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Fritzsch B. Evolution and development of extraocular motor neurons, nerves and muscles in vertebrates. Ann Anat 2024; 253:152225. [PMID: 38346566 DOI: 10.1016/j.aanat.2024.152225] [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: 11/02/2023] [Revised: 01/16/2024] [Accepted: 02/05/2024] [Indexed: 02/17/2024]
Abstract
The purpose of this review is to analyze the origin of ocular motor neurons, define the pattern of innervation of nerve fibers that project to the extraocular eye muscles (EOMs), describe congenital disorders that alter the development of ocular motor neurons, and provide an overview of vestibular pathway inputs to ocular motor nuclei. Six eye muscles are innervated by axons of three ocular motor neurons, the oculomotor (CNIII), trochlear (CNIV), and abducens (CNVI) neurons. Ocular motor neurons (CNIII) originate in the midbrain and innervate the ipsilateral orbit, except for the superior rectus and the levator palpebrae, which are contralaterally innervated. Trochlear motor neurons (CNIV) originate at the midbrain-hindbrain junction and innervate the contralateral superior oblique muscle. Abducens motor neurons (CNVI) originate variously in the hindbrain of rhombomeres r4-6 that innervate the posterior (or lateral) rectus muscle and innervate the retractor bulbi. Genes allow a distinction between special somatic (CNIII, IV) and somatic (CNVI) ocular motor neurons. Development of ocular motor neurons and their axonal projections to the EOMs may be derailed by various genetic causes, resulting in the congenital cranial dysinnervation disorders. The ocular motor neurons innervate EOMs while the vestibular nuclei connect with the midbrain-brainstem motor neurons.
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Affiliation(s)
- Bernd Fritzsch
- Department of Neurological Sciences, University of Nebraska Medical Center, NE, USA.
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Lin Q, Wang X, Zhan X, Peng X, Wang Y, Zhou X. Genetic investigation in a four-generation Chinese family with congenital fibrosis of extraocular muscles and keratoconus. Heliyon 2024; 10:e28036. [PMID: 38524541 PMCID: PMC10958419 DOI: 10.1016/j.heliyon.2024.e28036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2023] [Revised: 02/29/2024] [Accepted: 03/11/2024] [Indexed: 03/26/2024] Open
Abstract
Here, we have reported the genetic and clinical characteristics of four generations of a family patient from China with congenital fibrosis of extraocular muscles 1 (CFEOM1) and keratoconus (KC). The history of diseases, clinical observations, and blood samples of all family members were collected. A total of 100 healthy participants were recruited as normal controls. The whole exome sequencing of the genomic DNA and polymerase chain reaction were performed on samples obtained from the controls and their family members to verify the gene variants. The functional analyses of the variants were performed by using different software. Two single nucleotide polymorphisms were detected in the proband and other patients in his families, including a heterozygous missense variation, g.39726207C > T (c.2860C > T, p.R954W, rs121912585), in the third highly conserved coiled-coil domain of KIF21A, and a heterozygous missense variant, g.30664732A > C (c.136A > C, p.S46R, rs200111443) in TGFBR2. The variant p.R954W in KIF21A was predicted to be pathogenic using software, whereas p.S46R in TGFBR2 was predicted to be of uncertain significance (VUS). Thus, KC might have occurred in the proband and his daughter because of a combination of genetic mutations and involuntary eye rubbing induced by CFEOM1. This is the first case of concomitant KC in a family having CFEOM1. Thus, the study provides new information about patients with KC having CFEOM1. Furthermore, the study suggests that attention should be paid to the early detection and diagnosis of KC in patients with CFEOM1.
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Affiliation(s)
- Qinghong Lin
- Department of Ophthalmology, Eye and ENT Hospital of Fudan University, Shanghai, 200000, China
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, 200031, China
- NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, 200031, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, 200000, China
- Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care (20DZ2255000), Shanghai, 200000, China
- Refractive Surgery Department, Bright Eye Hospital, Fuzhou, 350000, China
| | - Xuejun Wang
- Department of Ophthalmology, Eye and ENT Hospital of Fudan University, Shanghai, 200000, China
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, 200031, China
- NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, 200031, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, 200000, China
- Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care (20DZ2255000), Shanghai, 200000, China
| | - Xin Zhan
- Refractive Surgery Department, Bright Eye Hospital, Fuzhou, 350000, China
| | - Xiaoliao Peng
- Department of Ophthalmology, Eye and ENT Hospital of Fudan University, Shanghai, 200000, China
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, 200031, China
- NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, 200031, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, 200000, China
- Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care (20DZ2255000), Shanghai, 200000, China
| | - Yan Wang
- Refractive Surgery Department, Bright Eye Hospital, Fuzhou, 350000, China
| | - Xingtao Zhou
- Department of Ophthalmology, Eye and ENT Hospital of Fudan University, Shanghai, 200000, China
- Eye Institute and Department of Ophthalmology, Eye & ENT Hospital, Fudan University, Shanghai, 200031, China
- NHC Key Laboratory of Myopia (Fudan University), Key Laboratory of Myopia, Chinese Academy of Medical Sciences, Shanghai, 200031, China
- Shanghai Research Center of Ophthalmology and Optometry, Shanghai, 200000, China
- Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care (20DZ2255000), Shanghai, 200000, China
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Manso-Bazús C, Spataro N, Gabau E, Beltrán-Salazar VP, Trujillo-Quintero JP, Capdevila N, Brunet-Vega A, Baena N, Jeyaprakash AA, Martinez-Glez V, Ruiz A. Case report: Identification of a novel variant p.Gly215Arg in the CHN1 gene causing Moebius syndrome. Front Genet 2024; 15:1291063. [PMID: 38356699 PMCID: PMC10865368 DOI: 10.3389/fgene.2024.1291063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 01/15/2024] [Indexed: 02/16/2024] Open
Abstract
Background: Moebius Syndrome (MBS) is a rare congenital neurological disorder characterized by paralysis of facial nerves, impairment of ocular abduction and other variable abnormalities. MBS has been attributed to both environmental and genetic factors as potential causes. Until now only two genes, PLXND1 and REV3L have been identified to cause MBS. Results: We present a 9-year-old male clinically diagnosed with MBS, presenting facial palsy, altered ocular mobility, microglossia, dental anomalies and congenital torticollis. Radiologically, he lacks both abducens nerves and shows altered symmetry of both facial and vestibulocochlear nerves. Whole-exome sequence identified a de novo missense variant c.643G>A; p.Gly215Arg in CHN1, encoding the α2-chimaerin protein. The p.Gly215Arg variant is located in the C1 domain of CHN1 where other pathogenic gain of function variants have been reported. Bioinformatic analysis and molecular structural modelling predict a deleterious effect of the missense variant on the protein function. Conclusion: Our findings support that pathogenic variants in the CHN1 gene may be responsible for different cranial congenital dysinnervation syndromes, including Moebius and Duane retraction syndromes. We propose to include CHN1 in the genetic diagnoses of MBS.
