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Gonçalves-Sánchez J, Sancho C, López DE, Castellano O, García-Cenador B, Servilha-Menezes G, Corchado JM, García-Cairasco N, Gonçalves-Estella JM. Effect of Vagus Nerve Stimulation on the GASH/Sal Audiogenic-Seizure-Prone Hamster. Int J Mol Sci 2023; 25:91. [PMID: 38203262 PMCID: PMC10778912 DOI: 10.3390/ijms25010091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2023] [Revised: 12/10/2023] [Accepted: 12/18/2023] [Indexed: 01/12/2024] Open
Abstract
Vagus nerve stimulation (VNS) is an adjuvant neuromodulation therapy for the treatment of refractory epilepsy. However, the mechanisms behind its effectiveness are not fully understood. Our aim was to develop a VNS protocol for the Genetic Audiogenic Seizure Hamster from Salamanca (GASH/Sal) in order to evaluate the mechanisms of action of the therapy. The rodents were subject to VNS for 14 days using clinical stimulation parameters by implanting a clinically available neurostimulation device or our own prototype for laboratory animals. The neuroethological assessment of seizures and general behavior were performed before surgery, and after 7, 10, and 14 days of VNS. Moreover, potential side effects were examined. Finally, the expression of 23 inflammatory markers in plasma and the left-brain hemisphere was evaluated. VNS significantly reduced seizure severity in GASH/Sal without side effects. No differences were observed between the neurostimulation devices. GASH/Sal treated with VNS showed statistically significant reduced levels of interleukin IL-1β, monocyte chemoattractant protein MCP-1, matrix metalloproteinases (MMP-2, MMP-3), and tumor necrosis factor TNF-α in the brain. The described experimental design allows for the study of VNS effects and mechanisms of action using an implantable device. This was achieved in a model of convulsive seizures in which VNS is effective and shows an anti-inflammatory effect.
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Affiliation(s)
- Jaime Gonçalves-Sánchez
- Department of Cellular Biology and Pathology, School of Medicine, University of Salamanca, 37007 Salamanca, Spain; (D.E.L.); (O.C.)
- Institute for Biomedical Research of Salamanca (IBSAL), 37007 Salamanca, Spain; (C.S.); (B.G.-C.); (J.M.C.); (J.M.G.-E.)
- Institute of Neuroscience of Castilla y León, 37007 Salamanca, Spain
| | - Consuelo Sancho
- Institute for Biomedical Research of Salamanca (IBSAL), 37007 Salamanca, Spain; (C.S.); (B.G.-C.); (J.M.C.); (J.M.G.-E.)
- Institute of Neuroscience of Castilla y León, 37007 Salamanca, Spain
- Department of Physiology and Pharmacology, School of Medicine, University of Salamanca, 37007 Salamanca, Spain
| | - Dolores E. López
- Department of Cellular Biology and Pathology, School of Medicine, University of Salamanca, 37007 Salamanca, Spain; (D.E.L.); (O.C.)
- Institute for Biomedical Research of Salamanca (IBSAL), 37007 Salamanca, Spain; (C.S.); (B.G.-C.); (J.M.C.); (J.M.G.-E.)
- Institute of Neuroscience of Castilla y León, 37007 Salamanca, Spain
| | - Orlando Castellano
- Department of Cellular Biology and Pathology, School of Medicine, University of Salamanca, 37007 Salamanca, Spain; (D.E.L.); (O.C.)
- Institute for Biomedical Research of Salamanca (IBSAL), 37007 Salamanca, Spain; (C.S.); (B.G.-C.); (J.M.C.); (J.M.G.-E.)
- Institute of Neuroscience of Castilla y León, 37007 Salamanca, Spain
| | - Begoña García-Cenador
- Institute for Biomedical Research of Salamanca (IBSAL), 37007 Salamanca, Spain; (C.S.); (B.G.-C.); (J.M.C.); (J.M.G.-E.)
- Department of Surgery, School of Medicine, University of Salamanca, 37007 Salamanca, Spain
| | - Gabriel Servilha-Menezes
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto 14040-900, SP, Brazil; (G.S.-M.); (N.G.-C.)
| | - Juan M. Corchado
- Institute for Biomedical Research of Salamanca (IBSAL), 37007 Salamanca, Spain; (C.S.); (B.G.-C.); (J.M.C.); (J.M.G.-E.)
- Bioinformatics, Intelligent Systems and Educational Technology (BISITE) Research Group, 37007 Salamanca, Spain
| | - Norberto García-Cairasco
- Department of Physiology, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto 14040-900, SP, Brazil; (G.S.-M.); (N.G.-C.)
| | - Jesús M. Gonçalves-Estella
- Institute for Biomedical Research of Salamanca (IBSAL), 37007 Salamanca, Spain; (C.S.); (B.G.-C.); (J.M.C.); (J.M.G.-E.)
- Department of Surgery, School of Medicine, University of Salamanca, 37007 Salamanca, Spain
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Woo AM, Sontheimer H. Interactions between astrocytes and extracellular matrix structures contribute to neuroinflammation-associated epilepsy pathology. FRONTIERS IN MOLECULAR MEDICINE 2023; 3:1198021. [PMID: 39086689 PMCID: PMC11285605 DOI: 10.3389/fmmed.2023.1198021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/31/2023] [Accepted: 05/31/2023] [Indexed: 08/02/2024]
Abstract
Often considered the "housekeeping" cells of the brain, astrocytes have of late been rising to the forefront of neurodegenerative disorder research. Identified as crucial components of a healthy brain, it is undeniable that when astrocytes are dysfunctional, the entire brain is thrown into disarray. We offer epilepsy as a well-studied neurological disorder in which there is clear evidence of astrocyte contribution to diseases as evidenced across several different disease models, including mouse models of hippocampal sclerosis, trauma associated epilepsy, glioma-associated epilepsy, and beta-1 integrin knockout astrogliosis. In this review we suggest that astrocyte-driven neuroinflammation, which plays a large role in the pathology of epilepsy, is at least partially modulated by interactions with perineuronal nets (PNNs), highly structured formations of the extracellular matrix (ECM). These matrix structures affect synaptic placement, but also intrinsic neuronal properties such as membrane capacitance, as well as ion buffering in their immediate milieu all of which alters neuronal excitability. We propose that the interactions between PNNs and astrocytes contribute to the disease progression of epilepsy vis a vis neuroinflammation. Further investigation and alteration of these interactions to reduce the resultant neuroinflammation may serve as a potential therapeutic target that provides an alternative to the standard anti-seizure medications from which patients are so frequently unable to benefit.
