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Letko A, Minor KM, Friedenberg SG, Shelton GD, Salvador JP, Mandigers PJJ, Leegwater PAJ, Winkler PA, Petersen-Jones SM, Stanley BJ, Ekenstedt KJ, Johnson GS, Hansen L, Jagannathan V, Mickelson JR, Drögemüller C. A CNTNAP1 Missense Variant Is Associated with Canine Laryngeal Paralysis and Polyneuropathy. Genes (Basel) 2020; 11:E1426. [PMID: 33261176 PMCID: PMC7761076 DOI: 10.3390/genes11121426] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 11/25/2020] [Accepted: 11/26/2020] [Indexed: 02/06/2023] Open
Abstract
Laryngeal paralysis associated with a generalized polyneuropathy (LPPN) most commonly exists in geriatric dogs from a variety of large and giant breeds. The purpose of this study was to discover the underlying genetic and molecular mechanisms in a younger-onset form of this neurodegenerative disease seen in two closely related giant dog breeds, the Leonberger and Saint Bernard. Neuropathology of an affected dog from each breed showed variable nerve fiber loss and scattered inappropriately thin myelinated fibers. Using across-breed genome-wide association, haplotype analysis, and whole-genome sequencing, we identified a missense variant in the CNTNAP1 gene (c.2810G>A; p.Gly937Glu) in which homozygotes in both studied breeds are affected. CNTNAP1 encodes a contactin-associated protein important for organization of myelinated axons. The herein described likely pathogenic CNTNAP1 variant occurs in unrelated breeds at variable frequencies. Individual homozygous mutant LPPN-affected Labrador retrievers that were on average four years younger than dogs affected by geriatric onset laryngeal paralysis polyneuropathy could be explained by this variant. Pathologic changes in a Labrador retriever nerve biopsy from a homozygous mutant dog were similar to those of the Leonberger and Saint Bernard. The impact of this variant on health in English bulldogs and Irish terriers, two breeds with higher CNTNAP1 variant allele frequencies, remains unclear. Pathogenic variants in CNTNAP1 have previously been reported in human patients with lethal congenital contracture syndrome and hypomyelinating neuropathy, including vocal cord palsy and severe respiratory distress. This is the first report of contactin-associated LPPN in dogs characterized by a deleterious variant that most likely predates modern breed establishment.
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Affiliation(s)
- Anna Letko
- Institute of Genetics, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland; (V.J.); (C.D.)
| | - Katie M. Minor
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN 55108, USA; (K.M.M.); (J.R.M.)
| | - Steven G. Friedenberg
- Department of Veterinary Clinical Sciences, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN 55108, USA;
| | - G. Diane Shelton
- Department of Pathology, School of Medicine, University of California San Diego, La Jolla, CA 92093-0709, USA; (G.D.S.); (J.P.S.)
| | - Jill Pesayco Salvador
- Department of Pathology, School of Medicine, University of California San Diego, La Jolla, CA 92093-0709, USA; (G.D.S.); (J.P.S.)
| | - Paul J. J. Mandigers
- Department of Clinical Sciences, Utrecht University, 3584 CM Utrecht, The Netherlands; (P.J.J.M.); (P.A.J.L.)
| | - Peter A. J. Leegwater
- Department of Clinical Sciences, Utrecht University, 3584 CM Utrecht, The Netherlands; (P.J.J.M.); (P.A.J.L.)
| | - Paige A. Winkler
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA; (P.A.W.); (S.M.P.-J.); (B.J.S.)
| | - Simon M. Petersen-Jones
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA; (P.A.W.); (S.M.P.-J.); (B.J.S.)
| | - Bryden J. Stanley
- Department of Small Animal Clinical Sciences, College of Veterinary Medicine, Michigan State University, East Lansing, MI 48824, USA; (P.A.W.); (S.M.P.-J.); (B.J.S.)
| | - Kari J. Ekenstedt
- Department of Basic Medical Sciences, College of Veterinary Medicine, Purdue University, West Lafayette, IN 47907, USA;
| | - Gary S. Johnson
- Department of Veterinary Pathobiology, University of Missouri, Columbia, MO 65211, USA; (G.S.J.); (L.H.)
| | - Liz Hansen
- Department of Veterinary Pathobiology, University of Missouri, Columbia, MO 65211, USA; (G.S.J.); (L.H.)
| | - Vidhya Jagannathan
- Institute of Genetics, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland; (V.J.); (C.D.)
| | - James R. Mickelson
- Department of Veterinary and Biomedical Sciences, College of Veterinary Medicine, University of Minnesota, Saint Paul, MN 55108, USA; (K.M.M.); (J.R.M.)
| | - Cord Drögemüller
- Institute of Genetics, Vetsuisse Faculty, University of Bern, 3012 Bern, Switzerland; (V.J.); (C.D.)
