1
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Winter CC, Jacobi A, Su J, Chung L, van Velthoven CTJ, Yao Z, Lee C, Zhang Z, Yu S, Gao K, Duque Salazar G, Kegeles E, Zhang Y, Tomihiro MC, Zhang Y, Yang Z, Zhu J, Tang J, Song X, Donahue RJ, Wang Q, McMillen D, Kunst M, Wang N, Smith KA, Romero GE, Frank MM, Krol A, Kawaguchi R, Geschwind DH, Feng G, Goodrich LV, Liu Y, Tasic B, Zeng H, He Z. A transcriptomic taxonomy of mouse brain-wide spinal projecting neurons. Nature 2023; 624:403-414. [PMID: 38092914 PMCID: PMC10719099 DOI: 10.1038/s41586-023-06817-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2023] [Accepted: 11/01/2023] [Indexed: 12/17/2023]
Abstract
The brain controls nearly all bodily functions via spinal projecting neurons (SPNs) that carry command signals from the brain to the spinal cord. However, a comprehensive molecular characterization of brain-wide SPNs is still lacking. Here we transcriptionally profiled a total of 65,002 SPNs, identified 76 region-specific SPN types, and mapped these types into a companion atlas of the whole mouse brain1. This taxonomy reveals a three-component organization of SPNs: (1) molecularly homogeneous excitatory SPNs from the cortex, red nucleus and cerebellum with somatotopic spinal terminations suitable for point-to-point communication; (2) heterogeneous populations in the reticular formation with broad spinal termination patterns, suitable for relaying commands related to the activities of the entire spinal cord; and (3) modulatory neurons expressing slow-acting neurotransmitters and/or neuropeptides in the hypothalamus, midbrain and reticular formation for 'gain setting' of brain-spinal signals. In addition, this atlas revealed a LIM homeobox transcription factor code that parcellates the reticulospinal neurons into five molecularly distinct and spatially segregated populations. Finally, we found transcriptional signatures of a subset of SPNs with large soma size and correlated these with fast-firing electrophysiological properties. Together, this study establishes a comprehensive taxonomy of brain-wide SPNs and provides insight into the functional organization of SPNs in mediating brain control of bodily functions.
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Affiliation(s)
- Carla C Winter
- F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
- Department of Neurology, Harvard Medical School, Boston, MA, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
- PhD Program in Biological and Biomedical Sciences, Harvard Medical School, Boston, MA, USA
- Harvard-MIT MD-PhD Program, Harvard Medical School, Boston, MA, USA
| | - Anne Jacobi
- F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA.
- Department of Neurology, Harvard Medical School, Boston, MA, USA.
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA.
- F. Hoffman-La Roche, pRED, Basel, Switzerland.
| | - Junfeng Su
- F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
- Department of Neurology, Harvard Medical School, Boston, MA, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Leeyup Chung
- F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
- Department of Neurology, Harvard Medical School, Boston, MA, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | | | - Zizhen Yao
- Allen Institute for Brain Science, Seattle, WA, USA
| | - Changkyu Lee
- Allen Institute for Brain Science, Seattle, WA, USA
| | - Zicong Zhang
- F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
- Department of Neurology, Harvard Medical School, Boston, MA, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Shuguang Yu
- F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
- Department of Neurology, Harvard Medical School, Boston, MA, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Kun Gao
- Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
- Program in Neurogenetics, Department of Neurology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Geraldine Duque Salazar
- F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
- Department of Neurology, Harvard Medical School, Boston, MA, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Evgenii Kegeles
- F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
- Department of Neurology, Harvard Medical School, Boston, MA, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
- PhD Program in Biological and Biomedical Sciences, Harvard Medical School, Boston, MA, USA
| | - Yu Zhang
- F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
- Department of Neurology, Harvard Medical School, Boston, MA, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Makenzie C Tomihiro
- F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
- Department of Neurology, Harvard Medical School, Boston, MA, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Yiming Zhang
- F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
- Department of Neurology, Harvard Medical School, Boston, MA, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Zhiyun Yang
- F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
- Department of Neurology, Harvard Medical School, Boston, MA, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Junjie Zhu
- F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
- Department of Neurology, Harvard Medical School, Boston, MA, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Jing Tang
- F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
- Department of Neurology, Harvard Medical School, Boston, MA, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Xuan Song
- F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
- Department of Neurology, Harvard Medical School, Boston, MA, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Ryan J Donahue
- F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
- Department of Neurology, Harvard Medical School, Boston, MA, USA
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA
| | - Qing Wang
- Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
- Program in Neurogenetics, Department of Neurology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | | | | | - Ning Wang
- Allen Institute for Brain Science, Seattle, WA, USA
| | | | - Gabriel E Romero
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Michelle M Frank
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Alexandra Krol
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Riki Kawaguchi
- Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
- Program in Neurogenetics, Department of Neurology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Daniel H Geschwind
- Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
- Program in Neurogenetics, Department of Neurology, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Guoping Feng
- McGovern Institute for Brain Research, Department of Brain and Cognitive Sciences, Massachusetts Institute of Technology, Cambridge, MA, USA
| | - Lisa V Goodrich
- Department of Neurobiology, Harvard Medical School, Boston, MA, USA
| | - Yuanyuan Liu
- Somatosensation and Pain Unit, National Institute of Dental and Craniofacial Research, National Center for Complementary and Integrative Health, National Institutes of Health, Bethesda, MD, USA
| | | | - Hongkui Zeng
- Allen Institute for Brain Science, Seattle, WA, USA.
| | - Zhigang He
- F. M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA.
- Department of Neurology, Harvard Medical School, Boston, MA, USA.
- Department of Ophthalmology, Harvard Medical School, Boston, MA, USA.
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2
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D'Elia KP, Hameedy H, Goldblatt D, Frazel P, Kriese M, Zhu Y, Hamling KR, Kawakami K, Liddelow SA, Schoppik D, Dasen JS. Determinants of motor neuron functional subtypes important for locomotor speed. Cell Rep 2023; 42:113049. [PMID: 37676768 PMCID: PMC10600875 DOI: 10.1016/j.celrep.2023.113049] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2023] [Revised: 05/12/2023] [Accepted: 08/11/2023] [Indexed: 09/09/2023] Open
Abstract
Locomotion requires precise control of the strength and speed of muscle contraction and is achieved by recruiting functionally distinct subtypes of motor neurons (MNs). MNs are essential to movement and differentially susceptible in disease, but little is known about how MNs acquire functional subtype-specific features during development. Using single-cell RNA profiling in embryonic and larval zebrafish, we identify novel and conserved molecular signatures for MN functional subtypes and identify genes expressed in both early post-mitotic and mature MNs. Assessing MN development in genetic mutants, we define a molecular program essential for MN functional subtype specification. Two evolutionarily conserved transcription factors, Prdm16 and Mecom, are both functional subtype-specific determinants integral for fast MN development. Loss of prdm16 or mecom causes fast MNs to develop transcriptional profiles and innervation similar to slow MNs. These results reveal the molecular diversity of vertebrate axial MNs and demonstrate that functional subtypes are specified through intrinsic transcriptional codes.
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Affiliation(s)
- Kristen P D'Elia
- Department of Neuroscience & Physiology and Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA; Department of Otolaryngology, New York University Grossman School of Medicine, New York, NY, USA
| | - Hanna Hameedy
- Department of Neuroscience & Physiology and Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA; Department of Otolaryngology, New York University Grossman School of Medicine, New York, NY, USA
| | - Dena Goldblatt
- Department of Neuroscience & Physiology and Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA; Department of Otolaryngology, New York University Grossman School of Medicine, New York, NY, USA; Center for Neural Science, New York University, New York, NY, USA
| | - Paul Frazel
- Department of Neuroscience & Physiology and Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA
| | - Mercer Kriese
- Department of Neuroscience & Physiology and Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA; Department of Otolaryngology, New York University Grossman School of Medicine, New York, NY, USA
| | - Yunlu Zhu
- Department of Neuroscience & Physiology and Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA; Department of Otolaryngology, New York University Grossman School of Medicine, New York, NY, USA
| | - Kyla R Hamling
- Department of Neuroscience & Physiology and Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA; Department of Otolaryngology, New York University Grossman School of Medicine, New York, NY, USA
| | - Koichi Kawakami
- Laboratory of Molecular and Developmental Biology, National Institute of Genetics, Mishima, Japan
| | - Shane A Liddelow
- Department of Neuroscience & Physiology and Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA
| | - David Schoppik
- Department of Neuroscience & Physiology and Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA; Department of Otolaryngology, New York University Grossman School of Medicine, New York, NY, USA.
| | - Jeremy S Dasen
- Department of Neuroscience & Physiology and Neuroscience Institute, New York University Grossman School of Medicine, New York, NY, USA.
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3
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Khan MN, Cherukuri P, Negro F, Rajput A, Fabrowski P, Bansal V, Lancelin C, Lee TI, Bian Y, Mayer WP, Akay T, Müller D, Bonn S, Farina D, Marquardt T. ERR2 and ERR3 promote the development of gamma motor neuron functional properties required for proprioceptive movement control. PLoS Biol 2022; 20:e3001923. [PMID: 36542664 PMCID: PMC9815657 DOI: 10.1371/journal.pbio.3001923] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Revised: 01/05/2023] [Accepted: 11/16/2022] [Indexed: 12/24/2022] Open
Abstract
The ability of terrestrial vertebrates to effectively move on land is integrally linked to the diversification of motor neurons into types that generate muscle force (alpha motor neurons) and types that modulate muscle proprioception, a task that in mammals is chiefly mediated by gamma motor neurons. The diversification of motor neurons into alpha and gamma types and their respective contributions to movement control have been firmly established in the past 7 decades, while recent studies identified gene expression signatures linked to both motor neuron types. However, the mechanisms that promote the specification of gamma motor neurons and/or their unique properties remained unaddressed. Here, we found that upon selective loss of the orphan nuclear receptors ERR2 and ERR3 (also known as ERRβ, ERRγ or NR3B2, NR3B3, respectively) in motor neurons in mice, morphologically distinguishable gamma motor neurons are generated but do not acquire characteristic functional properties necessary for regulating muscle proprioception, thus disrupting gait and precision movements. Complementary gain-of-function experiments in chick suggest that ERR2 and ERR3 could operate via transcriptional activation of neural activity modulators to promote a gamma motor neuron biophysical signature of low firing thresholds and high firing rates. Our work identifies a mechanism specifying gamma motor neuron functional properties essential for the regulation of proprioceptive movement control.
