101
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Ablinger C, Geisler SM, Stanika RI, Klein CT, Obermair GJ. Neuronal α 2δ proteins and brain disorders. Pflugers Arch 2020; 472:845-863. [PMID: 32607809 PMCID: PMC7351808 DOI: 10.1007/s00424-020-02420-2] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2020] [Revised: 06/08/2020] [Accepted: 06/12/2020] [Indexed: 01/31/2023]
Abstract
α2δ proteins are membrane-anchored extracellular glycoproteins which are abundantly expressed in the brain and the peripheral nervous system. They serve as regulatory subunits of voltage-gated calcium channels and, particularly in nerve cells, regulate presynaptic and postsynaptic functions independently from their role as channel subunits. α2δ proteins are the targets of the widely prescribed anti-epileptic and anti-allodynic drugs gabapentin and pregabalin, particularly for the treatment of neuropathic pain conditions. Recently, the human genes (CACNA2D1-4) encoding for the four known α2δ proteins (isoforms α2δ-1 to α2δ-4) have been linked to a large variety of neurological and neuropsychiatric disorders including epilepsy, autism spectrum disorders, bipolar disorders, schizophrenia, and depressive disorders. Here, we provide an overview of the hitherto identified disease associations of all known α2δ genes, hypothesize on the pathophysiological mechanisms considering their known physiological roles, and discuss the most immanent future research questions. Elucidating their specific physiological and pathophysiological mechanisms may open the way for developing entirely novel therapeutic paradigms for treating brain disorders.
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Affiliation(s)
- Cornelia Ablinger
- Institute of Physiology, Medical University Innsbruck, 6020, Innsbruck, Austria
| | - Stefanie M Geisler
- Department of Pharmacology and Toxicology, University of Innsbruck, 6020, Innsbruck, Austria
| | - Ruslan I Stanika
- Division Physiology, Karl Landsteiner University of Health Sciences, 3500, Krems, Austria
| | - Christian T Klein
- Department of Life Sciences, IMC University of Applied Sciences, 3500, Krems, Austria
| | - Gerald J Obermair
- Institute of Physiology, Medical University Innsbruck, 6020, Innsbruck, Austria.
- Division Physiology, Karl Landsteiner University of Health Sciences, 3500, Krems, Austria.
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102
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Kiyoshi C, Tedeschi A. Axon growth and synaptic function: A balancing act for axonal regeneration and neuronal circuit formation in CNS trauma and disease. Dev Neurobiol 2020; 80:277-301. [PMID: 32902152 PMCID: PMC7754183 DOI: 10.1002/dneu.22780] [Citation(s) in RCA: 14] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 08/29/2020] [Accepted: 08/31/2020] [Indexed: 12/13/2022]
Abstract
Axons in the adult mammalian central nervous system (CNS) fail to regenerate inside out due to intrinsic and extrinsic neuronal determinants. During CNS development, axon growth, synapse formation, and function are tightly regulated processes allowing immature neurons to effectively grow an axon, navigate toward target areas, form synaptic contacts and become part of information processing networks that control behavior in adulthood. Not only immature neurons are able to precisely control the expression of a plethora of genes necessary for axon extension and pathfinding, synapse formation and function, but also non-neuronal cells such as astrocytes and microglia actively participate in sculpting the nervous system through refinement, consolidation, and elimination of synaptic contacts. Recent evidence indicates that a balancing act between axon regeneration and synaptic function may be crucial for rebuilding functional neuronal circuits after CNS trauma and disease in adulthood. Here, we review the role of classical and new intrinsic and extrinsic neuronal determinants in the context of CNS development, injury, and disease. Moreover, we discuss strategies targeting neuronal and non-neuronal cell behaviors, either alone or in combination, to promote axon regeneration and neuronal circuit formation in adulthood.
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Affiliation(s)
- Conrad Kiyoshi
- Department of Neuroscience, Wexner Medical Center, The Ohio State University, Columbus, OH 43210, USA
| | - Andrea Tedeschi
- Department of Neuroscience, Wexner Medical Center, The Ohio State University, Columbus, OH 43210, USA
- Discovery Theme on Chronic Brain Injury, The Ohio State University, Columbus, OH 43210, USA
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103
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Bikbaev A, Ciuraszkiewicz-Wojciech A, Heck J, Klatt O, Freund R, Mitlöhner J, Enrile Lacalle S, Sun M, Repetto D, Frischknecht R, Ablinger C, Rohlmann A, Missler M, Obermair GJ, Di Biase V, Heine M. Auxiliary α2δ1 and α2δ3 Subunits of Calcium Channels Drive Excitatory and Inhibitory Neuronal Network Development. J Neurosci 2020; 40:4824-4841. [PMID: 32414783 PMCID: PMC7326358 DOI: 10.1523/jneurosci.1707-19.2020] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/17/2019] [Revised: 03/31/2020] [Accepted: 05/09/2020] [Indexed: 01/21/2023] Open
Abstract
VGCCs are multisubunit complexes that play a crucial role in neuronal signaling. Auxiliary α2δ subunits of VGCCs modulate trafficking and biophysical properties of the pore-forming α1 subunit and trigger excitatory synaptogenesis. Alterations in the expression level of α2δ subunits were implicated in several syndromes and diseases, including chronic neuropathic pain, autism, and epilepsy. However, the contribution of distinct α2δ subunits to excitatory/inhibitory imbalance and aberrant network connectivity characteristic for these pathologic conditions remains unclear. Here, we show that α2δ1 overexpression enhances spontaneous neuronal network activity in developing and mature cultures of hippocampal neurons. In contrast, overexpression, but not downregulation, of α2δ3 enhances neuronal firing in immature cultures, whereas later in development it suppresses neuronal activity. We found that α2δ1 overexpression increases excitatory synaptic density and selectively enhances presynaptic glutamate release, which is impaired on α2δ1 knockdown. Overexpression of α2δ3 increases the excitatory synaptic density as well but also facilitates spontaneous GABA release and triggers an increase in the density of inhibitory synapses, which is accompanied by enhanced axonaloutgrowth in immature interneurons. Together, our findings demonstrate that α2δ1 and α2δ3 subunits play distinct but complementary roles in driving formation of structural and functional network connectivity during early development. An alteration in α2δ surface expression during critical developmental windows can therefore play a causal role and have a profound impact on the excitatory-to-inhibitory balance and network connectivity.SIGNIFICANCE STATEMENT The computational capacity of neuronal networks is determined by their connectivity. Chemical synapses are the main interface for transfer of information between individual neurons. The initial formation of network connectivity requires spontaneous electrical activity and the calcium channel-mediated signaling. We found that, in early development, auxiliary α2δ3 subunits of calcium channels foster presynaptic release of GABA, trigger formation of inhibitory synapses, and promote axonal outgrowth in inhibitory interneurons. In contrast, later in development, α2δ1 subunits promote the glutamatergic neurotransmission and synaptogenesis, as well as strongly enhance neuronal network activity. We propose that formation of connectivity in neuronal networks is associated with a concerted interplay of α2δ1 and α2δ3 subunits of calcium channels.
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Affiliation(s)
- Arthur Bikbaev
- RG Functional Neurobiology, Institute for Developmental Biology and Neurobiology, Johannes Gutenberg University Mainz, Mainz, 55128, Germany
| | - Anna Ciuraszkiewicz-Wojciech
- RG Molecular Physiology, Leibniz Institute for Neurobiology, Magdeburg, 39118, Germany
- Center for Behavioral Brain Sciences, Otto-von-Guericke University Magdeburg, Magdeburg, 39106, Germany
| | - Jennifer Heck
- RG Functional Neurobiology, Institute for Developmental Biology and Neurobiology, Johannes Gutenberg University Mainz, Mainz, 55128, Germany
| | - Oliver Klatt
- Institute for Anatomy and Molecular Neurobiology, University of Münster, Münster, 48149, Germany
| | - Romy Freund
- RG Molecular Physiology, Leibniz Institute for Neurobiology, Magdeburg, 39118, Germany
| | - Jessica Mitlöhner
- RG Brain Extracellular Matrix, Leibniz Institute for Neurobiology, Magdeburg, 39118, Germany
| | - Sara Enrile Lacalle
- RG Molecular Physiology, Leibniz Institute for Neurobiology, Magdeburg, 39118, Germany
| | - Miao Sun
- Institute for Anatomy and Molecular Neurobiology, University of Münster, Münster, 48149, Germany
| | - Daniele Repetto
- Institute for Anatomy and Molecular Neurobiology, University of Münster, Münster, 48149, Germany
| | - Renato Frischknecht
- RG Brain Extracellular Matrix, Leibniz Institute for Neurobiology, Magdeburg, 39118, Germany
- Department of Biology, Animal Physiology, Friedrich Alexander University of Erlangen-Nuremberg, Erlangen, 91058, Germany
| | - Cornelia Ablinger
- Institute of Physiology, Medical University Innsbruck, Innsbruck, 6020, Austria
| | - Astrid Rohlmann
- Institute for Anatomy and Molecular Neurobiology, University of Münster, Münster, 48149, Germany
| | - Markus Missler
- Institute for Anatomy and Molecular Neurobiology, University of Münster, Münster, 48149, Germany
| | - Gerald J Obermair
- Division Physiology, Karl Landsteiner University of Health Sciences, Krems, 3500, Austria
| | - Valentina Di Biase
- Institute of Molecular and Clinical Pharmacology, Medical University Innsbruck, Innsbruck, 6020, Austria
| | - Martin Heine
- RG Functional Neurobiology, Institute for Developmental Biology and Neurobiology, Johannes Gutenberg University Mainz, Mainz, 55128, Germany
- Center for Behavioral Brain Sciences, Otto-von-Guericke University Magdeburg, Magdeburg, 39106, Germany
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104
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Cragg JJ, Jutzeler CR, Grassner L, Ramer M, Bradke F, Kramer JLK. Beneficial "Pharmaceutical Pleiotropy" of Gabapentinoids in Spinal Cord Injury: A Case for Refining Standard-of-Care. Neurorehabil Neural Repair 2020; 34:686-689. [PMID: 32508248 DOI: 10.1177/1545968320931516] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Spinal cord injury results in devastating neurological deficits accompanied by lifelong disability and significant economic burden. While the development of novel compounds or cell-based interventions for spinal cord injury is unquestionably worthwhile, a complementary approach examines current standards of care and the degree to which these can be optimized to benefit long-term neurological function. Numerous classes of drugs, already in use in the acute phase of spinal cord injury, are intriguing because they (1) readily cross the blood-spinal cord barrier to modulate activity in the central nervous system and (2) are administered during a window of time in which neuroprotection, and even some repair, are feasible. Here, we review a rare case of convergent lines of evidence from both preclinical and human studies to support the early administration of a class of drug (ie, gabapentinoids) to both foster motor recovery and reduce the severity of neuropathic pain.
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Affiliation(s)
- Jacquelyn J Cragg
- Faculty of Pharmaceutical Sciences, University of British Columbia, Vancouver, British Columbia, Canada
| | | | - Lukas Grassner
- Paracelsus Medical University, Salzburg, Austria.,Medical University Innsbruck, Innsbruck, Austria
| | - Matt Ramer
- International Collaboration on Repair Discoveries (ICORD), Vancouver, British Columbia, Canada
| | - Frank Bradke
- German Centre for Neurodegenerative Disease (DZNE), Bonn, Germany
| | - John L K Kramer
- International Collaboration on Repair Discoveries (ICORD), Vancouver, British Columbia, Canada
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105
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Risher WC, Eroglu C. Emerging roles for α2δ subunits in calcium channel function and synaptic connectivity. Curr Opin Neurobiol 2020; 63:162-169. [PMID: 32521436 DOI: 10.1016/j.conb.2020.04.007] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2020] [Accepted: 04/29/2020] [Indexed: 12/17/2022]
Abstract
Central nervous system function requires the proper formation and function of synapses. The α2δ auxiliary subunits of voltage-gated calcium channels have emerged as regulators of a number of critical events associated with regulation of synaptic function, including channel trafficking and localization, as well as the initial establishment of synaptic structures. In this review, we will discuss some of these recent studies which have uncovered novel mechanisms for α2δ function at the synapse, including the regulation of calcium channel α1 subunit specificity and the promotion of dendritic spine growth. Moreover, we will cover recent advances that have been made in understanding the consequences of aberrant α2δ signaling in injury and disease.
