1
|
Simons M, Gibson EM, Nave KA. Oligodendrocytes: Myelination, Plasticity, and Axonal Support. Cold Spring Harb Perspect Biol 2024; 16:a041359. [PMID: 38621824 PMCID: PMC11444305 DOI: 10.1101/cshperspect.a041359] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/17/2024]
Abstract
The myelination of axons has evolved to enable fast and efficient transduction of electrical signals in the vertebrate nervous system. Acting as an electric insulator, the myelin sheath is a multilamellar membrane structure around axonal segments generated by the spiral wrapping and subsequent compaction of oligodendroglial plasma membranes. These oligodendrocytes are metabolically active and remain functionally connected to the subjacent axon via cytoplasmic-rich myelinic channels for movement of metabolites and macromolecules to and from the internodal periaxonal space under the myelin sheath. Increasing evidence indicates that oligodendrocyte numbers, specifically in the forebrain, and myelin as a dynamic cellular compartment can both respond to physiological demands, collectively referred to as adaptive myelination. This review summarizes our current understanding of how myelin is generated, how its function is dynamically regulated, and how oligodendrocytes support the long-term integrity of myelinated axons.
Collapse
Affiliation(s)
- Mikael Simons
- Institute of Neuronal Cell Biology, Technical University Munich, Munich 80802, Germany
- German Center for Neurodegenerative Diseases, Munich Cluster of Systems Neurology (SyNergy), Institute for Stroke and Dementia Research, Munich 81377, Germany
| | - Erin M Gibson
- Department of Psychiatry and Behavioral Sciences, Stanford University School of Medicine, Stanford 94305, California, USA
| | - Klaus-Armin Nave
- Department of Neurogenetics, Max Planck Institute for Multidisciplinary Sciences, Göttingen 37075, Germany
| |
Collapse
|
2
|
Curran BM, Nickerson KR, Yung AR, Goodrich LV, Jaworski A, Tessier-Lavigne M, Ma L. Multiple guidance mechanisms control axon growth to generate precise T-shaped bifurcation during dorsal funiculus development in the spinal cord. eLife 2024; 13:RP94109. [PMID: 39159057 PMCID: PMC11333043 DOI: 10.7554/elife.94109] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 08/21/2024] Open
Abstract
The dorsal funiculus in the spinal cord relays somatosensory information to the brain. It is made of T-shaped bifurcation of dorsal root ganglion (DRG) sensory axons. Our previous study has shown that Slit signaling is required for proper guidance during bifurcation, but loss of Slit does not affect all DRG axons. Here, we examined the role of the extracellular molecule Netrin-1 (Ntn1). Using wholemount staining with tissue clearing, we showed that mice lacking Ntn1 had axons escaping from the dorsal funiculus at the time of bifurcation. Genetic labeling confirmed that these misprojecting axons come from DRG neurons. Single axon analysis showed that loss of Ntn1 did not affect bifurcation but rather altered turning angles. To distinguish their guidance functions, we examined mice with triple deletion of Ntn1, Slit1, and Slit2 and found a completely disorganized dorsal funiculus. Comparing mice with different genotypes using immunolabeling and single axon tracing revealed additive guidance errors, demonstrating the independent roles of Ntn1 and Slit. Moreover, the same defects were observed in embryos lacking their cognate receptors. These in vivo studies thus demonstrate the presence of multi-factorial guidance mechanisms that ensure proper formation of a common branched axonal structure during spinal cord development.
Collapse
Affiliation(s)
- Bridget M Curran
- Department of Neuroscience, Jefferson Synaptic Biology Center, Vickie and Jack Farber, Institute for Neuroscience, Sydney Kimmel Medical College, Thomas Jefferson UniversityPhiladelphiaUnited States
| | - Kelsey R Nickerson
- Department of Neuroscience, Brown UniversityProvidenceUnited States
- Robert J. and Nancy D. Carney Institute for Brain ScienceProvidenceUnited States
| | - Andrea R Yung
- Department of Neurobiology, Harvard Medical SchoolBostonUnited States
| | - Lisa V Goodrich
- Department of Neurobiology, Harvard Medical SchoolBostonUnited States
| | - Alexander Jaworski
- Department of Neuroscience, Brown UniversityProvidenceUnited States
- Robert J. and Nancy D. Carney Institute for Brain ScienceProvidenceUnited States
| | | | - Le Ma
- Department of Neuroscience, Jefferson Synaptic Biology Center, Vickie and Jack Farber, Institute for Neuroscience, Sydney Kimmel Medical College, Thomas Jefferson UniversityPhiladelphiaUnited States
| |
Collapse
|
3
|
Zehtabian A, Fuchs J, Eickholt BJ, Ewers H. Automated Analysis of Neuronal Morphology in 2D Fluorescence Micrographs through an Unsupervised Semantic Segmentation of Neurons. Neuroscience 2024; 551:333-344. [PMID: 38838980 DOI: 10.1016/j.neuroscience.2024.05.024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 05/17/2024] [Accepted: 05/20/2024] [Indexed: 06/07/2024]
Abstract
Brain function emerges from a highly complex network of specialized cells that are interlinked by billions of synapses. The synaptic connectivity between neurons is established between the elongated processes of their axons and dendrites or, together, neurites. To establish these connections, cellular neurites have to grow in highly specialized, cell-type dependent patterns covering extensive distances and connecting with thousands of other neurons. The outgrowth and branching of neurites are tightly controlled during development and are a commonly used functional readout of imaging in the neurosciences. Manual analysis of neuronal morphology from microscopy images, however, is very time intensive and prone to bias. Most automated analyses of neurons rely on reconstruction of the neuron as a whole without a semantic analysis of each neurite. A fully-automated classification of all neurites still remains unavailable in open-source software. Here we present a standalone, GUI-based software for batch-quantification of neuronal morphology in two-dimensional fluorescence micrographs of cultured neurons with minimal requirements for user interaction. Single neurons are first reconstructed into binarized images using a Hessian-based segmentation algorithm to detect thin neurite structures combined with intensity- and shape-based reconstruction of the cell body. Neurites are then classified into axon, dendrites and their branches of increasing order using a geodesic distance transform of the cell skeleton. The software was benchmarked against a published dataset and reproduced the phenotype observed after manual annotation. Our tool promises accelerated and improved morphometric studies of neuronal morphology by allowing for consistent and automated analysis of large datasets.
Collapse
Affiliation(s)
- Amin Zehtabian
- Institute for Chemistry and Biochemistry, Freie Universität Berlin, Thielallee 63, 14195 Berlin, Germany.
| | - Joachim Fuchs
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Molecular Biology and Biochemistry, Virchowweg 6, 10117 Berlin, Germany
| | - Britta J Eickholt
- Charité - Universitätsmedizin Berlin, Corporate Member of Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Institute of Molecular Biology and Biochemistry, Virchowweg 6, 10117 Berlin, Germany
| | - Helge Ewers
- Institute for Chemistry and Biochemistry, Freie Universität Berlin, Thielallee 63, 14195 Berlin, Germany
| |
Collapse
|
4
|
Bjorklund GR, Rees KP, Balasubramanian K, Hewitt LT, Nishimura K, Newbern JM. Hyperactivation of MEK1 in cortical glutamatergic neurons results in projection axon deficits and aberrant motor learning. Dis Model Mech 2024; 17:dmm050570. [PMID: 38826084 PMCID: PMC11247507 DOI: 10.1242/dmm.050570] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2023] [Accepted: 05/21/2024] [Indexed: 06/04/2024] Open
Abstract
Abnormal extracellular signal-regulated kinase 1/2 (ERK1/2, encoded by Mapk3 and Mapk1, respectively) signaling is linked to multiple neurodevelopmental diseases, especially the RASopathies, which typically exhibit ERK1/2 hyperactivation in neurons and non-neuronal cells. To better understand how excitatory neuron-autonomous ERK1/2 activity regulates forebrain development, we conditionally expressed a hyperactive MEK1 (MAP2K1) mutant, MEK1S217/221E, in cortical excitatory neurons of mice. MEK1S217/221E expression led to persistent hyperactivation of ERK1/2 in cortical axons, but not in soma/nuclei. We noted reduced axonal arborization in multiple target domains in mutant mice and reduced the levels of the activity-dependent protein ARC. These changes did not lead to deficits in voluntary locomotion or accelerating rotarod performance. However, skilled motor learning in a single-pellet retrieval task was significantly diminished in these MEK1S217/221E mutants. Restriction of MEK1S217/221E expression to layer V cortical neurons recapitulated axonal outgrowth deficits but did not affect motor learning. These results suggest that cortical excitatory neuron-autonomous hyperactivation of MEK1 is sufficient to drive deficits in axon outgrowth, which coincide with reduced ARC expression, and deficits in skilled motor learning. Our data indicate that neuron-autonomous decreases in long-range axonal outgrowth may be a key aspect of neuropathogenesis in RASopathies.
Collapse
Affiliation(s)
- George R. Bjorklund
- School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA
- School of Biological and Health Systems Engineering, Arizona State University, Tempe, AZ 85287, USA
| | - Katherina P. Rees
- School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA
| | | | - Lauren T. Hewitt
- School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA
| | - Kenji Nishimura
- School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA
| | - Jason M. Newbern
- School of Life Sciences, Arizona State University, Tempe, AZ 85287, USA
| |
Collapse
|
5
|
Cada AK, Mizuno N. Molecular cartography within axons. Curr Opin Cell Biol 2024; 88:102358. [PMID: 38608424 DOI: 10.1016/j.ceb.2024.102358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 03/22/2024] [Accepted: 03/24/2024] [Indexed: 04/14/2024]
Abstract
Recent advances in imaging methods begin to further illuminate the inner workings of neurons. Views of the axonal landscape through the lens of in situ cryo-electron tomography (cryo-ET) provide a high-resolution atlas of the macromolecular organization in near-native conditions, leading to our growing understanding of the vital roles of compositional and structural organization in maintaining neuronal homeostasis. In this review, we discuss the latest observations concerning the fundamental components found within neuronal compartments, with special emphasis on the axon, branch points, and growth cone. We describe the similarity and difference in organization of organelles and molecules in varying compartments. Finally, we highlight outstanding questions on the dynamics and localization of various components along the axon that may be answered using orthogonal approaches.
Collapse
Affiliation(s)
- A King Cada
- Laboratory of Structural Cell Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, 50 South Drive, Bethesda, MD, 20892, USA
| | - Naoko Mizuno
- Laboratory of Structural Cell Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, 50 South Drive, Bethesda, MD, 20892, USA; National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, 50 South Drive, Bethesda, MD, 20892, USA.
| |
Collapse
|
6
|
Le Dréan ME, Le Berre-Scoul C, Paillé V, Caillaud M, Oullier T, Gonzales J, Hulin P, Neunlist M, Talon S, Boudin H. The regulation of enteric neuron connectivity by semaphorin 5A is affected by the autism-associated S956G missense mutation. iScience 2024; 27:109638. [PMID: 38650986 PMCID: PMC11033180 DOI: 10.1016/j.isci.2024.109638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2023] [Revised: 02/29/2024] [Accepted: 03/26/2024] [Indexed: 04/25/2024] Open
Abstract
The neural network of the enteric nervous system (ENS) underlies gastrointestinal functions. However, the molecular mechanisms involved in enteric neuronal connectivity are poorly characterized. Here, we studied the role of semaphorin 5A (Sema5A), previously characterized in the central nervous system, on ENS neuronal connectivity. Sema5A is linked to autism spectrum disorder (ASD), a neurodevelopmental disorder frequently associated with gastrointestinal comorbidities, and potentially associated with ENS impairments. This study investigated in rat enteric neuron cultures and gut explants the role of Sema5A on enteric neuron connectivity and the impact of ASD-associated mutations on Sema5A activity. Our findings demonstrated that Sema5A promoted axonal complexity and reduced functional connectivity in enteric neurons. Strikingly, the ASD-associated mutation S956G in Sema5A strongly affected these activities. This study identifies a critical role of Sema5A in the ENS as a regulator of neuronal connectivity that might be compromised in ASD.
Collapse
Affiliation(s)
- Morgane E. Le Dréan
- Nantes Université, Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Nantes, France
| | - Catherine Le Berre-Scoul
- Nantes Université, Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Nantes, France
| | - Vincent Paillé
- Nantes Université, INRAE, UMR 1280, PhAN, IMAD, 44000 Nantes, France
| | - Martial Caillaud
- Nantes Université, Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Nantes, France
| | - Thibauld Oullier
- Nantes Université, Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Nantes, France
| | - Jacques Gonzales
- Nantes Université, Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Nantes, France
| | - Philippe Hulin
- Plateforme MicroPICell Nantes Université, CHU Nantes, CNRS, INSERM, BioCore, US16, SFR Bonamy, Nantes, France
| | - Michel Neunlist
- Nantes Université, Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Nantes, France
| | - Sophie Talon
- Nantes Université, Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Nantes, France
| | - Hélène Boudin
- Nantes Université, Inserm, TENS, The Enteric Nervous System in Gut and Brain Diseases, IMAD, Nantes, France
| |
Collapse
|
7
|
Sutton N, Gutiérrez-Guzmán B, Dannenberg H, Ascoli GA. A Continuous Attractor Model with Realistic Neural and Synaptic Properties Quantitatively Reproduces Grid Cell Physiology. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.04.29.591748. [PMID: 38746202 PMCID: PMC11092518 DOI: 10.1101/2024.04.29.591748] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2024]
Abstract
Computational simulations with data-driven physiological detail can foster a deeper understanding of the neural mechanisms involved in cognition. Here, we utilize the wealth of cellular properties from Hippocampome.org to study neural mechanisms of spatial coding with a spiking continuous attractor network model of medial entorhinal cortex circuit activity. The primary goal was to investigate if adding such realistic constraints could produce firing patterns similar to those measured in real neurons. Biological characteristics included in the work are excitability, connectivity, and synaptic signaling of neuron types defined primarily by their axonal and dendritic morphologies. We investigate the spiking dynamics in specific neuron types and the synaptic activities between groups of neurons. Modeling the rodent hippocampal formation keeps the simulations to a computationally reasonable scale while also anchoring the parameters and results to experimental measurements. Our model generates grid cell activity that well matches the spacing, size, and firing rates of grid fields recorded in live behaving animals from both published datasets and new experiments performed for this study. Our simulations also recreate different scales of those properties, e.g., small and large, as found along the dorsoventral axis of the medial entorhinal cortex. Computational exploration of neuronal and synaptic model parameters reveals that a broad range of neural properties produce grid fields in the simulation. These results demonstrate that the continuous attractor network model of grid cells is compatible with a spiking neural network implementation sourcing data-driven biophysical and anatomical parameters from Hippocampome.org. The software is released as open source to enable broad community reuse and encourage novel applications.