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Affiliation(s)
- Carmen Manso-Bazús
- Center for Genomic Medicine, Parc Taulí Hospital Universitari, Institut d’Investigació i Innovació Parc Taulí (I3PT-CERCA), Universitat Autònoma de Barcelona, Sabadell, Spain
| | - Nino Spataro
- Center for Genomic Medicine, Parc Taulí Hospital Universitari, Institut d’Investigació i Innovació Parc Taulí (I3PT-CERCA), Universitat Autònoma de Barcelona, Sabadell, Spain
| | - Elisabeth Gabau
- Paediatric Service, Parc Taulí Hospital Universitari, Institut d’Investigació i Innovació Parc Taulí (I3PT-CERCA), Universitat Autònoma de Barcelona, Sabadell, Spain
| | - Viviana P. Beltrán-Salazar
- Radiology Service, Parc Taulí Hospital Universitari, Institut d’investigación i innovació Parc Taulí (I3PT-CERCA), Universitat Autónoma de Barcelona, Sabadell, Spain
| | - Juan Pablo Trujillo-Quintero
- Center for Genomic Medicine, Parc Taulí Hospital Universitari, Institut d’Investigació i Innovació Parc Taulí (I3PT-CERCA), Universitat Autònoma de Barcelona, Sabadell, Spain
| | - Nuria Capdevila
- Center for Genomic Medicine, Parc Taulí Hospital Universitari, Institut d’Investigació i Innovació Parc Taulí (I3PT-CERCA), Universitat Autònoma de Barcelona, Sabadell, Spain
| | - Anna Brunet-Vega
- Center for Genomic Medicine, Parc Taulí Hospital Universitari, Institut d’Investigació i Innovació Parc Taulí (I3PT-CERCA), Universitat Autònoma de Barcelona, Sabadell, Spain
| | - Neus Baena
- Center for Genomic Medicine, Parc Taulí Hospital Universitari, Institut d’Investigació i Innovació Parc Taulí (I3PT-CERCA), Universitat Autònoma de Barcelona, Sabadell, Spain
| | - A Arockia Jeyaprakash
- Wellcome Centre for Cell Biology, University of Edinburgh, Edinburgh, United Kingdom
- The Gene Centre and Department of Biochemistry, Ludwig Maximilian Universität, München, Germany
| | - Victor Martinez-Glez
- Center for Genomic Medicine, Parc Taulí Hospital Universitari, Institut d’Investigació i Innovació Parc Taulí (I3PT-CERCA), Universitat Autònoma de Barcelona, Sabadell, Spain
| | - Anna Ruiz
- Center for Genomic Medicine, Parc Taulí Hospital Universitari, Institut d’Investigació i Innovació Parc Taulí (I3PT-CERCA), Universitat Autònoma de Barcelona, Sabadell, Spain
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Atkins M, Nicol X, Fassier C. Microtubule remodelling as a driving force of axon guidance and pruning. Semin Cell Dev Biol 2023; 140:35-53. [PMID: 35710759 DOI: 10.1016/j.semcdb.2022.05.030] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Revised: 04/26/2022] [Accepted: 05/31/2022] [Indexed: 01/28/2023]
Abstract
The establishment of neuronal connectivity relies on the microtubule (MT) cytoskeleton, which provides mechanical support, roads for axonal transport and mediates signalling events. Fine-tuned spatiotemporal regulation of MT functions by tubulin post-translational modifications and MT-associated proteins is critical for the coarse wiring and subsequent refinement of neuronal connectivity. The defective regulation of these processes causes a wide range of neurodevelopmental disorders associated with connectivity defects. This review focuses on recent studies unravelling how MT composition, post-translational modifications and associated proteins influence MT functions in axon guidance and/or pruning to build functional neuronal circuits. We here summarise experimental evidence supporting the key role of this network as a driving force for growth cone steering and branch-specific axon elimination. We further provide a global overview of the MT-interactors that tune developing axon behaviours, with a special emphasis on their emerging versatility in the regulation of MT dynamics/structure. Recent studies establishing the key and highly selective role of the tubulin code in the regulation of MT functions in axon pathfinding are also reported. Finally, our review highlights the emerging molecular links between these MT regulation processes and guidance signals that wire the nervous system.
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Affiliation(s)
- Melody Atkins
- INSERM, UMR-S 1270, Institut du Fer à Moulin, Sorbonne Université, F-75005 Paris, France
| | - Xavier Nicol
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, F-75012 Paris, France
| | - Coralie Fassier
- Institut de la Vision, Sorbonne Université, INSERM, CNRS, F-75012 Paris, France.