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Affiliation(s)
- AnnaLin M. Woo
- Neuroscience Graduate Program, Neuroscience Department, University of Virginia, Charlottesville, VA, United States
| | - Harald Sontheimer
- Neuroscience Department, University of Virginia, Charlottesville, VA, United States
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Pappas A, Shankaran S, McDonald SA, Carlo WA, Laptook AR, Tyson JE, Das A, Skogstrand K, Hougaard DM, Higgins RD. Blood Biomarkers and 6- to 7-Year Childhood Outcomes Following Neonatal Encephalopathy. Am J Perinatol 2022; 39:732-749. [PMID: 33038899 PMCID: PMC8765716 DOI: 10.1055/s-0040-1717072] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
OBJECTIVE This study aimed to profile the cytokine/chemokine response from day 0 to 7 in infants (≥36 weeks of gestational age) with neonatal encephalopathy (NE) and to explore the association with long-term outcomes. STUDY DESIGN This was a secondary study of the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) Neonatal Research Network randomized controlled trial of whole body hypothermia for NE. Eligible infants with moderate-severe NE were randomized to cooling or normothermia. Blood spots were collected on days 0 to 1, 2 to 4, and 6 to 7. Twenty-four cytokines/chemokines were measured using a multiplex platform. Surviving infants underwent neurodevelopmental assessment at 6 to 7 years. Primary outcome was death or moderate-severe impairment defined by any of the following: intelligence quotient <70, moderate-severe cerebral palsy (CP), blindness, hearing impairment, or epilepsy. RESULTS Cytokine blood spots were collected from 109 participants. In total 99 of 109 (91%) were assessed at 6 to 7 years; 54 of 99 (55%) developed death/impairment. Neonates who died or were impaired had lower early regulated upon activation normal T cell expressed and secreted (RANTES) and higher day 7 monocyte chemotactic protein (MCP)-1 levels than neonates who survived without impairment. Though TNF-α levels had no association with death/impairment, higher day 0 to 1 levels were observed among neonates who died/developed CP. On multiple regression analysis adjusted for center, treatment group, sex, race, and level of hypoxic ischemic encephalopathy, higher RANTES was inversely associated with death/impairment (odds ratio (OR): 0.31, 95% confidence interval [CI]: 0.13-0.74), while day seven MCP-1 level was directly associated with death/impairment (OR: 3.70, 95% CI: 1.42-9.61). Targeted cytokine/chemokine levels demonstrated little variation with hypothermia treatment. CONCLUSION RANTES and MCP-1 levels in the first week of life may provide potential targets for future therapies among neonates with encephalopathy. KEY POINTS · Elevation of specific cytokines and chemokines in neonates with encephalopathy has been noted along with increased risk of neurodevelopmental impairment in infancy.. · Cytokine/chemokines at <7 days were assessed among neonates in a trial of hypothermia for HIE.. · Neonates who died or were impaired at 6 to 7 years following hypoxic-ischemic encephalopathy had lower RANTES and higher MCP-1 levels than those who survived without impairment..
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Affiliation(s)
- Athina Pappas
- Department of Pediatrics, Wayne State University, Detroit, MI
| | | | - Scott A. McDonald
- Social, Statistical and Environmental Sciences Unit, RTI International, Research Triangle Park, NC
| | - Waldemar A. Carlo
- Department of Pediatrics, University of Alabama at Birmingham and Children’s Hospital of Alabama, Birmingham, AL
| | - Abbot R. Laptook
- Department of Pediatrics, Women & Infant’s Hospital, Brown University, Providence, RI
| | - Jon E. Tyson
- Department of Pediatrics, University of Texas Medical School at Houston, Houston, TX
| | - Abhik Das
- Social, Statistical and Environmental Sciences Unit, RTI International, Rockville, MD
| | - Kristin Skogstrand
- Department for Congenital Disorders, Center for Neonatal Screening, Statens Serum Institut, Copenhagen
| | - David M. Hougaard
- Department for Congenital Disorders, Center for Neonatal Screening, Statens Serum Institut, Copenhagen
| | - Rosemary D. Higgins
- Department of Global and Community Health, George Mason University, Fairfax, Virginia
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DePaula-Silva AB, Bell LA, Wallis GJ, Wilcox KS. Inflammation Unleashed in Viral-Induced Epileptogenesis. Epilepsy Curr 2021; 21:433-440. [PMID: 34924851 PMCID: PMC8652320 DOI: 10.1177/15357597211040939] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023] Open
Abstract
Viral infection of the central nervous system increasingly places people at risk of developing life-threatening and treatment-resistant acute and chronic seizures (epilepsy). The emergence of new human viruses due to ongoing social, political, and ecological changes places people at risk more than ever before. The development of new preventative or curative strategies is critical to address this burden. However, our understanding of the complex relationship between viruses and the brain has been hindered by the lack of animal models that survive the initial infection and are amenable for long-term mechanistic, behavioral, and pharmacological studies in the process of viral-induced epileptogenesis. In this review, we focus on the Theiler’s murine encephalomyelitis virus (TMEV) mouse model of viral infection–induced epilepsy. The TMEV model has a number of important advantages to address the quintessential processes underlying the development of epilepsy following a viral infection, as well as fuel new therapeutic development. In this review, we highlight the contributions of the TMEV model to our current understanding of the relationship between viral infection, inflammation, and seizures.
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Affiliation(s)
| | - Laura A. Bell
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT, USA
- Interdepartmental Program in Neuroscience, University of Utah, Salt Lake City, UT, USA
| | - Glenna J. Wallis
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT, USA
| | - Karen S. Wilcox
- Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT, USA
- Interdepartmental Program in Neuroscience, University of Utah, Salt Lake City, UT, USA
- Karen S. Wilcox, PhD, Department of Pharmacology and Toxicology, University of Utah, Salt Lake City, UT 84112, USA.
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Cerebrospinal Fluid Pleocytosis Not Attributable to Status Epilepticus in First 24 Hours. Can J Neurol Sci 2021; 49:210-217. [PMID: 33902768 DOI: 10.1017/cjn.2021.83] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
BACKGROUND Status epilepticus (SE) has traditionally been thought to cause cerebrospinal fluid (CSF) pleocytosis. However, attributing CSF pleocytosis solely to SE without addressing the underlying etiology may lead to poor outcomes. Leukocyte recruitment to CSF has been shown to peak around 24 hours after prolonged seizures in animal studies, suggesting that CSF pleocytosis within the first 24 hours of SE onset may be due to underlying causes. The goal of this study is to assess if SE is associated with CSF pleocytosis, independent of other causes within the first 24 hours of onset. METHODS We completed a historical cohort study of adult patients with SE admitted to the intensive care unit of Vancouver General Hospital between March 2010 and May 2019. RESULTS Of the 441 patients admitted with SE during the study period, 107 met our inclusion criteria leading to 111 lumbar punctures (LPs), with 4 patients receiving two LPs. CSF pleocytosis was seen in 12 of 72 patients who underwent an LP within the first 24 hours of SE onset. In all 12 patients, a secondary etiology for the pleocytosis was observed aside from SE. Of the six CSF samples collected after 24 hours of onset that demonstrated pleocytosis, four had no cause for pleocytosis other than SE. CONCLUSIONS In all 12 patients with CSF pleocytosis in the first 24 hours of onset of SE, an underlying etiology was identified. Therefore, any pleocytosis noticed within the first 24 hours of onset of refractory SE should not be attributed solely to SE.
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Links between Immune Cells from the Periphery and the Brain in the Pathogenesis of Epilepsy: A Narrative Review. Int J Mol Sci 2021; 22:ijms22094395. [PMID: 33922369 PMCID: PMC8122797 DOI: 10.3390/ijms22094395] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Revised: 04/19/2021] [Accepted: 04/21/2021] [Indexed: 12/13/2022] Open
Abstract
Accumulating evidence has demonstrated that the pathogenesis of epilepsy is linked to neuroinflammation and cerebrovascular dysfunction. Peripheral immune cell invasion into the brain, along with these responses, is implicitly involved in epilepsy. This review explored the current literature on the association between the peripheral and central nervous systems in the pathogenesis of epilepsy, and highlights novel research directions for therapeutic interventions targeting these reactions. Previous experimental and human studies have demonstrated the activation of the innate and adaptive immune responses in the brain. The time required for monocytes (responsible for innate immunity) and T cells (involved in acquired immunity) to invade the central nervous system after a seizure varies. Moreover, the time between the leakage associated with blood–brain barrier (BBB) failure and the infiltration of these cells varies. This suggests that cell infiltration is not merely a secondary disruptive event associated with BBB failure, but also a non-disruptive event facilitated by various mediators produced by the neurovascular unit consisting of neurons, perivascular astrocytes, microglia, pericytes, and endothelial cells. Moreover, genetic manipulation has enabled the differentiation between peripheral monocytes and resident microglia, which was previously considered difficult. Thus, the evidence suggests that peripheral monocytes may contribute to the pathogenesis of seizures.
