1
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Mardell LC, Spedden ME, O'Neill GC, Tierney TM, Timms RC, Zich C, Barnes GR, Bestmann S. Concurrent spinal and brain imaging with optically pumped magnetometers. J Neurosci Methods 2024; 406:110131. [PMID: 38583588 DOI: 10.1016/j.jneumeth.2024.110131] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2023] [Revised: 03/11/2024] [Accepted: 04/03/2024] [Indexed: 04/09/2024]
Abstract
BACKGROUND The spinal cord and its interactions with the brain are fundamental for movement control and somatosensation. However, brain and spinal electrophysiology in humans have largely been treated as distinct enterprises, in part due to the relative inaccessibility of the spinal cord. Consequently, there is a dearth of knowledge on human spinal electrophysiology, including the multiple pathologies that affect the spinal cord as well as the brain. NEW METHOD Here we exploit recent advances in the development of wearable optically pumped magnetometers (OPMs) which can be flexibly arranged to provide coverage of both the spinal cord and the brain in relatively unconstrained environments. This system for magnetospinoencephalography (MSEG) measures both spinal and cortical signals simultaneously by employing custom-made scanning casts. RESULTS We evidence the utility of such a system by recording spinal and cortical evoked responses to median nerve stimulation at the wrist. MSEG revealed early (10 - 15 ms) and late (>20 ms) responses at the spinal cord, in addition to typical cortical evoked responses (i.e., N20). COMPARISON WITH EXISTING METHODS Early spinal evoked responses detected were in line with conventional somatosensory evoked potential recordings. CONCLUSION This MSEG system demonstrates the novel ability for concurrent non-invasive millisecond imaging of brain and spinal cord.
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Affiliation(s)
- Lydia C Mardell
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, WC1N 3BG, UK.
| | - Meaghan E Spedden
- Wellcome Centre for Human Neuroimaging, Department of Imaging Neuroscience, UCL Queen Square Institute of Neurology, University College London, WC1N 3AR, UK
| | - George C O'Neill
- Wellcome Centre for Human Neuroimaging, Department of Imaging Neuroscience, UCL Queen Square Institute of Neurology, University College London, WC1N 3AR, UK
| | - Tim M Tierney
- Wellcome Centre for Human Neuroimaging, Department of Imaging Neuroscience, UCL Queen Square Institute of Neurology, University College London, WC1N 3AR, UK
| | - Ryan C Timms
- Wellcome Centre for Human Neuroimaging, Department of Imaging Neuroscience, UCL Queen Square Institute of Neurology, University College London, WC1N 3AR, UK
| | - Catharina Zich
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, WC1N 3BG, UK
| | - Gareth R Barnes
- Wellcome Centre for Human Neuroimaging, Department of Imaging Neuroscience, UCL Queen Square Institute of Neurology, University College London, WC1N 3AR, UK
| | - Sven Bestmann
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, University College London, WC1N 3BG, UK; Wellcome Centre for Human Neuroimaging, Department of Imaging Neuroscience, UCL Queen Square Institute of Neurology, University College London, WC1N 3AR, UK
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2
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Mu J, Hao L, Wang Z, Fu X, Li Y, Hao F, Duan H, Yang Z, Li X. Visualizing Wallerian degeneration in the corticospinal tract after sensorimotor cortex ischemia in mice. Neural Regen Res 2024; 19:636-641. [PMID: 37721295 PMCID: PMC10581571 DOI: 10.4103/1673-5374.380903] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Revised: 03/11/2023] [Accepted: 06/06/2023] [Indexed: 09/19/2023] Open
Abstract
Stroke can cause Wallerian degeneration in regions outside of the brain, particularly in the corticospinal tract. To investigate the fate of major glial cells and axons within affected areas of the corticospinal tract following stroke, we induced photochemical infarction of the sensorimotor cortex leading to Wallerian degeneration along the full extent of the corticospinal tract. We first used a routine, sensitive marker of axonal injury, amyloid precursor protein, to examine Wallerian degeneration of the corticospinal tract. An antibody to amyloid precursor protein mapped exclusively to proximal axonal segments within the ischemic cortex, with no positive signal in distal parts of the corticospinal tract, at all time points. To improve visualization of Wallerian degeneration, we next utilized an orthograde virus that expresses green fluorescent protein to label the corticospinal tract and then quantitatively evaluated green fluorescent protein-expressing axons. Using this approach, we found that axonal degeneration began on day 3 post-stroke and was almost complete by 7 days after stroke. In addition, microglia mobilized and activated early, from day 7 after stroke, but did not maintain a phagocytic state over time. Meanwhile, astrocytes showed relatively delayed mobilization and a moderate response to Wallerian degeneration. Moreover, no anterograde degeneration of spinal anterior horn cells was observed in response to Wallerian degeneration of the corticospinal tract. In conclusion, our data provide evidence for dynamic, pathogenic spatiotemporal changes in major cellular components of the corticospinal tract during Wallerian degeneration.
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Affiliation(s)
- Jiao Mu
- Beijing Key Laboratory for Biomaterials and Neural Regeneration, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Liufang Hao
- Department of Neurobiology, School of Basic Medical Sciences, Capital Medical University, Beijing, China
| | - Zijue Wang
- Department of Neurobiology, School of Basic Medical Sciences, Capital Medical University, Beijing, China
| | - Xuyang Fu
- Department of Neurobiology, School of Basic Medical Sciences, Capital Medical University, Beijing, China
| | - Yusen Li
- Department of Neurobiology, School of Basic Medical Sciences, Capital Medical University, Beijing, China
| | - Fei Hao
- Beijing Key Laboratory for Biomaterials and Neural Regeneration, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
| | - Hongmei Duan
- Department of Neurobiology, School of Basic Medical Sciences, Capital Medical University, Beijing, China
| | - Zhaoyang Yang
- Department of Neurobiology, School of Basic Medical Sciences, Capital Medical University, Beijing, China
| | - Xiaoguang Li
- Beijing Key Laboratory for Biomaterials and Neural Regeneration, School of Biological Science and Medical Engineering, Beihang University, Beijing, China
- Department of Neurobiology, School of Basic Medical Sciences, Capital Medical University, Beijing, China
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3
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Ritter K, Somnuke P, Hu L, Griemert EV, Schäfer MKE. Current state of neuroprotective therapy using antibiotics in human traumatic brain injury and animal models. BMC Neurosci 2024; 25:10. [PMID: 38424488 PMCID: PMC10905838 DOI: 10.1186/s12868-024-00851-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2023] [Accepted: 02/02/2024] [Indexed: 03/02/2024] Open
Abstract
TBI is a leading cause of death and disability in young people and older adults worldwide. There is no gold standard treatment for TBI besides surgical interventions and symptomatic relief. Post-injury infections, such as lower respiratory tract and surgical site infections or meningitis are frequent complications following TBI. Whether the use of preventive and/or symptomatic antibiotic therapy improves patient mortality and outcome is an ongoing matter of debate. In contrast, results from animal models of TBI suggest translational perspectives and support the hypothesis that antibiotics, independent of their anti-microbial activity, alleviate secondary injury and improve neurological outcomes. These beneficial effects were largely attributed to the inhibition of neuroinflammation and neuronal cell death. In this review, we briefly outline current treatment options, including antibiotic therapy, for patients with TBI. We then summarize the therapeutic effects of the most commonly tested antibiotics in TBI animal models, highlight studies identifying molecular targets of antibiotics, and discuss similarities and differences in their mechanistic modes of action.
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Affiliation(s)
- Katharina Ritter
- Department of Anesthesiology, University Medical Center, Johannes Gutenberg-University Mainz, Langenbeckstraße 1 (Bld. 505), Mainz, 55131, Germany
| | - Pawit Somnuke
- Department of Anesthesiology, University Medical Center, Johannes Gutenberg-University Mainz, Langenbeckstraße 1 (Bld. 505), Mainz, 55131, Germany
- Department of Anesthesiology, Faculty of Medicine Siriraj Hospital, Mahidol University, Bangkok, 10700, Thailand
| | - Lingjiao Hu
- Department of Anesthesiology, University Medical Center, Johannes Gutenberg-University Mainz, Langenbeckstraße 1 (Bld. 505), Mainz, 55131, Germany
- Department of Gastroenterology, Nanxishan Hospital of Guangxi Zhuang Autonomous Region, Guilin, China
| | - Eva-Verena Griemert
- Department of Anesthesiology, University Medical Center, Johannes Gutenberg-University Mainz, Langenbeckstraße 1 (Bld. 505), Mainz, 55131, Germany
| | - Michael K E Schäfer
- Department of Anesthesiology, University Medical Center, Johannes Gutenberg-University Mainz, Langenbeckstraße 1 (Bld. 505), Mainz, 55131, Germany.
- Focus Program Translational Neurosciences (FTN, Johannes Gutenberg-University Mainz, Mainz, Germany.
- Research Center for Immunotherapy, University Medical Center, Johannes Gutenberg- University Mainz, Mainz, Germany.
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4
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Fisher KM, Garner JP, Darian-Smith C. Chronic Adaptations in the Dorsal Horn Following a Cervical Spinal Cord Injury in Primates. J Neurosci 2024; 44:e0877232023. [PMID: 38233220 PMCID: PMC10860610 DOI: 10.1523/jneurosci.0877-23.2023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2023] [Revised: 11/21/2023] [Accepted: 12/01/2023] [Indexed: 01/19/2024] Open
Abstract
Spinal cord injury (SCI) is devastating, with limited treatment options and variable outcomes. Most in vivo SCI research has focused on the acute and early post-injury periods, and the promotion of axonal growth, so little is understood about the clinically stable chronic state, axonal growth over time, and what plasticity endures. Here, we followed animals into the chronic phase following SCI, to address this gap. Male macaques received targeted deafferentation, affecting three digits of one hand, and were divided into short (4-6 months) or long-term (11-12 months) groups, based on post-injury survival times. Monkeys were assessed behaviorally, where possible, and all exhibited an initial post-injury deficit in manual dexterity, with gradual functional recovery over 2 months. We previously reported extensive sprouting of somatosensory corticospinal (S1 CST) fibers in the dorsal horn in the first five post-injury months. Here, we show that by 1 year, the S1 CST sprouting is pruned, with the terminal territory resembling control animals. This was reflected in the number of putatively "functional" synapses observed, which increased over the first 4-5 months, and then returned to baseline by 1 year. Microglia density also increased in the affected dorsal horn at 4-6 months and then decreased, but did not return to baseline by 1 year, suggesting refinement continues beyond this time. Overall, there is a long period of reorganization and consolidation of adaptive circuitry in the dorsal horn, extending well beyond the initial behavioral recovery. This provides a potential window to target therapeutic opportunities during the chronic phase.
