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Li A, Yi J, Li X, Dong L, Ostrow LW, Ma J, Zhou J. Distinct transcriptomic profile of satellite cells contributes to preservation of neuromuscular junctions in extraocular muscles of ALS mice. eLife 2024; 12:RP92644. [PMID: 38661532 PMCID: PMC11045223 DOI: 10.7554/elife.92644] [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: 04/26/2024] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neuromuscular disorder characterized by progressive weakness of almost all skeletal muscles, whereas extraocular muscles (EOMs) are comparatively spared. While hindlimb and diaphragm muscles of end-stage SOD1G93A (G93A) mice (a familial ALS mouse model) exhibit severe denervation and depletion of Pax7+satellite cells (SCs), we found that the pool of SCs and the integrity of neuromuscular junctions (NMJs) are maintained in EOMs. In cell sorting profiles, SCs derived from hindlimb and diaphragm muscles of G93A mice exhibit denervation-related activation, whereas SCs from EOMs of G93A mice display spontaneous (non-denervation-related) activation, similar to SCs from wild-type mice. Specifically, cultured EOM SCs contain more abundant transcripts of axon guidance molecules, including Cxcl12, along with more sustainable renewability than the diaphragm and hindlimb counterparts under differentiation pressure. In neuromuscular co-culture assays, AAV-delivery of Cxcl12 to G93A-hindlimb SC-derived myotubes enhances motor neuron axon extension and innervation, recapitulating the innervation capacity of EOM SC-derived myotubes. G93A mice fed with sodium butyrate (NaBu) supplementation exhibited less NMJ loss in hindlimb and diaphragm muscles. Additionally, SCs derived from G93A hindlimb and diaphragm muscles displayed elevated expression of Cxcl12 and improved renewability following NaBu treatment in vitro. Thus, the NaBu-induced transcriptomic changes resembling the patterns of EOM SCs may contribute to the beneficial effects observed in G93A mice. More broadly, the distinct transcriptomic profile of EOM SCs may offer novel therapeutic targets to slow progressive neuromuscular functional decay in ALS and provide possible 'response biomarkers' in pre-clinical and clinical studies.
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Affiliation(s)
- Ang Li
- Department of Kinesiology, College of Nursing and Health Innovation, The University of Texas at ArlingtonArlingtonUnited States
| | - Jianxun Yi
- Department of Kinesiology, College of Nursing and Health Innovation, The University of Texas at ArlingtonArlingtonUnited States
| | - Xuejun Li
- Department of Kinesiology, College of Nursing and Health Innovation, The University of Texas at ArlingtonArlingtonUnited States
| | - Li Dong
- Department of Kinesiology, College of Nursing and Health Innovation, The University of Texas at ArlingtonArlingtonUnited States
| | - Lyle W Ostrow
- Department of Neurology, Lewis Katz School of Medicine at Temple UniversityPhiladelphiaUnited States
| | - Jianjie Ma
- Department of Surgery, Division of Surgical Sciences, University of VirginiaCharlottesvilleUnited States
| | - Jingsong Zhou
- Department of Kinesiology, College of Nursing and Health Innovation, The University of Texas at ArlingtonArlingtonUnited States
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2
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Li A, Yi J, Li X, Dong L, Ostrow LW, Ma J, Zhou J. Distinct transcriptomic profile of satellite cells contributes to preservation of neuromuscular junctions in extraocular muscles of ALS mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.02.12.528218. [PMID: 36824725 PMCID: PMC9949002 DOI: 10.1101/2023.02.12.528218] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/16/2023]
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neuromuscular disorder characterized by progressive weakness of almost all skeletal muscles, whereas extraocular muscles (EOMs) are comparatively spared. While hindlimb and diaphragm muscles of end-stage SOD1G93A (G93A) mice (a familial ALS mouse model) exhibit severe denervation and depletion of Pax7 + satellite cells (SCs), we found that the pool of SCs and the integrity of neuromuscular junctions (NMJs) are maintained in EOMs. In cell sorting profiles, SCs derived from hindlimb and diaphragm muscles of G93A mice exhibit denervation-related activation, whereas SCs from EOMs of G93A mice display spontaneous (non-denervation-related) activation, similar to SCs from wild-type mice. Specifically, cultured EOM SCs contain more abundant transcripts of axon guidance molecules, including Cxcl12 , along with more sustainable renewability than the diaphragm and hindlimb counterparts under differentiation pressure. In neuromuscular co-culture assays, AAV-delivery of Cxcl12 to G93A-hindlimb SC-derived myotubes enhances motor neuron axon extension and innervation, recapitulating the innervation capacity of EOM SC-derived myotubes. G93A mice fed with sodium butyrate (NaBu) supplementation exhibited less NMJ loss in hindlimb and diaphragm muscles. Additionally, SCs derived from G93A hindlimb and diaphragm muscles displayed elevated expression of Cxcl12 and improved renewability following NaBu treatment in vitro . Thus, the NaBu-induced transcriptomic changes resembling the patterns of EOM SCs may contribute to the beneficial effects observed in G93A mice. More broadly, the distinct transcriptomic profile of EOM SCs may offer novel therapeutic targets to slow progressive neuromuscular functional decay in ALS and provide possible "response biomarkers" in pre-clinical and clinical studies.
