in the pathophysiology of depression. Many studies have revealed the cellular types, neural circuits, and morphological changes of the DG involved in the development of depression. However, the molecular regulating its intrinsic activity in depression is unknown. METHODS Utilizing the mode of depression induced by lipopolysaccharide (LPS), we investigate the involvement of the sodium leak channel (NALCN) in inflammation-induced depressive-like behaviors of male mice. The expression of NALCN was detected by immunohistochemistry and real-time polymerase chain reaction. DG microinjection of the adeno-associated virus or lentivirus was carried out using a stereotaxic instrument and followed by behavioral tests. Neuronal excitability and NALCN conductance were recorded by whole-cell patch-clamp techniques. RESULTS The expression and function of NALCN were reduced in both the dorsal and ventral DG in LPS-treated mice; whereas, only knocking down NALCN in the ventral pole produced depressive-like behaviors and this effect of NALCN was specific to ventral glutamatergic neurons. The excitability of ventral glutamatergic neurons was impaired by both the knockdown of NALCN and/or the treatment of LPS. Then, the overexpression of NALCN in the ventral glutamatergic neurons decreased the susceptibility of mice to inflammation-induced depression, and the intracranial injection of substance P (non-selective NALCN activator) into the ventral DG rapidly ameliorated inflammation-induced depression-like behaviors in an NALCN-dependent manner. CONCLUSIONS NALCN, which drives the neuronal activity of the ventral DG glutamatergic neurons, uniquely regulates depressive-like behaviors and susceptibility to depression. Therefore, the NALCN of glutamatergic neurons in the ventral DG may present a molecular target for rapid antidepressant drugs.
Collapse
Affiliation(s)
- Jinping Wang
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China; Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Yaoxin Yang
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Jin Liu
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China; Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Jingxuan Qiu
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China; Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Donghang Zhang
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Mengchan Ou
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Yi Kang
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Tao Zhu
- Department of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China.
| | - Cheng Zhou
- Laboratory of Anesthesia and Critical Care Medicine, National-Local Joint Engineering Research Centre of Translational Medicine of Anesthesiology, West China Hospital, Sichuan University, Chengdu 610041, China.
| |
Collapse
|
15
|
Hopkins CE, Brock T, Caulfield TR, Bainbridge M. Phenotypic screening models for rapid diagnosis of genetic variants and discovery of personalized therapeutics. Mol Aspects Med 2022; 91:101153. [PMID: 36411139 PMCID: PMC10073243 DOI: 10.1016/j.mam.2022.101153] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 10/22/2022] [Accepted: 10/23/2022] [Indexed: 11/19/2022]
Abstract
Precision medicine strives for highly individualized treatments for disease under the notion that each individual's unique genetic makeup and environmental exposures imprints upon them not only a disposition to illness, but also an optimal therapeutic approach. In the realm of rare disorders, genetic predisposition is often the predominant mechanism driving disease presentation. For such, mostly, monogenic disorders, a causal gene to phenotype association is likely. As a result, it becomes important to query the patient's genome for the presence of pathogenic variations that are likely to cause the disease. Determining whether a variant is pathogenic or not is critical to these analyses and can be challenging, as many disease-causing variants are novel and, ergo, have no available functional data to help categorize them. This problem is exacerbated by the need for rapid evaluation of pathogenicity, since many genetic diseases present in young children who will experience increased morbidity and mortality without rapid diagnosis and therapeutics. Here, we discuss the utility of animal models, with a focus mainly on C. elegans, as a contrast to tissue culture and in silico approaches, with emphasis on how these systems are used in determining pathogenicity of variants with uncertain significance and then used to screen for novel therapeutics.
Collapse
Affiliation(s)
| | | | - Thomas R Caulfield
- Mayo Clinic, Department of Neuroscience, Department of Computational Biology, Department of Clinical Genomics, Jacksonville, FL, 32224, Rochester, MN, 55905, USA
| | | |
Collapse
|
16
|
Maselli K, Park H, Breilyn MS, Arens R. Severe central sleep apnea in a child with biallelic variants in NALCN. J Clin Sleep Med 2022; 18:2507-2513. [PMID: 35808948 PMCID: PMC9516572 DOI: 10.5664/jcsm.10146] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2022] [Revised: 06/06/2022] [Accepted: 06/07/2022] [Indexed: 11/13/2022]
Abstract
The sodium leak channel, nonselective (NALCN), is necessary for the proper function of the neurons that play an important role in the sleep-wake cycle and regulation of breathing patterns during wakefulness and sleep. We report a 38-month-old male with developmental delay, hypotonia, and severe central sleep apnea with periodic breathing requiring noninvasive ventilation during sleep, who was found to have novel biallelic pathogenic variants in NALCN. A review of the literature illustrates 17 additional children with biallelic variants in the NALCN gene. The clinical and sleep manifestations of these children are discussed. CITATION Maselli K, Park H, Breilyn MS, Arens R. Severe central sleep apnea in a child with biallelic variants in NALCN. J Clin Sleep Med. 2022;18(10):2507-2513.
Collapse
Affiliation(s)
- Kristina Maselli
- Sleep Wake Disorders Center, Department of Neurology, Montefiore Medical Center, Albert Einstein College of Medicine, Bronx, New York
| | - Hyunbin Park
- Division of Pediatric Respiratory and Sleep Medicine, Department of Pediatrics, Children’s Hospital at Montefiore, Albert Einstein College of Medicine, Bronx, New York
| | - Margo Sheck Breilyn
- Genetics and Genomics, Department of Pediatrics, The Mount Sinai Hospital, New York, New York
| | - Raanan Arens
- Division of Pediatric Respiratory and Sleep Medicine, Department of Pediatrics, Children’s Hospital at Montefiore, Albert Einstein College of Medicine, Bronx, New York
| |
Collapse
|
17
|
Singh P, Agrawal N, Maurya RK, Moirangthem A. Novel variant c.1838A>G, p.(Gln613Arg) in NALCNcauses camptodactyly and cognitive delay. Clin Dysmorphol 2022; 31:206-210. [PMID: 36094358 DOI: 10.1097/mcd.0000000000000431] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Affiliation(s)
- Parshw Singh
- Department of Medical Genetics, Sanjay Gandhi Postgraduate Institute of Medical Sciences, Lucknow, India
| | | | | | | |
Collapse
|
18
|
Kang Y, Chen L. Structure and mechanism of NALCN-FAM155A-UNC79-UNC80 channel complex. Nat Commun 2022; 13:2639. [PMID: 35550517 PMCID: PMC9098444 DOI: 10.1038/s41467-022-30403-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2022] [Accepted: 04/27/2022] [Indexed: 11/09/2022] Open
Abstract
NALCN channel mediates sodium leak currents and is important for maintaining proper resting membrane potential. NALCN and FAM155A form the core complex of the channel, the activity of which essentially depends on the presence of both UNC79 and UNC80, two auxiliary proteins. NALCN, FAM155A, UNC79, and UNC80 co-assemble into a large hetero-tetrameric channel complex. Genetic mutations of NALCN channel components lead to neurodevelopmental diseases. However, the structure and mechanism of the intact channel complex remain elusive. Here, we present the cryo-EM structure of the mammalian NALCN-FAM155A-UNC79-UNC80 quaternary complex. The structure shows that UNC79-UNC80 form a large piler-shaped heterodimer which was tethered to the intracellular side of the NALCN channel through tripartite interactions with the cytoplasmic loops of NALCN. Two interactions are essential for proper cell surface localization of NALCN. The other interaction relieves the self-inhibition of NALCN by pulling the auto-inhibitory CTD Interacting Helix (CIH) out of its binding site. Our work defines the structural mechanism of NALCN modulation by UNC79 and UNC80.
Collapse
Affiliation(s)
- Yunlu Kang
- State Key Laboratory of Membrane Biology, College of Future Technology, Institute of Molecular Medicine, Peking. University, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Beijing, 100871, China.,National Biomedical Imaging Center, Peking University, Beijing, 100871, China
| | - Lei Chen
- State Key Laboratory of Membrane Biology, College of Future Technology, Institute of Molecular Medicine, Peking. University, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Beijing, 100871, China. .,National Biomedical Imaging Center, Peking University, Beijing, 100871, China. .,Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China. .,Academy for Advanced Interdisciplinary Studies, Peking University, Beijing, 100871, China.
| |
Collapse
|
19
|
Abstract
NALCN regulates the resting membrane potential by mediating the Na+ leak current in neurons, and it functions as a channelosome in complex with FAM155A, UNC79, and UNC80. Dysfunction of the NALCN channelosome causes a broad range of neurological and developmental diseases called NALCN channelopathies in humans. How the auxiliary subunits, especially the two large components UNC79 and UNC80, assemble with NALCN and regulate its function remains unclear. Here we report an overall architecture of the human NALCN channelosome. UNC79 and UNC80 each adopt an S-shape super-helical structure consisting of HEAT and armadillo repeats, forming a super-coiled heterodimeric assembly in the cytoplasmic side, which may provide a scaffold for the binding of other potential modulators of the channelosome. The UNC79-UNC80 assembly specifically associates with the NALCN-FAM155A subcomplex through the intracellular II-III linker of NALCN. Disruptions of the interaction interfaces between UNC79 and UNC80, and between the II-III linker of NALCN and the UNC79-UNC80 assembly, significantly reduce the NALCN-mediated currents in HEK293T system, suggesting the importance of the UNC79-UNC80 assembly in regulating channelosome function. Cross-linking mass spectrometry analysis identified an additional calmodulin (CaM) bound in the carboxyl-terminal domain of NALCN. Our study thus provides a structural basis for understanding the unique assembly mechanism and functional regulation of the NALCN channelosome, and also provides an opportunity for the interpretation of many disease-related mutations in UNC80.
Collapse
|
20
|
Chakraborty R, Acharya TK, Tiwari N, Majhi RK, Kumar S, Goswami L, Goswami C. Hydrogel-Mediated Release of TRPV1 Modulators to Fine Tune Osteoclastogenesis. ACS OMEGA 2022; 7:9537-9550. [PMID: 35350319 PMCID: PMC8945112 DOI: 10.1021/acsomega.1c06915] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/07/2021] [Accepted: 02/01/2022] [Indexed: 06/14/2023]
Abstract
Bone defects, including bone loss due to increased osteoclast activity, have become a global health-related issue. Osteoclasts attach to the bone matrix and resorb the same, playing a vital role in bone remodeling. Ca2+ homeostasis plays a pivotal role in the differentiation and maturation of osteoclasts. In this work, we examined the role of TRPV1, a nonselective cation channel, in osteoclast function and differentiation. We demonstrate that endogenous TRPV1 is functional and causes Ca2+ influx upon activation with pharmacological activators [resiniferatoxin (RTX) and capsaicin] at nanomolar concentration, which enhances the generation of osteoclasts, whereas the TRPV1 inhibitor (5'-IRTX) reduces osteoclast differentiation. Activation of TRPV1 upregulates tartrate-resistant acid phosphatase activity and the expression of cathepsin K and calcitonin receptor genes, whereas TRPV1 inhibition reverses this effect. The slow release of capsaicin or RTX at a nanomolar concentration from a polysaccharide-based hydrogel enhances bone marrow macrophage (BMM) differentiation into osteoclasts whereas release of 5'-IRTX, an inhibitor of TRPV1, prevents macrophage fusion and osteoclast formation. We also characterize several subcellular parameters, including reactive oxygen (ROS) and nitrogen (RNS) species in the cytosol, mitochondrial, and lysosomal profiles in BMMs. ROS were found to be unaltered upon TRPV1 modulation. NO, however, had elevated levels upon RTX-mediated TRPV1 activation. Capsaicin altered mitochondrial membrane potential (ΔΨm) of BMMs but not 5'-IRTX. Channel modulation had no significant impact on cytosolic pH but significantly altered the pH of lysosomes, making these organelles less acidic. Since BMMs are precursors for osteoclasts, our findings of the cellular physiology of these cells may have broad implications in understanding the role of thermosensitive ion channels in bone formation and functions, and the TRPV1 modulator-releasing hydrogel may have application in bone tissue engineering and other biomedical sectors.
