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Colmers PLW, Antonoudiou P, Basu T, Scapa G, Fuller P, Maguire J. Loss of PV interneurons in the BLA contributes to altered network and behavioral states in chronically epileptic mice. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.05.570112. [PMID: 38106120 PMCID: PMC10723361 DOI: 10.1101/2023.12.05.570112] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Psychiatric disorders, including anxiety and depression, are highly comorbid in people with epilepsy. However, the mechanisms mediating the shared pathophysiology are currently unknown. There is considerable evidence implicating the basolateral amygdala (BLA) in the network communication of anxiety and fear, a process demonstrated to involve parvalbumin-positive (PV) interneurons. The loss of PV interneurons has been well described in the hippocampus of chronically epileptic mice and in postmortem human tissue of patients with temporal lobe epilepsy (TLE). We hypothesize that a loss of PV interneurons in the BLA may contribute to comorbid mood disorders in epilepsy. To test this hypothesis, we employed a ventral intrahippocampal kainic acid (vIHKA) model of chronic epilepsy in mice, which exhibits profound behavioral deficits associated with chronic epilepsy. We demonstrate a loss of PV interneurons and dysfunction of remaining PV interneurons in the BLA of chronically epileptic mice. Further, we demonstrate altered principal neuron function and impaired coordination of BLA network and behavioral states in chronically epileptic mice. To determine whether these altered network and behavioral states were due to the loss of PV interneurons, we ablated a similar percentage of PV interneurons observed in chronically epileptic mice by stereotaxically injecting AAV-Flex-DTA into the BLA of PV-Cre mice. Loss of PV interneurons in the BLA is sufficient to alter behavioral states, inducing deficits in fear learning and recall of fear memories. These data suggest that compromised inhibition in the BLA in chronically epileptic mice contributes to behavioral deficits, suggesting a novel mechanism contributing to comorbid anxiety and epilepsy. Significance Statement Psychiatric illnesses and epilepsy are highly comorbid and negatively impact the quality of life of people with epilepsy. The pathophysiological mechanisms mediating the bidirectional relationship between mood disorders and epilepsy remain unknown and, therefore, treatment options remain inadequate. Here we demonstrate a novel mechanism, involving the loss of PV interneurons in the BLA, leading to a corruption of network and behavioral states in mice. These findings pinpoint a critical node and demonstrate a novel cellular and circuit mechanism involved in the comorbidity of psychiatric illnesses and epilepsy.
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Zhang S, Meor Azlan NF, Josiah SS, Zhou J, Zhou X, Jie L, Zhang Y, Dai C, Liang D, Li P, Li Z, Wang Z, Wang Y, Ding K, Wang Y, Zhang J. The role of SLC12A family of cation-chloride cotransporters and drug discovery methodologies. J Pharm Anal 2023; 13:1471-1495. [PMID: 38223443 PMCID: PMC10785268 DOI: 10.1016/j.jpha.2023.09.002] [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: 03/04/2023] [Revised: 06/20/2023] [Accepted: 09/05/2023] [Indexed: 09/12/2023] Open
Abstract
The solute carrier family 12 (SLC12) of cation-chloride cotransporters (CCCs) comprises potassium chloride cotransporters (KCCs, e.g. KCC1, KCC2, KCC3, and KCC4)-mediated Cl- extrusion, and sodium potassium chloride cotransporters (N[K]CCs, NKCC1, NKCC2, and NCC)-mediated Cl- loading. The CCCs play vital roles in cell volume regulation and ion homeostasis. Gain-of-function or loss-of-function of these ion transporters can cause diseases in many tissues. In recent years, there have been considerable advances in our understanding of CCCs' control mechanisms in cell volume regulations, with many techniques developed in studying the functions and activities of CCCs. Classic approaches to directly measure CCC activity involve assays that measure the transport of potassium substitutes through the CCCs. These techniques include the ammonium pulse technique, radioactive or nonradioactive rubidium ion uptake-assay, and thallium ion-uptake assay. CCCs' activity can also be indirectly observed by measuring γ-aminobutyric acid (GABA) activity with patch-clamp electrophysiology and intracellular chloride concentration with sensitive microelectrodes, radiotracer 36Cl-, and fluorescent dyes. Other techniques include directly looking at kinase regulatory sites phosphorylation, flame photometry, 22Na+ uptake assay, structural biology, molecular modeling, and high-throughput drug screening. This review summarizes the role of CCCs in genetic disorders and cell volume regulation, current methods applied in studying CCCs biology, and compounds developed that directly or indirectly target the CCCs for disease treatments.
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Affiliation(s)
- Shiyao Zhang
- Xiamen Cardiovascular Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, 363001, China
| | - Nur Farah Meor Azlan
- Institute of Biomedical and Clinical Sciences, Medical School, Faculty of Health and Life Sciences, University of Exeter, Exeter, EX4 4PS, UK
| | - Sunday Solomon Josiah
- Institute of Biomedical and Clinical Sciences, Medical School, Faculty of Health and Life Sciences, University of Exeter, Exeter, EX4 4PS, UK
| | - Jing Zhou
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute of Biological Science, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Xiaoxia Zhou
- Xiamen Cardiovascular Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, 363001, China
| | - Lingjun Jie
- Xiamen Cardiovascular Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, 363001, China
| | - Yanhui Zhang
- Xiamen Cardiovascular Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, 363001, China
| | - Cuilian Dai
- Xiamen Cardiovascular Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, 363001, China
| | - Dong Liang
- Aurora Discovery Inc., Foshan, Guangdong, 528300, China
| | - Peifeng Li
- Institute for Translational Medicine, Qingdao University, Qingdao, Shandong, 266021, China
| | - Zhengqiu Li
- School of Pharmacy, Jinan University, Guangzhou, 510632, China
| | - Zhen Wang
- State Key Laboratory of Chemical Biology, Research Center of Chemical Kinomics, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Yun Wang
- Department of Neurology, Institutes of Brain Science, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Institute of Biological Science, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Ke Ding
- State Key Laboratory of Chemical Biology, Research Center of Chemical Kinomics, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 200032, China
| | - Yan Wang
- Xiamen Cardiovascular Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, 363001, China
| | - Jinwei Zhang
- Xiamen Cardiovascular Hospital of Xiamen University, School of Medicine, Xiamen University, Xiamen, Fujian, 363001, China
- Institute of Biomedical and Clinical Sciences, Medical School, Faculty of Health and Life Sciences, University of Exeter, Exeter, EX4 4PS, UK
- State Key Laboratory of Chemical Biology, Research Center of Chemical Kinomics, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai, 200032, China
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Tescarollo FC, Valdivia D, Chen S, Sun H. Unilateral optogenetic kindling of hippocampus leads to more severe impairments of the inhibitory signaling in the contralateral hippocampus. Front Mol Neurosci 2023; 16:1268311. [PMID: 37942301 PMCID: PMC10627882 DOI: 10.3389/fnmol.2023.1268311] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2023] [Accepted: 09/20/2023] [Indexed: 11/10/2023] Open
Abstract
The kindling model has been used extensively by researchers to study the neurobiology of temporal lobe epilepsy (TLE) due to its capacity to induce intensification of seizures by the progressive recruitment of additional neuronal clusters into epileptogenic networks. We applied repetitive focal optogenetic activation of putative excitatory neurons in the dorsal CA1 area of the hippocampus of mice to investigate the role of inhibitory signaling during this process. This experimental protocol resulted in a kindling phenotype that was maintained for 2 weeks after the animals were fully kindled. As a result of the different phases of optogenetic kindling (OpK), key inhibitory signaling elements, such as KCC2 and NKCC1, exhibited distinct temporal and spatial dynamics of regulation. These alterations in protein expression were related to the distinct pattern of ictal activity propagation through the different hippocampal sublayers. Our results suggest the KCC2 disruption in the contralateral hippocampus of fully kindled animals progressively facilitated the creation of pathological pathways for seizure propagation through the hippocampal network. Upon completion of kindling, we observed animals that were restimulated after a rest period of 14-day showed, besides a persistent KCC2 downregulation, an NKCC1 upregulation in the bilateral dentate gyrus and hippocampus-wide loss of parvalbumin-positive interneurons. These alterations observed in the chronic phase of OpK suggest that the hippocampus of rekindled animals continued to undergo self-modifications during the rest period. The changes resulting from this period suggest the possibility of the development of a mirror focus on the hippocampus contralateral to the site of optical stimulations. Our results offer perspectives for preventing the recruitment and conversion of healthy neuronal networks into epileptogenic ones among patients with epilepsy.
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Affiliation(s)
| | | | | | - Hai Sun
- Department of Neurosurgery, Rutgers Robert Wood Johnson Medical School, New Brunswick, NJ, United States
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Egawa K, Watanabe M, Shiraishi H, Sato D, Takahashi Y, Nishio S, Fukuda A. Imbalanced expression of cation-chloride cotransporters as a potential therapeutic target in an Angelman syndrome mouse model. Sci Rep 2023; 13:5685. [PMID: 37069177 PMCID: PMC10110603 DOI: 10.1038/s41598-023-32376-z] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Accepted: 03/27/2023] [Indexed: 04/19/2023] Open
Abstract
Angelman syndrome is a neurodevelopmental disorder caused by loss of function of the maternally expressed UBE3A gene. Treatments for the main manifestations, including cognitive dysfunction or epilepsy, are still under development. Recently, the Cl- importer Na+-K+-Cl- cotransporter 1 (NKCC1) and the Cl- exporter K+-Cl- cotransporter 2 (KCC2) have garnered attention as therapeutic targets for many neurological disorders. Dysregulation of neuronal intracellular Cl- concentration ([Cl-]i) is generally regarded as one of the mechanisms underlying neuronal dysfunction caused by imbalanced expression of these cation-chloride cotransporters (CCCs). Here, we analyzed the regulation of [Cl-]i and the effects of bumetanide, an NKCC1 inhibitor, in Angelman syndrome models (Ube3am-/p+ mice). We observed increased NKCC1 expression and decreased KCC2 expression in the hippocampi of Ube3am-/p+ mice. The average [Cl-]i of CA1 pyramidal neurons was not significantly different but demonstrated greater variance in Ube3am-/p+ mice. Tonic GABAA receptor-mediated Cl- conductance was reduced, which may have contributed to maintaining the normal average [Cl-]i. Bumetanide administration restores cognitive dysfunction in Ube3am-/p+ mice. Seizure susceptibility was also reduced regardless of the genotype. These results suggest that an imbalanced expression of CCCs is involved in the pathophysiological mechanism of Ube3am-/p+ mice, although the average [Cl-]i is not altered. The blockage of NKCC1 may be a potential therapeutic strategy for patients with Angelman syndrome.
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Affiliation(s)
- Kiyoshi Egawa
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Kita 15, Nishi 7, Kita-Ku, Sapporo, 060-8638, Japan.
| | - Miho Watanabe
- Department of Neurophysiology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-Ku, Hamamatsu City, Shizuoka, 431-3192, Japan
| | - Hideaki Shiraishi
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Kita 15, Nishi 7, Kita-Ku, Sapporo, 060-8638, Japan
| | - Daisuke Sato
- Department of Pediatrics, Hokkaido University Graduate School of Medicine, Kita 15, Nishi 7, Kita-Ku, Sapporo, 060-8638, Japan
| | - Yukitoshi Takahashi
- Department of Clinical Research, National Epilepsy Center, NHO, Shizuoka Institute of Epilepsy and Neurological Disorders, Urushiyama 886, Aoi-Ku, Shizuoka, 420-8688, Japan
| | - Saori Nishio
- Department of Rheumatology, Endocrinology, and Nephrology, Hokkaido University Graduate School of Medicine, Kita 15, Nishi 7, Kita-Ku, Sapporo, 060-8638, Japan
| | - Atsuo Fukuda
- Department of Neurophysiology, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashi-Ku, Hamamatsu City, Shizuoka, 431-3192, Japan
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Welzel B, Johne M, Löscher W. Bumetanide potentiates the anti-seizure and disease-modifying effects of midazolam in a noninvasive rat model of term birth asphyxia. Epilepsy Behav 2023; 142:109189. [PMID: 37037061 DOI: 10.1016/j.yebeh.2023.109189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2023] [Revised: 03/15/2023] [Accepted: 03/16/2023] [Indexed: 04/12/2023]
Abstract
Birth asphyxia and the resulting hypoxic-ischemic encephalopathy (HIE) are highly associated with perinatal and neonatal death, neonatal seizures, and an adverse later-life outcome. Currently used drugs, including phenobarbital and midazolam, have limited efficacy to suppress neonatal seizures. There is a medical need to develop new therapies that not only suppress neonatal seizures but also prevent later-life consequences. We have previously shown that the loop diuretic bumetanide does not potentiate the effects of phenobarbital in a rat model of birth asphyxia. Here we compared the effects of bumetanide (0.3 or 10 mg/kg i.p.), midazolam (1 mg/kg i.p.), and a combination of bumetanide and midazolam on neonatal seizures and later-life outcomes in this model. While bumetanide at either dose was ineffective when administered alone, the higher dose of bumetanide markedly potentiated midazolam's effect on neonatal seizures. Median bumetanide brain levels (0.47-0.53 µM) obtained with the higher dose were in the range known to inhibit the Na-K-Cl-cotransporter NKCC1 but it remains to be determined whether brain NKCC1 inhibition was underlying the potentiation of midazolam. When behavioral and cognitive alterations were examined over three months after asphyxia, treatment with the bumetanide/midazolam combination, but not with bumetanide or midazolam alone, prevented impairment of learning and memory. Furthermore, the combination prevented the loss of neurons in the dentate hilus and aberrant mossy fiber sprouting in the CA3a area of the hippocampus. The molecular mechanisms that explain that bumetanide potentiates midazolam but not phenobarbital in the rat model of birth asphyxia remain to be determined.
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Affiliation(s)
- Björn Welzel
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany; Center for Systems Neuroscience Hannover, Germany
| | - Marie Johne
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany; Center for Systems Neuroscience Hannover, Germany
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany; Center for Systems Neuroscience Hannover, Germany.
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Pressey JC, de Saint-Rome M, Raveendran VA, Woodin MA. Chloride transporters controlling neuronal excitability. Physiol Rev 2023; 103:1095-1135. [PMID: 36302178 DOI: 10.1152/physrev.00025.2021] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023] Open
Abstract
Synaptic inhibition plays a crucial role in regulating neuronal excitability, which is the foundation of nervous system function. This inhibition is largely mediated by the neurotransmitters GABA and glycine that activate Cl--permeable ion channels, which means that the strength of inhibition depends on the Cl- gradient across the membrane. In neurons, the Cl- gradient is primarily mediated by two secondarily active cation-chloride cotransporters (CCCs), NKCC1 and KCC2. CCC-mediated regulation of the neuronal Cl- gradient is critical for healthy brain function, as dysregulation of CCCs has emerged as a key mechanism underlying neurological disorders including epilepsy, neuropathic pain, and autism spectrum disorder. This review begins with an overview of neuronal chloride transporters before explaining the dependent relationship between these CCCs, Cl- regulation, and inhibitory synaptic transmission. We then discuss the evidence for how CCCs can be regulated, including by activity and their protein interactions, which underlie inhibitory synaptic plasticity. For readers who may be interested in conducting experiments on CCCs and neuronal excitability, we have included a section on techniques for estimating and recording intracellular Cl-, including their advantages and limitations. Although the focus of this review is on neurons, we also examine how Cl- is regulated in glial cells, which in turn regulate neuronal excitability through the tight relationship between this nonneuronal cell type and synapses. Finally, we discuss the relatively extensive and growing literature on how CCC-mediated neuronal excitability contributes to neurological disorders.