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Affiliation(s)
- William Christopher Risher
- Department of Biomedical Sciences, Joan C. Edwards School of Medicine at Marshall University, Huntington, WV 25705, United States.
| | - Cagla Eroglu
- Department of Cell Biology, Duke University Medical Center, Durham, NC 27710, United States; Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, United States; Duke Institute for Brain Sciences (DIBS), Durham, NC 27710, United States; Regeneration Next Initiative, Duke University, Durham, NC 27710, United States
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106
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Neuronal Maturation: Challenges and Opportunities in a Nascent Field. Trends Neurosci 2020; 43:360-362. [PMID: 32459989 DOI: 10.1016/j.tins.2020.02.005] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Accepted: 02/29/2020] [Indexed: 12/17/2022]
Abstract
After its initial development, the nervous system matures to connect and shape the neuronal circuitry and to keep it functional in humans for decades. Here we conceptualize neuronal maturation as a research field that will have, we would argue, a strong impact on understanding the healthy and diseased nervous system. Identifying the key mechanisms underlying neuronal maturation has the potential to reverse this process in adulthood, thereby facilitating regeneration.
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107
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Smith TP, Sahoo PK, Kar AN, Twiss JL. Intra-axonal mechanisms driving axon regeneration. Brain Res 2020; 1740:146864. [PMID: 32360100 DOI: 10.1016/j.brainres.2020.146864] [Citation(s) in RCA: 22] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2020] [Revised: 04/24/2020] [Accepted: 04/27/2020] [Indexed: 12/27/2022]
Abstract
Traumatic injury to the peripheral and central nervous systems very often causes axotomy, where an axon loses connections with its target resulting in loss of function. The axon segments distal to the injury site lose connection with the cell body and degenerate. Axotomized neurons in the periphery can spontaneously mount a regenerative response and reconnect to their denervated target tissues, though this is rarely complete in humans. In contrast, spontaneous regeneration rarely occurs after axotomy in the spinal cord and brain. Here, we concentrate on the mechanisms underlying this spontaneous regeneration in the peripheral nervous system, focusing on events initiated from the axon that support regenerative growth. We contrast this with what is known for axonal injury responses in the central nervous system. Considering the neuropathy focus of this special issue, we further draw parallels and distinctions between the injury-response mechanisms that initiate regenerative gene expression programs and those that are known to trigger axon degeneration.
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Affiliation(s)
- Terika P Smith
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
| | - Pabitra K Sahoo
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
| | - Amar N Kar
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA
| | - Jeffery L Twiss
- Department of Biological Sciences, University of South Carolina, Columbia, SC, USA.
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108
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Liu HH, Jan YN. Mechanisms of neurite repair. Curr Opin Neurobiol 2020; 63:53-58. [PMID: 32278210 DOI: 10.1016/j.conb.2020.02.010] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Accepted: 02/23/2020] [Indexed: 10/24/2022]
Abstract
Upon receiving injury signals, neurons can activate various pathways to reduce harm, initiate neuroprotection, and repair damaged neurite without cell death. Here, we review recent progresses in the study of neurite repair focusing on neuronal cell-autonomous mechanisms, including new findings on ion channels that serve as key regulators to initiate neurite repair and intrinsic signaling pathways and transcriptional and post-transcriptional factors that facilitate neurite repair. We also touch upon reports on how dendrites may be affected upon axotomy and how the regeneration potential in injured neurites might be maximized.
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Affiliation(s)
- Han-Hsuan Liu
- Howard Hughes Medical Institute, Department of Physiology, University of California, San Francisco, CA 94158, USA
| | - Yuh-Nung Jan
- Howard Hughes Medical Institute, Department of Physiology, University of California, San Francisco, CA 94158, USA.
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109
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Regenerative Potential of Carbon Monoxide in Adult Neural Circuits of the Central Nervous System. Int J Mol Sci 2020; 21:ijms21072273. [PMID: 32218342 PMCID: PMC7177523 DOI: 10.3390/ijms21072273] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 03/17/2020] [Accepted: 03/23/2020] [Indexed: 01/04/2023] Open
Abstract
Regeneration of adult neural circuits after an injury is limited in the central nervous system (CNS). Heme oxygenase (HO) is an enzyme that produces HO metabolites, such as carbon monoxide (CO), biliverdin and iron by heme degradation. CO may act as a biological signal transduction effector in CNS regeneration by stimulating neuronal intrinsic and extrinsic mechanisms as well as mitochondrial biogenesis. CO may give directions by which the injured neurovascular system switches into regeneration mode by stimulating endogenous neural stem cells and endothelial cells to produce neurons and vessels capable of replacing injured neurons and vessels in the CNS. The present review discusses the regenerative potential of CO in acute and chronic neuroinflammatory diseases of the CNS, such as stroke, traumatic brain injury, multiple sclerosis and Alzheimer’s disease and the role of signaling pathways and neurotrophic factors. CO-mediated facilitation of cellular communications may boost regeneration, consequently forming functional adult neural circuits in CNS injury.
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110
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Griffin JM, Bradke F. Therapeutic repair for spinal cord injury: combinatory approaches to address a multifaceted problem. EMBO Mol Med 2020; 12:e11505. [PMID: 32090481 PMCID: PMC7059014 DOI: 10.15252/emmm.201911505] [Citation(s) in RCA: 110] [Impact Index Per Article: 27.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2019] [Revised: 01/07/2020] [Accepted: 01/31/2020] [Indexed: 12/21/2022] Open
Abstract
The recent years saw the advent of promising preclinical strategies that combat the devastating effects of a spinal cord injury (SCI) that are progressing towards clinical trials. However, individually, these treatments produce only modest levels of recovery in animal models of SCI that could hamper their implementation into therapeutic strategies in spinal cord injured humans. Combinational strategies have demonstrated greater beneficial outcomes than their individual components alone by addressing multiple aspects of SCI pathology. Clinical trial designs in the future will eventually also need to align with this notion. The scenario will become increasingly complex as this happens and conversations between basic researchers and clinicians are required to ensure accurate study designs and functional readouts.
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Affiliation(s)
- Jarred M Griffin
- Laboratory for Axonal Growth and Regeneration, German Centre for Neurodegenerative Diseases (DZNE), Bonn, Germany
| | - Frank Bradke
- Laboratory for Axonal Growth and Regeneration, German Centre for Neurodegenerative Diseases (DZNE), Bonn, Germany
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111
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Fu Y, Zhou N, Bai W, Sun Y, Chen X, Wang Y, Zhang M, Kou C, Yu Y, Yu Q. Association of the CACNA2D2 gene with schizophrenia in Chinese Han population. PeerJ 2020; 8:e8521. [PMID: 32071821 PMCID: PMC7007731 DOI: 10.7717/peerj.8521] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2019] [Accepted: 01/07/2020] [Indexed: 01/02/2023] Open
Abstract
Background Schizophrenia (SCZ) is a severely complex psychiatric disorder in which ~80% can be explained by genetic factors. Single nucleotide polymorphisms (SNPs) in calcium channel genes are potential genetic risk factors for a spectrum of psychiatric disorders including SCZ. This study evaluated the association between SNPs in the voltage-gated calcium channel auxiliary subunit alpha2delta 2 gene (CACNA2D2) and SCZ in the Han Chinese population of Northeast China. Methods A total of 761 SCZ patients and 775 healthy controls were involved in this case-control study. Three SNPs (rs3806706, rs45536634 and rs12496815) of CACNA2D2 were genotyped by the MALDI-TOF-MS technology. Genotype distribution and allele frequency differences between cases and controls were tested by Chi-square (χ2) in males and females respectively using SPSS 24.0 software. Linkage disequilibrium and haplotype analyses were conducted using Haploview4.2. The false discovery rate correction was utilized to control for Type I error by R3.2.3. Results There was a significant difference in allele frequencies (χ2 = 9.545, Padj = 0.006) and genotype distributions (χ2 = 9.275, Padj = 0.006) of rs45536634 between female SCZ patients and female healthy controls after adjusting for multiple comparisons. Minor allele A (OR = 1.871, 95% CI [1.251–2.798]) and genotype GA + AA (OR = 1.931, 95% CI [1.259–2.963]) were associated with an increased risk of SCZ. Subjects with haplotype AG consisting of rs45536634 and rs12496815 alleles had a higher risk of SCZ (OR = 1.91, 95% CI [1.26–2.90]) compared those with other haplotypes. Conclusions This study provides evidence that CACNA2D2 polymorphisms may influence the susceptibility to SCZ in Han Chinese women.
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Affiliation(s)
- Yingli Fu
- Department of Epidemiology and Statistics, School of Public Health, Jilin University, Changchun, Jilin, China.,Division of Clinical Research, First Hospital of Jilin University, Changchun, Jilin, China
| | - Na Zhou
- Department of Pharmacy, School and Hospital of Stomatology, Jilin University, Changchun, Jilin, China
| | - Wei Bai
- Department of Epidemiology and Statistics, School of Public Health, Jilin University, Changchun, Jilin, China
| | - Yaoyao Sun
- Department of Epidemiology and Statistics, School of Public Health, Jilin University, Changchun, Jilin, China
| | - Xin Chen
- Department of Epidemiology and Statistics, School of Public Health, Jilin University, Changchun, Jilin, China
| | - Yueying Wang
- Department of Epidemiology and Statistics, School of Public Health, Jilin University, Changchun, Jilin, China
| | - Mingyuan Zhang
- Department of Epidemiology and Statistics, School of Public Health, Jilin University, Changchun, Jilin, China
| | - Changgui Kou
- Department of Epidemiology and Statistics, School of Public Health, Jilin University, Changchun, Jilin, China
| | - Yaqin Yu
- Department of Epidemiology and Statistics, School of Public Health, Jilin University, Changchun, Jilin, China
| | - Qiong Yu
- Department of Epidemiology and Statistics, School of Public Health, Jilin University, Changchun, Jilin, China
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112
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Tejero R, Balk S, Franco-Espin J, Ojeda J, Hennlein L, Drexl H, Dombert B, Clausen JD, Torres-Benito L, Saal-Bauernschubert L, Blum R, Briese M, Appenzeller S, Tabares L, Jablonka S. R-Roscovitine Improves Motoneuron Function in Mouse Models for Spinal Muscular Atrophy. iScience 2020; 23:100826. [PMID: 31981925 PMCID: PMC6992996 DOI: 10.1016/j.isci.2020.100826] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2018] [Revised: 08/08/2019] [Accepted: 01/06/2020] [Indexed: 12/27/2022] Open
Abstract
Neurotransmission defects and motoneuron degeneration are hallmarks of spinal muscular atrophy, a monogenetic disease caused by the deficiency of the SMN protein. In the present study, we show that systemic application of R-Roscovitine, a Cav2.1/Cav2.2 channel modifier and a cyclin-dependent kinase 5 (Cdk-5) inhibitor, significantly improved survival of SMA mice. In addition, R-Roscovitine increased Cav2.1 channel density and sizes of the motor endplates. In vitro, R-Roscovitine restored axon lengths and growth cone sizes of Smn-deficient motoneurons corresponding to enhanced spontaneous Ca2+ influx and elevated Cav2.2 channel cluster formations independent of its capability to inhibit Cdk-5. Acute application of R-Roscovitine at the neuromuscular junction significantly increased evoked neurotransmitter release, increased the frequency of spontaneous miniature potentials, and lowered the activation threshold of silent terminals. These data indicate that R-Roscovitine improves Ca2+ signaling and Ca2+ homeostasis in Smn-deficient motoneurons, which is generally crucial for motoneuron differentiation, maturation, and function. R-Roscovitine prolongs survival of SMA mice R-Roscovitine increases Ca2+ influx and growth cone size of SMA motoneurons R-Roscovitine beneficially affects neurotransmission in SMA motor nerve terminals R-Roscovitine wakes up dormant synapses of SMA motoneurons
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Affiliation(s)
- Rocio Tejero
- Department of Medical Physiology and Biophysics, School of Medicine, University of Seville, 41009 Seville, Spain
| | - Stefanie Balk
- Institute of Clinical Neurobiology, University Hospital Würzburg, 97078 Würzburg, Germany
| | - Julio Franco-Espin
- Department of Medical Physiology and Biophysics, School of Medicine, University of Seville, 41009 Seville, Spain
| | - Jorge Ojeda
- Department of Medical Physiology and Biophysics, School of Medicine, University of Seville, 41009 Seville, Spain
| | - Luisa Hennlein
- Institute of Clinical Neurobiology, University Hospital Würzburg, 97078 Würzburg, Germany
| | - Hans Drexl
- Institute of Clinical Neurobiology, University Hospital Würzburg, 97078 Würzburg, Germany
| | - Benjamin Dombert
- Institute of Clinical Neurobiology, University Hospital Würzburg, 97078 Würzburg, Germany
| | - Jan-Dierk Clausen
- Institute of Clinical Neurobiology, University Hospital Würzburg, 97078 Würzburg, Germany
| | - Laura Torres-Benito
- Department of Medical Physiology and Biophysics, School of Medicine, University of Seville, 41009 Seville, Spain
| | | | - Robert Blum
- Institute of Clinical Neurobiology, University Hospital Würzburg, 97078 Würzburg, Germany
| | - Michael Briese
- Institute of Clinical Neurobiology, University Hospital Würzburg, 97078 Würzburg, Germany
| | - Silke Appenzeller
- Comprehensive Cancer Center Mainfranken, University Hospital Würzburg, 97080 Würzburg, Germany; Core Unit SysMed, University of Würzburg, 97080 Würzburg, Germany
| | - Lucia Tabares
- Department of Medical Physiology and Biophysics, School of Medicine, University of Seville, 41009 Seville, Spain.
| | - Sibylle Jablonka
- Institute of Clinical Neurobiology, University Hospital Würzburg, 97078 Würzburg, Germany.
