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Affrald R J, Narayan S. A review: oligodendrocytes in neuronal axonal conduction and methods for enhancing their performance. Int J Neurosci 2024:1-22. [PMID: 38850232 DOI: 10.1080/00207454.2024.2362200] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2022] [Accepted: 05/27/2024] [Indexed: 06/10/2024]
Abstract
OBJECTIVES This review explores the vital role of oligodendrocytes in axon myelination and efficient neuronal transmission and the impact of dysfunction resulting from neurotransmitter deficiencies related disorders. Furthermore, the review also provides insight into the potential of bionanotechnology for addressing neurodegenerative diseases by targeting oligodendrocytes. METHODS A review of literature in the field was conducted using Google scholar. Systematic searches were performed to identify relevant studies and reviews addressing the role of oligodendrocytes in neural function, the influence of neurotransmitters on oligodendrocyte differentiation, and the potential of nanotechnology-based strategies for targeted therapy of oligodendrocytes. RESULTS This review indicates the mechanisms underlying oligodendrocyte differentiation and the influence of neurotransmitters on this process. The importance of action potentials and neurotransmission in neural function and the susceptibility of damaged nerve axons to ischemic or toxic damage is provided in detail. The potential of bionanotechnology for targeting neurodegenerative diseases using nanotechnology-based strategies, including polymeric, lipid-based, inorganic, organic, and biomimetic nanoparticles, suggests better management of neurodegenerative disorders. CONCLUSION While nanotechnology-based biomaterials show promise for targeted oligodendrocyte therapy in addressing neurodegenerative disorders linked to oligodendrocyte dysfunction, encapsulating neuroprotective agents within nanoparticles offers additional advantages. Nano-based delivery systems effectively protect drugs from degradation and prolong their therapeutic effects, holding promise in overcoming the blood-brain barrier by facilitating drug transport. However, a multifaceted approach is essential to enhance oligodendrocyte differentiation, promote myelin repair, and facilitate myelin dynamics with reduced toxicity. Further research is needed to elucidate the optimal therapeutic approaches and enhance patient outcomes.
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Affiliation(s)
- Jino Affrald R
- Faculty of Allied Health Sciences, Chettinad Hospital and Research Institute, Chettinad Academy of Research and Education, Kelambakkam, Tamilnadu, India
| | - Shoba Narayan
- Faculty of Allied Health Sciences, Chettinad Hospital and Research Institute, Chettinad Academy of Research and Education, Kelambakkam, Tamilnadu, India
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2
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Tian Y, Qiao H, Zhu LQ, Man HY. Sexually dimorphic phenotypes and the role of androgen receptors in UBE3A-dependent autism spectrum disorder. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.02.592248. [PMID: 38746146 PMCID: PMC11092617 DOI: 10.1101/2024.05.02.592248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Autism spectrum disorders (ASDs) are characterized by social, communication, and behavioral challenges. UBE3A is one of the most common ASD genes. ASDs display a remarkable sex difference with a 4:1 male to female prevalence ratio; however, the underlying mechanism remains largely unknown. Using the UBE3A-overexpressing mouse model for ASD, we studied sex differences at behavioral, genetic, and molecular levels. We found that male mice with extra copies of Ube3A exhibited greater impairments in social interaction, repetitive self-grooming behavior, memory, and pain sensitivity, whereas female mice with UBE3A overexpression displayed greater olfactory defects. Social communication was impaired in both sexes, with males making more calls and females preferring complex syllables. At the molecular level, androgen receptor (AR) levels were reduced in both sexes due to enhanced degradation mediated by UBE3A. However, AR reduction significantly dysregulated AR target genes only in male, not female, UBE3A-overexpressing mice. Importantly, restoring AR levels in the brain effectively normalized the expression of AR target genes, and rescued the deficits in social preference, grooming behavior, and memory in male UBE3A-overexpressing mice, without affecting females. These findings suggest that AR and its signaling cascade play an essential role in mediating the sexually dimorphic changes in UBE3A-dependent ASD.
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Affiliation(s)
- Yuan Tian
- Department of Biology, Boston University, 5 Cummington Mall, Boston, MA 02215, USA
| | - Hui Qiao
- Department of Biology, Boston University, 5 Cummington Mall, Boston, MA 02215, USA
| | - Ling-Qiang Zhu
- Department of Pathophysiology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China
| | - Heng-Ye Man
- Department of Biology, Boston University, 5 Cummington Mall, Boston, MA 02215, USA
- Department of Pharmacology, Physiology & Biophysics, Boston University School of Medicine, 72 East Concord St., Boston, MA 02118, USA
- Center for Systems Neuroscience, Boston University, 610 Commonwealth Ave, Boston, MA 02215, USA
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3
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Hu Y, Tao W. Current perspectives on microglia-neuron communication in the central nervous system: Direct and indirect modes of interaction. J Adv Res 2024:S2090-1232(24)00006-7. [PMID: 38195039 DOI: 10.1016/j.jare.2024.01.006] [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: 04/07/2023] [Revised: 10/05/2023] [Accepted: 01/06/2024] [Indexed: 01/11/2024] Open
Abstract
BACKGROUND The incessant communication that takes place between microglia and neurons is essential the development, maintenance, and pathogenesis of the central nervous system (CNS). As mobile phagocytic cells, microglia serve a critical role in surveilling and scavenging the neuronal milieu to uphold homeostasis. AIM OF REVIEW This review aims to discuss the various mechanisms that govern the interaction between microglia and neurons, from the molecular to the organ system level, and to highlight the importance of these interactions in the development, maintenance, and pathogenesis of the CNS. KEY SCIENTIFIC CONCEPTS OF REVIEW Recent research has revealed that microglia-neuron interaction is vital for regulating fundamental neuronal functions, such as synaptic pruning, axonal remodeling, and neurogenesis. The review will elucidate the intricate signaling pathways involved in these interactions, both direct and indirect, to provide a better understanding of the fundamental mechanisms of brain function. Furthermore, gaining insights into these signals could lead to the development of innovative therapies for neural disorders.
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Affiliation(s)
- Yue Hu
- Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, and National and Local Collaborative Engineering Center of Chinese Medicinal Resources Industrialization and Formulae Innovative Medicine, Nanjing University of Chinese Medicine, Nanjing 220023, China; School of Integrated Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing 210023, China
| | - Weiwei Tao
- Jiangsu Collaborative Innovation Center of Chinese Medicinal Resources Industrialization, and National and Local Collaborative Engineering Center of Chinese Medicinal Resources Industrialization and Formulae Innovative Medicine, Nanjing University of Chinese Medicine, Nanjing 220023, China; School of Integrated Chinese and Western Medicine, Nanjing University of Chinese Medicine, Nanjing 210023, China.
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4
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Paul D, Agrawal R, Singh S. Alzheimer's disease and clinical trials. J Basic Clin Physiol Pharmacol 2024; 35:31-44. [PMID: 38491747 DOI: 10.1515/jbcpp-2023-0264] [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: 12/29/2023] [Accepted: 02/28/2024] [Indexed: 03/18/2024]
Abstract
Alzheimer's disease (AD) is spreading its root disproportionately among the worldwide population. Many genes have been identified as the hallmarks of AD. Based upon the knowledge, many clinical trials have been designed and conducted. Attempts have been made to alleviate the pathology associated with AD by targeting the molecular products of these genes. Irrespective of the understanding on the genetic component of AD, many clinical trials have failed and imposed greater challenges on the path of drug discovery. Therefore, this review aims to identify research and review articles to pinpoint the limitations of drug candidates (thiethylperazine, CT1812, crenezumab, CNP520, and lecanemab), which are under or withdrawn from clinical trials. Thorough analysis of the cross-talk pathways led to the identification of many confounding factors, which could interfere with the success of clinical trials with drug candidates such as thiethylperazine, CT1812, crenezumab, and CNP520. Though these drug candidates were enrolled in clinical trials, yet literature review shows many limitations. These limitations raise many questions on the rationale behind the enrollments of these drug candidates in clinical trials. A meticulous prior assessment of the outcome of clinical studies may stop risky clinical trials at their inceptions. This may save time, money, and resources.
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Affiliation(s)
- Deepraj Paul
- Department of Pharmacology, 621320 College of Pharmacy JSS Academy of Technical Education , Noida, Uttar Pradesh, India
| | - Rohini Agrawal
- Department of Pharmacology, 621320 College of Pharmacy JSS Academy of Technical Education , Noida, Uttar Pradesh, India
| | - Swati Singh
- Department of Pharmacology, 621320 College of Pharmacy JSS Academy of Technical Education , Noida, Uttar Pradesh, India
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5
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Zuccoli GS, Nascimento JM, Moraes-Vieira PM, Rehen SK, Martins-de-Souza D. Mitochondrial, cell cycle control and neuritogenesis alterations in an iPSC-based neurodevelopmental model for schizophrenia. Eur Arch Psychiatry Clin Neurosci 2023; 273:1649-1664. [PMID: 37039888 DOI: 10.1007/s00406-023-01605-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/21/2022] [Accepted: 03/29/2023] [Indexed: 04/12/2023]
Abstract
Schizophrenia is a severe psychiatric disorder of neurodevelopmental origin that affects around 1% of the world's population. Proteomic studies and other approaches have provided evidence of compromised cellular processes in the disorder, including mitochondrial function. Most of the studies so far have been conducted on postmortem brain tissue from patients, and therefore, do not allow the evaluation of the neurodevelopmental aspect of the disorder. To circumvent that, we studied the mitochondrial and nuclear proteomes of neural stem cells (NSCs) and neurons derived from induced pluripotent stem cells (iPSCs) from schizophrenia patients versus healthy controls to assess possible alterations related to energy metabolism and mitochondrial function during neurodevelopment in the disorder. Our results revealed differentially expressed proteins in pathways related to mitochondrial function, cell cycle control, DNA repair and neuritogenesis and their possible implication in key process of neurodevelopment, such as neuronal differentiation and axonal guidance signaling. Moreover, functional analysis of NSCs revealed alterations in mitochondrial oxygen consumption in schizophrenia-derived cells and a tendency of higher levels of intracellular reactive oxygen species (ROS). Hence, this study shows evidence that alterations in important cellular processes are present during neurodevelopment and could be involved with the establishment of schizophrenia, as well as the phenotypic traits observed in adult patients. Neural stem cells (NSCs) and neurons were derived from induced pluripotent stem cells (iPSCs) from schizophrenia patients and controls. Proteomic analyses were performed on the enriched mitochondrial and nuclear fractions of NSCs and neurons. Whole-cell proteomic analysis was also performed in neurons. Our results revealed alteration in proteins related to mitochondrial function, cell cycle control, among others. We also performed energy pathway analysis and reactive oxygen species (ROS) analysis of NSCs, which revealed alterations in mitochondrial oxygen consumption and a tendency of higher levels of intracellular ROS in schizophrenia-derived cells.
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Affiliation(s)
- Giuliana S Zuccoli
- Laboratory of Neuroproteomics, Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas, Campinas, Brazil
| | - Juliana M Nascimento
- Laboratory of Neuroproteomics, Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas, Campinas, Brazil
- D'Or Institute for Research and Education (IDOR), São Paulo, Brazil
| | - Pedro M Moraes-Vieira
- Laboratory of Immunometabolism, Department of Genetics, Evolution, Microbiology and Immunology, Institute of Biology, University of Campinas, Campinas, São Paulo, Brazil
- Experimental Medicine Research Cluster (EMRC), University of Campinas, Campinas, SP, 13083-862, Brazil
- Obesity and Comorbidities Research Center (OCRC), University of Campinas, São Paulo, Brazil
| | - Stevens K Rehen
- D'Or Institute for Research and Education (IDOR), São Paulo, Brazil
- Department of Genetics, Institute of Biology, Federal University of Rio de Janeiro (UFRJ), Rio de Janeiro, Brazil
| | - Daniel Martins-de-Souza
- Laboratory of Neuroproteomics, Department of Biochemistry and Tissue Biology, Institute of Biology, University of Campinas, Campinas, Brazil.
- D'Or Institute for Research and Education (IDOR), São Paulo, Brazil.
- Experimental Medicine Research Cluster (EMRC), University of Campinas, Campinas, SP, 13083-862, Brazil.
- Instituto Nacional de Biomarcadores em Neuropsiquiatria (INBION), Conselho Nacional de Desenvolvimento Científico e Tecnológico, São Paulo, Brazil.
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6
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Zang Y, Bashaw GJ. Systematic analysis of the Frazzled receptor interactome establishes previously unreported regulators of axon guidance. Development 2023; 150:dev201636. [PMID: 37526651 PMCID: PMC10445734 DOI: 10.1242/dev.201636] [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: 01/19/2023] [Accepted: 07/07/2023] [Indexed: 08/02/2023]
Abstract
The Netrin receptor Dcc and its Drosophila homolog Frazzled play crucial roles in diverse developmental process, including axon guidance. In Drosophila, Fra regulates midline axon guidance through a Netrin-dependent and a Netrin-independent pathway. However, what molecules regulate these distinct signaling pathways remain unclear. To identify Fra-interacting proteins, we performed affinity purification mass spectrometry to establish a neuronal-specific Fra interactome. In addition to known interactors of Fra and Dcc, including Netrin and Robo1, our screen identified 85 candidate proteins, the majority of which are conserved in humans. Many of these proteins are expressed in the ventral nerve cord, and gene ontology, pathway analysis and biochemical validation identified several previously unreported pathways, including the receptor tyrosine phosphatase Lar, subunits of the COP9 signalosome and Rho-5, a regulator of the metalloprotease Tace. Finally, genetic analysis demonstrates that these genes regulate axon guidance and may define as yet unknown signaling mechanisms for Fra and its vertebrate homolog Dcc. Thus, the Fra interactome represents a resource to guide future functional studies.