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5
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Jia H, Ma Q, Liang Y, Wang D, Chang Q, Zhao B, Zhang Z, Liang J, Song J, Wang Y, Zhang R, Tu Z, Jiao Y. Clinical and genetic characteristics of Chinese patients with congenital cranial dysinnervation disorders. Orphanet J Rare Dis 2022; 17:431. [PMID: 36494820 PMCID: PMC9733177 DOI: 10.1186/s13023-022-02582-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2022] [Accepted: 11/20/2022] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Congenital cranial dysinnervation disorders (CCDDs) are a group of diseases with high clinical and genetic heterogeneity. Clinical examinations combined with Magnetic resonance imaging (MRI) and whole exome sequencing (WES) were performed to reveal the phenotypic and genotypic characteristics in a cohort of Chinese CCDDs patients. RESULTS A total of 122 CCDDs patients from 96 families were enrolled. All patients showed restrictive eye movements, and 46 patients from 46 families (47.9%, 46/96) were accompanied by multiple congenital malformations. Multi-positional high-resolution MRI was performed in 94 patients from 88 families, of which, all patients had hypoplasia of the cranial nerves except HGPPS patients and 15 patients from 15 families (17.0%,15/88) were accompanied by other craniocerebral malformations. WES was performed in 122 CCDDs patients. Ten pathogenic variants were detected in KIF21A, TUBB3, and CHN1 genes in 43 families. Three variants were unreported, including KIF21A (c.1064T > C, p.F355S), TUBB3 (c.232T > A, p.S78T) and CHN1 (c.650A > G, p.H217R). Of the 43 probands harboring pathogenic variants, 42 were diagnosed with Congenital Fibrosis of Extraocular Muscles (CFEOM) and one was Duane Retraction Syndrome (DRS). No definite pathogenic variants in known candidate genes of CCDDs were found in sporadic DRS, Möbius Syndrome (MBS) and Horizontal Gaze Palsy with Progressive Scoliosis (HGPPS) patients. The CFEOM patients harboring R380C, E410K and R262H variants in TUBB3 gene and F355S variant in KIF21A gene exhibited syndromic phenotypes. CONCLUSIONS This study broadened the phenotypic and genotypic spectrums of CCDDs, and it was the largest clinical and genetic investigation for CCDDs patients from China. KIF21A and TUBB3 were the common pathogenic genes in Chinese CFEOM. MRI coupled with WES can provide a supportive diagnosis in patients with clinically suspected CCDDs.
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Affiliation(s)
- Hongyan Jia
- grid.24696.3f0000 0004 0369 153XBeijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730 China ,grid.414373.60000 0004 1758 1243Beijing Ophthalmology and Visual Science Key Lab, Beijing, 100730 China
| | - Qian Ma
- grid.24696.3f0000 0004 0369 153XBeijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730 China ,grid.414373.60000 0004 1758 1243Beijing Ophthalmology and Visual Science Key Lab, Beijing, 100730 China
| | - Yi Liang
- grid.24696.3f0000 0004 0369 153XBeijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730 China ,grid.414373.60000 0004 1758 1243Beijing Ophthalmology and Visual Science Key Lab, Beijing, 100730 China
| | - Dan Wang
- grid.24696.3f0000 0004 0369 153XBeijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730 China ,grid.414373.60000 0004 1758 1243Beijing Ophthalmology and Visual Science Key Lab, Beijing, 100730 China
| | - Qinglin Chang
- grid.24696.3f0000 0004 0369 153XDepartment of Radiology, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730 China
| | - Bo Zhao
- grid.24696.3f0000 0004 0369 153XDepartment of Radiology, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730 China
| | - Zongrui Zhang
- grid.24696.3f0000 0004 0369 153XDepartment of Radiology, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730 China
| | - Jing Liang
- grid.24696.3f0000 0004 0369 153XBeijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730 China ,grid.414373.60000 0004 1758 1243Beijing Ophthalmology and Visual Science Key Lab, Beijing, 100730 China
| | - Jing Song
- grid.24696.3f0000 0004 0369 153XBeijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730 China ,grid.414373.60000 0004 1758 1243Beijing Ophthalmology and Visual Science Key Lab, Beijing, 100730 China
| | - Yidi Wang
- grid.24696.3f0000 0004 0369 153XBeijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730 China ,grid.414373.60000 0004 1758 1243Beijing Ophthalmology and Visual Science Key Lab, Beijing, 100730 China
| | - Ranran Zhang
- grid.24696.3f0000 0004 0369 153XBeijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730 China ,grid.414373.60000 0004 1758 1243Beijing Ophthalmology and Visual Science Key Lab, Beijing, 100730 China
| | - Zhanhan Tu
- grid.9918.90000 0004 1936 8411Department of Neuroscience, Psychology and Behaviour, Ulverscroft Eye Unit, University of Leicester, Robert Kilpatrick Clinical Sciences Building, Leicester Royal Infirmary, Leicester, LE2 7LX UK
| | - Yonghong Jiao
- grid.24696.3f0000 0004 0369 153XBeijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing, 100730 China ,grid.414373.60000 0004 1758 1243Beijing Ophthalmology and Visual Science Key Lab, Beijing, 100730 China
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Sánchez-Huertas C, Herrera E. With the Permission of Microtubules: An Updated Overview on Microtubule Function During Axon Pathfinding. Front Mol Neurosci 2021; 14:759404. [PMID: 34924953 PMCID: PMC8675249 DOI: 10.3389/fnmol.2021.759404] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Accepted: 11/01/2021] [Indexed: 01/27/2023] Open
Abstract
During the establishment of neural circuitry axons often need to cover long distances to reach remote targets. The stereotyped navigation of these axons defines the connectivity between brain regions and cellular subtypes. This chemotrophic guidance process mostly relies on the spatio-temporal expression patterns of extracellular proteins and the selective expression of their receptors in projection neurons. Axon guidance is stimulated by guidance proteins and implemented by neuronal traction forces at the growth cones, which engage local cytoskeleton regulators and cell adhesion proteins. Different layers of guidance signaling regulation, such as the cleavage and processing of receptors, the expression of co-receptors and a wide variety of intracellular cascades downstream of receptors activation, have been progressively unveiled. Also, in the last decades, the regulation of microtubule (MT) assembly, stability and interactions with the submembranous actin network in the growth cone have emerged as crucial effector mechanisms in axon pathfinding. In this review, we will delve into the intracellular signaling cascades downstream of guidance receptors that converge on the MT cytoskeleton of the growing axon. In particular, we will focus on the microtubule-associated proteins (MAPs) network responsible of MT dynamics in the axon and growth cone. Complementarily, we will discuss new evidences that connect defects in MT scaffold proteins, MAPs or MT-based motors and axon misrouting during brain development.