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113
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Laredo F, Plebanski J, Tedeschi A. Pericytes: Problems and Promises for CNS Repair. Front Cell Neurosci 2019; 13:546. [PMID: 31866833 PMCID: PMC6908836 DOI: 10.3389/fncel.2019.00546] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Accepted: 11/25/2019] [Indexed: 12/14/2022] Open
Abstract
Microvascular complications are often associated with slow and progressive damage of various organs. Pericytes are multi-functional mural cells of the microcirculation that control blood flow, vascular permeability and homeostasis. Whereas accumulating evidence suggests that these cells are also implicated in a variety of diseases, pericytes represent promising targets that can be manipulated for therapeutic gain. Here, we review the role of pericytes in angiogenesis, blood-brain barrier (BBB) function, neuroinflammation, tissue fibrosis, axon regeneration failure, and neurodegeneration. In addition, we outline strategies altering pericyte behavior to point out problems and promises for axon regeneration and central nervous system (CNS) repair following injury or disease.
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Affiliation(s)
- Fabio Laredo
- Department of Neuroscience, Wexner Medical Center, The Ohio State University, Columbus, OH, United States.,Department of Life Sciences, University of Nottingham, Nottingham, United Kingdom
| | - Julia Plebanski
- Department of Neuroscience, Wexner Medical Center, The Ohio State University, Columbus, OH, United States
| | - Andrea Tedeschi
- Department of Neuroscience, Wexner Medical Center, The Ohio State University, Columbus, OH, United States.,Discovery Theme on Chronic Brain Injury, The Ohio State University, Columbus, OH, United States
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114
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Hutson TH, Di Giovanni S. The translational landscape in spinal cord injury: focus on neuroplasticity and regeneration. Nat Rev Neurol 2019; 15:732-745. [DOI: 10.1038/s41582-019-0280-3] [Citation(s) in RCA: 104] [Impact Index Per Article: 20.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/11/2019] [Indexed: 12/22/2022]
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115
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Ashammakhi N, Kim HJ, Ehsanipour A, Bierman RD, Kaarela O, Xue C, Khademhosseini A, Seidlits SK. Regenerative Therapies for Spinal Cord Injury. TISSUE ENGINEERING PART B-REVIEWS 2019; 25:471-491. [PMID: 31452463 DOI: 10.1089/ten.teb.2019.0182] [Citation(s) in RCA: 92] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Spinal cord injury (SCI) is a serious problem that primarily affects younger and middle-aged adults at its onset. To date, no effective regenerative treatment has been developed. Over the last decade, researchers have made significant advances in stem cell technology, biomaterials, nanotechnology, and immune engineering, which may be applied as regenerative therapies for the spinal cord. Although the results of clinical trials using specific cell-based therapies have proven safe, their efficacy has not yet been demonstrated. The pathophysiology of SCI is multifaceted, complex and yet to be fully understood. Thus, combinatorial therapies that simultaneously leverage multiple approaches will likely be required to achieve satisfactory outcomes. Although combinations of biomaterials with pharmacologic agents or cells have been explored, few studies have combined these modalities in a systematic way. For most strategies, clinical translation will be facilitated by the use of minimally invasive therapies, which are the focus of this review. In addition, this review discusses previously explored therapies designed to promote neuroregeneration and neuroprotection after SCI, while highlighting present challenges and future directions. Impact Statement To date there are no effective treatments that can regenerate the spinal cord after injury. Although there have been significant preclinical advances in bioengineering and regenerative medicine over the last decade, these have not translated into effective clinical therapies for spinal cord injury. This review focuses on minimally invasive therapies, providing extensive background as well as updates on recent technological developments and current clinical trials. This review is a comprehensive resource for researchers working towards regenerative therapies for spinal cord injury that will help guide future innovation.
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Affiliation(s)
- Nureddin Ashammakhi
- Division of Plastic Surgery, Department of Surgery, Oulu University, Oulu, Finland.,Center for Minimally Invasive Therapeutics (C-MIT), Los Angeles, California.,California NanoSystems Institute (CNSI), Los Angeles, California.,Department of Radiological Sciences, University of California, Los Angeles, Los Angeles, California.,Department of Bioengineering, University of California, Los Angeles, Los Angeles, California
| | - Han-Jun Kim
- Center for Minimally Invasive Therapeutics (C-MIT), Los Angeles, California.,California NanoSystems Institute (CNSI), Los Angeles, California.,Department of Bioengineering, University of California, Los Angeles, Los Angeles, California
| | | | | | - Outi Kaarela
- Division of Plastic Surgery, Department of Surgery, Oulu University, Oulu, Finland
| | - Chengbin Xue
- Center for Minimally Invasive Therapeutics (C-MIT), Los Angeles, California.,California NanoSystems Institute (CNSI), Los Angeles, California.,Department of Bioengineering, University of California, Los Angeles, Los Angeles, California.,Key Laboratory of Neuroregeneration of Jiangsu and Ministry of Education, Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, P.R. China.,Jiangsu Clinical Medicine Center of Tissue Engineering and Nerve Injury Repair, Research Center of Clinical Medicine, Affiliated Hospital of Nantong University, Nantong University, Nantong, P.R. China
| | - Ali Khademhosseini
- Center for Minimally Invasive Therapeutics (C-MIT), Los Angeles, California.,California NanoSystems Institute (CNSI), Los Angeles, California.,Department of Radiological Sciences, University of California, Los Angeles, Los Angeles, California.,Department of Bioengineering, University of California, Los Angeles, Los Angeles, California.,Center of Nanotechnology, King Abdulaziz University, Jeddah, Saudi Arabia.,Department of Chemical and Biological Engineering, University of California, Los Angeles, California
| | - Stephanie K Seidlits
- Center for Minimally Invasive Therapeutics (C-MIT), Los Angeles, California.,California NanoSystems Institute (CNSI), Los Angeles, California.,Jonsson Comprehensive Cancer Center, University of California, Los Angeles, Los Angeles, California.,Broad Stem Cell Research Center, University of California, Los Angeles, Los Angeles, California.,Brain Research Institute, University of California, Los Angeles, Los Angeles, California
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116
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Epigenomic signatures underpin the axonal regenerative ability of dorsal root ganglia sensory neurons. Nat Neurosci 2019; 22:1913-1924. [PMID: 31591560 DOI: 10.1038/s41593-019-0490-4] [Citation(s) in RCA: 57] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2018] [Accepted: 08/07/2019] [Indexed: 12/16/2022]
Abstract
Axonal injury results in regenerative success or failure, depending on whether the axon lies in the peripheral or the CNS, respectively. The present study addresses whether epigenetic signatures in dorsal root ganglia discriminate between regenerative and non-regenerative axonal injury. Chromatin immunoprecipitation for the histone 3 (H3) post-translational modifications H3K9ac, H3K27ac and H3K27me3; an assay for transposase-accessible chromatin; and RNA sequencing were performed in dorsal root ganglia after sciatic nerve or dorsal column axotomy. Distinct histone acetylation and chromatin accessibility signatures correlated with gene expression after peripheral, but not central, axonal injury. DNA-footprinting analyses revealed new transcriptional regulators associated with regenerative ability. Machine-learning algorithms inferred the direction of most of the gene expression changes. Neuronal conditional deletion of the chromatin remodeler CCCTC-binding factor impaired nerve regeneration, implicating chromatin organization in the regenerative competence. Altogether, the present study offers the first epigenomic map providing insight into the transcriptional response to injury and the differential regenerative ability of sensory neurons.
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117
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Skilled reaching deterioration contralateral to cervical hemicontusion in rats is reversed by pregabalin treatment conditional upon its early administration. Pain Rep 2019; 4:e749. [PMID: 31583362 PMCID: PMC6749902 DOI: 10.1097/pr9.0000000000000749] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2019] [Revised: 03/28/2019] [Accepted: 04/01/2019] [Indexed: 11/26/2022] Open
Abstract
Introduction Gabapentinoids are first-line treatments for painful traumatic and nontraumatic central nervous system disorders. Evidence from a large human study suggests that early use of gabapentinoids after spinal cord injury improves motor scores. The underlying mechanism is unknown. Objectives We sought to examine the effects of early pregabalin (PGB, a gabapentinoid) treatment on performance in a fine motor task (skilled reaching) after cervical hemicontusion. We also asked whether early PGB administration affected PGB responsiveness later on. Methods Rats received C4/5 cervical hemicontusions. Injury severities ranged from 80 to 150 kdyn. We monitored evidence of skin irritation (peri-incisional and elsewhere) and quantified food pellet retrieval using the Montoya staircase test. Behaviours were assessed in rats receiving early (for 3 weeks from injury induction) and/or late (resuming or beginning at week 8) PGB treatment in animals with 150-kdyn injuries. Results Contralateral skilled reaching waned in control animals with 150-kdyn injuries. This was prevented in animals, which received early PGB as long as treatment continued. Deterioration of skilled reaching was reversed by later (week 8) PGB only in animals that had received early treatment. Ipsilateral reaching impairment was not improved by PGB. Relief of skin irritation verified early PGB efficacy. Conclusion Hemicontusive spinal cord injury produces a contralateral motor phenotype evocative of on-going neuropathic pain. Early PGB preserves sensitivity to subsequent PGB treatment, indicating that motor function is impaired by neuropathic pain and can be improved indirectly by early PGB administration. Direct effects of PGB on motor circuitry cannot be excluded but are not supported by our data.
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118
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Functional Genome-wide Screen Identifies Pathways Restricting Central Nervous System Axonal Regeneration. Cell Rep 2019; 23:415-428. [PMID: 29642001 DOI: 10.1016/j.celrep.2018.03.058] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2017] [Revised: 02/12/2018] [Accepted: 03/14/2018] [Indexed: 12/22/2022] Open
Abstract
Axonal regrowth is crucial for recovery from CNS injury but is severely restricted in adult mammals. We used a genome-wide loss-of-function screen for factors limiting axonal regeneration from cerebral cortical neurons in vitro. Knockdown of 16,007 individual genes identified 580 significant phenotypes. These molecules share no significant overlap with those suggested by previous expression profiles. There is enrichment for genes in pathways related to transport, receptor binding, and cytokine signaling, including Socs4 and Ship2. Among transport-regulating proteins, Rab GTPases are prominent. In vivo assessment with C. elegans validates a cell-autonomous restriction of regeneration by Rab27. Mice lacking Rab27b show enhanced retinal ganglion cell axon regeneration after optic nerve crush and greater motor function and raphespinal sprouting after spinal cord trauma. Thus, a comprehensive functional screen reveals multiple pathways restricting axonal regeneration and neurological recovery after injury.
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119
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Wang S, Smith GM, Selzer ME, Li S. Emerging molecular therapeutic targets for spinal cord injury. Expert Opin Ther Targets 2019; 23:787-803. [PMID: 31460807 DOI: 10.1080/14728222.2019.1661381] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Introduction: Spinal cord injury (SCI) is a complicated and devastating neurological disorder. Patients with SCI usually have dramatically reduced quality of life. In recent years, numerous studies have reported advances in understanding the pathophysiology of SCI and developing preclinical therapeutic strategies for SCI, including various molecular therapies, and yet there is still no cure. Areas covered: After SCI, tissue damage, responses and repair involve interactions among many cellular components, including neurons, axons, glia, leukocytes, and other cells. Accordingly, numerous cellular genes and molecules have become therapeutic targets for neural tissue repair, circuit reconstruction, and behavioral restoration. Here, we review the major recent advances in biological and molecular strategies to enhance neuroprotection, axon regeneration, remyelination, neuroplasticity and functional recovery in preclinical studies of SCI. Expert opinion: Researchers have made tremendous progress in identifying individual and combined molecular therapies in animal studies. It is very important to identify additional highly effective treatments for early neuroprotective intervention and for functionally meaningful axon regeneration and neuronal reconnections. Because multiple mechanisms contribute to the functional loss after SCI, combining the most promising approaches that target different pathophysiological and molecular mechanisms should exhibit synergistic actions for maximal functional restoration. [Databases searched: PubMed; inclusive dates: 6/27/2019].