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Affiliation(s)
- Mudassar N. Khan
- Interfaculty Chair for Neurobiological Research, RWTH Aachen University: Medical Faculty (UKA), Clinic for Neurology & Faculty for Mathematics, Computer and Natural Sciences, Institute for Biology 2, Aachen, Germany
- Developmental Neurobiology Laboratory, European Neuroscience Institute (ENI-G), Göttingen, Germany
- Leibniz-Forschungsinstitut für Molekulare Pharmakologie (FMP), Berlin, Germany
- * E-mail: (MNK); (TM)
| | - Pitchaiah Cherukuri
- Interfaculty Chair for Neurobiological Research, RWTH Aachen University: Medical Faculty (UKA), Clinic for Neurology & Faculty for Mathematics, Computer and Natural Sciences, Institute for Biology 2, Aachen, Germany
- Developmental Neurobiology Laboratory, European Neuroscience Institute (ENI-G), Göttingen, Germany
- SRM University Andhra Pradesh, Mangalagiri-Mandal, Neeru Konda, Amaravati, Andhra Pradesh, India
| | - Francesco Negro
- Department of Clinical and Experimental Sciences, Università degli Studi di Brescia, Brescia, Italy
| | - Ashish Rajput
- University Medical Center Hamburg Eppendorf, Center for Molecular Neurobiology Hamburg (ZMNH), Institute of Medical Systems Biology, Hamburg, Germany
- Maximon AG, Zug, Switzerland
| | - Piotr Fabrowski
- Interfaculty Chair for Neurobiological Research, RWTH Aachen University: Medical Faculty (UKA), Clinic for Neurology & Faculty for Mathematics, Computer and Natural Sciences, Institute for Biology 2, Aachen, Germany
- Developmental Neurobiology Laboratory, European Neuroscience Institute (ENI-G), Göttingen, Germany
| | - Vikas Bansal
- University Medical Center Hamburg Eppendorf, Center for Molecular Neurobiology Hamburg (ZMNH), Institute of Medical Systems Biology, Hamburg, Germany
- Biomedical Data Science and Machine Learning Group, German Center for Neurodegenerative Diseases, Tübingen, Germany
| | - Camille Lancelin
- Developmental Neurobiology Laboratory, European Neuroscience Institute (ENI-G), Göttingen, Germany
| | - Tsung-I Lee
- Developmental Neurobiology Laboratory, European Neuroscience Institute (ENI-G), Göttingen, Germany
| | - Yehan Bian
- Interfaculty Chair for Neurobiological Research, RWTH Aachen University: Medical Faculty (UKA), Clinic for Neurology & Faculty for Mathematics, Computer and Natural Sciences, Institute for Biology 2, Aachen, Germany
- Developmental Neurobiology Laboratory, European Neuroscience Institute (ENI-G), Göttingen, Germany
| | - William P. Mayer
- Atlantic Mobility Action Project, Brain Repair Centre, Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Turgay Akay
- Atlantic Mobility Action Project, Brain Repair Centre, Department of Medical Neuroscience, Dalhousie University, Halifax, Nova Scotia, Canada
| | - Daniel Müller
- Interfaculty Chair for Neurobiological Research, RWTH Aachen University: Medical Faculty (UKA), Clinic for Neurology & Faculty for Mathematics, Computer and Natural Sciences, Institute for Biology 2, Aachen, Germany
- Developmental Neurobiology Laboratory, European Neuroscience Institute (ENI-G), Göttingen, Germany
| | - Stefan Bonn
- University Medical Center Hamburg Eppendorf, Center for Molecular Neurobiology Hamburg (ZMNH), Institute of Medical Systems Biology, Hamburg, Germany
| | - Dario Farina
- Department of Bioengineering, Imperial College London, Royal School of Mines, London, United Kingdom
| | - Till Marquardt
- Interfaculty Chair for Neurobiological Research, RWTH Aachen University: Medical Faculty (UKA), Clinic for Neurology & Faculty for Mathematics, Computer and Natural Sciences, Institute for Biology 2, Aachen, Germany
- Developmental Neurobiology Laboratory, European Neuroscience Institute (ENI-G), Göttingen, Germany
- * E-mail: (MNK); (TM)
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Patel T, Hammelman J, Aziz S, Jang S, Closser M, Michaels TL, Blum JA, Gifford DK, Wichterle H. Transcriptional dynamics of murine motor neuron maturation in vivo and in vitro. Nat Commun 2022; 13:5427. [PMID: 36109497 PMCID: PMC9477853 DOI: 10.1038/s41467-022-33022-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2022] [Accepted: 08/25/2022] [Indexed: 12/03/2022] Open
Abstract
Neurons born in the embryo can undergo a protracted period of maturation lasting well into postnatal life. How gene expression changes are regulated during maturation and whether they can be recapitulated in cultured neurons remains poorly understood. Here, we show that mouse motor neurons exhibit pervasive changes in gene expression and accessibility of associated regulatory regions from embryonic till juvenile age. While motifs of selector transcription factors, ISL1 and LHX3, are enriched in nascent regulatory regions, motifs of NFI factors, activity-dependent factors, and hormone receptors become more prominent in maturation-dependent enhancers. Notably, stem cell-derived motor neurons recapitulate ~40% of the maturation expression program in vitro, with neural activity playing only a modest role as a late-stage modulator. Thus, the genetic maturation program consists of a core hardwired subprogram that is correctly executed in vitro and an extrinsically-controlled subprogram that is dependent on the in vivo context of the maturing organism.
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Affiliation(s)
- Tulsi Patel
- Departments of Pathology & Cell Biology, Neuroscience, and Neurology, Columbia University Irving Medical Center, New York, NY, 10032, USA.
| | - Jennifer Hammelman
- Computer Science and Artificial Intelligence Laboratory, MIT, Cambridge, MA, 02139, USA
| | - Siaresh Aziz
- Departments of Pathology & Cell Biology, Neuroscience, and Neurology, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Sumin Jang
- Departments of Pathology & Cell Biology, Neuroscience, and Neurology, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Michael Closser
- Departments of Pathology & Cell Biology, Neuroscience, and Neurology, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Theodore L Michaels
- Departments of Pathology & Cell Biology, Neuroscience, and Neurology, Columbia University Irving Medical Center, New York, NY, 10032, USA
| | - Jacob A Blum
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - David K Gifford
- Computer Science and Artificial Intelligence Laboratory, MIT, Cambridge, MA, 02139, USA
| | - Hynek Wichterle
- Departments of Pathology & Cell Biology, Neuroscience, and Neurology, Columbia University Irving Medical Center, New York, NY, 10032, USA.
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5
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Abstract
Motor neurons are a remarkably powerful cell type in the central nervous system. They innervate and control the contraction of virtually every muscle in the body and their dysfunction underlies numerous neuromuscular diseases. Some motor neurons seem resistant to degeneration whereas others are vulnerable. The intrinsic heterogeneity of motor neurons in adult organisms has remained elusive. The development of high-throughput single-cell transcriptomics has changed the paradigm, empowering rapid isolation and profiling of motor neuron nuclei, revealing remarkable transcriptional diversity within the skeletal and autonomic nervous systems. Here, we discuss emerging technologies for defining motor neuron heterogeneity in the adult motor system as well as implications for disease and spinal cord injury. We establish a roadmap for future applications of emerging techniques - such as epigenetic profiling, spatial RNA sequencing, and single-cell somatic mutational profiling to adult motor neurons, which will revolutionize our understanding of the healthy and degenerating adult motor system.
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Affiliation(s)
- Jacob A Blum
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA; Neurosciences Interdepartmental Program, Stanford University School of Medicine, Stanford, CA, USA.
| | - Aaron D Gitler
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA; Chan Zuckerberg Biohub, San Francisco, CA 94158, USA.
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6
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Han X, He H, Shao L, Cui S, Yu H, Zhang X, Wu Q. Deletion of Meg8-DMR Enhances Migration and Invasion of MLTC-1 Depending on the CTCF Binding Sites. Int J Mol Sci 2022; 23:ijms23158828. [PMID: 35955961 PMCID: PMC9369160 DOI: 10.3390/ijms23158828] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Revised: 07/28/2022] [Accepted: 08/05/2022] [Indexed: 11/30/2022] Open
Abstract
The Dlk1-Dio3 imprinted domain on mouse chromosome 12 contains three well-characterized paternally methylated differentially methylated regions (DMRs): IG-DMR, Gtl2-DMR, and Dlk1-DMR. These DMRs control the expression of many genes involved in embryonic development, inherited diseases, and human cancer in this domain. The first maternal methylation DMR discovered in this domain was the Meg8-DMR, the targets and biological function of which are still unknown. Here, using an enhancer-blocking assay, we first dissected the functional parts of the Meg8-DMR and showed that its insulator activity is dependent on the CCCTC-binding factor (CTCF) in MLTC-1. Results from RNA-seq showed that the deletion of the Meg8-DMR and its compartment CTCF binding sites, but not GGCG repeats, lead to the downregulation of numerous genes on chromosome 12, in particular the drastically reduced expression of Dlk1 and Rtl1 in the Dlk1-Dio3 domain, while differentially expressed genes are enriched in the MAPK pathway. In vitro assays revealed that the deletion of the Meg8-DMR and CTCF binding sites enhances cell migration and invasion by decreasing Dlk1 and activating the Notch1-Rhoc-MAPK/ERK pathway. These findings enhance research into gene regulation in the Dlk1-Dio3 domain by indicating that the Meg8-DMR functions as a long-range regulatory element which is dependent on CTCF binding sites and affects multiple genes in this domain.
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Affiliation(s)
- Xiao Han
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
| | - Hongjuan He
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
| | - Lan Shao
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
| | - Shuang Cui
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
| | - Haoran Yu
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
| | - Ximeijia Zhang
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
| | - Qiong Wu
- School of Life Science and Technology, Harbin Institute of Technology, Harbin 150001, China
- State Key Laboratory of Urban Water Resource and Environment, Harbin Institute of Technology, Harbin 150001, China
- Correspondence: ; Tel./Fax: +86-0451-86416944
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7
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Veerakumar A, Yung AR, Liu Y, Krasnow MA. Molecularly defined circuits for cardiovascular and cardiopulmonary control. Nature 2022; 606:739-746. [PMID: 35650438 PMCID: PMC9297035 DOI: 10.1038/s41586-022-04760-8] [Citation(s) in RCA: 30] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Accepted: 04/13/2022] [Indexed: 01/29/2023]
Abstract
The sympathetic and parasympathetic nervous systems powerfully regulate internal organs1, but the molecular and functional diversity of their constituent neurons and circuits remains largely unknown. Here we use retrograde neuronal tracing, single-cell RNA sequencing, optogenetics, and physiological experiments to dissect the cardiac parasympathetic control circuit in mice. We show that cardiac-innervating neurons in the brainstem nucleus ambiguus (Amb) are comprised of two molecularly, anatomically, and functionally distinct subtypes. One we call ACV (ambiguus cardiovascular) neurons (~35 neurons per Amb), define the classical cardiac parasympathetic circuit. They selectively innervate a subset of cardiac parasympathetic ganglion neurons and mediate the baroreceptor reflex, slowing heart rate and atrioventricular node conduction in response to increased blood pressure. The other, ACP (ambiguus cardiopulmonary) neurons (~15 neurons per Amb) innervate cardiac ganglion neurons intermingled with and functionally indistinguishable from those innervated by ACV neurons, but surprisingly also innervate most or all lung parasympathetic ganglion neurons; clonal labeling shows individual ACP neurons innervate both organs. ACP neurons mediate the dive reflex, the simultaneous bradycardia and bronchoconstriction that follows water immersion. Thus, parasympathetic control of the heart is organized into two parallel circuits, one that selectively controls cardiac function (ACV circuit) and another that coordinates cardiac and pulmonary function (ACP circuit). This new understanding of cardiac control has implications for treating cardiac and pulmonary diseases and for elucidating the control and coordination circuits of other organs.
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Affiliation(s)
- Avin Veerakumar
- Department of Biochemistry, Wall Center for Pulmonary Vascular Disease, and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA, USA.,Department of Bioengineering, Stanford University, Stanford, CA, USA.,Medical Scientist Training Program, Stanford University School of Medicine, Stanford, CA, USA
| | - Andrea R Yung
- Department of Biochemistry, Wall Center for Pulmonary Vascular Disease, and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Yin Liu
- Department of Biochemistry, Wall Center for Pulmonary Vascular Disease, and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA, USA
| | - Mark A Krasnow
- Department of Biochemistry, Wall Center for Pulmonary Vascular Disease, and Howard Hughes Medical Institute, Stanford University School of Medicine, Stanford, CA, USA.
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8
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Smith CC, Brownstone RM. Electrical Properties of Adult Mammalian Motoneurons. Adv Neurobiol 2022; 28:191-232. [PMID: 36066827 DOI: 10.1007/978-3-031-07167-6_9] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/14/2022]
Abstract
Motoneurons are the 'final common path' between the central nervous system (that intends, selects, commands, and organises movement) and muscles (that produce the behaviour). Motoneurons are not passive relays, but rather integrate synaptic activity to appropriately tune output (spike trains) and therefore the production of muscle force. In this chapter, we focus on studies of mammalian motoneurons, describing their heterogeneity whilst providing a brief historical account of motoneuron recording techniques. Next, we describe adult motoneurons in terms of their passive, transition, and active (repetitive firing) properties. We then discuss modulation of these properties by somatic (C-boutons) and dendritic (persistent inward currents) mechanisms. Finally, we briefly describe select studies of human motor unit physiology and relate them to findings from animal preparations discussed earlier in the chapter. This interphyletic approach to the study of motoneuron physiology is crucial to progress understanding of how these diverse neurons translate intention into behaviour.
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Abstract
Motoneurons have long been considered as the final common pathway of the nervous system, transmitting the neural impulses that are transduced into action.While many studies have focussed on the inputs that motoneurons receive from local circuits within the spinal cord and from other parts of the CNS, relatively few have investigated the targets of local axonal projections from motoneurons themselves, with the notable exception of those contacting Renshaw cells or other motoneurons.Recent research has not only characterised the detailed features of the excitatory connections between motoneurons and Renshaw cells but has also established that Renshaw cells are not the only target of motoneurons axons within the spinal cord. Motoneurons also form synaptic contacts with other motoneurons as well as with a subset of ventrally located V3 interneurons. These findings indicate that motoneurons cannot be simply viewed as the last relay station delivering the command drive to muscles, but perform an active role in the generation and modulation of motor patterns.
