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Fritsch LE, Kelly C, Leonard J, de Jager C, Wei X, Brindley S, Harris EA, Kaloss AM, DeFoor N, Paul S, O'Malley H, Ju J, Olsen ML, Theus MH, Pickrell AM. STING-Dependent Signaling in Microglia or Peripheral Immune Cells Orchestrates the Early Inflammatory Response and Influences Brain Injury Outcome. J Neurosci 2024; 44:e0191232024. [PMID: 38360749 PMCID: PMC10957216 DOI: 10.1523/jneurosci.0191-23.2024] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 12/16/2023] [Accepted: 01/02/2024] [Indexed: 02/17/2024] Open
Abstract
While originally identified as an antiviral pathway, recent work has implicated that cyclic GMP-AMP-synthase-Stimulator of Interferon Genes (cGAS-STING) signaling is playing a critical role in the neuroinflammatory response to traumatic brain injury (TBI). STING activation results in a robust inflammatory response characterized by the production of inflammatory cytokines called interferons, as well as hundreds of interferon stimulated genes (ISGs). Global knock-out (KO) mice inhibiting this pathway display neuroprotection with evidence that this pathway is active days after injury; yet, the early neuroinflammatory events stimulated by STING signaling remain understudied. Furthermore, the source of STING signaling during brain injury is unknown. Using a murine controlled cortical impact (CCI) model of TBI, we investigated the peripheral immune and microglial response to injury utilizing male chimeric and conditional STING KO animals, respectively. We demonstrate that peripheral and microglial STING signaling contribute to negative outcomes in cortical lesion volume, cell death, and functional outcomes postinjury. A reduction in overall peripheral immune cell and neutrophil infiltration at the injury site is STING dependent in these models at 24 h. Transcriptomic analysis at 2 h, when STING is active, reveals that microglia drive an early, distinct transcriptional program to elicit proinflammatory genes including interleukin 1-β (IL-1β), which is lost in conditional knock-out mice. The upregulation of alternative innate immune pathways also occurs after injury in these animals, which supports a complex relationship between brain-resident and peripheral immune cells to coordinate the proinflammatory response and immune cell influx to damaged tissue after injury.
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Affiliation(s)
- Lauren E Fritsch
- Graduate Program in Translational Biology, Medicine, and Health, Virginia Polytechnic Institute and State University, Roanoke, Virginia 24016
| | - Colin Kelly
- Graduate Program in Translational Biology, Medicine, and Health, Virginia Polytechnic Institute and State University, Roanoke, Virginia 24016
| | - John Leonard
- Department of Biomedical Sciences and Pathobiology, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061
| | - Caroline de Jager
- Graduate Program in Translational Biology, Medicine, and Health, Virginia Polytechnic Institute and State University, Roanoke, Virginia 24016
| | - Xiaoran Wei
- Biomedical and Veterinary Sciences Graduate Program, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061
| | - Samantha Brindley
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061
| | - Elizabeth A Harris
- Biomedical and Veterinary Sciences Graduate Program, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061
| | - Alexandra M Kaloss
- Biomedical and Veterinary Sciences Graduate Program, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061
| | - Nicole DeFoor
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061
| | - Swagatika Paul
- Biomedical and Veterinary Sciences Graduate Program, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061
| | - Hannah O'Malley
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061
| | - Jing Ju
- Biomedical and Veterinary Sciences Graduate Program, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061
| | - Michelle L Olsen
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061
| | - Michelle H Theus
- Department of Biomedical Sciences and Pathobiology, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061
| | - Alicia M Pickrell
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, Virginia 24061
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Soliman E, Leonard J, Basso EKG, Gershenson I, Ju J, Mills J, de Jager C, Kaloss AM, Elhassanny M, Pereira D, Chen M, Wang X, Theus MH. Efferocytosis is restricted by axon guidance molecule EphA4 via ERK/Stat6/MERTK signaling following brain injury. J Neuroinflammation 2023; 20:256. [PMID: 37941008 PMCID: PMC10633953 DOI: 10.1186/s12974-023-02940-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2023] [Accepted: 10/30/2023] [Indexed: 11/10/2023] Open
Abstract