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Affiliation(s)
- Yixin Zang
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, 415 Curie Blvd, Philadelphia, PA, 19104, USA
| | - Greg J. Bashaw
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, 415 Curie Blvd, Philadelphia, PA, 19104, USA
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7
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Teixeira-Castro A, Sousa JC, Vieira C, Pereira-Sousa J, Vilasboas-Campos D, Marques F, Pinto-do-Ó P, Maciel P. Learning the Biochemical Basis of Axonal Guidance: Using Caenorhabditis elegans as a Model. Biomedicines 2023; 11:1731. [PMID: 37371826 DOI: 10.3390/biomedicines11061731] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2023] [Revised: 06/12/2023] [Accepted: 06/14/2023] [Indexed: 06/29/2023] Open
Abstract
AIM Experimental models are a powerful aid in visualizing molecular phenomena. This work reports how the worm Caenorhabditis elegans (C. elegans) can be effectively explored for students to learn how molecular cues dramatically condition axonal guidance and define nervous system structure and behavior at the organism level. Summary of work: A loosely oriented observational activity preceded detailed discussions on molecules implied in axonal migration. C. elegans mutants were used to introduce second-year medical students to the deleterious effects of gene malfunctioning in neuron response to extracellular biochemical cues and to establish links between molecular function, nervous system structure, and animal behavior. Students observed C. elegans cultures and associated animal behavior alterations with the lack of function of specific axon guidance molecules (the soluble cue netrin/UNC-6 or two receptors, DCC/UNC-40 and UNC-5H). Microscopical observations of these strains, in combination with pan-neuronal GFP expression, allowed optimal visualization of severely affected neurons. Once the list of mutated genes in each strain was displayed, students could also relate abnormal patterns in axon migration/ventral and dorsal nerve cord neuron formation in C. elegans with mutated molecular components homologous to those in humans. SUMMARY OF RESULTS Students rated the importance and effectiveness of the activity very highly. Ninety-three percent found it helpful to grasp human axonal migration, and all students were surprised with the power of the model in helping to visualize the phenomenon.
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Affiliation(s)
- Andreia Teixeira-Castro
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
- ICVS/3B's-PT Government Associate Laboratory, 4806-909 Guimarães, Portugal
| | - João Carlos Sousa
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
- ICVS/3B's-PT Government Associate Laboratory, 4806-909 Guimarães, Portugal
| | - Cármen Vieira
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
- ICVS/3B's-PT Government Associate Laboratory, 4806-909 Guimarães, Portugal
| | - Joana Pereira-Sousa
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
- ICVS/3B's-PT Government Associate Laboratory, 4806-909 Guimarães, Portugal
| | - Daniela Vilasboas-Campos
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
- ICVS/3B's-PT Government Associate Laboratory, 4806-909 Guimarães, Portugal
| | - Fernanda Marques
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
- ICVS/3B's-PT Government Associate Laboratory, 4806-909 Guimarães, Portugal
| | - Perpétua Pinto-do-Ó
- Instituto de Investigação e Inovação em Saúde (i3S), Universidade do Porto, 4200-135 Porto, Portugal
| | - Patrícia Maciel
- Life and Health Sciences Research Institute (ICVS), School of Medicine, University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal
- ICVS/3B's-PT Government Associate Laboratory, 4806-909 Guimarães, Portugal
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8
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Zang Y, Chaudhari K, Bashaw GJ. Tace/ADAM17 is a bi-directional regulator of axon guidance that coordinates distinct Frazzled and Dcc receptor signaling outputs. Cell Rep 2022; 41:111785. [PMID: 36476876 DOI: 10.1016/j.celrep.2022.111785] [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: 05/23/2022] [Revised: 10/07/2022] [Accepted: 11/15/2022] [Indexed: 12/12/2022] Open
Abstract
Frazzled (Fra) and deleted in colorectal cancer (Dcc) are homologous receptors that promote axon attraction in response to netrin. In Drosophila, Fra also acts independently of netrin by releasing an intracellular domain (ICD) that activates gene transcription. How neurons coordinate these pathways to make accurate guidance decisions is unclear. Here we show that the ADAM metalloprotease Tace cleaves Fra, and this instructs the switch between the two pathways. Genetic manipulations that either increase or decrease Tace levels disrupt midline crossing of commissural axons. These conflicting phenotypes reflect Tace's function as a bi-directional regulator of axon guidance, a function conserved in its vertebrate homolog ADAM17: while Tace induces the formation of the Fra ICD to activate transcription, excessive Tace cleavage of Fra and Dcc suppresses the response to netrin. We propose that Tace and ADAM17 are key regulators of midline axon guidance by establishing the balance between netrin-dependent and netrin-independent signaling.
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Affiliation(s)
- Yixin Zang
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Karina Chaudhari
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Greg J Bashaw
- Department of Neuroscience, Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
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Herrera E, Escalante A. Transcriptional Control of Axon Guidance at Midline Structures. Front Cell Dev Biol 2022; 10:840005. [PMID: 35265625 PMCID: PMC8900194 DOI: 10.3389/fcell.2022.840005] [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: 12/20/2021] [Accepted: 01/31/2022] [Indexed: 11/13/2022] Open
Abstract
The development of the nervous system is a time-ordered and multi-stepped process that includes neurogenesis and neuronal specification, axonal navigation, and circuits assembly. During axonal navigation, the growth cone, a dynamic structure located at the tip of the axon, senses environmental signals that guide axons towards their final targets. The expression of a specific repertoire of receptors on the cell surface of the growth cone together with the activation of a set of intracellular transducing molecules, outlines the response of each axon to specific guidance cues. This collection of axon guidance molecules is defined by the transcriptome of the cell which, in turn, depends on transcriptional and epigenetic regulators that modify the structure and DNA accessibility to determine what genes will be expressed to elicit specific axonal behaviors. Studies focused on understanding how axons navigate intermediate targets, such as the floor plate of vertebrates or the mammalian optic chiasm, have largely contributed to our knowledge of how neurons wire together during development. In fact, investigations on axon navigation at these midline structures led to the identification of many of the currently known families of proteins that act as guidance cues and their corresponding receptors. Although the transcription factors and the regulatory mechanisms that control the expression of these molecules are not well understood, important advances have been made in recent years in this regard. Here we provide an updated overview on the current knowledge about the transcriptional control of axon guidance and the selection of trajectories at midline structures.
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10
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Huang L, Guo J, Xie Y, Zhou Y, Wu X, Li H, Peng Y, Li N. Clinical features and genotypes of six patients from four families with horizontal gaze palsy with progressive scoliosis. Front Pediatr 2022; 10:949565. [PMID: 36186627 PMCID: PMC9515397 DOI: 10.3389/fped.2022.949565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/21/2022] [Accepted: 08/15/2022] [Indexed: 11/21/2022] Open
Abstract
BACKGROUND Horizontal gaze palsy with progressive scoliosis (HGPPS) is a rare disorder mainly involved in ocular movement and spinal development. It is caused by a roundabout guidance receptor 3 (ROBO3) gene mutation. This study aimed to describe the clinical features of six patients with HGPPS and investigate the corresponding ROBO3 gene mutations. METHODS Patients underwent detailed clinical and imaging examinations. Whole-exome sequencing was performed to detect nucleotide variations in the disease-causing genes of HGPPS. RESULTS Six pathogenic variants were detected in the ROBO3 gene from six patients with HGPPS, including two novel compound heterozygous mutations, c.1447C > T (p.R483X) and c.2462G > C (p.R821P); c.1033G > C (p.V345L) and c.3287G > T (p.C1096F); a novel homozygous indel mutation, c.565dupC (p.R191Pfs*61); and a known missense mutation, c.416G > T (p.G139V). Patients with HGPPS had horizontal conjugated eye movement defects and scoliosis with variable degrees, as well as flattened pontine tegmentum and uncrossed corticospinal tracts on magnetic resonance imaging. CONCLUSION Our genetic findings will expand the spectrum of ROBO3 mutations and help inform future research on the molecular mechanism of HGPPS.
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Affiliation(s)
- Lijuan Huang
- Department of Ophthalmology, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, China.,Department of Ophthalmology, Beijing Children's Hospital, Capital Medical University, Beijing, China
| | - Jianlin Guo
- Department of Radiology, Beijing Children's Hospital, Capital Medical University, Beijing, China
| | - Yan Xie
- Department of Ophthalmology, Beijing Children's Hospital, Capital Medical University, Beijing, China
| | - Yunyu Zhou
- Department of Ophthalmology, Beijing Children's Hospital, Capital Medical University, Beijing, China
| | - Xiaofei Wu
- Department of Ophthalmology, Beijing Children's Hospital, Capital Medical University, Beijing, China
| | - Hui Li
- Department of Ophthalmology, Changchun Children's Hospital, Changchun, China
| | - Yun Peng
- Department of Radiology, Beijing Children's Hospital, Capital Medical University, Beijing, China
| | - Ningdong Li
- Department of Ophthalmology, The Second Affiliated Hospital of Fujian Medical University, Quanzhou, China.,Department of Ophthalmology, Beijing Children's Hospital, Capital Medical University, Beijing, China.,Key Laboratory of Major Diseases in Children, Ministry of Education, Beijing, China.,Department of Ophthalmology, Children's Hospital, Capital Institute of Pediatrics, Beijing, China
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11
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Ahmed G, Shinmyo Y. Multiple Functions of Draxin/Netrin-1 Signaling in the Development of Neural Circuits in the Spinal Cord and the Brain. Front Neuroanat 2021; 15:766911. [PMID: 34899198 PMCID: PMC8655782 DOI: 10.3389/fnana.2021.766911] [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: 08/30/2021] [Accepted: 10/22/2021] [Indexed: 11/30/2022] Open
Abstract
Axon guidance proteins play key roles in the formation of neural circuits during development. We previously identified an axon guidance cue, named draxin, that has no homology with other axon guidance proteins. Draxin is essential for the development of various neural circuits including the spinal cord commissure, corpus callosum, and thalamocortical projections. Draxin has been shown to not only control axon guidance through netrin-1 receptors, deleted in colorectal cancer (Dcc), and neogenin (Neo1) but also modulate netrin-1-mediated axon guidance and fasciculation. In this review, we summarize the multifaceted functions of draxin and netrin-1 signaling in neural circuit formation in the central nervous system. Furthermore, because recent studies suggest that the distributions and functions of axon guidance cues are highly regulated by glycoproteins such as Dystroglycan and Heparan sulfate proteoglycans, we discuss a possible function of glycoproteins in draxin/netrin-1-mediated axon guidance.
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Affiliation(s)
- Giasuddin Ahmed
- Department of Neuroscience and Pharmacology, The University of Texas Southwestern Medical Center, Dallas, TX, United States
| | - Yohei Shinmyo
- Department of Medical Neuroscience, Graduate School of Medical Sciences, Kanazawa University, Kanazawa, Japan
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12
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Almeida N, Rodriguez J, Pla Parada I, Perez-Riverol Y, Woldmar N, Kim Y, Oskolas H, Betancourt L, Valdés JG, Sahlin KB, Pizzatti L, Szasz AM, Kárpáti S, Appelqvist R, Malm J, B. Domont G, C. S. Nogueira F, Marko-Varga G, Sanchez A. Mapping the Melanoma Plasma Proteome (MPP) Using Single-Shot Proteomics Interfaced with the WiMT Database. Cancers (Basel) 2021; 13:6224. [PMID: 34944842 PMCID: PMC8699267 DOI: 10.3390/cancers13246224] [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: 10/04/2021] [Revised: 11/30/2021] [Accepted: 12/08/2021] [Indexed: 12/26/2022] Open
Abstract
Plasma analysis by mass spectrometry-based proteomics remains a challenge due to its large dynamic range of 10 orders in magnitude. We created a methodology for protein identification known as Wise MS Transfer (WiMT). Melanoma plasma samples from biobank archives were directly analyzed using simple sample preparation. WiMT is based on MS1 features between several MS runs together with custom protein databases for ID generation. This entails a multi-level dynamic protein database with different immunodepletion strategies by applying single-shot proteomics. The highest number of melanoma plasma proteins from undepleted and unfractionated plasma was reported, mapping >1200 proteins from >10,000 protein sequences with confirmed significance scoring. Of these, more than 660 proteins were annotated by WiMT from the resulting ~5800 protein sequences. We could verify 4000 proteins by MS1t analysis from HeLA extracts. The WiMT platform provided an output in which 12 previously well-known candidate markers were identified. We also identified low-abundant proteins with functions related to (i) cell signaling, (ii) immune system regulators, and (iii) proteins regulating folding, sorting, and degradation, as well as (iv) vesicular transport proteins. WiMT holds the potential for use in large-scale screening studies with simple sample preparation, and can lead to the discovery of novel proteins with key melanoma disease functions.