Collapse
Affiliation(s)
- Nate Sutton
- Bioengineering Department, at George Mason University
| | | | - Holger Dannenberg
- Bioengineering Department, at George Mason University
- Interdisciplinary Program in Neuroscience at George Mason University
| | - Giorgio A. Ascoli
- Bioengineering Department, at George Mason University
- Interdisciplinary Program in Neuroscience at George Mason University
| |
Collapse
|
8
|
Curran BM, Nickerson KR, Yung AR, Goodrich LV, Jaworski A, Tessier-Lavigne M, Ma L. Multiple Guidance Mechanisms Control Axon Growth to Generate Precise T-shaped Bifurcation during Dorsal Funiculus Development in the Spinal Cord. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.11.17.567638. [PMID: 38014092 PMCID: PMC10680847 DOI: 10.1101/2023.11.17.567638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
The dorsal funiculus in the spinal cord relays somatosensory information to the brain. It is made of T-shaped bifurcation of dorsal root ganglion (DRG) sensory axons. Our previous study has shown that Slit signaling is required for proper guidance during bifurcation, but loss of Slit does not affect all DRG axons. Here, we examined the role of the extracellular molecule Netrin-1 (Ntn1). Using wholemount staining with tissue clearing, we showed that mice lacking Ntn1 have axons escaping from the dorsal funiculus at the time of bifurcation. Genetic labeling confirmed that these misprojecting axons come from DRG neurons. Single axon analysis showed that loss of Ntn1 does not affect bifurcation but rather alters turning angles. To distinguish their guidance functions, we examined mice with triple deletion of Ntn1, Slit1, and Slit2 and found a completely disorganized dorsal funiculus. Comparing mice with different genotypes using immunolabeling and single axon tracing revealed additive guidance errors, demonstrating the independent roles of Ntn1 and Slit. Moreover, the same defects were observed in embryos lacking their cognate receptors. These in vivo studies thus demonstrate the presence of multi-factorial guidance mechanisms that ensure proper formation of a common branched axonal structure during spinal cord development.
Collapse
Affiliation(s)
- Bridget M Curran
- Department of Neuroscience, Jefferson Synaptic Biology Center, Vickie and Jack Farber Institute for Neuroscience, Sydney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107
| | - Kelsey R Nickerson
- Department of Neuroscience, Brown University, Providence, RI 02912
- Robert J. and Nancy D. Carney Institute for Brain Science, Providence, RI 02912
| | - Andrea R Yung
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115
| | - Lisa V Goodrich
- Department of Neurobiology, Harvard Medical School, Boston, MA 02115
| | - Alexander Jaworski
- Department of Neuroscience, Brown University, Providence, RI 02912
- Robert J. and Nancy D. Carney Institute for Brain Science, Providence, RI 02912
| | | | - 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 19107
| |
Collapse
|
9
|
Vecchi JT, Rhomberg M, Guymon CA, Hansen MR. The geometry of photopolymerized topography influences neurite pathfinding by directing growth cone morphology and migration. J Neural Eng 2024; 21:026027. [PMID: 38547528 PMCID: PMC10993768 DOI: 10.1088/1741-2552/ad38dc] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2023] [Revised: 03/15/2024] [Accepted: 03/28/2024] [Indexed: 04/05/2024]
Abstract
Objective. Cochlear implants provide auditory perception to those with severe to profound sensorineural hearing loss: however, the quality of sound perceived by users does not approximate natural hearing. This limitation is due in part to the large physical gap between the stimulating electrodes and their target neurons. Therefore, directing the controlled outgrowth of processes from spiral ganglion neurons (SGNs) into close proximity to the electrode array could provide significantly increased hearing function.Approach.For this objective to be properly designed and implemented, the ability and limits of SGN neurites to be guided must first be determined. In this work, we engineer precise topographical microfeatures with angle turn challenges of various geometries to study SGN pathfinding and use live imaging to better understand how neurite growth is guided by these cues.Main Results.We find that the geometry of the angled microfeatures determines the ability of neurites to navigate the angled microfeature turns. SGN neurite pathfinding fidelity is increased by 20%-70% through minor increases in microfeature amplitude (depth) and by 25% if the angle of the patterned turn is made obtuse. Further, we see that dorsal root ganglion neuron growth cones change their morphology and migration to become more elongated within microfeatures. Our observations also indicate complexities in studying neurite turning. First, as the growth cone pathfinds in response to the various cues, the associated neurite often reorients across the angle topographical microfeatures. Additionally, neurite branching is observed in response to topographical guidance cues, most frequently when turning decisions are most uncertain.Significance.Overall, the multi-angle channel micropatterned substrate is a versatile and efficient system to assess neurite turning and pathfinding in response to topographical cues. These findings represent fundamental principles of neurite pathfinding that will be essential to consider for the design of 3D systems aiming to guide neurite growthin vivo.
Collapse
Affiliation(s)
- Joseph T Vecchi
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA, United States of America
- Department of Otolaryngology Head-Neck Surgery, University of Iowa, Iowa City, IA, United States of America
| | - Madeline Rhomberg
- Department of Otolaryngology Head-Neck Surgery, University of Iowa, Iowa City, IA, United States of America
| | - C Allan Guymon
- Department of Chemical and Biochemical Engineering, University of Iowa, Iowa City, IA, United States of America
| | - Marlan R Hansen
- Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA, United States of America
- Department of Otolaryngology Head-Neck Surgery, University of Iowa, Iowa City, IA, United States of America
| |
Collapse
|
10
|
Ziak J, Dorskind JM, Trigg B, Sudarsanam S, Jin XO, Hand RA, Kolodkin AL. Microtubule-binding protein MAP1B regulates interstitial axon branching of cortical neurons via the tubulin tyrosination cycle. EMBO J 2024; 43:1214-1243. [PMID: 38388748 PMCID: PMC10987652 DOI: 10.1038/s44318-024-00050-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 01/24/2024] [Accepted: 01/25/2024] [Indexed: 02/24/2024] Open
Abstract
Regulation of directed axon guidance and branching during development is essential for the generation of neuronal networks. However, the molecular mechanisms that underlie interstitial (or collateral) axon branching in the mammalian brain remain unresolved. Here, we investigate interstitial axon branching in vivo using an approach for precise labeling of layer 2/3 callosal projection neurons (CPNs). This method allows for quantitative analysis of axonal morphology at high acuity and also manipulation of gene expression in well-defined temporal windows. We find that the GSK3β serine/threonine kinase promotes interstitial axon branching in layer 2/3 CPNs by releasing MAP1B-mediated inhibition of axon branching. Further, we find that the tubulin tyrosination cycle is a key downstream component of GSK3β/MAP1B signaling. These data suggest a cell-autonomous molecular regulation of cortical neuron axon morphology, in which GSK3β can release a MAP1B-mediated brake on interstitial axon branching upstream of the posttranslational tubulin code.
Collapse
Affiliation(s)
- Jakub Ziak
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins Kavli Neuroscience Discovery Institute, The Johns Hopkins School of Medicine, 725 North Wolfe St., Baltimore, MD, 21205, USA
| | - Joelle M Dorskind
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins Kavli Neuroscience Discovery Institute, The Johns Hopkins School of Medicine, 725 North Wolfe St., Baltimore, MD, 21205, USA
- Novartis Institutes for BioMedical Research, Boston, MA, USA
| | - Brian Trigg
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins Kavli Neuroscience Discovery Institute, The Johns Hopkins School of Medicine, 725 North Wolfe St., Baltimore, MD, 21205, USA
| | - Sriram Sudarsanam
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins Kavli Neuroscience Discovery Institute, The Johns Hopkins School of Medicine, 725 North Wolfe St., Baltimore, MD, 21205, USA
| | - Xinyu O Jin
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins Kavli Neuroscience Discovery Institute, The Johns Hopkins School of Medicine, 725 North Wolfe St., Baltimore, MD, 21205, USA
| | - Randal A Hand
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins Kavli Neuroscience Discovery Institute, The Johns Hopkins School of Medicine, 725 North Wolfe St., Baltimore, MD, 21205, USA
- Prilenia Therapeutics, Boston, MA, USA
| | - Alex L Kolodkin
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins Kavli Neuroscience Discovery Institute, The Johns Hopkins School of Medicine, 725 North Wolfe St., Baltimore, MD, 21205, USA.
| |
Collapse
|
11
|
Lanfranchi M, Yandiev S, Meyer-Dilhet G, Ellouze S, Kerkhofs M, Dos Reis R, Garcia A, Blondet C, Amar A, Kneppers A, Polvèche H, Plassard D, Foretz M, Viollet B, Sakamoto K, Mounier R, Bourgeois CF, Raineteau O, Goillot E, Courchet J. The AMPK-related kinase NUAK1 controls cortical axons branching by locally modulating mitochondrial metabolic functions. Nat Commun 2024; 15:2487. [PMID: 38514619 PMCID: PMC10958033 DOI: 10.1038/s41467-024-46146-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2023] [Accepted: 02/15/2024] [Indexed: 03/23/2024] Open
Abstract
The cellular mechanisms underlying axonal morphogenesis are essential to the formation of functional neuronal networks. We previously identified the autism-linked kinase NUAK1 as a central regulator of axon branching through the control of mitochondria trafficking. However, (1) the relationship between mitochondrial position, function and axon branching and (2) the downstream effectors whereby NUAK1 regulates axon branching remain unknown. Here, we report that mitochondria recruitment to synaptic boutons supports collateral branches stabilization rather than formation in mouse cortical neurons. NUAK1 deficiency significantly impairs mitochondrial metabolism and axonal ATP concentration, and upregulation of mitochondrial function is sufficient to rescue axonal branching in NUAK1 null neurons in vitro and in vivo. Finally, we found that NUAK1 regulates axon branching through the mitochondria-targeted microprotein BRAWNIN. Our results demonstrate that NUAK1 exerts a dual function during axon branching through its ability to control mitochondrial distribution and metabolic activity.
Collapse
Affiliation(s)
- Marine Lanfranchi
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Inserm, Physiopathologie et Génétique du Neurone et du Muscle, UMR5261, U1315, Institut NeuroMyoGène, 69008, Lyon, France
| | - Sozerko Yandiev
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Inserm, Physiopathologie et Génétique du Neurone et du Muscle, UMR5261, U1315, Institut NeuroMyoGène, 69008, Lyon, France
| | - Géraldine Meyer-Dilhet
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Inserm, Physiopathologie et Génétique du Neurone et du Muscle, UMR5261, U1315, Institut NeuroMyoGène, 69008, Lyon, France
| | - Salma Ellouze
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Inserm, Physiopathologie et Génétique du Neurone et du Muscle, UMR5261, U1315, Institut NeuroMyoGène, 69008, Lyon, France
- Univ Lyon, Université Claude Bernard Lyon 1, Inserm, Stem Cell and Brain Research Institute U1208, 69500, Bron, France
| | - Martijn Kerkhofs
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Inserm, Physiopathologie et Génétique du Neurone et du Muscle, UMR5261, U1315, Institut NeuroMyoGène, 69008, Lyon, France
| | - Raphael Dos Reis
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Inserm, Physiopathologie et Génétique du Neurone et du Muscle, UMR5261, U1315, Institut NeuroMyoGène, 69008, Lyon, France
| | - Audrey Garcia
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Inserm, Physiopathologie et Génétique du Neurone et du Muscle, UMR5261, U1315, Institut NeuroMyoGène, 69008, Lyon, France
| | - Camille Blondet
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Inserm, Physiopathologie et Génétique du Neurone et du Muscle, UMR5261, U1315, Institut NeuroMyoGène, 69008, Lyon, France
| | - Alizée Amar
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Inserm, Physiopathologie et Génétique du Neurone et du Muscle, UMR5261, U1315, Institut NeuroMyoGène, 69008, Lyon, France
| | - Anita Kneppers
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Inserm, Physiopathologie et Génétique du Neurone et du Muscle, UMR5261, U1315, Institut NeuroMyoGène, 69008, Lyon, France
| | - Hélène Polvèche
- Laboratoire de Biologie et Modelisation de la Cellule, Ecole Normale Superieure de Lyon, CNRS, UMR 5239, Inserm, U1293, Universite Claude Bernard Lyon 1, 46 allée d'Italie F-69364, Lyon, France
- CECS/AFM, I-STEM, 28 rue Henri Desbruères, F-91100, Corbeil-Essonnes, France
| | - Damien Plassard
- CNRS UMR 7104, INSERM U1258, GenomEast Platform, Institut de Génétique et de Biologie Moléculaire et Cellulaire (IGBMC), Université de Strasbourg, Illkirch, France
| | - Marc Foretz
- Université Paris Cité, CNRS, Inserm, Institut Cochin, Paris, France
| | - Benoit Viollet
- Université Paris Cité, CNRS, Inserm, Institut Cochin, Paris, France
| | - Kei Sakamoto
- Novo Nordisk Foundation Center for Basic Metabolic Research, University of Copenhagen, Copenhagen, 2200, Denmark
| | - Rémi Mounier
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Inserm, Physiopathologie et Génétique du Neurone et du Muscle, UMR5261, U1315, Institut NeuroMyoGène, 69008, Lyon, France
| | - Cyril F Bourgeois
- Laboratoire de Biologie et Modelisation de la Cellule, Ecole Normale Superieure de Lyon, CNRS, UMR 5239, Inserm, U1293, Universite Claude Bernard Lyon 1, 46 allée d'Italie F-69364, Lyon, France
| | - Olivier Raineteau
- Univ Lyon, Université Claude Bernard Lyon 1, Inserm, Stem Cell and Brain Research Institute U1208, 69500, Bron, France
| | - Evelyne Goillot
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Inserm, Physiopathologie et Génétique du Neurone et du Muscle, UMR5261, U1315, Institut NeuroMyoGène, 69008, Lyon, France
| | - Julien Courchet
- Univ Lyon, Université Claude Bernard Lyon 1, CNRS, Inserm, Physiopathologie et Génétique du Neurone et du Muscle, UMR5261, U1315, Institut NeuroMyoGène, 69008, Lyon, France.
| |
Collapse
|
12
|
Gao J, Xu Y, Li Y, Lu F, Wang Z. Comprehensive exploration of multi-modal and multi-branch imaging markers for autism diagnosis and interpretation: insights from an advanced deep learning model. Cereb Cortex 2024; 34:bhad521. [PMID: 38220572 DOI: 10.1093/cercor/bhad521] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2023] [Revised: 12/11/2023] [Accepted: 12/12/2023] [Indexed: 01/16/2024] Open
Abstract
Autism spectrum disorder is a complex neurodevelopmental condition with diverse genetic and brain involvement. Despite magnetic resonance imaging advances, autism spectrum disorder diagnosis and understanding its neurogenetic factors remain challenging. We propose a dual-branch graph neural network that effectively extracts and fuses features from bimodalities, achieving 73.9% diagnostic accuracy. To explain the mechanism distinguishing autism spectrum disorder from healthy controls, we establish a perturbation model for brain imaging markers and perform a neuro-transcriptomic joint analysis using partial least squares regression and enrichment to identify potential genetic biomarkers. The perturbation model identifies brain imaging markers related to structural magnetic resonance imaging in the frontal, temporal, parietal, and occipital lobes, while functional magnetic resonance imaging markers primarily reside in the frontal, temporal, occipital lobes, and cerebellum. The neuro-transcriptomic joint analysis highlights genes associated with biological processes, such as "presynapse," "behavior," and "modulation of chemical synaptic transmission" in autism spectrum disorder's brain development. Different magnetic resonance imaging modalities offer complementary information for autism spectrum disorder diagnosis. Our dual-branch graph neural network achieves high accuracy and identifies abnormal brain regions and the neuro-transcriptomic analysis uncovers important genetic biomarkers. Overall, our study presents an effective approach for assisting in autism spectrum disorder diagnosis and identifying genetic biomarkers, showing potential for enhancing the diagnosis and treatment of this condition.