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Affiliation(s)
- Marco Beato
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK.
| | - Gary Bhumbra
- Department of Neuroscience, Physiology and Pharmacology, University College London, London, UK
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10
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Abstract
Spinal motoneurons are a remarkably diverse class of neurons responsible for facilitating a broad range of motor behaviors and autonomic functions. Studies of motoneuron differentiation have provided fundamental insights into the developmental mechanisms of neuronal diversification, and have illuminated principles of neural fate specification that operate throughout the central nervous system. Because of their relative anatomical simplicity and accessibility, motoneurons have provided a tractable model system to address multiple facets of neural development, including early patterning, neuronal migration, axon guidance, and synaptic specificity. Beyond their roles in providing direct communication between central circuits and muscle, recent studies have revealed that motoneuron subtype-specific programs also play important roles in determining the central connectivity and function of motor circuits. Cross-species comparative analyses have provided novel insights into how evolutionary changes in subtype specification programs may have contributed to adaptive changes in locomotor behaviors. This chapter focusses on the gene regulatory networks governing spinal motoneuron specification, and how studies of spinal motoneurons have informed our understanding of the basic mechanisms of neuronal specification and spinal circuit assembly.
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Affiliation(s)
- Jeremy S Dasen
- NYU Neuroscience Institute, Department of Neuroscience and Physiology, NYU School of Medicine, New York, NY, USA.
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11
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Haim LB, Schirmer L, Zulji A, Sabeur K, Tiret B, Ribon M, Chang S, Lamers WH, BoillEée S, Chaumeil MM, Rowitch DH. Evidence for glutamine synthetase function in mouse spinal cord oligodendrocytes. Glia 2021; 69:2812-2827. [PMID: 34396578 PMCID: PMC8502205 DOI: 10.1002/glia.24071] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2021] [Revised: 07/02/2021] [Accepted: 07/29/2021] [Indexed: 11/07/2022]
Abstract
Glutamine synthetase (GS) is a key enzyme that metabolizes glutamate into glutamine. While GS is highly enriched in astrocytes, expression in other glial lineages has been noted. Using a combination of reporter mice and cell type-specific markers, we show that GS is expressed in myelinating oligodendrocytes (OL) but not oligodendrocyte progenitor cells of the mouse and human ventral spinal cord. To investigate the role of GS in mature OL, we used a conditional knockout (cKO) approach to selectively delete GS-encoding gene (Glul) in OL, which caused a significant decrease in glutamine levels on mouse spinal cord extracts. GS cKO mice (CNP-cre+ :Glulfl/fl ) showed no differences in motor neuron numbers, size or axon density; OL differentiation and myelination in the ventral spinal cord was normal up to 6 months of age. Interestingly, GS cKO mice showed a transient and specific decrease in peak force while locomotion and motor coordination remained unaffected. Last, GS expression in OL was increased in chronic pathological conditions in both mouse and humans. We found a disease-stage dependent increase of OL expressing GS in the ventral spinal cord of SOD1(G93A) mouse model of amyotrophic lateral sclerosis. Moreover, we showed that GLUL transcripts levels were increased in OL in leukocortical tissue from multiple sclerosis but not control patients. These findings provide evidence towards OL-encoded GS function in spinal cord sensorimotor axis, which is dysregulated in chronic neurological diseases.
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Affiliation(s)
- Lucile Ben Haim
- Department of Pediatrics, Wellcome - MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
- Departments of Pediatrics and Neurosurgery, Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA, USA
| | - Lucas Schirmer
- Department of Pediatrics, Wellcome - MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
- Departments of Pediatrics and Neurosurgery, Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA, USA
- Department of Neurology, Mannheim Center for Translational Neuroscience, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
- Interdisciplinary Center for Neurosciences, Heidelberg University, Heidelberg, Germany
| | - Amel Zulji
- Department of Neurology, Mannheim Center for Translational Neuroscience, Medical Faculty Mannheim, Heidelberg University, Mannheim, Germany
| | - Khalida Sabeur
- Department of Pediatrics, Wellcome - MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
- Departments of Pediatrics and Neurosurgery, Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA, USA
| | - Brice Tiret
- Departments of Physical Therapy and Rehabilitation Science and of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA
| | - Matthieu Ribon
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, APHP, Hôpital de la Pitié Salpêtrière, Paris, France
| | - Sandra Chang
- Department of Pediatrics, Wellcome - MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
- Departments of Pediatrics and Neurosurgery, Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA, USA
| | - Wouter H. Lamers
- Tytgat Institute for Liver and Intestinal Research, Amsterdam University Medical Centers, Meibergdreef 15, 1105 BK Amsterdam, The Netherlands
| | - Séverine BoillEée
- Sorbonne Université, Institut du Cerveau - Paris Brain Institute - ICM, Inserm, CNRS, APHP, Hôpital de la Pitié Salpêtrière, Paris, France
| | - Myriam M. Chaumeil
- Departments of Physical Therapy and Rehabilitation Science and of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA
| | - David H. Rowitch
- Department of Pediatrics, Wellcome - MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge, UK
- Departments of Pediatrics and Neurosurgery, Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA, USA
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12
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Fralish Z, Lotz EM, Chavez T, Khodabukus A, Bursac N. Neuromuscular Development and Disease: Learning From in vitro and in vivo Models. Front Cell Dev Biol 2021; 9:764732. [PMID: 34778273 PMCID: PMC8579029 DOI: 10.3389/fcell.2021.764732] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2021] [Accepted: 10/06/2021] [Indexed: 01/02/2023] Open
Abstract
The neuromuscular junction (NMJ) is a specialized cholinergic synaptic interface between a motor neuron and a skeletal muscle fiber that translates presynaptic electrical impulses into motor function. NMJ formation and maintenance require tightly regulated signaling and cellular communication among motor neurons, myogenic cells, and Schwann cells. Neuromuscular diseases (NMDs) can result in loss of NMJ function and motor input leading to paralysis or even death. Although small animal models have been instrumental in advancing our understanding of the NMJ structure and function, the complexities of studying this multi-tissue system in vivo and poor clinical outcomes of candidate therapies developed in small animal models has driven the need for in vitro models of functional human NMJ to complement animal studies. In this review, we discuss prevailing models of NMDs and highlight the current progress and ongoing challenges in developing human iPSC-derived (hiPSC) 3D cell culture models of functional NMJs. We first review in vivo development of motor neurons, skeletal muscle, Schwann cells, and the NMJ alongside current methods for directing the differentiation of relevant cell types from hiPSCs. We further compare the efficacy of modeling NMDs in animals and human cell culture systems in the context of five NMDs: amyotrophic lateral sclerosis, myasthenia gravis, Duchenne muscular dystrophy, myotonic dystrophy, and Pompe disease. Finally, we discuss further work necessary for hiPSC-derived NMJ models to function as effective personalized NMD platforms.
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Affiliation(s)
- Zachary Fralish
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, United States
| | - Ethan M Lotz
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, United States
| | - Taylor Chavez
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, United States
| | - Alastair Khodabukus
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, United States
| | - Nenad Bursac
- Department of Biomedical Engineering, Pratt School of Engineering, Duke University, Durham, NC, United States
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13
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Zuccaro E, Piol D, Basso M, Pennuto M. Motor Neuron Diseases and Neuroprotective Peptides: A Closer Look to Neurons. Front Aging Neurosci 2021; 13:723871. [PMID: 34603008 PMCID: PMC8484953 DOI: 10.3389/fnagi.2021.723871] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 08/26/2021] [Indexed: 12/02/2022] Open
Abstract
Motor neurons (MNs) are specialized neurons responsible for muscle contraction that specifically degenerate in motor neuron diseases (MNDs), such as amyotrophic lateral sclerosis (ALS), spinal and bulbar muscular atrophy (SBMA), and spinal muscular atrophy (SMA). Distinct classes of MNs degenerate at different rates in disease, with a particular class named fast-fatigable MNs (FF-MNs) degenerating first. The etiology behind the selective vulnerability of FF-MNs is still largely under investigation. Among the different strategies to target MNs, the administration of protective neuropeptides is one of the potential therapeutic interventions. Pituitary adenylate cyclase-activating polypeptide (PACAP) is a neuropeptide with beneficial effects in many neurodegenerative diseases, including Alzheimer’s disease, Parkinson’s disease, and more recently SBMA. Another neuropeptide that has a neurotrophic effect on MNs is insulin-like growth factor 1 (IGF-1), also known as somatomedin C. These two peptides are implicated in the activation of neuroprotective pathways exploitable in the amelioration of pathological outcomes related to MNDs.
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Affiliation(s)
- Emanuela Zuccaro
- Department of Biomedical Sciences, University of Padua, Padua, Italy.,Veneto Institute of Molecular Medicine, Padua, Italy.,Padova Neuroscience Center, Padua, Italy
| | - Diana Piol
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - Manuela Basso
- Department of Cellular, Computational and Integrative Biology - CIBIO, University of Trento, Trento, Italy
| | - Maria Pennuto
- Department of Biomedical Sciences, University of Padua, Padua, Italy.,Veneto Institute of Molecular Medicine, Padua, Italy.,Padova Neuroscience Center, Padua, Italy
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14
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Abstract
DLK1 is a maternally imprinted, paternally expressed gene coding for the transmembrane protein Delta-like homologue 1 (DLK1), a non-canonical NOTCH ligand with well-described roles during development, and tumor-supportive functions in several aggressive cancer forms. Here, we review the many functions of DLK1 as a regulator of stem cell pools and tissue differentiation in tissues such as brain, muscle, and liver. Furthermore, we review recent evidence supporting roles for DLK1 in the maintenance of aggressive stem cell characteristics of tumor cells, specifically focusing on central nervous system tumors, neuroblastoma, and hepatocellular carcinoma. We discuss NOTCH -dependent as well as NOTCH-independent functions of DLK1, and focus particularly on the complex pattern of DLK1 expression and cleavage that is finely regulated from a spatial and temporal perspective. Progress in recent years suggest differential functions of extracellular, soluble DLK1 as a paracrine stem cell niche-secreted factor, and has revealed a role for the intracellular domain of DLK1 in cell signaling and tumor stemness. A better understanding of DLK1 regulation and signaling may enable therapeutic targeting of cancer stemness by interfering with DLK1 release and/or intracellular signaling.
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Affiliation(s)
- Elisa Stellaria Grassi
- Department of Medical Biotechnology and Translational Medicine, University of Milan, Milan, Italy
| | - Alexander Pietras
- Division of Translational Cancer Research, Department of Laboratory Medicine, Lund University, Lund, Sweden
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15
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Abbas E, Hassan MA, Sokpor G, Kiszka K, Pham L, Kerimoglu C, Fischer A, Nguyen HP, Staiger JF, Tuoc T. Conditional Loss of BAF (mSWI/SNF) Scaffolding Subunits Affects Specification and Proliferation of Oligodendrocyte Precursors in Developing Mouse Forebrain. Front Cell Dev Biol 2021; 9:619538. [PMID: 34336815 PMCID: PMC8320002 DOI: 10.3389/fcell.2021.619538] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2020] [Accepted: 06/24/2021] [Indexed: 12/24/2022] Open
Abstract
Oligodendrocytes are responsible for axon myelination in the brain and spinal cord. Generation of oligodendrocytes entails highly regulated multistage neurodevelopmental events, including proliferation, differentiation and maturation. The chromatin remodeling BAF (mSWI/SNF) complex is a notable regulator of neural development. In our previous studies, we determined the indispensability of the BAF complex scaffolding subunits BAF155 and BAF170 for neurogenesis, whereas their role in gliogenesis is unknown. Here, we show that the expression of BAF155 and BAF170 is essential for the genesis of oligodendrocytes during brain development. We report that the ablation of BAF155 and BAF170 in the dorsal telencephalic (dTel) neural progenitors or in oligodendrocyte-producing progenitors in the ventral telencephalon (vTel) in double-conditional knockout (dcKO) mouse mutants, perturbed the process of oligodendrogenesis. Molecular marker and cell cycle analyses revealed impairment of oligodendrocyte precursor specification and proliferation, as well as overt depletion of oligodendrocytes pool in dcKO mutants. Our findings unveil a central role of BAF155 and BAF170 in oligodendrogenesis, and thus substantiate the involvement of the BAF complex in the production of oligodendrocytes in the forebrain.
