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Boucher ML, Conley G, Morriss NJ, Ospina-Mora S, Qiu J, Mannix R, Meehan WP. Time-Dependent Long-Term Effect of Memantine following Repetitive Mild Traumatic Brain Injury. J Neurotrauma 2024. [PMID: 38666723 DOI: 10.1089/neu.2023.0423] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/16/2024] Open
Abstract
Repetitive mild traumatic brain injury (rmTBI, e.g., sports concussions) may be associated with both acute and chronic symptoms and neurological changes. Despite the common occurrence of these injuries, therapeutic strategies are limited. One potentially promising approach is N-methyl-D-aspartate receptor (NMDAR) blockade to alleviate the effects of post-injury glutamatergic excitotoxicity. Initial pre-clinical work using the NMDAR antagonist, memantine, suggests that immediate treatment following rmTBI improves a variety of acute outcomes. It remains unclear (1) whether acute memantine treatment has long-term benefits and (2) whether delayed treatment following rmTBI is beneficial, which are both clinically relevant concerns. To test this, animals were subjected to rmTBI via a weight drop model with rotational acceleration (five hits in 5 days) and randomized to memantine treatment immediately, 3 months, or 6 months post-injury, with a treatment duration of one month. Behavioral outcomes were assessed at 1, 4, and 7 months post-injury. Neuropathological outcomes were characterized at 7 months post-injury. We observed chronic changes in behavior (anxiety-like behavior, motor coordination, spatial learning, and memory), as well as neuroinflammation (microglia, astrocytes) and tau phosphorylation (T231). Memantine treatment, either immediately or 6 months post-injury, appears to confer greater rescue of neuroinflammatory changes (microglia) than vehicle or treatment at the 3-month time point. Although memantine is already being prescribed chronically to address persistent symptoms associated with rmTBI, this study represents the first evidence of which we are aware to suggest a small but durable effect of memantine treatment in mild, concussive injuries. This effect suggests that memantine, although potentially beneficial, is insufficient to treat all aspects of rmTBI alone and should be combined with other therapeutic agents in a multi-therapy approach, with attention given to the timing of treatment.
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Affiliation(s)
- Masen L Boucher
- Division of Emergency Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
| | | | - Nicholas J Morriss
- University of Rochester School of Medicine and Dentistry, University of Rochester Medical Center, Rochester, New York, USA
| | | | - Jianhua Qiu
- Division of Emergency Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
| | - Rebekah Mannix
- Division of Emergency Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
| | - William P Meehan
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
- Division of Sports Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
- The Micheli Center for Sports Injury Prevention, Waltham, Massachusetts, USA
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Orbach G, Melendes EJ, Warren K, Qiu J, Meehan WP, Mannix R, Guilhaume-Correa F. Visual Impairment in Pre-Clinical Models of Mild Traumatic Brain Injury. J Neurotrauma 2024. [PMID: 38497739 DOI: 10.1089/neu.2023.0574] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/19/2024] Open
Abstract
Impairment in visual function is common after traumatic brain injury (TBI) in the clinical setting, a phenomenon that translates to pre-clinical animal models as well. In Morris et al. (2021), we reported histological changes following weight-drop-induced TBI in a rodent model including retinal ganglion cell (RGC) loss, decreased electroretinogram (ERG) evoked potential, optic nerve diameter reduction, induced inflammation and gliosis, and loss of myelin accompanied by markedly impaired visual acuity. In this review, we will describe several pre-clinical TBI models that result in injuries to the visual system, indicating that visual function may be impaired following brain injury induced by a number of different injury modalities. This underscores the importance of understanding the role of the visual system and the potential detrimental sequelae to this sensory modality post-TBI. Given that most commonly employed behavioral tests such as the Elevated Plus Maze and Morris Water Maze rely on an intact visual system, interpretation of functional deficits in diffuse models may be confounded by off- target effects on the visual system.
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Affiliation(s)
- Gabriella Orbach
- Tufts University School of Medicine, Boston, Massachusetts, USA
- Division of Emergency Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Eva J Melendes
- Division of Emergency Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Kaitlyn Warren
- Division of Emergency Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Jianhua Qiu
- Division of Emergency Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
| | - William P Meehan
- Division of Sports Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
- The Micheli Center for Sports Injury Prevention, Waltham, Massachusetts, USA
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
| | - Rebekah Mannix
- Division of Emergency Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
| | - Fernanda Guilhaume-Correa
- Division of Emergency Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
- Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
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3
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Borucki DM, Rohrer B, Tomlinson S. Complement propagates visual system pathology following traumatic brain injury. J Neuroinflammation 2024; 21:98. [PMID: 38632569 PMCID: PMC11022420 DOI: 10.1186/s12974-024-03098-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2024] [Accepted: 04/10/2024] [Indexed: 04/19/2024] Open
Abstract
BACKGROUND Traumatic brain injury (TBI) is associated with the development of visual system disorders. Visual deficits can present with delay and worsen over time, and may be associated with an ongoing neuroinflammatory response that is known to occur after TBI. Complement system activation is strongly associated with the neuroinflammatory response after TBI, but whether it contributes to vision loss after TBI is unexplored. METHODS Acute and chronic neuroinflammatory changes within the dorsal lateral geniculate nucleus (dLGN) and retina were investigated subsequent to a moderate to severe murine unilateral controlled cortical impact. Neuroinflammatory and histopathological outcomes were interpreted in the context of behavioral and visual function data. To investigate the role of complement, cohorts were treated after TBI with the complement inhibitor, CR2-Crry. RESULTS At 3 days after TBI, complement component C3 was deposited on retinogeniculate synapses in the dLGN both ipsilateral and contralateral to the lesion, which was reduced in CR2-Crry treated animals. This was associated with microglia morphological changes in both the ipsilateral and contralateral dLGN, with a less ramified phenotype in vehicle compared to CR2-Crry treated animals. Microglia in vehicle treated animals also had a greater internalized VGlut2 + synaptic volume after TBI compared to CR2-Crry treated animals. Microglia morphological changes seen acutely persisted for at least 49 days after injury. Complement inhibition also reduced microglial synaptic internalization in the contralateral dLGN and increased the association between VGLUT2 and PSD95 puncta, indicating preservation of intact synapses. Unexpectedly, there were no changes in the thickness of the inner retina, retinal nerve fiber layer or retinal ganglion layer. Neuropathological changes in the dLGN were accompanied by reduced visual acuity at subacute and chronic time points after TBI, with improvement seen in CR2-Crry treated animals. CONCLUSION TBI induces complement activation within the dLGN and promotes microglial activation and synaptic internalization. Complement inhibition after TBI in a clinically relevant paradigm reduces complement activation, maintains a more surveillance-like microglia phenotype, and preserves synaptic density within the dLGN. Together, the data indicate that complement plays a key role in the development of visual deficits after TBI via complement-dependent microglial phagocytosis of synapses within the dLGN.
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Affiliation(s)
- Davis M Borucki
- Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, SC, USA
- Department of Neuroscience, Medical University of South Carolina, Charleston, SC, USA
| | - Baerbel Rohrer
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC, USA.
- Ralph Johnson VA Medical Center, Charleston, SC, USA.
| | - Stephen Tomlinson
- Department of Microbiology and Immunology, Medical University of South Carolina, Charleston, SC, USA.
- Ralph Johnson VA Medical Center, Charleston, SC, USA.
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Lyons HS, Sassani M, Hyder Y, Mitchell JL, Thaller M, Mollan SP, Sinclair AJ, Blanch RJ. A systematic review of optical coherence tomography findings in adults with mild traumatic brain injury. Eye (Lond) 2024; 38:1077-1083. [PMID: 38238577 PMCID: PMC11009235 DOI: 10.1038/s41433-023-02845-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2023] [Revised: 10/20/2023] [Accepted: 11/13/2023] [Indexed: 03/21/2024] Open
Abstract
Mild traumatic brain injury (mTBI) is common with many patients suffering disabling long-term sequelae, with visual symptoms frequently reported. There are no objective biomarkers of mTBI that are routinely used in clinical practice. Optical coherence tomography (OCT) has been used in mTBI research, as it enables visualisation of the neuroretina, allowing measurement of the retinal nerve fibre layer and ganglion cell layer. This systematic review aims to appraise the available literature and assess whether there are significant changes within the retinal nerve fibre layer and ganglion cell layer in subjects after mTBI. A systematic review was carried out in accordance with PRISMA guidelines and registered with PROSPERO (Number: CRD42022360498). Four databases were searched for relevant literature published from inception until 1 September 2022. Abstracts and full texts were screened by three independent reviewers. Initial screening of databases yielded 341 publications, of these, three fulfilled all the criteria for inclusion. All three studies showed thinning of the retinal nerve fibre layer, whereas there were no significant changes in the ganglion cell layer. This systematic review demonstrated that thinning of the retinal nerve fibre layer (but not of the ganglion cell layer) is associated with mTBI. It provides preliminary evidence for the use of the retinal nerve fibre layer as a potential biomarker of damage to the visual system in mTBI. Further prospective longitudinal studies ensuring uniform diagnosis and accurate phenotyping of mTBI are needed to understand the effects on the visual system and potential of OCT as a prognostic biomarker.
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Affiliation(s)
- Hannah S Lyons
- Translational Brain Science, Institute of Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
- Department of Neurology, University Hospitals Birmingham NHS Foundation Trust, Queen Elizabeth Hospital, Birmingham, B15 2WB, UK
| | - Matilde Sassani
- Translational Brain Science, Institute of Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
- Department of Neurology, University Hospitals Birmingham NHS Foundation Trust, Queen Elizabeth Hospital, Birmingham, B15 2WB, UK
| | - Yousef Hyder
- Translational Brain Science, Institute of Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
- Department of Neurology, University Hospitals Birmingham NHS Foundation Trust, Queen Elizabeth Hospital, Birmingham, B15 2WB, UK
| | - James L Mitchell
- Translational Brain Science, Institute of Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
- Department of Neurology, University Hospitals Birmingham NHS Foundation Trust, Queen Elizabeth Hospital, Birmingham, B15 2WB, UK
- Academic Department of Medical Rehabilitation, Defence Medical Rehabilitation, Stanford Hall, Loughborough, UK
| | - Mark Thaller
- Translational Brain Science, Institute of Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
- Department of Neurology, University Hospitals Birmingham NHS Foundation Trust, Queen Elizabeth Hospital, Birmingham, B15 2WB, UK
| | - Susan P Mollan
- Translational Brain Science, Institute of Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
- Department of Ophthalmology, University Hospitals Birmingham NHS Foundation Trust, West Midlands, UK
| | - Alexandra J Sinclair
- Translational Brain Science, Institute of Metabolism and Systems Research, College of Medical and Dental Sciences, University of Birmingham, Birmingham, B15 2TT, UK
- Department of Neurology, University Hospitals Birmingham NHS Foundation Trust, Queen Elizabeth Hospital, Birmingham, B15 2WB, UK
| | - Richard J Blanch
- Department of Ophthalmology, University Hospitals Birmingham NHS Foundation Trust, West Midlands, UK.
- Royal Centre for Defence Medicine, Birmingham, UK.
- Neuroscience and Ophthalmology Research Group, Institute of Inflammation and Ageing, University of Birmingham, Birmingham, UK.
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Navarro VM, Boehme N, Wasserman EA, Harper MM. Enhanced attention in rats following blast-induced traumatic brain injury. Heliyon 2024; 10:e25661. [PMID: 38384534 PMCID: PMC10878867 DOI: 10.1016/j.heliyon.2024.e25661] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2023] [Revised: 01/30/2024] [Accepted: 01/31/2024] [Indexed: 02/23/2024] Open
Abstract
Purpose To evaluate visuo-cognitive sequelae following blast-induced traumatic brain injury in a rat model. Methods Rats were randomly assigned to one of four groups depending on the intensity/quantity of a blast received in a blast chamber: sham (no blast), low intensity (22 psi), medium intensity (26 psi), or three medium intensity blasts (26 psi × 3). After recovery, all subjects were given visual discrimination tasks of increasing complexity, until mastery. After behavioral training, visual function was assessed via spectral-domain optical coherence tomography and pattern electroretinogram, and the extent of retinal damage was quantified via immunohistochemistry of retinal ganglion cells. Results None of the measures assessing visual function revealed significant differences as a function of blast intensity/quantity. Behavioral training did not disclose short-term effects of blast in general motivation or the development of anticipatory responding. No differences in general learning ability and the number of perseverative errors were observed. However, behavioral training found effects of blast in attentional function; relative to controls, subjects that received blasts were faster in learning to attend to informative (over non-informative) cues in the most difficult visual discrimination task. Conclusion Blast exposure in rats resulted in increased attention following blast, with no appreciable deficits in visual function. These results are contrary to what is often reported for human clinical populations; as such, more research bridging methodological differences is necessary.
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Affiliation(s)
- Victor M. Navarro
- Cardiff University, Cardiff, Wales, United Kingdom
- The Iowa City Department of Veterans Affairs Medical Center, Center for the Prevention and Treatment of Visual Loss, Iowa City, IA, United States
| | - Nickolas Boehme
- The Iowa City Department of Veterans Affairs Medical Center, Center for the Prevention and Treatment of Visual Loss, Iowa City, IA, United States
- Department of Ophthalmology and Visual Sciences, The University of Iowa, Iowa City, IA, United States
| | - Edward A. Wasserman
- Department of Psychological and Brain Sciences, The University of Iowa, Iowa City, IA, United States
| | - Matthew M. Harper
- The Iowa City Department of Veterans Affairs Medical Center, Center for the Prevention and Treatment of Visual Loss, Iowa City, IA, United States
- Department of Ophthalmology and Visual Sciences, The University of Iowa, Iowa City, IA, United States
- Department of Biology, The University of Iowa, Iowa City, IA, United States
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Borucki D, Rohrer B, Tomlinson S. Complement propagates visual system pathology following traumatic brain injury. RESEARCH SQUARE 2024:rs.3.rs-3970621. [PMID: 38464312 PMCID: PMC10925413 DOI: 10.21203/rs.3.rs-3970621/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/12/2024]
Abstract
Background Traumatic brain injury (TBI) is associated with the development of visual system disorders. Visual deficits can present with delay and worsen over time, and may be associated with an ongoing neuroinflammatory response that is known to occur after TBI. Complement activation is strongly associated with the neuroinflammatory response after TBI, but whether it contributes to vision loss after TBI is unexplored. Methods Acute and chronic neuroinflammatory changes within the dorsal lateral geniculate nucleus (dLGN) and retina were investigated subsequent to murine controlled unilateral cortical impact. Neuroinflammatory and histopathological data were interpreted in the context of behavioral and visual function data. To investigate the role of complement, cohorts were treated after TBI with the complement inhibitor, CR2-Crry. Results At 3 days after TBI, complement C3 was deposited on retinogeniculate synapses in the dLGN both ipsilateral and contralateral to the lesion, which was reduced in CR2-Crry treated animals. This was associated with microglia morphological changes in both the ipsilateral and contralateral dLGN, with a more amoeboid phenotype in vehicle compared to CR2-Crry treated animals. Microglia in vehicle treated animals also had a greater internalized VGlut2+ synaptic volume after TBI compared to CR2-Crry treated animals. Microglia morphological changes seen acutely persisted for at least 49 days after injury. Complement inhibition also reduced microglial synaptic internalization in the contralateral dLGN and increased the association between VGLUT2 and PSD95 puncta, indicating preservation of intact synapses. Unexpectedly, there were no changes in the thickness of the inner retina, retinal nerve fiber layer or retinal ganglion layer. Pathologies were accompanied by reduced visual acuity at subacute and chronic time points after TBI, with improvement seen in CR2-Crry treated animals. Conclusion TBI induces complement activation within the dLGN and promotes microglial activation and synaptic internalization. Complement inhibition after TBI in a clinically relevant paradigm reduces complement activation, maintains a more surveillance-like microglia phenotype, and preserves synaptic density within the dLGN. Together, the data indicate that complement plays a key role in the development of visual deficits after TBI via complement-dependent microglial phagocytosis of synapses within the dLGN.