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Affiliation(s)
- Natália Almeida
- Laboratory of Proteomics/LADETEC, Universidade Federal Do Rio de Janeiro, Rio de Janeiro 21941-598, Brazil;
- Proteomics Unit, Institute of Chemistry, Universidade Federal Do Rio de Janeiro, Rio de Janeiro 21941-909, Brazil;
- Clinical Protein Science & Imaging, Biomedical Center, Department of Biomedical Engineering, Lund University, BMC D13, 22184 Lund, Sweden; (N.W.); (K.B.S.); (G.M.-V.)
| | - Jimmy Rodriguez
- Division of Chemistry I, Department of Biochemistry and Biophysics, Karolinska Institute, 17165 Stockholm, Sweden;
| | - Indira Pla Parada
- Section for Clinical Chemistry, Department of Translational Medicine, Lund University, Skåne University Hospital Malmö, 20502 Malmö, Sweden; (I.P.P.); (J.M.)
| | - Yasset Perez-Riverol
- European Molecular Biology Laboratory, European Bioinformatics Institute (EMBL-EBI), Wellcome Trust Genome Campus, Hinxton, Cambridge CB10 1SD, UK;
| | - Nicole Woldmar
- Clinical Protein Science & Imaging, Biomedical Center, Department of Biomedical Engineering, Lund University, BMC D13, 22184 Lund, Sweden; (N.W.); (K.B.S.); (G.M.-V.)
- Laboratory of Molecular Biology and Blood Proteomics—LADETEC, Institute of Chemistry, Federal University of Rio de Janeiro, Rio de Janeiro 21941-598, Brazil;
| | - Yonghyo Kim
- Data Convergence Drug Research Center, Therapeutics and Biotechnology Division, Korea Research Institute of Chemical Technology (KRICT), Daejeon 34114, Korea;
- Division of Oncology, Department of Clinical Sciences Lund, Lund University, 22185 Lund, Sweden; (H.O.); (L.B.); (J.G.V.); (R.A.)
| | - Henriett Oskolas
- Division of Oncology, Department of Clinical Sciences Lund, Lund University, 22185 Lund, Sweden; (H.O.); (L.B.); (J.G.V.); (R.A.)
| | - Lazaro Betancourt
- Division of Oncology, Department of Clinical Sciences Lund, Lund University, 22185 Lund, Sweden; (H.O.); (L.B.); (J.G.V.); (R.A.)
| | - Jeovanis Gil Valdés
- Division of Oncology, Department of Clinical Sciences Lund, Lund University, 22185 Lund, Sweden; (H.O.); (L.B.); (J.G.V.); (R.A.)
| | - K. Barbara Sahlin
- Clinical Protein Science & Imaging, Biomedical Center, Department of Biomedical Engineering, Lund University, BMC D13, 22184 Lund, Sweden; (N.W.); (K.B.S.); (G.M.-V.)
- Section for Clinical Chemistry, Department of Translational Medicine, Lund University, Skåne University Hospital Malmö, 20502 Malmö, Sweden; (I.P.P.); (J.M.)
| | - Luciana Pizzatti
- Laboratory of Molecular Biology and Blood Proteomics—LADETEC, Institute of Chemistry, Federal University of Rio de Janeiro, Rio de Janeiro 21941-598, Brazil;
| | | | - Sarolta Kárpáti
- Department of Dermatology, Venereology and Dermatooncology, Semmelweis University, 1085 Budapest, Hungary;
| | - Roger Appelqvist
- Division of Oncology, Department of Clinical Sciences Lund, Lund University, 22185 Lund, Sweden; (H.O.); (L.B.); (J.G.V.); (R.A.)
| | - Johan Malm
- Section for Clinical Chemistry, Department of Translational Medicine, Lund University, Skåne University Hospital Malmö, 20502 Malmö, Sweden; (I.P.P.); (J.M.)
| | - Gilberto B. Domont
- Proteomics Unit, Institute of Chemistry, Universidade Federal Do Rio de Janeiro, Rio de Janeiro 21941-909, Brazil;
| | - Fábio C. S. Nogueira
- Laboratory of Proteomics/LADETEC, Universidade Federal Do Rio de Janeiro, Rio de Janeiro 21941-598, Brazil;
- Proteomics Unit, Institute of Chemistry, Universidade Federal Do Rio de Janeiro, Rio de Janeiro 21941-909, Brazil;
| | - György Marko-Varga
- Clinical Protein Science & Imaging, Biomedical Center, Department of Biomedical Engineering, Lund University, BMC D13, 22184 Lund, Sweden; (N.W.); (K.B.S.); (G.M.-V.)
- Chemical Genomics Global Research Lab, Department of Biotechnology, College of Life Science and Biotechnology, Yonsei University, Seoul 03722, Korea
- Department of Surgery, Tokyo Medical University, 6-7-1 Nishishinjiku Shinjiku-ku, Tokyo 160-0023, Japan
| | - Aniel Sanchez
- Section for Clinical Chemistry, Department of Translational Medicine, Lund University, Skåne University Hospital Malmö, 20502 Malmö, Sweden; (I.P.P.); (J.M.)
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13
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Bhattacharya A, Choi WWY, Muffat J, Li Y. Modeling Developmental Brain Diseases Using Human Pluripotent Stem Cells-Derived Brain Organoids - Progress and Perspective. J Mol Biol 2021; 434:167386. [PMID: 34883115 DOI: 10.1016/j.jmb.2021.167386] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2021] [Revised: 11/26/2021] [Accepted: 11/30/2021] [Indexed: 02/07/2023]
Abstract
Developmental brain diseases encompass a group of conditions resulting from genetic or environmental perturbations during early development. Despite the increased research attention in recent years following recognition of the prevalence of these diseases, there is still a significant lack of knowledge of their etiology and treatment options. The genetic and clinical heterogeneity of these diseases, in addition to the limitations of experimental animal models, contribute to this difficulty. In this regard, the advent of brain organoid technology has provided a new means to study the cause and progression of developmental brain diseases in vitro. Derived from human pluripotent stem cells, brain organoids have been shown to recapitulate key developmental milestones of the early human brain. Combined with technological advancements in genome editing, tissue engineering, electrophysiology, and multi-omics analysis, brain organoids have expanded the frontiers of human neurobiology, providing valuable insight into the cellular and molecular mechanisms of normal and pathological brain development. This review will summarize the current progress of applying brain organoids to model human developmental brain diseases and discuss the challenges that need to be overcome to further advance their utility.
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Affiliation(s)
- Afrin Bhattacharya
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada; The University of Toronto, Department of Molecular Genetics, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
| | - Wendy W Y Choi
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada; The University of Toronto, Department of Molecular Genetics, 1 King's College Circle, Toronto, ON M5S 1A8, Canada; Program in Genetics and Genome Biology, The Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Julien Muffat
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada; The University of Toronto, Department of Molecular Genetics, 1 King's College Circle, Toronto, ON M5S 1A8, Canada; Program in Neurosciences and Mental Health, The Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada
| | - Yun Li
- Program in Developmental and Stem Cell Biology, The Hospital for Sick Children, 686 Bay Street, Toronto, ON M5G 0A4, Canada; The University of Toronto, Department of Molecular Genetics, 1 King's College Circle, Toronto, ON M5S 1A8, Canada.
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14
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Choi K, Lee J, Kang HJ. Myelination defects in the medial prefrontal cortex of Fkbp5 knockout mice. FASEB J 2021; 35:e21297. [PMID: 33410216 DOI: 10.1096/fj.202001883r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 11/14/2020] [Accepted: 12/07/2020] [Indexed: 12/13/2022]
Abstract
The hypothalamic-pituitary-adrenal (HPA) axis plays a principal role in stress response regulation and has been implicated in the etiology of stress-related disorders. The HPA axis regulates the normal synthesis and release of glucocorticoids; dysregulation of the HPA axis causes abnormal responses to stress. FK506-binding protein 5 (FKBP5), a co-chaperone of heat shock protein 90 in the glucocorticoid receptor (GR) molecular complex, is a key GR sensitivity regulator. FKBP5 single nucleotide polymorphisms are associated with dysregulated HPA axis and increased risk of stress-related disorders, including posttraumatic stress disorder (PTSD) and depression. In this study, we profiled the microRNAs (miRNAs) in the medial prefrontal cortex of Fkbp5 knockout (Fkbp5-/- ) mice and identified the target genes of differentially expressed miRNAs using sequence-based miRNA target prediction. Gene ontology analysis revealed that the differentially expressed miRNAs were involved in nervous system development, regulation of cell migration, and intracellular signal transduction. The validation of the expression of predicted target genes using quantitative polymerase chain reaction revealed that the expression of axon development-related genes, specifically actin-binding LIM protein 1 (Ablim1), lemur tyrosine kinase 2 (Lmtk2), kinesin family member 5c (Kif5c), neurofascin (Nfasc), and ephrin type-A receptor 4 (Epha4), was significantly decreased, while that of brain-derived neurotrophic factor (Bdnf) was significantly increased in the brain of Fkbp5-/- mice. These results suggest that axonal development-related genes can serve as potential targets in future studies focused on understanding the pathophysiology of PTSD.
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Affiliation(s)
- Koeul Choi
- Department of Life Science, Chung-Ang University, Seoul, Korea
| | - Joonhee Lee
- Department of Life Science, Chung-Ang University, Seoul, Korea
| | - Hyo Jung Kang
- Department of Life Science, Chung-Ang University, Seoul, Korea
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15
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RHOA signaling defects result in impaired axon guidance in iPSC-derived neurons from patients with tuberous sclerosis complex. Nat Commun 2021; 12:2589. [PMID: 33972524 PMCID: PMC8110792 DOI: 10.1038/s41467-021-22770-4] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2019] [Accepted: 03/26/2021] [Indexed: 11/30/2022] Open
Abstract
Patients with Tuberous Sclerosis Complex (TSC) show aberrant wiring of neuronal connections formed during development which may contribute to symptoms of TSC, such as intellectual disabilities, autism, and epilepsy. Yet models examining the molecular basis for axonal guidance defects in developing human neurons have not been developed. Here, we generate human induced pluripotent stem cell (hiPSC) lines from a patient with TSC and genetically engineer counterparts and isogenic controls. By differentiating hiPSCs, we show that control neurons respond to canonical guidance cues as predicted. Conversely, neurons with heterozygous loss of TSC2 exhibit reduced responses to several repulsive cues and defective axon guidance. While TSC2 is a known key negative regulator of MTOR-dependent protein synthesis, we find that TSC2 signaled through MTOR-independent RHOA in growth cones. Our results suggest that neural network connectivity defects in patients with TSC may result from defects in RHOA-mediated regulation of cytoskeletal dynamics during neuronal development. Patients with Tuberous Sclerosis Complex (TSC) show aberrant wiring of neuronal connections. Here, the authors generate iPSC-derived neurons from patients with TSC. TSC2 +/− neurons show impaired mTOR-independent RhoA signaling-mediated axon guidance.
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16
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Schmidt H, Böttcher A, Gross T, Schmidtko A. cGMP signalling in dorsal root ganglia and the spinal cord: Various functions in development and adulthood. Br J Pharmacol 2021; 179:2361-2377. [PMID: 33939841 DOI: 10.1111/bph.15514] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2020] [Revised: 03/12/2021] [Accepted: 03/31/2021] [Indexed: 12/27/2022] Open
Abstract
Cyclic GMP (cGMP) is a second messenger that regulates numerous physiological and pathophysiological processes. In recent years, more and more studies have uncovered multiple roles of cGMP signalling pathways in the somatosensory system. Accumulating evidence suggests that cGMP regulates different cellular processes from embryonic development through to adulthood. During embryonic development, a cGMP-dependent signalling cascade in the trunk sensory system is essential for axon bifurcation, a specific form of branching of somatosensory axons. In adulthood, various cGMP signalling pathways in distinct cell populations of sensory neurons and dorsal horn neurons in the spinal cord play an important role in the processing of pain and itch. Some of the involved enzymes might serve as a target for future therapies. In this review, we summarise the knowledge regarding cGMP-dependent signalling pathways in dorsal root ganglia and the spinal cord during embryonic development and adulthood, and the potential of targeting these pathways.