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Affiliation(s)
- Karen M Fisher
- Department of Comparative Medicine, Stanford University School of Medicine, Stanford 94305-5342, California
| | - Joseph P Garner
- Department of Comparative Medicine, Stanford University School of Medicine, Stanford 94305-5342, California
| | - Corinna Darian-Smith
- Department of Comparative Medicine, Stanford University School of Medicine, Stanford 94305-5342, California
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5
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Forouharshad M, Raspa A, Marchini A, Ciulla MG, Magnoni A, Gelain F. Biomimetic Electrospun Self-Assembling Peptide Scaffolds for Neural Stem Cell Transplantation in Neural Tissue Engineering. Pharmaceutics 2023; 15:2261. [PMID: 37765230 PMCID: PMC10536048 DOI: 10.3390/pharmaceutics15092261] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2023] [Revised: 08/28/2023] [Accepted: 08/29/2023] [Indexed: 09/29/2023] Open
Abstract
Spinal cord regeneration using stem cell transplantation is a promising strategy for regenerative therapy. Stem cells transplanted onto scaffolds that can mimic natural extracellular matrix (ECM) have the potential to significantly improve outcomes. In this study, we strived to develop a cell carrier by culturing neural stem cells (NSCs) onto electrospun 2D and 3D constructs made up of specific crosslinked functionalized self-assembling peptides (SAPs) featuring enhanced biomimetic and biomechanical properties. Morphology, architecture, and secondary structures of electrospun scaffolds in the solid-state and electrospinning solution were studied step by step. Morphological studies showed the benefit of mixed peptides and surfactants as additives to form thinner, uniform, and defect-free fibers. It has been observed that β-sheet conformation as evidence of self-assembling has been predominant throughout the process except for the electrospinning solution. In vitro NSCs seeded on electrospun SAP scaffolds in 2D and 3D conditions displayed desirable proliferation, viability, and differentiation in comparison to the gold standard. In vivo biocompatibility assay confirmed the permissibility of implanted fibrous channels by foreign body reaction. The results of this study demonstrated that fibrous 2D/3D electrospun SAP scaffolds, when shaped as micro-channels, can be suitable to support NSC transplantation for regeneration following spinal cord injury.
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Affiliation(s)
- Mahdi Forouharshad
- Institute for Stem-Cell Biology, Regenerative Medicine and Innovative Therapies, IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo, Italy
| | - Andrea Raspa
- Institute for Stem-Cell Biology, Regenerative Medicine and Innovative Therapies, IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo, Italy
- Center for Nanomedicine and Tissue Engineering (CNTE), ASST Grande Ospedale Metropolitano Niguarda, 20162 Milan, Italy
| | - Amanda Marchini
- Institute for Stem-Cell Biology, Regenerative Medicine and Innovative Therapies, IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo, Italy
| | - Maria Gessica Ciulla
- Institute for Stem-Cell Biology, Regenerative Medicine and Innovative Therapies, IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo, Italy
| | - Alice Magnoni
- Department of Biotechnology and Biosciences, University of Milan-Bicocca, 20125 Milan, Italy
| | - Fabrizio Gelain
- Institute for Stem-Cell Biology, Regenerative Medicine and Innovative Therapies, IRCCS Casa Sollievo della Sofferenza, 71013 San Giovanni Rotondo, Italy
- Center for Nanomedicine and Tissue Engineering (CNTE), ASST Grande Ospedale Metropolitano Niguarda, 20162 Milan, Italy
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6
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Xu L, Wang J, Ding Y, Wang L, Zhu YJ. Current Knowledge of Microglia in Traumatic Spinal Cord Injury. Front Neurol 2022; 12:796704. [PMID: 35087472 PMCID: PMC8787368 DOI: 10.3389/fneur.2021.796704] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Accepted: 12/07/2021] [Indexed: 12/12/2022] Open
Abstract
Microglia are the resident immune cells in the central nervous system (CNS). After traumatic spinal cord injury (SCI), microglia undergo activation, proliferation, and changes in gene and protein expression and morphology, with detrimental and beneficial effects. Activated microglia cause secondary neuronal injury via the production of proinflammatory cytokines, reactive oxygen species, and proteases. However, activated microglia also promote neuronal repair through the secretion of anti-inflammatory growth factors and cytokines. Proinflammatory cytokines increase endothelial permeability, promote A1 astrocyte activation and axonal demyelination, and reduce neural stem/progenitor cells (NSPCs), leading to the exacerbation of neuronal injury. In contrast, anti-inflammatory factors facilitate angiogenesis, reduce reactive astrocytes, and promote axonal remyelination and the propagation of NSPCs, contributing to tissue repair and locomotor recovery. Due to its limited regenerative capacity, the CNS requires beneficial microglia for continuous protection against injury. Understanding and regulating microglial activation status are beneficial to reducing detrimental effects and promoting repair behaviors and to obtain more information on efficient therapies for traumatic SCI. This review discusses microglial activation and the differences between microglia and similar immune cells, microglial interactions with other cells in the spinal cord, and the progress in the development of therapies targeting microglia in SCI.
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Affiliation(s)
- Lintao Xu
- Department of Neurosurgery, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Jingyu Wang
- Department of Neurosurgery, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
| | - Yueming Ding
- School of Medicine, Zhejiang University City College, Hangzhou, China
| | - Linlin Wang
- Department of Basic Medicine Sciences, and Department of Orthopaedics of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, China
| | - Yong-Jian Zhu
- Department of Neurosurgery, Second Affiliated Hospital of Zhejiang University School of Medicine, Hangzhou, China
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7
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Co-Expression of Nogo-A in Dopaminergic Neurons of the Human Substantia Nigra Pars Compacta Is Reduced in Parkinson’s Disease. Cells 2021; 10:cells10123368. [PMID: 34943877 PMCID: PMC8699585 DOI: 10.3390/cells10123368] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2021] [Revised: 11/19/2021] [Accepted: 11/27/2021] [Indexed: 12/21/2022] Open
Abstract
Parkinson’s disease is mainly characterized by a progressive loss of dopaminergic neurons in the substantia nigra pars compacta. Together with the small number, the high vulnerability of the dopaminergic neurons is a major pathogenic culprit of Parkinson’s disease. Our previous findings of a higher survival of dopaminergic neurons in the substantia nigra co-expressing Nogo-A in an animal model of Parkinson’s disease suggested that Nogo-A may be associated with dopaminergic neurons resilience against Parkinson’s disease neurodegeneration. In the present study, we have addressed the expression of Nogo-A in the dopaminergic neurons in the substantia nigra in postmortem specimens of diseased and non-diseased subjects of different ages. For this purpose, in a collaborative effort we developed a tissue micro array (TMA) that allows for simultaneous staining of many samples in a single run. Interestingly, and in contrast to the observations gathered during normal aging and in the animal model of Parkinson’s disease, increasing age was significantly associated with a lower co-expression of Nogo-A in nigral dopaminergic neurons of patients with Parkinson’s disease. In sum, while Nogo-A expression in dopaminergic neurons is higher with increasing age, the opposite is the case in Parkinson’s disease. These observations suggest that Nogo-A might play a substantial role in the vulnerability of dopaminergic neurons in Parkinson’s disease.
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8
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Graham NSN, Zimmerman KA, Moro F, Heslegrave A, Maillard SA, Bernini A, Miroz JP, Donat CK, Lopez MY, Bourke N, Jolly AE, Mallas EJ, Soreq E, Wilson MH, Fatania G, Roi D, Patel MC, Garbero E, Nattino G, Baciu C, Fainardi E, Chieregato A, Gradisek P, Magnoni S, Oddo M, Zetterberg H, Bertolini G, Sharp DJ. Axonal marker neurofilament light predicts long-term outcomes and progressive neurodegeneration after traumatic brain injury. Sci Transl Med 2021; 13:eabg9922. [PMID: 34586833 DOI: 10.1126/scitranslmed.abg9922] [Citation(s) in RCA: 74] [Impact Index Per Article: 24.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
[Figure: see text].