Collapse
Affiliation(s)
- Ranabir Chakraborty
- School
of Biological Sciences, National Institute
of Science Education and Research Bhubaneswar, P.O. Jatni, Khurda, Odisha 752050, India
| | - Tusar Kanta Acharya
- School
of Biological Sciences, National Institute
of Science Education and Research Bhubaneswar, P.O. Jatni, Khurda, Odisha 752050, India
- Homi
Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India
| | - Nikhil Tiwari
- School
of Biological Sciences, National Institute
of Science Education and Research Bhubaneswar, P.O. Jatni, Khurda, Odisha 752050, India
- Homi
Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India
| | - Rakesh Kumar Majhi
- School
of Biological Sciences, National Institute
of Science Education and Research Bhubaneswar, P.O. Jatni, Khurda, Odisha 752050, India
- Homi
Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India
| | - Satish Kumar
- School
of Biotechnology, Kalinga Institute of Industrial
Technology (KIIT), Deemed to be University, Bhubaneswar, Odisha 751024, India
| | - Luna Goswami
- School
of Biotechnology, Kalinga Institute of Industrial
Technology (KIIT), Deemed to be University, Bhubaneswar, Odisha 751024, India
- School of
Chemical Technology, Kalinga Institute of Industrial Technology (KIIT), Deemed to be University, Bhubaneswar, Odisha 751024, India
| | - Chandan Goswami
- School
of Biological Sciences, National Institute
of Science Education and Research Bhubaneswar, P.O. Jatni, Khurda, Odisha 752050, India
- Homi
Bhabha National Institute, Training School Complex, Anushakti Nagar, Mumbai 400094, India
| |
Collapse
|
21
|
Winczewska-Wiktor A, Hirschfeld AS, Badura-Stronka M, Wojsyk-Banaszak I, Sobkowiak P, Bartkowska-Śniatkowska A, Babak V, Steinborn B. Central Apneas Due to the CLIFAHDD Syndrome Successfully Treated with Pyridostigmine. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19020775. [PMID: 35055596 PMCID: PMC8776169 DOI: 10.3390/ijerph19020775] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Revised: 12/12/2021] [Accepted: 01/06/2022] [Indexed: 02/05/2023]
Abstract
NALCN mutations lead to complex neurodevelopmental syndromes, including infantile hypotonia with psychomotor retardation and characteristic facies (IHPRF) and congenital contractures of limbs and face, hypotonia, and developmental delay (CLIFAHDD), which are recessively and dominantly inherited, respectively. We present a patient in whom congenital myasthenic syndrome (CMS) was suspected due to the occurrence of hypotonia and apnea episodes requiring resuscitation. For this reason, treatment with pyridostigmine was introduced. After starting the treatment, a significant improvement was observed in reducing the apnea episodes and slight psychomotor progress. In the course of further diagnostics, CMS was excluded, and CLIFAHDD syndrome was confirmed. Thus, we try to explain a possible mechanism of clinical improvement after the introduction of treatment with pyridostigmine in a patient with a mutation in the NALCN gene.
Collapse
Affiliation(s)
- Anna Winczewska-Wiktor
- Chair and Department of Developmental Neurology, Poznan University of Medical Sciences, Przybyszewskiego 49, 60-355 Poznan, Poland;
- Correspondence:
| | - Adam Sebastian Hirschfeld
- Chair and Department of Medical Genetics, Poznan University of Medical Sciences, 60-352 Poznan, Poland; (A.S.H.); (M.B.-S.); (V.B.)
| | - Magdalena Badura-Stronka
- Chair and Department of Medical Genetics, Poznan University of Medical Sciences, 60-352 Poznan, Poland; (A.S.H.); (M.B.-S.); (V.B.)
- Centers of Medical Genetics GENESIS, 60-529 Poznan, Poland
| | - Irena Wojsyk-Banaszak
- Department of Pulmonology, Pediatric Allergy and Clinical Immunology, Poznan University of Medical Sciences, 60-572 Poznan, Poland; (I.W.-B.); (P.S.)
| | - Paulina Sobkowiak
- Department of Pulmonology, Pediatric Allergy and Clinical Immunology, Poznan University of Medical Sciences, 60-572 Poznan, Poland; (I.W.-B.); (P.S.)
| | - Alicja Bartkowska-Śniatkowska
- Department of Pediatric Anesthesiology and Intensive Therapy, Poznan University of Medical Sciences, 60-572 Poznan, Poland;
| | - Valeriia Babak
- Chair and Department of Medical Genetics, Poznan University of Medical Sciences, 60-352 Poznan, Poland; (A.S.H.); (M.B.-S.); (V.B.)
| | - Barbara Steinborn
- Chair and Department of Developmental Neurology, Poznan University of Medical Sciences, Przybyszewskiego 49, 60-355 Poznan, Poland;
| |
Collapse
|
22
|
Liao Z, Liu Y, Wang Y, Lu Q, Peng Y, Liu Q. Case Report: A de novo Variant in NALCN Associated With CLIFAHDD Syndrome in a Chinese Infant. Front Pediatr 2022; 10:927392. [PMID: 35911839 PMCID: PMC9326163 DOI: 10.3389/fped.2022.927392] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/26/2022] [Accepted: 06/13/2022] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND The NALCN encodes a sodium ion leak channel that regulates nerve-resting conductance and excitability. NALCN variants are associated with two neurodevelopmental disorders, one is CLIFAHDD (autosomal dominant congenital contractures of the limbs and face, hypotonia, and developmental delay, OMIM #616266) and another is IHPRF (infantile hypotonia with psychomotor retardation, and characteristic facies 1, OMIM #615419). CASE PRESENTATION In the current study, a Chinese infant that manifested abnormal facial features, adducted thumbs, and neurodevelopmental retardation was diagnosed with CLIFAHDD syndrome. A trio-based whole-exome sequencing revealed that the infant harbored a de novo variant of the NALCN gene (c.4300A>G, p.I1434V). CONCLUSIONS Our findings further enriched the variant spectrum of the NALCN gene and may expand the clinical range of NALCN-related disorders.
Collapse
Affiliation(s)
- Zhenyu Liao
- Neonatology Department of Hunan Children's Hospital, Changsha, China
| | - Yali Liu
- Neonatology Department of Changsha Country Maternal and Child Health Care Hospital, Changsha, China
| | - Yimin Wang
- GeneMind Biosciences Company Limited, ShenZhen, China.,College of Pharmacy, Xiangnan University, Chenzhou, China
| | - Qin Lu
- College of Pharmacy, Xiangnan University, Chenzhou, China.,GeneTalks Biotech Co., Ltd., Changsha, China
| | - Yu Peng
- Pediatrics Research Institute of Hunan Province, Hunan Children's Hospital, Changsha, China
| | - Qingsong Liu
- Department of Cardiothoracic Surgery, Hunan Children's Hospital, Changsha, China
| |
Collapse
|
23
|
Al-Muhaizea MA, Aldeeb H, Almass R, Jaber H, Binhumaid F, Alquait L, Abukhalid M, Aldhalaan H, Alsagob M, Al-Bakheet A, Aldosary M, Alkofide H, Alrasheed MM, Colak D, Kaya N. Genetics of ataxia telangiectasia in a highly consanguineous population. Ann Hum Genet 2021; 86:34-44. [PMID: 34582042 DOI: 10.1111/ahg.12445] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2020] [Revised: 08/31/2021] [Accepted: 09/03/2021] [Indexed: 12/17/2022]
Abstract
Ataxia telangiectasia (AT) is a rare autosomal recessive multisystemic disorder. It usually presents in toddler years with progressive ataxia and oculomotor apraxia, or less commonly, in the late-first or early-second decade of life with mixed movement disorders. Biallelic mutations in ataxia telangiectasia mutated gene (ATM) cause AT phenotype, a disease not well documented in Saudi Arabia, a highly consanguineous society. We studied several Saudi AT patients, identified ATM variants, and investigated associated clinical features. We included 17 patients from 12 consanguineous families. All patients had comprehensive clinical and radiological assessment, and most were examined through whole-exome sequencing (WES). Selected individuals were analyzed using various genetic approaches. We identified five different ATM variants in our patients: three previously reported mutations, and two novel variants. Nearly all patients had classical AT presentation except for two patients with a milder phenotype. Among the three known variants, a deletion causing truncation (c.381delA resulting in p.(Val128Ter)) was identified in 13 patients. Two patients harboured the other two truncating variants, (c.9001_9002delAG resulting in p.Ser3001Phefs*6) and (c.9066delA resulting in p.Glu3023Alafs*10) and two patients had novel compound heterozygous variants (NM_000051.3:Paternal Allele:c.8762C > G;p.Thr2921Arg and Maternal Allele:c.1057T > C;p.Cys353Arg). We speculate that c.381delA is a founder mutation in our population. This study provides a genotype-phenotype relationship in a previously unstudied consanguineous population. Our findings contribute to improve local clinical care, therapy, and genetic counseling.
Collapse
Affiliation(s)
- Mohammed A Al-Muhaizea
- Department of Neurosciences, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia
| | - Hanouf Aldeeb
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia.,Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia.,College of Pharmacy, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Rawan Almass
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia.,Department of Medical Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia
| | - Hadeel Jaber
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia.,College of Pharmacy, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Felwa Binhumaid
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia
| | - Laila Alquait
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia.,Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia
| | - Musaad Abukhalid
- Department of Neurosciences, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia
| | - Hesham Aldhalaan
- Department of Neurosciences, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia
| | - Maysoon Alsagob
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia.,King Abdulaziz City for Science and Technology, Riyadh, Kingdom of Saudi Arabia
| | - Albandary Al-Bakheet
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia.,Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia
| | - Mazhor Aldosary
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia.,Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia
| | - Hadeel Alkofide
- College of Pharmacy, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Maha M Alrasheed
- College of Pharmacy, King Saud University, Riyadh, Kingdom of Saudi Arabia
| | - Dilek Colak
- Department of Biostatistics, Epidemiology and Scientific Computing, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia
| | - Namik Kaya
- Department of Translational Genomics, Center for Genomic Medicine, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia.,Department of Genetics, King Faisal Specialist Hospital and Research Centre, Riyadh, Kingdom of Saudi Arabia
| |
Collapse
|
24
|
Kropp PA, Bauer R, Zafra I, Graham C, Golden A. Caenorhabditis elegans for rare disease modeling and drug discovery: strategies and strengths. Dis Model Mech 2021; 14:dmm049010. [PMID: 34370008 PMCID: PMC8380043 DOI: 10.1242/dmm.049010] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Although nearly 10% of Americans suffer from a rare disease, clinical progress in individual rare diseases is severely compromised by lack of attention and research resources compared to common diseases. It is thus imperative to investigate these diseases at their most basic level to build a foundation and provide the opportunity for understanding their mechanisms and phenotypes, as well as potential treatments. One strategy for effectively and efficiently studying rare diseases is using genetically tractable organisms to model the disease and learn about the essential cellular processes affected. Beyond investigating dysfunctional cellular processes, modeling rare diseases in simple organisms presents the opportunity to screen for pharmacological or genetic factors capable of ameliorating disease phenotypes. Among the small model organisms that excel in rare disease modeling is the nematode Caenorhabditis elegans. With a staggering breadth of research tools, C. elegans provides an ideal system in which to study human disease. Molecular and cellular processes can be easily elucidated, assayed and altered in ways that can be directly translated to humans. When paired with other model organisms and collaborative efforts with clinicians, the power of these C. elegans studies cannot be overstated. This Review highlights studies that have used C. elegans in diverse ways to understand rare diseases and aid in the development of treatments. With continuing and advancing technologies, the capabilities of this small round worm will continue to yield meaningful and clinically relevant information for human health.
Collapse
Affiliation(s)
| | | | | | | | - Andy Golden
- Laboratory of Biochemistry and Genetics, National Institute of Diabetes and Digestive and Kidney Diseases, National Institutes of Health, Bethesda, MD 20892, USA
| |
Collapse
|
25
|
Aldosary M, Baselm S, Abdulrahim M, Almass R, Alsagob M, AlMasseri Z, Huma R, AlQuait L, Al‐Shidi T, Al‐Obeid E, AlBakheet A, Alahideb B, Alahaidib L, Qari A, Taylor RW, Colak D, AlSayed MD, Kaya N. SLC25A42-associated mitochondrial encephalomyopathy: Report of additional founder cases and functional characterization of a novel deletion. JIMD Rep 2021; 60:75-87. [PMID: 34258143 PMCID: PMC8260478 DOI: 10.1002/jmd2.12218] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/24/2020] [Revised: 03/09/2021] [Accepted: 03/26/2021] [Indexed: 12/12/2022] Open
Abstract
SLC25A42 is the main transporter of coenzyme A (CoA) into mitochondria. To date, 15 individuals have been reported to have one of two bi-allelic homozygous missense variants in the SLC25A42 as the cause of mitochondrial encephalomyopathy, of which 14 of them were of Saudi origin and share the same founder variant, c.871A > G:p.Asn291Asp. The other subject was of German origin with a variant at canonical splice site, c.380 + 2 T > A. Here, we describe the clinical manifestations and the disease course in additional six Saudi patients from four unrelated consanguineous families. While five patients have the Saudi founder p.Asn291Asp variant, one subject has a novel deletion. Functional analyses on fibroblasts obtained from this patient revealed that the deletion causes significant decrease in mitochondrial oxygen consumption and ATP production compared to healthy individuals. Moreover, extracellular acidification rate revealed significantly reduced glycolysis, glycolytic capacity, and glycolytic reserve as compared to control individuals. There were no changes in the mitochondrial DNA (mtDNA) content of patient fibroblasts. Immunoblotting experiments revealed significantly diminished protein expression due to the deletion. In conclusion, we report additional patients with SLC25A42-associated mitochondrial encephalomyopathy. Our study expands the molecular spectrum of this condition and provides further evidence of mitochondrial dysfunction as a central cause of pathology. We therefore propose that this disorder should be included in the differential diagnosis of any patient with an unexplained motor and speech delay, recurrent encephalopathy with metabolic acidosis, intermittent or persistent dystonia, lactic acidosis, basal ganglia lesions and, especially, of Arab ethnicity. Finally, deep brain stimulation should be considered in the management of patients with life altering dystonia.