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3
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Vemula SK, Kim SA, Muvavarirwa T, Bell JL, Whitman MC. Impaired Extraocular Muscle Innervation Is Present Before Eye Opening in a Mouse Model of Infantile Nystagmus Syndrome. Invest Ophthalmol Vis Sci 2022; 63:4. [PMID: 36083589 PMCID: PMC9469029 DOI: 10.1167/iovs.63.10.4] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022] Open
Abstract
Purpose To determine if extraocular muscles (EOMs) from mice with nystagmus show abnormalities in myofiber composition and innervation, as seen in EOMs from human nystagmus patients, and to determine when in development those changes occur. Methods Balb/c albino mice were crossed to pigmented mice to generate heterozygous mice, which were mated to create experimental litters containing albinos and wild-type controls. Orbits were harvested from adult animals (12 weeks old); on postnatal day (P)0, P10, P14, and P21; and from 6-week-old animals. EOM sections were collected from the intraorbital portion of the muscles. Sections were immunostained for slow and fast myosin and for neuromuscular junctions (NMJs). The proportion of each myofiber subtype and the density and size of NMJs were quantified. Initial innervation patterns were assessed using whole-mount immunostaining of embryonic day (E)13.5 embryos expressing IslMN:GFP. Results Adult albino EOMs display an increased proportion of slow myofibers, larger slow myofibers, and a decreased density of NMJs—similar to human nystagmus patients. The percentage of NMJs on slow myofibers is also lower in albino animals. The initial innervation pattern of the incoming ocular motor neurons is normal in E13.5 albino embryos. Differences in the proportion of slow and fast myofiber subtypes are present as early as P14, and a lower percentage of NMJs on slow myofibers is present by P21. There is a lower density of NMJs on albino EOMs as early as P10, prior to eye opening. Conclusions Changes in NMJ development observed before eye opening indicate that nystagmus is not solely secondary to poor vision.