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Affiliation(s)
- Neil S N Graham
- Department of Brain Sciences, Imperial College London, London W12 0NN, UK.,UK DRI Centre for Care Research and Technology, Imperial College London, London W12 0BZ, UK
| | - Karl A Zimmerman
- Department of Brain Sciences, Imperial College London, London W12 0NN, UK.,UK DRI Centre for Care Research and Technology, Imperial College London, London W12 0BZ, UK
| | - Federico Moro
- Laboratory of Acute Brain Injury and Therapeutic Strategies, Department of Neuroscience, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo 24126, Italy.,Fondazione IRCCS, Ca' Granda Ospedale Maggiore Policlinico, Dipartimento di Anestesia e Rianimazione, 20122, Milan, Italy
| | - Amanda Heslegrave
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK.,UK Dementia Research Institute at UCL, London WC1N 3BG, UK
| | - Samia Abed Maillard
- Neuroscience Critical Care Research Group, Department of Intensive Care Medicine, CHUV Lausanne University Hospital and University of Lausanne, Lausanne 1011, Switzerland
| | - Adriano Bernini
- Neuroscience Critical Care Research Group, Department of Intensive Care Medicine, CHUV Lausanne University Hospital and University of Lausanne, Lausanne 1011, Switzerland
| | - John-Paul Miroz
- Neuroscience Critical Care Research Group, Department of Intensive Care Medicine, CHUV Lausanne University Hospital and University of Lausanne, Lausanne 1011, Switzerland
| | - Cornelius K Donat
- Department of Brain Sciences, Imperial College London, London W12 0NN, UK
| | - Maria Yanez Lopez
- Centre for the Developing Brain, School of Biomedical Engineering and Imaging Sciences, King's College London, London SE1 7EH, UK
| | - Niall Bourke
- Department of Brain Sciences, Imperial College London, London W12 0NN, UK.,UK DRI Centre for Care Research and Technology, Imperial College London, London W12 0BZ, UK
| | - Amy E Jolly
- Department of Brain Sciences, Imperial College London, London W12 0NN, UK.,UK DRI Centre for Care Research and Technology, Imperial College London, London W12 0BZ, UK
| | - Emma-Jane Mallas
- Department of Brain Sciences, Imperial College London, London W12 0NN, UK.,UK DRI Centre for Care Research and Technology, Imperial College London, London W12 0BZ, UK
| | - Eyal Soreq
- Department of Brain Sciences, Imperial College London, London W12 0NN, UK.,UK DRI Centre for Care Research and Technology, Imperial College London, London W12 0BZ, UK
| | - Mark H Wilson
- Department of Neurosurgery, Imperial College Healthcare NHS Trust, London W6 8RF, UK.,Department of Surgery and Cancer, Faculty of Medicine, Imperial College London, London SW7 2AZ, UK
| | - Gavin Fatania
- Department of Imaging, Imperial College Healthcare NHS Trust, London W6 8RF, UK
| | - Dylan Roi
- Department of Imaging, Imperial College Healthcare NHS Trust, London W6 8RF, UK
| | - Maneesh C Patel
- Department of Imaging, Imperial College Healthcare NHS Trust, London W6 8RF, UK
| | - Elena Garbero
- Laboratory of Clinical Epidemiology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo 24126, Italy
| | - Giovanni Nattino
- Laboratory of Clinical Epidemiology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo 24126, Italy
| | - Camelia Baciu
- Neurorianimazione, ASST Grande Ospedale Metropolitano Niguarda, Milano 20162, Italy
| | - Enrico Fainardi
- Department of Experimental and Clinical Sciences, Careggi University Hospital, University of Firenze, Florence 50139, Italy
| | - Arturo Chieregato
- Neurorianimazione, ASST Grande Ospedale Metropolitano Niguarda, Milano 20162, Italy
| | - Primoz Gradisek
- Clinical Department of Anaesthesiology and Intensive Therapy, University Medical Center, Ljubljana 1000, Slovenia
| | - Sandra Magnoni
- Department of Anesthesia and Intensive Care, Santa Chiara Hospital, Trento 38122, Italy
| | - Mauro Oddo
- Neuroscience Critical Care Research Group, Department of Intensive Care Medicine, CHUV Lausanne University Hospital and University of Lausanne, Lausanne 1011, Switzerland.,Medical Direction, CHUV Lausanne University Hospital, Lausanne 1011, Switzerland
| | - Henrik Zetterberg
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, Sahlgrenska Academy at University of Gothenburg, Mölndal 431 41, Sweden.,Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal 431 41, Sweden
| | - Guido Bertolini
- Laboratory of Clinical Epidemiology, Istituto di Ricerche Farmacologiche Mario Negri IRCCS, Bergamo 24126, Italy
| | - David J Sharp
- Department of Brain Sciences, Imperial College London, London W12 0NN, UK.,UK DRI Centre for Care Research and Technology, Imperial College London, London W12 0BZ, UK.,Centre for Injury Studies, Imperial College London, London SW7 2AZ, UK
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9
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Zhou Y, Chen Q, Wang Y, Wu H, Xu W, Pan Y, Gao S, Dong X, Zhang JH, Shao A. Persistent Neurovascular Unit Dysfunction: Pathophysiological Substrate and Trigger for Late-Onset Neurodegeneration After Traumatic Brain Injury. Front Neurosci 2020; 14:581. [PMID: 32581697 PMCID: PMC7296179 DOI: 10.3389/fnins.2020.00581] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Accepted: 05/12/2020] [Indexed: 12/14/2022] Open
Abstract
Traumatic brain injury (TBI) represents one of the major causes of death worldwide and leads to persisting neurological deficits in many of the survivors. One of the most significant long-term sequelae deriving from TBI is neurodegenerative disease, which is a group of incurable diseases that impose a heavy socio-economic burden. However, mechanisms underlying the increased susceptibility of TBI to neurodegenerative disease remain elusive. The neurovascular unit (NVU) is a functional unit composed of neurons, neuroglia, vascular cells, and the basal lamina matrix. The key role of NVU dysfunction in many central nervous system diseases has been revealed. Studies have proved the presence of prolonged structural and functional abnormalities of the NVU after TBI. Moreover, growing evidence suggests impaired NVU function is also implicated in neurodegenerative diseases. Therefore, we propose the Neurovascular Unit Dysfunction (NVUD) Hypothesis, in which the persistent NVU dysfunction is thought to underlie the development of post-TBI neurodegeneration. We deduce NVUD Hypothesis through relational inference and supporting evidence, and suggest continued NVU abnormalities following TBI serve as the pathophysiological substrate and trigger yielding chronic neuroinflammation, proteinopathies and oxidative stress, consequently leading to the progression of neurodegenerative diseases. The NVUD Hypothesis may provide potential treatment and prevention strategies for TBI and late-onset neurodegenerative diseases.
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Affiliation(s)
- Yunxiang Zhou
- Department of Surgical Oncology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Qiang Chen
- Department of Surgical Oncology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yali Wang
- Department of Surgical Oncology, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Haijian Wu
- Department of Neurosurgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Weilin Xu
- Department of Neurosurgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Yuanbo Pan
- Department of Neurosurgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Shiqi Gao
- Department of Neurosurgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - Xiao Dong
- Department of Neurosurgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
| | - John H. Zhang
- Department of Physiology and Pharmacology, Basic Sciences, School of Medicine, Loma Linda University, Loma Linda, CA, United States
- Department of Anesthesiology, Neurosurgery and Neurology, School of Medicine, Loma Linda University, Loma Linda, CA, United States
| | - Anwen Shao
- Department of Neurosurgery, The Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China
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10
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Vinueza-Veloz MF, Martín-Román C, Robalino-Valdivieso MP, White T, Kushner SA, De Zeeuw CI. Genetic risk for Alzheimer disease in children: Evidence from early-life IQ and brain white-matter microstructure. GENES BRAIN AND BEHAVIOR 2020; 19:e12656. [PMID: 32383552 PMCID: PMC7507145 DOI: 10.1111/gbb.12656] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/26/2019] [Revised: 04/01/2020] [Accepted: 04/17/2020] [Indexed: 01/21/2023]
Abstract
It remains unclear whether the genetic risk for late‐onset Alzheimer disease (AD) is linked to premorbid individual differences in general cognitive ability and brain structure. The objective of the present study was to determine whether the genetic risk of late‐onset AD is related to premorbid individual differences in intelligence quotient (IQ) and characteristics of the cerebral white‐matter in children. The study sample included children of the Generation R Study from Rotterdam, The Netherlands. IQ was measured using a well‐validated Dutch nonverbal IQ test (n = 1908) at ages 5 to 9 years. White‐matter microstructure was assessed by measuring fractional anisotropy (FA) of white‐matter tracts using diffusion tensor imaging (DTI) (n = 919) at ages 9 to 12 years. Genetic risk was quantified using three biologically defined genetic risk scores (GRSs) hypothesized to be related to the pathophysiology of late‐onset AD: immune response, cholesterol/lipid metabolism and endocytosis. Higher genetic risk for late‐onset AD that included genes associated with immune responsivity had a negative influence on cognition and cerebral white‐matter microstructure. For each unit increase in the immune response GRS, IQ decreased by 0.259 SD (95% CI [−0.500, −0.017]). For each unit increase in the immune response GRS, global FA decreased by 0.373 SD (95% CI [−0.721, −0.026]). Neither cholesterol/lipid metabolism nor endocytosis GRSs were associated with IQ or cerebral white‐matter microstructure. Our findings suggest that elevated genetic risk for late‐onset AD may in part be manifest during childhood neurodevelopment through alterations in immune responsivity.
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Affiliation(s)
- María Fernanda Vinueza-Veloz
- School of Medicine, Escuela Superior Politécnica de Chimborazo, Riobamba, Ecuador.,Department of Neuroscience, Erasmus MC, Rotterdam, The Netherlands
| | - Carlos Martín-Román
- Leiden Institute for Advanced Computer Science, Leiden University, Leiden, The Netherlands
| | | | - Tonya White
- Department of Child and Adolescent Psychiatry/Psychology, Erasmus MC, Rotterdam, The Netherlands.,Department of Radiology and Nuclear Medicine, Erasmus MC, Rotterdam, The Netherlands
| | - Steven A Kushner
- Department of Psychiatry, Erasmus MC, Rotterdam, The Netherlands.,Department of Psychiatry, Columbia University, New York City, United States of America, United States of America
| | - Chris I De Zeeuw
- Department of Neuroscience, Erasmus MC, Rotterdam, The Netherlands.,Royal Netherlands Academy of Arts and Sciences, The Netherlands Institute for Neuroscience, Amsterdam, The Netherlands
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11
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Motamed S, Del Borgo MP, Zhou K, Kulkarni K, Crack PJ, Merson TD, Aguilar MI, Finkelstein DI, Forsythe JS. Migration and Differentiation of Neural Stem Cells Diverted From the Subventricular Zone by an Injectable Self-Assembling β-Peptide Hydrogel. Front Bioeng Biotechnol 2019; 7:315. [PMID: 31788470 PMCID: PMC6856563 DOI: 10.3389/fbioe.2019.00315] [Citation(s) in RCA: 26] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2019] [Accepted: 10/24/2019] [Indexed: 11/13/2022] Open
Abstract
Neural stem cells, which are confined in localised niches are unable to repair large brain lesions because of an inability to migrate long distances and engraft. To overcome these problems, previous research has demonstrated the use of biomaterial implants to redirect increased numbers of endogenous neural stem cell populations. However, the fate of the diverted neural stem cells and their progeny remains unknown. Here we show that neural stem cells originating from the subventricular zone can migrate to the cortex with the aid of a long-lasting injectable hydrogel within a mouse brain. Specifically, large numbers of neuroblasts were diverted to the cortex through a self-assembling β-peptide hydrogel that acted as a tract from the subventricular zone to the cortex of transgenic mice (NestinCreERT2:R26eYFP) in which neuroblasts and their progeny are permanently fluorescently labelled. Moreover, neuroblasts differentiated into neurons and astrocytes 35 days post implantation, and the neuroblast-derived neurons were Syn1 positive suggesting integration into existing neural circuitry. In addition, astrocytes co-localised with neuroblasts along the hydrogel tract, suggesting that they assisted migration and simulated pathways similar to the native rostral migratory stream. Lower levels of astrocytes were found at the boundary of hydrogels with encapsulated brain-derived neurotrophic factor, comparing with hydrogel implants alone.