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The role of inflammatory mediators in epilepsy: Focus on developmental and epileptic encephalopathies and therapeutic implications. Epilepsy Res 2021; 172:106588. [PMID: 33721708 DOI: 10.1016/j.eplepsyres.2021.106588] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2020] [Revised: 01/28/2021] [Accepted: 02/16/2021] [Indexed: 02/06/2023]
Abstract
In recent years, there has been an increasing interest in the potential involvement of neuroinflammation in the pathogenesis of epilepsy. Specifically, the role of innate immunity (that includes cytokines and chemokines) has been extensively investigated either in animal models of epilepsy and in clinical settings. Developmental and epileptic encephalopathies (DEE) are a heterogeneous group of epileptic disorders, in which uncontrolled epileptic activity results in cognitive, motor and behavioral impairment. By definition, epilepsy in DEE is poorly controlled by common antiepileptic drugs but may respond to alternative treatments, including steroids and immunomodulatory drugs. In this review, we will focus on how cytokines and chemokines play a role in the pathogenesis of DEE and why expanding our knowledge about the role of neuroinflammation in DEE may be crucial to develop new and effective targeted therapeutic strategies to prevent seizure recurrence and developmental regression.
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Hung YW, Wang Y, Lee SL. DPP-4 inhibitor reduces striatal microglial deramification after sensorimotor cortex injury induced by external force impact. FASEB J 2020; 34:6950-6964. [PMID: 32246809 DOI: 10.1096/fj.201902818r] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2019] [Revised: 03/08/2020] [Accepted: 03/17/2020] [Indexed: 12/12/2022]
Abstract
Dipeptidyl peptidase-4 inhibitors (or gliptins), a class of antidiabetic drugs, have recently been shown to have protective actions in the central nervous system. Their cellular and molecular mechanisms responsible for these effects are largely unknown. In the present study, two structurally different gliptins, sitagliptin and vildagliptin, were examined for their therapeutic actions in a controlled cortical impact (CCI) model of moderate traumatic brain injury (TBI) in mice. Early post-CCI treatment with sitagliptin, but not vildagliptin, significantly reduced body asymmetry, locomotor hyperactivity, and brain lesion volume. Sitagliptin attenuated post-CCI microglial deramification in the ipsilateral dorsolateral (DL) striatum, while vildagliptin had no effect. Sitagliptin also reduced striatal expression of galectin-3 and monocyte chemoattractant protein 1(MCP-1), and increased the cortical and striatal levels of the anti-inflammatory cytokine IL-10 on the ipsilateral side. These data support a differential protective effect of sitagliptin against TBI, possibly mediated by an anti-inflammatory effect in striatum to preserve connective network. Both sitagliptin and vildagliptin produced similar increases of active glucagon-like peptide-1 (GLP-1) in blood and brain. Increasing active GLP-1 may not be the sole molecular mechanisms for the neurotherapeutic effect of sitagliptin in TBI.
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Affiliation(s)
- Yu-Wen Hung
- Institute of Cellular and System Medicine, National Health Research Institutes, Zhunan Town, Miaoli County, Taiwan, R.O.C
| | - Yun Wang
- Center for Neuropsychiatric Research, National Health Research Institutes, Zhunan Town, Miaoli County, Taiwan, R.O.C
| | - Sheau-Ling Lee
- Institute of Cellular and System Medicine, National Health Research Institutes, Zhunan Town, Miaoli County, Taiwan, R.O.C
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Treatment with CCR2 antagonist is neuroprotective but does not alter epileptogenesis in the pilocarpine rat model of epilepsy. Epilepsy Behav 2020; 102:106695. [PMID: 31785482 DOI: 10.1016/j.yebeh.2019.106695] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/18/2019] [Revised: 11/05/2019] [Accepted: 11/05/2019] [Indexed: 11/22/2022]
Abstract
Neuroinflammation role on epileptogenesis has been the subject of increasing interest. Many studies showed elevation in cytokines and chemokines expression following seizures, such as, CCL2 protein (C-C motif ligand 2 chemokine) and its specific receptor, CCR2. In addition, recent studies manipulating the CCL2/CCR2 complex verified improved seizure outcome in different seizure models. In the present study, the effects of CCR2 antagonist was investigated using the pilocarpine rat model of epilepsy. Status epilepticus (SE) was induced by pilocarpine i.p. injection in adult rats. Daily oral treatment with CCR2 antagonist or vehicle was initiated 5 h following SE and lasted 5 or 10 days. Rats were euthanized 5 days after SE to evaluate neuronal damage and glial density or 30 days after SE to investigate spontaneous seizures development and seizure susceptibility to a second hit pentylenetetrazol (PTZ) test. Rats that received CCR2 antagonist presented less degenerating cells at hippocampal CA1 region. There was also a significant decrease in CA1 volume after SE that was not observed in treated rats. On the other hand, microglia cell density increased after SE regardless of CCR2 antagonist use. Treatment with CCR2 antagonist did not alter spontaneous seizure occurrence or later seizure susceptibility to PTZ in chronic rats. Additional rats were pretreated with CCR2 antagonist prior to SE induction, but this did not change SE progression. The data show that oral treatment with CCR2 antagonist is neuroprotective, but does not alter other epileptogenic factors, such as, neuroinflammation, or seizure development, after pilocarpine-induced SE in rats.
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Broekaart DWM, Anink JJ, Baayen JC, Idema S, de Vries HE, Aronica E, Gorter JA, van Vliet EA. Activation of the innate immune system is evident throughout epileptogenesis and is associated with blood-brain barrier dysfunction and seizure progression. Epilepsia 2018; 59:1931-1944. [PMID: 30194729 DOI: 10.1111/epi.14550] [Citation(s) in RCA: 62] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Revised: 07/31/2018] [Accepted: 07/31/2018] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Because brain inflammation may contribute to the pathophysiology of temporal lobe epilepsy (TLE), we investigated the expression of various inflammatory markers of the innate and adaptive immune system in the epileptogenic human and rat hippocampus in relation to seizure activity and blood-brain barrier (BBB) dysfunction. METHODS Immunohistochemistry was performed using various immune cell markers (for microglia, monocytes, macrophages, T lymphocytes, and dendritic cells) on hippocampal sections of drug-resistant TLE patients and patients who died after status epilepticus. The expression of these markers was also studied in the electrical post-status epilepticus rat model for TLE, during the acute, latent, and chronic epileptic phase. BBB dysfunction was assessed using albumin immunohistochemistry and the BBB tracer fluorescein. RESULTS Monocyte infiltration, microglia, and perivascular macrophage activation were persistently increased in both epileptogenic human and rat hippocampus, whereas T lymphocytes and dendritic cells were not or were scarcely detected. In addition to this, increased expression of C-C motif ligand 2 (CCL2) and osteopontin was observed. In humans, the expression of CD68 and CCL2 was related to the duration of epilepsy and type of pathology. In rats, the expression of CD68, CCL2, and the perivascular macrophage marker CD163 was related to the duration of the initial insult and to the number of spontaneous seizures. Interestingly, the number of CD163-positive perivascular macrophages was also positively correlated to BBB dysfunction in chronic epileptic rats. SIGNIFICANCE These data suggest a proepileptogenic role for monocytes/macrophages and other cells of the innate immune response, possibly via increased BBB leakage, and indicate that T cells and dendritic cells, which are closely associated with the adaptive immune response, are only sparsely infiltrated during epileptogenesis in the electrical post-status epilepticus rat model. Future studies should reveal the relative importance of these immune cells and whether specific manipulation can modify or prevent epileptogenesis.
