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Hetzer SM, O'Connell C, Lallo V, Robson M, Evanson NK. Model matters: Differential outcomes in traumatic optic neuropathy pathophysiology between blunt and blast-wave mediated head injuries. Exp Neurol 2024; 372:114613. [PMID: 37995952 PMCID: PMC10870099 DOI: 10.1016/j.expneurol.2023.114613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2023] [Revised: 11/07/2023] [Accepted: 11/15/2023] [Indexed: 11/25/2023]
Abstract
Over 3 million people in the United States live with long-term disability because of a traumatic brain injury (TBI). The purpose of this study was to characterize and compare two different animal models of TBI (blunt head trauma and blast TBI) to determine common and divergent characteristics of these models. With recent literature reviews noting the prevalence of visual system injury in animal models of TBI, coupled with clinical estimates of 50-75% of all TBI cases, we decided to assess commonalities, if they existed, through visual system injury. A unilateral (left directed) blast and repeat blast model injury with coup-contra-coup injury patterns were compared to a midline blunt injury. Injuries were induced in adult male mice to observe and quantify visual deficits. Retinal ganglion cell loss and axonal degeneration in the optic tract, superior colliculus, and lateral geniculate nuclei were examined to trace injury outcomes throughout major vision-associated areas. Optokinetic response, immunohistochemistry, and western blots were analyzed. Where a single blunt injury produces significant visual deficits a single blast injury appears to have less severe visual consequences. Visual deficits after repeat blasts are similar to a single blast. Single blast injury induces contralateral damage to the right optic chiasm and tract whereas bilateral injury follows a single blunt TBI. Repeat blast injuries are required to see degeneration patterns in downstream regions similar to the damage seen in a single blunt injury. This finding is further supported by amyloid precursor protein (APP) staining in injured cohorts. Blunt injured groups present with staining 1.2 mm ahead of the optic nerve, indicating axonal breakage closer to the optic chiasm. In blast groups, APP was identifiable in a bilateral pattern only in the geniculate nucleus. Evidence for unilateral neuronal degeneration in brain tissue with bilateral axonal ruptures are pivotal discoveries in this model differentiation. Analysis of the two injury models suggests that there is a significant difference in the histological outcomes dependent on injury type, though visual system injury is likely present in more cases than are currently diagnosed clinically.
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Affiliation(s)
- S M Hetzer
- Neuroscience Graduate Program, University of Cincinnati College of Medicine, United States of America.
| | - C O'Connell
- Division of Pharmaceutical Sciences, James L. Winkle College of Pharmacy, University of Cincinnati, United States of America
| | - V Lallo
- College of Arts and Sciences, University of Cincinnati, United States of America
| | - M Robson
- Division of Pharmaceutical Sciences, James L. Winkle College of Pharmacy, University of Cincinnati, United States of America
| | - N K Evanson
- Department of Pediatrics, University of Cincinnati College of Medicine, United States of America; Division of Pediatric Rehabilitation Medicine, Cincinnati Children's Hospital Medical Center, United States of America
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2
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Kallel Z, Maalej A, Fourati H, Khallouli A, Rannen R. Évaluation médicolégale des blasts oculaires chez le militaire actif. J Fr Ophtalmol 2022; 45:928-936. [DOI: 10.1016/j.jfo.2022.04.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/01/2022] [Revised: 04/19/2022] [Accepted: 04/21/2022] [Indexed: 10/17/2022]
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3
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Dhakal S, He L, Lyuboslavsky P, Sidhu C, Chrenek MA, Sellers JT, Boatright JH, Geisert EE, Setterholm NA, McDonald FE, Iuvone PM. A Tropomycin-Related Kinase B Receptor Activator for the Management of Ocular Blast-Induced Vision Loss. J Neurotrauma 2021; 38:2896-2906. [PMID: 34353120 PMCID: PMC8820286 DOI: 10.1089/neu.2020.7392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Pressure waves from explosions or other traumatic events can damage the neurons of the eye and visual centers of the brain, leading to functional loss of vision. There are currently few treatments for such injuries that can be deployed rapidly to mitigate damage. Brain-derived neurotrophic factor (BDNF) and activation of its receptor tropomycin-related kinase B (TrkB) have neuroprotective effects in a number of degeneration models. Small molecule activators of TrkB, such as N-[2-(5-hydroxy-1H-indol-3-yl)ethyl]-2-oxopiperidine-3-carboxamide (HIOC), cross the blood-brain and blood-retina barriers after systemic administration. We characterize the effects of blast-induced ocular trauma on retinal and visual function. We show that systemic administration of HIOC, a potent small molecule activator of the BDNF/TrkB receptor, preserves visual function in mice exposed to ocular blast injury. The HIOC treatment for one week preserves visual function for at least four months. The HIOC treatment effectively protected vision when the initial dose was administered up to 3 h after blast, but not if the initial treatment was delayed for 24 h. We provide evidence that the therapeutic effect of HIOC is mediated by activation of BDNF/TrkB receptors. The results indicate that HIOC may be useful for managing ocular blast injury and other forms of traumatic optic neuropathy.