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Stern-Green EA, Klimo KR, Day E, Shelton ER, Robich ML, Jordan LA, Racine J, VanNasdale DA, McDaniel CE, Yuhas PT. Henle fiber layer thickening and deficits in objective retinal function in participants with a history of multiple traumatic brain injuries. Front Neurol 2024; 15:1330440. [PMID: 38379704 PMCID: PMC10876769 DOI: 10.3389/fneur.2024.1330440] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2023] [Accepted: 01/16/2024] [Indexed: 02/22/2024] Open
Abstract
Introduction This study tested whether multiple traumatic brain injuries (TBIs) alter the structure of the Henle fiber layer (HFL) and degrade cell-specific function in the retinas of human participants. Methods A cohort of case participants with multiple TBIs and a cohort of pair-matched control participants were prospectively recruited. Directional optical coherence tomography and scanning laser polarimetry measured HFL thickness and phase retardation, respectively. Full-field flash electroretinography (fERG) assessed retinal function under light-adapted (LA) 3.0, LA 30 Hz, dark-adapted (DA) 0.01, DA 3.0, and DA 10 conditions. Retinal imaging and fERG outcomes were averaged between both eyes, and paired t-tests or Wilcoxon signed-rank tests analyzed inter-cohort differences. Results Global HFL thickness was significantly (p = 0.02) greater in cases (8.4 ± 0.9 pixels) than in controls (7.7 ± 1.1 pixels). There was no statistically significant difference (p = 0.91) between the cohorts for global HFL phase retardation. For fERG, LA 3.0 a-wave amplitude was significantly reduced (p = 0.02) in cases (23.5 ± 4.2 μV) compared to controls (29.0 ± 8.0 μV). There were no other statistically significant fERG outcomes between the cohorts. Discussion In summary, the HFL thickens after multiple TBIs, but phase retardation remains unaltered in the macula. Multiple TBIs may also impair retinal function, indicated by a reduction in a-wave amplitude. These results support the potential of the retina as a site to detect TBI-associated pathology.
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Affiliation(s)
| | - Kelly R. Klimo
- College of Optometry, The Ohio State University, Columbus, OH, United States
| | - Elizabeth Day
- College of Optometry, The Ohio State University, Columbus, OH, United States
| | - Erica R. Shelton
- College of Optometry, The Ohio State University, Columbus, OH, United States
| | - Matthew L. Robich
- College of Optometry, The Ohio State University, Columbus, OH, United States
| | - Lisa A. Jordan
- College of Optometry, The Ohio State University, Columbus, OH, United States
| | - Julie Racine
- Department of Ophthalmology, Nationwide Children’s Hospital, Columbus, OH, United States
| | - Dean A. VanNasdale
- College of Optometry, The Ohio State University, Columbus, OH, United States
| | | | - Phillip T. Yuhas
- College of Optometry, The Ohio State University, Columbus, OH, United States
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Harper MM, Boehme NA, Dutca L, Navarro V. Increasing the number and intensity of shock tube generated blast waves leads to earlier retinal ganglion cell dysfunction and regional cell death. Exp Eye Res 2024; 239:109754. [PMID: 38113955 DOI: 10.1016/j.exer.2023.109754] [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: 07/25/2023] [Revised: 07/28/2023] [Accepted: 12/12/2023] [Indexed: 12/21/2023]
Abstract
The purpose of this study was to examine the effect of a blast exposure generated from a shock tube on retinal ganglion cell (RGC) function and structure. Mice were exposed to one of three blast conditions using a shock tube; a single blast wave of 20 PSI, a single blast wave of 30 PSI, or three blast waves of 30 PSI given on three consecutive days with a one-day inter-blast interval. The structure and function of the retina were analyzed using the pattern electroretinogram (PERG), the optomotor reflex (OMR), and optical coherence tomography (OCT). The in vivo parameters were examined at baseline, and then again 1-week, 4-weeks, and 16-weeks following blast exposure. The number of surviving RGCs was quantified at the end of the study. Analysis of mice receiving a 20 PSI injury showed decreased PERG and OMR responses 16-weeks post blast, without evidence of changed retinal thickness or RGC death. Mice subjected to a 30 PSI injury showed decreased PERG responses 4 weeks and 16 weeks after injury, without changes in the retinal thickness or RGC density. Mice subjected to 30 PSI X 3 blast exposures had PERG deficits 1-week and 4-weeks post exposure. There was also significant change in retinal thickness 1-week and 16-weeks post blast exposure. Mice receiving 30 PSI X 3 blast injuries had regional loss of RGCs in the central retina, but not in the mid-peripheral or peripheral retina. Overall, this study has shown that increasing the number of blast exposures and the intensity leads to earlier functional loss of RGCs. We have also shown regional RGC loss only when using the highest blast intensity and number of blast injuries.
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Affiliation(s)
- Matthew M Harper
- Department of Ophthalmology and Visual Sciences, The University of Iowa, Iowa City, IA, USA; Department of Biology, The University of Iowa, Iowa City, IA, USA; Veterans Administration Center for the Prevention and Treatment of Visual Loss, Iowa City VA Healthcare System, Iowa City, IA, USA.
| | - Nickolas A Boehme
- Veterans Administration Center for the Prevention and Treatment of Visual Loss, Iowa City VA Healthcare System, Iowa City, IA, USA
| | - Laura Dutca
- Veterans Administration Center for the Prevention and Treatment of Visual Loss, Iowa City VA Healthcare System, Iowa City, IA, USA
| | - Victor Navarro
- Veterans Administration Center for the Prevention and Treatment of Visual Loss, Iowa City VA Healthcare System, Iowa City, IA, USA
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Yang HC, Lavadi RS, Sauerbeck AD, Wallendorf M, Kummer TT, Song SK, Lin TH. Diffusion basis spectrum imaging detects subclinical traumatic optic neuropathy in a closed-head impact mouse model of traumatic brain injury. Front Neurol 2023; 14:1269817. [PMID: 38152638 PMCID: PMC10752006 DOI: 10.3389/fneur.2023.1269817] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2023] [Accepted: 10/12/2023] [Indexed: 12/29/2023] Open
Abstract
Introduction Traumatic optic neuropathy (TON) is the optic nerve injury secondary to brain trauma leading to visual impairment and vision loss. Current clinical visual function assessments often fail to detect TON due to slow disease progression and clinically silent lesions resulting in potentially delayed or missed treatment in patients with traumatic brain injury (TBI). Methods Diffusion basis spectrum imaging (DBSI) is a novel imaging modality that can potentially fill this diagnostic gap. Twenty-two, 16-week-old, male mice were equally divided into a sham or TBI (induced by moderate Closed-Head Impact Model of Engineered Rotational Acceleration device) group. Briefly, mice were anesthetized with isoflurane (5% for 2.5 min followed by 2.5% maintenance during injury induction), had a helmet placed over the head, and were placed in a holder prior to a 2.1-joule impact. Serial visual acuity (VA) assessments, using the Virtual Optometry System, and DBSI scans were performed in both groups of mice. Immunohistochemistry (IHC) and histological analysis of optic nerves was also performed after in vivo MRI. Results VA of the TBI mice showed unilateral or bilateral impairment. DBSI of the optic nerves exhibited bilateral involvement. IHC results of the optic nerves revealed axonal loss, myelin injury, axonal injury, and increased cellularity in the optic nerves of the TBI mice. Increased DBSI axon volume, decreased DBSI λ||, and elevated DBSI restricted fraction correlated with decreased SMI-312, decreased SMI-31, and increased DAPI density, respectively, suggesting that DBSI can detect coexisting pathologies in the optic nerves of TBI mice. Conclusion DBSI provides an imaging modality capable of detecting subclinical changes of indirect TON in TBI mice.
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Affiliation(s)
- Hsin-Chieh Yang
- Department of Radiology, Washington University School of Medicine, St. Louis, MO, United States
| | - Raj Swaroop Lavadi
- Department of Radiology, Washington University School of Medicine, St. Louis, MO, United States
| | - Andrew D. Sauerbeck
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, United States
- Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, United States
| | - Michael Wallendorf
- Department of Biostatistics, Washington University School of Medicine, St. Louis, MO, United States
| | - Terrance T. Kummer
- Department of Neurology, Washington University School of Medicine, St. Louis, MO, United States
- Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, United States
- VA Medical Center, St. Louis, MO, United States
| | - Sheng-Kwei Song
- Department of Radiology, Washington University School of Medicine, St. Louis, MO, United States
- Hope Center for Neurological Disorders, Washington University School of Medicine, St. Louis, MO, United States
| | - Tsen-Hsuan Lin
- Department of Radiology, Washington University School of Medicine, St. Louis, MO, United States
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Zhao X, Zeng W, Xu H, Sun Z, Hu Y, Peng B, McBride JD, Duan J, Deng J, Zhang B, Kim SJ, Zoll B, Saito T, Sasaguri H, Saido TC, Ballatore C, Yao H, Wang Z, Trojanowski JQ, Brunden KR, Lee VMY, He Z. A microtubule stabilizer ameliorates protein pathogenesis and neurodegeneration in mouse models of repetitive traumatic brain injury. Sci Transl Med 2023; 15:eabo6889. [PMID: 37703352 PMCID: PMC10787216 DOI: 10.1126/scitranslmed.abo6889] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2022] [Accepted: 08/24/2023] [Indexed: 09/15/2023]
Abstract
Tau pathogenesis is a hallmark of many neurodegenerative diseases, including Alzheimer's disease (AD). Although the events leading to initial tau misfolding and subsequent tau spreading in patient brains are largely unknown, traumatic brain injury (TBI) may be a risk factor for tau-mediated neurodegeneration. Using a repetitive TBI (rTBI) paradigm, we report that rTBI induced somatic accumulation of phosphorylated and misfolded tau, as well as neurodegeneration across multiple brain areas in 7-month-old tau transgenic PS19 mice but not wild-type (WT) mice. rTBI accelerated somatic tau pathology in younger PS19 mice and WT mice only after inoculation with tau preformed fibrils and AD brain-derived pathological tau (AD-tau), respectively, suggesting that tau seeds are needed for rTBI-induced somatic tau pathology. rTBI further disrupted axonal microtubules and induced punctate tau and TAR DNA binding protein 43 (TDP-43) pathology in the optic tracts of WT mice. These changes in the optic tract were associated with a decline of visual function. Treatment with a brain-penetrant microtubule-stabilizing molecule reduced rTBI-induced tau, TDP-43 pathogenesis, and neurodegeneration in the optic tract as well as visual dysfunction. Treatment with the microtubule stabilizer also alleviated rTBI-induced tau pathology in the cortices of AD-tau-inoculated WT mice. These results indicate that rTBI facilitates abnormal microtubule organization, pathological tau formation, and neurodegeneration and suggest microtubule stabilization as a potential therapeutic avenue for TBI-induced neurodegeneration.
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Affiliation(s)
- Xinyi Zhao
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Wen Zeng
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Hong Xu
- Department of Pathology and Laboratory Medicine, Institute on Aging and Center for Neurodegenerative Disease Research, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - Zihan Sun
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Yingxin Hu
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - Beibei Peng
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
| | - Jennifer D McBride
- Department of Pathology and Laboratory Medicine, Institute on Aging and Center for Neurodegenerative Disease Research, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - Jiangtao Duan
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
| | - Juan Deng
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
| | - Bin Zhang
- Department of Pathology and Laboratory Medicine, Institute on Aging and Center for Neurodegenerative Disease Research, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - Soo-Jung Kim
- Department of Pathology and Laboratory Medicine, Institute on Aging and Center for Neurodegenerative Disease Research, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - Bryan Zoll
- Department of Pathology and Laboratory Medicine, Institute on Aging and Center for Neurodegenerative Disease Research, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - Takashi Saito
- Laboratory of Proteolytic Neuroscience, RIKEN Center for Brain Science, Wako, Saitama 351-0198, Japan
- Department of Neurocognitive Science, Institute of Brain Science, Nagoya City University Graduate School of Medical Science, Nagoya, Aichi 467-8601, Japan
| | - Hiroki Sasaguri
- Laboratory of Proteolytic Neuroscience, RIKEN Center for Brain Science, Wako, Saitama 351-0198, Japan
| | - Takaomi C Saido
- Laboratory of Proteolytic Neuroscience, RIKEN Center for Brain Science, Wako, Saitama 351-0198, Japan
| | - Carlo Ballatore
- Skaggs School of Pharmacy and Pharmaceutical Sciences, University of California, San Diego, La Jolla, CA 92093, USA
| | - Haishan Yao
- Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
| | - Zhaoyin Wang
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
| | - John Q Trojanowski
- Department of Pathology and Laboratory Medicine, Institute on Aging and Center for Neurodegenerative Disease Research, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - Kurt R Brunden
- Department of Pathology and Laboratory Medicine, Institute on Aging and Center for Neurodegenerative Disease Research, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - Virginia M-Y Lee
- Department of Pathology and Laboratory Medicine, Institute on Aging and Center for Neurodegenerative Disease Research, University of Pennsylvania School of Medicine, Philadelphia, PA 19104, USA
| | - Zhuohao He
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201210, China
- University of the Chinese Academy of Sciences, Beijing 100049, China
- Center for Excellence in Brain Science and Intelligence Technology, Chinese Academy of Sciences, Shanghai 200031, China
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11
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Moe MC, Özmert E, Baudouin C, Binadra A, Crafoord S, Jo Y, Kiratli H, Moore M, Pitsiladis YP, Rolle U, Tan B, Yanik Ö, Budgett R, Erdener U, Steffen K, Engbretsen L. International Olympic Committee (IOC) consensus paper on sports-related ophthalmology issues in elite sports. BMJ Open Sport Exerc Med 2023; 9:e001644. [PMID: 37485004 PMCID: PMC10357794 DOI: 10.1136/bmjsem-2023-001644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/26/2023] [Indexed: 07/25/2023] Open
Abstract
Vision plays an important role in an athletes' success. In sports, nearly 80% of perceptual input is visual, and eye health and sports medicine are closely intertwined fields of utmost importance to athletes. The physical nature of sports activities renders individuals more prone to various eye injuries than the general population. Ocular trauma can lead to lifelong sequelae, and impaired vision requires careful follow-up and management. Apart from injuries, athletes may also experience vision problems that can hamper their performance, including blurred vision, double vision, and light sensitivity. The interdisciplinary nature of sports medicine necessitates collaboration between sports medicine professionals and ophthalmologists. Through such collaborations, athletes can receive appropriate eye care, education on proper eye protection and guidance on adopting good eye health practices. If any inconspicuous symptoms are not detected and treated promptly, athletes may acquire systemic injuries because of defective vision, preventing them from achieving high level athletic performance in competitions. The protection of the elite athlete is the responsibility of all of us in sports medicine. To advance a more unified, evidence-informed approach to ophthalmic health assessment and management in athletes and as relevant for sports medicine physicians, the International Olympic Committee Consensus Group aims for a critical evaluation of the current state of the science and practice of ophthalmologic issues and illness in high-level sports, and present recommendations for a unified approach to this important issue.
