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Li D, Li S, Pan M, Li Q, Song J, Zhang R. The role of extracellular glutamate homeostasis dysregulated by astrocyte in epileptic discharges: a model evidence. Cogn Neurodyn 2024; 18:485-502. [PMID: 38699615 PMCID: PMC11061099 DOI: 10.1007/s11571-023-10001-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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2023] [Revised: 07/26/2023] [Accepted: 08/13/2023] [Indexed: 05/05/2024] Open
Abstract
Glutamate (Glu) is a predominant excitatory neurotransmitter that acts on glutamate receptors to transfer signals in the central nervous system. Abnormally elevated extracellular glutamate levels is closely related to the generation and transition of epileptic seizures. However, there lacks of investigation regarding the role of extracellular glutamate homeostasis dysregulated by astrocyte in neuronal epileptic discharges. According to this, we propose a novel neuron-astrocyte computational model (NAG) by incorporating extracellular Glu concentration dynamics from three aspects of regulatory mechanisms: (1) the Glu uptake through astrocyte EAAT2; (2) the binding and release Glu via activating astrocyte mGluRs; and (3) the Glu free diffusion in the extracellular space. Then the proposed model NAG is analyzed theoretically and numerically to verify the effect of extracellular Glu homeostasis dysregulated by such three regulatory mechanisms on neuronal epileptic discharges. Our results demonstrate that the neuronal epileptic discharges can be aggravated by the downregulation expression of EAAT2, the aberrant activation of mGluRs, and the elevated Glu levels in extracellular micro-environment; as well as various discharge states (including bursting, mixed-mode spiking, and tonic firing) can be transited by their combination. Furthermore, we find that such factors can also alter the bifurcation threshold for the generation and transition of epileptic discharges. The results in this paper can be helpful for researchers to understand the astrocyte role in modulating extracellular Glu homeostasis, and provide theoretical basis for future related experimental studies.
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Affiliation(s)
- Duo Li
- The Medical Big Data Research Center and The School of Mathematics, Northwest University, Xi’an, 710127 China
| | - Sihui Li
- The Medical Big Data Research Center and The School of Mathematics, Northwest University, Xi’an, 710127 China
| | - Min Pan
- The Medical Big Data Research Center and The School of Mathematics, Northwest University, Xi’an, 710127 China
| | - Qiang Li
- The Medical Big Data Research Center and The School of Mathematics, Northwest University, Xi’an, 710127 China
| | - Jiangling Song
- The Medical Big Data Research Center and The School of Mathematics, Northwest University, Xi’an, 710127 China
| | - Rui Zhang
- The Medical Big Data Research Center and The School of Mathematics, Northwest University, Xi’an, 710127 China
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2
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Rylaarsdam L, Rakotomamonjy J, Pope E, Guemez-Gamboa A. iPSC-derived models of PACS1 syndrome reveal transcriptional and functional deficits in neuron activity. Nat Commun 2024; 15:827. [PMID: 38280846 PMCID: PMC10821916 DOI: 10.1038/s41467-024-44989-7] [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: 05/13/2022] [Accepted: 01/11/2024] [Indexed: 01/29/2024] Open
Abstract
PACS1 syndrome is a neurodevelopmental disorder characterized by intellectual disability and distinct craniofacial abnormalities resulting from a de novo p.R203W variant in phosphofurin acidic cluster sorting protein 1 (PACS1). PACS1 is known to have functions in the endosomal pathway and nucleus, but how the p.R203W variant affects developing neurons is not fully understood. Here we differentiated stem cells towards neuronal models including cortical organoids to investigate the impact of the PACS1 syndrome-causing variant on neurodevelopment. While few deleterious effects were detected in PACS1(+/R203W) neural precursors, mature PACS1(+/R203W) glutamatergic neurons exhibited impaired expression of genes involved in synaptic signaling processes. Subsequent characterization of neural activity using calcium imaging and multielectrode arrays revealed the p.R203W PACS1 variant leads to a prolonged neuronal network burst duration mediated by an increased interspike interval. These findings demonstrate the impact of the PACS1 p.R203W variant on developing human neural tissue and uncover putative electrophysiological underpinnings of disease.
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Affiliation(s)
- Lauren Rylaarsdam
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Jennifer Rakotomamonjy
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Eleanor Pope
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA
| | - Alicia Guemez-Gamboa
- Department of Neuroscience, Feinberg School of Medicine, Northwestern University, Chicago, IL, USA.
