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Wakonigg Alonso C, McElhatton F, O'Mahony B, Campbell M, Pollak TA, Stokes PRA. The blood-brain barrier in bipolar disorders: A systematic review. J Affect Disord 2024; 361:434-444. [PMID: 38897301 DOI: 10.1016/j.jad.2024.06.032] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/03/2024] [Revised: 05/13/2024] [Accepted: 06/13/2024] [Indexed: 06/21/2024]
Abstract
BACKGROUND Bipolar disorders (BD) are chronic, debilitating disorders. The blood-brain barrier (BBB) has been increasingly investigated in BD. This systematic review aimed to assess the available evidence on the relationship between BD and markers of BBB dysfunction. METHODS A systematic search in PubMed, Embase, PsycINFO, CINAHL and Web of Science was run where the primary outcomes were BBB markers such as S100B, albumin ratio, matrix metalloproteinase (MMP), cell adhesion molecule (CAM), and tight junction proteins. Techniques included blood, cerebrospinal fluid (CSF), post-mortem, genetic and imaging methods in BD compared to healthy controls. RESULTS 55 studies were identified, 38 of which found an association between BD and markers of BBB dysfunction. 16/29 studies found increased blood/CSF albumin ratio, S100B, CAMs or MMP levels in BD participants compared to controls. 5/19 post-mortem studies found increased levels of chondroitin sulphate proteoglycans, intercellular CAM, neurexin or claudin-5 mRNA in distinct locations throughout the brain in BD compared to controls. One imaging study identified extensive BBB leakage in 30 % of BD participants, compared to 0 % in controls. LIMITATIONS The diversity in methodologies used in the included studies makes direct comparison of results challenging. Furthermore, imaging methods are the gold standard, but only one study used them. Other markers are only indicative of BBB permeability. CONCLUSIONS This review suggests an association between BD and BBB dysfunction. Further research is needed to provide definite answers considering the existing literature's limitations, and to clarify whether this association provides a pathogenic mechanism, or is an epiphenomenon of BD.
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Affiliation(s)
- Clara Wakonigg Alonso
- Institute of Psychiatry & Psychology and Neuroscience, King's College London,United Kingdom.
| | - Frances McElhatton
- Institute of Psychiatry & Psychology and Neuroscience, King's College London,United Kingdom
| | - Brian O'Mahony
- Institute of Psychiatry & Psychology and Neuroscience, King's College London,United Kingdom
| | - Matthew Campbell
- Smurfit Institute of Genetics, Trinity College Dublin, Lincoln Place Gate, Dublin 2, Ireland
| | - Thomas A Pollak
- Dept of Psychosis Studies, Institute of Psychiatry & Psychology and Neuroscience, King's College London, United Kingdom; South London and Maudsley NHS Foundation Trust,Bethlem Royal Hospital, Monks Orchard Road, Beckenham, Kent, BR3 3BX, United Kingdom
| | - Paul R A Stokes
- South London and Maudsley NHS Foundation Trust,Bethlem Royal Hospital, Monks Orchard Road, Beckenham, Kent, BR3 3BX, United Kingdom; Centre for Affective Disorders, Department of Psychological Medicine, Institute of Psychiatry & Psychology and Neuroscience, King's College London,United Kingdom
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2
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Jara-Prado A, Guerrero-Camacho JL, Ángeles-López QD, Ochoa-Morales A, Dávila-Ortiz de Montellano DJ, Ramírez-García MÁ, Breda-Yepes M, Durón RM, Delgado-Escueta AV, Barrios-González DA, Martínez-Juárez IE. Association of variants in the ABCB1, CYP2C19 and CYP2C9 genes for Juvenile Myoclonic Epilepsy. Neurol Sci 2024; 45:1635-1643. [PMID: 37875597 DOI: 10.1007/s10072-023-07124-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2023] [Accepted: 10/06/2023] [Indexed: 10/26/2023]
Abstract
Juvenile myoclonic epilepsy (JME) is the most common of the generalized genetic epilepsies, with multiple causal and susceptibility genes; however, its etiopathogenesis is mainly unknown. The toxic effects caused by xenobiotics in cells occur during their metabolic transformation, mainly by enzymes belonging to cytochrome P450. The elimination of these compounds by transporters of the ABC type protects the central nervous system, but their accumulation causes neuronal damage, resulting in neurological diseases. The present study has sought the association between single nucleotide genetic variants of the CYP2C9, CYP2C19, and ABCB1 genes and the development of JME in patients compared to healthy controls. The CC1236 and GG2677 genotypes of ABCB1 in women; allele G 2677, genotypes GG 2677 and CC 3435 in men; the CYP2C19*2A allele, and the CYP2C19*3G/A genotype in both sexes were found to be risk factors for JME. Furthermore, carriers of the TTGGCC genotype combination of the ABCB1 gene (1236/2677/3435) have a 10.5 times higher risk of developing JME than non-carriers. Using the STRING database, we found an interaction between the proteins encoded by these genes and other possible proteins. These findings indicate that the CYP450 system and ABC transporters could interact with other genes in the JME.
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Affiliation(s)
- Aurelio Jara-Prado
- Genetics Department, National Institute of Neurology and Neurosurgery, Mexico City, Mexico
| | | | | | - Adriana Ochoa-Morales
- Genetics Department, National Institute of Neurology and Neurosurgery, Mexico City, Mexico
| | | | | | - Michelle Breda-Yepes
- National Institute of Neurology and Neurosurgery, Epilepsy Clinic, Mexico City, Mexico
| | - Reyna M Durón
- Universidad Tecnológica Centroamericana (UNITEC), Tegucigalpa, Honduras
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3
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Wu X, Xie D, Zheng Q, Peng S, Liu Y, Ma P, Ye L, Mo X, Feng Z. Downregulation of NHE1 expression attenuates apoptosis of primary hippocampal neurons of an epilepsy model through the calpain-1 pathway. Neurosci Lett 2023; 815:137494. [PMID: 37748674 DOI: 10.1016/j.neulet.2023.137494] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2023] [Revised: 09/10/2023] [Accepted: 09/20/2023] [Indexed: 09/27/2023]
Abstract
OBJECTIVE Na(+)/H(+) exchanger isoform 1 (NHE1), a membrane protein that regulates intracellular pH, is abundantly expressed in brain tissues. It is associated with pathophysiologies in several brain diseases. The present study aimed to investigate the effects of NHE1 on the apoptosis of primary neurons of an epilepsy model. METHODS Primary hippocampal neurons were cultured in an Mg2+-free medium to establish an epilepsy cell model. Designed shNHE1 lentivirus was used to silence NHE1 level in primary neurons. Nonselective pharmacological inhibitor MDL-28170 (20 μmol/L) was used to inhibit calpain-1 protein in neurons treated with Mg2+-free medium. The expression levels of NHE1 and calpain-1, intracellular Ca2+ (Ca2+i) and H+ (H+i) levels, and the expression levels of apoptosis-related proteins Bcl-2 and Bax were detected in neurons. TUNEL staining was performed to determine apoptosis in different groups. RESULTS NHE1 expression was increased in primary neurons treated with an Mg2+-free medium, and it was correlated with increased expression of calpain-1 and cell apoptosis. Neurons from the in vitro epilepsy model showed significantly decreased Bcl-2 protein expression and significantly increased Bax protein expression. In the presence of LV-shNHE1 and the calpain-1 inhibitor MDL-28170, the changes in the expression of apoptosis-related proteins Bcl-2 and Bax were blocked in the epileptic model, and the percentage of apoptotic neurons among neurons from the in vitro epilepsy model was significantly decreased. The increase in calpain-1 expression was suppressed by LV-shNHE1; however, the inhibition of calpain-1 did not affect NHE1 expression. CONCLUSION These results demonstrate that NHE1 participates in the promotion of neuronal apoptosis of epilepsy model in vitro through the calpain-1 pathway. Downregulation of NHE1 expression could exert a neuroprotective effect on epilepsy.
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Affiliation(s)
- Xuling Wu
- Department of Neurology, Affiliated Hospital of Guizhou Medical University, Guiyang, China
| | - Dongjun Xie
- Department of Neurology, Affiliated Hospital of Guizhou Medical University, Guiyang, China
| | - Qian Zheng
- Department of Neurology, Affiliated Hospital of Guizhou Medical University, Guiyang, China
| | - Shuang Peng
- Department of Neurology, Affiliated Hospital of Guizhou Medical University, Guiyang, China
| | - Ying Liu
- Department of Neurology, Affiliated Hospital of Guizhou Medical University, Guiyang, China
| | - Pengfei Ma
- Department of Neurology, Affiliated Hospital of Guizhou Medical University, Guiyang, China
| | - Lan Ye
- The Medical Science Function Laboratory of Experimental Teaching Center of Basic Medicine, School of Basic Medical Science, Guizhou Medical University, Guiyang, China.
| | - Xiangang Mo
- Department of Comprehensive Care Ward, Affiliated Hospital of Guizhou Medical University, Guiyang, China.
| | - Zhanhui Feng
- Department of Neurology, Affiliated Hospital of Guizhou Medical University, Guiyang, China.