Collapse
Affiliation(s)
- Jingjing Gao
- School of Information and Communication Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Yuhang Xu
- School of Information and Communication Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Yanling Li
- School of Electrical Engineering and Electronic Information, Xihua University, Chengdu 610039, China
| | - Fengmei Lu
- The Clinical Hospital of Chengdu Brain Science Institute, MOE Key Lab for Neuroinformation, School of Life Science and Technology, University of Electronic Science and Technology of China, Chengdu 611731, China
| | - Zhengning Wang
- School of Information and Communication Engineering, University of Electronic Science and Technology of China, Chengdu 611731, China
| |
Collapse
|
13
|
Liu S, Gao L, Chen J, Yan J. Single-neuron analysis of axon arbors reveals distinct presynaptic organizations between feedforward and feedback projections. Cell Rep 2024; 43:113590. [PMID: 38127620 DOI: 10.1016/j.celrep.2023.113590] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2023] [Revised: 07/18/2023] [Accepted: 11/30/2023] [Indexed: 12/23/2023] Open
Abstract
The morphology and spatial distribution of axon arbors and boutons are crucial for neuron presynaptic functions. However, the principles governing their whole-brain organization at the single-neuron level remain unclear. We developed a machine-learning method to separate axon arbors from passing axons in single-neuron reconstruction from fluorescence micro-optical sectioning tomography imaging data and obtained 62,374 axon arbors that displayed distinct morphology, spatial patterns, and scaling laws dependent on neuron types and targeted brain areas. Focusing on the axon arbors in the thalamus and cortex, we revealed the segregated spatial distributions and distinct morphology but shared topographic gradients between feedforward and feedback projections. Furthermore, we uncovered an association between arbor complexity and microglia density. Finally, we found that the boutons on terminal arbors show branch-specific clustering with a log-normal distribution that again differed between feedforward and feedback terminal arbors. Together, our study revealed distinct presynaptic structural organizations underlying diverse functional innervation of single projection neurons.
Collapse
Affiliation(s)
- Sang Liu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China; School of Future Technology, University of Chinese Academy of Sciences, Beijing 101408, China
| | - Le Gao
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Jiu Chen
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Jun Yan
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China; School of Future Technology, University of Chinese Academy of Sciences, Beijing 101408, China; Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai 201210, China.
| |
Collapse
|
14
|
Niemsiri V, Rosenthal SB, Nievergelt CM, Maihofer AX, Marchetto MC, Santos R, Shekhtman T, Alliey-Rodriguez N, Anand A, Balaraman Y, Berrettini WH, Bertram H, Burdick KE, Calabrese JR, Calkin CV, Conroy C, Coryell WH, DeModena A, Eyler LT, Feeder S, Fisher C, Frazier N, Frye MA, Gao K, Garnham J, Gershon ES, Goes FS, Goto T, Harrington GJ, Jakobsen P, Kamali M, Kelly M, Leckband SG, Lohoff FW, McCarthy MJ, McInnis MG, Craig D, Millett CE, Mondimore F, Morken G, Nurnberger JI, Donovan CO, Øedegaard KJ, Ryan K, Schinagle M, Shilling PD, Slaney C, Stapp EK, Stautland A, Tarwater B, Zandi PP, Alda M, Fisch KM, Gage FH, Kelsoe JR. Focal adhesion is associated with lithium response in bipolar disorder: evidence from a network-based multi-omics analysis. Mol Psychiatry 2024; 29:6-19. [PMID: 36991131 PMCID: PMC11078741 DOI: 10.1038/s41380-022-01909-9] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/23/2021] [Revised: 11/14/2022] [Accepted: 12/02/2022] [Indexed: 03/31/2023]
Abstract
Lithium (Li) is one of the most effective drugs for treating bipolar disorder (BD), however, there is presently no way to predict response to guide treatment. The aim of this study is to identify functional genes and pathways that distinguish BD Li responders (LR) from BD Li non-responders (NR). An initial Pharmacogenomics of Bipolar Disorder study (PGBD) GWAS of lithium response did not provide any significant results. As a result, we then employed network-based integrative analysis of transcriptomic and genomic data. In transcriptomic study of iPSC-derived neurons, 41 significantly differentially expressed (DE) genes were identified in LR vs NR regardless of lithium exposure. In the PGBD, post-GWAS gene prioritization using the GWA-boosting (GWAB) approach identified 1119 candidate genes. Following DE-derived network propagation, there was a highly significant overlap of genes between the top 500- and top 2000-proximal gene networks and the GWAB gene list (Phypergeometric = 1.28E-09 and 4.10E-18, respectively). Functional enrichment analyses of the top 500 proximal network genes identified focal adhesion and the extracellular matrix (ECM) as the most significant functions. Our findings suggest that the difference between LR and NR was a much greater effect than that of lithium. The direct impact of dysregulation of focal adhesion on axon guidance and neuronal circuits could underpin mechanisms of response to lithium, as well as underlying BD. It also highlights the power of integrative multi-omics analysis of transcriptomic and genomic profiling to gain molecular insights into lithium response in BD.
Collapse
Grants
- R01 MH095741 NIMH NIH HHS
- UL1 TR001442 NCATS NIH HHS
- U19 MH106434 NIMH NIH HHS
- U01 MH092758 NIMH NIH HHS
- T32 MH018399 NIMH NIH HHS
- U.S. Department of Health & Human Services | NIH | National Institute of Mental Health (NIMH)
- Department of Veterans Affairs | Veterans Affairs San Diego Healthcare System (VA San Diego Healthcare System)
- The Halifax group (MA, CVC, JG, CO, and CS) is supported by grants from Canadian Institutes of Health Research (#166098), ERA PerMed project PLOT-BD, Research Nova Scotia, Genome Atlantic, Nova Scotia Health Authority and Dalhousie Medical Research Foundation (Lindsay Family Fund).
- U.S. Department of Health & Human Services | NIH | National Center for Advancing Translational Sciences (NCATS)
- U19MH106434, part of the National Cooperative Reprogrammed Cell Research Groups (NCRCRG) to Study Mental Illness. AHA-Allen Initiative in Brain Health and Cognitive Impairment Award (19PABH134610000). The JPB Foundation, Bob and Mary Jane Engman, Annette C Merle-Smith, R01 MH095741, and Lynn and Edward Streim.
Collapse
Affiliation(s)
- Vipavee Niemsiri
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - Sara Brin Rosenthal
- Center for Computational Biology and Bioinformatics, University of California, San Diego, La Jolla, CA, USA
| | | | - Adam X Maihofer
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - Maria C Marchetto
- Department of Anthropology, University of California, San Diego, La Jolla, CA, USA
- Laboratory of Genetics, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - Renata Santos
- Laboratory of Genetics, Salk Institute for Biological Studies, La Jolla, CA, USA
- University of Paris, Institute of Psychiatry and Neuroscience of Paris (IPNP), INSERM U1261266, Laboratory of Dynamics of Neuronal Structure in Health and Disease, Paris, France
| | - Tatyana Shekhtman
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - Ney Alliey-Rodriguez
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, Chicago, IL, USA
- Department of Psychiatry and Behavioral Neuroscience, Northwestern University, Chicago, IL, USA
| | - Amit Anand
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Department of Psychiatry, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Yokesh Balaraman
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Wade H Berrettini
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, USA
| | - Holli Bertram
- Department of Psychiatry, University of Michigan, Ann Arbor, MI, USA
| | - Katherine E Burdick
- Department of Psychiatry, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Joseph R Calabrese
- Mood Disorders Program, Case Western Reserve University School of Medicine, Cleveland, OH, USA
- Mood Disorders Program, University Hospitals Cleveland Medical Center, Cleveland, OH, USA
| | - Cynthia V Calkin
- Department of Psychiatry and Medical Neuroscience, Dalhousie University, Halifax, NS, Canada
| | - Carla Conroy
- Mood Disorders Program, Case Western Reserve University School of Medicine, Cleveland, OH, USA
- Mood Disorders Program, University Hospitals Cleveland Medical Center, Cleveland, OH, USA
| | | | - Anna DeModena
- Psychiatry Service, VA San Diego Healthcare System, San Diego, CA, USA
| | - Lisa T Eyler
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - Scott Feeder
- Department of Psychiatry, The Mayo Clinic, Rochester, MN, USA
| | - Carrie Fisher
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Nicole Frazier
- Department of Psychiatry, University of Michigan, Ann Arbor, MI, USA
| | - Mark A Frye
- Department of Psychiatry, The Mayo Clinic, Rochester, MN, USA
| | - Keming Gao
- Mood Disorders Program, Case Western Reserve University School of Medicine, Cleveland, OH, USA
- Mood Disorders Program, University Hospitals Cleveland Medical Center, Cleveland, OH, USA
| | - Julie Garnham
- Department of Psychiatry, Dalhousie University, Halifax, NS, Canada
| | - Elliot S Gershon
- Department of Psychiatry and Behavioral Neuroscience, University of Chicago, Chicago, IL, USA
| | - Fernando S Goes
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - Toyomi Goto
- Mood Disorders Program, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | | | - Petter Jakobsen
- Norment, Division of Psychiatry, Haukeland University Hospital and Department of Clinical medicine, University of Bergen, Bergen, Norway
| | - Masoud Kamali
- Department of Psychiatry, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA
- Department of Psychiatry, University of Michigan, Ann Arbor, MI, USA
| | - Marisa Kelly
- Department of Psychiatry, University of Michigan, Ann Arbor, MI, USA
| | - Susan G Leckband
- Psychiatry Service, VA San Diego Healthcare System, San Diego, CA, USA
| | - Falk W Lohoff
- Department of Psychiatry, University of Pennsylvania, Philadelphia, PA, USA
| | - Michael J McCarthy
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - Melvin G McInnis
- Department of Psychiatry, University of Michigan, Ann Arbor, MI, USA
| | - David Craig
- Department of Translational Genomics, University of Southern California, Los Angeles, CA, USA
| | - Caitlin E Millett
- Department of Psychiatry, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA
| | - Francis Mondimore
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - Gunnar Morken
- Division of Mental Health Care, St Olavs University Hospital, and Department of Mental Health, Norwegian University of Science and Technology (NTNU), Trondheim, Norway
| | - John I Nurnberger
- Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA
- Medical and Molecular Genetics, Stark Neurosciences Research Institute, Indiana University School of Medicine, Indianapolis, IN, USA
| | | | - Ketil J Øedegaard
- Norment, Division of Psychiatry, Haukeland University Hospital and Department of Clinical medicine, University of Bergen, Bergen, Norway
| | - Kelly Ryan
- Department of Psychiatry, University of Michigan, Ann Arbor, MI, USA
| | - Martha Schinagle
- Mood Disorders Program, Case Western Reserve University School of Medicine, Cleveland, OH, USA
| | - Paul D Shilling
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA
| | - Claire Slaney
- Department of Psychiatry, Dalhousie University, Halifax, NS, Canada
| | - Emma K Stapp
- Department of Mental Health, Johns Hopkins Bloomberg School of Public Health, Johns Hopkins University, Baltimore, MD, USA
| | - Andrea Stautland
- Department of Clinical Medicine, University of Bergen, Bergen, Norway
| | - Bruce Tarwater
- Department of Psychiatry, University of Iowa, Iowa City, IA, USA
| | - Peter P Zandi
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins University, Baltimore, MD, USA
| | - Martin Alda
- Department of Psychiatry, Dalhousie University, Halifax, NS, Canada
- National Institute of Mental Health, Klecany, Czech Republic
| | - Kathleen M Fisch
- Center for Computational Biology and Bioinformatics, University of California, San Diego, La Jolla, CA, USA
- Department of Obstetrics, Gynecology & Reproductive Sciences, University of California, San Diego, La Jolla, CA, USA
| | - Fred H Gage
- Laboratory of Genetics, Salk Institute for Biological Studies, La Jolla, CA, USA
| | - John R Kelsoe
- Department of Psychiatry, University of California, San Diego, La Jolla, CA, USA.
- Institute for Genomic Medicine, University of California, San Diego, La Jolla, CA, USA.
| |
Collapse
|
15
|
Huang H, Majumder T, Khot B, Suriyaarachchi H, Yang T, Shao Q, Tirukovalluru S, Liu G. The role of microtubule-associated protein tau in netrin-1 attractive signaling. J Cell Sci 2024; 137:jcs261244. [PMID: 38197773 PMCID: PMC10906489 DOI: 10.1242/jcs.261244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/12/2023] [Accepted: 11/24/2023] [Indexed: 01/11/2024] Open
Abstract
Direct binding of netrin receptors with dynamic microtubules (MTs) in the neuronal growth cone plays an important role in netrin-mediated axon guidance. However, how netrin-1 (NTN1) regulates MT dynamics in axon turning remains a major unanswered question. Here, we show that the coupling of netrin-1 receptor DCC with tau (MAPT)-regulated MTs is involved in netrin-1-promoted axon attraction. Tau directly interacts with DCC and partially overlaps with DCC in the growth cone of primary neurons. Netrin-1 induces this interaction and the colocalization of DCC and tau in the growth cone. The netrin-1-induced interaction of tau with DCC relies on MT dynamics and TUBB3, a highly dynamic β-tubulin isotype in developing neurons. Netrin-1 increased cosedimentation of DCC with tau and TUBB3 in MTs, and knockdown of either tau or TUBB3 mutually blocked this effect. Downregulation of endogenous tau levels by tau shRNAs inhibited netrin-1-induced axon outgrowth, branching and commissural axon attraction in vitro, and led to defects in spinal commissural axon projection in vivo. These findings suggest that tau is a key MT-associated protein coupling DCC with MT dynamics in netrin-1-promoted axon attraction.
Collapse
Affiliation(s)
- Huai Huang
- Department of Biological Sciences, University of Toledo, M. S. 601, 2801 W. Bancroft St., Toledo, OH 43606, USA
| | - Tanushree Majumder
- Department of Biological Sciences, University of Toledo, M. S. 601, 2801 W. Bancroft St., Toledo, OH 43606, USA
| | - Bhakti Khot
- Department of Biological Sciences, University of Toledo, M. S. 601, 2801 W. Bancroft St., Toledo, OH 43606, USA
| | - Harindi Suriyaarachchi
- Department of Biological Sciences, University of Toledo, M. S. 601, 2801 W. Bancroft St., Toledo, OH 43606, USA
| | - Tao Yang
- Department of Biological Sciences, University of Toledo, M. S. 601, 2801 W. Bancroft St., Toledo, OH 43606, USA
| | - Qiangqiang Shao
- Department of Biological Sciences, University of Toledo, M. S. 601, 2801 W. Bancroft St., Toledo, OH 43606, USA
| | - Shraddha Tirukovalluru
- Department of Biological Sciences, University of Toledo, M. S. 601, 2801 W. Bancroft St., Toledo, OH 43606, USA
| | - Guofa Liu
- Department of Biological Sciences, University of Toledo, M. S. 601, 2801 W. Bancroft St., Toledo, OH 43606, USA
| |
Collapse
|
16
|
Dorskind JM, Sudarsanam S, Hand RA, Ziak J, Amoah-Dankwah M, Guzman-Clavel L, Soto-Vargas JL, Kolodkin AL. Drebrin Regulates Collateral Axon Branching in Cortical Layer II/III Somatosensory Neurons. J Neurosci 2023; 43:7745-7765. [PMID: 37798130 PMCID: PMC10648559 DOI: 10.1523/jneurosci.0553-23.2023] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2023] [Revised: 09/19/2023] [Accepted: 10/02/2023] [Indexed: 10/07/2023] Open
Abstract
Proper cortical lamination is essential for cognition, learning, and memory. Within the somatosensory cortex, pyramidal excitatory neurons elaborate axon collateral branches in a laminar-specific manner that dictates synaptic partners and overall circuit organization. Here, we leverage both male and female mouse models, single-cell labeling and imaging approaches to identify intrinsic regulators of laminar-specific collateral, also termed interstitial, axon branching. We developed new approaches for the robust, sparse, labeling of Layer II/III pyramidal neurons to obtain single-cell quantitative assessment of axon branch morphologies. We combined these approaches with cell-autonomous loss-of-function (LOF) and overexpression (OE) manipulations in an in vivo candidate screen to identify regulators of cortical neuron axon branch lamination. We identify a role for the cytoskeletal binding protein drebrin (Dbn1) in regulating Layer II/III cortical projection neuron (CPN) collateral axon branching in vitro LOF experiments show that Dbn1 is necessary to suppress the elongation of Layer II/III CPN collateral axon branches within Layer IV, where axon branching by Layer II/III CPNs is normally absent. Conversely, Dbn1 OE produces excess short axonal protrusions reminiscent of nascent axon collaterals that fail to elongate. Structure-function analyses implicate Dbn1S142 phosphorylation and Dbn1 protein domains known to mediate F-actin bundling and microtubule (MT) coupling as necessary for collateral branch initiation upon Dbn1 OE. Taken together, these results contribute to our understanding of the molecular mechanisms that regulate collateral axon branching in excitatory CPNs, a key process in the elaboration of neocortical circuit formation.SIGNIFICANCE STATEMENT Laminar-specific axon targeting is essential for cortical circuit formation. Here, we show that the cytoskeletal protein drebrin (Dbn1) regulates excitatory Layer II/III cortical projection neuron (CPN) collateral axon branching, lending insight into the molecular mechanisms that underlie neocortical laminar-specific innervation. To identify branching patterns of single cortical neurons in vivo, we have developed tools that allow us to obtain detailed images of individual CPN morphologies throughout postnatal development and to manipulate gene expression in these same neurons. Our results showing that Dbn1 regulates CPN interstitial axon branching both in vivo and in vitro may aid in our understanding of how aberrant cortical neuron morphology contributes to dysfunctions observed in autism spectrum disorder and epilepsy.