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Affiliation(s)
- Morten Carstens Moe
- Department of Ophthalmology, Oslo University Hospital Ullevaal, Oslo, Norway
| | - Emin Özmert
- Ophthalmology, Ankara University Faculty of Medicine, Ankara, Türkiye
- Department of Ophthalmology, Vehbi Koç Eye Hospital, Ankara, Türkiye
| | - Christophe Baudouin
- Department of Ophthalmology, Quinze-Vingts National Ophthalmology Hospital & Vision Institute, Paris, France
| | - Abhinav Binadra
- Medical & Scientific, International Olympic Committee, Lausanne, Switzerland
| | - Sven Crafoord
- Faculty of Medicine and Health, Department of Ophthalmology, Örebro University Hospital, Orebro, Sweden
| | - Young Jo
- Department of Ophthalmology, Chungnam National University Hospital, Daejeon, South Korea
| | - Hayyam Kiratli
- Department of Ophthalmology, Hacettepe University School of Medicine, Ankara, Türkiye
| | - Melita Moore
- Physical Medicine and Rehabilitation, University of California Davis Medical Center, Sacramento, California, USA
| | - Yannis P Pitsiladis
- School of Sport and Health Sciences, University of Brighton, Eastbourne, UK
- International Federation of Sports Medicine (FIMS), Lausanne, Switzerland
| | - Udo Rolle
- Department of Paediatric Surgery and Paediatric Urology, University Hospital Frankfurt, Goethe University Frankfurt, Frankfurt/M, Germany
| | - Ben Tan
- SingHealth Duke-NUS Sport & Exercise Medicine Centre, Singapore
| | - Özge Yanik
- Ophthalmology, Ankara University Faculty of Medicine, Ankara, Türkiye
- Department of Ophthalmology, Vehbi Koç Eye Hospital, Ankara, Türkiye
| | - Richard Budgett
- Medical & Scientific, International Olympic Committee, Lausanne, Switzerland
| | - Ugur Erdener
- Medical & Scientific, International Olympic Committee, Lausanne, Switzerland
- Department of Ophthalmology, Hacettepe University School of Medicine, Ankara, Türkiye
- World Archery, Lausanne, Switzerland
| | - Kathrin Steffen
- Oslo Sports Trauma Center, Institute of Sports Medicine, Norwegian School of Sport Sciences, Oslo, Norway
| | - Lars Engbretsen
- Medical & Scientific, International Olympic Committee, Lausanne, Switzerland
- Oslo Sports Trauma Center, Institute of Sports Medicine, Norwegian School of Sport Sciences, Oslo, Norway
- Division of Orthopaedic Surgery, University of Oslo Faculty of Medicine, Oslo, Norway
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12
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McCartan R, Gratkowski A, Browning M, Hahn-Townsend C, Ferguson S, Morin A, Bachmeier C, Pearson A, Brown L, Mullan M, Crawford F, Tzekov R, Mouzon B. Human amnionic progenitor cell secretome mitigates the consequence of traumatic optic neuropathy in a mouse model. Mol Ther Methods Clin Dev 2023; 29:303-318. [PMID: 37359418 PMCID: PMC10285248 DOI: 10.1016/j.omtm.2023.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2023] [Accepted: 04/12/2023] [Indexed: 06/28/2023]
Abstract
Traumatic optic neuropathy (TON) is a condition in which acute injury to the optic nerve from direct or indirect trauma results in vision loss. The most common cause of TON is indirect injury to the optic nerve caused by concussive forces that are transmitted to the optic nerve. TON occurs in up to 5% of closed-head trauma patients and there is currently no known effective treatment. One potential treatment option for TON is ST266, a cell-free biological solution containing the secretome of amnion-derived multipotent progenitor (AMP) cells. We investigated the efficacy of intranasal ST266 in a mouse model of TON induced by blunt head trauma. Injured mice treated with a 10-day regimen of ST266 showed an improvement in spatial memory and learning, a significant preservation of retinal ganglion cells, and a decrease in neuropathological markers in the optic nerve, optic tract, and dorsal lateral geniculate nucleus. ST266 treatment effectively downregulated the NLRP3 inflammasome-mediated neuroinflammation pathway after blunt trauma. Overall, treatment with ST266 was shown to improve functional and pathological outcomes in a mouse model of TON, warranting future exploration of ST266 as a cell-free therapeutic candidate for testing in all optic neuropathies.
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Affiliation(s)
- Robyn McCartan
- Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, USA
- University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | | | | | | | - Scott Ferguson
- Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, USA
| | - Alexander Morin
- Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, USA
| | - Corbin Bachmeier
- Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, USA
- Bay Pines Veterans’ Hospital, Saint Petersburg, FL 33708, USA
| | - Andrew Pearson
- Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, USA
| | - Larry Brown
- Noveome Biotherapeutics, Inc., Pittsburgh, PA 15219, USA
| | - Michael Mullan
- Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, USA
| | - Fiona Crawford
- Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, USA
- James A. Haley Veterans’ Hospital, Tampa, FL 33612, USA
| | | | - Benoit Mouzon
- Roskamp Institute, 2040 Whitfield Avenue, Sarasota, FL 34243, USA
- James A. Haley Veterans’ Hospital, Tampa, FL 33612, USA
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13
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Hepschke JL, Laws E, Bin Saliman NH, Juncu S, Courtie E, Belli A, Blanch RJ. Modifications in Macular Perfusion and Neuronal Loss After Acute Traumatic Brain Injury. Invest Ophthalmol Vis Sci 2023; 64:35. [PMID: 37115535 PMCID: PMC10150830 DOI: 10.1167/iovs.64.4.35] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/29/2023] Open
Abstract
Purpose Traumatic brain injury (TBI) causes structural damage and functional impairment in the visual system, often with retinal ganglion cell (RGC) degeneration occurring without visual symptoms. RGC degeneration is associated with reduced retinal blood-flow, however, it is not known whether reductions in perfusion precede or are secondary to neurodegeneration. Methods We conducted a prospective observational single-center case series. Patients were included if they were admitted to the hospital after acute TBI and underwent ophthalmic clinical examination, including optical coherence tomography (OCT) and OCT angiography (OCTA) acutely and at follow-up. Ganglion cell layer thickness (GCL) thickness, vascular density in the superficial vascular plexus (SVP), and intermediate capillary plexus (ICP) were quantified. Results Twenty-one patients aged 20 to 65 years (mean = 38 years) including 16 men and 5 women were examined less than 14 days after moderate to severe TBI, and again after 2 to 6 months. Macular structure and perfusion were normal at baseline in all patients. Visual function was abnormal at baseline in three patients and subsequent neurodegeneration and loss of perfusion corresponded to baseline visual function abnormalities. Nine patients (43%) had reduced macular GCL thickness at follow up. Perfusion in the SVP strongly associated with local GCL thickness. The strongest association of the SVP metrics was the sum of vessel density (P < 0.0001). Conclusions In cases of reduced visual function after TBI, macular perfusion remained normal until reductions in GCL thickness occurred, indicating that perfusion changes were secondary to local GCL loss.
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Affiliation(s)
- Jenny L Hepschke
- Ophthalmology Department, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom
| | - Elinor Laws
- Ophthalmology Department, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom
- Neuroscience and Ophthalmology, Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
- NIHR Surgical Reconstruction and Microbiology Centre, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom
| | - Noor H Bin Saliman
- Centre for Optometry Studies, Faculty of Health Sciences, Universiti Teknologi MARA Cawangan Selangor, Bandar Puncak Alam Selangor, Malaysia
| | - Stefana Juncu
- Department of Psychology, University of Portsmouth, Portsmouth, United Kingdom
| | - Ella Courtie
- Ophthalmology Department, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom
- Neuroscience and Ophthalmology, Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
- NIHR Surgical Reconstruction and Microbiology Centre, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom
| | - Antonio Belli
- Neurosurgery Department, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom
| | - Richard J Blanch
- Ophthalmology Department, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom
- Neuroscience and Ophthalmology, Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, United Kingdom
- NIHR Surgical Reconstruction and Microbiology Centre, University Hospitals Birmingham NHS Foundation Trust, Birmingham, United Kingdom
- Academic Department of Military Surgery and Trauma, Royal Centre for Defence Medicine, Birmingham, United Kingdom
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14
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Harris G, Rickard JJS, Butt G, Kelleher L, Blanch RJ, Cooper J, Oppenheimer PG. Review: Emerging Eye-Based Diagnostic Technologies for Traumatic Brain Injury. IEEE Rev Biomed Eng 2023; 16:530-559. [PMID: 35320105 PMCID: PMC9888755 DOI: 10.1109/rbme.2022.3161352] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2021] [Revised: 02/11/2022] [Accepted: 03/15/2022] [Indexed: 11/06/2022]
Abstract
The study of ocular manifestations of neurodegenerative disorders, Oculomics, is a growing field of investigation for early diagnostics, enabling structural and chemical biomarkers to be monitored overtime to predict prognosis. Traumatic brain injury (TBI) triggers a cascade of events harmful to the brain, which can lead to neurodegeneration. TBI, termed the "silent epidemic" is becoming a leading cause of death and disability worldwide. There is currently no effective diagnostic tool for TBI, and yet, early-intervention is known to considerably shorten hospital stays, improve outcomes, fasten neurological recovery and lower mortality rates, highlighting the unmet need for techniques capable of rapid and accurate point-of-care diagnostics, implemented in the earliest stages. This review focuses on the latest advances in the main neuropathophysiological responses and the achievements and shortfalls of TBI diagnostic methods. Validated and emerging TBI-indicative biomarkers are outlined and linked to ocular neuro-disorders. Methods detecting structural and chemical ocular responses to TBI are categorised along with prospective chemical and physical sensing techniques. Particular attention is drawn to the potential of Raman spectroscopy as a non-invasive sensing of neurological molecular signatures in the ocular projections of the brain, laying the platform for the first tangible path towards alternative point-of-care diagnostic technologies for TBI.
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Affiliation(s)
- Georgia Harris
- School of Chemical Engineering, Advanced Nanomaterials Structures and Applications Laboratories, College of Engineering and Physical SciencesUniversity of BirminghamB15 2TTBirminghamU.K.
| | - Jonathan James Stanley Rickard
- School of Chemical Engineering, Advanced Nanomaterials Structures and Applications Laboratories, College of Engineering and Physical SciencesUniversity of BirminghamB15 2TTBirminghamU.K.
- Department of Physics, Cavendish LaboratoryUniversity of CambridgeCB3 0HECambridgeU.K.
| | - Gibran Butt
- Ophthalmology DepartmentUniversity Hospitals Birmingham NHS Foundation TrustB15 2THBirminghamU.K.
| | - Liam Kelleher
- School of Chemical Engineering, Advanced Nanomaterials Structures and Applications Laboratories, College of Engineering and Physical SciencesUniversity of BirminghamB15 2TTBirminghamU.K.
| | - Richard James Blanch
- Department of Military Surgery and TraumaRoyal Centre for Defence MedicineB15 2THBirminghamU.K.
- Neuroscience and Ophthalmology, Department of Ophthalmology, University Hospitals Birmingham NHS Foundation TrustcBirminghamU.K.
| | - Jonathan Cooper
- School of Biomedical EngineeringUniversity of GlasgowG12 8LTGlasgowU.K.
| | - Pola Goldberg Oppenheimer
- School of Chemical Engineering, Advanced Nanomaterials Structures and Applications Laboratories, College of Engineering and Physical SciencesUniversity of BirminghamB15 2TTBirminghamU.K.
- Healthcare Technologies Institute, Institute of Translational MedicineB15 2THBirminghamU.K.
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15
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Klimo KR, Stern-Green EA, Shelton E, Day E, Jordan L, Robich M, Racine J, McDaniel CE, VanNasdale DA, Yuhas PT. Structure and function of retinal ganglion cells in subjects with a history of repeated traumatic brain injury. Front Neurol 2022; 13:963587. [PMID: 36034275 PMCID: PMC9412167 DOI: 10.3389/fneur.2022.963587] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2022] [Accepted: 07/22/2022] [Indexed: 01/21/2023] Open
Abstract
This study tested whether repeated traumatic brain injuries (TBIs) alter the objective structure or the objective function of retinal ganglion cells (RGCs) in human subjects recruited from an optometry clinic. Case subjects (n = 25) with a history of repeated TBIs (4.12 ± 2.76 TBIs over 0-41 years) and healthy pair-matched control subjects (n = 30) were prospectively recruited. Retinal nerve fiber layer (RNFL) thickness was quantified with spectral-domain optical coherence tomography, and scanning laser polarimetry measured RNFL phase retardation. Measurements of the photopic negative response were made using full-field flash electroretinography. There was no statistically significant difference (p = 0.42) in global RNFL thickness between the case cohort (96.6 ± 9.4 microns) and the control cohort (94.9 ± 7.0 microns). There was no statistically significant difference (p = 0.80) in global RNFL phase retardation between the case cohort (57.9 ± 5.7 nm) and the control cohort (58.2 ± 4.6 nm). There were no statistically significant differences in the peak time (p = 0.95) of the PhNR or in the amplitude (p = 0.11) of the PhNR between the case cohort (69.9 ± 6.9 ms and 24.1 ± 5.1 μV, respectively) and the control cohort (70.1 ± 8.9 ms and 27.8 ± 9.1 μV, respectively). However, PhNR amplitude was more variable (p < 0.025) in the control cohort than in the case cohort. Within the case cohort, there was a strong positive (r = 0.53), but not statistically significant (p = 0.02), association between time since last TBI and PhNR amplitude. There was also a modest positive (r = 0.45), but not statistically significant (p = 0.04), association between time since first TBI and PhNR amplitude. Our results suggest that there were no statistically significant differences in the objective structure or in the objective function of RGCs between the case cohort and the control cohort. Future large, longitudinal studies will be necessary to confirm our negative results and to more fully investigate the potential interaction between PhNR amplitude and time since first or last TBI.
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Affiliation(s)
- Kelly R. Klimo
- College of Optometry, The Ohio State University, Columbus, OH, United States
| | | | - Erica Shelton
- College of Optometry, The Ohio State University, Columbus, OH, United States
| | - Elizabeth Day
- College of Optometry, The Ohio State University, Columbus, OH, United States
| | - Lisa Jordan
- College of Optometry, The Ohio State University, Columbus, OH, United States
| | - Matthew Robich
- College of Optometry, The Ohio State University, Columbus, OH, United States
| | - Julie Racine
- Department of Ophthalmology, Nationwide Children's Hospital, Columbus, OH, United States
| | | | - Dean A. VanNasdale
- College of Optometry, The Ohio State University, Columbus, OH, United States
| | - Phillip T. Yuhas
- College of Optometry, The Ohio State University, Columbus, OH, United States,*Correspondence: Phillip T. Yuhas
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16
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Qiu J, Boucher M, Conley G, Li Y, Zhang J, Morriss N, Meehan Iii WP, Mannix R. Traumatic Brain Injury-Related Optic Nerve Damage. J Neuropathol Exp Neurol 2022; 81:344-355. [PMID: 35363316 DOI: 10.1093/jnen/nlac018] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
Abstract
Vision disorders are associated with traumatic brain injury (TBI) in 20%-40% of clinical cases and involve a diverse set of potential symptoms that can present acutely or chronically. Due to its structure and position, the optic nerve is vulnerable to multiple forms of primary injury, which can result in traumatic optic neuropathy (TON). Multiple studies have shown that the optic tract may also be injured during TBI, though data regarding the temporospatial resolution of injury to the optic nerve are sparse. We evaluated the time course of optic nerve injury and visual impairments in our closed head impact acceleration mouse model of mild TBI (mTBI) designed to mimic repetitive injuries experienced in the context of sport. Our results show that inflammation and gliosis occur acutely in response to injury. Additionally, indications of optic nerve degeneration and functional loss of vision beginning at 1-month postinjury, and retinal ganglion cell loss at 7 months, revealed that the degeneration is continuous and permanent. Together, this study demonstrated that the optic nerve is vulnerable to damage during mTBI, which can cause TON and vision loss. These findings will be important for clinicians to consider to determine whether optic nerve is injured in the TBI patients with vision problems.
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Affiliation(s)
- Jianhua Qiu
- From the Division of Emergency Medicine, Boston Children's Hospital, Boston, Massachusetts, USA.,Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
| | - Masen Boucher
- From the Division of Emergency Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Grace Conley
- From the Division of Emergency Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Yue Li
- From the Division of Emergency Medicine, Boston Children's Hospital, Boston, Massachusetts, USA.,Department of Neurology, Tongji Hospital of Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei, China
| | - Jingdong Zhang
- From the Division of Emergency Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Nicholas Morriss
- From the Division of Emergency Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
| | - William P Meehan Iii
- From the Division of Emergency Medicine, Boston Children's Hospital, Boston, Massachusetts, USA.,Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA.,Division of Sports Medicine, Boston Children's Hospital, Boston, Massachusetts, USA.,The Micheli Center for Sports Injury Prevention, Waltham, Massachusetts, USA
| | - Rebekah Mannix
- From the Division of Emergency Medicine, Boston Children's Hospital, Boston, Massachusetts, USA.,Department of Pediatrics, Harvard Medical School, Boston, Massachusetts, USA
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17
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Brain trauma impacts retinal processing: photoreceptor pathway interactions in traumatic light sensitivity. Doc Ophthalmol 2022; 144:179-190. [PMID: 35445376 PMCID: PMC9192363 DOI: 10.1007/s10633-022-09871-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 03/12/2022] [Indexed: 11/21/2022]
Abstract
Background Concussion-induced light sensitivity, or traumatic photalgia, is a lifelong debilitating problem for upwards of 50% of mild traumatic brain injury (mTBI) cases, though of unknown etiology. We employed spectral analysis of electroretinographic (ERG) responses to assess retinal changes in mTBI as a function of the degree of photalgia. Methods The design was a case–control study of the changes in the ERG waveform as a function of level of light sensitivity in individuals who had suffered incidents of mild traumatic brain injury. The mTBI participants were categorized into non-, mild-, and severe-photalgic groups based on their spectral nociophysical settings. Light-adapted ERG responses were recorded from each eye for 200 ms on–off stimulation of three spectral colors (R:red, G:green, and B:blue) and their sum (W:white) at the highest pain-free intensity level for each participant. The requirement of controls for testing hypersensitive individuals at lower light levels was addressed by recording a full light intensity series in the control group. Results Both the b-wave and the photopic negative response (PhNR) were significantly reduced in the non-photalgic mTBI group relative to controls. In the photalgic groups, the main b-wave peak shifted to the timing of the rod b-wave, with reduced amplitude at the timing of the cone response. Conclusion These results suggest the interpretation that the primary etiology of the painful light sensitivity in mTBI is release of the rod pathway from cone-mediated inhibition at high light levels, causing overactivation of the rod pathway.
