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Leonard J, Wei X, Browning J, Gudenschwager-Basso EK, Li J, Harris EA, Olsen ML, Theus MH. Transcriptomic alterations in cortical astrocytes following the development of post-traumatic epilepsy. Sci Rep 2024; 14:8367. [PMID: 38600221 PMCID: PMC11006850 DOI: 10.1038/s41598-024-58904-z] [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: 11/21/2023] [Accepted: 04/04/2024] [Indexed: 04/12/2024] Open
Abstract
Post-traumatic epilepsy (PTE) stands as one of the numerous debilitating consequences that follow traumatic brain injury (TBI). Despite its impact on many individuals, the current landscape offers only a limited array of reliable treatment options, and our understanding of the underlying mechanisms and susceptibility factors remains incomplete. Among the potential contributors to epileptogenesis, astrocytes, a type of glial cell, have garnered substantial attention as they are believed to promote hyperexcitability and the development of seizures in the brain following TBI. The current study evaluated the transcriptomic changes in cortical astrocytes derived from animals that developed seizures as a result of severe focal TBI. Using RNA-Seq and ingenuity pathway analysis (IPA), we unveil a distinct gene expression profile in astrocytes, including alterations in genes supporting inflammation, early response modifiers, and neuropeptide-amidating enzymes. The findings underscore the complex molecular dynamics in astrocytes during PTE development, offering insights into therapeutic targets and avenues for further exploration.
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Affiliation(s)
- John Leonard
- Department of Biomedical Sciences and Pathobiology, Faculty of Health Sciences, Virginia Tech, 970 Washington Street SW, Life Sciences I; Rm 249 (MC0910), Blacksburg, VA, 24061, USA
| | - Xiaoran Wei
- School of Neuroscience, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Jack Browning
- School of Neuroscience, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Erwin Kristobal Gudenschwager-Basso
- Department of Biomedical Sciences and Pathobiology, Faculty of Health Sciences, Virginia Tech, 970 Washington Street SW, Life Sciences I; Rm 249 (MC0910), Blacksburg, VA, 24061, USA
| | - Jiangtao Li
- School of Neuroscience, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Elizabeth A Harris
- Department of Biomedical Sciences and Pathobiology, Faculty of Health Sciences, Virginia Tech, 970 Washington Street SW, Life Sciences I; Rm 249 (MC0910), Blacksburg, VA, 24061, USA
| | - Michelle L Olsen
- School of Neuroscience, Virginia Tech, Blacksburg, VA, 24061, USA
| | - Michelle H Theus
- Department of Biomedical Sciences and Pathobiology, Faculty of Health Sciences, Virginia Tech, 970 Washington Street SW, Life Sciences I; Rm 249 (MC0910), Blacksburg, VA, 24061, USA.
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Stevenson VB, Gudenschwager-Basso EK, Klahn S, LeRoith T, Huckle WR. Inhibitory checkpoint molecule mRNA expression in canine soft tissue sarcoma. Vet Comp Oncol 2023; 21:709-716. [PMID: 37680007 PMCID: PMC10841275 DOI: 10.1111/vco.12934] [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: 02/16/2023] [Revised: 07/31/2023] [Accepted: 08/10/2023] [Indexed: 09/09/2023]
Abstract
Canine soft tissue sarcomas (STS) are common neoplasms and considered immune deserts. Tumour infiltrating lymphocytes are sparse in STS and, when present, tend to organize around blood vessels or at the periphery of the neoplasm. This pattern is associated with an immunosuppressive tumour microenvironment linked to overexpression of molecules of the PD-axis. PD-1, PD-L1 and PD-L2 expression correlates with malignancy and poor prognosis in other neoplasms in humans and dogs, but little is known about their role in canine STS, their relationship to tumour grade, and how different therapies affect expression. The objective of this study was to evaluate the expression of checkpoint molecules across STS tumour grades and after tumour ablation treatment. Gene expression analysis was performed by reverse-transcriptase real-time quantitative PCR in soft tissue sarcomas that underwent histotripsy and from histologic specimens of STS from the Virginia Tech Animal Laboratory Services archives. The expression of PD-1, PD-L1 and PD-L2 was detected in untreated STS tissue representing grades 1, 2, and 3. Numerically decreased expression of all markers was observed in tissue sampled from the treatment interface relative to untreated areas of the tumour. The relatively lower expression of these checkpoint molecules at the periphery of the treated area may be related to liquefactive necrosis induced by the histotripsy treatment, and would potentially allow TILs to infiltrate the tumour. Relative increases of these checkpoint molecules in tumours of a higher grade and alongside immune cell infiltration are consistent with previous reports that associate their expression with malignancy.
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Affiliation(s)
- Valentina Beatriz Stevenson
- Department of Biomedical Sciences & Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, Virginia, USA
| | - Erwin Kristobal Gudenschwager-Basso
- Department of Biomedical Sciences & Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, Virginia, USA
| | - Shawna Klahn
- Department of Small Animal Clinical Sciences, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, Virginia, USA
| | - Tanya LeRoith
- Department of Biomedical Sciences & Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, Virginia, USA
| | - William R. Huckle
- Department of Biomedical Sciences & Pathobiology, Virginia-Maryland College of Veterinary Medicine, Virginia Tech, Blacksburg, Virginia, USA
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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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