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Affiliation(s)
- Sampath Kumar Vemula
- Department of Ophthalmology, Boston Children's Hospital, Boston, Massachusetts, United States
| | - Seoyoung A Kim
- Department of Ophthalmology, Boston Children's Hospital, Boston, Massachusetts, United States
| | - Tapiwa Muvavarirwa
- Department of Ophthalmology, Boston Children's Hospital, Boston, Massachusetts, United States
| | - Jessica L Bell
- Department of Ophthalmology, Boston Children's Hospital, Boston, Massachusetts, United States
| | - Mary C Whitman
- Department of Ophthalmology, Boston Children's Hospital, Boston, Massachusetts, United States.,Department of Ophthalmology, Harvard Medical School, Boston, Massachusetts, United States.,F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, Massachusetts, United States
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Kamitakahara AK, Ali Marandi Ghoddousi R, Lanjewar AL, Magalong VM, Wu HH, Levitt P. MET Receptor Tyrosine Kinase Regulates Lifespan Ultrasonic Vocalization and Vagal Motor Neuron Development. Front Neurosci 2021; 15:768577. [PMID: 34803597 PMCID: PMC8600253 DOI: 10.3389/fnins.2021.768577] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 10/14/2021] [Indexed: 11/25/2022] Open
Abstract
The intrinsic muscles of the larynx are innervated by the vagal motor nucleus ambiguus (nAmb), which provides direct motor control over vocal production in humans and rodents. Here, we demonstrate in mice using the Phox2b Cre line, that conditional embryonic deletion of the gene encoding the MET receptor tyrosine kinase (MET) in the developing brainstem (cKO) results in highly penetrant, severe deficits in ultrasonic vocalization in early postnatal life. Major deficits and abnormal vocalization patterns persist into adulthood in more than 70% of mice, with the remaining recovering the ability to vocalize, reflecting heterogeneity in circuit restitution. We show that underlying the functional deficits, conditional deletion of Met results in a loss of approximately one-third of MET+ nAmb motor neurons, which begins as early as embryonic day 14.5. The loss of motor neurons is specific to the nAmb, as other brainstem motor and sensory nuclei are unaffected. In the recurrent laryngeal nerve, through which nAmb motor neurons project to innervate the larynx, there is a one-third loss of axons in cKO mice. Together, the data reveal a novel, heterogenous MET-dependence, for which MET differentially affects survival of a subset of nAmb motor neurons necessary for lifespan ultrasonic vocal capacity.
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Affiliation(s)
- Anna K. Kamitakahara
- Program in Developmental Neuroscience and Neurogenetics, Children’s Hospital Los Angeles, The Saban Research Institute, Los Angeles, CA, United States
- Department of Pediatrics, Keck School of Medicine of University of Southern California, Los Angeles, CA, United States
| | - Ramin Ali Marandi Ghoddousi
- Program in Developmental Neuroscience and Neurogenetics, Children’s Hospital Los Angeles, The Saban Research Institute, Los Angeles, CA, United States
- Department of Pediatrics, Keck School of Medicine of University of Southern California, Los Angeles, CA, United States
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, United States
| | - Alexandra L. Lanjewar
- Program in Developmental Neuroscience and Neurogenetics, Children’s Hospital Los Angeles, The Saban Research Institute, Los Angeles, CA, United States
- Department of Pediatrics, Keck School of Medicine of University of Southern California, Los Angeles, CA, United States
- Neuroscience Graduate Program, University of Southern California, Los Angeles, CA, United States
| | - Valerie M. Magalong
- Program in Developmental Neuroscience and Neurogenetics, Children’s Hospital Los Angeles, The Saban Research Institute, Los Angeles, CA, United States
- Department of Pediatrics, Keck School of Medicine of University of Southern California, Los Angeles, CA, United States
| | - Hsiao-Huei Wu
- Department of Pediatrics, Keck School of Medicine of University of Southern California, Los Angeles, CA, United States
| | - Pat Levitt
- Program in Developmental Neuroscience and Neurogenetics, Children’s Hospital Los Angeles, The Saban Research Institute, Los Angeles, CA, United States
- Department of Pediatrics, Keck School of Medicine of University of Southern California, Los Angeles, CA, United States
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Carretero-Rodriguez L, Guðjónsdóttir R, Poparic I, Reilly ML, Chol M, Bianco IH, Chiapello M, Feret R, Deery MJ, Guthrie S. The Rac-GAP alpha2-Chimaerin Signals via CRMP2 and Stathmins in the Development of the Ocular Motor System. J Neurosci 2021; 41:6652-6672. [PMID: 34168008 PMCID: PMC8336708 DOI: 10.1523/jneurosci.0983-19.2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2019] [Revised: 04/02/2021] [Accepted: 04/05/2021] [Indexed: 11/21/2022] Open
Abstract