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Affiliation(s)
- Hannes Schmidt
- Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany
| | - Alexandra Böttcher
- Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany
| | - Tilman Gross
- Institute of Pharmacology and Clinical Pharmacy, Goethe University, Frankfurt am Main, Germany
| | - Achim Schmidtko
- Institute of Pharmacology and Clinical Pharmacy, Goethe University, Frankfurt am Main, Germany
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17
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Goto-Silva L, Martins M, Murillo JR, Souza LRQ, Vitória G, Oliveira JT, Nascimento JM, Loiola EC, Nogueira FCS, Domont GB, Guimarães MZP, Tovar-Moll F, Rehen SK, Junqueira M. Quantitative profiling of axonal guidance proteins during the differentiation of human neurospheres. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2021; 1869:140656. [PMID: 33857633 DOI: 10.1016/j.bbapap.2021.140656] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Subscribe] [Scholar Register] [Received: 12/20/2020] [Revised: 03/01/2021] [Accepted: 03/23/2021] [Indexed: 12/14/2022]
Abstract
Axon guidance is required for the establishment of brain circuits. Whether much of the molecular basis of axon guidance is known from animal models, the molecular machinery coordinating axon growth and pathfinding in humans remains to be elucidated. The use of induced pluripotent stem cells (iPSC) from human donors has revolutionized in vitro studies of the human brain. iPSC can be differentiated into neuronal stem cells which can be used to generate neural tissue-like cultures, known as neurospheres, that reproduce, in many aspects, the cell types and molecules present in the brain. Here, we analyzed quantitative changes in the proteome of neurospheres during differentiation. Relative quantification was performed at early time points during differentiation using iTRAQ-based labeling and LC-MS/MS analysis. We identified 6438 proteins, from which 433 were downregulated and 479 were upregulated during differentiation. We show that human neurospheres have a molecular profile that correlates to the fetal brain. During differentiation, upregulated pathways are related to neuronal development and differentiation, cell adhesion, and axonal guidance whereas cell proliferation pathways were downregulated. We developed a functional assay to check for neurite outgrowth in neurospheres and confirmed that neurite outgrowth potential is increased after 10 days of differentiation and is enhanced by increasing cyclic AMP levels. The proteins identified here represent a resource to monitor neurosphere differentiation and coupled to the neurite outgrowth assay can be used to functionally explore neurological disorders using human neurospheres as a model.
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Affiliation(s)
- Livia Goto-Silva
- D'Or Institute for Research and Education (IDOR), Rua Diniz Cordeiro, 30 - Botafogo, Rio de Janeiro, RJ 22281-100, Brazil
| | - Michele Martins
- Department of Biochemistry, Chemistry Institute, Federal University of Rio de Janeiro (UFRJ), Av. Athos da Silveira Ramos, 149 - bloco A 5° andar - Cidade Universitária da Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-909, Brazil
| | - Jimmy Rodriguez Murillo
- Department of Biochemistry, Chemistry Institute, Federal University of Rio de Janeiro (UFRJ), Av. Athos da Silveira Ramos, 149 - bloco A 5° andar - Cidade Universitária da Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-909, Brazil
| | - Leticia R Q Souza
- D'Or Institute for Research and Education (IDOR), Rua Diniz Cordeiro, 30 - Botafogo, Rio de Janeiro, RJ 22281-100, Brazil
| | - Gabriela Vitória
- D'Or Institute for Research and Education (IDOR), Rua Diniz Cordeiro, 30 - Botafogo, Rio de Janeiro, RJ 22281-100, Brazil
| | - Júlia T Oliveira
- D'Or Institute for Research and Education (IDOR), Rua Diniz Cordeiro, 30 - Botafogo, Rio de Janeiro, RJ 22281-100, Brazil
| | - Juliana M Nascimento
- D'Or Institute for Research and Education (IDOR), Rua Diniz Cordeiro, 30 - Botafogo, Rio de Janeiro, RJ 22281-100, Brazil; Department of Biosciences, Institute Science and Society, Federal University of São Paulo (Unifesp), Rua Silva Jardim, 136, Santos, SP 11015-020, Brazil
| | - Erick Correia Loiola
- D'Or Institute for Research and Education (IDOR), Rua Diniz Cordeiro, 30 - Botafogo, Rio de Janeiro, RJ 22281-100, Brazil
| | - Fabio C S Nogueira
- Department of Biochemistry, Chemistry Institute, Federal University of Rio de Janeiro (UFRJ), Av. Athos da Silveira Ramos, 149 - bloco A 5° andar - Cidade Universitária da Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-909, Brazil
| | - Gilberto B Domont
- Department of Biochemistry, Chemistry Institute, Federal University of Rio de Janeiro (UFRJ), Av. Athos da Silveira Ramos, 149 - bloco A 5° andar - Cidade Universitária da Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-909, Brazil
| | - Marília Zaluar P Guimarães
- D'Or Institute for Research and Education (IDOR), Rua Diniz Cordeiro, 30 - Botafogo, Rio de Janeiro, RJ 22281-100, Brazil; Institute of Biomedical Sciences, Federal University of Rio de Janeiro (UFRJ), Rua Manoel Frota Moreira - Cidade Universitária da Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-590, Brazil
| | - Fernanda Tovar-Moll
- D'Or Institute for Research and Education (IDOR), Rua Diniz Cordeiro, 30 - Botafogo, Rio de Janeiro, RJ 22281-100, Brazil
| | - Stevens Kastrup Rehen
- D'Or Institute for Research and Education (IDOR), Rua Diniz Cordeiro, 30 - Botafogo, Rio de Janeiro, RJ 22281-100, Brazil; Institute of Biomedical Sciences, Federal University of Rio de Janeiro (UFRJ), Rua Manoel Frota Moreira - Cidade Universitária da Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-590, Brazil.
| | - Magno Junqueira
- Department of Biochemistry, Chemistry Institute, Federal University of Rio de Janeiro (UFRJ), Av. Athos da Silveira Ramos, 149 - bloco A 5° andar - Cidade Universitária da Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ 21941-909, Brazil.
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18
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Zhang J, Xia K, Ahn M, Jha SC, Blanchett R, Crowley JJ, Szatkiewicz JP, Zou F, Zhu H, Styner M, Gilmore JH, Knickmeyer RC. Genome-Wide Association Analysis of Neonatal White Matter Microstructure. Cereb Cortex 2021; 31:933-948. [PMID: 33009551 PMCID: PMC7786356 DOI: 10.1093/cercor/bhaa266] [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: 08/15/2019] [Revised: 07/15/2020] [Accepted: 08/16/2020] [Indexed: 11/14/2022] Open
Abstract
A better understanding of genetic influences on early white matter development could significantly advance our understanding of neurological and psychiatric conditions characterized by altered integrity of axonal pathways. We conducted a genome-wide association study (GWAS) of diffusion tensor imaging (DTI) phenotypes in 471 neonates. We used a hierarchical functional principal regression model (HFPRM) to perform joint analysis of 44 fiber bundles. HFPRM revealed a latent measure of white matter microstructure that explained approximately 50% of variation in our tractography-based measures and accounted for a large proportion of heritable variation in each individual bundle. An intronic SNP in PSMF1 on chromosome 20 exceeded the conventional GWAS threshold of 5 x 10-8 (p = 4.61 x 10-8). Additional loci nearing genome-wide significance were located near genes with known roles in axon growth and guidance, fasciculation, and myelination.
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Affiliation(s)
- J Zhang
- Department of Biostatistics, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - K Xia
- Department of Psychiatry, University of North Carolina, Chapel Hill, NC, USA
| | - M Ahn
- Department of Mathematics and Statistics, University of Nevada, Reno, NV, USA
| | - S C Jha
- Department of Epidemiology, Harvard T.H. Chan School of Public Health, Boston, MA, USA
| | - R Blanchett
- Genetics and Genome Sciences Program, Michigan State University, East Lansing, MI, USA
| | - J J Crowley
- Department of Psychiatry, University of North Carolina, Chapel Hill, NC, USA
- Department of Genetics, University of North Carolina, Chapel Hill, NC, USA
- Department of Clinical Neuroscience, Karolinska Institute, Stockholm, Sweden
| | - J P Szatkiewicz
- Department of Psychiatry, University of North Carolina, Chapel Hill, NC, USA
- Department of Genetics, University of North Carolina, Chapel Hill, NC, USA
| | - F Zou
- Department of Biostatistics, University of North Carolina, Chapel Hill, NC, USA
| | - H Zhu
- Department of Biostatistics, University of North Carolina, Chapel Hill, NC, USA
| | - M Styner
- Department of Psychiatry, University of North Carolina, Chapel Hill, NC, USA
| | - J H Gilmore
- Department of Psychiatry, University of North Carolina, Chapel Hill, NC, USA
| | - R C Knickmeyer
- Department of Psychiatry, University of North Carolina, Chapel Hill, NC, USA
- Department of Pediatrics and Human Development, Michigan State University, East Lansing, MI, USA
- Institute for Quantitative Health Sciences and Engineering, Michigan State University, East Lansing, MI, USA
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19
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Trans-Axonal Signaling in Neural Circuit Wiring. Int J Mol Sci 2020; 21:ijms21145170. [PMID: 32708320 PMCID: PMC7404203 DOI: 10.3390/ijms21145170] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 07/15/2020] [Accepted: 07/17/2020] [Indexed: 12/24/2022] Open
Abstract
The development of neural circuits is a complex process that relies on the proper navigation of axons through their environment to their appropriate targets. While axon–environment and axon–target interactions have long been known as essential for circuit formation, communication between axons themselves has only more recently emerged as another crucial mechanism. Trans-axonal signaling governs many axonal behaviors, including fasciculation for proper guidance to targets, defasciculation for pathfinding at important choice points, repulsion along and within tracts for pre-target sorting and target selection, repulsion at the target for precise synaptic connectivity, and potentially selective degeneration for circuit refinement. This review outlines the recent advances in identifying the molecular mechanisms of trans-axonal signaling and discusses the role of axon–axon interactions during the different steps of neural circuit formation.
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20
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Mutation in ROBO3 Gene in Patients with Horizontal Gaze Palsy with Progressive Scoliosis Syndrome: A Systematic Review. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17124467. [PMID: 32580277 PMCID: PMC7345006 DOI: 10.3390/ijerph17124467] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/23/2020] [Revised: 06/11/2020] [Accepted: 06/17/2020] [Indexed: 11/17/2022]
Abstract
Horizontal gaze palsy with progressive scoliosis (HGPPS) is a rare, inherited disorder characterized by a congenital absence of conjugate horizontal eye movements with progressive scoliosis developing in childhood and adolescence. Mutations in the Roundabout (ROBO3) gene located on chromosome 11q23–25 are responsible for the development of horizontal gaze palsy and progressive scoliosis. However, some studies redefined the locus responsible for this pathology to a 9-cM region. This study carried out a systematic review in which 25 documents were analyzed, following Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) standards. The search was made in the following electronic databases from January 1995 to October 2019: PubMed, Scopus, Web of Science, PEDRO, SPORT Discus, and CINAHL. HGPPS requires a multidisciplinary diagnostic approach, in which magnetic resonance imaging might be the first technique to suggest the diagnosis, which should be verified by an analysis of the ROBO3 gene. This is important to allow for adequate ocular follow up, apply supportive therapies to prevent the rapid progression of scoliosis, and lead to appropriate genetic counseling.
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21
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Dumoulin A, Schmidt H, Rathjen FG. Sensory Neurons: The Formation of T-Shaped Branches Is Dependent on a cGMP-Dependent Signaling Cascade. Neuroscientist 2020; 27:47-57. [PMID: 32321356 DOI: 10.1177/1073858420913844] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Axon bifurcation - a specific form of branching of somatosensory axons characterized by the splitting of the growth cone - is mediated by a cGMP-dependent signaling cascade composed of the extracellular ligand CNP (C-type natriuretic peptide), the transmembrane receptor guanylyl cyclase Npr2 (natriuretic peptide receptor 2), and the kinase cGKI (cGMP-dependent protein kinase I). In the absence of any one of these components, the formation of T-shaped axonal branches is impaired in neurons from DRGs (dorsal root ganglia), CSGs (cranial sensory ganglia) and MTNs (mesencephalic trigeminal neurons) in the murine spinal cord or hindbrain. Instead, axons from DRGs or from CSGs extend only either in an ascending or descending direction, while axons from MTNs either elongate within the hindbrain or extend via the trigeminal ganglion to the masseter muscles. Collateral formation from non-bifurcating stem axons is not affected by impaired cGMP signaling. Activation of Npr2 requires both binding of the ligand CNP as well as phosphorylation of serine and threonine residues at the juxtamembrane regions of the receptor. The absence of bifurcation results in an altered shape of termination fields of sensory afferents in the spinal cord and resulted in impaired noxious heat sensation and nociception whereas motor coordination appeared normal.