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18
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Kumar Das N, Das M. Structural changes in retina (Retinal nerve fiber layer) following mild traumatic brain injury and its association with development of visual field defects. Clin Neurol Neurosurg 2021; 212:107080. [PMID: 34883282 DOI: 10.1016/j.clineuro.2021.107080] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2021] [Revised: 09/26/2021] [Accepted: 11/21/2021] [Indexed: 11/25/2022]
Abstract
BACKGROUND Mild traumatic brain injury (mTBI)is the most common form of traumatic brain injury accounting for 70-80% of all brain injuries annually. There is increasing evidence that long lasting morphological and functional consequence can be present in visual system following mTBI. Among all the visual manifestation, awareness of Visual field defects is important because it may compromise the social, personal or professional life of any individual. Retinal structural changes such as thinning of Retinal nerve fiber layer (RFNL)captured using optical coherence tomography have emerged as a possible biomarker in many neurological diseases however very little is known in cases with mTBI OBJECTIVE: (I) To demonstrate the structural changes/morphological changes in retina if any following mTBI. (II) Whether the structural changes in retina have any association with the development of Visual field deficits leading to Visual function impairment following mTBI (III) Clinical relevance of structural changes in retina as a possible biomarker for visual function impairment due to visual field deficits. MATERIALS AND METHODS Our study included 60 patients with mTBI who fulfilled the inclusion criteria. All patients underwent a detailed ophthalmic evaluation with special focus on temporal recording of Retinal nerve layer thickness using SD- Optical Coherence Tomography and Visual field (Visual field Index) by Humphrey Automated Field Analyser. RESULTS 30% of eyes had significant thinning of RFNL (> 30% of the base line thickness) at 6 months following mTBI. Visual function impairment due to visual field deficits (VFI < 80%) at 6 months was seen in 40% of the eyes. The structural changes and visual function impairment peaked at 6 months' post injury. A strong Association was noted between RFNL thinning and manifestation of Visual field deficits (VFI < 80%) leading to visual function impairment (P < 0.001). The Correlation Co-efficient between thinning of RFNL and Visual field deficits had a positive correlation(p < 0.001). CONCLUSION This novel study has demonstrated that visual functional impairment due to Visual field deficits is a real possibility following mTBI. Monitoring of retinal parameter such as thinning of Retinal nerve fiber layer, using Optical coherence tomography, can be a biomarker for early detection or development of visual field defects in mTBI.
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Affiliation(s)
- Narendra Kumar Das
- Department of Neurosurgery, Kalinga Institute of Medical Sciences (KIMS), KIIT University, Patia, Bhubaneswar, Odisha, India.
| | - Matuli Das
- Department of Ophthalmology, Member-Medical Education Unit, Kalinga Institute of Medical Sciences (KIMS), KIIT University, Patia, Bhubaneswar, Odisha, India.
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19
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Honig MG, Del Mar NA, Henderson DL, O'Neal D, Doty JB, Cox R, Li C, Perry AM, Moore BM, Reiner A. Raloxifene Modulates Microglia and Rescues Visual Deficits and Pathology After Impact Traumatic Brain Injury. Front Neurosci 2021; 15:701317. [PMID: 34776838 PMCID: PMC8585747 DOI: 10.3389/fnins.2021.701317] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2021] [Accepted: 09/07/2021] [Indexed: 11/29/2022] Open
Abstract
Mild traumatic brain injury (TBI) involves widespread axonal injury and activation of microglia, which initiates secondary processes that worsen the TBI outcome. The upregulation of cannabinoid type-2 receptors (CB2) when microglia become activated allows CB2-binding drugs to selectively target microglia. CB2 inverse agonists modulate activated microglia by shifting them away from the harmful pro-inflammatory M1 state toward the helpful reparative M2 state and thus can stem secondary injury cascades. We previously found that treatment with the CB2 inverse agonist SMM-189 after mild TBI in mice produced by focal cranial blast rescues visual deficits and the optic nerve axon loss that would otherwise result. We have further shown that raloxifene, which is Food and Drug Administration (FDA)-approved as an estrogen receptor modulator to treat osteoporosis, but also possesses CB2 inverse agonism, yields similar benefit in this TBI model through its modulation of microglia. As many different traumatic events produce TBI in humans, it is widely acknowledged that diverse animal models must be used in evaluating possible therapies. Here we examine the consequences of TBI created by blunt impact to the mouse head for visual function and associated pathologies and assess raloxifene benefit. We found that mice subjected to impact TBI exhibited decreases in contrast sensitivity and the B-wave of the electroretinogram, increases in light aversion and resting pupil diameter, and optic nerve axon loss, which were rescued by daily injection of raloxifene at 5 or 10 mg/ml for 2 weeks. Raloxifene treatment was associated with reduced M1 activation and/or enhanced M2 activation in retina, optic nerve, and optic tract after impact TBI. Our results suggest that the higher raloxifene dose, in particular, may be therapeutic for the optic nerve by enhancing the phagocytosis of axonal debris that would otherwise promote inflammation, thereby salvaging less damaged axons. Our current work, together with our prior studies, shows that microglial activation drives secondary injury processes after both impact and cranial blast TBI and raloxifene mitigates microglial activation and visual system injury in both cases. The results thus provide a strong basis for phase 2 human clinical trials evaluating raloxifene as a TBI therapy.
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Affiliation(s)
- Marcia G Honig
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, United States
| | - Nobel A Del Mar
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, United States
| | - Desmond L Henderson
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, United States
| | - Dylan O'Neal
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, United States
| | - John B Doty
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, United States
| | - Rachel Cox
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, United States
| | - Chunyan Li
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, United States
| | - Aaron M Perry
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, United States
| | - Bob M Moore
- Department of Pharmaceutical Sciences, The University of Tennessee Health Science Center, Memphis, TN, United States
| | - Anton Reiner
- Department of Anatomy and Neurobiology, The University of Tennessee Health Science Center, Memphis, TN, United States.,Department of Ophthalmology, The University of Tennessee Health Science Center, Memphis, TN, United States
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20
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Morriss NJ, Conley GM, Hodgson N, Boucher M, Ospina-Mora S, Fagiolini M, Puder M, Mejia L, Qiu J, Meehan W, Mannix R. Visual Dysfunction after Repetitive Mild Traumatic Brain Injury in a Mouse Model and Ramifications on Behavioral Metrics. J Neurotrauma 2021; 38:2881-2895. [PMID: 34375128 PMCID: PMC10495212 DOI: 10.1089/neu.2021.0165] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Mild traumatic brain injury (mTBI) is a major cause of morbidity and mortality with a poorly understood pathophysiology. Animal models have been increasingly utilized to better understand mTBI and recent research has identified visual deficits in these models that correspond to human literature. While visual impairment is being further characterized within TBI, the implications of impaired vision on behavioral tasks commonly utilized in animal models has not been well described thus far. Visual deficits may well confound behavioral tests that are believed to be isolated to cognitive functioning such as learning and memory. We utilized a mouse model of repetitive mTBI (rmTBI) to further characterize visual deficits using an optomotor task, electroretinogram, and visually evoked potential, and located likely areas of damage to the visual pathway. Mice were tested on multiple behavioral metrics, including a touchscreen conditional learning task to better identify the contribution of visual dysfunction to behavioral alterations. We found that rmTBI caused visual dysfunction resulting from damage distal to the retina that likely involves pathology within the optic nerve. Moreover, loss of vision led to poorer performance of rmTBI animals on classic behavioral tests such as the Morris water maze that would otherwise be attributed solely to learning and memory deficits. The touchscreen conditional learning task was able to differentiate rmTBI induced learning and memory dysfunction from visual impairment and is a valuable tool for elucidating subtle changes resulting from TBI.
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Affiliation(s)
- Nicholas J. Morriss
- Division of Emergency Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Grace M. Conley
- Division of Emergency Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Nathaniel Hodgson
- Department of Neurology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Masen Boucher
- Division of Emergency Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Sara Ospina-Mora
- Division of Emergency Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Michaela Fagiolini
- Department of Neurology, Boston Children's Hospital, Boston, Massachusetts, USA
- Harvard Medical School, Boston, Massachusetts, USA
| | - Mark Puder
- Harvard Medical School, Boston, Massachusetts, USA
- Department of Surgery, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Leo Mejia
- Department of Neurology, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Jianhua Qiu
- Division of Emergency Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
- Harvard Medical School, Boston, Massachusetts, USA
| | - William Meehan
- Harvard Medical School, Boston, Massachusetts, USA
- The Micheli Center for Sports Injury Prevention, Boston, Massachusetts, USA
- Sports Concussion Clinic, Boston Children's Hospital, Boston, Massachusetts, USA
| | - Rebekah Mannix
- Division of Emergency Medicine, Boston Children's Hospital, Boston, Massachusetts, USA
- Harvard Medical School, Boston, Massachusetts, USA
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21
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Thomas CN, Bernardo-Colón A, Courtie E, Essex G, Rex TS, Blanch RJ, Ahmed Z. Effects of intravitreal injection of siRNA against caspase-2 on retinal and optic nerve degeneration in air blast induced ocular trauma. Sci Rep 2021; 11:16839. [PMID: 34413361 PMCID: PMC8377143 DOI: 10.1038/s41598-021-96107-y] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Accepted: 08/05/2021] [Indexed: 11/11/2022] Open
Abstract
Ocular repeated air blast injuries occur from low overpressure blast wave exposure, which are often repeated and in quick succession. We have shown that caspase-2 caused the death of retinal ganglion cells (RGC) after blunt ocular trauma. Here, we investigated if caspase-2 also mediates RGC apoptosis in a mouse model of air blast induced indirect traumatic optic neuropathy (b-ITON). C57BL/6 mice were exposed to repeated blasts of overpressure air (3 × 2 × 15 psi) and intravitreal injections of siRNA against caspase-2 (siCASP2) or against a control enhanced green fluorescent protein (siEGFP) at either 5 h after the first 2 × 15 psi ("post-blast") or 48 h before the first blast exposure ("pre-blast") and repeated every 7 days. RGC counts were unaffected by the b-ITON or intravitreal injections, despite increased degenerating ON axons, even in siCASP2 "post-blast" injection groups. Degenerating ON axons remained at sham levels after b-ITON and intravitreal siCASP2 "pre-blast" injections, but with less degenerating axons in siCASP2 compared to siEGFP-treated eyes. Intravitreal injections "post-blast" caused greater vitreous inflammation, potentiated by siCASP2, with less in "pre-blast" injected eyes, which was abrogated by siCASP2. We conclude that intravitreal injection timing after ocular trauma induced variable retinal and ON pathology, undermining our candidate neuroprotective therapy, siCASP2.
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Affiliation(s)
- Chloe N Thomas
- Neuroscience and Ophthalmology, Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
- School of Biomedical Sciences, Institute of Clinical Sciences, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | | | - Ella Courtie
- Neuroscience and Ophthalmology, Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
- Ophthalmology Department, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK
| | - Gareth Essex
- Neuroscience and Ophthalmology, Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK
| | - Tonia S Rex
- Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, TN, USA
- Department of Ophthalmology and Visual Sciences, Vanderbilt University School of Medicine, Nashville, TN, USA
| | - Richard J Blanch
- Neuroscience and Ophthalmology, Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK.
- Ophthalmology Department, University Hospitals Birmingham NHS Foundation Trust, Birmingham, UK.
- Academic Department of Military Surgery and Trauma, Royal Centre for Defence Medicine, Birmingham, UK.
- Centre for Trauma Sciences Research, University of Birmingham, Birmingham, B15 2TT, UK.
| | - Zubair Ahmed
- Neuroscience and Ophthalmology, Institute of Inflammation and Ageing, College of Medical and Dental Sciences, University of Birmingham, Birmingham, UK.
- Centre for Trauma Sciences Research, University of Birmingham, Birmingham, B15 2TT, UK.
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22
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Hussain SF, Raza Z, Cash ATG, Zampieri T, Mazzoli RA, Kardon RH, Gomes RSM. Traumatic brain injury and sight loss in military and veteran populations- a review. Mil Med Res 2021; 8:42. [PMID: 34315537 PMCID: PMC8317328 DOI: 10.1186/s40779-021-00334-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/15/2021] [Accepted: 06/23/2021] [Indexed: 01/14/2023] Open
Abstract
War and combat exposure pose great risks to the vision system. More recently, vision related deficiencies and impairments have become common with the increased use of powerful explosive devices and the subsequent rise in incidence of traumatic brain injury (TBI). Studies have looked at the effects of injury severity, aetiology of injury and the stage at which visual problems become apparent. There was little discrepancy found between the frequencies or types of visual dysfunctions across blast and non-blast related groups, however complete sight loss appeared to occur only in those who had a blast-related injury. Generally, the more severe the injury, the greater the likelihood of specific visual disturbances occurring, and a study found total sight loss to only occur in cases with greater severity. Diagnosis of mild TBI (mTBI) is challenging. Being able to identify a potential TBI via visual symptoms may offer a new avenue for diagnosis.
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Affiliation(s)
- Syeda F. Hussain
- Research & Innovation, Blind Veterans UK, 12-14 Harcourt Street, London, W1H 4HD UK
- Bravo Victor, Research, 12-14 Harcourt Street, London, W1H 4HD UK
| | - Zara Raza
- Research & Innovation, Blind Veterans UK, 12-14 Harcourt Street, London, W1H 4HD UK
- Bravo Victor, Research, 12-14 Harcourt Street, London, W1H 4HD UK
| | - Andrew T. G. Cash
- Research & Innovation, Blind Veterans UK, 12-14 Harcourt Street, London, W1H 4HD UK
- Bravo Victor, Research, 12-14 Harcourt Street, London, W1H 4HD UK
| | - Thomas Zampieri
- Blinded Veterans Association, 1101 King Street, Suite 300, Alexandria, Virginia 22314 USA
| | - Robert A. Mazzoli
- Department of Ophthalmology, Madigan Army Medical Center, 9040 Jackson Avenue, Tacoma, Washington, 98431 USA
| | - Randy H. Kardon
- Iowa City VA Health Care System and Iowa City VA Center for the Prevention and Treatment of Visual Loss, Iowa City, Iowa 52246 USA
- Department of Ophthalmology and Visual Sciences, The University of Iowa, Iowa City, Iowa 52242 USA
| | - Renata S. M. Gomes
- Research & Innovation, Blind Veterans UK, 12-14 Harcourt Street, London, W1H 4HD UK
- Bravo Victor, Research, 12-14 Harcourt Street, London, W1H 4HD UK
- Northern Hub for Veterans and Military Families Research, Department of Nursing, Midwifery and Health, Faculty of Health and Life Sciences, Northumbria University, Newcastle, NE7 7XA UK
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23
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Rajič Bumber J, Pilipović K, Janković T, Dolenec P, Gržeta N, Križ J, Župan G. Repetitive Traumatic Brain Injury Is Associated With TDP-43 Alterations, Neurodegeneration, and Glial Activation in Mice. J Neuropathol Exp Neurol 2021; 80:2-14. [PMID: 33212475 DOI: 10.1093/jnen/nlaa130] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Increasing evidence points to a relationship between repetitive mild traumatic brain injury (mTBI), the Tar DNA binding protein 43 (TDP-43) pathology and some neurodegenerative diseases, but the underlying pathophysiological mechanisms are still unknown. We examined TDP-43 regulation, neurodegeneration, and glial responses following repetitive mTBI in nontransgenic mice and in animals with overexpression of human mutant TDP-43 protein (TDP-43G348C). In the frontal cortices of the injured nontransgenic animals, early TDP-43 cytoplasmatic translocation and overexpression of the protein and its pathological forms were detected. In the injured animals of both genotypes, neurodegeneration and pronounced glial activity were detected in the optic tract. In TDP-43G348C mice, these changes were significantly higher at day 7 after the last mTBI compared with the values in the nontransgenic animals. Results of this study suggest that the changes in the TDP-43 regulation in the frontal cortices of the nontransgenic animals were a transient stress response to the brain injury. Repetitive mTBI did not produce additional TDP-43 dysregulation or neurodegeneration or pronounced gliosis in the frontal cortex of TDP-43G348C mice. Our research also suggests that overexpression of mutated human TDP-43 possibly predisposes the brain to more intense neurodegeneration and glial activation in the optic tract after repetitive mTBI.