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Affiliation(s)
- Jessica C Pressey
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Miranda de Saint-Rome
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Vineeth A Raveendran
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
| | - Melanie A Woodin
- Department of Cell and Systems Biology, University of Toronto, Toronto, Ontario, Canada
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Tahara M, Higurashi N, Hata J, Nishikawa M, Ito K, Hirose S, Kaneko T, Mashimo T, Sakuma T, Yamamoto T, Okano HJ. Developmental changes in brain activity of heterozygous Scn1a knockout rats. Front Neurol 2023; 14:1125089. [PMID: 36998780 PMCID: PMC10043303 DOI: 10.3389/fneur.2023.1125089] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2022] [Accepted: 02/20/2023] [Indexed: 03/17/2023] Open
Abstract
IntroductionDravet syndrome (DS) is an infantile-onset developmental and epileptic encephalopathy characterized by an age-dependent evolution of drug-resistant seizures and poor developmental outcomes. Functional impairment of gamma-aminobutyric acid (GABA)ergic interneurons due to loss-of-function mutation of SCN1A is currently considered the main pathogenesis. In this study, to better understand the age-dependent changes in the pathogenesis of DS, we characterized the activity of different brain regions in Scn1a knockout rats at each developmental stage.MethodsWe established an Scn1a knockout rat model and examined brain activity from postnatal day (P) 15 to 38 using a manganese-enhanced magnetic resonance imaging technique (MEMRI).ResultsScn1a heterozygous knockout (Scn1a+/−) rats showed a reduced expression of voltage-gated sodium channel alpha subunit 1 protein in the brain and heat-induced seizures. Neural activity was significantly higher in widespread brain regions of Scn1a+/− rats than in wild-type rats from P19 to P22, but this difference did not persist thereafter. Bumetanide, a Na+-K+-2Cl− cotransporter 1 inhibitor, mitigated hyperactivity to the wild-type level, although no change was observed in the fourth postnatal week. Bumetanide also increased heat-induced seizure thresholds of Scn1a+/− rats at P21.ConclusionsIn Scn1a+/− rats, neural activity in widespread brain regions increased during the third postnatal week, corresponding to approximately 6 months of age in humans, when seizures most commonly develop in DS. In addition to impairment of GABAergic interneurons, the effects of bumetanide suggest a possible contribution of immature type A gamma-aminobutyric acid receptor signaling to transient hyperactivity and seizure susceptibility during the early stage of DS. This hypothesis should be addressed in the future. MEMRI is a potential technique for visualizing changes in basal brain activity in developmental and epileptic encephalopathies.
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Affiliation(s)
- Mayu Tahara
- Department of Pediatrics, The Jikei University School of Medicine, Minato-ku, Tokyo, Japan
- Division of Regenerative Medicine, The Jikei University School of Medicine, Minato-ku, Tokyo, Japan
| | - Norimichi Higurashi
- Department of Pediatrics, The Jikei University School of Medicine, Minato-ku, Tokyo, Japan
- *Correspondence: Norimichi Higurashi
| | - Junichi Hata
- Division of Regenerative Medicine, The Jikei University School of Medicine, Minato-ku, Tokyo, Japan
- Graduate School of Human Health Sciences, Tokyo Metropolitan University, Arakawa-ku, Tokyo, Japan
| | - Masako Nishikawa
- Clinical Research Support Center, The Jikei University School of Medicine, Minato-ku, Tokyo, Japan
| | - Ken Ito
- Department of Pediatrics, The Jikei University School of Medicine, Minato-ku, Tokyo, Japan
- Division of Regenerative Medicine, The Jikei University School of Medicine, Minato-ku, Tokyo, Japan
| | - Shinichi Hirose
- General Medical Research Center, School of Medicine, Fukuoka University, Fukuoka, Japan
| | - Takehito Kaneko
- Division of Fundamental and Applied Sciences, Graduate School of Science and Engineering, Iwate University, Morioka, Japan
| | - Tomoji Mashimo
- Division of Animal Genetics, Laboratory Animal Research Center, Institute of Medical Science, University of Tokyo, Minato-ku, Tokyo, Japan
| | - Tetsushi Sakuma
- Division of Integrated Sciences for Life, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Takashi Yamamoto
- Division of Integrated Sciences for Life, Graduate School of Integrated Sciences for Life, Hiroshima University, Hiroshima, Japan
| | - Hirotaka James Okano
- Division of Regenerative Medicine, The Jikei University School of Medicine, Minato-ku, Tokyo, Japan
- Hirotaka James Okano
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Dossi E, Huberfeld G. GABAergic circuits drive focal seizures. Neurobiol Dis 2023; 180:106102. [PMID: 36977455 DOI: 10.1016/j.nbd.2023.106102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 03/10/2023] [Accepted: 03/23/2023] [Indexed: 03/28/2023] Open
Abstract
Epilepsy is based on abnormal neuronal activities that have historically been suggested to arise from an excess of excitation and a defect of inhibition, or in other words from an excessive glutamatergic drive not balanced by GABAergic activity. More recent data however indicate that GABAergic signaling is not defective at focal seizure onset and may even be actively involved in seizure generation by providing excitatory inputs. Recordings of interneurons revealed that they are active at seizure initiation and that their selective and time-controlled activation using optogenetics triggers seizures in a more general context of increased excitability. Moreover, GABAergic signaling appears to be mandatory at seizure onset in many models. The main pro-ictogenic effect of GABAergic signaling is the depolarizing action of GABAA conductance which may occur when an excessive GABAergic activity causes Cl- accumulation in neurons. This process may combine with background dysregulation of Cl-, well described in epileptic tissues. Cl- equilibrium is maintained by (Na+)/K+/Cl- co-transporters, which can be defective and therefore favor the depolarizing effects of GABA. In addition, these co-transporters further contribute to this effect as they mediate K+ outflow together with Cl- extrusion, a process that is responsible for K+ accumulation in the extracellular space and subsequent increase of local excitability. The role of GABAergic signaling in focal seizure generation is obvious but its complex dynamics and balance between GABAA flux polarity and local excitability still remain to be established, especially in epileptic tissues where receptors and ion regulators are disrupted and in which GABAergic signaling rather plays a 2 faces Janus role.
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Welzel B, Schmidt R, Kirchhoff L, Gramer M, Löscher W. The loop diuretic torasemide but not azosemide potentiates the anti-seizure and disease-modifying effects of midazolam in a rat model of birth asphyxia. Epilepsy Behav 2023; 139:109057. [PMID: 36586153 DOI: 10.1016/j.yebeh.2022.109057] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/07/2022] [Revised: 12/02/2022] [Accepted: 12/05/2022] [Indexed: 12/31/2022]
Abstract
Loop diuretics such as furosemide and bumetanide, which act by inhibiting the Na-K-2Cl cotransporter NKCC2 at the thick ascending limb of the loop of Henle, have been shown to exert anti-seizure effects. However, the exact mechanism of this effect is not known. For bumetanide, it has been suggested that inhibition of the NKCC isoform NKCC1 in the membrane of brain neurons may be involved; however, NKCC1 is expressed by virtually all cell types in the brain, which makes any specific targeting of neuronal NKCC1 by bumetanide impossible. In addition, bumetanide only poorly penetrates the brain. We have previously shown that loop diuretics azosemide and torasemide also potently inhibit NKCC1. In contrast to bumetanide and furosemide, azosemide and torasemide lack a carboxylic group, which should allow them to better penetrate through biomembranes by passive diffusion. Because of the urgent medical need to develop new treatments for neonatal seizures and their adverse outcome, we evaluated the effects of azosemide and torasemide, administered alone or in combination with phenobarbital or midazolam, in a rat model of birth asphyxia and neonatal seizures. Neither diuretic suppressed the seizures when administered alone but torasemide potentiated the anti-seizure effect of midazolam. Brain levels of torasemide were below those needed to inhibit NKCC1. In addition to suppressing seizures, the combination of torasemide and midazolam, but not midazolam alone, prevented the cognitive impairment of the post-asphyxial rats at 3 months after asphyxia. Furthermore, aberrant mossy fiber sprouting in the hippocampus was more effectively prevented by the combination. We assume that either an effect on NKCC1 at the blood-brain barrier and/or cells in the periphery or the NKCC2-mediated diuretic effect of torasemide are involved in the present findings. Our data suggest that torasemide may be a useful option for improving the treatment of neonatal seizures and their adverse outcome.
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Affiliation(s)
- Björn Welzel
- Dept. of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany; Center for Systems Neuroscience Hannover, Germany
| | - Ricardo Schmidt
- Dept. of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany; Center for Systems Neuroscience Hannover, Germany
| | - Larsen Kirchhoff
- Dept. of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany
| | - Martina Gramer
- Dept. of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany
| | - Wolfgang Löscher
- Dept. of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany; Center for Systems Neuroscience Hannover, Germany.
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Ots HD, Anderson T, Sherrerd-Smith W, DelBianco J, Rasic G, Chuprin A, Toor Z, Fitch E, Ahuja K, Reid F, Musto AE. Scoping review of disease-modifying effect of drugs in experimental epilepsy. Front Neurol 2023; 14:1097473. [PMID: 36908628 PMCID: PMC9997527 DOI: 10.3389/fneur.2023.1097473] [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: 11/13/2022] [Accepted: 02/02/2023] [Indexed: 02/25/2023] Open
Abstract
Objective Epilepsy affects ~50 million people worldwide causing significant medical, financial, and sociologic concerns for affected patients and their families. To date, treatment of epilepsy is primarily symptomatic management because few effective preventative or disease-modifying interventions exist. However, recent research has identified neurobiological mechanisms of epileptogenesis, providing new pharmacologic targets to investigate. The current scientific evidence remains scattered across multiple studies using different model and experimental designs. The review compiles different models of anti-epileptogenic investigation and highlights specific compounds with potential epileptogenesis-modifying experimental drugs. It provides a platform for standardization of future epilepsy research to allow a more robust compound analysis of compounds with potential for epilepsy prevention. Methods PubMed, Ovid MEDLINE, and Web of Science were searched from 2007 to 2021. Studies with murine models of epileptogenesis and explicitly detailed experimental procedures were included in the scoping review. In total, 51 articles were selected from 14,983 and then grouped by five core variables: (1) seizure frequency, (2) seizure severity, (3) spontaneous recurrent seizures (SRS), (4) seizure duration, and (5) mossy fiber sprouting (MFS). The variables were differentiated based on experimental models including methods of seizure induction, treatment schedule and timeline of data collection. Data was categorized by the five core variables and analyzed by converting original treatment values to units of percent of its respective control. Results Discrepancies in current epileptogenesis models significantly complicate inter-study comparison of potential anti-epileptogenic interventions. With our analysis, many compounds showed a potential to reduce epileptogenic characteristics defined by the five core variables. WIN55,212-2, aspirin, rapamycin, 1400W, and LEV + BQ788 were identified compounds with the potential of effective anti-epileptic properties. Significance Our review highlights the need for consistent methodology in epilepsy research and provides a novel approach for future research. Inconsistent experimental designs hinder study comparison, slowing the progression of treatments for epilepsy. If the research community can optimize and standardize parameters such as methods of seizure induction, administration schedule, sampling time, and aniMal models, more robust meta-analysis and collaborative research would follow. Additionally, some compounds such as rapamycin, WIN 55,212-2, aspirin, 1400W, and LEV + BQ788 showed anti-epileptogenic modulation across multiple variables. We believe they warrant further study both individually and synergistically.
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Affiliation(s)
- Heather D Ots
- School of Medicine, Eastern Virginia Medical School, Norfolk, VA, United States
| | - Taylor Anderson
- School of Medicine, Eastern Virginia Medical School, Norfolk, VA, United States
| | | | - John DelBianco
- School of Medicine, Eastern Virginia Medical School, Norfolk, VA, United States
| | - Gordana Rasic
- School of Medicine, Eastern Virginia Medical School, Norfolk, VA, United States
| | - Anthony Chuprin
- School of Medicine, Eastern Virginia Medical School, Norfolk, VA, United States
| | - Zeeshan Toor
- School of Medicine, Eastern Virginia Medical School, Norfolk, VA, United States
| | - Elizabeth Fitch
- School of Medicine, Eastern Virginia Medical School, Norfolk, VA, United States
| | - Kripa Ahuja
- School of Medicine, Eastern Virginia Medical School, Norfolk, VA, United States
| | - Faith Reid
- School of Medicine, Eastern Virginia Medical School, Norfolk, VA, United States
| | - Alberto E Musto
- Department of Pathology and Anatomy, Eastern Virginia Medical School, Norfolk, VA, United States.,Department of Neurology, Eastern Virginia Medical School, Norfolk, VA, United States
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11
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Löscher W, Stafstrom CE. Epilepsy and its neurobehavioral comorbidities: Insights gained from animal models. Epilepsia 2023; 64:54-91. [PMID: 36197310 DOI: 10.1111/epi.17433] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 10/04/2022] [Accepted: 10/04/2022] [Indexed: 01/21/2023]
Abstract
It is well established that epilepsy is associated with numerous neurobehavioral comorbidities, with a bidirectional relationship; people with epilepsy have an increased incidence of depression, anxiety, learning and memory difficulties, and numerous other psychosocial challenges, and the occurrence of epilepsy is higher in individuals with those comorbidities. Although the cause-and-effect relationship is uncertain, a fuller understanding of the mechanisms of comorbidities within the epilepsies could lead to improved therapeutics. Here, we review recent data on epilepsy and its neurobehavioral comorbidities, discussing mainly rodent models, which have been studied most extensively, and emphasize that clinically relevant information can be gained from preclinical models. Furthermore, we explore the numerous potential factors that may confound the interpretation of emerging data from animal models, such as the specific seizure induction method (e.g., chemical, electrical, traumatic, genetic), the role of species and strain, environmental factors (e.g., laboratory environment, handling, epigenetics), and the behavioral assays that are chosen to evaluate the various aspects of neural behavior and cognition. Overall, the interplay between epilepsy and its neurobehavioral comorbidities is undoubtedly multifactorial, involving brain structural changes, network-level differences, molecular signaling abnormalities, and other factors. Animal models are well poised to help dissect the shared pathophysiological mechanisms, neurological sequelae, and biomarkers of epilepsy and its comorbidities.
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Affiliation(s)
- Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany.,Center for Systems Neuroscience, Hannover, Germany
| | - Carl E Stafstrom
- Division of Pediatric Neurology, Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, Maryland, USA
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12
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Kaila K, Löscher W. Bumetanide for neonatal seizures: no light in the pharmacokinetic/dynamic tunnel. Epilepsia 2022; 63:1868-1873. [PMID: 35524446 PMCID: PMC9545618 DOI: 10.1111/epi.17279] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2022] [Accepted: 04/12/2022] [Indexed: 11/29/2022]
Abstract
In his editorial, Kevin Staley criticizes our recent work demonstrating the lack of effect of bumetanide in a novel model of neonatal seizures. The main points in our response are that (1) our work is on an asphyxia model, not one on "hypercarbia only"; (2) clinically relevant parenteral doses of bumetanide applied in vivo lead to concentrations in the brain parenchyma that are at least an order of magnitude lower than what would be sufficient to exert any direct effect—even a transient one—on neuronal functions, including neonatal seizures; and (3) moreover, bumetanide's molecular target in the brain is the Na‐K‐2Cl cotransporter NKCC1, which has vital functions in neurons, astrocytes, and oligodendrocytes as well as microglia. This would make it impossible even for highly brain‐permeant NKCC1 blockers to specifically target depolarizing and excitatory actions of γ‐aminobutyric acid in principal neurons of the brain, which is postulated as the rationale of clinical trials on neonatal seizures.