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Affiliation(s)
- Carlos Sánchez-Huertas
- Instituto de Neurociencias, Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández (CSIC-UMH), Alicante, Spain
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Chiodi V, Domenici MR, Biagini T, De Simone R, Tartaglione AM, Di Rosa M, Lo Re O, Mazza T, Micale V, Vinciguerra M. Systemic depletion of histone macroH2A1.1 boosts hippocampal synaptic plasticity and social behavior in mice. FASEB J 2021; 35:e21793. [PMID: 34320234 DOI: 10.1096/fj.202100569r] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2021] [Revised: 06/12/2021] [Accepted: 06/28/2021] [Indexed: 12/30/2022]
Abstract
Gene expression and epigenetic processes in several brain regions regulate physiological processes such as cognitive functions and social behavior. MacroH2A1.1 is a ubiquitous variant of histone H2A that regulates cell stemness and differentiation in various organs. Whether macroH2A1.1 has a modulatory role in emotional behavior is unknown. Here, we employed macroH2A1.1 knock-out (-/- ) mice to perform a comprehensive battery of behavioral tests, and an assessment of hippocampal synaptic plasticity (long-term potentiation) accompanied by whole hippocampus RNA sequencing. MacroH2A1.1-/- mice exhibit a stunningly enhancement both of sociability and of active stress-coping behavior, reflected by the increased social behavior in social activity tests and higher mobility time in the forced swim test, respectively. They also display an increased hippocampal synaptic plasticity, accompanied by significant neurotransmission transcriptional networks changes. These results suggest that systemic depletion of histone macroH2A1.1 supports an epigenetic control necessary for hippocampal function and social behavior.
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Affiliation(s)
- Valentina Chiodi
- National Centre for Drug Research and Evaluation, Istituto Superiore di Sanità, Rome, Italy
| | - Maria Rosaria Domenici
- National Centre for Drug Research and Evaluation, Istituto Superiore di Sanità, Rome, Italy
| | - Tommaso Biagini
- IRCCS Casa Sollievo della Sofferenza, Bioinformatics Unit, San Giovanni Rotondo, Italy
| | - Roberta De Simone
- National Centre for Drug Research and Evaluation, Istituto Superiore di Sanità, Rome, Italy
| | - Anna Maria Tartaglione
- Centre for Behavioral Sciences and Mental Health, Istituto Superiore di Sanità, Rome, Italy
| | - Michelino Di Rosa
- Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy
| | - Oriana Lo Re
- International Clinical Research Center, St Anne's University Hospital, Brno, Czech Republic
| | - Tommaso Mazza
- IRCCS Casa Sollievo della Sofferenza, Bioinformatics Unit, San Giovanni Rotondo, Italy
| | - Vincenzo Micale
- National Centre for Drug Research and Evaluation, Istituto Superiore di Sanità, Rome, Italy.,Department of Biomedical and Biotechnological Sciences, School of Medicine, University of Catania, Catania, Italy
| | - Manlio Vinciguerra
- International Clinical Research Center, St Anne's University Hospital, Brno, Czech Republic.,ERA Chair in Translational Stem Cell Biology, Medical University-Varna, Varna, Bulgaria.,Division of Medicine, University College London (UCL), London, UK
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8
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Carretero-Rodriguez L, Guðjónsdóttir R, Poparic I, Reilly ML, Chol M, Bianco IH, Chiapello M, Feret R, Deery MJ, Guthrie S. The Rac-GAP alpha2-Chimaerin Signals via CRMP2 and Stathmins in the Development of the Ocular Motor System. J Neurosci 2021; 41:6652-6672. [PMID: 34168008 PMCID: PMC8336708 DOI: 10.1523/jneurosci.0983-19.2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 04/02/2021] [Accepted: 04/05/2021] [Indexed: 11/21/2022] Open
Abstract
A precise sequence of axon guidance events is required for the development of the ocular motor system. Three cranial nerves grow toward, and connect with, six extraocular muscles in a stereotyped pattern, to control eye movements. The signaling protein alpha2-chimaerin (α2-CHN) plays a pivotal role in the formation of the ocular motor system; mutations in CHN1, encoding α2-CHN, cause the human eye movement disorder Duane Retraction Syndrome (DRS). Our research has demonstrated that the manipulation of α2-chn signaling in the zebrafish embryo leads to ocular motor axon wiring defects, although the signaling cascades regulated by α2-chn remain poorly understood. Here, we demonstrate that several cytoskeletal regulatory proteins-collapsin response mediator protein 2 (CRMP2; encoded by the gene dpysl2), stathmin1, and stathmin 2-bind to α2-CHN. dpysl2, stathmin1, and especially stathmin2 are expressed by ocular motor neurons. We find that the manipulation of dpysl2 and of stathmins in zebrafish larvae leads to defects in both the axon wiring of the ocular motor system and the optokinetic reflex, impairing horizontal eye movements. Knockdowns of these molecules in zebrafish larvae of either sex caused axon guidance phenotypes that included defasciculation and ectopic branching; in some cases, these phenotypes were reminiscent of DRS. chn1 knock-down phenotypes were rescued by the overexpression of CRMP2 and STMN1, suggesting that these proteins act in the same signaling pathway. These findings suggest that CRMP2 and stathmins signal downstream of α2-CHN to orchestrate ocular motor axon guidance and to control eye movements.SIGNIFICANCE STATEMENT The precise control of eye movements is crucial for the life of vertebrate animals, including humans. In humans, this control depends on the arrangement of nerve wiring of the ocular motor system, composed of three nerves and six muscles, a system that is conserved across vertebrate phyla. Mutations in the protein alpha2-chimaerin have previously been shown to cause eye movement disorders (squint) and axon wiring defects in humans. Our recent work has unraveled how alpha2-chimaerin coordinates axon guidance of the ocular motor system in animal models. In this article, we demonstrate key roles for the proteins CRMP2 and stathmin 1/2 in the signaling pathway orchestrated by alpha2-chimaerin, potentially giving insight into the etiology of eye movement disorders in humans.