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Affiliation(s)
- Jelena Rajič Bumber
- From the Department of Pharmacology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Kristina Pilipović
- From the Department of Pharmacology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Tamara Janković
- From the Department of Pharmacology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Petra Dolenec
- From the Department of Pharmacology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Nika Gržeta
- From the Department of Pharmacology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
| | - Jasna Križ
- Department of Psychiatry and Neuroscience, Faculty of Medicine, University of Laval, Quebec, QC, Canada
| | - Gordana Župan
- From the Department of Pharmacology, Faculty of Medicine, University of Rijeka, Rijeka, Croatia
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24
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Pilipović K, Rajič Bumber J, Dolenec P, Gržeta N, Janković T, Križ J, Župan G. Long-Term Effects of Repetitive Mild Traumatic Injury on the Visual System in Wild-Type and TDP-43 Transgenic Mice. Int J Mol Sci 2021; 22:ijms22126584. [PMID: 34205342 PMCID: PMC8235442 DOI: 10.3390/ijms22126584] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 06/11/2021] [Accepted: 06/17/2021] [Indexed: 01/29/2023] Open
Abstract
Little is known about the impairments and pathological changes in the visual system in mild brain trauma, especially repetitive mild traumatic brain injury (mTBI). The goal of this study was to examine and compare the effects of repeated head impacts on the neurodegeneration, axonal integrity, and glial activity in the optic tract (OT), as well as on neuronal preservation, glial responses, and synaptic organization in the lateral geniculate nucleus (LGN) and superior colliculus (SC), in wild-type mice and transgenic animals with overexpression of human TDP-43 mutant protein (TDP-43G348C) at 6 months after repeated closed head traumas. Animals were also assessed in the Barnes maze (BM) task. Neurodegeneration, axonal injury, and gliosis were detected in the OT of the injured animals of both genotypes. In the traumatized mice, myelination of surviving axons was mostly preserved, and the expression of neurofilament light chain was unaffected. Repetitive mTBI did not induce changes in the LGN and the SC, nor did it affect the performance of the BM task in the traumatized wild-type and TDP-43 transgenic mice. Differences in neuropathological and behavioral assessments between the injured wild-type and TDP-43G348C mice were not revealed. Results of the current study suggest that repetitive mTBI was associated with chronic damage and inflammation in the OT in wild-type and TDP-43G348C mice, which were not accompanied with behavioral problems and were not affected by the TDP-43 genotype, while the LGN and the SC remained preserved in the used experimental conditions.
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Affiliation(s)
- Kristina Pilipović
- Department of Basic and Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Rijeka, Braće Branchetta 20, 51 000 Rijeka, Croatia; (K.P.); (J.R.B.); (P.D.); (N.G.); (T.J.)
| | - Jelena Rajič Bumber
- Department of Basic and Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Rijeka, Braće Branchetta 20, 51 000 Rijeka, Croatia; (K.P.); (J.R.B.); (P.D.); (N.G.); (T.J.)
| | - Petra Dolenec
- Department of Basic and Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Rijeka, Braće Branchetta 20, 51 000 Rijeka, Croatia; (K.P.); (J.R.B.); (P.D.); (N.G.); (T.J.)
| | - Nika Gržeta
- Department of Basic and Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Rijeka, Braće Branchetta 20, 51 000 Rijeka, Croatia; (K.P.); (J.R.B.); (P.D.); (N.G.); (T.J.)
| | - Tamara Janković
- Department of Basic and Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Rijeka, Braće Branchetta 20, 51 000 Rijeka, Croatia; (K.P.); (J.R.B.); (P.D.); (N.G.); (T.J.)
| | - Jasna Križ
- Department of Psychiatry and Neuroscience, Faculty of Medicine, University Laval, Québec City, QC G1V 0A6, Canada;
| | - Gordana Župan
- Department of Basic and Clinical Pharmacology and Toxicology, Faculty of Medicine, University of Rijeka, Braće Branchetta 20, 51 000 Rijeka, Croatia; (K.P.); (J.R.B.); (P.D.); (N.G.); (T.J.)
- Correspondence:
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25
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Myers A, Ford J, Decker S, Crawford F, Tzekov R. Volumetric histological characterization of optic nerve degeneration using tissue clearing: literature review and practical study. J Histotechnol 2021; 44:206-216. [PMID: 34132156 DOI: 10.1080/01478885.2021.1938808] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
Tissue clearing technologies can greatly improve the depth and accuracy with which the three-dimensional structure of tissues, especially those of the nervous system, can be visualized. A review of the present literature suggests that the growing diversity and sophistication of various approaches have contributed to the expansion of this method to a greater variety of tissue types, experimental conditions, and imaging modalities. In the proof-of-concept study presented in this paper, a simplified and modified version of the tissue clearing method CUBIC (clear, unobstructed brain imaging cocktails and computational analysis) was used in conjunction with fluorescent staining and immunohistochemistry to illustrate the three-dimensional structure and molecular characteristics of inflammatory and degenerative activity in the mouse optic nerve. Based on the studies summarized in this mini-review, and our impression from using the mCUBIC method, it appears that tissue clearing could be a viable approach revealing three-dimensional histological features of myelin-rich tissues under normal conditions and after injury.
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Affiliation(s)
- April Myers
- Vision Research Program, The Roskamp Institute, Sarasota, FL, USA.,Department of Neurobiology, New College of Florida, Sarasota, FL, USA.,Vision Science Graduate Program, University of California Berkeley, Berkeley, CA, USA
| | - Jonathan Ford
- Department of Radiology, University of South Florida, Tampa, FL, USA
| | - Summer Decker
- Department of Radiology, University of South Florida, Tampa, FL, USA
| | - Fiona Crawford
- Vision Research Program, The Roskamp Institute, Sarasota, FL, USA.,James A. Haley Veterans' Administration Hospital, Tampa, FL, USA
| | - Radouil Tzekov
- Vision Research Program, The Roskamp Institute, Sarasota, FL, USA.,James A. Haley Veterans' Administration Hospital, Tampa, FL, USA.,Department of Ophthalmology, University of South Florida, Tampa, FL, USA
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26
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High-frequency head impact causes chronic synaptic adaptation and long-term cognitive impairment in mice. Nat Commun 2021; 12:2613. [PMID: 33972519 PMCID: PMC8110563 DOI: 10.1038/s41467-021-22744-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2020] [Accepted: 03/24/2021] [Indexed: 02/03/2023] Open
Abstract
Repeated head impact exposure can cause memory and behavioral impairments. Here, we report that exposure to non-damaging, but high frequency, head impacts can alter brain function in mice through synaptic adaptation. High frequency head impact mice develop chronic cognitive impairments in the absence of traditional brain trauma pathology, and transcriptomic profiling of mouse and human chronic traumatic encephalopathy brain reveal that synapses are strongly affected by head impact. Electrophysiological analysis shows that high frequency head impacts cause chronic modification of the AMPA/NMDA ratio in neurons that underlie the changes to cognition. To demonstrate that synaptic adaptation is caused by head impact-induced glutamate release, we pretreated mice with memantine prior to head impact. Memantine prevents the development of the key transcriptomic and electrophysiological signatures of high frequency head impact, and averts cognitive dysfunction. These data reveal synapses as a target of high frequency head impact in human and mouse brain, and that this physiological adaptation in response to head impact is sufficient to induce chronic cognitive impairment in mice.
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27
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Hetzer SM, Guilhaume-Correa F, Day D, Bedolla A, Evanson NK. Traumatic Optic Neuropathy Is Associated with Visual Impairment, Neurodegeneration, and Endoplasmic Reticulum Stress in Adolescent Mice. Cells 2021; 10:cells10050996. [PMID: 33922788 PMCID: PMC8146890 DOI: 10.3390/cells10050996] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 04/02/2021] [Accepted: 04/17/2021] [Indexed: 02/02/2023] Open
Abstract
Traumatic brain injury (TBI) results in a number of impairments, often including visual symptoms. In some cases, visual impairments after head trauma are mediated by traumatic injury to the optic nerve, termed traumatic optic neuropathy (TON), which has few effective options for treatment. Using a murine closed-head weight-drop model of head trauma, we previously reported in adult mice that there is relatively selective injury to the optic tract and thalamic/brainstem projections of the visual system. In the current study, we performed blunt head trauma on adolescent C57BL/6 mice and investigated visual impairment in the primary visual system, now including the retina and using behavioral and histologic methods at new time points. After injury, mice displayed evidence of decreased optomotor responses illustrated by decreased optokinetic nystagmus. There did not appear to be a significant change in circadian locomotor behavior patterns, although there was an overall decrease in locomotor behavior in mice with head injury. There was evidence of axonal degeneration of optic nerve fibers with associated retinal ganglion cell death. There was also evidence of astrogliosis and microgliosis in major central targets of optic nerve projections. Further, there was elevated expression of endoplasmic reticulum (ER) stress markers in retinas of injured mice. Visual impairment, histologic markers of gliosis and neurodegeneration, and elevated ER stress marker expression persisted for at least 30 days after injury. The current results extend our previous findings in adult mice into adolescent mice, provide direct evidence of retinal ganglion cell injury after head trauma and suggest that axonal degeneration is associated with elevated ER stress in this model of TON.
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Affiliation(s)
- Shelby M. Hetzer
- Neuroscience Graduate Program, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA; (S.M.H.); (D.D.); (A.B.)
| | - Fernanda Guilhaume-Correa
- Translational Biology, Medicine and Health, Virginia Polytechnic Institute and State University, Roanoke, VA 24016, USA;
| | - Dylan Day
- Neuroscience Graduate Program, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA; (S.M.H.); (D.D.); (A.B.)
| | - Alicia Bedolla
- Neuroscience Graduate Program, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA; (S.M.H.); (D.D.); (A.B.)
| | - Nathan K. Evanson
- Neuroscience Graduate Program, University of Cincinnati College of Medicine, Cincinnati, OH 45267, USA; (S.M.H.); (D.D.); (A.B.)
- Division of Pediatric Rehabilitation Medicine, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA
- Department of Pediatrics, University of Cincinnati, Cincinnati, OH 45229, USA
- Correspondence:
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28
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A 3-month-delayed treatment with anatabine improves chronic outcomes in two different models of repetitive mild traumatic brain injury in hTau mice. Sci Rep 2021; 11:7900. [PMID: 33846461 PMCID: PMC8041866 DOI: 10.1038/s41598-021-87161-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2020] [Accepted: 03/24/2021] [Indexed: 02/01/2023] Open
Abstract
To date, an overwhelming number of preclinical studies have addressed acute treatment in mild TBI (mTBI) and repetitive mTBI (r-mTBI), whereas, in humans, there often exists a significant time gap between the injury and the first medical intervention. Our study focused on a delayed treatment with anatabine, an anti-inflammatory compound, in hTau mice using two different models of r-mTBI. The rationale for using two models of the same impact but different frequencies (5 hit mTBI over 9 days and 24 hit mTBI over 90 days) was chosen to address the heterogeneity of r-mTBI in clinical population. Following the last injury in each model, three months elapsed before the initiation of treatment. Anatabine was administered in drinking water for 3 months thereafter. Our data demonstrated that a 3-month delayed treatment with anatabine mitigated astrogliosis in both TBI paradigms but improved cognitive functions only in more-frequently-injured mice (24 hit mTBI). We also found that anatabine decreased the phosphorylation of tau protein and NFκB, which were increased after r-mTBI in both models. The ability of anatabine to suppress these mechanisms suggests that delayed treatment can be effective for clinical population of r-mTBI. The discrepancy between the two models with regard to changes in cognitive performance suggests that r-mTBI heterogeneity may influence treatment efficiency and should be considered in therapeutic development.
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29
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Khan RS, Ross AG, Aravand P, Dine K, Selzer EB, Shindler KS. RGC and Vision Loss From Traumatic Optic Neuropathy Induced by Repetitive Closed Head Trauma Is Dependent on Timing and Force of Impact. Transl Vis Sci Technol 2021; 10:8. [PMID: 33505775 PMCID: PMC7794277 DOI: 10.1167/tvst.10.1.8] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Accepted: 12/09/2020] [Indexed: 12/24/2022] Open
Abstract
Purpose Traumatic optic neuropathy (TON) is often caused by blunt head trauma and has no currently effective treatment. Common animal models of TON induced by surgical crush injury are plagued by variability and do not mimic typical mechanisms of TON injury. Traumatic head impact models have recently shown evidence of TON, but the degree of head impact necessary to consistently induce TON is not well characterized, and it is examined here. Methods Traumatic skull impacts to C57BL/6J mice were induced using an electromagnetic controlled impact device. One impact performed at two depths (mild and severe), as well as three and five repetitive impacts with an interconcussion interval of 48 hours, were tested. Optokinetic responses (OKRs) and retinal ganglion cell (RGC) loss were measured. Results Five repetitive mild impacts significantly decreased OKR scores and RGC numbers compared with control mice 10 weeks after initial impact, with maximal pathology observed by 6 weeks and partial but significant loss present by 3 weeks. One severe impact induced similar TON. Three mild impacts also induced early OKR and RGC loss, but one mild impact did not. Equivalent degrees of TON were induced bilaterally, and a significant correlation was observed between OKR scores and RGC numbers. Conclusions Repetitive, mild closed head trauma in mice induces progressive RGC and vision loss that worsens with increasing impacts. Translational Relevance Results detail a reproducible model of TON that provides a reliable platform for studying potential treatments over a 3- to 6-week time course.
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Affiliation(s)
- Reas S Khan
- Department of Ophthalmology, F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA, USA
| | - Ahmara G Ross
- Department of Ophthalmology, F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA, USA.,Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA
| | - Puya Aravand
- Department of Ophthalmology, F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA, USA
| | - Kimberly Dine
- Department of Ophthalmology, F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA, USA
| | - Evan B Selzer
- Thomas Jefferson University School of Medicine, Philadelphia, PA, USA
| | - Kenneth S Shindler
- Department of Ophthalmology, F.M. Kirby Center for Molecular Ophthalmology, Scheie Eye Institute, University of Pennsylvania, Philadelphia, PA, USA.,Department of Neurology, University of Pennsylvania, Philadelphia, PA, USA
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30
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Gilmore CS, Lim KO, Garvin MK, Wang JK, Ledolter J, Fenske AL, Gentz CL, Nellis J, Armstrong MT, Kardon RH. Association of Optical Coherence Tomography With Longitudinal Neurodegeneration in Veterans With Chronic Mild Traumatic Brain Injury. JAMA Netw Open 2020; 3:e2030824. [PMID: 33351088 PMCID: PMC7756235 DOI: 10.1001/jamanetworkopen.2020.30824] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
IMPORTANCE Mild traumatic brain injury (TBI) may predispose individuals to progressive neurodegeneration. OBJECTIVE To identify evidence of neurodegeneration through longitudinal evaluation of changes in retinal layer thickness using optical coherence tomography in veterans with a history of mild TBI. DESIGN, SETTING, AND PARTICIPANTS This longitudinal cohort study evaluated veterans who were receiving services at the Minneapolis Veterans Affairs Health Care System. Symptomatic or mild TBI was diagnosed according to the Mayo TBI Severity Classification System. Participants in the age-matched control group had no history of TBI. Participants with any history or evidence of retinal or optic nerve disease that could affect retinal thickness were excluded. Data analysis was performed from July 2019 to February 2020. EXPOSURES The presence and severity of mild TBI were determined through consensus review of self-report responses during the Minnesota Blast Exposure Screening Tool semistructured interview. MAIN OUTCOMES AND MEASURES Change over time of retinal nerve fiber layer (RNFL) thickness. RESULTS A total of 139 veterans (117 men [84%]; mean [SD] age, 49.9 [11.1] years) were included in the study, 69 in the TBI group and 70 in the control group. Veterans with mild TBI showed significantly greater RNFL thinning compared with controls (mean [SE] RNFL slope, -1.47 [0.24] μm/y vs -0.31 [0.32] μm/y; F1,122 = 8.42; P = .004; Cohen d = 0.52). Functionally, veterans with mild TBI showed greater declines in visual field mean deviation (mean [SE] slope, -0.09 [0.14] dB/y vs 0.46 [0.23] dB/y; F1,122 = 4.08; P = .046; Cohen d = 0.36) and pattern standard deviation (mean [SE] slope, 0.09 [0.06] dB/y vs -0.10 [0.07] dB/y; F1,122 = 4.78; P = .03; Cohen d = 0.39) and high spatial frequency (12 cycles/degree) contrast sensitivity compared with controls. Cognitively, there was a significantly greater decrease in the number of errors over time during the Groton Maze Learning Test (GMLT) in controls compared with veterans with mild TBI (mean [SE] slope, -9.30 [1.48] errors/y vs -5.23 [1.24] errors/y; F1,127 = 4.43; P = .04; Cohen d = 0.37). RNFL tissue loss was significantly correlated with both worsening performance on the GMLT over time (Spearman ρ = -0.20; P = .03) and mild TBI severity (Spearman ρ = -0.25; P = .006). The more severe the mild TBI (larger Minnesota Blast Exposure Screening Tool severity score), the faster the reduction in RNFL thickness (ie, the more negative the slope) across time. CONCLUSIONS AND RELEVANCE This cohort study found longitudinal evidence for significant, progressive neural degeneration over time in veterans with mild TBI, as indicated by greater RNFL tissue loss in patients with mild TBI vs controls, as well as measures of function. These results suggest that these longitudinal measures may be useful biomarkers of neurodegeneration. Changes in this biomarker may provide early detection of subsequent cognitive and functional deficits that may impact veterans' independence and need for care.