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Affiliation(s)
- Susov Dhakal
- Department of Ophthalmology, Emory University, Atlanta, Georgia, USA
| | - Li He
- Department of Ophthalmology, Emory University, Atlanta, Georgia, USA
| | | | - Curran Sidhu
- Department of Ophthalmology, Emory University, Atlanta, Georgia, USA
| | - Micah A. Chrenek
- Department of Ophthalmology, Emory University, Atlanta, Georgia, USA
| | - Jana T. Sellers
- Department of Ophthalmology, Emory University, Atlanta, Georgia, USA
| | | | - Eldon E. Geisert
- Department of Ophthalmology, Emory University, Atlanta, Georgia, USA
| | | | | | - P. Michael Iuvone
- Department of Ophthalmology, Emory University, Atlanta, Georgia, USA
- Department of Pharmacology and Chemical Biology, Emory University, Atlanta, Georgia, USA
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4
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Harper MM, Boehme N, Dutca LM, Anderson MG. The Retinal Ganglion Cell Response to Blast-Mediated Traumatic Brain Injury Is Genetic Background Dependent. Invest Ophthalmol Vis Sci 2021; 62:13. [PMID: 34106210 PMCID: PMC8196410 DOI: 10.1167/iovs.62.7.13] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/24/2022] Open
Abstract
Purpose The purpose of this study was to examine the influence of genetic background on the retinal ganglion cell (RGC) response to blast-mediated traumatic brain injury (TBI) in Jackson Diversity Outbred (J:DO), C57BL/6J and BALB/cByJ mice. Methods Mice were subject to one blast injury of 137 kPa. RGC structure was analyzed by optical coherence tomography (OCT), function by the pattern electroretinogram (PERG), and histologically using BRN3A antibody staining. Results Comparison of the change in each group from baseline for OCT and PERG was performed. There was a significant difference in the J:DOΔOCT compared to C57BL/6J mice (P = 0.004), but not compared to BALB/cByJ (P = 0.21). There was a significant difference in the variance of the ΔOCT in J:DO compared to both C57BL/6J and BALB/cByJ mice. The baseline PERG amplitude was 20.33 ± 9.32 µV, which decreased an average of −4.14 ± 12.46 µV following TBI. Baseline RGC complex + RNFL thickness was 70.92 ± 4.52 µm, which decreased an average of −1.43 ± 2.88 µm following blast exposure. There was not a significant difference in the ΔPERG between J:DO and C57BL/6J (P = 0.13), although the variances of the groups were significantly different. Blast exposure in J:DO mice results in a density change of 558.6 ± 440.5 BRN3A-positive RGCs/mm2 (mean ± SD). Conclusions The changes in retinal outcomes had greater variance in outbred mice than what has been reported, and largely replicated herein, for inbred mice. These results demonstrate that the RGC response to blast injury is highly dependent upon genetic background.
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Affiliation(s)
- Matthew M Harper
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, The University of Iowa, Iowa City, IA, United States.,Center for the Prevention and Treatment of Visual Loss, Iowa City VA Healthcare System, Department of Veterans Affairs, Iowa City, IA, United States
| | - Nickolas Boehme
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, The University of Iowa, Iowa City, IA, United States.,Center for the Prevention and Treatment of Visual Loss, Iowa City VA Healthcare System, Department of Veterans Affairs, Iowa City, IA, United States
| | - Laura M Dutca
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, The University of Iowa, Iowa City, IA, United States.,Center for the Prevention and Treatment of Visual Loss, Iowa City VA Healthcare System, Department of Veterans Affairs, Iowa City, IA, United States
| | - Michael G Anderson
- Department of Ophthalmology and Visual Sciences, Carver College of Medicine, The University of Iowa, Iowa City, IA, United States.,Center for the Prevention and Treatment of Visual Loss, Iowa City VA Healthcare System, Department of Veterans Affairs, Iowa City, IA, United States.,The Department of Molecular Physiology and Biophysics, Carver College of Medicine, The University of Iowa, Iowa City, IA, United States
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5
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Axonopathy precedes cell death in ocular damage mediated by blast exposure. Sci Rep 2021; 11:11774. [PMID: 34083587 PMCID: PMC8175471 DOI: 10.1038/s41598-021-90412-2] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 05/04/2021] [Indexed: 12/13/2022] Open
Abstract
Traumatic brain injuries (TBI) of varied types are common across all populations and can cause visual problems. For military personnel in combat settings, injuries from blast exposures (bTBI) are prevalent and arise from a myriad of different situations. To model these diverse conditions, we are one of several groups modeling bTBI using mice in varying ways. Here, we report a refined analysis of retinal ganglion cell (RGC) damage in male C57BL/6J mice exposed to a blast-wave in an enclosed chamber. Ganglion cell layer thickness, RGC density (BRN3A and RBPMS immunoreactivity), cellular density of ganglion cell layer (hematoxylin and eosin staining), and axon numbers (paraphenylenediamine staining) were quantified at timepoints ranging from 1 to 17-weeks. RNA sequencing was performed at 1-week and 5-weeks post-injury. Earliest indices of damage, evident by 1-week post-injury, are a loss of RGC marker expression, damage to RGC axons, and increase in glial markers expression. Blast exposure caused a loss of RGC somas and axons—with greatest loss occurring by 5-weeks post-injury. While indices of glial involvement are prominent early, they quickly subside as RGCs are lost. The finding that axonopathy precedes soma loss resembles pathology observed in mouse models of glaucoma, suggesting similar mechanisms.
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6
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Wang J, Struebing FL, Geisert EE. Commonalities of optic nerve injury and glaucoma-induced neurodegeneration: Insights from transcriptome-wide studies. Exp Eye Res 2021; 207:108571. [PMID: 33844961 PMCID: PMC9890784 DOI: 10.1016/j.exer.2021.108571] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Revised: 03/28/2021] [Accepted: 04/02/2021] [Indexed: 02/03/2023]
Abstract
Glaucoma is a collection of diseases that lead to an irreversible vision loss due to damage of retinal ganglion cells (RGCs). Although the underlying events leading to RGC death are not fully understood, recent research efforts are beginning to define the genetic changes that play a critical role in the initiation and progression of glaucomatous injury and RGC death. Several genetic and experimental animal models have been developed to mimic glaucomatous neurodegeneration. These models differ in many respects but all result in the loss of RGCs. Assessing transcriptional changes across different models could provide a more complete perspective on the molecular drivers of RGC degeneration. For the past several decades, changes in the retinal transcriptome during neurodegeneration process were defined using microarray methods, RNA sequencing and now single cell RNA sequencing. It is understood that these methods have strengths and weaknesses due to technical differences and variations in the analytical tools used. In this review, we focus on the use of transcriptome-wide expression profiling of the changes occurring as RGCs are lost across different glaucoma models. Commonalities of optic nerve crush and glaucoma-induced neurodegeneration are identified and discussed.