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Affiliation(s)
- Sepideh Motamed
- Department of Materials Science and Engineering, Monash Institute of Medical Engineering, Monash University, Clayton, VIC, Australia.,Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Mark P Del Borgo
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Kun Zhou
- Department of Materials Science and Engineering, Monash Institute of Medical Engineering, Monash University, Clayton, VIC, Australia
| | - Ketav Kulkarni
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - Peter J Crack
- Department of Pharmacology, The University of Melbourne, Parkville, VIC, Australia
| | - Tobias D Merson
- Australian Regenerative Medicine Institute, Monash University, Clayton, VIC, Australia
| | - Marie-Isabel Aguilar
- Department of Biochemistry and Molecular Biology, Biomedicine Discovery Institute, Monash University, Clayton, VIC, Australia
| | - David I Finkelstein
- Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Parkville, VIC, Australia
| | - John S Forsythe
- Department of Materials Science and Engineering, Monash Institute of Medical Engineering, Monash University, Clayton, VIC, Australia
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12
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Scott G, Zetterberg H, Jolly A, Cole JH, De Simoni S, Jenkins PO, Feeney C, Owen DR, Lingford-Hughes A, Howes O, Patel MC, Goldstone AP, Gunn RN, Blennow K, Matthews PM, Sharp DJ. Minocycline reduces chronic microglial activation after brain trauma but increases neurodegeneration. Brain 2019; 141:459-471. [PMID: 29272357 PMCID: PMC5837493 DOI: 10.1093/brain/awx339] [Citation(s) in RCA: 121] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2017] [Accepted: 10/19/2017] [Indexed: 12/12/2022] Open
Abstract
Survivors of a traumatic brain injury can deteriorate years later, developing brain atrophy and dementia. Traumatic brain injury triggers chronic microglial activation, but it is unclear whether this is harmful or beneficial. A successful chronic-phase treatment for traumatic brain injury might be to target microglia. In experimental models, the antibiotic minocycline inhibits microglial activation. We investigated the effect of minocycline on microglial activation and neurodegeneration using PET, MRI, and measurement of the axonal protein neurofilament light in plasma. Microglial activation was assessed using 11C-PBR28 PET. The relationships of microglial activation to measures of brain injury, and the effects of minocycline on disease progression, were assessed using structural and diffusion MRI, plasma neurofilament light, and cognitive assessment. Fifteen patients at least 6 months after a moderate-to-severe traumatic brain injury received either minocycline 100 mg orally twice daily or no drug, for 12 weeks. At baseline, 11C-PBR28 binding in patients was increased compared to controls in cerebral white matter and thalamus, and plasma neurofilament light levels were elevated. MRI measures of white matter damage were highest in areas of greater 11C-PBR28 binding. Minocycline reduced 11C-PBR28 binding (mean Δwhite matter binding = −23.30%, 95% confidence interval −40.9 to −5.64%, P = 0.018), but increased plasma neurofilament light levels. Faster rates of brain atrophy were found in patients with higher baseline neurofilament light levels. In this experimental medicine study, minocycline after traumatic brain injury reduced chronic microglial activation while increasing a marker of neurodegeneration. These findings suggest that microglial activation has a reparative effect in the chronic phase of traumatic brain injury.
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Affiliation(s)
- Gregory Scott
- Division of Brain Sciences, Department of Medicine, Imperial College London, UK
| | - Henrik Zetterberg
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, the Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden.,Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden.,Department of Molecular Neuroscience, UCL Institute of Neurology, London, UK
| | - Amy Jolly
- Division of Brain Sciences, Department of Medicine, Imperial College London, UK
| | - James H Cole
- Division of Brain Sciences, Department of Medicine, Imperial College London, UK
| | - Sara De Simoni
- Division of Brain Sciences, Department of Medicine, Imperial College London, UK
| | - Peter O Jenkins
- Division of Brain Sciences, Department of Medicine, Imperial College London, UK
| | - Claire Feeney
- Division of Brain Sciences, Department of Medicine, Imperial College London, UK
| | - David R Owen
- Division of Brain Sciences, Department of Medicine, Imperial College London, UK
| | | | - Oliver Howes
- Division of Brain Sciences, Department of Medicine, Imperial College London, UK
| | - Maneesh C Patel
- Charing Cross Hospital, Imperial College Healthcare NHS Trust, London, UK
| | - Anthony P Goldstone
- Division of Brain Sciences, Department of Medicine, Imperial College London, UK
| | | | - Kaj Blennow
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, the Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden.,Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
| | - Paul M Matthews
- Division of Brain Sciences, Department of Medicine, Imperial College London, UK
| | - David J Sharp
- Division of Brain Sciences, Department of Medicine, Imperial College London, UK
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13
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Fisher KM, Lilak A, Garner J, Darian-Smith C. Extensive somatosensory and motor corticospinal sprouting occurs following a central dorsal column lesion in monkeys. J Comp Neurol 2018; 526:2373-2387. [PMID: 30014461 DOI: 10.1002/cne.24491] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Revised: 06/08/2018] [Accepted: 06/11/2018] [Indexed: 01/16/2023]
Abstract
The corticospinal tract (CST) forms the major descending pathway mediating voluntary hand movements in primates, and originates from ∼nine cortical subdivisions in the macaque. While the terminals of spared motor CST axons are known to sprout locally within the cord in response to spinal injury, little is known about the response of the other CST subcomponents. We previously reported that following a cervical dorsal root lesion (DRL), the primary somatosensory (S1) CST terminal projection retracts to 60% of its original terminal domain, while the primary motor (M1) projection remains robust (Darian-Smith et al., J. Neurosci., 2013). In contrast, when a dorsal column lesion (DCL) is added to the DRL, the S1 CST, in addition to the M1 CST, extends its terminal projections bilaterally and caudally, well beyond normal range (Darian-Smith et al., J. Neurosci., 2014). Are these dramatic responses linked entirely to the inclusion of a CNS injury (i.e., DCL), or do the two components summate or interact? We addressed this directly, by comparing data from monkeys that received a unilateral DCL alone, with those that received either a DRL or a combined DRL/DCL. Approximately 4 months post-lesion, the S1 hand region was mapped electrophysiologically, and anterograde tracers were injected bilaterally into the region deprived of normal input, to assess spinal terminal labeling. Using multifactorial analyses, we show that following a DCL alone (i.e., cuneate fasciculus lesion), the S1 and M1 CSTs also sprout significantly and bilaterally beyond normal range, with a termination pattern suggesting some interaction between the peripheral and central lesions.
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Affiliation(s)
- Karen M Fisher
- Department of Comparative Medicine, Stanford University School of Medicine, Stanford, California
| | - Alayna Lilak
- Department of Comparative Medicine, Stanford University School of Medicine, Stanford, California
| | - Joseph Garner
- Department of Comparative Medicine, Stanford University School of Medicine, Stanford, California
| | - Corinna Darian-Smith
- Department of Comparative Medicine, Stanford University School of Medicine, Stanford, California
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14
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Wang Y, Sawyer TW, Tse YC, Fan C, Hennes G, Barnes J, Josey T, Weiss T, Nelson P, Wong TP. Primary Blast-Induced Changes in Akt and GSK 3β Phosphorylation in Rat Hippocampus. Front Neurol 2017; 8:413. [PMID: 28868045 PMCID: PMC5563325 DOI: 10.3389/fneur.2017.00413] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2017] [Accepted: 07/31/2017] [Indexed: 12/30/2022] Open
Abstract
Traumatic brain injury (TBI) due to blast from improvised explosive devices has been a leading cause of morbidity and mortality in recent conflicts in Iraq and Afghanistan. However, the mechanisms of primary blast-induced TBI are not well understood. The Akt signal transduction pathway has been implicated in various brain pathologies including TBI. In the present study, the effects of simulated primary blast waves on the phosphorylation status of Akt and its downstream effector kinase, glycogen synthase kinase 3β (GSK3β), in rat hippocampus, were investigated. Male Sprague-Dawley (SD) rats (350–400 g) were exposed to a single pulse shock wave (25 psi; ~7 ms duration) and sacrificed 1 day, 1 week, or 6 weeks after exposure. Total and phosphorylated Akt, as well as phosphorylation of its downstream effector kinase GSK3β (at serine 9), were detected with western blot analysis and immunohistochemistry. Results showed that Akt phosphorylation at both serine 473 and threonine 308 was increased 1 day after blast on the ipsilateral side of the hippocampus, and this elevation persisted until at least 6 weeks postexposure. Similarly, phosphorylation of GSK3β at serine 9, which inhibits GSK3β activity, was also increased starting at 1 day and persisted until at least 6 weeks after primary blast on the ipsilateral side. In contrast, p-Akt was increased at 1 and 6 weeks on the contralateral side, while p-GSK3β was increased 1 day and 1 week after primary blast exposure. No significant changes in total protein levels of Akt and GSK were observed on either side of the hippocampus at any time points. Immunohistochemical results showed that increased p-Akt was mainly of neuronal origin in the CA1 region of the hippocampus and once phosphorylated, the majority was translocated to the dendritic and plasma membranes. Finally, electrophysiological data showed that evoked synaptic N-methyl-d-aspartate (NMDA) receptor activity was significantly increased 6 weeks after primary blast, suggesting that increased Akt phosphorylation may enhance synaptic NMDA receptor activation, or that enhanced synaptic NMDA receptor activation may increase Akt phosphorylation.
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Affiliation(s)
- Yushan Wang
- Defence Research and Development Canada, Suffield Research Centre, Medicine Hat, AB, Canada
| | - Thomas W Sawyer
- Defence Research and Development Canada, Suffield Research Centre, Medicine Hat, AB, Canada
| | - Yiu Chung Tse
- Department of Psychiatry, Douglas Mental Health University Institute, McGill University, Montreal, QC, Canada
| | - Changyang Fan
- Defence Research and Development Canada, Suffield Research Centre, Medicine Hat, AB, Canada
| | - Grant Hennes
- Defence Research and Development Canada, Suffield Research Centre, Medicine Hat, AB, Canada
| | - Julia Barnes
- Defence Research and Development Canada, Suffield Research Centre, Medicine Hat, AB, Canada
| | - Tyson Josey
- Defence Research and Development Canada, Suffield Research Centre, Medicine Hat, AB, Canada
| | - Tracy Weiss
- Defence Research and Development Canada, Suffield Research Centre, Medicine Hat, AB, Canada
| | - Peggy Nelson
- Defence Research and Development Canada, Suffield Research Centre, Medicine Hat, AB, Canada
| | - Tak Pan Wong
- Department of Psychiatry, Douglas Mental Health University Institute, McGill University, Montreal, QC, Canada
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15
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Donat CK, Scott G, Gentleman SM, Sastre M. Microglial Activation in Traumatic Brain Injury. Front Aging Neurosci 2017; 9:208. [PMID: 28701948 PMCID: PMC5487478 DOI: 10.3389/fnagi.2017.00208] [Citation(s) in RCA: 271] [Impact Index Per Article: 38.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2017] [Accepted: 06/12/2017] [Indexed: 12/15/2022] Open
Abstract
Microglia have a variety of functions in the brain, including synaptic pruning, CNS repair and mediating the immune response against peripheral infection. Microglia rapidly become activated in response to CNS damage. Depending on the nature of the stimulus, microglia can take a number of activation states, which correspond to altered microglia morphology, gene expression and function. It has been reported that early microglia activation following traumatic brain injury (TBI) may contribute to the restoration of homeostasis in the brain. On the other hand, if they remain chronically activated, such cells display a classically activated phenotype, releasing pro-inflammatory molecules, resulting in further tissue damage and contributing potentially to neurodegeneration. However, new evidence suggests that this classification is over-simplistic and the balance of activation states can vary at different points. In this article, we review the role of microglia in TBI, analyzing their distribution, morphology and functional phenotype over time in animal models and in humans. Animal studies have allowed genetic and pharmacological manipulations of microglia activation, in order to define their role. In addition, we describe investigations on the in vivo imaging of microglia using translocator protein (TSPO) PET and autoradiography, showing that microglial activation can occur in regions far remote from sites of focal injuries, in humans and animal models of TBI. Finally, we outline some novel potential therapeutic approaches that prime microglia/macrophages toward the beneficial restorative microglial phenotype after TBI.