A precise sequence of axon guidance events is required for the development of the ocular motor system. Three cranial nerves grow toward, and connect with, six extraocular muscles in a stereotyped pattern, to control eye movements. The signaling protein alpha2-chimaerin (α2-CHN) plays a pivotal role in the formation of the ocular motor system; mutations in CHN1, encoding α2-CHN, cause the human eye movement disorder Duane Retraction Syndrome (DRS). Our research has demonstrated that the manipulation of α2-chn signaling in the zebrafish embryo leads to ocular motor axon wiring defects, although the signaling cascades regulated by α2-chn remain poorly understood. Here, we demonstrate that several cytoskeletal regulatory proteins-collapsin response mediator protein 2 (CRMP2; encoded by the gene dpysl2), stathmin1, and stathmin 2-bind to α2-CHN. dpysl2, stathmin1, and especially stathmin2 are expressed by ocular motor neurons. We find that the manipulation of dpysl2 and of stathmins in zebrafish larvae leads to defects in both the axon wiring of the ocular motor system and the optokinetic reflex, impairing horizontal eye movements. Knockdowns of these molecules in zebrafish larvae of either sex caused axon guidance phenotypes that included defasciculation and ectopic branching; in some cases, these phenotypes were reminiscent of DRS. chn1 knock-down phenotypes were rescued by the overexpression of CRMP2 and STMN1, suggesting that these proteins act in the same signaling pathway. These findings suggest that CRMP2 and stathmins signal downstream of α2-CHN to orchestrate ocular motor axon guidance and to control eye movements.SIGNIFICANCE STATEMENT The precise control of eye movements is crucial for the life of vertebrate animals, including humans. In humans, this control depends on the arrangement of nerve wiring of the ocular motor system, composed of three nerves and six muscles, a system that is conserved across vertebrate phyla. Mutations in the protein alpha2-chimaerin have previously been shown to cause eye movement disorders (squint) and axon wiring defects in humans. Our recent work has unraveled how alpha2-chimaerin coordinates axon guidance of the ocular motor system in animal models. In this article, we demonstrate key roles for the proteins CRMP2 and stathmin 1/2 in the signaling pathway orchestrated by alpha2-chimaerin, potentially giving insight into the etiology of eye movement disorders in humans.
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Affiliation(s)
| | | | - Ivana Poparic
- Department of Developmental Neurobiology, King's College London, London SE1 1UL, United Kingdom
| | | | - Mary Chol
- Department of Developmental Neurobiology, King's College London, London SE1 1UL, United Kingdom
| | - Isaac H Bianco
- Department of Neuroscience, Physiology and Pharmacology, University College London, London WC1E 6BT, United Kingdom
| | - Marco Chiapello
- Cambridge Centre for Proteomics, Cambridge Systems Biology Centre, Department of Biochemistry, University of Cambridge, Cambridge CB2 1QR, United Kingdom
| | - Renata Feret
- Institute for Sustainable Plant Protection, National Research Council, 10135 Torino, Italy
| | - Michael J Deery
- Institute for Sustainable Plant Protection, National Research Council, 10135 Torino, Italy
| | - Sarah Guthrie
- School of Life Sciences, University of Sussex, Brighton BN7 9QG, United Kingdom
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Whitman MC. Axonal Growth Abnormalities Underlying Ocular Cranial Nerve Disorders. Annu Rev Vis Sci 2021; 7:827-850. [PMID: 34081534 DOI: 10.1146/annurev-vision-093019-114307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Abnormalities in cranial motor nerve development cause paralytic strabismus syndromes, collectively referred to as congenital cranial dysinnervation disorders, in which patients cannot fully move their eyes. These disorders can arise through one of two mechanisms: (a) defective motor neuron specification, usually by loss of a transcription factor necessary for brainstem patterning, or (b) axon growth and guidance abnormalities of the oculomotor, trochlear, and abducens nerves. This review focuses on our current understanding of axon guidance mechanisms in the cranial motor nerves and how disease-causing mutations disrupt axon targeting. Abnormalities of axon growth and guidance are often limited to a single nerve or subdivision, even when the causative gene is ubiquitously expressed. Additionally, when one nerve is absent, its normal target muscles attract other motor neurons. Study of these disorders highlights the complexities of axon guidance and how each population of neurons uses a unique but overlapping set of axon guidance pathways. Expected final online publication date for the Annual Review of Vision Science, Volume 7 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Mary C Whitman
- Department of Ophthalmology, Boston Children's Hospital and Harvard Medical School, Boston, Massachusetts 02115, USA;
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7
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Abstract
The extraordinary diversity, variability, and complexity of cell types in the vertebrate brain is overwhelming and far exceeds that of any other organ. This complexity is the result of multiple cell divisions and intricate gene regulation and cell movements that take place during embryonic development. Understanding the cellular and molecular mechanisms underlying these complicated developmental processes requires the ability to obtain a complete registry of interconnected events often taking place far apart from each other. To assist with this challenging task, developmental neuroscientists take advantage of a broad set of methods and technologies, often adopted from other fields of research. Here, we review some of the methods developed in recent years whose use has rapidly spread for application in the field of developmental neuroscience. We also provide several considerations regarding the promise that these techniques hold for the near future and share some ideas on how existing methods from other research fields could help with the analysis of how neural circuits emerge.