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3
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Vizcarra EA, Ulu A, Landrith TA, Qiu X, Godzik A, Wilson EH. Group 1 metabotropic glutamate receptor expression defines a T cell memory population during chronic Toxoplasma infection that enhances IFN-gamma and perforin production in the CNS. Brain Behav Immun 2023; 114:131-143. [PMID: 37604212 DOI: 10.1016/j.bbi.2023.08.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/06/2023] [Revised: 08/11/2023] [Accepted: 08/15/2023] [Indexed: 08/23/2023] Open
Abstract
Within the brain, a pro-inflammatory response is essential to prevent clinical disease due to Toxoplasma gondii reactivation. Infection in the immunocompromised leads to lethal Toxoplasmic encephalitis while in the immunocompetent, there is persistent low-grade inflammation which is devoid of clinical symptoms. This signifies that there is a well-balanced and regulated inflammatory response to T. gondii in the brain. T cells are the dominant immune cells that prevent clinical disease, and this is mediated through the secretion of effector molecules such as perforins and IFN-γ. The presence of cognate antigen, the expression of survival cytokines, and the alteration of the epigenetic landscape drive the development of memory T cells. However, specific extrinsic signals that promote the formation and maintenance of memory T cells within tissue are poorly understood. During chronic infection, there is an increase in extracellular glutamate that, due to its function as an excitatory neurotransmitter, is normally tightly controlled in the CNS. Here we demonstrate that CD8+ T cells from the T. gondii-infected brain parenchyma are enriched for metabotropic glutamate receptors (mGluR's). Characterization studies determined that mGluR+ expression by CD8+ T cells defines a distinct memory population at the transcriptional and protein level. Finally, using receptor antagonists and agonists we demonstrate mGluR signaling is required for optimal CD8+ T cell production of the effector cytokine IFNγ. This work suggests that glutamate is an important environmental signal of inflammation that promotes T cell function. Understanding glutamate's influence on T cells in the brain can provide insights into the mechanisms that govern protective immunity against CNS-infiltrating pathogens and neuroinflammation.
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Affiliation(s)
- Edward A Vizcarra
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA 92521, United States
| | - Arzu Ulu
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA 92521, United States
| | - Tyler A Landrith
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA 92521, United States
| | - Xinru Qiu
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA 92521, United States
| | - Adam Godzik
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA 92521, United States
| | - Emma H Wilson
- Division of Biomedical Sciences, School of Medicine, University of California, Riverside, CA 92521, United States.
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Rajput A, Sharma P, Kumar N, Singh H, Singh T, Singh S, Singh Bedi PM, Singh B, Arora S, Kaur S. Anticonvulsant potential of Grewia tiliaefolia in pentylenetetrazole induced epilepsy: insights from in vivo and in silico studies. Metab Brain Dis 2023; 38:2355-2367. [PMID: 37436587 DOI: 10.1007/s11011-023-01252-0] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Accepted: 06/07/2023] [Indexed: 07/13/2023]
Abstract
Epilepsy, a chronic neurological condition, impacts millions of individuals globally and remains a significant contributor to both illness and mortality. Available antiepileptic drugs have serious side effects which warrants to explore different medicinal plants used for the management of epilepsy reported in Traditional Indian Medicinal System (TIMS). Therefore, we explored the antiepileptic potential of the Grewia tiliaefolia (Tiliaeceae) which is known for its neuroprotective properties. Aerial parts of G. tiliaefolia were subjected to extraction with increasing order of polarity viz. hexane, chloroform and methanol. Antioxidant potential of hexane, chloroform and methanol extracts of G. tiliaefolia was evaluated by 2,2-diphenyl-1-picryl-hydrazyl-hydrate (DPPH) assay, total antioxidant capacity (TAC) assay, reducing power assay (RPA) and DNA nicking assay. Additionally, quantitative antioxidant assays were also conducted to quantify total phenolic (TPC) and total flavonoid content (TFC). As revealed by in vitro assays, methanol extract was found to contain more phenolic content. Hence, the methanol extract was further explored for its anticonvulsant potential in pentylenetetrazole (PTZ) induced acute seizures in mice. The methanol extract (400 mg/kg) significantly increased the latency to occurrence of myoclonic jerks and generalized tonic clonic seizures (GTCS). Additionally, it also reduced duration and seizure severity score associated with GTCS. The Grewia tiliaefolia methanol extract was further screened by Ultra High-Performance Liquid Chromatography (UHPLC) for presence of polyphenolic compounds, among which gallic acid and kaempferol were present in higher amount and were further analysed by in silico study to predict their possible binding sites and type of interactions these compounds show with gamma amino butyric acid (GABA) receptor and glutamate α amino-3- hydroxyl-5-methyl-4-isoxazolepropionic acid (Glu-AMPA) receptor. It was revealed that gallic acid and kaempferol had shown agonistic interaction for GABA receptor and antagonistic interaction for Glu-AMPA receptor. We concluded that G. tiliaefolia showed anticonvulsant potential possibly because of gallic acid and kaempferol possibly mediated through GABA and Glu-AMPA receptor.