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4
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Chen C, Zhu T, Gong L, Hu Z, Wei H, Fan J, Lin D, Wang X, Xu J, Dong X, Wang Y, Xia N, Zeng L, Jiang P, Xie Y. Trpm2 deficiency in microglia attenuates neuroinflammation during epileptogenesis by upregulating autophagy via the AMPK/mTOR pathway. Neurobiol Dis 2023; 186:106273. [PMID: 37648036 DOI: 10.1016/j.nbd.2023.106273] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2023] [Revised: 08/15/2023] [Accepted: 08/27/2023] [Indexed: 09/01/2023] Open
Abstract
Epilepsy is one of the most common neurological disorders. Neuroinflammation involving the activation of microglia and astrocytes constitutes an important and common mechanism in epileptogenesis. Transient receptor potential melastatin 2 (TRPM2) is a calcium-permeable, non-selective cation channel that plays pathological roles in various inflammation-related diseases. Our previous study demonstrated that Trpm2 knockout exhibits therapeutic effects on pilocarpine-induced glial activation and neuroinflammation. However, whether TRPM2 in microglia and astrocytes plays a common pathogenic role in this process and the underlying molecular mechanisms remained undetermined. Here, we demonstrate a previously unknown role for microglial TRPM2 in epileptogenesis. Trpm2 knockout in microglia attenuated kainic acid (KA)-induced glial activation, inflammatory cytokines production and hippocampal paroxysmal discharges, whereas Trpm2 knockout in astrocytes exhibited no significant effects. Furthermore, we discovered that these therapeutic effects were mediated by upregulated autophagy via the adenosine monophosphate activated protein kinase (AMPK)/mammalian target of rapamycin (mTOR) pathway in microglia. Thus, our findings highlight an important deleterious role of microglial TRPM2 in temporal lobe epilepsy.
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Affiliation(s)
- Chen Chen
- Department of Neurology, Department of Neurobiology and Department of Rehabilitation, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center For Child Health, Hangzhou 310052, China
| | - Tao Zhu
- Department of Critical Care Medicine, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou 310030, China
| | - Lifen Gong
- Department of Neurology, Department of Neurobiology and Department of Rehabilitation, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center For Child Health, Hangzhou 310052, China
| | - Zhe Hu
- Department of Neurology, Department of Neurobiology and Department of Rehabilitation, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center For Child Health, Hangzhou 310052, China
| | - Hao Wei
- Department of Pharmacy, Xuzhou Medical University, 221004 Xuzhou, China
| | - Jianchen Fan
- Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang Province, School of Medicine, Hangzhou City University, Hangzhou 310015, China
| | - Donghui Lin
- Department of Neurology, Department of Neurobiology and Department of Rehabilitation, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center For Child Health, Hangzhou 310052, China
| | - Xiaojun Wang
- Department of Neurology, Department of Neurobiology and Department of Rehabilitation, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center For Child Health, Hangzhou 310052, China
| | - Junyu Xu
- Department of Neurology, Department of Neurobiology and Department of Rehabilitation, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center For Child Health, Hangzhou 310052, China
| | - Xinyan Dong
- Department of Neurology, Department of Neurobiology and Department of Rehabilitation, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center For Child Health, Hangzhou 310052, China
| | - Yifan Wang
- Department of Neurology, Department of Neurobiology and Department of Rehabilitation, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center For Child Health, Hangzhou 310052, China
| | - Ningxiao Xia
- Department of Neurology, Department of Neurobiology and Department of Rehabilitation, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center For Child Health, Hangzhou 310052, China
| | - Linghui Zeng
- Key Laboratory of Novel Targets and Drug Study for Neural Repair of Zhejiang Province, School of Medicine, Hangzhou City University, Hangzhou 310015, China
| | - Peifang Jiang
- Department of Neurology, Department of Neurobiology and Department of Rehabilitation, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center For Child Health, Hangzhou 310052, China.
| | - Yicheng Xie
- Department of Neurology, Department of Neurobiology and Department of Rehabilitation, Children's Hospital, Zhejiang University School of Medicine, National Clinical Research Center For Child Health, Hangzhou 310052, China.
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5
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Peng S, Wu X, Zheng Q, Xu J, Xie D, Zhou M, Wang M, Cheng Y, Ye L, Mo X, Feng Z. Downregulating NHE-1 decreases the apoptosis of hippocampal cells in epileptic model rats based on the NHE-1/calpain1 pathway. Heliyon 2023; 9:e18336. [PMID: 37539113 PMCID: PMC10395532 DOI: 10.1016/j.heliyon.2023.e18336] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2022] [Revised: 07/08/2023] [Accepted: 07/13/2023] [Indexed: 08/05/2023] Open
Abstract
Seizure is associated with pathological changes of hippocampus, but the mechanism by which hippocampal neuronal apoptosis promotes epilepsy is unclear. Our previous study showed that the expression of NHE-1 was increased in epileptic model rats. Therefore, this study further explores the effect of NHE-1 on hippocampal cells apoptosis and seizure in lithium chloride-pilocarpine epileptic model rats. First, we established a lithium chloride-pilocarpine induced epileptic rat model and detected the expression of NHE-1, calpain1 and apoptosis in the hippocampus. Then, we further down-regulated NHE-1 to observe the expression of calpain1 and apoptosis in the hippocampus, as well as its effect on seizures in rats. We found that the expression of NHE-1 and calpain1 and apoptosis in the hippocampus was significant increased in the model group. After down-regulating NHE-1, the expression of calpain1 was decreased, and hippocampal cell apoptosis was alleviated. In addition, down-regulation of NHE-1 reduced the frequency and duration of seizures in epileptic rats. Therefore, hippocampal NHE-1 overexpression is closely related to the development of neuronal apoptosis in a rat model of epilepsy, and downregulating NHE-1 expression can reduce cell apoptosis. Moreover, the NHE-1/calpain1 signaling pathway may be an important mechanism leading to hippocampal cell apoptosis.
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Affiliation(s)
- Shuang Peng
- Department of Neurology, The Affiliated Hospital of Guizhou Medical University. Guiyang, China
| | - Xuling Wu
- Department of Neurology, The Affiliated Hospital of Guizhou Medical University. Guiyang, China
| | - Qian Zheng
- Department of Neurology, The Affiliated Hospital of Guizhou Medical University. Guiyang, China
| | - Jianwei Xu
- Center for Tissue Engineering and Stem Cell Research, School of Basic Medicine,Guizhou Medical University, Guiyang, China
| | - Dongjun Xie
- Department of Neurology, The Affiliated Hospital of Guizhou Medical University. Guiyang, China
| | - Mengyun Zhou
- Department of Molecular and Cellular Physiology, Shinshu University School of Medicine, Matsumoto, Japan
| | - Mingwei Wang
- Department of Cardiology, Affiliated Hospital of Hangzhou Normal University, Hangzhou, China
| | - Yongran Cheng
- School of Public Health, Hangzhou Medical College, Hangzhou, China
| | - Lan Ye
- The Medical Function Laboratory of Experimental Teaching Center of Basic Medicine, School of Basic Medical Sciences, Guizhou Medical University, Guiyang, China
| | - Xiangang Mo
- Comprehensive Ward, The Affiliated Hospital of Guizhou Medical University, Guiyang, China
| | - Zhanhui Feng
- Department of Neurology, The Affiliated Hospital of Guizhou Medical University. Guiyang, China
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6
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Gnanasekaran R, Aickareth J, Hawwar M, Sanchez N, Croft J, Zhang J. CmPn/CmP Signaling Networks in the Maintenance of the Blood Vessel Barrier. J Pers Med 2023; 13:jpm13050751. [PMID: 37240921 DOI: 10.3390/jpm13050751] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2023] [Revised: 04/19/2023] [Accepted: 04/26/2023] [Indexed: 05/28/2023] Open
Abstract
Cerebral cavernous malformations (CCMs) arise when capillaries within the brain enlarge abnormally, causing the blood-brain barrier (BBB) to break down. The BBB serves as a sophisticated interface that controls molecular interactions between the bloodstream and the central nervous system. The neurovascular unit (NVU) is a complex structure made up of neurons, astrocytes, endothelial cells (ECs), pericytes, microglia, and basement membranes, which work together to maintain blood-brain barrier (BBB) permeability. Within the NVU, tight junctions (TJs) and adherens junctions (AJs) between endothelial cells play a critical role in regulating the permeability of the BBB. Disruptions to these junctions can compromise the BBB, potentially leading to a hemorrhagic stroke. Understanding the molecular signaling cascades that regulate BBB permeability through EC junctions is, therefore, essential. New research has demonstrated that steroids, including estrogens (ESTs), glucocorticoids (GCs), and metabolites/derivatives of progesterone (PRGs), have multifaceted effects on blood-brain barrier (BBB) permeability by regulating the expression of tight junctions (TJs) and adherens junctions (AJs). They also have anti-inflammatory effects on blood vessels. PRGs, in particular, have been found to play a significant role in maintaining BBB integrity. PRGs act through a combination of its classic and non-classic PRG receptors (nPR/mPR), which are part of a signaling network known as the CCM signaling complex (CSC). This network couples both nPR and mPR in the CmPn/CmP pathway in endothelial cells (ECs).