Collapse
Affiliation(s)
- Mazhor Aldosary
- Department of GeneticsKing Faisal Specialist Hospital and Research CenterRiyadhSaudi Arabia
- Translational Genomics Department, Center for Genomic Medicine (CGM)King Faisal Specialist Hospital and Research CenterRiyadhSaudi Arabia
| | - Shahad Baselm
- Department of GeneticsKing Faisal Specialist Hospital and Research CenterRiyadhSaudi Arabia
| | - Maha Abdulrahim
- Department of GeneticsKing Faisal Specialist Hospital and Research CenterRiyadhSaudi Arabia
| | - Rawan Almass
- Department of GeneticsKing Faisal Specialist Hospital and Research CenterRiyadhSaudi Arabia
- Translational Genomics Department, Center for Genomic Medicine (CGM)King Faisal Specialist Hospital and Research CenterRiyadhSaudi Arabia
- Department of Medical GeneticsKing Faisal Specialist Hospital and Research CenterRiyadhSaudi Arabia
| | - Maysoon Alsagob
- Department of GeneticsKing Faisal Specialist Hospital and Research CenterRiyadhSaudi Arabia
- Translational Genomics Department, Center for Genomic Medicine (CGM)King Faisal Specialist Hospital and Research CenterRiyadhSaudi Arabia
- King Abdulaziz City for Science and TechnologyRiyadhSaudi Arabia
| | - Zainab AlMasseri
- Department of Medical GeneticsKing Faisal Specialist Hospital and Research CenterRiyadhSaudi Arabia
| | - Rozeena Huma
- Department of Medical GeneticsKing Faisal Specialist Hospital and Research CenterRiyadhSaudi Arabia
| | - Laila AlQuait
- Department of GeneticsKing Faisal Specialist Hospital and Research CenterRiyadhSaudi Arabia
- Translational Genomics Department, Center for Genomic Medicine (CGM)King Faisal Specialist Hospital and Research CenterRiyadhSaudi Arabia
| | - Tarfa Al‐Shidi
- Department of GeneticsKing Faisal Specialist Hospital and Research CenterRiyadhSaudi Arabia
- Translational Genomics Department, Center for Genomic Medicine (CGM)King Faisal Specialist Hospital and Research CenterRiyadhSaudi Arabia
| | - Eman Al‐Obeid
- Department of GeneticsKing Faisal Specialist Hospital and Research CenterRiyadhSaudi Arabia
| | - Albandary AlBakheet
- Department of GeneticsKing Faisal Specialist Hospital and Research CenterRiyadhSaudi Arabia
- Translational Genomics Department, Center for Genomic Medicine (CGM)King Faisal Specialist Hospital and Research CenterRiyadhSaudi Arabia
| | - Basma Alahideb
- Department of GeneticsKing Faisal Specialist Hospital and Research CenterRiyadhSaudi Arabia
| | - Lujane Alahaidib
- Department of GeneticsKing Faisal Specialist Hospital and Research CenterRiyadhSaudi Arabia
| | - Alya Qari
- Department of Medical GeneticsKing Faisal Specialist Hospital and Research CenterRiyadhSaudi Arabia
| | - Robert W. Taylor
- Wellcome Centre for Mitochondrial Research, Translational and Clinical Research Institute, Newcastle UniversityNewcastle upon TyneUK
- NHS Highly Specialised Mitochondrial Diagnostic LaboratoryNewcastle upon Tyne Hospitals NHS Foundation TrustNewcastle upon TyneUK
| | - Dilek Colak
- Department of Biostatistics, Epidemiology, and Scientific ComputingKing Faisal Specialist Hospital and Research CenterRiyadhSaudi Arabia
| | - Moeenaldeen D. AlSayed
- Department of Medical GeneticsKing Faisal Specialist Hospital and Research CenterRiyadhSaudi Arabia
- College of MedicineAlfaisal UniversityRiyadhSaudi Arabia
| | - Namik Kaya
- Department of GeneticsKing Faisal Specialist Hospital and Research CenterRiyadhSaudi Arabia
- Translational Genomics Department, Center for Genomic Medicine (CGM)King Faisal Specialist Hospital and Research CenterRiyadhSaudi Arabia
| |
Collapse
|
26
|
Martiszus BJ, Tsintsadze T, Chang W, Smith SM. Enhanced excitability of cortical neurons in low-divalent solutions is primarily mediated by altered voltage-dependence of voltage-gated sodium channels. eLife 2021; 10:67914. [PMID: 33973519 PMCID: PMC8163501 DOI: 10.7554/elife.67914] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2021] [Accepted: 05/10/2021] [Indexed: 11/17/2022] Open
Abstract
Increasing extracellular [Ca2+] ([Ca2+]o) strongly decreases intrinsic excitability in neurons but the mechanism is unclear. By one hypothesis, [Ca2+]o screens surface charge, reducing voltage-gated sodium channel (VGSC) activation and by another [Ca2+]o activates Calcium-sensing receptor (CaSR) closing the sodium-leak channel (NALCN). Here we report that neocortical neurons from CaSR-deficient (Casr-/-) mice had more negative resting potentials and did not fire spontaneously in reduced divalent-containing solution (T0.2) in contrast with wild-type (WT). However, after setting membrane potential to −70 mV, T0.2 application similarly depolarized and increased action potential firing in Casr-/- and WT neurons. Enhanced activation of VGSCs was the dominant contributor to the depolarization and increase in excitability by T0.2 and occurred due to hyperpolarizing shifts in VGSC window currents. CaSR deletion depolarized VGSC window currents but did not affect NALCN activation. Regulation of VGSC gating by external divalents is the key mechanism mediating divalent-dependent changes in neocortical neuron excitability.
Collapse
Affiliation(s)
- Briana J Martiszus
- Section of Pulmonary & Critical Care Medicine, VA Portland Health Care System, Portland, United States.,Department of Medicine, Division of Pulmonary & Critical Care Medicine, Oregon Health & Science University, Portland, United States
| | - Timur Tsintsadze
- Section of Pulmonary & Critical Care Medicine, VA Portland Health Care System, Portland, United States.,Department of Medicine, Division of Pulmonary & Critical Care Medicine, Oregon Health & Science University, Portland, United States
| | - Wenhan Chang
- Endocrine Research Unit, Veterans Affairs Medical Center and University of California, San Francisco, San Francisco, United States
| | - Stephen M Smith
- Section of Pulmonary & Critical Care Medicine, VA Portland Health Care System, Portland, United States.,Department of Medicine, Division of Pulmonary & Critical Care Medicine, Oregon Health & Science University, Portland, United States
| |
Collapse
|
27
|
Na + leak-current channel (NALCN) at the junction of motor and neuropsychiatric symptoms in Parkinson's disease. J Neural Transm (Vienna) 2021; 128:749-762. [PMID: 33961117 DOI: 10.1007/s00702-021-02348-6] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 04/30/2021] [Indexed: 12/27/2022]
Abstract
Parkinson's disease (PD) is a debilitating movement disorder often accompanied by neuropsychiatric symptoms that stem from the loss of dopaminergic function in the basal ganglia and altered neurotransmission more generally. Akinesia, postural instability, tremors and frozen gait constitute the major motor disturbances, whereas neuropsychiatric symptoms include altered circadian rhythms, disordered sleep, depression, psychosis and cognitive impairment. Evidence is emerging that the motor and neuropsychiatric symptoms may share etiologic factors. Calcium/ion channels (CACNA1C, NALCN), synaptic proteins (SYNJ1) and neuronal RNA-binding proteins (RBFOX1) are among the risk genes that are common to PD and various psychiatric disorders. The Na+ leak-current channel (NALCN) is the focus of this review because it has been implicated in dystonia, regulation of movement, cognitive impairment, sleep and circadian rhythms. It regulates the resting membrane potential in neurons, mediates pace-making activity, participates in synaptic vesicle recycling and is functionally co-localized to the endoplasmic reticulum (ER)-several of the major processes adversely affected in PD. Here, we summarize the literature on mechanisms and pathways that connect the motor and neuropsychiatric symptoms of PD with a focus on recurring relationships to the NALCN. It is hoped that the various connections outlined here will stimulate further discussion, suggest additional areas for exploration and ultimately inspire novel treatment strategies.
Collapse
|
28
|
Mishra S, Girisha KM, Shukla A. Expanding the phenotype of PURA-related neurodevelopmental disorder: a close differential diagnosis of infantile hypotonia with psychomotor retardation and characteristic facies. Clin Dysmorphol 2021; 30:1-5. [PMID: 33229923 PMCID: PMC9944571 DOI: 10.1097/mcd.0000000000000360] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
Purine-rich element-binding protein A (PURA) encodes Pur-alpha, a transcriptional activator protein is crucial for normal brain development. Pathogenic variants in PURA are known to cause mental retardation, autosomal dominant 31, characterized by psychomotor delay, absent or poor speech, hypotonia, feeding difficulties, seizures or 'seizure-like' movements, and dysmorphism. PURA-related neurodevelopmental disorder (PURA-related NDD) result either from heterozygous pathogenic sequence variants in PURA or microdeletions spanning PURA. Singleton whole-exome sequencing (WES) was performed for the proband after a clinical diagnosis of infantile hypotonia with psychomotor retardation and characteristic facies (IHPRF) was made. The pathogenic variant was validated by Sanger sequencing in the proband and parents. Comparison of PURA-related NDD and IHPRF was carried out. WES identified a novel, de-novo stop-gain variant c.178G>T in PURA. In addition to typical phenotype, subject also had hypersensitivity to various stimuli which was not reported in PURA-related NDD. Significant phenotypic overlap was observed in subjects with PURA-related NDD and IHPRF especially with IHPRF2, caused by biallelic pathogenic variants in UNC80. This study expands the phenotypic and mutational spectrum of PURA-related NDD. We propose PURA-related NDD to be considered as a close differential diagnosis of IHPRF.
Collapse
Affiliation(s)
- Shivani Mishra
- Department of Medical Genetics, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Katta Mohan Girisha
- Department of Medical Genetics, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| | - Anju Shukla
- Department of Medical Genetics, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, Karnataka 576104, India
| |
Collapse
|
29
|
Kang Y, Wu JX, Chen L. Structure of voltage-modulated sodium-selective NALCN-FAM155A channel complex. Nat Commun 2020; 11:6199. [PMID: 33273469 PMCID: PMC7712781 DOI: 10.1038/s41467-020-20002-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2020] [Accepted: 11/10/2020] [Indexed: 12/18/2022] Open
Abstract
Resting membrane potential determines the excitability of the cell and is essential for the cellular electrical activities. The NALCN channel mediates sodium leak currents, which positively adjust resting membrane potential towards depolarization. The NALCN channel is involved in several neurological processes and has been implicated in a spectrum of neurodevelopmental diseases. Here, we report the cryo-EM structure of rat NALCN and mouse FAM155A complex to 2.7 Å resolution. The structure reveals detailed interactions between NALCN and the extracellular cysteine-rich domain of FAM155A. We find that the non-canonical architecture of NALCN selectivity filter dictates its sodium selectivity and calcium block, and that the asymmetric arrangement of two functional voltage sensors confers the modulation by membrane potential. Moreover, mutations associated with human diseases map to the domain-domain interfaces or the pore domain of NALCN, intuitively suggesting their pathological mechanisms. The NALCN channel mediates sodium leak currents, which in turn adjusts resting membrane potential and neuronal excitability. Here the authors describe a cryo-EM structure of mammalian NALCN-FAM155A channel complex, showing how selectivity filter contributes to sodium permeation and calcium block and how the voltage sensors contribute to current modulation.