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Affiliation(s)
- Ankita Rajput
- Department of Botanical and Environmental Sciences, Guru Nanak Dev University, Amritsar, Punjab, India
| | - Palvi Sharma
- Department of Botanical and Environmental Sciences, Guru Nanak Dev University, Amritsar, Punjab, India
| | - Nitish Kumar
- Department of Pharmaceutical Sciences, Guru Nanak Dev University, Amritsar, Punjab, India
| | - Hasandeep Singh
- Department of Pharmaceutical Sciences, Guru Nanak Dev University, Amritsar, Punjab, India
| | - Tanveer Singh
- Department of Neuroscience and Experimental Therapeutics, College of Medicine, Texas A&M University Health Science Center, Bryan, TX, 77807, USA
| | - Sharabjit Singh
- Department of Botanical and Environmental Sciences, Guru Nanak Dev University, Amritsar, Punjab, India
| | | | - Balbir Singh
- Department of Pharmaceutical Sciences, Guru Nanak Dev University, Amritsar, Punjab, India
| | - Saroj Arora
- Department of Botanical and Environmental Sciences, Guru Nanak Dev University, Amritsar, Punjab, India.
| | - Sarabjit Kaur
- Department of Pharmaceutical Sciences, Guru Nanak Dev University, Amritsar, Punjab, India.
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Nadeem MD, Memon S, Qureshi K, Farooq U, Memon UA, Aparna F, Kachhadia MP, Shahzeen F, Ali S, Varrassi G, Kumar L, Kumar S, Kumar S, Khatri M. Seizing the Connection: Exploring the Interplay Between Epilepsy and Glycemic Control in Diabetes Management. Cureus 2023; 15:e45606. [PMID: 37868449 PMCID: PMC10588297 DOI: 10.7759/cureus.45606] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/08/2023] [Accepted: 09/20/2023] [Indexed: 10/24/2023] Open
Abstract
Epilepsy, a neurological disorder characterized by recurrent seizures, and diabetes, a metabolic disorder characterized by impaired regulation of glucose levels, are two distinct conditions that may appear unrelated at first glance. Nevertheless, recent scholarly investigations have revealed these entities' intricate and ever-evolving interplay. This review initially delves into the intricate interplay between epilepsy and its potential ramifications on glycemic control. Seizures, particularly those accompanied by convulsive manifestations, have the potential to induce acute perturbations in blood glucose levels via diverse mechanisms, encompassing the liberation of stress hormones, the emergence of insulin resistance, and the dysregulation of the autonomic nervous system. Comprehending these intricate mechanisms is paramount in customizing productive strategies for managing diabetes in individuals with epilepsy. On the contrary, it is worth noting that diabetes can substantially impact the trajectory and control of epilepsy. The correlation between hyperglycemia and an elevated susceptibility to seizures, as well as the potential for exacerbating the intensity of epilepsy, has been established. This narrative review offers a concise exposition of the intricate interplay between epilepsy and glycemic control within diabetes management. The objective of exploring reciprocal influences, underlying mechanisms, and common risk factors is to augment the clinical comprehension of this intricate interconnection. In essence, this acquired knowledge possesses the potential to serve as a guiding compass for healthcare professionals, enabling them to craft bespoke therapeutic approaches that enhance the holistic welfare of individuals grappling with the coexistence of epilepsy and diabetes.