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Affiliation(s)
- Shuo Wang
- Shriners Hospitals Pediatric Research Center, Temple University School of Medicine , Philadelphia , PA , USA.,Department of Anatomy and Cell Biology, Temple University School of Medicine , Philadelphia , PA , USA
| | - George M Smith
- Shriners Hospitals Pediatric Research Center, Temple University School of Medicine , Philadelphia , PA , USA.,Department of Neuroscience, Temple University School of Medicine , Philadelphia , PA , USA
| | - Michael E Selzer
- Shriners Hospitals Pediatric Research Center, Temple University School of Medicine , Philadelphia , PA , USA.,Department of Neurology, Temple University School of Medicine , Philadelphia , PA , USA
| | - Shuxin Li
- Shriners Hospitals Pediatric Research Center, Temple University School of Medicine , Philadelphia , PA , USA.,Department of Anatomy and Cell Biology, Temple University School of Medicine , Philadelphia , PA , USA
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120
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Abstract
Permanent disabilities following CNS injuries result from the failure of injured axons to regenerate and rebuild functional connections with their original targets. By contrast, injury to peripheral nerves is followed by robust regeneration, which can lead to recovery of sensory and motor functions. This regenerative response requires the induction of widespread transcriptional and epigenetic changes in injured neurons. Considerable progress has been made in recent years in understanding how peripheral axon injury elicits these widespread changes through the coordinated actions of transcription factors, epigenetic modifiers and, to a lesser extent, microRNAs. Although many questions remain about the interplay between these mechanisms, these new findings provide important insights into the pivotal role of coordinated gene expression and chromatin remodelling in the neuronal response to injury.
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Affiliation(s)
- Marcus Mahar
- Department of Neuroscience, Hope Center for Neurological Disorders and Center of Regenerative Medicine, Washington University School of Medicine, St Louis, MO, USA
| | - Valeria Cavalli
- Department of Neuroscience, Hope Center for Neurological Disorders and Center of Regenerative Medicine, Washington University School of Medicine, St Louis, MO, USA.
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121
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Tedeschi A, Dupraz S, Curcio M, Laskowski CJ, Schaffran B, Flynn KC, Santos TE, Stern S, Hilton BJ, Larson MJE, Gurniak CB, Witke W, Bradke F. ADF/Cofilin-Mediated Actin Turnover Promotes Axon Regeneration in the Adult CNS. Neuron 2019; 103:1073-1085.e6. [PMID: 31400829 DOI: 10.1016/j.neuron.2019.07.007] [Citation(s) in RCA: 62] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 06/06/2019] [Accepted: 07/08/2019] [Indexed: 11/27/2022]
Abstract
Injured axons fail to regenerate in the adult CNS, which contrasts with their vigorous growth during embryonic development. We explored the potential of re-initiating axon extension after injury by reactivating the molecular mechanisms that drive morphogenetic transformation of neurons during development. Genetic loss- and gain-of-function experiments followed by time-lapse microscopy, in vivo imaging, and whole-mount analysis show that axon regeneration is fueled by elevated actin turnover. Actin depolymerizing factor (ADF)/cofilin controls actin turnover to sustain axon regeneration after spinal cord injury through its actin-severing activity. This pinpoints ADF/cofilin as a key regulator of axon growth competence, irrespective of developmental stage. These findings reveal the central role of actin dynamics regulation in this process and elucidate a core mechanism underlying axon growth after CNS trauma. Thereby, neurons maintain the capacity to stimulate developmental programs during adult life, expanding their potential for plasticity. Thus, actin turnover is a key process for future regenerative interventions.
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Affiliation(s)
- Andrea Tedeschi
- Axonal Growth and Regeneration, German Center for Neurodegenerative Diseases (DZNE), Sigmund-Freud-Str. 27, 53127 Bonn, Germany
| | - Sebastian Dupraz
- Axonal Growth and Regeneration, German Center for Neurodegenerative Diseases (DZNE), Sigmund-Freud-Str. 27, 53127 Bonn, Germany
| | - Michele Curcio
- Axonal Growth and Regeneration, German Center for Neurodegenerative Diseases (DZNE), Sigmund-Freud-Str. 27, 53127 Bonn, Germany
| | - Claudia J Laskowski
- Axonal Growth and Regeneration, German Center for Neurodegenerative Diseases (DZNE), Sigmund-Freud-Str. 27, 53127 Bonn, Germany
| | - Barbara Schaffran
- Axonal Growth and Regeneration, German Center for Neurodegenerative Diseases (DZNE), Sigmund-Freud-Str. 27, 53127 Bonn, Germany
| | - Kevin C Flynn
- Axonal Growth and Regeneration, German Center for Neurodegenerative Diseases (DZNE), Sigmund-Freud-Str. 27, 53127 Bonn, Germany
| | - Telma E Santos
- Axonal Growth and Regeneration, German Center for Neurodegenerative Diseases (DZNE), Sigmund-Freud-Str. 27, 53127 Bonn, Germany
| | - Sina Stern
- Axonal Growth and Regeneration, German Center for Neurodegenerative Diseases (DZNE), Sigmund-Freud-Str. 27, 53127 Bonn, Germany
| | - Brett J Hilton
- Axonal Growth and Regeneration, German Center for Neurodegenerative Diseases (DZNE), Sigmund-Freud-Str. 27, 53127 Bonn, Germany
| | - Molly J E Larson
- Center for Brain and Spinal Cord Repair, Department of Neuroscience, Wexner Medical Center, The Ohio State University, 460 W. 12th Ave., Columbus, OH 43210, USA
| | - Christine B Gurniak
- Institute of Genetics, University of Bonn, Karlrobert-Kreiten-Str. 13, 53115 Bonn, Germany
| | - Walter Witke
- Institute of Genetics, University of Bonn, Karlrobert-Kreiten-Str. 13, 53115 Bonn, Germany
| | - Frank Bradke
- Axonal Growth and Regeneration, German Center for Neurodegenerative Diseases (DZNE), Sigmund-Freud-Str. 27, 53127 Bonn, Germany.
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122
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Fawcett JW. The Struggle to Make CNS Axons Regenerate: Why Has It Been so Difficult? Neurochem Res 2019; 45:144-158. [PMID: 31388931 PMCID: PMC6942574 DOI: 10.1007/s11064-019-02844-y] [Citation(s) in RCA: 69] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2019] [Revised: 07/09/2019] [Accepted: 07/19/2019] [Indexed: 12/12/2022]
Abstract
Axon regeneration in the CNS is inhibited by many extrinsic and intrinsic factors. Because these act in parallel, no single intervention has been sufficient to enable full regeneration of damaged axons in the adult mammalian CNS. In the external environment, NogoA and CSPGs are strongly inhibitory to the regeneration of adult axons. CNS neurons lose intrinsic regenerative ability as they mature: embryonic but not mature neurons can grow axons for long distances when transplanted into the adult CNS, and regeneration fails with maturity in in vitro axotomy models. The causes of this loss of regeneration include partitioning of neurons into axonal and dendritic fields with many growth-related molecules directed specifically to dendrites and excluded from axons, changes in axonal signalling due to changes in expression and localization of receptors and their ligands, changes in local translation of proteins in axons, and changes in cytoskeletal dynamics after injury. Also with neuronal maturation come epigenetic changes in neurons, with many of the transcription factor binding sites that drive axon growth-related genes becoming inaccessible. The overall aim for successful regeneration is to ensure that the right molecules are expressed after axotomy and to arrange for them to be transported to the right place in the neuron, including the damaged axon tip.
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Affiliation(s)
- James W Fawcett
- John Van Geest Centre for Brain Repair, University of Cambridge, Robinson Way, Cambridge, CB2 0PY, UK.
- Centre of Reconstructive Neuroscience, Institute for Experimental Medicine ASCR, Prague, Czech Republic.
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123
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Roberts-Thomson SJ, Chalmers SB, Monteith GR. The Calcium-Signaling Toolkit in Cancer: Remodeling and Targeting. Cold Spring Harb Perspect Biol 2019; 11:cshperspect.a035204. [PMID: 31088826 DOI: 10.1101/cshperspect.a035204] [Citation(s) in RCA: 58] [Impact Index Per Article: 11.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Processes that are important in cancer progression, such as sustained cell growth, invasion to other organs, and resistance to cell death inducers, have a clear overlap with pathways regulated by Ca2+ signaling. It is therefore not surprising that proteins important in Ca2+ signaling, sometimes referred to as the "Ca2+ signaling toolkit," can contribute to cancer cell proliferation and invasiveness, and the ability of agents to induce cancer cell death. Ca2+ signaling is also critical in other aspects of cancer progression, including events in the tumor microenvironment and processes involved in the acquisition of resistance to anticancer therapies. This review will consider the role of Ca2+ signaling in tumor progression and highlight areas in which a better understanding of the interplay between the Ca2+-signaling toolkit and tumorigenesis is still required.
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Affiliation(s)
| | - Silke B Chalmers
- The School of Pharmacy, The University of Queensland, Brisbane, Queensland 4072, Australia
| | - Gregory R Monteith
- The School of Pharmacy, The University of Queensland, Brisbane, Queensland 4072, Australia.,Mater Research Institute, The University of Queensland, Translational Research Institute, Brisbane, Queensland 4072, Australia
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124
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Combining molecular intervention with in vivo imaging to untangle mechanisms of axon pathology and outgrowth following spinal cord injury. Exp Neurol 2019; 318:1-11. [DOI: 10.1016/j.expneurol.2019.04.003] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2018] [Revised: 03/20/2019] [Accepted: 04/07/2019] [Indexed: 12/17/2022]
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125
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Bieler L, Vogl M, Kirchinger M, Urmann C, Riepl H, Bandtlow C, Klimaschewski L, Aigner L, Couillard-Despres S. The Prenylflavonoid ENDF1 Overrules Central Nervous System Growth Inhibitors and Facilitates Regeneration of DRG Neurons. Front Cell Neurosci 2019; 13:332. [PMID: 31396054 PMCID: PMC6668039 DOI: 10.3389/fncel.2019.00332] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2019] [Accepted: 07/04/2019] [Indexed: 01/04/2023] Open
Abstract
Restoration of neuronal connectivity after lesion of the central nervous system, such as spinal cord injury, is one of the biggest challenges in modern medicine. In particular, the accumulation of axon growth inhibitory factors at the site of injury constitutes a major obstacle to structural and thus functional repair. We previously investigated a group of prenylflavonoids derived from hops for their capacity to promote neuroregeneration. We identified a molecule called ENDF1 that was very potent to enhance regrowth and branching of neurites from dorsal root ganglion neurons in culture on growth promoting substrates. In the present study, we investigated ENDF1’s capacity to promote regeneration of rat dorsal root ganglion neurons in vitro in the presence of three main components of the extracellular matrix acting as axon growth inhibitors: Semaphorin 3A, Ephrin A4 and mixed chondroitin sulfate proteoglycans. We report that ENDF1 application significantly promoted the percentages of sensory neurons able to regrow their neurites regardless of the presence of those inhibitors, and this to an extent similar to the one obtained after NGF treatment. Moreover, ENDF1 strongly enhanced the total neurite length and the complexity of neurites extending from neurons challenged with axon growth inhibitors. Although the impact of NGF and ENDF1 on the regeneration of neurons was similar, the activity of ENDF1 was not mediated by signaling through the TrkA receptor, indicating that each molecule act through different signaling pathways. In addition, ENDF1 did not decrease the phosphorylation of cofilin, a downstream effector of the regeneration-associated RhoA/ROCK signaling pathway. Hence, ENDF1 is a potent pro-neuroregenerative factors that could help in identifying new efficient targets for regenerative therapies of the nervous system.