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Affiliation(s)
- Kai Kaila
- Molecular and Integrative Biosciences (MIBS) and Neuroscience Center (HiLIFE), University of Helsinki, Finland
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany.,Center for Systems Neuroscience, Hannover, Germany
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13
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Löscher W, Kaila K. CNS pharmacology of NKCC1 inhibitors. Neuropharmacology 2021; 205:108910. [PMID: 34883135 DOI: 10.1016/j.neuropharm.2021.108910] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 11/25/2021] [Accepted: 11/26/2021] [Indexed: 12/21/2022]
Abstract
The Na-K-2Cl cotransporter NKCC1 and the neuron-specific K-Cl cotransporter KCC2 are considered attractive CNS drug targets because altered neuronal chloride regulation and consequent effects on GABAergic signaling have been implicated in numerous CNS disorders. While KCC2 modulators are not yet clinically available, the loop diuretic bumetanide has been used off-label in attempts to treat brain disorders and as a tool for NKCC1 inhibition in preclinical models. Bumetanide is known to have anticonvulsant and neuroprotective effects under some pathophysiological conditions. However, as shown in several species from neonates to adults (mice, rats, dogs, and by extrapolation in humans), at the low clinical doses of bumetanide approved for diuresis, this drug has negligible access into the CNS, reaching levels that are much lower than what is needed to inhibit NKCC1 in cells within the brain parenchyma. Several drug discovery strategies have been initiated over the last ∼15 years to develop brain-permeant compounds that, ideally, should be selective for NKCC1 to eliminate the diuresis mediated by inhibition of renal NKCC2. The strategies employed to improve the pharmacokinetic and pharmacodynamic properties of NKCC1 blockers include evaluation of other clinically approved loop diuretics; development of lipophilic prodrugs of bumetanide; development of side-chain derivatives of bumetanide; and unbiased high-throughput screening approaches of drug discovery based on large chemical compound libraries. The main outcomes are that (1), non-acidic loop diuretics such as azosemide and torasemide may have advantages as NKCC1 inhibitors vs. bumetanide; (2), bumetanide prodrugs lead to significantly higher brain levels than the parent drug and have lower diuretic activity; (3), the novel bumetanide side-chain derivatives do not exhibit any functionally relevant improvement of CNS accessibility or NKCC1 selectivity vs. bumetanide; (4) novel compounds discovered by high-throughput screening may resolve some of the inherent problems of bumetanide, but as yet this has not been achieved. Thus, further research is needed to optimize the design of brain-permeant NKCC1 inhibitors. In parallel, a major challenge is to identify the mechanisms whereby various NKCC1-expressing cellular targets of these drugs within (e.g., neurons, oligodendrocytes or astrocytes) and outside the brain parenchyma (e.g., the blood-brain barrier, the choroid plexus, and the endocrine system), as well as molecular off-target effects, might contribute to their reported therapeutic and adverse effects.
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Affiliation(s)
- Wolfgang Löscher
- Dept. of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany; Center for Systems Neuroscience Hannover, Germany.
| | - Kai Kaila
- Molecular and Integrative Biosciences and Neuroscience Center (HiLIFE), University of Helsinki, Finland
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14
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Atefimanash P, Pourhamzeh M, Susanabadi A, Arabi M, Jamali-Raeufy N, Mehrabi S. Hippocampal chloride transporter KCC2 contributes to excitatory GABA dysregulation in the developmental rat model of schizophrenia. J Chem Neuroanat 2021; 118:102040. [PMID: 34695562 DOI: 10.1016/j.jchemneu.2021.102040] [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: 08/12/2021] [Revised: 10/18/2021] [Accepted: 10/18/2021] [Indexed: 10/20/2022]
Abstract
Recent studies have revealed an altered expression of NKCC1 and KCC2 in prefrontal cortex (PFC) and hippocampus of schizophrenic patients. Despite extensive considerations, the alteration of NKCC1 and KCC2 co-transporters at different stages of development has not been fully studied. Therefore, we evaluated the expression of these transporters in PFC and hippocampus at time points of four, eight, and twelve weeks in post-weaning social isolation rearing rat model. For this purpose, 23-25 days-old rats were classified into social- or isolation-reared groups. The levels of NKCC1 and KCC2 mRNA expression were evaluated at hippocampus or PFC regions at the time-points of four, eight, and twelve weeks following housing. Post-weaning isolation rearing decreased the hippocampal KCC2 mRNA expression level, but does not affect the NKCC1 mRNA expression. However, no significant difference was observed in the PFC mRNA levels of NKCC1 and KCC2 in the isolation-reared group compared to the socially-reared group during the course of modeling. Further, we assessed the therapeutic effect of selective NKCC1 inhibitor bumetanide (10 mg/kg), on improvement of prepulse inhibition (PPI) test on twelve weeks isolation-reared rats. Intraperitoneal administration of bumetanide (10 mg/kg) did not exert beneficial effects on PPI deficit. Our findings show that isolation rearing reduces hippocampal KCC2 expression level and may underlie hippocampal GABA excitatory. In addition, 10 mg/kg bumetanide is not effective in improving the reduced PPI of twelve weeks isolation-reared rats. Collectively, our findings show that hippocampal chloride transporter KCC2 contributes to excitatory GABA dysregulation in the developmental rat model of schizophrenia.
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Affiliation(s)
- Pezhman Atefimanash
- Division of Neuroscience, Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Mahsa Pourhamzeh
- Division of Neuroscience, Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Alireza Susanabadi
- Department of Anesthesia and pain medicine, Arak University of Medical Sciences, Arak, Iran
| | - Mehrnoosh Arabi
- Division of Neuroscience, Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran; Department of Radiology and Medical Physics, Faculty of Paramedicine, Kashan University of Medical Sciences, Kashan, Iran
| | - Nida Jamali-Raeufy
- Department of Physiology, Faculty of Medicine, Iran University of Medical Science, Tehran, Iran
| | - Soraya Mehrabi
- Division of Neuroscience, Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran; Department of Neuroscience, Faculty of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran; Department of Physiology, Faculty of Medicine, Iran University of Medical Science, Tehran, Iran.
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15
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Selected Molecular Targets for Antiepileptogenesis. Int J Mol Sci 2021; 22:ijms22189737. [PMID: 34575901 PMCID: PMC8466306 DOI: 10.3390/ijms22189737] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2021] [Revised: 09/02/2021] [Accepted: 09/02/2021] [Indexed: 02/07/2023] Open
Abstract
The term epileptogenesis defines the usually durable process of converting normal brain into an epileptic one. The resistance of a significant proportion of patients with epilepsy to the available pharmacotherapy prompted the concept of a causative treatment option consisting in stopping or modifying the progress of epileptogenesis. Most antiepileptic drugs possess only a weak or no antiepileptogenic potential at all, but a few of them appear promising in this regard; these include, for example, eslicarbazepine (a sodium and T-type channel blocker), lamotrigine (a sodium channel blocker and glutamate antagonist) or levetiracetam (a ligand of synaptic vehicle protein SV2A). Among the approved non-antiepileptic drugs, antiepileptogenic potential seems to reside in losartan (a blocker of angiotensin II type 1 receptors), biperiden (an antiparkinsonian drug), nonsteroidal anti-inflammatory drugs, antioxidative drugs and minocycline (a second-generation tetracycline with anti-inflammatory and antioxidant properties). Among other possible antiepileptogenic compounds, antisense nucleotides have been considered, among these an antagomir targeting microRNA-134. The drugs and agents mentioned above have been evaluated in post-status epilepticus models of epileptogenesis, so their preventive efficacy must be verified. Limited clinical data indicate that biperiden in patients with brain injuries is well-tolerated and seems to reduce the incidence of post-traumatic epilepsy. Exceptionally, in this regard, our own original data presented here point to c-Fos as an early seizure duration, but not seizure intensity-related, marker of early epileptogenesis. Further research of reliable markers of early epileptogenesis is definitely needed to improve the process of designing adequate antiepileptogenic therapies.
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16
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Dai Y, Zhang L, Yu J, Zhou X, He H, Ji Y, Wang K, Du X, Liu X, Tang Y, Deng S, Langley C, Li WG, Zhang J, Feng J, Sahakian BJ, Luo Q, Li F. Improved symptoms following bumetanide treatment in children aged 3-6 years with autism spectrum disorder: a randomized, double-blind, placebo-controlled trial. Sci Bull (Beijing) 2021; 66:1591-1598. [PMID: 36654288 DOI: 10.1016/j.scib.2021.01.008] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2020] [Revised: 10/26/2020] [Accepted: 12/23/2020] [Indexed: 02/03/2023]
Abstract
With the current limited drug therapy for the core symptoms of autism spectrum disorder (ASD), we herein report a randomized, double-blind, placebo-controlled trial to investigate the efficacy, safety, and potential neural mechanism of bumetanide in children with ASD aged 3-6 years old. A total of 120 children were enrolled into the study and randomly assigned to either 0.5 mg bumetanide or placebo. In the final sample, 119 children received at least one dose of bumetanide (59 children) or placebo (60 children) were included in the final analysis. The primary outcome was a reduction in the Childhood Autism Rating Scale (CARS) score, and the secondary outcomes were the Clinical Global Impressions Scale (CGI) -Global Improvement (CGI-I) score at 3 months and the change from baseline to 3-month in the Autism Diagnostic Observation Schedule (ADOS). Magnetic resonance spectroscopy (MRS) was used to measure γ-aminobutyric acid (GABA) and glutamate neurotransmitter concentrations in the insular cortex (IC) before and after the treatment. As compared with the placebo, bumetanide treatment was significantly better in reducing the severity. No patient withdrew from the trial due to adverse events. The superiority of bumetanide to placebo in reducing insular GABA, measured using MRS, was demonstrated. The clinical improvement was associated with a decrease in insular GABA in the bumetanide group. In conclusion, this trial in a large group of young children with predominantly moderate and severe ASD demonstrated that bumetanide is safe and effective in improving the core symptoms of ASD. However, the clinical significance remains uncertain, and future multi-center clinical trials are required to replicate these findings and confirm the clinical significance using a variety of outcome measures.
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Affiliation(s)
- Yuan Dai
- Department of Developmental and Behavioural Pediatric & Child Primary Care, Brain and Behavioural Research Unit of Shanghai Institute for Pediatric Research and MOE-Shanghai Key Laboratory for Children's Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
| | - Lingli Zhang
- Department of Developmental and Behavioural Pediatric & Child Primary Care, Brain and Behavioural Research Unit of Shanghai Institute for Pediatric Research and MOE-Shanghai Key Laboratory for Children's Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
| | - Juehua Yu
- Department of Developmental and Behavioural Pediatric & Child Primary Care, Brain and Behavioural Research Unit of Shanghai Institute for Pediatric Research and MOE-Shanghai Key Laboratory for Children's Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China; Centre for Experimental Studies and Research, The First Affiliated Hospital of Kunming Medical University, Kunming 650032, China
| | - Xin Zhou
- Clinical Research Unit, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
| | - Hua He
- Department of Developmental and Behavioural Pediatric & Child Primary Care, Brain and Behavioural Research Unit of Shanghai Institute for Pediatric Research and MOE-Shanghai Key Laboratory for Children's Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
| | - Yiting Ji
- Department of Developmental and Behavioural Pediatric & Child Primary Care, Brain and Behavioural Research Unit of Shanghai Institute for Pediatric Research and MOE-Shanghai Key Laboratory for Children's Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
| | - Kai Wang
- Department of Developmental and Behavioural Pediatric & Child Primary Care, Brain and Behavioural Research Unit of Shanghai Institute for Pediatric Research and MOE-Shanghai Key Laboratory for Children's Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
| | - Xiujuan Du
- Department of Developmental and Behavioural Pediatric & Child Primary Care, Brain and Behavioural Research Unit of Shanghai Institute for Pediatric Research and MOE-Shanghai Key Laboratory for Children's Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
| | - Xin Liu
- Department of Developmental and Behavioural Pediatric & Child Primary Care, Brain and Behavioural Research Unit of Shanghai Institute for Pediatric Research and MOE-Shanghai Key Laboratory for Children's Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
| | - Yun Tang
- Department of Developmental and Behavioural Pediatric & Child Primary Care, Brain and Behavioural Research Unit of Shanghai Institute for Pediatric Research and MOE-Shanghai Key Laboratory for Children's Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China; The School of Psychology and Cognitive Science, East China Normal University, Shanghai 200062, China
| | - Shining Deng
- Department of Developmental and Behavioural Pediatric & Child Primary Care, Brain and Behavioural Research Unit of Shanghai Institute for Pediatric Research and MOE-Shanghai Key Laboratory for Children's Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
| | - Christelle Langley
- Department of Psychiatry and the Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge CB21TN, UK
| | - Wei-Guang Li
- Collaborative Innovation Center for Brain Science, Department of Anatomy and Physiology, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Jun Zhang
- Department of Developmental and Behavioural Pediatric & Child Primary Care, Brain and Behavioural Research Unit of Shanghai Institute for Pediatric Research and MOE-Shanghai Key Laboratory for Children's Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China
| | - Jianfeng Feng
- Institute of Science and Technology for Brain-Inspired Intelligence, Ministry of Education-Key Laboratory of Computational Neuroscience and Brain-Inspired Intelligence and Research and Research Institute of Intelligent Complex Systems, Fudan University, Shanghai 200433, China
| | - Barbara J Sahakian
- Department of Developmental and Behavioural Pediatric & Child Primary Care, Brain and Behavioural Research Unit of Shanghai Institute for Pediatric Research and MOE-Shanghai Key Laboratory for Children's Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China; Department of Psychiatry and the Behavioural and Clinical Neuroscience Institute, University of Cambridge, Cambridge CB21TN, UK; Institute of Science and Technology for Brain-Inspired Intelligence, Ministry of Education-Key Laboratory of Computational Neuroscience and Brain-Inspired Intelligence and Research and Research Institute of Intelligent Complex Systems, Fudan University, Shanghai 200433, China
| | - Qiang Luo
- Institute of Science and Technology for Brain-Inspired Intelligence, Ministry of Education-Key Laboratory of Computational Neuroscience and Brain-Inspired Intelligence and Research and Research Institute of Intelligent Complex Systems, Fudan University, Shanghai 200433, China; State Key Laboratory of Medical Neurobiology and Ministry of Education Frontiers Center for Brain Science, Institutes of Brain Science and National Clinical Research Center for Aging and Medicine, Huashan Hospital, Fudan University, Shanghai 200040, China.
| | - Fei Li
- Department of Developmental and Behavioural Pediatric & Child Primary Care, Brain and Behavioural Research Unit of Shanghai Institute for Pediatric Research and MOE-Shanghai Key Laboratory for Children's Environmental Health, Xinhua Hospital, Shanghai Jiao Tong University School of Medicine, Shanghai 200092, China.
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17
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Scopolamine prevents aberrant mossy fiber sprouting and facilitates remission of epilepsy after brain injury. Neurobiol Dis 2021; 158:105446. [PMID: 34280524 DOI: 10.1016/j.nbd.2021.105446] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2021] [Revised: 07/01/2021] [Accepted: 07/13/2021] [Indexed: 11/21/2022] Open
Abstract
Prevention or modification of acquired epilepsy in patients at risk is an urgent, yet unmet, clinical need. Following acute brain insults, there is an increased risk of mesial temporal lobe epilepsy (mTLE), which is often associated with debilitating comorbidities and reduced life expectancy. The latent period between brain injury and the onset of epilepsy may offer a therapeutic window for interfering with epileptogenesis. The pilocarpine model of mTLE is widely used in the search for novel antiepileptogenic treatments. Recent biochemical studies indicated that cholinergic mechanisms play a role in the epileptogenic alterations induced by status epilepticus (SE) in this and other models of mTLE, which prompted us to evaluate whether treatment with the muscarinic antagonist scopolamine during the latent period after SE is capable of preventing or modifying epilepsy and associated behavioral and cognitive alterations in female Sprague-Dawley rats. First, in silico pharmacokinetic modeling was used to select a dosing protocol by which M-receptor inhibitory brain levels of scopolamine are maintained during prolonged treatment. This protocol was verified by drug analysis in vivo. Rats were then treated twice daily with scopolamine over 17 days after SE, followed by drug wash-out and behavioral and video/EEG monitoring up to ~6 months after SE. Compared to vehicle controls, rats that were treated with scopolamine during the latent period exhibited a significantly lower incidence of spontaneous recurrent seizures during periods of intermittent recording in the chronic phase of epilepsy, less behavioral excitability, less cognitive impairment, and significantly reduced aberrant mossy fiber sprouting in the hippocampus. The present data may indicate that scopolamine exerts antiepileptogenic/disease-modifying activity in the lithium-pilocarpine rat model, possibly involving increased remission of epilepsy as a new mechanism of disease-modification. For evaluating the rigor of the present data, we envision a study that more thoroughly addresses the gender bias and video-EEG recording limitations of the present study.