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Affiliation(s)
- Casey S. Gilmore
- Minneapolis VA Healthcare System, Minneapolis, Minnesota
- Defense and Veterans Brain Injury Center, Minneapolis, Minnesota
| | - Kelvin O. Lim
- Minneapolis VA Healthcare System, Minneapolis, Minnesota
- Defense and Veterans Brain Injury Center, Minneapolis, Minnesota
- Department of Psychiatry, University of Minnesota, Minneapolis
| | - Mona K. Garvin
- Center for the Prevention and Treatment of Visual Loss, Iowa City VA Healthcare System, Iowa City, Iowa
- Department of Electrical and Computer Engineering, University of Iowa, Iowa City
| | - Jui-Kai Wang
- Center for the Prevention and Treatment of Visual Loss, Iowa City VA Healthcare System, Iowa City, Iowa
- Department of Electrical and Computer Engineering, University of Iowa, Iowa City
| | - Johannes Ledolter
- Department of Electrical and Computer Engineering, University of Iowa, Iowa City
- Department of Business Analytics and Department of Statistics and Actuarial Science, University of Iowa, Iowa City
| | - Alicia L. Fenske
- Minneapolis VA Healthcare System, Minneapolis, Minnesota
- Defense and Veterans Brain Injury Center, Minneapolis, Minnesota
| | - Carolyn L. Gentz
- Minneapolis VA Healthcare System, Minneapolis, Minnesota
- Defense and Veterans Brain Injury Center, Minneapolis, Minnesota
| | - Julie Nellis
- Center for the Prevention and Treatment of Visual Loss, Iowa City VA Healthcare System, Iowa City, Iowa
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City
| | - Michael T. Armstrong
- Minneapolis VA Healthcare System, Minneapolis, Minnesota
- Defense and Veterans Brain Injury Center, Minneapolis, Minnesota
| | - Randy H. Kardon
- Center for the Prevention and Treatment of Visual Loss, Iowa City VA Healthcare System, Iowa City, Iowa
- Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City
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Vu PA, McNamara EH, Liu J, Tucker LB, Fu AH, McCabe JT. Behavioral responses following repeated bilateral frontal region closed head impacts and fear conditioning in male and female mice. Brain Res 2020; 1750:147147. [PMID: 33091394 DOI: 10.1016/j.brainres.2020.147147] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2020] [Revised: 09/30/2020] [Accepted: 10/01/2020] [Indexed: 02/01/2023]
Abstract
The frontal lobes are among the most vulnerable sites in traumatic brain injuries. In the current study, a balanced 2 × 2 × 2 design (n = 18 mice/group), female and male C57Bl/6J mice received repeated bilateral frontal concussive brain injury (frCBI) and underwent fear conditioning (FC) to assess how injured mice respond to adverse conditions. Shocks received during FC impacted behavior on all subsequent tests except the tail suspension test. FC resulted in more freezing behavior in all mice that received foot shocks when evaluated in subsequent context and cue tests and induced hypoactivity in the open field (OF) and elevated zero maze (EZM). Mice that sustained frCBI learned the FC association between tone and shock. Injured mice froze less than sham controls during context and cue tests, which could indicate memory impairment, but could also suggest that frCBI resulted in hyperactivity that overrode the rodent's natural freezing response to threat, as injured mice were also more active in the OF and EZM. There were notable sex differences, where female mice exhibited more freezing behavior than male mice during FC context and cue tests. The findings suggest frCBI impaired, but did not eliminate, FC retention and resulted in an overall increase in general activity. The injury was characterized pathologically by increased inflammation (CD11b staining) in cortical regions underlying the injury site and in the optic tracts. The performance of male and female mice after injury suggested the complexity of possible sex differences for neuropsychiatric symptoms.
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Affiliation(s)
- Patricia A Vu
- Department of Anatomy, Physiology & Genetics, F.E. Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, United States; Graduate Program in Neuroscience, F.E. Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, United States
| | - Eileen H McNamara
- Department of Anatomy, Physiology & Genetics, F.E. Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, United States; Graduate Program in Neuroscience, F.E. Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, United States
| | - Jiong Liu
- Department of Anatomy, Physiology & Genetics, F.E. Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, United States
| | - Laura B Tucker
- Department of Anatomy, Physiology & Genetics, F.E. Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, United States; Pre-Clinical Studies Core, Center for Neuroscience and Regenerative Medicine, F.E. Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, United States
| | - Amanda H Fu
- Department of Anatomy, Physiology & Genetics, F.E. Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, United States; Pre-Clinical Studies Core, Center for Neuroscience and Regenerative Medicine, F.E. Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, United States
| | - Joseph T McCabe
- Department of Anatomy, Physiology & Genetics, F.E. Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, United States; Graduate Program in Neuroscience, F.E. Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, United States; Pre-Clinical Studies Core, Center for Neuroscience and Regenerative Medicine, F.E. Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, United States.
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Nilvadipine suppresses inflammation via inhibition of P-SYK and restores spatial memory deficits in a mouse model of repetitive mild TBI. Acta Neuropathol Commun 2020; 8:166. [PMID: 33076989 PMCID: PMC7574534 DOI: 10.1186/s40478-020-01045-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2020] [Accepted: 10/02/2020] [Indexed: 12/20/2022] Open
Abstract
Repeated exposure to mild TBI (mTBI) has been linked to an increased risk of Alzheimer’s disease (AD), chronic traumatic encephalopathy (CTE) and other neurodegenerative diseases. Some pathological features typically observed in AD have been found in postmortem brains of TBI and CTE, hence treatments tested for AD have a potential to be effective against r-mTBI outcomes. Neuroinflammation may present a possible answer due to its central role both in acute brain injury and in chronic degenerative-like disorders. Our previous studies have shown that drug nilvadipine, acting as an inhibitor of spleen tyrosine kinase (SYK), is effective at reducing inflammation, tau hyperphosphorylation and amyloid production in AD mouse models. To demonstrate the effect of nilvadipine in the absence of age-related variables, we introduced the same treatment to young r-mTBI mice. We further investigate therapeutic mechanisms of nilvadipine using its racemic properties. Both enantiomers, (+)-nilvadipine and (−)-nilvadipine, can lower SYK activity, whereas (+)-nilvadipine is also a potent L-type calcium channel blocker (CCB) and shown to be anti-hypertensive. All r-mTBI mice exhibited increased neuroinflammation and impaired cognitive performance and motor functions. Treatment with racemic nilvadipine mitigated the TBI-induced inflammatory response and significantly improved spatial memory, whereas (−)-enantiomer decreased microgliosis and improved spatial memory but failed to reduce the astroglial response to as much as the racemate. These results suggest the therapeutic potential of SYK inhibition that is enhanced when combined with the CCB effect, which indicate a therapeutic advantage of multi-action drugs for r-mTBI.
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33
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Silverstein SM, Demmin DL, Schallek JB, Fradkin SI. Measures of Retinal Structure and Function as Biomarkers in Neurology and Psychiatry. Biomark Neuropsychiatry 2020. [DOI: 10.1016/j.bionps.2020.100018] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
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34
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Kelman JC, Hodge C, Stanwell P, Mustafic N, Fraser CL. Retinal nerve fibre changes in sports-related repetitive traumatic brain injury. Clin Exp Ophthalmol 2020; 48:204-211. [PMID: 31691473 DOI: 10.1111/ceo.13673] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/26/2019] [Revised: 10/08/2019] [Accepted: 10/23/2019] [Indexed: 12/15/2022]
Abstract
IMPORTANCE There is limited literature on the use of optical coherence tomography in the assessment of retinal nerve fibre layer (RNFL) thickness in sports-related repetitive mild traumatic brain injury. BACKGROUND To evaluate RNFL thickness in professional rugby league players. RNFL thinning may serve as a proxy for wider white matter degeneration. DESIGN Cross-sectional observational study. PARTICIPANTS Thirteen retired Australian professional rugby league players were recruited. METHODS Participants underwent binocular optical coherence tomography to measure RNFL thickness. Each participant underwent a complete ophthalmic assessment to exclude concurrent disease. MAIN OUTCOME MEASURES RNFL thickness of each eye were compared with a normative database. RESULTS Participants had played professional Rugby League for 18 years on average and reported sustaining 15 sports-related concussions throughout their career. The RNFL in participants was four micrometres thinner than that of matched normative data. Cohort average RNFL thickness was reduced in 12 out of 14 optical coherence testing parameters. These findings were statistically significant in the left inferonasal [P = .013] and left nasal [P = .006] sectors. There was no statistically significant relationship between RNFL thickness and other visual measures. CONCLUSIONS AND RELEVANCE This study is the first to demonstrate RNFL thinning in a cohort of retired Australian professional Rugby League players. RNFL changes have been shown to correlate with cerebral white matter loss and neurodegeneration. Optical coherence tomography may serve as a safe and economical means of screening for repetitive traumatic brain injury related neurodegeneration in contact sport athletes.
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Affiliation(s)
- Julian C Kelman
- Save Sight Institute, Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia
| | - Christopher Hodge
- Save Sight Institute, Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia
- Graduate School of Health, University of Technology Sydney, Sydney, New South Wales, Australia
| | - Peter Stanwell
- Faculty of Health and Medicine, University of Newcastle, Newcastle, New South Wales, Australia
| | - Nina Mustafic
- Save Sight Institute, Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia
| | - Clare L Fraser
- Save Sight Institute, Faculty of Medicine and Health, University of Sydney, Sydney, New South Wales, Australia
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35
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Cheng H, Deaton LM, Qiu M, Ha S, Pacoma R, Lao J, Tolley V, Moran R, Keeton A, Lamb JR, Fathman J, Walker JR, Schumacher AM. Tau overexpression exacerbates neuropathology after repeated mild head impacts in male mice. Neurobiol Dis 2019; 134:104683. [PMID: 31765727 DOI: 10.1016/j.nbd.2019.104683] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 10/22/2019] [Accepted: 11/20/2019] [Indexed: 02/07/2023] Open
Abstract
Repeated mild traumatic brain injury (rmTBI) can lead to development of chronic traumatic encephalopathy (CTE), which is characterized by progressive neurodegeneration with presence of white matter damage, gliosis and hyper-phosphorylated tau. While animal models of rmTBI have been documented, few characterize the molecular pathogenesis and expression profiles of relevant injured brain regions. Additionally, while the usage of transgenic tau mice in rmTBI is prevalent, the effects of tau on pathological outcomes has not been well studied. Here we characterized a 42-impact closed-head rmTBI paradigm on 3-4 month old male C57BL/6 (WT) and Tau-overexpressing mice (Tau58.4). This injury paradigm resulted in chronic gliosis, T-cell infiltration, and demyelination of the optic nerve and associated white matter tracts at 1-month post-injury. At 3-months post-injury, Tau58.4 mice showed progressive neuroinflammation and neurodegeneration in multiple brain regions compared to WT mice. Corresponding to histopathology, RNAseq of the optic nerve tract at 1-month post-injury showed significant upregulation of inflammatory pathways and downregulation of myelin synthetic pathways in both genotypes. However, Tau58.4 mice showed additional changes in neurite development, protein processing, and cell stress. Comparisons with published transcriptomes of human Alzheimer's Disease and CTE revealed common signatures including neuroinflammation and downregulation of protein phosphatases. We next investigated the demyelination and T-cell infiltration phenotypes to determine whether these offer potential avenues for therapeutic intervention. Tau58.4 mice were treated with the histamine H3 receptor antagonist GSK239512 for 1-month post-injury to promote remyelination of white matter lesions. This restored myelin gene expression to sham levels but failed to repair the histopathologic lesions. Likewise, injured T-cell-deficient Rag2/Il2rg (R2G2) mice also showed evidence for inflammation and loss of myelin. However, unlike immune-competent mice, R2G2 mice had altered myeloid cell gene expression and fewer demyelinated lesions. Together this data shows that rmTBI leads to chronic white matter inflammatory demyelination and axonal loss exacerbated by human tau overexpression but suggests that immune-suppression and remyelination alone are insufficient to reverse damage.
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Affiliation(s)
- Hank Cheng
- Department of General Medical Biology, Genomics Institute for the Novartis Research Foundation, San Diego, CA 92121, USA.
| | - Lisa M Deaton
- Department of General Medical Biology, Genomics Institute for the Novartis Research Foundation, San Diego, CA 92121, USA.
| | - Minhua Qiu
- Department of General Medical Biology, Genomics Institute for the Novartis Research Foundation, San Diego, CA 92121, USA.
| | - Sukwon Ha
- Department of General Medical Biology, Genomics Institute for the Novartis Research Foundation, San Diego, CA 92121, USA.
| | - Reynand Pacoma
- Department of General Medical Biology, Genomics Institute for the Novartis Research Foundation, San Diego, CA 92121, USA.
| | - Jianmin Lao
- Department of General Medical Biology, Genomics Institute for the Novartis Research Foundation, San Diego, CA 92121, USA.
| | - Valerie Tolley
- Department of General Medical Biology, Genomics Institute for the Novartis Research Foundation, San Diego, CA 92121, USA.
| | - Rita Moran
- Department of General Medical Biology, Genomics Institute for the Novartis Research Foundation, San Diego, CA 92121, USA.
| | - Amber Keeton
- Department of General Medical Biology, Genomics Institute for the Novartis Research Foundation, San Diego, CA 92121, USA.
| | - John R Lamb
- Department of General Medical Biology, Genomics Institute for the Novartis Research Foundation, San Diego, CA 92121, USA
| | - John Fathman
- Department of General Medical Biology, Genomics Institute for the Novartis Research Foundation, San Diego, CA 92121, USA.
| | - John R Walker
- Department of General Medical Biology, Genomics Institute for the Novartis Research Foundation, San Diego, CA 92121, USA.
| | - Andrew M Schumacher
- Department of General Medical Biology, Genomics Institute for the Novartis Research Foundation, San Diego, CA 92121, USA.
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Godoy-Calderón MJ, González-Marcano E, Carballo J, Convit AF. Evaluation of a ConvitVax/anti-PD-1 combined immunotherapy for breast cancer treatment. Oncotarget 2019; 10:6546-6560. [PMID: 31762937 PMCID: PMC6859918 DOI: 10.18632/oncotarget.27283] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2019] [Accepted: 09/24/2019] [Indexed: 02/06/2023] Open
Abstract
Breast cancer therapies using checkpoints alone have not been highly effective. Based on previous experiences using the ConvitVax, an autologous tumor cells/bacillus Calmette-Guérin (BCG)/formalin-based vaccine, in breast cancer and the potential success of combined therapies, we sought to ascertain whether the ConvitVax combined with anti-PD-1 enhances the antitumor effect in a 4T1 breast cancer model. Animals received four weekly injections of either PBS (G1), ConvitVax (200 μg cell homogenate, 0.0625 mg BCG, 0.02% formalin) (G2), 50 μg anti-PD-1 (G3), or ConvitVax plus anti-PD-1 (200 μg cell homogenate, 0.0625 mg BCG, 0.02% formalin, 50 μg anti-PD-1) (G4). Five weeks post tumor induction all mice were euthanized, tumors extracted and evaluated pathologically and by immunohistochemistry. The combination group (G4) showed 10% more tumor necrosis, greater infiltration of PD-1+ cells and lower infiltration of TAMs, evidencing that the combination of ConvitVax and anti-PD-1 can improve the antitumor effect of the vaccine. Using a higher anti-PD-1 dose and administering each treatment at different times could further potentiate the effect of our therapy. Given the vaccine’s low cost and simple preparation, its use in combination with checkpoints or other target-specific compounds may lead to a highly effective personalized breast cancer immunotherapy.