Collapse
Affiliation(s)
- Yunlu Kang
- State Key Laboratory of Membrane Biology, College of Future Technology, Institute of Molecular Medicine, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, 100871, Beijing, China
| | - Jing-Xiang Wu
- State Key Laboratory of Membrane Biology, College of Future Technology, Institute of Molecular Medicine, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, 100871, Beijing, China.,Peking-Tsinghua Center for Life Sciences, Peking University, 100871, Beijing, China.,Academy for Advanced Interdisciplinary Studies, Peking University, 100871, Beijing, China
| | - Lei Chen
- State Key Laboratory of Membrane Biology, College of Future Technology, Institute of Molecular Medicine, Beijing Key Laboratory of Cardiometabolic Molecular Medicine, Peking University, 100871, Beijing, China. .,Peking-Tsinghua Center for Life Sciences, Peking University, 100871, Beijing, China. .,Academy for Advanced Interdisciplinary Studies, Peking University, 100871, Beijing, China.
| |
Collapse
|
30
|
Xie J, Ke M, Xu L, Lin S, Huang J, Zhang J, Yang F, Wu J, Yan Z. Structure of the human sodium leak channel NALCN in complex with FAM155A. Nat Commun 2020; 11:5831. [PMID: 33203861 PMCID: PMC7672056 DOI: 10.1038/s41467-020-19667-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2020] [Accepted: 10/26/2020] [Indexed: 01/18/2023] Open
Abstract
NALCN, a sodium leak channel expressed mainly in the central nervous system, is responsible for the resting Na+ permeability that controls neuronal excitability. Dysfunctions of the NALCN channelosome, NALCN with several auxiliary subunits, are associated with a variety of human diseases. Here, we report the cryo-EM structure of human NALCN in complex with FAM155A at an overall resolution of 3.1 angstroms. FAM155A forms extensive interactions with the extracellular loops of NALCN that may help stabilize NALCN in the membrane. A Na+ ion-binding site, reminiscent of a Ca2+ binding site in Cav channels, is identified in the unique EEKE selectivity filter. Despite its 'leaky' nature, the channel is closed and the intracellular gate is sealed by S6I, II-III linker and III-IV linker. Our study establishes the molecular basis of Na+ permeation and voltage sensitivity, and provides important clues to the mechanistic understanding of NALCN regulation and NALCN channelosome-related diseases.
Collapse
Affiliation(s)
- Jiongfang Xie
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 310024, Hangzhou, Zhejiang, China
- Westlake Laboratory of Life Sciences and Biomedicine, 310024, Hangzhou, Zhejiang, China
- Institute of Biology, Westlake Institute for Advanced Study, 310024, Hangzhou, Zhejiang, China
| | - Meng Ke
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 310024, Hangzhou, Zhejiang, China
- Westlake Laboratory of Life Sciences and Biomedicine, 310024, Hangzhou, Zhejiang, China
- Institute of Biology, Westlake Institute for Advanced Study, 310024, Hangzhou, Zhejiang, China
| | - Lizhen Xu
- Department of Biophysics and Kidney Disease Center, First Affiliated Hospital, Zhejiang University School of Medicine, 310058, Hangzhou, China
| | - Shiyi Lin
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 310024, Hangzhou, Zhejiang, China
- Westlake Laboratory of Life Sciences and Biomedicine, 310024, Hangzhou, Zhejiang, China
- Institute of Biology, Westlake Institute for Advanced Study, 310024, Hangzhou, Zhejiang, China
| | - Jin Huang
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 310024, Hangzhou, Zhejiang, China
- Westlake Laboratory of Life Sciences and Biomedicine, 310024, Hangzhou, Zhejiang, China
- Institute of Biology, Westlake Institute for Advanced Study, 310024, Hangzhou, Zhejiang, China
| | - Jiabei Zhang
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 310024, Hangzhou, Zhejiang, China
- Westlake Laboratory of Life Sciences and Biomedicine, 310024, Hangzhou, Zhejiang, China
- Institute of Biology, Westlake Institute for Advanced Study, 310024, Hangzhou, Zhejiang, China
| | - Fan Yang
- Department of Biophysics and Kidney Disease Center, First Affiliated Hospital, Zhejiang University School of Medicine, 310058, Hangzhou, China.
| | - Jianping Wu
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 310024, Hangzhou, Zhejiang, China.
- Westlake Laboratory of Life Sciences and Biomedicine, 310024, Hangzhou, Zhejiang, China.
- Institute of Biology, Westlake Institute for Advanced Study, 310024, Hangzhou, Zhejiang, China.
| | - Zhen Yan
- Key Laboratory of Structural Biology of Zhejiang Province, School of Life Sciences, Westlake University, 310024, Hangzhou, Zhejiang, China.
- Westlake Laboratory of Life Sciences and Biomedicine, 310024, Hangzhou, Zhejiang, China.
- Institute of Biology, Westlake Institute for Advanced Study, 310024, Hangzhou, Zhejiang, China.
| |
Collapse
|
31
|
Piras IS, Perdigones N, Zismann V, Briones N, Facista S, Rivera JL, Rozanski E, London CA, Hendricks WPD. Identification of Genetic Susceptibility Factors Associated with Canine Gastric Dilatation-Volvulus. Genes (Basel) 2020; 11:genes11111313. [PMID: 33167491 PMCID: PMC7694454 DOI: 10.3390/genes11111313] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 10/29/2020] [Accepted: 10/31/2020] [Indexed: 12/16/2022] Open
Abstract
Canine gastric dilatation-volvulus (GDV) is a common life-threatening condition occurring primarily in large and giant breeds with a 3.9% to 36.7% lifetime risk. The genetic correlates of GDV have not previously been systematically explored. We undertook an inter-breed genome-wide association analysis (GWAS) of 253 dogs from ten breeds including 106 healthy dogs and 147 dogs with at least one GDV episode. SNP array genotyping followed by imputation was conducted on 241 samples to identify GDV-associated single-nucleotide polymorphisms (SNPs) and copy number variations (CNVs). A subset of 33 dogs (15 healthy dogs and 18 GDV patients from the three most represented breeds) was characterized by whole genome sequencing (WGS). After genome-wide Bonferroni correction, we identified a significant putatively protective intergenic SNP (rs851737064) across all breeds. The signal was most significant in Collies, German Shorthaired Pointers, and Great Danes. Subsequent focused analysis across these three breeds identified 12 significant additional putatively protective or deleterious SNPs. Notable significant SNPs included those occurring in genes involved in gastric tone and motility including VHL, NALCN, and PRKCZ. These data provide important new clues to canine GDV risk factors and facilitate generation of hypotheses regarding the genetic and molecular underpinnings this syndrome.
Collapse
Affiliation(s)
- Ignazio S. Piras
- Neurogenomics Division, Translational Genomics Research Institute, Phoenix, AZ 85004, USA;
| | - Nieves Perdigones
- Integrated Cancer Genomics Division, Translational Genomics Research Institute, Phoenix, AZ 85004, USA; (N.P.); (V.Z.); (N.B.); (S.F.); (J.L.R.)
| | - Victoria Zismann
- Integrated Cancer Genomics Division, Translational Genomics Research Institute, Phoenix, AZ 85004, USA; (N.P.); (V.Z.); (N.B.); (S.F.); (J.L.R.)
| | - Natalia Briones
- Integrated Cancer Genomics Division, Translational Genomics Research Institute, Phoenix, AZ 85004, USA; (N.P.); (V.Z.); (N.B.); (S.F.); (J.L.R.)
| | - Salvatore Facista
- Integrated Cancer Genomics Division, Translational Genomics Research Institute, Phoenix, AZ 85004, USA; (N.P.); (V.Z.); (N.B.); (S.F.); (J.L.R.)
| | - José Luis Rivera
- Integrated Cancer Genomics Division, Translational Genomics Research Institute, Phoenix, AZ 85004, USA; (N.P.); (V.Z.); (N.B.); (S.F.); (J.L.R.)
| | - Elizabeth Rozanski
- Cummings School of Veterinary Medicine, Tufts University, Grafton, MA 01536, USA; (E.R.); (C.A.L.)
| | - Cheryl A. London
- Cummings School of Veterinary Medicine, Tufts University, Grafton, MA 01536, USA; (E.R.); (C.A.L.)
| | - William P. D. Hendricks
- Integrated Cancer Genomics Division, Translational Genomics Research Institute, Phoenix, AZ 85004, USA; (N.P.); (V.Z.); (N.B.); (S.F.); (J.L.R.)
- Correspondence:
| |
Collapse
|
32
|
Karimi AH, Karimi MR, Farnia P, Parvini F, Foroutan M. A Homozygous Truncating Mutation in NALCN Causing IHPRF1: Detailed Clinical Manifestations and a Review of Literature. APPLICATION OF CLINICAL GENETICS 2020; 13:151-157. [PMID: 32943903 PMCID: PMC7459142 DOI: 10.2147/tacg.s261781] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/12/2020] [Accepted: 08/08/2020] [Indexed: 12/15/2022]
Abstract
Infantile hypotonia, with psychomotor retardation and characteristic facies 1 (IHPRF1), is a rare disorder characterized by global developmental delay and dysmorphic features. This syndrome is caused by genetic anomalies within the NALCN gene. The current report examines a 9-year-old female IHPRF1 patient. Our objective was to contribute to the delineation of the underlying factors influencing this rare condition. Whole exome sequencing (WES) was utilized to identify the disease-causing mutation in the affected individual. Subsequently, Sanger sequencing was performed for the patient, her parents, and two close relatives in order to confirm the detected mutation. Moreover, detailed clinical examinations including EEG, echocardiography, and biochemical/physical tests were carried out to elucidate the effects of the mutation. WES identified a homozygous nonsense mutation in the NALCN gene (c.2563C>T p.R855X). This mutation was confirmed by Sanger sequencing in the patient and her family members and segregated with the autosomal recessive inheritance pattern of IHPRF1. Moreover, genotype-phenotype correlation analysis confirmed the disease-causing nature of this mutation. The current report provides the first detailed description of a patient with this homozygous nonsense mutation (c.2563C>T p.R855X) and expands the clinical spectrum of IHPRF1 disease. Possible influences of sex and other factors on this disease are discussed and a review of the literature is also provided.
Collapse
Affiliation(s)
- Amir Hossein Karimi
- Department of Biology, Faculty of Basic Sciences, Semnan University, Semnan, Iran
| | - Mohammad Reza Karimi
- Department of Biology, Faculty of Basic Sciences, Semnan University, Semnan, Iran
| | - Poopak Farnia
- Mycobacteriology Research Centre (MRC), National Research Institute of Tuberculosis and Lung Disease (NRITLD), Shahid Beheshti University of Medical Sciences, Tehran, Iran.,Department of Biotechnology, School of Advanced Technologies in Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Farshid Parvini
- Department of Biology, Faculty of Basic Sciences, Semnan University, Semnan, Iran
| | - Majid Foroutan
- Department of Internal Medicine, Semnan University of Medical Sciences, Semnan, Iran
| |
Collapse
|
33
|
Wie J, Bharthur A, Wolfgang M, Narayanan V, Ramsey K, Aranda K, Zhang Q, Zhou Y, Ren D. Intellectual disability-associated UNC80 mutations reveal inter-subunit interaction and dendritic function of the NALCN channel complex. Nat Commun 2020; 11:3351. [PMID: 32620897 PMCID: PMC7335163 DOI: 10.1038/s41467-020-17105-8] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Accepted: 06/11/2020] [Indexed: 01/08/2023] Open
Abstract
The sodium-leak channel NALCN forms a subthreshold sodium conductance that controls the resting membrane potentials of neurons. The auxiliary subunits of the channel and their functions in mammals are largely unknown. In this study, we demonstrate that two large proteins UNC80 and UNC79 are subunits of the NALCN complex. UNC80 knockout mice are neonatal lethal. The C-terminus of UNC80 contains a domain that interacts with UNC79 and overcomes a soma-retention signal to achieve dendritic localization. UNC80 lacking this domain, as found in human patients, still supports whole-cell NALCN currents but lacks dendritic localization. Our results establish the subunit composition of the NALCN complex, uncover the inter-subunit interaction domains, reveal the functional significance of regulation of dendritic membrane potential by the sodium-leak channel complex, and provide evidence supporting that genetic variations found in individuals with intellectual disability are the causes for the phenotype observed in patients.
