1
|
Zhou Y, Bhatt H, Mojica CA, Xin H, Pessina MA, Rosene DL, Moore TL, Medalla M. Mesenchymal-derived extracellular vesicles enhance microglia-mediated synapse remodeling after cortical injury in aging Rhesus monkeys. J Neuroinflammation 2023; 20:201. [PMID: 37660145 PMCID: PMC10475204 DOI: 10.1186/s12974-023-02880-0] [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: 05/10/2023] [Accepted: 08/23/2023] [Indexed: 09/04/2023] Open
Abstract
Understanding the microglial neuro-immune interactions in the primate brain is vital to developing therapeutics for cortical injury, such as stroke or traumatic brain injury. Our previous work showed that mesenchymal-derived extracellular vesicles (MSC-EVs) enhanced motor recovery in aged rhesus monkeys following injury of primary motor cortex (M1), by promoting homeostatic ramified microglia, reducing injury-related neuronal hyperexcitability, and enhancing synaptic plasticity in perilesional cortices. A focal lesion was induced via surgical ablation of pial blood vessels over lying the cortical hand representation of M1 of aged female rhesus monkeys, that received intravenous infusions of either vehicle (veh) or EVs 24 h and again 14 days post-injury. The current study used this same cohort to address how these injury- and recovery-associated changes relate to structural and molecular interactions between microglia and neuronal synapses. Using multi-labeling immunohistochemistry, high-resolution microscopy, and gene expression analysis, we quantified co-expression of synaptic markers (VGLUTs, GLURs, VGAT, GABARs), microglia markers (Iba1, P2RY12), and C1q, a complement pathway protein for microglia-mediated synapse phagocytosis, in perilesional M1 and premotor cortices (PMC). We compared this lesion cohort to age-matched non-lesion controls (ctr). Our findings revealed a lesion-related loss of excitatory synapses in perilesional areas, which was ameliorated by EV treatment. Further, we found region-dependent effects of EVs on microglia and C1q expression. In perilesional M1, EV treatment and enhanced functional recovery were associated with increased expression of C1q + hypertrophic microglia, which are thought to have a role in debris-clearance and anti-inflammatory functions. In PMC, EV treatment was associated with decreased C1q + synaptic tagging and microglia-spine contacts. Our results suggest that EV treatment may enhance synaptic plasticity via clearance of acute damage in perilesional M1, and thereby preventing chronic inflammation and excessive synaptic loss in PMC. These mechanisms may act to preserve synaptic cortical motor networks and a balanced normative M1/PMC synaptic function to support functional recovery after injury.
Collapse
Affiliation(s)
- Yuxin Zhou
- Department of Anatomy & Neurobiology, Boston University, Chobanian & Avedisian School of Medicine, Boston, MA, 02118, USA
| | - Hrishti Bhatt
- Department of Anatomy & Neurobiology, Boston University, Chobanian & Avedisian School of Medicine, Boston, MA, 02118, USA
| | - Chromewell A Mojica
- Department of Anatomy & Neurobiology, Boston University, Chobanian & Avedisian School of Medicine, Boston, MA, 02118, USA
| | - Hongqi Xin
- Department of Neurology, Henry Ford Health Systems, Detroit, MI, 48202, USA
| | - Monica A Pessina
- Department of Anatomy & Neurobiology, Boston University, Chobanian & Avedisian School of Medicine, Boston, MA, 02118, USA
| | - Douglas L Rosene
- Department of Anatomy & Neurobiology, Boston University, Chobanian & Avedisian School of Medicine, Boston, MA, 02118, USA
- Center for Systems Neuroscience, Boston University, Boston, MA, 02215, USA
| | - Tara L Moore
- Department of Anatomy & Neurobiology, Boston University, Chobanian & Avedisian School of Medicine, Boston, MA, 02118, USA
- Center for Systems Neuroscience, Boston University, Boston, MA, 02215, USA
| | - Maria Medalla
- Department of Anatomy & Neurobiology, Boston University, Chobanian & Avedisian School of Medicine, Boston, MA, 02118, USA.
- Center for Systems Neuroscience, Boston University, Boston, MA, 02215, USA.
| |
Collapse
|
2
|
Zhang H, Kang DH, Piantino M, Tominaga D, Fujimura T, Nakatani N, Taylor JN, Furihata T, Matsusaki M, Fujita S. Rapid Quantification of Microvessels of Three-Dimensional Blood-Brain Barrier Model Using Optical Coherence Tomography and Deep Learning Algorithm. BIOSENSORS 2023; 13:818. [PMID: 37622905 PMCID: PMC10452445 DOI: 10.3390/bios13080818] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/19/2023] [Revised: 08/02/2023] [Accepted: 08/09/2023] [Indexed: 08/26/2023]
Abstract
The blood-brain barrier (BBB) is a selective barrier that controls the transport between the blood and neural tissue features and maintains brain homeostasis to protect the central nervous system (CNS). In vitro models can be useful to understand the role of the BBB in disease and assess the effects of drug delivery. Recently, we reported a 3D BBB model with perfusable microvasculature in a Transwell insert. It replicates several key features of the native BBB, as it showed size-selective permeability of different molecular weights of dextran, activity of the P-glycoprotein efflux pump, and functionality of receptor-mediated transcytosis (RMT), which is the most investigated pathway for the transportation of macromolecules through endothelial cells of the BBB. For quality control and permeability evaluation in commercial use, visualization and quantification of the 3D vascular lumen structures is absolutely crucial. Here, for the first time, we report a rapid, non-invasive optical coherence tomography (OCT)-based approach to quantify the microvessel network in the 3D in vitro BBB model. Briefly, we successfully obtained the 3D OCT images of the BBB model and further processed the images using three strategies: morphological imaging processing (MIP), random forest machine learning using the Trainable Weka Segmentation plugin (RF-TWS), and deep learning using pix2pix cGAN. The performance of these methods was evaluated by comparing their output images with manually selected ground truth images. It suggested that deep learning performed well on object identification of OCT images and its computation results of vessel counts and surface areas were close to the ground truth results. This study not only facilitates the permeability evaluation of the BBB model but also offers a rapid, non-invasive observational and quantitative approach for the increasing number of other 3D in vitro models.
Collapse
Affiliation(s)
- Huiting Zhang
- AIST-Osaka University Advanced Photonics and Biosensing Open Innovation Laboratory, National Institute of Advanced Industrial Science and Technology (AIST), 2-1 Yamadaoka, Suita 565-0871, Osaka, Japan; (H.Z.); (J.N.T.); (M.M.)
- Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita 565-0871, Osaka, Japan; (D.-H.K.); (M.P.)
| | - Dong-Hee Kang
- Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita 565-0871, Osaka, Japan; (D.-H.K.); (M.P.)
| | - Marie Piantino
- Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita 565-0871, Osaka, Japan; (D.-H.K.); (M.P.)
| | - Daisuke Tominaga
- Cellular and Molecular Biotechnology Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), 1-1-1 Higashi, Tsukuba 305-8565, Ibaraki, Japan;
| | - Takashi Fujimura
- SCREEN Holdings Co., Ltd., 322 Furukawa-cho, Hazukashi, Fushimi-ku, Kyoto 612-8486, Kyoto, Japan; (T.F.); (N.N.)
| | - Noriyuki Nakatani
- SCREEN Holdings Co., Ltd., 322 Furukawa-cho, Hazukashi, Fushimi-ku, Kyoto 612-8486, Kyoto, Japan; (T.F.); (N.N.)
| | - J. Nicholas Taylor
- AIST-Osaka University Advanced Photonics and Biosensing Open Innovation Laboratory, National Institute of Advanced Industrial Science and Technology (AIST), 2-1 Yamadaoka, Suita 565-0871, Osaka, Japan; (H.Z.); (J.N.T.); (M.M.)
| | - Tomomi Furihata
- School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji 192-0392, Tokyo, Japan;
| | - Michiya Matsusaki
- AIST-Osaka University Advanced Photonics and Biosensing Open Innovation Laboratory, National Institute of Advanced Industrial Science and Technology (AIST), 2-1 Yamadaoka, Suita 565-0871, Osaka, Japan; (H.Z.); (J.N.T.); (M.M.)
- Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita 565-0871, Osaka, Japan; (D.-H.K.); (M.P.)
| | - Satoshi Fujita
- AIST-Osaka University Advanced Photonics and Biosensing Open Innovation Laboratory, National Institute of Advanced Industrial Science and Technology (AIST), 2-1 Yamadaoka, Suita 565-0871, Osaka, Japan; (H.Z.); (J.N.T.); (M.M.)
- Graduate School of Engineering, Osaka University, 2-1 Yamadaoka, Suita 565-0871, Osaka, Japan; (D.-H.K.); (M.P.)
| |
Collapse
|
3
|
Xingi E, Koutsoudaki PN, Thanou I, Phan MS, Margariti M, Scheller A, Tinevez JY, Kirchhoff F, Thomaidou D. LPS-Induced Systemic Inflammation Affects the Dynamic Interactions of Astrocytes and Microglia with the Vasculature of the Mouse Brain Cortex. Cells 2023; 12:1418. [PMID: 37408252 DOI: 10.3390/cells12101418] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2023] [Revised: 05/05/2023] [Accepted: 05/13/2023] [Indexed: 07/07/2023] Open
Abstract
The Neurovascular Unit (NVU), composed of glia (astrocytes, oligodendrocytes, microglia), neurons, pericytes and endothelial cells, is a dynamic interface ensuring the physiological functioning of the central nervous system (CNS), which gets affected and contributes to the pathology of several neurodegenerative diseases. Neuroinflammation is a common feature of neurodegenerative diseases and is primarily related to the activation state of perivascular microglia and astrocytes, which constitute two of its major cellular components. Our studies focus on monitoring in real time the morphological changes of perivascular astrocytes and microglia, as well as their dynamic interactions with the brain vasculature, under physiological conditions and following systemic neuroinflammation triggering both microgliosis and astrogliosis. To this end, we performed 2-photon laser scanning microscopy (2P-LSM) for intravital imaging of the cortex of transgenic mice visualizing the dynamics of microglia and astroglia following neuroinflammation induced by systemic administration of the endotoxin lipopolysaccharide (LPS). Our results indicate that following neuroinflammation the endfeet of activated perivascular astrocytes lose their close proximity and physiological cross-talk with vasculature, an event that most possibly contributes to a loss of blood-brain barrier (BBB) integrity. At the same time, microglial cells become activated and exhibit a higher extent of physical contact with the blood vessels. These dynamic responses of perivascular astrocytes and microglia are peaking at 4 days following LPS administration; however, they still persist at a lower level at 8 days after LPS injection, revealing incomplete reversal of inflammation affecting the glial properties and interactions within the NVU.
Collapse
Affiliation(s)
- Evangelia Xingi
- Light Microscopy Unit, Hellenic Pasteur Institute, 11521 Athens, Greece
| | - Paraskevi N Koutsoudaki
- Neural Stem Cells and Neuroimaging Group, Department of Neurobiology, Hellenic Pasteur Institute, 11521 Athens, Greece
| | - Irini Thanou
- Neural Stem Cells and Neuroimaging Group, Department of Neurobiology, Hellenic Pasteur Institute, 11521 Athens, Greece
| | - Minh-Son Phan
- Institut Pasteur, Université de Paris, Image Analysis Hub, F-75015 Paris, France
| | - Maria Margariti
- Neural Stem Cells and Neuroimaging Group, Department of Neurobiology, Hellenic Pasteur Institute, 11521 Athens, Greece
| | - Anja Scheller
- Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, 66421 Homburg, Germany
| | - Jean-Yves Tinevez
- Institut Pasteur, Université de Paris, Image Analysis Hub, F-75015 Paris, France
| | - Frank Kirchhoff
- Molecular Physiology, Center for Integrative Physiology and Molecular Medicine (CIPMM), University of Saarland, 66421 Homburg, Germany
| | - Dimitra Thomaidou
- Light Microscopy Unit, Hellenic Pasteur Institute, 11521 Athens, Greece
- Neural Stem Cells and Neuroimaging Group, Department of Neurobiology, Hellenic Pasteur Institute, 11521 Athens, Greece
| |
Collapse
|
4
|
Gu N, Yi MH, Murugan M, Xie M, Parusel S, Peng J, Eyo UB, Hunt CL, Dong H, Wu LJ. Spinal microglia contribute to sustained inflammatory pain via amplifying neuronal activity. Mol Brain 2022; 15:86. [PMID: 36289499 PMCID: PMC9609165 DOI: 10.1186/s13041-022-00970-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2022] [Accepted: 10/10/2022] [Indexed: 01/05/2023] Open
Abstract
Microglia are highly dynamic immune cells of the central nervous system (CNS). Microglial processes interact with neuronal elements constantly on the order of minutes. The functional significance of this acute microglia-neuron interaction and its potential role in the context of pain is still largely unknown. Here, we found that spinal microglia increased their process motility and electrophysiological reactivity within an hour after the insult in a mouse model of formalin-induced acute, sustained, inflammatory pain. Using an ablation strategy to specifically deplete resident microglia in the CNS, we demonstrate that microglia participate in formalin-induced acute sustained pain behaviors by amplifying neuronal activity in the spinal dorsal horn. Moreover, we identified that the P2Y12 receptor, which is specifically expressed in microglia in the CNS, was required for microglial function in formalin-induced pain. Taken together, our study provides a novel insight into the contribution of microglia and the P2Y12 receptor in inflammatory pain that could be used for potential therapeutic strategies.