BACKGROUND Efferocytosis is a process that removes apoptotic cells and cellular debris. Clearance of these cells alleviates neuroinflammation, prevents the release of inflammatory molecules, and promotes the production of anti-inflammatory cytokines to help maintain tissue homeostasis. The underlying mechanisms by which this occurs in the brain after injury remain ill-defined. METHODS We used GFP bone marrow chimeric knockout (KO) mice to demonstrate that the axon guidance molecule EphA4 receptor tyrosine kinase is involved in suppressing MERTK in the brain to restrict efferocytosis of resident microglia and peripheral-derived monocyte/macrophages. RESULTS Single-cell RNAseq identified MERTK expression, the primary receptor involved in efferocytosis, on monocytes, microglia, and a subset of astrocytes in the damaged cortex following brain injury. Loss of EphA4 on infiltrating GFP-expressing immune cells improved functional outcome concomitant with enhanced efferocytosis and overall protein expression of p-MERTK, p-ERK, and p-Stat6. The percentage of GFP+ monocyte/macrophages and resident microglia engulfing NeuN+ or TUNEL+ cells was significantly higher in KO chimeric mice. Importantly, mRNA expression of Mertk and its cognate ligand Gas6 was significantly elevated in these mice compared to the wild-type. Analysis of cell-specific expression showed that p-ERK and p-Stat6 co-localized with MERTK-expressing GFP + cells in the peri-lesional area of the cortex following brain injury. Using an in vitro efferocytosis assay, co-culturing pHrodo-labeled apoptotic Jurkat cells and bone marrow (BM)-derived macrophages, we demonstrate that efferocytosis efficiency and mRNA expression of Mertk and Gas6 was enhanced in the absence of EphA4. Selective inhibitors of ERK and Stat6 attenuated this effect, confirming that EphA4 suppresses monocyte/macrophage efferocytosis via inhibition of the ERK/Stat6 pathway. CONCLUSIONS Our findings implicate the ERK/Stat6/MERTK axis as a novel regulator of apoptotic debris clearance in brain injury that is restricted by peripheral myeloid-derived EphA4 to prevent the resolution of inflammation.
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Affiliation(s)
- Eman Soliman
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, 24061, USA
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Zagazig University, Zagazig, Egypt
| | - John Leonard
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, 24061, USA
| | | | - Ilana Gershenson
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Jing Ju
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Jatia Mills
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Caroline de Jager
- Translational Biology Medicine and Health Graduate Program, Roanoke, VA, 24001, USA
| | - Alexandra M Kaloss
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Mohamed Elhassanny
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Daniela Pereira
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Michael Chen
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Xia Wang
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Michelle H Theus
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, 24061, USA.
- Translational Biology Medicine and Health Graduate Program, Roanoke, VA, 24001, USA.
- Center for Engineered Health, Virginia Tech, Blacksburg, VA, 24061, USA.
- VT-Biomedical Engineering and School of Neuroscience, 970 Washington Street SW, Life Sciences I; Rm 249 (MC0910), Blacksburg, VA, 24061, USA.
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Cash A, de Jager C, Brickler T, Soliman E, Ladner L, Kaloss AM, Zhu Y, Pridham KJ, Mills J, Ju J, Basso EKG, Chen M, Johnson Z, Sotiropoulos Y, Wang X, Xie H, Matson JB, Marvin EA, Theus MH. Endothelial deletion of EPH receptor A4 alters single-cell profile and Tie2/Akap12 signaling to preserve blood-brain barrier integrity. Proc Natl Acad Sci U S A 2023; 120:e2204700120. [PMID: 37796990 PMCID: PMC10576133 DOI: 10.1073/pnas.2204700120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2022] [Accepted: 09/06/2023] [Indexed: 10/07/2023] Open
Abstract
Neurobiological consequences of traumatic brain injury (TBI) result from a complex interplay of secondary injury responses and sequela that mediates chronic disability. Endothelial cells are important regulators of the cerebrovascular response to TBI. Our work demonstrates that genetic deletion of endothelial cell (EC)-specific EPH receptor A4 (EphA4) using conditional EphA4f/f/Tie2-Cre and EphA4f/f/VE-Cadherin-CreERT2 knockout (KO) mice promotes blood-brain barrier (BBB) integrity and tissue protection, which correlates with improved motor function and cerebral blood flow recovery following controlled cortical impact (CCI) injury. scRNAseq of capillary-derived KO ECs showed increased differential gene expression of BBB-related junctional and actin cytoskeletal regulators, namely, A-kinase anchor protein 12, Akap12, whose presence at Tie2 clustering domains is enhanced in KO microvessels. Transcript and protein analysis of CCI-injured whole cortical tissue or cortical-derived ECs suggests that EphA4 limits the expression of Cldn5, Akt, and Akap12 and promotes Ang2. Blocking Tie2 using sTie2-Fc attenuated protection and reversed Akap12 mRNA and protein levels cortical-derived ECs. Direct stimulation of Tie2 using Vasculotide, angiopoietin-1 memetic peptide, phenocopied the neuroprotection. Finally, we report a noteworthy rise in soluble Ang2 in the sera of individuals with acute TBI, highlighting its promising role as a vascular biomarker for early detection of BBB disruption. These findings describe a contribution of the axon guidance molecule, EphA4, in mediating TBI microvascular dysfunction through negative regulation of Tie2/Akap12 signaling.