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Affiliation(s)
- Alexandre Dumoulin
- Department of Molecular Life Sciences, University of Zürich, Zürich, Switzerland
| | - Hannes Schmidt
- Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany
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22
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Accogli A, Calabretta S, St-Onge J, Boudrahem-Addour N, Dionne-Laporte A, Joset P, Azzarello-Burri S, Rauch A, Krier J, Fieg E, Pallais JC, McConkie-Rosell A, McDonald M, Freedman SF, Rivière JB, Lafond-Lapalme J, Simpson BN, Hopkin RJ, Trimouille A, Van-Gils J, Begtrup A, McWalter K, Delphine H, Keren B, Genevieve D, Argilli E, Sherr EH, Severino M, Rouleau GA, Yam PT, Charron F, Srour M. De Novo Pathogenic Variants in N-cadherin Cause a Syndromic Neurodevelopmental Disorder with Corpus Collosum, Axon, Cardiac, Ocular, and Genital Defects. Am J Hum Genet 2019; 105:854-868. [PMID: 31585109 DOI: 10.1016/j.ajhg.2019.09.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2019] [Accepted: 09/05/2019] [Indexed: 01/06/2023] Open
Abstract
Cadherins constitute a family of transmembrane proteins that mediate calcium-dependent cell-cell adhesion. The extracellular domain of cadherins consists of extracellular cadherin (EC) domains, separated by calcium binding sites. The EC interacts with other cadherin molecules in cis and in trans to mechanically hold apposing cell surfaces together. CDH2 encodes N-cadherin, whose essential roles in neural development include neuronal migration and axon pathfinding. However, CDH2 has not yet been linked to a Mendelian neurodevelopmental disorder. Here, we report de novo heterozygous pathogenic variants (seven missense, two frameshift) in CDH2 in nine individuals with a syndromic neurodevelopmental disorder characterized by global developmental delay and/or intellectual disability, variable axon pathfinding defects (corpus callosum agenesis or hypoplasia, mirror movements, Duane anomaly), and ocular, cardiac, and genital anomalies. All seven missense variants (c.1057G>A [p.Asp353Asn]; c.1789G>A [p.Asp597Asn]; c.1789G>T [p.Asp597Tyr]; c.1802A>C [p.Asn601Thr]; c.1839C>G [p.Cys613Trp]; c.1880A>G [p.Asp627Gly]; c.2027A>G [p.Tyr676Cys]) result in substitution of highly conserved residues, and six of seven cluster within EC domains 4 and 5. Four of the substitutions affect the calcium-binding site in the EC4-EC5 interdomain. We show that cells expressing these variants in the EC4-EC5 domains have a defect in cell-cell adhesion; this defect includes impaired binding in trans with N-cadherin-WT expressed on apposing cells. The two frameshift variants (c.2563_2564delCT [p.Leu855Valfs∗4]; c.2564_2567dupTGTT [p.Leu856Phefs∗5]) are predicted to lead to a truncated cytoplasmic domain. Our study demonstrates that de novo heterozygous variants in CDH2 impair the adhesive activity of N-cadherin, resulting in a multisystemic developmental disorder, that could be named ACOG syndrome (agenesis of corpus callosum, axon pathfinding, cardiac, ocular, and genital defects).
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Affiliation(s)
- Andrea Accogli
- Department of Pediatrics, Division of Pediatric Neurology, McGill University, H4A 3J1, Montreal, QC, Canada; Medical Genetics Unit, IRCCS Ospedale Policlinico San Martino, 16132 Genova, Italy; Dipartimento di Neuroscienze, Reabilitazione, Oftalmologia, Genetica e Scienze Materno-Infantili, Università degli Studi di Genova, 16132 Genova Italy
| | - Sara Calabretta
- Montreal Clinical Research Institute, H2W 1R7 Montreal, QC, Canada
| | - Judith St-Onge
- McGill University Health Center Research Institute, H4A 3J1, Montreal, QC, Canada
| | | | | | - Pascal Joset
- Institute of Medical Genetics, University of Zurich, CH-8952 Schlieren, Switzerland
| | | | - Anita Rauch
- Institute of Medical Genetics, University of Zurich, CH-8952 Schlieren, Switzerland
| | - Joel Krier
- Brigham and Women's Hospital, Boston, MA 02115, USA
| | | | | | - Allyn McConkie-Rosell
- Division of Medical Genetics, Department of Pediatrics, Duke University, Durham, NC 27707, USA
| | - Marie McDonald
- Division of Medical Genetics, Department of Pediatrics, Duke University, Durham, NC 27707, USA
| | - Sharon F Freedman
- Department of Ophthalmology, Duke University Medical Center, Durham, NC 27710, USA
| | | | - Joël Lafond-Lapalme
- McGill University Health Center Research Institute, H4A 3J1, Montreal, QC, Canada
| | - Brittany N Simpson
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Robert J Hopkin
- Division of Human Genetics, Cincinnati Children's Hospital Medical Center, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Aurélien Trimouille
- Centre Hospitalier Universitaire Bordeaux, Service de Génétique Médicale, 33076 Bordeaux, France; Laboratoire Maladies Rares: Génétique et Métabolisme, Inserm U1211, Université de Bordeaux, 33076 Bordeaux, France
| | - Julien Van-Gils
- Centre Hospitalier Universitaire Bordeaux, Service de Génétique Médicale, 33076 Bordeaux, France; Laboratoire Maladies Rares: Génétique et Métabolisme, Inserm U1211, Université de Bordeaux, 33076 Bordeaux, France
| | | | | | - Heron Delphine
- Département de Génétique, Centre de Référence des Déficiences Intellectuelles de Causes Rares, Groupe Hospitalier Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris, 75013 Paris
| | - Boris Keren
- Département de Génétique, Centre de Référence des Déficiences Intellectuelles de Causes Rares, Groupe Hospitalier Pitié-Salpêtrière, Assistance Publique-Hôpitaux de Paris, 75013 Paris
| | - David Genevieve
- Département de Genetique Médicale, Maladies Rares et Médecine Personnalisée, Centre de Référence Anomalies du Développement, Université Montpellier, Unité Inserm U1183, Centre Hospitalier Universitaire Montpellier, 34000 Montpellier, France
| | - Emanuela Argilli
- Departments of Neurology and Pediatrics, Weill Institute of Neuroscience and Institute of Human Genetics, University of California, CA 94143 San Francisco
| | - Elliott H Sherr
- Departments of Neurology and Pediatrics, Weill Institute of Neuroscience and Institute of Human Genetics, University of California, CA 94143 San Francisco
| | - Mariasavina Severino
- Istituto di Ricovero e Cura a Carattere Scientifico, Istituto Giannina Gaslini, 16147 Genova, Italy
| | - Guy A Rouleau
- Montreal Neurological Institute, McGill University, H3A 2B4, Montreal, QC, Canada; Department of Neurology and Neurosurgery, McGill University, H3A 2B4, Montreal, QC, Canada
| | - Patricia T Yam
- Montreal Clinical Research Institute, H2W 1R7 Montreal, QC, Canada
| | - Frédéric Charron
- Montreal Clinical Research Institute, H2W 1R7 Montreal, QC, Canada; Department of Medicine, University of Montreal, H3C 3J7, Montreal, QC, Canada; Department of Anatomy and Cell Biology, McGill University, H4A 3J1, Montreal, QC, Canada; Department of Experimental Medicine, McGill University, H4A 3J1, Montreal, QC, Canada.
| | - Myriam Srour
- Department of Pediatrics, Division of Pediatric Neurology, McGill University, H4A 3J1, Montreal, QC, Canada; McGill University Health Center Research Institute, H4A 3J1, Montreal, QC, Canada; Department of Neurology and Neurosurgery, McGill University, H3A 2B4, Montreal, QC, Canada.
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23
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Comer JD, Alvarez S, Butler SJ, Kaltschmidt JA. Commissural axon guidance in the developing spinal cord: from Cajal to the present day. Neural Dev 2019; 14:9. [PMID: 31514748 PMCID: PMC6739980 DOI: 10.1186/s13064-019-0133-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2019] [Accepted: 08/23/2019] [Indexed: 12/11/2022] Open
Abstract
During neuronal development, the formation of neural circuits requires developing axons to traverse a diverse cellular and molecular environment to establish synaptic contacts with the appropriate postsynaptic partners. Essential to this process is the ability of developing axons to navigate guidance molecules presented by specialized populations of cells. These cells partition the distance traveled by growing axons into shorter intervals by serving as intermediate targets, orchestrating the arrival and departure of axons by providing attractive and repulsive guidance cues. The floor plate in the central nervous system (CNS) is a critical intermediate target during neuronal development, required for the extension of commissural axons across the ventral midline. In this review, we begin by giving a historical overview of the ventral commissure and the evolutionary purpose of decussation. We then review the axon guidance studies that have revealed a diverse assortment of midline guidance cues, as well as genetic and molecular regulatory mechanisms required for coordinating the commissural axon response to these cues. Finally, we examine the contribution of dysfunctional axon guidance to neurological diseases.
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Affiliation(s)
- J D Comer
- Neuroscience Program, Weill Cornell Graduate School of Medical Sciences, New York, NY, USA.,Developmental Biology Program, Sloan Kettering Institute, New York, NY, USA.,Weill Cornell/Rockefeller/Sloan Kettering Tri-Institutional MD-PhD Program, New York, NY, USA
| | - S Alvarez
- Department of Neurobiology, University of California, Los Angeles, Los Angeles, CA, 90095, USA.,Molecular Biology Interdepartmental Graduate Program, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - S J Butler
- Department of Neurobiology, University of California, Los Angeles, Los Angeles, CA, 90095, USA.,Eli and Edythe Broad Center of Regenerative Medicine and Stem Cell Research, University of California, Los Angeles, Los Angeles, CA, 90095, USA
| | - J A Kaltschmidt
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, 94305, USA.
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24
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Di Gioia SA, Shaaban S, Tüysüz B, Elcioglu NH, Chan WM, Robson CD, Ecklund K, Gilette NM, Hamzaoglu A, Tayfun GA, Traboulsi EI, Engle EC. Recessive MYF5 Mutations Cause External Ophthalmoplegia, Rib, and Vertebral Anomalies. Am J Hum Genet 2018; 103:115-124. [PMID: 29887215 DOI: 10.1016/j.ajhg.2018.05.003] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Accepted: 05/04/2018] [Indexed: 12/23/2022] Open
Abstract
MYF5 is member of the Myc-like basic helix-loop-helix transcription factor family and, in cooperation with other myogenic regulatory factors MYOD and MYF5, is a key regulator of early stages of myogenesis. Here, we report three consanguineous families with biallelic homozygous loss-of-function mutations in MYF5 who define a clinical disorder characterized by congenital ophthalmoplegia with scoliosis and vertebral and rib anomalies. The clinical phenotype overlaps strikingly with that reported in several Myf5 knockout mouse models. Affected members of two families share a haploidentical region that contains a homozygous 10 bp frameshift mutation in exon 1 of MYF5 (c.23_32delAGTTCTCACC [p.Gln8Leufs∗86]) predicted to undergo nonsense-mediated decay. Affected members of the third family harbor a homozygous missense change in exon 1 of MYF5 (c.283C>T [p.Arg95Cys]). Using in vitro assays, we show that this missense mutation acts as a loss-of-function allele by impairing MYF5 DNA binding and nuclear localization. We performed whole-genome sequencing in one affected individual with the frameshift mutation and did not identify additional rare variants in the haploidentical region that might account for differences in severity among the families. These data support the direct role of MYF5 in rib, spine, and extraocular muscle formation in humans.
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25
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Ter-Avetisyan G, Dumoulin A, Herrel A, Schmidt H, Strump J, Afzal S, Rathjen FG. Loss of Axon Bifurcation in Mesencephalic Trigeminal Neurons Impairs the Maximal Biting Force in Npr2-Deficient Mice. Front Cell Neurosci 2018; 12:153. [PMID: 29962937 PMCID: PMC6013911 DOI: 10.3389/fncel.2018.00153] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2018] [Accepted: 05/16/2018] [Indexed: 11/13/2022] Open
Abstract
Bifurcation of axons from dorsal root ganglion (DRG) and cranial sensory ganglion (CSG) neurons is mediated by a cGMP-dependent signaling pathway composed of the ligand C-type natriuretic peptide (CNP), the receptor guanylyl cyclase Npr2 and the cGMP-dependent protein kinase I (cGKI). Here, we demonstrate that mesencephalic trigeminal neurons (MTN) which are the only somatosensory neurons whose cell bodies are located within the CNS co-express Npr2 and cGKI. Afferents of MTNs form Y-shaped branches in rhombomere 2 where the ligand CNP is expressed. Analyzing mouse mutants deficient for CNP or Npr2 we found that in the absence of CNP-induced cGMP signaling MTN afferents no longer bifurcate and instead extend either into the trigeminal root or caudally in the hindbrain. Since MTNs provide sensory information from jaw closing muscles and periodontal ligaments we measured the bite force of conditional mouse mutants of Npr2 (Npr2flox/flox;Engr1Cre ) that lack bifurcation of MTN whereas the bifurcation of trigeminal afferents is normal. Our study revealed that the maximal biting force of both sexes is reduced in Npr2flox/flox;Engr1Cre mice as compared to their Npr2flox/flox littermate controls. In conclusion sensory feedback mechanisms from jaw closing muscles or periodontal ligaments might be impaired in the absence of MTN axon bifurcation.