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Affiliation(s)
- Revathi Gnanasekaran
- Department of Molecular and Translational Medicine (MTM), Texas Tech University Health Science Center El Paso, El Paso, TX 79905, USA
| | - Justin Aickareth
- Department of Molecular and Translational Medicine (MTM), Texas Tech University Health Science Center El Paso, El Paso, TX 79905, USA
| | - Majd Hawwar
- Department of Molecular and Translational Medicine (MTM), Texas Tech University Health Science Center El Paso, El Paso, TX 79905, USA
| | - Nickolas Sanchez
- Department of Molecular and Translational Medicine (MTM), Texas Tech University Health Science Center El Paso, El Paso, TX 79905, USA
| | - Jacob Croft
- Department of Molecular and Translational Medicine (MTM), Texas Tech University Health Science Center El Paso, El Paso, TX 79905, USA
| | - Jun Zhang
- Department of Molecular and Translational Medicine (MTM), Texas Tech University Health Science Center El Paso, El Paso, TX 79905, USA
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7
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Santos RO, Secolin R, Barbalho PG, Silva-Alves MS, Alvim MKM, Yasuda CL, Rogerio F, Velasco TR, Sakamoto AC, Teixeira AL, Cendes F, Maurer-Morelli CV, Lopes-Cendes I. Multidimensional Approach Assessing the Role of Interleukin 1 Beta in Mesial Temporal Lobe Epilepsy. Front Neurol 2021; 12:690847. [PMID: 34421794 PMCID: PMC8375265 DOI: 10.3389/fneur.2021.690847] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2021] [Accepted: 06/28/2021] [Indexed: 11/25/2022] Open
Abstract
We aimed to investigate the role of interleukin-1 beta (IL-1β) in the mechanisms underlying mesial temporal lobe epilepsy with hippocampal sclerosis (MTLE+HS). We assessed a cohort of 194 patients with MTLE+HS and 199 healthy controls. Patients were divided into those with positive and negative antecedent febrile seizures (FS). We used a multidimensional approach, including (i) genetic association with single nucleotide polymorphisms (SNPs) in the IL1B gene; (ii) quantification of the IL1B transcript in the hippocampal tissue of patients with refractory seizures; and (iii) quantification of the IL-1β protein in the plasma. We found a genetic association signal for two SNPs, rs2708928 and rs3730364*C in the IL1B gene, regardless of the presence of FS (adjusted p = 9.62e–11 and 5.14e–07, respectively). We found no difference between IL1B transcript levels when comparing sclerotic hippocampal tissue from patients with MTLE+HS, without FS, and hippocampi from autopsy controls (p > 0.05). Nevertheless, we found increased IL-1β in the plasma of patients with MTLE+HS with FS compared with controls (p = 0.0195). Our results support the hypothesis of a genetic association between MTLE+HS and the IL1B gene
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Affiliation(s)
- Renato O Santos
- Department of Translational Medicine, University of Campinas, Campinas, Brazil.,Brazilian Institute of Neuroscience and Neurotechnology, Campinas, Brazil
| | - Rodrigo Secolin
- Department of Translational Medicine, University of Campinas, Campinas, Brazil.,Brazilian Institute of Neuroscience and Neurotechnology, Campinas, Brazil
| | - Patrícia G Barbalho
- Department of Translational Medicine, University of Campinas, Campinas, Brazil.,Brazilian Institute of Neuroscience and Neurotechnology, Campinas, Brazil
| | - Mariana S Silva-Alves
- Department of Translational Medicine, University of Campinas, Campinas, Brazil.,Brazilian Institute of Neuroscience and Neurotechnology, Campinas, Brazil
| | - Marina K M Alvim
- Brazilian Institute of Neuroscience and Neurotechnology, Campinas, Brazil.,Department of Neurology, University of Campinas, Campinas, Brazil
| | - Clarissa L Yasuda
- Brazilian Institute of Neuroscience and Neurotechnology, Campinas, Brazil.,Department of Neurology, University of Campinas, Campinas, Brazil
| | - Fábio Rogerio
- Brazilian Institute of Neuroscience and Neurotechnology, Campinas, Brazil.,Department of Pathology, University of Campinas, Campinas, Brazil
| | - Tonicarlo R Velasco
- Department of Neuroscience and Behavioral Science, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Americo C Sakamoto
- Department of Neuroscience and Behavioral Science, Ribeirão Preto Medical School, University of São Paulo, Ribeirão Preto, Brazil
| | - Antonio L Teixeira
- Department of Internal Medicine, Federal University of Minas Gerais, Belo Horizonte, Brazil
| | - Fernando Cendes
- Brazilian Institute of Neuroscience and Neurotechnology, Campinas, Brazil.,Department of Neurology, University of Campinas, Campinas, Brazil
| | - Claudia V Maurer-Morelli
- Department of Translational Medicine, University of Campinas, Campinas, Brazil.,Brazilian Institute of Neuroscience and Neurotechnology, Campinas, Brazil
| | - Iscia Lopes-Cendes
- Department of Translational Medicine, University of Campinas, Campinas, Brazil.,Brazilian Institute of Neuroscience and Neurotechnology, Campinas, Brazil
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8
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Kwon HH, Lee JS, Park H, Shin J, Yin Y, Shin N, Shin HJ, Hwang JA, Kim DW, Kang JW. Vitamin E reduces spasms caused by prenatal stress by lowering calpain expression. Epilepsy Behav 2021; 114:107609. [PMID: 33257295 DOI: 10.1016/j.yebeh.2020.107609] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 10/28/2020] [Accepted: 10/28/2020] [Indexed: 12/13/2022]
Abstract
BACKGROUND Prenatal stress increases the susceptibility of infants to seizures and is known to be associated with oxidative stress. Recent studies suggest that vitamin E has beneficial effects in various neurological diseases due to its antioxidant properties. In this study, we investigated the relationship between prenatal stress and vitamin E treatment on N-methyl-D-aspartate (NMDA)-induced spasms. METHODS We used pregnant female Sprague Dawley rats and induced prenatal stress with an injection of betamethasone on G15. They were then treated orally with 200 mg/kg vitamin E or saline twice a day from G15-G21. On postnatal day 15, NMDA was administered to trigger spasms in offspring. The total number of spasms and latency to the first spasm were recorded. We also measured oxidative stress in the medial cortex using western blot, and calpain activity, thiobarbituric acid reactive substances (TBARS), glutathione (GSH)/GSH/glutathione disulfide (GSSG), superoxide dismutase (SOD) activity, catalase activity, and nitric oxide (NO) assays. RESULTS We observed that rats treated with vitamin E while exposed to prenatal stress demonstrated reduced total number and frequency of spasms. Expression of glutamate decarboxylase 67 (GAD67) and K+/Cl- co-transporter (KCC2) were reduced after prenatal stress; this recovered in the vitamin E treated group. Further, expression of calpain 2 was decreased and various markers of oxidative stress (malondialdehyde (MDA), GSH/GSSG, SOD, catalase, and NO) were reduced in the vitamin E treated group. CONCLUSIONS Our results provide evidence that vitamin E lowers oxidative stress and decreases seizure susceptibility in rat offspring exposed to prenatal stress. Given the well-known safety profile of vitamin E, these results indicate its potential as a strategy for preventing seizures.
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Affiliation(s)
- Hyeok Hee Kwon
- Department of Medical Science, School of Medicine, Chungnam National University, Daejeon, Republic of Korea; Department of Anatomy, School of Medicine, Chungnam National University, Daejeon, Republic of Korea; Department of Pediatrics, Chungnam National University Hospital, School of Medicine, Chungnam National University, Daejeon, Republic of Korea
| | - Jin-Seok Lee
- Liver and Immunology Research Center, Oriental Medical College of Daejeon University, 22-5 Daehung-dong, Jung-gu, Daejeon 301-724, Republic of Korea
| | - Hyewon Park
- Department of Medical Science, School of Medicine, Chungnam National University, Daejeon, Republic of Korea; Department of Anatomy, School of Medicine, Chungnam National University, Daejeon, Republic of Korea
| | - Juhee Shin
- Department of Medical Science, School of Medicine, Chungnam National University, Daejeon, Republic of Korea; Department of Anatomy, School of Medicine, Chungnam National University, Daejeon, Republic of Korea
| | - Yuhua Yin
- Department of Medical Science, School of Medicine, Chungnam National University, Daejeon, Republic of Korea; Department of Anatomy, School of Medicine, Chungnam National University, Daejeon, Republic of Korea
| | - Nara Shin
- Department of Medical Science, School of Medicine, Chungnam National University, Daejeon, Republic of Korea; Department of Anatomy, School of Medicine, Chungnam National University, Daejeon, Republic of Korea
| | - Hyo Jung Shin
- Department of Medical Science, School of Medicine, Chungnam National University, Daejeon, Republic of Korea; Department of Anatomy, School of Medicine, Chungnam National University, Daejeon, Republic of Korea
| | - Jeong-Ah Hwang
- Department of Medical Science, School of Medicine, Chungnam National University, Daejeon, Republic of Korea; Department of Anatomy, School of Medicine, Chungnam National University, Daejeon, Republic of Korea
| | - Dong Woon Kim
- Department of Medical Science, School of Medicine, Chungnam National University, Daejeon, Republic of Korea; Department of Anatomy, School of Medicine, Chungnam National University, Daejeon, Republic of Korea.
| | - Joon Won Kang
- Department of Medical Science, School of Medicine, Chungnam National University, Daejeon, Republic of Korea; Department of Pediatrics, Chungnam National University Hospital, School of Medicine, Chungnam National University, Daejeon, Republic of Korea.
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9
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Gollihue J, Norris C. Astrocyte mitochondria: Central players and potential therapeutic targets for neurodegenerative diseases and injury. Ageing Res Rev 2020; 59:101039. [PMID: 32105849 DOI: 10.1016/j.arr.2020.101039] [Citation(s) in RCA: 37] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2019] [Revised: 01/23/2020] [Accepted: 02/23/2020] [Indexed: 01/16/2023]
Abstract
Mitochondrial function has long been the focus of many therapeutic strategies for ameliorating age-related neurodegeneration and cognitive decline. Historically, the role of mitochondria in non-neuronal cell types has been overshadowed by neuronal mitochondria, which are responsible for the bulk of oxidative metabolism in the brain. Despite this neuronal bias, mitochondrial function in glial cells, particularly astrocytes, is increasingly recognized to play crucial roles in overall brain metabolism, synaptic transmission, and neuronal protection. Changes in astrocytic mitochondrial function appear to be intimately linked to astrocyte activation/reactivity found in most all age-related neurodegenerative diseases. Here, we address the importance of mitochondrial function to astrocyte signaling and consider how mitochondria could contribute to both the detrimental and protective properties of activated astrocytes. Strategies for protecting astrocytic mitochondrial function, promoting bidirectional transfer of mitochondria between astrocytes and neurons, and transplanting healthy mitochondria to diseased nervous tissue are also discussed.