Collapse
Affiliation(s)
- Joelle M Dorskind
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins Kavli Neuroscience Discovery Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Sriram Sudarsanam
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins Kavli Neuroscience Discovery Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Randal A Hand
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins Kavli Neuroscience Discovery Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Jakub Ziak
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins Kavli Neuroscience Discovery Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Maame Amoah-Dankwah
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins Kavli Neuroscience Discovery Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Luis Guzman-Clavel
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins Kavli Neuroscience Discovery Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
- Summer Internship Program (NeuroSIP), Solomon H. Snyder Department of Neuroscience, Johns Hopkins Kavli Neuroscience Discovery Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - John Lee Soto-Vargas
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins Kavli Neuroscience Discovery Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
- Basic Science Institute-Summer Internship Program (BSI-SIP), Johns Hopkins Kavli Neuroscience Discovery Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| | - Alex L Kolodkin
- Solomon H. Snyder Department of Neuroscience, Johns Hopkins Kavli Neuroscience Discovery Institute, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205
| |
Collapse
|
17
|
Martinek J, Cifrová P, Vosolsobě S, García-González J, Malínská K, Mauerová Z, Jelínková B, Krtková J, Sikorová L, Leaves I, Sparkes I, Schwarzerová K. ARP2/3 complex associates with peroxisomes to participate in pexophagy in plants. NATURE PLANTS 2023; 9:1874-1889. [PMID: 37845336 DOI: 10.1038/s41477-023-01542-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 09/11/2023] [Indexed: 10/18/2023]
Abstract
Actin-related protein (ARP2/3) complex is a heteroheptameric protein complex, evolutionary conserved in all eukaryotic organisms. Its conserved role is based on the induction of actin polymerization at the interface between membranes and the cytoplasm. Plant ARP2/3 has been reported to participate in actin reorganization at the plasma membrane during polarized growth of trichomes and at the plasma membrane-endoplasmic reticulum contact sites. Here we demonstrate that individual plant subunits of ARP2/3 fused to fluorescent proteins form motile spot-like structures in the cytoplasm that are associated with peroxisomes in Arabidopsis and tobacco. ARP2/3 is found at the peroxisome periphery and contains the assembled ARP2/3 complex and the WAVE/SCAR complex subunit NAP1. This ARP2/3-positive peroxisomal domain colocalizes with the autophagosome and, under conditions that affect the autophagy, colocalization between ARP2/3 and the autophagosome increases. ARP2/3 subunits co-immunoprecipitate with ATG8f and peroxisome-associated ARP2/3 interact in vivo with the ATG8f marker. Since mutants lacking functional ARP2/3 complex have more peroxisomes than wild type, we suggest that ARP2/3 has a novel role in the process of peroxisome degradation by autophagy, called pexophagy.
Collapse
Affiliation(s)
- Jan Martinek
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Petra Cifrová
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Stanislav Vosolsobě
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Judith García-González
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Kateřina Malínská
- Imaging Facility of Institute of Experimental Botany AS CR, Prague, Czech Republic
| | - Zdeňka Mauerová
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Barbora Jelínková
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Jana Krtková
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Lenka Sikorová
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czech Republic
| | - Ian Leaves
- Biosciences, CLES, Exeter University, Exeter, UK
| | - Imogen Sparkes
- School of Biological Sciences, University of Bristol, Bristol, UK
| | - Kateřina Schwarzerová
- Department of Experimental Plant Biology, Faculty of Science, Charles University, Prague, Czech Republic.
| |
Collapse
|
18
|
Tomé D, Dias MS, Correia J, Almeida RD. Fibroblast growth factor signaling in axons: from development to disease. Cell Commun Signal 2023; 21:290. [PMID: 37845690 PMCID: PMC10577959 DOI: 10.1186/s12964-023-01284-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Accepted: 08/18/2023] [Indexed: 10/18/2023] Open
Abstract
The fibroblast growth factor (FGF) family regulates various and important aspects of nervous system development, ranging from the well-established roles in neuronal patterning to more recent and exciting functions in axonal growth and synaptogenesis. In addition, FGFs play a critical role in axonal regeneration, particularly after spinal cord injury, confirming their versatile nature in the nervous system. Due to their widespread involvement in neural development, the FGF system also underlies several human neurological disorders. While particular attention has been given to FGFs in a whole-cell context, their effects at the axonal level are in most cases undervalued. Here we discuss the endeavor of the FGF system in axons, we delve into this neuronal subcompartment to provide an original view of this multipurpose family of growth factors in nervous system (dys)function. Video Abstract.
Collapse
Affiliation(s)
- Diogo Tomé
- Institute of Biomedicine, Department of Medical Sciences - iBiMED, University of Aveiro, Aveiro, Portugal
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Marta S Dias
- Institute of Biomedicine, Department of Medical Sciences - iBiMED, University of Aveiro, Aveiro, Portugal
| | - Joana Correia
- Institute of Biomedicine, Department of Medical Sciences - iBiMED, University of Aveiro, Aveiro, Portugal
| | - Ramiro D Almeida
- Institute of Biomedicine, Department of Medical Sciences - iBiMED, University of Aveiro, Aveiro, Portugal.
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal.
| |
Collapse
|
19
|
Ziak J, Dorskind J, Trigg B, Sudarsanam S, Hand R, Kolodkin AL. MAP1B Regulates Cortical Neuron Interstitial Axon Branching Through the Tubulin Tyrosination Cycle. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.10.02.560024. [PMID: 37873083 PMCID: PMC10592918 DOI: 10.1101/2023.10.02.560024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/25/2023]
Abstract
Regulation of directed axon guidance and branching during development is essential for the generation of neuronal networks. However, the molecular mechanisms that underlie interstitial axon branching in the mammalian brain remain unresolved. Here, we investigate interstitial axon branching in vivo using an approach for precise labeling of layer 2/3 callosal projection neurons (CPNs), allowing for quantitative analysis of axonal morphology at high acuity and also manipulation of gene expression in well-defined temporal windows. We find that the GSK3β serine/threonine kinase promotes interstitial axon branching in layer 2/3 CPNs by releasing MAP1B-mediated inhibition of axon branching. Further, we find that the tubulin tyrosination cycle is a key downstream component of GSK3β/MAP1B signaling. We propose that MAP1B functions as a brake on axon branching that can be released by GSK3β activation, regulating the tubulin code and thereby playing an integral role in sculpting cortical neuron axon morphology.
Collapse
Affiliation(s)
- Jakub Ziak
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins Kavli Neuroscience Discovery Institute, The Johns Hopkins School of Medicine, 725 North Wolfe St., Baltimore, MD 21205
| | - Joelle Dorskind
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins Kavli Neuroscience Discovery Institute, The Johns Hopkins School of Medicine, 725 North Wolfe St., Baltimore, MD 21205
- Novartis Institutes for BioMedical Research, Boston, MA
| | - Brian Trigg
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins Kavli Neuroscience Discovery Institute, The Johns Hopkins School of Medicine, 725 North Wolfe St., Baltimore, MD 21205
| | - Sriram Sudarsanam
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins Kavli Neuroscience Discovery Institute, The Johns Hopkins School of Medicine, 725 North Wolfe St., Baltimore, MD 21205
| | - Randal Hand
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins Kavli Neuroscience Discovery Institute, The Johns Hopkins School of Medicine, 725 North Wolfe St., Baltimore, MD 21205
- Prilenia Therapeutics, Boston, MA
| | - Alex L. Kolodkin
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins Kavli Neuroscience Discovery Institute, The Johns Hopkins School of Medicine, 725 North Wolfe St., Baltimore, MD 21205
| |
Collapse
|
20
|
DeGiosio RA, Needham PG, Andrews OA, Tristan H, Grubisha MJ, Brodsky JL, Camacho C, Sweet RA. Differential regulation of MAP2 by phosphorylation events in proline-rich versus C-terminal domains. FASEB J 2023; 37:e23194. [PMID: 37702880 PMCID: PMC10539048 DOI: 10.1096/fj.202300486r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 07/31/2023] [Accepted: 08/29/2023] [Indexed: 09/14/2023]
Abstract
MAP2 is a critical cytoskeletal regulator in neurons. The phosphorylation of MAP2 (MAP2-P) is well known to regulate core functions of MAP2, including microtubule (MT)/actin binding and facilitation of tubulin polymerization. However, site-specific studies of MAP2-P function in regions outside of the MT-binding domain (MTBD) are lacking. We previously identified a set of MAP2 phosphopeptides which are differentially expressed and predominantly increased in the cortex of individuals with schizophrenia relative to nonpsychiatric comparison subjects. The phosphopeptides originated not from the MTBD, but from the flanking proline-rich and C-terminal domains of MAP2. We sought to understand the contribution of MAP2-P at these sites on MAP2 function. To this end, we isolated a series of phosphomimetic MAP2C constructs and subjected them to cell-free tubulin polymerization, MT-binding, actin-binding, and actin polymerization assays. A subset of MAP2-P events significantly impaired these functions, with the two domains displaying different patterns of MAP2 regulation: proline-rich domain mutants T293E and T300E impaired MT assembly and actin-binding affinity but did not affect MT-binding, while C-terminal domain mutants S426E and S439D impaired all three functions. S443D also impaired MT assembly with minimal effects on MT- or actin-binding. Using heterologous cells, we also found that S426E but not T293E had a lower capability for process formation than the wild-type protein. These findings demonstrate the functional utility of MAP2-P in the proline-rich and C-terminal domains and point to distinct, domain-dependent regulations of MAP2 function, which can go on to affect cellular morphology.
Collapse
Affiliation(s)
- R A DeGiosio
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - P G Needham
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - O A Andrews
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - H Tristan
- Department of Neuroscience, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - M J Grubisha
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - J L Brodsky
- Department of Biological Sciences, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - C Camacho
- Department of Computational and Systems Biology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - R A Sweet
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| |
Collapse
|
21
|
Yao M, Pan Y, Ren T, Yang C, Lei Y, Xing X, Zhang L, Cui X, Zheng Y, Xing L, Wu C. Loss of Dip2b leads to abnormal neural differentiation from mESCs. Stem Cell Res Ther 2023; 14:248. [PMID: 37705068 PMCID: PMC10500737 DOI: 10.1186/s13287-023-03482-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Accepted: 08/29/2023] [Indexed: 09/15/2023] Open
Abstract
BACKGROUND Disco-interacting protein 2 homolog B is a member of the Dip2 family encoded by the Dip2b gene. Dip2b is widely expressed in neuro-related tissues and is essential in axonal outgrowth during embryogenesis. METHODS Dip2b knockout mouse embryonic stem cell line was established by CRISPR/Cas9 gene-editing technology. The commercial kits were utilized to detect cell cycle and growth rate. Flow cytometry, qRT-PCR, immunofluorescence, and RNA-seq were employed for phenotype and molecular mechanism assessment. RESULTS Our results suggested that Dip2b is dispensable for the pluripotency maintenance of mESCs. Dip2b knockout could not alter the cell cycle and proliferation of mECSs, or the ability to differentiate into three germ layers in vitro. Furthermore, genes associated with axon guidance, channel activity, and synaptic membrane were significantly downregulated during neural differentiation upon Dip2b knockout. CONCLUSIONS Our results suggest that Dip2b plays an important role in neural differentiation, which will provide a valuable model for studying the exact mechanisms of Dip2b during neural differentiation.
Collapse
Affiliation(s)
- Mingze Yao
- Institutes of Biomedical Sciences, Shanxi Provincial Key Laboratory for Medical Molecular Cell Biology, Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Shanxi University, Taiyuan, 030006, China.
| | - Yuanqing Pan
- Institutes of Biomedical Sciences, Shanxi Provincial Key Laboratory for Medical Molecular Cell Biology, Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Shanxi University, Taiyuan, 030006, China
| | - Tinglin Ren
- Institutes of Biomedical Sciences, Shanxi Provincial Key Laboratory for Medical Molecular Cell Biology, Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Shanxi University, Taiyuan, 030006, China
| | - Caiting Yang
- Institutes of Biomedical Sciences, Shanxi Provincial Key Laboratory for Medical Molecular Cell Biology, Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Shanxi University, Taiyuan, 030006, China
| | - Yu Lei
- Institutes of Biomedical Sciences, Shanxi Provincial Key Laboratory for Medical Molecular Cell Biology, Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Shanxi University, Taiyuan, 030006, China
| | - Xiaoyu Xing
- Institutes of Biomedical Sciences, Shanxi Provincial Key Laboratory for Medical Molecular Cell Biology, Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Shanxi University, Taiyuan, 030006, China
| | - Lei Zhang
- Institutes of Biomedical Sciences, Shanxi Provincial Key Laboratory for Medical Molecular Cell Biology, Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Shanxi University, Taiyuan, 030006, China
| | - Xiaogang Cui
- Institutes of Biomedical Sciences, Shanxi Provincial Key Laboratory for Medical Molecular Cell Biology, Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Shanxi University, Taiyuan, 030006, China
| | - Yaowu Zheng
- Institutes of Biomedical Sciences, Shanxi Provincial Key Laboratory for Medical Molecular Cell Biology, Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Shanxi University, Taiyuan, 030006, China
| | - Li Xing
- Institutes of Biomedical Sciences, Shanxi Provincial Key Laboratory for Medical Molecular Cell Biology, Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Shanxi University, Taiyuan, 030006, China
| | - Changxin Wu
- Institutes of Biomedical Sciences, Shanxi Provincial Key Laboratory for Medical Molecular Cell Biology, Key Laboratory of Chemical Biology and Molecular Engineering of Ministry of Education, Shanxi University, Taiyuan, 030006, China
| |
Collapse
|
22
|
Vecchi JT, Rhomberg M, Guymon CA, Hansen MR. The geometry of photopolymerized topography influences neurite pathfinding by directing growth cone morphology and migration. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.08.28.555111. [PMID: 37693432 PMCID: PMC10491164 DOI: 10.1101/2023.08.28.555111] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 09/12/2023]
Abstract
Cochlear implants (CIs) provide auditory perception to those with profound sensorineural hearing loss: however, the quality of sound perceived by a CI user does not approximate natural hearing. This limitation is due in part to the large physical gap between the stimulating electrodes and their target neurons. Therefore, directing the controlled outgrowth of processes from spiral ganglion neurons (SGNs) into close proximity to the electrode array could provide significantly increased hearing function. For this objective to be properly designed and implemented, the ability and limits of SGN neurites to be guided must first be determined. In this work, we engineered precise topographical microfeatures with angle turn challenges of various geometries to study SGN pathfinding. Additionally, we analyze sensory neurite growth in response to topographically patterned substrates and use live imaging to better understand how neurite growth is guided by these cues. In assessing the ability of neurites to sense and turn in response to topographical cues, we find that the geometry of the angled microfeatures determines the ability of neurites to navigate the angled microfeature turns. SGN neurite pathfinding fidelity can be increased by 20-70% through minor increases in microfeature amplitude (depth) and by 25% if the angle of the patterned turn is made more obtuse. Further, by using engineered topographies and live imaging of dorsal root ganglion neurons (DRGNs), we see that DRGN growth cones change their morphology and migration to become more elongated within microfeatures. However, our observations also indicate complexities in studying neurite turning. First, as the growth cone pathfinds in response to the various cues, the associated neurite often reorients across the angle topographical microfeatures. This reorientation is likely related to the tension the neurite shaft experiences when the growth cone elongates in the microfeature around a turn. Additionally, neurite branching is observed in response to topographical guidance cues, most frequently when turning decisions are most uncertain. Overall, the multi-angle channel micropatterned substrate is a versatile and efficient system to assess SGN neurite turning and pathfinding in response to topographical cues. These findings represent fundamental principles of neurite pathfinding that will be essential to consider for the design of 3D systems aiming to guide neurite growth in vivo.