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Affiliation(s)
- Augusto Escalante
- Instituto de Neurociencias (Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández, CSIC-UMH), Campus San Juan, Av. Ramón y Cajal s/n, Alicante 03550, Spain
| | - Rocío González-Martínez
- Instituto de Neurociencias (Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández, CSIC-UMH), Campus San Juan, Av. Ramón y Cajal s/n, Alicante 03550, Spain
| | - Eloísa Herrera
- Instituto de Neurociencias (Consejo Superior de Investigaciones Científicas-Universidad Miguel Hernández, CSIC-UMH), Campus San Juan, Av. Ramón y Cajal s/n, Alicante 03550, Spain
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8
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Senthilkumar S, Venugopal C, Parveen S, K S, Rai KS, Kutty BM, Dhanushkodi A. Remarkable migration propensity of dental pulp stem cells towards neurodegenerative milieu: An in vitro analysis. Neurotoxicology 2020; 81:89-100. [PMID: 32905802 DOI: 10.1016/j.neuro.2020.08.006] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2020] [Revised: 07/25/2020] [Accepted: 08/30/2020] [Indexed: 02/07/2023]
Abstract
Stem cell therapy provides a ray of hope for treating neurodegenerative diseases (ND). Bone marrow mesenchymal stem cells (BM-MSC) were extensively investigated for their role in neuroregeneration. However, drawbacks like painful bone marrow extraction, less proliferation and poor CNS engraftment following systemic injections of BM-MSC prompt us to search for alternate/appropriate source of MSC for treating ND. In this context, dental pulp stem cells (DPSC) could be an alternative to BM-MSC as it possess both mesenchymal and neural characteristic features due to its origin from ectoderm, ease of isolation, higher proliferation index and better neuroprotection. A study on the migration potential of DPSC compared to BM-MSC in a neurodegenerative condition is warranted. Given the neural crest origin, we hypothesize that DPSC possess better migration towards neurodegenerative milieu as compared to BM-MSC. In this prospect, we investigated the migration potential of DPSC in an in vitro neurodegenerative condition. Towards this, transwell, Matrigel and chorioallantoic membrane (CAM) migration assays were carried-out by seeding hippocampal neurons in the lower chamber and treated with 300 μM kainic acid (KA) for 6 h to induce neurodegeneration. Subsequently, the upper chamber of transwell was loaded with DPSC/BM-MSC and their migration potential was assessed following 24 h of incubation. Our results revealed that the migration potential of DPSC/BM-MSC was comparable in non-degenerative condition. However, following injury the migration potential of DPSC towards the degenerating site was significantly higher as compared to BM-MSC. Furthermore, upon exposure of naïve DPSC/BM-MSCs to culture medium derived from neurodegenerative milieu resulted in significant upregulation of homing factors like SDF-1alpha, CXCR-4, VCAM-1, VLA-4, CD44, MMP-2 suggesting that the superior migration potential of DPSC might be due to prompt expression of homing factors in DPSC compared to BM-MSCs.
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Affiliation(s)
- Sivapriya Senthilkumar
- Manipal Institute of Regenerative Medicine, Manipal Academy of Higher Education, Bangalore, Karnataka, India
| | - Chaitra Venugopal
- Manipal Institute of Regenerative Medicine, Manipal Academy of Higher Education, Bangalore, Karnataka, India
| | - Shagufta Parveen
- Manipal Institute of Regenerative Medicine, Manipal Academy of Higher Education, Bangalore, Karnataka, India
| | - Shobha K
- Manipal Institute of Regenerative Medicine, Manipal Academy of Higher Education, Bangalore, Karnataka, India
| | - Kiranmai S Rai
- Dept. of Physiology, Melaka Manipal Medical College, Manipal Academy of Higher Education, Manipal, Karnataka, India
| | - Bindu M Kutty
- Department of Neurophysiology, National Institute of Mental Health and Neurosciences, Bangalore, Karnataka, India
| | - Anandh Dhanushkodi
- Manipal Institute of Regenerative Medicine, Manipal Academy of Higher Education, Bangalore, Karnataka, India.