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Affiliation(s)
- María José Godoy-Calderón
- Unidad Experimental de Inmunoterapia, Fundación Jacinto Convit, Caracas, Venezuela.,Jacinto Convit World Organization, Inc., Palo Alto, CA, USA
| | - Eglys González-Marcano
- Unidad Experimental de Inmunoterapia, Fundación Jacinto Convit, Caracas, Venezuela.,Jacinto Convit World Organization, Inc., Palo Alto, CA, USA
| | | | - Ana Federica Convit
- Unidad Experimental de Inmunoterapia, Fundación Jacinto Convit, Caracas, Venezuela.,Jacinto Convit World Organization, Inc., Palo Alto, CA, USA
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37
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Desai A, Chen H, Kim HY. Multiple Mild Traumatic Brain Injuries Lead to Visual Dysfunction in a Mouse Model. J Neurotrauma 2019; 37:286-294. [PMID: 31530220 DOI: 10.1089/neu.2019.6602] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023] Open
Abstract
Visual dysfunction is a common occurrence after traumatic brain injury (TBI). We investigated in this study effects of single or multiple mild TBI on visual function in mice using a closed head injury model that permits unconstrained head movement after impact. Adult mice were briefly anesthetized with isoflurane and given one or three mild TBI with the closed head injury by mechanically engineered rotational acceleration (CHIMERA) device with an interinjury interval of 24 h. Mice were then tested in the Morris water maze, visual cliff, and open field tests from day 19 to day 32 and for visual evoked potential at 5 weeks after the last injury and euthanized. Mice with multiple TBI showed impaired performance in the visible platform water maze test and had increased errors in the visual cliff test. Further, there was a graded difference in visual evoked potential, with the single injury mice showing modest reduction in N1 amplitude whereas the multiple injuries produced significant reduction compared to sham and single injury groups. The optic tract of the injured mice showed increases in glial cell immunostaining. The increase in glial fibrillary acid protein immunostaining reached statistical significance for both injured groups whereas the ionized calcium binding adaptor molecule 1 immunostaining was only significantly increased in the optic tract of repeatedly injured mice. These results indicate that multiple injuries using CHIMERA may result in visual deficits, which can affect certain behavioral performances. The change in vision may be a useful marker when monitoring repeated TBI outcome and screening for protective agents from TBI.
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Affiliation(s)
- Abhishek Desai
- Laboratory of Molecular Signaling, NIAAA, NIH, Rockville, Maryland
| | - Huazhen Chen
- Laboratory of Molecular Signaling, NIAAA, NIH, Rockville, Maryland.,Center for Neuroscience and Regenerative Medicine at the Uniformed Services University of Health Sciences, Bethesda, Maryland
| | - Hee-Yong Kim
- Laboratory of Molecular Signaling, NIAAA, NIH, Rockville, Maryland
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Das M, Tang X, Mohapatra SS, Mohapatra S. Vision impairment after traumatic brain injury: present knowledge and future directions. Rev Neurosci 2019; 30:305-315. [PMID: 30226209 DOI: 10.1515/revneuro-2018-0015] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 06/15/2018] [Indexed: 01/23/2023]
Abstract
Traumatic brain injury (TBI) is a major cause of mortality and morbidity in the USA as well as in the world. As a result of TBI, the visual system is also affected often causing complete or partial visual loss, which in turn affects the quality of life. It may also lead to ocular motor dysfunction, defective accommodation, and impaired visual perception. As a part of the therapeutic strategy, early rehabilitative optometric intervention is important. Orthoptic therapy, medication, stem cell therapy, motor and attention trainings are the available treatment options. Gene therapy is one of the most promising emerging strategies. Use of state-of-the-art nanomedicine approaches to deliver drug(s) and/or gene(s) might enhance the therapeutic efficacy of the present and future modalities. More research is needed in these fields to improve the outcome of this debilitating condition. This review focuses on different visual pathologies caused by TBI, advances in pre-clinical and clinical research, and available treatment options.
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Affiliation(s)
- Mahasweta Das
- James A. Haley Veterans Administration Hospital, Tampa, FL 33612, USA.,Department of Molecular Medicine, University of South Florida College of Medicine, Tampa, FL 33612, USA
| | - Xiaolan Tang
- James A. Haley Veterans Administration Hospital, Tampa, FL 33612, USA.,Department of Molecular Medicine, University of South Florida College of Medicine, Tampa, FL 33612, USA
| | - Shyam S Mohapatra
- James A. Haley Veterans Administration Hospital, Tampa, FL 33612, USA.,Department of Internal Medicine, University of South Florida College of Medicine, Tampa, FL 33612, USA
| | - Subhra Mohapatra
- James A. Haley Veterans Administration Hospital, Tampa, FL 33612, USA.,Department of Molecular Medicine, University of South Florida College of Medicine, Tampa, FL 33612, USA
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Mufti O, Mathew S, Harris A, Siesky B, Burgett KM, Verticchio Vercellin AC. Ocular changes in traumatic brain injury: A review. Eur J Ophthalmol 2019; 30:867-873. [PMID: 31378077 DOI: 10.1177/1120672119866974] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Traumatic brain injury is represented by a penetrating or non-penetrating head injury, which causes disruption in the normal functioning of the brain. Traumatic brain injury has been an ardently debated topic of discussion due to its prevalence in media centric persons such as military personnel and athletes. Current assessments for traumatic brain injury have looked at vestibulo-ocular and vascular parameters to aid in diagnosis. Innovations in non-invasive ophthalmic imaging have allowed for the visualization of specific tissue structure/function relationships in a variety of ophthalmic and neurodegenerative diseases. As the eye and brain share significant embryological and physiological pathways, ocular imaging modalities may provide a novel and impactful tool in advancing assessment of traumatic brain injury. Herein, we examined the available literature and data on visual fields, mean retinal nerve fiber layer thickness, retinal ganglion cell layer thickness, and cerebral blood flow following traumatic brain injury. This review of published individual and population-based studies was performed in order to explore the feasibility and importance of considering ocular imaging biomarkers following traumatic brain injury.
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Affiliation(s)
- Osama Mufti
- Department of Ophthalmology, Eugene and Marilyn Glick Eye Institute, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Sunu Mathew
- Department of Ophthalmology, Eugene and Marilyn Glick Eye Institute, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Alon Harris
- Department of Ophthalmology, Eugene and Marilyn Glick Eye Institute, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Brent Siesky
- Department of Ophthalmology, Eugene and Marilyn Glick Eye Institute, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Kendall M Burgett
- Department of Ophthalmology, Eugene and Marilyn Glick Eye Institute, Indiana University School of Medicine, Indianapolis, IN, USA
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Das M, Tang X, Han JY, Mayilsamy K, Foran E, Biswal MR, Tzekov R, Mohapatra SS, Mohapatra S. CCL20-CCR6 axis modulated traumatic brain injury-induced visual pathologies. J Neuroinflammation 2019; 16:115. [PMID: 31151410 PMCID: PMC6544928 DOI: 10.1186/s12974-019-1499-z] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2018] [Accepted: 05/06/2019] [Indexed: 12/16/2022] Open
Abstract
BACKGROUND Traumatic brain injury (TBI) is a major cause of death and disability in the USA and the world; it constitutes 30% of injury-related deaths (Taylor et al., MMWR Surveill Summ 66:1-16, 2017). Contact sports athletes often experience repetitive TBI (rTBI), which exerts a cumulative effect later in life. Visual impairment is a common after-effect of TBI. Previously, we have shown that C-C chemokine 20 (CCL20) plays a critical role in neurodegeneration and inflammation following TBI (Das et al., J Neuroinflammation 8:148, 2011). C-C chemokine receptor 6 (CCR6) is the only receptor that CCL20 interacts with. The objective of the present study was to investigate the role of CCL20-CCR6 axis in mediating rTBI-induced visual dysfunction (TVD). METHODS Wild type (WT) or CCR6 knock out (CCR6-/-) mice were subjected to closed head rTBI. Pioglitazone (PG) is a peroxisome proliferator-activated receptor γ (PPARγ) agonist which downregulates CCL20 production. Subsets of WT mice were treated with PG following final rTBI. A subset of mice was also treated with anti-CCL20 antibody to neutralize the CCL20 produced after rTBI. Histopathological assessments were performed to show cerebral pathologies, retinal pathologies, and inflammatory changes induced by rTBI. RESULTS rTBI induced cerebral neurodegeneration, retinal degeneration, microgliosis, astrogliosis, and CCL20 expression. CCR6-/- mice showed reduced retinal degeneration, microgliosis, and inflammation. Treatment with CCL20 neutralization antibody or PG showed reduced CCL20 expression along with reduced retinal degeneration and inflammation. rTBI-induced GFAP-positive glial activation in the optic nerve was not affected by knocking out CCR6. CONCLUSION The present data indicate that rTBI-induced retinal pathology is mediated at least in part by CCL20 in a CCR6-dependent manner.
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Affiliation(s)
- Mahasweta Das
- James A. Haley Veterans Hospital, Tampa, FL, USA.,Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Xiaolan Tang
- James A. Haley Veterans Hospital, Tampa, FL, USA.,Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Jung Yeon Han
- James A. Haley Veterans Hospital, Tampa, FL, USA.,Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Karthick Mayilsamy
- James A. Haley Veterans Hospital, Tampa, FL, USA.,Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Elspeth Foran
- James A. Haley Veterans Hospital, Tampa, FL, USA.,Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, USA
| | - Manas R Biswal
- Graduate Programs at College of Pharmacy, University of South Florida, Tampa, FL, USA
| | - Radouil Tzekov
- James A. Haley Veterans Hospital, Tampa, FL, USA.,Department of Ophthalmology, Morsani College of Medicine, University of South Florida, Tampa, FL, USA.,Graduate Programs at College of Pharmacy, University of South Florida, Tampa, FL, USA.,Department of Medical Engineering, University of South Florida, Tampa, FL, USA.,The Roskamp Institute, Sarasota, FL, USA
| | - Shyam S Mohapatra
- James A. Haley Veterans Hospital, Tampa, FL, USA.,Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, USA.,Graduate Programs at College of Pharmacy, University of South Florida, Tampa, FL, USA
| | - Subhra Mohapatra
- James A. Haley Veterans Hospital, Tampa, FL, USA. .,Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL, USA.
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Chan JW, Hills NK, Bakall B, Fernandez B. Indirect Traumatic Optic Neuropathy in Mild Chronic Traumatic Brain Injury. ACTA ACUST UNITED AC 2019; 60:2005-2011. [DOI: 10.1167/iovs.18-26094] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Affiliation(s)
- Jane W. Chan
- Department of Ophthalmology, University of Arizona College of Medicine, Phoenix, Arizona, United States
- Phoenix Veterans Affairs Health Care System, Phoenix, Arizona, United States
| | - Nancy K. Hills
- Department of Neurology, University of California, San Francisco, School of Medicine, San Francisco, California, United States
| | - Benjamin Bakall
- Department of Ophthalmology, University of Arizona College of Medicine, Phoenix, Arizona, United States
- Associated Retinal Consultants, Phoenix, Arizona, United States
| | - Brian Fernandez
- Heidelberg Engineering, Inc., Franklin, Massachusetts, United States
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Gupta R, Saha P, Sen T, Sen N. An augmentation in histone dimethylation at lysine nine residues elicits vision impairment following traumatic brain injury. Free Radic Biol Med 2019; 134:630-643. [PMID: 30790655 PMCID: PMC6588499 DOI: 10.1016/j.freeradbiomed.2019.02.015] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/20/2018] [Revised: 01/16/2019] [Accepted: 02/13/2019] [Indexed: 12/26/2022]
Abstract
Traumatic Brain Injury (TBI) affects more than 1.7 million Americans each year and about 30% of TBI-patients having visual impairments. The loss of retinal ganglion cells (RGC) in the retina and axonal degeneration in the optic nerve have been attributed to vision impairment following TBI; however, the molecular mechanism has not been elucidated. Here we have shown that an increase in histone di-methylation at lysine 9 residue (H3K9Me2), synthesized by the catalytic activity of a histone methyltransferase, G9a is responsible for RGC loss and axonal degeneration in the optic nerve following TBI. To elucidate the molecular mechanism, we found that an increase in H3K9Me2 results in the induction of oxidative stress both in the RGC and optic nerve by decreasing the mRNA level of antioxidants such as Superoxide dismutase (sod) and catalase through impairing the transcriptional activity of Nuclear factor E2-related factor 2 (Nrf2) via direct interaction. The induction of oxidative stress is associated with death in RGC and oligodendrocyte precursor cells (OPCs). The death in OPCs is correlated with a reduction in myelination, and the expression of myelin binding protein (MBP) in association with degeneration of neurofilaments in the optic nerve. This event allied to an impairment of the retrograde transport of axons and loss of nerve fiber layer in the optic nerve following TBI. An administration of G9a inhibitor, UNC0638 attenuates the induction of H3K9Me2 both in RGC and optic nerve and subsequently activates Nrf2 to reduce oxidative stress. This event was concomitant with the rescue in the loss of retinal thickness, attenuation in optic nerve degeneration and improvement in the retrograde transport of axons following TBI.
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Affiliation(s)
- Rajaneesh Gupta
- Department of Neurological Surgery, University of Pittsburgh, 200 Lothrop Street, Scaife Hall, Pittsburgh, 15213, USA
| | - Pampa Saha
- Department of Neurological Surgery, University of Pittsburgh, 200 Lothrop Street, Scaife Hall, Pittsburgh, 15213, USA
| | - Tanusree Sen
- Department of Neurological Surgery, University of Pittsburgh, 200 Lothrop Street, Scaife Hall, Pittsburgh, 15213, USA
| | - Nilkantha Sen
- Department of Neurological Surgery, University of Pittsburgh, 200 Lothrop Street, Scaife Hall, Pittsburgh, 15213, USA.
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43
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Vest V, Bernardo-Colón A, Watkins D, Kim B, Rex TS. Rapid Repeat Exposure to Subthreshold Trauma Causes Synergistic Axonal Damage and Functional Deficits in the Visual Pathway in a Mouse Model. J Neurotrauma 2019; 36:1646-1654. [PMID: 30451083 DOI: 10.1089/neu.2018.6046] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
We examined the effect of repeat exposure to a non-damaging insult on central nervous system axons using the optic projection as a model. The optic projection is attractive because its axons are spatially separated from the cell bodies, it is easily accessible, it is composed of long axons, and its function can be measured. We performed closed-system ocular neurotrauma in C57Bl/6 mice using bursts of 15 or 26-psi (pounds per square inch) overpressure air that caused no gross damage. We quantified the visual evoked potential (VEP) and total and degenerative axons in the optic nerve. Repeat exposure to a 15-psi air blast caused more axon damage and vision loss than a single exposure to a 26-psi air blast. However, an increased VEP latency was detected in both groups. Exposure to three 15-psi air blasts separated by 0.5 sec caused 15% axon degeneration at 2 weeks. In contrast, no axon degeneration above sham levels was detected when the interinjury interval was increased to 10 min. Exposure to 15-psi air blasts once a day for 6 consecutive days caused 3% axon degeneration. Therefore, repeat mild trauma within an interinjury interval of 1 min or less causes synergistic axon damage, whereas mild trauma repeated at a longer interinjury interval causes additive, cumulative damage. The synergistic damage may underlie the high incidence of traumatic brain injury and traumatic optic neuropathy in blast-injured service members given that explosive blasts are multiple injury events that occur in a very short time span. This study also supports the use of the VEP as a biomarker for traumatic optic neuropathy.