Collapse
Affiliation(s)
- Nan Gu
- grid.430387.b0000 0004 1936 8796Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08854 USA ,grid.417295.c0000 0004 1799 374XDepartment of Anesthesiology & Perioperative Medicine, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi 710032 PR China
| | - Min-Hee Yi
- grid.66875.3a0000 0004 0459 167XDepartment of Neurology, Mayo Clinic, Rochester, MN 55905 USA
| | - Madhuvika Murugan
- grid.430387.b0000 0004 1936 8796Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08854 USA ,grid.66875.3a0000 0004 0459 167XDepartment of Neurology, Mayo Clinic, Rochester, MN 55905 USA
| | - Manling Xie
- grid.66875.3a0000 0004 0459 167XDepartment of Neurology, Mayo Clinic, Rochester, MN 55905 USA
| | - Sebastian Parusel
- grid.66875.3a0000 0004 0459 167XDepartment of Neurology, Mayo Clinic, Rochester, MN 55905 USA
| | - Jiyun Peng
- grid.430387.b0000 0004 1936 8796Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08854 USA ,grid.66875.3a0000 0004 0459 167XDepartment of Neurology, Mayo Clinic, Rochester, MN 55905 USA
| | - Ukpong B. Eyo
- grid.430387.b0000 0004 1936 8796Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08854 USA ,grid.66875.3a0000 0004 0459 167XDepartment of Neurology, Mayo Clinic, Rochester, MN 55905 USA
| | - Christine L. Hunt
- grid.417467.70000 0004 0443 9942Department of Pain Medicine, Mayo Clinic, Jacksonville, FL 32224 USA
| | - Hailong Dong
- grid.417295.c0000 0004 1799 374XDepartment of Anesthesiology & Perioperative Medicine, Xijing Hospital, Fourth Military Medical University, Xi’an, Shaanxi 710032 PR China
| | - Long-Jun Wu
- grid.430387.b0000 0004 1936 8796Department of Cell Biology and Neuroscience, Rutgers University, Piscataway, NJ 08854 USA ,grid.66875.3a0000 0004 0459 167XDepartment of Neurology, Mayo Clinic, Rochester, MN 55905 USA ,grid.417467.70000 0004 0443 9942Department of Neuroscience, Mayo Clinic, Jacksonville, FL 32224 USA ,grid.66875.3a0000 0004 0459 167XDepartment of Immunology, Mayo Clinic, Rochester, MN 55905 USA
| |
Collapse
|
5
|
A tool for mapping microglial morphology, morphOMICs, reveals brain-region and sex-dependent phenotypes. Nat Neurosci 2022; 25:1379-1393. [PMID: 36180790 PMCID: PMC9534764 DOI: 10.1038/s41593-022-01167-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Accepted: 08/16/2022] [Indexed: 11/10/2022]
Abstract
Environmental cues influence the highly dynamic morphology of microglia. Strategies to characterize these changes usually involve user-selected morphometric features, which preclude the identification of a spectrum of context-dependent morphological phenotypes. Here we develop MorphOMICs, a topological data analysis approach, which enables semiautomatic mapping of microglial morphology into an atlas of cue-dependent phenotypes and overcomes feature-selection biases and biological variability. We extract spatially heterogeneous and sexually dimorphic morphological phenotypes for seven adult mouse brain regions. This sex-specific phenotype declines with maturation but increases over the disease trajectories in two neurodegeneration mouse models, with females showing a faster morphological shift in affected brain regions. Remarkably, microglia morphologies reflect an adaptation upon repeated exposure to ketamine anesthesia and do not recover to control morphologies. Finally, we demonstrate that both long primary processes and short terminal processes provide distinct insights to morphological phenotypes. MorphOMICs opens a new perspective to characterize microglial morphology. Colombo et al. build a morphological spectrum of over 40,000 microglia across development and disease with a topological data analysis approach that allows mapping of new conditions along these sex-region-specific and brain-region-specific atlases.
Collapse
|
6
|
Kalluri SR, Srivastava R, Kenet S, Tanti GK, Dornmair K, Bennett JL, Misgeld T, Hemmer B, Wyss MT, Herwerth M. P2R Inhibitors Prevent Antibody-Mediated Complement Activation in an Animal Model of Neuromyelitis Optica : P2R Inhibitors Prevent Autoantibody Injury. Neurotherapeutics 2022; 19:1603-1616. [PMID: 35821382 PMCID: PMC9606199 DOI: 10.1007/s13311-022-01269-w] [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] [Accepted: 06/28/2022] [Indexed: 11/28/2022] Open
Abstract
Purinergic 2 receptors (P2Rs) contribute to disease-related immune cell signaling and are upregulated in various pathological settings, including neuroinflammation. P2R inhibitors have been used to treat inflammatory diseases and can protect against complement-mediated cell injury. However, the mechanisms behind these anti-inflammatory properties of P2R inhibitors are not well understood, and their potential in CNS autoimmunity is underexplored. Here, we tested the effects of P2R inhibitors on glial toxicity in a mouse model of neuromyelitis optica spectrum disorder (NMOSD). NMOSD is a destructive CNS autoimmune disorder, in which autoantibodies against astrocytic surface antigen Aquaporin 4 (AQP4) mediate complement-dependent loss of astrocytes. Using two-photon microscopy in vivo, we found that various classes of P2R inhibitors prevented AQP4-IgG/complement-dependent astrocyte death. In vitro, these drugs inhibited the binding of AQP4-IgG or MOG-IgG to their antigen in a dose-dependent manner. Size-exclusion chromatography and circular dichroism spectroscopy revealed a partial unfolding of antibodies in the presence of various P2R inhibitors, suggesting a shared interference with IgG antibodies leading to their conformational change. Our study demonstrates that P2R inhibitors can disrupt complement activation by direct interaction with IgG. This mechanism is likely to influence the role of P2R inhibitors in autoimmune disease models and their therapeutic impact in human disease.
Collapse
Affiliation(s)
- Sudhakar Reddy Kalluri
- Department of Neurology, Klinikum Rechts Der Isar, Technical University of Munich, Munich, Germany
| | - Rajneesh Srivastava
- Department of Neurology, Klinikum Rechts Der Isar, Technical University of Munich, Munich, Germany
| | - Selin Kenet
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
- Graduate School of Systemic Neurosciences, Ludwig-Maximilians-Universität, Munich, Germany
| | - Goutam K Tanti
- Department of Neurology, Klinikum Rechts Der Isar, Technical University of Munich, Munich, Germany
| | - Klaus Dornmair
- Institute of Clinical Neuroimmunology, University Hospital and Biomedical Center, LMU Munich, Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Jeffrey L Bennett
- Departments of Neurology and Ophthalmology, Programs in Neuroscience and Immunology, University of Colorado School of Medicine, Colorado, USA
| | - Thomas Misgeld
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Bernhard Hemmer
- Department of Neurology, Klinikum Rechts Der Isar, Technical University of Munich, Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Matthias T Wyss
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland
- Neuroscience Center Zurich, University Zurich and ETH Zurich, Zurich, Switzerland
| | - Marina Herwerth
- Department of Neurology, Klinikum Rechts Der Isar, Technical University of Munich, Munich, Germany.
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany.
- Institute of Pharmacology and Toxicology, University of Zurich, Zurich, Switzerland.
- Neuroscience Center Zurich, University Zurich and ETH Zurich, Zurich, Switzerland.
| |
Collapse
|
7
|
Herwerth M, Kenet S, Schifferer M, Winkler A, Weber M, Snaidero N, Wang M, Lohrberg M, Bennett JL, Stadelmann C, Hemmer B, Misgeld T. A new form of axonal pathology in a spinal model of neuromyelitis optica. Brain 2022; 145:1726-1742. [PMID: 35202467 PMCID: PMC9166560 DOI: 10.1093/brain/awac079] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2021] [Revised: 01/31/2022] [Accepted: 02/12/2022] [Indexed: 11/14/2022] Open
Abstract
Neuromyelitis optica is a chronic neuroinflammatory disease, which primarily targets astrocytes and often results in severe axon injury of unknown mechanism. Neuromyelitis optica patients harbour autoantibodies against the astrocytic water channel protein, aquaporin-4 (AQP4-IgG), which induce complement-mediated astrocyte lysis and subsequent axon damage. Using spinal in vivo imaging in a mouse model of such astrocytopathic lesions, we explored the mechanism underlying neuromyelitis optica-related axon injury. Many axons showed a swift and morphologically distinct 'pearls-on-string' transformation also readily detectable in human neuromyelitis optica lesions, which especially affected small calibre axons independently of myelination. Functional imaging revealed that calcium homeostasis was initially preserved in this 'acute axonal beading' state, ruling out disruption of the axonal membrane, which sets this form of axon injury apart from previously described forms of traumatic and inflammatory axon damage. Morphological, pharmacological and genetic analyses showed that AQP4-IgG-induced axon injury involved osmotic stress and ionic overload, but does not appear to use canonical pathways of Wallerian-like degeneration. Subcellular analysis demonstrated remodelling of the axonal cytoskeleton in beaded axons, especially local loss of microtubules. Treatment with the microtubule stabilizer epothilone, a putative therapy approach for traumatic and degenerative axonopathies, prevented axonal beading, while destabilizing microtubules sensitized axons for beading. Our results reveal a distinct form of immune-mediated axon pathology in neuromyelitis optica that mechanistically differs from known cascades of post-traumatic and inflammatory axon loss, and suggest a new strategy for neuroprotection in neuromyelitis optica and related diseases.
Collapse
Affiliation(s)
- Marina Herwerth
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
- Department of Neurology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Selin Kenet
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
- Graduate School of Systemic Neurosciences, Ludwig-Maximilians University, Munich, Germany
| | - Martina Schifferer
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Anne Winkler
- Institute of Neuropathology, University Medical Center Göttingen, Göttingen, Germany
| | - Melanie Weber
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
| | - Nicolas Snaidero
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
| | - Mengzhe Wang
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
| | - Melanie Lohrberg
- Institute of Neuropathology, University Medical Center Göttingen, Göttingen, Germany
| | - Jeffrey L. Bennett
- Departments of Neurology and Ophthalmology, Programs in Neuroscience and Immunology, University of Colorado School of Medicine, Aurora, USA
| | - Christine Stadelmann
- Institute of Neuropathology, University Medical Center Göttingen, Göttingen, Germany
| | - Bernhard Hemmer
- Department of Neurology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| | - Thomas Misgeld
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
- German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
- Munich Cluster of Systems Neurology (SyNergy), Munich, Germany
| |
Collapse
|
8
|
Long-term in vivo imaging of mouse spinal cord through an optically cleared intervertebral window. Nat Commun 2022; 13:1959. [PMID: 35414131 PMCID: PMC9005710 DOI: 10.1038/s41467-022-29496-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2021] [Accepted: 03/17/2022] [Indexed: 11/08/2022] Open
Abstract
The spinal cord accounts for the main communication pathway between the brain and the peripheral nervous system. Spinal cord injury is a devastating and largely irreversible neurological trauma, and can result in lifelong disability and paralysis with no available cure. In vivo spinal cord imaging in mouse models without introducing immunological artifacts is critical to understand spinal cord pathology and discover effective treatments. We developed a minimally invasive intervertebral window by retaining the ligamentum flavum to protect the underlying spinal cord. By introducing an optical clearing method, we achieve repeated two-photon fluorescence and stimulated Raman scattering imaging at subcellular resolution with up to 15 imaging sessions over 6-167 days and observe no inflammatory response. Using this optically cleared intervertebral window, we study neuron-glia dynamics following laser axotomy and observe strengthened contact of microglia with the nodes of Ranvier during axonal degeneration. By enabling long-term, repetitive, stable, high-resolution and inflammation-free imaging of mouse spinal cord, our method provides a reliable platform in the research aiming at interpretation of spinal cord physiology and pathology.
Collapse
|
9
|
Deng J, Li M, Meng F, Liu Z, Wang S, Zhang Y, Li M, Li Z, Zhang L, Tang P. 3D spheroids of human placenta-derived mesenchymal stem cells attenuate spinal cord injury in mice. Cell Death Dis 2021; 12:1096. [PMID: 34803160 PMCID: PMC8606575 DOI: 10.1038/s41419-021-04398-w] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2021] [Revised: 11/01/2021] [Accepted: 11/10/2021] [Indexed: 12/23/2022]
Abstract
Mesenchymal stem cell (MSC) is an absorbing candidate for cell therapy in treating spinal cord injury (SCI) due to its great potential for multiple cell differentiation, mighty paracrine secretion as well as vigorous immunomodulatory effect, of which are beneficial to the improvement of functional recovery post SCI. However, the therapeutic effects of MSC on SCI have been limited because of the gradual loss of MSC stemness in the process of expanding culture. Therefore, in this study, we aimed to maintain those beneficial properties of MSC via three-dimensional spheroid cell culture and then compared them with conventionally-cultured MSCs in the treatment of SCI both in vitro and in vivo with the aid of two-photon microscope. We found that 3D human placenta-derived MSCs (3D-HPMSCs) demonstrated a significant increase in secretion of anti-inflammatory factors and trophic factors like VEGF, PDGF, FGF via QPCR and Bio-Plex assays, and showed great potentials on angiogenesis and neurite morphogenesis when co-cultured with HUVECs or DRGs in vitro. After transplantation into the injured spinal cord, 3D-HPMSCs managed to survive for the entire experiment and retained their advantageous properties in secretion, and exhibited remarkable effects on neuroprotection by minimizing the lesion cavity, inhibiting the inflammation and astrogliosis, and promoting angiogenesis. Further investigation of axonal dieback via two-photon microscope indicated that 3D-HPMSCs could effectively alleviate axonal dieback post injury. Further, mice only treated with 3D-HPMSCs obtained substantial improvement of functional recovery on electrophysiology, BMS score, and Catwalk analysis. RNA sequencing suggested that the 3D-HPMSCs structure organization-related gene was significantly changed, which was likely to potentiate the angiogenesis and inflammation regulation after SCI. These results suggest that 3D-HPMSCs may hold great potential for the treatment of SCI.
Collapse
Affiliation(s)
- Junhao Deng
- Medical School of Chinese PLA, Beijing, 100853, China
- Department of Orthopedics, The Chinese PLA General Hospital, Beijing, 100853, China
| | - Miao Li
- Key Laboratory of Chemical Genomics, Shenzhen Graduate School, Peking University, Shenzhen, 518055, China
- Department of Anesthesiology, Columbia University, New York, NY, 10032, USA
| | - Fanqi Meng
- Department of Spine Surgery, Peking University People's hospital, Beijing, 100044, China
| | - Zhongyang Liu
- Department of Orthopedics, The Chinese PLA General Hospital, Beijing, 100853, China
| | - Song Wang
- Department of Orthopedics, The Chinese PLA General Hospital, Beijing, 100853, China
- Medical college, Nankai University, Tianjin, 300071, China
| | - Yuan Zhang
- IBM Research-China, Beijing, 100193, China
| | - Ming Li
- Department of Orthopedics, The Chinese PLA General Hospital, Beijing, 100853, China
| | - Zhirui Li
- Department of Orthopedics, The Chinese PLA General Hospital, Beijing, 100853, China.
| | - Licheng Zhang
- Department of Orthopedics, The Chinese PLA General Hospital, Beijing, 100853, China.
| | - Peifu Tang
- Medical School of Chinese PLA, Beijing, 100853, China.