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Whitman MC, Miyake N, Nguyen EH, Bell JL, Matos Ruiz PM, Chan WM, Di Gioia SA, Mukherjee N, Barry BJ, Bosley TM, Khan AO, Engle EC. Decreased ACKR3 (CXCR7) function causes oculomotor synkinesis in mice and humans. Hum Mol Genet 2020; 28:3113-3125. [PMID: 31211835 DOI: 10.1093/hmg/ddz137] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2019] [Revised: 06/08/2019] [Accepted: 06/10/2019] [Indexed: 01/17/2023] Open
Abstract
Oculomotor synkinesis is the involuntary movement of the eyes or eyelids with a voluntary attempt at a different movement. The chemokine receptor CXCR4 and its ligand CXCL12 regulate oculomotor nerve development; mice with loss of either molecule have oculomotor synkinesis. In a consanguineous family with congenital ptosis and elevation of the ptotic eyelid with ipsilateral abduction, we identified a co-segregating homozygous missense variant (c.772G>A) in ACKR3, which encodes an atypical chemokine receptor that binds CXCL12 and functions as a scavenger receptor, regulating levels of CXCL12 available for CXCR4 signaling. The mutant protein (p.V258M) is expressed and traffics to the cell surface but has a lower binding affinity for CXCL12. Mice with loss of Ackr3 have variable phenotypes that include misrouting of the oculomotor and abducens nerves. All embryos show oculomotor nerve misrouting, ranging from complete misprojection in the midbrain, to aberrant peripheral branching, to a thin nerve, which aberrantly innervates the lateral rectus (as seen in Duane syndrome). The abducens nerve phenotype ranges from complete absence, to aberrant projections within the orbit, to a normal trajectory. Loss of ACKR3 in the midbrain leads to downregulation of CXCR4 protein, consistent with reports that excess CXCL12 causes ligand-induced degradation of CXCR4. Correspondingly, excess CXCL12 applied to ex vivo oculomotor slices causes axon misrouting, similar to inhibition of CXCR4. Thus, ACKR3, through its regulation of CXCL12 levels, is an important regulator of axon guidance in the oculomotor system; complete loss causes oculomotor synkinesis in mice, while reduced function causes oculomotor synkinesis in humans.
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Affiliation(s)
- Mary C Whitman
- Department of Ophthalmology, Boston Children's Hospital, Boston, MA, USA.,Department of Ophthalmology, Harvard Medical School, Boston, MA, USA.,F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
| | - Noriko Miyake
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
| | - Elaine H Nguyen
- Department of Ophthalmology, Boston Children's Hospital, Boston, MA, USA.,F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
| | - Jessica L Bell
- Department of Ophthalmology, Boston Children's Hospital, Boston, MA, USA.,F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
| | - Paola M Matos Ruiz
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA.,Department of Neurology, Boston Children's Hospital, Boston, MA, USA
| | - Wai-Man Chan
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA.,Department of Neurology, Boston Children's Hospital, Boston, MA, USA.,Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - Silvio Alessandro Di Gioia
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA.,Department of Neurology, Boston Children's Hospital, Boston, MA, USA
| | - Nisha Mukherjee
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA
| | - Brenda J Barry
- F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA.,Department of Neurology, Boston Children's Hospital, Boston, MA, USA.,Howard Hughes Medical Institute, Chevy Chase, MD, USA
| | - T M Bosley
- Department of Ophthalmology, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia
| | - Arif O Khan
- Division of Pediatric Ophthalmology, King Khaled Eye Specialist Hospital, Riyadh, Saudi Arabia
| | - Elizabeth C Engle
- Department of Ophthalmology, Boston Children's Hospital, Boston, MA, USA.,Department of Ophthalmology, Harvard Medical School, Boston, MA, USA.,F.M. Kirby Neurobiology Center, Boston Children's Hospital, Boston, MA, USA.,Department of Neurology, Boston Children's Hospital, Boston, MA, USA.,Department of Neurology, Harvard Medical School, Boston, MA, USA.,Howard Hughes Medical Institute, Chevy Chase, MD, USA
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10
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Xie Y, Schneider KJ, Ali SA, Hogikyan ND, Feldman EL, Brenner MJ. Current landscape in motoneuron regeneration and reconstruction for motor cranial nerve injuries. Neural Regen Res 2020; 15:1639-1649. [PMID: 32209763 PMCID: PMC7437597 DOI: 10.4103/1673-5374.276325] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