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Affiliation(s)
| | | | - Ivana Poparic
- Department of Developmental Neurobiology, King's College London, London SE1 1UL, United Kingdom
| | | | - Mary Chol
- Department of Developmental Neurobiology, King's College London, London SE1 1UL, United Kingdom
| | - Isaac H Bianco
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, United Kingdom
| | - Marco Chiapello
- Cambridge Centre for Proteomics, Cambridge Systems Biology Centre, Department of Biochemistry, University of Cambridge, Cambridge CB2 1QR, United Kingdom
| | - Renata Feret
- Institute for Sustainable Plant Protection, National Research Council, 10135 Torino, Italy
| | - Michael J Deery
- Institute for Sustainable Plant Protection, National Research Council, 10135 Torino, Italy
| | - Sarah Guthrie
- School of Life Sciences, University of Sussex, Brighton BN7 9QG, United Kingdom
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Bjorke B, Weller KG, Jones LE, Robinson GE, Vesser M, Chen L, Gage PJ, Gould TW, Mastick GS. Oculomotor nerve guidance and terminal branching requires interactions with differentiating extraocular muscles. Dev Biol 2021; 476:272-281. [PMID: 33905720 PMCID: PMC8284410 DOI: 10.1016/j.ydbio.2021.04.006] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2019] [Revised: 04/20/2021] [Accepted: 04/20/2021] [Indexed: 11/25/2022]
Abstract
Muscle function is dependent on innervation by the correct motor nerves. Motor nerves are composed of motor axons which extend through peripheral tissues as a compact bundle, then diverge to create terminal nerve branches to specific muscle targets. As motor nerves approach their targets, they undergo a transition where the fasciculated nerve halts further growth then after a pause, the nerve later initiates branching to muscles. This transition point is potentially an intermediate target or guidepost to present specific cellular and molecular signals for navigation. Here we describe the navigation of the oculomotor nerve and its association with developing muscles in mouse embryos. We found that the oculomotor nerve initially grew to the eye three days prior to the appearance of any extraocular muscles. The oculomotor axons spread to form a plexus within a mass of cells, which included precursors of extraocular muscles and other orbital tissues and expressed the transcription factor Pitx2. The nerve growth paused in the plexus for more than two days, persisting during primary extraocular myogenesis, with a subsequent phase in which the nerve branched out to specific muscles. To test the functional significance of the nerve contact with Pitx2+ cells in the plexus, we used two strategies to genetically ablate Pitx2+ cells or muscle precursors early in nerve development. The first strategy used Myf5-Cre-mediated expression of diphtheria toxin A to ablate muscle precursors, leading to loss of extraocular muscles. The oculomotor axons navigated to the eye to form the main nerve, but subsequently largely failed to initiate terminal branches. The second strategy studied Pitx2 homozygous mutants, which have early apoptosis of Pitx2-expressing precursor cells, including precursors for extraocular muscles and other orbital tissues. Oculomotor nerve fibers also grew to the eye, but failed to stop to form the plexus, instead grew long ectopic projections. These results show that neither Pitx2 function nor Myf5-expressing cells are required for oculomotor nerve navigation to the eye. However, Pitx2 function is required for oculomotor axons to pause growth in the plexus, while Myf5-expressing cells are required for terminal branch initiation.
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Affiliation(s)
- Brielle Bjorke
- Department of Biology, University of Nevada, Reno, NV, 89557, USA
| | | | - Lauren E Jones
- Department of Biology, University of Nevada, Reno, NV, 89557, USA
| | - G Eric Robinson
- Department of Biology, University of Nevada, Reno, NV, 89557, USA
| | - Michelle Vesser
- Department of Biology, University of Nevada, Reno, NV, 89557, USA
| | - Lisheng Chen
- Department of Ophthalmology & Visual Science, University of Michigan Medical School, Ann Arbor, MI, 48105, USA
| | - Philip J Gage
- Department of Ophthalmology & Visual Science, University of Michigan Medical School, Ann Arbor, MI, 48105, USA
| | - Thomas W Gould
- Department of Physiology and Cell Biology, University of Nevada School of Medicine, Reno, United States
| | - Grant S Mastick
- Department of Biology, University of Nevada, Reno, NV, 89557, USA.
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10
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Ye XC, Roslin NM, Paterson AD, Lyons CJ, Pegado V, Richmond P, Shyr C, Fornes O, Han X, Higginson M, Ross CJ, Giaschi D, Gregory-Evans C, Patel MS, Wasserman WW. Linkage analysis identifies an isolated strabismus locus at 14q12 overlapping with FOXG1 syndrome region. J Med Genet 2020; 59:46-55. [PMID: 33257509 PMCID: PMC8685624 DOI: 10.1136/jmedgenet-2020-107226] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2020] [Revised: 09/05/2020] [Accepted: 09/29/2020] [Indexed: 11/21/2022]
Abstract
Strabismus is a common condition, affecting 1%–4% of individuals. Isolated strabismus has been studied in families with Mendelian inheritance patterns. Despite the identification of multiple loci via linkage analyses, no specific genes have been identified from these studies. The current study is based on a seven-generation family with isolated strabismus inherited in an autosomal dominant manner. A total of 13 individuals from a common ancestor have been included for linkage analysis. Among these, nine are affected and four are unaffected. A single linkage signal has been identified at an 8.5 Mb region of chromosome 14q12 with a multipoint LOD (logarithm of the odds) score of 4.69. Disruption of this locus is known to cause FOXG1 syndrome (or congenital Rett syndrome; OMIM #613454 and *164874), in which 84% of affected individuals present with strabismus. With the incorporation of next-generation sequencing and in-depth bioinformatic analyses, a 4 bp non-coding deletion was prioritised as the top candidate for the observed strabismus phenotype. The deletion is predicted to disrupt regulation of FOXG1, which encodes a transcription factor of the Forkhead family. Suggestive of an autoregulation effect, the disrupted sequence matches the consensus FOXG1 and Forkhead family transcription factor binding site and has been observed in previous ChIP-seq studies to be bound by Foxg1 in early mouse brain development. Future study of this specific deletion may shed light on the regulation of FOXG1 expression and may enhance our understanding of the mechanisms contributing to strabismus and FOXG1 syndrome.