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Affiliation(s)
| | - Siraj Memon
- Medicine, Liaquat University of Medical & Health Sciences, Jamshoro, PAK
| | - Kashifa Qureshi
- Medicine, Liaquat University of Medical & Health Sciences, Jamshoro, PAK
| | - Umer Farooq
- Medicine, CMH Lahore Medical College and Institute of Dentistry, Lahore, PAK
| | - Unaib Ahmed Memon
- Neurology and Internal Medicine, Liaquat University of Medical and Health Sciences, Jamshoro, PAK
| | - Fnu Aparna
- Medicine, Ghulam Muhammad Mahar Medical College, Sukkur, PAK
| | | | - Fnu Shahzeen
- Internal Medicine, Jinnah Sindh Medical University, Karachi, PAK
| | - Sameer Ali
- Internal Medicine, Liaquat University of Medical and Health Sciences, Jamshoro, PAK
| | | | - Lakshya Kumar
- General Medicine, Pandit Deendayal Upadhyay Medical College, Rajkot, IND
| | - Sumeet Kumar
- Internal Medicine, Dow University of Health Sciences, Karachi, PAK
| | - Satesh Kumar
- Medicine and Surgery, Shaheed Mohtarma Benazir Bhutto Medical College, Karachi, PAK
| | - Mahima Khatri
- Medicine and Surgery, Dow University of Health Sciences, Karachi, PAK
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Faissner A. Low-density lipoprotein receptor-related protein-1 (LRP1) in the glial lineage modulates neuronal excitability. Front Netw Physiol 2023; 3:1190240. [PMID: 37383546 PMCID: PMC10293750 DOI: 10.3389/fnetp.2023.1190240] [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] [Figures] [Subscribe] [Scholar Register] [Received: 03/20/2023] [Accepted: 05/25/2023] [Indexed: 06/30/2023]
Abstract
The low-density lipoprotein related protein receptor 1 (LRP1), also known as CD91 or α-Macroglobulin-receptor, is a transmembrane receptor that interacts with more than 40 known ligands. It plays an important biological role as receptor of morphogens, extracellular matrix molecules, cytokines, proteases, protease inhibitors and pathogens. In the CNS, it has primarily been studied as a receptor and clearance agent of pathogenic factors such as Aβ-peptide and, lately, Tau protein that is relevant for tissue homeostasis and protection against neurodegenerative processes. Recently, it was found that LRP1 expresses the Lewis-X (Lex) carbohydrate motif and is expressed in the neural stem cell compartment. The removal of Lrp1 from the cortical radial glia compartment generates a strong phenotype with severe motor deficits, seizures and a reduced life span. The present review discusses approaches that have been taken to address the neurodevelopmental significance of LRP1 by creating novel, lineage-specific constitutive or conditional knockout mouse lines. Deficits in the stem cell compartment may be at the root of severe CNS pathologies.
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Lim D, Tapella L, Dematteis G, Talmon M, Genazzani AA. Calcineurin Signalling in Astrocytes: From Pathology to Physiology and Control of Neuronal Functions. Neurochem Res 2023; 48:1077-1090. [PMID: 36083398 PMCID: PMC10030417 DOI: 10.1007/s11064-022-03744-4] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2022] [Revised: 07/31/2022] [Accepted: 08/29/2022] [Indexed: 10/14/2022]
Abstract
Calcineurin (CaN), a Ca2+/calmodulin-activated serine/threonine phosphatase, acts as a Ca2+-sensitive switch regulating cellular functions through protein dephosphorylation and activation of gene transcription. In astrocytes, the principal homeostatic cells in the CNS, over-activation of CaN is known to drive pathological transcriptional remodelling, associated with neuroinflammation in diseases such as Alzheimer's disease, epilepsy and brain trauma. Recent reports suggest that, in physiological conditions, the activity of CaN in astrocytes is transcription-independent and is required for maintenance of basal protein synthesis rate and activation of astrocytic Na+/K+ pump thereby contributing to neuronal functions such as neuronal excitability and memory formation. In this contribution we overview the role of Ca2+ and CaN signalling in astroglial pathophysiology focusing on the emerging physiological role of CaN in astrocytes. We propose a model for the context-dependent switch of CaN activity from the post-transcriptional regulation of cell proteostasis in healthy astrocytes to the CaN-dependent transcriptional activation in neuroinflammation-associated diseases.