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Affiliation(s)
- Jiaxing Wang
- Emory Eye Center, Department of Ophthalmology, Emory University, 1365B Clifton Road NE, Atlanta, GA, 30322, USA
| | - Felix L. Struebing
- Center for Neuropathology and Prion Research, Ludwig Maximilian University of Munich, Germany,Department for Translational Brain Research, German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
| | - Eldon E. Geisert
- Emory Eye Center, Department of Ophthalmology, Emory University, 1365B Clifton Road NE, Atlanta, GA, 30322, USA,Corresponding author: (E.E. Geisert)
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7
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Evans LP, Boehme N, Wu S, Burghardt EL, Akurathi A, Todd BP, Newell EA, Ferguson PJ, Mahajan VB, Dutca LM, Harper MM, Bassuk AG. Sex Does Not Influence Visual Outcomes After Blast-Mediated Traumatic Brain Injury but IL-1 Pathway Mutations Confer Partial Rescue. Invest Ophthalmol Vis Sci 2021; 61:7. [PMID: 33030508 PMCID: PMC7582458 DOI: 10.1167/iovs.61.12.7] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Purpose In a mouse model of blast-mediated traumatic brain injury (bTBI), interleukin-1 (IL-1)-pathway components were tested as potential therapeutic targets for bTBI-mediated retinal ganglion cell (RGC) dysfunction. Sex was also evaluated as a variable for RGC outcomes post-bTBI. Methods Male and female mice with null mutations in genes encoding IL-1α, IL-1β, or IL-1RI were compared to C57BL/6J wild-type (WT) mice after exposure to three 20-psi blast waves given at an interblast interval of 1 hour or to mice receiving sham injury. To determine if genetic blockade of IL-1α, IL-1β, or IL-1RI could prevent damage to RGCs, the function and structure of these cells were evaluated by pattern electroretinogram and optical coherence tomography, respectively, 5 weeks following blast or sham exposure. RGC survival was also quantitatively assessed via immunohistochemical staining of BRN3A at the completion of the study. Results Our results showed that male and female WT mice had a similar response to blast-induced retinal injury. Generally, constitutive deletion of IL-1α, IL-1β, or IL-1RI did not provide full protection from the effects of bTBI on visual outcomes; however, injured WT mice had significantly worse visual outcomes compared to the injured genetic knockout mice. Conclusions Sex does not affect RGC outcomes after bTBI. The genetic studies suggest that deletion of these IL-1 pathway components confers some protection, but global deletion from birth did not result in a complete rescue.
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Affiliation(s)
- Lucy P Evans
- Department of Pediatrics, University of Iowa, Iowa City, Iowa, United States.,Medical Scientist Training Program, University of Iowa, Iowa City, Iowa, United States
| | - Nickolas Boehme
- Iowa City VA Health Care System Center for the Prevention and Treatment of Visual Loss, Iowa City, Iowa, United States
| | - Shu Wu
- Department of Pediatrics, University of Iowa, Iowa City, Iowa, United States
| | - Elliot L Burghardt
- Medical Scientist Training Program, University of Iowa, Iowa City, Iowa, United States.,Department of Biostatistics, University of Iowa, Iowa City, Iowa, United States
| | - Abhigna Akurathi
- Iowa City VA Health Care System Center for the Prevention and Treatment of Visual Loss, Iowa City, Iowa, United States
| | - Brittany P Todd
- Department of Pediatrics, University of Iowa, Iowa City, Iowa, United States.,Medical Scientist Training Program, University of Iowa, Iowa City, Iowa, United States
| | - Elizabeth A Newell
- Department of Pediatrics, University of Iowa, Iowa City, Iowa, United States
| | - Polly J Ferguson
- Department of Pediatrics, University of Iowa, Iowa City, Iowa, United States
| | - Vinit B Mahajan
- Omics Laboratory, Byers Eye Institute, Department of Ophthalmology, Stanford University School of Medicine, Palo Alto, California, United States.,Veterans Affairs Palo Alto Health Care System, Palo Alto, California, United States
| | - Laura M Dutca
- Iowa City VA Health Care System Center for the Prevention and Treatment of Visual Loss, Iowa City, Iowa, United States.,Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, United States
| | - Matthew M Harper
- Iowa City VA Health Care System Center for the Prevention and Treatment of Visual Loss, Iowa City, Iowa, United States.,Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, Iowa, United States
| | - Alexander G Bassuk
- Department of Pediatrics, University of Iowa, Iowa City, Iowa, United States
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8
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Proteomic Analysis Revealed the Characteristics of Key Proteins Involved in the Regulation of Inflammatory Response, Leukocyte Transendothelial Migration, Phagocytosis, and Immune Process during Early Lung Blast Injury. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:8899274. [PMID: 34007409 PMCID: PMC8099533 DOI: 10.1155/2021/8899274] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2020] [Revised: 03/29/2021] [Accepted: 04/08/2021] [Indexed: 12/17/2022]
Abstract
Previous studies found that blast injury caused a significant increased expression of interleukin-1, IL-6, and tumor necrosis factor, a significant decrease in the expression of IL-10, an increase in Evans blue leakage, and a significant increase in inflammatory cell infiltration in the lungs. However, the molecular characteristics of lung injury at different time points after blast exposure have not yet been reported. Therefore, in this study, tandem mass spectrometry (TMT) quantitative proteomics and bioinformatics analysis were used for the first time to gain a deeper understanding of the molecular mechanism of lung blast injury at different time points. Forty-eight male C57BL/6 mice were randomly divided into six groups: control, 12 h, 24 h, 48 h, 72 h, and 1 w after low-intensity blast exposure. TMT quantitative proteomics and bioinformatics analysis were performed to analyze protein expression profiling in the lungs from control and blast-exposed mice, and differential protein expression was verified by Western blotting. The results demonstrated that blast exposure induced severe lung injury, leukocyte infiltration, and the production of inflammatory factors in mice. After analyzing the expression changes in global proteins and inflammation-related proteomes after blast exposure, the results showed that a total of 6861 global proteins and 608 differentially expressed proteins were identified, of which 215, 128, 187, 232, and 65 proteins were identified at 12 h, 24 h, 48 h, 72 h, and 1 week after blast exposure, respectively. Moreover, blast exposure-induced 177 differentially expressed proteins were associated with inflammatory responses, which were enriched in the inflammatory response regulation, leukocyte transendothelial migration, phagocytosis, and immune response. Therefore, blast exposure may induce early inflammatory response of lung tissue by regulating the expression of key proteins in the inflammatory process, suggesting that early inflammatory response may be the initiating factor of lung blast injury. These data can provide potential therapeutic candidates or approaches for the development of future treatment of lung blast injury.