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Affiliation(s)
| | | | | | - Magdalena Sastre
- Division of Brain Sciences, Department of Medicine, Imperial College LondonLondon, United Kingdom
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16
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Orihuela R, McPherson CA, Harry GJ. Microglial M1/M2 polarization and metabolic states. Br J Pharmacol 2016; 173:649-65. [PMID: 25800044 PMCID: PMC4742299 DOI: 10.1111/bph.13139] [Citation(s) in RCA: 1242] [Impact Index Per Article: 155.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2014] [Revised: 03/05/2015] [Accepted: 03/13/2015] [Indexed: 02/06/2023] Open
Abstract
Microglia are critical nervous system-specific immune cells serving as tissue-resident macrophages influencing brain development, maintenance of the neural environment, response to injury and repair. As influenced by their environment, microglia assume a diversity of phenotypes and retain the capability to shift functions to maintain tissue homeostasis. In comparison with peripheral macrophages, microglia demonstrate similar and unique features with regards to phenotype polarization, allowing for innate immunological functions. Microglia can be stimulated by LPS or IFN-γ to an M1 phenotype for expression of pro-inflammatory cytokines or by IL-4/IL-13 to an M2 phenotype for resolution of inflammation and tissue repair. Increasing evidence suggests a role of metabolic reprogramming in the regulation of the innate inflammatory response. Studies using peripheral immune cells demonstrate that polarization to an M1 phenotype is often accompanied by a shift in cells from oxidative phosphorylation to aerobic glycolysis for energy production. More recently, the link between polarization and mitochondrial energy metabolism has been considered in microglia. Under these conditions, energy demands would be associated with functional activities and cell survival and thus, may serve to influence the contribution of microglia activation to various neurodegenerative conditions. This review examines the polarization states of microglia and their relationship to mitochondrial metabolism. Additional supporting experimental data are provided to demonstrate mitochondrial metabolic shifts in primary microglia and the BV-2 microglia cell line induced under LPS (M1) and IL-4/IL-13 (M2) polarization.
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Affiliation(s)
- Ruben Orihuela
- Neurotoxicology Group, National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, USA
| | - Christopher A McPherson
- Neurotoxicology Group, National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, USA
| | - Gaylia Jean Harry
- Neurotoxicology Group, National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, National Institutes of Health, Research Triangle Park, NC, USA
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17
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Nagamoto-Combs K, Manocha GD, Puig K, Combs CK. An improved approach to align and embed multiple brain samples in a gelatin-based matrix for simultaneous histological processing. J Neurosci Methods 2015; 261:155-60. [PMID: 26743972 DOI: 10.1016/j.jneumeth.2015.12.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Revised: 12/15/2015] [Accepted: 12/17/2015] [Indexed: 11/25/2022]
Abstract
BACKGROUND Preparation and processing of free-floating histological sections involve a series of steps. The amount of labor, particularly sectioning and mounting, quickly multiplies as the number of samples increases. Embedding tissue samples in a flexible matrix allows simultaneous handling of multiple samples and preserves the integrity of the tissue during histological processing. However, aligning multiple asymmetrical samples, for example small-animal brains, in a particular orientation requires skillful arrangement and securing of the samples by pinning onto a solid surface. Consequently, costly technical services offered by contract research organizations are often sought. NEW METHOD An improved approach to align and embed multiple whole or half rodent brain samples into a gelatin-based matrix is described. Using a template specifically designed to form arrayed mouse brain-shaped cavities, a "receiving matrix" is prepared. Inserting brain samples directly into the cavities allows the samples to be effortlessly positioned into a uniform orientation and embedded in a block of matrix. RESULTS Multiple mouse brains were arrayed in a uniform orientation in a gelatin matrix block with ease using the receiving matrix. The gelatin-embedded brains were simultaneously sectioned and stained, and effortlessly mounted onto glass slides. COMPARISON WITH EXISTING METHODS The improved approach allowed multiple whole or half mouse brains to be easily arrayed without pinning the samples onto a solid surface and prevented damages or shifting of the samples during embedding. CONCLUSIONS The new approach to array multiple brain samples provides a simple way to prepare gelatin-embedded whole or half brain arrays of commercial quality.
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Affiliation(s)
- Kumi Nagamoto-Combs
- Department of Pathology, University of North Dakota School of Medicine and Health Sciences, 501N. Columbia Road Stop 9037, Grand Forks, ND 58202-9037, USA.
| | - Gunjan D Manocha
- Department of Basic Sciences, University of North Dakota School of Medicine and Health Sciences, 501N. Columbia Road Stop 9037, Grand Forks, ND 58202-9037, USA
| | - Kendra Puig
- Department of Basic Sciences, University of North Dakota School of Medicine and Health Sciences, 501N. Columbia Road Stop 9037, Grand Forks, ND 58202-9037, USA
| | - Colin K Combs
- Department of Basic Sciences, University of North Dakota School of Medicine and Health Sciences, 501N. Columbia Road Stop 9037, Grand Forks, ND 58202-9037, USA
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18
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Morecraft RJ, Ge J, Stilwell-Morecraft KS, McNeal DW, Hynes SM, Pizzimenti MA, Rotella DL, Darling WG. Frontal and frontoparietal injury differentially affect the ipsilateral corticospinal projection from the nonlesioned hemisphere in monkey (Macaca mulatta). J Comp Neurol 2015. [PMID: 26224429 DOI: 10.1002/cne.23861] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Upper extremity hemiplegia is a common consequence of unilateral cortical stroke. Understanding the role of the unaffected cerebral hemisphere in the motor recovery process has been encouraged, in part, by the presence of ipsilateral corticospinal projections (iCSP). We examined the neuroplastic response of the iCSP from the contralesional primary motor cortex (cM1) hand/arm area to spinal levels C5-T1 after spontaneous long-term recovery from isolated frontal lobe injury and isolated frontoparietal injury. High-resolution tract tracing, stereological, and behavioral methodologies were applied. Recovery from frontal motor injury resulted in enhanced numbers of terminal labeled boutons in the iCSP from cM1 compared with controls. Increases occurred in lamina VIII and the adjacent ventral sectors of lamina VII, which are involved in axial/proximal limb sensorimotor processing. Larger frontal lobe lesions were associated with greater numbers of terminal boutons than smaller frontal lobe lesions. In contrast, frontoparietal injury blocked this response; total bouton number was similar to controls, demonstrating that disruption of somatosensory input to one hemisphere has a suppressive effect on the iCSP from the nonlesioned hemisphere. However, compared with controls, elevated bouton numbers occurred in lamina VIII, at the expense of lamina VII bouton labeling. Lamina IX boutons were also elevated in two frontoparietal lesion cases with extensive cortical injury. Because laminae VIII and IX collectively harbor axial, proximal, and distal motoneurons, therapeutic intervention targeting the ipsilateral corticospinal linkage from cM1 may promote proximal, and possibly distal, upper-limb motor recovery following frontal and frontoparietal injury.
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Affiliation(s)
- R J Morecraft
- Division of Basic Biomedical Sciences, Laboratory of Neurological Sciences, The University of South Dakota Sanford School of Medicine, Vermillion, South Dakota, 57069
| | - J Ge
- Division of Basic Biomedical Sciences, Laboratory of Neurological Sciences, The University of South Dakota Sanford School of Medicine, Vermillion, South Dakota, 57069
| | - K S Stilwell-Morecraft
- Division of Basic Biomedical Sciences, Laboratory of Neurological Sciences, The University of South Dakota Sanford School of Medicine, Vermillion, South Dakota, 57069
| | - D W McNeal
- Division of Basic Biomedical Sciences, Laboratory of Neurological Sciences, The University of South Dakota Sanford School of Medicine, Vermillion, South Dakota, 57069
| | - S M Hynes
- Department of Health and Human Physiology, Motor Control Laboratories, The University of Iowa, Iowa City, Iowa, 52242
| | - M A Pizzimenti
- Department of Health and Human Physiology, Motor Control Laboratories, The University of Iowa, Iowa City, Iowa, 52242.,Department of Anatomy and Cell Biology, Carver College of Medicine, The University of Iowa, Iowa City, Iowa, 52242
| | - D L Rotella
- Department of Health and Human Physiology, Motor Control Laboratories, The University of Iowa, Iowa City, Iowa, 52242
| | - W G Darling
- Department of Health and Human Physiology, Motor Control Laboratories, The University of Iowa, Iowa City, Iowa, 52242
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19
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Brain damage of the preterm infant: new insights into the role of inflammation. Biochem Soc Trans 2015; 42:557-63. [PMID: 24646278 DOI: 10.1042/bst20130284] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Epidemiological studies have shown a strong association between perinatal infection/inflammation and brain damage in preterm infants and/or neurological handicap in survivors. Experimental studies have shown a causal effect of infection/inflammation on perinatal brain damage. Infection including inflammatory factors can disrupt programmes of brain development and, in particular, induce death and/or blockade of oligodendrocyte maturation, leading to myelin defects. Alternatively, in the so-called multiple-hit hypothesis, infection/inflammation can act as predisposing factors, making the brain more susceptible to a second stress (sensitization process), such as hypoxic-ischaemic or excitotoxic insults. Epidemiological data also suggest that perinatal exposure to inflammatory factors could predispose to long-term diseases including psychiatric disorders.