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Affiliation(s)
- Alison Cash
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA24061
| | - Caroline de Jager
- Translational Biology Medicine and Health Graduate Program, Virginia Tech, Blacksburg, VA24061
| | - Thomas Brickler
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA24061
| | - Eman Soliman
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA24061
| | - Liliana Ladner
- Virginia Tech Carilion School of Medicine, Virginia Tech, Roanoke, VA24016
| | - Alexandra M. Kaloss
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA24061
| | - Yumeng Zhu
- Department of Chemistry, Virginia Tech, Blacksburg, VA24061
| | - Kevin J. Pridham
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA24061
| | - Jatia Mills
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA24061
| | - Jing Ju
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA24061
| | | | - Michael Chen
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA24061
| | - Zachary Johnson
- Genetics, Bioinformatics and Computational Biology Program, Virginia Tech, Blacksburg, VA24061
- Epigenomics and Computational Biology Lab, Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA24061
| | - Yianni Sotiropoulos
- Summer Veterinary Student Research Program, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA24061
| | - Xia Wang
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA24061
| | - Hehuang Xie
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA24061
- Genetics, Bioinformatics and Computational Biology Program, Virginia Tech, Blacksburg, VA24061
- Epigenomics and Computational Biology Lab, Fralin Life Sciences Institute, Virginia Tech, Blacksburg, VA24061
- Center for Engineered Health, Virginia Tech, Blacksburg, VA24061
| | - John B. Matson
- Department of Chemistry, Virginia Tech, Blacksburg, VA24061
| | - Eric A. Marvin
- Virginia Tech Carilion School of Medicine, Virginia Tech, Roanoke, VA24016
| | - Michelle H. Theus
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA24061
- Summer Veterinary Student Research Program, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA24061
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Soliman E, Leonard J, Basso EK, Gershenson I, Ju J, Mills J, Jager C, Kaloss AM, Elhassanny M, Pereira D, Chen M, Wang X, Theus MH. Efferocytosis is restricted by axon guidance molecule EphA4 via ERK/Stat6/Mertk signaling following brain injury. Res Sq 2023:rs.3.rs-3079466. [PMID: 37461720 PMCID: PMC10350120 DOI: 10.21203/rs.3.rs-3079466/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/24/2023]
Abstract
Background Efferocytosis is a process that removes apoptotic cells and cellular debris. Clearance of these cells alleviates neuroinflammation and prevents the release of inflammatory molecules and promotes the production of anti-inflammatory cytokines to help maintain tissue homeostasis. The underlying mechanisms by which this occurs in the brain after injury remains ill-defined. Methods We demonstrate using GFP bone marrow chimeric knockout (KO) mice, that the axon guidance molecule EphA4 receptor tyrosine kinase is involved in suppressing Mertk signaling in the brain to restrict the function of efferocytosis on resident microglia and peripheral-derived monocyte/macrophages. Results Single-cell RNAseq identified Mertk expression, the primary receptor involved in efferocytosis, on monocytes, microglia, and a subset of astrocytes in the damaged cortex following brain injury. Loss of EphA4 on infiltrating GFP-expressing immune cells improved functional outcome concomitant with enhanced efferocytosis, and overall protein expression of p-Mertk, p-ERK, and p-Stat6. The percentage of GFP+ monocyte/macrophages and resident microglia engulfing NeuN+ or TUNEL+ cells was significantly higher in KO chimeric mice. Importantly, mRNA expression of Mertk and its cognate ligand Gas6 was significantly elevated in these mice compared to wild-type. Analysis of cell-specific expression showed that p-ERK and p-Stat6 co-localized with Mertk-expressing GFP + cells in the peri-lesional area of the cortex following brain injury. Using an in vitro efferocytosis assay, co-culturing pHrodo-labeled apoptotic Jurkat cells and bone marrow (BM)-derived macrophages, we demonstrate that efferocytosis efficiency and mRNA expression of Mertk and Gas6 was enhanced in the absence of EphA4. Select inhibitors of ERK and Stat6 attenuated this effect confirming that EphA4 suppresses monocyte/macrophage efferocytosis via inhibition of the ERK/Stat6 pathway. Conclusions Our findings implicate the Mertk/ERK/Stat6 axis as a novel regulator of apoptotic debris clearance in brain injury that is restricted by peripheral myeloid-derived EphA4 to prevent the resolution of inflammation.