- Department of Orthopedics, The Chinese PLA General Hospital, Beijing, 100853, China.
| |
Collapse
|
10
|
Investigating the blood-spinal cord barrier in preclinical models: a systematic review of in vivo imaging techniques. Spinal Cord 2021; 59:596-612. [PMID: 33742118 DOI: 10.1038/s41393-021-00623-7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2020] [Revised: 02/25/2021] [Accepted: 03/01/2021] [Indexed: 01/31/2023]
Abstract
STUDY DESIGN This study is a systematic review. OBJECTIVES To evaluate current in vivo techniques used in the investigation of the blood-spinal cord barrier (BSCB). METHODS Search of English language literature for animal studies that investigated the BSCB in vivo. Data extraction included animal model/type, protocol for BSCB evaluation, and study outcomes. Descriptive syntheses are provided. RESULTS A total of 40 studies were included, which mainly investigated rodent models of experimental autoimmune encephalomyelitis (EAE) or spinal cord injury (SCI). The main techniques used were magnetic resonance imaging (MRI) and intravital microscopy (IVM). MRI served as a reliable tool to longitudinally track BSCB permeability changes with dynamic contrast enhancement (DCE) using gadolinium, or assess inflammatory infiltrations with targeted alternative contrast agents. IVM provided high-resolution visualization of cellular and molecular interactions across the microvasculature, commonly with either epi-fluorescence or two-photon microscopy. MRI and IVM techniques enabled the evaluation of therapeutic interventions and mechanisms that drive spinal cord dysfunction in EAE and SCI. A small number of studies demonstrated the feasibility of DCE-computed tomography, ultrasound, bioluminescent, and fluorescent optical imaging methods to evaluate the BSCB. Technique-specific limitations and multiple protocols for image acquisition and data analyses are described for all techniques. CONCLUSION There are few in vivo investigations of the BSCB. Additional studies are needed in less commonly studied spinal cord disorders, and to establish standardized protocols for data acquisition and analysis. Further development of techniques and multimodal approaches could overcome current imaging limitations to the spinal cord. These advancements might promote wider adoption of techniques, and can provide greater potential for clinical translation.
Collapse
|
11
|
Liang Y, Walczak P. Long term intravital single cell tracking under multiphoton microscopy. J Neurosci Methods 2020; 349:109042. [PMID: 33340557 DOI: 10.1016/j.jneumeth.2020.109042] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Revised: 12/07/2020] [Accepted: 12/11/2020] [Indexed: 12/13/2022]
Abstract
Visualizing and tracking cells over time in a living organism has been a much-coveted dream before the invention of intravital microscopy. The opaque nature of tissue was a major hurdle that was remedied by the multiphoton microscopy. With the advancement of optical imaging and fluorescent labeling tools, intravital high resolution imaging has become increasingly accessible over the past few years. Long-term intravital tracking of single cells (LIST) under multiphoton microscopy provides a unique opportunity to gain insight into the longitudinal changes in the morphology, migration, or function of cells or subcellular structures. It is particularly suitable for studying slow-evolving cellular and molecular events during normal development or disease progression, without losing the opportunity of catching fast events such as calcium signals. Here, we review the application of LIST under 2-photon microscopy in various fields of neurobiology and discuss challenges and new directions in labeling and imaging methods for LIST. Overall, this review provides an overview of current applications of LIST in mammals, which is an emerging field that will contribute to a better understanding of essential molecular and cellular events in health and disease.
Collapse
Affiliation(s)
- Yajie Liang
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, USA.
| | - Piotr Walczak
- Department of Diagnostic Radiology and Nuclear Medicine, University of Maryland School of Medicine, Baltimore, MD, USA
| |
Collapse
|
12
|
Abstract
The quantitative analysis of blood vessel networks is an important component in many animal models of disease. We describe a nondestructive technique for blood vessel imaging that visualizes in situ vasculature in harvested tissues. The method allows for further analysis of the same tissues with histology and other methods that can be performed on fixed tissue. Consequently, it can easily be incorporated upstream to analysis methods to augment these with a three-dimensional reconstruction of the vascular network in the tissues to be analyzed. The method combines iodine-enhanced micro-computed tomography with a deep learning algorithm to segment vasculature within tissues. The procedure is relatively simple and can provide insight into complex changes in the vascular structure in the tissues.
Collapse
|
13
|
Long-term high-resolution in vivo imaging of cerebral cortical structures following ischemic stroke. BIOPHYSICS REPORTS 2020. [DOI: 10.1007/s41048-020-00105-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/24/2022] Open
|
14
|
Oxytocin prevents neuronal network pain-related changes on spinal cord dorsal horn in vitro. Cell Calcium 2020; 90:102246. [PMID: 32590238 DOI: 10.1016/j.ceca.2020.102246] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 06/02/2020] [Accepted: 06/16/2020] [Indexed: 12/28/2022]
Abstract
Recently, oxytocin (OT) has been studied as a potential modulator of endogenous analgesia by acting upon pain circuits at the spinal cord and supraspinal levels. Yet the detailed action mechanisms of OT are still undetermined. The present study aimed to evaluate the action of OT in the spinal cord dorsal horn network under nociceptive-like conditions induced by the activation of the N-methyl-d-aspartate (NMDA) receptor and formalin injection, using calcium imaging techniques. Results demonstrate that the spontaneous Ca2+-dependent activity of the dorsal horn cells was scarce, and the coactivity of cells was mainly absent. When NMDA was applied, high rates of activity and coactivity occurred in the dorsal horn cells; these rates of high activity mimicked the activity dynamics evoked by a neuropathic pain condition. In addition, although OT treatment increased activity rates, it was also capable of disrupting the conformation of coordinated activity previously consolidated by NMDA treatment, without showing any effect by itself. Altogether, our results suggest that OT globally prevents the formation of coordinated patterns previously generated by nociceptive-like conditions on dorsal horn cells by NMDA application, which supports previous evidence showing that OT represents a potential therapeutic alternative for the treatment of chronic neuropathic pain.
Collapse
|
15
|
Harding EK, Fung SW, Bonin RP. Insights Into Spinal Dorsal Horn Circuit Function and Dysfunction Using Optical Approaches. Front Neural Circuits 2020; 14:31. [PMID: 32595458 PMCID: PMC7303281 DOI: 10.3389/fncir.2020.00031] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Accepted: 05/01/2020] [Indexed: 12/13/2022] Open
Abstract
Somatosensation encompasses a variety of essential modalities including touch, pressure, proprioception, temperature, pain, and itch. These peripheral sensations are crucial for all types of behaviors, ranging from social interaction to danger avoidance. Somatosensory information is transmitted from primary afferent fibers in the periphery into the central nervous system via the dorsal horn of the spinal cord. The dorsal horn functions as an intermediary processing center for this information, comprising a complex network of excitatory and inhibitory interneurons as well as projection neurons that transmit the processed somatosensory information from the spinal cord to the brain. It is now known that there can be dysfunction within this spinal cord circuitry in pathological pain conditions and that these perturbations contribute to the development and maintenance of pathological pain. However, the complex and heterogeneous network of the spinal dorsal horn has hampered efforts to further elucidate its role in somatosensory processing. Emerging optical techniques promise to illuminate the underlying organization and function of the dorsal horn and provide insights into the role of spinal cord sensory processing in shaping the behavioral response to somatosensory input that we ultimately observe. This review article will focus on recent advances in optogenetics and fluorescence imaging techniques in the spinal cord, encompassing findings from both in vivo and in vitro preparations. We will also discuss the current limitations and difficulties of employing these techniques to interrogate the spinal cord and current practices and approaches to overcome these challenges.
Collapse
Affiliation(s)
- Erika K Harding
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON, Canada.,Department of Comparative Biology and Experimental Medicine, University of Calgary, Calgary, AB, Canada
| | - Samuel Wanchi Fung
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON, Canada
| | - Robert P Bonin
- Department of Pharmaceutical Sciences, Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, ON, Canada.,University of Toronto Centre for the Study of Pain, University of Toronto, Toronto, ON, Canada
| |
Collapse
|
16
|
Soulet D, Lamontagne-Proulx J, Aubé B, Davalos D. Multiphoton intravital microscopy in small animals: motion artefact challenges and technical solutions. J Microsc 2020; 278:3-17. [PMID: 32072642 PMCID: PMC7187339 DOI: 10.1111/jmi.12880] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2019] [Revised: 02/06/2020] [Accepted: 02/14/2020] [Indexed: 12/28/2022]
Abstract
Since its invention 29 years ago, two‐photon laser‐scanning microscopy has evolved from a promising imaging technique, to an established widely available imaging modality used throughout the biomedical research community. The establishment of two‐photon microscopy as the preferred method for imaging fluorescently labelled cells and structures in living animals can be attributed to the biophysical mechanism by which the generation of fluorescence is accomplished. The use of powerful lasers capable of delivering infrared light pulses within femtosecond intervals, facilitates the nonlinear excitation of fluorescent molecules only at the focal plane and determines by objective lens position. This offers numerous benefits for studies of biological samples at high spatial and temporal resolutions with limited photo‐damage and superior tissue penetration. Indeed, these attributes have established two‐photon microscopy as the ideal method for live‐animal imaging in several areas of biology and have led to a whole new field of study dedicated to imaging biological phenomena in intact tissues and living organisms. However, despite its appealing features, two‐photon intravital microscopy is inherently limited by tissue motion from heartbeat, respiratory cycles, peristalsis, muscle/vascular tone and physiological functions that change tissue geometry. Because these movements impede temporal and spatial resolution, they must be properly addressed to harness the full potential of two‐photon intravital microscopy and enable accurate data analysis and interpretation. In addition, the sources and features of these motion artefacts are varied, sometimes unpredictable and unique to specific organs and multiple complex strategies have previously been devised to address them. This review will discuss these motion artefacts requirement and technical solutions for their correction and after intravital two‐photon microscopy.
Collapse
Affiliation(s)
- D Soulet
- Centre de recherche du CHUL, Department of Neurosciences, Quebec, Canada.,Faculty of Pharmacy, Université Laval, Quebec, Canada
| | - J Lamontagne-Proulx
- Centre de recherche du CHUL, Department of Neurosciences, Quebec, Canada.,Faculty of Pharmacy, Université Laval, Quebec, Canada
| | - B Aubé
- Centre de recherche du CHUL, Department of Neurosciences, Quebec, Canada
| | - D Davalos
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, U.S.A
| |
Collapse
|
17
|
Dusi S, Angiari S, Pietronigro EC, Lopez N, Angelini G, Zenaro E, Della Bianca V, Tosadori G, Paris F, Amoruso A, Carlucci T, Constantin G, Rossi B. LFA-1 Controls Th1 and Th17 Motility Behavior in the Inflamed Central Nervous System. Front Immunol 2019; 10:2436. [PMID: 31681316 PMCID: PMC6813462 DOI: 10.3389/fimmu.2019.02436] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2019] [Accepted: 09/30/2019] [Indexed: 12/28/2022] Open
Abstract
Leukocyte trafficking is a key event during autoimmune and inflammatory responses. The subarachnoid space (SAS) and cerebrospinal fluid are major routes for the migration of encephalitogenic T cells into the central nervous system (CNS) during experimental autoimmune encephalomyelitis (EAE), the animal model of multiple sclerosis, and are sites of T cell activation before the invasion of CNS parenchyma. In particular, autoreactive Th1 and Th17 cell trafficking and reactivation in the CNS are required for the pathogenesis of EAE. However, the molecular mechanisms controlling T cell dynamics during EAE are unclear. We used two-photon laser microscopy to show that autoreactive Th1 and Th17 cells display distinct motility behavior within the SAS in the spinal cords of mice immunized with the myelin oligodendrocyte glycoprotein peptide MOG35−55. Th1 cells showed a strong directional bias at the disease peak, moving in a straight line and covering long distances, whereas Th17 cells exhibited more constrained motility. The dynamics of both Th1 and Th17 cells were strongly affected by blocking the integrin LFA-1, which interfered with the deformability and biomechanics of Th1 but not Th17 cells. The intrathecal injection of a blocking anti-LFA-1 antibody at the onset of disease significantly inhibited EAE progression and also strongly reduced neuro-inflammation in the immunized mice. Our results show that LFA-1 plays a pivotal role in T cell motility during EAE and suggest that interfering with the molecular mechanisms controlling T cell motility can help to reduce the pathogenic potential of autoreactive lymphocytes.
Collapse
Affiliation(s)
- Silvia Dusi
- Department of Medicine, Section of General Pathology, University of Verona, Verona, Italy
| | - Stefano Angiari
- Department of Medicine, Section of General Pathology, University of Verona, Verona, Italy
| | | | - Nicola Lopez
- Department of Medicine, Section of General Pathology, University of Verona, Verona, Italy
| | - Gabriele Angelini
- Department of Medicine, Section of General Pathology, University of Verona, Verona, Italy
| | - Elena Zenaro
- Department of Medicine, Section of General Pathology, University of Verona, Verona, Italy
| | - Vittorina Della Bianca
- Department of Medicine, Section of General Pathology, University of Verona, Verona, Italy
| | - Gabriele Tosadori
- Department of Medicine, Section of General Pathology, University of Verona, Verona, Italy.,The Center for Biomedical Computing (CBMC), University of Verona, Verona, Italy
| | - Francesca Paris
- Department of Medicine, Section of General Pathology, University of Verona, Verona, Italy
| | - Antonella Amoruso
- Department of Medicine, Section of General Pathology, University of Verona, Verona, Italy
| | - Tommaso Carlucci
- Department of Medicine, Section of General Pathology, University of Verona, Verona, Italy
| | - Gabriela Constantin
- Department of Medicine, Section of General Pathology, University of Verona, Verona, Italy.,The Center for Biomedical Computing (CBMC), University of Verona, Verona, Italy
| | - Barbara Rossi
- Department of Medicine, Section of General Pathology, University of Verona, Verona, Italy
| |
Collapse
|
18
|
Olivares-Moreno R, López-Hidalgo M, Altamirano-Espinoza A, González-Gallardo A, Antaramian A, Lopez-Virgen V, Rojas-Piloni G. Mouse corticospinal system comprises different functional neuronal ensembles depending on their hodology. BMC Neurosci 2019; 20:50. [PMID: 31547806 PMCID: PMC6757377 DOI: 10.1186/s12868-019-0533-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2019] [Accepted: 09/17/2019] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Movement performance depends on the synaptic interactions generated by coherent parallel sensorimotor cortical outputs to different downstream targets. The major outputs of the neocortex to subcortical structures are driven by pyramidal tract neurons (PTNs) located in layer 5B. One of the main targets of PTNs is the spinal cord through the corticospinal (CS) system, which is formed by a complex collection of distinct CS circuits. However, little is known about intracortical synaptic interactions that originate CS commands and how different populations of CS neurons are functionally organized. To further understand the functional organization of the CS system, we analyzed the activity of unambiguously identified CS neurons projecting to different zones of the same spinal cord segment using two-photon calcium imaging and retrograde neuronal tracers. RESULTS Sensorimotor cortex slices obtained from transgenic mice expressing GCaMP6 funder the Thy1 promoter were used to analyze the spontaneous calcium transients in layer 5 pyramidal neurons. Distinct subgroups of CS neurons projecting to dorsal horn and ventral areas of the same segment show more synchronous activity between them than with other subgroups. CONCLUSIONS The results indicate that CS neurons projecting to different spinal cord zones segregated into functional ensembles depending on their hodology, suggesting that a modular organization of CS outputs controls sensorimotor behaviors in a coordinated manner.