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Affiliation(s)
- Diede W M Broekaart
- Department of (Neuro) Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Jasper J Anink
- Department of (Neuro) Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Johannes C Baayen
- Department of Neurosurgery, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Sander Idema
- Department of Neurosurgery, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Helga E de Vries
- Department of Molecular Cell Biology and Immunology, Amsterdam UMC, Vrije Universiteit Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands
| | - Eleonora Aronica
- Department of (Neuro) Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands.,Stichting Epilepsie Instellingen Nederland (SEIN), The Netherlands
| | - Jan A Gorter
- Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Amsterdam, The Netherlands
| | - Erwin A van Vliet
- Department of (Neuro) Pathology, Amsterdam UMC, University of Amsterdam, Amsterdam Neuroscience, Amsterdam, The Netherlands.,Swammerdam Institute for Life Sciences, Center for Neuroscience, University of Amsterdam, Amsterdam, The Netherlands
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Cerri C, Caleo M, Bozzi Y. Chemokines as new inflammatory players in the pathogenesis of epilepsy. Epilepsy Res 2017; 136:77-83. [PMID: 28780154 DOI: 10.1016/j.eplepsyres.2017.07.016] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Revised: 07/13/2017] [Accepted: 07/25/2017] [Indexed: 12/22/2022]
Abstract
A large series of clinical and experimental studies supports a link between inflammation and epilepsy, indicating that inflammatory processes within the brain are important contributors to seizure recurrence and precipitation. Systemic inflammation can precipitate seizures in children suffering from epileptic encephalopathies, and hallmarks of a chronic inflammatory state have been found in patients with temporal lobe epilepsy. Research performed on animal models of epilepsy further corroborates the idea that seizures upregulate inflammatory mediators, which in turn may enhance brain excitability and neuronal degeneration. Several inflammatory molecules and their signaling pathways have been implicated in epilepsy. Among these, the chemokine pathway has increasingly gained attention. Chemokines are small cytokines secreted by blood cells, which act as chemoattractants for leukocyte migration. Recent studies indicate that chemokines and their receptors are also produced by brain cells, and are involved in various neurological disorders including epilepsy. In this review, we will focus on a subset of pro-inflammatory chemokines (namely CCL2, CCL3, CCL5, CX3CL1) and their receptors, and their increasingly recognized role in seizure control.
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Affiliation(s)
- Chiara Cerri
- CNR Neuroscience Institute, via G. Moruzzi 1, 56124, Pisa, Italy; Fondazione Umberto Veronesi, Piazza Velasca 5, 20122 Milano, Italy.
| | - Matteo Caleo
- CNR Neuroscience Institute, via G. Moruzzi 1, 56124, Pisa, Italy.
| | - Yuri Bozzi
- CNR Neuroscience Institute, via G. Moruzzi 1, 56124, Pisa, Italy; Neurodevelopmental Disorders Research Group, Centre for Mind/Brain Sciences, University of Trento, via Sommarive 9, 38123 Povo, Trento, Italy.
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Chemokine CCL2-CCR2 Signaling Induces Neuronal Cell Death via STAT3 Activation and IL-1β Production after Status Epilepticus. J Neurosci 2017; 37:7878-7892. [PMID: 28716963 DOI: 10.1523/jneurosci.0315-17.2017] [Citation(s) in RCA: 124] [Impact Index Per Article: 17.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2017] [Revised: 06/20/2017] [Accepted: 07/12/2017] [Indexed: 12/17/2022] Open
Abstract
Elevated levels of chemokine C-C motif ligand 2 (CCL2) and its receptor CCR2 have been reported in patients with temporal lobe epilepsy and in experimental seizures. However, the functional significance and molecular mechanism underlying CCL2-CCR2 signaling in epileptic brain remains largely unknown. In this study, we found that the upregulated CCL2 was mainly expressed in hippocampal neurons and activated microglia from mice 1 d after kainic acid (KA)-induced seizures. Taking advantage of CX3CR1GFP/+:CCR2RFP/+ double-transgenic mice, we demonstrated that CCL2-CCR2 signaling has a role in resident microglial activation and blood-derived monocyte infiltration. Moreover, seizure-induced degeneration of neurons in the hippocampal CA3 region was attenuated in mice lacking CCL2 or CCR2. We further showed that CCR2 activation induced STAT3 (signal transducer and activator of transcription 3) phosphorylation and IL-1β production, which are critical for promoting neuronal cell death after status epilepticus. Consistently, pharmacological inhibition of STAT3 by WP1066 reduced seizure-induced IL-1β production and subsequent neuronal death. Two weeks after KA-induced seizures, CCR2 deficiency not only reduced neuronal loss, but also attenuated seizure-induced behavioral impairments, including anxiety, memory decline, and recurrent seizure severity. Together, we demonstrated that CCL2-CCR2 signaling contributes to neurodegeneration via STAT3 activation and IL-1β production after status epilepticus, providing potential therapeutic targets for the treatment of epilepsy.SIGNIFICANCE STATEMENT Epilepsy is a global concern and epileptic seizures occur in many neurological conditions. Neuroinflammation associated with microglial activation and monocyte infiltration are characteristic of epileptic brains. However, molecular mechanisms underlying neuroinflammation in neuronal death following epilepsy remain to be elucidated. Here we demonstrate that CCL2-CCR2 signaling is required for monocyte infiltration, which in turn contributes to kainic acid (KA)-induced neuronal cell death. The downstream of CCR2 activation involves STAT3 (signal transducer and activator of transcription 3) phosphorylation and IL-1β production. Two weeks after KA-induced seizures, CCR2 deficiency not only reduced neuronal loss, but also attenuated seizure-induced behavioral impairments, including anxiety, memory decline, and recurrent seizure severity. The current study provides a novel insight on the function and mechanisms of CCL2-CCR2 signaling in KA-induced neurodegeneration and behavioral deficits.
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Liao ET, Tang NY, Lin YW, Liang Hsieh C. Long-term electrical stimulation at ear and electro-acupuncture at ST36-ST37 attenuated COX-2 in the CA1 of hippocampus in kainic acid-induced epileptic seizure rats. Sci Rep 2017; 7:472. [PMID: 28352122 PMCID: PMC5428861 DOI: 10.1038/s41598-017-00601-1] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2016] [Accepted: 03/07/2017] [Indexed: 11/09/2022] Open
Abstract
Seizures produce brain inflammation, which in turn enhances neuronal excitability. Therefore, anti-inflammation has become a therapeutic strategy for antiepileptic treatment. Cycloxygenase-2 (COX-2) plays a critical role in postseizure brain inflammation and neuronal hyperexcitability. Our previous studies have shown that both electrical stimulation (ES) at the ear and electro-acupuncture (EA) at the Zusanli and Shangjuxu acupoints (ST36–ST37) for 6 weeks can reduce mossy fiber sprouting, spike population, and high-frequency hippocampal oscillations in kainic acid (KA)-induced epileptic seizure rats. This study further investigated the effect of long-term ear ES and EA at ST36–ST37 on the inflammatory response in KA-induced epileptic seizure rats. Both the COX-2 levels in the hippocampus and the number of COX-2 immunoreactive cells in the hippocampal CA1 region were increased after KA-induced epileptic seizures, and these were reduced through the 6-week application of ear ES or EA at ST36–ST37. Thus, long-term ear ES or long-term EA at ST36–ST37 have an anti-inflammatory effect, suggesting that they are beneficial for the treatment of epileptic seizures.
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Affiliation(s)
- En-Tzu Liao
- Graduate Institute of Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung, 40402, Taiwan
| | - Nou-Ying Tang
- School of Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung, 40402, Taiwan
| | - Yi-Wen Lin
- School of Post-Baccalaureate Chinese Medicine, College of Chinese Medicine, China Medical University, Taichung, 40402, Taiwan.,Graduate Institute of Acupuncture Science, College of Chinese Medicine, China Medical University, Taichung, 40402, Taiwan.,Research Center for Chinese Medicine and Acupuncture, China Medical University, Taichung, 40402, Taiwan
| | - Ching Liang Hsieh
- Graduate Institute of Acupuncture Science, College of Chinese Medicine, China Medical University, Taichung, 40402, Taiwan. .,Research Center for Chinese Medicine and Acupuncture, China Medical University, Taichung, 40402, Taiwan. .,Graduate Institute of Integrated Medicine, College of Chinese Medicine, China Medical University, Taichung, 40402, Taiwan. .,Department of Chinese Medicine, China Medical University Hospital, Taichung, 40447, Taiwan.