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18
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Dubanet O, Ferreira Gomes Da Silva A, Frick A, Hirase H, Beyeler A, Leinekugel X. Probing the polarity of spontaneous perisomatic GABAergic synaptic transmission in the mouse CA3 circuit in vivo. Cell Rep 2021; 36:109381. [PMID: 34260906 DOI: 10.1016/j.celrep.2021.109381] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 11/18/2020] [Accepted: 06/18/2021] [Indexed: 11/27/2022] Open
Abstract
The hypothesis that reversed, excitatory GABA may be involved in various brain pathologies, including epileptogenesis, is appealing but controversial because of the technical difficulty of probing endogenous GABAergic synaptic function in vivo. We overcome this challenge by non-invasive extracellular recording of neuronal firing responses to optogenetically evoked and spontaneously occurring inhibitory perisomatic GABAergic field potentials, generated by individual parvalbumin interneurons on their target pyramidal cells. Our direct probing of GABAergic transmission suggests a rather anecdotal participation of excitatory GABA in two specific models of epileptogenesis in the mouse CA3 circuit in vivo, even though this does not preclude its expression in other brain areas or pathological conditions. Our approach allows the detection of distinct alterations of inhibition during spontaneous activity in vivo, with high sensitivity. It represents a promising tool for the investigation of excitatory GABA in different pathological conditions that may affect the hippocampal circuit.
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Affiliation(s)
- Olivier Dubanet
- University of Bordeaux, INSERM U1215, Neurocentre Magendie, 33077 Bordeaux, France
| | - Arnaldo Ferreira Gomes Da Silva
- University of Bordeaux, INSERM U1215, Neurocentre Magendie, 33077 Bordeaux, France; INMED, INSERM, Aix Marseille Univ, France
| | - Andreas Frick
- University of Bordeaux, INSERM U1215, Neurocentre Magendie, 33077 Bordeaux, France
| | - Hajime Hirase
- Center for Translational Neuromedicine, University of Copenhagen, Copenhagen, Denmark
| | - Anna Beyeler
- University of Bordeaux, INSERM U1215, Neurocentre Magendie, 33077 Bordeaux, France
| | - Xavier Leinekugel
- University of Bordeaux, INSERM U1215, Neurocentre Magendie, 33077 Bordeaux, France; INMED, INSERM, Aix Marseille Univ, France.
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19
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Löscher W, Klein P. New approaches for developing multi-targeted drug combinations for disease modification of complex brain disorders. Does epilepsy prevention become a realistic goal? Pharmacol Ther 2021; 229:107934. [PMID: 34216705 DOI: 10.1016/j.pharmthera.2021.107934] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 06/16/2021] [Accepted: 06/16/2021] [Indexed: 12/14/2022]
Abstract
Over decades, the prevailing standard in drug discovery was the concept of designing highly selective compounds that act on individual drug targets. However, more recently, multi-target and combinatorial drug therapies have become an important treatment modality in complex diseases, including neurodegenerative diseases such as Alzheimer's and Parkinson's disease. The development of such network-based approaches is facilitated by the significant advance in our understanding of the pathophysiological processes in these and other complex brain diseases and the adoption of modern computational approaches in drug discovery and repurposing. However, although drug combination therapy has become an effective means for the symptomatic treatment of many complex diseases, the holy grail of identifying clinically effective disease-modifying treatments for neurodegenerative and other brain diseases remains elusive. Thus, despite extensive research, there remains an urgent need for novel treatments that will modify the progression of the disease or prevent its development in patients at risk. Here we discuss recent approaches with a focus on multi-targeted drug combinations for prevention or modification of epilepsy. Over the last ~10 years, several novel promising multi-targeted therapeutic approaches have been identified in animal models. We envision that synergistic combinations of repurposed drugs as presented in this review will be demonstrated to prevent epilepsy in patients at risk within the next 5-10 years.
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Affiliation(s)
- Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany; Center for Systems Neuroscience, Hannover, Germany.
| | - Pavel Klein
- Mid-Atlantic Epilepsy and Sleep Center, Bethesda, MD, USA
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20
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Bazard P, Frisina RD, Acosta AA, Dasgupta S, Bauer MA, Zhu X, Ding B. Roles of Key Ion Channels and Transport Proteins in Age-Related Hearing Loss. Int J Mol Sci 2021; 22:6158. [PMID: 34200434 PMCID: PMC8201059 DOI: 10.3390/ijms22116158] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2021] [Revised: 05/30/2021] [Accepted: 05/31/2021] [Indexed: 12/25/2022] Open
Abstract
The auditory system is a fascinating sensory organ that overall, converts sound signals to electrical signals of the nervous system. Initially, sound energy is converted to mechanical energy via amplification processes in the middle ear, followed by transduction of mechanical movements of the oval window into electrochemical signals in the cochlear hair cells, and finally, neural signals travel to the central auditory system, via the auditory division of the 8th cranial nerve. The majority of people above 60 years have some form of age-related hearing loss, also known as presbycusis. However, the biological mechanisms of presbycusis are complex and not yet fully delineated. In the present article, we highlight ion channels and transport proteins, which are integral for the proper functioning of the auditory system, facilitating the diffusion of various ions across auditory structures for signal transduction and processing. Like most other physiological systems, hearing abilities decline with age, hence, it is imperative to fully understand inner ear aging changes, so ion channel functions should be further investigated in the aging cochlea. In this review article, we discuss key various ion channels in the auditory system and how their functions change with age. Understanding the roles of ion channels in auditory processing could enhance the development of potential biotherapies for age-related hearing loss.
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Affiliation(s)
- Parveen Bazard
- Department of Medical Engineering, College of Engineering, University of South Florida, Tampa, FL 33620, USA; (P.B.); (A.A.A.); (S.D.); (M.A.B.); (X.Z.); (B.D.)
- Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL 33612, USA
| | - Robert D. Frisina
- Department of Medical Engineering, College of Engineering, University of South Florida, Tampa, FL 33620, USA; (P.B.); (A.A.A.); (S.D.); (M.A.B.); (X.Z.); (B.D.)
- Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL 33612, USA
- Department Communication Sciences and Disorders, College of Behavioral & Communication Sciences, Tampa, FL 33620, USA
| | - Alejandro A. Acosta
- Department of Medical Engineering, College of Engineering, University of South Florida, Tampa, FL 33620, USA; (P.B.); (A.A.A.); (S.D.); (M.A.B.); (X.Z.); (B.D.)
- Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL 33612, USA
| | - Sneha Dasgupta
- Department of Medical Engineering, College of Engineering, University of South Florida, Tampa, FL 33620, USA; (P.B.); (A.A.A.); (S.D.); (M.A.B.); (X.Z.); (B.D.)
- Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL 33612, USA
| | - Mark A. Bauer
- Department of Medical Engineering, College of Engineering, University of South Florida, Tampa, FL 33620, USA; (P.B.); (A.A.A.); (S.D.); (M.A.B.); (X.Z.); (B.D.)
- Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL 33612, USA
| | - Xiaoxia Zhu
- Department of Medical Engineering, College of Engineering, University of South Florida, Tampa, FL 33620, USA; (P.B.); (A.A.A.); (S.D.); (M.A.B.); (X.Z.); (B.D.)
- Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL 33612, USA
| | - Bo Ding
- Department of Medical Engineering, College of Engineering, University of South Florida, Tampa, FL 33620, USA; (P.B.); (A.A.A.); (S.D.); (M.A.B.); (X.Z.); (B.D.)
- Global Center for Hearing and Speech Research, University of South Florida, Tampa, FL 33612, USA
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Johne M, Käufer C, Römermann K, Gailus B, Gericke B, Löscher W. A combination of phenobarbital and the bumetanide derivative bumepamine prevents neonatal seizures and subsequent hippocampal neurodegeneration in a rat model of birth asphyxia. Epilepsia 2021; 62:1460-1471. [PMID: 33955541 DOI: 10.1111/epi.16912] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2021] [Revised: 04/07/2021] [Accepted: 04/07/2021] [Indexed: 12/26/2022]
Abstract
OBJECTIVES Bumetanide was suggested as an adjunct to phenobarbital for suppression of neonatal seizures. This suggestion was based on the idea that bumetanide, by reducing intraneuronal chloride accumulation through inhibition of the Na-K-2Cl cotransporter NKCC1, may attenuate or abolish depolarizing γ-aminobutyric acid (GABA) responses caused by birth asphyxia. However, a first proof-of-concept clinical trial failed. This could have had several reasons, including bumetanide's poor brain penetration, the wide cellular NKCC1 expression pattern in the brain, and problems with the general concept of NKCC1's role in neonatal seizures. We recently replicated the clinical failure of bumetanide to potentiate phenobarbital's effect in a novel rat model of birth asphyxia. In this study, a clinically relevant dose (0.3 mg/kg) of bumetanide was used that does not lead to NKCC1-inhibitory brain levels. The aim of the present experiments was to examine whether a much higher dose (10 mg/kg) of bumetanide is capable of potentiating phenobarbital in this rat model. Furthermore, the effects of the two lipophilic bumetanide derivatives, the ester prodrug N,N-dimethylaminoethylester of bumetanide (DIMAEB) and the benzylamine derivative bumepamine, were examined at equimolar doses. METHODS Intermittent asphyxia was induced for 30 min by exposing male and female P11 rat pups to three 7 + 3 min cycles of 9% and 5% O2 at constant 20% CO2 . All control pups exhibited neonatal seizures after the asphyxia. RESULTS Even at 10 mg/kg, bumetanide did not potentiate the effect of a submaximal dose (15 mg/kg) of phenobarbital on seizure incidence, whereas a significant suppression of neonatal seizures was determined for combinations of phenobarbital with DIMAEB or, more effectively, bumepamine, which, however, does not inhibit NKCC1. Of interest, the bumepamine/phenobarbital combination prevented the neurodegenerative consequences of asphyxia and seizures in the hippocampus. SIGNIFICANCE Both bumepamine and DIMAEB are promising tools that may help to develop more effective lead compounds for clinical trials.
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Affiliation(s)
- Marie Johne
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Hannover, Germany.,Center for Systems Neuroscience Hannover, Hannover, Germany
| | - Christopher Käufer
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Kerstin Römermann
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Björn Gailus
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Hannover, Germany.,Center for Systems Neuroscience Hannover, Hannover, Germany
| | - Birthe Gericke
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Hannover, Germany.,Center for Systems Neuroscience Hannover, Hannover, Germany
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Hannover, Germany.,Center for Systems Neuroscience Hannover, Hannover, Germany
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22
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Löscher W, Kaila K. Reply to the commentary by Ben-Ari and Delpire: Bumetanide and neonatal seizures: Fiction versus reality. Epilepsia 2021; 62:941-946. [PMID: 33764535 DOI: 10.1111/epi.16866] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2021] [Accepted: 02/16/2021] [Indexed: 12/18/2022]
Abstract
In this response to a commentary by Ben-Ari and Delpire on our recent study on the pharmacology of neonatal seizures in a novel, physiologically validated rat model of birth asphyxia, we wish to rectify their inaccurate descriptions of our model and data. Furthermore, because Ben-Ari and Delpire suggest that negative data on bumetanide from preclinical and clinical trials of neonatal seizures have few implications for (alleged) bumetanide actions on neurons in other brain disorders, we will discuss this topic as well. Based on the poor brain penetration of bumetanide, combined with the extremely wide cellular expression patterns of the target protein NKCC1, it is obvious that the numerous actions of systemically applied bumetanide described in the literature are not mediated by the drug's effects on central neurons.
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Affiliation(s)
- Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany.,Center for Systems Neuroscience, Hannover, Germany
| | - Kai Kaila
- Molecular and Integrative Biosciences, University of Helsinki, Helsinki, Finland.,Neuroscience Center (HiLIFE), University of Helsinki, Helsinki, Finland
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23
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Hampel P, Johne M, Gailus B, Vogel A, Schidlitzki A, Gericke B, Töllner K, Theilmann W, Käufer C, Römermann K, Kaila K, Löscher W. Deletion of the Na-K-2Cl cotransporter NKCC1 results in a more severe epileptic phenotype in the intrahippocampal kainate mouse model of temporal lobe epilepsy. Neurobiol Dis 2021; 152:105297. [PMID: 33581254 DOI: 10.1016/j.nbd.2021.105297] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2021] [Revised: 01/29/2021] [Accepted: 02/06/2021] [Indexed: 12/18/2022] Open
Abstract
Increased neuronal expression of the Na-K-2Cl cotransporter NKCC1 has been implicated in the generation of seizures and epilepsy. However, conclusions from studies on the NKCC1-specific inhibitor, bumetanide, are equivocal, which is a consequence of the multiple potential cellular targets and poor brain penetration of this drug. Here, we used Nkcc1 knockout (KO) and wildtype (WT) littermate control mice to study the ictogenic and epileptogenic effects of intrahippocampal injection of kainate. Kainate (0.23 μg in 50 nl) induced limbic status epilepticus (SE) in both KO and WT mice with similar incidence, latency to SE onset, and SE duration, but the number of intermittent generalized convulsive seizures during SE was significantly higher in Nkcc1 KO mice, indicating increased SE severity. Following SE, spontaneous recurrent seizures (SRS) were recorded by continuous (24/7) video/EEG monitoring at 0-1, 4-5, and 12-13 weeks after kainate, using depth electrodes in the ipsilateral hippocampus. Latency to onset of electrographic SRS and the incidence of electrographic SRS were similar in WT and KO mice. However, the frequency of electrographic seizures was lower whereas the frequency of electroclinical seizures was higher in Nkcc1 KO mice, indicating a facilitated progression from electrographic to electroclinical seizures during chronic epilepsy, and a more severe epileptic phenotype, in the absence of NKCC1. The present findings suggest that NKCC1 is dispensable for the induction, progression and manifestation of epilepsy, and they do not support the widely held notion that inhibition of NKCC1 in the brain is a useful strategy for preventing or modifying epilepsy.
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Affiliation(s)
- Philip Hampel
- Dept. of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany; Neurona Therapeutics, San Francisco, CA, USA
| | - Marie Johne
- Dept. of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany; Center for Systems Neuroscience, Hannover, Germany
| | - Björn Gailus
- Dept. of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany; Center for Systems Neuroscience, Hannover, Germany
| | - Alexandra Vogel
- Dept. of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany
| | - Alina Schidlitzki
- Dept. of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany
| | - Birthe Gericke
- Dept. of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany; Center for Systems Neuroscience, Hannover, Germany
| | - Kathrin Töllner
- Dept. of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany
| | - Wiebke Theilmann
- Dept. of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany
| | - Christopher Käufer
- Dept. of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany
| | - Kerstin Römermann
- Dept. of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany
| | - Kai Kaila
- Molecular and Integrative Biosciences and Neuroscience Center (HiLIFE), University of Helsinki, Finland
| | - Wolfgang Löscher
- Dept. of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany; Center for Systems Neuroscience, Hannover, Germany.