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Gudenschwager-Basso EK, Shandra O, Volanth T, Patel DC, Kelly C, Browning JL, Wei X, Harris EA, Mahmutovic D, Kaloss AM, Correa FG, Decker J, Maharathi B, Robel S, Sontheimer H, VandeVord PJ, Olsen ML, Theus MH. Atypical Neurogenesis, Astrogliosis, and Excessive Hilar Interneuron Loss Are Associated with the Development of Post-Traumatic Epilepsy. Cells 2023; 12:1248. [PMID: 37174647 PMCID: PMC10177146 DOI: 10.3390/cells12091248] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2023] [Revised: 04/02/2023] [Accepted: 04/11/2023] [Indexed: 05/15/2023] Open
Abstract
BACKGROUND Traumatic brain injury (TBI) remains a significant risk factor for post-traumatic epilepsy (PTE). The pathophysiological mechanisms underlying the injury-induced epileptogenesis are under investigation. The dentate gyrus-a structure that is highly susceptible to injury-has been implicated in the evolution of seizure development. METHODS Utilizing the murine unilateral focal control cortical impact (CCI) injury, we evaluated seizure onset using 24/7 EEG video analysis at 2-4 months post-injury. Cellular changes in the dentate gyrus and hilus of the hippocampus were quantified by unbiased stereology and Imaris image analysis to evaluate Prox1-positive cell migration, astrocyte branching, and morphology, as well as neuronal loss at four months post-injury. Isolation of region-specific astrocytes and RNA-Seq were performed to determine differential gene expression in animals that developed post-traumatic epilepsy (PTE+) vs. those animals that did not (PTE-), which may be associated with epileptogenesis. RESULTS CCI injury resulted in 37% PTE incidence, which increased with injury severity and hippocampal damage. Histological assessments uncovered a significant loss of hilar interneurons that coincided with aberrant migration of Prox1-positive granule cells and reduced astroglial branching in PTE+ compared to PTE- mice. We uniquely identified Cst3 as a PTE+-specific gene signature in astrocytes across all brain regions, which showed increased astroglial expression in the PTE+ hilus. CONCLUSIONS These findings suggest that epileptogenesis may emerge following TBI due to distinct aberrant cellular remodeling events and key molecular changes in the dentate gyrus of the hippocampus.
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Affiliation(s)
| | - Oleksii Shandra
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35233, USA
- Department of Biomedical Engineering, Florida International University, Miami, FL 33199, USA
| | - Troy Volanth
- School of Neuroscience, Virginia Tech, Blacksburg, VA 24061, USA
| | - Dipan C. Patel
- School of Neuroscience, Virginia Tech, Blacksburg, VA 24061, USA
| | - Colin Kelly
- Translational Biology Medicine and Health Graduate Program, Blacksburg, VA 24061, USA
| | - Jack L. Browning
- School of Neuroscience, Virginia Tech, Blacksburg, VA 24061, USA
| | - Xiaoran Wei
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA 24061, USA (E.A.H.)
| | - Elizabeth A. Harris
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA 24061, USA (E.A.H.)
| | - Dzenis Mahmutovic
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35233, USA
| | - Alexandra M. Kaloss
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA 24061, USA (E.A.H.)
| | | | - Jeremy Decker
- Department of Biomedical Engineering and Mechanics, Blacksburg, VA 24061, USA
| | - Biswajit Maharathi
- Department of Neurology and Rehabilitation, University of Illinois at Chicago, Chicago, IL 60612, USA
| | - Stefanie Robel
- Department of Cell, Developmental and Integrative Biology, University of Alabama at Birmingham, Birmingham, AL 35233, USA
| | | | - Pamela J. VandeVord
- Department of Biomedical Engineering and Mechanics, Blacksburg, VA 24061, USA
| | | | - Michelle H. Theus
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA 24061, USA (E.A.H.)
