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Oganezovi N, Lagani V, Kikvidze M, Gamkrelidze G, Tsverava L, Lepsveridze E, Kelly KM, Solomonia R. Long-term effects of myo-inositol on traumatic brain injury: Epigenomic and transcriptomic studies. IBRO Neurosci Rep 2024; 16:291-299. [PMID: 38374956 PMCID: PMC10875114 DOI: 10.1016/j.ibneur.2024.01.009] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2023] [Accepted: 01/27/2024] [Indexed: 02/21/2024] Open
Abstract
Background and purpose Traumatic brain injury (TBI) and its consequences remain great challenges for neurology. Consequences of TBI are associated with various alterations in the brain but little is known about long-term changes of epigenetic DNA methylation patterns. Moreover, nothing is known about potential treatments that can alter these epigenetic changes in beneficial ways. Therefore, we have examined myo-inositol (MI), which has positive effects on several pathological conditions. Methods TBI was induced in mice by controlled cortical impact (CCI). One group of CCI animals received saline injections for two months (TBI+SAL), another CCI group received MI treatment (TBI+MI) for the same period and one group served as a sham-operated control. Mice were sacrificed 4 months after CCI and changes in DNA methylome and transcriptomes were examined. Results For the first time we: (i) provide comprehensive map of long-term DNA methylation changes after CCI in the hippocampus; (ii) identify differences by methylation sites between the groups; (iii) characterize transcriptome changes; (iv) provide association between DNA methylation sites and gene expression. MI treatment is linked with upregulation of genes covering 33 biological processes, involved in immune response and inflammation. In support of these findings, we have shown that expression of BATF2, a transcription factor involved in immune-regulatory networks, is upregulated in the hippocampus of the TBI+MI group where the BATF2 gene is demethylated. Conclusion TBI is followed by long-term epigenetic and transcriptomic changes in hippocampus. MI treatment has a significant effect on these processes by modulation of immune response and biological pathways of inflammation.
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Affiliation(s)
- Nino Oganezovi
- School of Natural Sciences and Medicine, Institute of Chemical Biology, Ilia State University, Tbilisi, Georgia
| | - Vincenzo Lagani
- School of Natural Sciences and Medicine, Institute of Chemical Biology, Ilia State University, Tbilisi, Georgia
- Biological and Environmental Sciences and Engineering Division, King Abdullah University of Science and Technology, Thuwal 23955, Saudi Arabia
| | - Marine Kikvidze
- School of Natural Sciences and Medicine, Institute of Chemical Biology, Ilia State University, Tbilisi, Georgia
| | - Georgi Gamkrelidze
- School of Natural Sciences and Medicine, Institute of Chemical Biology, Ilia State University, Tbilisi, Georgia
| | - Lia Tsverava
- School of Natural Sciences and Medicine, Institute of Chemical Biology, Ilia State University, Tbilisi, Georgia
- Iv. Beritashvili Centre of Experimental Biomedicine, Tbilisi, Georgia
| | - Eka Lepsveridze
- School of Natural Sciences and Medicine, Institute of Chemical Biology, Ilia State University, Tbilisi, Georgia
| | - Kevin M. Kelly
- Department of Neurobiology and Anatomy, Drexel University College of Medicine, Philadelphia, PA, United States
- Department of Neurology, Philadelphia, PA, United States
- Department of Neurology, Allegheny General Hospital, Pittsburgh, PA, United States
- Center for Neuroscience Research, Allegheny Health Network Research Institute, Pittsburgh, PA, United States, Drexel University College of Medicine, Philadelphia, PA, United States
| | - Revaz Solomonia
- School of Natural Sciences and Medicine, Institute of Chemical Biology, Ilia State University, Tbilisi, Georgia
- Iv. Beritashvili Centre of Experimental Biomedicine, Tbilisi, Georgia
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Kang YJ, Lee SH, Boychuk JA, Butler CR, Juras JA, Cloyd RA, Smith BN. Adult Born Dentate Granule Cell Mediated Upregulation of Feedback Inhibition in a Mouse Model of Traumatic Brain Injury. J Neurosci 2022; 42:7077-7093. [PMID: 36002261 PMCID: PMC9480876 DOI: 10.1523/jneurosci.2263-21.2022] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Revised: 08/09/2022] [Accepted: 08/11/2022] [Indexed: 11/21/2022] Open
Abstract