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Hampel P, Römermann K, Gailus B, Johne M, Gericke B, Kaczmarek E, Löscher W. Effects of the NKCC1 inhibitors bumetanide, azosemide, and torasemide alone or in combination with phenobarbital on seizure threshold in epileptic and nonepileptic mice. Neuropharmacology 2021; 185:108449. [PMID: 33450274 DOI: 10.1016/j.neuropharm.2021.108449] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/19/2020] [Revised: 12/07/2020] [Accepted: 12/22/2020] [Indexed: 12/31/2022]
Abstract
The sodium-potassium-chloride (Na-K-Cl) cotransporter NKCC1 is found in the plasma membrane of a wide variety of cell types, including neurons, glia and endothelial cells in the brain. Increased expression of neuronal NKCC1 has been implicated in several brain disorders, including neonatal seizures and epilepsy. The loop diuretic and NKCC inhibitor bumetanide has been evaluated as an antiseizure agent alone or together with approved antiseizure drugs such as phenobarbital (PB) in pre-clinical and clinical studies with varying results. The equivocal efficacy of bumetanide may be a result of its poor brain penetration. We recently reported that the loop diuretic azosemide is more potent to inhibit NKCC1 than bumetanide. In contrast to bumetanide, azosemide is not acidic, which should favor its brain penetration. Thus, azosemide may be a promising alternative to bumetanide for treatment of brain disorders such as epilepsy. In the present study, we determined the effect of azosemide and bumetanide on seizure threshold in adult epileptic mice. A structurally related non-acidic loop diuretic, torasemide, which also blocks NKCC1, was included in the experiments. The drug effects were assessed by determing the maximal electroshock seizure threshold (MEST) in epileptic vs. nonepileptic mice. Epilepsy was induced by pilocarpine, which was shown to produce long-lasting increases in NKCC1 in the hippocampus, whereas MEST did not alter NKCC1 mRNA in this region. None of the three loop diuretics increased MEST or the effect of PB on MEST in nonepileptic mice. In epileptic mice, all three diuretics significantly increased PB's seizure threshold increasing efficacy, but the effect was variable upon repeated MEST determinations and not correlated with the drugs' diuretic potency. These data may indicate that inhibition of NKCC1 by loop diuretics is not an effective means of increasing seizure threshold in adult epilepsy.
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Affiliation(s)
- Philip Hampel
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany; Center for Systems Neuroscience, Hannover, Germany.
| | - Kerstin Römermann
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany
| | - Björn Gailus
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany; Center for Systems Neuroscience, Hannover, Germany
| | - Marie Johne
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany; Center for Systems Neuroscience, Hannover, Germany
| | - Birthe Gericke
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany; Center for Systems Neuroscience, Hannover, Germany
| | - Edith Kaczmarek
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany; Center for Systems Neuroscience, Hannover, Germany
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25
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Hampel P, Römermann K, Gramer M, Löscher W. The search for brain-permeant NKCC1 inhibitors for the treatment of seizures: Pharmacokinetic-pharmacodynamic modelling of NKCC1 inhibition by azosemide, torasemide, and bumetanide in mouse brain. Epilepsy Behav 2021; 114:107616. [PMID: 33279441 DOI: 10.1016/j.yebeh.2020.107616] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/05/2020] [Accepted: 10/30/2020] [Indexed: 01/23/2023]
Abstract
Because of its potent inhibitory effect on the Na+-K+-2Cl- symporter isotype 1 (NKCC1) in brain neurons, bumetanide has been tested with varying results for treatment of seizures that potentially evolve as a consequence of abnormal NKCC1 activity. However, because of its physicochemical properties, bumetanide only poorly penetrates into the brain. We previously demonstrated that NKCC1 can be also inhibited by azosemide and torasemide, which lack the carboxyl group of bumetanide and thus should be better brain-permeable. Here we studied the brain distribution kinetics of azosemide and torasemide in comparison with bumetanide in mice and used pharmacokinetic-pharmacodynamic modelling to determine whether the drugs reach NKCC1-inhibitory brain concentrations. All three drugs hardly distributed into the brain, which seemed to be the result of probenecid-sensitive efflux transport at the blood-brain barrier. When fractions unbound in plasma and brain were determined by equilibrium dialysis, only about 6-17% of the brain drug concentration were freely available. With the systemic doses (10 mg/kg i.v.) used, free brain concentrations of bumetanide and torasemide were in the NKCC1-inhibitory concentration range, while levels of azosemide were slightly below this range. However, all three drugs exhibited free plasma levels that would be sufficient to block NKCC1 at the apical membrane of brain capillary endothelial cells. These data suggest that azosemide and torasemide are interesting alternatives to bumetanide for treatment of seizures involving abnormal NKCC1 functionality, particularly because of their longer duration of action and their lower diuretic potency, which is an advantage in patients with seizures.
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Affiliation(s)
- Philip Hampel
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany
| | - Kerstin Römermann
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany
| | - Martina Gramer
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Germany; Center for Systems Neuroscience, Hannover, Germany.
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26
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Müller J, Timmermann A, Henning L, Müller H, Steinhäuser C, Bedner P. Astrocytic GABA Accumulation in Experimental Temporal Lobe Epilepsy. Front Neurol 2020; 11:614923. [PMID: 33391173 PMCID: PMC7775561 DOI: 10.3389/fneur.2020.614923] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2020] [Accepted: 11/30/2020] [Indexed: 01/17/2023] Open
Abstract
An imbalance of excitation and inhibition has been associated with the pathophysiology of epilepsy. Loss of GABAergic interneurons and/or synaptic inhibition has been shown in various epilepsy models and in human epilepsy. Despite this loss, several studies reported preserved or increased tonic GABAA receptor-mediated currents in epilepsy, raising the question of the source of the inhibitory transmitter. We used the unilateral intracortical kainate mouse model of temporal lobe epilepsy (TLE) with hippocampal sclerosis (HS) to answer this question. In our model we observed profound loss of interneurons in the sclerotic hippocampal CA1 region and dentate gyrus already 5 days after epilepsy induction. Consistent with the literature, the absence of interneurons caused no reduction of tonic inhibition of CA1 pyramidal neurons. In dentate granule cells the inhibitory currents were even increased in epileptic tissue. Intriguingly, immunostaining of brain sections from epileptic mice with antibodies against GABA revealed strong and progressive accumulation of the neurotransmitter in reactive astrocytes. Pharmacological inhibition of the astrocytic GABA transporter GAT3 did not affect tonic inhibition in the sclerotic hippocampus, suggesting that this transporter is not responsible for astrocytic GABA accumulation or release. Immunostaining further indicated that both decarboxylation of glutamate and putrescine degradation accounted for the increased GABA levels in reactive astrocytes. Together, our data provide evidence that the preserved tonic inhibitory currents in the epileptic brain are mediated by GABA overproduction and release from astrocytes. A deeper understanding of the underlying mechanisms may lead to new strategies for antiepileptic drug therapy.
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Affiliation(s)
- Julia Müller
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Aline Timmermann
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Lukas Henning
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Hendrik Müller
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Christian Steinhäuser
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
| | - Peter Bedner
- Institute of Cellular Neurosciences, Medical Faculty, University of Bonn, Bonn, Germany
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27
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Koltai T. Targeting the pH Paradigm at the Bedside: A Practical Approach. Int J Mol Sci 2020; 21:E9221. [PMID: 33287221 PMCID: PMC7730959 DOI: 10.3390/ijms21239221] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2020] [Revised: 11/27/2020] [Accepted: 11/28/2020] [Indexed: 02/07/2023] Open
Abstract
The inversion of the pH gradient in malignant tumors, known as the pH paradigm, is increasingly becoming accepted by the scientific community as a hallmark of cancer. Accumulated evidence shows that this is not simply a metabolic consequence of a dysregulated behavior, but rather an essential process in the physiopathology of accelerated proliferation and invasion. From the over-simplification of increased lactate production as the cause of the paradigm, as initially proposed, basic science researchers have arrived at highly complex and far-reaching knowledge, that substantially modified that initial belief. These new developments show that the paradigm entails a different regulation of membrane transporters, electrolyte exchangers, cellular and membrane enzymes, water trafficking, specialized membrane structures, transcription factors, and metabolic changes that go far beyond fermentative glycolysis. This complex world of dysregulations is still shuttered behind the walls of experimental laboratories and has not yet reached bedside medicine. However, there are many known pharmaceuticals and nutraceuticals that are capable of targeting the pH paradigm. Most of these products are well known, have low toxicity, and are also inexpensive. They need to be repurposed, and this would entail shorter clinical studies and enormous cost savings if we compare them with the time and expense required for the development of a new molecule. Will targeting the pH paradigm solve the "cancer problem"? Absolutely not. However, reversing the pH inversion would strongly enhance standard treatments, rendering them more efficient, and in some cases permitting lower doses of toxic drugs. This article's goal is to describe how to reverse the pH gradient inversion with existing drugs and nutraceuticals that can easily be used in bedside medicine, without adding toxicity to established treatments. It also aims at increasing awareness among practicing physicians that targeting the pH paradigm would be able to improve the results of standard therapies. Some clinical cases will be presented as well, showing how the pH gradient inversion can be treated at the bedside in a simple manner with repurposed drugs.
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Affiliation(s)
- Tomas Koltai
- Centro de Diagnostico y Tratamiento de la Obra Social del Personal de la Alimentacion, Talar de Pacheco, Buenos Aires 1617, Argentina
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28
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Johne M, Römermann K, Hampel P, Gailus B, Theilmann W, Ala-Kurikka T, Kaila K, Löscher W. Phenobarbital and midazolam suppress neonatal seizures in a noninvasive rat model of birth asphyxia, whereas bumetanide is ineffective. Epilepsia 2020; 62:920-934. [PMID: 33258158 DOI: 10.1111/epi.16778] [Citation(s) in RCA: 31] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2020] [Revised: 11/03/2020] [Accepted: 11/05/2020] [Indexed: 12/12/2022]
Abstract
OBJECTIVE Neonatal seizures are the most frequent type of neurological emergency in newborn infants, often being a consequence of prolonged perinatal asphyxia. Phenobarbital is currently the most widely used antiseizure drug for treatment of neonatal seizures, but fails to stop them in ~50% of cases. In a neonatal hypoxia-only model based on 11-day-old (P11) rats, the NKCC1 inhibitor bumetanide was reported to potentiate the antiseizure activity of phenobarbital, whereas it was ineffective in a human trial in neonates. The aim of this study was to evaluate the effect of clinically relevant doses of bumetanide as add-on to phenobarbital on neonatal seizures in a noninvasive model of birth asphyxia in P11 rats, designed for better translation to the human term neonate. METHODS Intermittent asphyxia was induced for 30 minutes by exposing the rat pups to three 7 + 3-minute cycles of 9% and 5% O2 at constant 20% CO2 . Drug treatments were administered intraperitoneally either before or immediately after asphyxia. RESULTS All untreated rat pups had seizures within 10 minutes after termination of asphyxia. Phenobarbital significantly blocked seizures when applied before asphyxia at 30 mg/kg but not 15 mg/kg. Administration of phenobarbital after asphyxia was ineffective, whereas midazolam (0.3 or 1 mg/kg) exerted significant antiseizure effects when administered before or after asphyxia. In general, focal seizures were more resistant to treatment than generalized convulsive seizures. Bumetanide (0.3 mg/kg) alone or in combination with phenobarbital (15 or 30 mg/kg) exerted no significant effect on seizure occurrence. SIGNIFICANCE The data demonstrate that bumetanide does not increase the efficacy of phenobarbital in a model of birth asphyxia, which is consistent with the negative data of the recent human trial. The translational data obtained with the novel rat model of birth asphyxia indicate that it is a useful tool to evaluate novel treatments for neonatal seizures.
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Affiliation(s)
- Marie Johne
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany.,Center for Systems Neuroscience, Hannover, Germany
| | - Kerstin Römermann
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany
| | - Philip Hampel
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany.,Center for Systems Neuroscience, Hannover, Germany
| | - Björn Gailus
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany.,Center for Systems Neuroscience, Hannover, Germany
| | - Wiebke Theilmann
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany
| | - Tommi Ala-Kurikka
- Molecular and Integrative Biosciences and Neuroscience Center (HiLIFE), University of Helsinki, Helsinki, Finland
| | - Kai Kaila
- Molecular and Integrative Biosciences and Neuroscience Center (HiLIFE), University of Helsinki, Helsinki, Finland
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany.,Center for Systems Neuroscience, Hannover, Germany
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Verhoog QP, Holtman L, Aronica E, van Vliet EA. Astrocytes as Guardians of Neuronal Excitability: Mechanisms Underlying Epileptogenesis. Front Neurol 2020; 11:591690. [PMID: 33324329 PMCID: PMC7726323 DOI: 10.3389/fneur.2020.591690] [Citation(s) in RCA: 73] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2020] [Accepted: 10/26/2020] [Indexed: 12/11/2022] Open
Abstract
Astrocytes are key homeostatic regulators in the central nervous system and play important roles in physiology. After brain damage caused by e.g., status epilepticus, traumatic brain injury, or stroke, astrocytes may adopt a reactive phenotype. This process of reactive astrogliosis is important to restore brain homeostasis. However, persistent reactive astrogliosis can be detrimental for the brain and contributes to the development of epilepsy. In this review, we will focus on physiological functions of astrocytes in the normal brain as well as pathophysiological functions in the epileptogenic brain, with a focus on acquired epilepsy. We will discuss the role of astrocyte-related processes in epileptogenesis, including reactive astrogliosis, disturbances in energy supply and metabolism, gliotransmission, and extracellular ion concentrations, as well as blood-brain barrier dysfunction and dysregulation of blood flow. Since dysfunction of astrocytes can contribute to epilepsy, we will also discuss their role as potential targets for new therapeutic strategies.
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Affiliation(s)
- Quirijn P. Verhoog
- Leiden Academic Center for Drug Research, Leiden University, Leiden, Netherlands
- Department of Neuropathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
| | - Linda Holtman
- Leiden Academic Center for Drug Research, Leiden University, Leiden, Netherlands
| | - Eleonora Aronica
- Department of Neuropathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
- Stichting Epilepsie Instellingen Nederland (SEIN), Heemstede, Netherlands
| | - Erwin A. van Vliet
- Department of Neuropathology, Amsterdam Neuroscience, Amsterdam UMC, University of Amsterdam, Amsterdam, Netherlands
- Center for Neuroscience, Swammerdam Institute for Life Sciences, University of Amsterdam, Amsterdam, Netherlands
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30
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Theilmann W, Brandt C, Bohnhorst B, Winstroth AM, Das AM, Gramer M, Kipper A, Kalesse M, Löscher W. Hydrolytic biotransformation of the bumetanide ester prodrug DIMAEB to bumetanide by esterases in neonatal human and rat serum and neonatal rat brain-A new treatment strategy for neonatal seizures? Epilepsia 2020; 62:269-278. [PMID: 33140458 DOI: 10.1111/epi.16746] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 10/06/2020] [Accepted: 10/08/2020] [Indexed: 01/08/2023]
Abstract
OBJECTIVES The loop diuretic bumetanide has been proposed previously as an adjunct treatment for neonatal seizures because bumetanide is thought to potentiate the action of γ-aminobutyric acid (GABA)ergic drugs such as phenobarbital by preventing abnormal intracellular accumulation of chloride and the subsequent "GABA shift." However, a clinical trial in neonates failed to demonstrate such a synergistic effect of bumetanide, most likely because this drug only poorly penetrates into the brain. This prompted us to develop lipophilic prodrugs of bumetanide, such as the N,N-dimethylaminoethyl ester of bumetanide (DIMAEB), which rapidly enter the brain where they are hydrolyzed by esterases to the parent compound, as demonstrated previously by us in adult rodents. However, it is not known whether esterase activity in neonates is sufficient to hydrolyze ester prodrugs such as DIMAEB. METHODS In the present study, we examined whether esterases in neonatal serum of healthy term infants are capable of hydrolyzing DIMAEB to bumetanide and whether this activity is different from the serum of adults. Furthermore, to extrapolate the findings to brain tissue, we performed experiments with brain tissue and serum of neonatal and adult rats. RESULTS Serum from 1- to 2-day-old infants was capable of hydrolyzing DIMAEB to bumetanide at a rate similar to that of serum from adult individuals. Similarly, serum and brain tissue of neonatal rats rapidly hydrolyzed DIMAEB to bumetanide. SIGNIFICANCE These data provide a prerequisite for further evaluating the potential of bumetanide prodrugs as add-on therapy to phenobarbital and other antiseizure drugs as a new strategy for improving pharmacotherapy of neonatal seizures.