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Affiliation(s)
- Lara Bieler
- Institute of Experimental Neuroregeneration, Paracelsus Medical University, Salzburg, Austria.,Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Salzburg, Austria
| | - Michael Vogl
- Institute of Experimental Neuroregeneration, Paracelsus Medical University, Salzburg, Austria.,Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Salzburg, Austria
| | - Michael Kirchinger
- Organic-Analytical Chemistry, Weihenstephan-Triesdorf University of Applied Sciences, Straubing, Germany.,TUM Campus Straubing, Straubing, Germany
| | - Corinna Urmann
- Organic-Analytical Chemistry, Weihenstephan-Triesdorf University of Applied Sciences, Straubing, Germany.,TUM Campus Straubing, Straubing, Germany
| | - Herbert Riepl
- Organic-Analytical Chemistry, Weihenstephan-Triesdorf University of Applied Sciences, Straubing, Germany.,TUM Campus Straubing, Straubing, Germany
| | - Christine Bandtlow
- Division of Neurobiochemistry, Innsbruck Medical University, Innsbruck, Austria
| | - Lars Klimaschewski
- Department of Anatomy, Histology and Embryology, Division of Neuroanatomy, Medical University of Innsbruck, Innsbruck, Austria
| | - Ludwig Aigner
- Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Salzburg, Austria.,Institute of Molecular Regenerative Medicine, Paracelsus Medical University, Salzburg, Austria.,Austrian Cluster for Tissue Regeneration, Vienna, Austria
| | - Sebastien Couillard-Despres
- Institute of Experimental Neuroregeneration, Paracelsus Medical University, Salzburg, Austria.,Spinal Cord Injury and Tissue Regeneration Center Salzburg (SCI-TReCS), Salzburg, Austria.,Austrian Cluster for Tissue Regeneration, Vienna, Austria
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126
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Endo T, Kadoya K, Kawamura D, Iwasaki N. Evidence for cell-contact factor involvement in neurite outgrowth of dorsal root ganglion neurons stimulated by Schwann cells. Exp Physiol 2019; 104:1447-1454. [PMID: 31294871 DOI: 10.1113/ep087634] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2019] [Accepted: 07/08/2019] [Indexed: 12/14/2022]
Abstract
NEW FINDINGS What is the central question of this study? Although the factors secreted from Schwann cells that promote axonal growth in the peripheral nervous system have been well studied, the effect of cell-contact factors on Schwann cells remains to be determined. What is the main finding and its importance? This study demonstrates that Schwann cells stimulate neurite outgrowth by direct contact with neurites and by secreting factors. Notably, the effect of cell-contact factors in neurite outgrowth is comparable to that of secreted factors, indicating that the identification of cell surface molecules on Schwann cells that promote neurite outgrowth could lead to development of a new therapy for peripheral nervous system injury. ABSTRACT Schwann cells (SCs) play a variety of roles in the regeneration process after injury to the peripheral nervous system. The factors secreted from SCs that promote axonal growth have been well studied. However, the involvement of cell-contact factors on SCs remains to be determined. Here, we demonstrate a significant contribution of a cell-contact mechanism in the effect of SCs on promotion of neuronal outgrowth. Neurite outgrowth of adult sensory neurons from dorsal root ganglia was quantified during co-culture with adult SCs. Direct contact of SCs with neurons was eliminated by culturing SCs on an insert placed in the same well; this resulted in a 51% reduction in the length of neurite outgrowth. In addition, when dorsal root ganglion neurons were cultured on sparsely seeded SCs, neurons that made contact with SCs on their neurites had 118% longer neurites than neurons that lacked contacts with SCs. Collectively, these findings provide evidence that SCs stimulate neurite outgrowth via direct contact with neurites in addition to secreting factors. The identification of cell surface molecules on SCs that promote neurite outgrowth could lead to development of a new therapy for peripheral nervous system injury.
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Affiliation(s)
- Takeshi Endo
- Department of Orthopaedic Surgery, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, Japan
| | - Ken Kadoya
- Department of Orthopaedic Surgery, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, Japan
| | - Daisuke Kawamura
- Department of Orthopaedic Surgery, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, Japan
| | - Norimasa Iwasaki
- Department of Orthopaedic Surgery, Hokkaido University Graduate School of Medicine, Sapporo, Hokkaido, Japan
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127
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Shin JE, Ha H, Kim YK, Cho Y, DiAntonio A. DLK regulates a distinctive transcriptional regeneration program after peripheral nerve injury. Neurobiol Dis 2019; 127:178-192. [PMID: 30735704 PMCID: PMC6588443 DOI: 10.1016/j.nbd.2019.02.001] [Citation(s) in RCA: 44] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 01/03/2019] [Accepted: 02/04/2019] [Indexed: 12/13/2022] Open
Abstract
Following damage to a peripheral nerve, injury signaling pathways converge in the cell body to generate transcriptional changes that support axon regeneration. Here, we demonstrate that dual leucine zipper kinase (DLK), a central regulator of injury responses including axon regeneration and neuronal apoptosis, is required for the induction of the pro-regenerative transcriptional program in response to peripheral nerve injury. Using a sensory neuron-conditional DLK knockout mouse model, we show a time course for the dependency of gene expression changes on the DLK pathway after sciatic nerve injury. Gene ontology analysis reveals that DLK-dependent gene sets are enriched for specific functional annotations such as ion transport and immune response. A series of comparative analyses shows that the DLK-dependent transcriptional program is distinct from that promoted by the importin-dependent retrograde signaling pathway, while it is partially shared between PNS and CNS injury responses. We suggest that DLK-dependency might provide a selective filter for regeneration-associated genes among the injury-responsive transcriptome.
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Affiliation(s)
- Jung Eun Shin
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA; Division of Life Sciences, Korea University, Seoul 02841, Republic of Korea
| | - Hongseok Ha
- Division of Life Sciences, Korea University, Seoul 02841, Republic of Korea; Creative Research Initiatives Center for Molecular Biology of Translation, Korea University, Seoul 02841, Republic of Korea
| | - Yoon Ki Kim
- Division of Life Sciences, Korea University, Seoul 02841, Republic of Korea; Creative Research Initiatives Center for Molecular Biology of Translation, Korea University, Seoul 02841, Republic of Korea
| | - Yongcheol Cho
- Division of Life Sciences, Korea University, Seoul 02841, Republic of Korea.
| | - Aaron DiAntonio
- Department of Developmental Biology, Washington University School of Medicine, St. Louis, MO 63110, USA.
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128
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Zhang Y, Williams PR, Jacobi A, Wang C, Goel A, Hirano AA, Brecha NC, Kerschensteiner D, He Z. Elevating Growth Factor Responsiveness and Axon Regeneration by Modulating Presynaptic Inputs. Neuron 2019; 103:39-51.e5. [PMID: 31122676 DOI: 10.1016/j.neuron.2019.04.033] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2018] [Revised: 03/01/2019] [Accepted: 04/23/2019] [Indexed: 12/24/2022]
Abstract
Despite robust effects on immature neurons, growth factors minimally promote axon regeneration in the adult central nervous system (CNS). Attempting to improve growth-factor responsiveness in mature neurons by dedifferentiation, we overexpressed Lin28 in the retina. Lin28-treated retinas responded to insulin-like growth factor-1 (IGF1) by initiating retinal ganglion cell (RGC) axon regeneration after axotomy. Surprisingly, this effect was cell non-autonomous. Lin28 expression was required only in amacrine cells, inhibitory neurons that innervate RGCs. Ultimately, we found that optic-nerve crush pathologically upregulated activity in amacrine cells, which reduced RGC electrical activity and suppressed growth-factor signaling. Silencing amacrine cells or pharmacologically blocking inhibitory neurotransmission also induced IGF1 competence. Remarkably, RGCs regenerating across these manipulations localized IGF1 receptor to their primary cilia, which maintained their signaling competence and regenerative ability. Thus, our results reveal a circuit-based mechanism that regulates CNS axon regeneration and implicate primary cilia as a regenerative signaling hub.
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Affiliation(s)
- Yiling Zhang
- F.M. Kirby Neurobiology Center, Children's Hospital, and Department of Neurology, Harvard Medical School, Boston, MA, USA
| | - Philip R Williams
- F.M. Kirby Neurobiology Center, Children's Hospital, and Department of Neurology, Harvard Medical School, Boston, MA, USA; Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO, USA.
| | - Anne Jacobi
- F.M. Kirby Neurobiology Center, Children's Hospital, and Department of Neurology, Harvard Medical School, Boston, MA, USA
| | - Chen Wang
- F.M. Kirby Neurobiology Center, Children's Hospital, and Department of Neurology, Harvard Medical School, Boston, MA, USA
| | - Anurag Goel
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO, USA
| | - Arlene A Hirano
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; United States Veterans Administration Greater Los Angeles Healthcare System, Los Angeles, CA, USA
| | - Nicholas C Brecha
- Department of Neurobiology, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095, USA; United States Veterans Administration Greater Los Angeles Healthcare System, Los Angeles, CA, USA
| | - Daniel Kerschensteiner
- Department of Ophthalmology and Visual Sciences, Washington University School of Medicine, St. Louis, MO, USA
| | - Zhigang He
- F.M. Kirby Neurobiology Center, Children's Hospital, and Department of Neurology, Harvard Medical School, Boston, MA, USA
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129
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Perrin FE, Noristani HN. Serotonergic mechanisms in spinal cord injury. Exp Neurol 2019; 318:174-191. [PMID: 31085200 DOI: 10.1016/j.expneurol.2019.05.007] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Revised: 05/07/2019] [Accepted: 05/08/2019] [Indexed: 12/12/2022]
Abstract
Spinal cord injury (SCI) is a tragic event causing irreversible losses of sensory, motor, and autonomic functions, that may also be associated with chronic neuropathic pain. Serotonin (5-HT) neurotransmission in the spinal cord is critical for modulating sensory, motor, and autonomic functions. Following SCI, 5-HT axons caudal to the lesion site degenerate, and the degree of axonal degeneration positively correlates with lesion severity. Rostral to the lesion, 5-HT axons sprout, irrespective of the severity of the injury. Unlike callosal fibers and cholinergic projections, 5-HT axons are more resistant to an inhibitory milieu and undergo active sprouting and regeneration after central nervous system (CNS) traumatism. Numerous studies suggest that a chronic increase in serotonergic neurotransmission promotes 5-HT axon sprouting in the intact CNS. Moreover, recent studies in invertebrates suggest that 5-HT has a pro-regenerative role in injured axons. Here we present a brief description of 5-HT discovery, 5-HT innervation of the CNS, and physiological functions of 5-HT in the spinal cord, including its role in controlling bladder function. We then present a comprehensive overview of changes in serotonergic axons after CNS damage, and discuss their plasticity upon altered 5-HT neurotransmitter levels. Subsequently, we provide an in-depth review of therapeutic approaches targeting 5-HT neurotransmission, as well as other pre-clinical strategies to promote an increase in re-growth of 5-HT axons, and their functional consequences in SCI animal models. Finally, we highlight recent findings signifying the direct role of 5-HT in axon regeneration and suggest strategies to further promote robust long-distance re-growth of 5-HT axons across the lesion site and eventually achieve functional recovery following SCI.
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Affiliation(s)
- Florence Evelyne Perrin
- University of Montpellier, Montpellier, F-34095 France; INSERM, U1198, Montpellier, F-34095 France; EPHE, Paris, F-75014 France
| | - Harun Najib Noristani
- Shriners Hospitals Pediatric Research Center, Center for Neural Repair, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA; Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA 19140, USA.
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130
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Abstract
BACKGROUND Recent observational studies have shown an association between gabapentinoid anticonvulsants and greater motor recovery after spinal cord injury. There is preclinical evidence to suggest that other anticonvulsants, such as sodium channel blockers, may also confer beneficial effects. PURPOSE The aim of the current study was to determine if non-gabapentinoid anticonvulsants were associated with neurological recovery after acute, traumatic spinal cord injury. METHODS This was an observational cohort study using data from the Sygen clinical trial. The primary outcome was total motor score recovery in the first year after injury. Anticonvulsant use was extracted from concomitant medication records; individuals were classified based on early administration (within 30 days of injury), or late/no administration. Motor recovery was compared using linear mixed effects regression models with a drug-by-time interaction, and adjustment for confounders. A secondary analysis incorporated a propensity score matched cohort. RESULTS Of the cohort (n = 570), 6% received anticonvulsants (carbamazepine, phenytoin, clonazepam, phenobarbital, and valproic acid) early after injury. After adjustments for initial injury level and severity, early exposure to non-gabapentinoid anticonvulsants was not associated with motor neurological outcomes (p = 0.38 for all anticonvulsants, p = 0.83 for sodium channel blockers, p = 0.82 in propensity-matched cohort). CONCLUSION Non-gabapentinoid anticonvulsant exposure was not associated with greater or lesser neurological recovery. This suggests that these medications, as administered for the acute management of spinal cord injury, do not impact long-term neurological outcomes.