- School of Neuroscience, Virginia Tech, Blacksburg, VA 24061, USA
- Center for Engineered Health, Viginia Tech, Blacksburg, VA 24061, USA
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Kowalski EA, Soliman E, Kelly C, Basso EKG, Leonard J, Pridham KJ, Ju J, Cash A, Hazy A, de Jager C, Kaloss AM, Ding H, Hernandez RD, Coleman G, Wang X, Olsen ML, Pickrell AM, Theus MH. Monocyte proinflammatory phenotypic control by ephrin type A receptor 4 mediates neural tissue damage. JCI Insight 2022; 7:e156319. [PMID: 35737458 PMCID: PMC9462496 DOI: 10.1172/jci.insight.156319] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2021] [Accepted: 06/21/2022] [Indexed: 11/29/2022] Open
Abstract
Circulating monocytes have emerged as key regulators of the neuroinflammatory milieu in a number of neuropathological disorders. Ephrin type A receptor 4 (Epha4) receptor tyrosine kinase, a prominent axon guidance molecule, has recently been implicated in the regulation of neuroinflammation. Using a mouse model of brain injury and a GFP BM chimeric approach, we found neuroprotection and a lack of significant motor deficits marked by reduced monocyte/macrophage cortical infiltration and an increased number of arginase-1+ cells in the absence of BM-derived Epha4. This was accompanied by a shift in monocyte gene profile from pro- to antiinflammatory that included increased Tek (Tie2 receptor) expression. Inhibition of Tie2 attenuated enhanced expression of M2-like genes in cultured Epha4-null monocytes/macrophages. In Epha4-BM-deficient mice, cortical-isolated GFP+ monocytes/macrophages displayed a phenotypic shift from a classical to an intermediate subtype, which displayed reduced Ly6chi concomitant with increased Ly6clo- and Tie2-expressing populations. Furthermore, clodronate liposome-mediated monocyte depletion mimicked these effects in WT mice but resulted in attenuation of phenotype in Epha4-BM-deficient mice. This demonstrates that monocyte polarization not overall recruitment dictates neural tissue damage. Thus, coordination of monocyte proinflammatory phenotypic state by Epha4 is a key regulatory step mediating brain injury.
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Affiliation(s)
- Elizabeth A. Kowalski
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, Virginia, USA
| | - Eman Soliman
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, Virginia, USA
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Zagazig University, Zagazig, Egypt
| | - Colin Kelly
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, Virginia, USA
- School of Neuroscience, and
| | | | - John Leonard
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, Virginia, USA
| | - Kevin J. Pridham
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, Virginia, USA
| | - Jing Ju
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, Virginia, USA
| | - Alison Cash
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, Virginia, USA
| | - Amanda Hazy
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, Virginia, USA
| | - Caroline de Jager
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, Virginia, USA
| | - Alexandra M. Kaloss
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, Virginia, USA
| | - Hanzhang Ding
- Translational Biology Medicine and Health Graduate Program, Virginia Tech, Blacksburg, Virginia, USA
| | - Raymundo D. Hernandez
- Translational Biology Medicine and Health Graduate Program, Virginia Tech, Blacksburg, Virginia, USA
| | | | - Xia Wang
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, Virginia, USA
| | | | | | - Michelle H. Theus
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, Virginia, USA
- School of Neuroscience, and
- Translational Biology Medicine and Health Graduate Program, Virginia Tech, Blacksburg, Virginia, USA
- Center for Engineered Health, Virginia Tech, Blacksburg, Virginia, USA
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Kaloss AM, Arnold LN, Soliman E, Langman M, Groot N, Vlaisavljevich E, Theus MH. Noninvasive Low-Intensity Focused Ultrasound Mediates Tissue Protection following Ischemic Stroke. BME Front 2022; 2022:9864910. [PMID: 37850177 PMCID: PMC10521672 DOI: 10.34133/2022/9864910] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Accepted: 05/25/2022] [Indexed: 10/19/2023] Open
Abstract
Objective and Impact Statement. This study examined the efficacy and safety of pulsed, low-intensity focused ultrasound (LIFU) and determined its ability to provide neuroprotection in a murine permanent middle cerebral artery occlusion (pMCAO) model. Introduction. Focused ultrasound (FUS) has emerged as a new therapeutic strategy for the treatment of ischemic stroke; however, its nonthrombolytic properties remain ill-defined. Therefore, we examined how LIFU influenced neuroprotection and vascular changes following stroke. Due to the critical role of leptomeningeal anastomoses or pial collateral vessels, in cerebral blood flow restoration and tissue protection following ischemic stroke, we also investigated their growth and remodeling. Methods. Mice were exposed to transcranial LIFU (fundamental frequency: 1.1 MHz, sonication duration: 300 ms, interstimulus interval: 3 s, pulse repetition frequency: 1 kHz, duty cycle per pulse: 50%, and peak negative pressure: -2.0 MPa) for 30 minutes following induction of pMCAO and then evaluated for infarct volume, blood-brain barrier (BBB) disruption, and pial collateral remodeling at 24 hrs post-pMCAO. Results. We found significant neuroprotection in mice exposed to LIFU compared to mock treatment. These findings correlated with a reduced area of IgG deposition in the cerebral cortex, suggesting attenuation of BBB breakdown under LIFU conditions. We also observed increased diameter of CD31-postive microvessels in the ischemic cortex. We observed no significant difference in pial collateral vessel size between FUS and mock treatment at 24 hrs post-pMCAO. Conclusion. Our data suggests that therapeutic use of LIFU may induce protection through microvascular remodeling that is not related to its thrombolytic activity.