Collapse
Affiliation(s)
- Rafael Olivares-Moreno
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus UNAM-Juriquilla, Querétaro, Mexico
| | - Mónica López-Hidalgo
- Escuela Nacional de Estudios Superiores, Juriquilla, UNAM, Universidad Nacional Autónoma de México, Campus UNAM-Juriquilla, Querétaro, Mexico
| | - Alain Altamirano-Espinoza
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus UNAM-Juriquilla, Querétaro, Mexico
| | - Adriana González-Gallardo
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus UNAM-Juriquilla, Querétaro, Mexico
| | - Anaid Antaramian
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus UNAM-Juriquilla, Querétaro, Mexico
| | - Verónica Lopez-Virgen
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus UNAM-Juriquilla, Querétaro, Mexico
| | - Gerardo Rojas-Piloni
- Departamento de Neurobiología del Desarrollo y Neurofisiología, Instituto de Neurobiología, Universidad Nacional Autónoma de México, Campus UNAM-Juriquilla, Querétaro, Mexico.
| |
Collapse
|
19
|
Borjini N, Paouri E, Tognatta R, Akassoglou K, Davalos D. Imaging the dynamic interactions between immune cells and the neurovascular interface in the spinal cord. Exp Neurol 2019; 322:113046. [PMID: 31472115 DOI: 10.1016/j.expneurol.2019.113046] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 08/16/2019] [Accepted: 08/27/2019] [Indexed: 12/19/2022]
Abstract
Imaging the dynamic interactions between immune cells, glia, neurons and the vasculature in living rodents has revolutionized our understanding of physiological and pathological mechanisms of the CNS. Emerging microscopy and imaging technologies have enabled longitudinal tracking of structural and functional changes in a plethora of different cell types in the brain. The development of novel methods also allowed stable and longitudinal optical access to the spinal cord with minimum tissue perturbation. These important advances facilitated the application of in vivo imaging using two-photon microscopy for studies of the healthy, diseased, or injured spinal cord. Indeed, decoding the interactions between peripheral and resident cells with the spinal cord vasculature has shed new light on neuroimmune and vascular mechanisms regulating the onset and progression of neurological diseases. This review focuses on imaging studies of the interactions between the vasculature and peripheral immune cells or microglia, with emphasis on their contribution to neuroinflammation. We also discuss in vivo imaging studies highlighting the importance of neurovascular changes following spinal cord injury. Real-time imaging of blood-brain barrier (BBB) permeability and other vascular changes, perivascular glial responses, and immune cell entry has revealed unanticipated cellular mechanisms and novel molecular pathways that can be targeted to protect the injured or diseased CNS. Imaging the cell-cell interactions between the vasculature, immune cells, and neurons as they occur in real time, is a powerful tool both for testing the efficacy of existing therapeutic approaches, and for identifying new targets for limiting damage or enhancing the potential for repair of the affected spinal cord tissue.
Collapse
Affiliation(s)
- Nozha Borjini
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | - Evi Paouri
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA
| | | | - Katerina Akassoglou
- Gladstone Institutes, San Francisco, CA, USA; Department of Neurology, University of California, San Francisco, San Francisco, CA, USA
| | - Dimitrios Davalos
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH, USA; Department of Molecular Medicine, Cleveland Clinic Lerner College of Medicine, Case Western Reserve University, Cleveland, OH, USA.
| |
Collapse
|
20
|
Mattedi F, Vagnoni A. Temporal Control of Axonal Transport: The Extreme Case of Organismal Ageing. Front Cell Neurosci 2019; 13:393. [PMID: 31555095 PMCID: PMC6716446 DOI: 10.3389/fncel.2019.00393] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 08/09/2019] [Indexed: 01/05/2023] Open
Abstract
A fundamental question in cell biology is how cellular components are delivered to their destination with spatial and temporal precision within the crowded cytoplasmic environment. The long processes of neurons represent a significant spatial challenge and make these cells particularly dependent on mechanisms for long-range cytoskeletal transport of proteins, RNA and organelles. Although many studies have substantiated a role for defective transport of axonal cargoes in the pathogenesis of neurodevelopmental and neurodegenerative diseases, remarkably little is known about how transport is regulated throughout ageing. The scale of the challenge posed by ageing is considerable because, in this case, the temporal regulation of transport is ultimately dictated by the length of organismal lifespan, which can extend to days, years or decades. Recent methodological advances to study live axonal transport during ageing in situ have provided new tools to scratch beneath the surface of this complex problem and revealed that age-dependent decline in the transport of mitochondria is a common feature across different neuronal populations of several model organisms. In certain instances, the molecular pathways that affect transport in ageing animals have begun to emerge. However, the functional implications of these observations are still not fully understood. Whether transport decline is a significant determinant of neuronal ageing or a mere consequence of decreased cellular fitness remains an open question. In this review, we discuss the latest developments in axonal trafficking in the ageing nervous system, along with the early studies that inaugurated this new area of research. We explore the possibility that the interplay between mitochondrial function and motility represents a crucial driver of ageing in neurons and put forward the hypothesis that declining axonal transport may be legitimately considered a hallmark of neuronal ageing.
Collapse
Affiliation(s)
| | - Alessio Vagnoni
- Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, IoPPN, King’s College London, London, United Kingdom
| |
Collapse
|
21
|
Evans TA, Barkauskas DS, Silver J. Intravital imaging of immune cells and their interactions with other cell types in the spinal cord: Experiments with multicolored moving cells. Exp Neurol 2019; 320:112972. [PMID: 31234058 DOI: 10.1016/j.expneurol.2019.112972] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2019] [Revised: 05/25/2019] [Accepted: 06/04/2019] [Indexed: 12/25/2022]
Abstract
Intravital imaging of the immune system is a powerful technique for studying biology of the immune response in the spinal cord using a variety of disease models ranging from traumatic injury to autoimmune disorders. Here, we will discuss specific technical aspects as well as many intriguing biological phenomena that have been revealed with the use of intravital imaging for investigation of the immune system in the spinal cord. We will discuss surgical techniques for exposing and stabilizing the spine that are critical for obtaining images, visualizing immune and CNS cells with genetically expressed fluorescent proteins, fluorescent labeling techniques and briefly discuss some of the challenges of image analysis.
Collapse
Affiliation(s)
- Teresa A Evans
- Department of Pediatrics, Stanford University, Stanford, CA, USA.
| | | | - Jerry Silver
- Department of Neurosciences, Case Western Reserve University, Cleveland, OH, USA
| |
Collapse
|
22
|
Imaging the execution phase of neuroinflammatory disease models. Exp Neurol 2019; 320:112968. [PMID: 31152743 DOI: 10.1016/j.expneurol.2019.112968] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2019] [Revised: 05/22/2019] [Accepted: 05/28/2019] [Indexed: 12/15/2022]
Abstract
In vivo imaging of the rodent spinal cord has advanced our understanding of how resident cells of the central nervous system (CNS) respond to neuroinflammation. By combining two-photon imaging and experimental autoimmune encephalomyelitis (EAE), the most widely used rodent model of multiple sclerosis (MS), it has been possible, for example, to study how axons degenerate when confronted with inflammatory cells, how oligodendrocytes get damaged in inflammatory lesions, and how immune cells themselves adapt their phenotype and functionality to the changing lesion environment. Similar approaches are now increasingly used to study other forms of neuroinflammation, such as antibody/complement-mediated neuromyelitis optica spectrum disease (NMOSD). To tackle the most pressing open questions in the field, new biosensors and indicator mice that report the metabolic state and interaction of cells in neuroinflammatory lesions are being developed. Moreover, the field is moving towards new anatomical sites of inflammation, such as the cortical gray matter, but also towards longer observation intervals to reveal the chronic perturbations and adaptations that characterize advanced stages of MS.
Collapse
|
23
|
Cheng YT, Lett KM, Schaffer CB. Surgical preparations, labeling strategies, and optical techniques for cell-resolved, in vivo imaging in the mouse spinal cord. Exp Neurol 2019; 318:192-204. [PMID: 31095935 DOI: 10.1016/j.expneurol.2019.05.010] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 04/25/2019] [Accepted: 05/10/2019] [Indexed: 11/16/2022]
Abstract
In vivo optical imaging has enabled detailed studies of cellular dynamics in the brain of rodents in both healthy and diseased states. Such studies were made possible by three advances: surgical preparations that give optical access to the brain; strategies for in vivo labeling of cells with structural and functional fluorescent indicators; and optical imaging techniques that are relatively insensitive to light scattering by tissue. In vivo imaging in the rodent spinal cord has lagged behind than that in the brain, largely due to the anatomy around the spinal cord that complicates the surgical preparation, and to the strong optical scattering of the dorsal white matter that limits the ability to image deep into the spinal cord. Here, we review recent advances in surgical methods, labeling strategies, and optical tools that have enabled in vivo, high-resolution imaging of the dynamic behaviors of cells in the spinal cord in mice. Surgical preparations that enable long-term optical access and robust stabilization of the spinal cord are now available. Labeling strategies that have been used in the spinal cord tend to follow those that have been used in the brain, and some recent advances in genetically-encoded labeling strategies remain to be capitalized on. The optical imaging methods used to date, including two photon excited fluorescence microscopy, are largely limited to imaging the superficial layers of the spinal cord by the optical scattering of the white matter. Finally, we show preliminary data that points to the use of higher-order nonlinear optical processes, such as three photon excited fluorescence, as a means to image deeper into the mouse spinal cord.
Collapse
Affiliation(s)
- Yu-Ting Cheng
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA; Department of Neurobiology and Behavior, Cornell University, Ithaca, NY, USA
| | - Kawasi M Lett
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA
| | - Chris B Schaffer
- Nancy E. and Peter C. Meinig School of Biomedical Engineering, Cornell University, Ithaca, NY, USA.
| |
Collapse
|
24
|
Zheng B, Lorenzana AO, Ma L. Understanding the axonal response to injury by in vivo imaging in the mouse spinal cord: A tale of two branches. Exp Neurol 2019; 318:277-285. [PMID: 30986398 PMCID: PMC6588497 DOI: 10.1016/j.expneurol.2019.04.008] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2019] [Revised: 04/05/2019] [Accepted: 04/11/2019] [Indexed: 01/01/2023]
Abstract
Understanding the basic properties of how axons respond to injury in the mammalian central nervous system (CNS) is of fundamental value for developing strategies to promote neural repair. Axons possess complex morphologies with stereotypical branching patterns. However, current knowledge of the axonal response to injury gives little consideration to axonal branches, nor do strategies to promote axon regeneration. This article reviews evidence from in vivo spinal cord imaging that axonal branches markedly impact the degenerative and regenerative responses to injury. At a major bifurcation point, depending on whether one or both axonal branches are injured, neurons may choose either a more self-preservative response or a more dynamic response. The stabilizing effect of the spared branch may underlie a well-known divergence in neuronal responses to injury, and illustrates an example where in vivo spinal cord imaging reveals insights that are difficult to elucidate with conventional histological methods.
Collapse
Affiliation(s)
- Binhai Zheng
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA; VA San Diego Healthcare System, San Diego, CA, USA.
| | - Ariana O Lorenzana
- Department of Neurosciences, School of Medicine, University of California San Diego, La Jolla, CA, USA
| | - Le Ma
- Department of Neuroscience, Jefferson Synaptic Biology Center, Vickie and Jack Farber Institute for Neuroscience, Sydney Kimmel Medical College, Thomas Jefferson University, Philadelphia, PA, USA
| |
Collapse
|
25
|
Schaffran B, Hilton BJ, Bradke F. Imaging in vivo dynamics of sensory axon responses to CNS injury. Exp Neurol 2019; 317:110-118. [PMID: 30794766 DOI: 10.1016/j.expneurol.2019.02.010] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2018] [Revised: 02/13/2019] [Accepted: 02/17/2019] [Indexed: 01/25/2023]
Abstract
Axons in the adult mammalian brain and spinal cord fail to regenerate upon lesion. In vivo imaging serves as a tool to investigate the immediate response of axons to injury and how the same injured axons behave over time. Here, we describe the dynamic changes that injured sensory axons undergo and methods of imaging them in vivo. First, we explain how sensory axons in the dorsal column of the adult mouse spinal cord respond to axotomy. Then, we highlight practical considerations for implementing two-photon based in vivo imaging of these axons. Finally, we describe future directions for this technique, including the possibility of in vivo imaging of subcellular dynamics within the axon.
Collapse
Affiliation(s)
| | - Brett J Hilton
- German Center for Neurodegenerative Diseases, Bonn, Germany
| | - Frank Bradke
- German Center for Neurodegenerative Diseases, Bonn, Germany.
| |
Collapse
|
26
|
Witte ME, Schumacher AM, Mahler CF, Bewersdorf JP, Lehmitz J, Scheiter A, Sánchez P, Williams PR, Griesbeck O, Naumann R, Misgeld T, Kerschensteiner M. Calcium Influx through Plasma-Membrane Nanoruptures Drives Axon Degeneration in a Model of Multiple Sclerosis. Neuron 2019; 101:615-624.e5. [PMID: 30686733 PMCID: PMC6389591 DOI: 10.1016/j.neuron.2018.12.023] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Revised: 11/09/2018] [Accepted: 12/12/2018] [Indexed: 11/15/2022]
Abstract
Axon loss determines persistent disability in multiple sclerosis patients. Here, we use in vivo calcium imaging in a multiple sclerosis model to show that cytoplasmic calcium levels determine the choice between axon loss and survival. We rule out the endoplasmic reticulum, glutamate excitotoxicity, and the reversal of the sodium-calcium exchanger as sources of intra-axonal calcium accumulation and instead identify nanoscale ruptures of the axonal plasma membrane as the critical path of calcium entry.