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10
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Löscher W, Friedman A. Structural, Molecular, and Functional Alterations of the Blood-Brain Barrier during Epileptogenesis and Epilepsy: A Cause, Consequence, or Both? Int J Mol Sci 2020; 21:E591. [PMID: 31963328 PMCID: PMC7014122 DOI: 10.3390/ijms21020591] [Citation(s) in RCA: 128] [Impact Index Per Article: 32.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2019] [Revised: 01/12/2020] [Accepted: 01/14/2020] [Indexed: 02/06/2023] Open
Abstract
The blood-brain barrier (BBB) is a dynamic, highly selective barrier primarily formed by endothelial cells connected by tight junctions that separate the circulating blood from the brain extracellular fluid. The endothelial cells lining the brain microvessels are under the inductive influence of neighboring cell types, including astrocytes and pericytes. In addition to the anatomical characteristics of the BBB, various specific transport systems, enzymes and receptors regulate molecular and cellular traffic across the BBB. While the intact BBB prevents many macromolecules and immune cells from entering the brain, following epileptogenic brain insults the BBB changes its properties. Among BBB alterations, albumin extravasation and diapedesis of leucocytes from blood into brain parenchyma occur, inducing or contributing to epileptogenesis. Furthermore, seizures themselves may modulate BBB functions, permitting albumin extravasation, leading to activation of astrocytes and the innate immune system, and eventually modifications of neuronal networks. BBB alterations following seizures are not necessarily associated with enhanced drug penetration into the brain. Increased expression of multidrug efflux transporters such as P-glycoprotein likely act as a 'second line defense' mechanism to protect the brain from toxins. A better understanding of the complex alterations in BBB structure and function following seizures and in epilepsy may lead to novel therapeutic interventions allowing the prevention and treatment of epilepsy as well as other detrimental neuro-psychiatric sequelae of brain injury.
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Affiliation(s)
- Wolfgang Löscher
- Department of Pharmacology, Toxicology and Pharmacy, University of Veterinary Medicine Hannover, 30559 Hannover, Germany
- Center of Systems Neuroscience, 30559 Hannover, Germany
| | - Alon Friedman
- Departments of Physiology and Cell Biology, Brain and Cognitive Sciences, Zlowotski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva 8410501, Israel;
- Department of Medical Neuroscience, Dalhousie University, Halifax, NS B3H 4R2, Canada
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11
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Löscher W. Epilepsy and Alterations of the Blood-Brain Barrier: Cause or Consequence of Epileptic Seizures or Both? Handb Exp Pharmacol 2020; 273:331-350. [PMID: 33136189 DOI: 10.1007/164_2020_406] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
The blood-brain barrier (BBB) is a dynamic, highly selective barrier primarily formed by endothelial cells connected by tight junctions that separate the circulating blood from the brain extracellular fluid, thereby preserving a narrow and stable homeostatic control of the neuronal environment. The endothelial cells lining the brain microvessels are under the inductive influence of neighboring cell types within the "neurovascular unit" including astrocytes and pericytes. In addition to the morphological characteristics of the BBB, various specific transport systems, enzymes, and receptors regulate the molecular and cellular traffic across the barrier. Furthermore, the intact BBB prevents many macromolecules and immune cells from entering the brain. This changes dramatically following epileptogenic brain insults; such insults, among other BBB alterations, lead to albumin extravasation and diapedesis of leukocytes from blood into brain parenchyma, inducing or contributing to epileptogenesis, which finally leads to development of spontaneous recurrent seizures and epilepsy. Furthermore, seizures themselves may cause BBB disruption with albumin extravasation, which has been shown to be associated with activation of astrocytes, activation of innate immune systems, and modifications of neuronal networks. However, seizure-induced BBB disruption is not necessarily associated with enhanced drug penetration into the brain, because the BBB expression of multidrug efflux transporters such as P-glycoprotein increases, most likely as a "second line defense" mechanism to protect the brain from drug toxicity. Hopefully, a better understanding of the complex BBB alterations in response to seizures and epilepsy can lead to novel therapeutic intervention to prevent epileptogenesis and the development of other detrimental sequelae of brain injury.
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Affiliation(s)
- Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Hannover, Germany.
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12
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Kwon HH, Neupane C, Shin J, Gwon DH, Yin Y, Shin N, Shin HJ, Hong J, Park JB, Yi Y, Kim DW, Kang JW. Calpain-2 as a Treatment Target in Prenatal Stress-induced Epileptic Spasms in Infant Rats. Exp Neurobiol 2019; 28:529-536. [PMID: 31495081 PMCID: PMC6751866 DOI: 10.5607/en.2019.28.4.529] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2019] [Revised: 05/21/2019] [Accepted: 07/08/2019] [Indexed: 12/23/2022] Open
Abstract
Stress can induce a serious epileptic encephalopathy that occurs during early infancy. Recent studies have revealed that prenatal stress exposure is a risk factor for the development of infantile spasms. Our previous work demonstrates that prenatal stress with betamethasone-induced alterations to the expression of the K+/Cl- co-transporter (KCC2) in gamma-aminobutyric acid (GABA) interneurons lowers the seizure threshold in exposed animals. Here, we further investigated the mechanisms involved in this KCC2 dysfunction and explored possible treatment options. We stressed Sprague-Dawley rats prenatally and further treated dams with betamethasone on gestational day 15, which increases seizure susceptibility and NMDA (N-Methyl-D-aspartate)-triggered spasms on postnatal day 15. In this animal model, first, we evaluated baseline calpain activity. Second, we examined the cleavage and dephosphorylation of KCC2. Finally, we checked the effect of a calpain inhibitor on seizure occurrence. The phosphorylated-N-methyl-Daspartate Receptor 2B (NR2B):non-phosphorylated NR2B ratio was found to be higher in the cortex of the prenatally stressed betamethasone model. We further found that the betamethasone model exhibited increased phosphorylation of calpain-2 and decreased phosphorylation of KCC2 and Glutamic acid decarboxylase 67 (GAD67). After using a calpain inhibitor in prenatal-stress rats, the seizure frequency decreased, while latency increased. GABAergic depolarization was further normalized in prenatal-stress rats treated with the calpain inhibitor. Our study suggests that calpain-dependent cleavage and dephosphorylation of KCC2 decreased the seizure threshold of rats under prenatal stress. Calpain-2 functions might, thus, be targeted in the future for the development of treatments for epileptic spasms.
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Affiliation(s)
- Hyeok Hee Kwon
- Department of Medical Science, Chungnam National University, Daejeon 35015, Korea.,Department of Anatomy, School of Medicine, Chungnam National University, Daejeon 35015, Korea.,Department of Pediatrics, Chungnam National University Hospital, Daejeon 35015, Korea
| | - Chiranjivi Neupane
- Department of Medical Science, Chungnam National University, Daejeon 35015, Korea.,Department of Physiology, School of Medicine, Chungnam National University, Daejeon 35015, Korea
| | - Juhee Shin
- Department of Medical Science, Chungnam National University, Daejeon 35015, Korea.,Department of Anatomy, School of Medicine, Chungnam National University, Daejeon 35015, Korea
| | - Do Hyeong Gwon
- Department of Medical Science, Chungnam National University, Daejeon 35015, Korea.,Department of Anatomy, School of Medicine, Chungnam National University, Daejeon 35015, Korea
| | - Yuhua Yin
- Department of Medical Science, Chungnam National University, Daejeon 35015, Korea.,Department of Anatomy, School of Medicine, Chungnam National University, Daejeon 35015, Korea
| | - Nara Shin
- Department of Medical Science, Chungnam National University, Daejeon 35015, Korea.,Department of Anatomy, School of Medicine, Chungnam National University, Daejeon 35015, Korea
| | - Hyo Jung Shin
- Department of Medical Science, Chungnam National University, Daejeon 35015, Korea.,Department of Anatomy, School of Medicine, Chungnam National University, Daejeon 35015, Korea.,Brain Research Institute, School of Medicine, Chungnam National University, Daejeon 35015, Korea
| | - Jinpyo Hong
- Department of Anatomy, School of Medicine, Chungnam National University, Daejeon 35015, Korea.,Brain Research Institute, School of Medicine, Chungnam National University, Daejeon 35015, Korea
| | - Jin Bong Park
- Department of Medical Science, Chungnam National University, Daejeon 35015, Korea.,Brain Research Institute, School of Medicine, Chungnam National University, Daejeon 35015, Korea.,Department of Physiology, School of Medicine, Chungnam National University, Daejeon 35015, Korea
| | - YoonYoung Yi
- Department of Pediatrics, Chungnam National University Hospital, Daejeon 35015, Korea
| | - Dong Woon Kim
- Department of Medical Science, Chungnam National University, Daejeon 35015, Korea.,Department of Anatomy, School of Medicine, Chungnam National University, Daejeon 35015, Korea.,Brain Research Institute, School of Medicine, Chungnam National University, Daejeon 35015, Korea
| | - Joon Won Kang
- Department of Medical Science, Chungnam National University, Daejeon 35015, Korea.,Brain Research Institute, School of Medicine, Chungnam National University, Daejeon 35015, Korea.,Department of Pediatrics, Chungnam National University Hospital, Daejeon 35015, Korea
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13
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Lam PM, González MI. Calpain activation and neuronal death during early epileptogenesis. Neurobiol Dis 2018; 124:141-151. [PMID: 30423475 DOI: 10.1016/j.nbd.2018.11.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2018] [Revised: 11/02/2018] [Accepted: 11/09/2018] [Indexed: 12/21/2022] Open
Abstract
Epilepsy is a brain disorder characterized by a predisposition to suffer epileptic seizures. Acquired epilepsy might be the result of brain insults like head trauma, stroke, brain infection, or status epilepticus (SE) when one of these triggering injuries starts a transformative process known as epileptogenesis. There is some data to suggest that, during epileptogenesis, seizures themselves damage the brain but there is no conclusive evidence to demonstrate that spontaneous recurrent seizures themselves injure the brain. Our recent evidence indicates that calpain overactivation might be relevant for epileptogenesis. Here, we investigated if spontaneous recurrent seizures that occur during an early period of epileptogenesis show any correlation with the levels of calpain activation and/or expression. In addition, we also investigated a possible association between the occurrence of spontaneous seizures and increased levels of cell death, gliosis and inflammation (typical markers associated with epileptogenesis). We found that the number of spontaneous seizures detected prior to sample collection was correlated with altered calpain activity and expression. Moreover, the levels of hippocampal neurodegeneration were also correlated with seizure occurrence. Our findings suggest that, at least during early epileptogenesis, there is a correlation between seizure occurrence, calpain activity and neurodegeneration. Thus, this study opens the possibility that aberrant calpain reactivation by spontaneous seizures might contribute to the manifestation of future spontaneous seizures.