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Affiliation(s)
- Xin Cynthia Ye
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada.,Department of Medical Genetics, The University of British Columbia, Vancouver, British Columbia, Canada.,BC Children's Hospital Research Institute, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Nicole M Roslin
- The Centre for Applied Genomics, Hospital for Sick Children Research Institute, University of Toronto, Toronto, Ontario, Canada
| | - Andrew D Paterson
- The Centre for Applied Genomics, Hospital for Sick Children Research Institute, University of Toronto, Toronto, Ontario, Canada.,Genetics and Genome Biology, Hospital for Sick Children, Toronto, Ontario, Canada.,Divisions of Epidemiology and Biostatistics, Dalla Lana School of Public Health, University of Toronto, Toronto, Ontario, Canada
| | - Christopher J Lyons
- BC Children's Hospital Research Institute, The University of British Columbia, Vancouver, British Columbia, Canada.,Department of Ophthalmology and Visual Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Victor Pegado
- Department of Ophthalmology and Visual Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Phillip Richmond
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada.,BC Children's Hospital Research Institute, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Casper Shyr
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada.,BC Children's Hospital Research Institute, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Oriol Fornes
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada.,BC Children's Hospital Research Institute, The University of British Columbia, Vancouver, British Columbia, Canada
| | - XiaoHua Han
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Michelle Higginson
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Colin J Ross
- Faculty of Pharmaceutical Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Deborah Giaschi
- BC Children's Hospital Research Institute, The University of British Columbia, Vancouver, British Columbia, Canada.,Department of Ophthalmology and Visual Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Cheryl Gregory-Evans
- Department of Ophthalmology and Visual Sciences, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Millan S Patel
- Department of Medical Genetics, The University of British Columbia, Vancouver, British Columbia, Canada .,BC Children's Hospital Research Institute, The University of British Columbia, Vancouver, British Columbia, Canada
| | - Wyeth W Wasserman
- Centre for Molecular Medicine and Therapeutics, The University of British Columbia, Vancouver, British Columbia, Canada .,Department of Medical Genetics, The University of British Columbia, Vancouver, British Columbia, Canada.,BC Children's Hospital Research Institute, The University of British Columbia, Vancouver, British Columbia, Canada
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11
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Patil SJ, Karthik GA, Bhavani GS, Bhat V, Matalia J, Shah J, Shukla A, Girisha KM. Bosley-Salih-Alorainy syndrome in patients from India. Am J Med Genet A 2020; 182:2699-2703. [PMID: 32864817 DOI: 10.1002/ajmg.a.61809] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2019] [Revised: 02/05/2020] [Accepted: 07/20/2020] [Indexed: 11/07/2022]
Abstract
Bi-allelic HOXA1 pathogenic variants clinically manifest as two distinct syndromes, Bosley-Salih-Alorainy syndrome (BSAS) and Athabascan brainstem dysgenesis syndrome, mainly reported in two different populations from Saudi Arabia and southwest North America, respectively. Here we report two siblings of Indian origin with BSAS phenotype caused by a novel homozygous exon 2 HOXA1 pathogenic variants.
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Affiliation(s)
- Siddaramappa J Patil
- Division of Medical Genetics, Mazumdar Shaw Medical Center, Narayana Hrudayalaya Hospitals, Bangalore, India
| | | | - Gandham SriLakshmi Bhavani
- Department of Medical Genetics, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, India
| | - Venkatraman Bhat
- Department of Radiology, Mazumdar Shaw Medical Center, Narayana Hrudayalaya Hospitals, Bangalore, India
| | - Jyoti Matalia
- Department of Pediatric Ophthalmology & Strabismology, Narayana Nethralaya, Bangalore, India
| | - Jhanvi Shah
- Division of Medical Genetics, Mazumdar Shaw Medical Center, Narayana Hrudayalaya Hospitals, Bangalore, India
| | - Anju Shukla
- Department of Medical Genetics, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, India
| | - Katta Mohan Girisha
- Department of Medical Genetics, Kasturba Medical College, Manipal Academy of Higher Education, Manipal, India
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12
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Protocadherin-Mediated Cell Repulsion Controls the Central Topography and Efferent Projections of the Abducens Nucleus. Cell Rep 2020; 24:1562-1572. [PMID: 30089266 DOI: 10.1016/j.celrep.2018.07.024] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 05/31/2018] [Accepted: 07/06/2018] [Indexed: 11/21/2022] Open
Abstract
Cranial motor nuclei in the brainstem innervate diverse types of head and neck muscles. Failure in establishing these neuromuscular connections causes congenital cranial dysinnervation disorders (CCDDs) characterized by abnormal craniofacial movements. However, mechanisms that link cranial motor nuclei to target muscles are poorly understood at the molecular level. Here, we report that protocadherin-mediated repulsion mediates neuromuscular connection in the ocular motor system in zebrafish. We identify pools of abducens motor neurons that are topographically arranged according to soma size and convergently innervate a single muscle. Disruptions of Duane retraction syndrome-associated transcription factors reveal that these neurons require Mafba/MAFB, but not Sall4/SALL4, for differentiation. Furthermore, genetic perturbations of Pcdh17/protocadherin-17 result in defective axon growth and soma clumping, thereby abolishing neuromuscular connectivity. Our results suggest that protocadherin-mediated repulsion forms the central topography and efferent projection pattern of the abducens nucleus following Mafba-dependent specification and imply potential involvement of protocadherins in CCDD etiology.