Post-traumatic epilepsy (PTE) and behavioral comorbidities frequently develop after traumatic brain injury (TBI). Aberrant neurogenesis of dentate granule cells (DGCs) after TBI may contribute to the synaptic reorganization that occurs in PTE, but how neurogenesis at different times relative to the injury contributes to feedback inhibition and recurrent excitation in the dentate gyrus is unknown. Thus, we examined whether DGCs born at different postnatal ages differentially participate in feedback inhibition and recurrent excitation in the dentate gyrus using the controlled cortical impact (CCI) model of TBI. Both sexes of transgenic mice expressing channelrhodopsin2 (ChR2) in postnatally born DGCs were used for optogenetic activation of three DGC cohorts: postnatally early born DGCs, or those born just before or after CCI. We performed whole-cell patch-clamp recordings from ChR2-negative, mature DGCs and parvalbumin-expressing basket cells (PVBCs) in hippocampal slices to determine whether optogenetic activation of postnatally born DGCs increases feedback inhibition and/or recurrent excitation in mice 8-10 weeks after CCI and whether PVBCs are targets of ChR2-positive DGCs. In the dentate gyrus ipsilateral to CCI, activation of ChR2-expressing DGCs born before CCI produced increased feedback inhibition in ChR2-negative DGCs and increased excitation in PVBCs compared with those from sham controls. This upregulated feedback inhibition was less prominent in DGCs born early in life or after CCI. Surprisingly, ChR2-positive DGC activation rarely evoked recurrent excitation in mature DGCs from any cohort. These results support that DGC birth date-related increased feedback inhibition in of DGCs may contribute to altered excitability after TBI.SIGNIFICANCE STATEMENT Dentate granule cells (DGCs) control excitability of the dentate gyrus through synaptic interactions with inhibitory GABAergic interneurons. Persistent changes in DGC synaptic connectivity develop after traumatic brain injury, contributing to hyperexcitability in post-traumatic epilepsy (PTE). However, the impact of DGC neurogenesis on synaptic reorganization, especially on inhibitory circuits, after brain injury is not adequately described. Here, upregulation of feedback inhibition in mature DGCs from male and female mice was associated with increased excitation of parvalbumin-expressing basket cells by postnatally born DGCs, providing novel insights into underlying mechanisms of altered excitability after brain injury. A better understanding of these inhibitory circuit changes can help formulate hypotheses for development of novel, evidence-based treatments for post-traumatic epilepsy by targeting birth date-specific subsets of DGCs.
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Affiliation(s)
- Young-Jin Kang
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado 80523
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, Kentucky 40536
| | - Sang-Hun Lee
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado 80523
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, Kentucky 40536
- Epilepsy Research Center, University of Kentucky, Lexington, Kentucky 40536
| | - Jeffery A Boychuk
- Epilepsy Research Center, University of Kentucky, Lexington, Kentucky 40536
- Department of Physiology, College of Medicine, University of Kentucky, Lexington, Kentucky 40536
| | - Corwin R Butler
- Department of Physiology, College of Medicine, University of Kentucky, Lexington, Kentucky 40536
| | - J Anna Juras
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, Kentucky 40536
| | - Ryan A Cloyd
- Department of Physiology, College of Medicine, University of Kentucky, Lexington, Kentucky 40536
| | - Bret N Smith
- Department of Biomedical Sciences, Colorado State University, Fort Collins, Colorado 80523
- Department of Neuroscience, College of Medicine, University of Kentucky, Lexington, Kentucky 40536
- Epilepsy Research Center, University of Kentucky, Lexington, Kentucky 40536
- Department of Physiology, College of Medicine, University of Kentucky, Lexington, Kentucky 40536
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky 40536
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Sharma S, Tiarks G, Haight J, Bassuk AG. Neuropathophysiological Mechanisms and Treatment Strategies for Post-traumatic Epilepsy. Front Mol Neurosci 2021; 14:612073. [PMID: 33708071 PMCID: PMC7940684 DOI: 10.3389/fnmol.2021.612073] [Citation(s) in RCA: 20] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2020] [Accepted: 01/26/2021] [Indexed: 12/11/2022] Open
Abstract