Collapse
Affiliation(s)
- Joseph T. Vecchi
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, Iowa City, IA, USA
- Department of Otolaryngology Head-Neck Surgery, Carver College of Medicine, Iowa City, IA, USA
| | - Madeline Rhomberg
- Department of Otolaryngology Head-Neck Surgery, Carver College of Medicine, Iowa City, IA, USA
| | - C. Allan Guymon
- Department of Chemical and Biochemical Engineering, University of Iowa, Iowa City, IA, USA
| | - Marlan R. Hansen
- Department of Molecular Physiology and Biophysics, Carver College of Medicine, Iowa City, IA, USA
- Department of Otolaryngology Head-Neck Surgery, Carver College of Medicine, Iowa City, IA, USA
| |
Collapse
|
23
|
Smith G, Sweeney ST, O’Kane CJ, Prokop A. How neurons maintain their axons long-term: an integrated view of axon biology and pathology. Front Neurosci 2023; 17:1236815. [PMID: 37564364 PMCID: PMC10410161 DOI: 10.3389/fnins.2023.1236815] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2023] [Accepted: 07/06/2023] [Indexed: 08/12/2023] Open
Abstract
Axons are processes of neurons, up to a metre long, that form the essential biological cables wiring nervous systems. They must survive, often far away from their cell bodies and up to a century in humans. This requires self-sufficient cell biology including structural proteins, organelles, and membrane trafficking, metabolic, signalling, translational, chaperone, and degradation machinery-all maintaining the homeostasis of energy, lipids, proteins, and signalling networks including reactive oxygen species and calcium. Axon maintenance also involves specialised cytoskeleton including the cortical actin-spectrin corset, and bundles of microtubules that provide the highways for motor-driven transport of components and organelles for virtually all the above-mentioned processes. Here, we aim to provide a conceptual overview of key aspects of axon biology and physiology, and the homeostatic networks they form. This homeostasis can be derailed, causing axonopathies through processes of ageing, trauma, poisoning, inflammation or genetic mutations. To illustrate which malfunctions of organelles or cell biological processes can lead to axonopathies, we focus on axonopathy-linked subcellular defects caused by genetic mutations. Based on these descriptions and backed up by our comprehensive data mining of genes linked to neural disorders, we describe the 'dependency cycle of local axon homeostasis' as an integrative model to explain why very different causes can trigger very similar axonopathies, providing new ideas that can drive the quest for strategies able to battle these devastating diseases.
Collapse
Affiliation(s)
- Gaynor Smith
- Cardiff University, School of Medicine, College of Biomedical and Life Sciences, Cardiff, United Kingdom
| | - Sean T. Sweeney
- Department of Biology, University of York and York Biomedical Research Institute, York, United Kingdom
| | - Cahir J. O’Kane
- Department of Genetics, University of Cambridge, Cambridge, United Kingdom
| | - Andreas Prokop
- Manchester Academic Health Science Centre, Faculty of Biology, Medicine and Health, School of Biology, The University of Manchester, Manchester, United Kingdom
| |
Collapse
|
24
|
Itoh Y, Sahni V, Shnider SJ, McKee H, Macklis JD. Inter-axonal molecular crosstalk via Lumican proteoglycan sculpts murine cervical corticospinal innervation by distinct subpopulations. Cell Rep 2023; 42:112182. [PMID: 36934325 PMCID: PMC10167627 DOI: 10.1016/j.celrep.2023.112182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 11/07/2022] [Accepted: 02/14/2023] [Indexed: 03/19/2023] Open
Abstract
How CNS circuits sculpt their axonal arbors into spatially and functionally organized domains is not well understood. Segmental specificity of corticospinal connectivity is an exemplar for such regional specificity of many axon projections. Corticospinal neurons (CSN) innervate spinal and brainstem targets with segmental precision, controlling voluntary movement. Multiple molecularly distinct CSN subpopulations innervate the cervical cord for evolutionarily enhanced precision of forelimb movement. Evolutionarily newer CSNBC-lat exclusively innervate bulbar-cervical targets, while CSNmedial are heterogeneous; distinct subpopulations extend axons to either bulbar-cervical or thoraco-lumbar segments. We identify that Lumican controls balance of cervical innervation between CSNBC-lat and CSNmedial axons during development, which is maintained into maturity. Lumican, an extracellular proteoglycan expressed by CSNBC-lat, non-cell-autonomously suppresses cervical collateralization by multiple CSNmedial subpopulations. This inter-axonal molecular crosstalk between CSN subpopulations controls murine corticospinal circuitry refinement and forelimb dexterity. Such crosstalk is generalizable beyond the corticospinal system for evolutionary incorporation of new neuron populations into preexisting circuitry.
Collapse
Affiliation(s)
- Yasuhiro Itoh
- Department of Stem Cell and Regenerative Biology and Center for Brain Science, Harvard University, Cambridge, MA 02138, USA
| | - Vibhu Sahni
- Department of Stem Cell and Regenerative Biology and Center for Brain Science, Harvard University, Cambridge, MA 02138, USA
| | - Sara J Shnider
- Department of Stem Cell and Regenerative Biology and Center for Brain Science, Harvard University, Cambridge, MA 02138, USA
| | - Holly McKee
- Department of Stem Cell and Regenerative Biology and Center for Brain Science, Harvard University, Cambridge, MA 02138, USA
| | - Jeffrey D Macklis
- Department of Stem Cell and Regenerative Biology and Center for Brain Science, Harvard University, Cambridge, MA 02138, USA.
| |
Collapse
|
25
|
Song JHT, Ruven C, Patel P, Ding F, Macklis JD, Sahni V. Cbln1 Directs Axon Targeting by Corticospinal Neurons Specifically toward Thoraco-Lumbar Spinal Cord. J Neurosci 2023; 43:1871-1887. [PMID: 36823038 PMCID: PMC10027075 DOI: 10.1523/jneurosci.0710-22.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2022] [Revised: 01/24/2023] [Accepted: 02/02/2023] [Indexed: 02/25/2023] Open
Abstract
Corticospinal neurons (CSN) are centrally required for skilled voluntary movement, which necessitates that they establish precise subcerebral connectivity with the brainstem and spinal cord. However, molecular controls regulating specificity of this projection targeting remain largely unknown. We previously identified that developing CSN subpopulations exhibit striking axon targeting specificity in the spinal white matter. These CSN subpopulations with segmentally distinct spinal projections are also molecularly distinct; a subset of differentially expressed genes between these distinct CSN subpopulations regulate differential axon projection targeting. Rostrolateral CSN extend axons exclusively to bulbar-cervical segments (CSNBC-lat), while caudomedial CSN (CSNmedial) are more heterogeneous, with distinct, intermingled subpopulations extending axons to either bulbar-cervical or thoraco-lumbar segments. Here, we report, in male and female mice, that Cerebellin 1 (Cbln1) is expressed specifically by CSN in medial, but not lateral, sensorimotor cortex. Cbln1 shows highly dynamic temporal expression, with Cbln1 levels in CSN highest during the period of peak axon extension toward thoraco-lumbar segments. Using gain-of-function experiments, we identify that Cbln1 is sufficient to direct thoraco-lumbar axon extension by CSN. Misexpression of Cbln1 in CSNBC-lat either by in utero electroporation, or by postmitotic AAV-mediated gene delivery, redirects these axons past their normal bulbar-cervical targets toward thoracic segments. Further, Cbln1 overexpression in postmitotic CSNBC-lat increases the number of CSNmedial axons that extend past cervical segments into the thoracic cord. Collectively, these results identify that Cbln1 functions as a potent molecular control over thoraco-lumbar CSN axon extension, part of an integrated network of controls over segmentally-specific CSN axon projection targeting.SIGNIFICANCE STATEMENT Corticospinal neurons (CSN) exhibit remarkable diversity and precision of axonal projections to targets in the brainstem and distinct spinal segments; the molecular basis for this targeting diversity is largely unknown. CSN subpopulations projecting to distinct targets are also molecularly distinguishable. Distinct subpopulations degenerate in specific motor neuron diseases, further suggesting that intrinsic molecular differences might underlie differential vulnerability to disease. Here, we identify a novel molecular control, Cbln1, expressed by CSN extending axons to thoraco-lumbar spinal segments. Cbln1 is sufficient, but not required, for CSN axon extension toward distal spinal segments, and Cbln1 expression is controlled by recently identified, CSN-intrinsic regulators of axon extension. Our results identify that Cbln1, together with other regulators, coordinates segmentally precise CSN axon targeting.
Collapse
Affiliation(s)
- Janet H T Song
- Department of Stem Cell and Regenerative Biology, and Center for Brain Science, Harvard University, Cambridge, Massachusetts 02138
| | - Carolin Ruven
- Burke Neurological Institute, White Plains, New York 10605
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York 10065
| | - Payal Patel
- Burke Neurological Institute, White Plains, New York 10605
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York 10065
| | - Frances Ding
- Department of Stem Cell and Regenerative Biology, and Center for Brain Science, Harvard University, Cambridge, Massachusetts 02138
| | - Jeffrey D Macklis
- Department of Stem Cell and Regenerative Biology, and Center for Brain Science, Harvard University, Cambridge, Massachusetts 02138
| | - Vibhu Sahni
- Department of Stem Cell and Regenerative Biology, and Center for Brain Science, Harvard University, Cambridge, Massachusetts 02138
- Burke Neurological Institute, White Plains, New York 10605
- Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, New York 10065
| |
Collapse
|
26
|
Zocchi R, Compagnucci C, Bertini E, Sferra A. Deciphering the Tubulin Language: Molecular Determinants and Readout Mechanisms of the Tubulin Code in Neurons. Int J Mol Sci 2023; 24:ijms24032781. [PMID: 36769099 PMCID: PMC9917122 DOI: 10.3390/ijms24032781] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2022] [Revised: 01/17/2023] [Accepted: 01/27/2023] [Indexed: 02/04/2023] Open
Abstract
Microtubules (MTs) are dynamic components of the cell cytoskeleton involved in several cellular functions, such as structural support, migration and intracellular trafficking. Despite their high similarity, MTs have functional heterogeneity that is generated by the incorporation into the MT lattice of different tubulin gene products and by their post-translational modifications (PTMs). Such regulations, besides modulating the tubulin composition of MTs, create on their surface a "biochemical code" that is translated, through the action of protein effectors, into specific MT-based functions. This code, known as "tubulin code", plays an important role in neuronal cells, whose highly specialized morphologies and activities depend on the correct functioning of the MT cytoskeleton and on its interplay with a myriad of MT-interacting proteins. In recent years, a growing number of mutations in genes encoding for tubulins, MT-interacting proteins and enzymes that post-translationally modify MTs, which are the main players of the tubulin code, have been linked to neurodegenerative processes or abnormalities in neural migration, differentiation and connectivity. Nevertheless, the exact molecular mechanisms through which the cell writes and, downstream, MT-interacting proteins decipher the tubulin code are still largely uncharted. The purpose of this review is to describe the molecular determinants and the readout mechanisms of the tubulin code, and briefly elucidate how they coordinate MT behavior during critical neuronal events, such as neuron migration, maturation and axonal transport.
Collapse
Affiliation(s)
- Riccardo Zocchi
- Unit of Neuromuscular Disorders, Translational Pediatrics and Clinical Genetics, Bambino Gesù Children’s Hospital, IRCCS, 00146 Rome, Italy
| | - Claudia Compagnucci
- Molecular Genetics and Functional Genomics, Bambino Gesù Children’s Research Hospital, IRCCS, 00146 Rome, Italy
| | - Enrico Bertini
- Unit of Neuromuscular Disorders, Translational Pediatrics and Clinical Genetics, Bambino Gesù Children’s Hospital, IRCCS, 00146 Rome, Italy
- Correspondence: (E.B.); or (A.S.); Tel.: +39-06-6859-2104 (E.B. & A.S.)
| | - Antonella Sferra
- Unit of Neuromuscular Disorders, Translational Pediatrics and Clinical Genetics, Bambino Gesù Children’s Hospital, IRCCS, 00146 Rome, Italy
- Correspondence: (E.B.); or (A.S.); Tel.: +39-06-6859-2104 (E.B. & A.S.)
| |
Collapse
|
27
|
Pinho-Correia LM, Prokop A. Maintaining essential microtubule bundles in meter-long axons: a role for local tubulin biogenesis? Brain Res Bull 2023; 193:131-145. [PMID: 36535305 DOI: 10.1016/j.brainresbull.2022.12.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2022] [Revised: 12/12/2022] [Accepted: 12/14/2022] [Indexed: 12/23/2022]
Abstract
Axons are the narrow, up-to-meter long cellular processes of neurons that form the biological cables wiring our nervous system. Most axons must survive for an organism's lifetime, i.e. up to a century in humans. Axonal maintenance depends on loose bundles of microtubules that run without interruption all along axons. The continued turn-over and the extension of microtubule bundles during developmental, regenerative or plastic growth requires the availability of α/β-tubulin heterodimers up to a meter away from the cell body. The underlying regulation in axons is poorly understood and hardly features in past and contemporary research. Here we discuss potential mechanisms, particularly focussing on the possibility of local tubulin biogenesis in axons. Current knowledge might suggest that local translation of tubulin takes place in axons, but far less is known about the post-translational machinery of tubulin biogenesis involving three chaperone complexes: prefoldin, CCT and TBC. We discuss functional understanding of these chaperones from a range of model organisms including yeast, plants, flies and mice, and explain what is known from human diseases. Microtubules across species depend on these chaperones, and they are clearly required in the nervous system. However, most chaperones display a high degree of functional pleiotropy, partly through independent functions of individual subunits outside their complexes, thus posing a challenge to experimental studies. Notably, we found hardly any studies that investigate their presence and function particularly in axons, thus highlighting an important gap in our understanding of axon biology and pathology.