Collapse
Affiliation(s)
- Jinhong Wie
- Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA.
| | - Apoorva Bharthur
- Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Morgan Wolfgang
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, 85012, USA
| | - Vinodh Narayanan
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, 85012, USA
| | - Keri Ramsey
- Center for Rare Childhood Disorders, Translational Genomics Research Institute, Phoenix, AZ, 85012, USA
| | - Kimberly Aranda
- Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Qi Zhang
- Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - Yandong Zhou
- Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA
- Department of Cellular and Molecular Physiology, Pennsylvania State University College of Medicine, Hershey, PA, 17033, USA
| | - Dejian Ren
- Department of Biology, University of Pennsylvania, Philadelphia, PA, 19104, USA.
| |
Collapse
|
34
|
Al-Muhaizea MA, AlQuait L, AlRasheed A, AlHarbi S, Albader AA, AlMass R, Albakheet A, Alhumaidan A, AlRasheed MM, Colak D, Kaya N. Pyrostigmine therapy in a patient with VAMP1-related congenital myasthenic syndrome. Neuromuscul Disord 2020; 30:611-615. [DOI: 10.1016/j.nmd.2020.04.007] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2019] [Revised: 03/25/2020] [Accepted: 04/27/2020] [Indexed: 12/19/2022]
|
35
|
Ozekin YH, Isner T, Bates EA. Ion Channel Contributions to Morphological Development: Insights From the Role of Kir2.1 in Bone Development. Front Mol Neurosci 2020; 13:99. [PMID: 32581710 PMCID: PMC7296152 DOI: 10.3389/fnmol.2020.00099] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2020] [Accepted: 05/08/2020] [Indexed: 12/21/2022] Open
Abstract
The role of ion channels in neurons and muscles has been well characterized. However, recent work has demonstrated both the presence and necessity of ion channels in diverse cell types for morphological development. For example, mutations that disrupt ion channels give rise to abnormal structural development in species of flies, frogs, fish, mice, and humans. Furthermore, medications and recreational drugs that target ion channels are associated with higher incidence of birth defects in humans. In this review we establish the effects of several teratogens on development including epilepsy treatment drugs (topiramate, valproate, ethosuximide, phenobarbital, phenytoin, and carbamazepine), nicotine, heat, and cannabinoids. We then propose potential links between these teratogenic agents and ion channels with mechanistic insights from model organisms. Finally, we talk about the role of a particular ion channel, Kir2.1, in the formation and development of bone as an example of how ion channels can be used to uncover important processes in morphogenesis. Because ion channels are common targets of many currently used medications, understanding how ion channels impact morphological development will be important for prevention of birth defects. It is becoming increasingly clear that ion channels have functional roles outside of tissues that have been classically considered excitable.
Collapse
Affiliation(s)
- Yunus H Ozekin
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Trevor Isner
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| | - Emily A Bates
- Department of Pediatrics, University of Colorado Anschutz Medical Campus, Aurora, CO, United States
| |
Collapse
|
36
|
Seidahmed MZ, Hamad MH, AlBakheet A, Elmalik SA, AlDrees A, Al-Sufayan J, Alorainy I, Ghozzi IM, Colak D, Salih MA, Kaya N. Ancient founder mutation in RUBCN: a second unrelated family confirms Salih ataxia (SCAR15). BMC Neurol 2020; 20:207. [PMID: 32450808 PMCID: PMC7249383 DOI: 10.1186/s12883-020-01761-w] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2020] [Accepted: 05/03/2020] [Indexed: 11/24/2022] Open
Abstract
Background Homozygous frameshift mutation in RUBCN (KIAA0226), known to result in endolysosomal machinery defects, has previously been reported in a single Saudi family with autosomal recessive spinocerebellar ataxia (Salih ataxia, SCAR15, OMIM # 615705). The present report describes the clinical, neurophysiologic, neuroimaging, and genetic findings in a second unrelated Saudi family with two affected children harboring identical homozygous frameshift mutation in the gene. It also explores and documents an ancient founder cerebellar ataxia mutation in the Arabian Peninsula. Case presentation The present family has two affected males (aged 6.5 and 17 years) with unsteady gait apparent since learning to walk at 2.5 and 3 years, respectively. The younger patient showed gait ataxia and normal reflexes. The older patient had saccadic eye movement, dysarthria, mild upper and lower limb and gait ataxia (on tandem walking), and enhanced reflexes in the lower limbs. Cognitive abilities were mildly impaired in the younger sibling (IQ 67) and borderline in the older patient (IQ 72). Nerve conduction studies were normal in both patients. MRI was normal at 2.5 years in the younger sibling. Brain MRI showed normal cerebellar volume and folia in the older sibling at the age of 6 years, and revealed minimal superior vermian atrophy at the age of 16 years. Autozygome and exome analysis showed both affected have previously reported homoallelic mutation in RUBCN (NM_014687:exon18:c.2624delC:p.A875fs), whereas the parents are carriers. Autozygosity mapping focused on smallest haplotype on chromosome 3 and mutation age analysis revealed the mutation occurred approximately 1550 years ago spanning about 62 generations. Conclusions Our findings validate the slowly progressive phenotype of Salih ataxia (SCAR15, OMIM # 615705) by an additional family. Haplotype sharing attests to a common founder, an ancient RUBCN mutation in the Arab population.
Collapse
Affiliation(s)
- Mohammed Z Seidahmed
- Neonatology Unit, Department of Pediatrics, Security Forces Hospital, Riyadh, 11481, Saudi Arabia.
| | - Muddathir H Hamad
- Division of Pediatric Neurology, Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Albandary AlBakheet
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, MBC: 03, P.O. Box 3354, Riyadh, 11211, Kingdom of Saudi Arabia
| | - Salah A Elmalik
- Department of Physiology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Abdulmajeed AlDrees
- Department of Physiology, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Jumanah Al-Sufayan
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, MBC: 03, P.O. Box 3354, Riyadh, 11211, Kingdom of Saudi Arabia
| | - Ibrahim Alorainy
- Department of Radiology and Diagnostic Imaging, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Ibrahim M Ghozzi
- Department of Internal Medicine, Division of Neurology, Security Forces Hospital, Riyadh, Saudi Arabia
| | - Dilek Colak
- Department of Biostatistics, Epidemiology, and Scientific Computing, King Faisal Specialist Hospital and Research Center, Riyadh, Saudi Arabia
| | - Mustafa A Salih
- Division of Pediatric Neurology, Department of Pediatrics, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Namik Kaya
- Department of Genetics, King Faisal Specialist Hospital and Research Centre, MBC: 03, P.O. Box 3354, Riyadh, 11211, Kingdom of Saudi Arabia.
| |
Collapse
|
37
|
Chua HC, Wulf M, Weidling C, Rasmussen LP, Pless SA. The NALCN channel complex is voltage sensitive and directly modulated by extracellular calcium. SCIENCE ADVANCES 2020; 6:eaaz3154. [PMID: 32494638 PMCID: PMC7182417 DOI: 10.1126/sciadv.aaz3154] [Citation(s) in RCA: 42] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/29/2019] [Accepted: 02/03/2020] [Indexed: 05/24/2023]
Abstract
The sodium leak channel (NALCN) is essential for survival in mammals: NALCN mutations are life-threatening in humans and knockout is lethal in mice. However, the basic functional and pharmacological properties of NALCN have remained elusive. Here, we found that robust function of NALCN in heterologous systems requires co-expression of UNC79, UNC80, and FAM155A. The resulting NALCN channel complex is constitutively active and conducts monovalent cations but is blocked by physiological concentrations of extracellular divalent cations. Our data support the notion that NALCN is directly responsible for the increased excitability observed in a variety of neurons in reduced extracellular Ca2+. Despite the smaller number of voltage-sensing residues in NALCN, the constitutive activity is modulated by voltage, suggesting that voltage-sensing domains can give rise to a broader range of gating phenotypes than previously anticipated. Our work points toward formerly unknown contributions of NALCN to neuronal excitability and opens avenues for pharmacological targeting.
Collapse
|
38
|
The NALCN Channel Regulator UNC-80 Functions in a Subset of Interneurons To Regulate Caenorhabditis elegans Reversal Behavior. G3-GENES GENOMES GENETICS 2020; 10:199-210. [PMID: 31690562 PMCID: PMC6945035 DOI: 10.1534/g3.119.400692] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
NALCN (Na+leak channel, non-selective) is a conserved, voltage-insensitive cation channel that regulates resting membrane potential and neuronal excitability. UNC79 and UNC80 are key regulators of the channel function. However, the behavioral effects of the channel complex are not entirely clear and the neurons in which the channel functions remain to be identified. In a forward genetic screen for C. elegans mutants with defective avoidance response to the plant hormone methyl salicylate (MeSa), we isolated multiple loss-of-function mutations in unc-80 and unc-79. C. elegans NALCN mutants exhibited similarly defective MeSa avoidance. Interestingly, NALCN, unc-80 and unc-79 mutants all showed wild type-like responses to other attractive or repelling odorants, suggesting that NALCN does not broadly affect odor detection or related forward and reversal behaviors. To understand in which neurons the channel functions, we determined the identities of a subset of unc-80-expressing neurons. We found that unc-79 and unc-80 are expressed and function in overlapping neurons, which verified previous assumptions. Neuron-specific transgene rescue and knockdown experiments suggest that the command interneurons AVA and AVE and the anterior guidepost neuron AVG can play a sufficient role in mediating unc-80 regulation of the MeSa avoidance. Though primarily based on genetic analyses, our results further imply that MeSa might activate NALCN by direct or indirect actions. Altogether, we provide an initial look into the key neurons in which the NALCN channel complex functions and identify a novel function of the channel in regulating C. elegans reversal behavior through command interneurons.
Collapse
|
39
|
Liachko NF, Saxton AD, McMillan PJ, Strovas TJ, Keene CD, Bird TD, Kraemer BC. Genome wide analysis reveals heparan sulfate epimerase modulates TDP-43 proteinopathy. PLoS Genet 2019; 15:e1008526. [PMID: 31834878 PMCID: PMC6934317 DOI: 10.1371/journal.pgen.1008526] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 12/27/2019] [Accepted: 11/15/2019] [Indexed: 12/31/2022] Open
Abstract
Pathological phosphorylated TDP-43 protein (pTDP) deposition drives neurodegeneration in amyotrophic lateral sclerosis (ALS) and frontotemporal lobar degeneration (FTLD-TDP). However, the cellular and genetic mechanisms at work in pathological TDP-43 toxicity are not fully elucidated. To identify genetic modifiers of TDP-43 neurotoxicity, we utilized a Caenorhabditis elegans model of TDP-43 proteinopathy expressing human mutant TDP-43 pan-neuronally (TDP-43 tg). In TDP-43 tg C. elegans, we conducted a genome-wide RNAi screen covering 16,767 C. elegans genes for loss of function genetic suppressors of TDP-43-driven motor dysfunction. We identified 46 candidate genes that when knocked down partially ameliorate TDP-43 related phenotypes; 24 of these candidate genes have conserved homologs in the human genome. To rigorously validate the RNAi findings, we crossed the TDP-43 transgene into the background of homozygous strong genetic loss of function mutations. We have confirmed 9 of the 24 candidate genes significantly modulate TDP-43 transgenic phenotypes. Among the validated genes we focused on, one of the most consistent genetic modifier genes protecting against pTDP accumulation and motor deficits was the heparan sulfate-modifying enzyme hse-5, the C. elegans homolog of glucuronic acid epimerase (GLCE). We found that knockdown of human GLCE in cultured human cells protects against oxidative stress induced pTDP accumulation. Furthermore, expression of glucuronic acid epimerase is significantly decreased in the brains of FTLD-TDP cases relative to normal controls, demonstrating the potential disease relevance of the candidate genes identified. Taken together these findings nominate glucuronic acid epimerase as a novel candidate therapeutic target for TDP-43 proteinopathies including ALS and FTLD-TDP. The protein TDP-43 forms aggregates in disease-affected neurons in patients with ALS and FTLD-TDP. In addition, mutations in the human gene coding for TDP-43 can cause inherited ALS. By expressing human mutant TDP-43 protein in C. elegans neurons, we have modelled aspects of ALS pathobiology. This animal model exhibits severe motor dysfunction, progressive neurodegeneration, and accumulation of abnormally modified TDP-43 protein. To identify genes controlling TDP-43 neurotoxicity in C. elegans, we have conducted a genome-wide reverse genetic screen and found 46 genes that participate in TDP-43 neurotoxicity. We demonstrated that one of them, glucuronic acid epimerase, is decreased in patients with FTLD-TDP suggesting inhibitors of glucuronic acid epimerase could have therapeutic value for ALS and FTLD.