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131
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Song Y, Li D, Farrelly O, Miles L, Li F, Kim SE, Lo TY, Wang F, Li T, Thompson-Peer KL, Gong J, Murthy SE, Coste B, Yakubovich N, Patapoutian A, Xiang Y, Rompolas P, Jan LY, Jan YN. The Mechanosensitive Ion Channel Piezo Inhibits Axon Regeneration. Neuron 2019; 102:373-389.e6. [PMID: 30819546 PMCID: PMC6487666 DOI: 10.1016/j.neuron.2019.01.050] [Citation(s) in RCA: 123] [Impact Index Per Article: 24.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2017] [Revised: 11/27/2018] [Accepted: 01/23/2019] [Indexed: 01/09/2023]
Abstract
Neurons exhibit a limited ability of repair. Given that mechanical forces affect neuronal outgrowth, it is important to investigate whether mechanosensitive ion channels may regulate axon regeneration. Here, we show that DmPiezo, a Ca2+-permeable non-selective cation channel, functions as an intrinsic inhibitor for axon regeneration in Drosophila. DmPiezo activation during axon regeneration induces local Ca2+ transients at the growth cone, leading to activation of nitric oxide synthase and the downstream cGMP kinase Foraging or PKG to restrict axon regrowth. Loss of DmPiezo enhances axon regeneration of sensory neurons in the peripheral and CNS. Conditional knockout of its mammalian homolog Piezo1 in vivo accelerates regeneration, while its pharmacological activation in vitro modestly reduces regeneration, suggesting the role of Piezo in inhibiting regeneration may be evolutionarily conserved. These findings provide a precedent for the involvement of mechanosensitive channels in axon regeneration and add a potential target for modulating nervous system repair.
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Affiliation(s)
- Yuanquan Song
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children's Hospital of Philadelphia, Philadelphia, PA 19104, USA; Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA.
| | - Dan Li
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA,Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA,These authors contributed equally
| | - Olivia Farrelly
- Department of Dermatology, University of Pennsylvania, Philadelphia, PA 19104, USA,These authors contributed equally
| | - Leann Miles
- The Graduate Group in Biochemistry and Molecular Biophysics, University of Pennsylvania, Philadelphia, PA 19104, USA,These authors contributed equally
| | - Feng Li
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA,Department of Pathology and Laboratory Medicine, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Sung Eun Kim
- Departments of Physiology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA,Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Tsz Y. Lo
- Raymond G. Perelman Center for Cellular and Molecular Therapeutics, The Children’s Hospital of Philadelphia, Philadelphia, PA 19104, USA
| | - Fei Wang
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Tun Li
- Departments of Physiology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA,Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Katherine L. Thompson-Peer
- Departments of Physiology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA,Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Jiaxin Gong
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Swetha E. Murthy
- Department of Neuroscience, The Scripps Research Institute, Howard Hughes Medical Institute, La Jolla, CA 92037, USA
| | - Bertrand Coste
- Department of Neuroscience, The Scripps Research Institute, Howard Hughes Medical Institute, La Jolla, CA 92037, USA,Present address: Aix Marseille Université, CNRS, LNC-UMR 7291, 13344 Marseille, France
| | - Nikita Yakubovich
- Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Ardem Patapoutian
- Department of Neuroscience, The Scripps Research Institute, Howard Hughes Medical Institute, La Jolla, CA 92037, USA
| | - Yang Xiang
- Department of Neurobiology, University of Massachusetts Medical School, Worcester, MA 01605, USA
| | - Panteleimon Rompolas
- Department of Dermatology, University of Pennsylvania, Philadelphia, PA 19104, USA
| | - Lily Yeh Jan
- Departments of Physiology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA,Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA,Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA
| | - Yuh Nung Jan
- Departments of Physiology, Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA; Howard Hughes Medical Institute, University of California, San Francisco, San Francisco, CA 94158, USA; Department of Biochemistry and Biophysics, University of California, San Francisco, San Francisco, CA 94158, USA.
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132
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Zheng B, Lorenzana AO, Ma L. Understanding the axonal response to injury by in vivo imaging in the mouse spinal cord: A tale of two branches. Exp Neurol 2019; 318:277-285. [PMID: 30986398 PMCID: PMC6588497 DOI: 10.1016/j.expneurol.2019.04.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 04/05/2019] [Accepted: 04/11/2019] [Indexed: 01/01/2023]
Abstract
Understanding the basic properties of how axons respond to injury in the mammalian central nervous system (CNS) is of fundamental value for developing strategies to promote neural repair. Axons possess complex morphologies with stereotypical branching patterns. However, current knowledge of the axonal response to injury gives little consideration to axonal branches, nor do strategies to promote axon regeneration. This article reviews evidence from in vivo spinal cord imaging that axonal branches markedly impact the degenerative and regenerative responses to injury. At a major bifurcation point, depending on whether one or both axonal branches are injured, neurons may choose either a more self-preservative response or a more dynamic response. The stabilizing effect of the spared branch may underlie a well-known divergence in neuronal responses to injury, and illustrates an example where in vivo spinal cord imaging reveals insights that are difficult to elucidate with conventional histological methods.
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Affiliation(s)
- Binhai Zheng
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA; VA San Diego Healthcare System, San Diego, CA, USA.
| | - Ariana O Lorenzana
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Le Ma
- Department of Neuroscience, Jefferson Synaptic Biology Center, Vickie and Jack Farber Institute for Neuroscience, Sydney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
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133
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Geisler S, Schöpf CL, Stanika R, Kalb M, Campiglio M, Repetto D, Traxler L, Missler M, Obermair GJ. Presynaptic α 2δ-2 Calcium Channel Subunits Regulate Postsynaptic GABA A Receptor Abundance and Axonal Wiring. J Neurosci 2019; 39:2581-2605. [PMID: 30683685 PMCID: PMC6445987 DOI: 10.1523/jneurosci.2234-18.2019] [Citation(s) in RCA: 31] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2018] [Revised: 01/03/2019] [Accepted: 01/08/2019] [Indexed: 01/26/2023] Open
Abstract
Presynaptic α2δ subunits of voltage-gated calcium channels regulate channel abundance and are involved in glutamatergic synapse formation. However, little is known about the specific functions of the individual α2δ isoforms and their role in GABAergic synapses. Using primary neuronal cultures of embryonic mice of both sexes, we here report that presynaptic overexpression of α2δ-2 in GABAergic synapses strongly increases clustering of postsynaptic GABAARs. Strikingly, presynaptic α2δ-2 exerts the same effect in glutamatergic synapses, leading to a mismatched localization of GABAARs. This mismatching is caused by an aberrant wiring of glutamatergic presynaptic boutons with GABAergic postsynaptic positions. The trans-synaptic effect of α2δ-2 is independent of the prototypical cell-adhesion molecules α-neurexins (α-Nrxns); however, α-Nrxns together with α2δ-2 can modulate postsynaptic GABAAR abundance. Finally, exclusion of the alternatively spliced exon 23 of α2δ-2 is essential for the trans-synaptic mechanism. The novel function of α2δ-2 identified here may explain how abnormal α2δ subunit expression can cause excitatory-inhibitory imbalance often associated with neuropsychiatric disorders.SIGNIFICANCE STATEMENT Voltage-gated calcium channels regulate important neuronal functions such as synaptic transmission. α2δ subunits modulate calcium channels and are emerging as regulators of brain connectivity. However, little is known about how individual α2δ subunits contribute to synapse specificity. Here, we show that presynaptic expression of a single α2δ variant can modulate synaptic connectivity and the localization of inhibitory postsynaptic receptors. Our findings provide basic insights into the development of specific synaptic connections between nerve cells and contribute to our understanding of normal nerve cell functions. Furthermore, the identified mechanism may explain how an altered expression of calcium channel subunits can result in aberrant neuronal wiring often associated with neuropsychiatric disorders such as autism or schizophrenia.
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Affiliation(s)
- Stefanie Geisler
- Division of Physiology, Medical University Innsbruck, 6020 Innsbruck, Austria, and
| | - Clemens L Schöpf
- Division of Physiology, Medical University Innsbruck, 6020 Innsbruck, Austria, and
| | - Ruslan Stanika
- Division of Physiology, Medical University Innsbruck, 6020 Innsbruck, Austria, and
| | - Marcus Kalb
- Division of Physiology, Medical University Innsbruck, 6020 Innsbruck, Austria, and
| | - Marta Campiglio
- Division of Physiology, Medical University Innsbruck, 6020 Innsbruck, Austria, and
| | - Daniele Repetto
- Institute of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-University, 48149 Münster, Germany
| | - Larissa Traxler
- Division of Physiology, Medical University Innsbruck, 6020 Innsbruck, Austria, and
| | - Markus Missler
- Institute of Anatomy and Molecular Neurobiology, Westfälische Wilhelms-University, 48149 Münster, Germany
| | - Gerald J Obermair
- Division of Physiology, Medical University Innsbruck, 6020 Innsbruck, Austria, and
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134
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Hilton BJ, Blanquie O, Tedeschi A, Bradke F. High-resolution 3D imaging and analysis of axon regeneration in unsectioned spinal cord with or without tissue clearing. Nat Protoc 2019; 14:1235-1260. [DOI: 10.1038/s41596-019-0140-z] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2018] [Accepted: 01/17/2019] [Indexed: 12/12/2022]
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135
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Abstract
Traumatic brain and spinal cord injuries cause permanent disability. Although progress has been made in understanding the cellular and molecular mechanisms underlying the pathophysiological changes that affect both structure and function after injury to the brain or spinal cord, there are currently no cures for either condition. This may change with the development and application of multi-layer omics, new sophisticated bioinformatics tools, and cutting-edge imaging techniques. Already, these technical advances, when combined, are revealing an unprecedented number of novel cellular and molecular targets that could be manipulated alone or in combination to repair the injured central nervous system with precision. In this review, we highlight recent advances in applying these new technologies to the study of axon regeneration and rebuilding of injured neural circuitry. We then discuss the challenges ahead to translate results produced by these technologies into clinical application to help improve the lives of individuals who have a brain or spinal cord injury.
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Affiliation(s)
- Andrea Tedeschi
- Department of Neuroscience and Discovery Themes Initiative, College of Medicine, Ohio State University, Columbus, Ohio, 43210, USA
| | - Phillip G Popovich
- Center for Brain and Spinal Cord Repair, Institute for Behavioral Medicine Research, Ohio State University, Columbus, Ohio, 43210, USA
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136
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Schaffran B, Hilton BJ, Bradke F. Imaging in vivo dynamics of sensory axon responses to CNS injury. Exp Neurol 2019; 317:110-118. [PMID: 30794766 DOI: 10.1016/j.expneurol.2019.02.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 02/13/2019] [Accepted: 02/17/2019] [Indexed: 01/25/2023]
Abstract
Axons in the adult mammalian brain and spinal cord fail to regenerate upon lesion. In vivo imaging serves as a tool to investigate the immediate response of axons to injury and how the same injured axons behave over time. Here, we describe the dynamic changes that injured sensory axons undergo and methods of imaging them in vivo. First, we explain how sensory axons in the dorsal column of the adult mouse spinal cord respond to axotomy. Then, we highlight practical considerations for implementing two-photon based in vivo imaging of these axons. Finally, we describe future directions for this technique, including the possibility of in vivo imaging of subcellular dynamics within the axon.
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Affiliation(s)
| | - Brett J Hilton
- German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Frank Bradke
- German Center for Neurodegenerative Diseases, Bonn, Germany.
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137
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Epigenetic regulator UHRF1 inactivates REST and growth suppressor gene expression via DNA methylation to promote axon regeneration. Proc Natl Acad Sci U S A 2018; 115:E12417-E12426. [PMID: 30530687 DOI: 10.1073/pnas.1812518115] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Injured peripheral sensory neurons switch to a regenerative state after axon injury, which requires transcriptional and epigenetic changes. However, the roles and mechanisms of gene inactivation after injury are poorly understood. Here, we show that DNA methylation, which generally leads to gene silencing, is required for robust axon regeneration after peripheral nerve lesion. Ubiquitin-like containing PHD ring finger 1 (UHRF1), a critical epigenetic regulator involved in DNA methylation, increases upon axon injury and is required for robust axon regeneration. The increased level of UHRF1 results from a decrease in miR-9. The level of another target of miR-9, the transcriptional regulator RE1 silencing transcription factor (REST), transiently increases after injury and is required for axon regeneration. Mechanistically, UHRF1 interacts with DNA methyltransferases (DNMTs) and H3K9me3 at the promoter region to repress the expression of the tumor suppressor gene phosphatase and tensin homolog (PTEN) and REST. Our study reveals an epigenetic mechanism that silences tumor suppressor genes and restricts REST expression in time after injury to promote axon regeneration.
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138
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Abstract
Voltage-gated calcium (CaV) channels are associated with β and α2δ auxiliary subunits. This review will concentrate on the function of the α2δ protein family, which has four members. The canonical role for α2δ subunits is to convey a variety of properties on the CaV1 and CaV2 channels, increasing the density of these channels in the plasma membrane and also enhancing their function. More recently, a diverse spectrum of non-canonical interactions for α2δ proteins has been proposed, some of which involve competition with calcium channels for α2δ or increase α2δ trafficking and others which mediate roles completely unrelated to their calcium channel function. The novel roles for α2δ proteins which will be discussed here include association with low-density lipoprotein receptor-related protein 1 (LRP1), thrombospondins, α-neurexins, prion proteins, large conductance (big) potassium (BK) channels, and N-methyl-d-aspartate (NMDA) receptors.