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Long-Term Intake of Uncaria rhynchophylla Reduces S100B and RAGE Protein Levels in Kainic Acid-Induced Epileptic Seizures Rats. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2017; 2017:9732854. [PMID: 28386293 PMCID: PMC5343263 DOI: 10.1155/2017/9732854] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/30/2016] [Revised: 01/13/2017] [Accepted: 01/24/2017] [Indexed: 12/19/2022]
Abstract
Epileptic seizures are crucial clinical manifestations of recurrent neuronal discharges in the brain. An imbalance between the excitatory and inhibitory neuronal discharges causes brain damage and cell loss. Herbal medicines offer alternative treatment options for epilepsy because of their low cost and few side effects. We established a rat epilepsy model by injecting kainic acid (KA, 12 mg/kg, i.p.) and subsequently investigated the effect of Uncaria rhynchophylla (UR) and its underlying mechanisms. Electroencephalogram and epileptic behaviors revealed that the KA injection induced epileptic seizures. Following KA injection, S100B levels increased in the hippocampus. This phenomenon was attenuated by the oral administration of UR and valproic acid (VA, 250 mg/kg). Both drugs significantly reversed receptor potentiation for advanced glycation end product proteins. Rats with KA-induced epilepsy exhibited no increase in the expression of metabotropic glutamate receptor 3, monocyte chemoattractant protein 1, and chemokine receptor type 2, which play a role in inflammation. Our results provide novel and detailed mechanisms, explaining the role of UR in KA-induced epileptic seizures in hippocampal CA1 neurons.
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Infiltrating monocytes promote brain inflammation and exacerbate neuronal damage after status epilepticus. Proc Natl Acad Sci U S A 2016; 113:E5665-74. [PMID: 27601660 DOI: 10.1073/pnas.1604263113] [Citation(s) in RCA: 238] [Impact Index Per Article: 29.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The generalized seizures of status epilepticus (SE) trigger a series of molecular and cellular events that produce cognitive deficits and can culminate in the development of epilepsy. Known early events include opening of the blood-brain barrier (BBB) and astrocytosis accompanied by activation of brain microglia. Whereas circulating monocytes do not infiltrate the healthy CNS, monocytes can enter the brain in response to injury and contribute to the immune response. We examined the cellular components of innate immune inflammation in the days following SE by discriminating microglia vs. brain-infiltrating monocytes. Chemokine receptor 2 (CCR2(+)) monocytes invade the hippocampus between 1 and 3 d after SE. In contrast, only an occasional CD3(+) T lymphocyte was encountered 3 d after SE. The initial cellular sources of the chemokine CCL2, a ligand for CCR2, included perivascular macrophages and microglia. The induction of the proinflammatory cytokine IL-1β was greater in FACS-isolated microglia than in brain-invading monocytes. However, Ccr2 knockout mice displayed greatly reduced monocyte recruitment into brain and reduced levels of the proinflammatory cytokine IL-1β in hippocampus after SE, which was explained by higher expression of the cytokine in circulating and brain monocytes in wild-type mice. Importantly, preventing monocyte recruitment accelerated weight regain, reduced BBB degradation, and attenuated neuronal damage. Our findings identify brain-infiltrating monocytes as a myeloid-cell subclass that contributes to neuroinflammation and morbidity after SE. Inhibiting brain invasion of CCR2(+) monocytes could represent a viable method for alleviating the deleterious consequences of SE.
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Bozzi Y, Caleo M. Epilepsy, Seizures, and Inflammation: Role of the C-C Motif Ligand 2 Chemokine. DNA Cell Biol 2016; 35:257-60. [PMID: 27167681 DOI: 10.1089/dna.2016.3345] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Epilepsy is a chronic disorder characterized by spontaneous recurrent seizures. Several lines of evidence demonstrate that inflammatory processes within the brain parenchyma contribute to recurrence and precipitation of seizures. In both epileptic patients and animal models, seizures upregulate inflammatory mediators, which in turn may enhance brain excitability. We recently showed that the C-C motif ligand 2 (CCL2) chemokine (also known as monocyte chemoattractant protein-1 [MCP-1]) mediates the seizure-promoting effects of inflammation. Systemic inflammatory challenge in chronically epileptic mice markedly enhanced seizure frequency and upregulated CCL2 expression in the brain. Selective pharmacological blockade of CCL2 synthesis or C-C chemokine receptor type 2 (CCR2) significantly suppressed inflammation-induced seizures. These results have important implications for the development of novel anticonvulsant therapies: drugs interfering with CCL2 signaling are used clinically for several human disorders and might be redirected for use in pharmacoresistant epilepsy. Here we review the role of CCL2/CCR2 signaling in linking systemic inflammation with seizure susceptibility and discuss some open questions that arise from our recent studies.
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Affiliation(s)
- Yuri Bozzi
- 1 Centre for Integrative Biology (CIBIO), University of Trento , Trento, Italy .,2 Neuroscience Institute , National Research Council (CNR), Pisa, Italy
| | - Matteo Caleo
- 2 Neuroscience Institute , National Research Council (CNR), Pisa, Italy
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Dennie D, Louboutin JP, Strayer DS. Migration of bone marrow progenitor cells in the adult brain of rats and rabbits. World J Stem Cells 2016; 8:136-157. [PMID: 27114746 PMCID: PMC4835673 DOI: 10.4252/wjsc.v8.i4.136] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 09/11/2015] [Accepted: 02/16/2016] [Indexed: 02/06/2023] Open
Abstract
Neurogenesis takes place in the adult mammalian brain in three areas: Subgranular zone of the dentate gyrus (DG); subventricular zone of the lateral ventricle; olfactory bulb. Different molecular markers can be used to characterize the cells involved in adult neurogenesis. It has been recently suggested that a population of bone marrow (BM) progenitor cells may migrate to the brain and differentiate into neuronal lineage. To explore this hypothesis, we injected recombinant SV40-derived vectors into the BM and followed the potential migration of the transduced cells. Long-term BM-directed gene transfer using recombinant SV40-derived vectors leads to expression of the genes delivered to the BM firstly in circulating cells, then after several months in mature neurons and microglial cells, and thus without central nervous system (CNS) lesion. Most of transgene-expressing cells expressed NeuN, a marker of mature neurons. Thus, BM-derived cells may function as progenitors of CNS cells in adult animals. The mechanism by which the cells from the BM come to be neurons remains to be determined. Although the observed gradual increase in transgene-expressing neurons over 16 mo suggests that the pathway involved differentiation of BM-resident cells into neurons, cell fusion as the principal route cannot be totally ruled out. Additional studies using similar viral vectors showed that BM-derived progenitor cells migrating in the CNS express markers of neuronal precursors or immature neurons. Transgene-positive cells were found in the subgranular zone of the DG of the hippocampus 16 mo after intramarrow injection of the vector. In addition to cells expressing markers of mature neurons, transgene-positive cells were also positive for nestin and doublecortin, molecules expressed by developing neuronal cells. These cells were actively proliferating, as shown by short term BrdU incorporation studies. Inducing seizures by using kainic acid increased the number of BM progenitor cells transduced by SV40 vectors migrating to the hippocampus, and these cells were seen at earlier time points in the DG. We show that the cell membrane chemokine receptor, CCR5, and its ligands, enhance CNS inflammation and seizure activity in a model of neuronal excitotoxicity. SV40-based gene delivery of RNAi targeting CCR5 to the BM results in downregulating CCR5 in circulating cells, suggesting that CCR5 plays an important role in regulating traffic of BM-derived cells into the CNS, both in the basal state and in response to injury. Furthermore, reduction in CCR5 expression in circulating cells provides profound neuroprotection from excitotoxic neuronal injury, reduces neuroinflammation, and increases neuronal regeneration following this type of insult. These results suggest that BM-derived, transgene-expressing, cells can migrate to the brain and that they become neurons, at least in part, by differentiating into neuron precursors and subsequently developing into mature neurons.