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Affiliation(s)
- Alexandra M. Kaloss
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA 24061, USA
| | - Lauren N. Arnold
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg VA 24061, USA
| | - Eman Soliman
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA 24061, USA
| | - Maya Langman
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg VA 24061, USA
| | - Nathalie Groot
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA 24061, USA
| | - Eli Vlaisavljevich
- Department of Biomedical Engineering and Mechanics, Virginia Tech, Blacksburg VA 24061, USA
- Center for Engineered Health, Virginia Tech, Blacksburg Virginia 24061, USA
| | - Michelle H. Theus
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA 24061, USA
- Center for Engineered Health, Virginia Tech, Blacksburg Virginia 24061, USA
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Fritsch LE, Ju J, Basso EKG, Soliman E, Paul S, Chen J, Kaloss AM, Kowalski EA, Tuhy TC, Somaiya RD, Wang X, Allen IC, Theus MH, Pickrell AM. Corrigendum: Type I Interferon Response Is Mediated by NLRX1-cGAS-STING Signaling in Brain Injury. Front Mol Neurosci 2022; 15:965564. [PMID: 35845611 PMCID: PMC9278162 DOI: 10.3389/fnmol.2022.965564] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Accepted: 06/10/2022] [Indexed: 11/16/2022] Open
Affiliation(s)
- Lauren E. Fritsch
- Translational Biology, Medicine, and Health Graduate Program, Virginia Polytechnic Institute and State University, Roanoke, VA, United States
| | - Jing Ju
- Molecular and Cellular Biology Graduate Program, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | | | - Eman Soliman
- Department of Biomedical Sciences and Pathobiology, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Swagatika Paul
- Biomedical and Veterinary Sciences Graduate Program, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Jiang Chen
- Molecular and Cellular Biology Graduate Program, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Alexandra M. Kaloss
- Department of Biomedical Sciences and Pathobiology, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Elizabeth A. Kowalski
- Department of Biomedical Sciences and Pathobiology, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Taylor C. Tuhy
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Rachana Deven Somaiya
- Translational Biology, Medicine, and Health Graduate Program, Virginia Polytechnic Institute and State University, Roanoke, VA, United States
| | - Xia Wang
- Department of Biomedical Sciences and Pathobiology, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Irving Coy Allen
- Department of Biomedical Sciences and Pathobiology, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Michelle H. Theus
- Department of Biomedical Sciences and Pathobiology, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
- Michelle H. Theus
| | - Alicia M. Pickrell
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
- *Correspondence: Alicia M. Pickrell
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Fritsch LE, Ju J, Gudenschwager Basso EK, Soliman E, Paul S, Chen J, Kaloss AM, Kowalski EA, Tuhy TC, Somaiya RD, Wang X, Allen IC, Theus MH, Pickrell AM. Type I Interferon Response Is Mediated by NLRX1-cGAS-STING Signaling in Brain Injury. Front Mol Neurosci 2022; 15:852243. [PMID: 35283725 PMCID: PMC8916033 DOI: 10.3389/fnmol.2022.852243] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2022] [Accepted: 02/02/2022] [Indexed: 01/05/2023] Open
Abstract
Background Inflammation is a significant contributor to neuronal death and dysfunction following traumatic brain injury (TBI). Recent evidence suggests that interferons may be a key regulator of this response. Our studies evaluated the role of the Cyclic GMP-AMP Synthase-Stimulator of Interferon Genes (cGAS-STING) signaling pathway in a murine model of TBI. Methods Male, 8-week old wildtype, STING knockout (−/−), cGAS−/−, and NLRX1−/− mice were subjected to controlled cortical impact (CCI) or sham injury. Histopathological evaluation of tissue damage was assessed using non-biased stereology, which was complemented by analysis at the mRNA and protein level using qPCR and western blot analysis, respectively. Results We found that STING and Type I interferon-stimulated genes were upregulated after CCI injury in a bi-phasic manner and that loss of cGAS or STING conferred neuroprotection concomitant with a blunted inflammatory response at 24 h post-injury. cGAS−/− animals showed reduced motor deficits 4 days after injury (dpi), and amelioration of tissue damage was seen in both groups of mice up to 14 dpi. Given that cGAS requires a cytosolic damage- or pathogen-associated molecular pattern (DAMP/PAMP) to prompt downstream STING signaling, we further demonstrate that mitochondrial DNA is present in the cytosol after TBI as one possible trigger for this pathway. Recent reports suggest that the immune modulator NLR containing X1 (NLRX1) may sequester STING during viral infection. Our findings show that NLRX1 may be an additional regulator that functions upstream to regulate the cGAS-STING pathway in the brain. Conclusions These findings suggest that the canonical cGAS-STING-mediated Type I interferon signaling axis is a critical component of neural tissue damage following TBI and that mtDNA may be a possible trigger in this response.