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Affiliation(s)
- Annette C Dolphin
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK
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139
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Kim KW, Tang NH, Piggott CA, Andrusiak MG, Park S, Zhu M, Kurup N, Cherra SJ, Wu Z, Chisholm AD, Jin Y. Expanded genetic screening in Caenorhabditis elegans identifies new regulators and an inhibitory role for NAD + in axon regeneration. eLife 2018; 7:39756. [PMID: 30461420 PMCID: PMC6281318 DOI: 10.7554/elife.39756] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2018] [Accepted: 11/19/2018] [Indexed: 12/15/2022] Open
Abstract
The mechanisms underlying axon regeneration in mature neurons are relevant to the understanding of normal nervous system maintenance and for developing therapeutic strategies for injury. Here, we report novel pathways in axon regeneration, identified by extending our previous function-based screen using the C. elegans mechanosensory neuron axotomy model. We identify an unexpected role of the nicotinamide adenine dinucleotide (NAD+) synthesizing enzyme, NMAT-2/NMNAT, in axon regeneration. NMAT-2 inhibits axon regrowth via cell-autonomous and non-autonomous mechanisms. NMAT-2 enzymatic activity is required to repress regrowth. Further, we find differential requirements for proteins in membrane contact site, components and regulators of the extracellular matrix, membrane trafficking, microtubule and actin cytoskeleton, the conserved Kelch-domain protein IVNS-1, and the orphan transporter MFSD-6 in axon regrowth. Identification of these new pathways expands our understanding of the molecular basis of axonal injury response and regeneration.
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Affiliation(s)
- Kyung Won Kim
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, United States
| | - Ngang Heok Tang
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, United States
| | - Christopher A Piggott
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, United States
| | - Matthew G Andrusiak
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, United States
| | - Seungmee Park
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, United States
| | - Ming Zhu
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, United States
| | - Naina Kurup
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, United States
| | - Salvatore J Cherra
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, United States
| | - Zilu Wu
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, United States
| | - Andrew D Chisholm
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, United States
| | - Yishi Jin
- Section of Neurobiology, Division of Biological Sciences, University of California, San Diego, La Jolla, United States.,Department of Cellular and Molecular Medicine, University of California, San Diego, School of Medicine, La Jolla, United States
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140
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Tran AP, Warren PM, Silver J. The Biology of Regeneration Failure and Success After Spinal Cord Injury. Physiol Rev 2018. [PMID: 29513146 DOI: 10.1152/physrev.00017.2017] [Citation(s) in RCA: 497] [Impact Index Per Article: 82.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Since no approved therapies to restore mobility and sensation following spinal cord injury (SCI) currently exist, a better understanding of the cellular and molecular mechanisms following SCI that compromise regeneration or neuroplasticity is needed to develop new strategies to promote axonal regrowth and restore function. Physical trauma to the spinal cord results in vascular disruption that, in turn, causes blood-spinal cord barrier rupture leading to hemorrhage and ischemia, followed by rampant local cell death. As subsequent edema and inflammation occur, neuronal and glial necrosis and apoptosis spread well beyond the initial site of impact, ultimately resolving into a cavity surrounded by glial/fibrotic scarring. The glial scar, which stabilizes the spread of secondary injury, also acts as a chronic, physical, and chemo-entrapping barrier that prevents axonal regeneration. Understanding the formative events in glial scarring helps guide strategies towards the development of potential therapies to enhance axon regeneration and functional recovery at both acute and chronic stages following SCI. This review will also discuss the perineuronal net and how chondroitin sulfate proteoglycans (CSPGs) deposited in both the glial scar and net impede axonal outgrowth at the level of the growth cone. We will end the review with a summary of current CSPG-targeting strategies that help to foster axonal regeneration, neuroplasticity/sprouting, and functional recovery following SCI.
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Affiliation(s)
- Amanda Phuong Tran
- Department of Neurosciences, Case Western Reserve University , Cleveland, Ohio ; and School of Biomedical Sciences, University of Leeds , Leeds , United Kingdom
| | - Philippa Mary Warren
- Department of Neurosciences, Case Western Reserve University , Cleveland, Ohio ; and School of Biomedical Sciences, University of Leeds , Leeds , United Kingdom
| | - Jerry Silver
- Department of Neurosciences, Case Western Reserve University , Cleveland, Ohio ; and School of Biomedical Sciences, University of Leeds , Leeds , United Kingdom
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141
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Regulation of Neuroregeneration by Long Noncoding RNAs. Mol Cell 2018; 72:553-567.e5. [PMID: 30401432 DOI: 10.1016/j.molcel.2018.09.021] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Revised: 07/27/2018] [Accepted: 09/14/2018] [Indexed: 12/24/2022]
Abstract
In mammals, neurons in the peripheral nervous system (PNS) have regenerative capacity following injury, but it is generally absent in the CNS. This difference is attributed, at least in part, to the intrinsic ability of PNS neurons to activate a unique regenerative transcriptional program following injury. Here, we profiled gene expression following sciatic nerve crush in mice and identified long noncoding RNAs (lncRNAs) that act in the regenerating neurons and which are typically not expressed in other contexts. We show that two of these lncRNAs regulate the extent of neuronal outgrowth. We then focus on one of these, Silc1, and show that it regulates neuroregeneration in cultured cells and in vivo, through cis-acting activation of the transcription factor Sox11.
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142
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Fawcett JW, Verhaagen J. Intrinsic Determinants of Axon Regeneration. Dev Neurobiol 2018; 78:890-897. [PMID: 30345655 DOI: 10.1002/dneu.22637] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2018] [Revised: 09/16/2018] [Accepted: 09/16/2018] [Indexed: 12/21/2022]
Abstract
The failure of axons to regenerate in the damaged mammalian CNS is the main impediment to functional recovery. There are many molecules and structures in the environment of the injured nervous system that can inhibit regeneration, but even when these are removed or replaced with a permissive environment, most CNS neurons exhibit little regeneration of their axons. This contrasts with the extensive and vigorous axon growth that may occur when embryonic neurons are transplanted into the adult CNS. In the peripheral nervous system, the axons usually respond to axotomy with a vigorous regenerative response accompanied by a regenerative program of gene expression, usually referred to as the regeneration-associated gene (RAG) program. These different responses to axotomy in the mature and immature CNS and the PNS lead to the concept of the intrinsic regenerative response of axons. Analysis of the many mechanisms and issues that affect the intrinsic regenerative response is the topic of this special issue of Developmental Neurobiology. The review articles highlight the control of expression of growth and regeneration-associated genes, emphasizing the role of epigenetic mechanisms. The reviews also discuss changes within axons that lead to the developmental loss of regenerative ability. This is caused by changes in axonal transport and trafficking, in the cytoskeleton and in signaling pathways.
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Affiliation(s)
- James W Fawcett
- John van Geest Centre for Brain Repair, Department Clinical Neurosciences, University of Cambridge, Cambridge, CB2 0PY, United Kingdom
| | - Joost Verhaagen
- Department of Regeneration of Sensorimotor Systems, Netherlands Institute for Neuroscience, Institute of the Royal Netherlands Academy of Arts and Sciences, Amsterdam, 1105 BA, The Netherlands
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143
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Curcio M, Bradke F. Axon Regeneration in the Central Nervous System: Facing the Challenges from the Inside. Annu Rev Cell Dev Biol 2018; 34:495-521. [DOI: 10.1146/annurev-cellbio-100617-062508] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
After an injury in the adult mammalian central nervous system (CNS), lesioned axons fail to regenerate. This failure to regenerate contrasts with axons’ remarkable potential to grow during embryonic development and after an injury in the peripheral nervous system (PNS). Several intracellular mechanisms—including cytoskeletal dynamics, axonal transport and trafficking, signaling and transcription of regenerative programs, and epigenetic modifications—control axon regeneration. In this review, we describe how manipulation of intrinsic mechanisms elicits a regenerative response in different organisms and how strategies are implemented to form the basis of a future regenerative treatment after CNS injury.
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Affiliation(s)
- Michele Curcio
- Laboratory for Axon Growth and Regeneration, German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany;,
| | - Frank Bradke
- Laboratory for Axon Growth and Regeneration, German Center for Neurodegenerative Diseases (DZNE), 53127 Bonn, Germany;,
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144
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Petrova V, Eva R. The Virtuous Cycle of Axon Growth: Axonal Transport of Growth-Promoting Machinery as an Intrinsic Determinant of Axon Regeneration. Dev Neurobiol 2018; 78:898-925. [PMID: 29989351 DOI: 10.1002/dneu.22608] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2018] [Revised: 05/25/2018] [Accepted: 05/26/2018] [Indexed: 02/02/2023]
Abstract
Injury to the brain and spinal cord has devastating consequences because adult central nervous system (CNS) axons fail to regenerate. Injury to the peripheral nervous system (PNS) has a better prognosis, because adult PNS neurons support robust axon regeneration over long distances. CNS axons have some regenerative capacity during development, but this is lost with maturity. Two reasons for the failure of CNS regeneration are extrinsic inhibitory molecules, and a weak intrinsic capacity for growth. Extrinsic inhibitory molecules have been well characterized, but less is known about the neuron-intrinsic mechanisms which prevent axon re-growth. Key signaling pathways and genetic/epigenetic factors have been identified which can enhance regenerative capacity, but the precise cellular mechanisms mediating their actions have not been characterized. Recent studies suggest that an important prerequisite for regeneration is an efficient supply of growth-promoting machinery to the axon; however, this appears to be lacking from non-regenerative axons in the adult CNS. In the first part of this review, we summarize the evidence linking axon transport to axon regeneration. We discuss the developmental decline in axon regeneration capacity in the CNS, and comment on how this is paralleled by a similar decline in the selective axonal transport of regeneration-associated receptors such as integrins and growth factor receptors. In the second part, we discuss the mechanisms regulating selective polarized transport within neurons, how these relate to the intrinsic control of axon regeneration, and whether they can be targeted to enhance regenerative capacity. © 2018 Wiley Periodicals, Inc. Develop Neurobiol 00: 000-000, 2018.
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Affiliation(s)
- Veselina Petrova
- John Van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 OPY, United Kingdom
| | - Richard Eva
- John Van Geest Centre for Brain Repair, Department of Clinical Neurosciences, University of Cambridge, Cambridge, CB2 OPY, United Kingdom
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145
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Venkatesh I, Mehra V, Wang Z, Califf B, Blackmore MG. Developmental Chromatin Restriction of Pro-Growth Gene Networks Acts as an Epigenetic Barrier to Axon Regeneration in Cortical Neurons. Dev Neurobiol 2018; 78:960-977. [PMID: 29786967 PMCID: PMC6204296 DOI: 10.1002/dneu.22605] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2018] [Revised: 05/01/2018] [Accepted: 05/04/2018] [Indexed: 12/21/2022]
Abstract
Axon regeneration in the central nervous system is prevented in part by a developmental decline in the intrinsic regenerative ability of maturing neurons. This loss of axon growth ability likely reflects widespread changes in gene expression, but the mechanisms that drive this shift remain unclear. Chromatin accessibility has emerged as a key regulatory mechanism in other cellular contexts, raising the possibility that chromatin structure may contribute to the age-dependent loss of regenerative potential. Here we establish an integrated bioinformatic pipeline that combines analysis of developmentally dynamic gene networks with transcription factor regulation and genome-wide maps of chromatin accessibility. When applied to the developing cortex, this pipeline detected overall closure of chromatin in sub-networks of genes associated with axon growth. We next analyzed mature CNS neurons that were supplied with various pro-regenerative transcription factors. Unlike prior results with SOX11 and KLF7, here we found that neither JUN nor an activated form of STAT3 promoted substantial corticospinal tract regeneration. Correspondingly, chromatin accessibility in JUN or STAT3 target genes was substantially lower than in predicted targets of SOX11 and KLF7. Finally, we used the pipeline to predict pioneer factors that could potentially relieve chromatin constraints at growth-associated loci. Overall this integrated analysis substantiates the hypothesis that dynamic chromatin accessibility contributes to the developmental decline in axon growth ability and influences the efficacy of pro-regenerative interventions in the adult, while also pointing toward selected pioneer factors as high-priority candidates for future combinatorial experiments. © 2018 Wiley Periodicals, Inc. Develop Neurobiol 00: 000-000, 2018.