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Affiliation(s)
- Dmitry Lim
- Department of Pharmaceutical Sciences, Università del Piemonte Orientale "Amedeo Avogadro", Via Bovio 6, 28100, Novara, Italy.
| | - Laura Tapella
- Department of Pharmaceutical Sciences, Università del Piemonte Orientale "Amedeo Avogadro", Via Bovio 6, 28100, Novara, Italy
| | - Giulia Dematteis
- Department of Pharmaceutical Sciences, Università del Piemonte Orientale "Amedeo Avogadro", Via Bovio 6, 28100, Novara, Italy
| | - Maria Talmon
- Department of Health Sciences, School of Medicine, Università del Piemonte Orientale "Amedeo Avogadro", Via Solaroli 17, 28100, Novara, Italy
| | - Armando A Genazzani
- Department of Pharmaceutical Sciences, Università del Piemonte Orientale "Amedeo Avogadro", Via Bovio 6, 28100, Novara, Italy.
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Alijanpour S, Miryounesi M, Ghafouri-Fard S. The role of excitatory amino acid transporter 2 (EAAT2) in epilepsy and other neurological disorders. Metab Brain Dis 2023; 38:1-16. [PMID: 36173507 DOI: 10.1007/s11011-022-01091-5] [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] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/14/2022] [Accepted: 09/15/2022] [Indexed: 02/03/2023]
Abstract
Glutamate is the major excitatory neurotransmitter in the central nervous system (CNS). Excitatory amino acid transporters (EAATs) have important roles in the uptake of glutamate and termination of glutamatergic transmission. Up to now, five EAAT isoforms (EAAT1-5) have been identified in mammals. The main focus of this review is EAAT2. This protein has an important role in the pathoetiology of epilepsy. De novo dominant mutations, as well as inherited recessive mutation in this gene, have been associated with epilepsy. Moreover, dysregulation of this protein is implicated in a range of neurological diseases, namely amyotrophic lateral sclerosis, alzheimer's disease, parkinson's disease, schizophrenia, epilepsy, and autism. In this review, we summarize the role of EAAT2 in epilepsy and other neurological disorders, then provide an overview of the therapeutic modulation of this protein.
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Affiliation(s)
- Sahar Alijanpour
- Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Miryounesi
- Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Soudeh Ghafouri-Fard
- Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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Qu Q, Zhang W, Wang J, Mai D, Ren S, Qu S, Zhang Y. Functional investigation of SLC1A2 variants associated with epilepsy. Cell Death Dis 2022; 13:1063. [PMID: 36543780 DOI: 10.1038/s41419-022-05457-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 11/15/2022] [Accepted: 11/18/2022] [Indexed: 12/24/2022]
Abstract
Epilepsy is a common neurological disorder and glutamate excitotoxicity plays a key role in epileptic pathogenesis. Astrocytic glutamate transporter GLT-1 is responsible for preventing excitotoxicity via clearing extracellular accumulated glutamate. Previously, three variants (G82R, L85P, and P289R) in SLC1A2 (encoding GLT-1) have been clinically reported to be associated with epilepsy. However, the functional validation and underlying mechanism of these GLT-1 variants in epilepsy remain undetermined. In this study, we reported that these disease-linked mutants significantly decrease glutamate uptake, cell membrane expression of the glutamate transporter, and glutamate-elicited current. Additionally, we found that these variants may disturbed stromal-interacting molecule 1 (STIM1)/Orai1-mediated store-operated Ca2+ entry (SOCE) machinery in the endoplasmic reticulum (ER), in which GLT-1 may be a new partner of SOCE. Furthermore, knock-in mice with disease-associated variants showed a hyperactive phenotype accompanied by reduced glutamate transporter expression. Therefore, GLT-1 is a promising and reliable therapeutic target for epilepsy interventions.
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Jones ER, Griffitt RJ. Oil and hypoxia alter DNA methylation and transcription of genes related to neurological function in larval Cyprinodon variegatus. Aquat Toxicol 2022; 251:106267. [PMID: 36058102 DOI: 10.1016/j.aquatox.2022.106267] [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] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2022] [Revised: 08/17/2022] [Accepted: 08/18/2022] [Indexed: 06/15/2023]
Abstract
DNA methylation is an important epigenetic mark involved in modulating transcription. While multiple studies document the ability of environmental stressors to alter methylation patterns, there is little information regarding the effects of oil and hypoxia on the methylome. Oil and hypoxic stress are threats in coastal ecosystems, which act as nursery habitats for developing fish. To explore the methylation altering effects of oil and hypoxia on developing fish, we exposed larval Cyprinodon variegatus to oil, hypoxia, or both for 48 h followed by 48 h of depuration in clean, normoxic conditions. We then used immunoprecipitation coupled with high-throughput sequencing (MeDIP seq) to evaluate genome-wide methylation changes. We also performed RNA seq to associate methylation and altered transcription. Oil and hypoxia together elicited greater impacts to methylation than either stressor individually. Additionally, the oil+hypoxia treatment exhibited an overlap between differentially methylated regions and differential gene expression at 20 loci. Functional analyses of these loci revealed enrichment of processes related to neurological function and development. Two neurological genes (slc1a2, asxl2) showed altered methylation of promoter CpG islands and transcriptional changes, suggesting epigenetic modulation of gene expression. Our results suggest a possible mechanism explaining altered behavior patterns noted in fish following oil exposure.