Collapse
Affiliation(s)
- Liliana Maria Pinho-Correia
- The University of Manchester, Manchester Academic Health Science Centre, Faculty of Biology, Medicine and Health, School of Biology, Manchester, UK
| | - Andreas Prokop
- The University of Manchester, Manchester Academic Health Science Centre, Faculty of Biology, Medicine and Health, School of Biology, Manchester, UK.
| |
Collapse
|
28
|
Imanaka C, Shimada S, Ito S, Kamada M, Iguchi T, Konishi Y. A model for generating differences in microtubules between axonal branches depending on the distance from terminals. Brain Res 2023; 1799:148166. [PMID: 36402177 DOI: 10.1016/j.brainres.2022.148166] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2022] [Revised: 09/11/2022] [Accepted: 11/13/2022] [Indexed: 11/18/2022]
Abstract
In the remodeling of axonal arbor, the growth and retraction of branches are differentially regulated within a single axon. Although cell-autonomously generated differences in microtubule (MT) turnover are thought to be involved in selective branch regulation, the cellular system whereby neurons generate differences of MTs between axonal branches has not been clarified. Because MT turnover tends to be slower in longer branches compared with neighboring shorter branches, feedback regulation depending on branch length is thought to be involved. In the present study, we generated a model of MT lifetime in axonal terminal branches by adapting a length-dependent model in which parameters for MT dynamics were constant in the arbor. The model predicted that differences in MT lifetime between neighboring branches could be generated depending on the distance from terminals. In addition, the following points were predicted. Firstly, destabilization of MTs throughout the arbor decreased the differences in MT lifetime between branches. Secondly, differences of MT lifetime existed even before MTs entered the branch point. In axonal MTs in primary neurons, treatment with a low concentration of nocodazole significantly decreased the differences of detyrosination (deTyr) and tyrosination (Tyr) of tubulins, indicators of MT turnover. Expansion microscopy of the axonal shaft before the branch point revealed differences in deTyr/Tyr modification on MTs. Our model recapitulates the differences in MT turnover between branches and provides a feedback mechanism for MT regulation that depends on the axonal arbor geometry.
Collapse
Affiliation(s)
- Chiaki Imanaka
- Department of Applied Chemistry and Biotechnology, Artificial Intelligence Systems, Faculty of Engineering, University of Fukui, Fukui 910-8507, Japan
| | - Satoshi Shimada
- Department of Human and Artificial Intelligence Systems, Faculty of Engineering, University of Fukui, Fukui 910-8507, Japan
| | - Shino Ito
- Department of Applied Chemistry and Biotechnology, Artificial Intelligence Systems, Faculty of Engineering, University of Fukui, Fukui 910-8507, Japan
| | - Marina Kamada
- Department of Applied Chemistry and Biotechnology, Artificial Intelligence Systems, Faculty of Engineering, University of Fukui, Fukui 910-8507, Japan
| | - Tokuichi Iguchi
- Department of Applied Chemistry and Biotechnology, Artificial Intelligence Systems, Faculty of Engineering, University of Fukui, Fukui 910-8507, Japan; Department of Nursing, Faculty of Health Science, Fukui Health Science University, Fukui 910-3190, Japan
| | - Yoshiyuki Konishi
- Department of Applied Chemistry and Biotechnology, Artificial Intelligence Systems, Faculty of Engineering, University of Fukui, Fukui 910-8507, Japan; Life Science Innovation Center, University of Fukui, Fukui 910-8507, Japan.
| |
Collapse
|
29
|
Wit CB, Hiesinger PR. Neuronal filopodia: From stochastic dynamics to robustness of brain morphogenesis. Semin Cell Dev Biol 2023; 133:10-19. [PMID: 35397971 DOI: 10.1016/j.semcdb.2022.03.038] [Citation(s) in RCA: 13] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2021] [Revised: 03/26/2022] [Accepted: 03/29/2022] [Indexed: 12/30/2022]
Abstract
Brain development relies on dynamic morphogenesis and interactions of neurons. Filopodia are thin and highly dynamic membrane protrusions that are critically required for neuronal development and neuronal interactions with the environment. Filopodial interactions are typically characterized by non-deterministic dynamics, yet their involvement in developmental processes leads to stereotypic and robust outcomes. Here, we discuss recent advances in our understanding of how filopodial dynamics contribute to neuronal differentiation, migration, axonal and dendritic growth and synapse formation. Many of these advances are brought about by improved methods of live observation in intact developing brains. Recent findings integrate known and novel roles ranging from exploratory sensors and decision-making agents to pools for selection and mechanical functions. Different types of filopodial dynamics thereby reveal non-deterministic subcellular decision-making processes as part of genetically encoded brain development.
Collapse
Affiliation(s)
- Charlotte B Wit
- Devision of Neurobiology, Institute of Biology, Freie Universität Berlin, Berlin, Germany
| | - P Robin Hiesinger
- Devision of Neurobiology, Institute of Biology, Freie Universität Berlin, Berlin, Germany.
| |
Collapse
|
30
|
The Time Course of MHC-I Expression in C57BL/6J and A/J Mice Correlates with the Degree of Retrograde Gliosis in the Spinal Cord following Sciatic Nerve Crush. Cells 2022; 11:cells11233710. [PMID: 36496969 PMCID: PMC9740909 DOI: 10.3390/cells11233710] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2022] [Revised: 11/02/2022] [Accepted: 11/03/2022] [Indexed: 11/23/2022] Open
Abstract
The pleiotropic role of the major histocompatibility complex class I (MHC-I) reflects the close association between the nervous and immune systems. In turn, MHC-I upregulation postinjury is associated with a better regenerative outcome in isogenic mice following peripheral nerve damage. In the present work, we compared the time course of neuronal, glial, and sensorimotor recovery (1, 3, 5, 7, and 28 days after lesion—dal) following unilateral sciatic nerve crush in A/J and C57BL/6J mice. The A/J strain showed higher expression of MHC-I (7 dal, ** p < 0.01), Iba-1 (microglial reaction, 7 dal, *** p < 0.001), and GFAP (astrogliosis, 5 dal, * p < 0.05) than the C57BL/6J counterpart. Synaptic coverage (synaptophysin) was equivalent in both strains over time. In addition, mRNA expression of microdissected spinal motoneurons revealed an increase in cytoskeleton-associated molecules (cofilin, shp2, and crmp2, * p < 0.05), but not trkB, in C57BL/6J mice. Gait recovery, studied by the sciatic functional index, was faster in the A/J strain, despite the equivalent results of C57BL/6J at 28 days after injury. A similar recovery was also seen for the nociceptive threshold (von Frey test). Interestingly, when evaluating proprioceptive recovery, C57BL/6J animals showed an enlarged base of support, indicating abnormal ambulation postinjury. Overall, the present results reinforce the role of MHC-I expression in the plasticity of the nervous system following axotomy, which in turn correlates with the variable recovery capacity among strains of mice.
Collapse
|
31
|
Ferretti G, Romano A, Sirabella R, Serafini S, Maier TJ, Matrone C. An increase in Semaphorin 3A biases the axonal direction and induces an aberrant dendritic arborization in an in vitro model of human neural progenitor differentiation. Cell Biosci 2022; 12:182. [DOI: 10.1186/s13578-022-00916-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 10/17/2022] [Indexed: 11/10/2022] Open
Abstract
Abstract
Background
Semaphorins (Sema) belong to a large family of repellent guidance cues instrumental in guiding axons during development. In particular, Class 3 Sema (Sema 3) is among the best characterized Sema family members and the only produced as secreted proteins in mammals, thereby exerting both autocrine and paracrine functions. Intriguingly, an increasing number of studies supports the crucial role of the Sema 3A in hippocampal and cortical neurodevelopment. This means that alterations in Sema 3A signaling might compromise hippocampal and cortical circuits and predispose to disorders such as autism and schizophrenia. Consistently, increased Sema 3A levels have been detected in brain of patients with schizophrenia and many polymorphisms in Sema 3A or in the Sema 3A receptors, Neuropilins (Npn 1 and 2) and Plexin As (Plxn As), have been associated to autism.
Results
Here we present data indicating that when overexpressed, Sema 3A causes human neural progenitors (NP) axonal retraction and an aberrant dendritic arborization. Similarly, Sema 3A, when overexpressed in human microglia, triggers proinflammatory processes that are highly detrimental to themselves as well as NP. Indeed, NP incubated in microglia overexpressing Sema 3A media retract axons within an hour and then start suffering and finally die. Sema 3A mediated retraction appears to be related to its binding to Npn 1 and Plxn A2 receptors, thus activating the downstream Fyn tyrosine kinase pathway that promotes the threonine-serine kinase cyclin-dependent kinase 5, CDK5, phosphorylation at the Tyr15 residue and the CDK5 processing to generate the active fragment p35.
Conclusions
All together this study identifies Sema 3A as a critical regulator of human NP differentiation. This may imply that an insult due to Sema 3A overexpression during the early phases of neuronal development might compromise neuronal organization and connectivity and make neurons perhaps more vulnerable to other insults across their lifespan.
Collapse
|
32
|
Cason SE, Mogre SS, Holzbaur ELF, Koslover EF. Spatiotemporal analysis of axonal autophagosome-lysosome dynamics reveals limited fusion events and slow maturation. Mol Biol Cell 2022; 33:ar123. [PMID: 36044338 PMCID: PMC9634976 DOI: 10.1091/mbc.e22-03-0111] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023] Open
Abstract
Macroautophagy is a homeostatic process required to clear cellular waste. Neuronal autophagosomes form constitutively in the distal tip of the axon and are actively transported toward the soma, with cargo degradation initiated en route. Cargo turnover requires autophagosomes to fuse with lysosomes to acquire degradative enzymes; however, directly imaging these fusion events in the axon is impractical. Here we use a quantitative model, parameterized and validated using data from primary hippocampal neurons, to explore the autophagosome maturation process. We demonstrate that retrograde autophagosome motility is independent of fusion and that most autophagosomes fuse with only a few lysosomes during axonal transport. Our results indicate that breakdown of the inner autophagosomal membrane is much slower in neurons than in nonneuronal cell types, highlighting the importance of this late maturation step. Together, rigorous quantitative measurements and mathematical modeling elucidate the dynamics of autophagosome-lysosome interaction and autophagosomal maturation in the axon.
Collapse
Affiliation(s)
- Sydney E. Cason
- Department of Physiology, University of Pennsylvania, Philadelphia, PA 19104
| | - Saurabh S. Mogre
- Department of Physics, University of California, San Diego, La Jolla, CA 92093
| | | | - Elena F. Koslover
- Department of Physics, University of California, San Diego, La Jolla, CA 92093,*Address correspondence to: Elena F. Koslover ()
| |
Collapse
|
33
|
Antagonistic Activities of Fmn2 and ADF Regulate Axonal F-Actin Patch Dynamics and the Initiation of Collateral Branching. J Neurosci 2022; 42:7355-7369. [PMID: 36481742 PMCID: PMC9525169 DOI: 10.1523/jneurosci.3107-20.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2020] [Revised: 08/17/2022] [Accepted: 08/22/2022] [Indexed: 12/15/2022] Open
Abstract
Interstitial collateral branching of axons is a critical component in the development of functional neural circuits. Axon collateral branches are established through a series of cellular processes initiated by the development of a specialized, focal F-actin network in axons. The formation, maintenance and remodeling of this F-actin patch is critical for the initiation of axonal protrusions that are subsequently consolidated to form a collateral branch. However, the mechanisms regulating F-actin patch dynamics are poorly understood. Fmn2 is a formin family member implicated in multiple neurodevelopmental disorders. We find that Fmn2 regulates the initiation of axon collateral protrusions in chick spinal neurons and in zebrafish motor neurons. Fmn2 localizes to the protrusion-initiating axonal F-actin patches and regulates the lifetime and size of these F-actin networks. The F-actin nucleation activity of Fmn2 is necessary for F-actin patch stability but not for initiating patch formation. We show that Fmn2 insulates the F-actin patches from disassembly by the actin-depolymerizing factor, ADF, and promotes long-lived, larger patches that are competent to initiate axonal protrusions. The regulation of axonal branching can contribute to the neurodevelopmental pathologies associated with Fmn2 and the dynamic antagonism between Fmn2 and ADF may represent a general mechanism of formin-dependent protection of Arp2/3-initiated F-actin networks from disassembly.SIGNIFICANCE STATEMENT Axonal branching is a key process in the development of functional circuits and neural plasticity. Axon collateral branching is initiated by the elaboration of F-actin filaments from discrete axonal F-actin networks. We show that the neurodevelopmental disorder-associated formin, Fmn2, is a critical regulator of axon collateral branching. Fmn2 localizes to the collateral branch-inducing F-actin patches in axons and regulates the stability of these actin networks. The F-actin nucleation activity of Fmn2 protects the patches from ADF-mediated disassembly. Opposing activities of Fmn2 and ADF exert a dynamic regulatory control on axon collateral branch initiation and may underly the neurodevelopmental defects associated with Fmn2.
Collapse
|
34
|
Fuchs J, Bareesel S, Kroon C, Polyzou A, Eickholt BJ, Leondaritis G. Plasma membrane phospholipid phosphatase-related proteins as pleiotropic regulators of neuron growth and excitability. Front Mol Neurosci 2022; 15:984655. [PMID: 36187351 PMCID: PMC9520309 DOI: 10.3389/fnmol.2022.984655] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2022] [Accepted: 08/23/2022] [Indexed: 11/22/2022] Open
Abstract
Neuronal plasma membrane proteins are essential for integrating cell extrinsic and cell intrinsic signals to orchestrate neuronal differentiation, growth and plasticity in the developing and adult nervous system. Here, we shed light on the family of plasma membrane proteins phospholipid phosphatase-related proteins (PLPPRs) (alternative name, PRGs; plasticity-related genes) that fine-tune neuronal growth and synaptic transmission in the central nervous system. Several studies uncovered essential functions of PLPPRs in filopodia formation, axon guidance and branching during nervous system development and regeneration, as well as in the control of dendritic spine number and excitability. Loss of PLPPR expression in knockout mice increases susceptibility to seizures, and results in defects in sensory information processing, development of psychiatric disorders, stress-related behaviors and abnormal social interaction. However, the exact function of PLPPRs in the context of neurological diseases is largely unclear. Although initially described as active lysophosphatidic acid (LPA) ecto-phosphatases that regulate the levels of this extracellular bioactive lipid, PLPPRs lack catalytic activity against LPA. Nevertheless, they emerge as atypical LPA modulators, by regulating LPA mediated signaling processes. In this review, we summarize the effects of this protein family on cellular morphology, generation and maintenance of cellular protrusions as well as highlight their known neuronal functions and phenotypes of KO mice. We discuss the molecular mechanisms of PLPPRs including the deployment of phospholipids, actin-cytoskeleton and small GTPase signaling pathways, with a focus on identifying gaps in our knowledge to stimulate interest in this understudied protein family.
Collapse
Affiliation(s)
- Joachim Fuchs
- Institute of Molecular Biology and Biochemistry, Charité – Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Shannon Bareesel
- Institute of Molecular Biology and Biochemistry, Charité – Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Cristina Kroon
- Institute of Molecular Biology and Biochemistry, Charité – Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
| | - Alexandra Polyzou
- Department of Pharmacology, Faculty of Medicine, School of Health Sciences, University of Ioannina, Ioannina, Greece
| | - Britta J. Eickholt
- Institute of Molecular Biology and Biochemistry, Charité – Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, and Berlin Institute of Health, Berlin, Germany
- *Correspondence: Britta J. Eickholt,
| | - George Leondaritis
- Department of Pharmacology, Faculty of Medicine, School of Health Sciences, University of Ioannina, Ioannina, Greece
- Institute of Biosciences, University Research Center Ioannina, University of Ioannina, Ioannina, Greece
- George Leondaritis,
| |
Collapse
|
35
|
Sugawara H, Norimoto H, Zhou Z. Methyl vinyl ketone disrupts neuronal survival and axonal morphogenesis. J Toxicol Sci 2022; 47:375-380. [PMID: 36047111 DOI: 10.2131/jts.47.375] [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: 11/02/2022]
Abstract
Methyl vinyl ketone (MVK) is an environmental hazardous substrate which is mainly present in cigarette smoke, industrial waste, and exhaust gas. Despite many chances to be exposed to MVK, the cellular toxicity of MVK is largely unknown. Neurons are the main component of the brain, which is one the most vital organs to human beings. Nevertheless, the influence of MVK to neurons has not been investigated. Here, we determined whether MVK treatment negatively affects neuronal survival and axonal morphogenesis using primary hippocampal neuronal cultures. We treated hippocampal neurons with 0.1 μM to 3.0 μM MVK and observed a concentration-dependent increase of neuronal death rate. We also demonstrated that the treatment with a low concentration of MVK 0.1 μM or 0.3 μM inhibited axonal branching specifically without affecting axon outgrowth. Our results suggest that MVK is highly toxic to neurons.