Collapse
Affiliation(s)
- Maarten E Witte
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians Universität München, Marchioninistraße 15, 81377 Munich, Germany; Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians Universität München, Großhaderner Strasse 9, 82152 Planegg Martinsried, Germany
| | - Adrian-Minh Schumacher
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians Universität München, Marchioninistraße 15, 81377 Munich, Germany; Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians Universität München, Großhaderner Strasse 9, 82152 Planegg Martinsried, Germany
| | - Christoph F Mahler
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians Universität München, Marchioninistraße 15, 81377 Munich, Germany; Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians Universität München, Großhaderner Strasse 9, 82152 Planegg Martinsried, Germany
| | - Jan P Bewersdorf
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians Universität München, Marchioninistraße 15, 81377 Munich, Germany; Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians Universität München, Großhaderner Strasse 9, 82152 Planegg Martinsried, Germany
| | - Jonas Lehmitz
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians Universität München, Marchioninistraße 15, 81377 Munich, Germany; Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians Universität München, Großhaderner Strasse 9, 82152 Planegg Martinsried, Germany; Institute of Neuronal Cell Biology, Technische Universität München, Biedersteiner Straße 29, 80802 Munich, Germany
| | - Alexander Scheiter
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians Universität München, Marchioninistraße 15, 81377 Munich, Germany; Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians Universität München, Großhaderner Strasse 9, 82152 Planegg Martinsried, Germany; Institute of Neuronal Cell Biology, Technische Universität München, Biedersteiner Straße 29, 80802 Munich, Germany
| | - Paula Sánchez
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians Universität München, Marchioninistraße 15, 81377 Munich, Germany; Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians Universität München, Großhaderner Strasse 9, 82152 Planegg Martinsried, Germany
| | - Philip R Williams
- Institute of Neuronal Cell Biology, Technische Universität München, Biedersteiner Straße 29, 80802 Munich, Germany
| | - Oliver Griesbeck
- Max-Planck Institute of Neurobiology, Am Klopferspitz 18, 82152 Planegg-Martinsried, Germany
| | - Ronald Naumann
- Max-Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstrasse 108, 01307 Dresden, Germany
| | - Thomas Misgeld
- Institute of Neuronal Cell Biology, Technische Universität München, Biedersteiner Straße 29, 80802 Munich, Germany; Munich Cluster for Systems Neurology (SyNergy), Feodor-Lynen-Straße 17, 81377 Munich, Germany; German Center for Neurodegenerative Diseases (DZNE), Feodor-Lynen-Straße 17, 81377 Munich, Germany; Center of Integrated Protein Science (CIPSM), Butenandtstraße 5-13, 81377 Munich, Germany.
| | - Martin Kerschensteiner
- Institute of Clinical Neuroimmunology, University Hospital, Ludwig-Maximilians Universität München, Marchioninistraße 15, 81377 Munich, Germany; Biomedical Center (BMC), Faculty of Medicine, Ludwig-Maximilians Universität München, Großhaderner Strasse 9, 82152 Planegg Martinsried, Germany; Munich Cluster for Systems Neurology (SyNergy), Feodor-Lynen-Straße 17, 81377 Munich, Germany.
| |
Collapse
|
27
|
Liu T, Rajadhyaksha M, Dickensheets DL. MEMS-in-the-lens architecture for a miniature high-NA laser scanning microscope. LIGHT, SCIENCE & APPLICATIONS 2019; 8:59. [PMID: 31263558 PMCID: PMC6592906 DOI: 10.1038/s41377-019-0167-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2018] [Revised: 05/24/2019] [Accepted: 05/30/2019] [Indexed: 05/16/2023]
Abstract
Laser scanning microscopes can be miniaturized for in vivo imaging by substituting optical microelectromechanical system (MEMS) devices in place of larger components. The emergence of multifunctional active optical devices can support further miniaturization beyond direct component replacement because those active devices enable diffraction-limited performance using simpler optical system designs. In this paper, we propose a catadioptric microscope objective lens that features an integrated MEMS device for performing biaxial scanning, axial focus adjustment, and control of spherical aberration. The MEMS-in-the-lens architecture incorporates a reflective MEMS scanner between a low-numerical-aperture back lens group and an aplanatic hyperhemisphere front refractive element to support high-numerical-aperture imaging. We implemented this new optical system using a recently developed hybrid polymer/silicon MEMS three-dimensional scan mirror that features an annular aperture that allows it to be coaxially aligned within the objective lens without the need for a beam splitter. The optical performance of the active catadioptric system is simulated and imaging of hard targets and human cheek cells is demonstrated with a confocal microscope that is based on the new objective lens design.
Collapse
Affiliation(s)
- Tianbo Liu
- Electrical and Computer Engineering Department, Montana State University, Bozeman, MT 59715 USA
| | - Milind Rajadhyaksha
- Dermatology Department, Memorial Sloan Kettering Cancer Center, New York, NY 10022 USA
| | - David L. Dickensheets
- Electrical and Computer Engineering Department, Montana State University, Bozeman, MT 59715 USA
| |
Collapse
|
28
|
Nobis M, Warren SC, Lucas MC, Murphy KJ, Herrmann D, Timpson P. Molecular mobility and activity in an intravital imaging setting - implications for cancer progression and targeting. J Cell Sci 2018; 131:131/5/jcs206995. [PMID: 29511095 DOI: 10.1242/jcs.206995] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Molecular mobility, localisation and spatiotemporal activity are at the core of cell biological processes and deregulation of these dynamic events can underpin disease development and progression. Recent advances in intravital imaging techniques in mice are providing new avenues to study real-time molecular behaviour in intact tissues within a live organism and to gain exciting insights into the intricate regulation of live cell biology at the microscale level. The monitoring of fluorescently labelled proteins and agents can be combined with autofluorescent properties of the microenvironment to provide a comprehensive snapshot of in vivo cell biology. In this Review, we summarise recent intravital microscopy approaches in mice, in processes ranging from normal development and homeostasis to disease progression and treatment in cancer, where we emphasise the utility of intravital imaging to observe dynamic and transient events in vivo We also highlight the recent integration of advanced subcellular imaging techniques into the intravital imaging pipeline, which can provide in-depth biological information beyond the single-cell level. We conclude with an outlook of ongoing developments in intravital microscopy towards imaging in humans, as well as provide an overview of the challenges the intravital imaging community currently faces and outline potential ways for overcoming these hurdles.
Collapse
Affiliation(s)
- Max Nobis
- The Garvan Institute of Medical Research and The Kinghorn Cancer Centre, Cancer Division, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - Sean C Warren
- The Garvan Institute of Medical Research and The Kinghorn Cancer Centre, Cancer Division, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - Morghan C Lucas
- The Garvan Institute of Medical Research and The Kinghorn Cancer Centre, Cancer Division, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - Kendelle J Murphy
- The Garvan Institute of Medical Research and The Kinghorn Cancer Centre, Cancer Division, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - David Herrmann
- The Garvan Institute of Medical Research and The Kinghorn Cancer Centre, Cancer Division, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| | - Paul Timpson
- The Garvan Institute of Medical Research and The Kinghorn Cancer Centre, Cancer Division, St. Vincent's Clinical School, Faculty of Medicine, University of New South Wales, Sydney, NSW 2010, Australia
| |
Collapse
|
29
|
Abstract
Intravital imaging is a powerful tool for analyzing cellular functions in living animals. In particular, after the two-photon microscopy technique was introduced, a number of studies have visualized important processes. Here, we describe the methods for performing intravital imaging of the central nervous system. This method can be used for imaging not only lymphocytes but also blood vessels for ischemia studies, as well as glia cell activities.
Collapse
|
30
|
Chen C, Zhang YP, Sun Y, Xiong W, Shields LBE, Shields CB, Jin X, Xu XM. An In Vivo Duo-color Method for Imaging Vascular Dynamics Following Contusive Spinal Cord Injury. J Vis Exp 2017:56565. [PMID: 29364252 PMCID: PMC5908407 DOI: 10.3791/56565] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023] Open
Abstract
Spinal cord injury (SCI) causes significant vascular disruption at the site of injury. Vascular pathology occurs immediately after SCI and continues throughout the acute injury phase. In fact, endothelial cells appear to be the first to die after a contusive SCI. The early vascular events, including increased permeability of the blood-spinal cord barrier (BSCB), induce vasogenic edema and contribute to detrimental secondary injury events caused by complex injury mechanisms. Targeting the vascular disruption, therefore, could be a key strategy to reduce secondary injury cascades that contribute to histological and functional impairments after SCI. Previous studies were mostly performed on postmortem samples and were unable to capture the dynamic changes of the vascular network. In this study, we have developed an in vivo duo-color two-photon imaging method to monitor acute vascular dynamic changes following contusive SCI. This approach allows detecting blood flow, vessel diameter, and other vascular pathologies at various sites of the same rat pre- and post-injury. Overall, this method provides an excellent venue for investigating vascular dynamics.
Collapse
Affiliation(s)
- Chen Chen
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, and Department of Neurological Surgery, Indiana University School of Medicine; Program in Medical Neuroscience, Stark Neurosciences Research Institute, Indiana University School of Medicine
| | | | - Yan Sun
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, and Department of Neurological Surgery, Indiana University School of Medicine; Department of Human Anatomy & Histoembryology, School of Basic Medical Sciences, Fudan University
| | - Wenhui Xiong
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, and Department of Neurological Surgery, Indiana University School of Medicine
| | | | - Christopher B Shields
- Norton Neuroscience Institute, Norton Healthcare; Department of Neurological Surgery, University of Louisville School of Medicine
| | - Xiaoming Jin
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, and Department of Neurological Surgery, Indiana University School of Medicine
| | - Xiao-Ming Xu
- Spinal Cord and Brain Injury Research Group, Stark Neurosciences Research Institute, and Department of Neurological Surgery, Indiana University School of Medicine;
| |
Collapse
|
31
|
In Vivo Imaging of CNS Injury and Disease. J Neurosci 2017; 37:10808-10816. [PMID: 29118209 DOI: 10.1523/jneurosci.1826-17.2017] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2017] [Revised: 10/02/2017] [Accepted: 10/03/2017] [Indexed: 02/06/2023] Open
Abstract
In vivo optical imaging has emerged as a powerful tool with which to study cellular responses to injury and disease in the mammalian CNS. Important new insights have emerged regarding axonal degeneration and regeneration, glial responses and neuroinflammation, changes in the neurovascular unit, and, more recently, neural transplantations. Accompanying a 2017 SfN Mini-Symposium, here, we discuss selected recent advances in understanding the neuronal, glial, and other cellular responses to CNS injury and disease with in vivo imaging of the rodent brain or spinal cord. We anticipate that in vivo optical imaging will continue to be at the forefront of breakthrough discoveries of fundamental mechanisms and therapies for CNS injury and disease.
Collapse
|
32
|
Anderson M, Zheng Q, Dong X. Investigation of Pain Mechanisms by Calcium Imaging Approaches. Neurosci Bull 2017; 34:194-199. [PMID: 28501905 PMCID: PMC5799123 DOI: 10.1007/s12264-017-0139-9] [Citation(s) in RCA: 38] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2017] [Accepted: 03/12/2017] [Indexed: 12/12/2022] Open
Abstract
Due to the complex circuitry and plethora of cell types involved in somatosensation, it is becoming increasingly important to be able to observe cellular activity at the population level. In addition, since cells rely on an intricate variety of extracellular factors, it is important to strive to maintain the physiological environment. Many electrophysiological techniques require the implementation of artificially-produced physiological environments and it can be difficult to assess the activity of many cells simultaneously. Moreover, imaging Ca2+ transients using Ca2+-sensitive dyes often requires in vitro preparations or in vivo injections, which can lead to variable expression levels. With the development of more sensitive genetically-encoded Ca2+ indicators (GECIs) it is now possible to observe changes in Ca2+ transients in large populations of cells at the same time. Recently, groups have used a GECI called GCaMP to address fundamental questions in somatosensation. Researchers can now induce GCaMP expression in the mouse genome using viral or gene knock-in approaches and observe the activity of populations of cells in the pain pathway such as dorsal root ganglia (DRG), spinal neurons, or glia. This approach can be used in vivo and thus maintains the organism’s biological integrity. The implementation of GCaMP imaging has led to many advances in our understanding of somatosensation. Here, we review the current findings in pain research using GCaMP imaging as well as discussing potential methodological considerations.
Collapse
Affiliation(s)
- Michael Anderson
- The Solomon H. Snyder Department of Neuroscience, Center for Sensory Biology, School of Medicine, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Qin Zheng
- The Solomon H. Snyder Department of Neuroscience, Center for Sensory Biology, School of Medicine, Johns Hopkins University, Baltimore, MD, 21205, USA
| | - Xinzhong Dong
- The Solomon H. Snyder Department of Neuroscience, Center for Sensory Biology, School of Medicine, Johns Hopkins University, Baltimore, MD, 21205, USA. .,Howard Hughes Medical Institute, School of Medicine, Johns Hopkins University, Baltimore, MD, 21205, USA.
| |
Collapse
|
33
|
Haghayegh Jahromi N, Tardent H, Enzmann G, Deutsch U, Kawakami N, Bittner S, Vestweber D, Zipp F, Stein JV, Engelhardt B. A Novel Cervical Spinal Cord Window Preparation Allows for Two-Photon Imaging of T-Cell Interactions with the Cervical Spinal Cord Microvasculature during Experimental Autoimmune Encephalomyelitis. Front Immunol 2017; 8:406. [PMID: 28443093 PMCID: PMC5387098 DOI: 10.3389/fimmu.2017.00406] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 03/22/2017] [Indexed: 11/13/2022] Open
Abstract
T-cell migration across the blood-brain barrier (BBB) is a crucial step in the pathogenesis of experimental autoimmune encephalomyelitis (EAE), an animal model of multiple sclerosis (MS). Two-photon intravital microscopy (2P-IVM) has been established as a powerful tool to study cell-cell interactions in inflammatory EAE lesions in living animals. In EAE, central nervous system inflammation is strongly pronounced in the spinal cord, an organ in which 2P-IVM imaging is technically very challenging and has been limited to the lumbar spinal cord. Here, we describe a novel spinal cord window preparation allowing to use 2P-IVM to image immune cell interactions with the cervical spinal cord microvascular endothelium during EAE. We describe differences in the angioarchitecture of the cervical spinal cord versus the lumbar spinal cord, which will entail different hemodynamic parameters in these different vascular beds. Using T cells as an example, we demonstrate the suitability of this novel methodology in imaging the post-arrest multistep T-cell extravasation across the cervical spinal cord microvessels. The novel methodology includes an outlook to the analysis of the cellular pathway of T-cell diapedesis across the BBB by establishing visualization of endothelial junctions in this vascular bed.