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Affiliation(s)
- Elizabeth R Jones
- School of Ocean Science and Engineering, The University of Southern Mississippi, 112 McIlwain Drive, Ocean Springs, MS 39564, USA; Department of Biology, Francis Marion University, 4822 Palmetto Street, Florence, South Carolina, 29506, USA.
| | - Robert J Griffitt
- School of Ocean Science and Engineering, The University of Southern Mississippi, 112 McIlwain Drive, Ocean Springs, MS 39564, USA
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Myren‐Svelstad S, Jamali A, Ophus SS, D'gama PP, Ostenrath AM, Mutlu AK, Hoffshagen HH, Hotz AL, Neuhauss SCF, Jurisch‐Yaksi N, Yaksi E. Elevated photic response is followed by a rapid decay and depressed state in ictogenic networks. Epilepsia 2022; 63:2543-2560. [PMID: 36222083 PMCID: PMC9804334 DOI: 10.1111/epi.17380] [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: 02/04/2022] [Revised: 07/27/2022] [Accepted: 07/27/2022] [Indexed: 01/05/2023]
Abstract
OBJECTIVE The switch between nonseizure and seizure states involves profound alterations in network excitability and synchrony. In this study, we aimed to identify and compare features of neural excitability and dynamics across multiple zebrafish seizure and epilepsy models. METHODS Inspired by video-electroencephalographic recordings in patients, we developed a framework to study spontaneous and photically evoked neural and locomotor activity in zebrafish larvae, by combining high-throughput behavioral tracking and whole-brain in vivo two-photon calcium imaging. RESULTS Our setup allowed us to dissect behavioral and physiological features that are divergent or convergent across multiple models. We observed that spontaneous locomotor and neural activity exhibit great diversity across models. Nonetheless, during photic stimulation, hyperexcitability and rapid response dynamics were well conserved across multiple models, highlighting the reliability of photically evoked activity for high-throughput assays. Intriguingly, in several models, we observed that the initial elevated photic response is often followed by rapid decay of neural activity and a prominent depressed state. Elevated photic response and following depressed state in seizure-prone networks are significantly reduced by the antiseizure medication valproic acid. Finally, rapid decay and depression of neural activity following photic stimulation temporally overlap with slow recruitment of astroglial calcium signals that are enhanced in seizure-prone networks. SIGNIFICANCE We argue that fast decay of neural activity and depressed states following photic response are likely due to homeostatic mechanisms triggered by excessive neural activity. An improved understanding of the interplay between elevated and depressed excitability states might suggest tailored epilepsy therapies.