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Affiliation(s)
- Eman Abbas
- Institute for Neuroanatomy, University Medical Center, Georg-August-University Göttingen, Göttingen, Germany.,Department of Zoology, Faculty of Science, Alexandria University, Alexandria, Egypt.,Department of Neuro- and Sensory Physiology, University Medical Center Göttingen, Göttingen, Germany
| | - Mohamed A Hassan
- Protein Research Department, Genetic Engineering and Biotechnology Research Institute (GEBRI), City of Scientific Research and Technological Applications (SRTA-City), New Borg El-Arab City, Egypt
| | - Godwin Sokpor
- Institute for Neuroanatomy, University Medical Center, Georg-August-University Göttingen, Göttingen, Germany.,Department of Human Genetics, Ruhr University of Bochum, Bochum, Germany
| | - Kamila Kiszka
- Institute for Neuroanatomy, University Medical Center, Georg-August-University Göttingen, Göttingen, Germany
| | - Linh Pham
- Institute for Neuroanatomy, University Medical Center, Georg-August-University Göttingen, Göttingen, Germany.,Department of Human Genetics, Ruhr University of Bochum, Bochum, Germany
| | - Cemil Kerimoglu
- German Center for Neurodegenerative Diseases, Göttingen, Germany
| | - Andre Fischer
- German Center for Neurodegenerative Diseases, Göttingen, Germany.,Cluster of Excellence "Multiscale Bioimaging: From Molecular Machines to Networks of Excitable Cells" (MBExC), University of Göttingen, Göttingen, Germany.,Department for Psychiatry and Psychotherapy, University Medical Center Göttingen, Göttingen, Germany
| | - Huu Phuc Nguyen
- Protein Research Department, Genetic Engineering and Biotechnology Research Institute (GEBRI), City of Scientific Research and Technological Applications (SRTA-City), New Borg El-Arab City, Egypt
| | - Jochen F Staiger
- Institute for Neuroanatomy, University Medical Center, Georg-August-University Göttingen, Göttingen, Germany
| | - Tran Tuoc
- Institute for Neuroanatomy, University Medical Center, Georg-August-University Göttingen, Göttingen, Germany.,Department of Human Genetics, Ruhr University of Bochum, Bochum, Germany
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16
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Blum JA, Klemm S, Shadrach JL, Guttenplan KA, Nakayama L, Kathiria A, Hoang PT, Gautier O, Kaltschmidt JA, Greenleaf WJ, Gitler AD. Single-cell transcriptomic analysis of the adult mouse spinal cord reveals molecular diversity of autonomic and skeletal motor neurons. Nat Neurosci 2021; 24:572-583. [PMID: 33589834 PMCID: PMC8016743 DOI: 10.1038/s41593-020-00795-0] [Citation(s) in RCA: 81] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2020] [Accepted: 12/23/2020] [Indexed: 01/30/2023]
Abstract
The spinal cord is a fascinating structure that is responsible for coordinating movement in vertebrates. Spinal motor neurons control muscle activity by transmitting signals from the spinal cord to diverse peripheral targets. In this study, we profiled 43,890 single-nucleus transcriptomes from the adult mouse spinal cord using fluorescence-activated nuclei sorting to enrich for motor neuron nuclei. We identified 16 sympathetic motor neuron clusters, which are distinguishable by spatial localization and expression of neuromodulatory signaling genes. We found surprising skeletal motor neuron heterogeneity in the adult spinal cord, including transcriptional differences that correlate with electrophysiologically and spatially distinct motor pools. We also provide evidence for a novel transcriptional subpopulation of skeletal motor neuron (γ*). Collectively, these data provide a single-cell transcriptional atlas ( http://spinalcordatlas.org ) for investigating the organizing molecular logic of adult motor neuron diversity, as well as the cellular and molecular basis of motor neuron function in health and disease.
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Affiliation(s)
- Jacob A Blum
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
- Stanford Neurosciences Graduate Program, Stanford University School of Medicine, Stanford, CA, USA
| | - Sandy Klemm
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Jennifer L Shadrach
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| | - Kevin A Guttenplan
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
- Stanford Neurosciences Graduate Program, Stanford University School of Medicine, Stanford, CA, USA
| | - Lisa Nakayama
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Arwa Kathiria
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
| | - Phuong T Hoang
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
- Department of Neurology and Neurological Science, Stanford University School of Medicine, Stanford, CA, USA
| | - Olivia Gautier
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
- Stanford Neurosciences Graduate Program, Stanford University School of Medicine, Stanford, CA, USA
| | - Julia A Kaltschmidt
- Department of Neurosurgery, Stanford University School of Medicine, Stanford, CA, USA
| | - William J Greenleaf
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA
- Department of Applied Physics, Stanford University, Stanford, CA, USA
- Chan Zuckerberg Biohub, San Francisco, CA, USA
| | - Aaron D Gitler
- Department of Genetics, Stanford University School of Medicine, Stanford, CA, USA.
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17
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Filipchuk A, Pambo-Pambo A, Gaudel F, Liabeuf S, Brocard C, Gueritaud JP, Durand J. Early Hypoexcitability in a Subgroup of Spinal Motoneurons in Superoxide Dismutase 1 Transgenic Mice, a Model of Amyotrophic Lateral Sclerosis. Neuroscience 2021; 463:337-53. [PMID: 33556455 DOI: 10.1016/j.neuroscience.2021.01.039] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2020] [Revised: 01/22/2021] [Accepted: 01/31/2021] [Indexed: 11/24/2022]
Abstract
In amyotrophic lateral sclerosis (ALS), large motoneurons degenerate first, causing muscle weakness. Transgenic mouse models with a mutation in the gene encoding the enzyme superoxide dismutase 1 (SOD1) revealed that motoneurons innervating the fast-fatigable muscular fibres disconnect very early. The cause of this peripheric disconnection has not yet been established. Early pathological signs were described in motoneurons during the postnatal period of SOD1 transgenic mice. Here, we investigated whether the early changes of electrical and morphological properties previously reported in the SOD1G85R strain also occur in the SOD1G93A-low expressor line with particular attention to the different subsets of motoneurons defined by their discharge firing pattern (transient, sustained, or delayed-onset firing). Intracellular staining and recording were performed in lumbar motoneurons from entire brainstem-spinal cord preparations of SOD1G93A-low transgenic mice and their WT littermates during the second postnatal week. Our results show that SOD1G93A-low motoneurons exhibit a dendritic overbranching similar to that described previously in the SOD1G85R strain at the same age. Further we found an hypoexcitability in the delayed-onset firing SOD1G93A-low motoneurons (lower gain and higher voltage threshold). We conclude that dendritic overbranching and early hypoexcitability are common features of both low expressor SOD1 mutants (G85R and G93A-low). In the high-expressor SOD1G93A line, we found hyperexcitability in the sustained firing motoneurons at the same period, suggesting a delay in compensatory mechanisms. Overall, our results suggest that the hypoexcitability indicate an early dysfunction of the delayed-onset motoneurons and could account as early pathological signs of the disease.
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18
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Harris T, Bugescu R, Kelly J, Makela A, Sotzen M, Sisk C, Atkin G, Pratt R, Crockett E, Leinninger G. DLK1 Expressed in Mouse Orexin Neurons Modulates Anxio-Depressive Behavior but Not Energy Balance. Brain Sci 2020; 10:brainsci10120975. [PMID: 33322758 PMCID: PMC7764426 DOI: 10.3390/brainsci10120975] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2020] [Revised: 12/08/2020] [Accepted: 12/09/2020] [Indexed: 11/16/2022] Open
Abstract
Lateral hypothalamic area (LHA) neurons expressing the neuropeptide orexin (OX) are implicated in obesity and anxio-depression. However, these neurons release OX as well as a host of other proteins that might contribute to normal physiology and disease states. We hypothesized that delta-like homolog 1 (DLK1), a protein reported to be co-expressed by all OX neurons, contributes to the regulation of energy balance and/or anxio-depression. Consistent with previous reports, we found that all rat OX neurons co-express DLK1. Yet, in mice and humans only a subset of OX neurons co-expressed DLK1. Since human OX-DLK1 distribution is more similar to mice than rats, mice are a comparable model to assess the human physiologic role of DLK1. We therefore used a viral lesion strategy to selectively delete DLK1 within the LHA of adult mice (DLK1Null) to reveal its role in body weight and behavior. Adult-onset DLK1 deletion had no impact on body weight or ingestive behavior. However, DLK1Null mice engaged in more locomotor activity than control mice and had decreased anxiety and depression measured via the elevated plus maze and forced swim tests. These data suggest that DLK1 expression via DLK1-expressing OX neurons primarily contributes to anxio-depression behaviors without impacting body weight.
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Affiliation(s)
- Tatiyana Harris
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA; (T.H.); (R.B.); (J.K.); (A.M.); (M.S.)
| | - Raluca Bugescu
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA; (T.H.); (R.B.); (J.K.); (A.M.); (M.S.)
| | - Jaylyn Kelly
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA; (T.H.); (R.B.); (J.K.); (A.M.); (M.S.)
| | - Anna Makela
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA; (T.H.); (R.B.); (J.K.); (A.M.); (M.S.)
| | - Morgan Sotzen
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA; (T.H.); (R.B.); (J.K.); (A.M.); (M.S.)
| | - Cheryl Sisk
- Neuroscience Program, Department of Psychology, Michigan State University, East Lansing, MI 48824, USA;
| | - Graham Atkin
- Department of Radiology, Michigan State University, East Lansing, MI 48824, USA;
| | - Rebecca Pratt
- Department of Foundational Medical Studies, Oakland University William Beaumont School of Medicine, Rochester, MI 48309, USA;
| | - Elahé Crockett
- Department of Medicine, Michigan State University, East Lansing, MI 48824, USA;
| | - Gina Leinninger
- Department of Physiology, Michigan State University, East Lansing, MI 48824, USA; (T.H.); (R.B.); (J.K.); (A.M.); (M.S.)
- Correspondence:
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19
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Abstract
Over the past several decades, theories about cerebellar learning have evolved. A relatively simple view that highlighted the contribution of one major form of heterosynaptic plasticity to cerebellar motor learning has given way to a plethora of perspectives that suggest that many different forms of synaptic and non-synaptic plasticity, acting at various sites, can control multiple types of learning behaviour. However, there still seem to be contradictions between the various hypotheses with regard to the mechanisms underlying cerebellar learning. The challenge is therefore to reconcile these different views and unite them into a single overall concept. Here I review our current understanding of the changes in the activity of cerebellar Purkinje cells in different 'microzones' during various forms of learning. I describe an emerging model that indicates that the activity of each microzone is bound to either increase or decrease during the initial stages of learning, depending on the directional and temporal demands of its downstream circuitry and the behaviour involved.
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Affiliation(s)
- Chris I De Zeeuw
- Department of Neuroscience, Erasmus MC, Rotterdam, Netherlands. .,Netherlands Institute for Neuroscience, Royal Academy of Arts and Sciences (KNAW), Amsterdam, Netherlands.
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20
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Dos Santos M, Backer S, Saintpierre B, Izac B, Andrieu M, Letourneur F, Relaix F, Sotiropoulos A, Maire P. Single-nucleus RNA-seq and FISH identify coordinated transcriptional activity in mammalian myofibers. Nat Commun 2020; 11:5102. [PMID: 33037211 PMCID: PMC7547110 DOI: 10.1038/s41467-020-18789-8] [Citation(s) in RCA: 108] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2020] [Accepted: 09/10/2020] [Indexed: 12/20/2022] Open
Abstract
Skeletal muscle fibers are large syncytia but it is currently unknown whether gene expression is coordinately regulated in their numerous nuclei. Here we show by snRNA-seq and snATAC-seq that slow, fast, myotendinous and neuromuscular junction myonuclei each have different transcriptional programs, associated with distinct chromatin states and combinations of transcription factors. In adult mice, identified myofiber types predominantly express either a slow or one of the three fast isoforms of Myosin heavy chain (MYH) proteins, while a small number of hybrid fibers can express more than one MYH. By snRNA-seq and FISH, we show that the majority of myonuclei within a myofiber are synchronized, coordinately expressing only one fast Myh isoform with a preferential panel of muscle-specific genes. Importantly, this coordination of expression occurs early during post-natal development and depends on innervation. These findings highlight a previously undefined mechanism of coordination of gene expression in a syncytium. Whether skeletal muscle fibre gene expression is coordinated as a whole in different nuclei in the fibre is unclear. Here, the authors use single nucleus RNAseq and ATACseq to show the transcriptome heterogeneity of muscle nuclei in the adult mouse fibre, with correlations between the two datasets.
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Affiliation(s)
| | - Stéphanie Backer
- Université de Paris, Institut Cochin, INSERM, CNRS., 75014, Paris, France
| | | | - Brigitte Izac
- Université de Paris, Institut Cochin, INSERM, CNRS., 75014, Paris, France
| | - Muriel Andrieu
- Université de Paris, Institut Cochin, INSERM, CNRS., 75014, Paris, France
| | - Franck Letourneur
- Université de Paris, Institut Cochin, INSERM, CNRS., 75014, Paris, France
| | - Frederic Relaix
- Université Paris-Est Creteil, INSERM U955 IMRB., 94000, Creteil, France
| | | | - Pascal Maire
- Université de Paris, Institut Cochin, INSERM, CNRS., 75014, Paris, France.