Collapse
Affiliation(s)
- Nicole F. Liachko
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, Washington, United States of America
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Aleen D. Saxton
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, Washington, United States of America
| | - Pamela J. McMillan
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, Washington, United States of America
| | - Timothy J. Strovas
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, Washington, United States of America
| | - C. Dirk Keene
- Department of Pathology, University of Washington, Seattle, Washington, United States of America
| | - Thomas D. Bird
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, Washington, United States of America
- Department of Neurology, University of Washington, Seattle, Washington, United States of America
- Division of Medical Genetics, Department of Medicine, University of Washington, Seattle, Washington, United States of America
| | - Brian C. Kraemer
- Geriatrics Research Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, Washington, United States of America
- Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington, Seattle, Washington, United States of America
- Department of Psychiatry and Behavioral Sciences, University of Washington, Seattle, Washington, United States of America
- Division of Medical Genetics, Department of Medicine, University of Washington, Seattle, Washington, United States of America
- * E-mail:
| |
Collapse
|
40
|
Bouasse M, Impheng H, Servant Z, Lory P, Monteil A. Functional expression of CLIFAHDD and IHPRF pathogenic variants of the NALCN channel in neuronal cells reveals both gain- and loss-of-function properties. Sci Rep 2019; 9:11791. [PMID: 31409833 PMCID: PMC6692409 DOI: 10.1038/s41598-019-48071-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 07/29/2019] [Indexed: 12/24/2022] Open
Abstract
The excitability of neurons is tightly dependent on their ion channel repertoire. Among these channels, the leak sodium channel NALCN plays a crucial role in the maintenance of the resting membrane potential. Importantly, NALCN mutations lead to complex neurodevelopmental syndromes, including infantile hypotonia with psychomotor retardation and characteristic facies (IHPRF) and congenital contractures of limbs and face, hypotonia and developmental delay (CLIFAHDD), which are recessively and dominantly inherited, respectively. Unfortunately, the biophysical properties of NALCN are still largely unknown to date, as well as the functional consequences of both IHPRF and CLIFAHDD mutations on NALCN current. Here we have set-up the heterologous expression of NALCN in the neuronal cell line NG108-15 to investigate the electrophysiological properties of NALCN carrying representative IHPRF and CLIFAHDD mutations. Several original properties of the wild-type (wt) NALCN current were retrieved: mainly carried by external Na+, blocked by Gd3+, insensitive to TTX and potentiated by low external Ca2+ concentration. However, we found that this current displays a time-dependent inactivation in the −80/−40 mV range of membrane potential, and a non linear current-voltage relationship indicative of voltage sensitivity. Importantly, no detectable current was recorded with the IHPRF missense mutation p.Trp1287Leu (W1287L), while the CLIFAHDD mutants, p.Leu509Ser (L509S) and p.Tyr578Ser (Y578S), showed higher current densities and slower inactivation, compared to wt NALCN current. This study reveals that heterologous expression of NALCN channel can be achieved in the neuronal cell line NG108-15 to study the electrophysiological properties of wt and mutants. From our results, we conclude that IHPRF and CLIFAHDD missense mutations are loss- and gain-of-function variants, respectively.
Collapse
Affiliation(s)
- Malik Bouasse
- IGF, CNRS, INSERM, University of Montpellier, LabEx 'Ion Channel Science and Therapeutics', Montpellier, France
| | - Hathaichanok Impheng
- IGF, CNRS, INSERM, University of Montpellier, LabEx 'Ion Channel Science and Therapeutics', Montpellier, France
| | - Zoe Servant
- IGF, CNRS, INSERM, University of Montpellier, LabEx 'Ion Channel Science and Therapeutics', Montpellier, France
| | - Philippe Lory
- IGF, CNRS, INSERM, University of Montpellier, LabEx 'Ion Channel Science and Therapeutics', Montpellier, France
| | - Arnaud Monteil
- IGF, CNRS, INSERM, University of Montpellier, LabEx 'Ion Channel Science and Therapeutics', Montpellier, France.
| |
Collapse
|
41
|
Abstract
During morphogenesis, cells communicate with each other to shape tissues and organs. Several lines of recent evidence indicate that ion channels play a key role in cellular signaling and tissue morphogenesis. However, little is known about the scope of specific ion-channel types that impinge upon developmental pathways. The Drosophila melanogaster wing is an excellent model in which to address this problem as wing vein patterning is acutely sensitive to changes in developmental pathways. We conducted a screen of 180 ion channels expressed in the wing using loss-of-function mutant and RNAi lines. Here we identify 44 candidates that significantly impacted development of the Drosophila melanogaster wing. Calcium, sodium, potassium, chloride, and ligand-gated cation channels were all identified in our screen, suggesting that a wide variety of ion channel types are important for development. Ion channels belonging to the pickpocket family, the ionotropic receptor family, and the bestrophin family were highly represented among the candidates of our screen. Seven new ion channels with human orthologs that have been implicated in human channelopathies were also identified. Many of the human orthologs of the channels identified in our screen are targets of common general anesthetics, anti-seizure and anti-hypertension drugs, as well as alcohol and nicotine. Our results confirm the importance of ion channels in morphogenesis and identify a number of ion channels that will provide the basis for future studies to understand the role of ion channels in development.
Collapse
|
42
|
Martin HC, Jones WD, McIntyre R, Sanchez-Andrade G, Sanderson M, Stephenson JD, Jones CP, Handsaker J, Gallone G, Bruntraeger M, McRae JF, Prigmore E, Short P, Niemi M, Kaplanis J, Radford EJ, Akawi N, Balasubramanian M, Dean J, Horton R, Hulbert A, Johnson DS, Johnson K, Kumar D, Lynch SA, Mehta SG, Morton J, Parker MJ, Splitt M, Turnpenny PD, Vasudevan PC, Wright M, Bassett A, Gerety SS, Wright CF, FitzPatrick DR, Firth HV, Hurles ME, Barrett JC. Quantifying the contribution of recessive coding variation to developmental disorders. Science 2018; 362:1161-1164. [PMID: 30409806 DOI: 10.1126/science.aar6731] [Citation(s) in RCA: 123] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2017] [Revised: 08/10/2018] [Accepted: 10/29/2018] [Indexed: 12/13/2022]
Abstract
We estimated the genome-wide contribution of recessive coding variation in 6040 families from the Deciphering Developmental Disorders study. The proportion of cases attributable to recessive coding variants was 3.6% in patients of European ancestry, compared with 50% explained by de novo coding mutations. It was higher (31%) in patients with Pakistani ancestry, owing to elevated autozygosity. Half of this recessive burden is attributable to known genes. We identified two genes not previously associated with recessive developmental disorders, KDM5B and EIF3F, and functionally validated them with mouse and cellular models. Our results suggest that recessive coding variants account for a small fraction of currently undiagnosed nonconsanguineous individuals, and that the role of noncoding variants, incomplete penetrance, and polygenic mechanisms need further exploration.
Collapse
Affiliation(s)
- Hilary C Martin
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK.
| | - Wendy D Jones
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK.,Great Ormond Street Hospital for Children, National Health Service (NHS) Foundation Trust, Great Ormond Street Hospital, Great Ormond Street, London WC1N 3JH, UK
| | - Rebecca McIntyre
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK
| | | | - Mark Sanderson
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK
| | - James D Stephenson
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK.,European Molecular Biology Laboratory-European Bioinformatics Institute, Wellcome Trust Genome Campus, Hinxton, Cambridgeshire CB10 1SD, UK
| | - Carla P Jones
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK
| | - Juliet Handsaker
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK
| | - Giuseppe Gallone
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK
| | | | - Jeremy F McRae
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK
| | - Elena Prigmore
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK
| | - Patrick Short
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK
| | - Mari Niemi
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK
| | - Joanna Kaplanis
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK
| | - Elizabeth J Radford
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK.,Department of Paediatrics, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Nadia Akawi
- Division of Cardiovascular Medicine, Radcliffe Department of Medicine, University of Oxford, Oxford, UK
| | - Meena Balasubramanian
- Sheffield Clinical Genetics Service, Sheffield Children's NHS Foundation Trust, OPD2, Northern General Hospital, Herries Rd., Sheffield, S5 7AU, UK
| | - John Dean
- Department of Genetics, Aberdeen Royal Infirmary, Aberdeen, UK
| | - Rachel Horton
- Wessex Clinical Genetics Service, G Level, Princess Anne Hospital, Coxford Road, Southampton SO16 5YA, UK
| | - Alice Hulbert
- Cheshire and Merseyside Clinical Genetic Service, Liverpool Women's NHS Foundation Trust, Crown Street, Liverpool L8 7SS, UK
| | - Diana S Johnson
- Sheffield Clinical Genetics Service, Sheffield Children's NHS Foundation Trust, OPD2, Northern General Hospital, Herries Rd., Sheffield, S5 7AU, UK
| | - Katie Johnson
- Department of Clinical Genetics, City Hospital Campus, Hucknall Road, Nottingham NG5 1PB, UK
| | - Dhavendra Kumar
- Institute of Cancer and Genetics, University Hospital of Wales, Cardiff, UK
| | | | - Sarju G Mehta
- Department of Clinical Genetics, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Jenny Morton
- Clinical Genetics Unit, Birmingham Women's Hospital, Edgbaston, Birmingham B15 2TG, UK
| | - Michael J Parker
- Sheffield Clinical Genetics Service, Sheffield Children's Hospital, Western Bank, Sheffield S10 2TH, UK
| | - Miranda Splitt
- Northern Genetics Service, Newcastle upon Tyne Hospitals, NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Peter D Turnpenny
- Clinical Genetics, Royal Devon and Exeter NHS Foundation Trust, Exeter, UK
| | - Pradeep C Vasudevan
- Department of Clinical Genetics, University Hospitals of Leicester NHS Trust, Leicester Royal Infirmary, Leicester LE1 5WW, UK
| | - Michael Wright
- Northern Genetics Service, Newcastle upon Tyne Hospitals, NHS Foundation Trust, Newcastle upon Tyne, UK
| | - Andrew Bassett
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK
| | - Sebastian S Gerety
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK
| | - Caroline F Wright
- University of Exeter Medical School, Institute of Biomedical and Clinical Science, Research, Innovation, Learning and Development (RILD), Royal Devon and Exeter Hospital, Barrack Road, Exeter, EX2 5DW, UK
| | - David R FitzPatrick
- Medical Research Council (MRC) Human Genetics Unit, MRC Institute of Genetics and Molecular Medicine (IGMM), University of Edinburgh, Western General Hospital, Edinburgh EH4 2XU, UK
| | - Helen V Firth
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK.,Department of Clinical Genetics, Cambridge University Hospitals NHS Foundation Trust, Cambridge, UK
| | - Matthew E Hurles
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK
| | - Jeffrey C Barrett
- Wellcome Trust Sanger Institute, Wellcome Trust Genome Campus, Hinxton, UK.
| | | |
Collapse
|
43
|
Bramswig NC, Bertoli-Avella AM, Albrecht B, Al Aqeel AI, Alhashem A, Al-Sannaa N, Bah M, Bröhl K, Depienne C, Dorison N, Doummar D, Ehmke N, Elbendary HM, Gorokhova S, Héron D, Horn D, James K, Keren B, Kuechler A, Ismail S, Issa MY, Marey I, Mayer M, McEvoy-Venneri J, Megarbane A, Mignot C, Mohamed S, Nava C, Philip N, Ravix C, Rolfs A, Sadek AA, Segebrecht L, Stanley V, Trautman C, Valence S, Villard L, Wieland T, Engels H, Strom TM, Zaki MS, Gleeson JG, Lüdecke HJ, Bauer P, Wieczorek D. Genetic variants in components of the NALCN-UNC80-UNC79 ion channel complex cause a broad clinical phenotype (NALCN channelopathies). Hum Genet 2018; 137:753-768. [PMID: 30167850 PMCID: PMC6671679 DOI: 10.1007/s00439-018-1929-5] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2018] [Accepted: 08/13/2018] [Indexed: 12/30/2022]
Abstract
NALCN is a conserved cation channel, which conducts a permanent sodium leak current and regulates resting membrane potential and neuronal excitability. It is part of a large ion channel complex, the "NALCN channelosome", consisting of multiple proteins including UNC80 and UNC79. The predominant neuronal expression pattern and its function suggest an important role in neuronal function and disease. So far, biallelic NALCN and UNC80 variants have been described in a small number of individuals leading to infantile hypotonia, psychomotor retardation, and characteristic facies 1 (IHPRF1, OMIM 615419) and 2 (IHPRF2, OMIM 616801), respectively. Heterozygous de novo NALCN missense variants in the S5/S6 pore-forming segments lead to congenital contractures of the limbs and face, hypotonia, and developmental delay (CLIFAHDD, OMIM 616266) with some clinical overlap. In this study, we present detailed clinical information of 16 novel individuals with biallelic NALCN variants, 1 individual with a heterozygous de novo NALCN missense variant and an interesting clinical phenotype without contractures, and 12 individuals with biallelic UNC80 variants. We report for the first time a missense NALCN variant located in the predicted S6 pore-forming unit inherited in an autosomal-recessive manner leading to mild IHPRF1. We show evidence of clinical variability, especially among IHPRF1-affected individuals, and discuss differences between the IHPRF1- and IHPRF2 phenotypes. In summary, we provide a comprehensive overview of IHPRF1 and IHPRF2 phenotypes based on the largest cohort of individuals reported so far and provide additional insights into the clinical phenotypes of these neurodevelopmental diseases to help improve counseling of affected families.