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9
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Evans LP, Roghair AM, Gilkes NJ, Bassuk AG. Visual Outcomes in Experimental Rodent Models of Blast-Mediated Traumatic Brain Injury. Front Mol Neurosci 2021; 14:659576. [PMID: 33935648 PMCID: PMC8081965 DOI: 10.3389/fnmol.2021.659576] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 03/18/2021] [Indexed: 11/24/2022] Open
Abstract
Blast-mediated traumatic brain injuries (bTBI) cause long-lasting physical, cognitive, and psychological disorders, including persistent visual impairment. No known therapies are currently utilized in humans to lessen the lingering and often serious symptoms. With TBI mortality decreasing due to advancements in medical and protective technologies, there is growing interest in understanding the pathology of visual dysfunction after bTBI. However, this is complicated by numerous variables, e.g., injury location, severity, and head and body shielding. This review summarizes the visual outcomes observed by various, current experimental rodent models of bTBI, and identifies data showing that bTBI activates inflammatory and apoptotic signaling leading to visual dysfunction. Pharmacologic treatments blocking inflammation and cell death pathways reported to alleviate visual deficits in post-bTBI animal models are discussed. Notably, techniques for assessing bTBI outcomes across exposure paradigms differed widely, so we urge future studies to compare multiple models of blast injury, to allow data to be directly compared.
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Affiliation(s)
- Lucy P. Evans
- Department of Pediatrics, University of Iowa, Iowa City, IA, United States
- Medical Scientist Training Program, University of Iowa, Iowa City, IA, United States
| | - Ariel M. Roghair
- Department of Pediatrics, University of Iowa, Iowa City, IA, United States
| | - Noah J. Gilkes
- Department of Pediatrics, University of Iowa, Iowa City, IA, United States
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10
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Geisert EE, Williams RW. Using BXD mouse strains in vision research: A systems genetics approach. Mol Vis 2020; 26:173-187. [PMID: 32180682 PMCID: PMC7058434] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/11/2019] [Accepted: 03/04/2020] [Indexed: 11/06/2022] Open
Abstract
We illustrate the growing power of the BXD family of mice (recombinant inbred strains from a cross of C57BL/6J and DBA/2J mice) and companion bioinformatic tools to study complex genome-phenome relations related to glaucoma. Over the past 16 years, our group has integrated powerful murine resources and web-accessible tools to identify networks modulating visual system traits-from photoreceptors to the visual cortex. Recent studies focused on retinal ganglion cells and glaucoma risk factors, including intraocular pressure (IOP), central corneal thickness (CCT), and susceptibility of cellular stress. The BXD family was exploited to define key gene variants and then establish linkage to glaucoma in human cohorts. The power of this experimental approach to precision medicine is highlighted by recent studies that defined cadherin 11 (Cdh11) and a calcium channel (Cacna2d1) as genes modulating IOP, Pou6f2 as a genetic link between CCT and retinal ganglion cell (RGC) death, and Aldh7a1 as a gene that modulates the susceptibility of RGCs to death after elevated IOP. The role of three of these gene variants in glaucoma is discussed, along with the pathways activated in the disease process.
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Affiliation(s)
- Eldon E. Geisert
- Department of Ophthalmology, Emory University, 1365B Clifton Road NE Atlanta GA, 30322
| | - Robert W. Williams
- Department of Genetics, Genomics and Informatics, University of Tennessee Health Science Center, 71 S Manassas St, Memphis TN 38163
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11
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Edwards KA, Motamedi V, Osier ND, Kim HS, Yun S, Cho YE, Lai C, Dell KC, Carr W, Walker P, Ahlers S, LoPresti M, Yarnell A, Tschiffley A, Gill JM. A Moderate Blast Exposure Results in Dysregulated Gene Network Activity Related to Cell Death, Survival, Structure, and Metabolism. Front Neurol 2020; 11:91. [PMID: 32174881 PMCID: PMC7054450 DOI: 10.3389/fneur.2020.00091] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Accepted: 01/27/2020] [Indexed: 12/11/2022] Open
Abstract
Blast exposure is common in military personnel during training and combat operations, yet biological mechanisms related to cell survival and function that coordinate recovery remain poorly understood. This study explored how moderate blast exposure influences gene expression; specifically, gene-network changes following moderate blast exposure. On day 1 (baseline) of a 10-day military training program, blood samples were drawn, and health and demographic information collected. Helmets equipped with bilateral sensors worn throughout training measured overpressure in pounds per square inch (psi). On day 7, some participants experienced moderate blast exposure (peak pressure ≥5 psi). On day 10, 3 days post-exposure, blood was collected and compared to baseline with RNA-sequencing to establish gene expression changes. Based on dysregulation data from RNA-sequencing, followed by top gene networks identified with Ingenuity Pathway Analysis, a subset of genes was validated (NanoString). Five gene networks were dysregulated; specifically, two highly significant networks: (1) Cell Death and Survival (score: 42), including 70 genes, with 50 downregulated and (2) Cell Structure, Function, and Metabolism (score: 41), including 69 genes, with 41 downregulated. Genes related to ubiquitination, including neuronal development and repair: UPF1, RNA Helicase and ATPase (UPF1) was upregulated while UPF3 Regulator of Nonsense Transcripts Homolog B (UPF3B) was downregulated. Genes related to inflammation were upregulated, including AKT serine/threonine kinase 1 (AKT1), a gene coordinating cellular recovery following TBIs. Moderate blast exposure induced significant gene expression changes including gene networks involved in (1) cell death and survival and (2) cellular development and function. The present findings may have implications for understanding blast exposure pathology and subsequent recovery efforts.