The intricate anatomy and physiology of cranial nerves have inspired clinicians and scientists to study their roles in the nervous system. Damage to motor cranial nerves may result from a variety of organic or iatrogenic insults and causes devastating functional impairment and disfigurement. Surgical innovations directed towards restoring function to injured motor cranial nerves and their associated organs have evolved to include nerve repair, grafting, substitution, and muscle transposition. In parallel with this progress, research on tissue-engineered constructs, development of bioelectrical interfaces, and modulation of the regenerative milieu through cellular, immunomodulatory, or neurotrophic mechanisms has proliferated to enhance the available repertoire of clinically applicable reconstructive options. Despite these advances, patients continue to suffer from functional limitations relating to inadequate cranial nerve regeneration, aberrant reinnervation, or incomplete recovery of neuromuscular function. These shortfalls have profound quality of life ramifications and provide an impetus to further elucidate mechanisms underlying cranial nerve denervation and to improve repair. In this review, we summarize the literature on reconstruction and regeneration of motor cranial nerves following various injury patterns. We focus on seven cranial nerves with predominantly efferent functions and highlight shared patterns of injuries and clinical manifestations. We also present an overview of the existing reconstructive approaches, from facial reanimation, laryngeal reinnervation, to variations of interposition nerve grafts for reconstruction. We discuss ongoing endeavors to promote nerve regeneration and to suppress aberrant reinnervation and the development of synkinesis. Insights from these studies will shed light on recent progress and new horizons in understanding the biomechanics of peripheral nerve neurobiology, with emphasis on promising strategies for optimizing neural regeneration and identifying future directions in the field of motor cranial neuron research.
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Affiliation(s)
- Yanjun Xie
- Department of Otolaryngology-Head and Neck Surgery, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Kevin J Schneider
- Department of Otolaryngology-Head and Neck Surgery, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Syed A Ali
- Department of Otolaryngology-Head and Neck Surgery, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Norman D Hogikyan
- Department of Otolaryngology-Head and Neck Surgery, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Eva L Feldman
- Department of Neurology, University of Michigan Medical School, Ann Arbor, MI, USA
| | - Michael J Brenner
- Department of Otolaryngology-Head and Neck Surgery, University of Michigan Medical School, Ann Arbor, MI, USA
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11
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Fujiki R, Lee JY, Jurgens JA, Whitman MC, Engle EC. Isolation and Culture of Oculomotor, Trochlear, and Spinal Motor Neurons from Prenatal Islmn:GFP Transgenic Mice. J Vis Exp 2019:10.3791/60440. [PMID: 31789317 PMCID: PMC7036286 DOI: 10.3791/60440] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
Oculomotor neurons (CN3s) and trochlear neurons (CN4s) exhibit remarkable resistance to degenerative motor neuron diseases such as amyotrophic lateral sclerosis (ALS) when compared to spinal motor neurons (SMNs). The ability to isolate and culture primary mouse CN3s, CN4s, and SMNs would provide an approach to study mechanisms underlying this selective vulnerability. To date, most protocols use heterogeneous cell cultures, which can confound the interpretation of experimental outcomes. To minimize the problems associated with mixed-cell populations, pure cultures are indispensable. Here, the first protocol describes in detail how to efficiently purify and cultivate CN3s/CN4s alongside SMNs counterparts from the same embryos using embryonic day 11.5 (E11.5) IslMN:GFP transgenic mouse embryos. The protocol provides details on the tissue dissection and dissociation, FACS-based cell isolation, and in vitro cultivation of cells from CN3/CN4 and SMN nuclei. This protocol adds a novel in vitro CN3/CN4 culture system to existing protocols and simultaneously provides a pure species- and age-matched SMN culture for comparison. Analyses focusing on the morphological, cellular, molecular, and electrophysiological characteristics of motor neurons are feasible in this culture system. This protocol will enable research into the mechanisms that define motor neuron development, selective vulnerability, and disease.