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21
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Lin CY, Niwa A, Hou CY, Tsai CM, Chang H. Bidirectional myofiber transition through altering the photobiomodulation condition. J Photochem Photobiol B 2020; 212:112041. [PMID: 33002778 DOI: 10.1016/j.jphotobiol.2020.112041] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 08/09/2020] [Accepted: 09/22/2020] [Indexed: 11/20/2022]
Abstract
Despite remarkable advancements in modern medicine, muscular atrophy remains as an unsolved problem. It is well known that pathological characteristics of different atrophy types could vary according to the pathophysiological causes. In fact, the lesion of atrophy is not always homogenously distributed but often predominantly evident in either fast or slow myofibers. As the focalization of the atrophic lesions, the existence and the functional impairment of each fast and slow progenitor/satellite cell (SC) are suspected though there are still controversies about this hypothesis. In this study, we isolated Pax7 positive (Pax7+ve) SCs from the tibia anterior (fast) and soleus (slow) muscles respectively and successfully demonstrated, for the first time, the difference between optimal exposure durations of photobiomodulation (PBM) which was known as low level laser irradiation (LLLI) in promoting proliferation of Pax7+ve SC which were acquired from fast and slow muscles respectively. Moreover, a hypertrophy-accompanied bidirectional change in myofiber composition with neuromuscular junction alteration, either from slow to fast or fast to slow, were achieved by applying different PBM durations. Simultaneously, PBM exhibited a synergistic effect with muscle exercise on the increase in myofiber size. Our data suggested the existence of at least two different populations of Pax7+ve SC which possess distinct sensitivities towards PBM. As our data revealed the capability of PBM in bidirectional changes of skeletal muscle composition and neuromuscular junction constitution thereby strengthen its contractility through altering the irradiation condition, we believe PBM showed the potential to be as a promising clinical treatment for muscular atrophy.
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22
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Soulard C, Salsac C, Mouzat K, Hilaire C, Roussel J, Mezghrani A, Lumbroso S, Raoul C, Scamps F. Spinal Motoneuron TMEM16F Acts at C-boutons to Modulate Motor Resistance and Contributes to ALS Pathogenesis. Cell Rep 2020; 30:2581-2593.e7. [DOI: 10.1016/j.celrep.2020.02.001] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Revised: 11/12/2019] [Accepted: 01/31/2020] [Indexed: 12/11/2022] Open
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23
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24
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Tamura K, Sugita S, Tokunaga T, Minegishi Y, Ota N. TRPM8-mediated cutaneous stimulation modulates motor neuron activity during treadmill stepping in mice. J Physiol Sci 2019; 69:931-938. [PMID: 31482469 PMCID: PMC10717255 DOI: 10.1007/s12576-019-00707-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2019] [Accepted: 08/26/2019] [Indexed: 11/29/2022]
Abstract
Motor units are generally recruited from the smallest to the largest following the size principle, while cutaneous stimulation has the potential to affect spinal motor control. We aimed to examine the effects of stimulating transient receptor potential channel sub-family M8 (TRPM8) combined with exercise on the modulation of spinal motor neuron (MN) excitability. Mice were topically administrated 1.5% icilin on the hindlimbs, followed by treadmill stepping. Spinal cord sections were immunostained with antibodies against c-fos and choline acetyltransferase. Icilin stimulation did not change the number of c-fos+ MNs, but increased the average soma size of the c-fos+ MNs during low-speed treadmill stepping. Furthermore, icilin stimulation combined with stepping increased c-fos+ cholinergic interneurons near the central canal, which are thought to modulate MN excitability. These findings suggest that TRPM8-mediated cutaneous stimulation with low-load exercise promotes preferential recruitment of large MNs and is potentially useful as a new training method for rehabilitation.
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Affiliation(s)
- Kotaro Tamura
- Biological Science Research, Kao Corporation, 2606 Akabane, Ichikai-machi, Haga-gun, Tochigi, 321-3497, Japan
| | - Satoshi Sugita
- Biological Science Research, Kao Corporation, 2606 Akabane, Ichikai-machi, Haga-gun, Tochigi, 321-3497, Japan
| | - Tadayuki Tokunaga
- Personal Health Care Products Research, Kao Corporation, Tokyo, Japan
| | - Yoshihiko Minegishi
- Biological Science Research, Kao Corporation, 2606 Akabane, Ichikai-machi, Haga-gun, Tochigi, 321-3497, Japan.
| | - Noriyasu Ota
- Biological Science Research, Kao Corporation, 2606 Akabane, Ichikai-machi, Haga-gun, Tochigi, 321-3497, Japan
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25
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Traustadóttir GÁ, Lagoni LV, Ankerstjerne LBS, Bisgaard HC, Jensen CH, Andersen DC. The imprinted gene Delta like non-canonical Notch ligand 1 (Dlk1) is conserved in mammals, and serves a growth modulatory role during tissue development and regeneration through Notch dependent and independent mechanisms. Cytokine Growth Factor Rev 2019; 46:17-27. [DOI: 10.1016/j.cytogfr.2019.03.006] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2019] [Revised: 03/21/2019] [Accepted: 03/21/2019] [Indexed: 12/22/2022]
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26
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Rodriques SG, Stickels RR, Goeva A, Martin CA, Murray E, Vanderburg CR, Welch J, Chen LM, Chen F, Macosko EZ. Slide-seq: A scalable technology for measuring genome-wide expression at high spatial resolution. Science 2019; 363:1463-1467. [PMID: 30923225 DOI: 10.1126/science.aaw1219] [Citation(s) in RCA: 1015] [Impact Index Per Article: 203.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2018] [Accepted: 02/28/2019] [Indexed: 12/24/2022]
Abstract
Spatial positions of cells in tissues strongly influence function, yet a high-throughput, genome-wide readout of gene expression with cellular resolution is lacking. We developed Slide-seq, a method for transferring RNA from tissue sections onto a surface covered in DNA-barcoded beads with known positions, allowing the locations of the RNA to be inferred by sequencing. Using Slide-seq, we localized cell types identified by single-cell RNA sequencing datasets within the cerebellum and hippocampus, characterized spatial gene expression patterns in the Purkinje layer of mouse cerebellum, and defined the temporal evolution of cell type-specific responses in a mouse model of traumatic brain injury. These studies highlight how Slide-seq provides a scalable method for obtaining spatially resolved gene expression data at resolutions comparable to the sizes of individual cells.
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Affiliation(s)
- Samuel G Rodriques
- Department of Physics, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,MIT Media Lab, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.,Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Robert R Stickels
- Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA.,Graduate School of Arts and Sciences, Harvard University, Cambridge, MA 02138, USA.,Division of Medical Science, Harvard Medical School, Boston, MA 02115, USA
| | | | - Carly A Martin
- Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Evan Murray
- Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | | | - Joshua Welch
- Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Linlin M Chen
- Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA
| | - Fei Chen
- Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA.
| | - Evan Z Macosko
- Broad Institute of Harvard and MIT, Cambridge, MA 02142, USA. .,Department of Psychiatry, Massachusetts General Hospital, Boston, MA 02114, USA
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27
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Garcia-Gallastegi P, Ruiz-García A, Ibarretxe G, Rivero-Hinojosa S, González-Siccha AD, Laborda J, Crende O, Unda F, García-Ramírez JJ. Similarities and differences in tissue distribution of DLK1 and DLK2 during E16.5 mouse embryogenesis. Histochem Cell Biol 2019; 152:47-60. [DOI: 10.1007/s00418-019-01778-4] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/12/2019] [Indexed: 10/27/2022]
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28
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Abstract
The field of motoneuron and motor unit physiology in mammals has deeply evolved the last decade thanks to the parallel development of mouse genetics and transcriptomic analysis and of in vivo mouse preparations that allow intracellular electrophysiological recordings of motoneurons. We review the efforts made to investigate the electrophysiological properties of the different functional subtypes of mouse motoneurons, to decipher the mosaic of molecular markers specifically expressed in each subtype, and to elucidate which of those factors drive the identity of motoneurons.
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Affiliation(s)
- Marin Manuel
- Center for Neurophysics, Physiology and Pathology, Paris Descartes University, CNRS UMR 8119, Paris, France
| | - Daniel Zytnicki
- Center for Neurophysics, Physiology and Pathology, Paris Descartes University, CNRS UMR 8119, Paris, France
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29
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Yen YP, Hsieh WF, Tsai YY, Lu YL, Liau ES, Hsu HC, Chen YC, Liu TC, Chang M, Li J, Lin SP, Hung JH, Chen JA. Dlk1-Dio3 locus-derived lncRNAs perpetuate postmitotic motor neuron cell fate and subtype identity. eLife 2018; 7:38080. [PMID: 30311912 PMCID: PMC6221546 DOI: 10.7554/elife.38080] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2018] [Accepted: 10/11/2018] [Indexed: 12/28/2022] Open
Abstract
The mammalian imprinted Dlk1-Dio3 locus produces multiple long non-coding RNAs (lncRNAs) from the maternally inherited allele, including Meg3 (i.e., Gtl2) in the mammalian genome. Although this locus has well-characterized functions in stem cell and tumor contexts, its role during neural development is unknown. By profiling cell types at each stage of embryonic stem cell-derived motor neurons (ESC~MNs) that recapitulate spinal cord development, we uncovered that lncRNAs expressed from the Dlk1-Dio3 locus are predominantly and gradually enriched in rostral motor neurons (MNs). Mechanistically, Meg3 and other Dlk1-Dio3 locus-derived lncRNAs facilitate Ezh2/Jarid2 interactions. Loss of these lncRNAs compromises the H3K27me3 landscape, leading to aberrant expression of progenitor and caudal Hox genes in postmitotic MNs. Our data thus illustrate that these lncRNAs in the Dlk1-Dio3 locus, particularly Meg3, play a critical role in maintaining postmitotic MN cell fate by repressing progenitor genes and they shape MN subtype identity by regulating Hox genes. When a gene is active, its DNA sequence is ‘transcribed’ to form a molecule of RNA. Many of these RNAs act as templates for making proteins. But for some genes, the protein molecules are not their final destinations. Their RNA molecules instead help to control gene activity, which can alter the behaviour or the identity of a cell. For example, experiments performed in individual cells suggest that so-called long non-coding RNAs (or lncRNAs for short) guide how stem cells develop into different types of mature cells. However, it is not clear whether lncRNAs play the same critical role in embryos. Yen et al. used embryonic stem cells to model how motor neurons develop in the spinal cord of mouse embryos. This revealed that motor neurons produce large amounts of a specific group of lncRNAs, particularly one called Meg3. Further experiments showed that motor neurons in mouse embryos that lack Meg3 do not correctly silence a set of genes called the Hox genes, which are crucial for laying out the body plans of many different animal embryos. These neurons also incorrectly continue to express genes that are normally active in an early phase of the stem-like cells that make motor neurons. There is wide interest in how lncRNAs help to regulate embryonic development. With this new knowledge of how Meg3 regulates the activity of Hox genes in motor neurons, research could now be directed toward investigating whether lncRNAs help other tissues to develop in a similar way.
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Affiliation(s)
- Ya-Ping Yen
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, Republic of China.,Institute of Biotechnology, College of Bio-Resources and Agriculture, National Taiwan University, Taipei, Taiwan, Republic of China
| | - Wen-Fu Hsieh
- Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu, Taiwan, Republic of China
| | - Ya-Yin Tsai
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, Republic of China
| | - Ya-Lin Lu
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, Republic of China
| | - Ee Shan Liau
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, Republic of China
| | - Ho-Chiang Hsu
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, Republic of China
| | - Yen-Chung Chen
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, Republic of China
| | - Ting-Chun Liu
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, Republic of China
| | - Mien Chang
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, Republic of China
| | - Joye Li
- Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu, Taiwan, Republic of China
| | - Shau-Ping Lin
- Institute of Biotechnology, College of Bio-Resources and Agriculture, National Taiwan University, Taipei, Taiwan, Republic of China
| | - Jui-Hung Hung
- Institute of Bioinformatics and Systems Biology, National Chiao Tung University, Hsinchu, Taiwan, Republic of China.,Department of Computer Science, National Chiao Tung University, Hsinchu, Taiwan, Republic of China
| | - Jun-An Chen
- Institute of Molecular Biology, Academia Sinica, Taipei, Taiwan, Republic of China
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30
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García-Gutiérrez MS, Navarrete F, Laborda J, Manzanares J. Deletion of Dlk1 increases the vulnerability to developing anxiety-like behaviors and ethanol consumption in mice. Biochem Pharmacol 2018; 158:37-44. [PMID: 30268817 DOI: 10.1016/j.bcp.2018.09.029] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Accepted: 09/26/2018] [Indexed: 12/18/2022]
Abstract
Anxiety and alcohol use disorders (AUD) often present together, constituting a significant public health problem worldwide. In this study, we investigated the role of DLK1, a ligand of the Delta/NOTCH epidermal growth factor (EGF)-like protein family, reported to play a role in DA neurons differentiation in the striatum, as a neurobiological factor involved in the mechanisms regulating this psychiatric comorbidity. We exposed Dlk1 knockout mice (Dlk1-/- mice) to the open-field (OF), the light-dark box (LBD) and the elevated plus maze (EPM) tests, evaluating motivation to drink and ethanol consumption using the oral ethanol self-administration (OEA) paradigm. Quantitative real time polymerase chain reaction (qPCR) studies were carried out to evaluate alterations in targets closely related to DA neurotransmission in the reward system, tyrosine hydroxylase (Th) in the ventral tegmental area (VTA), and μ-opioid receptor (Oprm1) in the nucleus accumbens (NAc). No differences were observed in the total or peripheral distances travelled by Dlk1-/- compared to wild-type (WT) mice in OF. However, central distance travelled significantly decreased in Dlk1-/- mice. Deletion of Dlk1 increased anxiety-like behaviors in the LDB and EPM, and, Dlk1-/- mice also presented higher ethanol intake and motivation to drink (number of effective responses) in the OEA. In addition, Th and Oprm1 gene expression was reduced in the VTA and NAc of Dlk1-/- mice. We conclude that deletion of Dlk1 increases anxiety-related behaviors and vulnerability to ethanol consumption and modifies the gene expression of key targets closely related with DA neurotransmission involved in the reinforcing actions of ethanol.