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Affiliation(s)
- Katie A Edwards
- National Institute of Nursing Research, National Institutes of Health, Bethesda, MD, United States.,The Henry M. Jackson Foundation for the Advancement of Military Medicine, Bethesda, MD, United States
| | - Vida Motamedi
- Wake Forest School of Medicine, Wake Forest University, Winston-Salem, NC, United States
| | - Nicole D Osier
- School of Nursing, University of Texas at Austin, Austin, TX, United States.,Department of Neurology, University of Texas, Austin, TX, United States
| | - Hyung-Suk Kim
- National Institute of Nursing Research, National Institutes of Health, Bethesda, MD, United States
| | - Sijung Yun
- National Institute of Nursing Research, National Institutes of Health, Bethesda, MD, United States
| | - Young-Eun Cho
- College of Nursing, University of Iowa, Iowa City, IA, United States
| | - Chen Lai
- National Institute of Nursing Research, National Institutes of Health, Bethesda, MD, United States
| | - Kristine C Dell
- Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Walter Carr
- Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Peter Walker
- Naval Medical Research Center, Silver Spring, MD, United States
| | - Stephen Ahlers
- Naval Medical Research Center, Silver Spring, MD, United States
| | - Matthew LoPresti
- Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Angela Yarnell
- Walter Reed Army Institute of Research, Silver Spring, MD, United States
| | - Anna Tschiffley
- Naval Medical Research Center, Silver Spring, MD, United States
| | - Jessica M Gill
- National Institute of Nursing Research, National Institutes of Health, Bethesda, MD, United States.,CNRM Co-Director Biomarkers Core, Uniformed Services University of the Health Sciences, Bethesda, MD, United States
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12
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Harper MM, Rudd D, Meyer KJ, Kanthasamy AG, Anantharam V, Pieper AA, Vázquez-Rosa E, Shin MK, Chaubey K, Koh Y, Evans LP, Bassuk AG, Anderson MG, Dutca L, Kudva IT, John M. Identification of chronic brain protein changes and protein targets of serum auto-antibodies after blast-mediated traumatic brain injury. Heliyon 2020; 6:e03374. [PMID: 32099918 PMCID: PMC7029173 DOI: 10.1016/j.heliyon.2020.e03374] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2019] [Revised: 07/19/2019] [Accepted: 02/03/2020] [Indexed: 12/13/2022] Open
Abstract
In addition to needing acute emergency management, blast-mediated traumatic brain injury (TBI) is also a chronic disorder with delayed-onset symptoms that manifest and progress over time. While the immediate consequences of acute blast injuries are readily apparent, chronic sequelae are harder to recognize. Indeed, the identification of individuals with mild-TBI or TBI-induced symptoms is greatly impaired in large part due to the lack of objective and robust biomarkers. The purpose of this study was to address these need by identifying candidates for serum-based biomarkers of blast TBI, and also to identify unique or differentially regulated protein expression in the thalamus in C57BL/6J mice exposed to blast using high throughput qualitative screens of protein expression. To identify thalamic proteins differentially or uniquely associated with blast exposure, we utilized an antibody-based affinity-capture strategy (referred to as "proteomics-based analysis of depletomes"; PAD) to deplete thalamic lysates from blast-treated mice of endogenous thalamic proteins also found in control mice. Analysis of this "depletome" detected 75 unique proteins, many with associations to the myelin sheath. To identify blast-associated proteins eliciting production of circulating autoantibodies, serum antibodies of blast-treated mice were immobilized, and their immunogens subsequently identified by proteomic analysis of proteins specifically captured following incubation with thalamic lysates (a variant of a strategy referred to as "proteomics-based expression library screening"; PELS). This analysis identified 46 blast-associated immunogenic proteins, including 6 shared in common with the PAD analysis (ALDOA, PHKB, HBA-A1, DPYSL2, SYN1, and CKB). These proteins and their autoantibodies are appropriate for further consideration as biomarkers of blast-mediated TBI.
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Affiliation(s)
- Matthew M. Harper
- The Iowa City Department of Veterans Affairs Medical Center, Center for the Prevention and Treatment of Visual Loss, Iowa City, IA, USA
- The University of Iowa Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, USA
| | - Danielle Rudd
- The Iowa City Department of Veterans Affairs Medical Center, Center for the Prevention and Treatment of Visual Loss, Iowa City, IA, USA
| | - Kacie J. Meyer
- The University of Iowa Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA, USA
| | | | | | - Andrew A. Pieper
- Harrington Discovery Institute, University Hospitals of Cleveland, Department of Psychiatry Case Western Reserve University, Geriatric Research Education and Clinical Centers, Louis Stokes VA Medical Center, Cleveland, OH 44106, USA
| | - Edwin Vázquez-Rosa
- Harrington Discovery Institute, University Hospitals of Cleveland, Department of Psychiatry Case Western Reserve University, Geriatric Research Education and Clinical Centers, Louis Stokes VA Medical Center, Cleveland, OH 44106, USA
| | - Min-Kyoo Shin
- Harrington Discovery Institute, University Hospitals of Cleveland, Department of Psychiatry Case Western Reserve University, Geriatric Research Education and Clinical Centers, Louis Stokes VA Medical Center, Cleveland, OH 44106, USA
| | - Kalyani Chaubey
- Harrington Discovery Institute, University Hospitals of Cleveland, Department of Psychiatry Case Western Reserve University, Geriatric Research Education and Clinical Centers, Louis Stokes VA Medical Center, Cleveland, OH 44106, USA
| | - Yeojung Koh
- Harrington Discovery Institute, University Hospitals of Cleveland, Department of Psychiatry Case Western Reserve University, Geriatric Research Education and Clinical Centers, Louis Stokes VA Medical Center, Cleveland, OH 44106, USA
| | - Lucy P. Evans
- The University of Iowa Department of Pediatrics, University of Iowa, Iowa City, IA, USA
- The University of Iowa Department of Neurology, University of Iowa, Iowa City, IA, USA
- The University of Iowa Department of Medical Scientist Training Program, University of Iowa, Iowa City, IA, USA
| | - Alexander G. Bassuk
- The University of Iowa Department of Pediatrics, University of Iowa, Iowa City, IA, USA
- The University of Iowa Department of Neurology, University of Iowa, Iowa City, IA, USA