Traumatic brain injury (TBI) is a leading cause of death in young adults and a risk factor for acquired epilepsy. Severe TBI, after a period of time, causes numerous neuropsychiatric and neurodegenerative problems with varying comorbidities; and brain homeostasis may never be restored. As a consequence of disrupted equilibrium, neuropathological changes such as circuit remodeling, reorganization of neural networks, changes in structural and functional plasticity, predisposition to synchronized activity, and post-translational modification of synaptic proteins may begin to dominate the brain. These pathological changes, over the course of time, contribute to conditions like Alzheimer disease, dementia, anxiety disorders, and post-traumatic epilepsy (PTE). PTE is one of the most common, devastating complications of TBI; and of those affected by a severe TBI, more than 50% develop PTE. The etiopathology and mechanisms of PTE are either unknown or poorly understood, which makes treatment challenging. Although anti-epileptic drugs (AEDs) are used as preventive strategies to manage TBI, control acute seizures and prevent development of PTE, their efficacy in PTE remains controversial. In this review, we discuss novel mechanisms and risk factors underlying PTE. We also discuss dysfunctions of neurovascular unit, cell-specific neuroinflammatory mediators and immune response factors that are vital for epileptogenesis after TBI. Finally, we describe current and novel treatments and management strategies for preventing PTE.
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Affiliation(s)
- Shaunik Sharma
- Medical Laboratories, Department of Pediatrics, University of Iowa, Iowa City, IA, United States
| | - Grant Tiarks
- Medical Laboratories, Department of Pediatrics, University of Iowa, Iowa City, IA, United States
| | - Joseph Haight
- Medical Laboratories, Department of Pediatrics, University of Iowa, Iowa City, IA, United States
| | - Alexander G Bassuk
- Medical Laboratories, Department of Pediatrics, University of Iowa, Iowa City, IA, United States
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Perucca P, Smith G, Santana-Gomez C, Bragin A, Staba R. Electrophysiological biomarkers of epileptogenicity after traumatic brain injury. Neurobiol Dis 2018; 123:69-74. [PMID: 29883622 DOI: 10.1016/j.nbd.2018.06.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2018] [Revised: 05/30/2018] [Accepted: 06/03/2018] [Indexed: 02/08/2023] Open
Abstract
Post-traumatic epilepsy is the architype of acquired epilepsies, wherein a brain insult initiates an epileptogenic process culminating in an unprovoked seizure after weeks, months or years. Identifying biomarkers of such process is a prerequisite for developing and implementing targeted therapies aimed at preventing the development of epilepsy. Currently, there are no validated electrophysiological biomarkers of post-traumatic epileptogenesis. Experimental EEG studies using the lateral fluid percussion injury model have identified three candidate biomarkers of post-traumatic epileptogenesis: pathological high-frequency oscillations (HFOs, 80-300 Hz); repetitive HFOs and spikes (rHFOSs); and reduction in sleep spindle duration and dominant frequency at the transition from stage III to rapid eye movement sleep. EEG studies in humans have yielded conflicting data; recent evidence suggests that epileptiform abnormalities detected acutely after traumatic brain injury carry a significantly increased risk of subsequent epilepsy. Well-designed studies are required to validate these promising findings, and ultimately establish whether there are post-traumatic electrophysiological features which can guide the development of 'antiepileptogenic' therapies.
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Affiliation(s)
- Piero Perucca
- Department of Neuroscience, Central Clinical School, Monash University, Melbourne, VIC, Australia; Department of Neurology, The Royal Melbourne Hospital, Melbourne, VIC, Australia; Department of Neurology, Alfred Health, Melbourne, VIC, Australia; Melbourne Medical School, The University of Melbourne, Melbourne, VIC, Australia.
| | - Gregory Smith
- Department of Neurosurgery, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Cesar Santana-Gomez
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Anatol Bragin
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
| | - Richard Staba
- Department of Neurology, David Geffen School of Medicine at UCLA, Los Angeles, CA, USA
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