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20
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Schawkat K, Di Santo S, Seiler S, Ducray AD, Widmer HR. Loss of Nogo-A-expressing neurons in a rat model of Parkinson's disease. Neuroscience 2014; 288:59-72. [PMID: 25554426 DOI: 10.1016/j.neuroscience.2014.12.035] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2014] [Revised: 12/15/2014] [Accepted: 12/15/2014] [Indexed: 11/15/2022]
Abstract
The myelin-associated protein Nogo-A is among the most potent neurite growth inhibitors in the adult CNS. Recently, Nogo-A expression was demonstrated in a number of neuronal subpopulations of the adult and developing CNS but at present, little is known about the expression of Nogo-A in the nigrostriatal system, a brain structure severely affected in Parkinson's disease (PD). The present study sought to characterize the expression pattern of Nogo-A immunoreactive (ir) cells in the adult ventral mesencephalon of control rats and in the 6-hydroxydopamine (6-OHDA) rat model of PD. Immunohistochemical analyses of normal adult rat brain showed a distinct expression of Nogo-A in the ventral mesencephalon, with the highest level in the substantia nigra pars compacta (SNc) where it co-localized with dopaminergic neurons. Analyses conducted 1week and 1 month after unilateral striatal injections of 6-OHDA disclosed a severe loss of the number of Nogo-A-ir cells in the SNc. Notably, at 1week after treatment, more dopaminergic neurons expressing Nogo-A were affected by the 6-OHDA toxicity than Nogo-A-negative dopaminergic neurons. However, at later time points more of the surviving dopaminergic neurons expressed Nogo-A. In the striatum, both small and large Nogo-A-positive cells were detected. The large cells were identified as cholinergic interneurons. Our results suggest yet unidentified functions of Nogo-A in the CNS beyond the inhibition of axonal regeneration and plasticity, and may indicate a role for Nogo-A in PD.
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Affiliation(s)
- K Schawkat
- Department of Neurosurgery, Neurocenter and Regenerative Neuroscience Cluster, University of Bern, Inselspital, CH-3010 Bern, Switzerland.
| | - S Di Santo
- Department of Neurosurgery, Neurocenter and Regenerative Neuroscience Cluster, University of Bern, Inselspital, CH-3010 Bern, Switzerland.
| | - S Seiler
- Department of Neurosurgery, Neurocenter and Regenerative Neuroscience Cluster, University of Bern, Inselspital, CH-3010 Bern, Switzerland.
| | - A D Ducray
- Department of Neurosurgery, Neurocenter and Regenerative Neuroscience Cluster, University of Bern, Inselspital, CH-3010 Bern, Switzerland.
| | - H R Widmer
- Department of Neurosurgery, Neurocenter and Regenerative Neuroscience Cluster, University of Bern, Inselspital, CH-3010 Bern, Switzerland.
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Spejo AB, Oliveira ALR. Synaptic rearrangement following axonal injury: Old and new players. Neuropharmacology 2014; 96:113-23. [PMID: 25445484 DOI: 10.1016/j.neuropharm.2014.11.002] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 11/03/2014] [Accepted: 11/04/2014] [Indexed: 10/24/2022]
Abstract
Following axotomy, the contact between motoneurons and muscle fibers is disrupted, triggering a retrograde reaction at the neuron cell body within the spinal cord. Together with chromatolysis, a hallmark of such response to injury is the elimination of presynaptic terminals apposing to the soma and proximal dendrites of the injured neuron. Excitatory inputs are preferentially eliminated, leaving the cells under an inhibitory influence during the repair process. This is particularly important to avoid glutamate excitotoxicity. Such shift from transmission to a regeneration state is also reflected by deep metabolic changes, seen by the regulation of several genes related to cell survival and axonal growth. It is unclear, however, how exactly synaptic stripping occurs, but there is substantial evidence that glial cells play an active role in this process. In one hand, immune molecules, such as the major histocompatibility complex (MHC) class I, members of the complement family and Toll-like receptors are actively involved in the elimination/reapposition of presynaptic boutons. On the other hand, plastic changes that involve sprouting might be negatively regulated by extracellular matrix proteins such as Nogo-A, MAG and scar-related chondroitin sulfate proteoglycans. Also, neurotrophins, stem cells, physical exercise and several drugs seem to improve synaptic stability, leading to functional recovery after lesion. This article is part of a Special Issue entitled 'Neuroimmunology and Synaptic Function'.
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Affiliation(s)
- Aline Barroso Spejo
- Laboratory of Nerve Regeneration, Department of Structural and Functional Biology, University of Campinas - UNICAMP, Campinas, SP, Brazil
| | - Alexandre L R Oliveira
- Laboratory of Nerve Regeneration, Department of Structural and Functional Biology, University of Campinas - UNICAMP, Campinas, SP, Brazil.
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Respiratory viral infection in neonatal piglets causes marked microglia activation in the hippocampus and deficits in spatial learning. J Neurosci 2014; 34:2120-9. [PMID: 24501353 DOI: 10.1523/jneurosci.2180-13.2014] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023] Open
Abstract
Environmental insults during sensitive periods can affect hippocampal development and function, but little is known about peripheral infection, especially in humans and other animals whose brain is gyrencephalic and experiences major perinatal growth. Using a piglet model, the present study showed that inoculation on postnatal day 7 with the porcine reproductive and respiratory syndrome virus (PRRSV) caused microglial activation within the hippocampus with 82% and 43% of isolated microglia being MHC II(+) 13 and 20 d after inoculation, respectively. In control piglets, <5% of microglia isolated from the hippocampus were MHC II(+). PRRSV piglets were febrile (p < 0.0001), anorectic (p < 0.0001), and weighed less at the end of the study (p = 0.002) compared with control piglets. Increased inflammatory gene expression (e.g., IL-1β, IL-6, TNF-α, and IFN-γ) was seen across multiple brain regions, including the hippocampus, whereas reductions in CD200, NGF, and MBP were evident. In a test of spatial learning, PRRSV piglets took longer to acquire the task, had a longer latency to choice, and had a higher total distance moved. Overall, these data demonstrate that viral respiratory infection is associated with a marked increase in activated microglia in the hippocampus, neuroinflammation, and impaired performance in a spatial cognitive task. As respiratory infections are common in human neonates and infants, approaches to regulate microglial cell activity are likely to be important.
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LIU FENG, LIAO FAN, LI WEI, HAN YONGFENG, LIAO DAGUANG. Progesterone alters Nogo-A, GFAP and GAP-43 expression in a rat model of traumatic brain injury. Mol Med Rep 2014; 9:1225-31. [DOI: 10.3892/mmr.2014.1967] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Accepted: 01/31/2014] [Indexed: 11/06/2022] Open
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Cho H, Sajja V, VandeVord P, Lee Y. Blast induces oxidative stress, inflammation, neuronal loss and subsequent short-term memory impairment in rats. Neuroscience 2013; 253:9-20. [DOI: 10.1016/j.neuroscience.2013.08.037] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Revised: 08/06/2013] [Accepted: 08/21/2013] [Indexed: 12/17/2022]
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Abstract
Cerebral palsy is a chronic childhood disorder that can have diverse etiologies. Injury to the developing brain that occurs either in utero or soon after birth can result in the motor, sensory, and cognitive deficits seen in cerebral palsy. Although the etiologies for cerebral palsy are variable, neuroinflammation plays a key role in the pathophysiology of the brain injury irrespective of the etiology. Currently, there is no effective cure for cerebral palsy. Nanomedicine offers a new frontier in the development of therapies for prevention and treatment of brain injury resulting in cerebral palsy. Nanomaterials such as dendrimers provide opportunities for the targeted delivery of multiple drugs that can mitigate several pathways involved in injury and can be delivered specifically to the cells that are responsible for neuroinflammation and injury. These materials also offer the opportunity to deliver agents that would promote repair and regeneration in the brain, resulting not only in attenuation of injury, but also enabling normal growth. In this review, the current advances in nanotechnology for treatment of brain injury are discussed with specific relevance to cerebral palsy. Future directions that would facilitate clinical translation in neonates and children are also addressed.
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Affiliation(s)
- Bindu Balakrishnan
- Department of Anesthesiology and Critical Care Medicine, Johns Hopkins University; Baltimore, MD, USA
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Abstract
Microglia are critical nervous system-specific cells influencing brain development, maintenance of the neural environment, response to injury, and repair. They contribute to neuronal proliferation and differentiation, pruning of dying neurons, synaptic remodeling and clearance of debris and aberrant proteins. Colonization of the brain occurs during gestation with an expansion following birth with localization stimulated by programmed neuronal death, synaptic pruning, and axonal degeneration. Changes in microglia phenotype relate to cellular processes including specific neurotransmitter, pattern recognition, or immune-related receptor activation. Upon activation, microglia cells have the capacity to release a number of substances, e.g., cytokines, chemokines, nitric oxide, and reactive oxygen species, which could be detrimental or beneficial to the surrounding cells. With aging, microglia shift their morphology and may display diminished capacity for normal functions related to migration, clearance, and the ability to shift from a pro-inflammatory to an anti-inflammatory state to regulate injury and repair. This shift in microglia potentially contributes to increased susceptibility and neurodegeneration as a function of age. In the current review, information is provided on the colonization of the brain by microglia, the expression of various pattern recognition receptors to regulate migration and phagocytosis, and the shift in related functions that occur in normal aging.
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Affiliation(s)
- G Jean Harry
- National Toxicology Program Laboratory, National Institute of Environmental Health Sciences, MD C1-04, 111 T.W. Alexander Drive, Research Triangle Park, NC 27709, USA.
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Abstract
Increasing attention is being paid to nutritional and metabolic management of traumatic brain injury patients. The gross metabolic changes that occur after injury have been found to be influenced by both macronutrients, that is, dietary ratios of fat, carbohydrates, and protein, and micronutrients, for example, vitamins and minerals. Alterations in diet and nutritional strategies have been shown to decrease both morbidity and mortality after injury. Despite this knowledge, defining optimal nutritional support following traumatic brain injury continues to be an ongoing challenge.