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Abstract
The nodes of Ranvier have clustered Na+ and K+ channels necessary for rapid and efficient axonal action potential conduction. However, detailed mechanisms of channel clustering have only recently been identified: they include two independent axon-glia interactions that converge on distinct axonal cytoskeletons. Here, we discuss how glial cell adhesion molecules and the extracellular matrix molecules that bind them assemble combinations of ankyrins, spectrins and other cytoskeletal scaffolding proteins, which cluster ion channels. We present a detailed molecular model, incorporating these overlapping mechanisms, to explain how the nodes of Ranvier are assembled in both the peripheral and central nervous systems.
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Li W, Yang L, Tang C, Liu K, Lu Y, Wang H, Yan K, Qiu Z, Zhou W. Mutations of CNTNAP1 led to defects in neuronal development. JCI Insight 2020; 5:135697. [PMID: 33148880 PMCID: PMC7710280 DOI: 10.1172/jci.insight.135697] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2019] [Accepted: 09/30/2020] [Indexed: 12/20/2022] Open
Abstract
Mutations of CNTNAP1 were associated with myelination disorders, suggesting the role of CNTNAP1 in myelination processes. Whether CNTNAP1 may have a role in early cortical neuronal development is largely unknown. In this study, we identified 4 compound heterozygous mutations of CNTNAP1 in 2 Chinese families. Using mouse models, we found that CNTNAP1 is highly expressed in neurons and is located predominantly in MAP2+ neurons during the early developmental stage. Importantly, Cntnap1 deficiency results in aberrant dendritic growth and spine development in vitro and in vivo, and it delayed migration of cortical neurons during early development. Finally, we found that the number of parvalbumin+ neurons in the cortex and hippocampus of Cntnap1–/– mice is strikingly increased by P15, suggesting that excitation/inhibition balance is impaired. Together, this evidence elucidates a critical function of CNTNAP1 in cortical development, providing insights underlying molecular and circuit mechanisms of CNTNAP1-related disease. Deficiency of CNTNAP1 causes severe cortical developmental deficits, leading to human lethal perinatal symptoms.
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Affiliation(s)
| | - Lin Yang
- Key Laboratory of Birth Defects.,Division of Endocrinology, Genetics and Metabolic Disease, and
| | - Chuanqing Tang
- Stem Cell Research Center, Institute of Pediatrics, Children's Hospital, Fudan University, Shanghai, China
| | | | | | | | | | - Zilong Qiu
- Institute of Neuroscience, State Key Laboratory of Neuroscience.,CAS Center for Excellence in Brain Science and Intelligence Technology.,Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology.,Chinese Academy of Sciences, and.,National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai, China
| | - Wenhao Zhou
- Division of Neonatology.,Key Laboratory of Birth Defects.,Key Laboratory of Neonatal Diseases, Ministry of Health, Children's Hospital of Fudan University, Shanghai, China
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Molecular organization and function of vertebrate septate-like junctions. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183211. [PMID: 32032590 DOI: 10.1016/j.bbamem.2020.183211] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 01/22/2020] [Accepted: 01/26/2020] [Indexed: 12/21/2022]
Abstract
Septate-like junctions display characteristic ladder-like ultrastructure reminiscent of the invertebrate epithelial septate junctions and are present at the paranodes of myelinated axons. The paranodal junctions where the myelin loops attach to the axon at the borders of the node of Ranvier provide both a paracellular barrier to ion diffusion and a lateral fence along the axonal membrane. The septate-like junctions constrain the proper distribution of nodal Na+ channels and juxtaparanodal K+ channels, which are required for the safe propagation of the nerve influx and rapid saltatory conduction. The paranodal cell adhesion molecules have been identified as target antigens in peripheral demyelinating autoimmune diseases and the pathogenic mechanisms described. This review aims at presenting the recent knowledge on the molecular and structural organization of septate-like junctions, their formation and stabilization during development, and how they are involved in demyelinating diseases.
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