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Affiliation(s)
- Sverre Myren‐Svelstad
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Faculty of Medicine and Health SciencesNorwegian University of Science and TechnologyTrondheimNorway,Department of Neuromedicine and Movement Science, Faculty of Medicine and Health SciencesNorwegian University of Science and TechnologyTrondheimNorway,Department of Neurology and Clinical NeurophysiologySt Olav's University HospitalTrondheimNorway
| | - Ahmed Jamali
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Faculty of Medicine and Health SciencesNorwegian University of Science and TechnologyTrondheimNorway,Department of Neuromedicine and Movement Science, Faculty of Medicine and Health SciencesNorwegian University of Science and TechnologyTrondheimNorway,Department of Neurology and Clinical NeurophysiologySt Olav's University HospitalTrondheimNorway
| | - Sunniva S. Ophus
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Faculty of Medicine and Health SciencesNorwegian University of Science and TechnologyTrondheimNorway
| | - Percival P. D'gama
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Faculty of Medicine and Health SciencesNorwegian University of Science and TechnologyTrondheimNorway,Department of Clinical and Molecular Medicine, Faculty of Medicine and Health SciencesNorwegian University of Science and TechnologyTrondheimNorway
| | - Anna M. Ostenrath
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Faculty of Medicine and Health SciencesNorwegian University of Science and TechnologyTrondheimNorway
| | - Aytac Kadir Mutlu
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Faculty of Medicine and Health SciencesNorwegian University of Science and TechnologyTrondheimNorway
| | - Helene Homme Hoffshagen
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Faculty of Medicine and Health SciencesNorwegian University of Science and TechnologyTrondheimNorway
| | - Adriana L. Hotz
- Department of Molecular Life SciencesUniversity of ZürichZürichSwitzerland
| | | | - Nathalie Jurisch‐Yaksi
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Faculty of Medicine and Health SciencesNorwegian University of Science and TechnologyTrondheimNorway,Department of Neurology and Clinical NeurophysiologySt Olav's University HospitalTrondheimNorway,Department of Clinical and Molecular Medicine, Faculty of Medicine and Health SciencesNorwegian University of Science and TechnologyTrondheimNorway
| | - Emre Yaksi
- Kavli Institute for Systems Neuroscience and Centre for Neural Computation, Faculty of Medicine and Health SciencesNorwegian University of Science and TechnologyTrondheimNorway,Koç University Research Center for Translational Medicine, Department of NeurologyKoç University School of MedicineIstanbulTurkey
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Chang A, Chang Y, Wang SJ. Rutin prevents seizures in kainic acid-treated rats: evidence of glutamate levels, inflammation and neuronal loss modulation. Food Funct 2022; 13:10401-10414. [PMID: 36148811 DOI: 10.1039/d2fo01490d] [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] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Rutin, a naturally derived flavonoid molecule with known neuroprotective properties, has been demonstrated to have anticonvulsive potential, but the mechanism of this effect is still unclear. The current study aimed to investigate the probable antiseizure mechanisms of rutin in rats using the kainic acid (KA) seizure model. Rutin (50 and 100 mg kg-1) and carbamazepine (100 mg kg-1) were administered daily by oral gavage for 7 days before KA (15 mg kg-1) intraperitoneal (i.p.) injection. Seizure behavior, neuronal cell death, glutamate concentration, excitatory amino acid transporters (EAATs), glutamine synthetase (GS), glutaminase, α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid (AMPA) receptor subunits GluA1 and GluA2, N-methyl-D-aspartate (NMDA) receptor subunits GluN2A and GluN2B, activated astrocytes, and inflammatory and anti-inflammatory molecules in the hippocampus were evaluated. Supplementation with rutin attenuated seizure severity in KA-treated rats and reversed KA-induced neuronal loss and glutamate elevation in the hippocampus. Decreased glutaminase and GluN2B, and increased EAATs, GS, GluA1, GluA2 and GluN2A were observed with rutin administration. Rutin pretreatment also suppressed activated astrocytes, downregulated the protein levels of inflammatory molecules [interleukin-1β (IL-1β), interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), high mobility group Box 1 (HMGB1), interleukin-1 receptor 1 (IL-1R1), and Toll-like receptor-4 (TLR-4)] and upregulated anti-inflammatory molecule interleukin-10 (IL-10) protein expression. Taken together, the results indicate that the preventive treatment of rats with rutin attenuated KA-induced seizures and neuronal loss by decreasing glutamatergic hyperactivity and suppressing the IL-1R1/TLR4-related neuroinflammatory cascade.
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Affiliation(s)
- Anna Chang
- School of Medicine, Fu Jen Catholic University, New Taipei City 24205, Taiwan. .,Department of Neurology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei 22060, Taiwan
| | - Yi Chang
- School of Medicine, Fu Jen Catholic University, New Taipei City 24205, Taiwan. .,Department of Anesthesiology, Shin Kong Wu Ho-Su Memorial Hospital, Taipei 22060, Taiwan
| | - Su-Jane Wang
- School of Medicine, Fu Jen Catholic University, New Taipei City 24205, Taiwan. .,Research Center for Chinese Herbal Medicine, College of Human Ecology, Chang Gung University of Science and Technology, Taoyuan 33303, Taiwan
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Özsoy Ç, Hotz AL, Rieser NN, Chen Z, Deán-Ben XL, Neuhauss SCF, Razansky D. Volumetric optoacoustic neurobehavioral tracking of epileptic seizures in freely-swimming zebrafish larvae. Front Mol Neurosci 2022; 15:1004518. [PMID: 36176960 PMCID: PMC9514119 DOI: 10.3389/fnmol.2022.1004518] [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] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Accepted: 08/15/2022] [Indexed: 11/25/2022] Open
Abstract
Fast three-dimensional imaging of freely-swimming zebrafish is essential to understand the link between neuronal activity and behavioral changes during epileptic seizures. Studying the complex spatiotemporal patterns of neuronal activity at the whole-brain or -body level typically requires physical restraint, thus hindering the observation of unperturbed behavior. Here we report on real-time volumetric optoacoustic imaging of aberrant circular swimming activity and calcium transients in freely behaving zebrafish larvae, continuously covering their motion across an entire three-dimensional region. The high spatiotemporal resolution of the technique enables capturing ictal-like epileptic seizure events and quantifying their propagation speed, independently validated with simultaneous widefield fluorescence recordings. The work sets the stage for discerning functional interconnections between zebrafish behavior and neuronal activity for studying fundamental mechanisms of epilepsy and in vivo validation of treatment strategies.