Collapse
Affiliation(s)
- Nuria C Bramswig
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Hufelandstr. 55, 45122, Essen, Germany.
| | | | - Beate Albrecht
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Hufelandstr. 55, 45122, Essen, Germany
| | - Aida I Al Aqeel
- Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
- American University of Beirut, Beirut, Lebanon
- Alfaisal University, Riyadh, Saudi Arabia
| | - Amal Alhashem
- Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
- Department of Anatomy and Cell Biology, College of Medicine, Alfaisal University, Riyadh, Saudi Arabia
| | - Nouriya Al-Sannaa
- John Hopkins Aramco Health Care, Pediatric Services, Dhahran, Saudi Arabia
| | - Maissa Bah
- Groupe de Recherche Clinique sorbonne Université "Déficiences Intellectuelles et Autisme", Département de Génétique, Centre de Référence Déficiences Intellectuelles de Causes Rares, AP-HP, Hôpital de la Pitié Salpêtrière, 75013, Paris, France
| | - Katharina Bröhl
- Internal Medicine Department, Waldkrankenhaus Evangelical Hospital, Berlin, Germany
| | - Christel Depienne
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Hufelandstr. 55, 45122, Essen, Germany
- Sorbonne Universités, UPMC Univ Paris 06, UMR S 1127, and Inserm U 1127, and CNRS UMR 7225, and ICM, 75013, Paris, France
| | - Nathalie Dorison
- Service de Neurochirurgie Pédiatrique, Fondation Ophtalmologique Adolphe de Rothschild, Paris, France
| | - Diane Doummar
- AP-HP, Département de neuropédiatrie, GHUEP, Hôpital Armand Trousseau, Paris, France
| | - Nadja Ehmke
- Institute of Medical and Human Genetics, Charité-Universitätsmedizin Berlin, Berlin, Germany
- Berlin Institute of Health, Berlin, Germany
| | - Hasnaa M Elbendary
- Human Genetics and Genome Research Division, Clinical Genetics Department, National Research Centre, Cairo, Egypt
| | - Svetlana Gorokhova
- Département de Génétique Médicale, APHM, CHU Timone Enfants, Marseille, France
- Aix Marseille Univ, MMG, INSERM, Marseille, France
| | - Delphine Héron
- Groupe de Recherche Clinique sorbonne Université "Déficiences Intellectuelles et Autisme", Département de Génétique, Centre de Référence Déficiences Intellectuelles de Causes Rares, AP-HP, Hôpital de la Pitié Salpêtrière, 75013, Paris, France
| | - Denise Horn
- Institute of Medical and Human Genetics, Charité-Universitätsmedizin Berlin, Berlin, Germany
| | - Kiely James
- Departments of Neurosciences and Pediatrics, Howard Hughes Medical Institute, University of California San Diego, Rady Children's Institute for Genomic Medicine, La Jolla, CA, 92093, USA
| | - Boris Keren
- Groupe de Recherche Clinique sorbonne Université "Déficiences Intellectuelles et Autisme", Département de Génétique, Centre de Référence Déficiences Intellectuelles de Causes Rares, AP-HP, Hôpital de la Pitié Salpêtrière, 75013, Paris, France
| | - Alma Kuechler
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Hufelandstr. 55, 45122, Essen, Germany
| | - Samira Ismail
- Human Genetics and Genome Research Division, Clinical Genetics Department, National Research Centre, Cairo, Egypt
| | - Mahmoud Y Issa
- Human Genetics and Genome Research Division, Clinical Genetics Department, National Research Centre, Cairo, Egypt
| | - Isabelle Marey
- Groupe de Recherche Clinique sorbonne Université "Déficiences Intellectuelles et Autisme", Département de Génétique, Centre de Référence Déficiences Intellectuelles de Causes Rares, AP-HP, Hôpital de la Pitié Salpêtrière, 75013, Paris, France
| | - Michèle Mayer
- AP-HP, Département de neuropédiatrie, GHUEP, Hôpital Armand Trousseau, Paris, France
| | - Jennifer McEvoy-Venneri
- Departments of Neurosciences and Pediatrics, Howard Hughes Medical Institute, University of California San Diego, Rady Children's Institute for Genomic Medicine, La Jolla, CA, 92093, USA
| | - Andre Megarbane
- CEMEDIPP-Centre Medico Psychopedagogique, Beirut, Lebanon
- Institut Jerome Lejeune, Paris, France
| | - Cyril Mignot
- Groupe de Recherche Clinique sorbonne Université "Déficiences Intellectuelles et Autisme", Département de Génétique, Centre de Référence Déficiences Intellectuelles de Causes Rares, AP-HP, Hôpital de la Pitié Salpêtrière, 75013, Paris, France
| | - Sarar Mohamed
- Department of Pediatrics, Prince Sultan Military Medical City, Riyadh, Saudi Arabia
- Prince Abdullah bin Khaled Coeliac Disease Research Chair, College of Medicine, King Saud University, Riyadh, Saudi Arabia
| | - Caroline Nava
- Groupe de Recherche Clinique sorbonne Université "Déficiences Intellectuelles et Autisme", Département de Génétique, Centre de Référence Déficiences Intellectuelles de Causes Rares, AP-HP, Hôpital de la Pitié Salpêtrière, 75013, Paris, France
- Sorbonne Universités, UPMC Univ Paris 06, UMR S 1127, and Inserm U 1127, and CNRS UMR 7225, and ICM, 75013, Paris, France
| | - Nicole Philip
- Département de Génétique Médicale, APHM, CHU Timone Enfants, Marseille, France
- Aix Marseille Univ, MMG, INSERM, Marseille, France
| | - Cecile Ravix
- Aix Marseille Univ, MMG, INSERM, Marseille, France
| | - Arndt Rolfs
- CENTOGENE AG, The Rare Disease Company, Rostock, Germany
- Albrecht Kossel Institute, University of Rostock, Rostock, Germany
| | - Abdelrahim Abdrabou Sadek
- Pediatric Neurology Unit, Department of Pediatrics, Faculty of Medicine, Sohag University, Sohâg, Egypt
| | - Lara Segebrecht
- Institute of Medical and Human Genetics, Charité-Universitätsmedizin Berlin, Berlin, Germany
- Berlin Institute of Health, Berlin, Germany
| | - Valentina Stanley
- Departments of Neurosciences and Pediatrics, Howard Hughes Medical Institute, University of California San Diego, Rady Children's Institute for Genomic Medicine, La Jolla, CA, 92093, USA
| | - Camille Trautman
- Departments of Neurosciences and Pediatrics, Howard Hughes Medical Institute, University of California San Diego, Rady Children's Institute for Genomic Medicine, La Jolla, CA, 92093, USA
| | - Stephanie Valence
- AP-HP, Département de neuropédiatrie, GHUEP, Hôpital Armand Trousseau, Paris, France
| | - Laurent Villard
- Département de Génétique Médicale, APHM, CHU Timone Enfants, Marseille, France
- Aix Marseille Univ, MMG, INSERM, Marseille, France
| | - Thomas Wieland
- Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany
| | - Hartmut Engels
- Institute of Human Genetics, University of Bonn, School of Medicine and University Hospital Bonn, Bonn, Germany
| | - Tim M Strom
- Institute of Human Genetics, Helmholtz Zentrum München, Neuherberg, Germany
- Institute of Human Genetics, Technische Universität München, Munich, Germany
| | - Maha S Zaki
- Human Genetics and Genome Research Division, Clinical Genetics Department, National Research Centre, Cairo, Egypt
| | - Joseph G Gleeson
- Departments of Neurosciences and Pediatrics, Howard Hughes Medical Institute, University of California San Diego, Rady Children's Institute for Genomic Medicine, La Jolla, CA, 92093, USA
| | - Hermann-Josef Lüdecke
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Hufelandstr. 55, 45122, Essen, Germany
- Institut für Humangenetik, Universitätsklinikum Düsseldorf, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| | - Peter Bauer
- CENTOGENE AG, The Rare Disease Company, Rostock, Germany
| | - Dagmar Wieczorek
- Institut für Humangenetik, Universitätsklinikum Essen, Universität Duisburg-Essen, Hufelandstr. 55, 45122, Essen, Germany
- Institut für Humangenetik, Universitätsklinikum Düsseldorf, Heinrich-Heine-Universität Düsseldorf, Düsseldorf, Germany
| |
Collapse
|
44
|
Bourque DK, Dyment DA, MacLusky I, Kernohan KD, McMillan HJ. Periodic breathing in patients with NALCN mutations. J Hum Genet 2018; 63:1093-1096. [PMID: 29968795 DOI: 10.1038/s10038-018-0484-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 05/30/2018] [Accepted: 05/30/2018] [Indexed: 01/10/2023]
Abstract
Biallelic mutations in NALCN are responsible for infantile hypotonia with psychomotor retardation and characteristic facies 1 (IHPRF1). Common features of this condition include severe neonatal-onset hypotonia and profound global developmental delay. Given the rarity of this condition, long-term natural history studies are limited. Here, we present a 9-year-old male with a homozygous nonsense mutation in NALCN (c.3910C>T, p.Arg1304X) leading to profound intellectual disability, seizures, feeding difficulties, and significant periodic breathing. Breathing irregularity was also reported in three previous patients; similar to our patient, those children demonstrated periodic breathing that was characterized by alternating apneic periods with deep, rapid breathing. As the phenotype associated with NALCN mutations continues to be delineated, attention should be given to abnormal respiratory patterns, which may be an important distinguishing feature of this condition.
Collapse
Affiliation(s)
- Danielle K Bourque
- Department of Genetics, Children's Hospital of Eastern Ontario, Ottawa, ON, Canada
| | - David A Dyment
- Department of Genetics, Children's Hospital of Eastern Ontario, Ottawa, ON, Canada.,Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON, Canada
| | - Ian MacLusky
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON, Canada.,Division of Respirology, Children's Hospital of Eastern Ontario, Ottawa, ON, Canada
| | - Kristin D Kernohan
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON, Canada
| | | | - Hugh J McMillan
- Children's Hospital of Eastern Ontario Research Institute, University of Ottawa, Ottawa, ON, Canada. .,Division of Neurology, Children's Hospital of Eastern Ontario, Ottawa, ON, Canada.
| |
Collapse
|
45
|
Bélteky J, Agnvall B, Bektic L, Höglund A, Jensen P, Guerrero-Bosagna C. Epigenetics and early domestication: differences in hypothalamic DNA methylation between red junglefowl divergently selected for high or low fear of humans. Genet Sel Evol 2018; 50:13. [PMID: 29609558 PMCID: PMC5880090 DOI: 10.1186/s12711-018-0384-z] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2017] [Accepted: 03/09/2018] [Indexed: 12/11/2022] Open
Abstract
Background Domestication of animals leads to large phenotypic alterations within a short evolutionary time-period. Such alterations are caused by genomic variations, yet the prevalence of modified traits is higher than expected if they were caused only by classical genetics and mutations. Epigenetic mechanisms may also be important in driving domesticated phenotypes such as behavior traits. Gene expression can be modulated epigenetically by mechanisms such as DNA methylation, resulting in modifications that are not only variable and susceptible to environmental stimuli, but also sometimes transgenerationally stable. To study such mechanisms in early domestication, we used as model two selected lines of red junglefowl (ancestors of modern chickens) that were bred for either high or low fear of humans over five generations, and investigated differences in hypothalamic DNA methylation between the two populations. Results Twenty-two 1-kb windows were differentially methylated between the two selected lines at p < 0.05 after false discovery rate correction. The annotated functions of the genes within these windows indicated epigenetic regulation of metabolic and signaling pathways, which agrees with the changes in gene expression that were previously reported for the same tissue and animals. Conclusions Our results show that selection for an important domestication-related behavioral trait such as tameness can cause divergent epigenetic patterns within only five generations, and that these changes could have an important role in chicken domestication. Electronic supplementary material The online version of this article (10.1186/s12711-018-0384-z) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
- Johan Bélteky
- AVIAN Behavioural Physiology and Genomics Group, IFM Biology, Linköping University, 581 83, Linköping, Sweden
| | - Beatrix Agnvall
- AVIAN Behavioural Physiology and Genomics Group, IFM Biology, Linköping University, 581 83, Linköping, Sweden
| | - Lejla Bektic
- AVIAN Behavioural Physiology and Genomics Group, IFM Biology, Linköping University, 581 83, Linköping, Sweden
| | - Andrey Höglund
- AVIAN Behavioural Physiology and Genomics Group, IFM Biology, Linköping University, 581 83, Linköping, Sweden
| | - Per Jensen
- AVIAN Behavioural Physiology and Genomics Group, IFM Biology, Linköping University, 581 83, Linköping, Sweden
| | - Carlos Guerrero-Bosagna
- AVIAN Behavioural Physiology and Genomics Group, IFM Biology, Linköping University, 581 83, Linköping, Sweden.
| |
Collapse
|
46
|
Campbell J, FitzPatrick DR, Azam T, Gibson NA, Somerville L, Joss SK, Urquhart DS. NALCN Dysfunction as a Cause of Disordered Respiratory Rhythm With Central Apnea. Pediatrics 2018; 141:S485-S490. [PMID: 29610177 DOI: 10.1542/peds.2017-0026] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/31/2017] [Indexed: 11/24/2022] Open
Abstract
The sodium leak channel nonselective protein (NALCN) is a regulator of the pacemaker neurons that are responsible for rhythmic behavior (including respiration), maintaining the resting membrane potential, and are required for action potential production. NALCN-null mice show early death associated with disrupted respiratory rhythms, characterized by frequent and profound apneas. We report 3 children (2 siblings) with compound heterozygous mutations in NALCN associated with developmental impairment, hypotonia, and central sleep-disordered breathing causing apneas. Supplemental oxygen normalized the respiratory rhythm. NALCN mutations have been previously reported to cause severe hypotonia, speech impairment, and cognitive delay as well as infantile neuroaxonal dystrophy and facial dysmorphism. Nonsynonymous changes in the 2 affected extracellular loops may be responsible for the deleterious effect on the stability of the respiratory rhythm. Although oxygen is known to be a stabilizer of respiratory rhythm in central apnea in children, its role in NALCN dysfunction requires further investigation.