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Affiliation(s)
- Tiffany Greco
- Department of Neurosurgery, UCLA Brain Injury Research Center, David Geffen School of Medicine at UCLA, Los Angeles, CA 90095-7039, USA
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Zhang W, Miao Y, Xing Z, Li H, Liu H, Li Z. Growth-associated protein-43 expression in cocultures of dorsal root ganglion neurons and skeletal muscle cells with different neurotrophins. Muscle Nerve 2013; 47:909-15. [PMID: 23666783 DOI: 10.1002/mus.23689] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/22/2012] [Indexed: 11/10/2022]
Affiliation(s)
- Weiwei Zhang
- Department of Anatomy; Shandong University School of Medicine; 44 Wehua Xi Road; Jinan; Shandong Province 250012; China
| | - Yajun Miao
- Second Department of Internal Medicine; Shandong Communication Hospital; Jinan; China
| | - Ziying Xing
- Department of Anatomy; Shandong University School of Medicine; 44 Wehua Xi Road; Jinan; Shandong Province 250012; China
| | - Hao Li
- Department of Orthopaedics; Shandong University Qilu Hospital; Jinan; China
| | - Huangxiang Liu
- Department of Rheumatology; Shandong University Qilu Hospital; Jinan; China
| | - Zhenzhong Li
- Department of Anatomy; Shandong University School of Medicine; 44 Wehua Xi Road; Jinan; Shandong Province 250012; China
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Darling WG, Helle N, Pizzimenti MA, Rotella DL, Hynes SM, Ge J, Stilwell-Morecraft KS, Morecraft RJ. Laterality affects spontaneous recovery of contralateral hand motor function following motor cortex injury in rhesus monkeys. Exp Brain Res 2013; 228:9-24. [PMID: 23652723 DOI: 10.1007/s00221-013-3533-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2012] [Accepted: 04/16/2013] [Indexed: 10/26/2022]
Abstract
The purpose of this study was to test whether brain laterality influences spontaneous recovery of hand motor function after controlled brain injuries to arm areas of M1 and lateral premotor cortex (LPMC) of the hemisphere contralateral to the preferred hand in rhesus monkeys. We hypothesized that monkeys with stronger hand preference would exhibit poorer recovery of skilled hand use after such brain injury. Degree of handedness was assessed using a standard dexterity board task in which subjects could use either hand to retrieve small food pellets. Fine hand/digit motor function was assessed using a modified dexterity board before and after the M1 and LPMC lesions in ten monkeys. We found a strong negative relationship between the degree of handedness and the recovery of manipulation skill, demonstrating that higher hand preference was associated with poorer recovery of hand fine motor function. We also observed that monkeys with larger lesions within M1 and LPMC had greater initial impairment of manipulation and poorer recovery of reaching skill. We conclude that monkeys with a stronger hand preference are likely to show poorer recovery of contralesional hand fine motor skill after isolated brain lesions affecting the lateral frontal motor areas. These data may be extended to suggest that humans who exhibit weak hand dominance, and perhaps individuals who use both hands for fine motor tasks, may have a more favorable potential for recovery after a unilateral stroke or brain injury affecting the lateral cortical motor areas than individuals with a high degree of hand dominance.
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Affiliation(s)
- Warren G Darling
- Department of Health and Human Physiology, Motor Control Laboratories, The University of Iowa, Iowa City, IA 52242, USA.
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Hernandez-Ontiveros DG, Tajiri N, Acosta S, Giunta B, Tan J, Borlongan CV. Microglia activation as a biomarker for traumatic brain injury. Front Neurol 2013; 4:30. [PMID: 23531681 PMCID: PMC3607801 DOI: 10.3389/fneur.2013.00030] [Citation(s) in RCA: 189] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2012] [Accepted: 03/10/2013] [Indexed: 12/24/2022] Open
Abstract
Traumatic brain injury (TBI) has become the signature wound of wars in Afghanistan and Iraq. Injury may result from a mechanical force, a rapid acceleration-deceleration movement, or a blast wave. A cascade of secondary cell death events ensues after the initial injury. In particular, multiple inflammatory responses accompany TBI. A series of inflammatory cytokines and chemokines spreads to normal brain areas juxtaposed to the core impacted tissue. Among the repertoire of immune cells involved, microglia is a key player in propagating inflammation to tissues neighboring the core site of injury. Neuroprotective drug trials in TBI have failed, likely due to their sole focus on abrogating neuronal cell death and ignoring the microglia response despite these inflammatory cells’ detrimental effects on the brain. Another relevant point to consider is the veracity of results of animal experiments due to deficiencies in experimental design, such as incomplete or inadequate method description, data misinterpretation, and reporting may introduce bias and give false-positive results. Thus, scientific publications should follow strict guidelines that include randomization, blinding, sample-size estimation, and accurate handling of all data (Landis et al., 2012). A prolonged state of inflammation after brain injury may linger for years and predispose patients to develop other neurological disorders, such as Alzheimer’s disease. TBI patients display progressive and long-lasting impairments in their physical, cognitive, behavioral, and social performance. Here, we discuss inflammatory mechanisms that accompany TBI in an effort to increase our understanding of the dynamic pathological condition as the disease evolves over time and begin to translate these findings for defining new and existing inflammation-based biomarkers and treatments for TBI.
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Affiliation(s)
- Diana G Hernandez-Ontiveros
- Department of Neurosurgery and Brain Repair, Center of Excellence for Aging and Brain Repair, Morsani College of Medicine, University of South Florida Tampa, FL, USA
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Li Y, Liu G, Li H, Xu Y, Zhang H, Liu Z. Capsaicin-Induced Activation of ERK1/2 and Its Involvement in GAP-43 Expression and CGRP Depletion in Organotypically Cultured DRG Neurons. Cell Mol Neurobiol 2013; 33:433-41. [DOI: 10.1007/s10571-013-9909-8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2012] [Accepted: 01/09/2013] [Indexed: 12/19/2022]
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The effects of target skeletal muscle cells on dorsal root ganglion neuronal outgrowth and migration in vitro. PLoS One 2013; 8:e52849. [PMID: 23341911 PMCID: PMC3544851 DOI: 10.1371/journal.pone.0052849] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Accepted: 11/21/2012] [Indexed: 11/19/2022] Open
Abstract
Targets of neuronal innervations play a vital role in regulating the survival and differentiation of innervating neurotrophin-responsive neurons. During development, neurons extend axons to their targets, and then their survival become dependent on the trophic substances secreted by their target cells. Sensory endings were present on myoblasts, myotubes, and myofibers in all intrafusal bundles regardless of age. The interdependence of sensory neurons and skeletal muscle (SKM) cells during both embryonic development and the maintenance of the mature functional state has not been fully understood. In the present study, neuromuscular cocultures of organotypic dorsal root ganglion (DRG) explants and dissociate SKM cells were established. Using this culture system, the morphological relationship between DRG neurons and SKM cells, neurites growth and neuronal migration were investigated. The migrating neurons were determined by fluorescent labeling of microtubule-associated protein-2 (MAP-2) and neurofilament 200 (NF-200) or growth-associated protein 43 (GAP-43). The expression of NF-200 and GAP-43 and their mRNAs was evaluated by Western blot assay and real time-PCR analysis. The results reveal that DRG explants showed more dense neurites outgrowth in neuromuscular cocultures as compared with that in the culture of DRG explants alone. The number of total migrating neurons (the MAP-2-expressing neurons) and the percentage NF-200-immunoreactive (IR) and GAP-43-IR neurons increased significantly in the presence of SKM cells. The levels of NF-200 and GAP-43 and their mRNAs increased significantly in neuromuscular cocultures as compared with that in the culture of DRG explants alone. These results suggested that target SKM cells play an important role in regulating neuronal protein synthesis, promoting neuritis outgrowth and neuronal migration of DRG explants in vitro. These results not only provide new clues for a better understanding of the association of SKM cells with DRG sensory neurons during development, they may also have implications for axonal regeneration after nerve injury.
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Wu J, Pajoohesh-Ganji A, Stoica BA, Dinizo M, Guanciale K, Faden AI. Delayed expression of cell cycle proteins contributes to astroglial scar formation and chronic inflammation after rat spinal cord contusion. J Neuroinflammation 2012; 9:169. [PMID: 22784881 PMCID: PMC3410790 DOI: 10.1186/1742-2094-9-169] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2012] [Accepted: 07/11/2012] [Indexed: 02/01/2023] Open
Abstract
BACKGROUND Traumatic spinal cord injury (SCI) induces secondary tissue damage that is associated with astrogliosis and inflammation. We previously reported that acute upregulation of a cluster of cell-cycle-related genes contributes to post-mitotic cell death and secondary damage after SCI. However, it remains unclear whether cell cycle activation continues more chronically and contributes to more delayed glial change. Here we examined expression of cell cycle-related proteins up to 4 months following SCI, as well as the effects of the selective cyclin-dependent kinase (CDKs) inhibitor CR8, on astrogliosis and microglial activation in a rat SCI contusion model. METHODS Adult male rats were subjected to moderate spinal cord contusion injury at T8 using a well-characterized weight-drop model. Tissue from the lesion epicenter was obtained 4 weeks or 4 months post-injury, and processed for protein expression and lesion volume. Functional recovery was assessed over the 4 months after injury. RESULTS Immunoblot analysis demonstrated a marked continued upregulation of cell cycle-related proteins - including cyclin D1 and E, CDK4, E2F5 and PCNA - for 4 months post-injury that were highly expressed by GFAP+ astrocytes and microglia, and co-localized with inflammatory-related proteins. CR8 administrated systemically 3 h post-injury and continued for 7 days limited the sustained elevation of cell cycle proteins and immunoreactivity of GFAP, Iba-1 and p22PHOX - a key component of NADPH oxidase - up to 4 months after SCI. CR8 treatment significantly reduced lesion volume, which typically progressed in untreated animals between 1 and 4 months after trauma. Functional recovery was also significantly improved by CR8 treatment after SCI from week 2 through week 16. CONCLUSIONS These data demonstrate that cell cycle-related proteins are chronically upregulated after SCI and may contribute to astroglial scar formation, chronic inflammation and further tissue loss.
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Affiliation(s)
- Junfang Wu
- Department of Anesthesiology & Center for Shock, Trauma and Anesthesiology Research (STAR), University of Maryland, School of Medicine, Baltimore, MD 21201, USA.