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Affiliation(s)
- Çağla Özsoy
- Faculty of Medicine, Institute of Pharmacology and Toxicology and Institute for Biomedical Engineering, University of Zurich, Zurich, Switzerland
- Department of Information Technology and Electrical Engineering, Institute for Biomedical Engineering, ETH Zurich, Zurich, Switzerland
| | - Adriana L. Hotz
- Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
| | - Nicolas N. Rieser
- Department of Molecular Life Sciences, University of Zurich, Zurich, Switzerland
| | - Zhenyue Chen
- Faculty of Medicine, Institute of Pharmacology and Toxicology and Institute for Biomedical Engineering, University of Zurich, Zurich, Switzerland
- Department of Information Technology and Electrical Engineering, Institute for Biomedical Engineering, ETH Zurich, Zurich, Switzerland
| | - Xosé Luís Deán-Ben
- Faculty of Medicine, Institute of Pharmacology and Toxicology and Institute for Biomedical Engineering, University of Zurich, Zurich, Switzerland
- Department of Information Technology and Electrical Engineering, Institute for Biomedical Engineering, ETH Zurich, Zurich, Switzerland
| | | | - Daniel Razansky
- Faculty of Medicine, Institute of Pharmacology and Toxicology and Institute for Biomedical Engineering, University of Zurich, Zurich, Switzerland
- Department of Information Technology and Electrical Engineering, Institute for Biomedical Engineering, ETH Zurich, Zurich, Switzerland
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Hentig J, Campbell LJ, Cloghessy K, Lee M, Boggess W, Hyde DR. Prophylactic Activation of Shh Signaling Attenuates TBI-Induced Seizures in Zebrafish by Modulating Glutamate Excitotoxicity through Eaat2a. Biomedicines 2021; 10:32. [PMID: 35052712 DOI: 10.3390/biomedicines10010032] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2021] [Revised: 12/16/2021] [Accepted: 12/22/2021] [Indexed: 12/21/2022] Open
Abstract
Approximately 2 million individuals experience a traumatic brain injury (TBI) every year in the United States. Secondary injury begins within minutes after TBI, with alterations in cellular function and chemical signaling that contribute to excitotoxicity. Post-traumatic seizures (PTS) are experienced in an increasing number of TBI individuals that also display resistance to traditional anti-seizure medications (ASMs). Sonic hedgehog (Shh) is a signaling pathway that is upregulated following central nervous system damage in zebrafish and aids injury-induced regeneration. Using a modified Marmarou weight drop on adult zebrafish, we examined PTS following TBI and Shh modulation. We found that inhibiting Shh signaling by cyclopamine significantly increased PTS in TBI fish, prolonged the timeframe PTS was observed, and decreased survival across all TBI severities. Shh-inhibited TBI fish failed to respond to traditional ASMs, but were attenuated when treated with CNQX, which blocks ionotropic glutamate receptors. We found that the Smoothened agonist, purmorphamine, increased Eaat2a expression in undamaged brains compared to untreated controls, and purmorphamine treatment reduced glutamate excitotoxicity following TBI. Similarly, purmorphamine reduced PTS, edema, and cognitive deficits in TBI fish, while these pathologies were increased and/or prolonged in cyclopamine-treated TBI fish. However, the increased severity of TBI phenotypes with cyclopamine was reduced by cotreating fish with ceftriaxone, which induces Eaat2a expression. Collectively, these data suggest that Shh signaling induces Eaat2a expression and plays a role in regulating TBI-induced glutamate excitotoxicity and TBI sequelae.
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