Collapse
Affiliation(s)
| | - Heidi Tardent
- Theodor Kocher Institute, University of Bern, Bern, Switzerland
| | - Gaby Enzmann
- Theodor Kocher Institute, University of Bern, Bern, Switzerland
| | - Urban Deutsch
- Theodor Kocher Institute, University of Bern, Bern, Switzerland
| | - Naoto Kawakami
- Max Planck Institute of Neurobiology, Martinsried, Germany.,Institute of Clinical Neuroimmunology, Biomedical Center and University Hospital, Ludwig-Maximilians University of Munich, Martinsried, Germany
| | - Stefan Bittner
- Focus Program Translational Neuroscience (FTN) and Immunotherapy (FZI), Rhine Main Neuroscience Network (rmn2), University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | | | - Frauke Zipp
- Focus Program Translational Neuroscience (FTN) and Immunotherapy (FZI), Rhine Main Neuroscience Network (rmn2), University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Jens V Stein
- Theodor Kocher Institute, University of Bern, Bern, Switzerland
| | | |
Collapse
|
34
|
Yang Z, Xie W, Ju F, khan A, Zhang S. In vivo two-photon imaging reveals a role of progesterone in reducing axonal dieback after spinal cord injury in mice. Neuropharmacology 2017; 116:30-37. [DOI: 10.1016/j.neuropharm.2016.12.007] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2016] [Revised: 11/29/2016] [Accepted: 12/09/2016] [Indexed: 01/10/2023]
|
35
|
Sleigh JN, Vagnoni A, Twelvetrees AE, Schiavo G. Methodological advances in imaging intravital axonal transport. F1000Res 2017; 6:200. [PMID: 28344778 PMCID: PMC5333613 DOI: 10.12688/f1000research.10433.1] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 02/27/2017] [Indexed: 11/25/2022] Open
Abstract
Axonal transport is the active process whereby neurons transport cargoes such as organelles and proteins anterogradely from the cell body to the axon terminal and retrogradely in the opposite direction. Bi-directional transport in axons is absolutely essential for the functioning and survival of neurons and appears to be negatively impacted by both aging and diseases of the nervous system, such as Alzheimer’s disease and amyotrophic lateral sclerosis. The movement of individual cargoes along axons has been studied
in vitro in live neurons and tissue explants for a number of years; however, it is currently unclear as to whether these systems faithfully and consistently replicate the
in vivo situation. A number of intravital techniques originally developed for studying diverse biological events have recently been adapted to monitor axonal transport in real-time in a range of live organisms and are providing novel insight into this dynamic process. Here, we highlight these methodological advances in intravital imaging of axonal transport, outlining key strengths and limitations while discussing findings, possible improvements, and outstanding questions.
Collapse
Affiliation(s)
- James N Sleigh
- Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, London, UK
| | - Alessio Vagnoni
- Division of Cell Biology, MRC Laboratory of Molecular Biology, Cambridge, UK; Department of Basic and Clinical Neuroscience, Maurice Wohl Clinical Neuroscience Institute, Institute of Psychiatry, Psychology and Neuroscience, King's College London, London, UK
| | - Alison E Twelvetrees
- Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, London, UK
| | - Giampietro Schiavo
- Sobell Department of Motor Neuroscience and Movement Disorders, Institute of Neurology, University College London, London, UK
| |
Collapse
|
36
|
Cao Y, Zhou Y, Ni S, Wu T, Li P, Liao S, Hu J, Lu H. Three Dimensional Quantification of Microarchitecture and Vessel Regeneration by Synchrotron Radiation Microcomputed Tomography in a Rat Model of Spinal Cord Injury. J Neurotrauma 2016; 34:1187-1199. [PMID: 27676128 DOI: 10.1089/neu.2016.4697] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
A full understanding of the mechanisms behind spinal cord injury (SCI) processes requires reliable three-dimensional (3D) imaging tools for a thorough analysis of changes in angiospatial architecture. We aimed to use synchrotron radiation μCT (SRμCT) to characterize 3D temporal-spatial changes in microvasculature post-SCI. Morphometrical measurements revealed a significant decrease in vascular volume fraction, vascular bifurcation density, vascular segment density, and vascular connectivity density 1 day post-injury, followed by a gradual increase at 3, 7, and 14 days. At 1 day post-injury, SRμCT revealed an increase in vascular tortuosity (VT), which reached a plateau after 7 days and decreased slightly during the healing process. In addition, SRμCT images showed that vessels were largely concentrated in the gray matter 1 day post-injury. The maximal endothelial cell proliferation rate was detected at 7 days post-injury. The 3D morphology of the cavity appears in the spinal cord at 28 days post-injury. We describe a methodology for 3D analysis of vascular repair in SCI and reveal that endogenous revascularization occurs during the healing process. The spinal cord microvasculature configuration undergoes 3D remodeling and modification during the post-injury repair process. Examination of these processes might contribute to a full understanding of the compensatory vascular mechanisms after injury and aid in the development of novel and effective treatment for SCI.
Collapse
Affiliation(s)
- Yong Cao
- 1 Department of Spine Surgery, Central South University , Changsha, China
| | - Yuan Zhou
- 2 Department of Thoracic Surgery, Xiangya Hospital, Central South University , Changsha, China
| | - Shuangfei Ni
- 1 Department of Spine Surgery, Central South University , Changsha, China
| | - Tianding Wu
- 1 Department of Spine Surgery, Central South University , Changsha, China
| | - Ping Li
- 1 Department of Spine Surgery, Central South University , Changsha, China
| | - Shenghui Liao
- 3 School of Information Science and Engineering, Central South University , Changsha, Changsha, China
| | - Jianzhong Hu
- 1 Department of Spine Surgery, Central South University , Changsha, China
| | - Hongbin Lu
- 4 Department of Sports Medicine, Research Centre of Sports Medicine, Xiangya Hospital, Central South University , Changsha, China
| |
Collapse
|
37
|
Wang F, Bélanger E, Paquet ME, Côté DC, De Koninck Y. Probing pain pathways with light. Neuroscience 2016; 338:248-271. [PMID: 27702648 DOI: 10.1016/j.neuroscience.2016.09.035] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2016] [Revised: 09/19/2016] [Accepted: 09/20/2016] [Indexed: 02/06/2023]
Abstract
We have witnessed an accelerated growth of photonics technologies in recent years to enable not only monitoring the activity of specific neurons, while animals are performing certain types of behavior, but also testing whether specific cells, circuits, and regions are sufficient or necessary for initiating, maintaining, or altering this or that behavior. Compared to other sensory systems, however, such as the visual or olfactory system, photonics applications in pain research are only beginning to emerge. One reason pain studies have lagged behind is that many of the techniques originally developed cannot be directly implemented to study key relay sites within pain pathways, such as the skin, dorsal root ganglia, spinal cord, and brainstem. This is due, in part, to difficulties in accessing these structures with light. Here we review a number of recent advances in design and delivery of light-sensitive molecular probes (sensors and actuators) into pain relay circuits to help decipher their structural and functional organization. We then discuss several challenges that have hampered hardware access to specific structures including light scattering, tissue movement and geometries. We review a number of strategies to circumvent these challenges, by delivering light into, and collecting it from the different key sites to unravel how nociceptive signals are encoded at each level of the neuraxis. We conclude with an outlook on novel imaging modalities for label-free chemical detection and opportunities for multimodal interrogation in vivo. While many challenges remain, these advances offer unprecedented opportunities to bridge cellular approaches with context-relevant behavioral testing, an essential step toward improving translation of basic research findings into clinical applications.
Collapse
Affiliation(s)
- Feng Wang
- Institut universitaire en santé mentale de Québec, Université Laval, Québec, QC, Canada
| | - Erik Bélanger
- Institut universitaire en santé mentale de Québec, Université Laval, Québec, QC, Canada; Centre d'optique, photonique et laser, Université Laval, Québec, QC, Canada
| | - Marie-Eve Paquet
- Institut universitaire en santé mentale de Québec, Université Laval, Québec, QC, Canada; Département de biochimie, microbiologie et bioinformatique, Université Laval, Québec, QC, Canada
| | - Daniel C Côté
- Institut universitaire en santé mentale de Québec, Université Laval, Québec, QC, Canada; Centre d'optique, photonique et laser, Université Laval, Québec, QC, Canada; Département de physique, de génie physique et d'optique, Université Laval, Québec, QC, Canada
| | - Yves De Koninck
- Institut universitaire en santé mentale de Québec, Université Laval, Québec, QC, Canada; Centre d'optique, photonique et laser, Université Laval, Québec, QC, Canada; Département de psychiatrie et neurosciences, Université Laval, Québec, QC, Canada.
| |
Collapse
|
38
|
Microglial P2Y12 receptors regulate microglial activation and surveillance during neuropathic pain. Brain Behav Immun 2016; 55:82-92. [PMID: 26576724 PMCID: PMC4864135 DOI: 10.1016/j.bbi.2015.11.007] [Citation(s) in RCA: 94] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2015] [Revised: 10/15/2015] [Accepted: 11/09/2015] [Indexed: 11/20/2022] Open
Abstract
Microglial cells are critical in the pathogenesis of neuropathic pain and several microglial receptors have been proposed to mediate this process. Of these receptors, the P2Y12 receptor is a unique purinergic receptor that is exclusively expressed by microglia in the central nervous system (CNS). In this study, we set forth to investigate the role of P2Y12 receptors in microglial electrophysiological and morphological (static and dynamic) activation during spinal nerve transection (SNT)-induced neuropathic pain in mice. First, we found that a genetic deficiency of the P2Y12 receptor (P2Y12(-/-) mice) ameliorated pain hypersensitivities during the initiation phase of neuropathic pain. Next, we characterised both the electrophysiological and morphological properties of microglia in the superficial spinal cord dorsal horn following SNT injury. We show dramatic alterations including a peak at 3days post injury in microglial electrophysiology while high resolution two-photon imaging revealed significant changes of both static and dynamic microglial morphological properties by 7days post injury. Finally, in P2Y12(-/-) mice, these electrophysiological and morphological changes were ameliorated suggesting roles for P2Y12 receptors in SNT-induced microglial activation. Our results therefore indicate that P2Y12 receptors regulate microglial electrophysiological as well as static and dynamic microglial properties after peripheral nerve injury, suggesting that the microglial P2Y12 receptor could be a potential therapeutic target for the treatment of neuropathic pain.
Collapse
|
39
|
Kawakami N. In vivo imaging in autoimmune diseases in the central nervous system. Allergol Int 2016; 65:235-42. [PMID: 26935215 DOI: 10.1016/j.alit.2016.02.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 02/02/2016] [Indexed: 11/18/2022] Open
Abstract
Intravital imaging is becoming more popular and is being used to visualize cellular motility and functions. In contrast to in vitro analysis, which resembles in vivo analysis, intravital imaging can be used to observe and analyze cells directly in vivo. In this review, I will summarize recent imaging studies of autoreactive T cell infiltration into the central nervous system (CNS) and provide technical background. During their in vivo journey, autoreactive T cells interact with many different cells. At first, autoreactive T cells interact with endothelial cells in the airways of the lung or with splenocytes, where they acquire a migratory phenotype to infiltrate into the CNS. After arriving at the CNS, they interact with endothelial cells of the leptomeningeal vessels or the choroid plexus before passing through the blood-brain barrier. CNS-infiltrating T cells become activated by recognizing endogenous autoantigens presented by local antigen-presenting cells (APCs). This activation was visualized in vivo by using protein-based sensors. One such sensor detects changes in intracellular calcium concentration as an early marker of T cell activation. Another sensor detects translocation of Nuclear factor of activated T-cells (NFAT) from cytosol to nucleus as a definitive sign of T cell activation. Importantly, intravital imaging is not just used to visualize cellular behavior. Together with precise analysis, intravital imaging deepens our knowledge of cellular functions in living organs and also provides a platform for developing therapeutic treatments.