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Affiliation(s)
| | | | - Anthony Herrel
- Département Adaptations du Vivant, UMR 7179 Centre National de la Recherche Scientifique/MNHN, Paris, France
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26
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Solmaz B, Özyurt MG, Ata DB, Akçimen F, Shabsog M, Türker KS, Dalçik H, Algin O, Başak AN, Özgür M, Çavdar S. Assessment of the corticospinal fiber integrity in mirror movement disorder. J Clin Neurosci 2018; 54:69-76. [PMID: 29907388 DOI: 10.1016/j.jocn.2018.06.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2018] [Accepted: 06/03/2018] [Indexed: 10/14/2022]
Abstract
Mirror movements are unintended movements occurring on one side of the body that mirror the contralateral voluntary ones. It has been proposed that mirror movements occur due to abnormal decussation of the corticospinal pathways. Using detailed multidisciplinary approach, we aimed to enlighten the detailed mechanism underlying the mirror movements in a case subject who is diagnosed with mirror movements of the hands and we compared the findings with the unaffected control subjects. To evaluate the characteristics of mirror movements, we used several techniques including whole exome sequencing, computed tomography, diffusion tensor imaging and transcranial magnetic stimulation. Computed tomography showed the absence of a spinous process of C5, fusion of the body of C5-C6 vertebrae, hypoplastic dens and platybasia of the posterior cranial fossa. A syrinx cavity was present between levels C3-C4 of the spinal cord. Diffusion tensor imaging of the corticospinal fibers showed disorganization and minimal decussations at the lower medulla oblongata. Transcranial magnetic stimulation showed that motor commands were distributed to the motor neuron pools on the left and right sides of the spinal cord via fast-conducting corticospinal tract fibers. Moreover, a heterozygous missense variation in the deleted in colorectal carcinoma gene has been observed. Developmental absence of the axonal guidance molecules or their receptors may result in abnormalities in the leading of the corticospinal fibers. Clinical evaluations and basic neuroscience techniques, in this case, provide information for this rare disease and contribute to our understanding of the normal physiology of bimanual coordination.
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Affiliation(s)
- Bilgehan Solmaz
- Department of Neurosurgery, Istanbul Education and Research Hospital, Istanbul, Turkey
| | | | - Demir Berk Ata
- Department of Molecular Biology and Genetics, School of Medicine, Koç University, Istanbul, Turkey
| | - Fulya Akçimen
- Neurodegeneration Research Laboratory, Suna and İnan Kıraç Foundation, Boğaziçi University, İstanbul, Turkey
| | - Mohammed Shabsog
- Department of Physiology, School of Medicine, Koç University, Istanbul, Turkey
| | - Kemal Sıtkı Türker
- Department of Physiology, School of Medicine, Koç University, Istanbul, Turkey
| | - Hakkı Dalçik
- Department of Preclinical Science, Anatomy Unit, Faculty of Medicine, The University of the West Indies, St. Augustine, Trinidad and Tobago
| | - Oktay Algin
- Department of Radiology, Bilkent University, Ankara, Turkey
| | - Ayşe Nazlı Başak
- Neurodegeneration Research Laboratory, Suna and İnan Kıraç Foundation, Boğaziçi University, İstanbul, Turkey
| | - Merve Özgür
- Department of Anatomy, School of Medicine, Koç University, Istanbul, Turkey
| | - Safiye Çavdar
- Department of Anatomy, School of Medicine, Koç University, Istanbul, Turkey.
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27
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Dumoulin A, Ter-Avetisyan G, Schmidt H, Rathjen FG. Molecular Analysis of Sensory Axon Branching Unraveled a cGMP-Dependent Signaling Cascade. Int J Mol Sci 2018; 19:E1266. [PMID: 29695045 PMCID: PMC5983660 DOI: 10.3390/ijms19051266] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2018] [Revised: 04/15/2018] [Accepted: 04/20/2018] [Indexed: 01/11/2023] Open
Abstract
Axonal branching is a key process in the establishment of circuit connectivity within the nervous system. Molecular-genetic studies have shown that a specific form of axonal branching—the bifurcation of sensory neurons at the transition zone between the peripheral and the central nervous system—is regulated by a cyclic guanosine monophosphate (cGMP)-dependent signaling cascade which is composed of C-type natriuretic peptide (CNP), the receptor guanylyl cyclase Npr2, and cGMP-dependent protein kinase Iα (cGKIα). In the absence of any one of these components, neurons in dorsal root ganglia (DRG) and cranial sensory ganglia no longer bifurcate, and instead turn in either an ascending or a descending direction. In contrast, collateral axonal branch formation which represents a second type of axonal branch formation is not affected by inactivation of CNP, Npr2, or cGKI. Whereas axon bifurcation was lost in mouse mutants deficient for components of CNP-induced cGMP formation; the absence of the cGMP-degrading enzyme phosphodiesterase 2A had no effect on axon bifurcation. Adult mice that lack sensory axon bifurcation due to the conditional inactivation of Npr2-mediated cGMP signaling in DRG neurons demonstrated an altered shape of sensory axon terminal fields in the spinal cord, indicating that elaborate compensatory mechanisms reorganize neuronal circuits in the absence of bifurcation. On a functional level, these mice showed impaired heat sensation and nociception induced by chemical irritants, whereas responses to cold sensation, mechanical stimulation, and motor coordination are normal. These data point to a critical role of axon bifurcation for the processing of acute pain perception.
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Affiliation(s)
| | | | - Hannes Schmidt
- Interfaculty Institute of Biochemistry, University of Tübingen, Hoppe-Seyler-Str. 4, 72076 Tübingen, Germany.
| | - Fritz G Rathjen
- Max-Delbrück-Center, Robert-Rössle-Str. 10, 13092 Berlin, Germany.
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28
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Garcia-Monclús S, López-Alemany R, Almacellas-Rabaiget O, Herrero-Martín D, Huertas-Martinez J, Lagares-Tena L, Alba-Pavón P, Hontecillas-Prieto L, Mora J, de Álava E, Rello-Varona S, Giangrande PH, Tirado OM. EphA2 receptor is a key player in the metastatic onset of Ewing sarcoma. Int J Cancer 2018; 143:1188-1201. [PMID: 29582409 DOI: 10.1002/ijc.31405] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2017] [Revised: 03/05/2018] [Accepted: 03/15/2018] [Indexed: 02/06/2023]
Abstract
Ewing sarcoma (ES) is the second most common bone malignancy affecting children and young adults with poor prognosis due to high metastasis incidence. Our group previously described that EphA2, a tyrosine kinase receptor, promotes angiogenesis in Ewing sarcoma (ES) cells via ligand-dependent signaling. Now we wanted to explore EphA2 ligand-independent activity, controlled upon phosphorylation at S897 (p-EphA2S897 ), as it has been linked to metastasis in several malignancies. By reverse genetic engineering we explored the phenotypic changes after EphA2 removal or reintroduction. Gene expression microarray was used to identify key players in EphA2 signaling. Mice were employed to reproduce metastatic processes from orthotopically implanted engineered cells. We established a correlation between ES cells aggressiveness and p-EphA2S897 . Moreover, stable overexpression of EphA2 in low EphA2 expression ES cells enhanced proliferation and migration, but not a non-phosphorylable mutant (S987A). Consistently, silencing of EphA2 reduced tumorigenicity, migration and invasion in vitro, and lung metastasis incidence in experimental and spontaneous metastasis assays in vivo. A gene expression microarray revealed the implication of EphA2 in cell signaling, cellular movement and survival. ADAM19 knockdown by siRNA technology strongly reproduced the negative effects on cell migration observed after EphA2 silencing. Altogether, our results suggest that p-EphA2S897 correlates with aggressiveness in ES, so blocking its function may be a promising treatment.
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Affiliation(s)
- Silvia Garcia-Monclús
- Sarcoma Research Group, Oncobell Program, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain
| | - Roser López-Alemany
- Sarcoma Research Group, Oncobell Program, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain
| | - Olga Almacellas-Rabaiget
- Sarcoma Research Group, Oncobell Program, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain
| | - David Herrero-Martín
- Sarcoma Research Group, Oncobell Program, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain.,CIBERONC, Carlos III Institute of Health (ISCIII), Madrid, Spain
| | - Juan Huertas-Martinez
- Sarcoma Research Group, Oncobell Program, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain
| | - Laura Lagares-Tena
- Sarcoma Research Group, Oncobell Program, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain
| | - Piedad Alba-Pavón
- Sarcoma Research Group, Oncobell Program, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain
| | - Lourdes Hontecillas-Prieto
- CIBERONC, Carlos III Institute of Health (ISCIII), Madrid, Spain.,Laboratory of Molecular Pathology, Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocio/CSIC/Universidad de Sevilla, Sevilla, Spain
| | - Jaume Mora
- Developmental Tumor Biology Laboratory, Hospital Sant Joan de Deu, Barcelona, Spain
| | - Enrique de Álava
- CIBERONC, Carlos III Institute of Health (ISCIII), Madrid, Spain.,Laboratory of Molecular Pathology, Instituto de Biomedicina de Sevilla (IBiS), Hospital Universitario Virgen del Rocio/CSIC/Universidad de Sevilla, Sevilla, Spain
| | - Santi Rello-Varona
- Sarcoma Research Group, Oncobell Program, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain
| | | | - Oscar M Tirado
- Sarcoma Research Group, Oncobell Program, Bellvitge Biomedical Research Institute (IDIBELL), L'Hospitalet de Llobregat, Barcelona, Spain.,CIBERONC, Carlos III Institute of Health (ISCIII), Madrid, Spain.,Institut Català d'Oncologia (ICO), L'Hospitalet de Llobregat, Barcelona, Spain
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29
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Tröster P, Haseleu J, Petersen J, Drees O, Schmidtko A, Schwaller F, Lewin GR, Ter-Avetisyan G, Winter Y, Peters S, Feil S, Feil R, Rathjen FG, Schmidt H. The Absence of Sensory Axon Bifurcation Affects Nociception and Termination Fields of Afferents in the Spinal Cord. Front Mol Neurosci 2018; 11:19. [PMID: 29472841 PMCID: PMC5809486 DOI: 10.3389/fnmol.2018.00019] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2017] [Accepted: 01/15/2018] [Indexed: 12/16/2022] Open
Abstract
A cGMP signaling cascade composed of C-type natriuretic peptide, the guanylyl cyclase receptor Npr2 and cGMP-dependent protein kinase I (cGKI) controls the bifurcation of sensory axons upon entering the spinal cord during embryonic development. However, the impact of axon bifurcation on sensory processing in adulthood remains poorly understood. To investigate the functional consequences of impaired axon bifurcation during adult stages we generated conditional mouse mutants of Npr2 and cGKI (Npr2fl/fl;Wnt1Cre and cGKIKO/fl;Wnt1Cre) that lack sensory axon bifurcation in the absence of additional phenotypes observed in the global knockout mice. Cholera toxin labeling in digits of the hind paw demonstrated an altered shape of sensory neuron termination fields in the spinal cord of conditional Npr2 mouse mutants. Behavioral testing of both sexes indicated that noxious heat sensation and nociception induced by chemical irritants are impaired in the mutants, whereas responses to cold sensation, mechanical stimulation, and motor coordination are not affected. Recordings from C-fiber nociceptors in the hind limb skin showed that Npr2 function was not required to maintain normal heat sensitivity of peripheral nociceptors. Thus, the altered behavioral responses to noxious heat found in Npr2fl/fl;Wnt1Cre mice is not due to an impaired C-fiber function. Overall, these data point to a critical role of axonal bifurcation for the processing of pain induced by heat or chemical stimuli.
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Affiliation(s)
- Philip Tröster
- Developmental Neurobiology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Julia Haseleu
- Molecular Physiology of Somatic Sensation, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Jonas Petersen
- Institute of Pharmacology, College of Pharmacy, Goethe University, Frankfurt am Main, Germany.,Institute of Pharmacology and Toxicology, Zentrum für Biomedizinische Ausbildung und Forschung (ZBAF), Witten/Herdecke University, Witten, Germany
| | - Oliver Drees
- Institute of Pharmacology and Toxicology, Zentrum für Biomedizinische Ausbildung und Forschung (ZBAF), Witten/Herdecke University, Witten, Germany
| | - Achim Schmidtko
- Institute of Pharmacology, College of Pharmacy, Goethe University, Frankfurt am Main, Germany.,Institute of Pharmacology and Toxicology, Zentrum für Biomedizinische Ausbildung und Forschung (ZBAF), Witten/Herdecke University, Witten, Germany
| | - Frederick Schwaller
- Molecular Physiology of Somatic Sensation, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Gary R Lewin
- Molecular Physiology of Somatic Sensation, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Gohar Ter-Avetisyan
- Developmental Neurobiology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - York Winter
- Cognitive Neurobiology, Humboldt University of Berlin, Berlin, Germany
| | - Stefanie Peters
- Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany
| | - Susanne Feil
- Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany
| | - Robert Feil
- Interfaculty Institute of Biochemistry, University of Tübingen, Tübingen, Germany
| | - Fritz G Rathjen
- Developmental Neurobiology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
| | - Hannes Schmidt
- Developmental Neurobiology, Max Delbrück Center for Molecular Medicine in the Helmholtz Association, Berlin, Germany
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30
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Brown HE, Reichert MC, Evans TA. In Vivo Functional Analysis of Drosophila Robo1 Fibronectin Type-III Repeats. G3 (BETHESDA, MD.) 2018; 8:621-630. [PMID: 29217730 PMCID: PMC5919748 DOI: 10.1534/g3.117.300418] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/07/2017] [Accepted: 12/05/2017] [Indexed: 12/02/2022]
Abstract
The repellant ligand Slit and its Roundabout (Robo) family receptors regulate midline crossing of axons during development of the embryonic central nervous system (CNS). Slit proteins are produced at the midline and signal through Robo receptors to repel axons from the midline. Disruption of Slit-Robo signaling causes ectopic midline-crossing phenotypes in the CNS of a broad range of animals, including insects and vertebrates. While previous studies have investigated the roles of Drosophila melanogaster Robo1's five Immunoglobulin-like (Ig) domains, little is known about the importance of the three evolutionarily conserved Fibronectin (Fn) type-III repeats. We have individually deleted each of Drosophila Robo1's three Fn repeats, and then tested these Robo1 variants in vitro to determine their ability to bind Slit in cultured Drosophila cells and in vivo to investigate the requirement for each domain in regulating Robo1's embryonic expression pattern, axonal localization, midline repulsive function, and sensitivity to Commissureless (Comm) downregulation. We demonstrate that the Fn repeats are not required for Robo1 to bind Slit or for proper expression of Robo1 in Drosophila embryonic neurons. When expressed in a robo1 mutant background, these variants are able to restore midline repulsion to an extent equivalent to full-length Robo1. We identify a novel requirement for Fn3 in the exclusion of Robo1 from commissures and downregulation of Robo1 by Comm. Our results indicate that each of the Drosophila Robo1 Fn repeats are individually dispensable for the protein's role in midline repulsion, despite the evolutionarily conserved "5 + 3" protein structure.