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Affiliation(s)
- María S García-Gutiérrez
- Institute of Neurosciences, Miguel Hernández University-CSIC, Avda de Ramón y Cajal s/n, San Juan de Alicante, 03550 Alicante, Spain; Topic-based Network for Cooperative Health Research (RETICS), Substance Abuse Network, Health Institute Carlos III, MICINN and FEDER, Madrid, Spain
| | - Francisco Navarrete
- Institute of Neurosciences, Miguel Hernández University-CSIC, Avda de Ramón y Cajal s/n, San Juan de Alicante, 03550 Alicante, Spain; Topic-based Network for Cooperative Health Research (RETICS), Substance Abuse Network, Health Institute Carlos III, MICINN and FEDER, Madrid, Spain
| | - Jorge Laborda
- School of Pharmacy, Regional Center for Biomedical Research (CRIB), Biomedicine Unit UCLM-CSIC, Albacete, Spain
| | - Jorge Manzanares
- Institute of Neurosciences, Miguel Hernández University-CSIC, Avda de Ramón y Cajal s/n, San Juan de Alicante, 03550 Alicante, Spain; Topic-based Network for Cooperative Health Research (RETICS), Substance Abuse Network, Health Institute Carlos III, MICINN and FEDER, Madrid, Spain.
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31
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Misawa H, Morisaki Y. [Motor neuron heterogeneity and selective vulnerability in ALS]. Nihon Yakurigaku Zasshi 2018; 152:64-69. [PMID: 30101862 DOI: 10.1254/fpj.152.64] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/28/2022]
Abstract
Different and selective vulnerability among motor neuron subtypes are a fundamental, but unexplained, feature of amyotrophic lateral sclerosis (ALS): fast-fatigable (FF) motor neurons are the most vulnerable, and fast fatigue-resistant/slow (FR/S) motor neurons are relatively resistant. We identified that osteopontin (OPN) can serve as a marker of FR/S motor neurons, whereas matrix metalloproteinase-9 (MMP9) is expressed by FF motor neurons in mice. In SOD1G93A ALS model mice, as the disease progressed, OPN was secreted and accumulated as granular deposits in the extracellular matrix. We also detected OPN/MMP9 co-expressed motor neurons around the disease onset. These double positive motor neurons showed the expression of αvβ3 integrin (OPN receptor) and up-regulation of ER stress markers. We discovered that the double positive motor neurons are remodeled FR/S motor neurons, which compensated for FF motor neuron degeneration (the first wave of degeneration). Genetic ablation of OPN delayed the onset of disease, but later accelerated disease progression. This reflects two modes of OPN involvement in the pathogenesis of ALS: cell-autonomous and non-cell-autonomous effects on motor neuron vulnerability. Our study suggests that OPN expressed in FR/S motor neurons is involved in the second wave of motor neuron degeneration in ALS, and an OPN-αvβ3 integrin-MMP9 axis could be a potentially useful therapeutic target for ALS.
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Affiliation(s)
- Hidemi Misawa
- Division of Pharmacology, Faculty of Pharmacy, Keio University
| | - Yuta Morisaki
- Division of Pharmacology, Faculty of Pharmacy, Keio University
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32
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Tejero R, Lopez-manzaneda M, Franco-espín J, Tabares L. Maturation and heterogeneity of vertebrate motor synapses. Current Opinion in Physiology 2018; 4:1-6. [DOI: 10.1016/j.cophys.2018.02.009] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
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33
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Kelley KW, Ben Haim L, Schirmer L, Tyzack GE, Tolman M, Miller JG, Tsai HH, Chang SM, Molofsky AV, Yang Y, Patani R, Lakatos A, Ullian EM, Rowitch DH. Kir4.1-Dependent Astrocyte-Fast Motor Neuron Interactions Are Required for Peak Strength. Neuron 2018; 98:306-319.e7. [PMID: 29606582 PMCID: PMC5919779 DOI: 10.1016/j.neuron.2018.03.010] [Citation(s) in RCA: 75] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2017] [Revised: 11/08/2017] [Accepted: 03/05/2018] [Indexed: 12/11/2022]
Abstract
Diversified neurons are essential for sensorimotor function, but whether astrocytes become specialized to optimize circuit performance remains unclear. Large fast α-motor neurons (FαMNs) of spinal cord innervate fast-twitch muscles that generate peak strength. We report that ventral horn astrocytes express the inward-rectifying K+ channel Kir4.1 (a.k.a. Kcnj10) around MNs in a VGLUT1-dependent manner. Loss of astrocyte-encoded Kir4.1 selectively altered FαMN size and function and led to reduced peak strength. Overexpression of Kir4.1 in astrocytes was sufficient to increase MN size through activation of the PI3K/mTOR/pS6 pathway. Kir4.1 was downregulated cell autonomously in astrocytes derived from amyotrophic lateral sclerosis (ALS) patients with SOD1 mutation. However, astrocyte Kir4.1 was dispensable for FαMN survival even in the mutant SOD1 background. These findings show that astrocyte Kir4.1 is essential for maintenance of peak strength and suggest that Kir4.1 downregulation might uncouple symptoms of muscle weakness from MN cell death in diseases like ALS. Kir4.1 is upregulated in astrocytes around high-activity alpha motor neurons (MNs) Astrocyte Kir4.1 KO caused decreased peak strength without alpha MN loss ALS patient-derived astrocytes show cell-autonomous Kir4.1 downregulation Astrocyte Kir4.1 regulates MN size through PI3K/mTOR/pS6 activation
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Affiliation(s)
- Kevin W Kelley
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA; Departments of Pediatrics and Neurosurgery, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Lucile Ben Haim
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA; Departments of Pediatrics and Neurosurgery, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Lucas Schirmer
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA; Departments of Pediatrics and Neurosurgery, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Giulia E Tyzack
- Department of Molecular Neuroscience, Institute of Neurology, University College London, London WC1N 3BG, UK; The Francis Crick Institute, London NW1 1AT, UK
| | - Michaela Tolman
- Sackler School of Biomedical Sciences, Tufts University, Boston, MA 02111, USA
| | - John G Miller
- Department of Psychiatry, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Hui-Hsin Tsai
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA; Departments of Pediatrics and Neurosurgery, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Sandra M Chang
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA; Departments of Pediatrics and Neurosurgery, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Anna V Molofsky
- Department of Psychiatry, University of California, San Francisco, San Francisco, CA 94143, USA
| | - Yongjie Yang
- Sackler School of Biomedical Sciences, Tufts University, Boston, MA 02111, USA
| | - Rickie Patani
- Department of Molecular Neuroscience, Institute of Neurology, University College London, London WC1N 3BG, UK; The Francis Crick Institute, London NW1 1AT, UK
| | - Andras Lakatos
- John van Geest Centre for Brain Repair and Department of Clinical Neurosciences, University of Cambridge, Cambridge CB20QQ, UK
| | - Erik M Ullian
- Department of Ophthalmology, University of California, San Francisco, San Francisco, CA 94143, USA
| | - David H Rowitch
- Eli and Edythe Broad Center of Regeneration Medicine and Stem Cell Research, University of California, San Francisco, San Francisco, CA 94143, USA; Departments of Pediatrics and Neurosurgery, University of California, San Francisco, San Francisco, CA 94143, USA; Department of Paediatrics and Wellcome Trust-MRC Cambridge Stem Cell Institute, University of Cambridge, Cambridge CB20QQ, UK.
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Yu Y, Lu B, Lu W, Li S, Li X, Wang X, Wan X, Chen Y, Feng S, Jia Y, Yang R, Tang F, Li X, Zhang S, Wang X, Wei H, Peng Z, Lu L, Zhong H, Zhao L, Huang Z, Lin L, Shen W, Lu Y, Cao Z, Zou J, Ma Y, Chen X, Tian Q, Lu S, Liu P, Ma D, Xie X, Cheng X. Whole-exome sequencing reveals genetic variants in ERC1 and KCNG4 associated with complete hydatidiform mole in Chinese Han women. Oncotarget 2017; 8:75264-71. [PMID: 29088863 DOI: 10.18632/oncotarget.20769] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2017] [Accepted: 07/29/2017] [Indexed: 11/25/2022] Open
Abstract
Complete hydatidiform mole (CHM) is a rare pregnancy-related disease with invasive potential. The genetics underlying the sporadic form of CHM have not been addressed previously, but maternal genetic variants may be involved in biparental CHM. We performed whole-exome sequencing of 51 patients with CHM and 47 healthy women to identify genetic variants associated with CHM. In addition, candidate variants were analyzed using single base extension and Matrix Assisted Laser Desorption/Ionization-Time of Flight Mass Spectrometry in 199 CHM patients and 400 healthy controls. We validated candidate variants using Sanger sequencing in 250 cases and 652 controls, including 205 new controls. Two single nucleotide polymorphisms, c.G48C(p.Q16H) inERC1 and c.G1114A(p.G372S) in KCNG4, were associated with an increased risk of CHM (p<0.05). These variants may contribute to the pathogenesis of CHM and could be used to screen pregnant women for this genetic abnormality.
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Krieger B, Qiao M, Rousso DL, Sanes JR, Meister M. Four alpha ganglion cell types in mouse retina: Function, structure, and molecular signatures. PLoS One 2017; 12:e0180091. [PMID: 28753612 PMCID: PMC5533432 DOI: 10.1371/journal.pone.0180091] [Citation(s) in RCA: 139] [Impact Index Per Article: 19.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2016] [Accepted: 06/11/2017] [Indexed: 11/18/2022] Open
Abstract
The retina communicates with the brain using ≥30 parallel channels, each carried by axons of distinct types of retinal ganglion cells. In every mammalian retina one finds so-called "alpha" ganglion cells (αRGCs), identified by their large cell bodies, stout axons, wide and mono-stratified dendritic fields, and high levels of neurofilament protein. In the mouse, three αRGC types have been described based on responses to light steps: On-sustained, Off-sustained, and Off-transient. Here we employed a transgenic mouse line that labels αRGCs in the live retina, allowing systematic targeted recordings. We characterize the three known types and identify a fourth, with On-transient responses. All four αRGC types share basic aspects of visual signaling, including a large receptive field center, a weak antagonistic surround, and absence of any direction selectivity. They also share a distinctive waveform of the action potential, faster than that of other RGC types. Morphologically, they differ in the level of dendritic stratification within the IPL, which accounts for their response properties. Molecularly, each type has a distinct signature. A comparison across mammals suggests a common theme, in which four large-bodied ganglion cell types split the visual signal into four channels arranged symmetrically with respect to polarity and kinetics.