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Affiliation(s)
- Philip M Lam
- Department of Pediatrics, Division of Neurology and Translational Epilepsy Research Program, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Marco I González
- Department of Pediatrics, Division of Neurology and Translational Epilepsy Research Program, University of Colorado School of Medicine, Aurora, CO 80045, USA.
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14
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Sompol P, Norris CM. Ca 2+, Astrocyte Activation and Calcineurin/NFAT Signaling in Age-Related Neurodegenerative Diseases. Front Aging Neurosci 2018; 10:199. [PMID: 30038565 PMCID: PMC6046440 DOI: 10.3389/fnagi.2018.00199] [Citation(s) in RCA: 54] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2018] [Accepted: 06/12/2018] [Indexed: 12/12/2022] Open
Abstract
Mounting evidence supports a fundamental role for Ca2+ dysregulation in astrocyte activation. Though the activated astrocyte phenotype is complex, cell-type targeting approaches have revealed a number of detrimental roles of activated astrocytes involving neuroinflammation, release of synaptotoxic factors and loss of glutamate regulation. Work from our lab and others has suggested that the Ca2+/calmodulin dependent protein phosphatase, calcineurin (CN), provides a critical link between Ca2+ dysregulation and the activated astrocyte phenotype. A proteolyzed, hyperactivated form of CN appears at high levels in activated astrocytes in both human tissue and rodent tissue around regions of amyloid and vascular pathology. Similar upregulation of the CN-dependent transcription factor nuclear factor of activated T cells (NFAT4) also appears in activated astrocytes in mouse models of Alzheimer's disease (ADs) and traumatic brain injury (TBI). Major consequences of hyperactivated CN/NFAT4 signaling in astrocytes are neuroinflammation, synapse dysfunction and glutamate dysregulation/excitotoxicity, which will be covered in this review article.
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Affiliation(s)
- Pradoldej Sompol
- Sanders-Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, United States
| | - Christopher M Norris
- Sanders-Brown Center on Aging, University of Kentucky College of Medicine, Lexington, KY, United States.,Department of Pharmacology and Nutritional Sciences, University of Kentucky College of Medicine, Lexington, KY, United States
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15
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Schulte JT, Wierenga CJ, Bruining H. Chloride transporters and GABA polarity in developmental, neurological and psychiatric conditions. Neurosci Biobehav Rev 2018; 90:260-271. [PMID: 29729285 DOI: 10.1016/j.neubiorev.2018.05.001] [Citation(s) in RCA: 76] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Revised: 03/20/2018] [Accepted: 05/01/2018] [Indexed: 12/22/2022]
Abstract
Neuronal chloride regulation is a determinant factor for the dynamic tuning of GABAergic inhibition during and beyond brain development. This regulation is mainly dependent on the two co-transporters K+/Cl- co-transporter KCC2 and Na+/K+/Cl- co-transporter NKCC1, whose activity can decrease or increase neuronal chloride concentrations respectively. Altered expression and/or activity of either of these co-transporters has been associated with a wide variety of brain disorders including developmental disorders, epilepsy, schizophrenia and stroke. Here, we review current knowledge on chloride transporter expression and activity regulation and highlight the intriguing potential for existing and future interventions to support chloride homeostasis across a wide range of mental disorders and neurological conditions.
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Affiliation(s)
- Joran T Schulte
- Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Center, Heidelberglaan 100, 3508 GA Utrecht The Netherlands
| | - Corette J Wierenga
- Division of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Hilgo Bruining
- Department of Psychiatry, Brain Center Rudolf Magnus, University Medical Center, Heidelberglaan 100, 3508 GA Utrecht The Netherlands.
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16
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Matrix Metalloproteinase-Mediated Blood-Brain Barrier Dysfunction in Epilepsy. J Neurosci 2018; 38:4301-4315. [PMID: 29632167 DOI: 10.1523/jneurosci.2751-17.2018] [Citation(s) in RCA: 98] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/23/2017] [Revised: 03/12/2018] [Accepted: 03/21/2018] [Indexed: 01/08/2023] Open
Abstract
The blood-brain barrier is dysfunctional in epilepsy, thereby contributing to seizure genesis and resistance to antiseizure drugs. Previously, several groups reported that seizures increase brain glutamate levels, which leads to barrier dysfunction. One critical component of barrier dysfunction is brain capillary leakage. Based on our preliminary data, we hypothesized that glutamate released during seizures mediates an increase in matrix-metalloproteinase (MMP) expression and activity levels, thereby contributing to barrier leakage. To test this hypothesis, we exposed isolated brain capillaries from male Sprague Dawley rats to glutamate ex vivo and used an in vivo/ex vivo approach of isolated brain capillaries from female Wistar rats that experienced status epilepticus as an acute seizure model. We found that exposing isolated rat brain capillaries to glutamate increased MMP-2 and MMP-9 protein and activity levels, and decreased tight junction protein levels, which resulted in barrier leakage. We confirmed these findings in vivo in rats after status epilepticus and in brain capillaries from male mice lacking cytosolic phospholipase A2 Together, our data support the hypothesis that glutamate released during seizures signals an increase in MMP-2 and MMP-9 protein expression and activity levels, resulting in blood-brain barrier leakage.SIGNIFICANCE STATEMENT The mechanism leading to seizure-mediated blood-brain barrier dysfunction in epilepsy is poorly understood. In the present study, we focused on defining this mechanism in the brain capillary endothelium. We demonstrate that seizures trigger a pathway that involves glutamate signaling through cytosolic phospholipase A2, which increases MMP levels and decreases tight junction protein expression levels, resulting in barrier leakage. These findings may provide potential therapeutic avenues within the blood-brain barrier to limit barrier dysfunction in epilepsy and decrease seizure burden.
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17
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Nam HY, Na EJ, Lee E, Kwon Y, Kim HJ. Antiepileptic and Neuroprotective Effects of Oleamide in Rat Striatum on Kainate-Induced Behavioral Seizure and Excitotoxic Damage via Calpain Inhibition. Front Pharmacol 2017; 8:817. [PMID: 29209207 PMCID: PMC5702338 DOI: 10.3389/fphar.2017.00817] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2017] [Accepted: 10/27/2017] [Indexed: 01/07/2023] Open
Abstract
Oleamide was first known as a sleep-inducing fatty acid amide, and later shown to have wide range of neuropharmacological effects upon different neurochemical systems. However, the effects of oleamide on brain damage have scarcely been studied, and the molecular mechanisms and sites of its action remain elusive. Kainic acid (KA) has been used to produce an epileptic animal model that mimics human temporal lobe epilepsy and to induce calpain-activated excitotoxicity, which occurs in numerous neurodegenerative disorders. In this study, we examined whether oleamide protects against the KA-induced excitotoxic brain damage accompanied by behavioral seizure activity and neuronal cell death. Moreover, whether these effects of oleamide were mediated by calpain activity-related cellular mechanisms was investigated. KA-induced epileptic rats were produced by an intrastriatal injection of KA (5 nmole). Oral administration of oleamide (0.5, 2, and 10 mg/kg) 30 min prior to the KA injection showed dose-dependent inhibition of the KA-induced behavioral seizure activities that were monitored starting from 60 to 180 min post-surgery. Further repetitive oral administration of oleamide (once per day) for the next 4 consecutive days post-KA injection produced significant neuroprotection against the disrupted neuronal integrity that resulted from KA-induced excitotoxic damage that was also demonstrated by staining of striatal tissue sections with cresyl violet, hematoxylin/eosin, and fluoro-Jade B. In addition, oleamide blocked the KA-induced cleavage of cyclin-dependent kinase-5 coactivator (Cdk5-p35) and collapsin response mediator protein-2, which are believed to be mediated by calpain activation in striatal tissues dissected from KA-induced epileptic rats. Oleamide also reversed the KA-induced reduction in expression of an endogenous calpain inhibitory protein, calpastatin, and a marker of synaptic activity, synapsin-II. The hypothesis that oleamide could induce direct calpain inhibition was further investigated using in vitro calpain assays in both brain tissue and a cell-free and calpain-overexpressed neuronal cell system. These findings together suggest that oleamide has protective effects against excitotoxicity-induced neuronal death and behavioral seizure, partly via its direct calpain inhibitory activity.