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13
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Accogli A, Addour-Boudrahem N, Srour M. Neurogenesis, neuronal migration, and axon guidance. HANDBOOK OF CLINICAL NEUROLOGY 2020; 173:25-42. [PMID: 32958178 DOI: 10.1016/b978-0-444-64150-2.00004-6] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Development of the central nervous system (CNS) is a complex, dynamic process that involves a precisely orchestrated sequence of genetic, environmental, biochemical, and physical factors from early embryonic stages to postnatal life. Duringthe past decade, great strides have been made to unravel mechanisms underlying human CNS development through the employment of modern genetic techniques and experimental approaches. In this chapter, we review the current knowledge regarding the main developmental processes and signaling mechanisms of (i) neurogenesis, (ii) neuronal migration, and (iii) axon guidance. We discuss mechanisms related to neural stem cells proliferation, migration, terminal translocation of neuronal progenitors, and axon guidance and pathfinding. For each section, we also provide a comprehensive overview of the underlying regulatory processes, including transcriptional, posttranscriptional, and epigenetic factors, and a myriad of signaling pathways that are pivotal to determine the fate of neuronal progenitors and newly formed migrating neurons. We further highlight how impairment of this complex regulating system, such as mutations in its core components, may cause cortical malformation, epilepsy, intellectual disability, and autism in humans. A thorough understanding of normal human CNS development is thus crucial to decipher mechanisms responsible for neurodevelopmental disorders and in turn guide the development of effective and targeted therapeutic strategies.
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Affiliation(s)
- Andrea Accogli
- Unit of Medical Genetics, Istituto Giannina Gaslini Pediatric Hospital, Genova, Italy; Departments of Neuroscience, Rehabilitation, Ophthalmology, Genetics and Maternal-Child Science, Università degli Studi di Genova, Genova, Italy
| | | | - Myriam Srour
- Research Institute, McGill University Health Centre, Montreal, QC, Canada; Department of Pediatrics, Division of Pediatric Neurology, McGill University, Montreal, QC, Canada.
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14
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Liang X, Yin N, Liang S, Yang R, Liu S, Lu Y, Jiang L, Zhou Q, Jiang G, Faiola F. Bisphenol A and several derivatives exert neural toxicity in human neuron-like cells by decreasing neurite length. Food Chem Toxicol 2020; 135:111015. [DOI: 10.1016/j.fct.2019.111015] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Revised: 11/28/2019] [Accepted: 11/30/2019] [Indexed: 02/06/2023]
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15
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Magnetic resonance imaging of developmental facial paresis: a spectrum of complex anomalies. Neuroradiology 2018; 60:1053-1061. [PMID: 30074067 DOI: 10.1007/s00234-018-2063-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 07/05/2018] [Indexed: 10/28/2022]
Abstract
PURPOSE Despite its clinical implications, the MRI features of developmental facial paresis (DFP) were described in a few case reports. This study aims to describe MRI features of DFP in relation to the embryological development with a proposed radiological new grading system. METHODS The clinical records and MRI of the brain and internal auditory canal of 11 children with DFP were retrospectively reviewed. The following sequences were analyzed: axial, oblique sagittal SPACE of the internal auditory canal and brainstem; axial T2, T1WI and coronal T2WI of the brain. The severity of the maldevelopment of the seventh nerve was graded from 0 to 4: 0 = no abnormalities, 1 = unilateral facial nerve hypoplasia, 2 = unilateral facial nerve aplasia, 3 = aplasia or hypoplasia involving facial nerves on both sides, and 4 = facial nerve aplasia or hypoplasia associated with other cranial nerve palsy. RESULTS Isolated facial nerve palsy was diagnosed in seven patients. It was of grade 1 in five and grade 3 in two. Hypoplasia of the nerve with interrupted course was encountered in two cases. Other associated cranial nerve abnormalities (grade 4) were seen in four patients; two of them were diagnosed previously as Moebius syndrome. In addition to inner ear anomalies, middle and external ear and parotid gland anomalies were described. CONCLUSION To our knowledge, this is the largest series of patients with DFP that represents a continuum of isolated and combined malformations. Understanding of embryological basis can give insights into the anomalous development of the facial nerve.
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16
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Gustatory lid retraction: an unusual congenital cranial dysinnervation disorder. J AAPOS 2017; 21:511-512. [PMID: 29107795 DOI: 10.1016/j.jaapos.2017.07.214] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2017] [Revised: 07/17/2017] [Accepted: 07/17/2017] [Indexed: 11/23/2022]
Abstract
Congenital cranial dysinnervation disorders are developmental abnormalities of cranial nerves that often include abnormal synkinesis. Among the most common ophthalmic congenital cranial dysinnervation disorders are Duane retraction syndrome and the Marcus-Gunn jaw-winking phenomenon. This report documents gustatory lid retraction as an unusual congenital cranial dysinnervation.
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17
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Whitman MC, Engle EC. Ocular congenital cranial dysinnervation disorders (CCDDs): insights into axon growth and guidance. Hum Mol Genet 2017; 26:R37-R44. [PMID: 28459979 DOI: 10.1093/hmg/ddx168] [Citation(s) in RCA: 45] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2017] [Accepted: 04/27/2017] [Indexed: 12/11/2022] Open
Abstract
Unraveling the genetics of the paralytic strabismus syndromes known as congenital cranial dysinnervation disorders (CCDDs) is both informing physicians and their patients and broadening our understanding of development of the ocular motor system. Genetic mutations underlying ocular CCDDs alter either motor neuron specification or motor nerve development, and highlight the importance of modulations of cell signaling, cytoskeletal transport, and microtubule dynamics for axon growth and guidance. Here we review recent advances in our understanding of two CCDDs, congenital fibrosis of the extraocular muscles (CFEOM) and Duane retraction syndrome (DRS), and discuss what they have taught us about mechanisms of axon guidance and selective vulnerability. CFEOM presents with congenital ptosis and restricted eye movements, and can be caused by heterozygous missense mutations in the kinesin motor protein KIF21A or in the β-tubulin isotypes TUBB3 or TUBB2B. CFEOM-causing mutations in these genes alter protein function and result in axon growth and guidance defects. DRS presents with inability to abduct one or both eyes. It can be caused by decreased function of several transcription factors critical for abducens motor neuron identity, including MAFB, or by heterozygous missense mutations in CHN1, which encodes α2-chimaerin, a Rac-GAP GTPase that affects cytoskeletal dynamics. Examination of the orbital innervation in mice lacking Mafb has established that the stereotypical misinnervation of the lateral rectus by fibers of the oculomotor nerve in DRS is secondary to absence of the abducens nerve. Studies of a CHN1 mouse model have begun to elucidate mechanisms of selective vulnerability in the nervous system.