Collapse
Affiliation(s)
- Jamie Campbell
- Department of Clinical Genetics, Centre for Genomic and Experimental Medicine and
| | - David R FitzPatrick
- Medical Research Council Human Genetics Unit, Institute of Genetics and Molecular Medicine, University of Edinburgh, Edinburgh, United Kingdom
| | - Tara Azam
- South-East Scotland Regional Genetics Laboratories, Western General Hospital, Edinburgh, United Kingdom
| | - Neil A Gibson
- Department of Respiratory and Sleep Medicine, Royal Hospital for Children, Glasgow, United Kingdom
| | - Laura Somerville
- Specialist Children's Services, The West Centre, Glasgow, United Kingdom
| | - Shelagh K Joss
- West of Scotland Clinical Genetics Service, Queen Elizabeth University Hospital, Govan, United Kingdom
| | | | - Don S Urquhart
- Department of Pediatric Respiratory and Sleep Medicine, Royal Hospital for Sick Children, Edinburgh, United Kingdom
| |
Collapse
|
47
|
Angius A, Cossu S, Uva P, Oppo M, Onano S, Persico I, Fotia G, Atzeni R, Cuccuru G, Asunis M, Cucca F, Pruna D, Crisponi L. Novel NALCN biallelic truncating mutations in siblings with IHPRF1 syndrome. Clin Genet 2018; 93:1245-1247. [PMID: 29399786 DOI: 10.1111/cge.13162] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2017] [Revised: 10/18/2017] [Accepted: 10/22/2017] [Indexed: 11/27/2022]
Abstract
Infantile hypotonia with psychomotor retardation and characteristic facies-1 (IHPRF1) is a severe autosomal recessive neurologic disorder with onset at birth or in early infancy. It is caused by mutations in the NALCN gene that encodes a voltage-independent, cation channel permeable to NM, K+ and Ca2+ and forms a channel complex with UNCSO and UNC79. So far, only 4 homozygous mutations have been found in 11 cases belonging to 4 independent consanguineous families. We studied a Sardinian family with 2 siblings presenting dysmorphic facies, hypotonia, psychomotor retardation, epilepsy, absent speech, sleep disturbance, hyperkinetic movement disorder, cachexia and chronic constipation. Polymorphic generalized seizures started at 4 and 6 years, respectively. Anti-epileptic drugs (AEDs) therapy was efficient for female proband's epilepsy, but the male still has weekly seizures. Whole exome sequencing identified 2 novel truncating mutations in NALCN allowing to assess the clinical phenotype to IHPRF1. This is the fifth family reported worldwide, and these are the first European cases with IHPRF1 syndrome with biallelic truncating mutations of NALCN.
Collapse
Affiliation(s)
- A Angius
- Institute of Genetic and Biomedical Research, National Research Council (CNR), Cagliari, Italy
| | - S Cossu
- Department of Neuroscience and Neuro-Rehabilitation, UOC of Neurosurgery, Pediatric Hospital Bambino Gesù, Rome, Italy
| | - P Uva
- Centre for Advanced Studies, Research and Development in Sardinia (CRS4), Science and Technology Park Polaris, Pula, Italy
| | - M Oppo
- Institute of Genetic and Biomedical Research, National Research Council (CNR), Cagliari, Italy.,Department of Biomedical Science, University of Sassari, Sassari, Italy
| | - S Onano
- Institute of Genetic and Biomedical Research, National Research Council (CNR), Cagliari, Italy.,Department of Biomedical Science, University of Sassari, Sassari, Italy
| | - I Persico
- Institute of Genetic and Biomedical Research, National Research Council (CNR), Cagliari, Italy
| | - G Fotia
- Centre for Advanced Studies, Research and Development in Sardinia (CRS4), Science and Technology Park Polaris, Pula, Italy
| | - R Atzeni
- Centre for Advanced Studies, Research and Development in Sardinia (CRS4), Science and Technology Park Polaris, Pula, Italy
| | - G Cuccuru
- Centre for Advanced Studies, Research and Development in Sardinia (CRS4), Science and Technology Park Polaris, Pula, Italy
| | - M Asunis
- Azienda Ospedaliera Brotzu, SSD of Neurology and Pediatric Epilettology, Cagliari, Italy
| | - F Cucca
- Institute of Genetic and Biomedical Research, National Research Council (CNR), Cagliari, Italy.,Department of Biomedical Science, University of Sassari, Sassari, Italy
| | - D Pruna
- Azienda Ospedaliera Brotzu, SSD of Neurology and Pediatric Epilettology, Cagliari, Italy
| | - L Crisponi
- Institute of Genetic and Biomedical Research, National Research Council (CNR), Cagliari, Italy.,Department of Biomedical Science, University of Sassari, Sassari, Italy
| |
Collapse
|
48
|
Takenouchi T, Inaba M, Uehara T, Takahashi T, Kosaki K, Mizuno S. Biallelic mutations in NALCN: Expanding the genotypic and phenotypic spectra of IHPRF1. Am J Med Genet A 2017; 176:431-437. [PMID: 29168298 DOI: 10.1002/ajmg.a.38543] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2017] [Revised: 09/09/2017] [Accepted: 10/20/2017] [Indexed: 01/05/2023]
Abstract
Loss-of function mutations in NALCN on chromosome 13q, a sodium leak channel that maintains baseline neuronal excitability, cause infantile hypotonia with psychomotor retardation and characteristic faces 1 (IHPRF1, OMIM #615419). Here, we document two individuals with early onset hypotonia with poor feeding and intellectual disability who were compatible with a diagnosis of IHPRF1. The two patients had bi-allelic mutations in NALCN through two different genetic mechanisms: Patient 1 had bi-allelic splice site mutations, that is c.1267-2A>G, derived from heterozygous parents, while Patient 2 had a partial maternal uniparental isodisomy that harbored a frameshift mutation, that is c.2022_2023delAT, in chromosome 13 that was detected through a dedicated algorithm for homozygosity data mapping in whole exome sequencing. The delineation of the exact pattern of inheritance provided vital information regarding the risk of recurrence. In animal models with Nalcn mutations, two behavioral phenotypes, that are, postnatal dyspnea and sleep disturbance, have been reported. Our observations of the two patients with postnatal dyspnea and one patient with sleep disturbance support an association between these two behavioral phenotypes and NALCN mutations in humans. The routine use of a detection algorithm for homozygosity data mapping might improve the diagnostic yields of next-generation sequencing.
Collapse
Affiliation(s)
- Toshiki Takenouchi
- Center for Medical Genetics, Keio University School of Medicine, Tokyo, Japan.,Department of Pediatrics, Keio University School of Medicine, Tokyo, Japan
| | - Mie Inaba
- Department of Pediatrics, Aichi Human Service Center, Central Hospital, Aichi, Japan
| | - Tomoko Uehara
- Center for Medical Genetics, Keio University School of Medicine, Tokyo, Japan
| | - Takao Takahashi
- Department of Pediatrics, Keio University School of Medicine, Tokyo, Japan
| | - Kenjiro Kosaki
- Center for Medical Genetics, Keio University School of Medicine, Tokyo, Japan
| | - Seiji Mizuno
- Department of Pediatrics, Aichi Human Service Center, Central Hospital, Aichi, Japan
| |
Collapse
|
49
|
Symonds JD, Zuberi SM. Genetics update: Monogenetics, polygene disorders and the quest for modifying genes. Neuropharmacology 2017; 132:3-19. [PMID: 29037745 DOI: 10.1016/j.neuropharm.2017.10.013] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 10/09/2017] [Accepted: 10/11/2017] [Indexed: 12/19/2022]
Abstract
The genetic channelopathies are a broad collection of diseases. Many ion channel genes demonstrate wide phenotypic pleiotropy, but nonetheless concerted efforts have been made to characterise genotype-phenotype relationships. In this review we give an overview of the factors that influence genotype-phenotype relationships across this group of diseases as a whole, using specific individual channelopathies as examples. We suggest reasons for the limitations observed in these relationships. We discuss the role of ion channel variation in polygenic disease and highlight research that has contributed to unravelling the complex aetiological nature of these conditions. We focus specifically on the quest for modifying genes in inherited channelopathies, using the voltage-gated sodium channels as an example. Epilepsy related to genetic channelopathy is one area in which precision medicine is showing promise. We will discuss the successes and limitations of precision medicine in these conditions. This article is part of the Special Issue entitled 'Channelopathies.'
Collapse
Affiliation(s)
- Joseph D Symonds
- The Paediatric Neurosciences Research Group, Royal Hospital for Children, Queen Elizabeth University Hospitals, Glasgow, UK; School of Medicine, University of Glasgow, Glasgow, UK
| | - Sameer M Zuberi
- The Paediatric Neurosciences Research Group, Royal Hospital for Children, Queen Elizabeth University Hospitals, Glasgow, UK; School of Medicine, University of Glasgow, Glasgow, UK.
| |
Collapse
|
50
|
Topalidou I, Cooper K, Pereira L, Ailion M. Dopamine negatively modulates the NCA ion channels in C. elegans. PLoS Genet 2017; 13:e1007032. [PMID: 28968387 PMCID: PMC5638609 DOI: 10.1371/journal.pgen.1007032] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/29/2016] [Revised: 10/12/2017] [Accepted: 09/18/2017] [Indexed: 02/07/2023] Open
Abstract
The NALCN/NCA ion channel is a cation channel related to voltage-gated sodium and calcium channels. NALCN has been reported to be a sodium leak channel with a conserved role in establishing neuronal resting membrane potential, but its precise cellular role and regulation are unclear. The Caenorhabditis elegans orthologs of NALCN, NCA-1 and NCA-2, act in premotor interneurons to regulate motor circuit activity that sustains locomotion. Recently we found that NCA-1 and NCA-2 are activated by a signal transduction pathway acting downstream of the heterotrimeric G protein Gq and the small GTPase Rho. Through a forward genetic screen, here we identify the GPCR kinase GRK-2 as a new player affecting signaling through the Gq-Rho-NCA pathway. Using structure-function analysis, we find that the GPCR phosphorylation and membrane association domains of GRK-2 are required for its function. Genetic epistasis experiments suggest that GRK-2 acts on the D2-like dopamine receptor DOP-3 to inhibit Go signaling and positively modulate NCA-1 and NCA-2 activity. Through cell-specific rescuing experiments, we find that GRK-2 and DOP-3 act in premotor interneurons to modulate NCA channel function. Finally, we demonstrate that dopamine, through DOP-3, negatively regulates NCA activity. Thus, this study identifies a pathway by which dopamine modulates the activity of the NCA channels.
Collapse
Affiliation(s)
- Irini Topalidou
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
- * E-mail: (IT); (MA)
| | - Kirsten Cooper
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
| | - Laura Pereira
- Department of Biological Sciences, Howard Hughes Medical Institute, Columbia University, New York, New York, United States of America
| | - Michael Ailion
- Department of Biochemistry, University of Washington, Seattle, Washington, United States of America
- * E-mail: (IT); (MA)
| |
Collapse
|