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Affiliation(s)
- Victoria Vest
- 1 Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, Tennessee
| | | | - Dexter Watkins
- 3 Department of Mechanical Engineering, Vanderbilt University, Nashville, Tennessee
| | - Bohan Kim
- 2 Department of Ophthalmology & Visual Sciences, Vanderbilt University School of Medicine, Nashville, Tennessee
| | - Tonia S Rex
- 1 Vanderbilt Eye Institute, Vanderbilt University Medical Center, Nashville, Tennessee.,2 Department of Ophthalmology & Visual Sciences, Vanderbilt University School of Medicine, Nashville, Tennessee
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Kornguth S, Rutledge N. Integration of Biomarkers Into a Signature Profile of Persistent Traumatic Brain Injury Involving Autoimmune Processes Following Water Hammer Injury From Repetitive Head Impacts. Biomark Insights 2018; 13:1177271918808216. [PMID: 30397383 PMCID: PMC6207974 DOI: 10.1177/1177271918808216] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2018] [Accepted: 09/28/2018] [Indexed: 01/07/2023] Open
Abstract
OBJECTIVES To assemble an algorithm that will describe a "Signature" predictive of an individual's vulnerability to persistent traumatic brain injury (TBI). SUBJECTS AND METHODS Studies of athletes and warriors who are subjected to repeated head impacts with rapid acceleration/deceleration forces are used to assist in the diagnosis and management of TBI-affected individuals. Data from multiple areas, including clinical, anatomical, magnetic resonance imaging, cognitive function, and biochemical analyses, are integrated to provide a Signature of persistent TBI. RESULTS Studies to date indicate that susceptibility to TBI results from an interaction between host genetic and structural vulnerability factors and force and torque of impact on the head and torso. The host factors include molecular markers affecting immune and inflammatory responses to stress/insult as well as anatomical features such as the degree of transcortical fiber projections and vascular malformations. The host response to forceful impact includes the release of intracellular neural proteins and nucleic acids into the cerebrospinal fluid and vascular compartment as well as mobilization of cytokines and macrophages into the central nervous system with subsequent activation of microglia and inflammatory responses including autoimmune processes. Maximum impact to the base of the sulci via a "water hammer effect" is consistent with the localization of microvascular and inflammatory responses in the affected brain region. CONCLUSIONS An assessment of an individuals' predisposition to persistent TBI with delayed cognitive deficits and behavioral changes requires an understanding of host vulnerability (genetic factors and brain structure) and external stressors (force and torque of impact as well as repetitive head injury and time interval between impacts). An algorithm that has utility in predicting vulnerability to TBI will include qualitative and quantitative measures of the host factors weighted against post impact markers of neural injury. Implementation of the resulting "Signature" of vulnerability at early stages of injury will help inform athletes and warriors, along with commanders and management, of the risk/benefit approaches that will markedly diminish health care costs to the nation and suffering to this population. This report attempts to define a strategy to create such an algorithm.
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Affiliation(s)
- Steven Kornguth
- Department of Kinesiology and Health Education, The University of Texas at Austin, Austin, TX, USA
- Department of Neurology, Dell Medical School, The University of Texas at Austin
| | - Neal Rutledge
- Department of Psychology, The University of Texas at Austin and Austin Radiological Association, Austin, TX, USA
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45
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Morin A, Mouzon B, Ferguson S, Paris D, Saltiel N, Lungmus C, Mullan M, Crawford F. Treatment With Nilvadipine Mitigates Inflammatory Pathology and Improves Spatial Memory in Aged hTau Mice After Repetitive Mild TBI. Front Aging Neurosci 2018; 10:292. [PMID: 30364309 PMCID: PMC6193195 DOI: 10.3389/fnagi.2018.00292] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2018] [Accepted: 09/04/2018] [Indexed: 12/14/2022] Open
Abstract
Mild traumatic brain injury (mTBI) is the most common form of brain trauma worldwide. The effects of mTBI are not well-studied within the elderly population, yet older adults constitute a significant portion of all mTBI patients. Few preclinical studies have focused on the effects of mTBI, or mTBI treatments, in the aged brain, and none have explored repetitive mTBI (r-mTBI). In this study, we have administered our well-characterized 5-injury model (5 r-mTBI) to hTau mice aged 24 months to explore the neurobehavioral and neuropathological outcomes, and the effects of treatment with the dihydropyridine, Nilvadipine. Our previous studies have shown that Nilvadipine inhibits spleen tyrosine kinase (Syk), is effective at reducing inflammation, tau hyperphosphorylation, and amyloid production, and it has recently been investigated in a European Phase III clinical trial for Alzheimer’s disease (AD). In our 24-month-old r-mTBI mice, we observed increased neuroinflammation and a trend toward impaired cognitive performance compared to sham controls. Treatment with Nilvadipine mitigated the TBI-induced inflammatory response in aged r-mTBI animals and significantly improved spatial memory. To our knowledge, this is the only preclinical study focusing on the treatment of r-mTBI in aged, and these results suggest a therapeutic potential of Nilvadipine for consequences of mTBI.
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Affiliation(s)
- Alexander Morin
- The Roskamp Institute, Sarasota, FL, United States.,The Open University, Milton-Keynes, United Kingdom.,James A Haley Veterans Administration, Tampa, FL, United States
| | - Benoit Mouzon
- The Roskamp Institute, Sarasota, FL, United States.,The Open University, Milton-Keynes, United Kingdom.,James A Haley Veterans Administration, Tampa, FL, United States
| | - Scott Ferguson
- The Roskamp Institute, Sarasota, FL, United States.,The Open University, Milton-Keynes, United Kingdom.,James A Haley Veterans Administration, Tampa, FL, United States
| | - Daniel Paris
- The Roskamp Institute, Sarasota, FL, United States.,The Open University, Milton-Keynes, United Kingdom.,James A Haley Veterans Administration, Tampa, FL, United States
| | - Nicole Saltiel
- The Roskamp Institute, Sarasota, FL, United States.,James A Haley Veterans Administration, Tampa, FL, United States
| | | | - Mike Mullan
- The Roskamp Institute, Sarasota, FL, United States.,The Open University, Milton-Keynes, United Kingdom
| | - Fiona Crawford
- The Roskamp Institute, Sarasota, FL, United States.,The Open University, Milton-Keynes, United Kingdom.,James A Haley Veterans Administration, Tampa, FL, United States
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46
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Adams C, Bazzigaluppi P, Beckett TL, Bishay J, Weisspapir I, Dorr A, Mester JR, Steinman J, Hirschler L, Warnking JM, Barbier EL, McLaurin J, Sled JG, Stefanovic B. Neurogliovascular dysfunction in a model of repeated traumatic brain injury. Am J Cancer Res 2018; 8:4824-4836. [PMID: 30279740 PMCID: PMC6160760 DOI: 10.7150/thno.24747] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2018] [Accepted: 08/02/2018] [Indexed: 12/13/2022] Open
Abstract
Traumatic brain injury (TBI) research has focused on moderate to severe injuries as their outcomes are significantly worse than those of a mild TBI (mTBI). However, recent epidemiological evidence has indicated that a series of even mild TBIs greatly increases the risk of neurodegenerative and psychiatric disorders. Neuropathological studies of repeated TBI have identified changes in neuronal ionic concentrations, axonal injury, and cytoskeletal damage as important determinants of later life neurological and mood compromise; yet, there is a paucity of data on the contribution of neurogliovascular dysfunction to the progression of repeated TBI and alterations of brain function in the intervening period. Methods: Here, we established a mouse model of repeated TBI induced via three electromagnetically actuated impacts delivered to the intact skull at three-day intervals and determined the long-term deficits in neurogliovascular functioning in Thy1-ChR2 mice. Two weeks post the third impact, cerebral blood flow and cerebrovascular reactivity were measured with arterial spin labelling magnetic resonance imaging. Neuronal function was investigated through bilateral intracranial electrophysiological responses to optogenetic photostimulation. Vascular density of the site of impacts was measured with in vivo two photon fluorescence microscopy. Pathological analysis of neuronal survival and astrogliosis was performed via NeuN and GFAP immunofluorescence. Results: Cerebral blood flow and cerebrovascular reactivity were decreased by 50±16% and 70±20%, respectively, in the TBI cohort relative to sham-treated animals. Concomitantly, electrophysiological recordings revealed a 97±1% attenuation in peri-contusional neuronal reactivity relative to sham. Peri-contusional vascular volume was increased by 33±2% relative to sham-treated mice. Pathological analysis of the peri-contusional cortex demonstrated astrogliosis, but no changes in neuronal survival. Conclusion: This work provides the first in-situ characterization of the long-term deficits of the neurogliovascular unit following repeated TBI. The findings will help guide the development of diagnostic markers as well as therapeutics targeting neurogliovascular dysfunction.
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47
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Abstract
Mild traumatic brain injury (mTBI) represents a significant public healthcare concern, accounting for the majority of all head injuries. While symptoms are generally transient, some patients go on to experience long-term cognitive impairments and additional mild impacts can result in exacerbated and persisting negative outcomes. To date, studies using a range of experimental models have reported chronic behavioral deficits in the presence of axonal injury and inflammation following repeated mTBI; assessments of oxidative stress and myelin pathology have thus far been limited. However, some models employed induced acute focal damage more suggestive of moderate–severe brain injury and are therefore not relevant to repeated mTBI. Given that the nature of mechanical loading in TBI is implicated in downstream pathophysiological changes, the mechanisms of damage and chronic consequences of single and repeated closed-head mTBI remain to be fully elucidated. This review covers literature on potential mechanisms of damage following repeated mTBI, integrating known mechanisms of pathology underlying moderate–severe TBIs, with recent studies on adult rodent models relevant to direct impact injuries rather than blast-induced damage. Pathology associated with excitotoxicity and cerebral blood flow-metabolism uncoupling, oxidative stress, cell death, blood-brain barrier dysfunction, astrocyte reactivity, microglial activation, diffuse axonal injury, and dysmyelination is discussed, followed by a summary of functional deficits and preclinical assessments of therapeutic strategies. Comprehensive characterization of the pathology underlying delayed and persisting deficits following repeated mTBI is likely to facilitate further development of therapeutic strategies to limit long-term sequelae.
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Affiliation(s)
- Brooke Fehily
- 1 Experimental and Regenerative Neurosciences, School of Biological sciences, The University of Western Australia, Perth, Western Australia, Australia
| | - Melinda Fitzgerald
- 1 Experimental and Regenerative Neurosciences, School of Biological sciences, The University of Western Australia, Perth, Western Australia, Australia.,2 Curtin Health Innovation Research Institute, Curtin University, Perth, Western Australia, Australia.,3 Perron Institute for Neurological and Translational Science, Sarich Neuroscience Research Institute, Nedlands, Western Australia, Australia
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48
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Evanson NK, Guilhaume-Correa F, Herman JP, Goodman MD. Optic tract injury after closed head traumatic brain injury in mice: A model of indirect traumatic optic neuropathy. PLoS One 2018; 13:e0197346. [PMID: 29746557 PMCID: PMC5944994 DOI: 10.1371/journal.pone.0197346] [Citation(s) in RCA: 42] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Accepted: 05/01/2018] [Indexed: 12/14/2022] Open
Abstract
Adult male C57BL/6J mice have previously been reported to have motor and memory deficits after experimental closed head traumatic brain injury (TBI), without associated gross pathologic damage or neuroimaging changes detectable by magnetic resonance imaging or diffusion tensor imaging protocols. The presence of neurologic deficits, however, suggests neural damage or dysfunction in these animals. Accordingly, we undertook a histologic analysis of mice after TBI. Gross pathology and histologic analysis using Nissl stain and NeuN immunohistochemistry demonstrated no obvious tissue damage or neuron loss. However, Luxol Fast Blue stain revealed myelin injury in the optic tract, while Fluoro Jade B and silver degeneration staining revealed evidence of axonal neurodegeneration in the optic tract as well as the lateral geniculate nucleus of the thalamus and superior colliculus (detectable at 7 days, but not 24 hours, after injury). Fluoro Jade B staining was not detectable in other white matter tracts, brain regions or in cell somata. In addition, there was increased GFAP staining in these optic tract, lateral geniculate, and superior colliculus 7 days post-injury, and morphologic changes in optic tract microglia that were detectable 24 hours after injury but were more prominent 7 days post-injury. Interestingly, there were no findings of degeneration or gliosis in the suprachiasmatic nucleus, which is also heavily innervated by the optic tract. Using micro-computed tomography imaging, we also found that the optic canal appears to decrease in diameter with a dorsal-ventral load on the skull, which suggests that the optic canal may be the site of injury. These results suggest that there is axonal degeneration in the optic tract and a subset of directly innervated areas, with associated neuroinflammation and astrocytosis, which develop within 7 days of injury, and also suggest that this weight drop injury may be a model for studying indirect traumatic optic neuropathy.
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Affiliation(s)
- Nathan K. Evanson
- Division of Pediatric Rehabilitation Medicine, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
- Department of Pediatrics, University of Cincinnati, Cincinnati, Ohio, United States of America
- * E-mail:
| | - Fernanda Guilhaume-Correa
- Division of Pediatric Rehabilitation Medicine, Cincinnati Children’s Hospital Medical Center, Cincinnati, Ohio, United States of America
| | - James P. Herman
- Department of Psychiatry and Behavioral Neuroscience, University of Cincinnati, Cincinnati, Ohio, United States of America
| | - Michael D. Goodman
- Department of Surgery, University of Cincinnati, Cincinnati, Ohio, United States of America
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49
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Autologous tumor cells/bacillus Calmette-Guérin/formalin-based novel breast cancer vaccine induces an immune antitumor response. Oncotarget 2018; 9:20222-20238. [PMID: 29755647 PMCID: PMC5945537 DOI: 10.18632/oncotarget.25044] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 03/22/2018] [Indexed: 12/20/2022] Open
Abstract
Autologous cancer cell vaccines represent a multivalent patient-specific treatment. Studies have demonstrated that these immunotherapies should be combined with immunomodulators to improve results. We tested in breast cancer the antitumor effects of a 200 µg autologous tumor cells homogenate combined with 0.0625 mg of bacillus Calmette-Guérin (BCG), and 0.02% formalin. We used a 4T1 murine model of BALB/c receiving four weekly injections of either this vaccine or control treatments. The control treatments were either Phosphate Buffer Saline, BCG treated with formalin, or the tumor cells homogenate plus BCG alone. We found that mice treated with the vaccine had the lowest tumor growth rate and mitosis percentage. The vaccinated group also showed a marked increase in infiltration of antitumor cells (natural killer, CD8+ T and CD4+ Th1 cells), as well as a decrease of myeloid-derived suppressor cells (MDSCs) and tumor-associated macrophages (TAMs). Additionally, we also observed a possible activation of the immune memory response as indicated by plasma cell tumor infiltration. Our results demonstrate that our proposed breast cancer vaccine induces a potent antitumor effect in 4T1 tumor-bearing mice. Its effectiveness, low cost and simple preparation method, makes it a promising treatment candidate for personalized breast cancer immunotherapy.
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50
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Tucker LB, Velosky AG, McCabe JT. Applications of the Morris water maze in translational traumatic brain injury research. Neurosci Biobehav Rev 2018; 88:187-200. [PMID: 29545166 DOI: 10.1016/j.neubiorev.2018.03.010] [Citation(s) in RCA: 102] [Impact Index Per Article: 17.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Revised: 03/09/2018] [Accepted: 03/09/2018] [Indexed: 12/21/2022]
Abstract
Acquired traumatic brain injury (TBI) is frequently accompanied by persistent cognitive symptoms, including executive function disruptions and memory deficits. The Morris Water Maze (MWM) is the most widely-employed laboratory behavioral test for assessing cognitive deficits in rodents after experimental TBI. Numerous protocols exist for performing the test, which has shown great robustness in detecting learning and memory deficits in rodents after infliction of TBI. We review applications of the MWM for the study of cognitive deficits following TBI in pre-clinical studies, describing multiple ways in which the test can be employed to examine specific aspects of learning and memory. Emphasis is placed on dependent measures that are available and important controls that must be considered in the context of TBI. Finally, caution is given regarding interpretation of deficits as being indicative of dysfunction of a single brain region (hippocampus), as experimental models of TBI most often result in more diffuse damage that disrupts multiple neural pathways and larger functional networks that participate in complex behaviors required in MWM performance.
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Affiliation(s)
- Laura B Tucker
- Department of Anatomy, Physiology & Genetics, F.E. Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, 20814, USA; Pre-Clinical Studies Core, Center for Neuroscience and Regenerative Medicine, F.E. Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301, Jones Bridge Road, Bethesda, MD, 20814, USA.
| | - Alexander G Velosky
- Department of Anatomy, Physiology & Genetics, F.E. Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, 20814, USA.
| | - Joseph T McCabe
- Department of Anatomy, Physiology & Genetics, F.E. Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301 Jones Bridge Road, Bethesda, MD, 20814, USA; Pre-Clinical Studies Core, Center for Neuroscience and Regenerative Medicine, F.E. Hébert School of Medicine, Uniformed Services University of the Health Sciences, 4301, Jones Bridge Road, Bethesda, MD, 20814, USA.
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