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Rettenbeck ML, von Rüden EL, Bienas S, Carlson R, Stein VM, Tipold A, Potschka H. Microglial ROS production in an electrical rat post-status epilepticus model of epileptogenesis. Neurosci Lett 2015; 599:146-51. [PMID: 26007700 DOI: 10.1016/j.neulet.2015.05.041] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2015] [Revised: 04/30/2015] [Accepted: 05/20/2015] [Indexed: 11/26/2022]
Abstract
Reactive oxygen species and inflammatory signaling have been identified as pivotal pathophysiological factors contributing to epileptogenesis. Considering the development of combined anti-inflammatory and antioxidant treatment strategies with antiepileptogenic potential, a characterization of the time course of microglial reactive oxygen species generation during epileptogenesis is of major interest. Thus, we isolated microglia cells and analyzed the generation of reactive oxygen species by flow cytometric analysis in an electrical rat post-status epilepticus model. Two days post status epilepticus, a large-sized cell cluster exhibited a pronounced response with excessive production of reactive oxygen species upon stimulation with phorbol-myristate-acetate. Neither in the latency phase nor in the chronic phase with spontaneous seizures a comparable cell population with induction of reactive oxygen species was identified. We were able to demonstrate in the electrical rat post-status-epilepticus model, that microglial ROS generation reaches a peak after the initial insult, is only marginally increased in the latency phase, and returns to control levels during the chronic epileptic phase. The data suggest that a combination of anti-inflammatory and radical scavenging approaches might only be beneficial during a short time window after an epileptogenic brain insult.
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Affiliation(s)
- Maruja L Rettenbeck
- Institute of Pharmacology, Toxicology, and Pharmacy, Ludwig-Maximilians-University, Munich, Germany
| | - Eva-Lotta von Rüden
- Institute of Pharmacology, Toxicology, and Pharmacy, Ludwig-Maximilians-University, Munich, Germany
| | - Silvia Bienas
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Regina Carlson
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Veronika M Stein
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Andrea Tipold
- Department of Small Animal Medicine and Surgery, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Heidrun Potschka
- Institute of Pharmacology, Toxicology, and Pharmacy, Ludwig-Maximilians-University, Munich, Germany.
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Lv R, Xu X, Luo Z, Shen N, Wang F, Zhao Y. Pyrrolidine dithiocarbamate (PDTC) inhibits the overexpression of MCP-1 and attenuates microglial activation in the hippocampus of a pilocarpine-induced status epilepticus rat model. Exp Ther Med 2013; 7:39-45. [PMID: 24348761 PMCID: PMC3861516 DOI: 10.3892/etm.2013.1397] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2013] [Accepted: 08/02/2013] [Indexed: 01/09/2023] Open
Abstract
The aim of this study was to investigate the effects of pyrrolidine dithiocarbamate (PDTC) on MCP-1 expression and microglial activation in the hippocampus of a rat model of pilocarpine (PILO)-induced status epilepticus (SE). Moreover, seizure susceptibility, frequency and severity as well as brain damage were analyzed and changes in behavior were recorded. Chemokine MCP-1 expression and microglial activation were detected by immunohistochemistry (IHC). Fluoro-Jade C (FJC) and NeuN staining were used for the evaluation of tissue damage. Our results showed that although SE resulted in the upregulation of MCP-1 and microglial activation in the rat hippocampus 24 h after seizure onset, pretreatment with PDTC significantly inhibited the MCP-1 overexpression and attenuated the microglial activation. These effects were accompanied by neurodegenerative amelioration. To the best of our knowledge, these findings indicated for the first time that the activation of the nuclear factor-κB (NF-κB) pathway may contribute to MCP-1 upregulation and microglial activation in the context of epilepsy. PDTC was also shown to exert anticonvulsant activity and to have a neuroprotective effect on the hippocampal CA1 and CA3 regions, potentially through attenuating microglial activation.
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Affiliation(s)
- Rilang Lv
- Department of Neurology, Shanghai East Hospital Affiliated to Tongji University School of Medicine, Shanghai 200210, P.R. China
| | - Xiaoyun Xu
- Department of Neurology, Shanghai East Hospital Affiliated to Tongji University School of Medicine, Shanghai 200210, P.R. China ; Department of Neurology, Shanghai Pudong New Area Zhoupu Hospital, Shanghai 201318, P.R. China
| | - Zheng Luo
- Department of Neurology, Shanghai East Hospital Affiliated to Tongji University School of Medicine, Shanghai 200210, P.R. China
| | - Nan Shen
- Department of Neurology, Shanghai East Hospital Affiliated to Tongji University School of Medicine, Shanghai 200210, P.R. China
| | - Feng Wang
- Department of Neurology, Shanghai Jiaotong University Affiliated First People's Hospital, Shanghai 200080, P.R. China
| | - Yongbo Zhao
- Department of Neurology, Shanghai Jiaotong University Affiliated First People's Hospital, Shanghai 200080, P.R. China
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Bertini G, Bramanti P, Constantin G, Pellitteri M, Radu BM, Radu M, Fabene PF. New players in the neurovascular unit: insights from experimental and clinical epilepsy. Neurochem Int 2013; 63:652-9. [PMID: 23962437 DOI: 10.1016/j.neuint.2013.08.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2013] [Revised: 07/26/2013] [Accepted: 08/01/2013] [Indexed: 01/12/2023]
Abstract
The conventional notion that neurons are exclusively responsible for brain signaling is increasingly challenged by the idea that brain function in fact depends on a complex interplay between neurons, glial cells, vascular endothelium, and immune-related blood cells. Recent data demonstrates that neuronal activity is profoundly affected by an entire cellular and extracellular 'orchestra', the so-called neurovascular unit (NVU). Among the 'musical instruments' of this orchestra, there may be molecules long-known in biomedicine as important mediators of inflammatory and immune responses in the organism, as well as non-neuronal cells, e.g., leukocytes. We here review recent evidence on the structure and function of the NVU, both in the healthy brain and in pathological conditions, such as the abnormal NVU activation observed in epilepsy. We will argue that a better understanding of NVU function will require the addition of new players to the 'orchestra'.
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Affiliation(s)
- Giuseppe Bertini
- Department of Neurological and Movement Sciences, Section of Anatomy and Histology, University of Verona, Strada Le Grazie 8, Verona 37134, Italy
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Fabene PF, Laudanna C, Constantin G. Leukocyte trafficking mechanisms in epilepsy. Mol Immunol 2013; 55:100-4. [PMID: 23351392 DOI: 10.1016/j.molimm.2012.12.009] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2012] [Revised: 11/06/2012] [Accepted: 12/06/2012] [Indexed: 01/13/2023]
Abstract
Epilepsy is a chronic disorder that affects 1% of the world population and is characterized by chronically reoccurring seizures. Seizures are initiated by abnormal excessive or synchronous neuronal activity in the brain. Epilepsy requires life long anti-convulsant therapy and current therapies for epilepsy selectively target neuronal activity. In the last decade, cytokines and vascular alterations have been discussed in relation to the pathogenesis of epilepsy, suggesting a potential role for inflammation mechanisms in seizure induction. More recently, it has been shown that leukocyte trafficking plays a key role in seizure generation, and that anti-leukocyte adhesion therapy has therapeutic and preventative effects in an experimental model of human epilepsy. These results were supported by evidence in humans showing that leukocytes accumulate in the brain parenchyma of patients with different types of epilepsy. Finally, recent clinical observations suggest that therapies able to interfere with leukocyte trafficking may have a therapeutic effect in epilepsy. The emerging role for leukocytes and leukocyte adhesion mechanisms in seizure generation provides insight into the mechanisms of brain damage and may contribute to the development of novel therapeutic strategies in epilepsy.