| | - Michael G. Anderson
- The Iowa City Department of Veterans Affairs Medical Center, Center for the Prevention and Treatment of Visual Loss, Iowa City, IA, USA
- The University of Iowa Department of Ophthalmology and Visual Sciences, University of Iowa, Iowa City, IA, USA
- The University of Iowa Department of Molecular Physiology and Biophysics, University of Iowa, Iowa City, IA, USA
| | - Laura Dutca
- The Iowa City Department of Veterans Affairs Medical Center, Center for the Prevention and Treatment of Visual Loss, Iowa City, IA, USA
| | - Indira T. Kudva
- Food Safety and Enteric Pathogens Research Unit, National Animal Disease Center, Agricultural Research Service, U.S. Department of Agriculture, Ames, IA, USA
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13
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CD28 Deficiency Ameliorates Blast Exposure-Induced Lung Inflammation, Oxidative Stress, Apoptosis, and T Cell Accumulation in the Lungs via the PI3K/Akt/FoxO1 Signaling Pathway. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:4848560. [PMID: 31565151 PMCID: PMC6745179 DOI: 10.1155/2019/4848560] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/25/2019] [Revised: 05/14/2019] [Accepted: 05/22/2019] [Indexed: 02/07/2023]
Abstract
Although CD28 is associated with the expression of inflammatory mediators, apoptosis-related protein, immunosuppression, and tumorigenesis, the effects of CD28 deficiency on blast exposure-induced lung injury have not been investigated. In this study, we have explored the effects of CD28 on blast exposure-induced lung injury and studied its potential molecular mechanisms. A mouse model of blast exposure-induced acute lung injury was established. Sixty C57BL/6 wild-type (WT) and CD28 knockout (CD28−/−) mice were randomly divided into control or model groups. Lung tissue samples were collected 24 h and 48 h after blast injury. Histopathological changes and the expressions of inflammatory-related proteins were detected by hematoxylin-eosin, immunohistochemistry, and immunofluorescence staining. Apoptosis and oxidative stress were evaluated by terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) staining and reactive oxygen species (ROS). Inflammation, apoptosis, oxidative stress, and related pathway protein expression were studied by western blotting. In addition, the levels of CD3 and CD28 proteins were measured by flow cytometry. In the current study, we found that CD28 deficiency significantly inhibited blast exposure-induced increases in the lung weight/body weight ratio and wet weight/dry weight ratio; decreased the infiltration of CD44+ leukocytes, CD163+ macrophages, and CD3+ T cells into the lungs; reduced the expressions of proinflammatory cytokines including IL-1β, TNF-α, and IL-6; and markedly increased IL-10 expression. CD28 deficiency also significantly attenuated blast exposure-induced ROS, MDA5, and IREα expressions; increased SOD-1 expression; lowered the number of apoptotic cells and Bax, Caspase-3, and active Caspase-8 expressions; and increased Bcl-2 expression. Additionally, CD28 deficiency significantly ameliorated blast exposure-induced increases of p-PI3K and p-Akt and ameliorated the decrease in the p-FoxO1 expression. Our results suggest that CD28 deficiency has a protective effect on blast exposure-induced lung injury, which might be associated with the PI3K/Akt/FoxO1 signaling pathway.
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14
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Wang J, Geisert EE, Struebing FL. RNA sequencing profiling of the retina in C57BL/6J and DBA/2J mice: Enhancing the retinal microarray data sets from GeneNetwork. Mol Vis 2019; 25:345-358. [PMID: 31354228 PMCID: PMC6612415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 07/03/2019] [Indexed: 11/18/2022] Open
Abstract
Purpose The goal of the present study is to provide an independent assessment of the retinal transcriptome signatures of C57BL/6J (B6) and DBA/2J (D2) mice, and to enhance existing microarray data sets for accurately defining the allelic differences in the BXD recombinant inbred strains. Methods Retinas from B6 and D2 mice (three of each) were used for the RNA sequencing (RNA-seq) analysis. Transcriptome features were examined for both strains. Differentially expressed genes between the two strains were identified, and bioinformatic analysis was performed to analyze the transcriptome differences between the B6 and D2 strains, including Gene Ontology (GO) analysis, Phenotype and Reactome enrichment, and Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis. The RNA-seq data were then directly compared with one of the microarray data sets (Department of Defense [DoD] Retina Normal Affy MoGene 2.0 ST RMA Gene Level Microarray Database) hosted on GeneNetwork. Results RNA-seq provided an in-depth analysis of the transcriptome of the B6 and D2 retinas with a total of more than 30,000,000 reads per sample. More than 70% of the reads were uniquely mapped, resulting in a total of 18,100 gene counts for all six samples. A total of 1,665 genes were differentially expressed, with 858 of these more highly expressed in the B6 retinas and 807 more highly expressed in the D2 retinas. Several molecular pathways were differentially active between the two strains, including the retinoic acid metabolic process, endoplasmic reticulum lumen, extracellular matrix (ECM) organization, and the PI3K-Akt signaling pathway. The most enriched KEGG pathways were the pentose and glucuronate interconversions pathway, the cytochrome P450 pathway, the protein digestion and absorption pathway, and the ECM-receptor interaction pathway. Each of these pathways had a more than fourfold enrichment. The DoD Normal Retina Microarray Database provided expression profiling for 26,191 annotated transcripts for B6 mouse, D2 mouse, and 53 BXD strains. A total of 13,793 genes in this microarray data set were comparable to the RNA-seq data set. For the B6 and D2 retinas, the RNA-seq data and the microarray data were highly correlated with each other (Pearson's r=0.780 for the B6 mice and 0.784 for D2 mice). These results suggest that the microarray data set can reliably detect differentially expressed genes between the B6 and D2 retinas, with an overall accuracy of 91.1%. Examples of true positive and false positive genes are provided. Conclusions Retinal transcriptome features of B6 and D2 mouse strains provide a useful reference for a better understanding of the mouse retina. Generally, the microarray database presented on GeneNetwork shows good agreement with the RNA-seq data, but we note that any allelic difference between B6 and D2 mice should be verified with the latter.