Collapse
Affiliation(s)
- Naoto Kawakami
- Institute of Clinical Neuroimmunology, Biomedical Center and University Hospital, Ludwig-Maximilians Universitaet Muenchen, Munich, Germany; Neuroimmunology Group, Max-Planck Institute of Neurobiology, Martinsried, Germany.
| |
Collapse
|
40
|
Herwerth M, Kalluri SR, Srivastava R, Kleele T, Kenet S, Illes Z, Merkler D, Bennett JL, Misgeld T, Hemmer B. In vivo imaging reveals rapid astrocyte depletion and axon damage in a model of neuromyelitis optica-related pathology. Ann Neurol 2016; 79:794-805. [PMID: 26946517 PMCID: PMC5021140 DOI: 10.1002/ana.24630] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 03/02/2016] [Accepted: 03/03/2016] [Indexed: 01/27/2023]
Abstract
Objective Neuromyelitis optica (NMO) is an autoimmune disease of the central nervous system, which resembles multiple sclerosis (MS). NMO differs from MS, however, in the distribution and histology of neuroinflammatory lesions and shows a more aggressive clinical course. Moreover, the majority of NMO patients carry immunoglobulin G autoantibodies against aquaporin‐4 (AQP4), an astrocytic water channel. Antibodies against AQP4 can damage astrocytes by complement, but NMO histopathology also shows demyelination, and — importantly—axon injury, which may determine permanent deficits following NMO relapses. The dynamics of astrocyte injury in NMO and the mechanisms by which toxicity spreads to axons are not understood. Methods Here, we establish in vivo imaging of the spinal cord, one of the main sites of NMO pathology, as a powerful tool to study the formation of experimental NMO‐related lesions caused by human AQP4 antibodies in mice. Results We found that human AQP4 antibodies caused acute astrocyte depletion with initial oligodendrocyte survival. Within 2 hours of antibody application, we observed secondary axon injury in the form of progressive swellings. Astrocyte toxicity and axon damage were dependent on AQP4 antibody titer and complement, specifically C1q. Interpretation In vivo imaging of the spinal cord reveals the swift development of NMO‐related acute axon injury after AQP4 antibody‐mediated astrocyte depletion. This approach will be useful in studying the mechanisms underlying the spread of NMO pathology beyond astrocytes, as well as in evaluating potential neuroprotective interventions. Ann Neurol 2016;79:794–805
Collapse
Affiliation(s)
- Marina Herwerth
- Department of Neurology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany.,Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany
| | - Sudhakar Reddy Kalluri
- Department of Neurology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Rajneesh Srivastava
- Department of Neurology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany
| | - Tatjana Kleele
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
| | - Selin Kenet
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany
| | - Zsolt Illes
- Department of Neurology, Division of Clinical and Experimental Neuroimmunology, University of Pecs, Pecs, Hungary.,Department of Neurology and Institute of Clinical Research, Odense University Hospital, University of Southern Denmark, Odense, Denmark
| | - Doron Merkler
- Department of Pathology and Immunology, University of Geneva, Geneva, Switzerland.,Division of Clinical Pathology, Geneva University Hospital, Geneva, Switzerland.,Department of Neuropathology, University Medical Center, Göttingen, Germany
| | - Jeffrey L Bennett
- Departments of Neurology and Ophthalmology, Program in Neuroscience, University of Colorado Denver School of Medicine, Aurora, CO
| | - Thomas Misgeld
- Institute of Neuronal Cell Biology, Technical University of Munich, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.,German Center for Neurodegenerative Diseases (DZNE), Munich, Germany.,Center of Integrated Protein Science (CIPSM), Munich, Germany.,equal contributing senior authors
| | - Bernhard Hemmer
- Department of Neurology, Klinikum rechts der Isar, Technical University of Munich, Munich, Germany.,Munich Cluster for Systems Neurology (SyNergy), Munich, Germany.,equal contributing senior authors
| |
Collapse
|
41
|
Pietronigro E, Zenaro E, Constantin G. Imaging of Leukocyte Trafficking in Alzheimer's Disease. Front Immunol 2016; 7:33. [PMID: 26913031 PMCID: PMC4753285 DOI: 10.3389/fimmu.2016.00033] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2015] [Accepted: 01/23/2016] [Indexed: 12/17/2022] Open
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disorder and is characterized by a progressive decline of cognitive functions. The neuropathological features of AD include amyloid beta (Aβ) deposition, intracellular neurofibrillary tangles derived from the cytoskeletal hyperphosphorylated tau protein, amyloid angiopathy, the loss of synapses, and neuronal degeneration. In the last decade, inflammation has emerged as a key feature of AD, but most studies have focused on the role of microglia-driven neuroinflammation mechanisms. A dysfunctional blood-brain barrier has also been implicated in the pathogenesis of AD, and several studies have demonstrated that the vascular deposition of Aβ induces the expression of adhesion molecules and alters the expression of tight junction proteins, potentially facilitating the transmigration of circulating leukocytes. Two-photon laser scanning microscopy (TPLSM) has become an indispensable tool to dissect the molecular mechanisms controlling leukocyte trafficking in the central nervous system (CNS). Recent TPLSM studies have shown that vascular deposition of Aβ in the CNS promotes intraluminal neutrophil adhesion and crawling on the brain endothelium and also that neutrophils extravasate in the parenchyma preferentially in areas with Aβ deposits. These studies have also highlighted a role for LFA-1 integrin in neutrophil accumulation in the CNS of AD-like disease models, revealing that LFA-1 inhibition reduces the corresponding cognitive deficit and AD neuropathology. In this article, we consider how current imaging techniques can help to unravel new inflammation mechanisms in the pathogenesis of AD and identify novel therapeutic strategies to treat the disease by interfering with leukocyte trafficking mechanisms.
Collapse
Affiliation(s)
- Enrica Pietronigro
- Section of General Pathology, Department of Medicine, University of Verona , Verona , Italy
| | - Elena Zenaro
- Section of General Pathology, Department of Medicine, University of Verona , Verona , Italy
| | - Gabriela Constantin
- Section of General Pathology, Department of Medicine, University of Verona , Verona , Italy
| |
Collapse
|
42
|
Shaked I, Hanna RN, Shaked H, Chodaczek G, Nowyhed HN, Tweet G, Tacke R, Basat AB, Mikulski Z, Togher S, Miller J, Blatchley A, Salek-Ardakani S, Darvas M, Kaikkonen MU, Thomas GD, Lai-Wing-Sun S, Rezk A, Bar-Or A, Glass CK, Bandukwala H, Hedrick CC. Transcription factor Nr4a1 couples sympathetic and inflammatory cues in CNS-recruited macrophages to limit neuroinflammation. Nat Immunol 2015; 16:1228-34. [PMID: 26523867 DOI: 10.1038/ni.3321] [Citation(s) in RCA: 91] [Impact Index Per Article: 10.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 10/13/2015] [Indexed: 12/11/2022]
Abstract
The molecular mechanisms that link the sympathetic stress response and inflammation remain obscure. Here we found that the transcription factor Nr4a1 regulated the production of norepinephrine (NE) in macrophages and thereby limited experimental autoimmune encephalomyelitis (EAE), a mouse model of multiple sclerosis. Lack of Nr4a1 in myeloid cells led to enhanced NE production, accelerated infiltration of leukocytes into the central nervous system (CNS) and disease exacerbation in vivo. In contrast, myeloid-specific deletion of tyrosine hydroxylase (TH), the rate-limiting enzyme in catecholamine biosynthesis, protected mice against EAE. Furthermore, we found that Nr4a1 repressed autocrine NE production in macrophages by recruiting the corepressor CoREST to the Th promoter. Our data reveal a new role for macrophages in neuroinflammation and identify Nr4a1 as a key regulator of catecholamine production by macrophages.
Collapse
Affiliation(s)
- Iftach Shaked
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California, USA
| | - Richard N Hanna
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California, USA
| | - Helena Shaked
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California, USA
| | - Grzegorz Chodaczek
- Microscopy Core, La Jolla Institute for Allergy and Immunology, La Jolla, California, USA
| | - Heba N Nowyhed
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California, USA
| | - George Tweet
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California, USA
| | - Robert Tacke
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California, USA
| | - Alp Bugra Basat
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California, USA
| | - Zbigniew Mikulski
- Microscopy Core, La Jolla Institute for Allergy and Immunology, La Jolla, California, USA
| | - Susan Togher
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California, USA
| | - Jacqueline Miller
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California, USA
| | - Amy Blatchley
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California, USA
| | - Shahram Salek-Ardakani
- Department of Pathology, Immunology &Laboratory Medicine, University of Florida College of Medicine, Gainesville, Florida, USA
| | - Martin Darvas
- Department of Pathology, University of Washington, Seattle, Washington, USA
| | - Minna U Kaikkonen
- Department of Biotechnology and Molecular Medicine, University of Eastern Finland, Kuopio, Finland
| | - Graham D Thomas
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California, USA
| | | | - Ayman Rezk
- Montreal Neurological Institute, McGill University, Montreal, Canada
| | - Amit Bar-Or
- Montreal Neurological Institute, McGill University, Montreal, Canada
| | - Christopher K Glass
- Department of Cellular &Molecular Medicine, University of California San Diego, San Diego, California, USA
| | - Hozefa Bandukwala
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California, USA
| | - Catherine C Hedrick
- Division of Inflammation Biology, La Jolla Institute for Allergy and Immunology, La Jolla, California, USA
| |
Collapse
|
43
|
Tang P, Zhang Y, Chen C, Ji X, Ju F, Liu X, Gan WB, He Z, Zhang S, Li W, Zhang L. In vivo two-photon imaging of axonal dieback, blood flow, and calcium influx with methylprednisolone therapy after spinal cord injury. Sci Rep 2015; 5:9691. [PMID: 25989524 PMCID: PMC4437044 DOI: 10.1038/srep09691] [Citation(s) in RCA: 39] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2014] [Accepted: 03/17/2015] [Indexed: 12/30/2022] Open
Abstract
Severe spinal cord injury (SCI) can cause neurological dysfunction and paralysis. However, the early dynamic changes of neurons and their surrounding environment after SCI are poorly understood. Although methylprednisolone (MP) is currently the standard therapeutic agent for treating SCI, its efficacy remains controversial. The purpose of this project was to investigate the early dynamic changes and MP's efficacy on axonal damage, blood flow, and calcium influx into axons in a mouse SCI model. YFP H-line and Thy1-GCaMP transgenic mice were used in this study. Two-photon microscopy was used for imaging of axonal dieback, blood flow, and calcium influx post-injury. We found that MP treatment attenuated progressive damage of axons, increased blood flow, and reduced calcium influx post-injury. Furthermore, microglia/macrophages accumulated in the lesion site after SCI and expressed the proinflammatory mediators iNOS, MCP-1 and IL-1β. MP treatment markedly inhibited the accumulation of microglia/macrophages and reduced the expression of the proinflammatory mediators. MP treatment also improved the recovery of behavioral function post-injury. These findings suggest that MP exerts a neuroprotective effect on SCI treatment by attenuating progressive damage of axons, increasing blood flow, reducing calcium influx, and inhibiting the accumulation of microglia/macrophages after SCI.
Collapse
Affiliation(s)
- Peifu Tang
- Department of Orthopedics, the General Hospital of Chinese People's Liberation Army, Beijing, China, 100853
| | - Yiling Zhang
- 1] Department of Orthopedics, the General Hospital of Chinese People's Liberation Army, Beijing, China, 100853 [2] Key Laboratory of Chemical Genomics, Shenzhen Graduate School, Peking University, Shenzhen, China, 518055
| | - Chao Chen
- 1] Department of Orthopedics, the General Hospital of Chinese People's Liberation Army, Beijing, China, 100853 [2] Key Laboratory of Chemical Genomics, Shenzhen Graduate School, Peking University, Shenzhen, China, 518055
| | - Xinran Ji
- Department of Orthopedics, the General Hospital of Chinese People's Liberation Army, Beijing, China, 100853
| | - Furong Ju
- School of Life Sciences, Lanzhou University, Lanzhou, China, 73000
| | - Xingyu Liu
- Beijing YouAn Hospital, Capital Medical University, Beijing, China, 100069
| | - Wen-Biao Gan
- 1] Key Laboratory of Chemical Genomics, Shenzhen Graduate School, Peking University, Shenzhen, China, 518055 [2] Skirball Institute, Department of Neuroscience and Physiology, New York University School of Medicine, New York, USA, 10016
| | - Zhigang He
- F.M. Kirby Program in Neuroscience, Children's Hospital Boston, Harvard Medical School, Boston, Massachusetts, USA, 02115
| | - Shengxiang Zhang
- School of Life Sciences, Lanzhou University, Lanzhou, China, 73000
| | - Wei Li
- Key Laboratory of Chemical Genomics, Shenzhen Graduate School, Peking University, Shenzhen, China, 518055
| | - Lihai Zhang
- Department of Orthopedics, the General Hospital of Chinese People's Liberation Army, Beijing, China, 100853
| |
Collapse
|
44
|
A surviving intact branch stabilizes remaining axon architecture after injury as revealed by in vivo imaging in the mouse spinal cord. Neuron 2015; 86:947-954. [PMID: 25937174 DOI: 10.1016/j.neuron.2015.03.061] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2014] [Revised: 02/17/2015] [Accepted: 03/24/2015] [Indexed: 01/21/2023]
Abstract
The complex morphology of axons presents a challenge in understanding axonal responses to injury and disease. By in vivo two-photon imaging of spinal dorsal column sensory axons, we systematically examined the effect of injury location relative to the main bifurcation point on axon degeneration and regeneration following highly localized laser injuries. Retrograde but not anterograde degeneration was strongly blocked at the bifurcation point at both the acute and subacute phases. Eliminating either the ascending or descending branch led to a poor regenerative response, while eliminating both led to a strong regenerative response. Thus, a surviving intact branch suppresses both retrograde degeneration and regeneration of the injured branch, thereby preserving the remaining axon architecture. Regenerating axons exhibited a dynamic pattern with alternating phases of regeneration and pruning over a chronic period. In vivo imaging continues to reveal new insights on axonal responses to injury in the mammalian spinal cord.
Collapse
|
45
|
Zhang Y, Zhang L, Ji X, Pang M, Ju F, Zhang J, Li W, Zhang S, He Z, Gan WB, Tang P. Two-photon microscopy as a tool to investigate the therapeutic time window of methylprednisolone in a mouse spinal cord injury model. Restor Neurol Neurosci 2015; 33:291-300. [PMID: 25698110 DOI: 10.3233/rnn-140463] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
PURPOSE The aim of the present study was to explore the use of two-photon microscopy for investigating the therapeutic time window of methylprednisolone (MP) treatment after spinal cord injury (SCI). METHODS Twenty-four YFP H-line mice were subjected to hemisection SCI and then divided into four groups. Group 1 received MP at 30 min post-injury; group 2 received MP at 8 h post-injury; group 3 received MP at 24 h post-injury; and group 4 received saline at 30 min post-injury. Post-injury axonal dieback was imaged in vivo using two-photon microscopy. After all imaging sessions, histological examination of the surviving neurons and microglial/macrophage accumulation was performed. RESULTS Two-photon imaging revealed the degree of progressive axon damage after SCI. Group 1 exhibited a shorter axonal dieback distance and slower axonal dieback speed than groups 2, 3, and 4 (p < 0.01). MAP-2 staining revealed greater neuronal survival in group 1 than in groups 2, 3, and 4 (p < 0.05). F4/80 staining revealed greater microglial/macrophage density in groups 2, 3, and 4 than in group 1 (p< 0.05). CONCLUSIONS MP therapy may help attenuate progressive axon damage, reduce neuronal death, and inhibit microglial/macrophage accumulation, especially when initiated shortly after SCI.