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Affiliation(s)
- Hye Yeon Nam
- College of Pharmacy, Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul, South Korea
| | - Eun Jung Na
- College of Pharmacy, Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul, South Korea
| | - Eunyoung Lee
- College of Pharmacy, Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul, South Korea
| | - Youngjoo Kwon
- College of Pharmacy, Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul, South Korea
| | - Hwa-Jung Kim
- College of Pharmacy, Graduate School of Pharmaceutical Sciences, Ewha Womans University, Seoul, South Korea
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18
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Schaefer KA, Toral MA, Velez G, Cox AJ, Baker SA, Borcherding NC, Colgan DF, Bondada V, Mashburn CB, Yu CG, Geddes JW, Tsang SH, Bassuk AG, Mahajan VB. Calpain-5 Expression in the Retina Localizes to Photoreceptor Synapses. Invest Ophthalmol Vis Sci 2017; 57:2509-21. [PMID: 27152965 PMCID: PMC4868102 DOI: 10.1167/iovs.15-18680] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Purpose We characterize calpain-5 (CAPN5) expression in retinal and neuronal subcellular compartments. Methods CAPN5 gene variants were classified using the exome variant server, and RNA-sequencing was used to compare expression of CAPN5 mRNA in the mouse and human retina and in retinoblastoma cells. Expression of CAPN5 protein was ascertained in humans and mice in silico, in mouse retina by immunohistochemistry, and in neuronal cancer cell lines and fractionated central nervous system tissue extracts by Western analysis with eight antibodies targeting different CAPN5 regions. Results Most CAPN5 genetic variation occurs outside its protease core; and searches of cancer and epilepsy/autism genetic databases found no variants similar to hyperactivating retinal disease alleles. The mouse retina expressed one transcript for CAPN5 plus those of nine other calpains, similar to the human retina. In Y79 retinoblastoma cells, the level of CAPN5 transcript was very low. Immunohistochemistry detected CAPN5 expression in the inner and outer nuclear layers and at synapses in the outer plexiform layer. Western analysis of fractionated retinal extracts confirmed CAPN5 synapse localization. Western blots of fractionated brain neuronal extracts revealed distinct subcellular patterns and the potential presence of autoproteolytic CAPN5 domains. Conclusions CAPN5 is moderately expressed in the retina and, despite higher expression in other tissues, hyperactive disease mutants of CAPN5 only manifest as eye disease. At the cellular level, CAPN5 is expressed in several different functional compartments. CAPN5 localization at the photoreceptor synapse and with mitochondria explains the neural circuitry phenotype in human CAPN5 disease alleles.
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Affiliation(s)
- Kellie A Schaefer
- Omics Laboratory, University of Iowa, Iowa City, Iowa, United States 2Department of Ophthalmology & Visual Sciences, University of Iowa, Iowa City, Iowa, United States
| | - Marcus A Toral
- Omics Laboratory, University of Iowa, Iowa City, Iowa, United States 2Department of Ophthalmology & Visual Sciences, University of Iowa, Iowa City, Iowa, United States 3Medical Scientist Training Program, University of Iowa, Iowa City, Iowa, United States
| | - Gabriel Velez
- Omics Laboratory, University of Iowa, Iowa City, Iowa, United States 2Department of Ophthalmology & Visual Sciences, University of Iowa, Iowa City, Iowa, United States 3Medical Scientist Training Program, University of Iowa, Iowa City, Iowa, United States
| | - Allison J Cox
- Department of Pediatrics, University of Iowa, Iowa City, Iowa, United States
| | - Sheila A Baker
- Department of Ophthalmology & Visual Sciences, University of Iowa, Iowa City, Iowa, United States 5Department of Biochemistry, University of Iowa, Iowa City, Iowa, United States
| | - Nicholas C Borcherding
- Omics Laboratory, University of Iowa, Iowa City, Iowa, United States 3Medical Scientist Training Program, University of Iowa, Iowa City, Iowa, United States
| | - Diana F Colgan
- Omics Laboratory, University of Iowa, Iowa City, Iowa, United States 2Department of Ophthalmology & Visual Sciences, University of Iowa, Iowa City, Iowa, United States
| | - Vimala Bondada
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky, United States
| | - Charles B Mashburn
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky, United States
| | - Chen-Guang Yu
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky, United States
| | - James W Geddes
- Spinal Cord and Brain Injury Research Center, University of Kentucky, Lexington, Kentucky, United States
| | - Stephen H Tsang
- Barbara & Donald Jonas Stem Cell Laboratory, and Bernard & Shirlee Brown Glaucoma Laboratory, Department of Pathology & Cell Biology, Institute of Human Nutrition, College of Physicians and Surgeons, Columbia University, New York, New York, United States
| | - Alexander G Bassuk
- Department of Pediatrics, University of Iowa, Iowa City, Iowa, United States 9Neurology, University of Iowa, Iowa City, Iowa, United States
| | - Vinit B Mahajan
- Omics Laboratory, University of Iowa, Iowa City, Iowa, United States 2Department of Ophthalmology & Visual Sciences, University of Iowa, Iowa City, Iowa, United States
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19
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Lam PM, Carlsen J, González MI. A calpain inhibitor ameliorates seizure burden in an experimental model of temporal lobe epilepsy. Neurobiol Dis 2017; 102:1-10. [PMID: 28237317 DOI: 10.1016/j.nbd.2017.02.003] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2016] [Revised: 01/27/2017] [Accepted: 02/20/2017] [Indexed: 01/08/2023] Open
Abstract
In this study, we used the pilocarpine model of epilepsy to evaluate the involvement of calpain dysregulation on epileptogenesis. Detection of spectrin breakdown products (SBDPs, a hallmark of calpain activation) after induction of pilocarpine-induced status epilepticus (SE) and before appearance of spontaneous seizure suggested the existence of sustained calpain activation during epileptogenesis. Acute treatment with a cell permeable inhibitor of calpain, MDL-28170, resulted in a partial but significant reduction on seizure burden. The reduction on seizure burden was associated with a limited reduction on the generation of SBDPs but was correlated with a reduction in astrocytosis, microglia activation and cell sprouting. Together, these observations provide evidence for the role of calpain in epileptogenesis. In addition, provide proof-of-principle for the use of calpain inhibitors as a novel strategy to prevent epileptic seizures and its associated pathologies.
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Affiliation(s)
- Philip M Lam
- Department of Pediatrics, Division of Neurology and Translational Epilepsy Research Program, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Jessica Carlsen
- Department of Pediatrics, Division of Neurology and Translational Epilepsy Research Program, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - Marco I González
- Department of Pediatrics, Division of Neurology and Translational Epilepsy Research Program, University of Colorado School of Medicine, Aurora, CO 80045, USA.
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20
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Sedmak G, Jovanov-Milošević N, Puskarjov M, Ulamec M, Krušlin B, Kaila K, Judaš M. Developmental Expression Patterns of KCC2 and Functionally Associated Molecules in the Human Brain. Cereb Cortex 2016; 26:4574-4589. [PMID: 26428952 DOI: 10.1093/cercor/bhv218] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Work on rodents demonstrated that steep upregulation of KCC2, a neuron-specific Cl- extruder of cation-chloride cotransporter (CCC) family, commences in supraspinal structures at around birth, leading to establishment of hyperpolarizing GABAergic responses. We describe spatiotemporal expression profiles of the entire CCC family in human brain. KCC2 mRNA was observed already at 10th postconceptional week (PCW) in amygdala, cerebellum, and thalamus. KCC2-immunoreactive (KCC2-ir) neurons were abundant in subplate at 18 PCW. By 25 PCW, numerous subplate and cortical plate neurons became KCC2-ir. The mRNA expression profiles of α- and β-isoforms of Na-K ATPase, which fuels cation-chloride cotransport, as well of tropomyosin receptor kinase B (TrkB), which promotes developmental upregulation of KCC2, were consistent with data from studies on rodents about their interactions with KCC2. Thus, in human brain, expression of KCC2 and its functionally associated proteins begins in early fetal period. Our work facilitates translation of results on CCC functions from animal studies to human and refutes the view that poor efficacy of anticonvulsants in the term human neonate is attributable to the lack of KCC2. We propose that perinatally low threshold for activation of Ca2+-dependent protease calpain renders neonates susceptible to downregulation of KCC2 by traumatic events, such as perinatal hypoxia ischemia.
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Affiliation(s)
| | | | - Martin Puskarjov
- Department of Biosciences and Neuroscience Center, University of Helsinki, Viikinkaari 1, Helsinki FI-00014, Finland
| | - Monika Ulamec
- Department of Pathology, Clinical Hospital Center Sisters of Mercy, University of Zagreb School of Medicine, Zagreb 10 000, Croatia
| | - Božo Krušlin
- Department of Pathology, Clinical Hospital Center Sisters of Mercy, University of Zagreb School of Medicine, Zagreb 10 000, Croatia
| | - Kai Kaila
- Department of Biosciences and Neuroscience Center, University of Helsinki, Viikinkaari 1, Helsinki FI-00014, Finland
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21
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Differential Activation of Calpain-1 and Calpain-2 following Kainate-Induced Seizure Activity in Rats and Mice. eNeuro 2016; 3:eN-NWR-0088-15. [PMID: 27622212 PMCID: PMC5011686 DOI: 10.1523/eneuro.0088-15.2016] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2015] [Revised: 07/30/2016] [Accepted: 08/02/2016] [Indexed: 11/30/2022] Open
Abstract
Systemic injection of kainate produces repetitive seizure activity in both rats and mice. It also results in short-term synaptic modifications as well as delayed neurodegeneration. The signaling cascades involved in both short-term and delayed responses are not clearly defined. The calcium-dependent protease calpain is activated in various brain structures following systemic kainate injection, although the precise involvement of the two major brain calpain isoforms, calpain-1 and calpain-2, remains to be defined. It has recently been reported that calpain-1 and calpain-2 play opposite roles in NMDA receptor-mediated neuroprotection or neurodegeneration, with calpain-1 being neuroprotective and calpain-2 being neurodegenerative. In the present study, we determined the activation pattern of calpain-1 and calpain-2 by analyzing changes in levels of different calpain substrates, including spectrin, drebrin, and PTEN (phosphatase and tensin homolog; a specific calpain-2 substrate) in both rats, and wild-type and calpain-1 knock-out mice. The results indicate that, while calpain-2 is rapidly activated in pyramidal cells throughout CA1 and CA3, rapid calpain-1 activation is restricted to parvalbumin-positive and to a lesser extent CCK-positive, but not somatostatin-positive, interneurons. In addition, calpain-1 knock-out mice exhibit increased long-term neurodegeneration in CA1, reinforcing the notion that calpain-1 activation is neuroprotective.