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Affiliation(s)
- Jiaxing Wang
- Emory Eye Center, Department of Ophthalmology, Emory University, 1365B Clifton Road NE, Atlanta GA
| | - Eldon E. Geisert
- Emory Eye Center, Department of Ophthalmology, Emory University, 1365B Clifton Road NE, Atlanta GA
| | - Felix L. Struebing
- Emory Eye Center, Department of Ophthalmology, Emory University, 1365B Clifton Road NE, Atlanta GA
- Center for Neuropathology and Prion Research, Ludwig Maximilian University of Munich, Germany
- Department for Translational Brain Research, German Center for Neurodegenerative Diseases (DZNE), Munich, Germany
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15
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Mukherjee S, Klaus C, Pricop-Jeckstadt M, Miller JA, Struebing FL. A Microglial Signature Directing Human Aging and Neurodegeneration-Related Gene Networks. Front Neurosci 2019; 13:2. [PMID: 30733664 PMCID: PMC6353788 DOI: 10.3389/fnins.2019.00002] [Citation(s) in RCA: 51] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 01/03/2019] [Indexed: 01/06/2023] Open
Abstract
Aging is regarded as a major risk factor for neurodegenerative diseases. Thus, a better understanding of the similarities between the aging process and neurodegenerative diseases at the cellular and molecular level may reveal better understanding of this detrimental relationship. In the present study, we mined publicly available gene expression datasets from healthy individuals and patients affected by neurodegenerative diseases (Alzheimer's disease, Parkinson's disease, and Huntington's disease) across a broad age spectrum and compared those with mouse aging and mouse cell-type specific gene expression profiles. We performed weighted gene co-expression network analysis (WGCNA) and found a gene network strongly related with both aging and neurodegenerative diseases. This network was significantly enriched with a microglial signature as imputed from cell type-specific sequencing data. Since mouse models are extensively used for the study of human diseases, we further compared these human gene regulatory networks with age-specific mouse brain transcriptomes. We discovered significantly preserved networks with both human aging and human disease and identified 17 shared genes in the top-ranked immune/microglia module, among which we found five human hub genes TYROBP, FCER1G, ITGB2, MYO1F, PTPRC, and two mouse hub genes Trem2 and C1qa. Taken together, these results support the hypothesis that microglia are key players involved in human aging and neurodegenerative diseases, and suggest that mouse models should be appropriate for studying these microglial changes in human.
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Affiliation(s)
- Shradha Mukherjee
- Health Informatics Advanced Science Masters Program, Arizona State University, Tempe, AZ, United States
- Department of Neurology, University of California, Los Angeles, Los Angeles, CA, United States
- Department of Bioinformatics, University of California, Los Angeles, Los Angeles, CA, United States
| | - Christine Klaus
- Neural Regeneration Group, Institute of Reconstructive Neurobiology, University of Bonn, Bonn, Germany
| | - Mihaela Pricop-Jeckstadt
- Institute for Medical Informatics and Biometry, Faculty of Medicine “Carl Gustav Carus”, TU Dresden, Dresden, Germany
| | | | - Felix L. Struebing
- Department of Translational Brain Research, German Center for Neurodegenerative Diseases, Munich, Germany
- Center for Neuropathology and Prion Research, Ludwig Maximilian University of Munich, Munich, Germany
- Department of Ophthalmology, Emory University, Atlanta, GA, United States
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16
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Abstract
Intraocular pressure (IOP) is the primary risk factor for developing glaucoma, yet little is known about the contribution of genomic background to IOP regulation. The present study leverages an array of systems genetics tools to study genomic factors modulating normal IOP in the mouse. The BXD recombinant inbred (RI) strain set was used to identify genomic loci modulating IOP. We measured the IOP in a total of 506 eyes from 38 different strains. Strain averages were subjected to conventional quantitative trait analysis by means of composite interval mapping. Candidate genes were defined, and immunohistochemistry and quantitative PCR (qPCR) were used for validation. Of the 38 BXD strains examined the mean IOP ranged from a low of 13.2mmHg to a high of 17.1mmHg. The means for each strain were used to calculate a genome wide interval map. One significant quantitative trait locus (QTL) was found on Chr.8 (96 to 103 Mb). Within this 7 Mb region only 4 annotated genes were found: Gm15679, Cdh8, Cdh11 and Gm8730. Only two genes (Cdh8 and Cdh11) were candidates for modulating IOP based on the presence of non-synonymous SNPs. Further examination using SIFT (Sorting Intolerant From Tolerant) analysis revealed that the SNPs in Cdh8 (Cadherin 8) were predicted to not change protein function; while the SNPs in Cdh11 (Cadherin 11) would not be tolerated, affecting protein function. Furthermore, immunohistochemistry demonstrated that CDH11 is expressed in the trabecular meshwork of the mouse. We have examined the genomic regulation of IOP in the BXD RI strain set and found one significant QTL on Chr. 8. Within this QTL, there is one good candidate gene, Cdh11.
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17
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Wang J, Li Y, King R, Struebing FL, Geisert EE. Optic nerve regeneration in the mouse is a complex trait modulated by genetic background. Mol Vis 2018; 24:174-186. [PMID: 29463955 PMCID: PMC5815339] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2017] [Accepted: 02/13/2018] [Indexed: 10/24/2022] Open
Abstract
Purpose The present study is designed to identify the influences of genetic background on optic nerve regeneration using the two parental strains (C57BL/6J and DBA/2J) and seven BXD recombinant inbred mouse strains. Methods To study regeneration in the optic nerve, Pten was knocked down in the retinal ganglion cells using adenoassociated virus (AAV) delivery of shRNA, and a mild inflammatory response was induced with an intravitreal injection of zymosan with CPT-cAMP. The axons of the retinal ganglion cells were damaged by optic nerve crush (ONC). Following a 12-day survival period, regenerating axons were labeled by cholera toxin B, and 2 days later, the regenerating axons within the optic nerve were examined. The number of axons at 0.5 mm and 1 mm from the crush site were counted. In addition, we measured the distance that five axons had grown down the nerve and the longest distance a single axon reached. Results The analysis revealed a considerable amount of differential axonal regeneration across the seven BXD strains and the parental strains. There was a statistically significant difference (p=0.014 Mann-Whitney U test) in the regenerative capacity in the number of axons reaching 0.5 mm from a low of 236.1±24.4 axons in the BXD102 mice to a high of 759.8±79.2 axons in the BXD29 mice. There were also statistically significant differences (p=0.014 Mann-Whitney U test) in the distance axons traveled. Looking at a minimum of five axons, the shortest distance was 787.2±46.5 µm in the BXD102 mice, and the maximum distance was 2025.5±223.3 µm in the BXD29 mice. Conclusions Differences in genetic background can have a profound effect on axonal regeneration causing a threefold increase in the number of regenerating axons at 0.5 mm from the crush site and a 2.5-fold increase in the distance traveled by at least five axons in the damaged optic nerve.