Collapse
Affiliation(s)
| | | | - Zhiwen Zhou
- Graduate School of Medicine, Hokkaido University
| |
Collapse
|
36
|
Travica N, Aslam H, O'Neil A, Lane MM, Berk M, Gamage E, Walder K, Liu ZS, Segasby T, Marx W. Brain derived neurotrophic factor in perioperative neurocognitive disorders: Current evidence and future directions. Neurobiol Learn Mem 2022; 193:107656. [DOI: 10.1016/j.nlm.2022.107656] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2022] [Revised: 05/25/2022] [Accepted: 06/28/2022] [Indexed: 10/17/2022]
|
37
|
Molecular Mechanism and Regulation of Autophagy and Its Potential Role in Epilepsy. Cells 2022; 11:cells11172621. [PMID: 36078029 PMCID: PMC9455075 DOI: 10.3390/cells11172621] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2022] [Revised: 08/14/2022] [Accepted: 08/22/2022] [Indexed: 01/18/2023] Open
Abstract
Autophagy is an evolutionally conserved degradation mechanism for maintaining cell homeostasis whereby cytoplasmic components are wrapped in autophagosomes and subsequently delivered to lysosomes for degradation. This process requires the concerted actions of multiple autophagy-related proteins and accessory regulators. In neurons, autophagy is dynamically regulated in different compartments including soma, axons, and dendrites. It determines the turnover of selected materials in a spatiotemporal control manner, which facilitates the formation of specialized neuronal functions. It is not surprising, therefore, that dysfunctional autophagy occurs in epilepsy, mainly caused by an imbalance between excitation and inhibition in the brain. In recent years, much attention has been focused on how autophagy may cause the development of epilepsy. In this article, we overview the historical landmarks and distinct types of autophagy, recent progress in the core machinery and regulation of autophagy, and biological roles of autophagy in homeostatic maintenance of neuronal structures and functions, with a particular focus on synaptic plasticity. We also discuss the relevance of autophagy mechanisms to the pathophysiology of epileptogenesis.
Collapse
|
38
|
The Mechanical Microenvironment Regulates Axon Diameters Visualized by Cryo-Electron Tomography. Cells 2022; 11:cells11162533. [PMID: 36010609 PMCID: PMC9406316 DOI: 10.3390/cells11162533] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/07/2022] [Accepted: 08/10/2022] [Indexed: 12/21/2022] Open
Abstract
Axonal varicosities or swellings are enlarged structures along axon shafts and profoundly affect action potential propagation and synaptic transmission. These structures, which are defined by morphology, are highly heterogeneous and often investigated concerning their roles in neuropathology, but why they are present in the normal brain remains unknown. Combining confocal microscopy and cryo-electron tomography (Cryo-ET) with in vivo and in vitro systems, we report that non-uniform mechanical interactions with the microenvironment can lead to 10-fold diameter differences within an axon of the central nervous system (CNS). In the brains of adult Thy1-YFP transgenic mice, individual axons in the cortex displayed significantly higher diameter variation than those in the corpus callosum. When being cultured on lacey carbon film-coated electron microscopy (EM) grids, CNS axons formed varicosities exclusively in holes and without microtubule (MT) breakage, and they contained mitochondria, multivesicular bodies (MVBs), and/or vesicles, similar to the axonal varicosities induced by mild fluid puffing. Moreover, enlarged axon branch points often contain MT free ends leading to the minor branch. When the axons were fasciculated by mimicking in vivo axonal bundles, their varicosity levels reduced. Taken together, our results have revealed the extrinsic regulation of the three-dimensional ultrastructures of central axons by the mechanical microenvironment under physiological conditions.
Collapse
|
39
|
Morphogenesis of vascular and neuronal networks and the relationships between their remodeling processes. Brain Res Bull 2022; 186:62-69. [DOI: 10.1016/j.brainresbull.2022.05.015] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2022] [Revised: 05/18/2022] [Accepted: 05/29/2022] [Indexed: 11/21/2022]
|
40
|
Grignard J, Lamamy V, Vermersch E, Delagrange P, Stephan JP, Dorval T, Fages F. Mathematical modeling of the microtubule detyrosination/tyrosination cycle for cell-based drug screening design. PLoS Comput Biol 2022; 18:e1010236. [PMID: 35759459 PMCID: PMC9236252 DOI: 10.1371/journal.pcbi.1010236] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 05/20/2022] [Indexed: 11/18/2022] Open
Abstract
Microtubules and their post-translational modifications are involved in major cellular processes. In severe diseases such as neurodegenerative disorders, tyrosinated tubulin and tyrosinated microtubules are in lower concentration. We present here a mechanistic mathematical model of the microtubule tyrosination cycle combining computational modeling and high-content image analyses to understand the key kinetic parameters governing the tyrosination status in different cellular models. That mathematical model is parameterized, firstly, for neuronal cells using kinetic values taken from the literature, and, secondly, for proliferative cells, by a change of two parameter values obtained, and shown minimal, by a continuous optimization procedure based on temporal logic constraints to formalize experimental high-content imaging data. In both cases, the mathematical models explain the inability to increase the tyrosination status by activating the Tubulin Tyrosine Ligase enzyme. The tyrosinated tubulin is indeed the product of a chain of two reactions in the cycle: the detyrosinated microtubule depolymerization followed by its tyrosination. The tyrosination status at equilibrium is thus limited by both reaction rates and activating the tyrosination reaction alone is not effective. Our computational model also predicts the effect of inhibiting the Tubulin Carboxy Peptidase enzyme which we have experimentally validated in MEF cellular model. Furthermore, the model predicts that the activation of two particular kinetic parameters, the tyrosination and detyrosinated microtubule depolymerization rate constants, in synergy, should suffice to enable an increase of the tyrosination status in living cells.
Collapse
Affiliation(s)
- Jeremy Grignard
- Pole of Activity Data Sciences and Data Management, Institut de Recherches Servier (IdRS), Croissy-sur-Seine, France
- * E-mail: (JG); (TD); (FF)
| | - Véronique Lamamy
- Pole of Activity Cellular Sciences, Institut de Recherches Servier (IdRS), Croissy-sur-Seine, France
| | - Eva Vermersch
- Pole of Activity Cellular Sciences, Institut de Recherches Servier (IdRS), Croissy-sur-Seine, France
| | - Philippe Delagrange
- Therapeutic Area Neuropsychiatry and Immunoinflammation, Institut de Recherches Servier (IdRS), Croissy-sur-Seine, France
| | - Jean-Philippe Stephan
- In Vitro Pharmacology Unit, Institut de Recherches Servier (IdRS), Croissy-sur-Seine, France
| | - Thierry Dorval
- Pole of Activity Data Sciences and Data Management, Institut de Recherches Servier (IdRS), Croissy-sur-Seine, France
- * E-mail: (JG); (TD); (FF)
| | - François Fages
- Team Project Lifeware, Institut National de Recherche en Informatique et Automatique, Inria Saclay, Palaiseau, France
- * E-mail: (JG); (TD); (FF)
| |
Collapse
|
41
|
Gyllenhammer LE, Rasmussen JM, Bertele N, Halbing A, Entringer S, Wadhwa PD, Buss C. Maternal Inflammation During Pregnancy and Offspring Brain Development: The Role of Mitochondria. BIOLOGICAL PSYCHIATRY. COGNITIVE NEUROSCIENCE AND NEUROIMAGING 2022; 7:498-509. [PMID: 34800727 PMCID: PMC9086015 DOI: 10.1016/j.bpsc.2021.11.003] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/18/2021] [Revised: 10/20/2021] [Accepted: 11/04/2021] [Indexed: 01/06/2023]
Abstract
The association between maternal immune activation (MIA) during pregnancy and risk for offspring neuropsychiatric disorders has been increasingly recognized over the past several years. Among the mechanistic pathways that have been described through which maternal inflammation during pregnancy may affect fetal brain development, the role of mitochondria has received little attention. In this review, the role of mitochondria as a potential mediator of the association between MIA during pregnancy and offspring brain development and risk for psychiatric disorders will be proposed. As a basis for this postulation, convergent evidence is presented supporting the obligatory role of mitochondria in brain development, the role of mitochondria as mediators and initiators of inflammatory processes, and evidence of mitochondrial dysfunction in preclinical MIA exposure models and human neurodevelopmental disorders. Elucidating the role of mitochondria as a potential mediator of MIA-induced alterations in brain development and neurodevelopmental disease risk may not only provide new insight into the pathophysiology of mental health disorders that have their origins in exposure to infection/immune activation during pregnancy but also offer new therapeutic targets.
Collapse
Affiliation(s)
- Lauren E Gyllenhammer
- Development, Health and Disease Research Program, University of California, Irvine, School of Medicine, Irvine, California; Department of Pediatrics, University of California, Irvine, School of Medicine, Irvine, California
| | - Jerod M Rasmussen
- Development, Health and Disease Research Program, University of California, Irvine, School of Medicine, Irvine, California; Department of Pediatrics, University of California, Irvine, School of Medicine, Irvine, California
| | - Nina Bertele
- Department of Medical Psychology, Charité - Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Amy Halbing
- Department of Medical Psychology, Charité - Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany; Einstein Center for Neurosciences Berlin, Department of Medical Psychology, Charité - Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Sonja Entringer
- Development, Health and Disease Research Program, University of California, Irvine, School of Medicine, Irvine, California; Department of Pediatrics, University of California, Irvine, School of Medicine, Irvine, California; Department of Medical Psychology, Charité - Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany
| | - Pathik D Wadhwa
- Development, Health and Disease Research Program, University of California, Irvine, School of Medicine, Irvine, California; Department of Pediatrics, University of California, Irvine, School of Medicine, Irvine, California; Department of Psychiatry and Human Behavior, University of California, Irvine, School of Medicine, Irvine, California; Department of Obstetrics and Gynecology, University of California, Irvine, School of Medicine, Irvine, California; Department of Epidemiology, University of California, Irvine, School of Medicine, Irvine, California
| | - Claudia Buss
- Development, Health and Disease Research Program, University of California, Irvine, School of Medicine, Irvine, California; Department of Pediatrics, University of California, Irvine, School of Medicine, Irvine, California; Department of Medical Psychology, Charité - Universitätsmedizin Berlin, Freie Universität Berlin, Humboldt-Universität zu Berlin, Berlin, Germany.
| |
Collapse
|
42
|
de Kort AR, Joosten EAJ, Patijn J, Tibboel D, van den Hoogen NJ. The development of descending serotonergic modulation of the spinal nociceptive network: a life span perspective. Pediatr Res 2022; 91:1361-1369. [PMID: 34257402 DOI: 10.1038/s41390-021-01638-9] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Revised: 06/10/2021] [Accepted: 06/16/2021] [Indexed: 02/06/2023]
Abstract
The nociceptive network, responsible for transmission of nociceptive signals that generate the pain experience, is not fully developed at birth. Descending serotonergic modulation of spinal nociception, an important part of the pain network, undergoes substantial postnatal maturation and is suggested to be involved in the altered pain response observed in human newborns. This review summarizes preclinical data of the development of descending serotonergic modulation of the spinal nociceptive network across the life span, providing a comprehensive background to understand human newborn pain experience and treatment. Sprouting of descending serotonergic axons, originating from the rostroventral medulla, as well as changes in receptor function and expression take place in the first postnatal weeks of rodents, corresponding to human neonates in early infancy. Descending serotonergic modulation switches from facilitation in early life to bimodal control in adulthood, masking an already functional 5-HT inhibitory system at early ages. Specifically the 5-HT3 and 5-HT7 receptors seem distinctly important for pain facilitation at neonatal and early infancy, while the 5-HT1a, 5-HT1b, and 5-HT2 receptors mediate inhibitory effects at all ages. Analgesic therapy that considers the neurodevelopmental phase is likely to result in a more targeted treatment of neonatal pain and may improve both short- and long-term effects. IMPACT: The descending serotonergic system undergoes anatomical changes from birth to early infancy, as its sprouts and descending projections increase and the dorsal horn innervation pattern changes. Descending serotonergic modulation from the rostral ventral medulla switches from facilitation in early life via the 5-HT3 and 5-HT7 receptors to bimodal control in adulthood. A functional inhibitory serotonergic system mainly via 5-HT1a, 5-HT1b, and 5-HT2a receptors at the spinal level exists already at the neonatal phase but is masked by descending facilitation.
Collapse
Affiliation(s)
- Anne R de Kort
- Department of Anesthesiology and Pain Management, Maastricht University Medical Centre+, Maastricht, the Netherlands. .,Department of Translational Neuroscience, School of Mental Health and Neuroscience, Maastricht University, Maastricht, the Netherlands.
| | - Elbert A J Joosten
- Department of Anesthesiology and Pain Management, Maastricht University Medical Centre+, Maastricht, the Netherlands.,Department of Translational Neuroscience, School of Mental Health and Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Jacob Patijn
- Department of Anesthesiology and Pain Management, Maastricht University Medical Centre+, Maastricht, the Netherlands.,Department of Translational Neuroscience, School of Mental Health and Neuroscience, Maastricht University, Maastricht, the Netherlands
| | - Dick Tibboel
- Intensive Care and Department of Pediatric Surgery, Erasmus MC-Sophia Children's Hospital, Rotterdam, the Netherlands
| | - Nynke J van den Hoogen
- Department of Anesthesiology and Pain Management, Maastricht University Medical Centre+, Maastricht, the Netherlands.,Department of Translational Neuroscience, School of Mental Health and Neuroscience, Maastricht University, Maastricht, the Netherlands.,Department of Comparative Biology and Experimental Medicine, Hotchkiss Brain Institute, University of Calgary, Calgary, AB, Canada
| |
Collapse
|
43
|
Tymanskyj SR, Curran BM, Ma L. Selective axonal transport through branch junctions is directed by growth cone signaling and mediated by KIF1/kinesin-3 motors. Cell Rep 2022; 39:110748. [PMID: 35476993 PMCID: PMC9097860 DOI: 10.1016/j.celrep.2022.110748] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2021] [Revised: 01/27/2022] [Accepted: 04/06/2022] [Indexed: 11/16/2022] Open
Abstract
Development and function of nerve cells rely on the orchestration of microtubule-based transport from the cell body into distal axonal terminals. Neurons often have highly elaborate branches innervating multiple targets, but how protein or membrane cargos navigate through branch junctions to specific branch targets is unknown. Here, we demonstrate that anterograde transport of membrane vesicles through axonal branch junctions is highly selective, which is influenced by branch length and more strongly by growth cone motility. Using an optogenetic tool, we demonstrate that signaling from the growth cone can rapidly direct transport through branch junctions. We further demonstrate that such transport selectivity is differentially regulated for different vesicles and mediated by the KIF1/kinesin-3 family motors. We propose that this transport regulation through branch junctions could broadly impact neuronal development, function, and regeneration.