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Affiliation(s)
- Paolo F Fabene
- Department of Neurological, Neuropsychological, Morphological and Movement Sciences, Section of Anatomy, University of Verona, Verona, Italy.
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Hung YW, Lai MT, Tseng YJ, Chou CC, Lin YY. Monocyte chemoattractant protein-1 affects migration of hippocampal neural progenitors following status epilepticus in rats. J Neuroinflammation 2013; 10:11. [PMID: 23339567 PMCID: PMC3563591 DOI: 10.1186/1742-2094-10-11] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2012] [Accepted: 01/07/2013] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND Epilepsy is a common brain disorder characterized by a chronic predisposition to generate spontaneous seizures. The mechanisms for epilepsy formation remain unknown. A growing body of evidence suggests the involvement of inflammatory processes in epileptogenesis. In the present study, we investigated the involvement of monocyte chemoattractant protein-1 (MCP-1) in aberrant migration of hippocampal progenitors in rats after the insult of status epilepticus (SE). METHODS SE was induced with pilocarpine in Sprague-Dawley rats. Transcriptional expression of MCP-1 in the dentate gyrus (DG) was measured using quantitative real-time PCR. From 1 to 28 days after SE, the temporal profiles of MCP-1 protein expression in DG were evaluated using enzyme-linked immunosorbent assay. Chemokine (C-C motif) receptor 2 (CCR2) expression in doublecortin-positive neuronal progenitors was examined using double-labeling immunohistochemistry. The involvement of MCP-1/CCR2 signaling in aberrant neuronal progenitor migration in the epileptic hippocampus was assessed in the SE rats using a CCR2 antagonist, RS102895, and the ectopic migration of neuronal progenitors was determined using Prox1/doublecortin double immunostaining. RESULTS After SE, MCP-1 gene was significantly upregulated and its corresponding protein expression in the DG was significantly increased on days 1 and 3. Some hilar ectopic progenitor cells of SE rats expressed the MCP-1 receptor, CCR2. Notably, the ectopic migration of neuronal progenitors into hilus was attenuated by a blockade of the MCP-1/CCR2 interaction with a selective CCR2 inhibitor, RS102895. CONCLUSIONS An increase in dentate MCP-1 is associated with seizure-induced aberrant migration of neuronal progenitors through the interaction with CCR2. The upregulation of MCP-1 after an insult of SE may play a role in the generation of epilepsy.
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Affiliation(s)
- Yu-Wen Hung
- Institute of Physiology, National Yang-Ming University, No,155, Sec, 2, Linong Street, Taipei, 112, Taiwan
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Zhu XB, Wang YB, Chen O, Zhang DQ, Zhang ZH, Cao AH, Huang SY, Sun RP. Characterization of the expression of macrophage inflammatory protein-1α (MIP-1α) and C-C chemokine receptor 5 (CCR5) after kainic acid-induced status epilepticus (SE) in juvenile rats. Neuropathol Appl Neurobiol 2012; 38:602-16. [DOI: 10.1111/j.1365-2990.2012.01251.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
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Prolonged increase in rat hippocampal chemokine signalling after status epilepticus. J Neuroimmunol 2012; 245:15-22. [DOI: 10.1016/j.jneuroim.2012.01.012] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2011] [Revised: 01/24/2012] [Accepted: 01/28/2012] [Indexed: 12/30/2022]
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Ding Z, Liu J, Lin R, Hou XH. Experimental pancreatitis results in increased blood-brain barrier permeability in rats: a potential role of MCP-1. J Dig Dis 2012; 13:179-185. [PMID: 22356313 DOI: 10.1111/j.1751-2980.2011.00568.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
OBJECTIVE To measure the changes of blood-brain barrier (BBB) permeability in rats with acute pancreatitis (AP) and to investigate the role of monocyte chemoattractant protein (MCP)-1 expression in this alteration. METHODS Rat model of severe acute pancreatitis (SAP) and mild acute pancreatitis (MAP) was induced by pancreatic duct infusion of 5% and 0.5% sodium choleate, respectively, and a saline infusion was used in the control. The severity of AP was evaluated by a pathological score system. BBB permeability was detected by Evan's blue tracer and BBB tight junction was assessed by brain occludin expression. Immunohistochemistry and real-time polymerase chain reaction were used to detect MCP-1 expression in the brain. Nifedipine was used as the antagonist of MCP-1. RESULTS Compared to the control group, change of BBB permeability was more significant in SAP groups, but not in MAP groups. Occludin level decreased 12 h after SAP induction. Pathological score of SAP group was higher than that in MAP group. BBB opening was associated with pancreatic injury. Brain MCP-1 expression was detected in all the SAP groups, which was correlated with increased BBB permeability, but was not found in the control group or the MAP group. After treatment with nifedipine, brain MCP-1 level decreased and BBB function improved synchronously in SAP groups. CONCLUSIONS BBB permeability increased in SAP significantly and time-dependently, and was correlated with brain MCP-1 expression. Nifedipine may improve BBB function by inhibiting MCP-1 expression.
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Affiliation(s)
- Zhen Ding
- Department of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
| | - Jun Liu
- Department of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
| | - Rong Lin
- Department of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
| | - Xiao Hua Hou
- Department of Gastroenterology, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, Hubei Province, China
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Johnson EA, Dao TL, Guignet MA, Geddes CE, Koemeter-Cox AI, Kan RK. Increased expression of the chemokines CXCL1 and MIP-1α by resident brain cells precedes neutrophil infiltration in the brain following prolonged soman-induced status epilepticus in rats. J Neuroinflammation 2011; 8:41. [PMID: 21535896 PMCID: PMC3104356 DOI: 10.1186/1742-2094-8-41] [Citation(s) in RCA: 89] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2011] [Accepted: 05/02/2011] [Indexed: 11/30/2022] Open
Abstract
Background Exposure to the nerve agent soman (GD) causes neuronal cell death and impaired behavioral function dependent on the induction of status epilepticus (SE). Little is known about the maturation of this pathological process, though neuroinflammation and infiltration of neutrophils are prominent features. The purpose of this study is to quantify the regional and temporal progression of early chemotactic signals, describe the cellular expression of these factors and the relationship between expression and neutrophil infiltration in damaged brain using a rat GD seizure model. Methods Protein levels of 4 chemokines responsible for neutrophil infiltration and activation were quantified up to 72 hours in multiple brain regions (i.e. piriform cortex, hippocampus and thalamus) following SE onset using multiplex bead immunoassays. Chemokines with significantly increased protein levels were localized to resident brain cells (i.e. neurons, astrocytes, microglia and endothelial cells). Lastly, neutrophil infiltration into these brain regions was quantified and correlated to the expression of these chemokines. Results We observed significant concentration increases for CXCL1 and MIP-1α after seizure onset. CXCL1 expression originated from neurons and endothelial cells while MIP-1α was expressed by neurons and microglia. Lastly, the expression of these chemokines directly preceded and positively correlated with significant neutrophil infiltration in the brain. These data suggest that following GD-induced SE, a strong chemotactic response originating from various brain cells, recruits circulating neutrophils to the injured brain. Conclusions A strong induction of neutrophil attractant chemokines occurs following GD-induced SE resulting in neutrophil influx into injured brain tissues. This process may play a key role in the progressive secondary brain pathology observed in this model though further study is warranted.
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Affiliation(s)
- Erik A Johnson
- Research Division, Pharmacology Branch, US Army Medical Research Institute of Chemical Defense, Aberdeen Proving Ground, MD 21010, USA.