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Affiliation(s)
- Jiaxing Wang
- Department of Ophthalmology, Tianjin Medical University General Hospital, Tianjin, China,Department of Ophthalmology, Emory University, Atlanta, GA
| | - Ying Li
- Department of Ophthalmology, Emory University, Atlanta, GA
| | - Rebecca King
- Department of Ophthalmology, Emory University, Atlanta, GA
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18
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Struebing FL, King R, Li Y, Cooke Bailey JN, Wiggs JL, Geisert EE. Genomic loci modulating retinal ganglion cell death following elevated IOP in the mouse. Exp Eye Res 2018; 169:61-67. [PMID: 29421330 PMCID: PMC5939594 DOI: 10.1016/j.exer.2017.12.013] [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: 09/13/2017] [Revised: 11/13/2017] [Accepted: 12/28/2017] [Indexed: 12/25/2022]
Abstract
The present study was designed to identify genomic loci modulating the susceptibility of retinal ganglion cells (RGC) to elevated intraocular pressure (IOP) in the BXD recombinant inbred mouse strain set. IOP was elevated by injecting magnetic microspheres into the anterior chamber and blocking the trabecular meshwork using a handheld magnet to impede drainage. The IOP was then measured over the next 21 days. Only animals with IOP greater than 25 mmHg for two consecutive days or an IOP above 30 mmHg on a single day after microsphere-injection were used in this study. On day 21, mice were sacrificed and the optic nerve was processed for histology. Axons were counted for both the injected and the control eye in 49 BXD strains, totaling 181 normal counts and 191 counts associated with elevated IOP. The axon loss for each strain was calculated and the data were entered into genenetwork.org. The average number of normal axons in the optic nerve across all strains was 54,788 ± 16% (SD), which dropped to 49,545 ± 20% in animals with artificially elevated IOP. Interval mapping demonstrated a relatively similar genome-wide map for both conditions with a suggestive Quantitative Trait Locus (QTL) on proximal Chromosome 3. When the relative axon loss was used to generate a genome-wide interval map, we identified one significant QTL (p < 0.05) on Chromosome 18 between 53.6 and 57 Mb. Within this region, the best candidate gene for modulating axon loss was Aldh7a1. Immunohistochemistry demonstrated ALDH7A1 expression in mouse RGCs. ALDH7A1 variants were not significantly associated with glaucoma in the NEIGHBORHOOD GWAS dataset, but this enzyme was identified as part of the butanoate pathway previously associated with glaucoma risk. Our results suggest that genomic background influences susceptibility to RGC degeneration and death in an inducible glaucoma model.
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Affiliation(s)
- Felix L Struebing
- Department of Ophthalmology, Emory University, 1365B Clifton Road NE, Atlanta, GA, 30322, USA
| | - Rebecca King
- Department of Ophthalmology, Emory University, 1365B Clifton Road NE, Atlanta, GA, 30322, USA
| | - Ying Li
- Department of Ophthalmology, Emory University, 1365B Clifton Road NE, Atlanta, GA, 30322, USA
| | - Jessica N Cooke Bailey
- Department of Population and Quantitative Health Sciences, Case Western Reserve University School of Medicine, USA
| | | | - Janey L Wiggs
- Department of Ophthalmology, Harvard Medical School, Massachusetts Eye and Ear Infirmary, USA
| | - Eldon E Geisert
- Department of Ophthalmology, Emory University, 1365B Clifton Road NE, Atlanta, GA, 30322, USA.
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19
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Struebing FL, Wang J, Li Y, King R, Mistretta OC, English AW, Geisert EE. Differential Expression of Sox11 and Bdnf mRNA Isoforms in the Injured and Regenerating Nervous Systems. Front Mol Neurosci 2017; 10:354. [PMID: 29209164 PMCID: PMC5701613 DOI: 10.3389/fnmol.2017.00354] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2017] [Accepted: 10/18/2017] [Indexed: 01/13/2023] Open
Abstract
In both the central nervous system (CNS) and the peripheral nervous system (PNS), axonal injury induces changes in neuronal gene expression. In the PNS, a relatively well-characterized alteration in transcriptional activation is known to promote axonal regeneration. This transcriptional cascade includes the neurotrophin Bdnf and the transcription factor Sox11. Although both molecules act to facilitate successful axon regeneration in the PNS, this process does not occur in the CNS. The present study examines the differential expression of Sox11 and Bdnf mRNA isoforms in the PNS and CNS using three experimental paradigms at different time points: (i) the acutely injured CNS (retina after optic nerve crush) and PNS (dorsal root ganglion after sciatic nerve crush), (ii) a CNS regeneration model (retina after optic nerve crush and induced regeneration); and (iii) the retina during a chronic form of central neurodegeneration (the DBA/2J glaucoma model). We find an initial increase of Sox11 in both PNS and CNS after injury; however, the expression of Bdnf isoforms is higher in the PNS relative to the CNS. Sustained upregulation of Sox11 is seen in the injured retina following regeneration treatment, while the expression of two Bdnf mRNA isoforms is suppressed. Furthermore, two isoforms of Sox11 with different 3′UTR lengths are present in the retina, and the long isoform is specifically upregulated in later stages of glaucoma. These results provide insight into the molecular cascades active during axonal injury and regeneration in mammalian neurons.
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Affiliation(s)
- Felix L Struebing
- Department of Ophthalmology, Emory University, Atlanta, GA, United States
| | - Jiaxing Wang
- Department of Ophthalmology, Emory University, Atlanta, GA, United States.,Department of Ophthalmology, Tianjin Medical University General Hospital, Tianjin, China
| | - Ying Li
- Department of Ophthalmology, Emory University, Atlanta, GA, United States
| | - Rebecca King
- Department of Ophthalmology, Emory University, Atlanta, GA, United States
| | - Olivia C Mistretta
- Department of Cell Biology, Emory University, Atlanta, GA, United States
| | - Arthur W English
- Department of Cell Biology, Emory University, Atlanta, GA, United States
| | - Eldon E Geisert
- Department of Ophthalmology, Emory University, Atlanta, GA, United States
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