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Affiliation(s)
- Haley E Brown
- Department of Biological Sciences, University of Arkansas, Fayetteville, Arkansas 72701
| | - Marie C Reichert
- Department of Biological Sciences, University of Arkansas, Fayetteville, Arkansas 72701
| | - Timothy A Evans
- Department of Biological Sciences, University of Arkansas, Fayetteville, Arkansas 72701
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31
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Sedarous F, Chan TYB, Makar I. Alternating Hypotropia with Pseudoptosis: A New Phenotype of Congenital Cranial Dysinnervation Disorder. Case Rep Ophthalmol 2018; 9:96-101. [PMID: 29643789 PMCID: PMC5892332 DOI: 10.1159/000485832] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Accepted: 11/29/2017] [Indexed: 12/03/2022] Open
Abstract
Congenital cranial dysinnervation disorders, also known as CCDDs, are characterized by aberrant innervation to extraocular and facial muscles resulting in unusual forms of incomitant strabismus. Anomalous innervation to extraocular muscles can result in a wide variety of phenotypes causing various clinical conditions such as Duane syndrome, congenital fibrosis of the extraocular muscles, and Möbius syndrome. We report a case of bilateral dysinnervation disorder causing atypical ocular movements in both eyes as the patient changes fixation from one eye to the other and from right gaze to left gaze that fits with the wider diagnosis of CCDDs.
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Affiliation(s)
| | - Toby Y B Chan
- McMaster University, Waterloo Regional Campus, Kitchener, Ontario, Canada
| | - Inas Makar
- Ivey Eye Institute, University of Western Ontario, London, Ontario, Canada
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32
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Abstract
The formation of the nervous system is a multistep process that yields a mature brain. Failure in any of the steps of this process may cause brain malfunction. In the early stages of embryonic development, neural progenitors quickly proliferate and then, at a specific moment, differentiate into neurons or glia. Once they become postmitotic neurons, they migrate to their final destinations and begin to extend their axons to connect with other neurons, sometimes located in quite distant regions, to establish different neural circuits. During the last decade, it has become evident that Zic genes, in addition to playing important roles in early development (e.g., gastrulation and neural tube closure), are involved in different processes of late brain development, such as neuronal migration, axon guidance, and refinement of axon terminals. ZIC proteins are therefore essential for the proper wiring and connectivity of the brain. In this chapter, we review our current knowledge of the role of Zic genes in the late stages of neural circuit formation.
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Howard LJ, Brown HE, Wadsworth BC, Evans TA. Midline axon guidance in the Drosophila embryonic central nervous system. Semin Cell Dev Biol 2017; 85:13-25. [PMID: 29174915 DOI: 10.1016/j.semcdb.2017.11.029] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Revised: 11/13/2017] [Accepted: 11/21/2017] [Indexed: 02/02/2023]
Abstract
Studies in the fruit fly Drosophila melanogaster have provided many fundamental insights into the genetic regulation of neural development, including the identification and characterization of evolutionarily conserved axon guidance pathways and their roles in important guidance decisions. Due to its highly organized and fast-developing embryonic nervous system, relatively small number of neurons, and molecular and genetic tools for identifying, labeling, and manipulating individual neurons or small neuronal subsets, studies of axon guidance in the Drosophila embryonic CNS have allowed researchers to dissect these genetic mechanisms with a high degree of precision. In this review, we discuss the major axon guidance pathways that regulate midline crossing of axons and the formation and guidance of longitudinal axon tracts, two processes that contribute to the development of the precise three-dimensional structure of the insect nerve cord. We focus particularly on recent insights into the roles and regulation of canonical midline axon guidance pathways, and on additional factors and pathways that have recently been shown to contribute to axon guidance decisions at and near the midline.
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Affiliation(s)
- LaFreda J Howard
- Department of Biological Sciences, University of Arkansas, Fayetteville AR 72701, USA
| | - Haley E Brown
- Department of Biological Sciences, University of Arkansas, Fayetteville AR 72701, USA
| | - Benjamin C Wadsworth
- Department of Biological Sciences, University of Arkansas, Fayetteville AR 72701, USA
| | - Timothy A Evans
- Department of Biological Sciences, University of Arkansas, Fayetteville AR 72701, USA.
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Abstract
Brain function requires connecting neuronal networks to empower movement, sensation, behavior, and cognition. Studies published early this year provide evidence that in humans, Netrin receptor, Deleted in Colorectal Cancer (DCC), is a master regulator of axonal crossing throughout the neuraxis.
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Affiliation(s)
- Raphael M Bendriem
- Feil Family Brain and Mind Research Institute and Center for Neurogenetics, Weill Cornell Medicine, New York, NY 10021, USA
| | - M Elizabeth Ross
- Feil Family Brain and Mind Research Institute and Center for Neurogenetics, Weill Cornell Medicine, New York, NY 10021, USA.
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Behavioral Consequences of a Bifacial Map in the Mouse Somatosensory Cortex. J Neurosci 2017; 37:7209-7218. [PMID: 28663199 DOI: 10.1523/jneurosci.0598-17.2017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2017] [Revised: 06/14/2017] [Accepted: 06/19/2017] [Indexed: 02/04/2023] Open
Abstract
The whisker system is an important sensory organ with extensive neural representations in the brain of the mouse. Patterned neural modules (barrelettes) in the ipsilateral principal sensory nucleus of the trigeminal nerve (PrV) correspond to the whiskers. Axons of the PrV barrelette neurons cross the midline and confer the whisker-related patterning to the contralateral ventroposteromedial nucleus of the thalamus, and subsequently to the cortex. In this way, specific neural modules called barreloids and barrels in the contralateral thalamus and cortex represent each whisker. Partial midline crossing of the PrV axons, in a conditional Robo3 mutant (Robo3R3-5cKO) mouse line, leads to the formation of bilateral whisker maps in the ventroposteromedial, as well as the barrel cortex. We used voltage-sensitive dye optical imaging and somatosensory and motor behavioral tests to characterize the consequences of bifacial maps in the thalamocortical system. Voltage-sensitive dye optical imaging verified functional, bilateral whisker representation in the barrel cortex and activation of distinct cortical loci following ipsilateral and contralateral stimulation of the specific whiskers. The mutant animals were comparable with the control animals in sensorimotor tests. However, they showed noticeable deficits in all of the whisker-dependent or -related tests, including Y-maze exploration, horizontal surface approach, bridge crossing, gap crossing, texture discrimination, floating in water, and whisking laterality. Our results indicate that bifacial maps along the thalamocortical system do not offer a functional advantage. Instead, they lead to impairments, possibly due to the smaller size of the whisker-related modules and interference between the ipsilateral and contralateral whisker representations in the same thalamus and cortex.SIGNIFICANCE STATEMENT The whisker sensory system plays a quintessentially important role in exploratory behavior of mice and other nocturnal rodents. Here, we studied a novel mutant mouse line, in which the projections from the brainstem to the thalamus are disrupted. This led to formation of bilateral whisker maps in both the thalamus and the cortex. The two whisker maps crowd in a space normally devoted to the contralateral map alone and in a nonoverlapping fashion. Stimulation of the whiskers on either side activates the corresponding region of the map. Mice with bilateral whisker maps perform well in general sensorimotor tasks but show poor performance in specific tests that require whisker-dependent tactile discrimination. These observations indicate that contralateral, instead of bilateral, representation of the sensory space plays a critical role in acuity and fine discrimination during somesthesis.
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Nugent AA, Park JG, Wei Y, Tenney AP, Gilette NM, DeLisle MM, Chan WM, Cheng L, Engle EC. Mutant α2-chimaerin signals via bidirectional ephrin pathways in Duane retraction syndrome. J Clin Invest 2017; 127:1664-1682. [PMID: 28346224 DOI: 10.1172/jci88502] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2016] [Accepted: 02/02/2017] [Indexed: 01/18/2023] Open
Abstract
Duane retraction syndrome (DRS) is the most common form of congenital paralytic strabismus in humans and can result from α2-chimaerin (CHN1) missense mutations. We report a knockin α2-chimaerin mouse (Chn1KI/KI) that models DRS. Whole embryo imaging of Chn1KI/KI mice revealed stalled abducens nerve growth and selective trochlear and first cervical spinal nerve guidance abnormalities. Stalled abducens nerve bundles did not reach the orbit, resulting in secondary aberrant misinnervation of the lateral rectus muscle by the oculomotor nerve. By contrast, Chn1KO/KO mice did not have DRS, and embryos displayed abducens nerve wandering distinct from the Chn1KI/KI phenotype. Murine embryos lacking EPH receptor A4 (Epha4KO/KO), which is upstream of α2-chimaerin in corticospinal neurons, exhibited similar abducens wandering that paralleled previously reported gait alterations in Chn1KO/KO and Epha4KO/KO adult mice. Findings from Chn1KI/KI Epha4KO/KO mice demonstrated that mutant α2-chimaerin and EphA4 have different genetic interactions in distinct motor neuron pools: abducens neurons use bidirectional ephrin signaling via mutant α2-chimaerin to direct growth, while cervical spinal neurons use only ephrin forward signaling, and trochlear neurons do not use ephrin signaling. These findings reveal a role for ephrin bidirectional signaling upstream of mutant α2-chimaerin in DRS, which may contribute to the selective vulnerability of abducens motor neurons in this disorder.
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Rollins NK, Booth TN, Chahrour MH. Variability of Ponto-cerebellar Fibers by Diffusion Tensor Imaging in Diverse Brain Malformations. J Child Neurol 2017; 32:271-285. [PMID: 27920266 DOI: 10.1177/0883073816680734] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
To describe pontine axonal anomalies across diverse brain malformations. Institutional review board-approved review of magnetic resonance imaging (MRI) and genetic testing of 31 children with brain malformations and abnormal pons by diffusion tensor imaging. Anomalous dorsal pontocerebellar tracts were seen in mid-hindbrain anomalies and in diffuse malformations of cortical development including lissencephaly, gyral disorganization with dysplastic basal ganglia, presumed congenital fibrosis of extraocular muscles type 3, and in callosal agenesis without malformations of cortical development. Heterotopic and hypoplastic corticospinal tracts were seen in callosal agenesis and in focal malformations of cortical development. There were no patterns by chromosomal microarray analysis in the non-lissencephalic brains. In lissencephaly, there was no relationship between severity, deletion size, or appearance of the pontocerebellar tract. Pontine axonal anomalies may relate to defects in precerebellar neuronal migration, chemotactic signaling of the pontine neurons, and/or corticospinal tract pathfinding and collateral branching not detectable with routine genetic testing.
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Affiliation(s)
- Nancy K Rollins
- 1 Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, USA.,2 Department of Radiology, Children's Health System of Texas, Dallas, TX, USA
| | - Timothy N Booth
- 1 Department of Radiology, University of Texas Southwestern Medical Center, Dallas, TX, USA.,2 Department of Radiology, Children's Health System of Texas, Dallas, TX, USA
| | - Maria H Chahrour
- 3 Departments of Neuroscience and Psychiatry, Eugene McDermott Center for Human Growth and Development, University of Texas Southwestern Medical Center, Dallas, TX, USA
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Congenital mirror movements in a patient with alpha-dystroglycanopathy due to a novel POMK mutation. Neuromuscul Disord 2017; 27:239-242. [DOI: 10.1016/j.nmd.2016.12.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2016] [Revised: 12/05/2016] [Accepted: 12/12/2016] [Indexed: 11/21/2022]
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Biallelic mutations in human DCC cause developmental split-brain syndrome. Nat Genet 2017; 49:606-612. [PMID: 28250456 PMCID: PMC5374027 DOI: 10.1038/ng.3804] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2016] [Accepted: 02/03/2017] [Indexed: 12/14/2022]
Abstract
Motor, sensory, and integrative activities of the brain are coordinated by a series of midline-bridging neuronal commissures whose development is tightly regulated. Here we report a new human syndrome in which these commissures are widely disrupted, thus causing clinical manifestations of horizontal gaze palsy, scoliosis, and intellectual disability. Affected individuals were found to possess biallelic loss-of-function mutations in the gene encoding the axon-guidance receptor 'deleted in colorectal carcinoma' (DCC), which has been implicated in congenital mirror movements when it is mutated in the heterozygous state but whose biallelic loss-of-function human phenotype has not been reported. Structural MRI and diffusion tractography demonstrated broad disorganization of white-matter tracts throughout the human central nervous system (CNS), including loss of all commissural tracts at multiple levels of the neuraxis. Combined with data from animal models, these findings show that DCC is a master regulator of midline crossing and development of white-matter projections throughout the human CNS.