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Affiliation(s)
- Wiebke Theilmann
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Claudia Brandt
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Bettina Bohnhorst
- Department of Pediatric Pulmonology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
| | - Anne-Mieke Winstroth
- Department of Pediatric Pulmonology, Allergology and Neonatology, Hannover Medical School, Hannover, Germany
| | - Anibh Martin Das
- Clinic for Pediatric Kidney, Liver and Metabolic Diseases, Hannover Medical School, Hannover, Germany
| | - Martina Gramer
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Hannover, Germany
| | - Andi Kipper
- Institute for Organic Chemistry, Leibniz Universität Hannover, Hannover, Germany
| | - Markus Kalesse
- Institute for Organic Chemistry, Leibniz Universität Hannover, Hannover, Germany
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Hannover, Germany.,Center for Systems Neuroscience Hannover, Hannover, Germany
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31
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Sawant-Pokam PA, Vail TJ, Metcalf CS, Maguire JL, McKean TO, McKean NO, Brennan K. Preventing neuronal edema increases network excitability after traumatic brain injury. J Clin Invest 2020; 130:6005-6020. [PMID: 33044227 PMCID: PMC7598047 DOI: 10.1172/jci134793] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 08/06/2020] [Indexed: 12/31/2022] Open
Abstract
Edema is an important target for clinical intervention after traumatic brain injury (TBI). We used in vivo cellular resolution imaging and electrophysiological recording to examine the ionic mechanisms underlying neuronal edema and their effects on neuronal and network excitability after controlled cortical impact (CCI) in mice. Unexpectedly, we found that neuronal edema 48 hours after CCI was associated with reduced cellular and network excitability, concurrent with an increase in the expression ratio of the cation-chloride cotransporters (CCCs) NKCC1 and KCC2. Treatment with the CCC blocker bumetanide prevented neuronal swelling via a reversal in the NKCC1/KCC2 expression ratio, identifying altered chloride flux as the mechanism of neuronal edema. Importantly, bumetanide treatment was associated with increased neuronal and network excitability after injury, including increased susceptibility to spreading depolarizations (SDs) and seizures, known agents of clinical worsening after TBI. Treatment with mannitol, a first-line edema treatment in clinical practice, was also associated with increased susceptibility to SDs and seizures after CCI, showing that neuronal volume reduction, regardless of mechanism, was associated with an excitability increase. Finally, we observed an increase in excitability when neuronal edema normalized by 1 week after CCI. We conclude that neuronal swelling may exert protective effects against damaging excitability in the aftermath of TBI and that treatment of edema has the potential to reverse these effects.
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Affiliation(s)
| | | | - Cameron S. Metcalf
- Anticonvulsant Drug Development Program, Department of Pharmacology and Toxicology, College of Pharmacy, University of Utah, Salt Lake City, Utah, USA
| | - Jamie L. Maguire
- Neuroscience Department, Tufts University School of Medicine, Boston, Massachusetts, USA
| | | | | | - K.C. Brennan
- Department of Neurology, School of Medicine, and
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32
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Granados-Rojas L, Jerónimo-Cruz K, Juárez-Zepeda TE, Tapia-Rodríguez M, Tovar AR, Rodríguez-Jurado R, Carmona-Aparicio L, Cárdenas-Rodríguez N, Coballase-Urrutia E, Ruíz-García M, Durán P. Ketogenic Diet Provided During Three Months Increases KCC2 Expression but Not NKCC1 in the Rat Dentate Gyrus. Front Neurosci 2020; 14:673. [PMID: 32733191 PMCID: PMC7358437 DOI: 10.3389/fnins.2020.00673] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 06/02/2020] [Indexed: 01/01/2023] Open
Abstract
Ketogenic diet, a high fat and low carbohydrate diet, has been used as a non-pharmacological treatment in refractory epilepsy since 1920. In recent years, it has demonstrated to be effective in the treatment of numerous neurological and non-neurological diseases. Some neurological and neuropsychiatric disorders are known to be caused by gamma-aminobutyric acid (GABA)-mediated neurotransmission dysfunction. The strength and polarity of GABA-mediated neurotransmission are determined by the intracellular chloride concentration, which in turn is regulated by cation-chloride cotransporters NKCC1 and KCC2. Currently, it is unknown if the effect of ketogenic diet is due to the modulation of these cotransporters. Thus, we analyzed the effect of a ketogenic diet on the cation-chloride cotransporters expression in the dentate gyrus. We estimated the total number of NKCC1 immunoreactive (NKCC1-IR) neuronal and glial cells by stereology and determined KCC2 labeling intensity by densitometry in the molecular and granule layers as well as in the hilus of dentate gyrus of rats fed with normal or ketogenic diet for 3 months. The results indicated that ketogenic diet provided during 3 months increased KCC2 expression, but not NKCC1 in the dentate gyrus of the rat. The significant increase of KCC2 expression could explain, at least in part, the beneficial effect of ketogenic diet in the diseases where the GABAergic system is altered by increasing its inhibitory efficiency.
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Affiliation(s)
| | - Karina Jerónimo-Cruz
- Laboratorio de Neurociencias, Instituto Nacional de Pediatría, Mexico City, Mexico
| | | | - Miguel Tapia-Rodríguez
- Unidad de Microscopía, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, Mexico City, Mexico
| | - Armando R Tovar
- Departamento de Fisiología de la Nutrición, Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán, Mexico City, Mexico
| | | | | | | | | | - Matilde Ruíz-García
- Servicio de Neurología, Instituto Nacional de Pediatría, Mexico City, Mexico
| | - Pilar Durán
- Laboratorio de Biología Animal Experimental, Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico
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33
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Ahmed Juvale II, Che Has AT. The evolution of the pilocarpine animal model of status epilepticus. Heliyon 2020; 6:e04557. [PMID: 32775726 PMCID: PMC7393986 DOI: 10.1016/j.heliyon.2020.e04557] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 07/05/2020] [Accepted: 07/22/2020] [Indexed: 02/02/2023] Open
Abstract
The pilocarpine animal model of status epilepticus is a well-established, clinically translatable model that satisfies all of the criteria essential for an animal model of status epilepticus: a latency period followed by spontaneous recurrent seizures, replication of behavioural, electrographic, metabolic, and neuropathological changes, as well as, pharmacoresistance to anti-epileptic drugs similar to that observed in human status epilepticus. However, this model is also characterized by high mortality rates and studies in recent years have also seen difficulties in seizure induction due to pilocarpine resistant animals. This can be attributed to differences in rodent strains, species, gender, and the presence of the multi-transporter, P-glycoprotein at the blood brain barrier. The current paper highlights the various alterations made to the original pilocarpine model over the years to combat both the high mortality and low induction rates. These range from the initial lithium-pilocarpine model to the more recent Reduced Intensity Status Epilepticus (RISE) model, which finally brought the mortality rates down to 1%. These modifications are essential to improve animal welfare and future experimental outcomes.
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Affiliation(s)
- Iman Imtiyaz Ahmed Juvale
- Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
| | - Ahmad Tarmizi Che Has
- Department of Neurosciences, School of Medical Sciences, Universiti Sains Malaysia, Health Campus, 16150 Kubang Kerian, Kelantan, Malaysia
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34
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Jones RS, Ruszaj D, Parker MD, Morris ME. Contribution of Monocarboxylate Transporter 6 to the Pharmacokinetics and Pharmacodynamics of Bumetanide in Mice. Drug Metab Dispos 2020; 48:788-795. [PMID: 32587098 DOI: 10.1124/dmd.120.000068] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2020] [Accepted: 06/08/2020] [Indexed: 12/29/2022] Open
Abstract
Bumetanide, a sulfamyl loop diuretic, is used for the treatment of edema in association with congestive heart failure. Being a polar, anionic compound at physiologic pH, bumetanide uptake and efflux into different tissues is largely transporter-mediated. Of note, organic anion transporters (SLC22A) have been extensively studied in terms of their importance in transporting bumetanide to its primary site of action in the kidney. The contribution of one of the less-studied bumetanide transporters, monocarboxylate transporter 6 (MCT6; SLC16A5), to bumetanide pharmacokinetics (PK) and pharmacodynamics (PD) has yet to be characterized. The affinity of bumetanide for murine Mct6 was evaluated using Mct6-transfected Xenopus laevis oocytes. Furthermore, bumetanide was intravenously and orally administered to wild-type mice (Mct6+/+) and homozygous Mct6 knockout mice (Mct6-/-) to elucidate the contribution of Mct6 to bumetanide PK/PD in vivo. We demonstrated that murine Mct6 transports bumetanide at a similar affinity compared with human MCT6 (78 and 84 μM, respectively, at pH 7.4). After bumetanide administration, there were no significant differences in plasma PK. Additionally, diuresis was significantly decreased by ∼55% after intravenous bumetanide administration in Mct6-/- mice. Kidney cortex concentrations of bumetanide were decreased, suggesting decreased Mct6-mediated bumetanide transport to its site of action in the kidney. Overall, these results suggest that Mct6 does not play a major role in the plasma PK of bumetanide in mice; however, it significantly contributes to bumetanide's pharmacodynamics due to changes in kidney concentrations. SIGNIFICANCE STATEMENT: Previous evidence suggested that MCT6 transports bumetanide in vitro; however, no studies to date have evaluated the in vivo contribution of this transporter. In vitro studies indicated that mouse and human MCT6 transport bumetanide with similar affinities. Using Mct6 knockout mice, we demonstrated that murine Mct6 does not play a major role in the plasma pharmacokinetics of bumetanide; however, the pharmacodynamic effect of diuresis was attenuated in the knockout mice, likely because of the decreased bumetanide concentrations in the kidney.
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Affiliation(s)
- Robert S Jones
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences (R.S.J., D.R., M.E.M.) and Department of Physiology and Biophysics, Jacobs School of Medicine and Biomedical Sciences (M.D.P.), University at Buffalo, State University of New York, Buffalo, New York
| | - Donna Ruszaj
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences (R.S.J., D.R., M.E.M.) and Department of Physiology and Biophysics, Jacobs School of Medicine and Biomedical Sciences (M.D.P.), University at Buffalo, State University of New York, Buffalo, New York
| | - Mark D Parker
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences (R.S.J., D.R., M.E.M.) and Department of Physiology and Biophysics, Jacobs School of Medicine and Biomedical Sciences (M.D.P.), University at Buffalo, State University of New York, Buffalo, New York
| | - Marilyn E Morris
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences (R.S.J., D.R., M.E.M.) and Department of Physiology and Biophysics, Jacobs School of Medicine and Biomedical Sciences (M.D.P.), University at Buffalo, State University of New York, Buffalo, New York
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35
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Tao D, Liu F, Sun X, Qu H, Zhao S, Zhou Z, Xiao T, Zhao C, Zhao M. Bumetanide: A review of its neuroplasticity and behavioral effects after stroke. Restor Neurol Neurosci 2020; 37:397-407. [PMID: 31306143 DOI: 10.3233/rnn-190926] [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: 12/29/2022]
Abstract
Stroke often leads to neuronal injury and neurological functional deficits. Whilst spontaneous neurogenesis and axon regeneration are induced by ischemic stroke, effective pharmacological treatments are also essential for the improvement of neuroplasticity and functional recovery after stroke. However, no pharmacological therapy has been demonstrated to be able to effectively improve the functional recovery after stroke. Bumetanide is a specific Na+-K+-Cl- co-transporter inhibitor which can maintain chloride homeostasis in neurons. Therefore, many studies have focused on this drug's effect in stroke recovery in recent years. Here, we first review the function of Na+-K+-Cl- co-transporter in neurons, then how bumetanide's role in reducing brain damage, promoting neuroplasticity, leading to functional recovery after stroke, is elucidated. Finally, we discuss current limitations of bumetanide's efficiency and their potential solutions. These results may provide new avenues for further exploring mechanisms of post-stroke functional recovery as well as promising therapeutic targets for functional disability rehabilitation after ischemic stroke.
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Affiliation(s)
- Dongxia Tao
- Neurology, The First Hospital of China Medical University, Shenyang, China
| | - Fangxi Liu
- Neurology, The First Hospital of China Medical University, Shenyang, China
| | - Xiaoyu Sun
- Neurology, The People's Hospital of Liaoning Province, Shenyang, China
| | - Huiling Qu
- Neurology, The People's Hospital of Liaoning Province, Shenyang, China
| | - Shanshan Zhao
- Neurology, The First Hospital of China Medical University, Shenyang, China
| | - Zhike Zhou
- Geriatrics, The First Hospital of China Medical University, Shenyang, China
| | - Ting Xiao
- Dermatology, The First Hospital of China Medical University, Shenyang, China.,Key Laboratory of Immunodermatology, Ministry of Health, Ministry of Education, Shenyang, China
| | - Chuansheng Zhao
- Neurology, The First Hospital of China Medical University, Shenyang, China
| | - Mei Zhao
- Cardiology, The Shengjing Affiliated Hospital, China Medical University, Shenyang, China
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36
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Klein P, Friedman A, Hameed MQ, Kaminski RM, Bar-Klein G, Klitgaard H, Koepp M, Jozwiak S, Prince DA, Rotenberg A, Twyman R, Vezzani A, Wong M, Löscher W. Repurposed molecules for antiepileptogenesis: Missing an opportunity to prevent epilepsy? Epilepsia 2020; 61:359-386. [PMID: 32196665 PMCID: PMC8317585 DOI: 10.1111/epi.16450] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2019] [Revised: 01/26/2020] [Accepted: 01/27/2020] [Indexed: 12/11/2022]
Abstract
Prevention of epilepsy is a great unmet need. Acute central nervous system (CNS) insults such as traumatic brain injury (TBI), cerebrovascular accidents (CVA), and CNS infections account for 15%-20% of all epilepsy. Following TBI and CVA, there is a latency of days to years before epilepsy develops. This allows treatment to prevent or modify postinjury epilepsy. No such treatment exists. In animal models of acquired epilepsy, a number of medications in clinical use for diverse indications have been shown to have antiepileptogenic or disease-modifying effects, including medications with excellent side effect profiles. These include atorvastatin, ceftriaxone, losartan, isoflurane, N-acetylcysteine, and the antiseizure medications levetiracetam, brivaracetam, topiramate, gabapentin, pregabalin, vigabatrin, and eslicarbazepine acetate. In addition, there are preclinical antiepileptogenic data for anakinra, rapamycin, fingolimod, and erythropoietin, although these medications have potential for more serious side effects. However, except for vigabatrin, there have been almost no translation studies to prevent or modify epilepsy using these potentially "repurposable" medications. We may be missing an opportunity to develop preventive treatment for epilepsy by not evaluating these medications clinically. One reason for the lack of translation studies is that the preclinical data for most of these medications are disparate in terms of types of injury, models within different injury type, dosing, injury-treatment initiation latencies, treatment duration, and epilepsy outcome evaluation mode and duration. This makes it difficult to compare the relative strength of antiepileptogenic evidence across the molecules, and difficult to determine which drug(s) would be the best to evaluate clinically. Furthermore, most preclinical antiepileptogenic studies lack information needed for translation, such as dose-blood level relationship, brain target engagement, and dose-response, and many use treatment parameters that cannot be applied clinically, for example, treatment initiation before or at the time of injury and dosing higher than tolerated human equivalent dosing. Here, we review animal and human antiepileptogenic evidence for these medications. We highlight the gaps in our knowledge for each molecule that need to be filled in order to consider clinical translation, and we suggest a platform of preclinical antiepileptogenesis evaluation of potentially repurposable molecules or their combinations going forward.