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Affiliation(s)
- Brenna Krieger
- Harvard Biophysics Program, Harvard Medical School, Boston, Massachusetts, United States of America
| | - Mu Qiao
- Center for Brain Science and Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, United States of America
| | - David L. Rousso
- Center for Brain Science and Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, United States of America
| | - Joshua R. Sanes
- Center for Brain Science and Department of Molecular and Cellular Biology, Harvard University, Cambridge, Massachusetts, United States of America
- * E-mail: (JRS); (MM)
| | - Markus Meister
- Division of Biology and Biological Engineering, California Institute of Technology, Pasadena, California, United States of America
- * E-mail: (JRS); (MM)
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Nijssen J, Comley LH, Hedlund E. Motor neuron vulnerability and resistance in amyotrophic lateral sclerosis. Acta Neuropathol 2017; 133:863-885. [PMID: 28409282 PMCID: PMC5427160 DOI: 10.1007/s00401-017-1708-8] [Citation(s) in RCA: 196] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2017] [Revised: 03/29/2017] [Accepted: 04/01/2017] [Indexed: 12/11/2022]
Abstract
In the fatal disease-amyotrophic lateral sclerosis (ALS)-upper (corticospinal) motor neurons (MNs) and lower somatic MNs, which innervate voluntary muscles, degenerate. Importantly, certain lower MN subgroups are relatively resistant to degeneration, even though pathogenic proteins are typically ubiquitously expressed. Ocular MNs (OMNs), including the oculomotor, trochlear and abducens nuclei (CNIII, IV and VI), which regulate eye movement, persist throughout the disease. Consequently, eye-tracking devices are used to enable paralysed ALS patients (who can no longer speak) to communicate. Additionally, there is a gradient of vulnerability among spinal MNs. Those innervating fast-twitch muscle are most severely affected and degenerate first. MNs innervating slow-twitch muscle can compensate temporarily for the loss of their neighbours by re-innervating denervated muscle until later in disease these too degenerate. The resistant OMNs and the associated extraocular muscles (EOMs) are anatomically and functionally very different from other motor units. The EOMs have a unique set of myosin heavy chains, placing them outside the classical characterization spectrum of all skeletal muscle. Moreover, EOMs have multiple neuromuscular innervation sites per single myofibre. Spinal fast and slow motor units show differences in their dendritic arborisations and the number of myofibres they innervate. These motor units also differ in their functionality and excitability. Identifying the molecular basis of cell-intrinsic pathways that are differentially activated between resistant and vulnerable MNs could reveal mechanisms of selective neuronal resistance, degeneration and regeneration and lead to therapies preventing progressive MN loss in ALS. Illustrating this, overexpression of OMN-enriched genes in spinal MNs, as well as suppression of fast spinal MN-enriched genes can increase the lifespan of ALS mice. Here, we discuss the pattern of lower MN degeneration in ALS and review the current literature on OMN resistance in ALS and differential spinal MN vulnerability. We also reflect upon the non-cell autonomous components that are involved in lower MN degeneration in ALS.
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Bocksteins E, Snyders DJ, Holmgren M. Independent movement of the voltage sensors in K V2.1/K V6.4 heterotetramers. Sci Rep 2017; 7:41646. [PMID: 28139741 PMCID: PMC5282584 DOI: 10.1038/srep41646] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 12/20/2016] [Indexed: 01/11/2023] Open
Abstract
Heterotetramer voltage-gated K+ (KV) channels KV2.1/KV6.4 display a gating charge-voltage (QV) distribution composed by two separate components. We use state dependent chemical accessibility to cysteines substituted in either KV2.1 or KV6.4 to assess the voltage sensor movements of each subunit. By comparing the voltage dependences of chemical modification and gating charge displacement, here we show that each gating charge component corresponds to a specific subunit forming the heterotetramer. The voltage sensors from KV6.4 subunits move at more negative potentials than the voltage sensors belonging to KV2.1 subunits. These results indicate that the voltage sensors from the tetrameric channels move independently. In addition, our data shows that 75% of the total charge is attributed to KV2.1, while 25% to KV6.4. Thus, the most parsimonious model for KV2.1/KV6.4 channels’ stoichiometry is 3:1.
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Affiliation(s)
- Elke Bocksteins
- Laboratory for Molecular Biophysics, Physiology and Pharmacology, Department for Biomedical Sciences, University of Antwerp, Antwerp, Belgium.,Molecular Neurophysiology Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
| | - Dirk J Snyders
- Laboratory for Molecular Biophysics, Physiology and Pharmacology, Department for Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - Miguel Holmgren
- Molecular Neurophysiology Section, Porter Neuroscience Research Center, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, Maryland, USA
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Regnier G, Bocksteins E, Marei WF, Pintelon I, Timmermans JP, Leroy JLMR, Snyders DJ. Targeted deletion of the Kv6.4 subunit causes male sterility due to disturbed spermiogenesis. Reprod Fertil Dev 2017; 29:1567-1575. [DOI: 10.1071/rd16075] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Accepted: 07/16/2016] [Indexed: 12/18/2022] Open
Abstract
Electrically silent voltage-gated potassium (KvS) channel subunits (i.e. Kv5–Kv6 and Kv8–Kv9) do not form functional homotetrameric Kv channels, but co-assemble with Kv2 subunits, generating functional heterotetrameric Kv2–KvS channel complexes in which the KvS subunits modulate the Kv2 channel properties. Several KvS subunits are expressed in testis tissue but knowledge about their contribution to testis physiology is lacking. Here, we report that the targeted deletion of Kv6.4 in a transgenic mouse model (Kcng4–/–) causes male sterility as offspring from homozygous females were only obtained after mating with wild-type (WT) or heterozygous males. Semen quality analysis revealed that the sterility of the homozygous males was caused by a severe reduction in total sperm-cell count and the absence of motile spermatozoa in the semen. Furthermore, spermatozoa of homozygous mice showed an abnormal morphology characterised by a smaller head and a shorter tail compared with WT spermatozoa. Comparison of WT and Kcng4–/– testicular tissue indicated that this inability to produce (normal) spermatozoa was due to disturbed spermiogenesis. These results suggest that Kv6.4 subunits are involved in the regulation of the late stages of spermatogenesis, which makes them a potentially interesting pharmacological target for the development of non-hormonal male contraceptives.
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Abstract
Members of the electrically silent voltage-gated K+ (Kv) subfamilies (Kv5, Kv6, Kv8, and Kv9, collectively identified as electrically silent voltage-gated K+ channel [KvS] subunits) do not form functional homotetrameric channels but assemble with Kv2 subunits into heterotetrameric Kv2/KvS channels with unique biophysical properties. Unlike the ubiquitously expressed Kv2 subunits, KvS subunits show a more restricted expression. This raises the possibility that Kv2/KvS heterotetramers have tissue-specific functions, making them potential targets for the development of novel therapeutic strategies. Here, I provide an overview of the expression of KvS subunits in different tissues and discuss their proposed role in various physiological and pathophysiological processes. This overview demonstrates the importance of KvS subunits and Kv2/KvS heterotetramers in vivo and the importance of considering KvS subunits and Kv2/KvS heterotetramers in the development of novel treatments.
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Affiliation(s)
- Elke Bocksteins
- Laboratory for Molecular Biophysics, Physiology, and Pharmacology, Department for Biomedical Sciences, University of Antwerp, 2610 Antwerp, Belgium
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García-Gallastegui P, Luzuriaga J, Aurrekoetxea M, Baladrón V, Ruiz-Hidalgo MJ, García-Ramírez JJ, Laborda J, Unda F, Ibarretxe G. Reduced salivary gland size and increased presence of epithelial progenitor cells in DLK1-deficient mice. Cell Tissue Res 2015; 364:513-525. [DOI: 10.1007/s00441-015-2344-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2015] [Accepted: 12/10/2015] [Indexed: 01/23/2023]
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Stas JI, Bocksteins E, Labro AJ, Snyders DJ. Modulation of Closed-State Inactivation in Kv2.1/Kv6.4 Heterotetramers as Mechanism for 4-AP Induced Potentiation. PLoS One 2015; 10:e0141349. [PMID: 26505474 PMCID: PMC4623978 DOI: 10.1371/journal.pone.0141349] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 10/06/2015] [Indexed: 12/26/2022] Open
Abstract
The voltage-gated K+ (Kv) channel subunits Kv2.1 and Kv2.2 are expressed in almost every tissue. The diversity of Kv2 current is increased by interacting with the electrically silent Kv (KvS) subunits Kv5-Kv6 and Kv8-Kv9, into functional heterotetrameric Kv2/KvS channels. These Kv2/KvS channels possess unique biophysical properties and display a more tissue-specific expression pattern, making them more desirable pharmacological and therapeutic targets. However, little is known about the pharmacological properties of these heterotetrameric complexes. We demonstrate that Kv5.1, Kv8.1 and Kv9.3 currents were inhibited differently by the channel blocker 4-aminopyridine (4-AP) compared to Kv2.1 homotetramers. In contrast, Kv6.4 currents were potentiated by 4-AP while displaying moderately increased affinities for the channel pore blockers quinidine and flecainide. We found that the 4-AP induced potentiation of Kv6.4 currents was caused by modulation of the Kv6.4-mediated closed-state inactivation: suppression by 4-AP of the Kv2.1/Kv6.4 closed-state inactivation recovered a population of Kv2.1/Kv6.4 channels that was inactivated at resting conditions, i.e. at a holding potential of -80 mV. This modulation also resulted in a slower initiation and faster recovery from closed-state inactivation. Using chimeric substitutions between Kv6.4 and Kv9.3 subunits, we demonstrated that the lower half of the S6 domain (S6c) plays a crucial role in the 4-AP induced potentiation. These results demonstrate that KvS subunits modify the pharmacological response of Kv2 subunits when assembled in heterotetramers and illustrate the potential of KvS subunits to provide unique pharmacological properties to the heterotetramers, as is the case for 4-AP on Kv2.1/Kv6.4 channels.
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Affiliation(s)
- Jeroen I. Stas
- Laboratory for Molecular Biophysics, Physiology and Pharmacology, Department of Biomedical Sciences, University of Antwerp, CDE, Universiteitsplein 1, Antwerp, Belgium
| | - Elke Bocksteins
- Laboratory for Molecular Biophysics, Physiology and Pharmacology, Department of Biomedical Sciences, University of Antwerp, CDE, Universiteitsplein 1, Antwerp, Belgium
| | - Alain J. Labro
- Laboratory for Molecular Biophysics, Physiology and Pharmacology, Department of Biomedical Sciences, University of Antwerp, CDE, Universiteitsplein 1, Antwerp, Belgium
| | - Dirk J. Snyders
- Laboratory for Molecular Biophysics, Physiology and Pharmacology, Department of Biomedical Sciences, University of Antwerp, CDE, Universiteitsplein 1, Antwerp, Belgium
- * E-mail:
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Abstract
Control of movement is a fundamental and complex task of the vertebrate nervous system, which relies on communication between circuits distributed throughout the brain and spinal cord. Many of the networks essential for the execution of basic locomotor behaviors are composed of discrete neuronal populations residing within the spinal cord. The organization and connectivity of these circuits is established through programs that generate functionally diverse neuronal subtypes, each contributing to a specific facet of motor output. Significant progress has been made in deciphering how neuronal subtypes are specified and in delineating the guidance and synaptic specificity determinants at the core of motor circuit assembly. Recent studies have shed light on the basic principles linking locomotor circuit connectivity with function, and they are beginning to reveal how more sophisticated motor behaviors are encoded. In this review, we discuss the impact of developmental programs in specifying motor behaviors governed by spinal circuits.
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Affiliation(s)
- Catarina Catela
- Neuroscience Institute and Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY 10016;
| | - Maggie M Shin
- Neuroscience Institute and Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY 10016;
| | - Jeremy S Dasen
- Neuroscience Institute and Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY 10016;
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Durand J, Filipchuk A, Pambo-Pambo A, Amendola J, Borisovna Kulagina I, Guéritaud JP. Developing electrical properties of postnatal mouse lumbar motoneurons. Front Cell Neurosci 2015; 9:349. [PMID: 26388736 PMCID: PMC4557103 DOI: 10.3389/fncel.2015.00349] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2015] [Accepted: 08/20/2015] [Indexed: 11/13/2022] Open
Abstract
We studied the rapid changes in electrical properties of lumbar motoneurons between postnatal days 3 and 9 just before mice weight-bear and walk. The input conductance and rheobase significantly increased up to P8. A negative correlation exists between the input resistance (Rin) and rheobase. Both parameters are significantly correlated with the total dendritic surface area of motoneurons, the largest motoneurons having the lowest Rin and the highest rheobase. We classified the motoneurons into three groups according to their discharge firing patterns during current pulse injection (transient, delayed onset, sustained). The delayed onset firing type has the highest rheobase and the fastest action potential (AP) whereas the transient firing group has the lowest rheobase and the less mature AP. We found 32 and 10% of motoneurons with a transient firing at P3-P5 and P8, respectively. About 20% of motoneurons with delayed onset firing were detected at P8. At P9, all motoneurons exhibit a sustained firing. We defined five groups of motoneurons according to their discharge firing patterns in response to ascending and descending current ramps. In addition to the four classical types, we defined a fifth type called transient for the quasi-absence of discharge during the descending phase of the ramp. This transient type represents about 40% between P3-P5 and tends to disappear with age. Types 1 and 2 (linear and clockwise hysteresis) are the most preponderant at P6-P7. Types 3 and 4 (prolonged sustained and counter clockwise hysteresis) emerge at P8-P9. The emergence of types 3 and 4 probably depends on the maturation of L type calcium channels in the dendrites of motoneurons. No correlation was found between groups defined by step or triangular ramp of currents with the exception of transient firing patterns. Our data support the idea that a switch in the electrical properties of lumbar motoneurons might exist in the second postnatal week of life in mice.