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Affiliation(s)
- Lauren E. Fritsch
- Translational Biology, Medicine, and Health Graduate Program, Virginia Polytechnic Institute and State University, Roanoke, VA, United States
| | - Jing Ju
- Molecular and Cellular Biology Graduate Program, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | | | - Eman Soliman
- Department of Biomedical Sciences and Pathobiology, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Swagatika Paul
- Biomedical and Veterinary Sciences Graduate Program, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Jiang Chen
- Molecular and Cellular Biology Graduate Program, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Alexandra M. Kaloss
- Department of Biomedical Sciences and Pathobiology, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Elizabeth A. Kowalski
- Department of Biomedical Sciences and Pathobiology, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Taylor C. Tuhy
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Rachana Deven Somaiya
- Translational Biology, Medicine, and Health Graduate Program, Virginia Polytechnic Institute and State University, Roanoke, VA, United States
| | - Xia Wang
- Department of Biomedical Sciences and Pathobiology, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Irving Coy Allen
- Department of Biomedical Sciences and Pathobiology, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
| | - Michelle H. Theus
- Department of Biomedical Sciences and Pathobiology, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
- *Correspondence: Alicia M. Pickrell Michelle H. Theus
| | - Alicia M. Pickrell
- School of Neuroscience, Virginia Polytechnic Institute and State University, Blacksburg, VA, United States
- *Correspondence: Alicia M. Pickrell Michelle H. Theus
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10
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Kaloss AM, Theus MH. Leptomeningeal anastomoses: Mechanisms of pial collateral remodeling in ischemic stroke. WIREs Mech Dis 2022; 14:e1553. [PMID: 35118835 PMCID: PMC9283306 DOI: 10.1002/wsbm.1553] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Revised: 01/09/2022] [Accepted: 01/11/2022] [Indexed: 12/13/2022]
Abstract
Arterial collateralization, as determined by leptomeningeal anastomoses or pial collateral vessels, is a well‐established vital player in cerebral blood flow restoration and neurological recovery from ischemic stroke. A secondary network of cerebral collateral circulation apart from the Circle of Willis, exist as remnants of arteriole development that connect the distal arteries in the pia mater. Recent interest lies in understanding the cellular and molecular adaptations that control the growth and remodeling, or arteriogenesis, of these pre‐existing collateral vessels. New findings from both animal models and human studies of ischemic stroke suggest a multi‐factorial and complex, temporospatial interplay of endothelium, immune and vessel‐associated cell interactions may work in concert to facilitate or thwart arteriogenesis. These valuable reports may provide critical insight into potential predictors of the pial collateral response in patients with large vessel occlusion and may aid in therapeutics to enhance collateral function and improve recovery from stroke. This article is categorized under:Neurological Diseases > Molecular and Cellular Physiology
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Affiliation(s)
- Alexandra M Kaloss
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Tech, Blacksburg, Virginia, USA
| | - Michelle H Theus
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Tech, Blacksburg, Virginia, USA.,School of Neuroscience, Virginia Tech, Blacksburg, Virginia, USA.,Center for Regenerative Medicine, Virginia-Maryland Regional College of Veterinary Medicine, Virginia Tech, Blacksburg, Virginia, USA
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11
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Soliman E, Mills J, Ju J, Kaloss AM, Basso EKG, Groot N, Kelly C, Kowalski EA, Elhassanny M, Chen M, Wang X, Theus MH. Conditional Deletion of EphA4 on Cx3cr1-Expressing Microglia Fails to Influence Histopathological Outcome and Blood Brain Barrier Disruption Following Brain Injury. Front Mol Neurosci 2021; 14:747770. [PMID: 34630039 PMCID: PMC8497746 DOI: 10.3389/fnmol.2021.747770] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2021] [Accepted: 08/25/2021] [Indexed: 11/13/2022] Open
Abstract