Collapse
Affiliation(s)
- Stephen R Tymanskyj
- Department of Neuroscience, Jefferson Center for Synaptic Biology, Vickie and Jack Farber Institute for Neuroscience, Sydney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Bridget M Curran
- Department of Neuroscience, Jefferson Center for Synaptic Biology, Vickie and Jack Farber Institute for Neuroscience, Sydney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA
| | - Le Ma
- Department of Neuroscience, Jefferson Center for Synaptic Biology, Vickie and Jack Farber Institute for Neuroscience, Sydney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA 19107, USA.
| |
Collapse
|
44
|
Procès A, Luciano M, Kalukula Y, Ris L, Gabriele S. Multiscale Mechanobiology in Brain Physiology and Diseases. Front Cell Dev Biol 2022; 10:823857. [PMID: 35419366 PMCID: PMC8996382 DOI: 10.3389/fcell.2022.823857] [Citation(s) in RCA: 17] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2021] [Accepted: 03/08/2022] [Indexed: 12/11/2022] Open
Abstract
Increasing evidence suggests that mechanics play a critical role in regulating brain function at different scales. Downstream integration of mechanical inputs into biochemical signals and genomic pathways causes observable and measurable effects on brain cell fate and can also lead to important pathological consequences. Despite recent advances, the mechanical forces that influence neuronal processes remain largely unexplored, and how endogenous mechanical forces are detected and transduced by brain cells into biochemical and genetic programs have received less attention. In this review, we described the composition of brain tissues and their pronounced microstructural heterogeneity. We discuss the individual role of neuronal and glial cell mechanics in brain homeostasis and diseases. We highlight how changes in the composition and mechanical properties of the extracellular matrix can modulate brain cell functions and describe key mechanisms of the mechanosensing process. We then consider the contribution of mechanobiology in the emergence of brain diseases by providing a critical review on traumatic brain injury, neurodegenerative diseases, and neuroblastoma. We show that a better understanding of the mechanobiology of brain tissues will require to manipulate the physico-chemical parameters of the cell microenvironment, and to develop three-dimensional models that can recapitulate the complexity and spatial diversity of brain tissues in a reproducible and predictable manner. Collectively, these emerging insights shed new light on the importance of mechanobiology and its implication in brain and nerve diseases.
Collapse
Affiliation(s)
- Anthony Procès
- Mechanobiology and Biomaterials group, Interfaces and Complex Fluids Laboratory, Research Institute for Biosciences, University of Mons, Mons, Belgium.,Neurosciences Department, Research Institute for Biosciences, University of Mons, Mons, Belgium
| | - Marine Luciano
- Mechanobiology and Biomaterials group, Interfaces and Complex Fluids Laboratory, Research Institute for Biosciences, University of Mons, Mons, Belgium
| | - Yohalie Kalukula
- Mechanobiology and Biomaterials group, Interfaces and Complex Fluids Laboratory, Research Institute for Biosciences, University of Mons, Mons, Belgium
| | - Laurence Ris
- Neurosciences Department, Research Institute for Biosciences, University of Mons, Mons, Belgium
| | - Sylvain Gabriele
- Mechanobiology and Biomaterials group, Interfaces and Complex Fluids Laboratory, Research Institute for Biosciences, University of Mons, Mons, Belgium
| |
Collapse
|
45
|
Nedozralova H, Basnet N, Ibiricu I, Bodakuntla S, Biertümpfel C, Mizuno N. In situ cryo-electron tomography reveals local cellular machineries for axon branch development. J Biophys Biochem Cytol 2022; 221:213057. [PMID: 35262630 PMCID: PMC8916118 DOI: 10.1083/jcb.202106086] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2021] [Revised: 11/23/2021] [Accepted: 01/31/2022] [Indexed: 01/02/2023] Open
Abstract
Neurons are highly polarized cells forming an intricate network of dendrites and axons. They are shaped by the dynamic reorganization of cytoskeleton components and cellular organelles. Axon branching allows the formation of new paths and increases circuit complexity. However, our understanding of branch formation is sparse due to the lack of direct in-depth observations. Using in situ cellular cryo-electron tomography on primary mouse neurons, we directly visualized the remodeling of organelles and cytoskeleton structures at axon branches. Strikingly, branched areas functioned as hotspots concentrating organelles to support dynamic activities. Unaligned actin filaments assembled at the base of premature branches accompanied by filopodia-like protrusions. Microtubules and ER comigrated into preformed branches to support outgrowth together with accumulating compact, ∼500-nm mitochondria and locally clustered ribosomes. We obtained a roadmap of events supporting the hypothesis of local protein synthesis selectively taking place at axon branches, allowing them to serve as unique control hubs for axon development and downstream neural network formation.
Collapse
Affiliation(s)
- Hana Nedozralova
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Martinsried, Germany.,Laboratory of Structural Cell Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD
| | - Nirakar Basnet
- Laboratory of Structural Cell Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD
| | - Iosune Ibiricu
- Department of Structural Cell Biology, Max Planck Institute of Biochemistry, Martinsried, Germany
| | - Satish Bodakuntla
- Laboratory of Structural Cell Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD
| | - Christian Biertümpfel
- Laboratory of Structural Cell Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD
| | - Naoko Mizuno
- Laboratory of Structural Cell Biology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD.,National Institute of Arthritis and Musculoskeletal and Skin Diseases, National Institutes of Health, Bethesda, MD
| |
Collapse
|
46
|
Gao L, Liu S, Gou L, Hu Y, Liu Y, Deng L, Ma D, Wang H, Yang Q, Chen Z, Liu D, Qiu S, Wang X, Wang D, Wang X, Ren B, Liu Q, Chen T, Shi X, Yao H, Xu C, Li CT, Sun Y, Li A, Luo Q, Gong H, Xu N, Yan J. Single-neuron projectome of mouse prefrontal cortex. Nat Neurosci 2022; 25:515-529. [PMID: 35361973 DOI: 10.1038/s41593-022-01041-5] [Citation(s) in RCA: 77] [Impact Index Per Article: 38.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2021] [Accepted: 02/24/2022] [Indexed: 11/09/2022]
Abstract
Prefrontal cortex (PFC) is the cognitive center that integrates and regulates global brain activity. However, the whole-brain organization of PFC axon projections remains poorly understood. Using single-neuron reconstruction of 6,357 mouse PFC projection neurons, we identified 64 projectome-defined subtypes. Each of four previously known major cortico-cortical subnetworks was targeted by a distinct group of PFC subtypes defined by their first-order axon collaterals. Further analysis unraveled topographic rules of soma distribution within PFC, first-order collateral branch point-dependent target selection and terminal arbor distribution-dependent target subdivision. Furthermore, we obtained a high-precision hierarchical map within PFC and three distinct functionally related PFC modules, each enriched with internal recurrent connectivity. Finally, we showed that each transcriptome subtype corresponds to multiple projectome subtypes found in different PFC subregions. Thus, whole-brain single-neuron projectome analysis reveals organization principles of axon projections within and outside PFC and provides the essential basis for elucidating neuronal connectivity underlying diverse PFC functions.
Collapse
Affiliation(s)
- Le Gao
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Shanghai, China
| | - Sang Liu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Shanghai, China.,School of Future Technology, University of Chinese Academy of Sciences, Beijing, China
| | - Lingfeng Gou
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Yachuang Hu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Shanghai, China
| | - Yanhe Liu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Shanghai, China
| | - Li Deng
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Danyi Ma
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Shanghai, China
| | - Haifang Wang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Qiaoqiao Yang
- Department of Neurosurgery, Zhongshan Hospital, Fudan University, Shanghai, China
| | - Zhaoqin Chen
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Dechen Liu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Shou Qiu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China.,University of Chinese Academy of Sciences, Shanghai, China
| | - Xiaofei Wang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Danying Wang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Xinran Wang
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Biyu Ren
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Qingxu Liu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Tianzhi Chen
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Xiaoxue Shi
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Haishan Yao
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Chun Xu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Chengyu T Li
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Yangang Sun
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China
| | - Anan Li
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, MoE Key Laboratory for Biomedical Photonics, Huazhong University of Science and Technology, Wuhan, China.,HUST-Suzhou Institute for Brainsmatics, JITRI Institute for Brainsmatics, Suzhou, China
| | - Qingming Luo
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, MoE Key Laboratory for Biomedical Photonics, Huazhong University of Science and Technology, Wuhan, China.,HUST-Suzhou Institute for Brainsmatics, JITRI Institute for Brainsmatics, Suzhou, China.,School of Biomedical Engineering, Hainan University, Haikou, China
| | - Hui Gong
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, MoE Key Laboratory for Biomedical Photonics, Huazhong University of Science and Technology, Wuhan, China. .,HUST-Suzhou Institute for Brainsmatics, JITRI Institute for Brainsmatics, Suzhou, China.
| | - Ninglong Xu
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China. .,School of Future Technology, University of Chinese Academy of Sciences, Beijing, China. .,Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai, China.
| | - Jun Yan
- Institute of Neuroscience, State Key Laboratory of Neuroscience, CAS Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai, China. .,School of Future Technology, University of Chinese Academy of Sciences, Beijing, China. .,Shanghai Center for Brain Science and Brain-Inspired Intelligence Technology, Shanghai, China.
| |
Collapse
|
47
|
Steinecke A, Bolton MM, Taniguchi H. Neuromodulatory control of inhibitory network arborization in the developing postnatal neocortex. SCIENCE ADVANCES 2022; 8:eabe7192. [PMID: 35263136 PMCID: PMC8906727 DOI: 10.1126/sciadv.abe7192] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Accepted: 01/19/2022] [Indexed: 06/14/2023]
Abstract
Interregional neuronal communication is pivotal to instructing and adjusting cortical circuit assembly. Subcortical neuromodulatory systems project long-range axons to the cortex and affect cortical processing. However, their roles and signaling mechanisms in cortical wiring remain poorly understood. Here, we explored whether and how the cholinergic system regulates inhibitory axonal ramification of neocortical chandelier cells (ChCs), which control spike generation by innervating axon initial segments of pyramidal neurons. We found that acetylcholine (ACh) signaling through nicotinic ACh receptors (nAChRs) and downstream T-type voltage-dependent calcium (Ca2+) channels cell-autonomously controls axonal arborization in developing ChCs through regulating filopodia initiation. This signaling axis shapes the basal Ca2+ level range in varicosities where filopodia originate. Furthermore, the normal development of ChC axonal arbors requires proper levels of activity in subcortical cholinergic neurons. Thus, the cholinergic system regulates inhibitory network arborization in the developing neocortex and may tune cortical circuit properties depending on early-life experiences.
Collapse
Affiliation(s)
- André Steinecke
- Development and Function of Inhibitory Neural Circuits, Max Planck Florida Institute for Neuroscience, Jupiter, FL 33458, USA
| | - McLean M. Bolton
- Disorders of Neural Circuit Function, Max Planck Florida Institute for Neuroscience, Jupiter, FL 33458, USA
| | - Hiroki Taniguchi
- Development and Function of Inhibitory Neural Circuits, Max Planck Florida Institute for Neuroscience, Jupiter, FL 33458, USA
| |
Collapse
|
48
|
Ketschek A, Holland SM, Gallo G. SARM1 Suppresses Axon Branching Through Attenuation of Axonal Cytoskeletal Dynamics. Front Mol Neurosci 2022; 15:726962. [PMID: 35264929 PMCID: PMC8899016 DOI: 10.3389/fnmol.2022.726962] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2021] [Accepted: 01/20/2022] [Indexed: 12/18/2022] Open
Abstract
Axon branching is a fundamental aspect of neuronal morphogenesis, neuronal circuit formation, and response of the nervous system to injury. Sterile alpha and TIR motif containing 1 (SARM1) was initially identified as promoting Wallerian degeneration of axons. We now report a novel function of SARM1 in postnatal sensory neurons; the suppression of axon branching. Axon collateral branches develop from axonal filopodia precursors through the coordination of the actin and microtubule cytoskeleton. In vitro analysis revealed that cultured P0-2 dorsal root ganglion sensory neurons from a SARM1 knockout (KO) mouse exhibit increased numbers of collateral branches and axonal filopodia relative to wild-type neurons. In SARM1 KO mice, cutaneous sensory endings exhibit increased branching in the skin in vivo with normal density of innervation. Transient axonal actin patches serve as cytoskeletal platforms from which axonal filopodia emerge. Live imaging analysis of axonal actin dynamics showed that SARM1 KO neurons exhibit increased rates of axonal actin patch formation and increased probability that individual patches will give rise to a filopodium before dissipating. SARM1 KO axons contain elevated levels of drebrin and cortactin, two actin regulatory proteins that are positive regulators of actin patches, filopodia formation, and branching. Live imaging of microtubule plus tip dynamics revealed an increase in the rate of formation and velocity of polymerizing tips along the axons of SARM1 KO neurons. Stationary mitochondria define sites along the axon where branches may arise, and the axons of SARM1 KO sensory neurons exhibit an increase in stationary mitochondria. These data reveal SARM1 to be a negative regulator of axonal cytoskeletal dynamics and collateral branching.
Collapse
Affiliation(s)
- Andrea Ketschek
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Sabrina M. Holland
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Gianluca Gallo
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
- Department of Neural Sciences, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| |
Collapse
|
49
|
Differential Regulation of Neurite Outgrowth and Growth Cone Morphology by 3D Fibronectin and Fibronectin-Collagen Extracellular Matrices. Mol Neurobiol 2022; 59:1112-1123. [PMID: 34845592 PMCID: PMC8858852 DOI: 10.1007/s12035-021-02637-x] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Accepted: 11/02/2021] [Indexed: 02/03/2023]
Abstract
The extracellular matrix (ECM) plays a critical role in development, homeostasis, and regeneration of tissue structures and functions. Cell interactions with the ECM are dynamic and cells respond to ECM remodeling by changes in morphology and motility. During nerve regeneration, the ECM facilitates neurite outgrowth and guides axons with target specificity. Decellularized ECMs retain structural, biochemical, and biomechanical cues of native ECM and have the potential to replace damaged matrix to support cell activities during tissue repair. To determine the ECM components that contribute to nerve regeneration, we analyzed neuron-ECM interactions on two types of decellularized ECM. One matrix was composed primarily of fibronectin (FN) fibrils, and the other FN-rich ECM also contained significant numbers of type I collagen (COL I) fibrils. Using primary neurons dissociated from superior cervical ganglion (SCG) explants, we found that neurites were extended on both matrices without a significant difference in average neurite length after 24 h. The most distinctive features of neurites on the FN matrix were numerous short actin-filled protrusions and longer branches extending from neurite shafts. Very few protrusions and branches were detected on FN-COL matrix. Growth cone morphologies also differed with mostly filopodial growth cones on FN matrix whereas on FN-COL matrix, equivalent numbers of filopodial and slender growth cones were formed. Our work provides new information about how changes in major components of the ECM during tissue repair modulate neuron and growth cone morphologies and helps to define the contributions of neuron-ECM interactions to nerve development and regeneration.
Collapse
|
50
|
Abstract
The establishment of a functioning neuronal network is a crucial step in neural development. During this process, neurons extend neurites-axons and dendrites-to meet other neurons and interconnect. Therefore, these neurites need to migrate, grow, branch and find the correct path to their target by processing sensory cues from their environment. These processes rely on many coupled biophysical effects including elasticity, viscosity, growth, active forces, chemical signaling, adhesion and cellular transport. Mathematical models offer a direct way to test hypotheses and understand the underlying mechanisms responsible for neuron development. Here, we critically review the main models of neurite growth and morphogenesis from a mathematical viewpoint. We present different models for growth, guidance and morphogenesis, with a particular emphasis on mechanics and mechanisms, and on simple mathematical models that can be partially treated analytically.
Collapse
Affiliation(s)
- Hadrien Oliveri
- Mathematical Institute, University of Oxford, Oxford, OX2 6GG, UK
| | - Alain Goriely
- Mathematical Institute, University of Oxford, Oxford, OX2 6GG, UK.
| |
Collapse
|