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Vezzani A, Fujinami RS, White HS, Preux PM, Blümcke I, Sander JW, Löscher W. Infections, inflammation and epilepsy. Acta Neuropathol 2016; 131:211-234. [PMID: 26423537 DOI: 10.1007/s00401-015-1481-5] [Citation(s) in RCA: 301] [Impact Index Per Article: 37.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 09/18/2015] [Accepted: 09/20/2015] [Indexed: 12/15/2022]
Abstract
Epilepsy is the tendency to have unprovoked epileptic seizures. Anything causing structural or functional derangement of brain physiology may lead to seizures, and different conditions may express themselves solely by recurrent seizures and thus be labelled "epilepsy." Worldwide, epilepsy is the most common serious neurological condition. The range of risk factors for the development of epilepsy varies with age and geographic location. Congenital, developmental and genetic conditions are mostly associated with the development of epilepsy in childhood, adolescence and early adulthood. Head trauma, infections of the central nervous system (CNS) and tumours may occur at any age and may lead to the development of epilepsy. Infections of the CNS are a major risk factor for epilepsy. The reported risk of unprovoked seizures in population-based cohorts of survivors of CNS infections from developed countries is between 6.8 and 8.3 %, and is much higher in resource-poor countries. In this review, the various viral, bacterial, fungal and parasitic infectious diseases of the CNS which result in seizures and epilepsy are discussed. The pathogenesis of epilepsy due to brain infections, as well as the role of experimental models to study mechanisms of epileptogenesis induced by infectious agents, is reviewed. The sterile (non-infectious) inflammatory response that occurs following brain insults is also discussed, as well as its overlap with inflammation due to infections, and the potential role in epileptogenesis. Furthermore, autoimmune encephalitis as a cause of seizures is reviewed. Potential strategies to prevent epilepsy resulting from brain infections and non-infectious inflammation are also considered.
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Affiliation(s)
- Annamaria Vezzani
- Department of Neuroscience, IRCCS-"Mario Negri" Institute for Pharmacological Research, Milan, Italy
| | - Robert S Fujinami
- Department of Pathology, University of Utah, Salt Lake City, UT, USA
| | - H Steve White
- Department of Pharmacology, University of Utah, Salt Lake City, UT, USA
| | - Pierre-Marie Preux
- INSERM UMR1094, Tropical Neuroepidemiology, Limoges, France
- Institute of Neuroepidemiology and Tropical Neurology, School of Medicine, University of Limoges, Limoges, France
- Center of Epidemiology, Biostatistics, and Research Methodology, CHU Limoges, Limoges, France
| | - Ingmar Blümcke
- Department of Neuropathology, University Hospital Erlangen, Erlangen, Germany
| | - Josemir W Sander
- NIHR University College London Hospitals Biomedical Research Centre, UCL Institute of Neurology, London, WC1N £BG, UK
- Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, The Netherlands
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, 30559, Hannover, Germany.
- Center for Systems Neuroscience, Hannover, Germany.
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Jantzie LL, Getsy PM, Denson JL, Firl DJ, Maxwell JR, Rogers DA, Wilson CG, Robinson S. Prenatal Hypoxia-Ischemia Induces Abnormalities in CA3 Microstructure, Potassium Chloride Co-Transporter 2 Expression and Inhibitory Tone. Front Cell Neurosci 2015; 9:347. [PMID: 26388734 PMCID: PMC4558523 DOI: 10.3389/fncel.2015.00347] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 08/20/2015] [Indexed: 12/19/2022] Open
Abstract
Infants who suffer perinatal brain injury, including those with encephalopathy of prematurity, are prone to chronic neurological deficits, including epilepsy, cognitive impairment, and behavioral problems, such as anxiety, inattention, and poor social interaction. These deficits, especially in combination, pose the greatest hindrance to these children becoming independent adults. Cerebral function depends on adequate development of essential inhibitory neural circuits and the appropriate amount of excitation and inhibition at specific stages of maturation. Early neuronal synaptic responses to γ-amino butyric acid (GABA) are initially excitatory. During the early postnatal period, GABAAR responses switch to inhibitory with the upregulation of potassium-chloride co-transporter KCC2. With extrusion of chloride by KCC2, the Cl− reversal potential shifts and GABA and glycine responses become inhibitory. We hypothesized that prenatal hypoxic–ischemic brain injury chronically impairs the developmental upregulation of KCC2 that is essential for cerebral circuit formation. Following late gestation hypoxia–ischemia (HI), diffusion tensor imaging in juvenile rats shows poor microstructural integrity in the hippocampal CA3 subfield, with reduced fractional anisotropy and elevated radial diffusivity. The loss of microstructure correlates with early reduced KCC2 expression on NeuN-positive pyramidal neurons, and decreased monomeric and oligomeric KCC2 protein expression in the CA3 subfield. Together with decreased inhibitory post-synaptic currents during a critical window of development, we document for the first time that prenatal transient systemic HI in rats impairs hippocampal CA3 inhibitory tone. Failure of timely development of inhibitory tone likely contributes to a lower seizure threshold and impaired cognitive function in children who suffer perinatal brain injury.
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Affiliation(s)
- Lauren L Jantzie
- Department of Pediatrics, University of New Mexico , Albuquerque, NM , USA ; Department of Neurosciences, University of New Mexico , Albuquerque, NM , USA ; Department of Neurosurgery, Boston Children's Hospital, Harvard Medical School , Boston, MA , USA ; Department of Neurology, Boston Children's Hospital, Harvard Medical School , Boston, MA , USA
| | - Paulina M Getsy
- Department of Pediatrics, Case Western Reserve University School of Medicine , Cleveland, OH , USA
| | - Jesse L Denson
- Department of Pediatrics, University of New Mexico , Albuquerque, NM , USA ; Department of Neurosciences, University of New Mexico , Albuquerque, NM , USA
| | - Daniel J Firl
- Department of Neurosurgery, Boston Children's Hospital, Harvard Medical School , Boston, MA , USA ; Department of Neurology, Boston Children's Hospital, Harvard Medical School , Boston, MA , USA
| | - Jessie R Maxwell
- Department of Pediatrics, University of New Mexico , Albuquerque, NM , USA ; Department of Neurosciences, University of New Mexico , Albuquerque, NM , USA
| | - Danny A Rogers
- Department of Pediatrics, University of New Mexico , Albuquerque, NM , USA ; Department of Neurosciences, University of New Mexico , Albuquerque, NM , USA
| | - Christopher G Wilson
- Department of Pediatrics, Center for Perinatal Biology, Loma Linda University , Loma Linda, CA , USA
| | - Shenandoah Robinson
- Department of Neurosurgery, Boston Children's Hospital, Harvard Medical School , Boston, MA , USA ; Department of Neurology, Boston Children's Hospital, Harvard Medical School , Boston, MA , USA ; F.M. Kirby Center for Neurobiology, Boston Children's Hospital, Harvard Medical School , Boston, MA , USA
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The construction of common and specific significance subnetworks of Alzheimer's disease from multiple brain regions. BIOMED RESEARCH INTERNATIONAL 2015; 2015:394260. [PMID: 25866779 PMCID: PMC4383160 DOI: 10.1155/2015/394260] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 08/28/2014] [Accepted: 10/07/2014] [Indexed: 01/09/2023]
Abstract
Alzheimer's disease (AD) is a progressively and fatally neurodegenerative disorder and leads to irreversibly cognitive and memorial damage in different brain regions. The identification and analysis of the dysregulated pathways and subnetworks among affected brain regions will provide deep insights for the pathogenetic mechanism of AD. In this paper, commonly and specifically significant subnetworks were identified from six AD brain regions. Protein-protein interaction (PPI) data were integrated to add molecular biological information to construct the functional modules of six AD brain regions by Heinz algorithm. Then, the simulated annealing algorithm based on edge weight is applied to predicting and optimizing the maximal scoring networks for common and specific genes, respectively, which can remove the weak interactions and add the prediction of strong interactions to increase the accuracy of the networks. The identified common subnetworks showed that inflammation of the brain nerves is one of the critical factors of AD and calcium imbalance may be a link among several causative factors in AD pathogenesis. In addition, the extracted specific subnetworks for each brain region revealed many biologically functional mechanisms to understand AD pathogenesis.
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Kaila K, Ruusuvuori E, Seja P, Voipio J, Puskarjov M. GABA actions and ionic plasticity in epilepsy. Curr Opin Neurobiol 2014; 26:34-41. [PMID: 24650502 DOI: 10.1016/j.conb.2013.11.004] [Citation(s) in RCA: 167] [Impact Index Per Article: 16.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Revised: 10/23/2013] [Accepted: 11/06/2013] [Indexed: 11/18/2022]
Abstract
Concepts of epilepsy, based on a simple change in neuronal excitation/inhibition balance, have subsided in face of recent insights into the large diversity and context-dependence of signaling mechanisms at the molecular, cellular and neuronal network level. GABAergic transmission exerts both seizure-suppressing and seizure-promoting actions. These two roles are prone to short-term and long-term alterations, evident both during epileptogenesis and during individual epileptiform events. The driving force of GABAergic currents is controlled by ion-regulatory molecules such as the neuronal K-Cl cotransporter KCC2 and cytosolic carbonic anhydrases. Accumulating evidence suggests that neuronal ion regulation is highly plastic, thereby contributing to the multiple roles ascribed to GABAergic signaling during epileptogenesis and epilepsy.