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Affiliation(s)
- Pavel Klein
- Mid-Atlantic Epilepsy and Sleep Center, Bethesda, Maryland
| | - Alon Friedman
- Departments of Physiology and Cell Biology, and Brain and Cognitive Science, Zlotowski Center for Neuroscience, Ben-Gurion University of the Negev, Beer-Sheva, Israel
- Departments of Medical Neuroscience and Brain Repair Center, Dalhousie University, Halifax, Canada
| | - Mustafa Q. Hameed
- Neuromodulation Program, Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts
| | - Rafal M. Kaminski
- Neurosymptomatic Domains Section, Roche Pharma Research & Early Development, Roche Innovation Center, Basel, Switzerland
| | - Guy Bar-Klein
- McKusick-Nathans Institute of Genetic Medicine, Howard Hughes Medical Institute, Johns Hopkins University School of Medicine, Baltimore, Maryland
| | - Henrik Klitgaard
- Neurosciences Therapeutic Area, UCB Pharma, Braine-l’Alleud, Belgium
| | - Mathias Koepp
- Department of Clinical and Experimental Epilepsy, University College London Institute of Neurology, London, UK
| | - Sergiusz Jozwiak
- Department of Pediatric Neurology, Warsaw Medical University, Warsaw, Poland
| | - David A. Prince
- Neurology and the Neurological Sciences, Stanford University School of Medicine, Stanford, California
| | - Alexander Rotenberg
- Neuromodulation Program, Division of Epilepsy and Clinical Neurophysiology, Department of Neurology, Boston Children’s Hospital, Harvard Medical School, Boston, Massachusetts
| | | | - Annamaria Vezzani
- Department of Neuroscience, Mario Negri Institute for Pharmacological Research, Scientific Institute for Research and Health Care, Milan, Italy
| | - Michael Wong
- Department of Neurology, Washington University School of Medicine, St Louis, Missouri
| | - Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany
- Center for Systems Neuroscience, Hannover, Germany
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37
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Asisipo M, Gwladys NT, Musa MV. Effect of a novel prolonged febrile seizure model on GABA associated ion channels. Metab Brain Dis 2020; 35:441-449. [PMID: 31691144 DOI: 10.1007/s11011-019-00492-3] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2019] [Accepted: 09/10/2019] [Indexed: 11/25/2022]
Abstract
Prolonged febrile seizures are usually modelled in animals using hyperthermia as an inducer. In this study, a modified simple febrile seizure model using a combination of lipopolysaccharide (LPS) and kainic acid (KA) was used to develop a prolonged febrile seizure animal model, which we used to assess effects on the expression of the sodium- potassium-chloride cotransporter 1 (NKCC1) and potassium-chloride cotransporter 2 (KCC2) and their possible role in seizure exacerbation. At post-natal day (PND) 14, rat pups were divided into a saline (S), simple febrile seizure (FSA-), prolonged febrile seizure (FSB-), saline A (SA+) and saline B (SB+) groups. SA+ and SB+ groups received different concentrations of KA (1.75 mg/kg, 1.83 μg/kg respectively) but no LPS. Changes in temperature, seizure activity and duration were recorded. Gene and protein expression of NKCC1, KCC2 and KCC2 phosphorylated serine (KCC2 ser) 940 were measured 1 h post seizure termination and on PND 15 using RT- PCR and western blot. There was an initial increase in temperature that was immediately followed by a temperature decrease and an increase in seizure severity and duration in the FSB- group. There was a decrease in KCC2 ser 940 protein expression. NKCC1 protein expression was increased in both FS groups suggesting decreased GABA receptor functionality. Therefore, the novel FSB- model resulted in more severe and sustained seizure activity by altering cotransporter gene and protein expression. This suggests that this model can be used to mimic prolonged febrile seizures and hence can be used to investigate the physiological changes accompanying this condition.
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Affiliation(s)
- Mohamed Asisipo
- Discipline of Human Physiology, School of Laboratory Medicine & Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban, 4000, South Africa
| | - Ngoupaye Temkou Gwladys
- Department of Animal Biology, Faculty of Science, University of Dschang, P.O. Box 67, Dschang, Cameroon.
- Discipline of Human Physiology, School of Laboratory Medicine & Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban, 4000, South Africa.
| | - Mabandla Vuyisile Musa
- Discipline of Human Physiology, School of Laboratory Medicine & Medical Sciences, College of Health Sciences, University of KwaZulu-Natal, Durban, 4000, South Africa
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38
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Barker BS, Spampanato J, McCarren HS, Smolik M, Jackson CE, Hornung EN, Yeung DT, Dudek FE, McDonough JH. Screening for Efficacious Anticonvulsants and Neuroprotectants in Delayed Treatment Models of Organophosphate-induced Status Epilepticus. Neuroscience 2020; 425:280-300. [PMID: 31783100 PMCID: PMC6935402 DOI: 10.1016/j.neuroscience.2019.11.020] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2019] [Revised: 10/30/2019] [Accepted: 11/12/2019] [Indexed: 01/04/2023]
Abstract
Organophosphorus (OP) compounds are deadly chemicals that exert their intoxicating effects through the irreversible inhibition of acetylcholinesterase (AChE). In addition to an excess of peripheral ailments, OP intoxication induces status epilepticus (SE) which if left untreated may lead to permanent brain damage or death. Benzodiazepines are typically the primary therapies for OP-induced SE, but these drugs lose efficacy as treatment time is delayed. The CounterACT Neurotherapeutic Screening (CNS) Program was therefore established by the National Institutes of Health (NIH) to discover novel treatments that may be administered adjunctively with the currently approved medical countermeasures for OP-induced SE in a delayed treatment scenario. The CNS program utilizes in vivo EEG recordings and Fluoro-JadeB (FJB) histopathology in two established rat models of OP-induced SE, soman (GD) and diisopropylfluorophosphate (DFP), to evaluate the anticonvulsant and neuroprotectant efficacy of novel adjunct therapies when administered at 20 or 60 min after the induction of OP-induced SE. Here we report the results of multiple compounds that have previously shown anticonvulsant or neuroprotectant efficacy in other models of epilepsy or trauma. Drugs tested were ganaxolone, diazoxide, bumetanide, propylparaben, citicoline, MDL-28170, and chloroquine. EEG analysis revealed that ganaxolone demonstrated the most robust anticonvulsant activity, whereas all other drugs failed to attenuate ictal activity in both models of OP-induced SE. FJB staining demonstrated that none of the tested drugs had widespread neuroprotective abilities. Overall these data suggest that neurosteroids may represent the most promising anticonvulsant option for OP-induced SE out of the seven unique mechanisms tested here. Additionally, these results suggest that drugs that provide significant neuroprotection from OP-induced SE without some degree of anticonvulsant activity are elusive, which further highlights the necessity to continue screening novel adjunct treatments through the CNS program.
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Affiliation(s)
- Bryan S Barker
- Medical Toxicology Research Division, Neuroscience Department, U.S. Army Medical Research Institute of Chemical Defense, 8350 Ricketts Point Rd, Aberdeen Proving Ground, MD 21010, USA.
| | - Jay Spampanato
- Department of Neurosurgery, University of Utah School of Medicine, Salt Lake City, UT 84108, USA
| | - Hilary S McCarren
- Medical Toxicology Research Division, Neuroscience Department, U.S. Army Medical Research Institute of Chemical Defense, 8350 Ricketts Point Rd, Aberdeen Proving Ground, MD 21010, USA
| | - Melissa Smolik
- Department of Neurosurgery, University of Utah School of Medicine, Salt Lake City, UT 84108, USA
| | - Cecelia E Jackson
- Medical Toxicology Research Division, Neuroscience Department, U.S. Army Medical Research Institute of Chemical Defense, 8350 Ricketts Point Rd, Aberdeen Proving Ground, MD 21010, USA
| | - Eden N Hornung
- Medical Toxicology Research Division, Neuroscience Department, U.S. Army Medical Research Institute of Chemical Defense, 8350 Ricketts Point Rd, Aberdeen Proving Ground, MD 21010, USA
| | - David T Yeung
- Chemical Countermeasures Research Program, National Institute of Allergy and Infectious Disease, National Institutes of Health, Bethesda, MD 20892, USA
| | - F Edward Dudek
- Department of Neurosurgery, University of Utah School of Medicine, Salt Lake City, UT 84108, USA
| | - John H McDonough
- Medical Toxicology Research Division, Neuroscience Department, U.S. Army Medical Research Institute of Chemical Defense, 8350 Ricketts Point Rd, Aberdeen Proving Ground, MD 21010, USA
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39
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Kharod SC, Kang SK, Kadam SD. Off-Label Use of Bumetanide for Brain Disorders: An Overview. Front Neurosci 2019; 13:310. [PMID: 31068771 PMCID: PMC6491514 DOI: 10.3389/fnins.2019.00310] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2019] [Accepted: 03/19/2019] [Indexed: 01/17/2023] Open
Abstract
Bumetanide (BTN or BUM) is a FDA-approved potent loop diuretic (LD) that acts by antagonizing sodium-potassium-chloride (Na-K-Cl) cotransporters, NKCC1 (SLc12a2) and NKCC2. While NKCC1 is expressed both in the CNS and in systemic organs, NKCC2 is kidney-specific. The off-label use of BTN to modulate neuronal transmembrane Cl− gradients by blocking NKCC1 in the CNS has now been tested as an anti-seizure agent and as an intervention for neurological disorders in pre-clinical studies with varying results. BTN safety and efficacy for its off-label use has also been tested in several clinical trials for neonates, children, adolescents, and adults. It failed to meet efficacy criteria for hypoxic-ischemic encephalopathy (HIE) neonatal seizures. In contrast, positive outcomes in temporal lobe epilepsy (TLE), autism, and schizophrenia trials have been attributed to BTN in studies evaluating its off-label use. NKCC1 is an electroneutral neuronal Cl− importer and the dominance of NKCC1 function has been proposed as the common pathology for HIE seizures, TLE, autism, and schizophrenia. Therefore, the use of BTN to antagonize neuronal NKCC1 with the goal to lower internal Cl− levels and promote GABAergic mediated hyperpolarization has been proposed. In this review, we summarize the data and results for pre-clinical and clinical studies that have tested off-label BTN interventions and report variable outcomes. We also compare the data underlying the developmental expression profile of NKCC1 and KCC2, highlight the limitations of BTN’s brain-availability and consider its actions on non-neuronal cells.
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Affiliation(s)
- Shivani C Kharod
- Neuroscience Laboratory, Hugo W. Moser Research Institute at Kennedy Krieger, Baltimore, MD, United States
| | - Seok Kyu Kang
- Neuroscience Laboratory, Hugo W. Moser Research Institute at Kennedy Krieger, Baltimore, MD, United States
| | - Shilpa D Kadam
- Neuroscience Laboratory, Hugo W. Moser Research Institute at Kennedy Krieger, Baltimore, MD, United States.,Department of Neurology and Neurosurgery, Johns Hopkins University School of Medicine, Baltimore, MD, United States
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Löscher W. The holy grail of epilepsy prevention: Preclinical approaches to antiepileptogenic treatments. Neuropharmacology 2019; 167:107605. [PMID: 30980836 DOI: 10.1016/j.neuropharm.2019.04.011] [Citation(s) in RCA: 71] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 04/03/2019] [Accepted: 04/09/2019] [Indexed: 02/06/2023]
Abstract
A variety of acute brain insults can induce epileptogenesis, a complex process that results in acquired epilepsy. Despite advances in understanding mechanisms of epileptogenesis, there is currently no approved treatment that prevents the development or progression of epilepsy in patients at risk. The current concept of epileptogenesis assumes a window of opportunity following acute brain insults that allows intervention with preventive treatment. Recent results suggest that injury-induced epileptogenesis can be a much more rapid process than previously thought, suggesting that the 'therapeutic window' may only be open for a brief period, as in stroke therapy. However, experimental data also suggest a second, possibly delayed process ("secondary epileptogenesis") that influences the progression and refractoriness of the epileptic state over time, allowing interfering with this process even after onset of epilepsy. In this review, both methodological issues in preclinical drug development and novel targets for antiepileptogenesis will be discussed. Several promising drugs that either prevent epilepsy (antiepileptogenesis) or slow epilepsy progression and alleviate cognitive or behavioral comorbidities of epilepsy (disease modification) have been described in recent years, using diverse animal models of acquired epilepsy. Promising agents include TrkB inhibitors, losartan, statins, isoflurane, anti-inflammatory and anti-oxidative drugs, the SV2A modulator levetiracetam, and epigenetic interventions. Research on translational target validity and on prognostic biomarkers that can be used to stratify patients (or experimental animals) at high risk of developing epilepsy will hopefully soon lead to proof-of-concept clinical trials with the most promising drugs, which will be essential to make prevention of epilepsy a reality. This article is part of the special issue entitled 'New Epilepsy Therapies for the 21st Century - From Antiseizure Drugs to Prevention, Modification and Cure of Epilepsy'.
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Affiliation(s)
- Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine, Hannover, Germany; Center for Systems Neuroscience, Hannover, Germany.
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A Preliminary Study Evaluating the Safety and Efficacy of Bumetanide, an NKCC1 Inhibitor, in Patients with Drug-Resistant Epilepsy. CNS Drugs 2019; 33:283-291. [PMID: 30784026 DOI: 10.1007/s40263-019-00607-5] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
BACKGROUND Dysregulation of cation-chloride cotransporters NKCC1 and KCC2 expression was shown to be related to drug-resistant epilepsy. Previous studies suggested that bumetanide, an inhibitor of NKCC1, might have antiepileptic effects. OBJECTIVE The aim of this study was to investigate the safety and efficacy of bumetanide add-on therapy in patients with drug-resistant epilepsy and its relation to cation-chloride cotransporters NKCC1 and KCC2. METHODS We conducted an open-label, single-arm clinical trial in drug-resistant temporal lobe epilepsy (TLE) patients. This study consisted of three phases: pretreatment (3 months), titration (3 weeks), and active treatment (6 months). During the pretreatment phase, the dose of antiepileptic drugs was stabilized, and bumetanide was then added at an initial dose of 0.5 mg/day, increasing by 0.5 mg/week until a target dose of 2 mg/day was achieved. Bumetanide treatment was then continued for 6 months. Seizure frequency and adverse events were assessed at every monthly visit. Blood samples were collected from patients and 12 healthy controls were used for polymerase chain reaction and Western blot analyses. Primary clinical outcomes were drug safety and change in seizure frequency. Changes in NKCC1 and KCC2 expression were the non-clinical endpoints. RESULTS A total of 30 patients were enrolled, 27 of whom completed the study. The mean duration of epilepsy was 16.5 years. Median seizure frequency per month was 9 [interquartile range (IQR) 7-14.5] at baseline, 3.67 (IQR 1.84-6.17) at the first 3 months, and 2 (IQR 0.84-4.34) at the last 3 months (p < 0.001). Five adverse events were detected in six patients. The reported adverse events were anorexia in four patients, nausea and vomiting in two patients, and agitation, headache and increased seizure frequency in one patient each. The level of NKCC1 and KCC2 gene transcripts and KCC2 protein did not change significantly following treatment (p > 0.05); however, we observed a significant reduction in NKCC1 protein levels (p = 0.042). CONCLUSIONS Bumetanide might be an effective and relatively tolerable drug in patients with drug-resistant TLE. Downregulation of NKCC1 protein following bumetanide treatment may be responsible for its antiepileptic effects. IRANIAN REGISTRY OF CLINICAL TRIALS IDENTIFIER IRCT 201012115368N1.