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Abstract
Epilepsy is the third most common chronic brain disorder, and is characterized by an enduring predisposition to generate seizures. Despite progress in pharmacological and surgical treatments of epilepsy, relatively little is known about the processes leading to the generation of individual seizures, and about the mechanisms whereby a healthy brain is rendered epileptic. These gaps in our knowledge hamper the development of better preventive treatments and cures for the approximately 30% of epilepsy cases that prove resistant to current therapies. Here, we focus on the rapidly growing body of evidence that supports the involvement of inflammatory mediators-released by brain cells and peripheral immune cells-in both the origin of individual seizures and the epileptogenic process. We first describe aspects of brain inflammation and immunity, before exploring the evidence from clinical and experimental studies for a relationship between inflammation and epilepsy. Subsequently, we discuss how seizures cause inflammation, and whether such inflammation, in turn, influences the occurrence and severity of seizures, and seizure-related neuronal death. Further insight into the complex role of inflammation in the generation and exacerbation of epilepsy should yield new molecular targets for the design of antiepileptic drugs, which might not only inhibit the symptoms of this disorder, but also prevent or abrogate disease pathogenesis.
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Affiliation(s)
- Annamaria Vezzani
- Department of Neuroscience, Mario Negri Institute for Pharmacological Research, Via Giuseppe La Masa 19, 20156 Milan, Italy.
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28
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Louboutin JP, Chekmasova A, Marusich E, Agrawal L, Strayer DS. Role of CCR5 and its ligands in the control of vascular inflammation and leukocyte recruitment required for acute excitotoxic seizure induction and neural damage. FASEB J 2010; 25:737-53. [PMID: 20940264 DOI: 10.1096/fj.10-161851] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Chemokines may play a role in leukocyte migration across the blood-brain barrier (BBB) during neuroinflammation and other neuropathological processes, such as epilepsy. We investigated the role of the chemokine receptor CCR5 in seizures. We used a rat model based on intraperitoneal kainic acid (KA) administration. Four months before KA injection, adult rats were given femoral intramarrow inoculations of SV (RNAiR5-RevM10.AU1), which carries an interfering RNA (RNAi) against CCR5, plus a marker epitope (AU1), or its monofunctional RNAi-carrying homologue, SV(RNAiR5). This treatment lowered expression of CCR5 in circulating cells. In control rats, seizures induced elevated expression of CCR5 ligands MIP-1α and RANTES in the microvasculature, increased BBB leakage and CCR5(+) cells, as well as neuronal loss, inflammation, and gliosis in the hippocampi. Animals given either the bifunctional or the monofunctional vector were largely protected from KA-induced seizures, neuroinflammation, BBB damage, and neuron loss. Brain CCR5 mRNA was reduced. Rats receiving RNAiR5-bearing vectors showed far greater repair responses: increased neuronal proliferation, and decreased production of MIP-1α and RANTES. Controls received unrelated SV(BUGT) vectors. Decrease in CCR5 in circulating cells strongly protected from excitotoxin-induced seizures, BBB leakage, CNS injury, and inflammation, and facilitated neurogenic repair.
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Affiliation(s)
- Jean-Pierre Louboutin
- Department of Pathology, Jefferson Medical College, 1020 Locust St., Rm. 251, Philadelphia, PA 19107, USA.
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29
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Fabene PF, Bramanti P, Constantin G. The emerging role for chemokines in epilepsy. J Neuroimmunol 2010; 224:22-7. [PMID: 20542576 DOI: 10.1016/j.jneuroim.2010.05.016] [Citation(s) in RCA: 115] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2010] [Accepted: 05/04/2010] [Indexed: 01/13/2023]
Abstract
Epilepsy has been considered mainly a neuronal disease, without much attention to non-neuronal cells. In recent years growing evidence suggest that astrocytes, microglia, blood leukocytes and blood-brain barrier breakdown are involved in the pathogenesis of epilepsy. In particular, leukocyte-endothelium interactions and eventually subsequent leukocyte recruitment in the brain parenchyma seem to represent key players in the epileptogenic cascade. Chemokines are chemotactic factors controlling leukocyte migration under physiological and pathological conditions. In the light of recent advances in our understanding of the role of inflammation mechanisms in the pathogenesis of epilepsy, pro-inflammatory chemokines may play a critical role in epileptogenesis.
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Affiliation(s)
- Paolo F Fabene
- Department of Morphological and Biomedical Sciences, Section of Anatomy and Histology, University of Verona, Verona, Italy.
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30
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Xu JH, Long L, Tang YC, Zhang JT, Hut HT, Tang FR. CCR3, CCR2A and macrophage inflammatory protein (MIP)-1a, monocyte chemotactic protein-1 (MCP-1) in the mouse hippocampus during and after pilocarpine-induced status epilepticus (PISE) . Neuropathol Appl Neurobiol 2009; 35:496-514. [PMID: 19490431 DOI: 10.1111/j.1365-2990.2009.01022.x] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
AIMS To investigate protein and gene expressions of chemokine subtypes CCR3, CCR2A and their respective ligands macrophage inflammatory protein 1-alpha (MIP-1alpha), monocyte chemotactic protein-1 (MCP-1) in the normal mouse central nervous system (CNS) and in the hippocampus at different time points during and after pilocarpine-induced status epilepticus (PISE). METHODS CCR3 and MIP-1alpha protein expressions were mapped in the mouse CNS. The protein and gene expressions of CCR3 and CCR2A and their respective ligands MIP-1alpha, MCP-1 in the hippocampus were studies by immunocytochemical and quantitative real-time RT-PCR during and after PISE. RESULTS CCR3 and MIP-1alpha gene expression and immunopositive neurones were broadly distributed in the CNS. CCR3 and CCA2A gene and their protein expression were downregulated in the hippocampus at 1 h during PISE. The protein expression of MIP-1alpha, MCP-1 decreased but gene expression increased at 2 h during PISE. In the hilus of the dentate gyrus, significant reduction of the numbers of CCR3, CCR2A, MCP-1 immunopositive neurones occurred from 1 h during to 2 months after PISE, but the number of MIP-1alpha neurones reduced from 2 h during to 2 months after PISE. Induced expression of CCR3 at 1 week, CCR2A, MCP-1 or MIP-1alpha at 1 week and 2 months after PISE was found in reactive astrocytes. MCP-1 was also demonstrated in the blood vessels of the hippocampus at 2 months after PISE. CONCLUSIONS CCR3 and MIP-1alpha may play important functional roles in the mouse brain. The downregulation of CCR3, CCR2A, MIP-1alpha and MCP-1 in the hippocampal neurones at the acute stage during and after PISE may weaken the neuroprotective mechanisms. However, induced expression of MCP-1 in hippocampal blood vessel may be related to changes in permeability of the blood-brain barrier during epileptogenesis.
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Affiliation(s)
- J H Xu
- Epilepsy Research Lab, National Neuroscience Institute, Singapore
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31
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Abstract
Brain injury may result in the development of epilepsy, one of the most common neurological disorders. We previously demonstrated that albumin is critical in the generation of epilepsy after blood-brain barrier (BBB) compromise. Here, we identify TGF-beta pathway activation as the underlying mechanism. We demonstrate that direct activation of the TGF-beta pathway by TGF-beta1 results in epileptiform activity similar to that after exposure to albumin. Coimmunoprecipitation revealed binding of albumin to TGF-beta receptor II, and Smad2 phosphorylation confirmed downstream activation of this pathway. Transcriptome profiling demonstrated similar expression patterns after BBB breakdown, albumin, and TGF-beta1 exposure, including modulation of genes associated with the TGF-beta pathway, early astrocytic activation, inflammation, and reduced inhibitory transmission. Importantly, TGF-beta pathway blockers suppressed most albumin-induced transcriptional changes and prevented the generation of epileptiform activity. Our present data identifies the TGF-beta pathway as a novel putative epileptogenic signaling cascade and therapeutic target for the prevention of injury-induced epilepsy.
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