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Affiliation(s)
- Kai Kaila
- Department of Biosciences, University of Helsinki, FI-00014 Helsinki, Finland; Neuroscience Center, University of Helsinki, FI-00014 Helsinki, Finland.
| | - Eva Ruusuvuori
- Department of Biosciences, University of Helsinki, FI-00014 Helsinki, Finland; Neuroscience Center, University of Helsinki, FI-00014 Helsinki, Finland
| | - Patricia Seja
- Department of Biosciences, University of Helsinki, FI-00014 Helsinki, Finland; Neuroscience Center, University of Helsinki, FI-00014 Helsinki, Finland
| | - Juha Voipio
- Department of Biosciences, University of Helsinki, FI-00014 Helsinki, Finland
| | - Martin Puskarjov
- Department of Biosciences, University of Helsinki, FI-00014 Helsinki, Finland; Neuroscience Center, University of Helsinki, FI-00014 Helsinki, Finland
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26
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Wert KJ, Skeie JM, Bassuk AG, Olivier AK, Tsang SH, Mahajan VB. Functional validation of a human CAPN5 exome variant by lentiviral transduction into mouse retina. Hum Mol Genet 2013; 23:2665-77. [PMID: 24381307 DOI: 10.1093/hmg/ddt661] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Exome sequencing indicated that the gene encoding the calpain-5 protease, CAPN5, is the likely cause of retinal degeneration and autoimmune uveitis in human patients with autosomal dominant neovascular inflammatory vitreoretinopathy (ADNIV, OMIM #193235). To explore the mechanism of ADNIV, a human CAPN5 disease allele was expressed in mouse retinas with a lentiviral vector created to express either the wild-type human (h) CAPN5 or the ADNIV mutant hCAPN5-R243L allele under a rhodopsin promoter with tandem green fluorescent protein (GFP) expression. Vectors were injected into the subretinal space of perinatal mice. Mouse phenotypes were analyzed using electroretinography, histology and inflammatory gene expression profiling. Mouse calpain-5 showed high homology to its human ortholog with >98% sequence identity that includes the ADNIV mutant residue. Calpain-5 protein was expressed in the inner and outer segments of the photoreceptors and in the outer plexiform layer. Expression of the hCAPN5-R243L allele caused loss of the electroretinogram b-wave, photoreceptor degeneration and induction of immune cell infiltration and inflammatory genes in the retina, recapitulating major features of the ADNIV phenotype. Intraocular neovascularization and fibrosis were not observed during the study period. Our study shows that expression of the hCAPN5-R243L disease allele elicits an ADNIV-like disease in mice. It further suggests that ADNIV is due to CAPN5 gain-of-function rather than haploinsufficiency, and retinal expression may be sufficient to generate an autoimmune response. Genetic models of ADNIV in the mouse can be used to explore protease mechanisms in retinal degeneration and inflammation as well as preclinical therapeutic testing.
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Affiliation(s)
- Katherine J Wert
- Bernard and Shirlee Brown Glaucoma Laboratory, Department of Pathology and Cell Biology, College of Physicians and Surgeons
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27
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Pavlov I, Kaila K, Kullmann DM, Miles R. Cortical inhibition, pH and cell excitability in epilepsy: what are optimal targets for antiepileptic interventions? J Physiol 2013; 591:765-74. [PMID: 22890709 PMCID: PMC3591695 DOI: 10.1113/jphysiol.2012.237958] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2012] [Accepted: 08/10/2012] [Indexed: 12/14/2022] Open
Abstract
Epilepsy is characterised by the propensity of the brain to generate spontaneous recurrent bursts of excessive neuronal activity, seizures. GABA-mediated inhibition is critical for restraining neuronal excitation in the brain, and therefore potentiation of GABAergic neurotransmission is commonly used to prevent seizures. However, data obtained in animal models of epilepsy and from human epileptic tissue suggest that GABA-mediated signalling contributes to interictal and ictal activity. Prolonged activation of GABA(A) receptors during epileptiform bursts may even initiate a shift in GABAergic neurotransmission from inhibitory to excitatory and so have a proconvulsant action. Direct targeting of the membrane mechanisms that reduce spiking in glutamatergic neurons may better control neuronal excitability in epileptic tissue. Manipulation of brain pH may be a promising approach and recent advances in gene therapy and optogenetics seem likely to provide further routes to effective therapeutic intervention.
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Affiliation(s)
- Ivan Pavlov
- Department of Clinical and Experimental Epilepsy, UCL Institute of Neurology, London WC1N 3BG, UK.
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28
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Deeb TZ, Maguire J, Moss SJ. Possible alterations in GABAA receptor signaling that underlie benzodiazepine-resistant seizures. Epilepsia 2012; 53 Suppl 9:79-88. [PMID: 23216581 PMCID: PMC4402207 DOI: 10.1111/epi.12037] [Citation(s) in RCA: 78] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Benzodiazepines have been used for decades as first-line treatment for status epilepticus (SE). For reasons that are not fully understood, the efficacy of benzodiazepines decreases with increasing duration of seizure activity. This often forces clinicians to resort to more drastic second- and third-line treatments that are not always successful. The antiseizure properties of benzodiazepines are mediated by γ-aminobutyric acid type A (GABA(A) ) receptors. Decades of research have focused on the failure of GABAergic inhibition after seizure onset as the likely cause of the development benzodiazepine resistance during SE. However, the details of the deficits in GABA(A) signaling are still largely unknown. Therefore, it is necessary to improve our understanding of the mechanisms of benzodiazepine resistance so that more effective strategies can be formulated. In this review we discuss evidence supporting the role of altered GABA(A) receptor function as the major underlying cause of benzodiazepine-resistant SE in both humans and animal models. We specifically address the prevailing hypothesis, which is based on changes in the number and subtypes of GABA(A) receptors, as well as the potential influence of perturbed chloride homeostasis in the mature brain.
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Affiliation(s)
- Tarek Z Deeb
- Department of Neuroscience, Tufts University School of Medicine, Boston, Massachusetts 02111, USA
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29
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Puskarjov M, Ahmad F, Kaila K, Blaesse P. Activity-dependent cleavage of the K-Cl cotransporter KCC2 mediated by calcium-activated protease calpain. J Neurosci 2012; 32:11356-64. [PMID: 22895718 PMCID: PMC6621186 DOI: 10.1523/jneurosci.6265-11.2012] [Citation(s) in RCA: 118] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2011] [Revised: 06/29/2012] [Accepted: 07/03/2012] [Indexed: 11/21/2022] Open
Abstract
The K-Cl cotransporter KCC2 plays a crucial role in neuronal chloride regulation. In mature central neurons, KCC2 is responsible for the low intracellular Cl(-) concentration ([Cl(-)](i)) that forms the basis for hyperpolarizing GABA(A) receptor-mediated responses. Fast changes in KCC2 function and expression have been observed under various physiological and pathophysiological conditions. Here, we show that the application of protein synthesis inhibitors cycloheximide and emetine to acute rat hippocampal slices have no effect on total KCC2 protein level and K-Cl cotransporter function. Furthermore, blocking constitutive lysosomal degradation with leupeptin did not induce significant changes in KCC2 protein levels. These findings indicate a low basal turnover rate of the total KCC2 protein pool. In the presence of the glutamate receptor agonist NMDA, the total KCC2 protein level decreased to about 30% within 4 h, and this effect was blocked by calpeptin and MDL-28170, inhibitors of the calcium-activated protease calpain. Interictal-like activity induced by incubation of hippocampal slices in an Mg(2+)-free solution led to a fast reduction in KCC2-mediated Cl(-) transport efficacy in CA1 pyramidal neurons, which was paralleled by a decrease in both total and plasmalemmal KCC2 protein. These effects were blocked by the calpain inhibitor MDL-28170. Taken together, these findings show that calpain activation leads to cleavage of KCC2, thereby modulating GABAergic signaling.
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Affiliation(s)
- Martin Puskarjov
- Department of Biosciences and Neuroscience Center, University of Helsinki, FI-00014 Helsinki, Finland and
| | - Faraz Ahmad
- Department of Biosciences and Neuroscience Center, University of Helsinki, FI-00014 Helsinki, Finland and
| | - Kai Kaila
- Department of Biosciences and Neuroscience Center, University of Helsinki, FI-00014 Helsinki, Finland and
| | - Peter Blaesse
- Department of Biosciences and Neuroscience Center, University of Helsinki, FI-00014 Helsinki, Finland and
- Institute of Physiology I, Westfälische Wilhelms-University Münster, D-48149 Münster, Germany
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O'Dell CM, Das A, Wallace G, Ray SK, Banik NL. Understanding the basic mechanisms underlying seizures in mesial temporal lobe epilepsy and possible therapeutic targets: a review. J Neurosci Res 2012; 90:913-24. [PMID: 22315182 DOI: 10.1002/jnr.22829] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2011] [Revised: 10/05/2011] [Accepted: 10/09/2011] [Indexed: 12/13/2022]
Abstract
Despite years of research, epilepsy remains a poorly understood disorder. In the past several years, work has been conducted on a variety of projects with the goal of better understanding the pathogenesis and progression of mesial temporal lobe epilepsy (MTLE), in particular, and how to exploit those properties to generate innovative therapies for treatment of refractory epilepsies. This review seeks to give an overview of common morphological and biochemical changes associated with epilepsy and proposed treatments to address those changes. Furthering the understanding of ictogenesis and epileptogenesis remains an important goal for scientists seeking to find more effective treatments for MTLE.
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Affiliation(s)
- Casey M O'Dell
- Division of Neurology, Department of Neurosciences, Medical University of South Carolina, Charleston, South Carolina, USA
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