Erythropoietin-producing human hepatocellular receptors play a major role in central nervous system injury. Preclinical and clinical studies revealed the upregulation of erythropoietin-producing human hepatocellular A4 (EphA4) receptors in the brain after acute traumatic brain injury. We have previously reported that Cx3cr1-expressing cells in the peri-lesion show high levels of EphA4 after the induction of controlled cortical impact (CCI) injury in mice. Cx3cr1 is a fractalkine receptor expressed on both resident microglia and peripheral-derived macrophages. The current study aimed to determine the role of microglial-specific EphA4 in CCI-induced damage. We used Cx3cr1 CreER/+ knock-in/knock-out mice, which express EYFP in Cx3cr1-positive cells to establish microglia, EphA4-deficient mice following 1-month tamoxifen injection. Consistent with our previous findings, induction of CCI in wild-type (WT) Cx3cr1 CreER/+ EphA4 +/+ mice increased EphA4 expression on EYFP-positive cells in the peri-lesion. To distinguish between peripheral-derived macrophages and resident microglia, we exploited GFP bone marrow-chimeric mice and found that CCI injury increased EphA4 expression in microglia (TMEM119+GFP-) using immunohistochemistry. Using Cx3cr1 CreER/+ EphA4 f/f (KO) mice, we observed that the EphA4 mRNA transcript was undetected in microglia but remained present in whole blood when compared to WT. Finally, we found no difference in lesion volume or blood-brain barrier (BBB) disruption between WT and KO mice at 3 dpi. Our data demonstrate a nonessential role of microglial EphA4 in the acute histopathological outcome in response to CCI.
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Affiliation(s)
- Eman Soliman
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, United States.,Department of Pharmacology and Toxicology, Faculty of Pharmacy, Zagazig University, Zagazig, Egypt
| | - Jatia Mills
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, United States
| | - Jing Ju
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, United States
| | - Alexandra M Kaloss
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, United States
| | | | - Nathalie Groot
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, United States
| | - Colin Kelly
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, United States
| | - Elizabeth A Kowalski
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, United States
| | - Mohamed Elhassanny
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, United States
| | - Michael Chen
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, United States
| | - Xia Wang
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, United States
| | - Michelle H Theus
- Department of Biomedical Sciences and Pathobiology, Virginia Tech, Blacksburg, VA, United States.,School of Neuroscience, Virginia Tech, Blacksburg, VA, United States.,Center for Engineered Health, Virginia Tech, Blacksburg, VA, United States
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12
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Partridge B, Rossmeisl JH, Kaloss AM, Basso EKG, Theus MH. Novel ablation methods for treatment of gliomas. J Neurosci Methods 2020; 336:108630. [PMID: 32068011 DOI: 10.1016/j.jneumeth.2020.108630] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2019] [Revised: 02/05/2020] [Accepted: 02/05/2020] [Indexed: 12/18/2022]
Abstract
Primary brain tumors are among the deadliest cancers that remain highly incurable. A need exists for new approaches to tumor therapy that can circumvent the blood brain barrier (BBB), target highly resistant tumors and cancer stem-like cells (CSCs) as well create an anti-cancer immunomodulatory environment. Successful treatments may also require a combinatory approach utilizing surgery, chemotherapy, radiation and novel ablation strategies that can both eliminate the bulk tumor and prevent any potential residual CSCs from propagating in the resected tissue. A number of thermal and non-thermal ablation methods have been developed and tested, which have gained much enthusiasm for the treatment of brain tumors. Here we review the most common primary brain tumors and the candidate ablation methods for targeting the tumor and its microenvironment.
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Affiliation(s)
- Brittanie Partridge
- Veterinary and Comparative Neuro-oncology Laboratory, Department of Small Animal Clinical Sciences, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA, 24061, USA
| | - John H Rossmeisl
- Veterinary and Comparative Neuro-oncology Laboratory, Department of Small Animal Clinical Sciences, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Alexandra M Kaloss
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA 24061, USA
| | - Erwin Kristobal Gudenschwager Basso
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA 24061, USA
| | - Michelle H Theus
- Department of Biomedical Sciences and Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, VA 24061, USA; School of Neuroscience, Virginia Tech, Blacksburg VA 24061, USA; Center for Regenerative Medicine, VT College of Veterinary Medicine, Blacksburg, Virginia, 24061, USA.
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