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35
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Darling WG, Pizzimenti MA, Morecraft RJ. Functional recovery following motor cortex lesions in non-human primates: experimental implications for human stroke patients. J Integr Neurosci 2011; 10:353-84. [PMID: 21960307 PMCID: PMC3689229 DOI: 10.1142/s0219635211002737] [Citation(s) in RCA: 46] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2011] [Accepted: 05/04/2011] [Indexed: 12/19/2022] Open
Abstract
This review discusses selected classical works and contemporary research on recovery of contralesional fine hand motor function following lesions to motor areas of the cerebral cortex in non-human primates. Findings from both the classical literature and contemporary studies show that lesions of cortical motor areas induce paresis initially, but are followed by remarkable recovery of fine hand/digit motor function that depends on lesion size and post-lesion training. Indeed, in recent work where considerable quantification of fine digit function associated with grasping and manipulating small objects has been observed, very favorable recovery is possible with minimal forced use of the contralesional limb. Studies of the mechanisms underlying recovery have shown that following small lesions of the digit areas of primary motor cortex (M1), there is expansion of the digit motor representations into areas of M1 that did not produce digit movements prior to the lesion. However, after larger lesions involving the elbow, wrist and digit areas of M1, no such expansion of the motor representation was observed, suggesting that recovery was due to other cortical or subcortical areas taking over control of hand/digit movements. Recently, we showed that one possible mechanism of recovery after lesion to the arm areas of M1 and lateral premotor cortex is enhancement of corticospinal projections from the medially located supplementary motor area (M2) to spinal cord laminae containing neurons which have lost substantial input from the lateral motor areas and play a critical role in reaching and digit movements. Because human stroke and brain injury patients show variable, and usually poorer, recovery of hand motor function than that of nonhuman primates after motor cortex damage, we conclude with a discussion of implications of this work for further experimentation to improve recovery of hand function in human stroke patients.
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Affiliation(s)
- Warren G Darling
- Department of Health and Human Physiology, Motor Control Laboratories, The University of Iowa, Iowa City, Iowa 52242, USA.
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Ramlackhansingh AF, Brooks DJ, Greenwood RJ, Bose SK, Turkheimer FE, Kinnunen KM, Gentleman S, Heckemann RA, Gunanayagam K, Gelosa G, Sharp DJ. Inflammation after trauma: microglial activation and traumatic brain injury. Ann Neurol 2011; 70:374-83. [PMID: 21710619 DOI: 10.1002/ana.22455] [Citation(s) in RCA: 668] [Impact Index Per Article: 51.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2011] [Revised: 04/01/2011] [Accepted: 04/08/2011] [Indexed: 11/12/2022]
Abstract
OBJECTIVE Patient outcome after traumatic brain injury (TBI) is highly variable. The underlying pathophysiology of this is poorly understood, but inflammation is potentially an important factor. Microglia orchestrate many aspects of this response. Their activation can be studied in vivo using the positron emission tomography (PET) ligand [11C](R)PK11195 (PK). In this study, we investigate whether an inflammatory response to TBI persists, and whether this response relates to structural brain abnormalities and cognitive function. METHODS Ten patients, studied at least 11 months after moderate to severe TBI, underwent PK PET and structural magnetic resonance imaging (including diffusion tensor imaging). PK binding potentials were calculated in and around the site of focal brain damage, and in selected distant and subcortical brain regions. Standardized neuropsychological tests were administered. RESULTS PK binding was significantly raised in the thalami, putamen, occipital cortices, and posterior limb of the internal capsules after TBI. There was no increase in PK binding at the original site of focal brain injury. High PK binding in the thalamus was associated with more severe cognitive impairment, although binding was not correlated with either the time since the injury or the extent of structural brain damage. INTERPRETATION We demonstrate that increased microglial activation can be present up to 17 years after TBI. This suggests that TBI triggers a chronic inflammatory response particularly in subcortical regions. This highlights the importance of considering the response to TBI as evolving over time and suggests interventions may be beneficial for longer intervals after trauma than previously assumed.
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Affiliation(s)
- Anil F Ramlackhansingh
- Centre for Neuroscience, Department of Medicine, Imperial College London, Hammersmith Hospital Campus, London, UK
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Darling WG, Pizzimenti MA, Hynes SM, Rotella DL, Headley G, Ge J, Stilwell-Morecraft KS, McNeal DW, Solon-Cline KM, Morecraft RJ. Volumetric effects of motor cortex injury on recovery of ipsilesional dexterous movements. Exp Neurol 2011; 231:56-71. [PMID: 21703261 DOI: 10.1016/j.expneurol.2011.05.015] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2010] [Revised: 04/26/2011] [Accepted: 05/22/2011] [Indexed: 12/17/2022]
Abstract
Damage to the motor cortex of one hemisphere has classically been associated with contralateral upper limb paresis, but recent patient studies have identified deficits in both upper limbs. In non-human primates, we tested the hypothesis that the severity of ipsilesional upper limb motor impairment in the early post-injury phase depends on the volume of gray and white matter damage of the motor areas of the frontal lobe. We also postulated that substantial recovery would accompany minimal task practice and that ipsilesional limb recovery would be correlated with recovery of the contralesional limb. Gross (reaching) and fine hand motor functions were assessed for 3-12 months post-injury using two motor tests. Volumes of white and gray matter lesions were assessed using quantitative histology. Early changes in post-lesion motor performance were inversely correlated with white matter lesion volume indicating that larger lesions produced greater decreases in ipsilesional hand movement control. All monkeys showed improvements in ipsilesional hand motor skill during the post-lesion period, with reaching skill improvements being positively correlated with total lesion volume indicating that larger lesions were associated with greater ipsilesional motor skill recovery. We suggest that reduced trans-callosal inhibition from the lesioned hemisphere may play a role in the observed skill improvements. Our findings show that significant ipsilesional hand motor recovery is likely to accompany injury limited to frontal motor areas. In humans, more pronounced ipsilesional motor deficits that invariably develop after stroke may, in part, be a consequence of more extensive subcortical white and gray matter damage.
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Affiliation(s)
- Warren G Darling
- Department of Integrative Physiology, Motor Control Laboratory, The University of Iowa, Iowa City, Iowa 52242, USA.
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Weishaupt N, Silasi G, Colbourne F, Fouad K. Secondary damage in the spinal cord after motor cortex injury in rats. J Neurotrauma 2010; 27:1387-97. [PMID: 20515316 DOI: 10.1089/neu.2010.1346] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
When neurons within the motor cortex are fatally injured, their axons, many of which project into the spinal cord, undergo wallerian degeneration. Pathological processes occurring downstream of the cortical damage have not been extensively studied. We created a focal forelimb motor cortex injury in rats and found that axons from cell bodies located in the hindlimb motor cortex (spared by the cortical injury) become secondarily damaged in the spinal cord. To assess axonal degeneration in the spinal cord, we quantified silver staining in the corticospinal tract (CST) at 1 week and 4 weeks after the injury. We found a significant increase in silver deposition at the thoracic spinal cord level at 4 weeks compared to 1 week post-injury. At both time points, no degenerating neurons could be found in the hindlimb motor cortex. In a separate experiment, we showed that direct injury of neurons within the hindlimb motor cortex caused marked silver deposition in the thoracic CST at 1 week post-injury, and declined thereafter. Therefore, delayed axonal degeneration in the thoracic spinal cord after a focal forelimb motor cortex injury is indicative of secondary damage at the spinal cord level. Furthermore, immunolabeling of spinal cord sections showed that a local inflammatory response dominated by partially activated Iba-1-positive microglia is mounted in the CST, a viable mechanism to cause the observed secondary degeneration of fibers. In conclusion, we demonstrate that following motor cortex injury, wallerian degeneration of axons in the spinal cord leads to secondary damage, which is likely mediated by inflammatory processes.
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Affiliation(s)
- Nina Weishaupt
- Centre for Neuroscience, University of Alberta, Edmonton, Alberta, Canada
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Darling WG, Pizzimenti MA, Rotella DL, Hynes SM, Ge J, Stilwell-Morecraft KS, Vanadurongvan T, McNeal DW, Solon-Cline KM, Morecraft RJ. Minimal forced use without constraint stimulates spontaneous use of the impaired upper extremity following motor cortex injury. Exp Brain Res 2010; 202:529-42. [PMID: 20107980 DOI: 10.1007/s00221-010-2157-y] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2009] [Accepted: 12/29/2009] [Indexed: 01/02/2023]
Abstract
The purpose of this study was to determine if recovery of neurologically impaired hand function following isolated motor cortex injury would occur without constraint of the non-impaired limb, and without daily forced use of the impaired limb. Nine monkeys (Macaca mulatta) received neurosurgical lesions of various extents to arm representations of motor cortex in the hemisphere contralateral to the preferred hand. After the lesion, no physical constraints were placed on the ipsilesional arm/hand and motor testing was carried out weekly with a maximum of 40 attempts in two fine motor tasks that required use of the contralesional hand for successful food acquisition. These motor tests were the only "forced use" of the contralesional hand. We also tested regularly for spontaneous use of the contralesional hand in a fine motor task in which either hand could be used for successful performance. This minimal intervention was sufficient to induce recovery of the contralesional hand to such a functional level that eight of the monkeys chose to use that hand on some trials when either hand could be used. Percentage use of the contralesional hand (in the task when either hand could be used) varied considerably among monkeys and was not related to lesion volume or recovery of motor skill. These data demonstrate a remarkable capacity for recovery of spontaneous use of the impaired hand following localized frontal lobe lesions. Clinically, these observations underscore the importance of therapeutic intervention to inhibit the induction of the learned nonuse phenomenon after neurological injury.
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Affiliation(s)
- Warren G Darling
- Motor Performance Laboratory, Department of Integrative Physiology, The University of Iowa, Iowa City, IA 52242, USA.
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Volumetric effects of motor cortex injury on recovery of dexterous movements. Exp Neurol 2009; 220:90-108. [PMID: 19679127 DOI: 10.1016/j.expneurol.2009.07.034] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2009] [Revised: 07/27/2009] [Accepted: 07/28/2009] [Indexed: 11/23/2022]
Abstract
Due to the heterogeneous nature of most brain injuries, the contributions of gray and white matter involvement to motor deficits and recovery potential remain obscure. We tested the hypothesis that duration of hand motor impairment and recovery of skilled arm and hand motor function depends on the volume of gray and white matter damage of the frontal lobe. Lesions of the primary motor cortex (M1), M1 + lateral premotor cortex (LPMC), M1 + LPMC + supplementary motor cortex (M2) or multifocal lesions affecting motor areas and medial prefrontal cortex were evaluated in rhesus monkeys. Fine hand motor function was quantitatively assessed pre-lesion and for 3-12 months post-lesion using two motor tests. White and gray matter lesion volumes were determined using histological and quantitative methods. Regression analyses showed that duration of fine hand motor impairment was strongly correlated (R(2)>0.8) with the volume of gray and white matter lesions, with white matter lesion volume being the primary predictor of impairment duration. Level of recovery of fine hand motor skill was also well correlated (R(2)>0.5) with gray and white matter lesion volume. In some monkeys post-lesion skill exceeded pre-lesion skill in one or both motor tasks demonstrating that continued post-injury task practice can improve motor performance after localized loss of frontal motor cortex. These findings will assist in interpreting acute motor deficits, predicting the time course and expected level of functional recovery, and designing therapeutic strategies in patients with localized frontal lobe injury or neurosurgical resection.
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