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Affiliation(s)
- Jacques Durand
- Institut de Neurosciences de la Timone, Aix Marseille Université - CNRS, UMR 7289 Marseille, France
| | - Anton Filipchuk
- Institut de Neurosciences de la Timone, Aix Marseille Université - CNRS, UMR 7289 Marseille, France
| | - Arnaud Pambo-Pambo
- Institut de Neurosciences de la Timone, Aix Marseille Université - CNRS, UMR 7289 Marseille, France
| | - Julien Amendola
- Institut de Neurosciences de la Timone, Aix Marseille Université - CNRS, UMR 7289 Marseille, France
| | | | - Jean-Patrick Guéritaud
- Institut de Neurosciences de la Timone, Aix Marseille Université - CNRS, UMR 7289 Marseille, France
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Abdallah BM, Ditzel N, Laborda J, Karsenty G, Kassem M. DLK1 Regulates Whole-Body Glucose Metabolism: A Negative Feedback Regulation of the Osteocalcin-Insulin Loop. Diabetes 2015; 64:3069-80. [PMID: 25918236 DOI: 10.2337/db14-1642] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/29/2014] [Accepted: 04/21/2015] [Indexed: 11/13/2022]
Abstract
The endocrine role of the skeleton in regulating energy metabolism is supported by a feed-forward loop between circulating osteoblast (OB)-derived undercarboxylated osteocalcin (Glu-OCN) and pancreatic β-cell insulin; in turn, insulin favors osteocalcin (OCN) bioactivity. These data suggest the existence of a negative regulation of this cross talk between OCN and insulin. Recently, we identified delta like-1 (DLK1) as an endocrine regulator of bone turnover. Because DLK1 is colocalized with insulin in pancreatic β-cells, we examined the role of DLK1 in insulin signaling in OBs and energy metabolism. We show that Glu-OCN specifically stimulates Dlk1 expression by the pancreas. Conversely, Dlk1-deficient (Dlk1(-/-) ) mice exhibited increased circulating Glu-OCN levels and increased insulin sensitivity, whereas mice overexpressing Dlk1 in OB displayed reduced insulin secretion and sensitivity due to impaired insulin signaling in OB and lowered Glu-OCN serum levels. Furthermore, Dlk1(-/-) mice treated with Glu-OC experienced significantly lower blood glucose levels than Glu-OCN-treated wild-type mice. The data suggest that Glu-OCN-controlled production of DLK1 by pancreatic β-cells acts as a negative feedback mechanism to counteract the stimulatory effects of insulin on OB production of Glu-OCN, a potential mechanism preventing OCN-induced hypoglycemia.
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Affiliation(s)
- Basem M Abdallah
- Molecular Endocrinology Laboratory (KMEB), Department of Endocrinology, Odense University Hospital and University of Southern Denmark, Odense, Denmark
| | - Nicholas Ditzel
- Molecular Endocrinology Laboratory (KMEB), Department of Endocrinology, Odense University Hospital and University of Southern Denmark, Odense, Denmark
| | - Jorge Laborda
- Department of Inorganic and Organic Chemistry and Biochemistry, University of Castilla-La Mancha Medical School, Albacete, Spain
| | - Gerard Karsenty
- Department of Genetics and Development, College of Physicians and Surgeons, Columbia University, New York, NY
| | - Moustapha Kassem
- Molecular Endocrinology Laboratory (KMEB), Department of Endocrinology, Odense University Hospital and University of Southern Denmark, Odense, Denmark DanStem (Danish Stem Cell Center), Panum Institute, University of Copenhagen, Copenhagen, Denmark Stem Cell Unit, Department of Anatomy, College of Medicine, King Saud University, Riyadh, Saudi Arabia
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Martínez de Paz A, Sanchez-Mut JV, Samitier-Martí M, Petazzi P, Sáez M, Szczesna K, Huertas D, Esteller M, Ausió J. Circadian cycle-dependent MeCP2 and brain chromatin changes. PLoS One 2015; 10:e0123693. [PMID: 25875630 PMCID: PMC4395115 DOI: 10.1371/journal.pone.0123693] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Accepted: 03/06/2015] [Indexed: 11/30/2022] Open
Abstract
Methyl CpG binding protein 2 (MeCP2) is a chromosomal protein of the brain, very abundant especially in neurons, where it plays an important role in the regulation of gene expression. Hence it has the potential to be affected by the mammalian circadian cycle. We performed expression analyses of mice brain frontal cortices obtained at different time points and we found that the levels of MeCP2 are altered circadianly, affecting overall organization of brain chromatin and resulting in a circadian-dependent regulation of well-stablished MeCP2 target genes. Furthermore, this data suggests that alterations of MeCP2 can be responsible for the sleeping disorders arising from pathological stages, such as in autism and Rett syndrome.
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Affiliation(s)
- Alexia Martínez de Paz
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Catalonia, Spain
| | - Jose Vicente Sanchez-Mut
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Catalonia, Spain
| | - Mireia Samitier-Martí
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Catalonia, Spain
| | - Paolo Petazzi
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Catalonia, Spain
| | - Mauricio Sáez
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Catalonia, Spain
| | - Karolina Szczesna
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Catalonia, Spain
| | - Dori Huertas
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Catalonia, Spain
| | - Manel Esteller
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Catalonia, Spain
- Department of Physiological Sciences II, School of Medicine, University of Barcelona, Barcelona, Catalonia, Spain
- Institució Catalana de Recerca i Estudis Avançats (ICREA), Barcelona, Catalonia, Spain
- * E-mail: (ME); (JA)
| | - Juan Ausió
- Cancer Epigenetics and Biology Program (PEBC), Bellvitge Biomedical Research Institute (IDIBELL), Barcelona, Catalonia, Spain
- Department of Biochemistry and Microbiology, University of Victoria, Victoria, British Columbia, Canada
- * E-mail: (ME); (JA)
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Shamis Y, Cullen DE, Liu L, Yang G, Ng SF, Xiao L, Bell FT, Ray C, Takikawa S, Moskowitz IP, Cai CL, Yang X, Li X. Maternal and zygotic Zfp57 modulate NOTCH signaling in cardiac development. Proc Natl Acad Sci U S A 2015; 112:E2020-9. [PMID: 25848000 DOI: 10.1073/pnas.1415541112] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Zfp57 is a maternal-zygotic effect gene that maintains genomic imprinting. Here we report that Zfp57 mutants exhibited a variety of cardiac defects including atrial septal defect (ASD), ventricular septal defect (VSD), thin myocardium, and reduced trabeculation. Zfp57 maternal-zygotic mutant embryos displayed more severe phenotypes with higher penetrance than the zygotic ones. Cardiac progenitor cells exhibited proliferation and differentiation defects in Zfp57 mutants. ZFP57 is a master regulator of genomic imprinting, so the DNA methylation imprint was lost in embryonic heart without ZFP57. Interestingly, the presence of imprinted DLK1, a target of ZFP57, correlated with NOTCH1 activation in cardiac cells. These results suggest that ZFP57 may modulate NOTCH signaling during cardiac development. Indeed, loss of ZFP57 caused loss of NOTCH1 activation in embryonic heart with more severe loss observed in the maternal-zygotic mutant. Maternal and zygotic functions of Zfp57 appear to play redundant roles in NOTCH1 activation and cardiomyocyte differentiation. This serves as an example of a maternal effect that can influence mammalian organ development. It also links genomic imprinting to NOTCH signaling and particular developmental functions.
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Kim W, Noh H, Lee Y, Jeon J, Shanmugavadivu A, McPhie DL, Kim KS, Cohen BM, Seo H, Sonntag KC. MiR-126 Regulates Growth Factor Activities and Vulnerability to Toxic Insult in Neurons. Mol Neurobiol 2014; 53:95-108. [PMID: 25407931 DOI: 10.1007/s12035-014-8989-x] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2014] [Accepted: 11/04/2014] [Indexed: 01/19/2023]
Abstract
Dysfunction of growth factor (GF) activities contributes to the decline and death of neurons during aging and in neurodegenerative diseases. In addition, neurons become more resistant to GF signaling with age. Micro (mi)RNAs are posttranscriptional regulators of gene expression that may be crucial to age- and disease-related changes in GF functions. MiR-126 is involved in regulating insulin/IGF-1/phosphatidylinositol-3-kinase (PI3K)/AKT and extracellular signal-regulated kinase (ERK) signaling, and we recently demonstrated a functional role of miR-126 in dopamine neuronal cell survival in models of Parkinson's disease (PD)-associated toxicity. Here, we show that elevated levels of miR-126 increase neuronal vulnerability to ubiquitous toxicity mediated by staurosporine (STS) or Alzheimer's disease (AD)-associated amyloid beta 1-42 peptides (Aβ1-42). The neuroprotective factors IGF-1, nerve growth factor (NGF), brain-derived neurotrophic factor (BDNF), and soluble amyloid precursor protein α (sAPPα) could diminish but not abrogate the toxic effects of miR-126. In miR-126 overexpressing neurons derived from Tg6799 familial AD model mice, we observed an increase in Aβ1-42 toxicity, but surprisingly, both Aβ1-42 and miR-126 promoted neurite sprouting. Pathway analysis revealed that miR-126 overexpression downregulated elements in the GF/PI3K/AKT and ERK signaling cascades, including AKT, GSK-3β, ERK, their phosphorylation, and the miR-126 targets IRS-1 and PIK3R2. Finally, inhibition of miR-126 was neuroprotective against both STS and Aβ1-42 toxicity. Our data provide evidence for a novel mechanism of regulating GF/PI3K signaling in neurons by miR-126 and suggest that miR-126 may be an important mechanistic link between metabolic dysfunction and neurotoxicity in general, during aging, and in the pathogenesis of specific neurological disorders, including PD and AD.
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Affiliation(s)
- Woori Kim
- Department of Psychiatry, McLean Hospital, Harvard Medical School, MRC 223, 115 Mill Street, Belmont, MA, 02478, USA
| | - Haneul Noh
- Department of Molecular and Life Sciences, Hanyang University, Ansan, South Korea
| | - Yenarae Lee
- Department of Psychiatry, McLean Hospital, Harvard Medical School, MRC 223, 115 Mill Street, Belmont, MA, 02478, USA
| | - Jeha Jeon
- Department of Molecular and Life Sciences, Hanyang University, Ansan, South Korea
| | - Arthi Shanmugavadivu
- Department of Psychiatry, McLean Hospital, Harvard Medical School, MRC 223, 115 Mill Street, Belmont, MA, 02478, USA
| | - Donna L McPhie
- Department of Psychiatry, McLean Hospital, Harvard Medical School, MRC 223, 115 Mill Street, Belmont, MA, 02478, USA
| | - Kwang-Soo Kim
- Department of Psychiatry, McLean Hospital, Harvard Medical School, MRC 223, 115 Mill Street, Belmont, MA, 02478, USA
| | - Bruce M Cohen
- Department of Psychiatry, McLean Hospital, Harvard Medical School, MRC 223, 115 Mill Street, Belmont, MA, 02478, USA
| | - Hyemyung Seo
- Department of Molecular and Life Sciences, Hanyang University, Ansan, South Korea
| | - Kai C Sonntag
- Department of Psychiatry, McLean Hospital, Harvard Medical School, MRC 223, 115 Mill Street, Belmont, MA, 02478, USA.
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Abstract
Motor neurons (MNs) are neuronal cells located in the central nervous system (CNS) controlling a variety of downstream targets. This function infers the existence of MN subtypes matching the identity of the targets they innervate. To illustrate the mechanism involved in the generation of cellular diversity and the acquisition of specific identity, this review will focus on spinal MNs (SpMNs) that have been the core of significant work and discoveries during the last decades. SpMNs are responsible for the contraction of effector muscles in the periphery. Humans possess more than 500 different skeletal muscles capable to work in a precise time and space coordination to generate complex movements such as walking or grasping. To ensure such refined coordination, SpMNs must retain the identity of the muscle they innervate. Within the last two decades, scientists around the world have produced considerable efforts to elucidate several critical steps of SpMNs differentiation. During development, SpMNs emerge from dividing progenitor cells located in the medial portion of the ventral neural tube. MN identities are established by patterning cues working in cooperation with intrinsic sets of transcription factors. As the embryo develop, MNs further differentiate in a stepwise manner to form compact anatomical groups termed pools connecting to a unique muscle target. MN pools are not homogeneous and comprise subtypes according to the muscle fibers they innervate. This article aims to provide a global view of MN classification as well as an up-to-date review of the molecular mechanisms involved in the generation of SpMN diversity. Remaining conundrums will be discussed since a complete understanding of those mechanisms constitutes the foundation required for the elaboration of prospective MN regeneration therapies.
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Affiliation(s)
- Nicolas Stifani
- Medical Neuroscience, Dalhousie University Halifax, NS, Canada
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