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Wilkinson CM, Fedor BA, Aziz JR, Nadeau CA, Brar PS, Clark JJA, Colbourne F. Failure of bumetanide to improve outcome after intracerebral hemorrhage in rat. PLoS One 2019; 14:e0210660. [PMID: 30629699 PMCID: PMC6328169 DOI: 10.1371/journal.pone.0210660] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2018] [Accepted: 12/28/2018] [Indexed: 11/19/2022] Open
Abstract
After intracerebral hemorrhage (ICH), brain edema commonly occurs and can cause death. Along with edema, there are significant alterations in the concentrations of key ions such as sodium, potassium, and chloride, which are essential to brain function. NKCC1, a cation-chloride cotransporter, is upregulated after brain damage, such as traumatic injury and ischemic stroke. NKCC1 brings sodium and chloride into the cell, possibly worsening ion dyshomeostasis. Bumetanide, a specific NKCC1 antagonist, blocks the transport of chloride into cells, and thus should attenuate the increases in chloride, which should lessen brain edema and improve neuronal functioning post-ICH, as with other injuries. We used the collagenase model of ICH to test whether bumetanide treatment for three days (vs. vehicle) would improve outcome. We gave bumetanide beginning at two hours or seven days post-ICH and measured behavioural outcome, edema, and brain ion content after treatment. There was some evidence for a minor reduction in edema after early dosing, but this did not improve behaviour or lessen injury. Contrary to our hypothesis, bumetanide did not normalize ion concentrations after late dosing. Bumetanide did not improve behavioural outcome or affect lesion volume. After ICH, bumetanide is safe to use in rats but does not improve functional outcome in the majority of animals.
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Affiliation(s)
| | - Brittany A. Fedor
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Jasmine R. Aziz
- Department of Psychology, University of Alberta, Edmonton, Alberta, Canada
| | - Colby A. Nadeau
- Department of Psychology, University of Alberta, Edmonton, Alberta, Canada
| | - Paul S. Brar
- Department of Psychology, University of Alberta, Edmonton, Alberta, Canada
| | - Julia J. A. Clark
- Department of Psychology, University of Alberta, Edmonton, Alberta, Canada
| | - Frederick Colbourne
- Department of Psychology, University of Alberta, Edmonton, Alberta, Canada
- Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
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Wang Y, Wang Y, Chen Z. Double-edged GABAergic synaptic transmission in seizures: The importance of chloride plasticity. Brain Res 2018; 1701:126-136. [PMID: 30201259 DOI: 10.1016/j.brainres.2018.09.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2018] [Revised: 09/04/2018] [Accepted: 09/06/2018] [Indexed: 12/18/2022]
Abstract
GABAergic synaptic inhibition, which is a critical regulator of neuronal excitability, is closely involved in epilepsy. Interestingly, fast GABAergic transmission mediated by Cl- permeable GABAA receptors can bi-directionally exert both seizure-suppressing and seizure-promoting actions. Accumulating evidence suggests that chloride plasticity, the driving force of GABAA receptor-mediated synaptic transmission, contributes to the double-edged role of GABAergic synapses in seizures. Large amounts of Cl- influx can overwhelm Cl- extrusion during seizures not only in healthy tissue in a short-term "activity-dependent" manner, but also in chronic epilepsy in a long-term, irreversible "pathology-dependent" manner related to the dysfunction of two chloride transporters: the chloride importer NKCC1 and the chloride exporter KCC2. In this review, we address the importance of chloride plasticity for the "activity-dependent" and "pathology-dependent" mechanisms underlying epileptic events and provide possible directions for further research, which may be clinically important for the design of GABAergic synapse-targeted precise therapeutic interventions for epilepsy.
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Affiliation(s)
- Ying Wang
- Institute of Pharmacology & Toxicology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Yi Wang
- Institute of Pharmacology & Toxicology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China
| | - Zhong Chen
- Institute of Pharmacology & Toxicology, Key Laboratory of Medical Neurobiology of the Ministry of Health of China, College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, China; Epilepsy Center, Second Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, China.
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Brandt C, Seja P, Töllner K, Römermann K, Hampel P, Kalesse M, Kipper A, Feit PW, Lykke K, Toft-Bertelsen TL, Paavilainen P, Spoljaric I, Puskarjov M, MacAulay N, Kaila K, Löscher W. Bumepamine, a brain-permeant benzylamine derivative of bumetanide, does not inhibit NKCC1 but is more potent to enhance phenobarbital's anti-seizure efficacy. Neuropharmacology 2018; 143:186-204. [DOI: 10.1016/j.neuropharm.2018.09.025] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 08/30/2018] [Accepted: 09/16/2018] [Indexed: 01/01/2023]
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Rahmanzadeh R, Mehrabi S, Barati M, Ahmadi M, Golab F, Kazmi S, Joghataei MT, Seifi M, Gholipourmalekabadi M. Effect of Co-administration of Bumetanide and Phenobarbital on Seizure Attacks in Temporal Lobe Epilepsy. Basic Clin Neurosci 2018; 9:408-416. [PMID: 30719255 PMCID: PMC6359685 DOI: 10.32598/bcn.9.6.408] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2016] [Revised: 10/20/2016] [Accepted: 01/20/2018] [Indexed: 01/14/2023] Open
Abstract
Introduction: The resistance of temporal lobe epilepsy to classic drugs is thought to be due to disruption in the excitation/inhibition of this pathway. Two chloride transporters, NKCC1 and KCC2, are expressed differently for the excitatory state of Gamma-Amino Butyric Acid (GABA). The present study explored the effect of bumetanide as a selective NKCC1 inhibitor either alone or in combination with the phenobarbital in the pilocarpine model of epilepsy. Methods: An animal model of Status Epilepticus (SE) was induced with pilocarpine in Wistar male rats followed by phenobarbital and or bumetanide or saline administration for 45 days after the induction of SE by Intraperitoneal (IP) injection. The rats were monitored, their behavior was recorded, and after 24 hours they were sacrificed to study the expression of NKCC1 and KCC2 using real time PCR. Results: The data showed that the effects of a combination of bumetanide with phenobarbital on frequency rate and duration of seizure attack were more than those of the phenobarbital alone. In addition, in the bumetanide and combined treatment groups, NKCC1 expression decreased significantly, compared with untreated epileptic animals. A delayed decrement in NKCC1/KCC2 expression ratio after bumetanide application was also observed. Conclusion: The combination of bumetanide with phenobarbital increases the inhibition of SE and maximizes the potential of GABA signaling pathway, and can be considered as an effective therapeutic strategy in patients with epilepsy.
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Affiliation(s)
- Reza Rahmanzadeh
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Soraya Mehrabi
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Mahmood Barati
- Department of Biotechnology, School of Allied Medicine, Iran University of Medical Science, Tehran, Iran
| | - Milad Ahmadi
- Shefa Neuroscience Research Center, Tehran, Iran
| | - Fereshteh Golab
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Sareh Kazmi
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran
| | - Mohammad Taghi Joghataei
- Cellular and Molecular Research Center, Iran University of Medical Sciences, Tehran, Iran.,Department of Anatomy, School of Medicine, Iran University of Medical Sciences, Tehran, Iran
| | - Morteza Seifi
- Department of Medical Genetics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada
| | - Mazaher Gholipourmalekabadi
- Department of Tissue Engineering & Regenerative Medicine, School of Advanced Technologies in Medicine, Iran University of Medical Sciences, Tehran, Iran
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Oernbo EK, Lykke K, Steffensen AB, Töllner K, Kruuse C, Rath MF, Löscher W, MacAulay N. Cerebral influx of Na + and Cl - as the osmotherapy-mediated rebound response in rats. Fluids Barriers CNS 2018; 15:27. [PMID: 30249273 PMCID: PMC6154956 DOI: 10.1186/s12987-018-0111-8] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 08/19/2018] [Indexed: 02/01/2023] Open
Abstract
Background Cerebral edema can cause life-threatening increase in intracranial pressure. Besides surgical craniectomy performed in severe cases, osmotherapy may be employed to lower the intracranial pressure by osmotic extraction of cerebral fluid upon intravenous infusion of mannitol or NaCl. A so-called rebound effect can, however, hinder continuous reduction in cerebral fluid by yet unresolved mechanisms. Methods We determined the brain water and electrolyte content in healthy rats treated with osmotherapy. Osmotherapy (elevated plasma osmolarity) was mediated by intraperitoneal injection of NaCl or mannitol with inclusion of pharmacological inhibitors of selected ion-transporters present at the capillary lumen or choroidal membranes. Brain barrier integrity was determined by fluorescence detection following intravenous delivery of Na+-fluorescein. Results NaCl was slightly more efficient than mannitol as an osmotic agent. The brain water loss was only ~ 60% of that predicted from ideal osmotic behavior, which could be accounted for by cerebral Na+ and Cl− accumulation. This electrolyte accumulation represented the majority of the rebound response, which was unaffected by the employed pharmacological agents. The brain barriers remained intact during the elevated plasma osmolarity. Conclusions A brain volume regulatory response occurs during osmotherapy, leading to the rebound response. This response involves brain accumulation of Na+ and Cl− and takes place by unresolved molecular mechanisms that do not include the common ion-transporting mechanisms located in the capillary endothelium at the blood–brain barrier and in the choroid plexus epithelium at the blood–CSF barrier. Future identification of these ion-transporting routes could provide a pharmacological target to prevent the rebound effect associated with the widely used osmotherapy.
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Affiliation(s)
- Eva Kjer Oernbo
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark
| | - Kasper Lykke
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark.,AJVaccines, Copenhagen, Denmark
| | | | - Kathrin Töllner
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Hannover, Germany.,Center for Systems Neuroscience, Hannover, Germany
| | - Christina Kruuse
- Neurovascular Research Unit, Department of Neurology, Herlev Gentofte Hospital, University of Copenhagen, Herlev, Copenhagen, Denmark
| | | | - Wolfgang Löscher
- Department of Pharmacology, Toxicology, and Pharmacy, University of Veterinary Medicine Hannover, Hannover, Germany.,Center for Systems Neuroscience, Hannover, Germany
| | - Nanna MacAulay
- Department of Neuroscience, University of Copenhagen, Copenhagen, Denmark. .,Department of Neuroscience, Faculty of Health and Medical Sciences, University of Copenhagen, Blegdamsvej 3, 2200, Copenhagen, Denmark.
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Overexpression of miRNA-137 in the brain suppresses seizure activity and neuronal excitability: A new potential therapeutic strategy for epilepsy. Neuropharmacology 2018; 138:170-181. [DOI: 10.1016/j.neuropharm.2018.06.010] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2017] [Revised: 05/15/2018] [Accepted: 06/06/2018] [Indexed: 12/28/2022]
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Olde Engberink AHO, Meijer JH, Michel S. Chloride cotransporter KCC2 is essential for GABAergic inhibition in the SCN. Neuropharmacology 2018; 138:80-86. [PMID: 29782876 DOI: 10.1016/j.neuropharm.2018.05.023] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Revised: 04/26/2018] [Accepted: 05/17/2018] [Indexed: 12/31/2022]
Abstract
One of the principal neurotransmitters of the central nervous system is GABA. In the adult brain, GABA is predominantly inhibitory, but there is growing evidence indicating that GABA can shift to excitatory action depending on environmental conditions. In the mammalian central circadian clock of the suprachiasmatic nucleus (SCN) GABAergic activity shifts from inhibition to excitation when animals are exposed to long day photoperiod. The polarity of the GABAergic response (inhibitory versus excitatory) depends on the GABA equilibrium potential determined by the intracellular Cl- concentration ([Cl-]i). Chloride homeostasis can be regulated by Cl- cotransporters like NKCC1 and KCC2 in the membrane, but the mechanisms for maintaining [Cl-]i are still under debate. This study investigates the role of KCC2 on GABA-induced Ca2+ transients in SCN neurons from mice exposed to different photoperiods. We show for the first time that blocking KCC2 with the newly developed blocker ML077 can cause a shift in the polarity of the GABAergic response. This will increase the amount of excitatory responses in SCN neurons and thus cause a shift in excitatory/inhibitory ratio. These results indicate that KCC2 is an essential component in regulating [Cl-]i and the equilibrium potential of Cl- and thereby determining the sign of the GABAergic response. Moreover, our data suggest a role for the Cl- cotransporters in the switch from inhibition to excitation observed under long day photoperiod.
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Affiliation(s)
- A H O Olde Engberink
- Department of Cellular and Chemical Biology, Laboratory for Neurophysiology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, the Netherlands
| | - J H Meijer
- Department of Cellular and Chemical Biology, Laboratory for Neurophysiology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, the Netherlands
| | - S Michel
- Department of Cellular and Chemical Biology, Laboratory for Neurophysiology, Leiden University Medical Center, Einthovenweg 20, 2333 ZC, Leiden, the Netherlands.
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Azosemide is more potent than bumetanide and various other loop diuretics to inhibit the sodium-potassium-chloride-cotransporter human variants hNKCC1A and hNKCC1B. Sci Rep 2018; 8:9877. [PMID: 29959396 PMCID: PMC6026185 DOI: 10.1038/s41598-018-27995-w] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2017] [Accepted: 06/14/2018] [Indexed: 12/31/2022] Open
Abstract
The Na+–K+–2Cl− cotransporter NKCC1 plays a role in neuronal Cl− homeostasis secretion and represents a target for brain pathologies with altered NKCC1 function. Two main variants of NKCC1 have been identified: a full-length NKCC1 transcript (NKCC1A) and a shorter splice variant (NKCC1B) that is particularly enriched in the brain. The loop diuretic bumetanide is often used to inhibit NKCC1 in brain disorders, but only poorly crosses the blood-brain barrier. We determined the sensitivity of the two human NKCC1 splice variants to bumetanide and various other chemically diverse loop diuretics, using the Xenopus oocyte heterologous expression system. Azosemide was the most potent NKCC1 inhibitor (IC50s 0.246 µM for hNKCC1A and 0.197 µM for NKCC1B), being about 4-times more potent than bumetanide. Structurally, a carboxylic group as in bumetanide was not a prerequisite for potent NKCC1 inhibition, whereas loop diuretics without a sulfonamide group were less potent. None of the drugs tested were selective for hNKCC1B vs. hNKCC1A, indicating that loop diuretics are not a useful starting point to design NKCC1B-specific compounds. Azosemide was found to exert an unexpectedly potent inhibitory effect and as a non-acidic compound, it is more likely to cross the blood-brain barrier than bumetanide.
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Donovan MD, Abduljalil K, Cryan JF, Boylan GB, Griffin BT. Application of a physiologically-based pharmacokinetic model for the prediction of bumetanide plasma and brain concentrations in the neonate. Biopharm Drug Dispos 2018; 39:125-134. [DOI: 10.1002/bdd.2119] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 12/06/2017] [Accepted: 12/19/2017] [Indexed: 12/30/2022]
Affiliation(s)
- Maria D. Donovan
- Pharmacodelivery Group, School of Pharmacy; University College Cork; Cork Ireland
- Department of Anatomy and Neuroscience; University College Cork; Cork Ireland
| | | | - John F. Cryan
- Department of Anatomy and Neuroscience; University College Cork; Cork Ireland
- Alimentary Pharmabiotic Centre; University College Cork; Cork Ireland
| | - Geraldine B. Boylan
- Department of Paediatrics and Child Health; University College Cork; Cork Ireland
- Irish Centre for Fetal and Neonatal Translational Research; University College Cork and Cork University Maternity Hospital; Cork Ireland
| | - Brendan T. Griffin
- Pharmacodelivery Group, School of Pharmacy; University College Cork; Cork Ireland
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