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Affiliation(s)
| | - Vatsal Mehra
- Department of Biomedical Sciences, Marquette University, 53201
| | - Zimei Wang
- Department of Biomedical Sciences, Marquette University, 53201
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146
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Anderson MA, O'Shea TM, Burda JE, Ao Y, Barlatey SL, Bernstein AM, Kim JH, James ND, Rogers A, Kato B, Wollenberg AL, Kawaguchi R, Coppola G, Wang C, Deming TJ, He Z, Courtine G, Sofroniew MV. Required growth facilitators propel axon regeneration across complete spinal cord injury. Nature 2018; 561:396-400. [PMID: 30158698 PMCID: PMC6151128 DOI: 10.1038/s41586-018-0467-6] [Citation(s) in RCA: 309] [Impact Index Per Article: 51.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2018] [Accepted: 07/13/2018] [Indexed: 12/17/2022]
Abstract
Transected axons fail to regrow across anatomically complete spinal cord injuries (SCI) in adults. Diverse molecules can partially facilitate or attenuate axon growth during development or after injury1-3, but efficient reversal of this regrowth failure remains elusive4. Here we show that three factors that are essential for axon growth during development but are attenuated or lacking in adults-(i) neuron intrinsic growth capacity2,5-9, (ii) growth-supportive substrate10,11 and (iii) chemoattraction12,13-are all individually required and, in combination, are sufficient to stimulate robust axon regrowth across anatomically complete SCI lesions in adult rodents. We reactivated the growth capacity of mature descending propriospinal neurons with osteopontin, insulin-like growth factor 1 and ciliary-derived neurotrophic factor before SCI14,15; induced growth-supportive substrates with fibroblast growth factor 2 and epidermal growth factor; and chemoattracted propriospinal axons with glial-derived neurotrophic factor16,17 delivered via spatially and temporally controlled release from biomaterial depots18,19, placed sequentially after SCI. We show in both mice and rats that providing these three mechanisms in combination, but not individually, stimulated robust propriospinal axon regrowth through astrocyte scar borders and across lesion cores of non-neural tissue that was over 100-fold greater than controls. Stimulated, supported and chemoattracted propriospinal axons regrew a full spinal segment beyond lesion centres, passed well into spared neural tissue, formed terminal-like contacts exhibiting synaptic markers and conveyed a significant return of electrophysiological conduction capacity across lesions. Thus, overcoming the failure of axon regrowth across anatomically complete SCI lesions after maturity required the combined sequential reinstatement of several developmentally essential mechanisms that facilitate axon growth. These findings identify a mechanism-based biological repair strategy for complete SCI lesions that could be suitable to use with rehabilitation models designed to augment the functional recovery of remodelling circuits.
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Affiliation(s)
- Mark A Anderson
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
- Center for Neuroprosthetics and Brain Mind Institute, School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland
| | - Timothy M O'Shea
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Joshua E Burda
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Yan Ao
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Sabry L Barlatey
- Center for Neuroprosthetics and Brain Mind Institute, School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland
| | - Alexander M Bernstein
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Jae H Kim
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Nicholas D James
- Center for Neuroprosthetics and Brain Mind Institute, School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland
| | - Alexandra Rogers
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Brian Kato
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA
| | - Alexander L Wollenberg
- Departments of Bioengineering, Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, USA
| | - Riki Kawaguchi
- Departments of Psychiatry and Neurology, University of California, Los Angeles, Los Angeles, CA, USA
| | - Giovanni Coppola
- Departments of Psychiatry and Neurology, University of California, Los Angeles, Los Angeles, CA, USA
| | - Chen Wang
- F.M. Kirby Neurobiology Center, Department of Neurology, Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Timothy J Deming
- Departments of Bioengineering, Chemistry and Biochemistry, University of California, Los Angeles, Los Angeles, CA, USA
| | - Zhigang He
- F.M. Kirby Neurobiology Center, Department of Neurology, Children's Hospital, Harvard Medical School, Boston, MA, USA
| | - Gregoire Courtine
- Center for Neuroprosthetics and Brain Mind Institute, School of Life Sciences, Swiss Federal Institute of Technology (EPFL), Lausanne, Switzerland.
| | - Michael V Sofroniew
- Department of Neurobiology, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, CA, USA.
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147
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KLF6 and STAT3 co-occupy regulatory DNA and functionally synergize to promote axon growth in CNS neurons. Sci Rep 2018; 8:12565. [PMID: 30135567 PMCID: PMC6105645 DOI: 10.1038/s41598-018-31101-5] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Accepted: 08/10/2018] [Indexed: 11/26/2022] Open
Abstract
The failure of axon regeneration in the CNS limits recovery from damage and disease. Members of the KLF family of transcription factors can exert both positive and negative effects on axon regeneration, but the underlying mechanisms are unclear. Here we show that forced expression of KLF6 promotes axon regeneration by corticospinal tract neurons in the injured spinal cord. RNA sequencing identified 454 genes whose expression changed upon forced KLF6 expression in vitro, including sub-networks that were highly enriched for functions relevant to axon extension including cytoskeleton remodeling, lipid synthesis, and bioenergetics. In addition, promoter analysis predicted a functional interaction between KLF6 and a second transcription factor, STAT3, and genome-wide footprinting using ATAC-Seq data confirmed frequent co-occupancy. Co-expression of the two factors yielded a synergistic elevation of neurite growth in vitro. These data clarify the transcriptional control of axon growth and point the way toward novel interventions to promote CNS regeneration.
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148
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Danzi MC, Mehta ST, Dulla K, Zunino G, Cooper DJ, Bixby JL, Lemmon VP. The effect of Jun dimerization on neurite outgrowth and motif binding. Mol Cell Neurosci 2018; 92:114-127. [PMID: 30077771 DOI: 10.1016/j.mcn.2018.08.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2017] [Revised: 07/31/2018] [Accepted: 08/01/2018] [Indexed: 12/20/2022] Open
Abstract
Axon regeneration is a necessary step toward functional recovery after spinal cord injury. The AP-1 transcription factor c-Jun has long been known to play an important role in directing the transcriptional response of Dorsal Root Ganglion (DRG) neurons to peripheral axotomy that results in successful axon regeneration. Here we performed ChIPseq for Jun in mouse DRG neurons after a sciatic nerve crush or sham surgery in order to measure the changes in Jun's DNA binding in response to peripheral axotomy. We found that the majority of Jun's injury-responsive changes in DNA binding occur at putative enhancer elements, rather than proximal to transcription start sites. We also used a series of single polypeptide chain tandem transcription factors to test the effects of different Jun-containing dimers on neurite outgrowth in DRG, cortical and hippocampal neurons. These experiments demonstrated that dimers composed of Jun and Atf3 promoted neurite outgrowth in rat CNS neurons as well as mouse DRG neurons. Our work provides new insight into the mechanisms underlying Jun's role in axon regeneration.
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Affiliation(s)
- Matt C Danzi
- Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, USA; Center for Computational Science, University of Miami, Miami, FL, USA; Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Saloni T Mehta
- Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, USA; Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Kireeti Dulla
- Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Giulia Zunino
- Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, USA; Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Daniel J Cooper
- Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, USA; Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, USA
| | - John L Bixby
- Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, USA; Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, USA; Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL, USA.
| | - Vance P Lemmon
- Miami Project to Cure Paralysis, University of Miami Miller School of Medicine, Miami, FL, USA; Center for Computational Science, University of Miami, Miami, FL, USA; Department of Neurological Surgery, University of Miami Miller School of Medicine, Miami, FL, USA.
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149
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Palmisano I, Di Giovanni S. Advances and Limitations of Current Epigenetic Studies Investigating Mammalian Axonal Regeneration. Neurotherapeutics 2018; 15:529-540. [PMID: 29948919 PMCID: PMC6095777 DOI: 10.1007/s13311-018-0636-1] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Axonal regeneration relies on the expression of regenerative associated genes within a coordinated transcriptional programme, which is finely tuned as a result of the activation of several regenerative signalling pathways. In mammals, this chain of events occurs in neurons following peripheral axonal injury, however it fails upon axonal injury in the central nervous system, such as in the spinal cord and the brain. Accumulating evidence has been suggesting that epigenetic control is a key factor to initiate and sustain the regenerative transcriptional response and that it might contribute to regenerative success versus failure. This review will discuss experimental evidence so far showing a role for epigenetic regulation in models of peripheral and central nervous system axonal injury. It will also propose future directions to fill key knowledge gaps and to test whether epigenetic control might indeed discriminate between regenerative success and failure.
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Affiliation(s)
- Ilaria Palmisano
- Laboratory for Neuroregeneration, Centre for Restorative Neuroscience, Division of Brain Sciences, Department of Medicine, Imperial College London, London, UK.
| | - Simone Di Giovanni
- Laboratory for Neuroregeneration, Centre for Restorative Neuroscience, Division of Brain Sciences, Department of Medicine, Imperial College London, London, UK.
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150
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Weyn-Vanhentenryck SM, Feng H, Ustianenko D, Duffié R, Yan Q, Jacko M, Martinez JC, Goodwin M, Zhang X, Hengst U, Lomvardas S, Swanson MS, Zhang C. Precise temporal regulation of alternative splicing during neural development. Nat Commun 2018; 9:2189. [PMID: 29875359 PMCID: PMC5989265 DOI: 10.1038/s41467-018-04559-0] [Citation(s) in RCA: 127] [Impact Index Per Article: 21.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2018] [Accepted: 05/09/2018] [Indexed: 12/13/2022] Open
Abstract
Alternative splicing (AS) is one crucial step of gene expression that must be tightly regulated during neurodevelopment. However, the precise timing of developmental splicing switches and the underlying regulatory mechanisms are poorly understood. Here we systematically analyze the temporal regulation of AS in a large number of transcriptome profiles of developing mouse cortices, in vivo purified neuronal subtypes, and neurons differentiated in vitro. Our analysis reveals early-switch and late-switch exons in genes with distinct functions, and these switches accurately define neuronal maturation stages. Integrative modeling suggests that these switches are under direct and combinatorial regulation by distinct sets of neuronal RNA-binding proteins including Nova, Rbfox, Mbnl, and Ptbp. Surprisingly, various neuronal subtypes in the sensory systems lack Nova and/or Rbfox expression. These neurons retain the "immature" splicing program in early-switch exons, affecting numerous synaptic genes. These results provide new insights into the organization and regulation of the neurodevelopmental transcriptome.
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Affiliation(s)
- Sebastien M Weyn-Vanhentenryck
- Department of Systems Biology, Department of Biochemistry and Molecular Biophysics, Center for Motor Neuron Biology and Disease, Columbia University, New York, NY, 10032, USA
| | - Huijuan Feng
- Department of Systems Biology, Department of Biochemistry and Molecular Biophysics, Center for Motor Neuron Biology and Disease, Columbia University, New York, NY, 10032, USA
- Department of Automation, MOE Key Laboratory of Bioinformatics and Bioinformatics Division, TNLIST, Tsinghua University, Beijing, 100084, China
| | - Dmytro Ustianenko
- Department of Systems Biology, Department of Biochemistry and Molecular Biophysics, Center for Motor Neuron Biology and Disease, Columbia University, New York, NY, 10032, USA
| | - Rachel Duffié
- Department of Biochemistry and Molecular Biophysics, Mortimer B. Zuckerman Mind Brain and Behavior Institute, Columbia University, New York, NY, 10027, USA
| | - Qinghong Yan
- Department of Systems Biology, Department of Biochemistry and Molecular Biophysics, Center for Motor Neuron Biology and Disease, Columbia University, New York, NY, 10032, USA
- Department of Comparative Biology and Safety Sciences, Amgen Inc., Cambridge, MA, 02141, USA
| | - Martin Jacko
- Department of Systems Biology, Department of Biochemistry and Molecular Biophysics, Center for Motor Neuron Biology and Disease, Columbia University, New York, NY, 10032, USA
| | - Jose C Martinez
- Department of Pathology and Cell Biology, The Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, 10032, USA
| | - Marianne Goodwin
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, FL, 32610, USA
| | - Xuegong Zhang
- Department of Automation, MOE Key Laboratory of Bioinformatics and Bioinformatics Division, TNLIST, Tsinghua University, Beijing, 100084, China
| | - Ulrich Hengst
- Department of Pathology and Cell Biology, The Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, 10032, USA
| | - Stavros Lomvardas
- Department of Biochemistry and Molecular Biophysics, Mortimer B. Zuckerman Mind Brain and Behavior Institute, Columbia University, New York, NY, 10027, USA
| | - Maurice S Swanson
- Department of Molecular Genetics and Microbiology, Center for NeuroGenetics and the Genetics Institute, University of Florida, College of Medicine, Gainesville, FL, 32610, USA
| | - Chaolin Zhang
- Department of Systems Biology, Department of Biochemistry and Molecular Biophysics, Center for Motor Neuron Biology and Disease, Columbia University, New York, NY, 10032, USA.
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