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Affiliation(s)
- Mary C Whitman
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA.,Department of Ophthalmology, Boston Children's Hospital, Boston, MA 02115, USA.,Department of Ophthalmology, Harvard Medical School, Boston, MA 02115, USA
| | - Elizabeth C Engle
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA 02115, USA.,Department of Ophthalmology, Boston Children's Hospital, Boston, MA 02115, USA.,Department of Ophthalmology, Harvard Medical School, Boston, MA 02115, USA.,Department of Neurology, Boston Children's Hospital, Boston, MA 02115, USA.,Department of Neurology, Harvard Medical School, Boston, MA 02115, USA.,Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA
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18
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Nagata K, Takahashi M, Kiryu-Seo S, Kiyama H, Saido TC. Distinct functional consequences of ECEL1/DINE missense mutations in the pathogenesis of congenital contracture disorders. Acta Neuropathol Commun 2017; 5:83. [PMID: 29132416 PMCID: PMC5683451 DOI: 10.1186/s40478-017-0486-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 10/26/2017] [Indexed: 11/10/2022] Open
Abstract
Endothelin-converting enzyme-like 1 (ECEL1, also termed DINE in rodents), a membrane-bound metalloprotease, has been identified as a gene responsible for distal arthrogryposis (DA). ECEL1-mutated DA is generally characterized by ocular phenotypes in addition to the congenital limb contractures that are common to all DA subtypes. Until now, the consequences of the identified pathogenic mutations have remained incompletely understood because of a lack of detailed phenotypic analyses in relevant mouse models. In this study, we generated a new knock-in mouse strain that carries an ECEL1/DINE pathogenic G607S missense mutation, based on a previous study reporting atypical DA hindlimb phenotypes in two siblings with the mutation. We compared the morphological phenotypes of G607S knock-in mice with C760R knock-in mice that we previously established. Both C760R and G607S knock-in mouse embryos showed similar axonal arborization defects with normal trajectory patterns from the spinal cord to the target hindlimb muscles, as well as axon guidance defects of the abducens nerves. Intriguingly, distinct phenotypes in DINE protein localization and mRNA expression were identified in these knock-in mouse lines. For G607S, DINE mRNA and protein expression was decreased or almost absent in motor neurons. In the C760R mutant mice DINE was expressed and localized in the somata of motor neurons but not in axons. Our mutant mouse data suggest that ECEL1/DINE G607S and C760R mutations both lead to motor innervation defects as primary causes in ECEL1-mutated congenital contracture disorders. However, the functional consequences of the two mutations are distinct, with loss of axonal transport of ECEL1/DINE in C760R mutants and mRNA expression deficits in G607S mutants.
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19
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Vahidi Mehrjardi MY, Maroofian R, Kalantar SM, Jaafarinia M, Chilton J, Dehghani M. A Novel Loss-of-Function Mutation in HOXB1 Associated with Autosomal Recessive Hereditary Congenital Facial Palsy in a Large Iranian Family. Mol Syndromol 2017; 8:261-265. [PMID: 28878610 DOI: 10.1159/000477752] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/10/2017] [Indexed: 12/28/2022] Open
Abstract
Hereditary congenital facial palsy (HCFP) is a rare congenital cranial dysinnervation disorder, recognisable by non-progressive isolated facial nerve palsy (cranial nerve VII). It is caused by developmental abnormalities of the facial nerve nucleus and its nerve. So far, 4 homozygous mutations have been identified in 5 unrelated families (12 patients) with HCFP worldwide. In this study, a large Iranian consanguineous kindred with 5 members affected by HCFP underwent thorough clinical and genetic evaluation. The candidate gene HOXB1 was screened and analysed by Sanger sequencing. As in previous cases, the most remarkable findings in the affected members of the family were mask-like faces, bilateral facial palsy with variable sensorineural hearing loss, and some dysmorphic features. Direct sequencing of the candidate gene HOXB1 identified a novel homozygous frameshift mutation (c.296_302del; p.Y99Wfs*20) which co-segregated with the disease phenotype within the extended family. Our findings expand the mutational spectrum of HOXB1 involved in HCFP and consolidate the role of the gene in the development of autosomal recessive HCFP. Moreover, the truncating mutation identified in this family leads to a broadly similar presentation and severity observed in previous patients with nonsense and missense mutations. This study characterises and defines the phenotypic features of this rare syndrome in a larger family than has previously been reported.
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Affiliation(s)
| | - Reza Maroofian
- Wellcome Wolfson Medical Research Centre, University of Exeter Medical School, Exeter, UK
| | - Seyed M Kalantar
- Reproductive and Genetic Unit, Yazd Research and Clinical Center for Infertility, Yazd, Iran
| | | | - John Chilton
- Wellcome Wolfson Medical Research Centre, University of Exeter Medical School, Exeter, UK
| | - Mohammadreza Dehghani
- Medical Genetics Research Center, Shahid Sadoughi University of Medical Sciences, Yazd, Iran
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20
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Guthrie S, Chédotal A. Introduction to the special volume on axonal development and disorders. Dev Neurobiol 2017; 77:807-809. [PMID: 28470844 DOI: 10.1002/dneu.22504] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2017] [Revised: 04/21/2017] [Accepted: 04/21/2017] [Indexed: 11/06/2022]
Affiliation(s)
- Sarah Guthrie
- School of Life Sciences, University of Sussex, Falmer, Sussex, BN1 9QG, United Kingdom
| | - Alain Chédotal
- Sorbonne Universités, UPMC Univ. Paris 06, INSERM, CNRS, Institut de la Vision, Paris, 75012, France
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