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Affiliation(s)
- Ryosuke Fujiki
- Department of Neurology, Boston Children's Hospital; FM Kirby Neurobiology Center, Boston Children's Hospital; Department of Neurology, Harvard Medical School; Medical Genetics Training Program, Harvard Medical School; Department of Neurology, Kokura Memorial Hospital
| | - Joun Y Lee
- Department of Neurology, Boston Children's Hospital; FM Kirby Neurobiology Center, Boston Children's Hospital; Department of Genetics, Albert Einstein College of Medicine
| | - Julie A Jurgens
- Department of Neurology, Boston Children's Hospital; FM Kirby Neurobiology Center, Boston Children's Hospital; Department of Neurology, Harvard Medical School; Broad Institute of M.I.T. and Harvard
| | - Mary C Whitman
- FM Kirby Neurobiology Center, Boston Children's Hospital; Department of Ophthalmology, Boston Children's Hospital; Department of Ophthalmology, Harvard Medical School
| | - Elizabeth C Engle
- Department of Neurology, Boston Children's Hospital; FM Kirby Neurobiology Center, Boston Children's Hospital; Department of Neurology, Harvard Medical School; Medical Genetics Training Program, Harvard Medical School; Department of Ophthalmology, Boston Children's Hospital; Department of Ophthalmology, Harvard Medical School; Broad Institute of M.I.T. and Harvard; Howard Hughes Medical Institute;
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Whitman MC, Bell JL, Nguyen EH, Engle EC. Ex Vivo Oculomotor Slice Culture from Embryonic GFP-Expressing Mice for Time-Lapse Imaging of Oculomotor Nerve Outgrowth. J Vis Exp 2019. [PMID: 31380850 DOI: 10.3791/59911] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023] Open
Abstract
Accurate eye movements are crucial for vision, but the development of the ocular motor system, especially the molecular pathways controlling axon guidance, has not been fully elucidated. This is partly due to technical limitations of traditional axon guidance assays. To identify additional axon guidance cues influencing the oculomotor nerve, an ex vivo slice assay to image the oculomotor nerve in real-time as it grows towards the eye was developed. E10.5 IslMN-GFP embryos are used to generate ex vivo slices by embedding them in agarose, slicing on a vibratome, then growing them in a microscope stage-top incubator with time-lapse photomicroscopy for 24-72 h. Control slices recapitulate the in vivo timing of outgrowth of axons from the nucleus to the orbit. Small molecule inhibitors or recombinant proteins can be added to the culture media to assess the role of different axon guidance pathways. This method has the advantages of maintaining more of the local microenvironment through which axons traverse, not axotomizing the growing axons, and assessing the axons at multiple points along their trajectory. It can also identify effects on specific subsets of axons. For example, inhibition of CXCR4 causes axons still within the midbrain to grow dorsally rather than ventrally, but axons that have already exited ventrally are not affected.
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Affiliation(s)
- Mary C Whitman
- Department of Ophthalmology, Boston Children's Hospital; Department of Ophthalmology, Harvard Medical School; F.M. Kirby Neurobiology Center, Boston Children's Hospital;
| | - Jessica L Bell
- Department of Ophthalmology, Boston Children's Hospital; F.M. Kirby Neurobiology Center, Boston Children's Hospital
| | - Elaine H Nguyen
- Department of Ophthalmology, Boston Children's Hospital; F.M. Kirby Neurobiology Center, Boston Children's Hospital
| | - Elizabeth C Engle
- Department of Ophthalmology, Boston Children's Hospital; Department of Ophthalmology, Harvard Medical School; F.M. Kirby Neurobiology Center, Boston Children's Hospital; Department of Neurology, Boston Children's Hospital; Department of Neurology, Harvard Medical School; Howard Hughes Medical Institute
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