Collapse
Affiliation(s)
- Yiling Zhang
- Department of Orthopedics, the General Hospital of Chinese People's Liberation Army, Beijing, China.,Drug Discovery Center, Key Laboratory of Chemical Genomics, Shenzhen Graduate School, Peking University, Shenzhen, China
| | - Lihai Zhang
- Department of Orthopedics, the General Hospital of Chinese People's Liberation Army, Beijing, China
| | - Xinran Ji
- Department of Orthopedics, the General Hospital of Chinese People's Liberation Army, Beijing, China
| | - Mao Pang
- Department of Spine Surgery, The Third Affiliated Hospital, Sun Yat-sen University, Guangzhou, China
| | - Furong Ju
- School of Life Sciences, Lanzhou University, Lanzhou, China
| | - Jinhui Zhang
- Department of Orthopedics, the General Hospital of Chinese People's Liberation Army, Beijing, China.,Drug Discovery Center, Key Laboratory of Chemical Genomics, Shenzhen Graduate School, Peking University, Shenzhen, China
| | - Wei Li
- Drug Discovery Center, Key Laboratory of Chemical Genomics, Shenzhen Graduate School, Peking University, Shenzhen, China
| | | | - Zhigang He
- F.M. Kirby Program in Neuroscience, Children's Hospital Boston, Harvard Medical School, Boston, Massachusetts, USA
| | - Wen-Biao Gan
- Drug Discovery Center, Key Laboratory of Chemical Genomics, Shenzhen Graduate School, Peking University, Shenzhen, China.,Skirball Institute, Department of Neuroscience and Physiology, New York University School of Medicine, New York, USA
| | - Peifu Tang
- Department of Orthopedics, the General Hospital of Chinese People's Liberation Army, Beijing, China
| |
Collapse
|
46
|
Williams PR, Marincu BN, Sorbara CD, Mahler CF, Schumacher AM, Griesbeck O, Kerschensteiner M, Misgeld T. A recoverable state of axon injury persists for hours after spinal cord contusion in vivo. Nat Commun 2014; 5:5683. [PMID: 25511170 DOI: 10.1038/ncomms6683] [Citation(s) in RCA: 77] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2014] [Accepted: 10/28/2014] [Indexed: 01/25/2023] Open
Abstract
Therapeutic strategies for spinal cord injury (SCI) commonly focus on regenerating disconnected axons. An alternative approach would be to maintain continuity of damaged axons, especially after contusion. The viability of such neuropreservative strategies depends on the degree to which initially injured axons can recover. Here we use morphological and molecular in vivo imaging after contusion SCI in mice to show that injured axons persist in a metastable state for hours. Intra-axonal calcium dynamics influence fate, but the outcome is not invariably destructive in that many axons with calcium elevations recover homeostasis without intervention. Calcium enters axons primarily through mechanopores. Spontaneous pore resealing allows calcium levels to normalize and axons to survive long term. Axon loss can be halted by blocking calcium influx or calpain, even with delayed initiation. Our data identify an inherent self-preservation process in contused axons and a window of opportunity for rescuing connectivity after nontransecting SCI.
Collapse
Affiliation(s)
- Philip R Williams
- Institute of Neuronal Cell Biology, Technische Universität München, Munich 80802, Germany
| | - Bogdan-Nicolae Marincu
- Institute of Neuronal Cell Biology, Technische Universität München, Munich 80802, Germany
| | - Catherine D Sorbara
- 1] Institute of Neuronal Cell Biology, Technische Universität München, Munich 80802, Germany [2] Institute of Clinical Neuroimmunology, Ludwig-Maximilians Universität München, Munich 81377, Germany
| | - Christoph F Mahler
- Institute of Clinical Neuroimmunology, Ludwig-Maximilians Universität München, Munich 81377, Germany
| | - Adrian-Minh Schumacher
- Institute of Clinical Neuroimmunology, Ludwig-Maximilians Universität München, Munich 81377, Germany
| | - Oliver Griesbeck
- Max-Planck Institute of Neurobiology, Martinsried 82152, Germany
| | - Martin Kerschensteiner
- 1] Institute of Clinical Neuroimmunology, Ludwig-Maximilians Universität München, Munich 81377, Germany [2] Munich Cluster for Systems Neurology (SyNergy), Munich 81377, Germany
| | - Thomas Misgeld
- 1] Institute of Neuronal Cell Biology, Technische Universität München, Munich 80802, Germany [2] Munich Cluster for Systems Neurology (SyNergy), Munich 81377, Germany [3] Center of Integrated Protein Science (CIPSM), Munich 81377, Germany [4] German Center for Neurodegenerative Diseases (DZNE), Munich 81377, Germany
| |
Collapse
|
47
|
Sorbara CD, Wagner NE, Ladwig A, Nikić I, Merkler D, Kleele T, Marinković P, Naumann R, Godinho L, Bareyre FM, Bishop D, Misgeld T, Kerschensteiner M. Pervasive axonal transport deficits in multiple sclerosis models. Neuron 2014; 84:1183-90. [PMID: 25433639 DOI: 10.1016/j.neuron.2014.11.006] [Citation(s) in RCA: 96] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 10/31/2014] [Indexed: 01/06/2023]
Abstract
Impaired axonal transport can contribute to axon degeneration and has been described in many neurodegenerative diseases. Multiple sclerosis (MS) is a common neuroinflammatory disease, which is characterized by progressive axon degeneration-whether, when, and how axonal transport is affected in this condition is unknown. Here we used in vivo two-photon imaging to directly assay transport of organelles and the stability of microtubule tracks in individual spinal axons in mouse models of MS. We found widespread transport deficits, which preceded structural alterations of axons, cargos, or microtubules and could be reversed by acute anti-inflammatory interventions or redox scavenging. Our study shows that acute neuroinflammation induces a pervasive state of reversible axonal dysfunction, which coincides with acute disease symptoms. Moreover, perpetuated transport dysfunction, as we found in a model of progressive MS, led to reduced distal organelle supply and could thus contribute to axonal dystrophy in advanced stages of the disease.
Collapse
Affiliation(s)
- Catherine Diamante Sorbara
- Institute of Clinical Neuroimmunology, Ludwig-Maximilians Universität München, Marchioninistraße 17, 81377 Munich, Germany; Institute of Neuronal Cell Biology, Technische Universität München, Biedersteiner Straße 29, 80802 Munich, Germany
| | - Naomi Elizabeth Wagner
- Institute of Clinical Neuroimmunology, Ludwig-Maximilians Universität München, Marchioninistraße 17, 81377 Munich, Germany
| | - Anne Ladwig
- Institute of Clinical Neuroimmunology, Ludwig-Maximilians Universität München, Marchioninistraße 17, 81377 Munich, Germany
| | - Ivana Nikić
- Institute of Clinical Neuroimmunology, Ludwig-Maximilians Universität München, Marchioninistraße 17, 81377 Munich, Germany
| | - Doron Merkler
- Department of Pathology and Immunology, University of Geneva, Rue Michel Servet 1, 1211 Geneva, Switzerland; Division of Clinical Pathology, Geneva University Hospital, Rue Gabrielle-Perret-Gentil 4, 1205 Geneva, Switzerland; Department of Neuropathology, Georg-August-Universität Göttingen, Robert-Koch-Str. 40, 37099 Göttingen, Germany
| | - Tatjana Kleele
- Institute of Neuronal Cell Biology, Technische Universität München, Biedersteiner Straße 29, 80802 Munich, Germany
| | - Petar Marinković
- Institute of Neuronal Cell Biology, Technische Universität München, Biedersteiner Straße 29, 80802 Munich, Germany
| | - Ronald Naumann
- Transgenic Core Facility, Max-Planck-Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307 Dresden, Germany
| | - Leanne Godinho
- Institute of Neuronal Cell Biology, Technische Universität München, Biedersteiner Straße 29, 80802 Munich, Germany
| | - Florence Martine Bareyre
- Institute of Clinical Neuroimmunology, Ludwig-Maximilians Universität München, Marchioninistraße 17, 81377 Munich, Germany; Munich Cluster of Systems Neurology (SyNergy), Feodor-Lynen-Straße 17, 81377 Munich, Germany
| | - Derron Bishop
- Department of Physiology, Indiana University School of Medicine-Muncie, Cooper Science Building, CL 215, Muncie, IN 47306, USA
| | - Thomas Misgeld
- Institute of Neuronal Cell Biology, Technische Universität München, Biedersteiner Straße 29, 80802 Munich, Germany; Munich Cluster of Systems Neurology (SyNergy), Feodor-Lynen-Straße 17, 81377 Munich, Germany; German Center for Neurodegenerative Diseases (DZNE), Feodor-Lynen Straße 17, 81377 Munich, Germany; Center of Integrated Protein Science (CIPSM), Butenandtstraße 5-13, 81377 Munich, Germany.
| | - Martin Kerschensteiner
- Institute of Clinical Neuroimmunology, Ludwig-Maximilians Universität München, Marchioninistraße 17, 81377 Munich, Germany; Munich Cluster of Systems Neurology (SyNergy), Feodor-Lynen-Straße 17, 81377 Munich, Germany.
| |
Collapse
|
48
|
Okada SLM, Stivers NS, Stys PK, Stirling DP. An ex vivo laser-induced spinal cord injury model to assess mechanisms of axonal degeneration in real-time. J Vis Exp 2014:e52173. [PMID: 25490396 DOI: 10.3791/52173] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Injured CNS axons fail to regenerate and often retract away from the injury site. Axons spared from the initial injury may later undergo secondary axonal degeneration. Lack of growth cone formation, regeneration, and loss of additional myelinated axonal projections within the spinal cord greatly limits neurological recovery following injury. To assess how central myelinated axons of the spinal cord respond to injury, we developed an ex vivo living spinal cord model utilizing transgenic mice that express yellow fluorescent protein in axons and a focal and highly reproducible laser-induced spinal cord injury to document the fate of axons and myelin (lipophilic fluorescent dye Nile Red) over time using two-photon excitation time-lapse microscopy. Dynamic processes such as acute axonal injury, axonal retraction, and myelin degeneration are best studied in real-time. However, the non-focal nature of contusion-based injuries and movement artifacts encountered during in vivo spinal cord imaging make differentiating primary and secondary axonal injury responses using high resolution microscopy challenging. The ex vivo spinal cord model described here mimics several aspects of clinically relevant contusion/compression-induced axonal pathologies including axonal swelling, spheroid formation, axonal transection, and peri-axonal swelling providing a useful model to study these dynamic processes in real-time. Major advantages of this model are excellent spatiotemporal resolution that allows differentiation between the primary insult that directly injures axons and secondary injury mechanisms; controlled infusion of reagents directly to the perfusate bathing the cord; precise alterations of the environmental milieu (e.g., calcium, sodium ions, known contributors to axonal injury, but near impossible to manipulate in vivo); and murine models also offer an advantage as they provide an opportunity to visualize and manipulate genetically identified cell populations and subcellular structures. Here, we describe how to isolate and image the living spinal cord from mice to capture dynamics of acute axonal injury.
Collapse
Affiliation(s)
- Starlyn L M Okada
- KY Spinal Cord Injury Research Center, Department of Neurological Surgery, University of Louisville
| | - Nicole S Stivers
- KY Spinal Cord Injury Research Center, Department of Neurological Surgery, University of Louisville
| | - Peter K Stys
- Hotchkiss Brain Institute, Department of Clinical Neurosciences, University of Calgary
| | - David P Stirling
- KY Spinal Cord Injury Research Center, Department of Neurological Surgery, University of Louisville;
| |
Collapse
|
49
|
Evans TA, Barkauskas DS, Myers JT, Huang AY. Intravital imaging of axonal interactions with microglia and macrophages in a mouse dorsal column crush injury. J Vis Exp 2014:e52228. [PMID: 25489963 PMCID: PMC4275021 DOI: 10.3791/52228] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
Traumatic spinal cord injury causes an inflammatory reaction involving blood-derived macrophages and central nervous system (CNS)-resident microglia. Intra-vital two-photon microscopy enables the study of macrophages and microglia in the spinal cord lesion in the living animal. This can be performed in adult animals with a traumatic injury to the dorsal column. Here, we describe methods for distinguishing macrophages from microglia in the CNS using an irradiation bone marrow chimera to obtain animals in which only macrophages or microglia are labeled with a genetically encoded green fluorescent protein. We also describe a injury model that crushes the dorsal column of the spinal cord, thereby producing a simple, easily accessible, rectangular lesion that is easily visualized in an animal through a laminectomy. Furthermore, we will outline procedures to sequentially image the animals at the anatomical site of injury for the study of cellular interactions during the first few days to weeks after injury.
Collapse
Affiliation(s)
- Teresa A Evans
- Department of Neurosciences, Case Western Reserve University
| | | | - Jay T Myers
- Department of Pediatrics, Case Western Reserve University
| | - Alex Y Huang
- Department of Pediatrics, Case Western Reserve University;
| |
Collapse
|
50
|
Purinergic Modulation of Spinal Neuroglial Maladaptive Plasticity Following Peripheral Nerve Injury. Mol Neurobiol 2014; 52:1440-1457. [PMID: 25352445 DOI: 10.1007/s12035-014-8943-y] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 10/16/2014] [Indexed: 12/22/2022]
Abstract
Modulation of spinal reactive gliosis following peripheral nerve injury (PNI) is a promising strategy to restore synaptic homeostasis. Oxidized ATP (OxATP), a nonselective antagonist of purinergic P2X receptors, was found to recover a neuropathic behavior following PNI. We investigated the role of intraperitoneal (i.p.) OxATP treatment in restoring the expression of neuronal and glial markers in the mouse spinal cord after sciatic spared nerve injury (SNI). Using in vivo two-photon microscopy, we imaged Ca(2+) transients in neurons and astrocytes of the dorsal horn of spinal cord at rest and upon right hind paw electrical stimulation in sham, SNI, and OxATP-treated mice. Neuropathic behavior was investigated by von Frey and thermal plantar test. Glial [glial fibrillary acidic protein (GFAP), ionized calcium-binding adaptor molecule 1 (Iba1)] and GABAergic [vesicular GABA transporter (vGAT) and glutamic acid decarboxylase 65/76 (GAD65/67)] markers and glial [glutamate transporter (GLT1) and GLAST] and neuronal amino acid [EAAC1, vesicular glutamate transporter 1 (vGLUT1)] transporters have been evaluated. In SNI mice, we found (i) increased glial response, (ii) decreased glial amino acid transporters, and (iii) increased levels of neuronal amino acid transporters, and (iv) in vivo analysis of spinal neurons and astrocytes showed a persistent increase of Ca(2+) levels. OxATP administration reduced glial activation, modulated the expression of glial and neuronal glutamate/GABA transporters, restored neuronal and astrocytic Ca(2+) levels, and prevented neuropathic behavior. In vitro studies validated that OxATP (i) reduced levels of reactive oxygen species (ROS), (ii) reduced astrocytic proliferation, (iii) increase vGLUT expression. All together, these data support the correlation between reactive gliosis and perturbation of the spinal synaptic homeostasis and the role played by the purinergic system in modulating spinal plasticity following PNI.
Collapse
|