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40
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Chondroitin sulfates and their binding molecules in the central nervous system. Glycoconj J 2017; 34:363-376. [PMID: 28101734 PMCID: PMC5487772 DOI: 10.1007/s10719-017-9761-z] [Citation(s) in RCA: 84] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2016] [Revised: 12/31/2016] [Accepted: 01/04/2017] [Indexed: 01/05/2023]
Abstract
Chondroitin sulfate (CS) is the most abundant glycosaminoglycan (GAG) in the central nervous system (CNS) matrix. Its sulfation and epimerization patterns give rise to different forms of CS, which enables it to interact specifically and with a significant affinity with various signalling molecules in the matrix including growth factors, receptors and guidance molecules. These interactions control numerous biological and pathological processes, during development and in adulthood. In this review, we describe the specific interactions of different families of proteins involved in various physiological and cognitive mechanisms with CSs in CNS matrix. A better understanding of these interactions could promote a development of inhibitors to treat neurodegenerative diseases.
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Developmental Wiring of Specific Neurons Is Regulated by RET-1/Nogo-A in Caenorhabditis elegans. Genetics 2016; 205:295-302. [PMID: 27821431 PMCID: PMC5223509 DOI: 10.1534/genetics.115.185322] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2015] [Accepted: 11/01/2016] [Indexed: 11/18/2022] Open
Abstract
Nogo-A is a membrane-bound protein that functions to inhibit neuronal migration, adhesion, and neurite outgrowth during development. In the mature nervous system, Nogo-A stabilizes neuronal wiring to inhibit neuronal plasticity and regeneration after injury. Here, we show that RET-1, the sole Nogo-A homolog in Caenorhabditis elegans, is required to control developmental wiring of a specific subset of neurons. In ret-1 deletion mutant animals, specific ventral nerve cord axons are misguided where they fail to respect the ventral midline boundary. We found that ret-1 is expressed in multiple neurons during development, and, through mosaic analysis, showed that ret-1 controls axon guidance in a cell-autonomous manner. Finally, as in mammals, ret-1 regulates ephrin expression, and dysregulation of the ephrin ligand VAB-2 is partially responsible for the ret-1 mutant axonal defects. Together, our data present a previously unidentified function for RET-1 in the nervous system of C. elegans.
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42
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Cell adhesion and invasion mechanisms that guide developing axons. Curr Opin Neurobiol 2016; 39:77-85. [PMID: 27135389 DOI: 10.1016/j.conb.2016.04.012] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2016] [Revised: 04/18/2016] [Accepted: 04/19/2016] [Indexed: 01/15/2023]
Abstract
Axon extension, guidance and tissue invasion share many similarities to normal cell migration and cancer cell metastasis. Proper cell and growth cone migration requires tightly regulated adhesion complex assembly and detachment from the extracellular matrix (ECM). In addition, many cell types actively remodel the ECM using matrix metalloproteases (MMPs) to control tissue invasion and cell dispersal. Targeting and activating MMPs is a tightly regulated process, that when dysregulated, can lead to cancer cell metastasis. Interestingly, new evidence suggests that growth cones express similar cellular and molecular machinery as migrating cells to clutch retrograde actin flow on ECM proteins and target matrix degradation, which may be used to facilitate axon pathfinding through the basal lamina and across tissues.
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Yang R, Bentley M, Huang CF, Banker G. Analyzing kinesin motor domain translocation in cultured hippocampal neurons. Methods Cell Biol 2015; 131:217-232. [PMID: 26794516 DOI: 10.1016/bs.mcb.2015.06.021] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/06/2023]
Abstract
Neuronal microtubules are subject to extensive posttranslational modifications and are bound by MAPs, tip-binding proteins, and other accessory proteins. All of these features, which are difficult to replicate in vitro, are likely to influence the translocation of kinesin motors. Here we describe assays for evaluating the translocation of a population of fluorescently labeled kinesin motor domains, based on their accumulation in regions of the cell enriched in microtubule plus ends. Neurons lend themselves to these experiments because of their microtubule organization. In axons, microtubules are oriented with their plus ends out; dendrites contain a mixed population of microtubules, but those near the tips are also plus end out. The assays involve the expression of constitutively active kinesins that can walk processively, but that lack the autoinhibitory domain in the tail that normally prevents their binding to microtubules until they attach to vesicles. The degree to which such motor domains accumulate at neurite tips serves as a measure of the efficiency of their translocation. Although these assays cannot provide the kind of quantitative kinetic information obtained from in vitro assays, they offer a simple way to examine kinesin translocation in living neurons. They can be used to compare the translocation efficiency of different kinesin motors and to evaluate how mutations or posttranslational modifications within the motor domain influence kinesin translocation. Changes to motor domain accumulation in these assays can also serve as readout for changes in the microtubule cytoskeleton that affect kinesin translocation.
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Affiliation(s)
- Rui Yang
- Jungers Center for Neurosciences Research, Oregon Health and Science University, Portland, OR, USA
| | - Marvin Bentley
- Jungers Center for Neurosciences Research, Oregon Health and Science University, Portland, OR, USA
| | - Chung-Fang Huang
- Jungers Center for Neurosciences Research, Oregon Health and Science University, Portland, OR, USA
| | - Gary Banker
- Jungers Center for Neurosciences Research, Oregon Health and Science University, Portland, OR, USA
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Transcriptomic analysis of pancreatic cancer cells in response to metformin and aspirin: an implication of synergy. Sci Rep 2015; 5:13390. [PMID: 26294325 PMCID: PMC4543968 DOI: 10.1038/srep13390] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2015] [Accepted: 07/24/2015] [Indexed: 12/20/2022] Open
Abstract
Metformin and aspirin have been studied extensively as cancer preventative and therapeutic agents. However, the underlying molecular mechanisms for the inhibitory effects of pancreatic cancer development remain undefined. To gain further insight into their biological function in pancreatic cancer, we conducted a transcriptomic analysis using RNA sequencing to assess the differential gene expression induced by metformin (5 mM) and aspirin (2 mM), alone or in combination, after treatment of PANC-1 cells for 48 hours. Compared to an untreated control, metformin down-regulated 58 genes and up-regulated 91 genes, aspirin down-regulated 12 genes only, while metformin plus aspirin down-regulated 656 genes and up-regulated 449 genes (fold-change > 2, P < 10−5). Of the top 10 genes (fold-change > 10, P < 10−10) regulated by metformin plus aspirin, PCDH18, CCL2, RASL11A, FAM111B and BMP5 were down-regulated ≥ 20-fold, while NGFR, NPTX1, C7orf57, MRPL23AS1 and UNC5B were up-regulated ≥ 10-fold. Ingenuity Pathway Analysis (IPA) revealed that the pathways, “cholesterol biosynthesis”, “cell cycle: G1/S checkpoint regulation”, and “axonal guidance signaling” were the most statistically significant pathways modulated by metformin plus aspirin. Although the results need further functional validation, these data provide the first evidence for the synergistic action between metformin and aspirin in modulating the transcriptional profile of pancreatic cancer cells.
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45
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Badr E, Heath LS. Identifying splicing regulatory elements with de Bruijn graphs. J Comput Biol 2015; 21:880-97. [PMID: 25393830 DOI: 10.1089/cmb.2014.0183] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Splicing regulatory elements (SREs) are short, degenerate sequences on pre-mRNA molecules that enhance or inhibit the splicing process via the binding of splicing factors, proteins that regulate the functioning of the spliceosome. Existing methods for identifying SREs in a genome are either experimental or computational. Here, we propose a formalism based on de Bruijn graphs that combines genomic structure, word count enrichment analysis, and experimental evidence to identify SREs found in exons. In our approach, SREs are not restricted to a fixed length (i.e., k-mers, for a fixed k). As a result, we identify 2001 putative exonic enhancers and 3080 putative exonic silencers for human genes, with lengths varying from 6 to 15 nucleotides. Many of the predicted SREs overlap with experimentally verified binding sites. Our model provides a novel method to predict variable length putative regulatory elements computationally for further experimental investigation.
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Affiliation(s)
- Eman Badr
- Department of Computer Science, Virginia Tech , Blacksburg, Virginia
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46
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Abstract
Many neurological disorders are characterised by structural changes in neuronal connections, ranging from presymptomatic synaptic changes to the loss or rewiring of entire axon bundles. The molecular mechanisms that underlie this perturbed connectivity are poorly understood, but recent studies suggest a role for axon guidance proteins. Axon guidance proteins guide growing axons during development and control structural plasticity of synaptic connections in adults. Changes in expression or function of these proteins might induce pathological changes in neural circuits that predispose to, or cause, neurological diseases. For some neurological disorders, such as midline crossing disorders, investigators have identified causative mutations in genes for axon guidance. However, for most other disorders, evidence is correlative and further studies are needed to confirm the pathological role of defects in proteins for axon guidance. Importantly, further insight into how dysregulation of axon guidance proteins causes disease will help the development of therapeutic strategies for neurological disorders.
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Affiliation(s)
- Eljo Y Van Battum
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, Netherlands
| | - Sara Brignani
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, Netherlands
| | - R Jeroen Pasterkamp
- Department of Translational Neuroscience, Brain Center Rudolf Magnus, University Medical Center Utrecht, Utrecht, Netherlands.
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47
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48
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Alsunousi S, Marrif HI. Diabetic neuropathy and the sensory apparatus "meissner corpuscle and merkel cells". Front Neuroanat 2014; 8:79. [PMID: 25177276 PMCID: PMC4132297 DOI: 10.3389/fnana.2014.00079] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2014] [Accepted: 07/22/2014] [Indexed: 01/30/2023] Open
Affiliation(s)
- Salma Alsunousi
- Department of Histology, Faculty of Medicine, Benghazi University Benghazi, Libya
| | - Husnia I Marrif
- Department of Pharmaceutical Sciences, Princess Noura University Riyadh, Saudi Arabia
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Structural and functional brain rewiring clarifies preserved interhemispheric transfer in humans born without the corpus callosum. Proc Natl Acad Sci U S A 2014; 111:7843-8. [PMID: 24821757 DOI: 10.1073/pnas.1400806111] [Citation(s) in RCA: 78] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Why do humans born without the corpus callosum, the major interhemispheric commissure, lack the disconnection syndrome classically described in callosotomized patients? This paradox was discovered by Nobel laureate Roger Sperry in 1968, and has remained unsolved since then. To tackle the hypothesis that alternative neural pathways could explain this puzzle, we investigated patients with callosal dysgenesis using structural and functional neuroimaging, as well as neuropsychological assessments. We identified two anomalous white-matter tracts by deterministic and probabilistic tractography, and provide supporting resting-state functional neuroimaging and neuropsychological evidence for their functional role in preserved interhemispheric transfer of complex tactile information, such as object recognition. These compensatory pathways connect the homotopic posterior parietal cortical areas (Brodmann areas 39 and surroundings) via the posterior and anterior commissures. We propose that anomalous brain circuitry of callosal dysgenesis is determined by long-distance plasticity, a set of hardware changes occurring in the developing brain after pathological interference. So far unknown, these pathological changes somehow divert growing axons away from the dorsal midline, creating alternative tracts through the ventral forebrain and the dorsal midbrain midline, with partial compensatory effects to the interhemispheric transfer of cortical function.
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50
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Abstract
Rho GTPases regulate many essential processes during development, yet the full impact of their upstream regulation through guanine nucleotide exchange factors (GEFs) is only beginning to be appreciated. In this review, Laurin and Côté focus on emerging biological functions of the mammalian Dock family of GEFs in development and disease and discuss how recent discoveries might be exploited for novel therapeutic strategies. Rho GTPases play key regulatory roles in many aspects of embryonic development, regulating processes such as differentiation, proliferation, morphogenesis, and migration. Two families of guanine nucleotide exchange factors (GEFs) found in metazoans, Dbl and Dock, are responsible for the spatiotemporal activation of Rac and Cdc42 proteins and their downstream signaling pathways. This review focuses on the emerging roles of the mammalian DOCK family in development and disease. We also discuss, when possible, how recent discoveries concerning the biological functions of these GEFs might be exploited for the development of novel therapeutic strategies.
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Affiliation(s)
- Mélanie Laurin
- Institut de Recherches Cliniques de Montréal (IRCM), Montréal, Quebec H2W 1R7, Canada
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